Fuzzy control of piston displacement of a linear refrigerator compressor

In order to effectively control the piston displacement of a linear refrigerator compressor, a new fuzzy control system based on self-adjusting was proposed. The hardware and software of the fuzzy control system were developed with the piston motion model and the fuzzy control model. The control system is mainly composed of a displacement measurement unit, a DSP, a power driver unit, an electricity source unit, and a computer. The response curve of the fuzzy control system was measured. The experimental results show that the present control system can effectively measure and control the piston stroke and the top clearance distance of the linear compressor. The steady-state error of the top clearance distance is smaller than 0.25 mm, and there is almost no overshoot nearby the top dead center.