Showing papers by "Mingming Wang published in 2018"

Detumbling strategy and coordination control of kinematically redundant space robot after capturing a tumbling target

Abstract: This paper focuses on the motion planning to detumble and control of a space robot to capture a non-cooperative target satellite. The objective is to construct a detumbling strategy for the target and a coordination control scheme for the space robotic system in post-capture phase. First, the dynamics of the kinematically redundant space robot after grasping the target is presented, which lays the foundation for the coordination controller design. Subsequently, optimal detumbling strategy for the post-capture phase is proposed based on the quartic B $$\acute{\text{ e }}$$ zier curves and adaptive particle swarm optimization algorithm subject to the specific constraints. Both detumbling time and control torques were taken into account for the generation of the optimal detumbling strategy. Furthermore, a coordination control scheme is designed to track the designed reference path while regulating the attitude of the chaser to a desired value. The space robot successfully dumps the initial velocity of the tumbling satellite and controls the base attitude synchronously. Simulation results are presented for detumbling a target with rotational motion using a seven degree-of-freedom redundant space manipulator, which demonstrates the feasibility and effectiveness of the proposed method.

An Adaptive Robust Controller for a Mobile Robot Driven by Mecanum Wheels

Abstract: An adaptive sliding mode controller was designed for a mobile robot driven by four mecanum wheels.The original contribution of this paper is employing adaptive robust controller to mecanum wheels driven mobile robot for obtaining better tracking and robustness performance.To complete the design of the controller, the kinematic model of the mobile robot driven by mecanum wheels was firstly proposed.An adaptive robust controller was designed subsequently.A sliding surface was designed in Proportional-Differential-Integral form, which satisfied the robustness requirements of the system.Besides, a reaching law which has quick convergence was introduced, which reduced the time consumed by the setting parameters and resisting external disturbance.The controller was demonstrated in the presence of impulsive disturbance and sinusoidal signal disturbance, which proved the superiority of the proposed controller.Finally, an experimental verification of trajectory tracking was implemented to verify the practicability and effectiveness.

An Inflatable and Foldable Knee Exosuit Based on Intelligent Management of Biomechanical Energy

Abstract: Wearable robotics is a potential solution in aiding gait rehabilitation of lower limbs dyskinesia patients, such as knee osteoarthritis or stroke afflicted patients. Many wearable robots have been developed in the form of rigid exoskeletons, but their bulk devices, high cost and control complexity hinder their popularity in the field of gait rehabilitation. Thus, the development of a portable, compliant and low-cost wearable robot for gait rehabilitation is necessary. Inspired by Chinese traditional folding fans and balloon inflators, the authors present an inflatable, foldable and variable stiffness knee exosuit (IFVSKE) in this paper. The pneumatic actuator of IFVSKE was fabricated in the shape of folding fans by using thermoplastic polyurethane (TPU) fabric materials. The geometric and mechanical properties of IFVSKE were characterized with experimental methods. To assist the knee joint smartly, an intelligent control profile for IFVSKE was proposed based on the concept of full-cycle energy management of the biomechanical energy during human movement. The biomechanical energy of knee joints in a walking gait cycle of patients could be collected and released to assist the joint motion just by adjusting the inner pressure of IFVSKE. Finally, a healthy subject was involved to walk with and without the IFVSKE to evaluate the assisting effects. Keywords—Biomechanical energy management, gait rehabilitation, knee exosuit, wearable robotics.