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It is a key issue to ensure the safe operation of urban railway vehicle by avoiding the phenomenon of wheel slipping or locking under braking conditions, which can be implemented by looking for and keeping an optimal slip ratio. In this paper, the problem of anti-slip control for urban railway vehicle based on optimal slip ratio is studied. Forgetting factor recursive least-squares (FFRLS) algorithm...
In order to save energy and improve the driving distance of electric vehicle, a regenerative braking control strategy based on fuzzy control for the electric vehicle with four in-wheel motors is proposed in this paper. Firstly, the braking force is distributed between front axis and rear axis to ensure the safety and stability of the vehicle. Secondly, the braking force is distributed between hydraulic...
Use of a rotor type UAV that can perform three-dimensional movement and hover is being actively pursued. Although a multi-rotor type UAV is important, because it is driven by electric motors its application has the limitation of a short cruising time. In this study, the composition and control system of a single rotor UAV that achieves attitude control by pivotable vertical fins are proposed. Herein,...
We describe the concept and first prototype of a novel mechatronic design of a robotic gripper, which aims at being mounted on a humanoid robot to achieve firm (i.e. locked) and robust grasps. Such grasps could ideally support complex multi-contact motions, such as ladder climbing, or manipulation of complex tools, with energy efficiency. For this purpose, we propose a solution by designing a smart...
Physical human-robot interaction is one of the hottest topic in robotics and safety issues are its fundamental aspect. The present paper contributes to this aspect in that collision detections can be completed on the servo level in an intuitive way. The principle of the proposed collision detection strategy is based on the relative difference of the feedback commanded torque, which is able to identify...
In this paper, we present the control of and experimentation on an active dual-mode twisted string actuation mechanism for automatic transmission. This mechanism has a two-stage transmission ratio and is implemented by changing the twisted radius of the string in each mode (force mode or speed mode). Control algorithms for implementing different transmission ratios are proposed and experimentally...
We present the design of low-cost fabric-based Hat pneumatic actuators for soft assistive glove application. The soft assistive glove is designed to assist hand impaired patients in performing activities of daily living and rehabilitation. The actuators consist of flexible materials such as fabric and latex bladder. Using zero volume actuation concept, the 2D configuration of the actuators simplifies...
Some unilateral lower-limb amputees load the intact limb more than the prosthetic limb. This can cause chronic pains, fatigue, lumbago, and joint diseases, including knee osteoarthritis. To avoid and counteract these symptoms it is necessary to improve their asymmetric gait. Increasing the function of the hip abductor muscle is important to maintaining symmetrical weight distribution. Therefore, the...
In this paper, we present our cross-wire assist concept, for assisting a single joint in multiple degrees of freedom. It is comprised of four motor driven Bowden cable actuators (wires) per assisted joint, with the wires crossed over each other at the front and rear. Simulation results show that selectively actuating a subset of these wires allows torque to be generated in 6 directions, with the torque...
In this paper, we study the leader-follower formation control problem of multiple vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) with limited communication. In particular, the leader's trajectory is only accessible to a subset of the followers and the followers only have access to their neighbours' information. Distributed estimators are developed for each VTOL UAV to obtain accurately...
In this study, we developed a 4-degrees of freedom (DOF) force feedback device independent of its operational component comprising pneumatic artificial muscles and magnetorheological clutches. Research and development of force feedback devices is becoming popular in fields such as entertainment, remote operation, and rehabilitation. These areas of research are related to virtual reality and augmented...
We present a novel control approach for assistive lower-extremity exoskeletons. In particular, we implement a virtual pivot point (VPP) template model inspired leg force feedback based controller on a lower-extremity powered exoskeleton (LOPES II) and demonstrate that it can effectively assist humans during walking. It has been shown that the VPP template model is capable of stabilizing the trunk...
Robot-assisted gait training is becoming increasingly common to support recovery of walking function after neurological injury. How to formulate controllers capable of promoting desired features in gait, i.e. goals, is complicated by the limited understanding of the human response to robotic input. A possible method to formulate controllers for goal-oriented gait training is based on the analysis...
This paper proposes a novel technique for the real-time estimation of the joint torques variations in humans while performing heavy manipulation tasks. To achieve this, the method is based on the deviations of the Centre of Pressure (CoP) and Ground Reaction Force (GRF) in the presence of interaction forces. The CoP and GRF variations are calculated from the difference between the estimated values...
This paper describes the methods and experiment protocols for estimation of the human ankle impedance during turning and straight line walking. The ankle impedance of two human subjects during the stance phase of walking in both dorsiflexion plantarflexion (DP) and inversion eversion (IE) were estimated. The impedance was estimated about 8 axes of rotations of the human ankle combining different amounts...
This paper presents a distributed force/torque-based UAV(Unmanned Aerial Vehicle) collision avoidance scheme. This scheme is designed to deal in a distributed way with the problem of collisions among rotor craft UAVs, that are sharing the space and flying to different destinations. The proposed scheme has a modular architecture, so that it can be easily included into UAVs with a waypoint controller,...
This paper presents a systematic control synthesis method in order to achieve auto-transition for KH-Lion, a tail-sitter hybrid UAV. Although there are huge potentials in various applications of the hybrid tail-sitter UAVs, the transition between vertical take-off and landing mode and cruise mode is still a challenge now. Due to the complex behaviour that the transition can generate, it is very difficult...
This work describes the design, fabrication, and assembly of a MEMS aerodynamic control surface for use in millimeter-scale rockets and other miniature aerial vehicles (MAVs). Aerial vehicles of this scale require very small and light control surfaces to operate effectively. We designed MEMS aero-dynamic control surfaces using electrostatic inchworm motors and planar silicon pin-joints. These were...
This paper presents the design, mathematical model, and evaluation of a novel variant of a variable stiffness actuator. The actuator combines a cam and a variable lever mechanism. The lever length changes through the rotation of the follower and results in the change of the mechanism stiffness. The design of the actuator results in a nearly linear torque-deflection characteristic, earning it its name:...
Active exoskeleton controllers are designed to control the interaction force. Compliant exoskeletons need to be controlled in both position and force due to the coupling with a human in all rehabilitation conditions, which give rise to human-exoskeleton interaction dynamics, high nonlinear uncertain exoskeleton dynamics, noisy sensors and other parametric uncertainties, such as environmental contacts...
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