System identification of an ultra-quiet vibration isolation platform

• Main Author: Beavers, George D
• Other Authors: Agrawal, Brij
• Language: English
• Published: Monterey, California. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/9052

Approved for public release; distribution is unlimited === This thesis details the system identification and initial system validation of the an Ultra-Quiet Vibration Isolation Platform (UQP). With the move toward lighter and more flexible spacecraft, the effects of vibration are of immense concern. As natural or passive damping becomes less effective in controlling undesired vibrations, active vibration control becomes essential. The UQP uses a special configuration of the six degree of freedom Stewart Platform with piezoceramic strut actuators and geophone sensors. This combination gives an extremely sensitive and responsive six degree-of-freedom active vibration control system. Each actuator was designed to be controlled independently without coupling with other actuators. In order to develop control laws, the plant must be identified in terms of system zeros and poles and the uncoupled design validated. Dynamic modeling using parametric estimation methods can accurately describe a complex system. Using parameter estimation methods, models of the actuator system dynamics were obtained. A simple lead-lag controller was applied to individual actuators then all six actuators acting simultaneously to verify system coupling. Significant interaction between base adjoining actuators was discovered.