A Reference Synchronization Circuit for Resolver-to-Digital Conversion

Abstract

The invention discloses a reference synchronous circuit for resolver-to-digital conversion, which comprises a control transmission circuit, a multi-path selector and a comparator. The control transmission circuit receives a sine signal and a cosine signal which are generated by a resolver and three high bits of a resolver digital angle signal, and outputs two paths of signals A and B to the multi-path selector; the multi-path selector receives an externally input synchronization function enabling signal by a synchronization function enabling end, outputs resolver exciter reference signals REF_H and REF_L to the comparator when the synchronization function enabling signal is invalid, and outputs two paths of signals A and B to the comparator when the synchronization function enabling signal is valid; and the comparator compares sizes of two paths of input signals, and outputs a synchronous reference signal REF for providing a reference clock for a phase sensitive demodulation module so as to improve angle measurement accuracy of a resolver-to-digital conversion circuit.

Description

technical field [0001] The invention relates to a reference synchronous circuit for resolver-to-digital conversion. Background technique [0002] In the traditional tracking resolver-to-digital conversion, a phase-sensitive demodulation circuit is generally used to convert the AC angle error signal calculated by the shaft angle error into a DC error signal, and the DC error signal outputs a speed signal after an integral correction link to control the VCO output Pulse, the reversible counter counts the pulse, feeds back to the angle error calculation circuit and outputs the digitized angle. Based on this traditional tracking resolver-to-digital conversion method, there are hybrid integrated module products and analog (or digital) single-chip resolver-to-digital conversion circuit products. The phase-sensitive demodulation circuit references in these products are all resolver excitation inputs. Because the rotary is an electromechanical sensor, the internal sine and cosine c...

AI Technical Summary

Problems solved by technology

Based on this traditional tracking resolver-digital conversion method, there are hybrid integrated module products and analog (or digital) single-chip resolver-digital conversion circuit products. The phase-sensitive demodulation circuit references in these products are all resolver excitation inputs. Since the rotary is an electromechanical sensor, the internal sine and cosine coils are all inductive loads, which will cause the SIN and COS signals to lead in phase compared to the reference REF, resulting in an error in phase-sensitive demodulation. In high-precision angle measurement, this error has already It cannot be ignored that the traditional method is to correct the phase lag through an RC circuit before the SIN and COS signals are input into the single-chip circuit. Due to the matching accuracy of the resistance and capacitance values ​​and the temperature characteristics, this method is theoretically feasible, and the actual compensation accuracy cannot be quantified. Capacitor matching will introduce problems such as errors, poor temperature characteristics, and poor practical operability

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