基于多超声波传感器的自主移动机器人探测系统

超声波传感器在自主式移动机器人领域有着广泛的应用.本研究根据自主式移动机器人对实时探测未知环境的要求以及超声波传感器的特点,设计并实现了一种适用于自主式移动机器人的声纳环探测系统.首先,采用了多超声波分组循环发射的方法,极大地降低了多超声波传感器之间的回波干扰;然后在对原始数据进行初步处理的基础上,给出了多种距离信息表示形式;测试结果及其分析证明了本系统的鲁棒性及实用性.     

基于模糊控制信息融合方法的机器人导航系统

本文提出了一种基于模糊控制和信息融合的自主式移动机器人导航系统的实现方法.采用表格查询的模糊控制方法,对导航系统中的多传感器信息进行融合,实现了机器人的路径跟踪和自动纠偏的功能.该系统具有实现简单、响应快、鲁棒性好等特点,仿真实验和实际运行结果表明了该系统在具有引导线的环境中能有效实现自主式移动机器人的导航.     

自主式移动机器人系统的体系结构

本文在分析已有的几中多智能体协调模型的基础上，提出了一种用于自主式移动机器人系统的多智能体协调模型（离散）事件状态模型，用于组织协调自主式移动机器人系统中的传感器、规划、控制等智能体协调工作，确保自主式移动机器人在复杂、不断变化的环境中自主行驶，并在自主式移动机器人项目中较好地发挥了作用。     

移动机器人红外感测系统研制

文章充分利用红外传感器的优点,研制了基于红外传感器的移动机器人感测系统.该感测系统由基于分立反射式红外传感器的测距系统、基于一体反射式红外传感器的引导系统、基于热释电红外传感器的跟踪系统组成.文章完成了感测系统软硬件设计,并进行了详细的理论和实验研究.实验结果表明文章设计的系统结构简单、精度高、可靠性高、成本低,具有普遍的应用意义和广泛的应用价值.该感测系统在移动机器人避障导航中得到了良好的应用.     

基于超声传感器阵列的陆地自主车测距

目前,超声波传感器主要用于低速运动的自主式移动机器人短距离测量,采用的测距方法多把串音干扰看作有用信号的干扰项,尽可能排除.基于远距离超声波传感器,本文利用串音干扰设计了一种适用于高速行驶的陆地自主车进行远距离测量的方法.实验结果表明此方法的可靠性和精度都能满足陆地自主车的距离探测要求.     

基于模糊控制信息融合方法的机器人导航系统

本文提出了一种基于模糊控制和信息融合的自主式移动机器人导航系统的实现方法。采用表格查询的模糊控制方法,对导航系统中的多传感器信息进行融合,实现了机器人的路径跟踪和自动纠偏的功能。该系统具有实现简单、响应快、鲁棒性好等特点,仿真实验和实际运行结果表明了该系统在具有引导线的环境中能有效实现自主式移动机器人的导航。     

多传感器技术在机器人系统中的应用和研究

探讨了多传感器融合系统的软件结构设计方案，说明了如何设计一个基于多传感器的自主式智能机器人系统，提出了基于BP神经网络的融合方法。搭建了一个多传感器的智能机器人试验平台，实现了由两个摄像头组成的立体视觉和超声波传感器的融合。试验表明，多传感器融合技术在自主式智能系统中具有重要作用。     

基于多传感器信息融合的移动机器人导航综述

综述了自主式移动机器人导航技术,对其中的同步定位与地图创建、路径规划以及多传感器信息融合等技术进行了详细的分析,并从基于地图、基于环境和基于行为3个方面全面地阐述了移动机器人路径规划技术的研究现状.对当前的研究热点SLAM技术、遗传算法和基于行为的规划算法等进行了较为详细的介绍和分析.同时,展望了移动机器人导航技术的发展趋势.     

模糊神经网络在移动机器人信息融合中的应用

针对移动机器人所用的传感器,提出了一种用于多传感器信息融合的方法,将模糊逻辑和神经网络结合起来,构建了模糊神经网络,并建立了网络的计算模型.通过建立的模糊神经网络对移动机器人的多传感器信息进行融合,实现了移动机器人对动态环境中障碍和环境类型的实时识别以及无冲突运动.网络的训练和试验表明该方法在移动机器人躲避运动物体中是可行的.     

移动机器人的多传感器测距系统设计

在移动机器人的路径规划过程中,必须掌握障碍物的距离信息.基于超声波和红外传感器的测距原理,设计了一种移动机器人多传感器测距系统,可测量0～200 cm距离内存在的障碍物,测量误差小于1 %.采用超声波和红外2种传感器组成3组测距采集系统,采集机器人3个不同方位的障碍物信息,解决了单一传感器测距盲区的问题,并详细介绍了该系统的软件和硬件设计.     

A new space and time sensor fusion method for mobile robot navigation

To fully utilize the information from the sensors of mobile robot, this paper proposes a new sensor‐fusion technique where the sample data set obtained at a previous instant is properly transformed and fused with the current data sets to produce a reliable estimate for navigation control. Exploration of an unknown environment is an important task for the new generation of mobile service robots. The mobile robots may navigate by means of a number of monitoring systems such as the sonar‐sensing system or the visual‐sensing system. Notice that in the conventional fusion schemes, the measurement is dependent on the current data sets only. Therefore, more sensors are required to measure a given physical parameter or to improve the reliability of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequences of the data sets are stored and utilized for the purpose. The basic principle is illustrated by examples and the effectiveness is proved through simulations and experiments. The newly proposed STSF (space and time sensor fusion) scheme is applied to the navigation of a mobile robot in an environment using landmarks, and the experimental results demonstrate the effective performance of the system. © 2004 Wiley Periodicals, Inc.     

基于构件的移动机器人软件系统开发

论述了移动机器人系统的特点．针对其软件环境的设计目标,提出把软件构件的思想应用在机器人系统中．利用这种技术设计了几个具体的构件,并实现了移动机器人对运动目标的跟踪任务．实验结果表明,基于这种技术开发的机器人软件系统方便地实现了跨平台和多种语言编程;在不降低性能的前提下,简化了软件的复杂度,并且构件的可复用特点使开发周期和成本大大降低,在实际应用中达到了良好的效果．     

A Sequential Bi-criteria Search Algorithm for Robot Path Planning in the Box Pushing Problem

The collision-free trajectory planning method subject to control constraints for mobile manipulators is presented. The robot task is to move from the current configuration to a given final position in the workspace. The motions are planned in order to maximise an instantaneous manipulability measure to avoid manipulator singularities. Inequality constraints on state variables i.e. collision avoidance conditions and mechanical constraints are taken into consideration. The collision avoidance is accomplished by local perturbation of the mobile manipulator motion in the obstacles neighbourhood. The fulfilment of mechanical constraints is ensured by using a penalty function approach. The proposed method guarantees satisfying control limitations resulting from capabilities of robot actuators by applying the trajectory scaling approach. Nonholonomic constraints in a Pfaffian form are explicitly incorporated into the control algorithm. A computer example involving a mobile manipulator consisting of nonholonomic platform (2,0) class and 3DOF RPR type holonomic manipulator operating in a three-dimensional task space is also presented.     

Optimal Motion Planning of Robotic Manipulators Removing Mobile Objects Grasped in Motion

The following study deals with motion optimization of robot arms having to transfer mobile objects grasped when moving. This approach is aimed at performing repetitive transfer tasks at a rapid rate without interrupting the dynamics of both the manipulator and the moving object. The junction location of the robot gripper with the object, together with grasp conditions, are partly defined by a set of local constraints. Thus, optimizing the robot motion in the approach phase of the transfer task leads to the statement of an optimal junction problem between the robot and the moving object. This optimal control problem is characterized by constrained final state and unknown traveling time. In such a case, Pontryagin"s maximum principle is a powerful mathematical tool for solving this optimization problem. Three simulated results of removing a mobile object on a conveyor belt are presented; the object is grasped in motion by a planar three-link manipulator.     

Maximizing Reward in a Non-Stationary Mobile Robot Environment

The ability of a robot to improve its performance on a task can be critical, especially in poorly known and non-stationary environments where the best action or strategy is dependent upon the current state of the environment. In such systems, a good estimate of the current state of the environment is key to establishing high performance, however quantified. In this paper, we present an approach to state estimation in poorly known and non-stationary mobile robot environments, focusing on its application to a mine collection scenario, where performance is quantified using reward maximization. The approach is based on the use of augmented Markov models (AMMs), a sub-class of semi-Markov processes. We have developed an algorithm for incrementally constructing arbitrary-order AMMs on-line. It is used to capture the interaction dynamics between a robot and its environment in terms of behavior sequences executed during the performance of a task. For the purposes of reward maximization in a non-stationary environment, multiple AMMs monitor events at different timescales and provide statistics used to select the AMM likely to have a good estimate of the environmental state. AMMs with redundant or outdated information are discarded, while attempting to maintain sufficient data to reduce conformation to noise. This approach has been successfully implemented on a mobile robot performing a mine collection task. In the context of this task, we first present experimental results validating our reward maximization performance criterion. We then incorporate our algorithm for state estimation using multiple AMMs, allowing the robot to select appropriate actions based on the estimated state of the environment. The approach is tested first with a physical robot, in a non-stationary environment with an abrupt change, then with a simulation, in a gradually shifting environment.     

Achieving high performance sonar-based wall-following

In this paper we develop a technique to achieve robust high performance real-time wallfollowing behavior of a mobile robot in an indoor office environment, more specifically, in a corridor environment. The mobile robot achieves increasingly better performance by learning the environment's (most important) features in successive runs through it. This allows the robot to perform the task repeatedly, reliably, increasing the speed at which it is done after every step, without losing accuracy. We are basing our approach in the Spatial Semantic Hiearchy [Kuipers et. al. 1993].     

Discovering and restoring changes in object positions using an autonomous robot with laser rangefinders

This paper describes an object rearrangement system for an autonomous mobile robot. The objective of the robot is to autonomously explore and learn about an environment, to detect changes in the environment on a later visit after object disturbances and finally, to move objects back to their original positions. In the implementation, it is assumed that the robot does not have any prior knowledge of the environment and the positions of the objects. The system exploits Simultaneous Localisation and Mapping (SLAM) and autonomous exploration techniques to achieve the task. These techniques allow the robot to perform localisation and mapping which is required to perform the object rearrangement task autonomously. The system includes an arrangement change detector, object tracking and map update that work with a Polar Scan Match (PSM) Extended Kalman Filter (EKF) SLAM system. In addition, a path planning technique for dragging and pushing an object is also presented in this paper. Experimental results of the integrated approach are shown to demonstrate that the proposed approach provides real-time autonomous object rearrangements by a mobile robot in an initially unknown real environment. Experiments also show the limits of the system by investigating failure modes.     

A Neural Network Approach to Dynamic Task Assignment of Multirobots

In this paper, a neural network approach to task assignment, based on a self-organizing map (SOM), is proposed for a multirobot system in dynamic environments subject to uncertainties. It is capable of dynamically controlling a group of mobile robots to achieve multiple tasks at different locations, so that the desired number of robots will arrive at every target location from arbitrary initial locations. In the proposed approach, the robot motion planning is integrated with the task assignment, thus the robots start to move once the overall task is given. The robot navigation can be dynamically adjusted to guarantee that each target location has the desired number of robots, even under uncertainties such as when some robots break down. The proposed approach is capable of dealing with changing environments. The effectiveness and efficiency of the proposed approach are demonstrated by simulation studies.     

Task segmentation in a mobile robot by mnSOM: a new approach to training expert modules

Proposed is a new approach to task segmentation in a mobile robot by a modular network SOM (mnSOM). In a mobile robot the standard mnSOM is not applicable as it is, because it is based on the assumption that class labels are known a priori. In a mobile robot, only a sequence of data without segmentation is available. Hence, we propose to decompose it into many subsequences, supposing that a class label does not change within a subsequence. Accordingly, training of mnSOM is done for each subsequence in contrast to that for each class in the standard mnSOM. The resulting mnSOM demonstrates good segmentation performance of 94.05% for a novel dataset.     

基于模糊控制器的机器人路径规划研究

针对复杂环境下移动机器人路径规划实际问题,提出了一种基于行为的移动机器人控制体系结构,设计了一种基于模糊控制器的移动机器人实时路径规划算法,为移动机器人在未知环境中的导航提出了一种新的思路.仿真结果表明,移动机器人能够克服环境中的不确定性,可靠地完成复杂任务,该算法有计算量小,效率高,鲁棒性好等优点.