【作者】 杨金堂；

【导师】 孔建益；

【作者基本信息】 武汉科技大学 ， 机械设计及理论， 2009， 博士

【摘要】 传统机构学正在对其研究对象、内容、理论和方法等诸多方面发生深刻的变革。1990年以来,中国机构学经历了一个较大发展。其中受控机构(亦称可控机构或者混合输入机构或者混合驱动机构)分析与综合及其应用研究是10年来主要成果之一。本文在借鉴国内外相关研究成果的基础上,以平面五杆机构的型综合、分析与综合、结构参数和运动参数误差分布及对实现轨迹的影响、控制系统为研究对象,考虑五杆机构的运动学动力学特性,将新型智能计算方法与新设计理论引入其中,为平面五杆机构轨迹综合与创新设计提供了一种新的研究途径。首先,提出了两种五杆机构型综合的新方法:“基于两个类Ⅱ级杆组构成法”和“基于两连架杆+Ⅱ级杆组构成法”。提出了全移动副的平面机构自由度计算方法,通过当前热门研究的四种常用型的研究和特征分析,并运用杆组理论提出的两种型综合方法,得出13种基本型。并分析了这13种基本型在实现轨迹时的演化规律,分析了五杆机构实现轨迹时分析和综合的特点,为基于特征值的五杆机构分析与综合奠定了理论基础。其次,提出了两种五杆机构精确实现多点轨迹的两步尺度综合的新方法:“轨迹实现模型+补偿控制模型”的两步综合法和“轨迹实现模型+圆拟合模型”两步综合法。提出了“视角”“轨迹区内”“轨迹区外”的概念,运用该概念能够减少优化的计算模型;建立实现多点轨迹五杆机构全域最优设计模型:“轨迹实现模型+补偿控制模型”,考虑了五杆机构的运动学动力学特性,独立的设计变量为6个比传统的要少,但模型数较多;构造的适应度函数保证了满足约束条件的个体的适应度值优于不满足的个体,且增强了优化的吸引域,采用改进遗传算法获取全域最优解;建立了受控机构的“轨迹实现模型+圆拟合模型”优化模型,运用广义逆求解,实例计算表明:受控机构必须考虑受控原动件的机械特性,必须选择合适的控制策略和方法。再次,提出了刚性受控五杆机构结构参数误差合理分布方法;运用小波分析与变换,提高了补偿运动的低频特性。通过分析结构参数与运动参数误差对实现轨迹误差的影响,建立了全微分方程组,运用矩阵论的范数法,提出了刚性受控五杆机构结构参数误差合理分布方法,可以减少补偿运动不必要的调整,从而提高了五杆机构实现轨迹的精度和五杆机构的实用性;通过小波多分辨分析方法对可控五杆机构的补偿运动曲线进行分析,不仅有利于了解补偿运动在各频率段的分布,而且在满足要求的前提下使特征数据点大为减少,并且消除了补偿运动高频部分,优化了机构的运动学和动力特性,为机构动力学分析提供了一种新的方法。最后,开发了受控五杆机构的计算仿真和控制系统软件。针对五杆机构进行力学分析,运用“矩阵法”建立五杆机构力学模型,研制开发本文的全部计算与仿真模型及软件,研制开发五杆机构力的控制硬件系统及其软件,完成实验台研制;为五杆机构的设计理论验证和应用研究提供强有力的支持。更多还原

【Abstract】 The traditional mechanisms are taking place the deep change to such a great deal of respects as its research object, content, theory and method, etc. Since 1990, Chinese mechanisms go through a relatively develop on a large scale. Analysis, synthesize and its application of controlled mechanism is one main achievement of over the past 10 years among them.On the basis of drawing lessons from domestic and international relevant research results, type synthesis, analysis and synthesis, structural parameter and error distribution of movement parameter and its affection on realizing track, and control system of five-bar mechanism as the research object , considering kinematics and dynamics characteristics of five-bar mechanism, the new-type intellectual computing technology and new design theory are introduced , a kind of new research way has been offered for synthesis and innovation design of five-bar mechanism.Firstly, two new methods of type synthesis of five-bar mechanism are put forward, namely type synthesis method based on two similar ClassⅡbar groups and two framed links + ClassⅡbar groups. 13 basic types of the five-bar mechanism are deduced; then the evolutionary process and characteristic of the five-bar mechanism is proposed, which is based on .the selection of driving component and additive rod and so on. It offers theoretical basis for both the type and dimension synthesis of five-bar mechanism and the selection of its practical and reliable mechanism modes.Secondly, two new methods of two-step dimensional synthesis of five-bar mechanism accurately realizing the track of many points are built, namely two-step synthesis method of model of track realizing and compensation control, and model of track realizing and circle fitting. Basic conceptions of visual angle, in the track and outside the track are put forward, and then the optimal calculation models are reduced based on these conceptions. Global optimal design model, namely model of track realizing and compensation control, of controlled mechanism which accurately realizes the track of many points has been established. The number of individual design variable is six, which are less than the traditional method, but model is more. Fitness function build can satisfy that fitness value of satisfied individuals are better to the unsatisfied individuals and increase the optimal attraction zone. Global optimal solution is got by using genetic algorithm. Optimization models of track realizing model and circle fitting model of five-bar mechanism has been established. The generalized inverse method for solving compensation movement displacement has been presented. At last the instance indicates that mechanical features of controlled driving component and proper control strategy and methods are considered.Thirdly, proper distribution method of structural parameter error of five-bar mechanism is proposed.Low-frequence characteristic of compensation movement is enhanced by using wavelet transform and analysis method. In addition, the relation between error changes of controlled original power component and given track errors is also analyzed. It provides an important foundation for choosing controlled original power component. Numerical values of compensation movement are calculated by using basic methods of controlled mechanism, then wavelet transform and analysis method is put forward to analyze movement characteristic of compensation movement and its influence on realizing track. A feasible method is proposed to realize the random track and improve the characteristics of compensation movement only by changing compensation movement not changing structural parameters of five-bar mechanism.Finally, calculation simulation and control system software of five-bar mechanism is developed. Aiming at mechanical analysis of five-bar mechanism, mechanical model of five-bar mechanism is built by using matrix method. Then the all calculation, simulation model and software, control hardware system and its software are developed. All above offers design theories and application study of five-bar mechanism powerful support.更多还原