Development Of Magnetic Rotary Encoder For Servo Motor

With the development of industrial automation, the quantity demanded of magnetic rotary encoder for servo motor becomes greater and greater on the market. But the domestic industrialization of magnetic rotary encoder is immature, and the correlative products are low performance, which far from to meet the requirement of market. At present the multi-pole structure has been commonly adopted in the magnetic rotary encoder, because this structure needs complex technical process and difficult to realize high performance. Therefore, this paper has researched on the single-pole magnetic rotary encoder, and successfully developed the magnetic rotary encoder that is low-cost and high-performance, mini-type and industrialized easily for servo motor.At present the single-pole magnetic rotary encoder is difficult to generate high quality voltage signals and has complex hardware for signal processing, which are the main factors that restrict its development. In order to improve the quality of the voltage signals, this paper has adopted the scheme of three phases and six organs in signal-generator part, which can eliminate the errors caused by the assembly warp and the zero shift of organs. This paper also has analyzed the distribution and varying rules of the magnetic field in the signal-generator part, then based on the conclusion of the analysis improved the structure of signal-generator, which could completely eliminate the noise signal caused by the roughness of the face on the magnetic steel ring. The improvement not only met the requirement of this study, but established the theory foundation for the super-high precision magnetic encoder in future research. On the side of signal processing part, this paper has chosen the arithmetic that based on look-up table, which reduced the operand of signal processing and be realized by applying the 32-bits embedded SCMμPD70F3184, because of the application of this embedded SCM, not only cut down the number of hardware in signal processing part and achieved the requirement of the miniaturization design, but also realized the high calculating speed and real-time signal processing, and the precision and reliability of the encoder has been increased greatly.