【作者】 刘峰；

【导师】 王向军；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2009， 博士

【摘要】 为满足对运动目标进行多自由度跟踪的需求,并联跟踪台技术逐渐发展起来。本文主要围绕具备一个平移自由度和两个旋转自由度的并联跟踪台即马鞍型并联跟踪台中的若干关键技术进行探讨,主要有拓扑结构、可视化参数化设计方法、运动学和动力学建模、自动控制和手动介入控制方法以及标定技术。研究机构的拓扑结构是实现机构布局优化设计的关键,其目的是通过建立机构的拓扑特性衍生出能够实现所需要求的可能机构,而后通过判定准则从可能机构中优选出最佳布局方案。本文以单开链拓扑理论为基础,依据并联机构拓扑设计准则,着重对能够实现空间三自由度运动的并联机构的拓扑特性进行研究,给出了一种新型的呈马鞍型并联支撑布局的并联跟踪机构方案,即马鞍型并联跟踪台。机构尺寸的优化设计是通过参数化设计方法来实现。本文以空间两坐标系变换关系原理为依据,构建了马鞍型并联跟踪台的位置逆解模型,并以该模型为核心,提出了一种基于简化结构的并联跟踪台可视化、参数化设计方法。实验表明,该方法不但能够实现马鞍型并联跟踪台的尺寸优化设计、而且能够扩展应用到多自由度并联机构的尺寸优化设计中去。运动学和动力学建模和分析是研究机构动态特性的主要方面。本文概述了目前各种运动学和动力学方法各自的特点及适用范围,提出了一种基于点运动合成理论的运动学建模方法,并采用Kane方法建立了动力学模型。就模型的实现方法:编程实现方法和虚拟样机技术方法进行了分析和比较,在两者实现同等效果的基础上,以效率更高的虚拟样机技术实现方法为基础,通过仿真实验得到了反映马鞍型并联跟踪台动态特性的一系列运动学和动力学性能数据,为后续的跟踪控制系统各零部件的选型和系统搭建提供了理论依据。控制环节在跟踪系统的设计中占有重要地位,控制的好坏将直接决定跟踪的最终效果。本文首先依据已得到的运动学和动力学仿真实验数据完成了跟踪控制系统的硬件结构设计和系统搭建,而后,根据目标跟踪机理,以位置逆解模型实现了跟踪台的自动控制,并进行了自动控制实验,实验验证了模型的有效性。手动控制方面,分析了现有手控方法的特点和不足,提出了一种交互性更强的基于二轴操纵杆的手动介入控制方法,利用空间几何关系获取控制信息,结合操纵杆摆动方向与跟踪台运动方向间建立的映射关系,实现了跟踪台与人手的协同动作和控制。实现并联跟踪台的高精度跟踪和定位是通过对并联跟踪台的标定来实现。本文采用双CCD组合测量方法对马鞍型并联跟踪台的运动重复性精度进行了实验验证。更多还原

【Abstract】 Parallel tracking platform technology is developed gradually to meet the need of multi-freedom tracking of the moving target. In this paper ,the following key technology of the U-shaped parallel tracking platform, which is of one advection freedom and two revolution freedom, is deeply discussed: topological structure; methods of the visible parameterization design; modeling of the kinematics and the kinetics; auto-control and manual intervention control methods; calibration methods.The key of realizing the optimization design of the device layout is studying the device topological structure, which aims to derive the probable structure meeting the need by building the topological character of the device. According to the single-open-chain topological theory and the topological design principle of the parallel device, the topological character of the parallel device, which can realize the space three freedom movement of parallel device, is deeply studied in this paper and further gives a new plan of the parallel tracking device with U-shaped parallel support layout, namely the U-shaped parallel tracking platform.The optimization design of the device size is realized through the parameterization design method. The mathematical model of the U-shaped parallel tracking platform is built according to the transformation relationship between two coordinate systems. Basing on this model, a visual parameterization design method of the parallel tracking platform is given. Experiments show that, this method can realize the optimization design of the U-shaped parallel tracking platform and be applied to the optimization design of the multi freedom parallel devices.The main aspects of the device dynamic character study are the modeling and analysis of the kinematics and kinetics. The features and application range of the current kinematics and kinetics methods are summarized in this paper. The kinematics modeling method based on the point movement synthesis theory is given and the kinetics model is built using the Kane method.The kinematics and kinetics model of the U-shaped parallel tracking platform are built and the two model realization methods, which are coding and virtual prototype, are analyzed and compared. The virtual prototype technology has higher efficiency among the two methods to achieve the same effect. The kinematics and kinetics character data, which reflects the dynamic character of the U-shaped parallel tracking platform,is got through emulation experiments, which provides the theory support for the later accessory selection of the tracking control system and the system building.The control annulus is an important part in the tracking system design, which directly affects the final tracking result. In this paper, the hardware structure design and system building of the tracking control system is finished firstly according to the gotten emulation experiment data of the kinematics and kinetics. Then according to the target tracking mechanism, the auto-control model of the U-shaped parallel tracking platform is built, the auto-control experiments are done and its validity is validated. The feature and drawback of the current manual control methods are analyzed and a manual intervention control method with two-axis control stick is given, which is more interactive. The concerted movement and control are realized between the tracking platform and hand through using spatial geometrical relationship to get the control information and combining the control stick swinging direction and tracking platform moving direction to build the mapping relation.It is the calibration of the parallel tracking platform to realize its high accuracy tracking and positioning. The repeatability accuracy of the U-shaped parallel tracking platform is validated in this paper by two-CCD compound measurement.更多还原