一种带电压波动动态补偿的称重系统研究

Study on a weighing system based on dynamic supply voltage fluctuation compensation

为了消除称重传感器外部电源电压波动对称量不确定度造成的影响,对称重系统电压波动的检测和补偿方法进行了研究,分析了电阻应变片的应变效应和惠斯通电桥的测量原理,给出了称重传感器输出电压与外部电源电压之间的修正关系,提出了一种通过同步检测输出电压和外部电源电压信号动态补偿电压波动的方法,设计了基于数字信号处理器TMS320F28335以及模数转换芯片ADS1234的称重系统对所提出的方法进行了验证。研究结果表明,在外部电源电压的波动范围内,补偿后称量结果的相对误差始终小于1%,说明该方法能够用于有效提高称重系统的称量精度。

In order to eliminate the weighing errors caused by external supply voltage fluctuation of the weighing sensor,the method for detecting and compensating the voltage fluctuation of the weighing system was focused on.The strain effect of strain gauge and the measurement principle of the Wheatstone bridge were analyzed.Then the correcting relationship between the output voltage signal and external supply voltage signal was given.A dynamic voltage fluctuation compensation method by synchronously sampling output voltage and supply voltage was proposed subsequently.A weighing system based on digital signal processor TMS320F28335 and analog-digital conversion chip ADS1234 was designed to examine the proposed method.The results indicate that the weighing errors of the compensated weighing system are lower than 1％ within the fluctuation range of the external supply voltage,which verifies that this method is feasible for improving the weighing accuracy.