Control In The Copper Automatic Packaging Production Line And Research On Its Weighing System

China is the world's largest consumption country of copper strip. However, the backward copper producing equipments, especially the low level copper packaging mechanization restricted the overall national productivity improvement. In order to make the copper production meets growing market demand, improvements of the copper production packaging technology is needed, so we just developed the automatic packaging production copper line.This paper studies the DeviceNet Fieldbus's application in the copper control system of automatic packaging line, through integrating with the PLC, making the production line control system more simple and the maintenance more convenient. Also, the error source of the weighing system was analyzed, the partial load error was solved by adjusting circuit and dynamic error by error model method. Finally, designed low-pass digital filter by using MATLAB software, ensured the efficiency and the accuracy of the weighing system.The main research works are as follows:(1) Design of the copper automatic packaging production line's overall control scheme: On the basis of the copper packaging production process, using the DeviceNet Fieldbus and PLC integrated way to build copper automatic packaging production line control system and the whole control system can divided into computer control system and field-level control system.(2) Establishment of electronic scale problem model of the weighing system: Because the reasons for station design, there are deviations between the mass center which copper and the rack fell on the weighing platform and the platform's geometric center. Therefore, this paper designed signal conditioning circuit to solve the problem of unbalanced load weighing, ensuring the accuracy of copper weighing within the range of the error allowed.(3) Analysis of weighing system error: This system has three main errors, repeatability error, static error and dynamic error. Among which, the dynamic error accounts for about 95%, so detailed analysis was conducted to it in this paper and using model parameter estimation method to solve it. So that the speed and accuracy of weighing was guaranteed, also weighing efficiency was improved.(4) Digital filter design based on MATLAB: Low-pass digital FIR filter and elliptic low-pass digital IIR filter were designed by FDATool. Results from the simulation analysis, the system finally selected IIR filter as the weighing system.