| Angle displacement sensor,as a multidisciplinary and interwoven precision optical instrument,is becoming more and more prominent in the development of national basic research,economic development and national defense construction.However,the key core components required for high-end angle displacement sensor products are almost all imported from abroad,and the short plate of the industrial chain has long existed and become more serious.In this context,the Ministry of Science and Technology,the Ministry of Industry and Information Technology,the National Natural Science Foundation of China and other departments set up a series of "Development of major scientific instruments and equipment" special.The work of this paper comes from the above-mentioned project.The aim of the study is to develop a photo-electric integrated chip specifically designed for high-precision angle displacement sensors,including detector arrays that match the sensor system,high-performance photo-electric integrated circuits,and industrial-grade chip preparation solutions.This paper’s main innovative contributions are summarized below:A method for synchronizing pseudo-random and incremental signals is proposed.The mechanism which light and dark stripes corresponding to incremental code of a pseudo-random code in the range of no more than 1/4 cycle of code plate engraving error,without complex algorithm is required to find the first place of pseudo-random code,is used to read absolute position information directly.Based on this method,the angle displacement sensor effectively solves the problem of loss of position information and cumulative error after powered down by means of fast and continuous output absolute position.A line array detector designed to read pseudo-random information is designed.In order to better achieve high-speed low-light detection,the detector is designed to fully re-match the fan shape with the code plate,ensuring the consistency of each detector’s light sensing conditions,while each detector uses a separate reading unit for integral acquisition,and then the serial output is controlled by timing,in order to ensure consistency and signal-to-noise ratio can achieve 7.4k Hz frames rate.A photo-electric detector scheme is proposed to improve the quality of The Moir stripe signal.The detector of four split phases is subdivided into row combinations of different phases,and the sine of the incremental code signal read by photo-electric detection is improved by using the principle of phase difference filtering.The amplification circuit adopts the architecture of the first-stage high-gain TIA and the first-stage full differential amplifier,which effectively suppresses the noise while ensuring the phase difference.The preparation of ASIC photo-electric chip is realized by standard CMOS process,and the performance and stability of photo-electric chip are verified.The chip has been used to complete the development of high-precision angle displacement sensor,the resolution is 25 bit,the accuracy is 1",the mechanical speed is 1000 rpm,the form factor is 100x25 μm,and the domestic substitution and industrialization of high-precision angle displacement sensor is realized. |
