【作者】 左岗永；

【导师】 杨国来；

【作者基本信息】 兰州理工大学 ， 机械电子工程， 2011， 硕士

【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。更多还原

【Abstract】 Water hydraulic technology is an important research direction in the field of fluid transmission.It meets the requirements of energy-saving,environmental protection and sustainable development.It has a broad prospect of application.The synchronous control of water hydraulic parallel cylinders is an important application field of water hydraulic system.It has many advantages such as simple structure, non-pollution medium ,green and environmental protection, antiflaming, etc.It has been widely used in the environment of higher requirements such as food and medicine, with the development of science and technology, the application filds of Water hydraulic technology will be more and more widely .Combining the global development status of water hydraulic technology and synchronous control system, the operation process of the master-slave mode synchronous position control of water hydraulic parallel cylinders has unsatisfactory synchronous control results.Water hydraulic system and oil hydraulic system are compared.the different synchronous control mode are analyzed.the synchronous control strategys are researched. The main works of this thesis include:The mathematical model of the master-slave mode synchronous position control of water hydraulic parallel cylinders is established, especially the mathematical model of water hydraulic proportion flow valves and water hydraulic cylinder.the stability and dynamic performance of system are analysed.The influence of load to the natural frequency and damping of cylinder and the whole control system are researched.For the dynamic function of the system is not ideal, conventional PID controller is designed to rectify the system, and the proportional degrees meathod is used to set conventional PID parameters. Because the system exists factors such as time-varying and nonlinear, PID controller is hard to adapt to the changes of system parameters, the results of control is not ideal. Fuzzy self-tuning PID controller is designed to realize PID parameters online adjustment, small overshoots,fast response time, and the displacement of the two water hydraulic cylinders follows well, two cylinders synchronous displacement difference value is small,the control effect are superior to the conventional PID control.Lastly the controller based on the BP neural network fuzzy PID control technology is proposed.It combined the fuzzy control and neural network control. the control effect such as response time, overshoots and steady precision are superior to the fuzzy self-tuning PID control.更多还原