Methods and devices for active vibration damping of an optical structure
View Patent ↗A vibration damper assembly that may be attached and moved about a payload or optical mount surface of an optical structure such as an optical table. The vibration damper assembly may include a sensor and an actuator that may be disposed within a housing. In some embodiments, the vibration damper assembly or components thereof may be incorporated into an optical structure in the form of an optical component to be disposed or mounted on an optical mount surface of an optical structure such as an optical table. Embodiments of the vibration damper system may include a controller in communication with the damper assembly Embodiments of the controller may use adaptive tuning, auto-ranging selection of gain factors and other features in order to optimize damping performance.
1. A method of adaptively tuning a controller of an active vibration damper system, comprising:
disabling all control channels except one active channel in the vibration damper system for an optical structure, the vibration damper system including a plurality of vibration damper assemblies which each have a respective vibration sensor and actuator and the vibration damper system further including a controller coupled to the sensor and the actuator of each vibration damper assembly by a plurality of respective control channels;
increasing a gain factor of the active control channel until instability in the vibration damper system is detected;
reducing the gain factor by a small increment to re-achieve stability;
storing the gain factor that achieved stability;
repeating the above steps individually for any remaining control channels;
activating all control channels and increasing a gain factor to each control channel in an amount proportional to the respective stored gain factor for each respective control channel until instability is again detected; and
reducing the gain factor in small steps for each control channel until stability is achieved for the vibration damper system.
2. The method of claim 1 further comprising simultaneously reducing gain factor for each control channel in small steps proportional to the respective stored gain factor simultaneously to regain stability.
3. The method of claim 1 wherein reducing the gain factor is performed by a converging search method.
4. The method of claim 3 wherein the converging search method comprises a bisection method.
5. The method of claim 2 wherein reducing the gain factor is performed by a converging search method.
6. The method of claim 5 wherein the converging search method comprises a bisection method.
7. The method of claim 1 further comprising applying a safety factor reduction to each gain factor.