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The growing size of BOPs, longer drilling campaigns on wells, and operations in harsher environments has resulted in increased challenges in properly documenting wellhead fatigue during planned or executed drilling operations. The industry has started directing its efforts toward the calibration of analytical tools which are typically adopted for predicting wellhead fatigue. The ultimate goal for achieving this ambitious scope is to identify a benchmark set of analytical results that will predict field measurements. Early on Statoil identified a major obstacle: the absence of a good and comprehensive dataset of field measurements to serve as point of reference. Statoil and Aker Solutions cooperated on a pilot project with the intent of collecting a dataset of full scale measurements during drilling operations to be used to validate and calibrate the theoretical wellhead fatigue calculation methodologies. The main objective of the instrumentation campaign was to measure sectional forces as close as possible to typical wellhead hotspots by the use of three sets of strain gauges installed on the outside surface of the conductor and on the outside of the surface casing. With the objective of collecting an exhaustive dataset of measurements, accelerometers and inclinometers were installed on the BOP, the riser adapter, the riser below the upper flex joint and on the rig. An additional set of six strain gauges was installed on the riser to record riser tension variations. Environmental conditions were logged on board the rig and by the hindcast data provider. Operational events were carefully logged. This paper presents the following: • Data processing used for quality assurance and calibration of the measured data and the associated data challenges • Highlights of the instrumentation system capabilities to capture salient events of a typical drilling campaign and of ad-hoc performed rig operations to calibrate and validate the measured data • Effect of a controlled rig cross motion test, performed to evaluate quasi static loads on the well and calibrate strain gauge sensor orientations • A riser pull test, performed to validate strain gauge functioning • Several landing and disconnecting of the LMRP • Manipulation of the preload between the high pressure housing and the low pressure housing to investigate the effect of the preloading on the load sharing between the casings Since King and Soloman [2], the industry is still lacking quality field data to be used in order to validate the various analytical models used in the analyses of subsea conductor and wellheads. The results will confirm the quality of the measured data and will represent a first data point of comprehensive measured field data. This data will be used for future required work in calibrating the different building blocks pertaining to the analytical tools dedicated to well head fatigue predictions [3].

This paper reports the design, development, and initial evaluation of a robotic laparoscopic clipping tool for single manipulator wound closure and anastomosis (tubular reconnection). The tool deploys biodegradable clips and clasps with the goal of (i) integrating grasping and suturing into a single device for single hand or manipulator use, (ii) applying the equivalent of interrupted sutures without the need of managing suture thread, and (iii) allowing for full six degrees-of-freedom (DOFs) laparoscopic control when mounted on a robot arm. The specifications, workflow, and detailed design of the robotic laparoscopic tool and injection molded bio-absorbable T shaped clip and locking clasp are reported. The clipping tool integrates forceps to grab and stabilize tissue and a clip and clasp applier to approximate and fixate the tissue. A curved needle is advanced on a circular needle path and picks up and drags clips through tissue. The clip is then tightened through the tissue and a clasp is clamped around the clip, before the clip is released from the needle. Results of several bench test runs of the tool show: (a) repeatable circular needle drive, (b) successful pick-up and deployment of clips, (c) successful shear of the clip to release the clip from the needle, and (d) closure of clasp on clip with an average of 2.0 N holding force. These data indicate that the robotic laparoscopic clipping tool could be used for laparoscopic wound closure and anastomosis.

Joint loading is a recently developed mechanical modality, which potentially provides a therapeutic regimen to activate bone formation and prevent degradation of joint tissues. To our knowledge, however, few joint loading devices are available for clinical or point-of-care applications. Using a voice-coil actuator, we developed an electromechanical loading system appropriate for human studies and preclinical trials that should prove both safe and effective. Two specific tasks for this loading system were development of loading conditions (magnitude and frequency) suitable for humans, and provision of a convenient and portable joint loading apparatus. Desktop devices have been previously designed to evaluate the effects of various loading conditions using small and large animals. However, a portable knee loading device is more desirable from a usability point of view. In this paper, we present such a device that is designed to be portable, providing a compact, user-friendly loader. The portable device was employed to evaluate its capabilities using a human knee model. The portable device was characterized for force-pulse width modulation duty cycle and loading frequency properties. The results demonstrate that the device is capable of producing the necessary magnitude of forces at appropriate frequencies to promote the stimulation of bone growth and which can be used in clinical studies for further evaluations.

This study presents a methodology to determine thumb and index finger kinematics while utilizing a minimal set of markers. The motion capture of skin-surface markers presents inherent challenges for the accurate and comprehensive measurement of digit kinematics. As such, it is desirable to utilize robust methods for assessing digit kinematics with fewer markers. The approach presented in this study involved coordinate system alignment, locating joint centers of rotation, and a solution model to estimate three-dimensional (3-D) digit kinematics. The solution model for each digit was based on assumptions of rigid-body interactions, specific degrees of freedom (DOFs) at each located joint, and the aligned coordinate system definitions. Techniques of inverse kinematics and optimization were applied to calculate the 3-D position and orientation of digit segments during pinching between the thumb and index finger. The 3-D joint center locations were reliably fitted with mean coefficients of variation below 5%. A parameterized form of the solution model yielded feasible solutions that met specified tolerance and convergence criteria for over 85% of the test points. The solution results were intuitive to the pinching function. The thumb was measured to be rotated about the CMC joint to bring it into opposition to the index finger and larger rotational excursions (>10 deg) were observed in flexion/extension compared to abduction/adduction and axial rotation for all joints. While the solution model produced results similar to those computed from a full marker set, the model facilitated the usage of fewer markers, which inherently lessened the effects of passive motion error and reduced the post-experimental effort required for marker processing.

Muscle-driven simulations of human and animal motion are widely used to complement physical experiments for studying movement dynamics. Musculotendon models are an essential component of muscle-driven simulations, yet neither the computational speed nor the biological accuracy of the simulated forces has been adequately evaluated. Here we compare the speed and accuracy of three musculotendon models: two with an elastic tendon (an equilibrium model and a damped equilibrium model) and one with a rigid tendon. Our simulation benchmarks demonstrate that the equilibrium and damped equilibrium models produce similar force profiles but have different computational speeds. At low activation, the damped equilibrium model is 29 times faster than the equilibrium model when using an explicit integrator and 3 times faster when using an implicit integrator; at high activation, the two models have similar simulation speeds. In the special case of simulating a muscle with a short tendon, the rigid-tendon model produces forces that match those generated by the elastic-tendon models, but simulates 2–54 times faster when an explicit integrator is used and 6–31 times faster when an implicit integrator is used. The equilibrium, damped equilibrium, and rigid-tendon models reproduce forces generated by maximally-activated biological muscle with mean absolute errors less than 8.9%, 8.9%, and 20.9% of the maximum isometric muscle force, respectively. When compared to forces generated by submaximally-activated biological muscle, the forces produced by the equilibrium, damped equilibrium, and rigid-tendon models have mean absolute errors less than 16.2%, 16.4%, and 18.5%, respectively. To encourage further development of musculotendon models, we provide implementations of each of these models in OpenSim version 3.1 and benchmark data online, enabling others to reproduce our results and test their models of musculotendon dynamics.

The use of compliance chambers in mock circulatory loop construction is the predominant means of simulating arterial compliance. Utilizing mock circulatory loops as bench test methods for cardiac assist technologies necessitates that they must be capable of reproducing the circulatory conditions that would exist physiologically. Of particular interest is the ability to determine instantaneous compliance of the system, and the ability to change the compliance in real-time. This capability enables continuous battery testing of conditions without stopping the flow to change the compliance chamber settings, and the simulation of dynamic changes in arterial compliance. The method tested involves the use of a compliance chamber utilizing a circular natural latex rubber membrane separating the fluid and air portions of the device. Change in system compliance is affected by the airspace pressure, which creates more reaction force at the membrane to the fluid pressure. A pressure sensor in the fluid portion of the chamber and a displacement sensor monitoring membrane center deflection allow for real-time inputs to the control algorithm. A predefined numerical model correlates the displacement sensor data to the volume displacement of the membrane. The control algorithm involves a tuned π loop maintaining the volume distention of the membrane via regulation of the air space pressure. The proportional integral (PI) controller tuning was achieved by creating a computational model of the compliance chamber using Simulink™ Simscape® toolboxes. These toolboxes were used to construct a model of the hydraulic, mechanical, and pneumatic elements in the physical design. Parameter Estimation™ tools and Design Optimization™ methods were employed to determine unknown physical parameters in the system, and tune the process controller used to maintain the compliance setting. It was found that the resulting control architecture was capable of maintaining compliance along a pressure-volume curve and allowed for changes to the compliance set point curve without stopping the pulsatile flow.

The design of a brand new reciprocating compressor cylinder is a difficult and time expensive task, involving CAD, FEA and CFD tools, which can take several months. Following standard approach, usually several trials are needed in order to achieve the most suitable solution. Every time it is necessary to change some design/model features, all the following operations have to be repeated: modifying the CAD model; meshing the model; calculating new loads and/or boundary conditions; configuring the results analyses; post process the results. Following standard methods each described operation has to be performed manually by a user. This paper describes a method to achieve the automation of most of these manual operations, transferring the workload from human to hardware resources, with a consequent saving in time needed to achieve results and related quality. Paper will describe the process (including details about FEA and CFD analyses) to design a cylinder with this method, compared with a traditional one. The comparison will show differences in delivery time, weight and total cost (engineering + production) between the cylinders.

In this paper, we present a method for fabricating inexpensive, disposable, articulated instruments for minimally invasive surgery based on Japanese paper arts. Building on the literature covering the kinematics of origami, we introduce an articulated instrument design with antagonistic tendon actuation. A general method for achieving a fixed motion scaling ratio in these types of systems is also presented. Kinematic simulations and prototyping demonstrate feasibility of this concept.

In this paper, the design of the robotic cannula for minimally invasive robotic lumbar discectomy is presented. Lumbar discectomy is the surgery to remove the herniated disc material that is pressing on a nerve root or spinal cord. Recently, a robotic approach to performing this procedure has been proposed that utilizes multiple teleoperated articulated instruments inserted into the surgical workspace using a single cannula. In this paper, we propose a new robotic cannula system to work in conjunction with this new procedure. It allows for the independent teleoperated control of the axial position and rotation of up to three surgical instruments at the same time. The mechanical design, controller design, and prototype of new system are presented in this paper demonstrating a fully functioning device for this application. A novel worm gear and rack system allow for the instrument translation while and embedded gear trains produce the rotational movement. Steady-state errors of less than 50 μm for translation and less than 2° for rotational motion are obtained.

This paper presents a novel 6-DOF parallel manipulator for a new kind of vehicle motion simulation system, which is referred to as GVRV system. This system can realistically replicate the motion of any specified spot within the cabin of a real road vehicle in real time. Unlike traditional automobile testing platforms and vehicle motion simulators which are aimed at the vehicle, this system is aimed at the development of on-board equipment. The objective of this paper is to study how to do the modeling and motion planning work of this proposed manipulator to make it qualified as a generalized virtual road vehicle (GVRV) for on-board equipment test. First, the analytical characterization of the proposed 6-DOF parallel manipulator is presented. The forward and inverse kinematics problems of this manipulator are solved and its advantages such as high isotropy, well decoupling characteristic and no singular configuration within the demanded workspace are illustrated. Then, based on the full-size prototype of the manipulator, the whole GVRV system is built and described. By the study of the requirements for vehicle motion reproduction, the method of modeling is presented for this purpose. Finally, experiments are presented to demonstrate the validity of the model of the 6-DOF parallel manipulator for vehicle motion reproduction for use in on-board equipment test.

In this paper, a scheme of an ‘early warning’ system is developed for the combustion system of Industrial Gas Turbines (IGTs), which attains low computational workload and simple programming requirements, being therefore employable at an industrial level. The methodology includes trend analysis, which examines when the measurement shows different trends from the other measurements in the sensor group, and noise analysis, which examines when the measurement is displaying higher levels of noise compared to those of the other sensors. In this research, difficulties encountered by other data-driven methods due to temperature varying with load conditions of the IGT’s have also been overcome by the proposed approach. Furthermore, it brings other advantages, for instance, no historic training data is needed, and there is no requirement to set thresholds for each sensor in the system. The efficacy and effectiveness of the proposed approach has been demonstrated through experimental trials of previous pre-chamber burnout cases. And the resulting outcomes of the scheme will be of interest to IGT companies, especially in condition monitoring of the combustion system. Future work and possible improvements are also discussed at the end of the paper.

Turbomachinery active subspace performance maps are 2D contour plots that illustrate the variation of key flow performance metrics with different blade designs. While such maps are easy to construct for design parameterizations with two variables, in this paper maps will be generated for a fan blade with twenty-five design variables. Turbomachinery active subspace performance maps combine active subspaces — a new set of ideas for dimension reduction — with fundamental turbomachinery aerodynamics and design spaces. In this paper, contours of (i) cruise efficiency, (ii) cruise pressure ratio, (iii) maximum climb flow capacity and (iv) sensitivity to manufacturing variations, are plotted as objectives for the fan. These maps are then used to infer pedigree design rules: how best to increase fan efficiency; how best to desensitize blade aerodynamics to the impact of manufacturing variations? In the present study, the former required both a reduction in pressure ratio and flow capacity — leading to a reduction of the strength of the leading edge bow wave — while the latter required strictly a reduction in flow capacity. While such pedigree rules can be obtained from first principles, in this paper these rules are derived from the active subspaces. This facilitates a more detailed quantification of the aerodynamic trade-offs. Thus, instead of simply stating that a particular design is more sensitive to manufacturing variations; or that it lies on a hypothetical ‘efficiency cliff’, this paper seeks to visualize, quantify and make precise such notions of turbomachinery design.Copyright © 2017 by Rolls-Royce plc

Limb sensorimotor function plays an important role in activities of daily living (ADLs) and quality of life. Spinal cord dysfunctions, such as cervical spondylotic myelopathy (CSM), often affect limb function and limit independence. In this paper, we apply technologies from the emerging field of soft robotics to develop Soft Robotic 3rd Arms (SR3As) that branch out of the body — thus providing an artificial limb that enables effective execution of ADLs for CSM patients and the like. Soft robotics is a fairly recent addition to the field of robotics. Differing from traditional, “hard”, robotics, soft robotics are made of flexible materials such as silicone rather than stiff materials such as metals. One such soft robotic actuator is the fiber-reinforced actuator (FRA). Fabricated utilizing a combination of silicone bladder(s) and inextensible materials, these actuators are able to perform one of various motions through changes of pressure [1]. Supernumerary limbs (3rd arms), in contrast, are extra robotic limbs that can function cooperatively or independently of the user’s own limbs. These differ from exoskeletal robotics, as they are not fixated to the user’s limb to augment strength, but rather are placed elsewhere on the body to assist in tasks that would otherwise require multiple people. Examples of such devices include MIT/Boeing’s supernumerary arms to assist in the assembly of aircraft fuselage [2] or the supernumerary hand Softhand [3]. Combining these two concepts, an articulate SR3A was created (Fig. 1). By replacing traditional actuators with soft actuators, the limb is not only lighter, but it also better replicates the equivalent human limb. In addition to these benefits, the SR3A would also need to be less expensive to fabricate and actuate than an arm using rigid body components. This paper presents the design of a proof-of-concept prototype of a SR3A utilizing soft robotic actuators that could be used to assist individuals with hand impairments perform ADLs.

A two-loop learning outcomes assessment process was followed to evaluate the core curriculum in Mechanical Engineering at Rochester Institute of Technology. This initiative, originally called the Engineering Sciences Core Curriculum, provided systematic course learning outcomes and assessment data of examination performance in Statics, Mechanics, Dynamics, Thermodynamics, Fluid Mechanics and Heat Transfer. This paper reports longitudinal data and important observations in the Statics-Dynamics sequence to determine efficacy and obstacles in student performance. An earlier paper showed that students’ mastery of Dynamics is affected largely by weak retention of fundamentals of Statics and mathematics. New observations recorded in this report suggest the need for better instructional strategies to teach certain focal areas in Statics. Subsequesntly offered Dynamics and Fluid Mechanics classes further need reinforcement of some of these fundamental topics in Statics. This report completes a 9 year long broader feedback loop designed to achieve the educational goals in the Statics-Dynamics sequence.Copyright © 2016 by ASME

This paper focuses on the effects of aerodynamic aids on the lateral and longitudinal dynamics of high-speed road vehicles. Aerodynamic aids, such as spoilers, can reduce drag to improve vehicle’s fuel economy and acceleration performance. On the other hand, aerodynamic aids can be utilized to enhance the lateral stability of the vehicle at high speeds by generating downforce or negative lift. However, the co-existence of drag and lift creates a paradox, that is, the downforce generated to improve car’s high-speed stability acts as a parasitic force on the car-body and slows down the vehicle forward speed. This paper will illustrate the juxtaposed effects of the aerodynamic forces on the lateral stability of the vehicle. Airfoils in the role of external aerodynamic aids will be examined based on their shapes, geometrical configurations, and at varying relative positions using the CFD technique. Moreover, the effects of attack angles, change in Reynold’s numbers (air stream velocities), and varying ground clearance on the lateral dynamics of the vehicle will be analyzed using numerical simulations with ANSYS FLUENT software package. The results and reliability of CFD simulations has a high dependency on the size of the grid, thus the aim of this paper will be to ensure that the results are independent of the grid size. Selection of the optimum design will be based on performance parameters like drag and lift coefficients. The challenge posed here is to ensure the lateral stability of the vehicle while achieving high average speed. Therefore, the main goal of the study is to enhance handling capabilities of the road vehicles at high speeds while minimizing the drag.Copyright © 2016 by ASME

Modular Design has made an important contribution to the industrial evolution, increase of quality of products and goods and to economic development. It has produced an important evolution in design (technical modularity), in the organization of production and of companies. It allowed going beyond vertical integration, by fostering vertical specialization in both manufacturing and innovation. Several authors are appointing important question on the modular approach. They move observations of different nature concluding that the enthusiasm for modularity has gone too far. One of the critical positions sustains that modular design has imposed technical choices that conflicts with energy efficiency in vehicle design such as a gradual increase of weight over time and the consequent reduction of potential gains in terms of energy consumption and environmental footprint of vehicles. This paper agrees with some arguments of the revisionist literature in cautioning against errors that can be produced by a pervasive modularity. But it moves from an energetic analysis and has not the objective of defining an alternative theory. More modestly, it aims to present a possible way for coupling modular design with energy optimization in the case of an electric vehicle. The initial inspiration can be of this case study is Bejan’s preliminary modular definition of constructal optimization, which can fit perfectly with industrial modular design. Even if this modular optimization does not have the ambition of defining the best possible solution to a complex design problem, such as Multidisciplinary Design Optimization has, it allows defining configuration that can simply evolve over time by mean of a step by step optimization of the critical components that influences the behavior of a complex industrial system. It reveals then to be applicable to the concept of vehicle platform that is today widely in use. The specific test case is the design of an electric city vehicle which has been optimized by a step applying this modular optimization approach. This paper has also a romantic value because it ha taken the move from the emotion that has been caused by the stop to the production of an extraordinary myth, such as Land Rover Defender. 70 years of production without important changes means that Defender has been not only the most successful British vehicle, but also that it has been a fundamental part of our way of living. This extraordinary longevity is an extraordinary technical and cultural heritage to our time. This decision forces the authors to try to analyze the conceptual modular design of a vehicle that can compete with Defender in terms of use and performances. Results have been surprising demonstrating that the use of industrial grade components and their accurate choice will allow defining new vehicle platforms that can radically improve energy efficiency of vehicles.

Renewable energy technologies are a growing subject of concern these days. Wind energy is one among the renewable energy sources which has been implemented in a large scale for energy production. A large amount of capital has been invested in this field to harness energy and power homes. Wind energy from highways is usually unused and can provide a considerable amount of wind energy to drive a turbine due to high vehicle traffic and the speed of the vehicles. Extensive research on wind patterns is required to determine the average velocity of the wind created by oncoming vehicles. The objective of this work is to design and analyze a horizontal axis wind turbine to capture wind energy from moving vehicles on the highway. A computational fluid dynamics approach is used to solve this problem. The major innovation in this paper is that wind energy is being harvested in a very unique manner and also turbine power calculations have been done to quantify the amount of energy being harvested. Although a few of the literatures have discussed similar ideas power quantification has never been done. Also the entire mechanism has been simulated in MATLAB to find out the number of cars required to charge a battery which is very unique to this paper. Power calculations have been done for the turbine and validated against theoretical calculations which were done using the concept of velocity triangles. The idea is to have a separate mounting for cars and heavy vehicles which can be realized by having separate lanes on highways. The analysis will be done for vehicles moving in a range of speeds on the highway. The wind turbines will be placed on overhead shafts (the height of which is be determined suitably) thereby capturing the wind generated as a result of pressure difference. The mounts can also be used as signboards for vehicles moving on the highway and hence serve a dual purpose. In addition, extensive structural and fatigue analysis will be done for the turbines and the mounting structures in order to determine a suitable material for the turbine as well as the mounts to withstand the forces generated. Using all of the collected energy, existing amenities such as street lights on the medians can be powered by these wind turbines. Thus the main objective of this work is to complement the conventional electrical energy used for powering amenities along highways by a renewable source of energy (wind power) thereby leading to the concept of sustainable highways.Copyright © 2016 by ASME

The University of Connecticut Senior Design Capstone course developed by the Department of Mechanical Engineering is widely recognized by the Connecticut industry. The course provides fourth year students the opportunity for a major design experience in which they apply principles of engineering staring with the conceptual design through the basic science and mathematics, up to model, analysis, design of physical systems its components or processes as well as prepares students to work professionally [9]. This paper will discuss the issues and challenges associated with one of the Senior Design (SD) projects that was based on student generated inventive concept and sponsored by the student-inventor. The project demonstrated the design and prototyping problems on the example so called “Self-Cleaning Toilet”. The project addresses “self-cleaning” of facilities where infectious bacteria and viruses are prevalent in frequently used installations such as public restrooms. These areas tend to be difficult to keep clean often, without obstructing the functionality of the facility. The solution being proposed in this project is an intelligently designed, self-regulating, cleaning system that is able to be retroactively fitted onto a variety of toilet seats. UV germicidal irradiation was chosen as the primary method to eliminate germs for this device for several reasons. Using a UV light allows for more efficient, effortless elimination of germs as compared to conventional cleaning methods. The light encourages hands off operation, meaning that the user will not have to physically touch the toilet seat to clean it. Additionally, it allows the toilet seat surface to be cleaned continually throughout the day and in between uses, which is an unrealistic task to replicate with methods currently being employed. Multiple experiments were conducted that tested the ability of the UV light to reach all surfaces on a toilet seat. The germicidal effectiveness experiment tested the sanitation capability of the light under its intended operating conditions. Finally, the durability test indicated that the device would be able to withstand the conditions of the working environments commonly associated with bathrooms. Designs, building and testing of the prototype of such a toilet seat are described in the paper. Results from each of the testing experiments and experience gained in the creation of the Clean Light toilet design are described in the paper.

This paper aims to improve vehicle crashworthiness using vehicle dynamics control systems (VDCS) integrated with an extendable front-end structure (extendable bumper). The work carried out in this paper includes developing and analyzing a new vehicle dynamics/crash mathematical model and a multi-body occupant mathematical model in case of vehicle-to-vehicle full frontal impact. The first model integrates a vehicle dynamics model with the vehicle’s front-end structure to define the vehicle body crash kinematic parameters. In this model, the anti-lock braking system (ABS) and the active suspension control system (ASC) are co-simulated, and its associated equations of motion are developed and solved numerically. The second model is used to capture the occupant kinematics during full frontal collision. The simulations show considerable improvements using VDCS with and without the extendable bumper (EB), which produces additional significant improvements for both vehicle body acceleration and intrusion.

This paper deals in a first part with an experimental program aimed at studying mechanical impacts on pipelines. Tests have been performed at CRIGEN-ENGIE-LAB, the Center of Research and Innovation for Gas and New Energies of ENGIE (previously GDF SUEZ) on pipes under pressure and pipes without internal pressure with an impact tool whom length is greater than the external diameter of the pipes and a tool similar to an excavator tooth. In a first part, the paper presents the tests which show a very good behavior of the pipelines. None have failed for the large impact-tool, which is equivalent in terms of impact energy to a 1000 kg-vehicle impacting a pipeline at ∼32 km.h−1 (∼20 miles.h−1). In a second part, the paper deals with existing analytical solutions: the Det Norske Veritas model for dent assessment and the EPRG model for mechanical damage assessment due to an excavator tooth. Comparisons with the CRIGEN tests show that the DNV equation is not always conservative in terms of predicted rupture energy and that the third-party damage EPRG model predicts correctly the rupture for the tooth-like tool but does not seem adapted for the longer tool. In a third part, an explicit finite-element model (performed with the commercial software Abaqus) has then been used to simulate numerically the tests. Different material behavior laws have been tested: a classical elastic-plastic law and a law with a time-dependence (Cowper-Symonds). The comparison between the final geometry of the impacted pipeline and the computational solution is quite satisfactory. A numerical strain criterion is extrapolated and then applied to some real configurations. This paper presents the tests, the analytical comparisons, the computational models and some applications to the fall of heavy long objects as well as vehicle impact on pipelines.

Canada and the United States have vast energy resources, supported by thousands of kilometers (miles) of pipeline infrastructure built and maintained each year. Whether the pipeline runs through remote territory or passing through local city centers, keeping commodities flowing safely is a critical part of day-to-day operation for any pipeline. Real-time leak detection systems have become a critical system that companies require in order to provide safe operations, protection of the environment and compliance with regulations. The function of a leak detection system is the ability to identify and confirm a leak event in a timely and precise manner. Flow measurement devices are a critical input into many leak detection systems and in order to ensure flow measurement accuracy, custody transfer grade liquid ultrasonic meters (as defined in API MPMS chapter 5.8) can be utilized to provide superior accuracy, performance and diagnostics. This paper presents a sample of real-time data collected from a field install base of over 245 custody transfer grade liquid ultrasonic meters currently being utilized in pipeline leak detection applications. The data helps to identify upstream instrumentation anomalies and illustrate the abilities of the utilization of diagnostics within the liquid ultrasonic meters to further improve current leak detection real time transient models (RTTM) and pipeline operational procedures. The paper discusses considerations addressed while evaluating data and understanding the importance of accuracy within the metering equipment utilized. It also elaborates on significant benefits associated with the utilization of the ultrasonic meter’s capabilities and the importance of diagnosing other pipeline issues and uncertainties outside of measurement errors.

In this paper, a new leak detection system based on a pattern recognition algorithm in a shut-in condition of a pipeline is presented. For a fully shut-in pipeline, the governing fluid dynamic equations are simplified to the thermodynamic state postulates. Hence, the shut-in section can be treated as a closed thermodynamic system with no mass flow in or out of the system boundaries. The system always contains the same amount of matter, but heat and work can be exchanged across the boundaries of the system. The pattern recognition algorithm presented in this paper automatically monitors the pressure drop patterns and generates an alarm when the pattern of pressure gradients matches the leak signatures. The algorithm takes into account the effect of thermal cooling and other operational complexities to enhance the reliability performance of the scheme. Results of the performance of the shut-in leak detection system are presented and discussed in this paper. Both simulated and historical leak scenarios during shut-in state are used to investigate the performance of the shut-in leak detection scheme.Copyright © 2016 by ASME

The characterization of the noise emitted by positive displacement machines serves as an important metric for the design of positive displacement machines and their corresponding systems. One method of characterizing the noise produced by positive displacement machines utilizes the two microphone-intensity probes at various locations surrounding the unit to approximate the total sound power generated by the machine in question. This paper proposes a method of utilizing a robotic arm to perform automatic sound intensity measurements (ASIM). This paper will explain the various theoretical motivations and justifications for the basic design concept as well as the specific implementation. All the necessary theoretical considerations and technical difficulties were accounted for in the successful design and manufacturing of an ASIM robot. To highlight the usefulness of the automatic measurement procedure, three case studies was performed to evaluate the robotic ASIM’s ability to measure sound power. A total of 1086 measurement locations were taken in order for each grid study to quantify the convergence of the field non-uniformity.

In this paper, we present a tunable stiffness robot link for safe human-robot interaction. Stiffness of a manipulator determines the injury levels of a human from an impact between robots and operators, given a specific impact velocity. Compliance of a robot manipulator includes joint compliance and link compliance. Variable stiffness design from the viewpoint of actuators have been widely studied, while adjustable stiffness robotic link in the application of human robot interaction is rare in literatures. This paper details the design of a tunable stiffness robotic manipulator via four bar linkages which are actuated by servo motors. A 3D model of the morphing beam is constructed, and a robot which is made up of 3 morphing arms is designed. Prototypes using 3D printer are fabricated. Numerous tests have been done, and the results show that the stiffness is able to change 3.6 times given a morphing angle of π/4. Given an impact velocity of 2.2 m/s, the impact tests show that the acceleration has a 19.4% decrease comparing the curved beam and straight beam, and the head injury criteria (HIC) significantly decreases from 210.3 m5/2s−4 to 150.3 m5/2s−4, which is much safer to the operators. This paper explores the research of tunable stiffness on robotic links in the application of human robot interaction, expanding the research arena with regarding to human safe robot design.

This paper describes a dimensional synthesis method used in the design of a passively actuated finger exoskeleton that takes into account the user limb anthropometric dimensions and contact requirements for grasping objects. The paper is the first step in our current efforts on design of wearable devices that use a common slider at the hand to passively actuate each exo-finger. The finger exoskeleton is comprised of a 3R serial limb and is constrained to an eight-bar slider mechanism. To design the exo-limb, the pose of the index finger was captured using an optical motion capture and its dimensions were determined using a constrained least square optimization of its center of rotation. To facilitate the data capture, a 3D printed wearable Infra-red (IR) marker system was designed and placed on the finger’s phalanx. To illustrate the approach, an example of the design of an index exo-finger is described.

Lead-Acid battery was the earliest secondary battery to be developed. It is the battery that is most widely used in applications ranging from automotive to industrial storage. Nowadays it is often used to store energy from renewable energy sources. There is a growing interest to continue using Lead-Acid batteries in the energy systems due to the recyclability and the manufacturing infrastructure which is already in place. Due to this rising interest, there is also a need to improve the efficiency and extend the life cycle of Lead-Acid batteries. To achieve these objectives, it is necessary to gain a better understanding of the physics taking place within individual batteries. A physics based computational model can be used to simulate the mechanisms of the battery accurately and describe all the processes that are happening inside; including the interactions between the battery elements, based upon the physical processes that the model takes into account. In the present paper, we present a discharge/charge experimental study that has been carried out with small Lead-Acid batteries (with a capacity of 7 Ah). The experiments were performed with a constant current rate of 0.1C [A]1 for two different battery arrangements. An in-house zero dimensional model was developed to perform simulations of Lead-Acid batteries under different operating conditions. A validation analysis of the model was executed to confirm the accuracy of the results obtained by the model compared to the aforementioned experiments. Additional simulations of the battery were carried out under different current rates and geometry modifications in order to study how the performance of the battery may change under these conditions.

The Wave Energy Converter Simulator (WEC-Sim) is an open-source code jointly developed by Sandia National Laboratories and the National Renewable Energy Laboratory. It is used to model wave energy converters subjected to operational and extreme waves. In order for the WEC-Sim code to be beneficial to the wave energy community, code verification and physical model validation is necessary. This paper describes numerical modeling of the wave tank testing for the 1:33-scale experimental testing of the floating oscillating surge wave energy converter. The comparison between WEC-Sim and the Phase 1 experimental data set serves as code validation. This paper is a follow-up to the WEC-Sim paper on experimental testing, and describes the WEC-Sim numerical simulations for the floating oscillating surge wave energy converter.

This paper presents the often-neglected correlation terms for uncertainty propagation and shows their importance for rigorous uncertainty analysis. It shows that these terms can be leveraged, often through simple experimental design changes to substantially reduce uncertainty. The efficiency equation is particularly suited to this approach, with order of magnitude uncertainty reductions possible. The paper will present this effect from both a theoretical study and from data measured behind a transonic fan during a distortion response program. The efficiency equation is particularly suited to improving uncertainty by leveraging the correlation terms because the temperature uncertainty contributes most of the overall uncertainty. Systematic error sources usually dominate thermocouple measurement uncertainty because the slow time response leads to small random errors. The partial derivatives with respect to inlet and outlet total temperature have opposite signs. Correlations between these systematic errors are relatively easy to force through using a single data acquisition system and in-situ calibration standard. This paper presents performance comparisons of these effects for thermocouples. For a 1.35 pressure ratio, 85% efficiency fan, the uncertainty can be reduced by correlation from 85% ± 6.7% to 85% ± 0.48% for typical K-type thermocouples.

GEOTRACK is a software for track structure analysis under vertical quasi-dynamic loads. It uses a three dimensional, multilayer elastic model for determining track and subgrade responses. Originally developed by Chang et al. in 1980, GEOTRACK has been validated by several studies to closely match the elastic response of railroad tracks in operation. GEOTRACK can be used to calculate different track response values in the superstructure as well as substructure. The most recent version of GEOTRACK, GEOTRACK for Windows, was developed in 1992 at the University of Massachusetts, Amherst. However, the source code for this executable version was lost before the software rights were acquired by the Transportation Technology Center, Inc. (TTCI). Accordingly, the current executable version, which only runs on 32-bit Windows operating systems, cannot be upgraded. The source code currently available to TTCI does not correspond to the current executable version of GEOTRACK, and was written in the VAX FORTRAN language, making it incompatible with modern compilers and operating systems. Considering the widespread need for GEOTRACK by researchers and practitioners in the railroad industry, a research collaboration was recently initiated between Boise State University and TTCI to develop a new upgraded version of the GETORACK program. This paper will present preliminary results from this developmental effort, and will introduce different features being incorporated into the new version. Developed using the C#.net platform, the new program features an intuitive Graphical User Interface (GUI) with enhanced pre- and post-processing capabilities. Fundamental approach behind railroad track analysis using the multilayer elastic theory is presented in this paper along with basic analysis framework being used in the newly developed program.

Integrating Global Navigation Satellite System (GNSS) into railway application has a great potential because of its various advantages, such as lower cost, less trackside equipment, higher positioning accuracy, easier maintenance and so on. Railway system is a safety-critical system that requires high reliability, safety and real-time performance, so GNSS technology must be tested, verified and validated in railway system before putting into practical applications. However, due to the unavoidable restrictions and inconvenience of the railway field conditions, these tests cannot be accomplished on site. On this basis, this paper has developed a GNSS-based train trajectory simulation system which can provide GNSS data simulation of multi-train trajectory in multiple scenarios in order to support the tests and research of GNSS-based railway application, especially GNSS-based train localisation system and GNSS-based train control system. The GNSS-based train trajectory simulation system is based on the railway timetable (also called schedule), rolling stock information and digital track map. The paper firstly researches on the timetable that stores information of each train at each specified station, including arrival time, departure rime, track to be occupied, and connections to other trains. With the timetable simulation, the train’s trajectory can be generated using the information provided by the digital track map. The output trajectory data is mainly GGA sentence which is compliant with the National Marine Electronics Association (NMEA) 0183 standard. The paper also calculates the satellite visibility based on satellite ephemeris to simulate the number of visible satellites during the trajectory with changing time and space. All the information and data, such as timetable, speed/distance curve, distance/time curve, station track occupation state, can be visualized and updated in graphics and diagrams for better view. In addition, the train motion behavior of acceleration, cruising, coasting and braking can also be modelled in the system, as well as the driver’s behavior. The GNSS-based train trajectory simulation system has been realized using C# programming language in Microsoft Visual Studio 2010. And the field data of Shanxi coal railway transportation company railroad is used in the system. The simulation system is tested and the experimental results show that the developed simulation system can perform the expected functions, and provided data source for GNSS-based train localisation system. In addition, this simulation system has a good performance in compatibility and scalability.

This paper is the first in a two-part series on the puncture performance of railroad tank cars carrying hazardous materials in the event of an accident. Various metrics are often mentioned in the open literature to characterize the structural performance of tank cars under accident loading conditions. One of the consequences in terms of structural damage to the tank during accidents is puncture. This two-part series of papers focuses on four metrics to quantify the performance of tank cars against the threat of puncture: (1) speed, (2) force, (3) energy, and (4) conditional probability of release. In this paper (Part I), generalized tank car impact scenarios are illustrated. Particular focus is given to the generalized shell impact scenario because performance-based requirements for shell puncture resistance are being considered by the regulatory agencies in United States and Canada. Definitions for the four performance metrics are given. Physical and mathematical relationships among these metrics are outlined. Strengths and limitations of these performance metrics are discussed. In Part II, the multi-disciplinary approach to develop engineering tools to estimate the performance metrics will be described. The complementary connection between testing and modeling will be emphasized. Puncture performance metrics, which were estimated from other sources, will be compared for different tank car designs. These comparisons will be presented to interpret the metrics from a probabilistic point of view. In addition, sensitivity of the metrics to the operational and design factors will be examined qualitatively.

Analyzing track geometry defects is of crucial importance for railway safety. Understanding when a defect will need to be repaired can help in both planning a preventive maintenance schedule and reducing the probability of track failures. This paper discusses the data cleaning and analysis processes for modeling track geometry degradation. An analytical data model named the Support Vector Machine (SVM) was developed to model the deterioration of track geometry defects. This paper mainly focuses on the following three defect types — surface, cross level and dip. The model accounts for traffic volume, defect amplitude, track class, speed and other potential factors. Results demonstrate that the proposed analytical data model can have a prediction accuracy above 70%.Copyright © 2016 by ASME

Cloth has always been the most worldwide of all imported and exported commodities. It is an enlightening example of the movement of knowledge, skills, goods and investment across wide geographic seats. South Asia has been dominant for making of these worldwide interactions over period. This capacity grants advanced research that discovers the dynamic ways in which various textile production and trade regions generated the ‘first globalization’. A series of specialists connect this worldwide commodity with the dramatic political and economic alterations that characterised the India in the recent centuries. Together, the papers transform our understanding of the contribution of South Asian cloth, specifically Indian cloth to make the modern world economy. India is the largest share of its exports being textiles and apparels to the world. Also weaving is second only to agriculture sector in terms of providing employment in India. This paper a simple spreadsheet program method of calculations for the complete kinematics and dynamic analysis of the shedding mechanism of the classical powerloom is presented. Shedding is one of the important processes used in weaving technology of textile machineries. Most of the powerlooms of India uses staubli’s M5 module for shedding. These modules are activated through the traditional slider-crank mechanism. The source energy for these modules is through electric motor coupled with clutch and resulting output is shedding action of warp threads of cloth. Objective of this work is to address the kinematics and Dynamics simulation of linkage assembly of shedding mechanism of textile machinery considering all the links of the model as rigid one. Also this paper examines the effect of dynamic forces on various joints of conventional kinematic model. Subsequently the optimisation of mechanism is carried out by varying the design factor ratio of the slider crank mechanism. Length of connecting rod to radius of the crank shaft has been taken into account for defining design factor ratio for the analysis. Altered varieties of models having various design factors are modeled using 3D modeling package Solidworks. Simulation test results and force analysis of these models were carried out using ADAMS. Being a single degree of freedom mechanism as defined by its crank angle, the spreadsheet program can be used to answer what - if? situation queries through tables and graphical plots to evaluate variations of key motion and loading parameters with changes in the design factor. Thus, it allows for the conduct of parameter studies in selecting optimum crank-and-connecting-rod linkage dimensions and speeds. Thus, this work provides an alternative solution and scope for further research in shedding mechanism’s simulation analysis.Copyright © 2015 by ASME

In this paper, a joint simulat ion method based on nonlinear FEM and MBD is proposed. Firstly, the force-deformation character of single vehicle is analysed using nonlinear FEM software Dytran. Then, override simulations of two train units in frontal collision are carried out using multi-body dynamics. Simulation results indicate that the pitching motion of vehicles has great effect to the overriding phenomenon. It also depends on several factors, such as collision mass, pitching frequency, height of the center of mass above the rail level. Besides that, it is shown in this paper the overriding phenomenon is more sensitive to variations in pitching frequency and height of the center of mass, compared to the factor of collision mass.Copyright © 2015 by ASME

The aim of this paper is to design and develop a low-cost prosthetic arm based on surface electromyography (sEMG) signal activities of the biceps muscle during upper-limb movement. Different methods are described in the literature, but many problems are encountered in dealing with the online processing of raw EMG (rEMG) signals, such as signal sampling and memory requirements. In this paper, the enveloped EMG (eEMG) signal is used as a control signal that reduces signal sampling rate and memory requirements. The relationship between elbow motion and the activity level of the biceps muscle is characterized using relevant extracted features (root mean square (RMS)). Validation of the proposed low-cost system is conducted using comparison with a professional biomedical system (Bioback MP150). In addition, the estimated equation of movements of each subject is estimated based on the recorded data. From this equation, the angle of motion is calculated as the control of the movement of the robotic arm. Finally, the system proposed in this paper considers the eEMG signal rather than the rEMG signal and deals with the signal based on a sample of 1 KHz rather than 10 KHz. This system reduces our target cost (reduction in hardware requirements and processing time) with acceptable accuracy. The experimental results illustrate that the eEMG signal has the same features-print as that of the rEMG signal, and the eEMG signal can generate the control signal required to move the prosthetic arm.Copyright © 2015 by ASME

The lateral motion control is a key element for automated driving vehicle technology. Typically, the front steering system has been used as the primary actuator for vehicle lateral motion control. Alternatively, this paper presents a new method of the lateral motion control using a rear steer. When combined with the front steer actuator, the rear steer can generate more dynamically responsive turning of the vehicle. In addition, the rear steer can be used as a secondary back up actuator when the front steer actuator fails to operate during automated driving mode. Similar to the prior research that has used the front steer actuator for the lateral control, the control methodology presented in this paper maintains the same hierarchical framework, i.e., sensor fusion, path prediction, path planning, and motion control. Since the rear steer is in play for the vehicle lateral motion control, the equations for the path prediction and vehicle dynamics are re-derived with non-zero front steer and rear steer angles. Combined with the rear steering dynamics, the model predictive control (MPC) technique is applied for motion error minimization. This paper describes the theoretical part of the algorithm, and provides simulation results to show effectiveness of the algorithm. Future work will include vehicle implementation, testing, and evaluation.Copyright © 2015 by General Motors

Increasing demands on the productivity of complex systems, such as machine tools and their steadily growing technological importance will require the application of new methods in the product development process. This paper shows that the analysis of the simulation results from the simulation based mechatronic model of a complex system followed by a procedure that allows a better understanding of the dynamic behavior and interactions of the components. Mechatronics is a design philosophy, which is an integrating approach to engineering design. Through a mechanism of simulating interdisciplinary ideas and techniques, mechatronics provides ideal conditions to raise the synergy, thereby providing a catalytic effect for the new solutions to technically complex situations. This paper shows how the mechatronic products can exhibit performance characteristics that were previously difficult to achieve without the synergistic combination. The paper further examines an approach used in modeling, simulation and optimization of dynamic machine tools and adopts it for general optimized design of mechatronics instrumentation and portable products. By considering the machine tool as a complete mechatronic system, which can be broken down into subsystems, forms the fundamental basis for the procedure. Starting from this point of view it is necessary to establish appropriate simulation models, which are capable of representing the relevant properties of the subsystems and the dynamic interactions between the machine components. Many real-world systems can be modeled by the mass-spring-damper system and hence considering one such system, namely Mechatronics Technology Demonstrator (MTD) is discussed here. MTD is a portable low cost, technology demonstrator, developed and refined by the authors. It is suitable for studying the key elements of mechatronic systems including; mechanical system dynamics, sensors, actuators, computer interfacing, and application development. An important characteristic of mechatronic devices and systems is their built-in intelligence that results through a combination of precision, mechanical and electrical engineering, and real time programming integrated to the design process. The synergy can be generated by the right combination of parameters, that is, the final product can be better than just the sum of its parts. The paper highlights design optimization of several mechatronic products using the procedures derived by the use of mass spring damper based mechatronic system. The paper shows step by step development of a mechatronic product and the use of embedded software for portability of hand held equipment. A LabVIEW based platform was used as a control tool to control the MTD, perform data acquisition, post-processing, and optimization. In addition to the use of LabVIEW software, the use of embedded control system has been proposed for real-time control and optimization of the mass-spring-damper system. Integrating embedded control system with the mass-spring-damper system makes the MTD a multi-concepts Mechatronics platform. This allows interface with external sensors and actuators with closed-loop control and real-time monitoring of the physical system. This teaches students the skill set required for embedded control: design control algorithms (model-based embedded control software development, signal processing, communications), Computer Software (real-time computation, multitasking, interrupts), Computer hardware (interfacing, peripherals, memory constraints), and System Performance Optimization. This approach of deriving a mathematical model of system to be controlled, developing simulation model of the system, and using embedded control for rapid prototyping and optimization, will practically speed product development and improve productivity of complex systems.

The University of Connecticut Department of Mechanical Engineering has developed an industry recognized Senior Design Capstone course. The course provides fourth-year students the opportunity for a “major design experience in which they apply the principles of engineering, basic sciences, and mathematics to model, analyze, design, and realize physical systems, components or processes, and it prepares students to work professionally” [1]. The course is taught by a class instructor and is supported by the faculty of the Mechanical Engineering department at UConn. In the 2013–2014 academic year there were over 40 projects in the course. This paper presents the issues and challenges that students faced when working on a project for Koffee Karousel’s coin-operated K-Cup vending machine. Work on the project began with the problem statement, and was followed by the generation of possible solutions (accepting the most promising ones) and finally, choosing the ideal solution. The subsequent steps involved preliminary and detailed design, structural analysis, creating a 3D CAD representation, generating drawings, and producing a prototype. The prototype was then tested to verify its capabilities. The example of switching from a coin-operated design, with its limited potential use, to an electronically operated solution is described in this paper. The objective of this senior design project was to implement a credit card reader onto the original Koffee Karousel design. To accomplish this goal, a redesign of the Koffee-Karousel’s coin mechanism was required. An electrical engineering team of four students worked independently on the credit card and display setup, while a mechanical team worked on a lever mechanism and gears activated by the validation of a credit card. The implementation of this new mechanism included designing a replacement face, a couple of brackets for electrical hardware, and several new parts, including an actuator and a mini-stepper motor. In addition, students designed the new cam that would interface with stepper motor. Some parts were accepted from the current design of the lever and ejector. The new design still allows the customer to choose which K-Cup flavor they want by hand by operating a rotating knob at the top of the carousel, but no longer requires the user to trigger the ejector mechanism manually. Students tested the new mechanism to ensure it was not only efficient, but also worked properly. The stresses on each individual part were calculated for the first design iteration to ensure the new design would not yield or fail over time due to fatigue. The project and its challenges are described in this paper, as well as the students’ contributions to the design of the Karousel mechanisms, switching it from a purely mechanical to a mechatronik solution.

EI Consultants (formerly The Engineering Institute) has been studying solid rear axle tramp for well over a decade, and contributed several publications to the literature outlining recommended test methods and their results. Throughout the history of EI’s research, sustained tramp inputs have been achieved by use of a tire featuring affixed lumps of rubber to induce wheel hop at one end of the axle. The principal methodological guide for studying the vehicle response to this input has been the test methods and data analysis recommendations of test standard SAE J266: Steady-State Directional Control Characteristics for Passenger Cars and Light Trucks. More specifically, past testing has been patterned almost exclusively on the circle test (constant-radius/slowly-increasing-speed) method discussed in J266. Historically, the J266 recommendation for data analysis and presentation, i.e. understeer/oversteer gradients derived from a wheel angle versus lateral acceleration plot, were principally used. Recent research, along with fresh analysis of previous testing results, revealed limitations of the circle test and the J266 recommended manner of data analysis in the context of tramp resonance testing. During a constant-radius/slowly-increasing-speed test, a single control variable (speed) has the effect of changing both the lateral acceleration and the tramp input frequency simultaneously. This effect results in a non-steady-state test event where only a narrow portion of each test run expresses the resonant axle tramp phenomenon that is the intended object of the observation. To provide a wider view of vehicle response characteristics during sustained axle tramp, EI Consultants selected and evaluated expanded test methods in a recent testing project. These methods included performing circle tests at multiple radii, performing continuous tests modeled after the J266 constant-speed/variable-radius method, and performing path-following tests modeled after the slowly increasing steer method. Expanded data analysis and presentation methods were developed to quantify and understand the vehicle oversteer response in more effective ways than those recommended by J266. Due to the abrupt discontinuity in the vehicle’s response upon reaching the resonant tramp frequency, novel methods of data presentation were shown to be more useful in assessing vehicle characteristics during resonant tramp. Of particular value was examining the steering input delta in the vehicle speed and tramp input frequency domains during the phase of resonant axle response; and examining the difference between the actual yaw rate and the theoretical Ackerman yaw rate derived from the measured steer angle. This paper will detail the data analysis techniques that were developed to overcome the limitations of the J266 standard’s steer gradient methodology, and thus introduce a more useful approach to evaluating understeer/oversteer characteristics during non-steady-state test events. This paper is the first of two companion papers presenting theory and results from EI Consultants’ most recent axle tramp testing. This paper focuses on new understandings of test data analysis theory, while the second paper will summarize the results of numerous tests and their application to various suspension design strategies for improving solid rear axle tramp control, with a motivation for enhancing vehicle controllability and highway safety.

This paper conducts an in-depth research on mobile robotic drilling trajectory planning for large-scale components. And it proposes a path planning method of step-close for mobile robotic station. According to the thought of “drilling area-robot station-process step”, the drilling order is defined. By adding conditions and simulation, we also present a simple method of optimizing robot posture in this paper. Using the actual position and the nominal position of two reference holes, a correcting algorithm of three-dimensional transformation is introduced to improve the drilling accuracy. Taking the aircraft wing-box drilling as main study object, this paper develops a trajectory planning and a drilling simulation system on the CATIA and DELMIA platform to validate the effectiveness of the methods introduced. Experiments show that the trajectory planning method and the three-dimensional transformation method for correcting drilling position in this paper not only improves the wing-box drilling efficiency and accuracy, but also reduces the production cost.Copyright © 2015 by ASME

Knowledge of positional and force properties of surgical dissection in neurosurgery is essential in developing simulation platforms for neurosurgical training such that realistic motion and perception can be conveyed to the trainee during practice. Most proposed models in literature utilize computational techniques to formulate required parameters. However, these models are not realistic enough compared to data obtained from experiments on real brain. Therefore, developing a setup to measure the position, orientation, and interaction forces will help researchers formulate realistic parameters. This paper presents the development of such a setup for quantification of displacements and tool-tissue interaction forces during performance of microsurgical tasks. A bipolar forceps is equipped with a set of force sensing elements to measure the tool-tissue interaction force components. The position and orientation of the forceps tips are measured by attaching a tracker to the bipolar forceps. To show proof-of-concept, an experienced surgeon and one assistant surgeon performed 35 neurosurgical tasks (320 trials) on a cadaver brain (previously-frozen) using the instrumented setup. Positional and force data of the bipolar forceps were recorded during surgical dissection of different brain structures. This paper reports results collected from two microsurgical tasks over 40 trials: dissection of sylvian cistern arachnoid (SCA) and dissection of middle cerebral artery (MCA). Results showed that the mean values of interaction forces during dissection of MCA were smaller than dissecting SCA. The maximum forces observed were 1.94 N and 1.75 N for SCA and MCA, respectively. The application of quantifying such parameters using the developed setup will be in training neurosurgery residents using surgical simulators in which the knowledge of brain tissue parameters is required to formulate the tissue model.Copyright © 2015 by ASME

Common rail injection system (CRIS) is an advanced technology which meets the stringent emission standards of diesel engines and satisfies consumer demand for better fuel efficiency and increased power. The coherence of fuel injection quantity is the key injection characteristic for CRIS to match diesel engines successfully. As a critical component for CRIS, the variation of injector characteristic parameters has significant influence on the coherence of fuel injection quantity of the system. In this paper, combining numerical modeling and design of experiments, the response predicted relation between fuel injection quantity fluctuation of CRIS and its influence factors had been investigated. A numerical model of common rail injector was presented for the purpose of creating a tool for simulation experiments. The model is developed using power bond graph method, which is a modeling method that has shown its superiority in modeling systems consisting of sub-models from several energy domains in a unified approach. Experiments were conducted at the same model conditions to validate the model. The results are quite encouraging and in agreement with model predictions, which imply that the model can accurately predict the fuel injection quantity of CRIS and it can be used to simulation and design experiments. Experiments were designed using D-optimal method in which the characteristic parameters of common rail injector were chosen as design factors and the fuel injection quantity fluctuation was selected as the response. The fuel injection quantity fluctuation responses at different design factor levels were obtained using the developed numerical model which had been validated. A regressive prediction model of fuel injection quantity fluctuation was suggested according to the simulation experiments by means of partial least-squares regression (PLR) analysis. Analysis of variance, normal distribution of standardized residuals and relation between observed and predicted fuel injection quantity fluctuation for the regressive prediction model were analyzed which demonstrate the favorable goodness of fit and significance of the regressive model to predict fuel injection quantity fluctuation of the system. By changing design factor levels, the comparisons between numerical results of the bond graph model and the predicted fuel injection quantity fluctuation of the regressive prediction model were conducted. Results show that the regressive prediction model can reliably predict the fuel injection quantity fluctuation caused by the variation of characteristic parameters of common rail injector. Research results of this paper can provide novel ideas to predict fuel injection quantity fluctuation and a theoretical guidance for design and parameters optimization of CRIS.Copyright © 2015 by ASME

A touch-based probe of a coordinate measurement machine (CMM) is generally used to validate the dimensions of the artifacts and associated features which come out of the manufacturing line against its dimensions to ensure to be within prescribed GD&T [Wilson 14] limits. Although there could be other applications using a CMM like reverse engineering, however the stated inspection process is quite crucial for maintaining quality factor and to regulate merits of the manufacturing process especially with the continuous wear-tear of the involved tooling. However this inspection process, which is considered as auxiliary process, needs to have minimum cycle time in order to effectively have more quality units to be produced. In this paper we describe Computer Aided Process Planning (CAPP) in order to complete Computer Aided Inspection (CAI) process using CMM on the work-piece which is created through Computer Aided Design (CAD) and Manufacturing (CAM). This leads to Computer Integrated Manufacturing (CIM) process. As a result, the features, which need to be inspected, could be recognized from its corresponding CAD file and appropriate information could be culled out by the Dassault Software System to calculate the approach and retract points to inspect the features [Choudhury 03]. The main objective of this research paper is to determine the shortest collision free trajectory from the retract point of one feature being inspected to the approach point of another feature being inspected so that the sequencing for the set of trajectories could be calculated through existing Traveling Sales Person (TSP) algorithm in order to shorten the total distance travelled by the CMM probe, which in turn would linearly reflect in reducing the cycle inspection time. Further since different features in the work-piece might need to be inspected by different probes, an overhead time and displacement for probe change, needs to consider in order to shorten the cycle time. These include clustering of similar type of features, which can be inspected by the same probe. Also clustering of similar type of features need to be assessed against spatial distance of separation between the clusters that the probe has to travel. Since the CMM travels at a constant low speed and the different probes are of similar shape, size and comparatively very small weight, the motion dynamics of the CMM does not influence the total distance travelled for the inspection process. Our main contribution is in the development of a spatial algorithm which not only reduces the inter-feature distance but also does that by avoiding the potential for any collision with the feature or the artifact without the use of any computer vision or collision avoidance sensor information. The resulting spatial algorithm has implicit embedded information of feature clustering, which when fed into an optimization algorithm generates a path planning which would eventually shorten the cycle time. The illustration is done with two separate simulations.

Localization is an important required task for enabling vehicle autonomy. Localization entails the determination of the position of the center of mass and orientation of a vehicle from the available measurements. In this paper, we focus on localization by using the range measurements available to a vehicle from the communication of its multiple onboard receivers with roadside beacons. The model proposed for measurement is as follows: the true distance between a receiver and a beacon is at most equal to a predetermined function of the range measurement. The proposed procedure for localization is as follows: Based on the range measurements specific to a receiver from the beacons, a finite LP (linear programming) is proposed to estimate the location of the receiver. The estimate is essentially the Chebychev center of the set of possible locations of the receiver. In the second step, the location estimates of the vehicle are corrected using rigid body motion constraints and the orientation of the rigid body is thus determined. Two numerical examples provided at the end corroborate the procedures developed in this paper.

This paper presents a control approach for an experimental transtibial prosthesis that can actively realign the residual limb in relation to prosthetic foot during the stance phase of gait. The realignment objective is to inject positive power into the gait cycle while actively reducing the magnitude of the sagittal moment transferred to the residual limb. The altered gait dynamics of this new type of prosthesis require a control approach that coordinates its function with a user’s gait cycle. This paper overviews the mechanical design of the prosthesis development, the proposed finite-state adaptive controller, and presents experimental results for constant cadence walking and adaptation while changing walking speeds.Copyright © 2015 by ASME

This paper presents the design and modelling of a new powered ankle prosthesis which combines electrohydrostatic actuation with a controllable passive damper. The new powered ankle prosthesis can switch quickly between passive mode and powered assistance mode, and is intended to just give assistance at certain points within the gait cycles, such as during toe push-off. The design concept and a prototype built to demonstrate the concept are presented. A simulation model was developed to help analyse the performance characteristics. The structure and parameterisation of the simulation model are described. A comparison between simulation results and experiment results is undertaken in order to validate the model and assist in the optimisation of the design. Some results from an initial trial with amputees are included in the paper. According to subjective feedback from the amputees, the new powered ankle prosthesis provides sufficient force at push-off to assist with walking. Future investigations will be focusing on the compactness, weight reduction and control of the powered ankle prosthesis.

Pneumatic linear drives are widely used in manufacturing, mainly for handling tasks. Pneumatic drives are very versatile and reliable. They are easy to install and to maintain as well as economically priced. Due to rising interest in environmental matters and increasing energy costs, energy efficiency has become a major issue in industrial applications. There is a growing competition between pneumatic and electromechanical drives. Pneumatic drives are said to have high operating costs while the purchase of electromechanical drives is more expensive. The operating costs of pneumatics are mainly induced by the energy consumption to provide pressurized air. Therefore many different air saving measures for simple handling tasks are proposed in literature, which offer opportunities for reducing the air consumption in comparison to standard configurations. This paper provides an overview of different approaches for saving air and typical applications for these approaches. The thermodynamic concept of exergy is utilized in the paper. It provides a better standard of comparison between different technologies than common energy analysis because exergy accounts for a system’s ability to conduct work out of different forms of energy. An exergy based analysis and a comparison of different air saving circuits are presented. The approaches described in literature are suitable for different applications. The study includes an analysis of cross flow valves to recuperate parts of the exhaust air during backstroke. Furthermore shut-off-valves using the expansion energy saved in the pressurized air of meter-out controlled cylinders are evaluated. The use of expansion energy is applicable if the entire cylinder force is not required at the end stop. The circuits are simulated based on lumped parameter models (DSHplus). The simulations are validated by experiments. The exergy efficiency of the examined circuits is compared to a meter-out controlled standard drive. Furthermore possible restrictions for the use of these circuits are discussed. This includes stability problems caused by the reduced force in the end stop or influences on the drive dynamics. If these restrictions are considered in the design of the facility, the same level of process quality and reliability compared to a standard setup can be achieved. Large energy savings and therefore reductions of operating costs of the pneumatic drives are possible with limited effort.

This paper presents an approach for the evaluation of the effects related to the behavior of the journal bearings on the operation of external gear machines (EGMs). In EGMs journal bearings usually support shafts of both gears. The prediction of their instantaneous axis of rotation is a key feature of EGMs, affecting the displacing action of the inter-teeth volumes and the leakages at the tip of each tooth. Past approaches presented in the literature for the evaluation of the radial micro-motions of the gears are based on classic simplified models for the hydrodynamic journal bearings based on steady-state solutions of the fluid film neglecting important hydrodynamic effects due to film squeeze — which can be relevant in case of significant radial loads variations — or they concentrate the focus of the study on the journal bearing itself regardless of the impact on the global machine operation. This work presents a CFD model coupled with a rigid model for the evaluation of the radial motions of the journal that permits to overcome the above-mentioned limitations of the existing approaches of study. The paper details the proposed model, in particular as concerns the CFD approach to solve the film flow and its coupling with a previously developed model (HYGESim) developed by the authors’ team for the evaluation of the overall operation of the EGM, used also to find the instantaneous loads on the gears. The potentials of the proposed approach are shown for the case of a pump for high pressure applications. For this case the results show how it is necessary to have a detailed approach for the evaluation of the journal bearings for a correct evaluation of the overall EGM behavior. In particular, the importance of hydrodynamic squeeze effects are shown, by comparing the model prediction with those given by the commonly used simplified steady-state approach. The comparison of simulation results with experimental data is also shown as pertain to pump case wear associated to the break in process.

There exists the potential for major simplifications to current hybrid transmission architectures, which can lead to advances in powertrain performance. This paper assesses the technical merits of various hybrid powertrains in the context of high-performance vehicles and introduces a new transmission concept targeted at high performance hybrid applications. While many hybrid transmission configurations have been developed and implemented in mainstream and even luxury vehicles, ultra high performance sports cars have only recently begun to hybridize. The unique performance requirements of such vehicles place novel constraints on their transmissions designs. The goals become less about improved efficiency and smoothness and more centered on weight reduction, complexity reduction, and performance improvement. To identify the most critical aspects of a high performance transmission, a wide range of existing technologies is studied in concert with basic physical performance analysis of electrical motors and an internal combustion engine. The new transmission concepts presented here emphasize a reduction in inertial, frictional, and mechanical losses. A series of conceptual powertrain designs are evaluated against the goals of reducing mechanical complexity and maintaining functionality. The major innovation in these concepts is the elimination of a friction clutch to engage and disengage gears. Instead, the design proposes that the inclusion of a large electric motor enables the gears to be speed-matched and torque-zeroed without the inherent losses associated with a friction clutch. Additionally, these transmission concepts explore the merits of multiple electric motors and their placement as well as the reduction in synchronization interfaces. Ultimately, two strategies for speed-matched gear sets are considered, and a speed-matching prototype of the chosen methodology is presented to validate the feasibility of the proposed concept. The power flow and operational modes of both transmission architectures are studied to ensure required functionality and identify further areas of optimization. While there are still many unanswered questions about this concept, this paper introduces the base analysis and proof of concept for a technology that has great potential to advance hybrid vehicles at all levels.Copyright © 2015 by ASME

Flexible robot arms have been developed for various medical and industrial applications because of their compliant structures enabling safe environmental interactions. This paper introduces a novel flexible robot arm comprising a number of elastically deformable planar spring elements arranged in series. The effects of flexure design variations on their layer compliance properties are investigated. Numerical studies of the different layer configurations are presented and finite Element Analysis (FEA) simulation is conducted. Based on the suspended platform’s motion of each planar spring, this paper then provides a new method for kinematic modeling of the proposed robot arm. The approach is based on the concept of simultaneous rotation and the use of Rodrigues’ rotation formula and is applicable to a wide class of continuum-style robot arms. At last, the flexible robot arms respectively integrated with two different types of compliance layers are prototyped. Preliminary test results are reported.Copyright © 2015 by ASME