Research On A High Band-Width Position Follow-up Servo System

In the procedure of automat ic product ion and process o f modern factory, PMSM servo-system has been widely used gradually.Especially when it worked in position mode,the performance o f fast tracking and steady state accuracy is the most significant characteristic for the evaluat ion of a posit ion servo.Therefor,eliminat ion of tracking error and improvement of steady state accuracy and suppression of vibrat ion are the trend of high-end product and research orient of servo field.The purpose of this paper is to so le two fundamental problems o f posit io n servo contro l scheme.One is tracking problem which requires the contro l object moves along with desired position as fast as possible;The other is vibrat ion problem which means suppressing the vibration occurs in the tracking and posit ioning and eliminat ing the phase-lag.These two quest ions exists in both rigid and elast ic system.In a rigid servo system,vibrat ion occurs for the improper pa rameters o f the three loop controller.In this paper,tuning o f the parameter is introduced first ly to so lve the vibrat ion problem;Then based on the tuning method,a zero phase error tracking controller is adapted to eliminate the phase-lag and the tracking speed is improved.And the simulation results are given to prove its effect.In a elast ic servo system,vibrat ion occurs for elast ic connector between the motor and load.Tradit ional notch filter is adapted to suppress the vibration most co mmonly.However the vibrat ion is eliminated,large phase error is introduced and the band-width is narrowed.A zero phase error notch filter ZPNF is adapted in this paper to suppress the vibrat ion and eliminate the phase lag.Further research shows the combination of ZPNF and ZPETC has a better contro l performance.And the simulat ion results are given to prove its effect.At last,experiment are carried on on both rigid and elast ic platform. Experimental results o f parameter tuning,ZPETC,ZPNF and ZPETC+ZPNF are given and analyzed.It can be proved that the scheme of this paper achieves the performance o f fast tracking and little steady state error.