Optimization Techniques And Applications On The High-Speed Grinder Design

High-speed grinder is the important machine tool in the modern mechanical manufacturing. With the development of modern product design, the structural design of high speed grinder needs be promoted in order to ensure the precision and stability of products. Many researchers and engineers have done some foundational studies on the design of high speed grinder. There exit some bottleneck problems, caused by the structure characteristics of itself. As a manufacturing industry big country, our manufacturing industry development is restricted by the level of manufacturing equipment, which is still of relatively low quality compared with international advanced level. The technology of optimizing and reverse engineering are popular research fields, and play an important guiding role on engineering design. Therefore, in this paper, based on the exiting work of high-speed grinder design and optimization technique, the approximation model method and the global optimum algorithm are conducted to resolve some problems in the structural design.The main research content and contribution are summarized as follows:1. A structural optimization process is established and applied to the high-speed grinder components'design. The approximation model method is introduced into the design of components, instead of traditional numerical analysis, which are time-consuming. The global optimum algorithm is combined with approximation model method, which achieves at the goal of enhancing optimization precision and efficiency. By analysing the design requirements and the structural characteristics of high-speed grinder components, we can find that the common optimization methods are not suit for the design exactly, or the design cost is too high. The approximation model method is an effective way to solve the complex large-scale engineering computation problems. The radial basis function model can pass every sample point in the design space, and has better fitting accuracy for nonlinear problem in high-speed grinder's structural design.2. A simulation study combining dynamic analysis and structural analysis has been done in high-speed grinder, which can realize the real-time structural analysis under operating conditions. In the traditional dynamic analysis, the components in high-speed grinder are usually considered as rigid body, so that the performance data obtained from simulation such as displacement, velocity and applied load can not reflect the real situation. And the dynamic analysis and structural analysis are processed by separate systems where structural analysis uses the results obtained from dynmic analysis to compute. The characteristic leads to the low precision and efficiency of simulation. On the other hand, the elastic deformation of components can not be ignored during the precision manufacturing. Especially, some key parameters will affect the precision of high-speed grinder. In this thesis, the problem on simulation combining dynamic analysis and structural analysis has been make on the spindle-carriage machining system. The comparison with rigid model reveals that the elastic deformation of components has effect on the manufacturing precision.3. A uncertainty optimization design method of high-speed grinder is proposed. The uncertainty optimization method based on nonlinear interval number programming is introduced to solve the uncertain problem in the high-speed grinder design. There are many uncertain factors in the manufacture and work process of high-speed grinder, such as material property, boundary condition, external environment, especially for the grinding force in the grinding process, which was considered as determined parameter in the design before. But these uncertain factors affect the veracity and reliability of design. It is necessary to consider the uncertain factors in the design. In this paper, the main spindle system is taken as research subject. By considering the uncertainty of grinding forces, a real-time dynamic flexibility model of main spindle system is established. By using the uncertainty optimization based on intervals and intergeneration projection genetic algorithm, the goal of improving the main spindle system performance is achieved.4. A lightweight optimization design method of high-speed grinder based on the approximation model and mutative scale chaos optimization algorithm (MSCOA) is proposed. The premise of high-speed grinder lightweight is to ensure the performance requirement that the weight of components is reduced and the performance requirement such as strength, stiffness, and vibration resistance, must be satisfied. The purpose of lightweight is one of methods of reducing cost and an important requirement of high speed design of feed system, which can improve the velocity and acceleration of feed system. In this thesis, the approximation model and mutative scale chaos algorithm are employed to lightweight the structure. Chaos optimization algorithm as a method of global stochastic optimization has attracted much attention, which utilizes the characteristics of chaotic maps to search for the global optimal solutions. In compared with the other global optimum algorithms, such as micro genetic algorithms (μGA), the method is relatively simple and easy to be operated. Moreover, MSCOA has a good convergent performance with fast convergent rate. The method is validated by the lightweight problem of the grinder slider.5. The modeling method of joint surface and reverse identification method of dynamic parameters are proposed. With aid of these methods, the whole machine of high-speed grinder is analysed. There are many influencing factors of joint surface, which are always complex. Researchers have investigated the contact mechanism of joint surface and dynamic experiments. In this thesis, the dynamic parameter identification is regarded as a matching process of optimizing search combined with dynamic experiments, which avoids complex theoretical formula and costly experiment study.