A learning particle swarm optimization algorithm for odor source localization

This paper is concerned with the problem of odor source localization using multi-robot system. A learning particle swarm optimization algorithm, which can coordinate a multi-robot system to locate the odor source, is proposed. First, in order to develop the proposed algorithm, a source probability map for a robot is built and updated by using concentration magnitude information, wind information, and swarm information. Based on the source probability map, the new position of the robot can be generated. Second, a distributed coordination architecture, by which the proposed algorithm can run on the multi-robot system, is designed. Specifically, the proposed algorithm is used on the group level to generate a new position for the robot. A consensus algorithm is then adopted on the robot level in order to control the robot to move from the current position to the new position. Finally, the effectiveness of the proposed algorithm is illustrated for the odor source localization problem.     

基于头脑风暴优化算法的多机器人气味源定位

针对现有室内湍流环境下多机器人气味源搜索算法存在历史浓度信息利用率不高、缺少调节全局与局部搜索的机制等问题,提出头脑风暴优化（BSO）算法与逆风搜索结合的多机器人协同搜索算法。首先,将机器人已搜索位置初始化为个体,以机器人位置为中心聚类,有效利用了历史信息的指引作用;然后,将逆风搜索作为个体变异操作,动态调节选中一个类中个体或两个类中个体融合生成新个体的数量,有效调节了全局和局部搜索方式;最后,根据浓度和持久性两个指标对气味源进行确认。在有障碍和无障碍两个环境中将所提算法与三种群体智能多机器人气味源定位算法进行定位对比仿真实验,实验结果表明,所提算法的平均搜索时间减少33%以上,且定位准确率达到100%。该算法能够有效调节机器人全局和局部搜索关系,快速准确定位气味源。     

基于无线传感器网络的气体泄漏源定位机器人设计

如何确定有害气体泄漏源的位置是机器人主动嗅觉要解决的关键问题。围绕移动机器人气体泄漏源定位问题,将Z字形算法和浓度梯度法相结合用于机器人气味源搜索运动控制,使其快速找到气味源。同时,在传统的移动嗅觉机器人上增加了无线传感器定位模块,使操作人员在远离泄漏源的电脑上即可获得气味源的坐标信息。实验证明：机器人可以找到泄漏源,并确定气味源位置,搜索效率比单独使用浓度梯度法高。     

SPIRAL: A novel biologically-inspired algorithm for gas/odor source localization in an indoor environment with no strong airflow

This work describes the design and experimental results of an algorithm, designed to localize a gas source in an indoor environment with no strong airflow by using an autonomous agent. This condition exacerbates the patchiness and intermittency of odor distribution, typical of turbulent flows in the presence of strong mean flows. Furthermore, no information about the wind can be used to detect the position of the source. In the approach proposed here, the robot moves along spirals. A spiral can be reset and a new one started, based on the information acquired about gas distribution. This enables the robot to get close to the ejecting source, without relying on airflow measurements. Results from experiments are also described and discussed, to assess the efficiency of the proposed method.     

基于P-PSO 算法的室内有障碍通风环境下的多机器人气味源搜索

受湍流影响, 室内通风环境下的烟羽分布表现出波动变化且不连续的特性; 在一些角落处, 较大的漩涡会产生长时间的局部浓度极值区; 另外室内的障碍物也会改变烟羽的分布状况. 因此室内有障碍通风环境下的机器人气味源搜索问题变得很复杂. 本文提出了基于概率适应度函数的粒子群优化(Probability-fitness-function based particle swarm optimization, P-PSO)算法并用于多机器人气味源搜索. P-PSO算法的特点是采用概率而非确定数来表达适应度函数值. 针对气味源搜索问题, P-PSO算法的适应度函数值由贝叶斯和变论域模糊推理估计的气味源概率表达. 为验证提出的搜索策略, 构建了对应实际边界条件的室内通风环境的烟羽模型. 仿真研究证明了本文提出的P-PSO搜索算法用于解决气味源搜索问题的可行性.     

融合学习策略与导向果蝇机制的气味源主动定位方法研究

工业生产过程中常发生由有害气体泄漏引起的火灾或爆炸事故,利用载有气体传感器的移动机器人实时监测并搜索定位泄漏气体源是预防重大事故的有效方法,而高效的搜索策略是保证机器人快速准确定位气味源的关键因素.现有的气味源搜索算法存在定位成功率不高和对气味源定位不准的问题,本文提出一种将仿生果蝇算法和学习策略相融合的气味搜索策略.针对传统果蝇算法易陷入饱和收敛的问题,提出一种新的导向果蝇极值更新方式;针对寻优不精的问题,进一步提出一种基于学习策略的导向果蝇气味源搜索算法(OCGFOA).仿真实验结果表明OCGFOA算法完成定位速度更快且离泄漏气味源位置更近,其定位效果更能满足对危险气味源定位的要求;最后,在物理场景下进行气味源主动定位验证实验,证明本文所提算法在实际场景下也具有可行性.     

时变流场环境中机器人跟踪气味烟羽方法

机器人对气味烟羽的可靠跟踪是实现气味源定位的关键. 本文主要针对实际时变流场环境中的机器人跟踪气味烟羽问题进行研究. 文中在机器人测得气味时估计气味包的最大可能路径, 在此基础上结合流向信息, 规划搜寻路径并使机器人沿此路径运动以跟踪气味烟羽. 考虑到气味浓度场的时变特性以及可能存在的基本浓度, 采用浓度相对变化量表征气味信息. 室内时变流场环境实验表明, 使用本文所提方法的机器人可实时、有效地跟踪烟羽并趋向气味源.     

Mapping multiple gas/odor sources in an uncontrolled indoor environment using a Bayesian occupancy grid mapping based method

In this paper we address the problem of autonomously localizing multiple gas/odor sources in an indoor environment without a strong airflow. To do this, a robot iteratively creates an occupancy grid map. The produced map shows the probability each discrete cell contains a source. Our approach is based on a recent adaptation (Jakuba, 2007) [16] to traditional Bayesian occupancy grid mapping for chemical source localization problems. The approach is less sensitive, in the considered scenario, to the choice of the algorithm parameters. We present experimental results with a robot in an indoor uncontrolled corridor in the presence of different ejecting sources proving the method is able to build reliable maps quickly (5.5 minutes in a 6 m×2.1 m area) and in real time.     

基于移动机器人的主动嗅觉技术研究

使用移动机器人来定位气味源已经成为一个研究热点,机器人主动嗅觉是指使用机器人自主发现并跟踪烟羽,最终确定气味源所在位置的技术。本文对当前主动嗅觉技术进行概述,并根据生物嗅觉行为介绍一种气味源定位算法,这种算法不依赖某一点气味浓度值,仅依靠气味浓度变化率就可找到气味源。并在高斯模型下对烟羽分布模型进行仿真。     

Using naïve physics for odor localization in a cluttered indoor environment

This paper describes current progress of a project, which uses naïve physics to enable a robot to perform efficient odor localization. Odor localization is the problem of finding the source of an odor or other volatile chemical. Most localization methods require the robot to follow the odor plume along its entire length, which is time consuming and may be especially difficult in a cluttered environment. These drawbacks are significant in light of potential applications such as search and rescue operations in damaged buildings. In this project a map of the robot’s environment was used, together with a naïve physics model of airflow, to predict the pattern of air movement. The robot then used the airflow pattern to reason about the probable location of the odor source. This approach, based on naïve physics, has successfully located odor sources in a simplified environment. This demonstrates that naïve physics can be used to assist odor localization operations and indicates that similar techniques have great potential for allowing a robot operating in an unstructured environment to reason about its surroundings. This paper presents details of the naïve physical model of airflow, the reasoning system, the experimental equipment, and results of practical odor source localization experiments.     

Multi-robot olfactory search in structured environments

This paper presents a cooperative distributed approach for searching odor sources in unknown structured environments with multiple mobile robots. While searching and exploring the environment, the robots independently generate on-line local topological maps and by sharing them with each other they construct a global map. The proposed method is a decentralized frontier based algorithm enhanced by a cost/utility evaluation function that considers the odor concentration and airflow at each frontier. Therefore, frontiers with higher probability of containing an odor source will be searched and explored first. The method also improves path planning of the robots for the exploration process by presenting a priority policy. Since there is no global positioning system and each robot has its own coordinate reference system for its localization, this paper uses topological graph matching techniques for map merging. The proposed method was tested in both simulation and real world environments with different number of robots and different scenarios. The search time, exploration time, complexity of the environment and number of double-visited map nodes were investigated in the tests. The experimental results validate the functionality of the method in different configurations.     

基于进化梯度搜索的机器人主动嗅觉仿真研究

提出了基于进化梯度搜索的多机器人主动嗅觉的一种实现策略．首先用Fluent软件建立了一个时变的气态流体环境；其次给出了在此仿真环境中的基于进化梯度搜索的机器人主动嗅觉实现过程，包括发现气体、跟踪气体和气味源确认．为了弥补进化梯度搜索法在机器人数量有限情况下存在的不足，本文算法还使用了风向信息．仿真结果验证了该搜索策略的有效性．通过与传统的基于单机器人的浓度梯度搜索策略比较，验证了本文所用方法的优越性．     

The localization of a mobile robot using a pseudolite ultrasonic system and a dead reckoning integrated system

In this paper, an integration system is proposed to improve the positioning performance of a mobile robot by fusing a Pseudolite Ultrasonic System (PUS), an absolute position measurement system using direct ultrasonic waves, with a Dead Reckoning (DR) odometer. As an integration algorithm of the absolute position measurement system and DR, two methods are proposed. In the loosely coupled method, the PUS and the DR calculate the position independently and a Kalman filter estimates the position using position information from the PUS and the DR. In the tightly coupled method, the PUS provides the distance between the ultrasonic transmitters and receivers without calculating the position directly and the DR provides the translational and rotational displacement of the mobile robot. The Kalman filter then estimates the position using information from the PUS and the DR. In addition, to improve the positioning performance in case the line-of-sight (LOS) between the ultrasonic transmitter and receiver is blocked due to obstacles, a positioning failure detection algorithm and reckoning methods are proposed. The positioning performances of the proposed PUS/DR integrated systems and the validity of the positioning failure detection algorithm are verified and evaluated by experiments.     

Cooperative localization for disconnected sensor networks and a mobile robot in friendly environments

Localization for a disconnected sensor network is highly unlikely to be achieved by its own sensor nodes, since accessibility of the information between any pair of sensor nodes cannot be guaranteed. In this paper, a mobile robot (or a mobile sensor node) is introduced to establish correlations among sparsely distributed sensor nodes which are disconnected, even isolated. The robot and the sensor network operate in a friendly manner, in which they can cooperate to perceive each other for achieving more accurate localization, rather than trying to avoid being detected by each other. The mobility of the robot allows for the stationary and internally disconnected sensor nodes to be dynamically connected and correlated. On one hand, the robot performs simultaneous localization and mapping (SLAM) based on the constrained local submap filter (CLSF). The robot creates a local submap composed of the sensor nodes present in its immediate vicinity. The locations of these nodes and the pose (position and orientation angle) of the robot are estimated within the local submap. On the other hand, the sensor nodes in the submap estimate the pose of the robot. A parallax-based robot pose estimation and tracking (PROPET) algorithm, which uses the relationship between two successive measurements of the robot's range and bearing, is proposed to continuously track the robot's pose with each sensor node. Then, tracking results of the robot's pose from different sensor nodes are fused by the Kalman filter (KF). The multi-node fusion result are further integrated with the robot's SLAM result within the local submap to achieve more accurate localization for the robot and the sensor nodes. Finally, the submap is projected and fused into the global map by the CLSF to generate localization results represented in the global frame of reference. Simulation and experimental results are presented to show the performances of the proposed method for robot-sensor network cooperative localization. Especially, if the robot (or the mobile sensor node) has the same sensing ability as the stationary sensor nodes, the localization accuracy can be significantly enhanced using the proposed method.     

基于激光雷达与双目视觉的移动机器人SLAM研究

为解决移动机器人在环境未知条件下,利用单一传感器自主导航时不能及时定位、构建地图不精确的问题,提出采用一种改进RBPF算法,在计算提议分布时将移动机器人的观测数据(视觉信息与激光雷达信息)和里程计信息融合;针对一般视觉图像特征点提取算法较慢的问题,采用基于ORB算法对视觉图像进行处理以加快视觉图像处理速度的方法;最后通过在安装有开源机器人操作系统(ROS)的履带式移动机器人进行实验,验证了采用该方法可构建可靠性更高、更精确的2D栅格图,提高了移动机器人SLAM的鲁棒性.     

三维空间机器人主动嗅觉烟羽源自主定位策略

针对三维空间鲜有人研究烟羽源自主定位的问题，引入利用历史数据机制，提出了布谷鸟搜索算法结合改进的模糊C均值聚类算法的自主定位策略。采用布谷鸟搜索算法产生机器人定位的位置信息，避免了机器人采集烟羽浓度的盲目性，实现了定位的自主性。将产生的位置信息及采集的该位置处烟羽浓度构成特征向量，采用改进的模糊C均值聚类算法对该组特征向量和历史特征向量构成的一组新的特征向量聚类分析，获取三维空间烟羽浓度分布区域，为布谷鸟搜索算法提供了搜索范围。通过实例对所提出的方法进行验证，并与最近两年的定位算法进行对比，结果表明：该方法在平均运行时间和收敛精度方面均优于最近两年的定位算法，且能够以平均0.145 0 m的收敛精度自主定位到烟羽源附近，为烟羽源定位提供了方法支持。     

Decentralized behavior-based formation control of multiple robots considering obstacle avoidance

This paper proposes a decentralized behavior-based formation control algorithm for multiple robots considering obstacle avoidance. Using only the information of the relative position of a robot between neighboring robots and obstacles, the proposed algorithm achieves formation control based on a behavior-based algorithm. In addition, the robust formation is achieved by maintaining the distance and angle of each robot toward the leader robot without using information of the leader robot. To avoid the collisions with obstacles, the heading angles of all robots are determined by introducing the concept of an escape angle, which is related with three boundary layers between an obstacle and the robot. The layer on which the robot is located determines the start time of avoidance and escape angle; this, in turn, generates the escape path along which a robot can move toward the safe layer. In this way, the proposed method can significantly simplify the step of the information process. Finally, simulation results are provided to demonstrate the efficiency of the proposed algorithm.     

湍流环境中多弱感知机器人气味源搜索算法

针对湍流环境中机器人空间感知能力的不足, 提出一种多弱感知机器人气味源搜索算法. 该算法建立了气味源位置概率分布的近似表达式, 机器人通过自由能最小化获得移动方向. 各机器人之间通过共享位置信息实现协同, 通过设定内部温度达到搜索过程中探索和利用的平衡. 仿真结果验证了所提出算法的有效性.

     

Simultaneous Localization of a Mobile Robot and Multiple Sound Sources Using a Microphone Array

Sound source localization is an important function in robot audition. Most existing works perform sound source localization using static microphone arrays. This work proposes a framework that simultaneously localizes the mobile robot and multiple sound sources using a microphone array on the robot. First, an eigenstructure-based generalized cross-correlation method for estimating time delays between microphones under multi-source environments is described. Using the estimated time delays, a method to compute the farfield source directions as well as the speed of sound is proposed. In addition, the correctness of the sound speed estimate is utilized to eliminate spurious sources, which greatly enhances the robustness of sound source detection. The arrival angles of the detected sound sources are used as observations in a bearing-only simultaneous localization and mapping procedure. As the source signals are not persistent and there is no identification of the signal content, data association is unknown and it is solved using the FastSLAM algorithm. The experimental results demonstrate the effectiveness of the proposed method.     

基于多源信息融合的协作机器人演示编程及优化方法

为解决现有机器人装配学习过程复杂且对编程技术要求高等问题,提出一种基于前臂表面肌电信号和惯性多源信息融合的隐式交互方式来实现机器人演示编程.在通过演示学习获得演示人的装配经验的基础上,为提高对装配对象和环境变化的自适应能力,提出了一种多工深度确定性策略梯度算法（M-DDPG）来修正装配参数,在演示编程的基础上,进行强化学习确保机器人稳定执行任务.在演示编程实验中,提出一种改进的PCNN（并行卷积神经网络）,称作1维PCNN（1D-PCNN）,即通过1维的卷积与池化过程自动提取惯性信息与肌电信息特征,增强了手势识别的泛化性和准确率;在演示再现实验中,采用高斯混合模型（GMM）对演示数据进行统计编码,利用高斯混合回归（GMR）方法实现机器人轨迹动作再现,消除噪声点.最后,基于Primesense Carmine摄像机采用帧差法与多特征图核相关滤波算法（MKCF）的融合跟踪算法分别获取X轴与Y轴方向的环境变化,采用2个相同的网络结构并行进行连续过程的深度强化学习.在轴孔相对位置变化的情况下,机械臂能根据强化学习得到的泛化策略模型自动对机械臂末端位置进行调整,实现轴孔装配的演示学习.