【作者】 张珂；

【导师】 王生泽；

【作者基本信息】 东华大学 ， 机械设计及理论， 2005， 博士

【摘要】 随着科学技术的飞速发展和人类社会的不断进步,人们对现代机构的性能提出了越来越高的要求,尤其是要求机构能具有良好的柔性。混合驱动机构是一种具有良好柔性输出的新型机构,同时采用实时不可控电机(主电机)和实时可控电机(辅助电机)作为其动力源,两种类型的输入运动通过一个多自由度闭环机构合成后产生所需要的输出运动。它是现代机构学理论、传感器技术、微电子学、现代控制理论、计算机和信息科学以及人工智能等多学科交叉融合的产物,是现代机构学发展的重要方向之一。本文在传统机构学理论、现代动力学分析理论、现代控制理论、现代优化理论、统计分析和先进复合材料力学的基础上,以混合驱动五杆机构系统为例,对混合驱动连杆机构系统进行了系统研究。研究成果适用于其它类型混合驱动连杆机构系统。 混合驱动连杆机构系统是一种多自由度、多构件的复杂机构,本文首次采用键合图法对混合驱动五杆机构进行了动力学分析。键合图法以简明的图形方式揭示了机构运动学及动力学特性,可使人们直观地理解组成机构不同类型的元件对机构动态性能的作用,提高了对机构内涵理解的洞察力。机构动力学方程具有规则化的特点,便于计算机自动生成,无需进行机构加速度分析。仿真结果表明,与传统的动力学分析方法相比,大大地提高了动力学分析的效率和可靠性。 混合驱动连杆机构系统是一种高度非线性、强耦合的柔性可控机构,只有从系统的观点出发,才能揭示其自身的真实规律。本文首次提出了基于功率键合图和功率拓扑键图建立混合驱动五杆机构系统全局耦合动力学模型,用统一的方式处理多能域并存的混合驱动系统,以图形方式直观地揭示机构系统不同能域子系统间的相互作用关系,以及各杆件间的运动约束关系、作用力(力矩)间的相互作用关系。仿真结果表明所建立的系统全局动力学模型是正确有效的。与孤立研究各子系统相比,全局耦合动力学模型能更真实地描述系统动力学特性及各子系统之间的耦合带来的影响。 将现代混沌优化算法与MATLAB6.5程序语言的优化工具箱有机地结合,提出了机构非线性优化设计问题的混合优化算法,具有较好的全局搜索能力。在运动学和动力学分析的基础上,基于复合优化算法对混合驱动五杆机构的结构参数进行了运动学、动力学和多目标优化设计。优化结果表明,以运动学、动力学、机构构件尺度敏感性等为目标函数的多目标优化设计,可以使机构获得更佳的综更多还原

【Abstract】 With the rapid development of science and technology, and uninterrupted progress of society, demand on performance of modern mechanisms is more and more highness, especially for the better flexible output. Hybrid mechanism is a new type mechanism with good flexible output. A hybrid mechanism is a configuration that combines the motions of two characteristically different electric motors by means of a mechanism to produce programmable output. Where one of the motions coming from a constant speed motor provides the main power, a small servo-motor introduces programmability to the resultant actuator. Such machines will introduce to users greater flexibility with programmability option, and energy utilization will be realized at maximum. Hybrid mechanisms are products of combination of theory of modern mechanisms, sensor technology, microelectronics technology, modern control theory, computer and information science, and artificial intelligence etc. It is one of the trends of modern mechanism. Based on theory of traditional mechanisms, modern control theory, modern dynamics analysis theory, modern optimization theory, statistics analysis and advance composite mechanics, systemic studies on hybrid linkage mechanism are performed with an example of hybrid five-bar mechanism in this paper. The contributions achieved are suitable for the other types of hybrid linkage mechanism.Hybrid mechanism takes on the characteristic with multiple degree-of-freedom and multi-bar. Using classical techniques to derive the dynamics equations of hybrid mechanism can be a tedious and error-prone task. In this paper, dynamic analysis of hybrid five-bar mechanism was studied based on power bond graph for the first time. The kinematics and dynamics of the mechanism are represented in a form by compact graphics mode and concise notation. Thus, the understanding of the complex static and dynamic interactions within a hybrid mechanism is enhanced. The analyst may view the mechanism-dynamics problem from a fresh perspective-a point of view that often provides new insights into the complex behavior of hybrid mechanism. The unified formula of mechanism dynamics equations derived here is a regularized one. The bond graph method lead to a form suitable for automatic derivation and computation. The procedure does not have to analyze acceleration of hybrid mechanism. In terms of physical parameters of hybrid five bar mechanism and necessary input matrix, the bond graph-based computer programs can automatically derive and solve the dynamic equations of mechanism-dynamics problem on a computer, obviously enhancing efficiency and reliability of dynamics analysis for hybrid five bar mechanism.Hybrid mechanism is highly nonlinear and strong coupling flexible devices. From a point of view of system, the potential law in itself can be just opened out. In this paper, a global coupling dynamic model of a hybrid five-bar mechanism system is established by using power bond graph and power topo-bond graph for the first time. The hybrid system including multi-energy field is represented in a form by compact graphics mode. The coupling properties are depicted and its effect are analysed from this model. The results of simulation show that a global coupling dynamic model of a hybrid five-bar mechanism is correct. The study shows that simulation results of global mathematical model are much closer to experimental results than that of isolated mathematical model. The proposed method may be commonly applied to modeling and analysis of other controllable mechanism systems.By the combination of modern chaos optimization algorithm and the optimization Toolbox of MATLAB6.5 programming language, hybrid optimization algorithm for nonlinear optimization design of hybrid mechanism is proposed. The better capability of the global search is acquired by using the algorithm proposed. Using the hybrid optimization algorithm, kinematics, dynamics and multi objective optimization design for hybrid five-bar mechanism are performed respectively on the base of the analysis of kinematics and dynamics. The results of optimization show that the better integrative performance of mechanism can be obtained by using multi objective optimization design which kinematic, dynamic characteristics and sensitivity of dimensions of links act as objective function.Hybrid mechanism remains with position control following system. Position control accuracy of system determines the profile accuracy of hybrid actuator. Incorporating the grey prediction, repetitive control and the conventional PID control, a design method of the grey prediction repetitive PID control algorithm is presented for the first time. This control algorithm can be divided into three steps: to estimate unsure parameters and disturbance of system using grey prediction, to compensate PID control in terms of the prediction results, and then to add repetitive control for controlling cyclical motion. The simulation results show that this algorithm has better performances than that of the conventional repetitive control system. The control method has better application value for hybrid linkage mechanism taking on a characteristic of cyclical motion. In addition, The CMAC neural network control system is used in this paper. By means of the control system of hybrid driving linkage mechanism, following motion of high tracking precision can be obtained. Simulation results show that this method has better dynamic performance, robustness and anti-disturbance than the traditional PID control.Whereas the better performance and the development of 3-D braided composite, the damping and stiffness analysis of 2-step hollow-box-section 3-D braidedcomposite were performed in this paper. Then, the mathematical model for optimization of the damping and stiffness of bar were proposed. The results of numeral examples show that the better damping and stiffness characteristic could be obtained by using optimal design, contenting the determinate restriction. The method proposed here is useful for the design and engineering application of the kind of member.According to the theoretical model proposed, the experimental equipments of the hybrid actuator realizing flexible output motions were set up. The correlative experiment examinations were made. The results of experiment tallies with simulative results of theories comparatively, which proves that theories of this paper are correct. In addition, the comparison experiments were performed for hybrid five-bar mechanism with components of six kinds of materials respectively. The materials examined were carbon constructional quality steel, aluminum alloy, nylon plastics, phenolic cotton cloth laminated, 3-D braided composite and so on. The results of experiment show that the performance of system is improved obviously with the 3-D braided composites. It is an available approach improving dynamic performance of hybrid mechanism to use 3-D braided composite component. It is important for optimization of the material selection for hybrid mechanism components.There exists connatural effect to output error, from manufacturing error of component of hybrid linkage mechanism. In this paper, the sensitivity analysis of dimensions of links is made for hybrid five-bar mechanism. According to the effect of dimension error of each component for output error, the choice principia for dimension tolerance of each bar are given. In order to open out effect of input kinematic parameters for output error of system, the analysis of statistical dependence is made for hybrid five-bar mechanism in terms of experimental data for the first time. As can been seen, matching up reasonably input kinematic parameters can reduce output error availably. It has practical significance for design of hybrid mechanism.更多还原