Position Sensor-less Piston Stroke Estimation Method for Linear Oscillatory Machines Based on Sliding Mode Observer

摘要

For the linear compressor system driven by linear oscillatory machine (LOM), the piston stroke signal is very important to realize the efficient control of the motor. Since it is difficult to install a position sensor in the LOM, and the position sensor will increase the difficulty of system control, it is necessary to use an accurate and efficient position sensor-less method to estimate the piston stroke signal. In this paper, a novel position sensor-less piston stroke estimation method based on sliding-mode observer (SMO) is proposed. Besides, a self-adaptive band-pass filter (SABPF) is designed to filter the estimated piston stroke signal, which not only overcomes the pure integration problem, but also solves the chattering problem of SMO. Simulation results show that the proposed SMO has a good performance in estimation accuracy, and the chattering problem is well solved.