轮式移动机械臂倾覆与滑移问题研究

发布时间：2018-06-12 03:14

本文选题：轮式移动机械臂 + 动力学　；参考：《上海大学》2016年博士论文

【摘要】：近年来,轮式移动机械臂的研究得到了国际上的广泛关注。统计结果表明：在未来的几年中,工厂及家庭中超过三分之二的工作任务可由自主移动工业机械臂来实现。移动机械臂不仅能够有效克服固定式机械臂工作范围有限、灵活度不高等缺点,还具备固定式机械臂与移动机器人二者的优点。然而,机械臂与移动平台结合制成移动机械臂却产生了这两个领域均没有充分研究的新课题,即：机械臂作用于移动平台的力/力矩给系统带来的倾覆与滑移问题,其直接关系到系统及环境乃至人员的安全、系统对环境的适应能力、系统的稳定性及系统的工作效率等。本文对机械臂的运动学、动力学、机械臂作用于移动平台的力/力矩、不同动力学因素下轮式移动机械臂的倾覆规律、轮式移动机械臂的设计参数优化、轮式移动机械臂滑移等关键问题展开深入研究。具体的研究内容如下：第一,在运动学建模的基础上使用牛顿—欧拉方法对机械臂进行动力学建模,重点关注机械臂关节1上约束力/力矩。详细分析静态、静态且受力、动态三种情况下机械臂作用于移动平台的力/力矩的组成,并使用ADAMS软件验证了动力学建模与计算的正确性。第二,对倾覆稳定性判据进行研究。从系统倾覆根源出发,提出一种新的倾覆稳定性判据——倾覆力矩(Tip-Over Moment,TOM)。对该判据与ZMP判据对比研究以验证其正确性,结果同时显示出TOM判据的优越性。分别研究静态、静态且受力、关节角速度、关节角加速度四种情况下轮式移动机械臂系统的倾覆规律。静态情况表明倾覆与系统重心的水平位置有关；静态且受力情况表明倾覆与杆件构型(关节角组合)有关；关节角速度与关节角加速度情况表明倾覆同时受到机械臂向心力、陀螺力矩及惯性力的影响。在此基础上,以无倾覆为约束条件对轮式移动机械臂打铆路径进行轨迹规划,规划结果既能够保证系统不倾覆又能够实现整体运行时间最短。第三,为提升系统的抗倾覆能力,对轮式移动机械臂的设计参数进行优化。该优化可归结为极大极小值问题。即：在整个工作空间上最大化稳定区域比(SRR)的同时最小化倾覆力矩(TOM)。第一步,分别研究移动平台的支撑轮数量、移动平台尺寸与质量对系统倾覆稳定性的影响。第二步,分别以最大倾覆裕度和最大|dM|值为目标使用遗传算法对机械臂和附件的安装位置进行组合优化,并根据优化结果设计轮式移动机械臂系统。第四,就机械臂作用于移动平台的力/力矩引起的滑移问题进行研究。对系统滑移进行建模、分析与计算,分别研究轮式移动机械臂在铆接时刻、移动时刻的滑移问题；以无滑移为约束条件对轮式移动机械臂打铆路径进行轨迹规划,规划结果既能够保证系统不滑移又能够实现整体运行时间最短。本文对机械臂的动力学及轮式移动机械臂的倾覆与滑移问题展开了深入而细致的研究。通过与动力学仿真软件及其他学者的研究成果进行对比验证了本文所提出方法的正确性及优越性。研究成果可用于轮式移动机械臂的设计、控制及优化。本研究有助于提升轮式移动机械臂的安全性及工作性能,是轮式移动机械臂研究过程中不可或缺的一环。
[Abstract]:In recent years, the research on wheeled mobile arm has attracted wide attention. The results show that in the next few years, more than 2/3 of the work tasks in factories and families can be realized by independent mobile industrial manipulator. The mobile arm can not only effectively overcome the limited working range of the fixed arm, but not the flexibility. It also has the advantages of a fixed manipulator and a mobile robot. However, the combination of the manipulator and the mobile platform to make a mobile manipulator produces a new topic which has not been fully studied in the two fields, namely, the overturning and sliding problem of the force / torque of the manipulator on the moving platform, which is directly related to the force / torque of the mobile platform. To the safety of the system and environment and even the personnel, the adaptability of the system to the environment, the stability of the system and the efficiency of the system. This paper is the kinematics, dynamics, the force / torque of the manipulator on the moving platform, the overturning rule of the wheel moving manipulator under different dynamic factors, and the design parameters of the wheel moving manipulator. The key issues such as optimization, wheel moving manipulator slip and other key problems are studied. The specific research contents are as follows: firstly, based on the kinematic modeling, the Newton Euler method is used to model the dynamics of the manipulator, focusing on the 1 binding / torque of the manipulator joint. The static, static, force and dynamic three situations are detailed and analyzed. The composition of the force / torque of the moving platform under the action of the manipulator, and using the ADAMS software to verify the correctness of the dynamic modeling and calculation. Second, the stability criterion of the overturning is studied. From the root of the overturning of the system, a new criterion for overturning stability (Tip-Over Moment, TOM) is proposed. The criterion and the ZMP criterion To verify its correctness, the results show the superiority of the TOM criterion. The overturning rules of the wheeled mobile manipulator system are studied in four cases of static, static, force, joint angular velocity and joint angular acceleration. The static state shows that the overturning is related to the horizontal position of the center of gravity; the static and force condition indicates the inclination. It is related to the structure of the rod (joint angle combination), and the angle velocity of joint angle and the angle acceleration of the joint show that the overturning is influenced by the centripetal force, the gyroscopic moment and the inertia force of the manipulator. On this basis, the trajectory planning of the riveting path of the wheeled mobile manipulator is taken as a constraint without overturning, and the planning results can not only ensure that the system is not. The overturning can also achieve the shortest overall operation time. Third, to improve the anti overturning capability of the system, the design parameters of the wheeled mobile manipulator are optimized. This optimization can be attributed to the minimax value problem. The first step is to study the minimum overturning moment (TOM) at the same time (SRR) in the whole workspace. The number of supporting wheels of the mobile platform, the influence of the size and quality of the mobile platform on the overturning stability of the system. Second step, using the maximum overturning margin and the maximum |dM| value as the target, using genetic algorithm to optimize the installation position of the manipulator and accessories, and design the wheel moving manipulator system according to the optimization results. Fourth. The paper studies the sliding problem caused by the force / torque of the moving platform. The system slip is modeled, analyzed and calculated, and the sliding problem of the wheel moving arm at the riveting time and the moving time is studied respectively. The trajectory planning of the wheel moving arm riveting path is carried out with no slip as the constraint condition. The planning results can not only be used for the trajectory planning. In this paper, the dynamics of the manipulator and the overturning and sliding of the wheeled mobile arm are studied in detail in this paper. The correctness and superiority of the proposed method is verified by comparison with the research results of the dynamics simulation software and other scholars. The research results can be used in the design, control and optimization of the wheeled mobile manipulator. This study is helpful to improve the safety and performance of the wheeled mobile manipulator. It is an indispensable link in the research process of the wheeled mobile manipulator.
【学位授予单位】：上海大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP241

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