New technique of mobile robot navigation using a hybrid adaptive fuzzy potential field approach

This paper presents a summary of the research aimed at developing a new reliable methodology for robot navigation and obstacle avoidance. This new approach is based on the artificial potential field (APF) method, which is used extensively for obstacle avoidance. The classical APF is dependent only on the separation distance between the robot and the surrounding obstacles. The new scheme introduces a variable, which is used to determine the importance that each obstacle has on the robot's future path. The importance variable is dependent on the obstacles position, both angle and distance, with respect to the robot. Simulation results are presented demonstrating the ability of the algorithm to perform successfully in simple environments.     

基于动态模糊人工势场法的移动机器人路径规划

传统人工势场法在路径规划中存在局部极小值问题,而且不能满足动态环境中移动机器人路径规划对实时性、安全性和可达性的要求.针对传统人工势场法存在的问题,通过引入速度矢量,改势场力函数,并与模糊控制方法相结合,实时调节斥力势场系数,克服人工势场法的缺陷.在MATLAB平台中验证了方法的有效性,实验结果表明,该方法优于人工势场法模型的路径规划.     

A layered goal-oriented fuzzy motion planning strategy for mobile robot navigation.

Most conventional motion planning algorithms that are based on the model of the environment cannot perform well when dealing with the navigation problem for real-world mobile robots where the environment is unknown and can change dynamically. In this paper, a layered goal-oriented motion planning strategy using fuzzy logic is developed for a mobile robot navigating in an unknown environment. The information about the global goal and the long-range sensory data are used by the first layer of the planner to produce an intermediate goal, referred to as the way-point, that gives a favorable direction in terms of seeking the goal within the detected area. The second layer of the planner takes this way-point as a subgoal and, using short-range sensory data, guides the robot to reach the subgoal while avoiding collisions. The resulting path, connecting an initial point to a goal position, is similar to the path produced by the visibility graph motion planning method, but in this approach there is no assumption about the environment. Due to its simplicity and capability for real-time implementation, fuzzy logic has been used for the proposed motion planning strategy. The resulting navigation system is implemented on a real mobile robot, Koala, and tested in various environments. Experimental results are presented which demonstrate the effectiveness of the proposed fuzzy navigation system.     

基于传感器的非完整移动机器人运动规划

针对非完整移动机器人在未知室内环境中提出了一种路径规划方法, 通过利用传感器对周围环境的探测和实时处理传感器数据, 以及所设计的目标寻找函数, 可以有效地完成其运动规划. 该方法能够确保移动机器人在无障碍物区或障碍物对机器人不构成危险时加速前进, 在障碍物区能够慢速绕过, 从而使得移动机器人快速且安全地到达目标位置, 仿真的结果证明了该方法的有效性.     

动态环境下基于改进人工势场的机器人实时路径规划仿真研究

提出了一种基于改进人工势场法进行动态环境的路径规划的方法。通过梯度逼近进行运动目标的搜索,解决了在实时路径规划中因环境的运动信息难以准确获取而造成的路径规划无法完成的问题。仿真结果验证了方法的有效性,能够较好的解决动态环境下特别是存在随机运动物体情况下移动机器人的路径规划问题。     

非完整移动机器人鲁棒运动规划

非完整移动机器人利用传感器可以解决不确定性模型和未知环境中的许多问题. 利用移动机器人上配备的传感器的信息组合提出了一种在线视点寻求算法, 结合移动机器人的运动方程和传感器的量测方程采用扩展Kalman估计来对移动机器人的位置进行修正, 以降低运动的不确定性, 从而得到一种鲁棒的规划算法, 仿真的结果证明了上述方法是行之有效的.     

基于混合势场法的移动机器人路径规划

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。     

基于势场法的移动机器人路径规划仿真研究

针对势场法的障碍物附近目标不可达（GNRON）问题,采用改进斥力势场函数,把机器人和目标的相对距离考虑进去,从而确保目标点为整个势场的全局最小点,使得机器人能够顺利到达目标。针对局部极小引起的陷阱区域问题,提出了增加引导点的方法,使得机器人能够快速走出陷阱区域,向目标点移动。通过仿真实验,还实现了机器人在限定区域内漫游。改进后的势场法适用于复杂环境下的移动机器人路径规划。仿真结果证明了此方法的有效性。     

基于改进人工势场法的移动机器人路径规划

针对势场法的障碍物附近目标不可达的问题,改进了传统人工势场斥力函数,确保目标点是机器人的势场全局最小点,使得机器人顺利到达目标点。针对势场法的局部最小值问题,提出了一种连接局部最小值区域障碍物的方法,建立了机器人离散传感器模型,使机器人快速走出局部最小值区域。改进后的人工势场法适用于复杂室内环境下的机器人路径规划。仿真结果证明了该方法的有效性。     

Deadlock-free motion planning using the Laplace potential field

In this paper we introduce a motion planning method which uses an artificial potential field obtained by solving Laplace's differential equation. A potential field based on Laplace's equation has no minimal point; therefore, path planning is performed without falling into local minima. Furthermore, we propose an application of the motion planning method for recursive motion planning in an uncertain environment. We illustrate the robot motion generated by the proposed method with simulation examples.     

Autonomous fuzzy parking control of a car-like mobile robot

This paper is devoted to design and implement a car-like mobile robot (CLMR) that possesses autonomous garage-parking and parallel-parking capability by using real-time image processing. For fuzzy garage-parking control (FGPC) and fuzzy parallel-parking control (FPPC), feasible reference trajectories are provided for the fuzzy logic controller to maneuver the steering angle of the CLMR. We propose two FGPC methods and two FPPC methods to back-drive or head-in the CLMR to the garage and the parking lot, respectively. Simulation results illustrate the effectiveness of the developed schemes. The overall experimental setup of the parking system developed in this paper is composed of a host computer, a communication module, a CLMR, and a vision system. Finally, the image-based real-time implementation experiments of the CLMR demonstrate the feasibility and effectiveness of the proposed schemes.     

基于改进人工势场法的移动机器人路径规划

针对传统人工势场法在路径规划过程中容易陷入陷阱区域和局部极小点的问题,提出了一种改进人工势场法。首先,提出安全距离概念,避免了不必要的路径,从而解决了路径过长和算法运行时间过长问题;然后,为避免机器人陷入局部极小点和陷阱区域,在算法中引入预测距离,使得算法可以在机器人陷入局部极小点或陷阱区域之前做出反应;最后,通过合理设置虚拟目标点,引导机器人避开局部极小点和陷阱区域。实验结果表明,改进算法可以有效解决传统算法容易陷入局部极小点和陷阱区域的问题;同时,相较于传统人工势场法,所提算法规划出的路径长度减少了5.2%,计算速度提高了405.56%。     

轮足复合移动机器人运动规划发展现状及关键技术分析

地面移动机器人已经在资源勘探和灾难救援等多领域得到广泛应用,轮足复合机器人能够结合轮式运动速度快、平稳性高和足式运动的高越障性能等多方面优势,在理论创新和工程技术方面均有重要的研究价值.对近年来国内外轮足复合机器人的机械结构进行分析和比较,将轮足机构复合方式分为4类进行列举和总结.针对多模态运动的优势展开分析,列举轮足复合机器人主要采用的运动建模、规划和控制策略,不仅涉及单独的足式运动和轮式运动,同时涉及足端越障、变构型避障、轨迹规划的轮足复合运动.最后对运动规划关键技术进行总结和展望,指出轮足复合移动机器人后续的发展方向、研究思路和所面临的挑战.     

基于改进人工势场法的移动机器人路径规划

针对传统人工势场法在路径规划过程中容易陷入陷阱区域和局部极小点的问题，提出了一种改进人工势场法。首先，提出安全距离概念，避免了不必要的路径，从而解决了路径过长和算法运行时间过长问题；然后，为避免机器人陷入局部极小点和陷阱区域，在算法中引入预测距离，使得算法可以在机器人陷入局部极小点或陷阱区域之前做出反应；最后，通过合理设置虚拟目标点，引导机器人避开局部极小点和陷阱区域。实验结果表明，改进算法可以有效解决传统算法容易陷入局部极小点和陷阱区域的问题；同时，相较于传统人工势场法，所提算法规划出的路径长度减少了5.2%，计算速度提高了405.56%。     

An interactive tool for mobile robot motion planning

This paper presents an interactive tool aimed at facilitating the understanding of several well-known algorithms and techniques involved in solving mobile robot motion problems. These range from those modelling the mechanics of mobility to those used in navigation. The tool focuses on describing these problems in a simple manner in order to be useful for education purposes among different disciplines. By highlighting interactivity, the tool provides a novel means to study robot motion planning ideas in a manner that enhances full understanding. Furthermore, the paper discuses how the tool can be used in an introductory course of mobile robotics.     

Acquisition of obstacle motion patterns to improve mobile robot motion planning

Mobile robots for advanced applications have to act in environments which contain moving obstacles (humans). Even though the motions of such obstacles are not precisely predictable, usually they are not completely random; long-term observation of obstacle behavior may thus yield valuable knowledge about prevailing motion patterns. By incorporating such knowledge as statistical data, a new approach called statistical motion planning yields robot motions which are better adapted to the dynamic environment. To put these ideas into practice, an experimental system has been developed. Cameras observe the workspace in order to detect obstacle motion. Statistical data is derived and represented as a set of stochastic trajectories. This data can be directly employed in order to calculate collision probability, i.e. the probability of encountering an obstacle during the robot's motion. Further aspects of motion planning are addressed: path planning which minimizes collision probability, estimation of expected time to reach the goal and reactive planning.     

Two-wheeled mobile robot motion control in dynamic environments

In this paper, a feedback control scheme of a two-wheeled mobile robot is explored in dynamic environments. In the existence of local minima, the design of controller is based on Lyapunov function candidate and considers virtual forces information including detouring force. Simulation results are presented to show the effectiveness of the proposed control scheme.     

基于模糊人工势场法的智能全向车路径规划

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。     

模糊控制在移动机器人路径规划中的应用

针对移动机器人最优路径规划问题,设计了一种模糊智能控制方法。利用超声波传感器对机器人周围环境进行探测,得到关于障碍物和目标的信息。通过设计模糊控制器,把得到的障碍与目标位置信息模糊化,建立模糊规则并解模糊最终使机器人可以很好地避障,并且解决了模糊算法存在的死锁问题,从而实现了移动机器人的路径规划。仿真实验结果表明了模糊算法优于人工势场法,具有有效性和可行性。