一种采用AD2S1210实现LVDT到数字转换方法

An LVDT to digital conversion method based on AD2S1210

通过分析旋转变压器信号与线性差动式位移传感器信号的关系及AD2S1210的转换原理,推导出AD2S1210转换数据与LVDT位置量之间的三角函数关系,设计了一种高精度LVDT信号到数字转换电路。首先由AD2S1210将LVDT信号转换为数字量,再通过FPGA进行数据变换实现LVDT到数字转换。该方法与目前的基于AD698的LVDT转换方法相比,能有效地消除了转换电路中的抖码问题,并且具有外围电路简单、抗干扰能力强等优点。给出了转换电路的设计方法,以及查找表和近似计算两种方式的FPGA代码。实验结果表明设计电路的转换分辨率达到13位,线性度达到0.2‰。

By analyzing the relationship between the resolver signal and LVDT sensor and the AD2S1210 conversion principle,we derived the trigonometric function relationship between the converted data of AD2S1210 and the position of LVDT,and realize a high precision LVDT signal to digital conversion circuit.Firstly,the AD2S1210 is used to convert LVDT signals into digital,next,the LVDT to digital conversion is performed by the triangular transformation through FPGA.Compared with the traditional methods of LVDT signal to digital convert based on AD698.The proposed solution has features of simple hardware circuit,strong anti-interference ability,and can prevent the converter from“flickering”.The complete circuit of LVDT to digital conversion is given in this paper,meanwhile,the methods of lookup table and approximation of AD2S1210 to LVDT data conversion are also presented.The experimental results show that the conversion resolution of the circuit reaches 13 bits and the linearity reaches 0.2‰.