Compensation Control Of Electric Servo Systems With Backlash And Friction

Electric servo system is one kind of high precision position control systems, it is mainly applied to aero craft, aircraft, ship, robot, and so on. In this thesis, an electric servo motor is applied as an actuator, which controls the rudder to desired rotation angle.In electric servo system, backlash and friction often exist and be harmful. Backlash may bring servo system into static error and oscillation, even lead to instability. Friction causes creeping phenomenon and limit cycle oscillation in servo system, then reduce system’s accuracy and influence system’s dynamic performance.Model methods and compensation methods about backlash and friction are researched in theory and experimentally based on an electric motor.Based on analysis of backlash, backlash inverse model is used to compensate backlash in the servo system.Friction is described by LuGre model, which can present most characteristics of friction. LuGre model is used to compensate friction in this thesis.A platform of electric servo system is built in this thesis to research the compensation algorithm about backlash and friction. A DC motor is used as actuator, a TMS320F28335 DSP is used as controller, software in DSP is programed in Matlab/simulink, and mechanical hardware is designed with Solidworks software.Results of simulations and experiments show that backlash inverse model can compensate backlash well and LuGre model can compensate friction effectively.Finally, the servo system meets the requirements through compensation.