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Servomechanism
with elastic torsion shaft

Controller design with Sysquake and Calerga VR

Virtual Experimentation

Run   reset reset viewpoint fullscreen

Observe the system to get a basic understanding of its main features: the DC electrical motor is on the left, the load (a heavy wheel) on the right, and both are linked with an elastic shaft. Then interact with the system:

  • Drag a point not on the system to move the point of view around the system. You can revert to the initial view with the target icon reset viewpoint, and restart the simulation with the reset icon reset.
  • Drag the wheel to make it rotate. Observe the measured values.
  • Drag the square blue handle left and right.
  • Compare the system behavior when the handle is on the left (it becomes red) or not. Do you think the model structure is the same? Why?
  • Press the yellow button (second button from left) to apply a voltage of 2 V and observe the measured values. Brake the wheel by touching it. Touch the wheel at a point closer to the rotation axis and compare the effect.
  • Move the wheel left and right and observe what happens.
  • Press the small triangular arrows next to “1/3” above the measured values to switch the display. The second display shows the controller parameters used in feedback controller mode; the third display shows a scope with the measured values. Move and release the wheel. What can you observe on the scope?
  • Press the red button to halt the system. Press it a second time, a third time, rotate the wheel by hand or by switching one or two seconds the yellow button. Observe what happens.
  • Press the gray button (right-most button) and observe what happens.
  • Press the green button to switch to the feedback controller mode, with gray button off. Observe the measured values until the rotation speed of the wheel is constant.
  • Brake the wheel until the rotation speed becomes constant again and observe what happens. How is it different from the 2 V constant input?
  • Experiment more in controlled mode. Is it a good controller? Why?
  • Pause the simulation by unselecting the “Run” checkbox.

Model

For simulation and controller design, the system is represented as a state-space model.

Details

Controller design

The transfer function from motor input (voltage) to wheel velocity and a controller based on it can be computed with Sysquake.

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