刘明明+刘志红

摘 要： 提出以激光循迹小型PLC为基础的有轨小车运输方式提升效率，并对有轨小车实现高精度控制设计。利用激光发射器射出的光线对不同物体呈现不同颜色的特点，将收集的高低电平导入PLC系统中，对高低电平开关量编码，建立包括步进电动机模型、传动机构模型和小车转向系统闭环状态空间模型的小车寻线模型，并建立以PLC系统为基础结合PID控制器完成GPC?PID控制系统，利用该系统及时调控小车动态过程，根据动态性能变化完成控制器参数的重新调整与设定，通过GPC算法调整该系统目标函数的增量，确保小型PLC有轨小车寻线轨迹的精确度。实验证明，利用该方法可有效地确保基于小型PLC有轨小车寻线的精度。

关键词： 激光循迹； 有轨小车； 寻线； 高精度控制； 数学模型

中图分类号： TN911.1?34； TP391 文献标识码： A 文章编号： 1004?373X（2017）13?0144?04

Abstract： The rail guided vehicle transport mode based on laser tracking small PLC is put forward to improve its transport efficiency. The high?precision control design of the rail guided car is realized. By means of the characteristics that the laser rays send by laser generation appear different colors for different objects， the collected high?low level is input into the PLC system， and its switching value is coded. The stepping motor model， transmission mechanism model and vehicle line tracking model of the closed?loop vehicle steering system space state model were established. The GPC?PID control system combined PLC system with PID controller was established to control the vehicle dynamic process timely. The controller parameters are readjusted and set according to the change of dynamic performance. The increment of the system objective function is adjusted by means of GPC algorithm to ensure the accuracy of the rail guided vehicle line tracking based on small PLC. The experimental results show that the designed method can ensure the precision of the rail guided vehicle line tracking based on small PLC effectively.

Keywords： laser tracking； rail guided vehicle； line tracking； high?precision control； mathematical model

0 引 言

文献[1]中提到在经济迅猛发展的今天，我国工业化水平也获得了极大提升，同时也存在一些制约发展的因素显现出来。对于企业而言，日趋复杂的工艺、产量激增导致仓储成本上升以及人口老龄化引起的人力成本提高等众多因素影响，都迫使企业不断提升生产过程中的自动化水平和劳动生产率[2?3]。作为协调生产的重要环节，文献[4]提到工厂运输效率对生产成本以及生产效率的提高有直接影响。因传统物流模式已不能适应现今各行业的生产与发展，所以需要用一种新的全方位、全自动化的物流系统来替代传统物流运输系统[5?7]。……