Research on velocity-measurement of high speed linear motor

To solve the velocity-measurement difficult problem of linear motor in high speed and high acceleration occasions, a velocity-measurement method based on teeth-slots signals detection is proposed in this paper. In this method, the speed signal is obtained from the inductance periodic variation of probe coil, and the "teeth-slots" bar consisting of conductor and ferromagnetic materials alternating is employed to achieve the inductance variation of probe coil. The results show that both the inductance change range and change percentage is larger than traditional sensor based teeth-slots velocity measurement method. Also the probe coil inductance converges to the value in air at periodic position regardless of the detecting gap, which can enhance the robustness.