Stirling-cycle cryogenic cooler using adaptive feedforward vibration control

摘要

A Stirling-cycle cryogenic cooler employs a vibration control procedure based on adaptive feedforward principles. Such vibration control procedure is particularly adapted for use as a spacecraft cryogenic cooler, and may be used to cool a detector array or other sensor located on the spacecraft. The cooler comprises an expander module 15 and a compressor module 16. The expander and compressor modules employ separate motors that respectively drive an expander piston and a compressor piston, and a balancer piston is employed to dynamically balance the respective expander and compressor pistons. In the control procedure, current commands signals are injected into a selected motor drive of either the compressor or expander module. The injected current command signal comprise higher-order harmonies with adaptively determined phases and amplitudes that provide for complete force cancellation in the cooler. The desired phases and amplitudes of the injected current command signals are estimated in real time using outputs of force sensors, such as load cells 31, 32 coupled to the cooler housing that measure higher-order harmonic forces. IMAGE