Research On Signal Processing In Single Pair-Pore Magnetic Encoder

Magnetic encoder is one of the digital sensors to detect object’s signal including rotational position and angular velocity which can be converted to electrical signals real-time, as long as placing magnetic sensors near the rotational permanent magnet relatively, the encoder will sense and detect the changes in flux density, then output electrical signal with the standard form. Compare with the optical encoders, magnetic encoders is easy to implement precise combination of magnetic sensor components, and is not affected by water vapor or dust and so on. Relying on the characteristics of simple and compact structure, light weight, non-contact, small inertia, high respond speed, high sensitivity, the magnetic encoder makes up for optical encoder’s lack, while be restricted to improving resolution and accuracy. Magnetic Encoder is starting superiority and getting a lot of attention recently in the controlling and detecting system, which becomes hot research. Now it is widely used in factory automation system(such as servo motor running), transportation, robotics research and magnetic navigation systems.A novel method naming arithmetic operations is proposed to analyze and process the generated voltage-signals from the single pair-pole magnetic encoder. Dual orthogonal voltage-signals are generated by two vertical hall sensors which are placed in the bottom of a radial columned magnetization. The core component is FPGA chip. When analog signals conditioning completed, rotational angle value would be directly displayed after determined the quadrant, performed arithmetic operations and nonlinear correction. The subject developed through a program formulate, algorithms research, system architecture, hardware construction, software compile to the whole debugging, then analyze data’s deviation in detailed in the end. This paper designs and implements the single pair-pole magnetic encoder with high-speed, high-resolution and high-accuracy.