Back to results
US 5,392,607 AGranted
Stirling-cycle cyrogenic cooler using adaptive feedforward vibration control
AssigneeHughes Aircraft Company
InventorYeong-Wei A. Wu
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeHughes Aircraft Company
InventorYeong-Wei A. Wu
Estimating the term…
A Stirling-cycle cryogenic cooler that employs a vibration control procedure based on adaptive feedforward principles. The 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 vibration control procedure suppresses vibrational forces that occur during operation of the cooler. The cooler comprises an expander module and a compressor module. 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 command signals are injected into a selected motor drive of either the compressor or expander module. The injected current command signals comprise higher-order harmonics 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, coupled to the cooler housing that measure higher-order harmonic forces. In operation, when operational parameters of the cryogenic cooler have reached equilibrium, the harmonic content of its vibration force is very stable in time. Because of this unique characteristic, the phases and amplitudes of injected current command signal do not have to be determined quickly. Thus, the computation throughput required for the present control procedure are significantly reduced.
An adaptive feedforward vibration control procedure for use with a Stirling-cycle cryogenic cooler that comprises an expander module comprising an expander piston and a balancer piston that are each driven by respective motor drives, and a compressor module comprising an compressor piston and a balancer piston that are each driven by respective motor drives, and a force sensor coupled to the cooler that is adapted to measure higher-order harmonic forces present therein, wherein said control procedure comprises the steps of:
A spacecraft comprising:
An adaptive feedforward vibration control system for use with a Stirling-cycle cryogenic cooler that comprises an expander module comprising an expander piston and a balancer piston that are each driven by respective motor drives, and a compressor module comprising an compressor piston and a balancer piston that are each driven by respective motor drives, said control system comprising:
A Stirling-cycle cryogenic cooler comprising:
Dependencies are inferred from the claim text.