Hongxing Yang

TL;DR: The development of incremental displacement measuring grating interferometers achieved in recent years is summarized in detail, and studies on error analysis of a grates interferometer are briefly introduced.

TL;DR: A capacitive sensor is proposed to measure the departure from the vertical movement, designed to have a direct vertical direction reference, and the characteristics of the sensor, such as sensitivity, resolution, and short-time stability, have been analyzed through experiments.

TL;DR: In this paper, a system based on laser heterodyne interferometer is proposed to measure and control the movable coil position of a joule balance, where a damping system is used to suppress the movement of a movable wire in the horizontal direction while a piezoelectric ceramic control unit with PID controller is used in the vertical direction to inhibit the vibration and long term drift of the wire.

TL;DR: In this paper, a multi-frequency synchronization phase laser ranging device and a method based on dual-acousto-optic shift frequency is presented. But the method is not suitable for the measurement tape frequency.

TL;DR: A modified nonlinear-error correction method for errors due to PGC carrier phase delay and AOIM is proposed and results show that after correction, the nonlinear error is reduced to less than 1nm, and nanoscale displacement measurement is achieved.