基于DSP的电子天平称重单元设计

摘要

设计一种以DSP微处理器TMS320VC5502为信息处理核心的高精度电子天平称重单元.简述了电子天平的称重测量原理,给出了基于DSP的数据采集电路.采用加权递推平均滤波算法,保证测量的准确度和稳定性;建立了适合于称重数据变化判断的多级阈值判别方法,提高了电子天平的响应速度.实验表明:采用该方法的电子天平称重单元稳定性好、灵敏度高,满足了量程为210g、精度为0.1mg的电子天平设计要求,且最大允许误差不大于0.3 mg.%A high-precision weighing unit of electronic balance is designed by using DSP TMS320 VC5502 for information processing. The weighing measurement principle of electronic balance is introduced and a data acquisition circuit based on DSP is given. The weighted recursive average filtering algorithm is adopted to guarantee measurement accuracy and stability. A multiple-level threshold discrimination algorithm is set up for judging change of weighting data, and the response time to the weight changes is improved. The weighing unit of electronic balance with this method has been proved to be steady and sensitive. It meets the design requirements.The range is 210 g,the precision is 0.1 mg,and the maximum permissible error(MPE) is less than 0.3 mg.