FPGA实现旋转变压器R2D变换方法的研究

旋转变压器到数字信号转换的过程称之为R2D变换,也可称之为解码。实现R2D有专用的解码芯片,但实际使用中发现解码芯片很难通过电磁兼容实验,尝试采用软件的方式来实现。软件实现关键是对反三角函数的求解,经典方法是采用CORDIC算法实现,CORDIC在求解超越函数有一定的优越性,流水线结构更是可以满足高速运算,因此应用较为广泛。但解码方法是多样的,还同时介绍了一种角度跟随实现解码的方法,该方法通过构建反馈模型实现角度的逐渐逼近,最终实现解码。这两种方法都很容易在FPGA内实现,仿真分析表明它们的精度都能够满足需求,适合于大多数应用场合。

Research of resolver-to-digital conversion method in FPGA

The process of resolver to digital conversion is called R2D transform,also known as decoding.Achieving R2D has special chip decoder,but it’s difficult to pass the EMC test when the chip decoder is used.So the software R2D conversion method was used to replace the chip decoder.The key was the solution of inverse trigonometric functions in the software,while the CORDIC algorithm could do it.CORDIC had some advantages in the solution of beyond function.It could also get a higher speed while using the pipeline structure.Because of this,it had a wide application range.However,decoding methods were diverse,and an angle tracking method for decoding was also introduced in this paper.It could achieve decoding by constructing the feedback model of the gradual approximation of the angle.Both methods were easy to achieve in the FPGA,and the simulation analysis shows that their accuracy can meet the demand,suitable for most applications.