An investigation on fuzzy incremental control strategy of water membrane evaporator cooling loop for mars spacesuit

The safe and robust temperature control strategy is important for Mars spacesuit's thermal control subsystem. This paper presents a fuzzy incremental control strategy using a fuzzy logic for the spacesuit water membrane evaporator (SWME) cooling loop composed of the liquid cooling and ventilation garment (LCVG), the cold plate and the SWME. A thermodynamic model of the SWME cooling loop is developed, in which the SWME model considers the heat and mass transfer of water transmembrane transport. A detailed analysis of the open-loop response under the variation of water flow, Mars' atmospheric pressure and the opening of the backpressure valve in the SWME provides a basis for developing the fuzzy incremental control strategy. This paper also compares the control effect of a fuzzy incremental controller and the optimized proportional-integral-derivative (PID) controller. Numerical simulation results suggest that the proposed control strategy has the advantages of the small overshoot, short response time, and less oscillation period, which will benefit the adaptability of complex systems and expand the application field of fuzzy incremental control.