【作者】 张成钢；

【导师】 孙茂相；

【作者基本信息】 沈阳工业大学 ， 控制理论与控制工程， 2003， 硕士

【摘要】 本文研究移动机器人在移动障碍物具有不确定性时的运动规划问题。移动机器人在动态环境中运行时，它所处的环境经常会发生变化，如可能出现突发的障碍物，或在机器人的局部动态避碰过程中，机器人正在处理的障碍物的运动存在很强的不确定性，如果机器人在避碰时没有考虑到这一点就很可能导致避碰失败。本文主要研究下列问题： 1．针对移动障碍物运动速度的大小和运动方向的不确定性，本文采用概率统计的方法为移动障碍物的不确定性进行建模，根据中心极限定理，将移动障碍物运动的速度和方向用正态分布来描述，通过数理统计方法对正态分布的参数进行估计。 2．使用一种基于相对速度的实时避碰算法，根据对障碍物运动不确定性估计得来的数据对移动障碍物在下一时刻可能处在的位置的范围进行计算，据此范围对移动障碍物的尺寸进行膨化处理，机器人对膨化后的移动障碍物进行避碰，实现了对具有运动不确定性的障碍物的有效避碰。 3．使用一种通过改变机器人的运动速度来进行对移动障碍物的避碰方法。在机器人与移动障碍物不在同一条路径上运动及彼此的路径不平行相邻的条件下，仅需要改变机器人的运动速度的大小而不改变机器人的运动方向实现避碰。机器人在对移动障碍物的运动不确定性通过统计方法进行估计，近似计算出移动障碍物到达路径交叉点的时间，并对交叉点的位置进行修正，根据障碍物的运动不确定性计算出其在交叉点的位置分布范围，由这个分布范围修改机器人与移动障碍物之间的安全距离，最终确定出机器人所需的等待时间。 仿真实验证明了本文所提规划方法的正确性和可行性。更多还原

【Abstract】 In this thesis, motion planning for a mobile robot in a dynamic environment is studied. The environments of mobile robot locating always vary, if it is running in a dynamic environment. For instance, it is possible that unknown obstacles appear, or the motion of moving obstacles which robot is dealing with exist large uncertainty in process of local obstacle avoidance. It may cause obstacle avoidance failure without considering these situations in process of robot motion planning. The main results state as the following:1. Aiming at the uncertainty of velocity and direct of moving obstacle, this thesis models the motion uncertainty using the method of probability statistics. According to central limitation theorem, the velocity and direction of moving obstacle using normal distribution are represented, and the parameters of normal distribution through the method of probability statistics are estimated.2. A real-time obstacle avoidance algorithm underlying relative velocity is discussed. According to the estimated data of uncertainty, the range of the position of obstacle is computed at next time; furthermore, the dimension of obstacle according the range is enlarged. Robot will deal with the enlarged obstacle to realize obstacle avoidance.3. Another obstacle avoidance algorithm that only changes the magnitude of robot’s velocity is investigated. While the motion directions are not on a same straight line, according to the estimated data of uncertainty, the time of obstacle getting to cross point is computed, and the position of cross point is modified; furthermore, the range of obstacle at crossing point is computed. With this range, the safe distance is modified; finally, the waiting time of robot is computed.Simulation examples are presented to show the feasibility and effectiveness of the approaches and algorithms in this thesis.更多还原