Study On Structural Design And Control Technology Of Auxiliary Standing Wheelchair

With the increasing aging of population and the increasing number of disabled population,the electric wheelchair has been rapidly developed and applied as a means of transportation for these special groups.This paper design a smart auxiliary standing wheelchair that can help to stand up for these special groups,and study the motor control and obstacle avoidance control technology of intelligent wheelchair.This paper mainly complete the following sections:First of all,according to the national standards of adult human body size and electric wheelchair,using the Design Evaluation Tools Optimization module in Adams,complete the structural design of the auxiliary standing wheelchair and reduce the thrust of the electric putter.The 3D modeling is completed,and the steering scheme of wheelchair is determined to be differential wheel steering,and the movement status of wheelchair driving on flat ground is analyzed.Secondly,the angles,angular velocities,and angular accelerations of the seat bracket and the backrest bracket are planned by the fifth-order polynomial interpolation to ensure the wheelchair's stability during the shift of standing posture.The kinematic model is established using the complex vector method,the position change of mechanism and the change amount of the electric putter when performing standing posture transformation are obtained.The Newton-Euler iteration method and the force balance equation are used to establish the dynamic model,the thrust change of the electric putter is obtained.The kinematics and dynamics simulation by Adams validate the correctness of the theoretical analysis results.Then a genetic algorithm with adaptive crossover probability and mutation probability is designed.The mathematical model of DC motor is used as control object,and the PID controller's parameters are solved.The PID controller is simulated in MATLAB Simulink,compared with the PID controller designed by traditional Ziegler-Nichols method,the PID controller designed by genetic algorithm has better response and stability.Finally,the BP neural network toolbox is used in MATLAB to classify the environment according to the relative distance and orientation of the obstacle and the wheelchair.The fuzzy controller is designed,which takes the environment category and target position as input,speed and angle as output.The simulation shows thta the wheelchair successfully avoids the obstacles and reaches the target position.