Design Of Optical And Mechanical Systems For Absolute Position Measurement Sensor

Absolute grating position measurement sensor is a closed-loop feedback control element of CNC machine tool system,which is the most critical components of high-end CNC machine tools,and has an irreplaceable role in the field of high-precision measurement.Absolute grating displacement sensor has high precision and resolution,fast response and large measurement range,also can achieve dynamic measurement,therefore,it becomes the focal point of China's industrial modernization technology.Absolute position measuring device belongs to photoelectric measurement category,which has high requirements for optical systems.Absolute position measurement commonly used stripes read mode,when the beam is modulated into a parallel light by a lens,the stripes will be projected on the surface of the photodetector.Because the parallelism of light directly affects the image quality and the parallelism of light requirements are high,it is often necessary to design complex lens surfaces.This topic is based on the coding principle of the new pseudo-random code single code channel absolute grating,which can achieve a straight line position and information coding only corresponds.In order to improve the anti-pollution ability and measurement accuracy,this dissertation design the light source lighting system which according to the requirements.Then determine the model of the linear array CCD receiving element and use the ZEMAX software to design the imaging optical system.Finally,design package housing mechanical structure,the hardware circuit of output signal acquisition system and absolute position measurement test system.The main research contents include:(1)Analyse the advantages and disadvantages of commonly absolute coding,summarize the development of absolute grating sensors.(2)Determine the linear array CCD model and the light source model parameters,use the TracePro software to design the focus lens structure.(3)Calculate the optical path structure parameters,use the ZEMAX software to design optical imaging magnifying lens,then simulate and optimizate to meet the requirements.(4)Design the package housing mechanical structure to achieve miniaturization.(5)Design the hardware circuit of signal acquisition system and absolute position measurement test system in order to read raster coding information stable and accurate.