移动机器人结构光视觉

提出并实现了一种用于移动机器人实时自主导航系统的结构光视觉传感器.详细介绍了该视觉传感器的工作原理、数学模型、标定方法以及视觉图像的处理方法.这种主动式方法避开了立体匹配过程,实现了障碍物位置信息的快速探测.利用传感器几何约束,有效地剔除了的视觉图像中干扰的信息.该视觉传感器已成功应用于室内移动机器人避障与导航,说明该视觉方法是有效、可靠的.     

Sensor fusion for mobile robot navigation

We review techniques for sensor fusion in robot navigation, emphasizing algorithms for self-location. These find use when the sensor suite of a mobile robot comprises several different sensors, some complementary and some redundant. Integrating the sensor readings, the robot seeks to accomplish tasks such as constructing a map of its environment, locating itself in that map, and recognizing objects that should be avoided or sought. The review describes integration techniques in two categories: low-level fusion is used for direct integration of sensory data, resulting in parameter and state estimates; high-level fusion is used for indirect integration of sensory data in hierarchical architectures, through command arbitration and integration of control signals suggested by different modules. The review provides an arsenal of tools for addressing this (rather ill-posed) problem in machine intelligence, including Kalman filtering, rule-based techniques, behavior based algorithms, and approaches that borrow from information theory, Dempster-Shafer reasoning, fuzzy logic and neural networks.     

Onboard dynamic RGB-D simultaneous localization and mapping for mobile robot navigation

Although the actual visual simultaneous localization and mapping (SLAM) algorithms provide highly accurate tracking and mapping, most algorithms are too heavy to run live on embedded devices. In addition, the maps they produce are often unsuitable for path planning. To mitigate these issues, we propose a completely closed-loop online dense RGB-D SLAM algorithm targeting autonomous indoor mobile robot navigation tasks. The proposed algorithm runs live on an NVIDIA Jetson board embedded on a two-wheel differential-drive robot. It exhibits lightweight three-dimensional mapping, room-scale consistency, accurate pose tracking, and robustness to moving objects. Further, we introduce a navigation strategy based on the proposed algorithm. Experimental results demonstrate the robustness of the proposed SLAM algorithm, its computational efficiency, and its benefits for on-the-fly navigation while mapping.     

基于参数拟合的室内多用户定位算法

为了提高室内环境下对目标的定位精度,提出一种室内单站精确定位技术. 该技术利用室内电波传播多径效应构成的复杂信道信息,基于机器学习,构建卷积神经网络架构,通过卷积提取不同位置目标到达接收传感器的多径时延特征信息;然后通过多层全连接层深度神经网络的模型训练,将基于复杂信道的定位问题转化为回归模型的问题,建立信道指纹与位置之间的非线性关系来完成被动定位. 训练和仿真结果表明,在室内复杂电波传播环境下,基于神经网络的室内单站精确定位技术能够实现单接收站情况下对目标的精确定位. 本文主要对3×3网格大小的金属散射体进行定位,接收站位于室内时,平均定位误差为0.621个网格（12.42 cm）;接收站位于室外时,能够分别实现信噪比20 dB、30 dB、40 dB情况下44.09 cm、21.42 cm、20.96 cm的平均定位误差. 本文方法为室内复杂环境下的目标定位提供了一种新的定位方法.     

Sensor-based fuzzy reactive navigation of a mobile robot throughlocal target switching

Fuzzy reactive control, incorporating a local target switching scheme, is applied to the automatic navigation of an intelligent mobile robot in an unknown and changing environment. Sensed-ranging signals and relative target position signals are input to the fuzzy controller. The steering angle and the velocity change are inferred to drive the mobile robot. A reactive rule base governing the robot behavior is synthesized from the human heuristics with respect to various situations of environment. A local target switching scheme is proposed to serve as a front-end processor of the fuzzy active controller and to deal with the local trapping and wandering cycle problem in the navigation of a behavior based mobile robot. The algorithm is described, together with some particular considerations about implementation. Efficiency and effectiveness of the proposed approach are verified through simulation and experiments conducted on a Nomad 200 mobile robot     

Seed region selection and homogeneity criterion for doorplate image segmentation in mobile robot navigation

Focused on the seed region selection and homogeneity criterion in Seeded Region Growing （SRG）, an unsupervised seed region selection and a polynomial fitting homogeneity criterion for SRG are proposed in this paper. First of all, making use of Peer Group Filtering （PGF） techniques, an unsupervised seed region selection algorithm is presented to construct a seed region. Then based on the constructed seed region a polynomial fitting homogeneity criterion is applied to solve the concrete problem of doorplate segmentation appearing in the robot navigation along a corridor. At last, experiments are performed and the results demonstrate the effectiveness of the proposed algorithm.     

面向轮式机器人导航的轨迹推演

基于满足低成本轮式移动机器人平台的导航需求为目的,通过轮式机器人的运动模型,深入分析轮式机器的状态,实时地解算轮式机器人的相对位移和航向角,之后给上位机发送相对位移和航向角数据进行估算解析,最后通过解析出来的数据推演出轮式机器人的实时轨迹。实地实验验证了轮式机器人相对位移解算以及对上报数据进行解析算法的性能。本算法为轮式机器人的轨迹估算推演提供了新思路,实验结果证明了该算法的正确性与实用性。     

一种融合深度相机与激光雷达的室内移动机器人建图与导航方法

为解决室内移动机器人导航过程中容易碰撞障碍物的问题,本文提出一种融合深度相机和激光雷达的室内移动机器人建图与导航方法,在机器人底盘上安装激光雷达、深度相机和里程计,利用Gmapping算法进行室内二维地图构建,同时用ROS中depthimage_to_laserscan功能包对深度图像进行二维投影,生成的二维栅格地图与...     

Real-time payments for mobile IP

The mobile IP protocol has evolved from providing mobility support for portable computers to support for wireless handheld devices with high mobility patterns. A new category of micromobility protocols has been proposed to deal with the increased signaling loads that will be generated with large populations of such devices on a network. We argue that the authentication schemes presently employed in these networks do not scale well for large numbers of nodes, and that the lack of accounting procedures prevents the mass deployment of these networks. We envisage that future access networks will be operated by independent service providers, who will charge users for access to services in the fixed network but may not have long-term contractual relationships with them. These access networks may also employ a variety of micromobility protocols for fast handover support. We present a scheme based on hash chains, which allows for fast authentication of datagrams for secure updating of router entries within the access network, and real-time accounting of network usage by mobile nodes. Such a system will alleviate problems of fraud in mobile networks and eliminate the need for interoperator billing agreements.     

Real-time 3D multi-pedestrian detection and tracking using 3D LiDAR point cloud for mobile robot

Mobile robots are used in modern life; however, object recognition is still insufficient to realize robot navigation in crowded environments. Mobile robots must rapidly and accurately recognize the movements and shapes of pedestrians to navigate safely in pedestrian-rich spaces. This study proposes real-time, accurate, three-dimensional (3D) multi-pedestrian detection and tracking using a 3D light detection and ranging (LiDAR) point cloud in crowded environments. The pedestrian detection quickly segments a sparse 3D point cloud into individual pedestrians using a lightweight convolutional autoencoder and connected-component algorithm. The multi-pedestrian tracking identifies the same pedestrians considering motion and appearance cues in continuing frames. In addition, it estimates pedestrians' dynamic movements with various patterns by adaptively mixing heterogeneous motion models. We evaluate the computational speed and accuracy of each module using the KITTI dataset. We demonstrate that our integrated system, which rapidly and accurately recognizes pedestrian movement and appearance using a sparse 3D LiDAR, is applicable for robot navigation in crowded spaces.     

一种基于DSP的移动机器人运动控制器设计

分析了运动控制器对机器人的重要性;提出了一种高性能的基于DSP芯片的运动控制器的整体设计方案,该控制器集控制电路、数据采集模块和驱动电路于一体,能够很好的完成机器人运动轨迹和位置的控制。设计了控制器的硬件电路,重点介绍了驱动电路和电源电路的设计过程。最后,为了实现控制要求,对软件进行了相应的设计。     

北斗导航系统的移动导航定位终端设计分析

卫星定位导航技术目前应用极为广泛,与人民生活息息相关,在手机定位、精准授时、汽车导航、智能交通、智能监控、智能家居、国际救援等等领域应用比较成熟。文章介绍了北斗导航系统的移动导航定位终端的分类和北斗定位基本原理、结构;设计了北斗导航系统的移动导航定位终端,给出了设计的结构、硬件电路以及操作系统。     

Client-server-based mobile robot control

A control architecture for an autonomous mobile robot usually consists of two components: (1) intelligent control software and (2) an operating system for resource access. From the point of view of a computer scientist, it is desirable to achieve a certain level abstraction from the resource (be it sensor or effector). Here, this is achieved by introducing a client-server framework for realizing abstract resource access and intelligent control. Hardware details are hidden in a middleware layer, which is inserted in between operating system and applications. In this paper, we present the most important features of our client-server approach. The servers decouple hardware and software dependencies. Communication is realized through the use of classes, offering a wide variety of client-server interaction. Event-driven servers and clients lead to quick responses in dynamic environments. Our approach gives reusability, portability, testability, and maintainability through data abstraction. It was successfully applied in our experimental platform ARS     

Vision-based magnetic heading sensor for mobile robot guidance

A simple and intuitive heading direction sensor for mobile robot guidance is reported. The sensor consists of a needle-type analogue magnetic compass, image camera, and digital processing module. The image of a magnetic compass is captured by camera and is processed to compute the direction of a mobile robot.     

基于环境模型的移动机器人路径规划

介绍了一种新的移动机器人路径规划方法。采用链接图法,对工作空间建模。用Dijkstra算法决策出全局最短路径,然后用遗传算法对此路径进行优化,得到全局最优路径。最后提出了一种对路径几何改进的方法。仿真结果表明,该方法方便简单,对所规划的路径质量有所提高。     

Energy-efficient task offloading strategy in mobile edge computing for resource-intensive mobile applications

Mobile Edge Computing (MEC) has been considered a promising solution that can address capacity and performance challenges in legacy systems such as Mobile Cloud Computing (MCC). In particular, such challenges include intolerable delay, congestion in the core network, insufficient Quality of Experience (QoE), high cost of resource utility, such as energy and bandwidth. The aforementioned challenges originate from limited resources in mobile devices, the multi-hop connection between end-users and the cloud, high pressure from computation-intensive and delay-critical applications. Considering the limited resource setting at the MEC, improving the efficiency of task offloading in terms of both energy and delay in MEC applications is an important and urgent problem to be solved. In this paper, the key objective is to propose a task offloading scheme that minimizes the overall energy consumption along with satisfying capacity and delay requirements. Thus, we propose a MEC-assisted energy-efficient task offloading scheme that leverages the cooperative MEC framework. To achieve energy efficiency, we propose a novel hybrid approach established based on Particle Swarm Optimization (PSO) and Grey Wolf Optimizer (GWO) to solve the optimization problem. The proposed approach considers efficient resource allocation such as sub-carriers, power, and bandwidth for offloading to guarantee minimum energy consumption. The simulation results demonstrate that the proposed strategy is computational-efficient compared to benchmark methods. Moreover, it improves energy utilization, energy gain, response delay, and offloading utility.     

A novel offloading scheduling method for mobile application in mobile edge computing

Wireless Networks - In mobile edge computing (MEC), task offloading can solve the problem of resource constraints on mobile devices effectively, but it is not always optimal to offload all the...