单片机城中社稷

基于单片机的乳粉包装称重控制设计

摘 要

本论文在分析了国内外称重技术发展的基础上，着重对一个用于工业控制且功能较齐全的自动称重系统进行设计。随着自动化和管理现代化的进展，自动在线称重，快速动态称重在整个称重系统中有了很大的发展。因此，进一步采用新技术，开发各种自动称重系统和提高称重的准确度已经成为了多数国家科技发展的重中之重。

本称重系统除了有关于数据的收集，处理，运行和通信之外，还有更多的其他辅助功能：自动称重系统除了能够储存数据资料到资料库中，还可以将资料以打印稿的形式呈现。最重要的是，该自动称重系统还可以随时对资料库进行访问和查询。

本论文所设计的自动称重系统是应用于工业上的乳粉包装自动称重中的，它的实现有两个过程，第一阶段由异步电机带动粗螺旋推进器给料，这一阶段可看成为粗调过程，给料重量一定要小于额定重量。第二阶段由步进电机带动细螺旋推进器进料，可看成是细调过程，使实际重量等于要求的额定重量。

本称重系统采用单片机AT89C51为控制核心，实现称重仪的基本控制功能。系统的硬件部分包括数据采集和数据处理两大部分，其中数据采集部分由称重仪模拟器、信号的前级处理(采用仪表放大器INA121)和 双积分A/D 转换部分组成。由于称重仪设计中电路的精度及抗工频干扰能力要求较高，故选用精度较高的仪表放大器INA121和抗工频干扰能力较强的双积分A/D转换器MC14433。

本系统通过应用传感器，各种芯片及单片机使得该称重系统的实际操作性更强，便于应用于工业上。

双积分A/D转换；仪表放大；AT89C51单片机；数据采集

The Design of Weighing and Packing of Milk Powder ased on Singlechip

Abstract

Basis on the researching of the progress of the weighing technology, this paper introduces the development of automatic weighing system which has a complete function.

With the progress of automation in industry and modernization in management, there is much progress in weighing online, fast and dynamic weighing and system of weighing.Adopting newer technology, developing diversified automatic weighing system, improving accuracy and enhancing network function are emphasized in every country nowadays. .

Besides the function of collecting, processing, displaying and communication of data about weight, the automatic weighing system can also save data in database and print data in report form. It can also visit and query the records in database.

The article introduced the automatic named weighing system which is applied in the industry, its realization has two processes, the first stage is the spiral propeller by the asynchronous machine belt to afford the material, this age which is worthy of looking at is because of the coarse adjustment process,certainly it must be smaller than the schedule weight for the material weight. The second stage is impetus which is much more precise than the first spiral propeller feeding, it may be