Research On Signal Processing Method Of High-precision Grating Transducer

High-precision measurement technology is more and more widely used inmodern CNC machine tools and high-precision measuring instruments. Although avariety of laser interferometric techniques are applied to precise displacementmeasurement, the grating measurement technique is still the most important meansto achieve high-precision displacement measurement.Generally, there are twomethods to improve the grating accuracy. One is to increase the density of grating,but this method is high cost and low reliability. another method is the contents ofthis thesis, using the subdividing technology to improve the accuracy of grating andusing Mathematical algorithms to improve the quality of grating signal, reduce theerror in the measurement process.This thesis puts emphasis on signal processing of high-precision grating andproposes a software subdivision method based on the principle of tangent method.In addition, an effective error compensation algorithm to improve the accuracy andresolution of subdivision was proposed. Finally, an effective measurement systemwas established by using Lab VIEW software.In the signal acquisition, the grating signals are acquired by the NI PCI-6221data acquisition card for the major hardware and Lab VIEW as the main software.Several typical characteristics and basic principles of subdivision aresummarized. a new subdivision method is proposed, and this method is achieved byLab VIEW software.In the error compensation, the three error factors that affect the measurementaccuracy and resolution are summed up and an effective method of compensationfor the three main error are proposed. Finally, it is achieved by Lab VIEW.Based on the experiments, we can find the contents of paper have the referencevalue to the signal processing of the grating measurement technique and laserinterferometer.