A short-distance harmonic suppression method for position detection based on linear hall-effect sensors

Accurate position signals are essential for a vector control system. To obtain accurate position signals, high-precision position sensors such as optical encoder and resolver are employed. However, they are usually restricted by the environmental condition and cost. Linear Hall-effect sensors, possessing tiny size, light weight and low cost, are usually used to detect position signals. However, the position signals detected by linear Hall-effect sensors in low cost conditions always contain a large part of high-order harmonics, which will decrease the validity and reliability of sensor measurement. In this paper, to eliminate the influence of harmonics, a short-distance harmonic suppression method without any low-pass filter is proposed. The proposed method utilises three linear Hall-effect sensors displaced a certain electrical angle to dissolve the position signal. Through simulation analysis and experimental verification, the proposed method has been proven to be effective in suppressing the third-order and fifth-order harmonics.