基于最小二乘法的电子计数秤设计及偏差处理

Design and Error Processing of the Electronic Counting Scale Based on Least Square Method

电子产品生产所需物料种类多数量大,人工计数降低了生产效率,设计电子计数秤,通过对物料进行测量直接显示个数,有利于提高生产效率。基于STM32和HX711模块及平行梁应变式称重传感器的电子计数秤,存在传感器分辨率限制、测量和转换误差及噪声等问题,造成测量偏差。针对此问题,首先对采样二进制值进行滤波,提高数据稳定性;然后利用均值滤波算法进一步降噪,减小噪声的影响;采用最小二次乘法建立一次函数线性模型,实现采样值与重量的转换。通过实验验证,将重量误差控制在±1 g,个数偏差1%,能满足生产所需。

The production of electronic products requires a large variety of materials,and manual counting reduces the production efficiency.The electronic counting scale is designed to directly display the number by measuring the materials,and it is beneficial to improve the production efficiency.The electronic counting scale based on STM32 and HX711 module and parallel beam strain weighing sensor has problems such as sensor resolution limitations,measurement and conversion errors,and noise,which will cause measurement deviation.Aiming at the problems,this paper firstly filters the sampled binary value to improve the data stability,then uses the mean filter algorithm to further reduce noise and minimize the impact of noise.It uses the least square method to establish a linear model of the linear function to realize the conversion of sampled value and weight.Through experimental verification,the weight error is controlled within±1 g,and the number deviation is 1%,which can meet the needs of production.