Question

A steering mirror for a telescope has a maximum angular acceleration of 100 rad/sec^2 and hard stops at +/- 30 degrees. The software controlling it runs at 200 Hz. If the mirror hits the hard stop at faster than 15 rad/sec, it can damage the hard stops. To prevent this, a "soft stop" is implemented in software.

What is the largest value the soft stop can be set at that will ensure no damage is done to the hard stops in the event that the controller goes unstable and starts commanding the maximum acceleration? If the sample rate is increased to 500 Hz, how close to the hard stops can the soft stops be safely set?

Answer 1

6 500 112 en O-45