Smooth Switching Control Of Robots Driven By Permanent Magnet Synchronous Motors

With the continuous improvement of people's demand for a better life,robots have become a trend to replace people.The joint robot is one of the most widely used robots in various fields,and its development prospect will be better and better.Therefore,the precise control of industrial robots is particularly important.However,the dynamic response speed and tracking error of the control system are often contradictory to each other.In order to make the industrial robot control at the same time with good accuracy and rapidity,this paper takes the planar three-joint robot as an example and proposes a signal and energy smooth switching control algorithm for the robot dynamics control.In this paper,a new fast sliding mode signal controller is designed based on the dynamics model of robot body.A switching approach law is studied to improve the response speed of sliding mode.Based on the different speeds of the system when it is far from the sliding mode surface and near the sliding mode surface with different exponential approaching rates,a smooth switching approaching law is designed by using Gaussian function to make the system have fast dynamic response in various states.In order to eliminate the chattering problem inherent in sliding mode control,a Hamiltonian energy controller is designed.The controller has good steady-state performance and can form a complementary effect with sliding mode control.The arctangent smoothing switching function based on error is designed to make the signal and energy controllers switch smoothly automatically according to the magnitude of error.The system has a fast rise time and a small tracking error at the same time.The simulation results of Matlab /Simulink show that the smooth switching controller can make the system have the rapidity similar to the sliding mode control and the steady-state performance similar to the Hamiltonian control.In view of the situation that actuators are not considered in most researches on robot control at present,permanent magnet synchronous motor is adopted as the actuator of joint robot in this paper,and the control torque of robot body is understood as the motor load torque.On this basis,the dynamics model of the robot,the kinematics model of the motor and the electrical model of the motor are combined,and the whole model of the robot system driven by pmsm is calculated.Based on the overall model,the feedback linearization control is gotten,and the Hamiltonian model of the whole system is derived by cascading the Hamiltonian model of the robot system and the motor system.The arctangent smooth switching function is used to realize the feedback linearization control of the whole system and the Hamiltonian smooth switching control of voltage single loop.The superiority of the algorithm is verified on the Matlab /Simulink simulation platform,and the results show that the smooth handover control strategy still has good control effect when the actuator is considered.In view of the actual industrial field,the existing driver is generally adopted,and its current loop is closed source.In this paper,feedback linearization and Hamiltonian torque smooth switching control are designed.The control torque of the position loop is converted into the input current of the current loop,and the sliding mode control of the current loop is designed based on principle * 0di =.The algorithm is verified on the Matlab /Simulink simulation platform and the robot experimental platform,and the results show that the algorithm still makes the system have good dynamic response and small tracking error when the driver is closed.To sum up,based on the robot system driven by pmsm,this paper presents the above three different control schemes,and designs the smooth switching control of signal and energy respectively.The simulation results of three different schemes all prove that the smooth-switching control can make the system have a small rise time and a small tracking error.The three control schemes and their solutions provide solutions for the robot control under any working conditions in the field of industrial robots,which has far-reaching significance.