基于纯硬件电路的轴角-数字解码系统研究

Research on Resolver-to-digital Conversion System Based on Pure Hardware Circuit

针对旋转变压器解码系统需要软硬件协同合作及系统结构复杂的问题,提出了一种基于纯硬件电路的轴角-数字解码系统,主要包括解调模块和解算模块。解调模块基于与激励信号同步的脉冲信号控制采样/保持电路来得到低频的解调信号;为避免使用AD转换、昂贵的压控振荡器等复杂硬件,解算模块采用了负反馈结构,主要基于计数器实现,通过正余弦LUT查找表将计数值转换为旋转变压器角度的线性输出,计数值表示解算角度;当解算角度与实际角度不一致时,解算模块会控制计数值增加或者减少,直到解算角度与实际角度一致。为验证该方法的有效性,在Matlab/Simulink中搭建系统模型进行多工况仿真验证,结果表明,纯硬件解码方法在角度阶跃变化、匀速变化及系统存在噪声时均能稳定正常工作,并且误差不超过0.2°,响应时间不超过2 ms,优于常规软件解码方法。最后进一步制作了验证板卡进行了实物验证,验证结果表明该系统具有较好的稳定性及精度。

A hardware-based resolver-to-digital conversion(RDC) system was proposed to address the challenges of the complex system structure and the need for software-hardware collaboration,which consists of a demodulation module and a decoding module.The demodulation module utilizes a pulse signal control S/H circuit synchronized with the excitation signal to obtain low-frequency demodulated signals.To avoid the complexity of using AD conversion and expensive voltage-controlled oscillators,the decoding module adopts a negative feedback structure primarily based on a counter implementation.It converts the count value into a linear output representing the angle of the rotary transformer through a cosine-sine LUT lookup table.The count value indicates the decoded angle.When the decoded angle does not match the actual angle,the decoding module adjusts the count value incrementally or decrementally until the decoded angle aligns with the actual angle.To validate the effectiveness of the proposed method,a system model was built in Matlab/Simulink for multi-condition simulation verification.The results show that the hardware-based decoding method can operate stably under angle step changes,constant speed variations,and in the presence of system noise,with an error margin not exceeding 0.2° and a response time not exceeding 2 ms,outperforming conventional software decoding methods.Furthermore,a verification board was developed for physical validation,demonstrating that the system exhibits excellent stability and accuracy.