沥青搅拌站在公路建设中起着非常重要的作用，目前采用的沥青搅拌站分为间歇式和连续式两种，连续式沥青搅拌站较间歇式相比有很多优势，但是传统的连续式沥青搅拌站物料计量采用容积法，计量误差较大。 本课题研究连续滚筒式沥青搅拌站，在了解连续滚筒式沥青搅拌站发展过程、设备结构以及工艺要求的基础上，设计了其控制系统，包括PLC控制系统设计和监控系统设计。针对传统的计量方法的缺陷，本设计提出了采用比值控制对骨料级配比、石粉比以及油石比配比进行自动控制，并应用混合过程PID调节。 根据控制要求选型，本设计采用西门子S7-200PLC，在S7-200编译环境STEP7-Micro/WIN4.0 SP6下，进行了PLC软件的设计与调试，实现了系统所需要的控制功能。上位机监控系统用组态软件WinCC实现，可通过上位机向PLC发出控制命令，同时还可将现场的各种数据通过PLC传送给上位机，在上位机界面上用图形显示出来，实现对生产过程的实时监控。WinCC与PLC的通信通过PPI协议实现。 经过Matlab仿真结果可知，双闭环比值控制和混合过程PID算法的应用，能够有效地提高沥青混合料计量配比的准确性，大大地提高了沥青成品料的生产质量，具有很大的实用价值，对连续滚筒式沥青搅拌行业的发展和公路建设有重要意义。

It plays an important role of asphalt agitated plant in highway construction. Asphalt agitated plant used currently is divided into batch and continuous type. It has many advantages of continuous asphalt agitated plant compared to batch type. However, volumetric method is used in the material measurement of traditional continuous asphalt agitated plant, and the measuring error is very large. It is researched Continuous Drum Asphalt Agitated Plant in the paper. And the control system included PLC control system and monitored control system is designed on the base of understanding its development, equipment structure and technical requirements. For the defect of traditional measuring method, it is advanced using ratio control to control the ratios of aggregate, powder and asphalt automatically, and mixing process PID algorithm is used. According to the control requirement, it is used Siemens S7-200PLC in the design. In the compiling environment STEP7-Micro/WIN4.0 SP6, the PLC software is designed and debugged, and the functions of the system are realized. It is used WinCC to realize monitored control system. Control order to PLC can be issued by PC, and various of field data can be passed to PC and displayed in PC to realize the real-time monitoring of production process by PLC. The Communication of WinCC and PLC can be realized by PPI protocol. Through the result of Matlab simulation, we can see it is effectively improved the accuracy of mixture and production quality due to the application of double closed loop ratio control and mixing process PID algorithm. It has great practical value.