Design And Realization Of Absolute Linear Encoder Signal Detection System

With the development of modern processing technology toward precision and ultra-precision,people are putting more and more urgent demands on high-precision sensors.Absolute linear encoder was a new line displacement sensor appeared on the market in 2005.Compared with the traditional incremental linear encoder,it has the advantages of high measurement accuracy,strong anti-interference,no need to go back to work after power off,no cumulative error,position calculation done in the reading head and so on.Therefore,it is widely used in a variety of high-end CNC machine tools and sophisticated measurement equipment.With the promotion and use of absolute grating,in order to facilitate the us er of the grating ruler fast and convenient signal detect.In the meantime,in order to facilitate the manufacturer in the development stage of the grating ruler products repeatedly testing and debugging,as well as in the post-sale phase can be easily and effectively maintain the product,which requires a complete set of absolute linear encoder signal detection platform to achieve.In this paper,based on the existing domestic and foreign absolute linear encoder detection technology and the current product requirements,based on in-depth study of absolute linear encoder signal detection principle,the common fault types and diagnosis methods,error measurement and compensation way to design an absolute linear encoder signal detection system.The system consists of acquisition card and host computer,used to achieve absolute linear encoder online signal detection and repair,fault diagnosis,error measurement and compensation functions.Firstly,the principle and method of absolute linear encoder signal detection are researched.The method of signal detection is designed,including incremental signal and absolute signal.At the same time,the common fault types and diagnosis methods of absolute linear encoder are studied.A signal acquisition card with STM32 as the core controller is designed.The acquisition card is equipped with an absolute signal acquisition module,an incremental signal acquisition module,a laser interferometer interface module,and an upper computer interface module.The acquisition card acts as a bridge between the host computer and the grating,accepts commands and parameters from the host computer,reads and writes the scale,and feeds it back to the host computer.When used to make error measurements on absolute grating,the acquisition card provides a trigger signal for the laser interferometer.The upper computer software of the signal detection system is designed.The software is based on the Qt environment and developed in a modular way.Including network protocol module,product information and location value acquisition module,fault diagnosis module,signal detection module,photoelectric parameters adjustment module and error measurement and compensation module,each module is packaged independently,users can according to actual needs Load it.The main function of the host computer software is as the interface of human-computer interaction.It sends commands and parameters to the acquisition card according to the communication protocol with the acquisition card,and obtains feedback information from the acquisition card.After processing and analysis,it displays in real timeThe method of detecting and compensating the measurement error of absolute linear encoder is studied.The paper discusses in detail the error factors that affect the measurement accuracy of the absolute linear encoder ruler,sets up the error detection platform by using the signal detection system,and realizes the fast error detection of the on this platform.In addition,the error compensation methods are proposed,and finally the compensation data is written into the grating ruler reading head,so that the compensation error can be quickly and efficiently compensated.Using the research method of this paper,the design of the absolute linear encoder signal detection system is completed,and the functions of signal detection and correction,fault diagnosis,error detection and compensation of the absolute linear encoder online are realized.For the absolute linear encoder promotion and maintenance of great significance.