Abstract:Aiming at the problems that current absolute linear magneticfield type time grating displacement sensors do not provide incremental linear displacement feedback for full closedloop numerical control system, in this paper the measurement standard transformation method is adopted to process the spatial displacement information of the absolute linear displacement magneticfield type time grating sensors in time domain. The inherent relevant of the sampling data series of the absolute linear displacement time grating sensor is analyzed using time series algorithm, and the selfadaptive recursive algorithm is established. The measured linear absolute displacement data sampled in timetriggered pattern are employed as sample set, and the absolute linear displacement for the next sampling period is calculated through recursion. Then the incremental time clock pulses represented by the absolute linear displacement of the time grating sensor are sent continuously using pulse width modulation pattern during the next sampling period. In this way, the absolute linear time grating sensor is transformed into an incremental linear one. Experiment results prove that the dynamic displacement measurement error of the proposed incremental linear time grating sensor is within ±2 μm in the range of 76.604 mm. With the proposed method, the absolute linear time grating sensor can be applied for incremental linear displacement feedback required in full closedloop numerical control system.