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We report the effects of a particle surface charge during translocation through a thin micropore based on the simulation and experiments. The translocation of carboxylated and nonfunctionalized polystyrene beads through a fabricated micropore was measured. To compare the translocation behaviors of a particle with/without surface charge under the same driving force, we used a pressure-driven method low bias voltage. We then analyzed the signals with two factors: the translocation time and blocking current. Based on the analysis, we found that, at a low flow rate, the translocation time was largely dependent on the surface charge of the particles. More importantly, we found an unusual phenomenon that the flow rate can affect the blocking current, and the level of effect was significantly determined by the particle's surface charge. To understand this phenomenon, we suggest a plausible mechanism considering the effect of the convective flow on the counterion flux and FEM results. [ABSTRACT FROM AUTHOR]

The world experiences disasters caused by natural and industrial accidents. Various products have been developed and applied for manpower rescue and risk removal at disaster sites. However, in order to move debris and other obstacles generated after cutting and destroying operations to remove hazards at a disaster site, a mechanical device that can safely grasp various target objects is required. In this study, we developed a gripper that can be attached to a cutting machine typically used at disaster sites. The gripper proposed in this study can be attached and detached to the hydraulic cutter, and can stably hold a 100 kg object using the force generated from the hydraulic motor. In addition, a mechanism that can safely grip target objects regardless of shape has been applied. The gripper proposed in this study was verified through mathematical analysis and MFBD simulation. Finally, the gripper was actually manufactured and grip tested successfully. [ABSTRACT FROM AUTHOR]

This study aims to solve problems caused by misalignments between exoskeleton systems and the human body. Misalignments interfere with the achievement of the wearer's motion intention by generating unintended interaction forces between the wearer and the exoskeleton system. Therefore, this study attempts to overcome this problem by applying an additional degree of freedom (DOF) to the fixation of the human body. First, we analyzed a system of a human body and exoskeleton connected by serial chains. Second, we derived all possible DOF sets for a 7-DOF exoskeleton system and determined the final DOF set based on practical applicability. Finally, we measured the interaction forces generated during the operation of the exoskeleton system to verify the effects of the fixation mechanism. The significance of the results was confirmed by a t test with a significance level of p ≤ 0.05. [ABSTRACT FROM AUTHOR]

Quasi-passive or passive mechanisms used for exoskeleton robots for load-carrying augmentation have been developed for reducing development cost, robot weight, and external energy consumption for augmentation. These mechanisms have been developed based on biomechanical analyses of specific motions; however, few mechanisms do not include mechanical elements, such as springs and dampers. In this paper, a movable instantaneous center of rotation (M-ICR) linkage mechanism developed for the knee in the lower extremity exoskeleton without using mechanical elements is presented. Wearability and augmentation functions are considered. Based on these functions, design optimization is achieved using the PIAnO tool. To verify the augmentation function, the Solidworks tool is used. To verify the effectiveness of the M-ICR knee mechanism, oxygen consumption and the vertical ground reaction force are measured while walking with a barbell (0 kg, 10 kg, 20 kg) and while standing with a grinder with and without wearing the exoskeleton robot. [ABSTRACT FROM AUTHOR]

This study discussed application of a machine learning approach (Support vector machine, SVM) for the automatic cognition of gait changes due to scoliosis using gait measures: kinematic based on gait phase segmentation. The gaits of 18 controls and 24 scoliosis patients were recorded and analyzed using inertial measurement unit (IMU)-based systems during normal walking. Altogether, 72 gait features were extracted for developing gait recognition models. Cross-validation test results indicated that the performance of SVM was 90.5% to recognize scoliosis patients and controls gait patterns. When features were optimally selected, a feature selection algorithm could effectively distinguish the age groups with 95.2% accuracy. Applying the method that the previous test used, the severity of scoliosis was classified after clinician labeled the severity based on the Cobb angle. Test results indicated an accuracy of 81.0% by the SVM to recognize scoliosis severity gait patterns. Optimal selected features could effectively distinguish the scoliosis severity with 85.7% accuracy. When the measured features are ranked in order of high contribution, the abduction and adduction of left hip joint in the single support phase is most important in gait of patients with scoliosis. These results demonstrate considerable potential in applying SVMs in gait classification for medical applications. [ABSTRACT FROM AUTHOR]

Robot-assisted ambulatory training has become an increasingly popular method of rehabilitation. The present study aimed to evaluate the effectiveness of robot-assisted training on walking by measuring changes in gait pattern. In this pilot study, a lightweight, modular, wearable lower-limb robot that supports walking was tested in two male patients who became hemiplegic because of stroke. Wearing the lower-limb robot, 12 weeks of ambulatory training was conducted, 3 days a week, for 45 minutes per session. Gait analysis was conducted using a 3D motion analyzer to measure and evaluate the changes in walking aspects 4 times (pre-training, 6 weeks, 12 weeks, and 24 weeks); the evaluation measured temporal-spatial, kinematic, and kinetic variables. Several variables improved in the hemiplegic patients after the end of 12 weeks of training but regressed somewhat after an additional 12 weeks without ambulatory training. Future studies should be focused on improving certain aspects of the robotic training mechanism, such as the ankle joint torque generator, and should be expanded to include a larger population of controlled study participants. [ABSTRACT FROM AUTHOR]

In this paper, we develop an insole sensor system that can determine various dynamic models of a lower extremity exoskeleton. The study analyzed the kinematic model of exoskeleton robot for lower limb that changes according to the gait phase detection of a human. Based on the ground reaction force (GRF) that is generated when walking, the sensing type, location, and the number of sensors were selected to proceed on insole sensor development. Using the COP, an algorithm was developed that is capable of detecting gait phase with small number of sensors. An experiment was conducted to evaluate the developed insole sensor system and the gait phase detection algorithm. [ABSTRACT FROM AUTHOR]

Silver grid electrode is a promising candidate for transparent conductive film because of its outstanding electrical, thermal, and optical properties, which can be easily tuned by changing the line width, spacing, and thickness of the metal pattern. Here, we presented the fabrication method of transparent Ag electrode with line-pattern using contact transfer technique with thermal release tape (TRT) that is easy to adhere and/or release to the substrate. To fabricate a line-patterned Ag electrode, the following efficient processes were developed: 1) preparation of line-patterned recess using thermal-roll imprinting, 2) surface modification by the anti-adhesion layer coating, 3) Ag infilling into the line-patterned recess using a doctor blade, 4) transfer of Ag electrode to the target substrate using TRT. As a result, the Ag line-patterned film with low sheet resistance (17.94 Ω/sq) and high transparency (90.28% at 550 nm) was obtained. This film can be tailored on requirement for various electronic applications. [ABSTRACT FROM AUTHOR]

In this study, we developed a wearable robot operating on the external skeleton to support the movements of a weak person's upper limbs, mainly 3-degree of freedom (DOF) of the shoulder, 1-degree of freedom of the elbow. Moreover, we applied a redundant degree of freedom to design an upper extremities wearable robot that accurately follows the movement of the upper limbs. Namely, we applied 4 driving parts to the robot to enable 3-degree of freedom for shoulders by optimizing the conformance between the links and body movement range. The optimal design which minimizes error where the robot and the body is adjusted, improves wear sensation and signal input. We attached a multi-axes load-cell to generate motion intent signals detecting the movements of the body. According to the EMG signal measurements when moving the upper limbs with the robot on, the RMS value decreased compared to that without the robot. This is due to the decrease in muscle activity, which results from using smaller muscular strength. That is to say, when comparing the same movements, the person wearing the robot used less muscular strength with the help of the robot. Also through SEF50 analysis of the EMG signals, we were able to verify that the muscle fatigue lessened. [ABSTRACT FROM AUTHOR]

We present a new roadmap based on a generalized Voronoi graph (GVG) for two-identical-link (L) robots to explore an unknown planar environment. It is called the L hierarchical generalized Voronoi graph (L-HGVG). The L robot is formed by two equal length rods and a revolute joint between them. The configuration of the robot possesses four degree-of-freedom, two for position and two for orientation, and hence the roadmap is one-dimensional in an unknown configuration space R × T. L-HGVG is defined in terms of workspace distance measurements using only sensor information without prior knowledge of the environment, with the robot having the maximum distance from obstacles, and is therefore optimum in a point of view for exploration and obstacle avoidance. [ABSTRACT FROM AUTHOR]

We propose to use Lagrange interpolation method to express each joint trajectory function to realize trajectory planning for energy minimization of industrial robotic manipulators. We give the position constraints to the industrial robotic manipulators and the stability of the industrial robotic manipulators should be satisfied. In order to avoid Runge's phenomenon of Lagrange interpolation method, we use the Chebyshev interpolation points for our approach. Through derivation, the angular velocity functions and angular acceleration functions can be obtained. Lagrange interpolation method can satisfy position constraints, and ensure the smoothness of joint angular positions, velocities, accelerations, and joint torques. By taking these functions into the Performance Index (PI) of energy minimization, as well as the direct iteration method used for optimization of energy consumption, we can obtain the optimal trajectory for industrial robotic manipulators. [ABSTRACT FROM AUTHOR]

This study compares the gait of chronic ambulatory hemiplegic elderly (HE) with those of non-hemiplegic elderly (NHE) using Vicon® 512 motion analysis system to track movement trajectories. Subjects walked with self-selected gait speeds while temporal, spatial, and kinematic variables were analyzed. HE showed significantly decreased walking speed, cadence, stride length, and step length, and increased stride time, step time, and double limb support periods in comparison with NHE. Double limb support of stance phase was significantly increased in HE. In HE, affected pelvis showed marked upward elevation from terminal stance to mid swing phase, and greater external rotation than the NHE (p<0.05). Affected hip showed increased external rotation than the NHE. Affected knee showed loss of first and second flexion waves in sagittal plane. Affected ankle also showed reduced first rocker, and outward foot progression angle compared to NHE. Our results suggest that the major coping mechanism of HE to maintain balance and to continue walking is to increase the stance time of affected limb inevitably sacrificing walking speed. This study points to the importance and necessity of building a rehabilitation program that decrease the double limb support of affected limb while maintaining gait speed in the HE. [ABSTRACT FROM AUTHOR]

The assembly task involving complex parts by the dual-arm robot conducted in configuration space tends to require the heavy computational load, especially when the robot motion is constrained to avoid any collisions during the assembly task. Thus, this study suggested the path planning algorithm of the dual-arm robot in operational space for the assembly task involving complex parts and conducted the simulations to verify the effectiveness of the suggested method. The results show that the suggested path planning method on operational space is more effective compared to the conventional path planning method in configuration space, particularly in aspects of the computational time. [ABSTRACT FROM AUTHOR]

In this study, a link length determination method for the reduction of the performance deviation in the whole workspace of the manipulator was proposed. The structural length index (SLI), condition number (CN), and global conditioning index (GCI) were selected as performance indices for link length determination. To evaluate deviation, the CN was calculated in the whole workspace, and then the data was used to calculate the coefficient of variation. The Taguchi method was used to decrease the time of optimization for the whole workspace, and Grey relational analysis was performed to convert the values for multiple objective functions to one value defined by the Grey relational grade. Furthermore, the effects of the design factors on the objective function were analyzed through analysis of variance. Optimization was performed twice for each objective function to compare the result of the considering the performance deviation and the result of the considering the performance mean. Each objective function consists of (A) the SLI and the coefficient of variation of the CN and (B) the SLI and GCI. The validity of the proposed method was verified by comparing the results of (A) and (B) for performance deviation, mean and the rate of valid workspace. [ABSTRACT FROM AUTHOR]

Prior to developing the wearable walking assistant robot that supports walking for hemiplegia patients, a neural oscillator, a type of CPG (central pattern generation), was applied to 2-DOF double pendulum, which can replace the leg of a robot. The walking pattern generation method was proposed using the gait pattern of the non-affected side of hemiplegia patients. Because it is difficult for hemiplegia patients to distinguish the intended action signal of the patient wearing a robot on their affected side, we had to utilize a limited amount of information to get the maximum effect. We needed an effective solution for robot control in an outside environment where many unknown disturbances exist. In order to deal with these two problems, we used a nonlinear oscillator with a double pendulum as a test bed to explore the possibility of producing a robot walking pattern. [ABSTRACT FROM AUTHOR]

With the increasing number of high-rise and large-scale buildings, modern buildings are becoming intelligent, and are incurring high construction costs and requiring careful maintenance. Maintenance works for high-rise buildings significantly depend on human labor, unlike other construction processes that are gradually being automated. The resulting accidents may produce very high social and economic losses. To address this problem, herein, this paper proposes robotic building maintenance system using multi-robot concept, in specific, cleaning a building façade which is directly subjected to minimize human labor; that improves the process efficiency and economic feasibility. The sensor for detecting contamination of building's outer-wall glass is proposed; Kalman filter was used for estimating robots' status with the contamination of the window glass. Task allocation of the sensor based multi-robots for an effective way of task execution is introduced and the feasibility was verified through the simulations. [ABSTRACT FROM AUTHOR]

In the operations of laser gyros, geometric variations due to temperature, manufacturing misalignments and operation environments cause thermo-elastic deformations of their components, which lead to changes of the area and perimeter of their resonator block. The ray transfer matrix in the geometric optics can be utilized to predict the optical ray paths on the basis of the temperature environments as well as the misalignment of mirrors. The distance and orientation (or slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. The geometric scale factor variations can be corrected by the piezoelectric actuator based on the design parameters of optical path control in the resonator. For the effective corrections of it, the feasible designs of piezoelectric actuator are required. This paper presents the numerical formulation of the elastic behavior of each piezoelectric actuator and the numerical formulations are verified through the comparisons with the results of finite element simulation and experiments. [ABSTRACT FROM AUTHOR]

Climbing robots are robotic systems to move over 2D or complex 3D environments such as walls, ceilings, roofs, and geometric structures and to conduct various tasks. They will not only replace human workers for carrying out risky tasks in hazardous environments, but also increase operational efficiency by eliminating the costly erection of scaffolding and staffing costs. Climbing robots have special characteristics and the ability to adhere to different types of 2D or 3D surfaces, move around, and carry appropriate tools and sensors to work, while self-sustaining their bodies. Therefore, the most significant criterion for designing a climbing robot is to equip it with an appropriate locomotive and adhesion mechanism for adapting to the given environmental requirements. In this paper, a classification of climbing robots and proper examples with a brief outline are presented with considerations of the locomotive and adhesion mechanisms. Also, a list of climbing robots is provided with respect to fields of application that range from cleaning tasks in the construction industry to human care systems in the biomedical service industry. [ABSTRACT FROM AUTHOR]

In this paper, a path generation algorithm that uses sensor scannings is described. A scanning algorithm for recognizing the ambient environment of the Automatic Guided Vehicle (AGV) that uses the information from the sensor platform is proposed. An algorithm for computing the real path and obstacle length is developed by using a scanning method that controls rotating of the sensors on the platform. The AGV can recognize the given path by adopting this algorithm. As the AGV with two-wheel drive constitute a nonholonomic system, a linearized kinematic model is applied to the AGV motor control, An optimal controller is designed for tracking the reference path which is generated by recognizing the path pattern. Based on experimental results, the proposed algorithm that uses scanning with a sensor platform employing only a small number of sensors and a low cost controller for the AGV is shown to be adequate for path generation. [ABSTRACT FROM AUTHOR]

This paper presents a corrector method for analyzing the dynamic behaviour of constrained multibody systems. For correcting the state variables this method uses Lagrange-Newton method, which is a nonlinear programming technique. The Lagrange-Newton method uses the Lagrangian function that is a combined form of state variables with constraints, and the iteration formulation for convergence can be derived by the Newton-Raphson method. This algorithm does not update the Lagrange multipliers in the iteration formulation, for correcting the state variables, and is to project the state variables on the constraint manifold, in contrast to the previous local parametrization method. The validity of the algorithm and numerical solutions is verified through the convergence theorem denoting the convergence order of numerical solutions and the dynamic analysis of the full vehicle 3D model. The numerical solutions are compared with the ADAMS solutions [ABSTRACT FROM AUTHOR]

In this paper, a sensitivity analysis of a front wheel steering vehicle in the time domain is considered. For this study, a two degree-of-freedom bicycle model is used. This model displays the simplest lateral dynamic effect and is useful for understanding of the dynamic characteristics and control aspects of the target system. The side slip angle and yaw rate are selected as the system state variables. Vehicle mass, inertia, cornering stiffness, and wheel base are taken as design variables. Sensitivity analyses are performed by the direct differentiation method, which is an efficient tool for error control in numerical integration. This research proposes a basis for re-design and new-design of a vehicle by checking variations in the state variable with respect to changes in the design variable. Finally, dominant design variables are suggested through simulations. [ABSTRACT FROM AUTHOR]

In this paper, sensitivity analysis of side slip angle for a front wheel steering vehicle is performed in the frequency domain. For the derivation of the transfer function, a simple vehicle model with two degrees of freedom is used in the initial modeling stage. This model exhibits the simplest lateral dynamic effect, and is useful for understanding the dynamic characteristics and control aspects of the target system. Vehicle mass, inertia, cornering stiffness, and wheel base are taken to be the design variables. Sensitivity functions of the transfer function with respect to the design variables are derived. From this study, we see that a transition speed exists in the frequency response of side slip angle. This implies that the characteristics are changed from minimum phase to non-minimum phase as the vehicle speed increases. The objective of this study is to propose a basis for design and re-design of the vehicle by checking the side slip angle variations with respect to design variable changes in the frequency domain. Finally, dominant design variables are suggested based on the sensitivity analysis. [ABSTRACT FROM AUTHOR]

In this paper, the sensitivity analysis of yaw rate for a front wheel steering vehicle is performed in the frequency domain. A two degree of freedom system is used to represent a simple vehicle model in order to derive the system transfer function. The transfer function is defined between a steering angle input and a yaw rate output. This model shows the simplest lateral dynamic effect and is useful for understanding of the dynamic characteristics and control aspect of the target system. Vehicle mass, inertia, cornering stiffiness, and wheel base are selected as design variables. Sensitivity functions of the transfer function with repect to design variables are derived, and the results show that the response of the yaw rate always has stable minimum phase characteristics. The objective of this paper is the proposition of a base for re-design and new-design of the vehicle by checking the yaw rate variations with respect to the design variable change in the frequency domain. Finally, dominant design variables can be selected based on the sensitivity analysis. [ABSTRACT FROM AUTHOR]