基于三次多项式的磁弹性传感器非线性误差修正

Nonlinear Error Correction of Magnetoelastic Sensor Based on Cubic Polynomial

磁弹性传感器输出信号大,具有较高的过载能力,非常适合用于测量金属板材的轧制力和桥梁支撑柱的压力。理论上,传感器输入和输出之间是线性关系;但实际上,传感器的输入输出特性都是非线性的。非线性误差是传感器的关键指标,直接决定产品的定级。对于重复性好和回差小的传感器,可以用三次多项式修正降低其非线性误差,以提高产品等级。通过400 t磁弹性传感器在标准测力机上进行的测力试验,验证了非线性误差修正方法的可行性,将传感器的非线性误差从2.75%减小到了0.35%,大大降低了非线性误差,且修正方法简单实用,使用单片机的仪表在现场即可进行数据修正操作。对于电阻应变式传感器和其他线性仪表,此方法同样适用。

Magnetoelastic sensor has large output signal and high overload capacity,which is very suitable for measuring the rolling force of metal sheet and the pressure of bridge support column.Theoretically’there is a linear correspondence between the input and output of the sensor,but in fact,the input-output characteristics of the sensor are nonlinear.The nonlinear error is the key index of the sensor,which directly determines the grade of the product.For the sensor with good repeatability and small return error,the cubic polynomial can be used to reduce the nonlinear error and improve the grade of the product.By load test of 400 t magnetoelastic sensor in the standard dynamometer,the feasibility of nonlinear error correction method is verified.The nonlinear error is greatly reduced,as the nonlinear error of the sensor is lowered from 2.75%down to 0.35%,and correction method is simple and practical,easy to correct the data using the instrument with single chip,right at the scene.This method is also applicable to the resistance strain sensor and other types of linear instruments.