【作者】 芮光六；

【导师】 董艳秋；

【作者基本信息】 天津大学 ， 船舶与海洋结构物设计制造， 2004， 硕士

【摘要】 起重船不仅是港口船舶装卸的重要工具,而且在港建水工作业、造船工程、桥梁建筑、水下救捞以及各种海洋工程中均具有广泛的用途。起重船在起吊货物时,海上波浪的作用会引起船体的运动,导致吊物的摆动加大,给起吊操作带来危险,有时被迫中止起吊作业。本文研究起重船上的吊杆起重机工作时,吊物的摆动分析及其控制。利用延时定位反馈的概念来开发出一种新的控制系统,减小起重船上吊物的摆动,使得本来不能进行起吊作业的海况下可以进行货物的起吊与运送。1.起重船作业时,船体因受到海浪作用而发生的运动与吊物的运动相互耦合,这使得研究吊物系统的动力问题复杂化。本文忽略了吊物运动对船体的影响,假定吊杆上的吊物点P处由于船体运动而产生的运动为已知,并将它们作为对吊物系统的基础激励。本文重点是将吊物系统简化为球摆模型,推导了平面内、平面外的耦合非线性运动方程组。研究吊点激励对该系统产生的最危险的情况(称极端情况)的存在以及吊物系统的动力响应,并进行了分析讨论,得出非常有益的结论。2.研究延时定位反馈控制理论,明确其原理,同时讨论了它的稳定区域;并提出将这种控制方法用在起重船吊物摆动的控制上。3.根据延时定位反馈控制器的要求,结合起重船吊物摆动的特点,设计了延时定位反馈控制器。4.为了验证延时定位反馈控制器的可行性,本文以T-ACS起重船为例进行了计算机模拟。结果表明,设计合理的延时定位控制器,可以明显的减小吊物的摆动幅度。本文通过对起重船吊物系统的动力分析,给出了吊物摆动角的非线性方程组。为了减小吊物的摆动,研究了延迟定位反馈控制方法,成功地设计了一种控制器。模拟结果表明,吊物的摆动可以得到明显地控制,因此这种控制方法,一旦制成系列的延迟控制器应用到起重作业工程实际中,将可以带来很大的经济效益。更多还原

【Abstract】 Crane ships are not only the important tools to transfer cargos from ships to ships,but also of great use in building ports, shipbuilding engineerings, building bridges,rescuing work underwater and other kinds of ocean engineerings. The wave-inducedmotion of the crane ship produces large pendulation of hoisted cargo and causesoperation to be suspended.This work is to study the pendulation of hoisted cargo and design the controlsystem.The objective of this work is to use the concept of delayed-position feedbackto develop a control system to reduce pendulation of hoisted cargo on ship-mountedcranes to such an extent that cargo transfer could take place in sea states where theseoperations are now not possible.1. The wave-induced motion of the crane ship coupled with the motion of hoistedcargo, which makes it too complicated to analyze the dynamics of hoisted payload.Regardless of its impact on ship, this work assumes the motion of suspension pointknown and regards it as the base excitation. Firstly, the cable-payload assembly ismodeled as a spherical pendulum. Then we derive nonlinear equations set, within-plane motion coupled with out-plane motion. Consequently, we research theprobability that base excitation results in most critical scenario and the dynamicresponse. Finally, we get a positive conclusion.2. This work introduces the delayed-position feedback, and analyzes the stabilityof the response. Consequently, we apply the method to the cable-payload assembly toreduce the pendulation of cargo.3. According to the delayed-position feedback, a controller is developed underthe demand of the pendulation of cargo.4. To verify the effectiveness of the controller, numerical simulation based onT-ACS is given. The result demonstrates that the amplitude can be significantlyreduced in the controlled system.In this work, we get the nonlinear equations set after dynamic analysis ofcable-payload system. In order to reduce the pendulation, we develop a successfulcontrol strategy based on delayed-position feedback. The simulation resultsdemonstrate that the pendulation can be significantly reduced. Therefore, the strategyis of great use in engineering if it’ll be put into practice.更多还原