Bi-stable actuator measurement method based on voice coil motor

Abstract Bi-stable actuator (BA) has been widely used in industry as an energy converter because of low power consumption. However, the holding force, start-up force and dynamic performance under load are difficult to comprehensively test by existing measurement method. A measurement method is proposed in this paper, a voice coil motor (VCM) acts as both a force sensor and a load simulator, which significantly simplifies the complexity of device. The core VCM was designed based on the analysis of the system’s structure and principle. Besides, a force tracking controller was built without a feedback signal from routine force sensor. Meanwhile, the MAP of VCM’s displacement-current-force was obtained and the target force tracking test was carried out by VCM’s calibration experimental setup. Finally, the force characteristics and dynamic characteristics of a BA were tested to verify the effectiveness and reliability of the measurement method. The results show that the tracking precision of VCM under step signal and slope signal is ±2 N, which achieves the requirement of load simulator combining with fast response. Moreover, the results of BA’s force characteristic agree well with those through a traditional complex test system. Additionally, BA’s moving time under linear load is 3 ms, which is hard to obtain by traditional measurement methods. Although in this paper the methodology was employed to a BA, its structure can be used to test a wide range of linear actuator.