Dual-column hoist

The following application example illustrates the configuration of a dual-column hoist with external encoder in combined operation and combined encoder evaluation in the MultiAxisController Skewing. Proceed as follows:

  1. Measuring the load moment of inertia: There are two ways depending on the application:
    • If a motor alone can move the application in no-load weight condition, then the load cycling mode of the inverter can be used. In this case, the second inverter is switched to controller inhibit and the brake is released. Finally, the measured value of the load moment of inertia must be divided by two and entered in both inverters.
    • If one motor alone is not sufficient to move the application in no-load weight condition, then encoder evaluation in the MultiAxisController must be set to "Motor encoder" and load cycling must be performed using the IEC Editor or the monitor. For example in jog mode with direction of rotation reversal. The measured value for load moment of inertia of one inverter can then be transferred to the other inverter.
  2. Adjusting stiffness and zero clearance of the inverter: Here you can proceed as usual and increase the two parameters until a sustained or only weakly decaying oscillation can be detected on the torque/current. In this case, the encoder evaluation of the MultiAxisController is also set to "Motor encoder".
  3. Configuring the MultiAxisController: Encoder evaluation can now be set to "Motor encoder and external encoder". Next, the delay of the encoder in use must be parameterized in the encoder evaluation. For example to 2 ms for an AMS304i from Leuze. For the delay of the installed encoder, contact SEW-EURODRIVE or the manufacturer. The vertical drive must now be moved using the IEC Editor or the monitor, and the gain value of the position controller of the MultiAxisController must be decreased until no or a sufficiently small oscillation can be detected on the torque/current.