六自由度串联机器人空间轨迹生成方法的研究

发布时间：2018-01-19 14:41

本文关键词： 工业机器人运动学分析轨迹规划插补算法仿真　出处：《安徽工程大学》2017年硕士论文　论文类型：学位论文

【摘要】：机器人轨迹规划作为机器人技术的重要组成部分,是机器人运动的核心问题。六自由度机器人空间轨迹形成取决于六关节运动的合成,由空间轨迹规划关节运动,需要借助于运动的逆解,存在求解困难,多解的问题。在要求工业机器人能够快速有效地完成工作任务的同时,还应该要求工业机器人运行平稳,保证运动过程中各个关节无明显冲击,延长机器人的使用寿命。同时,在保证机器人稳定运行的同时,还应该尽量缩短运动时间。本文针对求逆解过程困难,运动多解的问题,对工业机器人的运动轨迹进行合理的规划,以提高工业机器人的使用寿命以及工作效率。本文主要研究内容如下:首先,通过机器人学的基础理论知识,对空间中刚体的位姿进行描述。对相邻坐标系之间进行旋转、平移、复合变换,得到了基本变换矩阵。利用D-H法对机器人进行数学建模,建立连杆坐标系,进行运动学分析,得到正运动学方程,这为机械臂的研究提供了理论依据。接着通过对正运动学方程求逆解,得到机器人在不同位姿下,机器人各个关节角的大小。机器人的正逆运动学分析,为后续的研究提供了理论支持。其次,分析MH50II机器人在轨迹规划中的一般方法,深入讨论了工业机器人在关节空间坐标系中和笛卡尔空间坐标系中的插补算法。其中,在关节空间坐标系中,分别用三次多项式插值法和五次多项式插值法以及用抛物线过渡的线性插值法进行轨迹规划的研究,计算插值点的坐标。在笛卡尔坐标空间中,对线性直线插补法和圆弧插补法进行了深入的研究和推导,最终得出在笛卡尔坐标空间中,计算插值点的坐标。对比两种空间插值算法的优缺点,区别不同条件下两种空间插值算法的选用。然后,分析基于遗传算法的时间最优轨迹规划方法,讨论了遗传算法的基本原理、B样条曲线的数学表达式和特点。采用遗传算法,考虑了角速度约束、角加速度约束、角加加速度约束、约束系数等,分析运动时间最短的轨迹规划方法。最后,主要研究机器人轨迹规划的实现与仿真,利用Matlab软件中的Robotics Tools工具箱对机器人进行仿真建模、运动学分析、建立工作空间、轨迹的实现。通过在关节空间坐标系和笛卡尔空间坐标系中进行仿真分析,得到相同路径点下的轨迹规划曲线,并进行比较分析得到最优的轨迹规划方法。结果表明,五次多项式轨迹规划方法得到的轨迹曲线平滑,从而验证了该算法的优越性。
[Abstract]:As an important part of robot technology, robot trajectory planning is the core problem of robot motion. The formation of space trajectory of six-degree-of-freedom robot depends on the synthesis of six-joint motion. In order to plan the motion of joints by space trajectory, it is necessary to use the inverse solution of motion to solve the problem of difficulty and multi-solution, which requires the industrial robot to complete the task quickly and effectively at the same time. Industrial robots should also be required to run smoothly, to ensure that there is no obvious impact on the joints in the process of motion, and to prolong the service life of the robot. At the same time, it is necessary to ensure the stable operation of the robot. In order to solve the problem that the inverse solution is difficult and the motion multiple solution is difficult, the motion trajectory of the industrial robot should be reasonably planned. In order to improve the service life and efficiency of industrial robots, the main contents of this paper are as follows: first, through the basic theoretical knowledge of robotics. The position and pose of rigid body in space are described. The basic transformation matrix is obtained by rotation, translation and composite transformation between adjacent coordinate systems. The mathematical model of robot is established by D-H method, and the coordinate system of connecting rod is established. Through kinematics analysis, the positive kinematics equation is obtained, which provides the theoretical basis for the research of the manipulator. Then, the inverse solution of the positive kinematics equation is obtained, and the robot under different position and pose is obtained. The size of each joint angle of the robot and the kinematics analysis of the robot provide theoretical support for further research. Secondly, the general method of trajectory planning for MH50II robot is analyzed. The interpolation algorithm of industrial robot in the joint space coordinate system and the Cartesian space coordinate system is discussed in depth, among which, in the joint space coordinate system. The cubic polynomial interpolation method, the fifth polynomial interpolation method and the parabola transition linear interpolation method are used to calculate the coordinates of interpolation points in Cartesian coordinate space. The linear linear interpolation method and arc interpolation method are deeply studied and deduced. Finally, the coordinates of interpolation points are calculated in Cartesian coordinate space. The advantages and disadvantages of the two spatial interpolation algorithms are compared. Then, the time optimal trajectory planning method based on genetic algorithm is analyzed, and the basic principle of genetic algorithm is discussed. The mathematical expression and characteristics of B-spline curve. Genetic algorithm is used to consider angular velocity constraint, angular acceleration constraint, angular plus acceleration constraint, constraint coefficient and so on. The shortest motion time trajectory planning method is analyzed. Finally, the realization and simulation of robot trajectory planning are mainly studied. Using Robotics Tools toolbox in Matlab software, the robot is simulated and modeled, kinematics is analyzed, and workspace is established. Through the simulation analysis in the joint space coordinate system and the Cartesian space coordinate system, the trajectory planning curve under the same path point is obtained. The optimal trajectory planning method is obtained by comparing and analyzing, and the results show that the trajectory curve obtained by the fifth degree polynomial trajectory planning method is smooth, which verifies the superiority of the algorithm.
【学位授予单位】：安徽工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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