Research On Coding And Decoding Algorithms Of 2-D Absolute Position Measurement Sensor

Based on the study of 2-D absolute measurement coding technologies and its measurement systems,this paper proposes a 2-D absolute coding algorithm by using the 1-D window sequences,and an efficient 2-D absolute decoding algorithm with fault correction and fault tolerance.On this basis,a 2-D absolute position measurement sensor system was designed,which can effectively reduce the Abbe error introduced by two discrete 1-D sensors mounted in the X and Y directions of the existing two-dimensional sensor and improve the integration of the 2-D position sensor.The main research work of this paper is as follows:(1)Based the research of the existing 2-D absolute position sensors and its coding and decoding algorithms,a 2-D absolute coding algorithm is proposed by arranging the 1-D cycle shifted de Bruijn sequences as the rows of the 2-D absolute array;the window property of the 2-D absolute array has been proved.(2)A corresponding decoding algorithm of the 2-D absolute array is proposed,which simplifies the complex 2-D decoding problem into 1-D decoding problem of window sequences;an efficient decoding algorithm with the ability of fault correction and fault tolerance is also proposed based on expanding the decoding window.(3)Based on the above coding theory,a 2-D plane coding disk is made and a 2-D absolute position measurement system is designed based on the mixed programming of LabVIEW and Matlab.(4)On the basis of the above research,a comparative experiment between the 2-D absolute position measurement sensor system and a two-dimensional electric microdisplacement platform is built.The experimental results show that the measuring resolution of the designed system is about 0.248),the average measurement accuracy is ±0.48)and the single measurement accuracy is ±0.68).