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Laparoscopic manipulation of delicate large intra-abdominal organs is a difficult task that needs special training programs to improve the surgeons' dexterity. In this study, the mechanical design of a robotic interface for haptic simulation of largeorgan laparoscopic surgery is described. The designed robot enjoys active active Degree of Freedoms (DOFs), back drivability, low inertia, friction and backlash, and sufficiently large force/moment production capacity. The kinematics of the robot was analyzed and a functional prototype was fabricated for experimental tests. Results indicated that the target workspace was fully covered with no singular points inside. The mechanism was highly isotropic and the torque requirements were in the acceptable range. The trajectory tracking experiments against a 1 kg payload revealed an Root Mean Square (RMS) of 0.9 mm, due to the simplifications of the kinematic model, i.e., not considering the friction and backlash effects. It was concluded that the designed robot could satisfy the mechanical requirements for being used as the robotic interface in a haptic large-organ laparoscopic surgery simulation system. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) facilitates the fabrication of compliant mechanisms through its free-form and design customisation capabilities. Specifically, the properties of kinetic mechanisms such as springs can be extended with regards to their inherent (non-)linear stiffness functions. This allows for the customisation of AM springs according to user preferences. By combining the design synthesis approach of building blocks with the structural optimisation approach for AM, it is possible to define and customise spring stiffness functionalities. The optimisation process employs an automated computational framework based on a genetic algorithm scheme, which has been demonstrated through randomised and reference case studies. This framework enables the attainment of linear, progressive (stiffening), and degressive (softening) stiffness curves. The manufacturability of the springs has been validated through laser powder bed fusion using stainless-steel material 17–4 PH (H900). The springs have resulted in an accuracy error of maximum 6.48% and precision error of maximum 5% through compression testing.

Micro-additive manufacturing techniques have the potential to meet the demand for miniaturised functional components for minimally invasive surgical instruments. These techniques create monolithic, compliant mechanisms with micro-sized free-form structures that can be tailored to patient-specific surgical procedures. The automated design synthesis of the mechanisms using building blocks results in structures that are shape-programmable. This is achieved through an algorithmic-based computational workflow, which automatically converts user-specified 2D and 3D curves into discrete curve segments. The actuated motion of the mechanisms can be designed to move in a specific way, both forwardly and inversely. The mechanisms are manufactured using micro-laser powder bed fusion and hardenable stainless steel 17-4 PH. By carefully selecting the process parameters, it is possible to 3D-print micro-sized features such as a compliant beam thickness of 80 μm and an actuation hole of 100 μm. Both 2D planar curved mechanisms and 3D spatial curved mechanisms have been implemented and experimentally validated.

Conceptual design synthesis, which focuses on generating solution alternatives, has a significant impact on the cost and quality of the final product. The development of radically new and significantly better solutions requires generation and exploration of a large solution space. Most of the existing literature on conceptual design synthesis of mechanical devices: (1) is on synthesising device concepts for a single relation of 'converting one input set to another output set'—this is called single-state design synthesis (SSDS); and (2) primarily employs 'composition of building blocks' as the approach for the synthesis of concepts. Multiple-state design synthesis (MSDS), on the other hand, refers to synthesising device concepts for more than one relation between an input set and an output set. Since not much literature is available on studies of MSDS, it is essential to understand how and how well designers currently carry out MSDS. This knowledge can be used as a benchmark and a source of knowledge for developing a prescriptive support to improve MSDS. Therefore, the objective of the work presented in this paper is to obtain a better understanding of this process by carrying out empirical studies on multiple-state synthesis. [ABSTRACT FROM AUTHOR]

The physical construct of a dual ontological product is essential for those products which physically interact directly with humans, whereas the product's emotional construct interconnects with human cognition. Multitude of human factor aspects must be considered when designing dual ontological products. To increase the product's impact and reach, designers should also understand the requirements of potential users. Designers find it difficult to achieve the right compromise between these constructions. This research therefore contributes a novel harmonistic knowledge-based computational support tool which makes designers aware of design stage conflicts and consequences of commitments made on human factors in the use phase of the artefact. This paper describes in detail the machine learning and harmonistic knowledge-based system which exploits information collected directly from potential users to proactively assist, guide, and motivate product designers. The paper takes the motorcycle artefact as a case of dual ontological product. The prototype support tool has been evaluated with 28 motorcycle design engineers. The results obtained from this evaluation have shown that the approach and design computational-based tool meet their goals, are beneficial, and are required in design engineering practice. [ABSTRACT FROM AUTHOR]

Earth rover is a class of emerging wheeled-leg robots for nature exploration. At present, few methods for these robots’ leg design utilize a side-mounted spatial parallel mechanism. Thus, this paper presents a complete design process of a novel 5-degree-of-freedom (5-DOF) hybrid leg mechanism for our quadruped earth rover BJTUBOT. First, a general approach is proposed for constructing the novel leg mechanism. Subsequently, by evaluating the basic locomotion task (LT) of the rover based on screw theory, we determine the desired motion characteristic of the side-mounted leg and carry out its two feasible configurations. With regard to the synthesis method of the parallel mechanism, a family of concise hybrid leg mechanisms using the 6-DOF limbs and an L1F1C limb (which can provide a constraint force and a couple) is designed. In verifying the motion characteristics of this kind of leg, we select a typical (3-UPRU&RRRR)&R mechanism and then analyze its kinematic model, singularities, velocity mapping, workspace, dexterity, statics, and kinetostatic performance. Furthermore, the virtual quadruped rover equipped with this innovative leg mechanism is built. Various basic and specific LTs of the rover are demonstrated by simulation, which indicates that the flexibility of the legs can help the rover achieve multitasking. [ABSTRACT FROM AUTHOR]

The expediency of conducting research in the direction of improving the energy efficiency of submersible induction motors due to the introduction of a set of tools for the design synthesis of their innovative designs was reasoned. Means of design synthesis of submersible induction motors of innovative designs are considered. The combination of which in the implementation of the design will allow to increase the level of improvement of submersible induction motors in accordance with the requirements for modern equipment, such as: reliability, energy efficiency, economy. The results of realization of the induction motor optimal design synthesis of the submersible pump of an innovative design on the basis of the ПЭДВ 2.8-140 motor by criterion of a maximum efficiency are resulted. Ref. 10, fig. 2, table.

Additive manufacturing (AM) facilitates the fabrication of compliant mechanisms through its freeform and design customisation capabilities. Specifically, the properties of kinetic mechanisms such as springs can be extended with regards to their inherent (non-)linear stiffness functions. This allows for the customisation of AM springs according to user preferences. By combining the design synthesis approach of building blocks with the structural optimisation approach for AM, it is possible to define and customise spring stiffness functionalities. The optimisation process employs an automated computational framework based on a genetic algorithm scheme, which has been demonstrated through randomised and reference case studies. This framework enables the attainment of linear, progressive (stiffening), and degressive (softening) stiffness curves. The manufacturability of the springs has been validated through laser powder bed fusion using stainless-steel material 17-4 PH (H900). The springs have resulted in an accuracy error of maximum 6.48% and precision error of maximum 5% through compression testing. [ABSTRACT FROM AUTHOR]

Micro-additive manufacturing techniques have the potential to meet the demand for miniaturised functional components for minimally invasive surgical instruments. These techniques create monolithic, compliant mechanisms with micro-sized free-form structures that can be tailored to patient-specific surgical procedures. The automated design synthesis of the mechanisms using building blocks results in structures that are shape-programmable. This is achieved through an algorithmic-based computational workflow, which automatically converts user-specified 2D and 3D curves into discrete curve segments. The actuated motion of the mechanisms can be designed to move in a specific way, both forwardly and inversely. The mechanisms are manufactured using micro-laser powder bed fusion and hardenable stainless steel 17-4 PH. By carefully selecting the process parameters, it is possible to 3D-print micro-sized features such as a compliant beam thickness of 80 μm and an actuation hole of 100 μm. Both 2D planar curved mechanisms and 3D spatial curved mechanisms have been implemented and experimentally validated. [ABSTRACT FROM AUTHOR]

This paper describes the process of integrating the Athena Vortex Lattice aerodynamics solver into a conceptual design environment for the multivariate design synthesis and optimisation of a Blended Wing Body (BWB) Aircraft. The work is derived from a PhD study, by one of the authors, which developed a design methodology for the conceptual design synthesis, analysis and optimisation of a BWB aircraft. This research was driven by the desire to utilise proven aerodynamic solvers, written in legacy codes, in modern computational design environments in order to improve the accuracy and fidelity in the design of novel aircraft configurations. The Athena Vortex Lattice code is a legacy code written in the FORTRAN programming language and developed at the Massachusetts Institute of Technology by Mark Drela while the multivariate conceptual design synthesis and optimisation was implemented in JAVA object oriented programming tool. The result from this study is the successful integration of the AVL software into the JAVA programming environment for the multivariate design synthesis optimisation of the BWB without loss of accuracy. The successful integration of these codes permit a more accurate design synthesis, analysis and optimisation of the novel aircraft configuration in the absence of a tailor-made and realistic empirical aerodynamic analysis model for the BWB Aircraft. Additionally, this research enables the automation of the design process and the accomplishment of the multivariate optimisation.

Design and optimization of hull shapes for optimal hydrodynamic performance have been a major challenge for naval architectures. Deep learning bears the promise of comprehensive geometric representation and new design synthesis. In this work, we develop a deep neural network (DNN)-based approach to encode the hull designs to condensed representations, synthesize novel designs, and optimize the synthetic design based on the hydrodynamic performance. A variational autoencoder (VAE) with the hydro-predictor is developed to learn the representation through reconstructing the Laplacian parameterized hulls and encode the geometry-drag function simulated through computational fluid dynamics (CFD). Two data augmentation techniques, Perlin noise mapping and free-form deformation (FFD), are implemented to create the training set from a parent hull. The trained VAE is leveraged to efficiently optimize from massive synthetic hull vessels toward the optimal predicted drag performance. The selected geometries are further investigated and virtually screened under CFD simulations. Experiments show that our convolutional neural network (CNN) model accurately reconstructs the input vessels and predicts the corresponding drag coefficients. The proposed framework is demonstrated to synthesize realistic hull designs and optimize toward new hull designs with the drag coefficient decreased by 35% comparing to the parent design. [ABSTRACT FROM AUTHOR]

Research into conceptual design of mechanical systems has been an area of interest for decades. Conceptual design plays a significant role as an early stage of design to produce designs with higher quality by economically exploring a larger solution space. Several attempts been proposed in literature to automate the conceptual design synthesis process using computer support. However, most of this has focused on single state design problems and generating a single solution. This paper deals with multiple state mechanical design problems and proposes a systematic 'prescriptive' process for supporting synthesis of a larger solution space. Further, a set of modification rules has been proposed, and a database of building blocks has been developed, to further support the synthesis process. Finally, a web-based tool has been developed to guide designers through the above 'prescriptive' synthesis process, where they can utilise the database of building blocks and modification rules as well as contribute to the database by adding new building blocks or modification rules. [ABSTRACT FROM AUTHOR]

Abstract The design synthesis is the key issue in the mechanical conceptual design to generate the design candidates that meet the design requirements. This paper devotes to propose a novel and computable synthesis approach of mechanisms based on graph theory and polynomial operation. The graph framework of the synthesis approach is built firstly, and it involves: (1) the kinematic function units extracted from mechanisms; (2) the kinematic link graph that transforms the synthesis problem from mechanical domain into graph domain; (3) two graph representations, i.e., walk representation and path representation, of design candidates; (4) a weighted matrix theorem that transforms the synthesis process into polynomial operation. Then, the formulas and algorithm to the polynomial operation are presented. Based on them, the computational flowchart to the synthesis approach is summarized. A design example is used to validate and illustrate the synthesis approach in detail. The proposed synthesis approach is not only supportive to enumerate the design candidates to the conceptual design of a mechanical system exhaustively and automatically, but also helpful to make that enumeration process computable.

Capturing human knowledge underlying the design and engineering of products has been among the main goals of computational engineering since its very beginning. Over the last decades, various approaches have been proposed to tackle this objective. Among the most promising approaches is the application of graph theory for representing product structures by defining nodes representing entities and edges representing relations among them. The concrete meaning of these structures ranges from geometry representations over hierarchical product breakdowns to functional descriptions and flows of information or resources. On top of these graph structures, graph rewriting techniques provide another powerful layer of technology. By enabling the formal definition of rules for transforming graph structures, they allow on the one hand side to formally capture the engineering development process. On the other hand, the assembly of rewriting rules into graph grammars allows for an exhaustive search of the solution space of the engineering problem at hand. In combination with search strategies, an automated optimization of the design under given constraints and objectives can be realized. The paper provides an overview of the current state-of-the-art in graph rewriting and its applications in engineering design, with a focus on the built environment. It concludes with a discussion of the progress achieved and the missing research gaps.

Literature suggests that people typically understand knowledge by induction and produce knowledge by synthesis. This paper revisits the various modes of reasoning – explanatory abduction, innovative abduction, deduction, and induction – that have been proposed by earlier researchers as crucial modes of reasoning underlying the design process. First, our paper expands earlier work on abductive reasoning – an essential mode of reasoning involved in the process of synthesis – by understanding its role with the help of the "SAPPhIRE" model of causality. The explanations of abductive reasoning in design using the SAPPhIRE model have been compared with those using existing models. Second, the paper captures and analyzes various modes of reasoning during design synthesis with the help of the "Extended Integrated Model of Designing". The analysis of participants' verbal speech and outcomes shows the model's ability to explain the various modes of reasoning that occur in design. The results indicate the above models to provide a more extensive account of reasoning in design synthesis. Earlier empirical validation of both the models lends further support to the claim of their explanatory capacity. [ABSTRACT FROM AUTHOR]

Compliant mechanisms gain motion through the elastic deformation of the monolithic flexible elements. The geometric design freedom of metallic additive manufacturing enables the fabrication of complex and three-dimensional (3D) compliant elements within mechanisms previously too complicated to produce. However, the design of metallic additive manufactured mechanisms faces various challenges of manufacturing restrictions, such as avoiding critical overhanging geometries and minimizing the amount of support structure, which has been reported in a few cases. This paper presents a synthesis approach for translational compliant elements, involving building blocks based on leaf-type springs and covering building orientations between 0 deg and 90 deg. In particular, this range is approached by the synthesis of self-supported 3D building blocks with orientations of 0 deg, 45 deg and 90 deg. The compliant elements are built based on linear and circular plane curves and compared numerically according to their mechanical performance to create preferable building blocks. The applicability of the presented procedure and the manufacturability of the compliant mechanisms are proven by printing individual 3D building blocks and their serial aggregation with laser-based powder bed fusion. Consequently, several prototypes are demonstrated, including a bistable switch mechanism and a large displaceable rotational spring joint. In addition, a small-scale highly maneuverable segment of a surgical instrument with a grasping mechanism at the distal end is proposed. [ABSTRACT FROM AUTHOR]

It is encouraged that designers should explore in wide multi-disciplinary solution spaces for finding novel and promising principle solutions to desired functions during conceptual design. However, due to lack of sufficient multi-disciplinary knowledge, it is often difficult for human designers to explore in wide multi-disciplinary solution spaces. Therefore, this paper proposes a multi-agent-based approach for assisting designers in achieving multi-disciplinary conceptual design synthesis. The roles of different kinds of designing agents are identified, and the collaborative mechanisms among these agents are also elaborated. The conceptual design test case of a solar toy demonstrates that the proposed multi-agent-based design synthesis approach, compared with our previous approach, can achieve higher efficiency and better robustness through collaborative conceptual design synthesis. [ABSTRACT FROM AUTHOR]

The development of autonomous greenhouses has caught the interest of many researchers and industrial considering their potential of offering an optimal environment for the growth of high-quality crops with minimum resources. Since an autonomous greenhouse is a mechatronic system, the consideration of its subsystem (e.g. heating systems) and component (e.g. actuators and sensors) interactions early in the design phase can ease the product development process. Indeed, this consideration could shorten the design process, reduce the number of redesign loops, and improve the performance of the overall mechatronic system. In the case of a greenhouse, it would lead to a higher quality of the crops and a better management of resources. In this work, the layout design of a general autonomous greenhouse is translated into an optimization problem statement while considering product-related dependencies. Then, a genetic algorithm is used to carry out the optimization of the layout design. The methodology is applied to the design of a fully autonomous greenhouse (45 cm × 30 cm × 30 cm) for the growth of plants in space. Although some objectives are conflictual, the developed algorithm proposes a compromise to obtain a near-optimal feasible layout design. The algorithm was also able to optimize the volume of components (occupied space) while considering the energy consumption and the overall mass. Their respective summed values are 2844.32 cm3, which represents 7% of the total volume, 5.86 W, and 655.8 g. [ABSTRACT FROM AUTHOR]

Application-specific instruction-set processors (ASIPs) utilize customized instructions to speedup a specific application or a set of applications. Thus, ASIPs execute the application(s) faster and are energy efficient compared to general-purpose processors. State-of-the-art custom instruction design methods typically target small applications or kernels of an application, often demanding an instruction designer’s ingenuity at some point (semi-automated) to achieve design goals. In this article, for the first time, a fully automated system called FINDER is presented, which finds parallel instructions for ASIPs to improve the performance of large applications and generate FLIX (flexible instructions extension instructions, which are VLIW-type instructions) configurations. Note that we do not synthesize accelerators to speedup. We demonstrate that the proposed method scales well when applied to large applications. The proposed method described in this article models parallel instructions as a graph, analyzes the graph, and finds maximum weighted cliques to create FLIX configurations for a given application. Moreover, hardware reuse within multiple FLIX configurations is incorporated into the methodology. From the configurations, a commercial processor design tool (Xtensa) creates the FLIX instructions and integrates it into a base processor. The results show that the FINDER methodology generates FLIX configurations which shows speedups of up to $2.1\times $ for large applications and $2.7\times $ for smaller applications when compared to the base processor (without FLIX instructions). The logic area increase on average is 11%, and in the worst case is 22%. The energy-delay product can be up to $7.3\times $ lower than when the application is executed on the base processor. Compared to the state-of-the-art systems which are typically demonstrated on applications with less than 100 lines of code, FINDER is capable of analyzing applications with thousands of lines of code and can automatically generate instructions for such applications. [ABSTRACT FROM AUTHOR]

Carbon materials such as graphene and porous carbon have been widely used in the field of electrochemical energy storage. Graphene/porous carbon-based composites with synergistic effect can give full play to the advantages of graphene and porous carbon, and exhibited excellent electrochemical performance as electrode materials of energy storage equipment. The research progress of binary/ternary composites of graphene and porous carbon in recent years was reviewed. A systematic elaboration was made mainly from the aspects of synthesis method, carbon precursor, structure design, structure-activity relationship and application in different energy storage devices. Finally, the research direction was prospected for graphene/porous carbon-based composites. [ABSTRACT FROM AUTHOR]

The design synthesis is the key issue in the mechanical conceptual design to generate the design candidates that meet the design requirements. This paper devotes to propose a novel and computable synthesis approach of mechanisms based on graph theory and polynomial operation. The graph framework of the synthesis approach is built firstly, and it involves: (1) the kinematic function units extracted from mechanisms; (2) the kinematic link graph that transforms the synthesis problem from mechanical domain into graph domain; (3) two graph representations, i.e., walk representation and path representation, of design candidates; (4) a weighted matrix theorem that transforms the synthesis process into polynomial operation. Then, the formulas and algorithm to the polynomial operation are presented. Based on them, the computational flowchart to the synthesis approach is summarized. A design example is used to validate and illustrate the synthesis approach in detail. The proposed synthesis approach is not only supportive to enumerate the design candidates to the conceptual design of a mechanical system exhaustively and automatically, but also helpful to make that enumeration process computable. [ABSTRACT FROM AUTHOR]

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Purpose. The work is dedicated to the presentation of the principle of construction and implementation of an automated synthesis system of the turbo-generator (TG) electromagnetic system in the case of its modernization. This is done on the example of changing the number of the stator core slots. Methodology. The basis of the synthesis is a TG basic construction. Its structure includes the mathematical and physical-geometrical models, as well as the calculation model for the FEMM software environment, providing the numerical calculations of the magnetic fields and electromagnetic parameters of TG. The mathematical model links the changing and basic dimensions and parameters of the electromagnetic system, provided that the TG power parameters are ensured. The physical-geometrical model is the geometric mapping of the electromagnetic system with the specified physical properties of its elements. This model converts the TG electromagnetic system in a calculation model for the FEMM program. Results. Testing of the created synthesis system is carried out on the example of the 340 MW TG. The geometric, electromagnetic and power parameters of its basic construction and its new variants at the different numbers of the stator slots are compared. The harmonic analysis of the temporal function of the stator winding EMF is also made for the variants being compared. Originality. The mathematical model, relating the new and base parameters of TG at the changing of the number of the stator slots is created. A Lua script, providing the numerical-field calculations of the TG electromagnetic parameters in the FEMM software environment is worked out. Construction of the constructive and calculation models, the numerical-field calculations and delivery of results are performed by a computer automatically, that ensures high efficiency of the TG design process. Practical value. The considered version of the TG modernization on the example of changing the number of the stator core slots provided an opportunity for the presentation of the principle of construction and implementation of design synthesis system. For the practical use in the TG designing process, the developed and presented system can be more detailed with specifying the individual components of the mathematical model and expanded for varying other parameters of TG and optimizing its design.

Synthesizing suitable principle solutions together to form the design solution is a universal method in conceptual design. For the modern mechatronic product, the conceptual design is often multi-disciplinary, which would be extremely time consuming and labour-intensive for designers to synthesize multi-disciplinary principle solutions together. Taking advantage of functional knowledge and structural knowledge of principle solution, this article proposes an integrated principle solution synthesis method which not only achieves the automated synthesis of multi-disciplinary principle solutions but also solves the undesired physical conflicts among principle solutions to be synthesized. In integrated principle solution synthesis, a synthesis agent is developed to chain the functional flows of principle solutions to form the combinatorial principle solution set, and synthesis agent selects the combinatorial principle solution with highest availability value as the recommended combinatorial principle solution. Then extensic theory is employed to deal with the partial design conflicts hidden in recommended combinatorial principle solution by extending and transforming the conflict functional structures. A case study on the emergency cutting off device design is given to prove the industrial applicability of integrated principle solution synthesis, which indicates that compared with traditional synthesis method, integrated principle solution synthesis can not only get multi-disciplinary design result of emergency cutting off device but also further resolve the design conflict (i.e. vibration impact) to optimize the functional structure of emergency cutting off device. [ABSTRACT FROM AUTHOR]

Tele-examination based on robotic technologies is a promising solution to solve the current worsening shortage of physicians. Echocardiography is among the examinations that would benefit more from robotic solutions. However, most of the state-of-the-art solutions are based on the development of specific robotic arms, instead of exploiting COTS (commercial-off-the-shelf) arms to reduce costs and make such systems affordable. In this paper, we address this problem by studying the design of an end-effector for tele-echography to be mounted on two popular and low-cost collaborative robots, i.e., the Universal Robot UR5, and the Franka Emika Panda. In the case of the UR5 robot, we investigate the possibility of adding a seventh rotational degree of freedom. The design is obtained by kinematic optimization, in which a manipulability measure is an objective function. The optimization domain includes the position of the patient with regards to the robot base and the pose of the end-effector frame. Constraints include the full coverage of the examination area, the possibility to orient the probe correctly, have the base of the robot far enough from the patient’s head, and a suitable distance from singularities. The results show that adding a degree of freedom improves manipulability by 65% and that adding a custom-designed actuated joint is better than adopting a native seven-degrees-freedom robot.