Research And Design Of Resolver-to-Digital Converter Taking The Signal Errors Consideration

The performance of the RDC(resolver-to-digital converter)is an important factor affecting the accuracy and reliability of the whole angle measuring system based on resolver.The special RDC which need complex interface circuits are quite expensive and inflexible.The resolver-to-digital converters set up by the separable components which take the digital controllers as core can not only guarantee the precision of the rotor position angle measurement,but also can save the cost and improve the flexibility.The whole program design and the performance tests of the all-digital RDC are carried out in this paper.The specific work is as follows:(1)The research and analysis of the RDC decoding algorithmsThere are several ways to achieve the arctangent decoding algorithm.But due to this algorithm is based on open-loop operation,the position angle can not be tracked real-timely;SRF-PLL(Synchronous Rotation Frame-based PLL)decoding algorithm which is based on closed-loop operation can track the position angle in real-time and quickly.For different angle position signals input,the measuring performance and position steady error are analyzed theoretically under SRF-PLL decoding algorithm.The simulation results verify the theory analysis in further.(2)The research of the improved decoding algorithms for the amplitude imbalance and non-quadrature phase error of the two output signals are carried outThe angle position calculation impacts brought by amplitude imbalance and non-quadrature phase error of the two output signals are analyzed and two improved decoding algorithms based on error position angle compensation and error signals correction are researched respectively.The principle of the compensation algorithm is simple,but this algorithm is not easy to be realized accurately.The DSRF-PLL decoding algorithm can bring high steady decoding accuracy by correcting error signals firstly.The main modules of the DSRF-PLL decoding algorithm are designed and its effectiveness is verified by simulation.(3)The whole program design and the performance tests of all-digital RDCThe overall scheme of the all-digital RDC is designed based on Infineon XMC4500.The excitation signal generator module,output signals demodulation module and angle position calculation module are designed respectively.The test platform is set up to compare the performance between the special RDC and the designed RDC.Comparative analysis is conducting under steady state and dynamic state respectively in this paper.At last the feasibility and effectivity of the DSRF-PLL decoding algorithm is verified also.