混凝土搅拌过程的辨识和自适应控制

本文针对国内混凝土搅拌设备提出一种自适应控制方案.首先根据手工操作的运行数据,离线辨识搅拌过程的数学模型,决定模型结构和其中的不变参数.然后在线辨识模型中的变化参数,根据在线辨识参数,预报混凝土终点调度的概率分布,由此决定应加的控制.具体控制过程分两步:先粗调,当终点稠度到达目标区的概率足够大时,暂停加水.待参数辨识足够准确后,再进行精调,确定最后的补加水量,以保证终点稠度以95%以上的概率落入目标区,而且达到目标值的概率最大.仿真结果说明本方案可以获得较好的控制效果.

IDENTIFICATION AND ADAPTIVE CONTROL OF THE CONCRETE MIXING PROCESS

In this paper, a method of adaptive control applied to a China -made concrete mixer is presented. Firstly, a mathematical model is determined by off -line identification making use of the date messed from manual control to determine the model structure and the deterministic parameters. Then, the on -line identification is performed in order to determine the rest parameters. According to the parameters determined by the om -line identification, the probability distribution of the final consistency of the fresh concrete is predicted. Finally, the necessary control action of determined from the prediction. The control process consists of two steps. First, a coarse regulation is adopted. The water supply is ceased when the probability of the final consistency which enters into the target region is large enough. Then, a fine regulation follows. The amount of final additional water is determined when the estimated parameters are precisely enough. This ensurs that the probability of the final consistency which is inside the target region is higher the 95 percent, and the probability of the final consistency which reached the target value is maximal. Simulation shows a good control performance can be achieved by the method suggested in this paper.