Showing papers on "Mobile robot navigation published in 2004"

Nearness diagram (ND) navigation: collision avoidance in troublesome scenarios

Abstract: This paper addresses the reactive collision avoidance for vehicles that move in very dense, cluttered, and complex scenarios. First, we describe the design of a reactive navigation method that uses a "divide and conquer" strategy based on situations to simplify the difficulty of the navigation. Many techniques could be used to implement this design (since it is described at symbolic level), leading to new reactive methods that must be able to navigate in arduous environments (as the difficulty of the navigation is simplified). We also propose a geometry-based implementation of our design called the nearness diagram navigation. The advantage of this reactive method is to successfully move robots in troublesome scenarios, where other methods present a high degree of difficulty in navigating. We show experimental results on a real vehicle to validate this research, and a discussion about the advantages and limitations of this new approach.

RFID in robot-assisted indoor navigation for the visually impaired

Abstract: We describe how radio frequency identification (RFID) can be used in robot-assisted indoor navigation for the visually impaired. We present a robotic guide for the visually impaired that was deployed and tested both with and without visually unpaired participants in two indoor environments. We describe how we modified the standard potential fields algorithms to achieve navigation at moderate walking speeds and to avoid oscillation in narrow spaces. The experiments illustrate that passive RFID tags deployed in the environment can act as reliable stimuli that trigger local navigation behaviors to achieve global navigation objectives.

Mobile robot navigation using a sensor network

Abstract: We describe an algorithm for robot navigation using a sensor network embedded in the environment. Sensor nodes act as signposts for the robot to follow, thus obviating the need for a map or localization on the part of the robot. Navigation directions are computed within the network (not on the robot) using value iteration. Using small low-power radios, the robot communicates with nodes in the network locally, and makes navigation decisions based on which node it is near. An algorithm based on processing of radio signal strength data was developed so the robot could successfully decide which node neighborhood it belonged to. Extensive experiments with a robot and a sensor network confirm the validity of the approach.

Adaptive navigation system with artificial intelligence

Abstract: A vehicle navigation system that is capable of learning user habits/preferences, mistakes in a digital map database, and new roads that may have been added or constructed after release of the digital map database is disclosed. The vehicle navigation system monitors a driver's habits and updates a database to thereby cause the vehicle navigation system to have a preference for the driver's habits. The vehicle navigation system may also monitor the geographic position of the vehicle and allow the driver to update or change data contained in the digital map database if an error exists. The vehicle navigation system is also capable of learning new roads that exist that are not included in the road network map of the digital map database and is also capable of adding these new roads to the digital map database.

Autonomous airborne navigation in unknown terrain environments

Abstract: We address the issue of autonomous navigation, that is, the ability for a navigation system to provide information about the states of a vehicle without the need for a priori infrastructure such as GPS, beacons, or a map. The algorithm is known as simultaneous localisation and mapping (SLAM) and it is a terrain aided navigation system (TANS) which has the capability for online map building, and simultaneously utilising the generated map to bound the errors in the navigation solution. Since the algorithm does not require any a priori terrain information or initial knowledge of the vehicle location, it presents a powerful navigation augmentation system or more importantly, it can be implemented as an independent navigation system. Results are first provided using computer simulation which analyses the effect of the spatial density of landmarks as well as the quality of observation and inertial navigation data, and then finally the real time implementation of the algorithm on an unmanned aerial vehicle (UAV).

Localization methods for a mobile robot in urban environments

Abstract: This paper addresses the problems of building a functional mobile robot for urban site navigation and modeling with focus on keeping track of the robot location. We have developed a localization system that employs two methods. The first method uses odometry, a compass and tilt sensor, and a global positioning sensor. An extended Kalman filter integrates the sensor data and keeps track of the uncertainty associated with it. The second method is based on camera pose estimation. It is used when the uncertainty from the first method becomes very large. The pose estimation is done by matching linear features in the image with a simple and compact environmental model. We have demonstrated the functionality of the robot and the localization methods with real-world experiments.

Development of the snake-like rescue robot "kohga"

Abstract: In this paper we report the development of a new rescue robot platform. The robot is constructed by connecting multiple crawler vehicles serially, resulting a long and thin structure so that it can enter narrow space. The units are connected by 2-DOF active joints and 3-DOF passive joints, so that the robot can have both the capability to climb over obstacles as well as adaptation to irregular surfaces. Basic steering and experiments for the robot are also shown.

Autonomous local path planning for a mobile robot using a genetic algorithm

Abstract: This work presents results of our work in development of a genetic algorithm based path-planning algorithm for local obstacle avoidance (local feasible path) of a mobile robot in a given search space. The method tries to find not only a valid path but also an optimal one. The objectives are to minimize the length of the path and the number of turns. The proposed path-planning method allows a free movement of the robot in any direction so that the path-planner can handle complicated search spaces.

Method and apparatus for optical odometry

Abstract: A method and apparatus for optical odometry are disclosed which inexpensively facilitate diverse applications including indoor/outdoor vehicle tracking in secure areas, industrial and home robot navigation, automated steering and navigation of autonomous farm vehicles, shopping cart navigation and tracking, and automotive anti-lock braking systems. In a preferred low-cost embodiment, a telecentric lens is used with an optical computer mouse chip and a microprocessor. In a two-sensor embodiment, both rotation and translation are accurately measured.

Navigation for human-robot interaction tasks

Abstract: One major design goal in human-robot interaction is that the robots behave in an intelligent manner, preferably in a similar way as humans. This constraint must also be taken into consideration when the navigation system for the platform is developed. However, research in human-robot interaction is often restricted to other components of the system including gestures, manipulation, and speech. On the other hand, research for mobile robot navigation focuses primarily on the task of reaching a certain goal point in an environment. We believe that these two problems can not be treated separately for a personal robot that coexists with humans in the same surrounding. Persons move constantly while they are interacting with each other. Hence, also a robot should do that, which poses constraints on the navigation system. This type of navigation is the focus of this paper. Methods have been developed for a robot to join a group of people engaged in a conversation. Preliminary results show that the platform's moving patterns are very similar to the ones of the persons. Moreover, this dynamic interaction has been judged naturally by the test subjects, which greatly increases the perceived intelligence of the robot.

Mobile Robot Navigation using a Sensor Network

Abstract: We describe an algorithm for robot navigation using a sensor network embedded in the environment. Sensor nodes act as signposts for the robot to follow, thus obviating the need for a map or localization on the part of the robot. Navigation directions are computed within the network (not on the robot) using value iteration. Using small low-power radios, the robot communicates with nodes in the network locally, and makes navigation decisions based on which node it is near. An algorithm based on processing of radio signal strength data was developed so the robot could successfully decide which node neighborhood it belonged to. Extensive experiments with a robot and a sensor network confirm the validity of the approach.

Neural Networks in Mobile Robot Motion

Abstract: Over the last few years, a number of studies were reported concerning a machine learning, and how it has been applied to help mobile robots to improve their operational capabilities. One of the most important issues in the design and development of intelligent mobile system is the navigation problem. This consists of the ability of a mobile robot to plan and execute collision-free motions within its environment. However, this environment may be imprecise, vast, dynamical and either partially or non-structure d. Robots must be able to understand the structure of this environment. To reach their targets without collisions, the robots must be en dowed with perception, data processing, recognition, learning, reasoning, interpreting, decision-making and action capacities. The ability to acquire these faculties to treat and transmit knowledge constitutes the key of a certain kind of artificial intelligence. Reproduce this kind of intelligence is, up to now, a human ambition in the construction and development of intelligent machines, and particularly autonomous mobile robots. To reach a reasonable degree of autonomy two basic requirements are sensing and reasoning. The former is provided by on-board sensory system that gathers information about robot with respect to the surrounding scene. The later is accomplished by devising algorithms that exploit this information in order to generate appropriate commands for robot. And with this algorithm we will deal in this chapter. We report on the objective of the motion planning problem well known in robotics. Given

Complete coverage navigation of cleaning robots using triangular-cell-based map

Abstract: This paper presents a novel approach for navigation of cleaning robots in an unknown workspace. To do so, we propose a new map representation method as well as a complete coverage navigation method. First, we discuss a triangular cell map representation which makes the cleaning robot navigate with a shorter path and increased flexibility than a rectangular cell map representation. Then, we propose the complete coverage navigation and map construction methods which enable the cleaning robot to navigate the complete workspace without complete information about the environment. Finally, we evaluate the performance of our proposed triangular cell map via the existing distance-transform-based path-planning method comparing it to that of the rectangular cell map. Also, we verify the effectiveness of the proposed methods through computer simulations.

Mobile robot, and system and method for autonomous navigation of the same

Abstract: Disclosed herein is a mobile robot, and system and method for autonomous navigation of the same. The mobile robot includes a communications module for transmitting a light source control signal to selectively control light sources of a landmark array to flicker, an image processing module for calculating image coordinates of the light sources from an image signal, a pose calculation module for calculating position coordinates of the mobile robot, a motion control module for calculating a moving path and controlling the mobile robot to move along the moving path, and a main control module for controlling interoperations of the modules and general operations of the mobile robot.

Navigation device and method for exchanging data between resident applications

Abstract: Navigation software is integrated with other kinds of software running on the same device so that capabilities of the navigation software can be made available from within the other applications. Those applications can export street, city or postcode format address data to the navigation software. The address data can then be converted to a co-ordinate system based address by the navigation software, which can then automatically be set as the destination address used by the navigation software in calculating the route and/or automatically marked on a map generated and displayed by the navigation software.

Experimental validation of the moving long base-line navigation concept

Abstract: This paper presents the moving long base-line (MLBL) navigation concept as well as simulation and experimental results. This multiple vehicle navigation technique consists of using vehicles fitted with accurate navigation systems as moving reference transponders to which other vehicles, fitted with less capable navigation systems, can acoustically range to update their position. Reliable acoustic communications are mandatory for the real time implementation of this navigation scheme. However, while enabling MLBL, acoustic communications reduce the range update rate and introduce delays that need to be dealt with in the navigation algorithm. Simulation results show that relative navigation accuracy between vehicles can be maintained although the absolute navigation accuracy of each vehicle decreases over time. This is a key enabling factor for AOFNC missions where contacts are called by vehicles and re-acquired by other vehicles in real-time.

A system and method for augmenting a satellite-based navigation solution

Abstract: A map-matching feedback interface uses added information to bound a mapping solution and calibrate a navigation system, thus enabling the navigation system to navigate more accurately over a longer period of time. The system recognizes erroneous measurements and reduces or eliminates them from the mapping solution, thus preventing position inaccuracies. The system interfaces the navigation system with a mapping system that feeds back map-based data to the navigation system and combines the map-matching feedback data with other sensor data to produce an accurate navigation solution even in environments where GPS or dead reckoning input data is inaccurate.

The connected user interface: realizing a personal situated navigation service

Abstract: Navigation services can be found in different situations and contexts: while connected to the web through a desktop PC, in cars, and more recently on PDAs while on foot. These services are usually well designed for their specific purpose, but fail to work in other situations. In this paper we present an approach that connects a variety of specialized user interfaces to achieve a personal navigation service spanning different situations. We describe the concepts behind the \bf BPN (BMW Personal Navigator), an entirely implemented system that combines a desktop event and route planner, a car navigation system, and a multi-modal, in- and outdoor pedestrian navigation system for a PDA. Rather than designing for one unified UI, we focus on connecting specialized UIs for desktop, in-car and on-foot use.

VIRTUOUS: vision-based road transportation for unmanned operation on urban-like scenarios

Abstract: This work presents an intelligent transportation system (ITS) that was implemented on an autonomous vehicle designed to perform global navigation missions on a network of unmarked roads. This is the first step toward the complete implementation of ITS in urban environments, which is the long-term goal of this work. Using a global positioning system, global navigation is achieved by means of a global planner and a task manager that recurrently coordinate the execution of vision-based perception tasks for the road tracking of nonstructured roads and the navigation of intersections. In addition, a vision-based vehicle-detection task has been developed, which endows the global navigation system with a reactive capacity. The complete system has been tested on the BABIECA prototype vehicle, which was autonomously driven for hundreds of kilometers around a private circuit, designed to emulate an urban quarter, at speeds of up to 50 km/h, successfully carrying out different navigation missions. During the tests, the vehicle drove itself across crossroads and performed the appropriate turning maneuvers at intersections. It also demonstrated its robustness with regard to shadows, road texture, weather conditions, and changing illumination.

3D location-pointing as a navigation aid in Virtual Environments

Abstract: The navigation support provided by user interfaces of Virtual Environments (VEs) is often inadequate and tends to be overly complex, especially in the case of large-scale VEs. In this paper, we propose a novel navigation aid that aims at allowing users to easily locate objects and places inside large-scale VEs. The aid exploits 3D arrows to point towards the objects and places the user is interested in. We illustrate and discuss the experimental evaluation we carried out to assess the usefulness of the proposed solution, contrasting it with more traditional 2D navigation aids. In particular, we compared subjects' performance in 4 conditions which differ for the type of provided navigation aid: three conditions employed respectively the proposed "3D arrows" aid, an aid based on 2D arrows, and a 2D aid based on a radar metaphor; the fourth condition was a control condition with no navigation aids available.

A neuro-wavelet method for multi-sensor system integration for vehicular navigation

Abstract: The last two decades have shown an increasing trend in the use of navigation technologies in several applications including land vehicles and automated car navigation. Navigation systems incorporate the global positioning system (GPS) and the inertial navigation system (INS). While GPS provides position information when there is direct line of sight to four or more satellites, INS utilizes the local measurements of angular velocity and linear acceleration to determine both the vehicle's position and attitude. Both systems are integrated together to provide reliable navigation solutions by overcoming each of their respective shortcomings. The present integration schemes, which are predominantly based on Kalman filtering, have several inadequacies related to sensor error models, immunity to noise and observability. This paper aims at introducing a multi-sensor system integration approach for fusing data from an INS and GPS hardware utilizing wavelet multi-resolution analysis (WMRA) and artificial neural networks (ANN). The WMRA is used to compare the INS and GPS position outputs at different resolution levels. The ANN module is then trained to predict the INS position errors in real time and provide accurate positioning of the moving vehicle. The field-test results have demonstrated that substantial improvements in INS/GPS positioning accuracy could be obtained by applying the proposed neuro-wavelet technique.

A tiered planning strategy for biped navigation

Abstract: This paper presents a three-tiered planner for biped navigation over large distances through complex environments where conventional 2D planning algorithms designed for wheeled robots fail to find a solution The lowest tier is a footstep planner which can plan sequences of footholds for navigating through obstacles or over rough terrain The second tier is a mobile robot planner, which plans outward from the goal to the robot's initial state, building a heuristic to aid the lowest level planner in directing the footholds toward a likely path The highest tier chooses a long-term path to follow, ignoring the details of how it will be implemented, and directs the lower levels during execution to provide footstep sequences for the robot and notification of when re-planning is necessary Results are demonstrated with simulated environments and execution

Visually augmented navigation in an unstructured environment using a delayed state history

Abstract: This work describes a framework for sensor fusion of navigation data with camera-based 5 DOF relative pose measurements for 6 DOF vehicle motion in an unstructured 3D underwater environment. The fundamental goal of this work is to concurrently estimate online current vehicle position and its past trajectory. This goal is framed within the context of improving mobile robot navigation to support sub-sea science and exploration. Vehicle trajectory is represented by a history of poses in an augmented state Kalman filter. Camera spatial constraints from overlapping imagery provide partial observation of these poses and are used to enforce consistency and provide a mechanism for loop-closure. The multi-sensor camera + navigation framework is shown to have compelling advantages over a camera-only based approach by: 1) improving the robustness of pairwise image registration, 2) setting the free gauge scale, and 3) allowing for a unconnected camera graph topology. Results are shown for a real world data set collected by an autonomous underwater vehicle in an unstructured undersea environment.

Performance of optical flow techniques for indoor navigation with a mobile robot

Abstract: We present a comparison of four optical flow methods and three spatio-temporal filters for mobile robot navigation in corridor-like environments. Previous comparisons of optical flow methods have evaluated performance only in terms of accuracy and/or efficiency, and typically in isolation. These comparisons are inadequate for addressing applicability to continuous, real-time operation as part of a robot control loop. We emphasise the need for comparisons that consider the context of a system, and that are confirmed by in-system results. To this end, we give results for on and off-board trials of two biologically inspired behaviours: corridor centring and visual odometry. Our results show the best in-system performances are achieved using Lucas and Kanade's gradient-based method in combination with a recursive temporal filter. Results for traditionally used Gaussian filters indicate that long latencies significantly impede performance for real-time tasks in the control loop.

Differential GPS and odometry-based outdoor navigation of a mobile robot

Abstract: This paper describes outdoor navigation for a mobile robot by using differential GPS (DGPS) and odometry in a campus walkway environment. The robot position is estimated by fusion of DGPS and odometry. The GPS receiver measures its position by radio waves from GPS satellites. The error of GPS measurement data increases near high buildings and trees because of multi-path and forward diffractions. Thus, it is necessary to pick up only accurate DGPS measurement data when the robot position is modified by fusing DGPS and odometry. In this paper, typical DGPS measurement data observed near high buildings and trees are reported. Then, the authors propose a novel position correction method by fusing GPS and odometry. Fusion of DGPS and odometry is realized using an extended Kalman filter framework. Moreover, outdoor navigation for a mobile robot is accomplished by using the proposed correction method.

Car navigation system

Abstract: A car navigation system by which a user can easily grasp a drop-in target in the course of a route. In a summary road map displayed in a two- or one-window display representation, contents of a two-dimensional road map is properly selected and simplified, roads are made linear, roads connected to an intersection are made orthogonal so that the user can easily see it, the position of a vehicle is expressed by a mark, and even the running route is expressed with a predetermined color or the like. Accordingly, the system offers the user such a display form as able to easily refer to. When the user specifies a target at which the user wants to drop in, the drop-in target is displayed at a corresponding position on the summary road map in the form of a land mark.