A MEASURING METHOD, SENSOR AND RUNNING METHOD THEREOF FOR ABSOLUTE POSITION MEASURING THE DISPLACEMENT OF A CAPACITIVE GRATING

摘要

A measuring method, sensor and running method thereof for absolute position measuring the displacement of a capacitive grating is provided. The measuring method includes: adopting a driving signal with fluctuation property to excite an emission grid (1.1), transforming the displacements of the position to be measured in each wavelength into initial phases of temporal fundamental wave, and obtaining the displacements of the position to be measured in each wavelength through an adding counter (15). A driving signal generator (5) of the sensor outputs a signal with fluctuation property, and connects with the emission grid (1.1). Master clock of an oscillator (12) accesses each circuit. Outputting of a receiving grid connects with a synchronous trap circuit (14) through a signal selection switch group (6) and an analog processing circuit. The synchronous trap circuit (14) connects with a controller (16), the adding counter (15) and a RAM (17). The running method of the sensor is that: an interface unit (8) enables a measuring unit; the controller (16) coordinates operations among circuits; and after finishing measurements of the displacements within coarse, moderate and fine wavelength in sequence, the interface unit (8) turns off the measuring unit, processes and displays the measuring results.