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1.
自主车的运动仿真   总被引:3,自引:2,他引:1  
在自主车的运动路径规划中,局部路径规划特别重要,而且是自主车的一项关键技术。该文提出了将自主式多智能体的任务和反应性行为模型嵌入到离散事件系统框架中作局部路径规划的方法,此方法克服了势场法(包括早期的虚力场法)的缺陷,为确保自主车运动路径规划的可靠性和合理性,该文就局部路径规划对自主车作运动仿真。  相似文献   

2.
基于混合势场法的移动机器人路径规划   总被引:1,自引:1,他引:0  
针对目前移动机器人在路径规划中出现的问题,提出一种自主移动机器人路径规划的新方法——混合势场法。分析了人工势场法的不足,找出局部极小值点的形成原因;针对人工势场法中障碍物附近目标不可达问题,采用了在斥力场函数中加入斥力因子,使得机器人顺利到达目标点;针对陷入局部极小值和振荡的问题,提出了混合势场法,通过将势场法和可视图法结合起来,使得机器人走出局部极小值和振荡区域。最后,将混合势场法应用于室内移动机器人的路径规划中,仿真实验证明了该方法的有效性。  相似文献   

3.
《工矿自动化》2016,(9):37-42
针对矿井障碍物复杂多变、救灾机器人采用传统人工势场法进行路径规划易陷入局部极小点的问题,提出一种基于改进人工势场法的救灾机器人路径规划方法。该方法通过在引力场中加入扰动场来改变引力场函数,使救灾机器人在陷入局部极小点时自主走出局部极小点;结合障碍填充法,通过对凹障碍物进行虚拟填充,形成新的障碍物并产生相应的斥力场函数,避免救灾机器人再次陷入局部极小点。仿真及测试结果验证了该方法的可行性及有效性。  相似文献   

4.
田静  黄亚楼  刘作军 《机器人》2005,27(6):521-525
采用电路映射地图进行环境建模,在等效尺寸的基础上对带拖车移动机器人的路径规划进行研究.这种方法在局部规划的同时,兼备了路径规划的全局性,有效地从根本上避免了人工势场法等局部分析方法容易陷入局部最优的不足.理论分析和仿真验证了本方法的可行性和正确性.  相似文献   

5.
针对于移动机器人在传统人工势场法路径规划中易于陷入局部最小点而无法抵达目标点的问题,同时考虑到实际环境中人工势场法相关参数的不确定性,提出了一种基于模糊人工势场法的动态路径规划方法。借助于专家经验进行模糊决策,调整移动机器人在各个时刻的合力大小和方向,进而解决斥力常数、引力方向偏角以及机器人行驶速度的不确定性问题。为了验证该方法的有效性,在智能全向车平台进行了应用,结果表明,智能全向车运动轨迹平滑,避免了实际应用中的震荡问题。  相似文献   

6.
复杂环境中基于人工势场优化算法的最优路径规划   总被引:9,自引:0,他引:9  
本文提出一种基于人工势场优化的路径规划方法.把人工势场的路径规划结果作为先验知识,对蚁群算法进行初始化,提高了蚁群算法的优化效率;另一方面,机器人的路径也同时得到优化,克服了人工势场法的局部极小问题.仿真实验结果表明,该方法在复杂环境中能有效地实现最优路径规划;并提供了一种把传统规划方法和统计优化相结合、提高规划效率的可行思路.  相似文献   

7.
传统的人工势场法由于存在局部极小值问题,使智能无人车无法到达目标点。本文提出一种角度偏移的改进人工势场方法来进行避障的路径规划。介绍传统人工势场模型,详细介绍改进人工势场方法,并且对改进人工势场法进行仿真,实验证明方法的有效性。  相似文献   

8.
张禹  徐红丽  韦茵  封锡盛 《机器人》2006,28(3):321-325
为了解决远程自主水下机器人(LAUV)路径规划问题,提出一种基于数字海图的路径规划算法.该算法对传统人工势场法进行了有效改进,克服了传统人工势场法固有的缺点和不足,可以用于LAUV离线和在线路径规划.其有效性已在半物理实时仿真平台上得到了验证.  相似文献   

9.
目前为止,已经存在多种路径规划方案,各有优缺点。文中结合栅格法与势场法的优点,而本身方法的缺点可以通过对方的优点来克服,为家居机器人提供一套有效可行的路径规划方案。由于局部采用势场法规划路径,栅格的大小可以适当变大,这样可提高全局路径的搜索效率;而在规划局部路径时可忽略当前局部以外的因素,能够处理好突发情况。该方案在"家庭生活支援多机器人系统"中得到较好的应用,机器人能够根据周边情况及时调整好自己的行走路线。  相似文献   

10.
基于传统人工势场法的机器人路径规划存在障碍物附近目标不可达和局部极小点的问题。在研究该问题产生原因的基础上,提出了一种基于改进人工势场法的移动机器人路径规划算法。该算法在斥力函数中引入了机器人和目标点之间的距离,在极小点附近自主建立虚拟目标牵引点并隔离原有目标点,解决了传统人工势场法的局部极小点问题,使机器人到达了目标点。仿真结果说明了改进后算法的有效性。  相似文献   

11.
In this article, a new collision-avoidance scheme is proposed for autonomous land vehicle (ALV) navigation in indoor corridors. The goal is to conduct indoor collisionfree navigation of a three-wheel ALV among static obstacles with no a priori position information as well as moving obstacles with unknown trajectories. Based on the predicted positions of obstacles, a local collision-free path is computed by the use of a modified version of the least-mean-square-error (LMSE) classifier in pattern recognition. Wall and obstacle boundaries are sampled as a set of 2D coordinates, which are then viewed as feature points. Different weights are assigned to different feature points according to the distances of the feature points to the ALV location to reflect the locality of path planning. The trajectory of each obstacle is predicted by a real-time LMSE estimation method. And the maneuvering board technique used for nautical navigation is employed to determine the speed of the ALV for each navigation cycle. Smooth collision-free paths found in the simulation results are presented to show the feasibility of the proposed approach.  相似文献   

12.
A vision-based approach to unsupervised learning of the indoor environment for autonomous land vehicle (ALV) navigation is proposed. The ALV may, without human's involvement, self-navigate systematically in an unexplored closed environment, collect the information of the environment features, and then build a top-view map of the environment for later planned navigation or other applications. The learning system consists of three subsystems: a feature location subsystem, a model management subsystem, and an environment exploration subsystem. The feature location subsystem processes input images, and calculates the locations of the local features and the ALV by model matching techniques. To facilitate feature collection, two laser markers are mounted on the vehicle which project laser light on the corridor walls to form easily detectable line and corner features. The model management subsystem attaches the local model into a global one by merging matched corner pairs as well as line segment pairs. The environment exploration subsystem guides the ALV to explore the entire navigation environment by using the information of the learned model and the current ALV location. The guidance scheme is based on the use of a pushdown transducer derived from automata theory. A prototype learning system was implemented on a real vehicle, and simulations and experimental results in real environments show the feasibility of the proposed approach.  相似文献   

13.
14.
A vision-based approach to obstacle avoidance for autonomous land vehicle (ALV) navigation in indoor environments is proposed. The approach is based on the use of a pattern recognition scheme, the quadratic classifier, to find collision-free paths in unknown indoor corridor environments. Obstacles treated in this study include the walls of the corridor and the objects that appear in the way of ALV navigation in the corridor. Detected obstacles as well as the two sides of the ALV body are considered as patterns. A systematic method for separating these patterns into two classes is proposed. The two pattern classes are used as the input data to design a quadratic classifier. Finally, the two-dimensional decision boundary of the classifier, which goes through the middle point between the two front vehicle wheels, is taken as a local collision-free path. This approach is implemented on a real ALV and successful navigations confirm the feasibility of the approach.  相似文献   

15.
A knowledge-based navigation system for autonomous land vehicles (ALVs) has been developed which can successfully negotiate an obstacle and threat-laden terrain, even if nothing is known beforehand about the terrain. The ALV stores new information in its memory as it travels, has the ability to backtrack out of unexpected dead ends, and performs spontaneous decision making in the field based on local sensor readings. The optimal global route of the ALV journey is obtained using dynamic programming, and decision making is accomplished via a production rule-based system. Execution examples demonstrate the power of the prototype system to solve navigation problems. This establishes the feasibility of constructing a valid ALV by combining search techniques with artificial intelligence tools such as production rule-based systems.  相似文献   

16.
Trajectory planning and trajectory tracking constitute two important functions of an autonomous overtaking system and a variety of strategies have been proposed in the literature for both functionalities. However, uncertainties in environment perception using the current generation of sensors has resulted in most proposed methods being applicable only during low-speed overtaking. In this paper, trajectory planning and trajectory tracking approaches for autonomous overtaking systems are reviewed. The trajectory planning techniques are compared based on aspects such as real-time implementation, computational requirements, and feasibility in real-world scenarios. This review shows that two important aspects of trajectory planning for high-speed overtaking are: (i) inclusion of vehicle dynamics and environmental constraints and (ii) accurate knowledge of the environment and surrounding obstacles. The review of trajectory tracking controllers for high-speed driving is based on different categories of control algorithms where their respective advantages and disadvantages are analysed. This study shows that while advanced control methods improve tracking performance, in most cases the results are valid only within well-regulated conditions. Therefore, existing autonomous overtaking solutions assume precise knowledge of surrounding environment which is not representative of real-world driving. The paper also discusses how in a connected driving environment, vehicles can access additional information that can expand their perception. Hence, the potential of cooperative information sharing for aiding autonomous high-speed overtaking manoeuvre is identified as a possible solution.  相似文献   

17.
The capability of following a moving target in an environment with obstacles is required as a basic and necessary function for realizing an autonomous unmanned surface vehicle (USV). Many target following scenarios involve a follower and target vehicles that may have different maneuvering capabilities. Moreover, the follower vehicle may not have prior information about the intended motion of the target boat. This paper presents a trajectory planning and tracking approach for following a differentially constrained target vehicle operating in an obstacle field. The developed approach includes a novel algorithm for computing a desired pose and surge speed in the vicinity of the target boat, jointly defined as a motion goal, and tightly integrates it with trajectory planning and tracking components of the entire system. The trajectory planner generates a dynamically feasible, collision-free trajectory to allow the USV to safely reach the computed motion goal. Trajectory planning needs to be sufficiently fast and yet produce dynamically feasible and short trajectories due to the moving target. This required speeding up the planning by searching for trajectories through a hybrid, pose-position state space using a multi-resolution control action set. The search in the velocity space is decoupled from the search for a trajectory in the pose space. Therefore, the underlying trajectory tracking controller computes desired surge speed for each segment of the trajectory and ensures that the USV maintains it. We have carried out simulation as well as experimental studies to demonstrate the effectiveness of the developed approach.  相似文献   

18.
针对越野环境下的地图创建问题,提出了一种自动创建自主车导航地图的方法。首先将车载摄像机获得的图像投影到车体坐标系,然后结合车辆行驶轨迹信息采用基于标记的分水岭算法判定可通行区域,最后融合局部俯视图信息生成全局一致地图,并在实时导航需求下对地图进行优化得到最终的导航地图。自主车实车实验结果表明,该方法生成的地图满足自主车实时导航需求,提高了路径规划效率。  相似文献   

19.
基于势场的运动路径规划   总被引:5,自引:2,他引:3  
耿兆丰  吴永敢 《机器人》1992,14(5):38-43
本文阐述了基于势场的三轮自治车(AV)运动路径规划,以由障碍物和目标产生的虚拟势场力作为 AV运动的驱动力.先讨论了势场力的存在条件包括距离条件和方向条件并提出了计算方法,然后讨论了把 AV 简化成杆的运动路径规划,包括 AV 及杆的运动机理、加权势场合力的求法及其控制作用和运动定位等问题.最后给出了仿真结果.本文首次将势场法应用于三轮 AV 的路径规划.  相似文献   

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