Sensorless Landing Control Strategy of Bistable Permanent Magnet Actuator

Bistable permanent magnet actuator (BPMA) has been widely used in on/off application. However, the response time and landing performance of on/off actuator are contradictory. Through analyzing the landing control goal of on/off actuator and sensorless technology features of the BPMA, a new sensorless landing control strategy was proposed using armature position detection instead of real-time displacement estimation or displacement sensor. The feasibility and effectiveness of the method are verified by experiment and simulation, the operation quality of BPMA is effectively improved. The results show that the first bounce decreases by 85.7% and the second bounce is avoided when the iteration converged, compared to the condition without landing control, while the response time increased by 6.8%. Meanwhile, the landing velocity decreased more than 50% and sound intensity at different frequencies reduced more than 4dB with sensorless landing control strategy. Although in this paper the control strategy was employed to a BPMA, its structure can be used to analyze and design a wide range of on/off actuator.