Active vibration isolation of rigid body using a pneumatic octostrut platform

An active control has been developed as a method to isolate a spacecraft from the launch vehicle to overcome the drawbacks of a passive octostrut platform found in the low frequency resonance introduced into the system. An active octostrut isolation platform is proposed, and pneumatic springs are used as its active actuators for their cleanness and long stroke. An analytical minimal norm redundancy has been identified and steady stiffness can be increased greatly by strut length feedback. Resonance peaks can be eliminated and the isolation frequencies can be reduced significantly by payload velocity and acceleration feedback. Grouped control strategy proposed in accordance with the characteristics of the system simplifies the design of a controller without sacrificing its control performance.