Omnidirectional vision-based ego-pose estimation for an autonomous in-pipe mobile robot

This paper describes the omnidirectional vision-based ego-pose estimation method of an in-pipe mobile robot. An in-pipe mobile robot has been developed for inspecting the inner surface of various pipeline configurations, such as the straight pipeline, the elbow and the multiple-branch. Because the proposed in-pipe mobile robot has four individual drive wheels, it has the ability of flexible motions in various pipelines. The ego-pose estimation is indispensable for the autonomous navigation of the proposed in-pipe robot. An omnidirectional camera and four laser modules mounted on the mobile robot are used for ego-pose estimation. An omnidirectional camera is also used for investigating the inner surface of the pipeline. The pose of the in-pipe mobile robot is estimated from the relationship equation between the pose of a robot and the pixel coordinates of four intersection points where light rays that emerge from four laser modules intersect the inside of the pipeline. This relationship equation is derived from the geometry analysis of an omnidirectional camera and four laser modules. In experiments, the performance of the proposed method is evaluated by comparing the result of our algorithm with the measurement value of a specifically designed sensor, which is a kind of a gyroscope.     

An autonomous fuzzy mobile robot

Autonomous mobile robots should have the capability of recognizing their environments and manoeuvring through those environments on the basis of their own judgement. Fuzzy control is suitable for autonomous mobile robot control where the amount of information to be handled is limited as much as possible and the processing is simple. Autonomous mobile control of a robot is derived from two kinds of controls: for obstacle avoidance and for guidance following an appropriate path to a destination point. Fuzzy control of a robot for obstacle avoidance based on finding permissible passageways using the edges between the floor and the wall or obstacles obtained by processing the image from a CCD camera in front of the robot is developed. Furthermore, guidance control of the robot over paths that are specified in terms of maps may be developed by a process that treats a wrong path as a virtual obstacle on the screen, and the robot advances in the designated direction when it reaches intersections. An autonomous fuzzy robot based on the above method is fabricated as a trial and its usefulness is demonstrated.     

Stability analysis of a vision-based control design for an autonomous mobile robot

We propose a simple control design allowing a mobile robot equipped with a camera to track a line on the ground. The control algorithm, as well as the image-processing algorithm, are very simple. We discuss the existence and the practical stability of an equilibrium trajectory of the robot when tracking a circular reference line. We then give a complementary analysis for arbitrary reference lines with bounded curvature. Experimental results confirm the theoretical analysis.     

An autonomous educational mobile robot mediator

So far, most of the applications of robotic technology to education have mainly focused on supporting the teaching of subjects that are closely related to the Robotics field, such as robot programming, robot construction, or mechatronics. Moreover, most of the applications have used the robot as an end or a passive tool of the learning activity, where the robot has been constructed or programmed. In this paper, we present a novel application of robotic technologies to education, where we use the real world situatedness of a robot to teach non-robotic related subjects, such as math and physics. Furthermore, we also provide the robot with a suitable degree of autonomy to actively guide and mediate in the development of the educational activity. We present our approach as an educational framework based on a collaborative and constructivist learning environment, where the robot is able to act as an interaction mediator capable of managing the interactions occurring among the working students. We illustrate the use of this framework by a 4-step methodology that is used to implement two educational activities. These activities were tested at local schools with encouraging results. Accordingly, the main contributions of this work are: i) A novel use of a mobile robot to illustrate and teach relevant concepts and properties of the real world; ii) A novel use of robots as mediators that autonomously guide an educational activity using a collaborative and constructivist learning approach; iii) The implementation and testing of these ideas in a real scenario, working with students at local schools.

Four-legged intelligent mobile autonomous robot

This paper presents the design and development of a four-legged mobile robot with intelligent sensing and decision-making capabilities. Multiple sensors with embedded knowledge bases and learning capabilities are used in a novel approach towards environmental perception and reaction. These sensors continuously monitor the environment as well as their own operating parameters. Priority is given to any one or a group of sensors based on prevailing environmental conditions. Intelligent sensing is shown to be the key towards a high degree of autonomy for a mobile robot. Nicknamed Flimar, this robot has the ability to function at varying degrees of intelligence made possible by an object-oriented architecture with embedded intelligence at various levels. This architecture is shown to be conducive towards incremental learning. Each of the four legs has three degrees of freedom, i.e. Flimar has a total of 12 motors on its four legs. Flimar can walk and turn without dragging or skidding, and also turns about its center of gravity with a zero radius. Flimar responds to light, sound and touch in different ways, based on prevailing environmental conditions. The overall goal of the paper is to present a novel walking principle and control architecture for a walking robot.     

自主移动机器人平台的设计研究

本文介绍的自主移动机器人平台具有开放性,平台开发采用模块化、分布式结构,能根据用户的不同需求实现相应的配置。可适用于服务、医疗、搬运等行业,具有广泛的参考价值。     

Prowling autonomous mobile robot with a network camera

This research aimed to develop an autonomous mobile robot that helps various kinds of people. The evasion of obstacles is absolutely imperative so that the robot can act in a human-life environment. Therefore, we developed a robot that moves through doors and avoids obstacles with the help of images taken by a camera set on the robot. This work was presented in part at the 13th International Symposium on Artifical Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Navigation with constraints for an autonomous mobile robot

This paper describes a navigation planning algorithm for a robot capable of autonomous navigation in a structured, partially known and dynamic environment. This algorithm is applied to a discrete workspace composed of a network of places and roads. The environment specification associates temporal constraints with any element of the network, and recharge or relocalisation possibilities with places. A mission specification associates several constraints with each navigation task (energy, time, position uncertainty and distance).

The algorithm computes an optimal path for each navigation task according to the optimization criterion and constraints. We introduce the notion of efficient path applied to a new best first search algorithm solving a multiple constraints problem. The path determination relies on a state representation adapted to deal with environment constraints. We then prove that the complexity chracteristics of our algorithm are similar to those of the A* algorithm.

The planner described in this paper has been implemented on a Spare station for a Robuter mobile platform equipped with ultra-sonic range sensors and an active stereo vision system. It was developed for the MITHRA family of autonomous surveillance robots as part of project EUREKA EU 110.     

The autonomous mobile robot AURORA for greenhouse operation

AURORA has been conceived in order to substitute hard and unhealthy human work inside greenhouses by means of an autonomous mobile robot outfitted with appropriate sensors and operation devices. Emphasis has been put in the development of a new robotic platform specifically designed for greenhouse tasks, governed by a control architecture that supports both autonomous navigation and shared human control     

SWAMI: An autonomous mobile robot for inspection of nuclear waste storage facilities

The Stored Waste Autonomous Mobile Inspector (SWAMI) is a prototype mobile robot designed to perform autonomous inspection of nuclear and hazardous waste storage facilities. The onboard control system, consisting of three Motorola 68030-based microcomputers, controls a number of subsystem components including barcode readers, cameras, and a radiation detector. The control system software, running under the VxWorks real-time operating system, is designed toward the client-server model and is implemented in C++. GENISAS, a communication library developed by the Sandia National Laboratories, is used extensively. Much of the onboard software was generated by a custom code generation tool called Moses.     

An autonomous mobile robot for carrying food trays to the aged and disabled

Our research objective is to realize sensor-based navigation for car-like mobile robots. We adopt the generalized Voronoi graph (GVG) for the robot's local path and a map representation. It has the advantage to describe the mobile robot's path for sensor-based navigation from the point of view of completeness and safety. However, it is impossible to apply the path to car-like mobile robots directly, because the limitation of the minimum turning radius for a car-like robot may prevent it from following the GVG exactly. To solve this problem, we propose a local smooth path-planning algorithm for car-like mobile robots. Basically, an initial local path is generated by a conventional path-planning algorithm using GVG theory and it is modified smoothly by a Bezier curve to enable the car-like robots to follow it by maximizing our evaluation function. In this paper, we introduce a local smooth path-planning algorithm based on the GVG and explain the details of our evaluation function. Simulation and experimental results support the validity of the algorithm.     

自主移动机器人局部路径规划综述

自主移动机器人技术是近年来的研究热点,而路径规划技术是自主移动机器人技术研究中的一个重要内容。讨论了自主移动机器人路径规划技术的分类和研究局部路径规划的重要性;分析了局部路径规划技术的发展现状;指出了局部路径规划各种方法的优点与不足;对局部路径规划技术今后的发展方向做出了展望。     

Intelligent control for the vision-based indoor navigation of an A-life mobile robot

Realizing steady and reliable navigation is a prerequisite for a mobile robot, but this facility is often weakened by an unavoidable slip or some irreparable drift errors of sensors in long-distance navigation. Although perceptual landmarks were solutions to such problems, it is impossible not to miss landmarks occasionally at some specific spots when the robot moves at different speeds, especially at higher speeds. If the landmarks are put at random intervals, or if the illumination conditions are not good, the landmarks will be easier to miss. In order to detect and extract artificial landmarks robustly under multiple illumination conditions, some low-level but robust image processing techniques were implemented. The moving speed and self-location were controlled by the visual servo control method. In cases where a robot suddenly misses some specific landmarks when it is moving, it will find them again in a short time based on its intelligence and the inertia of the previous search motion. These methods were verified by the reliable vision-based indoor navigation of an A-life mobile robot.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

Optimal path generation for a simulated autonomous mobile robot

The paper deals with a set of algorithms including path planning, trajectory planning, and path tracking for a tricycle type wheeled mobile robot. Path planning is carried out with parametric polynomial interpolation using an optimization algorithm based on robot geometric constraints. Trajectory characteristics are then derived from the planned geometric path with time varying parameters. A sliding mode control algorithm combined with an adaptive control law are used to track the planned trajectory. The technique deals with an environment free of obstacles. However, it can be easily integrated in a piecewise non colliding path generation. Simulation results are presented to show the validity of the different algorithms.Bissé Emmanuel is a Ph.D. student at the École Polytechnique de Montréal, Department of Mechanical Engineering.Bentounes Mohamed is a Ph.D. student at the École Polytechnique de Montréal, Department of Mechanical Engineering.Boukas El-Kébir is a Professor at the École Polytechnique de Montréal, Department of Mechanical Engineering.     

A distributed control architecture for an autonomous mobile robot

This paper describes a Distributed Control Architecture for an autonomous mobile robot. We start by characterizing the Conceptual Levels into which the various problem-solving activities of a mobile robot can be classified. In sequence, we discuss a Distributed Control System that provides scheduling and coordination of multiple concurrent activities on a mobile robot. Multiple Expert Modules are responsible for the various tasks and communicate through messages and over a Blackboard. As a testbed, the architecture of a specific system for Sonar-Based Mapping and Navigation is presented, and a distributed implementation is described.     

激光测距在移动机器人自主导航中的应用

移动机器人在运动范围内需要有足够的传感器信息可供利用来进行自主导航,在完全未知的环境中,由机器人依靠其自身携带的传感器所提供的信息建立环境模型是机器人进行自主定位和导航的前提之一。介绍了激光测距在移动机器人自主导航中的应用研究;通过二维测距传感器对其周围环境进行扫描,提出了自主导航中地图创建、定位如何用二维扫描获得三维数据流的算法描述,并实验验证该算法的运用使机器人获得一个很好的三维视觉结构图。     

Discovery of sound sources by an autonomous mobile robot

In this work, we describe an autonomous mobile robotic system for finding, investigating, and modeling ambient noise sources in the environment. The system has been fully implemented in two different environments, using two different robotic platforms and a variety of sound source types. Making use of a two-step approach to autonomous exploration of the auditory scene, the robot first quickly moves through the environment to find and roughly localize unknown sound sources using the auditory evidence grid algorithm. Then, using the knowledge gained from the initial exploration, the robot investigates each source in more depth, improving upon the initial localization accuracy, identifying volume and directivity, and, finally, building a classification vector useful for detecting the sound source in the future.     

Aimy: An autonomous mobile robot navigation in unknown environment with infrared detector system

Aimy — an Autonomous Mobile Robot (AMR), capable of moving in an unknown environment filled with obstacles, has been developed. To avoid collision with unexpected obstacles, an Infrared Detector System (IDS) for providing multiple reading data was designed and implemented. A navigation/obstacle avoidance strategy for a mobile robot, which is based on the use of infrared detector data only, is discussed. Experiment results are also presented which exhibit the power of the developed algorithm and Infrared Detector System.