Resolver R2d Circuit

To realize high precision control in servo system, rotor position of motor is needed. Optical Encoder and Resolver are two most widely used shaft angle transducers in servo system. Although Optical Encoder has high performance, its reliability isn't high and it couldn't be uesd in hard environmental conditions. In contrast, Resolver has simple structure and high reliability, it can be used in hard environmental conditions, so it's getting more and more used.A new kind of variable-reluctance resolver has been introduced in this paper. Its stator, rotor and windings have been studied especially. The expressions of sine and cosine back-emf signals have been studied. The resolver has been analyzed by finite element software at the same time.A R2D circuit has been designed in this paper. It's composed of DSP and some necessary circuits, such as, sine-wave signal generation circuit to provide exciting signal for resolver. Shaft angle and rotate speed of resolver have been resolved. Some factors which induce shaft angle errors have been analyzed too.The second R2D circuit has been designed. In contrast with the first, its difference is exciting signal. Square-wave signal that is generated by DSP has been filterd first and then is used as exciting signal. The two R2D circuits have been compared.The harmonics in sine and cosine back-emf signals which are induced by the harmonics content in excitation winding and their effect on resolved shaft angle have been studied.