Design Of Dynamic Weighing Control System Based On SOPC Technology

During producing the the chemical, cement, food, feed and other industries, they need quantify packing the product. Now, the design of quantitative control system commonly use SCM as the core of micro controller. However, the low handling capacity SCM can not meet fully the design requirement. Later, the controller with DSP core appears, although the processing power of DSP can meet demands, but because of this traditional design, the quantitative weighing control system, designed with the structure and function fixed, will be lack of flexibility. On the other hand, this paper generally use the way of the air of compensation for weighing control. In order to meet the requirement of accuracy expected, value gap was used for compensating imprecision which was caused by outside interference and machine inertia and so on. However, this paper adjust the expected value gap after putting materials. The process of putting materials is irreversible, value gap is a value which will be correct next time. It is difficult to enhance accuracy.The purpose of this project is using Altera's SOPC solutions, developing the quantitative weighing controller for the powder products. It is based on a dual-core structure of Nios II, one Nios II processor is dedicated to high-speed data acquisition and processing, another Nios II complete communication with PC processor. The FIR digital filter filtering algorithm which is high reliability stability,flexibility,and can be applied to low frequency signal filters the signal from data acquisition. The paper adopts Verilog HDL to achieve LCD controller and FIR digital filter by means of the features of custom peripheral of Quartus II and arbitration mechanism of Avalon bus. This way make this system minimal, so, it can cut under outside wide disturb. Then, this paper study the process of weighing the quantitative object in a dynamic situation in-depth, the author sets up a mathematical mode of weighing the quantitative object in a dynamic situation. On the basis of analysing the dynamic process of weighing, author proposed the way of predictive control. Thus, it effectively increases weighing accuracy.Compared with traditional embedded system solution, this issue adopted by the SOPC system solutions to shorten the development cycle, reduce the number of devices, and improve system performance. The system is easy to achieve, easy to upgrade, easy to transplant, and has strong adaptability and scalability.