| Aiming at the difficulty of pelvic motion control and knee flexion in the rehabilitation training of patients with limb motor dysfunction,this paper proposes a walking training robot with pelvic motion assistance function.The robot can realize the coordinated movement of pelvis and lower limbs,and assist patients with walking rehabilitation training to enable them to return to normal walking ability.At the same time,a passive training control method is proposed for patients,and passive training is performed through position servo control.The main research contents include :Firstly,the configuration of pelvic motion assisted rehabilitation training robot is studied.By analyzing the movement mechanism of human pelvis and lower limbs,the overall configuration of pelvic motion assisted rehabilitation training robot is proposed to assist patients in rehabilitation training.The robot system consists of pelvic motion assistance system and auxiliary stepping device.The configuration of the pelvic motion assistance system was determined by analyzing the type of the rope parallel mechanism.The Xsens MVN inertial motion capture device was used to collect the walking data,and the design and selection of the auxiliary stepping device were completed.Combined with the overall structure of the robot,the overall control scheme of the robot system is proposed.Secondly,the scale synthesis design of the auxiliary walking device mechanism is carried out.The auxiliary step device is a multi-link mechanism designed for the purpose of auxiliary step based on the collected normal walking data of human body.The auxiliary walking device mechanism is simplified and a mathematical model is built.The functional relationship between the input angle and the output angle of the rod is analyzed.Based on the Fourier transform method,the harmonic analysis of the output rod angle of the multi-link mechanism is carried out to find the relationship between the input and output functions and the size of the mechanism.In order to improve the accuracy of the mechanism obtained by the final scale synthesis,the genetic algorithm is used to optimize the synthesis results,and finally the specific size of the auxiliary stepping device mechanism is determined.Thirdly,the motion planning of pelvic motion assisted rehabilitation training robot is completed.The kinematics analysis of the sagittal and horizontal planes of the pelvic motion assist system was carried out by vector algebra method,and the displacement,velocity and acceleration of each rope during gait training were calculated.The motion planning of the pelvic auxiliary system is carried out and the rope displacement curve is simulated.The man-machine system model is established.The overall motion planning of the pelvic motion assisted rehabilitation training robot is carried out and used as the input signal of the subsequent control strategy.Finally,the position servo control of pelvic motion assisted rehabilitation training robot is studied.The dynamic analysis of the auxiliary stepping device and the pelvic motion auxiliary system was carried out respectively to solve the force of the rope and the lower limb walking rod during the walking training.The rope displacement curve obtained by motion planning and the input and output angle curve of the auxiliary stepping device are used as the input signals of the position servo system respectively.The simulation analysis verifies that the designed position servo control strategy can improve the dynamic characteristics of the forward channel of the system,so as to ensure that the response result of the loading command tends to be stable and fast. |
