Research On Permanent Magnet Synchronous Motor Servo System Based On MBD Development Metho

With the continuous development of electrical automation,the servo system has been changed from the earliest hydraulic and pneumatic servo system to the motor servo system.As an important part of the actuator of the motion control system,the performance of the servo system becomes an important index to measure the performance of the whole control system.Take collaborative robots as an example.In medical treatment,3C electronics manufacturing,metal processing and other industries,collaborative robots are required to have the advantages of fast response,high control accuracy,strong anti-disturbance ability and so on.Most joint modules of cooperative robots are driven by small size and high precision permanent magnet synchronous motor,which requires higher control performance of permanent magnet synchronous motor servo system.In this paper,the permanent magnet synchronous motor applied to the joint module of cooperative robot is taken as the research object.The compound control strategy of PI parameter setting using internal model control and integral terminal sliding mode control strategy based on load observer are proposed to improve the performance of the servo system.At the same time,the software of the permanent magnet synchronous motor servo system is developed using the development method of model-based design(MBD).The problems of long development cycle and low efficiency of traditional motor servo system are solved.The main research contents of this paper are as follows:(1)In order to solve the problem that the traditional three-loop PI control method can no longer satisfy the fast response,high precision and small overshoot of the servo system,the compound control strategy is applied to the servo system.Firstly,the position feedforward function is introduced into the velocity loop and the current loop,and then the differential term is added into the negative feedback loop of the position loop to form a compound control system.According to the closed-loop transmission function of the system,the specific feedforward function is derived.At the same time,in order to solve the problem that the parameters of traditional PI controller are easily affected by many motor parameters,the internal model control strategy is used to adjust the parameters of PI controller.Finally,simulation verified that the composite control strategy using internal model control for PI parameter tuning can improve the control performance of the servo system.(2)In order to further improve the control performance of the servo system,the sliding mode control strategy is applied to the servo system.Considering the position loop and the velocity loop as one loop,the integral terminal sliding mode controller of the positionvelocity loop is designed by using the integral terminal sliding mode surface and the improved exponential reaching law,which simplifies the system structure.At the same time,in order to improve the anti-disturbance ability of the servo system,the load torque observer with the differential term of state feedback error is used to observe the load change,and the observed value is fed forward to the integral terminal sliding mode controller.Finally,the simulation results show that the integral terminal sliding mode control strategy based on the load observer can further improve the response speed,tracking accuracy and antidisturbance ability of the system,and reduce the overshoot of the system.(3)In order to improve the efficiency of servo system software development,the development method of MBD is applied to the development of servo system software.Firstly,a discrete model of servo system capable of code generation was built in MATLAB/Simulink,and the model was verified.After the requirements are verified,Embedded Coder toolkit is used to generate embedded C code that can be used in hardware products,and software in loop test and processor in loop test are carried out on the code.After the test is completed,rapid control prototype experiments are carried out on the servo system research platform.The experiments verify that the proposed control strategy can improve the performance of the servo system,and also demonstrate the high efficiency of software development using MBD method.