水压双缸同步系统模糊PID控制的研究

发布时间：2018-02-01 04:21

本文关键词： 水压技术同步控制 PID 模糊控制神经网络　出处：《兰州理工大学》2011年硕士论文　论文类型：学位论文

【摘要】：水压技术是流体传动领域的重要研究方向,符合节能、环保、可持续发展的要求,具有很广泛的应用前景。水压双缸同步控制是水压系统中的重要应用领域之一,具有结构简单,介质无污染,绿色环保,阻燃等优点,已在食品、医药等对环境要求较高的场合有着广泛的运用,并且随着科学技术的不断发展,水压技术的应用领域也会越来越广。结合国内外水压技术和同步控制系统的发展现状,针对主从式水压双缸同步控制系统在运行过程中存在同步效果不理想的问题,对比了水压系统与油压系统的特点和难点;分析了不同同步控制元件的特点和不同同步控制结构的同步误差;研究了同步控制策略。重点做了如下研究: 建立主从式水压双缸同步控制系统的数学模型,重点是水压比例流量阀和水压缸的数学模型,对系统进行稳定性和动态性能的分析,并研究负载对水压缸固有频率和阻尼比以及整个控制系统的影响。针对系统的动态性能不理想,一般设计常规PID控制器对系统进行校正,并采用临界比例度法对PID参数进行整定。但是由于系统存在时变,非线性等因素,常规PID控制很难适应系统参数变化,控制效果不是很理想。设计模糊自整定PID控制器实现PID控制器参数的在线调整,超调量小,快速性好,并且两水压缸的位移跟随情况较好,两缸同步位移差值较小,控制效果明显优于常规PID控制。最后提出了基于BP神经网络模糊PID控制技术,将模糊控制与神经网络控制结合起来,实现控制器的在线自学习功能,其响应时间,超调量,稳态精度等综合控制效果优于模糊自整定PID控制,能更好的提高同步控制效果,可以使水压双缸同步系统实现高精度的同步跟随。
[Abstract]:Hydraulic technology is an important research direction in the field of fluid transmission, which meets the requirements of energy saving, environmental protection and sustainable development. Water pressure dual cylinder synchronous control is one of the important application fields in water pressure system. It has many advantages such as simple structure, no pollution of medium, green environment, flame retardant and so on. With the development of science and technology, the application of water pressure technology will be more and more extensive. Combined with the development of water pressure technology and synchronous control system at home and abroad, there is a problem that the synchronization effect is not ideal in the operation process of the master and slave water pressure double cylinder synchronous control system. The characteristics and difficulties of water pressure system and oil pressure system are compared. The characteristics of different synchronous control elements and the synchronization errors of different synchronous control structures are analyzed. The synchronization control strategy is studied. The mathematical model of the master-slave hydraulic double cylinder synchronous control system is established. The emphasis is on the mathematical model of the hydraulic proportional flow valve and the hydraulic cylinder. The stability and dynamic performance of the system are analyzed. The influence of load on the natural frequency and damping ratio of hydraulic cylinder and the whole control system is studied. In view of the unsatisfactory dynamic performance of the system, a conventional PID controller is generally designed to correct the system, and the critical ratio method is used to adjust the PID parameters. However, because of the time-varying of the system. Nonlinear factors such as conventional PID control is difficult to adapt to the system parameters change the control effect is not very ideal design of fuzzy self-tuning PID controller to achieve on-line adjustment of PID controller parameters small overshoot. The speed is good, and the displacement of the two hydraulic cylinders follows better, and the displacement difference between the two cylinders is small. The control effect is obviously superior to the conventional PID control. Finally, the fuzzy PID control technology based on BP neural network is proposed, which combines the fuzzy control with the neural network control to realize the on-line self-learning function of the controller. The response time, overshoot, steady-state precision and so on are better than fuzzy self-tuning PID control, which can improve the synchronous control effect better, and make the water pressure double-cylinder synchronous system achieve high-precision synchronous follow.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137

【引证文献】