Research Based On The New Magnet Structure And Signal Processing Of The Single-Pole Encoder

The technology of sensors is one of crucial components of the modern information technology. Sensors are the window of the system to acquire and detect information, and also the interface of the studied object and the information system. As an important branch of more sensors, the magnetic sensor has an important role in the detection system and can be used to detect the non-electronically characteristics through the magnetic field, it is easy to implement precise combination of components, has small size and is strongly adaptable in harsh environment. Compared with the optical encoder, magnetic encoder has the advantages of simple structure and it can be less affected by the external influences, but it has lower accuracy and resolution, which limit its improvement and application.The paper aims at improving the design of a two-pole magnetic encoder, designed for the measurement of the position of object and the angular velocity of object. Through the sensor, the information of the position and the angular velocity are output and display.Therefor, in order to improve the quality of the orginal voltage signal,we use two identical hall elements and radial magnetized permanet magnet sheet to get two orthogonal sine or cosine signal, the Magnetic-field distribution and the law around magnet was deduced on theory and analyzed by Finite element analysis, Then calculated with the results of the experimental, it was so detailed that we can determine the appropriate signal for the program. In the encoder signal processing, we selected high-performance signal processing chip TDS2812EVMB and based on the linear signal processing algorithms to calculate the two signals,which can improve the linearity of the original signal and reduce the computational complexity of chips.Because of the application of the TDS2812 EVMB,not only simplifies the signal processing hardware part of the peripheral circuits and achieved the requirement of the miniaturization design,but also realized the high calculating speed,output and display the angle real-time, the precision and reliablity of the encoder has been increased greatly.