Electrical shock absorber for docking control system

Results are reported from a preliminary experimental study examining an electromechanical actuator for a docking system in space, with emphasis on the attenuation and shock-absorbing characteristics of the actuator. A laboratory prototype of an electromechanical docking system which uses a sonar ranging system as a substitute for the laser range sensor and is controlled by a microprocessor is presented. The configuration of the experimental system consists of a rack and pinion gear actuator, a servo motor, sensors, a digital controller and an air-lifted docking target. For the design of the attenuator controller, the linear quadratic Gaussian (LQG) control design method is applied. For the purpose of attenuation on a specified frequency band, the application of a frequency-weighted LQG method and frequency domain method such as H2 and H-infinity control theory are considered.