Design Of Absolute Magnetic Encoder

The magnetic encoder is a sensor device that uses a magnetic sensor to detect a change in position.It converts the angle of rotation of the shaft into a digital or analog quantity,which enables measurement of angle,rotational speed,and other physical quantities.Compared with photoelectric encoders,magnetic encoders have the advantages of fast response speed,high stability and low price,and their key technologies have become a hot research topic in recent years.This topic studies the technology of magnetic encoder and gives a design scheme based on magnetoresistive sensor encoder.Firstly,the source of the detection error of the magnetic encoder and the cause of its error are analyzed,and the possible solutions are given.The magnetic field distribution of the magnetic steel model is simulated by Maxwell software.It is theoretically verified that the single magnetic pole is used to design the magnetic steel.The feasibility of the encoder.When the main shaft of the magnetic encoder rotates,the single magnetic pole connected to the main shaft rotates with the magnetic steel,and the rotating magnetic steel generates a periodically changing magnetic field.The magnetoresistive sensor senses the magnetic field and outputs two phase differences of ?/2.Sinusoidal signal.STM32 samples and converts two sinusoidal analog voltage signals through two A/Ds.The function module is designed by CORDIC algorithm.After STM32 controller solves,the rotation angle of the encoder shaft can be obtained,and the table is checked.Error compensation is performed on the angle of the solved encoder measurement.Finally,the absolute output is adopted through the SSI interface.At the same time,different reference voltages and high-precision A/D can be selected to design a magnetic encoder with higher precision and resolution to improve the measurement accuracy of the magnetic encoder.The experimental results show that the detection accuracy and related indicators of the magnetic encoder meet the requirements of graduation design,and it has the advantages of low power consumption,small size and strong anti-interference.