Why a PID ?,Objective: System with a correct behaviour Means: Feedback from loadController to limit error,Whats a PID controller ?,A PID controller concists of 3 parts:P-factor: proportional control based on the error valueI- factor: Integral control based on the error time D-factor: Derivative control based on the rate of error change,Whats a PID controller ?,PID regulation,The SyncPos PID Controller,The three controller parts Trajectory generator reference PID controller closed-loop / stiffness Feed-forward controller open-loop / dynamic TRACKERR and SYNCERR?,Optimizing procedure,Optimize VLT (AMA) + parameter settings. Set max allowed position error to a high value. Calculate PID sample time Optimize velocity feed-forward, PID off. Optimize acceleration feed-forward, PID off. Optimize Proportional factor. Optimize Derivative factor. Optimize Integral factor. Set integration limit. Set bandwidth. Set max allowed position error back to normal.,Optimizing tools,Calculate Feed Forward Velocity parameter,FFVEL = (62914560000 * #104) / (VNOM * ERES * Tsample sample * #205).#104: VLT parameter 104: Motor frequency #205 : VLT parameter 205: Maximum frequency VNOM: is the nominal encoder velocity at nominal motor frequency. The unit is RPM. ERES: is the number of quad-counts per encoder revolution. Tsample sample: is the PID controller sampling interval (TIMER).,Optimizing tools,SyncPos program for FFVEL calculation,fnom = GETVLT 104 refmax = GETVLT 205 % 1000 vnom = GET 131IF (GET ENCODERTYPE = 0) THEN eres = (4 * GET ENCODER) ELSE eres = (GET ENCODER) ENDIF tsample = (GET TIMER) FeedForwardVel = (6291456 * fnom % refmax % vnom *10000 % eres % tsample) SET FFVEL FeedForwardVel GOTO main,Optimizing tools: SyncPos testrun,First step !,Third step !,Second step !,Optimizing tools example,FFVEL too low,Optimizing tools example,Increase FFVEL,Optimizing tools example,Correct FFVEL,Optimizing tools example,Increase KPROP,Optimizing tools example,Correct positioning,Dynamic overshoot,Optimizing tools example,Increase KDER,注意：现在比例一般为100左右，此处的500只是个例子而已。微分一般设置要注意，可能会导致零速时抖动。,Optimizing tools example,Perfect Regulation !,Typical settings,Encoder resolution: 1024ppr. P702, P: 50-1000 P703, D: 5 100 times P702. P704, I: 0 10. 707, FFVel: 10000 708, FFAcc: 0 Sample time: 1msec. Rule of thumb: min. 10 20 qc/sample.,