函数拟合法力数字传感器的非线性和温度补偿

针对力数字传感器存在的分散性、非线性和温度特性问题,通过软件进行补偿.分析了力数字传感器的非线性特性,采用三次样条插值获得被测重力和输出频率的函数关系,将测量得到的输出频率通过三次样条插值计算得到被测重力.对于力数字传感器的温度特性,建立了分段三次插值函数,利用反函数得到不同温度下输出频率与被测重力的函数关系.将温度和频率量作为自变量,通过分段三次插值函数计算得到被测重力.函数拟合法实现力数字传感器的非线性和温度补偿使所需数据量减少.实测表明:该方法的测量精度高,非线性和温度补偿后的最大引用误差为0. 5%,满足实际工程的需要.

Function fitting method for non-linear and temperature compensation of force digital sensor

Aiming at problems of dispersion,nonlinear and temperature characteristics of force digital sensor, software is used to compensate. The nonlinear characteristics of force digital sensor are analyzed. Function relationship between gravity and output frequency is obtained by cubic spline interpolation,the measured output frequency is used to calculate the measured gravity. Temperature characteristics of force digital sensor piecewise cubic interpolation function is established,and function relationship between output frequency and measured gravity at different temperatures is obtained by inverse function. The temperature and frequency is used as independent variable,measured gravities is obtained by calculating piecewise cubic interpolation function. This method greatly reduces amount of data needed. Experimental results show that the measurement precision of this method is higher,the maximum reference error is 5 ‰after non-linear and temperature compensation,which meets the needs of practical engineering.