Design And Implementation Of Lorentz-Force-Driven Planar Motor Control System

Traditional three-degree platforms are mostly implemented by superimposing multiple linear motion units.This structure is complex which inertia is large and it is difficult to achieve precise motion.However,Lorentz-force-driven planar motor has attracted much attention in the field of high-speed and high-precision sports because of their small inertia,few intermediate links,and compact structure.Through the summary of the research results of Lorentz-force-driven planar motor at home and abroad,the design scheme and key control techniques of this thesis are determined and the control system is realized.The plane three-degree motion is realized by three Lorentz coils arranged side by side with the horizontal plane.A high-precision motion control model of planar motor is proposed to realize high-precision three-degree motion,which adopts PID feedback control and acceleration feedforward control method on each axis of three degrees to ensure the positioning accuracy of planar motor and improve its follow accuracy.A modular design of control hardware is proposed.The dynamic decoupling model of the planar motor is established to cancel the coupling between the axes and avoid the crosstalk between the axial forces to realize the plane motion without the guide rail;a displacement measurement model is established in order to measure the centroid displacement of the planar motor through the displacement of three points on the plane which are not collinear;a calibration method for controlling key parameters such as motor force constant and force decoupling matrix is proposed to improve the accuracy of the control and reduce the crosstalk between the axial forces of the planar motor caused by the manufacturing installation error;the motion interpolation algorithm and the trajectory planning algorithm are studied to ensure the accuracy,stability and flexibility of the motor running process and reduce the impact.A high response speed,high precision and high bandwidth motor driver is designed.The driver uses the PI feedback control idea to realize the hardware current loop.The PI parameters are designed and calculated to ensure the open loop characteristics of the driver which has large low-band gain and fast roll-off on the high-frequency;other control hardware and control software for the planar motor control system are designed.A planar motor positioning motion platform is built to verify the positioning accuracy and tracking accuracy of the planar motor and the maximum acceleration.The crosstalk between the X-axis and the Y-axis before and after calibration was compared by experiments.The results show that the two-axis crosstalk is significantly reduced after calibration.The micron-level positioning accuracy is achieved in the positioning accuracy measurement experiment;and the maximum acceleration can be achieved by experiment.The X-axis linear motion and the Y-axis linear motion are performed at different speeds.The good tracking accuracy is verified through the measured actual displacement curve is basically consistent with the theoretical displacement curve.