【作者】 卢志强；

【导师】 熊国良；

【作者基本信息】 华东交通大学 ， 载运工具运用工程， 2009， 硕士

【摘要】 桥式起重机作为一种运载工具,广泛应用于各种工业场合。由于起重机自身结构的原因,负载在吊运过程中不可避免产生摆动。以往起重机是由操作者手动控制,一般是等待重物的摆动自然衰减后再进行就位操作,这种消极的消除摆动方式是以降低生产效率为代价的。本文设计了起重机主动防摆控制系统,将防摆和小车的运行控制结合起来考虑,它对起重机快速、安全的运行具有重要意义。对起重机吊重系统的动力学分析是解决起重机快速对位问题的基础。根据起重机物理模型,应用理论力学的基本方法,运用拉格朗日方程建立了起重机吊重系统动力学方程,并在线性简化的基础上得出吊重二自由度摆角模型。本文结合变频调速技术,设计了以S7-200型PLC为核心的起重机防摆控制系统。变频调速技术在起重机中的应用,极大地提高了起重机控制系统的稳定性和可靠性。PLC以可靠性高、使用灵活、维护工作量少等突出优点在工业领域得到了广泛的应用。研究和仿真结果表明,采用常规PID控制方法对桥式起重机吊重防摆进行控制具有一定的局限性。本文应用模糊控制机理,提出了基于模糊控制的起重机防摆控制器。该方法将起重机防摆和定位控制分开设计,采用位置模糊控制器和角度模糊控制器两个控制器实现起重机的准确定位和防摆。降低了运算时间、提高了控制效率。借助MATLAB中的Simulink Fuzzy工具箱对所设计的方案进行仿真分析。结果表明,本文所设计的模糊控制器具有良好的控制性能,在速度和位移的跟踪上优于前者,鲁棒性强,不受外界扰动的影响,是一种较为理想的控制方法。针对模糊控制中存在的位置静差和角度幅值偏大问题,本文进而提出了采用模糊自整定PID控制器来消除位置偏差和改善摆角控制。仿真和实验结果显示该方法可以消除系统静差,减小摆角,缩短系统响应时间,抗干扰能力强。更多还原

【Abstract】 Overhead cranes are widely used in industry for load transfer. As its unique structure, it unavoidably causes swinging as working. Anciently the crane is controlled manually with the manipulator, and the next extent is available before the swing’s complete attenuation unaffectedly. This kind of swing elimination mode costs the efficiency of production. A active anti-swing control system to get the control of both anti-swing and movement of the trolley into account is designed in this paper, and has profound implications to the quick and safe work of crane.Dynamic analysis for the crane-load system is the foundation for solving the problem of the crane’s fast contraposition. Aiming at the crane model, the basic method of theoretic mechanics and Lagrange equation was used to establish the crane-load system’s dynamic equations, and the two-degree-of-freedom angle model was derived based on linear simplification for the system’s dynamic equations.In this paper, a anti-swing control system was designed which was based on S7-200series PLC according to conditions of variable-frequency speed control technology. The application of variable frequency speed control technology enhanced the stability and the reliability of the crane control system enormously.With the high reliability, the use of flexible and low maintenance working, PLC is widely used in industrial areas.The conventional method which is PID control has the shortage in crane anti-swing. In this paper two fuzzy anti-swing controllers were presented by means of the fuzzy control mechanism. Anti-swing and orientation controller was designed respectively. The fuzzy location controller and fuzzy angle controller were used to realize the accurate location and anti-swing. This new method needs little time to compute and gets the high efficiency. And the simulink result shows the good control effect. The fuzzy control effect is better in velocity and position tracking than above one and good robustness when having external disturbance.To eliminate the steady-state error and reduce the angle of amplitude in fuzzy control, a method was presented in this paper. In brief, it is using fuzzy auto-tuing PID controller to eliminate steady-state error and improve swing angle control. The results of simulation and actual experiments show the steady-state error can be eliminated, and response time of system can be shortened, the disturbance rejection ability of system can be strengthened.更多还原