【作者】 赵昊阳；

【导师】 季天晶；

【作者基本信息】 哈尔滨工业大学 ， 流体机械及工程， 2010， 硕士

【摘要】 近年来,随着海洋运输船舶的大型化、高度自动化及高速化,新型船舶液压自动舵要求具有高可靠性、高耐久性、高精度以及适应于舵叶负荷的转矩特性,从而能够广泛地应用在5万吨到100万吨的商船以及军用舰艇。自动舵机的基本元部件包括电气元件、机械元件以及液压元件等。其中,电液伺服单元是其“心脏”元件,它将电信号转换成机械信号并进行液压放大,进而实现反馈控制,执行控制规律,并且直接关系到整个自动装置控制的各种性能。因此,电液伺服单元对舵机控制精度及稳定性有着至关重要的影响,是典型的机电液一体化高科技产品。在以往的试验研究中发现电液伺服单元存在零位振荡和差动缸左右行程输出不对称的现象,同时其在跟踪性、稳定性和快速性上存在着一定的问题。本文仔细讨论了电液伺服单元各个组成环节的工作原理,并对存在影响系统的干扰因素及误差进行了详尽分析后,建立了系统的非线性数学模型,得到了零位振荡的产生机理,通过比较仿真曲线、试验曲线验证了数学模型的正确性。针对上述问题,在查阅了大量的国内外文献资料的基础上,并结合电液伺服单元自身的特点和工程实际要求,确定了相应的二次型性能指标的最优控制器控制策略。为了解决仿真和试验过程中发现的问题,在有无干扰两种情况下进行了仿真。其结果表明,最优控制器解决了零位振荡和差动缸左右行程不对称问题。采用其代替常规PID控制使电液伺服单元的快速性、稳定性和跟踪性得到了明显提高,且有较强的自适应能力和鲁棒性。更多还原

【Abstract】 In recent years, with the development of constantly large-scale, high automation, high-speed, environmental protection and safety in the ocean shipping, new ship hydraulic autopilots with high reliability, high durability, high precision and adapted to the rudder blade load torque characteristics, are widely used in 5 tons to 100 tons of merchant ships and military.Automatic steering gear is the basic components which contain electrical components, mechanical components, and hydraulic components. Electric-hydraulic servo unit is autopilot’s "heart" components, which is put signals converts mechanical and hydraulic amplifier, signal and implement feedback control, realize the control rule, direct relation of the automatic control device for the whole performance, and has important influence on control accuracy and stability, is typical of the electromechanical integration of high-tech products.The previous test study of electro-hydraulic servo unit possessed zero oscillation and the asymmetric output trip phenomenon of differential cylinder, and there also possessed some problems in its tracking, stability and quickness. This paper has discussed the working principle of electro-hydraulic servo unit’s each component part carefully, especially analyzed the interference factors of system and the error with detail, then set up a nonlinear mathematic model, and obtained the zero oscillation mechanism, finally proved the correctness of the mathematical model validation through comparing the simulation curves and test curves.In view of the above questions in a lot of domestic and foreign literature material, and on the basis of electro-hydraulic servo unit itself characteristic and actual requirements, this paper has ensured the corresponding quadratic performance indexes of the optimal control strategy.In order to solve the problems found in the experiment and simulation process, this paper has simulated in two kinds of situation without outside interference and interference. Simulation results show that the optimal controller to have solved main problems of the zero oscillation and differential cylinder around asymmetric trip. Using the optimal control instead of conventional PID control has greatly improved in the speed and stability and tracking of displacement output of piston rod, and a stronger adaptive ability and robustness.更多还原