It fully utilizes the wealthy peripheral and high-speed calculation funct i on of DSP, and uses the double CPU constituted PC and DSP, by utilizing PWM cont rol strategies, using a raster ruler as sensor of speed and position, and implem ents the task of position and speed control.

The focusing mechanism is composed of liner motor,liner orbit and raster ruler;Designed some tests in allusion to fulfill the need of this mechanism,and carried through tests to verify the precision,shake and high and low temperature;then.

The controller accepts the PC\'s order and triggers the pulse signal which can drive the step motor to move;at the same time,the raster ruler collects the actual displacement signal to feed back and compare with the theoretic value aiming at closeing with the desirable position uttermostly.

Design of displacement measurement for grating virtual oscilloscope based on labVIEW and dynamic link library;

This paper focuses on the way grating is counted by GAL and microcontroller.

At the same time the grating’s high precision is also more important to the CMM .

Using grating scale as sensor,which is fixed on NC machine tool,the equipment is easy to be used to measure the axial position error in x and y and z directions of NC machine tool,respectively.

A high speed and high precision displacement measurement method using double grating scales;

The working principle of the platform as well as the signal processing method of the linear encoder is explained.

An automatic inspection and grouping of the bolster spring is realized with PLC as the control unit and linear encoder and rotary encoder as the measuring units.

This paper makes deeply analyzing about the fundamental structure and principle of linear encoder, which is widely used in numerical control machine tool.