.DriveControl.UsersGuide.PositionController

Information

Simplifying the transfer function of the speed controlled drive, multiplied by the integrator φ = ω / s, we start with:

Since the drive has integral behaviour, we choose a simple proportioanl controller:

resulting in a transfer function of the closed loop:

We see second order behaviour with a time constant

To avoid overshot of the end position, we demand damping θ>1, getting an upper boundary for the proportional gain of the position controller:

Note: Since we simplified the transfer function of the speed controlled drive, we have to adapt the proportional gain kp of the position controller, using the parameter kTune<1 in the data record, to avoid overshot of the end position. Since maximum speed and maximum acceleration (defined by maximum torque) are limited, a point-to-point source block can be used to calculate an optmal reference trajectory.

The example PositionControlled applies a reference position trajectory to the position controlled drive at stand still, the load torque is linearly dependent on speed switched on after no-load positioning to demonstrate the effect of a disturbance.

The position controller demands reference speed in order to follow the reference position trajectory. With optimal controller parameterization, the desired end position at the end of the reference trajectory is met without overshot.


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