Study On Optimization Design Method Of The Internal Unloading Portal Shipunload Which Based On Genetic Algorithms

In recent years,with crane industry developed rapidly,the competition of the crane designing is getting more and more intense. The profit is getting less and less if a crane is being designed. In this case, the only one way to be number one in the design industry is seek for innovation.Different from the traditional door crane, the type of the crane related by this thesis rejected the turntable which is a normal structure in the crane,but adds a lateral system which can make the material to be transported to the bogry. With no rotary table which is a big structure, the weight of the crane is getting lighter, the mechanical properties is getting more improvement.In the engineering design, best optimization is the goal of almost every designer. But usually because of the complexity of the problem, it is difficult to find the optimal solution if we only use the conventional method.As optimization method is one kind of new technology which was developed over the past few decades,it provides theory basis for the people who seek for the optimal solution. The optimization method combined with the mechanical design and the computer technology, forming a new technology which called mechanical optimum design. It has an important role in solving the complex problem in the engineering design.The optimization design of arm frame system and luffing system of portal crane is a typical example in which optimization design is applied in engineering design. The crane discussed in this profit has a lot of design variables, and the target function is very complexity, so using the conventional optimization method is difficult to achieve the result. In recent years, there is a new optimization method named Genetic Algorithms which is based on nature selection and biological evolution.Because of Genetic Algorithms has such characteristics as no need for derivation for function, as no requirement for the continuty of the function, it gives the possibility to solve the optimization model which discussed in this profit.In the optimization system of arm frame system and luffing system of portal, we take the minimum mean square root force as the target function, take the maximal horizontal displacement of the goods as the constraint condition, and pick up10 design variables which will make great influence to the property of the crane. Then a single objective optimization model based on Genetic Algorithms was set up. At last, a solution for the mathematical model can be made out by the Genetic Algorithms toolbox of Matlab.The profit will mainly discussed in the following several aspects:(1)Setting up the mathematical model of the crane through design experience.(2)Analysis the characteristics of each optimization design method, for the feature of the mathematical model, selecting the Genetic Algorithms as the optimization method for the system.(3)Analysis the Genetic Algorithms toolbox of Matlab, using it to set up a optimization design model for the crane.(4) Develop a computer-aided software system based on Visual C++for the model of optimization design about the crane.