The Data Acquisition And Control System For The Precision Automatic Detection Device Of The Small Absolutely Photoelectric Encoder

Photoelectric encoder is a high resolution angular displacement sensor integrated with light,machine and electricity.It takes the photoelectric conversion technology as the core and outputs the digital pulse relative to the angular position information to achieve the measurement of angular displacement.It is widely used in aerospace,industrial control and other fields.The photoelectric encoder can be divided into two types: incremental and absolute.The position of each angle of the absolute encoder corresponds to the unique digital code,and there is no zero adjustment error.It has the advantages of small volume,high precision,stable and reliable.With the progress of science and technology,the accuracy and quantity of absolute encoder is higher and higher.At present,most of the detection devices can only achieve single precision detection,low efficiency and complex operation.Therefore,it is of great significance and value to study the automatic detection device with dynamic and static detection in one high precision and high efficiency.On the basis of related literature at home and abroad,research the development status at home and abroad of photoelectric encoder,detection method and device related;and analysis the method of data source and error absolute encoder dynamic and static error;automatic detecting device for permanent magnet synchronous motor and FPGA data acquisition system is the core of the building;The combination of permanent magnet synchronous motor and servo amplifier instead of the traditional stepper motor turntable,the controller hardware circuit with STM32F4 as the core of the design,through the optocoupler,differential driver,amplifier circuit design,combined with HAL library programming method,the speed and position control of the rotary table,can satisfy the dynamic and the static precision detection of small absolute encoder requirements.With the XC3S400 chip of Spartan-series of Xilinx company as the core,the interface circuit of the encoder data acquisition and the communication with the host computer is designed.The high speed and accurate data acquisition work has been realized.A large number of data processing works can be completed on the computer through the data transmission of USB and the upper computer.The accuracy test of the encoder is carried out by using the automatic detection device designed in this paper.It is proved that it can finish the automatic detection of the small absolute photoelectric code under 16 bits.On the basis of ensuring the accuracy of detection results,the detection efficiency is improved,and the detection time is shortened by 3-5 times.It is of great significance in the mass production and development of encoders.