Development And Research Of PMSM Drive Controller With Torque Feedback

Isokinetic rehabilitation training is a safe and efficient training method,which can effectively promote the recovery of motor nerves and the enhancement of physical function of patients,and is welcomed by the majority of rehabilitation patients.However,at present,the isokinetic training and rehabilitation equipment on the market depends on foreign imports,and the main application is professional rehabilitation hospitals.The equipment is huge,expensive and complex to operate.They are not suitable for patients to carry out isokinetic training independently at home,which limits the progress and effect of rehabilitation training,increases the time cost and treatment cost of patients,and hinders the development of China’s rehabilitation industry and the popularization of isokinetic rehabilitation training.In order to break this situation,it is necessary to conduct in-depth research on the isokinetic control system,reduce the volume and cost of the control system while realizing the isokinetic rehabilitation training,so as to promote the household and marketization of isokinetic training equipment.This paper analyzes the deficiencies of the current isokinetic control system and develops a permanent magnet synchronous drive controller with torque feedback.First of all,starting from the needs of patient muscle strength measurement,a wireless torque sensor using Wi-Fi technology to transmit the patient’s load torque to the drive controller is developed.The sensor elastomer adopts a double-hole spoke structure,and uses a double bridge circuit to measure the elastomer strain,and perform signal conditioning and software processing on the sensor output voltage.Secondly,the software and hardware architecture of the drive controller is studied,and STM32F405VGT6 is selected as the main control core.Based on the modular idea,the design of its hardware circuit and control program is completed,and the upper computer communication,motor drive,torque and speed control,Fault protection and other functions.Then,taking the servo motor as the controlled object,the isokinetic control technology is studied.In order to eliminate the motor speed fluctuation during the training process,a variable gain rotational speed control algorithm based on torque feedback is proposed.The control model is established in MATLAB and the algorithm simulation is carried out.The results show that the algorithm has a good effect of controlling the rotational speed and improves the load response speed and robustness of the control system.Finally,functional tests of the wireless torque sensor and drive controller were carried out,and an upper limb rehabilitation experimental bench was built up to test the isokinetic training performance of the drive controller.The experimental results show that the wireless torque sensor realizes the accurate acquisition and reliable transmission of the patient’s muscle strength,the hardware units of the drive controller work stably,and the deceleration control is reasonable during the training process,the motion speed is smooth,and can perform good isokinetic training.The successful development of the drive controller and isokinetic control algorithm provides a design reference for the research and development of household isokinetic training equipment,and lays the foundation for the integration and economy of isokinetic control system in the future.