Research On The Digital Controller About The Pressure Of Specimens Of Asphalt Mix

Base on the application of the Superpave asphalt mix design method in the highway project all over the country, the gyratory compactor used for the fabrication speciments of the Superpave asphalt mix has been getting more and more attention.This research is about the design of the digital controller for the gyratory compactor. The main work of the research is the closed loop control of the compression force of the asphalt mix, and completed the followings:First, using the experiments' data and the analysis method, the model of the compression force control system has been built and some simulation has been done. The new control algorithm ,which combines the traditional PID and the fuzzy self-adjusting PID, is proposed, and base on the simulation, the algorithm is verified to be right.Second, the hardware and software of the digital controller are designed. The core CPU is selected as the TMS320LF2407 which is manufactured by the Texas Instruments company in the hardware. The submodule such as impulsing, displaying and compression force controlling are accomplished with the assembly in the software. The effectual measures on anti-interference are taken in hardware and software for the stability and reliability of the system.The value of this paper is to make an attempt at building a mathematical model of the asphalt mix which is nonlinear and time-variation based at the visco-elasticity theory, the value of the parameters are predicted by the experiments and the mathematical model of the compact processing is presented.a control system which is practical and easily implemented is put forward and .it is a good peparation for future research.