【作者】 张邦成；

【导师】 王义强；

【作者基本信息】 吉林大学 ， 机械制造及其自动化， 2011， 博士

【摘要】 串并联数控机床打破了传统机床结构的概念,兼有传统C型串联机床工作空间大、数控系统成熟的特点及并联机床加工精度高,刚性好的特点,大大提高了机床的刚度,适于复杂曲面的加工,提高了加工精度和加工质量。其伺服进给系统是一类高精密的复杂机电系统,具有结构稳定、运动高效、控制准确的特点。论文以设计的3-PTT串并联数控机床为研究对象,研究其伺服进给系统机电耦合特性,根本目的是探索耦合对机构运动的约束机制,分析耦合参数与系统运动及控制的相关机理,指导数控机床结构优化设计及伺服系统的参数匹配,解决数控机床由于机电耦合问题而产生加工精度不能充分满足要求、工作效率低、可靠性不高的问题,以提高数控机床综合性能及生产水平。设计了一种适用于复杂曲面加工的串并联数控机床伺服进给系统结构并采用分解与综合的方法对机床机构构型、运动副类型、连接元件、空间自由度进行分析,采用基于奇异约束条件和耦合因素的方法分析了机床工作空间,并进行了串并联的仿真分析,仿真结果能够准确反映机床实际加工范围,为研究串并联机构构型规律、运动学及动力学分析提供了参考,为数控机床机电解耦控制提供依据。研究了串并联数控机床伺服进给系统力学耦合特性。分别进行了机床力学耦合参数计算、静力学耦合建模、静力学耦合仿真、动力学耦合建模及动力学耦合仿真的研究工作。解决了力学平衡规律、机构刚度、驱动参数与外负载之间关系等耦合问题,为运动学耦合问题的分析提供参考和依据。其中静力学有限元仿真分析表明:机床伺服进给系统关键构件的刚度及受力变形符合机床工作需要。动力学计算实例及联合仿真分析表明:根据负载的运动规律可有效地分析动平台和加工工具的受力与运动的关系,为系统的设计和优化提供依据。研究了串并联数控机床伺服进给系统运动学耦合特性。采用正、逆解的方法分析了运动学特性,详细分析了运动学数学模型,采用数学计算分析软件对串并联机构的牛顿——欧拉方程进行数学分析,得出串并联机构中各运动副的轨迹曲线图,并进行运动学仿真。进一步得出伺服进给机构的运动曲线图,将两次仿真分析得出的结果进行对比分析,计算实例及仿真结果表明:设计的机床运动速度快且运行平稳,无较大奇异状态及耦合误差,受力与速度关系符合动力学规律。建立了串并联数控机床伺服进给系统机电耦合模型。阐述了串并联数控机床复杂机电系统耦合理论及建模方法,通过耦联关系建立了伺服系统的数学模型。建立伺服系统模型后,利用软件对该模型进行了仿真,验证了耦合参数对系统的影响。为串并联数控机床解耦控制奠定了基础。针对串并联数控机床伺服进给系统机电耦合建模分析提出的问题,运用遗传算法整定PID参数,强跟踪滤波器解决负载扰动和工况干扰对系统性能影响的方法,对串并联数控机床的伺服进给系统进行解耦控制,消除了耦合因素对串并联数控机床伺服进给系统的影响,提高零件的加工精度和表面质量,使机床的机械系统与控制系统更好的配合,解决了数控机床由于机电耦合问题而产生加工精度不能充分满足要求、工作效率低、可靠性不高的问题,提高了数控机床的使用性能及加工效率。同时,也为数控机床生产厂家其伺服系统优化设计及参数调节,提高国产数控机床出厂的调试效率和生产水平提供了参考依据。这对加速数控机床核心技术的自主发展,提升我国机床制造业的制造生产水平具有深远意义。更多还原

【Abstract】 Series-parallel NC machine tools breaks up the concept of the traditional structure, and it has the features of the big working space and mature NC system of the traditional C-series machine, at the same time, it also has the features of high accuracy and good rigidity of the parallel machine tool, which greatly increases the stiffness of the machine, and improves processing accuracy and processing quality, so it is suitable for complex surface processing. The servo system is a high-precision complex electromechanical system with stability structural, efficient movement and accurate control.The electromechanical coupling characteristics of the servo system for 3-PTT series-parallel NC machine tools is studied in this paper, and the fundamental purpose is to explore the kinematic constraints on the coupling mechanism, and analysis the coupling parameters of this system and movement-related mechanisms. This study can guidance NC machine tools servo system design and optimization of the parameters match, and solve the problems of low machining accuracy ,efficiency, insufficient reliability, simultaneously, improve the overall performance and production levels of NC machine tools.This study designes a series-parallel NC servo system structure for complex surface machining, and analyzes machine body conformation, kinematic pair types, connected components, spatial degrees of freedom by using the method of decomposition and synthesis. And then, this study analyses the working space using singular constraints and couple factors, after analysing, the simulation is carried out, and the simulation results accurately reflect the actual range of machining. Reference basis for discipline of configuration and analysis of kinematics and dynamic has been provided.The mechanical coupling characteristics for series-parallel NC machine servo system is researched, which involves in the calculation of mechanical coupling parameters, model and simulation of statics coupling, model and simulation of dynamics coupling. The analysing of statics shows: the stiffness of the key componets of the NC machine servo system and the bearing forces and deformations conform to the needs of machine tool work. The calculation of Dynamics and simulation show: according to the movement regularity of loading, the relationship between bearing forces and movement of platform and processing tools can be analyzed, which can provide the basis for system design and optimization.It researches on kinematic coupling characteristics for series-parallel NC machine servo system. A detailed analysis of the kinematics mathematical model is shown based on the positive and inverse kinematics analysis .Using mathematical analysis software for series -parallel institutions Newton - Euler equations, it simulated as the kinematic pair trajectory curve. Further more, the servo kinematic curve and kinematic pair trajectory curve are analyzed and compared, and the simulation results are shown that: the designed machine can run fast and smooth movement, no larger singular state and coupling errors , and it accords with relations of force and velocity kinetics.This study establishes the electromechanical coupling model of series-parallel NC machine tool servo system, and explains electromechanical coupling theory .After the establishment of the electromechanical model, it verifies the impact of coupling parameters on the system for simulation model using of software. NC machine tools for the decoupling control of series-parallel basis. It lays on the foundation for decoupling control for series-parallel NC machine tool servo system.For the problems of electromechanical coupling for servo systems modeling, using of genetic algorithm to adjust PID parameters, and strong tracking filter to solve the load disturbance and interference conditions on the system performance, it eliminates coupling factors effects for decoupling control of series-parallel NC machine tool servo system, and increases the machining accuracy and surface quality. The mechanical system and control system can be better co-ordinated, and it solves the problems that machining precision can not fully meet the requirements, low efficiency, lack of reliability and improves the performance of NC machine tools and processing efficiency. Also reference based on optimization and parameter adjustment has been provided to increase the level of debugging efficiency and production for domestic NC machine tools. The core technology of NC machine tools accelerates self-development and enhances manufacturing standards for machine tool manufacturing industry, which has far-reaching significance.更多还原