Research Of Dynamic Detection System And Methods On The Errors Of Small Size Absolute Photoelectric Encoder

During the development of science, the progress of technology and the rapiddevelopment of aerospace technology, every research department requires higherprecision of encoder. Not only does they require the real time angle informationoutput but also the accuracy in angular velocity or acceleration state during theincreasing of sensibility to angular velocity and angular acceleration in photoelectricmeasuring and tracking equipment. Recently, it can only detect static state errorsinteriorly; there are not effective methods to detect dynamic errors. Therefore, theresearches of dynamic detection system and methods on the errors of photoelectricencoder are urgently needful.Thoroughly, this paper analyses the dynamic errors detection methods of smallsize photoelectric encoder on the base of substantive references at home and abroad;the merit and demerit of these detection methods are contrasted. The influences offactors on the errors of photoelectric encoder are analyzed by the study on dynamicerror theory; these works laid foundation for the dynamic errors detection of smallsize absolute photoelectric encoder.The dynamic errors detection system is established and its software and hardwareare designed; the data processing method is proposed. The experiments prove that thedynamic error detection system is reliable.The method of high precision, high resolution and real-time angle reference isproposed and the circuit of high speed subdivision is designed; the high speed errorcompensation is achieved by using the theory of RBF neural network; the resolutionratio, the precision and response of angle reference encoder are improved. The drive system of dynamic detection equipment using space-vector torquecombination is proposed. In the analysis of the composite torque by three phasewinding, this paper studies space-vector torque combination drive method. The motorcan rotate in stable speed with constant torque and the stable drive system effectivelyreduces the effect of speed fluctuation on the detection error.The error assessment method is proposed based on least square method optimizedby Bayesian theory. It can assess the errors of small size absolute photoelectricencoder when there are less sample data; the component assessment methods ofdynamic error are proposed based on wavelet transform and power spectrumestimation, they can decompose the dynamic errors into error components and assessthe error components.The detection system of small size photoelectric encoder is designed by usingthese methods. The error detection experiments of small size photoelectric encoderare completed by using the detection system. The detection precision of this system isbetter than1.26", the range of its speed is0~90r/min, and it can achieve dynamic errordetection of small size absolute photoelectric encoder below16bit. The experimentsshow that the detection equipment is high precision, convenient and no strictrequirements on the environment, the error assessment method is dependable. Theresults of research can be applied to the dynamic detection of photoelectric encoder,meanwhile provide evidence for the manufacture of small size photoelectric encoder.