Design And Implementation Of Dosing Machine Control System Based On Fieldbus

The progress of the floatation technology plays an important role in development of mineral processing technology, especially in quality improvement and impurity reduction. During the flotation process, both effective measurement and additional quantity of flotation agent are necessary. How to measure and control the amount of flotation agent exactly is the key point of the whole automatic control system. The dosing machine studied in this paper could complete measurement and the control in the amount of flotation agent accurately.In this paper, our dosing machine employs stepping motor to drive dosing pump as the drug-feeding equipment, which can put in certain kind of agent by timing and quantitative. We utilize the modular design and then develop the control system of dosing machine with C8051F920high performance microcontroller as the kernel controller based on fieldbus. It improves the presicion of measurement and the control in the quantity of dosing.Firstly, we analyse the existing situation of dosing machines at home and abroad in this paper, and the design scheme in the control system of the dosing machine is proposed, according to the background of application, and a comprehensive introduction of methods and features in this design method and fuctions are given.Secondly, during designing the control system of the dosing machine, we mainly devise a parameter control module, CANBUS communication sub-system, upper computer display module, and stepping motor driven controller module. This paper specifically introduces the design ideas and working principles of each modular, and also completes the software design according to the hardware principle diagram and practical requirements of the system. Moreover, quite a few of debugging of software and hardware as well as many data tests are maked. Furtherly, the issues in the design are resolved properly.Finally, as to the dosage adjustment, which is the core of dosing machine control system, the better control effect can not be obtained by utilizing the tradional PID controller purely when we control the amount of the dosing. Thus, in order to improve the control effect and accuracy of the system, the Fuzzy PID controller is employed, and in accordance with fuzzy control principle and the features of MCU, FUZZY-PID controller is designed. What’s more, this paper describes its working principle and designing procedure, and proposes the implementation method of fuzzy control applying in MCU, e.g., C8051F. Referring to CANBUS communication and data acquisition technology, we design the information exchange format fit to the background standard, carrying out the communication between the control modular and upper computer diplay modular, collection and control of paremeters in the control modular, and finally realize the requirement in controlling the dosing quantity much more accurately.