Study On The Application Of Fuzzy Control In Aggregate-Weighing System For Asphalt Mixing Plant

The quality of asphalt pavement and the use of performance are closely related to performance of raw materials on asphalt mixture, mixture gradation, construction control and so on. But an important factor is the control of production mix. In addition to the structure of mixing plant, the important impact of asphalt mixture with the ratio of production is the control of weighing accuracy and speed. Therefore, the study on aggregate-weighing system for asphalt mixing equipment is an important issue, with the actual meaning of the project.This paper studied the basic structure and working principle of aggregate-weighing system for asphalt mixing plant, on the basis of which, it analyzed the control of weighing accuracy and speed for aggregate-weighing system. Weighing system as a transient non-linear system, was equivalent to second-order system; then, we derived mathematical model of the weighing process; the issue was transformed into a question of dynamic weighing. Through the experimental analysis of the system, system output is an oscillation process, so the system should be corrected. But the general method of correction couldn't apply to the system; in order to achieve dynamic correction, it putted forward tracking compensation; so that the weighing system always keep the best second-order system and the signals came true.For the problems in weighing system of the general mixing equipment, and on the basis of the analysis for fuzzy and PID control theory, this paper putted forward a strategy that fuzzy and PID control leaded into weighing system; it made a certain amount of exploration of PID parameter self-adjusting fuzzy controller and designed fuzzy controller through the MATLAB simulation software. Finally, the weighing system was be simulated using the MATLAB simulation software; through comparison of simulating PID control system and PID parameter self-adjusting fuzzy control system, we found that system dynamic characteristics and stability of performance could be improved, if PID parameter self-adjusting fuzzy controller was joined to the weighing system. The use of this method can effectively control the dual-solenoid valve and greatly enhance the accuracy of the weighing system.