Research On Control System Of Assisted Movement Device Based On ROS

The lower extremity assistive exercise device is an intelligent device fixed on the lower limbs of the human body.It combines various technologies such as sensors and information fusion,and is mainly used in the fields of rehabilitation medicine and weight-bearing assistance.At present,great progress has been made in the gait planning and stability analysis of assistive exercise devices at home and abroad.The inverted pendulum model is one of the more commonly used models in the gait research of assistive exercise devices.Simulation technology is an indispensable means of robot research and development,which can effectively reduce scientific research expenditure and improve research and development efficiency.This paper focuses on the simulation platform and control system of auxiliary motion devices.The main research contents are as follows:In view of the fact that there are relatively few simulation platforms suitable for lower limb assistive motion devices,and the simulation research in this field is relatively lacking,this paper analyzes the functional requirements of assistive motion devices through the research on robot simulation technology and various simulation environments.Based on ROS-Gazebo the robot simulation system establishes the overall frame design scheme for the simulation platform of the lower limb auxiliary motion device.The kinematics analysis of the robot is the basis for developing the control algorithm of the auxiliary motion device.The lower limb auxiliary motion device is a multi-link model.This paper studies the D-H method to establish the kinematic model of the device,but this method requires the attitude of the local coordinate system to be changed with the link.This results in the accumulation of errors.In view of this situation,this paper decomposes the structure of the auxiliary motion device,uses a tree structure to establish a kinematic model,and completes the forward and inverse kinematics analysis of the model.Considering the error between the inverted pendulum model and the real physical model of the auxiliary motion device,the seven-link model is used to compensate the linear inverted pendulum model.Then,according to the preview control theory,the information of the future ZMP is used to adjust the current trajectory of the center of mass to improve the tracking accuracy of the ZMP.The simulation results show that the ZMP tracking performance is significantly improved after compensation,and the actual ZMP trajectory can track the reference trajectory well.The simulation platform of the lower limb assisted motion device was built through ROS,and the human-machine simulation model was able to complete the stable walking by combining the preview control algorithm of the multi-link compensation inverted pendulum.The simulation results show that the auxiliary motion device can realize straight and steering walking,which verifies the correctness and effectiveness of the control algorithm.