移动小车运动分析、模糊优化及仿真

【作者】 宋东峰；

【导师】 冯刚；

【作者基本信息】 大连理工大学 ， 机械制造及自动化， 2004， 硕士

【摘要】 本文首先详细调查了国内外卸船机使用情况。由于桥式卸船机在卸货中存在抓斗摆动现象，影响生产效率，因此，本文针对卸船机移动小车和抓斗的运动全过程进行了详细研究，把小车运行分为抓斗静止卸货和抓斗摆动卸货两种类型，针对每种类型，建立了运动模型，列出了运动方程，进行了优化计算，达到既消除抓斗摆动又缩短卸货时间、提高生产效率的目的。 本文详细介绍了求解小车运动模型的模糊优化方法，由于目标函数和约束条件的位置不可互换，因此本文小车运动模型属于非对称模糊优化问题。本文给出了最优水平值和容差的确定方法，阐述了通过选取最优水平值和容差把模糊优化问题转化为常规优化问题的详细解法；还介绍了软件编程中用来求解约束非线性规划算法的混和惩罚函数法，它是解约束优化问题的一种非常有效的方法。在用混合惩罚函数法把约束非线性优化问题转变为无约束优化问题后，所采用的算法是BFGS变尺度法，它是公认进行无约束优化最好的方法。在BFGS变尺度算法中所用的一维搜索方法是二次插值算法。 本文最后编制了软件对小车运动模型进行求解，绘制移动小车速度、加速度图，并对移动小车进行了动态仿真，操作人员只要输入工作条件就可以得到各阶段的加速度值、速度值和时间长短，不但能实现自动卸货，而且降低了对工人的技术要求，更重要的是，通过系统优化缩短了卸货时间、提高了生产率，显示出了模糊优化的优越性和采用模糊优化的必要性。从计算结果还可以看出，在条件允许情况下，采取抓斗摆动卸货方式能比抓斗静止卸货缩短卸货时间、提高生产效率。 　此外，本文首次提出了等式的模糊化方法，拓展了模糊优化的理论范围，对学术研究具有很大意义。更多还原

【Abstract】 The application of ship-unloaders is investigated in detail in this dissertation. The grab of bridge ship-unloader sways during unloading bulk cargoes, and this hampers its productivity, so in order to prevent the grab’s swaying and reduce the unloading time, the whole process of moving trolley and grab is analyzed at length in this dissertation. The state of the moving trolley is divided into two categories: the stationary unloading state and the asway unloading state. For each category, models are made, moving functions are drawn, and results are got.This dissertation discusses in detail the fuzzy optimization method of solving the model of moving trolley, and the model of moving trolley belongs to the unsymmetrical fuzzy optimization one. Methods of determining the optimal level value and tolerance are discussed. The fuzzy optimization problem is changed into a routine optimization problem by selecting a suitable optimal level value and tolerance. Hybrid SUMT (Sequential Unconstrained Minimization Technique) is used in this dissertation, and it is a very useful method in solving problems of constrained optimization. Variable metric method of BFGS is used to solve the problem of unconstrained optimization when a constrained one turns into an unconstrained one by using hybrid SUMT, and it is recognized as the best arithmetic for solving unconstrained optimization problems. The one dimension search method of second differential algorithm is used in the Variable metric method of BFGS.At the end of this dissertation, software is programmed to solve the problem of constrained nonlinear optimization, to draw chart of acceleration and velocity, and to simulate the whole moving process of the trolley and grab. The calculation results of acceleration, velocity, and time of every part of the moving trolley are easily obtained and workers only input the parameters of working condition, they will get the results. This not only makes it very easy to realize automatic unloading, but also reduces technical requirements for workers. Most important of all, it reduces unloading time and raises the productivity distinctly. So the advantages of fuzzy optimization are obvious and it is necessary to implement fuzzy optimization methods. It also can be seen from the calculation results that the proper introduction of asway unloading can reduce the unloading time and raise the productivity compared to stationary unloading.Besides, a equation fuzzy method has been introduced for the first time, and if it is right, it will enlarge the fuzzy method.更多还原