2018.B.2.5. Micro cold gas proportion thruster for deep interplanetary exploration

Author(s)

Xudong Wang (1)
Jinyue Geng (1)
Xuhui Liu (1)

Beijing Institute of Control Engineering, China

Session

B.2

Keywords

Cold gas micro-thruster, adaptive control, variable universe, fuzzy PID.

Abstract

The thruster is composed of control module, the thrust valve and a mass flow sensor. The control module adjusts the thrust output of the cold air micro-thruster according to the setting value of the thrust. The actor of the thrust output is the ratio of the nozzle throat area which lead to the respective mass flow. For maintaining a good setting value of the thrust output, it need fine-tuning the throat area of thrust valve according to the measurement of gas mass flow of mass flow sensor in real time. The locations of the body of the thruster valve is proportional to the current or voltage output of the driven circuits. And different positions of the valve body determines the size of the throat area. The current or voltage output of the driven circuits is controlled by the controller which can output a control signal by a certain arithmetic operations using the mass flow rate sensor signal and thrust setting value as the input signals. Then it achieves the purpose of adjusting the thrust of the cold air micro-thruster.

Micro cold gas proportion thruster isa multi-variable, nonlinear, strong coupling system; the traditional control methodis vulnerable to uncertain factors such as the satellite parameters change and load disturbance, difficult to obtain satisfactory control effect.This paper puts forward an adaptive variable universe fuzzy PID compound control strategy, control parameters is realized by using fuzzy control and variable region since the setting and control rules of self-adjustment. Apply it to the drag-free control of cold air thrusters based on the micro-thrust loop, the results show that the method has fast dynamic response, strong anti-interference ability and robustness, etc.