Sigma-II Series SGM*H/SGDH USER'S MANUAL - Esco Drives ...

9.4 Servo Gain Adjustment FunctionsUsing the Acceleration Level to Switch ModesWith this setting, the speed loop is switched to P control when themotor’s acceleration rate exceeds the acceleration rate set in parameterSpeedPn10E.Reference speedMotor speed+Pn10EAcceleration0- Pn10EMotor accelerationPIPPI controlPPI control• Operating ExampleIf the mode switch function is not being used and the SERVOPACK is always operated with PI control, the speed of themotor may overshoot or undershoot due to torque saturation during acceleration or deceleration. The mode switch functionsuppresses torque saturation and eliminates the overshooting or undershooting of the motor speed.Without Mode SwitchingWith Mode SwitchingOvershootMotorspeedUndershootMotorspeedTimeTimeUsing the Error Pulse Level to Switch ModesThis setting is effective with position control only.With this setting, the speed loop is switched to P control when Speedthe error pulse exceeds the value set in parameter Pn10F.Positionerror pulseReferenceMotorspeedTimePn10FPIP controlPI control• Operating ExampleIn this example, the mode switch is used to reduce the settling time. It is necessary to increase the speed loop gain to reducethe settling time. Using the mode switch suppresses overshooting and undershooting when speed loop gain is increased.Without Mode SwitchingMotorspeedSpeedreferenceMotor speedWith Mode Switching9Increase speed loop gain.Long settling timeOvershootMotorspeedUndershootMotorspeedTimeSettling time9-21