In our previous work, a novel force control actuator, called series damper actuator (SDA), has been proposed. This paper proposes a general design procedure for the SDA system. From design requirements, several key parameters of the SDA plant can be determined. Based on these parameters, the selection or design of the series damper and the motor can be carried out. A case study is included to illustrate the effectiveness of the procedure. As there could be more than one feasible solutions from the procedure, the mechatronic design quotient (MDQ) method can be adopted to select the best solution from a feasible solution space.

The present paper presents a new approach to a leader–follower-based dynamic trajectory planning for multirobot formation. A near-optimal trajectory is generated for each robot in a decentralized manner. The main contributions of the current paper are the proposal of a new objective function that considers both collision avoidance and formation requirement for the trajectory generation, and an analytical solution of trajectory parameters in the trajectory optimization. Simulations and experiments on multirobots are performed to demonstrate the effectiveness of the proposed approach to the multirobot formation in a dynamic environment.

Agile bionic leg mechanism (ABLM) has attracted more and more attention in the development of jumping robots and high-speed running robots. However, theoretical study of the global structure for motility characteristics and its evolution is few. By using the modern mathematical tools such as singular theory, geometric topology, and group theory, a global scale analysis method for kinematic performance of mechanisms is proposed. Taking 6-bar with two rings mechanism as an example, a detailed analysis process is studied. The 6-bar ABLM designed by this theory is verified by virtual prototype simulation experiment. The global scale analysis of 4-bar linkage is also carried out by using this method, and the result is compared with the “Grashof criterion” to verify the correctness of this method. It provides a general theory and method for innovative design and global scale analysis of ABLM.

The payload variation has been one of the principal reasons in reducing path tracking accuracy and complicating controller design. In this paper, the trajectory and input sensitivities for the payload variation are investigated for three different robot configurations which include unbalanced, inaccurately balanced and balanced configurations. Based upon the sensitivity theory, simulation studies were made to evaluate the sensitivities of these configurations with respect to payload variations. The simulation results are discussed in detail and compared for the three configurations.

The increase of human presence in the subsea and seabed environments necessitates the development of more capable and highly dexterous, innovative underwater manipulators. Biomimetic soft-robot arms represent a promising candidate for such manipulation systems. However, the well-known modeling techniques and control theories of traditional rigid robots do not apply to soft robots. The challenges of kinematic and dynamic modeling of soft robots with infinite degrees of freedom require the development of dedicated modeling methods. A novel procedure for representing soft-robotic arms and their motion in a rigid-body simulation environment is proposed in this paper. The proposed procedure relies on the piecewise constant curvature approach to simplify the very complex model of hyper-redundant soft-robotic arms, making it suitable for real-time applications. The proposed method is implemented and verified to be used in model-mediated teleoperation of the soft arms of a biomimetic robotic squid designed for underwater manipulation as a case study.

A comprehensive dynamic modeling and actuator torque minimization of a new symmetrical three-degree-of-freedom (3-DOF) 3-PṞR spherical parallel manipulator (SPM) is presented. Three actuating systems, each of which composed of an electromotor, a gearbox and a double Rzeppa-type driveshaft, produce input torques of the manipulator. Kinematics of the 3-PṞR SPM was recently studied by the author (Zarkandi, Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci. 2020, https://doi.org/10.1177%2F0954406220938806). In this paper, a closed-form dynamic equation of the manipulator is derived with the Newton–Euler approach. Then, an optimization problem with kinematic and dynamic constraints is presented to minimize torques of the actuators for implementing a given task. The results are also verified by the SimMechanics model of the manipulator.

This paper addresses widely applicable methods for solving the kinematics problem of any class of serial-link robot manipulators. First, the position and orientation of the manipulator hand, the Jacobian matrix and their symbolic generation are clearly presented using recursive relations. Second, the inverse problem to such formulations is posed as an unconstrained non-linear optimization one, where numerical techniques for the overdetermined and underdetermined kinematic problems are considered separately to derive consistent arm solutions. On the basis of several proposals on step lengths involved to maintain good numerical stability, the results of computer simulation show that performance is sufficiently reliable.

In this paper, a numerical approach is proposed to solve the time-optimal path-planning (TOPP) problem of kinematically redundant manipulators between two end-points. The first step is to transform the TOPP problem into a nonlinear programming problem by an iterative procedure. Then an approach to find the initial feasible solutions of the problem is proposed. Since initial feasible solutions can be found easily, the optimization process of the nonlinear programming problem can be started from different points to find the global minimum. A planar three-link robotic manipulator is used to illustrate the validity of the proposed approach.

A method has been developed for accurately determining the differential movement of known objects from multiple camera views. The method has been applied to a robot System to find the repeatability and accuracy of the robot in both rotational and translational terms and also for tracking an object using visual feedback.

In this paper obtaining the optimal configuration of the dual-arm cam-lock (DACL) robot at a specific point is addressed. The objective is to optimize the applicable task-space force in a desired direction. The DACL robot is a reconfigurable manipulator formed by two parallel cooperative arms. The arms normally operate redundantly but when needed, they can lock into each other in certain joints in order to achieve a higher stiffness, while losing some degrees of freedom. Furthermore, the dynamics of the DACL robot is discussed and parametrically formulated. Considering the geometrical constraints at a given point in the robot's workspace, the optimum configuration for maximizing the cooperatively applicable force by dual arms is determined.

For a kinematically redundant manipulator, some performance indices can be optimized while carrying out a given task. So far, the redundancy resolution has been solved at the joint angle level, the joint velocity level, or joint acceleration level depending on the performance indices. According to the resolution level, the solution is represented by high-order differential equations or superfluous number of equations. We propose a unified approach to the inverse kinematic solution which optimizes it at the joint velocity level regardless of the types of the performance indices. A unified approach to obtain an optimal joint velocity is derived by using the necessary condition for optimality so that the proposed method provides an optimal solution for any performance indices and tasks. The optimal solution becomes a set of the minimum number of first-order differential equations which requires a minimum search dimension.To show the validity of the approach, it is applied to a three-link planar manipulator for various types of performance indices.

The minimum-time motion of robot manipulators is solved by defining a suitable time history for the arm end-effector to traverse. As the planning is performed in the configuration space, the uniqueness of the proposed algorithm emerges from the combination of both cubic and quadratic polynomial splines. Furthermore, the highly efficient time optimisation procedure could be applied to local segments of each joint trajectory, leading to a significant reduction of the travelling time. In addition, the ability to perform a search in the work space is granted, exploiting all possible options for an optimum motion. The method proposed considers all realistic physical limitations inherent in the manipulator design, in addition to any geometric constraints imposed on the path. Simulation programs have been written, and results are reported for the Unimation PUMA 560 robot manipulator.

Enhancing graphical objects whose behaviors are governed by the laws of physics is an important requirement in modeling virtual physical environments. In such environments, the user can interact with graphical objects and is able to either feel the simulated reaction forces through a physical computer interface such as a force feedback mouse or through such interactions, objects behave in a natural way. One of the key requirements for such interaction is determination of the type of contact between the user controlled object and the objects representing the environment. This paper presents an approach for reconstructing the contact configuration between two objects. This is accomplished through usage of the time history of the motion of the approaching objects for inverse trajectory mapping of polygonal representation. In the case of deformable objects and through usage of mass-spring-damper system this paper also presents a special global filter that can map the local deformation of an object to the adjacent vertices of polygonal mesh. In addition to offering a fast computational framework, the proposed method also offers more realistic representation of the deformation. The results of this paper are shown through detailed examples and comparison analysis using different computational platforms.

Tools that make it possible to measure the performances of manipulators are essential in many technical applications, for instance, when the optimal path to accomplish a task has to be chosen, or when different manipulator architectures have to be compared. This paper proposes some indices that fully describe the passive dynamic performances of manipulators with two degrees of freedom (dof). The pro- posed indices make it possible to compare the passive dynamic performances of different manipulator architectures, which can perform the same tasks, and can be used to build diagrams which highlight the effects of variations in the manipulator geometry on the manipulator dynamics. These features make them easy to be used in a design context. Finally, some applications of the proposed indices will be presented and discussed.

This paper addresses the kinematic modelling, solutions and trajectory planning of a tele-laparoscopic manipulator. This type of manipulator can be used in remote positioning of laparoscopic tools through tele-operating system. Specifically the paper models kinematics of a typical manipulating system which can be used in such tele-surgery. Inverse kinematics solutions are also obtained for two kinematically constraint motions which are part of a typical trajectory of the laparoscopic tools. These are fixed axis rotation of the tool and its straight line motion. Simulation results are presented to demonstrate the validity of such models and solutions.

Smart devices used in continuous system, benefit from the addition of microelectronics and software that runs inside the device to perform control and diagnostic functions. Very small components, such as inputs/outputs blocks and overload relays, are too small to integrate data processing for technical-economic reason. However, it's possible to develop embedded intelligence and control for the smallest factory floor devices. In the paper, a generic model of smart equipment with reconfiguration functions is proposed. The interest of this functional model is that it can be used for smart devices but it can also be developed in modules for the nearest possible of the inputs and outputs in manufacturing equipment. This solution is economic for a great number of applications because it allows one to realise modular design and to standardise part of system in order to re-use it.

Walking locomotion involves complex movement of total center of mass. Not only the lower body behavior but also the upper body behavior affects the walking characteristics. Therefore, in this paper we derive the principle of parametrically excited inverted double pendulum to consider both lower body and upper body dynamics. We propose one approach to utilize the upper body behavior of the robot for energy efficient bipedal locomotion. In addition, we analyze the property of parametrically excited inverted double pendulum.

In the context of automated feeding (orienting) of industrial parts, we study the algorithmic design of traps in the bowl feeder track that filter out all but one orientation of a given polyhedral part. We propose a new class of traps that removes a V-shaped portion of the track. The proposed work advances the state-of-the-art in algorithmic trap design by extending earlier work1,6,17—which focuses solely on 2D parts—to 3D parts, and by incorporating a more realistic part motion model in the design algorithm. We exploit the geometric structure of the design problem and build on concepts and techniques from computational geometry to obtain an efficient algorithm that reports the complete set of valid traps.

In this paper, the wall-following problem of an AGV is characterized by keeping a constant distance from a wall. Four Polaroid ultrasonic range sensors (sonar) are used to obtain information of the distance between the AGV and the wall. Four sonars are divided into two groups being placed at the front and back end on the right side of the AGV, respectively. A digital filter is used to get rid of disturbance and wrong readings. The former results mainly from the door and the latter from the specular reflection and accidental scattering. To obtain good dynamic and steady performances, a new compound fuzzy-I control algorithm is presented. Our methods have been verified by following a 15-meter-long wall with one door by using our TIT-1 AGV (TIT: Tianjin Institute of Technology). The results show a good performance with an error of ±2 cm from the desired distance to the wall.

This paper proposes a new technique based on a Parameter-Optimal Iterative Learning Control (POILC) to track a command pitch rate of a high-speed supercavitating vehicle (HSSV). The pitch rate of a supercavitating vehicle has non-minimum phase behavior. Thus, tracking is fundamentally limited to poor performance. To solve this problem, a feed-forward control can be used while using the cavitator as a control input in the feed-forward path to modify the slow response caused by non-minimum phase behavior. The main idea of this paper is to apply the cavitator input with high precision as a feed-forward control to improve tracking performance. The exact value of the feed-forward control is achieved using POILC. However, in the presence of uncertainty, zero convergence of POILC algorithms is threatened. It will be shown that applying adaptive weight in the performance index, the convergence is guaranteed in the presence of uncertainty and also when the system is sign-indefinite. The proposed technique includes an optimal planning to make the error norm monotonically convergent to zero. The convergence and perfect tracking will be guaranteed through a Lyapunov candidate. Performance and significance of the proposed supercavitating vehicle control will be verified by simulation.