【作者】 张学锋；

【导师】 李团结；

【作者基本信息】 西安电子科技大学 ， 机械设计及理论， 2007， 硕士

【摘要】 球形机器人是一种具有球形外壳并以滚动运动为主要运动方式的新型智能机器人。由于球形机器人具有的外壳和运动形式的特殊性,使其与我们熟知的轮式或轨道式以及类人机器人相比较,具有能在失稳后获得最大的稳定性,可以实现全向滚动,能够更加灵活转弯等诸多优点。总的看来目前球形机器人的研究还处于实验研究阶段,出现了各种各样的具有不同驱动机构的球形机器人,但是很少有人对其进行深入的动力学分析和研究,所以球形机器人的运动性能分析和控制工作就不能深入地开展。为此,本论文对一种具有稳定平台的全向滚动球形机器人进行了动力学分析和轨迹规划方面的研究。首先介绍了球形机器人的发展概况以及在目前球形机器人研究中遇到的主要问题和未来的发展趋势。然后介绍了一种具有稳定平台的全向滚动球形机器人装置,该球形机器人由装在球体内部、呈空间对称的四根轮辐上的四台步进电机驱动。根据该球形机器人的结构、运动学模型及其所采用的步进电机所具有的运动离散性的特点,通过寻找在球形机器人运动过程中每一步四个驱动电机合适的运动状态组合,提出了一种驱动球形机器人运动到目标点的轨迹规划方法。并通过ADAMS软件仿真验证了该轨迹规划方法的可行性。为了进一步研究球形机器人的运动性能和动态控制,对该球形机器人应用Lagrange-routh方程分别建立了其在平面上以及斜面上的完整动力学方程,给出了消去由系统受到的非完整约束所引入的Lagrange乘子的方法和步骤,并针对几种典型的运动情况对其进行了运动分析仿真,验证了该球形机器人动力学模型的正确性并对其进行了爬坡性能分析。在得到球形机器人的完整动力学模型之后,借助现代控制理论和神经网络的知识,构建了基于对角递归神经网络的PID球形机器人控制器。通过控制四台步进电机的输入,实现了球形机器人到达指定的目标点的控制目标。最后通过实例仿真验证了该方法的可行性。更多还原

【Abstract】 Spherical robots are a new type of intelligent robots with a global shell, and take the rolling as their main motion mode. The spherical robots have the advantages such as: obtaining the great steady ability after being imposed a disturbance, achieving the omnidirectional rolling and agile swerving compared with wheeled robots and tracked robots and humanoid robots, because of the special shell and motion mode. Spherical robots are still studied in laboratories at present. A number of spherical robots with different driving mechanism come forth in these years. But few peoples have completed the dynamic analysis and study of the spherical robots. The research on the motion performance analysis and control of the spherical robots can not be developed well for this reason. So this work mainly studies the dynamic analysis and the motion planning of a kind of omnidirectional rolling spherical robot with a stable platform.At the beginning, the general situation and the intending tendency of the research on the spherical robots is stated. The existing main problems in the research on the spherical robots follow. And then a kind of omnidirectional spherical rolling robot with a stable platform is introduced. This spherical robot is driven by four linear stepper motors on four screwed spokes in the shell. The whole system has geometrical symmetry in the three dimensional space. A motion planning method is presented based on the structure and the motion model of the robot and the motors’discrete motion nature. This motion planning method can drive the spherical robot to the destination by finding the most appropriate combinations of the four motors’motion states at each step of the spherical robot motion process. The simulation of ADAMS testifies the motion planning method. To study the motion performance and the dynamic control of the spherical robot further, the complete dynamic model of the robot on a plane and an inclined plane are established respectively using the Lagrange-routh equations. The strategy and the approach of how to eliminate the Lagrangian multipliers that were brought because of the spherical robot’s nonholonomical constrain are given. The dynamics analysis and simulation of some typical examples are developed, and the results validate the effectiveness of the dynamic model and the method. Based on the diagonal recurrent neural networks PID control, the controller of the spherical robot is given after getting the complete dynamic model of the spherical robot, using the modern control theory and the knowledge of the neural networks. The spherical robot can reach any arbitrary appointed destination by controlling the inputs of the four stepper motors. For a number of missions, it is shown that the method agrees well with the results.更多还原