Research On Signal Error Compensation And Fault Diagnosis Of Optical Encoder

In recent years, with the rapid development of aviation and aerospace industries, especially in some special systems such as space laser communication. In order to achieve the precise target location, tracking, measurement made on a very high demand. As a high-precision measuring equipment, optical encoder can outputs position and velocity accurately in these systems. However, due to the particularity of its mechanical structure and the limitations of conventional decoding circuit, the encoder is often difficult to ensure reliability when the environmental factor is very poor. Based on this need, this article makes two sides of research on signal compensation and fault diagnosis.Firstly,according to the optical encoder of the actual using, introducing it's entire workflow,and from the mechanical point of view analysis the accuracy of the shaft of the encoder.Secondly,improving the common problems in traditional optical encoder decoder system, completing the design of new software and hardware decoding circuit.After testing,it can achieve 23 no code hopping. At the same time, make deep study of the impact of the key indicators of grating signal and make a quantitative analysis from the amplitude, the DC drift, sinusoidal and orthogonal. For the various errors and the appropriate compensation method proposed, make adaptive compensation on Amplitude and DC drift, adaptive neural network filtering on harmonic signal, phase correction of compensation on orthogonal bias dot product measured using a signal. After simulation testing, effectively improve the quality of the grating signal.Thirdly, taking into account the existing optical encoder code disk are mostly glass easy to breakage, when subjected to vibration and other factors. a method of Identification failure based on Hilbert-Huang Transform is proposed, Through simulation test, each code channel to detect whether there is a fault. According to fault information, the method can detect whether the failure of each code channel.Finally, according to fault information,if only a section of code channel is damaged, using of adjacent functional relationship between the code channels, calculate the fault code channel information with good code; when the encoder was seriously damaged, in accordance with absolute and incremental optical principle of the encoder, designed to make use of good code channel encoder work, which to some extent improved the reliability of optical encoder.