Research And Application Of Position Decoding Of Rotating Transformer

The resolver is an angle sensor,which is used to measure the rotational speed of the motor rotor and the rotating speed of the motor.also referred to as the rotary transformer,because of its high reliability,high resistance and high anti-interference ability and other characteristics,more and more application in the AC servo motor and switch reluctance motor rotor,as angle position test components,replacing the once widespread use of photoelectric encoder.Rotating transformer can output two orthogonal waveform and its special decoding circuit can parse out the absolute position of the motor rotor speed and rotor and its output is analog signal,with high-resolution,non-contact,long life,small volume,low cost and simple structure advantage.However,the use of a rotating transformer,it is necessary to decode the chip to use,easy to introduce errors,and high cost limits its application in many areas.In this paper,we mainly study the position decoding of the rotating transformer,mainly including the following.1.Design and realize the real time error compensation function of the rotary transformer decoding circuit.For the resolver decoding,the output value of existing angle error,using a special decoder chip,design based on FPGA of resolver decoding the compensation error correction decoding circuit and improve the decoding accuracy.2.A test platform system is designed to correct the angle error of the rotating transformer.The system to an absolute photoelectric encoder as the standard,photoelectric encoder and rotary transformer installation in with a rotating shaft,in testing resolver decoding error.By the same motor drive photoelectric encoder and measured rotation synchronous transformer operation,the position signal of the photoelectric encoder output numerical,and a rotary transformer by decoding ASIC of position signal,sending to the processor than dealing with,find the resolver decoding error.3.The FPGA+ARM control circuit of the error measurement system is studied,which improves the operation speed and decoding accuracy.The results show that resolver through the rotary transformer and photoelectric encoder of the motor with a view of decoding and the construction of correction system can decode of rotary transformer for measurement,compensation and correction.The results show that the resolver's angle error is 21.2 arc min before correcting,and reduced to 5.3 arc min after correction.The correction system can restrain errors effectively.