System for precision displacement measurement based on self-traceable grating interference

A system for precision displacement measurement based on a self-traceable grating interference, comprising a coherent light source, a photoelectric detection module, a self-traceable grating and a signal processing module, wherein the self-traceable grating is arranged on a to-be-measured displacement motion platform;

• the coherent light source, the photoelectric detection module and the signal processing module are sequentially connected;
• wherein
• after laser generated by the coherent light source propagates through the photoelectric detection module, the laser is incident on the self-traceable grating and diffracts with the self-traceable grating to obtain diffracted light, the diffracted light returns to the photoelectric detection module to continue propagating to obtain an interference signal, and the interference signal enters the signal processing module;
• and
• the signal processing module is configured to collect the interference signal to obtain a motion displacement and a motion direction.