Research on High Precision Cryocooler Control System for Satellite-Borne

Abstract

Aiming at meeting the precise temperature requirement (at mK level) of focal-plane in the remote sensing camera, this paper designs a highly accurate temperature control system based on a Pulse tube cryocooler. In order to ameliorate the control precision of temperature, firstly, the design of constant current source circuit is introduced, and the accuracy requirement of the constant current source is given in consideration of the temperature control requirement. Secondly, we devise the circuits for the two-stage amplifier and the filter, and the selection methods of parameters. Finally, the incremental PID control algorithm is introduced, and numerical experimental results of temperature control in vacuum environment are given: (1) The closed-loop accuracy of cryocooler system are given under different temperature control points, and the temperature control accuracy is all within 10mK; (2) When the temperature of the hot plate of cryocooler system changes within 5 °C, the cryocooler system reaches stability again, and the steady-state error is still within 10mK. Therefore, Experimental results indicate that the closed-loop control accuracy of cryocooler system is within 10mK, and it obtains certain robustness.