Showing papers on "Mobile robot navigation published in 1991"
09 Apr 1991
TL;DR: Based on a rigorous mathematical analysis, the authors present a systematic overview and a critical discussion of the inherent problems of potential field methods (PFMs) and developed a new method for fast obstacle avoidance.
Abstract: Based on a rigorous mathematical analysis, the authors present a systematic overview and a critical discussion of the inherent problems of potential field methods (PFMs). The authors previously (1989) developed a PFM called the virtual force field (VFF) method. Much insight has been gained into the strengths and weaknesses of this method. Four distinct drawbacks with PFMs are identified. Because of these drawbacks, the authors abandoned potential field methods and developed a new method for fast obstacle avoidance. This method, called the vector field histogram method, produces smooth, nonoscillatory motion, while sampling time and hardware are identical to those used in the VFF method. >
1,646 citations
01 Jun 1991
TL;DR: An algorithm for, model-based localization that relies on the concept of a geometric beacon, a naturally occurring environment feature that can be reliably observed in successive sensor measurements and can be accurately described in terms of a concise geometric parameterization, is developed.
Abstract: The application of the extended Kaman filter to the problem of mobile robot navigation in a known environment is presented. An algorithm for, model-based localization that relies on the concept of a geometric beacon, a naturally occurring environment feature that can be reliably observed in successive sensor measurements and can be accurately described in terms of a concise geometric parameterization, is developed. The algorithm is based on an extended Kalman filter that utilizes matches between observed geometric beacons and an a priori map of beacon locations. Two implementations of this navigation algorithm, both of which use sonar, are described. The first implementation uses a simple vehicle with point kinematics equipped with a single rotating sonar. The second implementation uses a 'Robuter' mobile robot and six static sonar transducers to provide localization information while the vehicle moves at typical speeds of 30 cm/s. >
1,394 citations
03 Nov 1991
TL;DR: Discusses a significant open problem in mobile robotics: simultaneous map building and localization, which the authors define as long-term globally referenced position estimation without a priori information.
Abstract: Discusses a significant open problem in mobile robotics: simultaneous map building and localization, which the authors define as long-term globally referenced position estimation without a priori information. This problem is difficult because of the following paradox: to move precisely, a mobile robot must have an accurate environment map; however, to build an accurate map, the mobile robot's sensing locations must be known precisely. In this way, simultaneous map building and localization can be seen to present a question of 'which came first, the chicken or the egg?' (The map or the motion?) When using ultrasonic sensing, to overcome this issue the authors equip the vehicle with multiple servo-mounted sonar sensors, to provide a means in which a subset of environment features can be precisely learned from the robot's initial location and subsequently tracked to provide precise positioning. >
898 citations
01 Jan 1991
TL;DR: HIMM has been implemented and tested on a mobile robot and its dual functionality was demonstrated through numerous tests in which maps of unknown obstacle courses were created, while the robot simultaneously performed real-time obstacle avoidance maneuvers at speeds of up to 0.78 m/s.
Abstract: Histogramic in-motion mapping (HIMM) is introduced as a new method for real-time map building with a mobile robot motion. HIMM represents data in a two-dimensional array, called a histogram grid, that is updated through rapid in-motion sampling of on-board range sensors. Rapid in-motion sampling results in a map representation that is well-suited to modeling inaccurate and noisy range-sensor data, such as those produced by ultrasonic sensors, and requires minimal computational overhead. Fast map building allows the robot to use immediately the mapped information in real-time obstacle-avoidance algorithms. The benefits of this integrated approach are quick, accurate mapping and safe navigation of the robot toward a given target. HIMM has been implemented and tested on a mobile robot. Its dual functionality was demonstrated through numerous tests in which maps of unknown obstacle courses were created, while the robot simultaneously performed real-time obstacle avoidance maneuvers at speeds of up to 0.78 m/s. >
449 citations
TL;DR: A sufficient condition for the stability of a desired formation pattern for a fleet of robots each equipped with the navigation strategy based on nearest neighbor tracking is developed and simple navigation strategies for robots moving in formation are derived.
Abstract: The problem of deriving navigation strategies for a fleet of autonomous mobile robots moving in formation is considered. Here, each robot is represented by a particle with a spherical effective spatial domain and a specified cone of visibility. The global motion of each robot in the world space is described by the equations of motion of the robot's center of mass. First, methods for formation generation are discussed. Then, simple navigation strategies for robots moving in formation are derived. A sufficient condition for the stability of a desired formation pattern for a fleet of robots each equipped with the navigation strategy based on nearest neighbor tracking is developed. The dynamic behavior of robot fleets consisting of three or more robots moving in formation in a plane is studied by means of computer simulation.
411 citations
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TL;DR: The result of an experiment in a typical indoor environment shows that image-based navigation is a feasible alternative to approaches using 3-D models and more complex model-based vision algorithms.
Abstract: A system that allows a robot to acquire a model of its environment and to use this model to navigate is described. The system maps the environment as a set of snapshots of the world taken at target locations. The robot uses an image-based local homing algorithm to navigate between neighboring target locations. Features of the approach include an imaging system that acquires a compact, 360 degrees representation of the environment and an image-based, qualitative homing algorithm that allows the robot to navigate without explicitly inferring three-dimensional structure from the image. The results of an experiment in a typical indoor environment are described, and its argued that image-based navigation is a feasible alternative to approaches using three-dimensional models. >
201 citations
09 Apr 1991
TL;DR: The authors have build a system, UNSCARF, which is based on pattern recognition techniques, for successfully navigating on a variety of unstructured roads, and has been integrated into a navigation system that has successfully driven a test vehicle in may types of weather conditions.
Abstract: The problem of navigating a robot vehicle on unstructured roads that have no lane markings, may have degraded surfaces and edges, and may be partially obscured by strong shadows is addressed These conditions cause many road following systems to fail The authors have build a system, UNSCARF, which is based on pattern recognition techniques, for successfully navigating on a variety of unstructured roads UNSCARF does not need a road location prediction to find the location of the road; therefore, UNSCARF can be used as a bootstrapping system It uses a clustering technique to group pixels with similar colors and locations It then matches models of road shape to locate the roads in the image These methods are more robust in noisy conditions than other road interpretation techniques UNSCARF has been integrated into a navigation system that has successfully driven a test vehicle in may types of weather conditions >
179 citations
01 Jun 1991
TL;DR: Models and control strategies for dynamic obstacle avoidance in visual guidance of mobile robots and a stochastic motion-control algorithm based on a hidden Markov model are presented, which simplifies the control process of robot motion.
Abstract: Models and control strategies for dynamic obstacle avoidance in visual guidance of mobile robots are presented. Characteristics that distinguish the visual computation and motion control requirements in dynamic environments from that in static environments are discussed. Objectives of the vision and motion planning are formulated, such as finding a collision-free trajectory that takes account of any possible motions of obstacles in the local environments. Such a trajectory should be consistent with a global goal or plan of the motion and the robot should move at as high a speed as possible, subject to its kinematic constraints. A stochastic motion-control algorithm based on a hidden Markov model is developed. Obstacle motion prediction applies a probabilistic evaluation scheme. Motion planning of the robot implements a trajectory-guided parallel-search strategy in accordance with the obstacle motion prediction models. The approach simplifies the control process of robot motion. >
174 citations
01 Mar 1991
TL;DR: In this paper, a mobile robotic materials transport system that performs fetch and carry tasks at Danbury Hospital is described, which can autonomously navigate along the main arteries of the hospital crossing between buildings via interconnecting hallways and uses radio to communicate with the elevator.
Abstract: HelpMate is a mobile robotic materials transport system that performs fetch and carry tasks at Danbury Hospital. It autonomously navigates along the main arteries of the hospital crossing between buildings via interconnecting hallways and uses radio to communicate with the elevator. HelpMate uses sensor information to follow straight paths down hallways and to successfully reach its destination. Also HelpMate has the ability to sense obstacles in its path and plot a course around them. A two part vision system is employed on HelpMate to aid in navigation and obstacle avoidance. One part determines the vehicle''s orientation and position in the hallway by looking at the ceiling lights. The other part uses structured light projecting forward into the immediate path of the robot to detect obstacles.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
97 citations
03 Nov 1991
TL;DR: A vehicle command system for the wheeled autonomous mobile robot with a high capability in describing the navigation task in the real environment, and a feedback control method to track along the given path by the vehicle commands is described.
Abstract: A vehicle command system for the wheeled autonomous mobile robot with a high capability in describing the navigation task in the real environment, is proposed. And a feedback control method to track along the given path by the vehicle commands is described. The effectiveness of the proposed vehicle command system and the trajectory control method are confirmed by numerical simulations and experiments in the real environment using a self-contained autonomous mobile robot. >
85 citations
01 Feb 1991
TL;DR: A novel agent architecture based on the idea that cognition is imagined interaction, i.e. that cognitive tasks are performed by interacting with an imaginary world, is described and demonstrated by its application to a subsumption-based mobile robot.
Abstract: A subsumption-based mobile robot is extended to perform cognitive tasks. Following directions, the robot navigates directly to previously unexplored goals. This robot exploits a novel architecture based on the idea that cognition uses the underlying machinery of interaction, imagining sensations and actions.
03 Nov 1991
TL;DR: The basic concept and strategy for path planning in a dynamically changing environment with multiple autonomous mobile robots are introduced and a method for collision avoidance based on rules and negotiation by communication is presented.
Abstract: An autonomous and decentralized robot system, ACTRESS, is being developed as an intelligent robot system which is composed of multiple robotic agents. The basic concept and strategy for path planning in a dynamically changing environment with multiple autonomous mobile robots are introduced. Collision avoidance with dynamic path planning according to the complexity of the situations is also discussed. A method for collision avoidance based on rules and negotiation by communication is presented. Finally, this method is applied to a developed prototype system consisting of two mobile robots, and the result of experiments operating on real robots is given. >
IBM1
TL;DR: A sensor-based navigation method using fuzzy control, whose purpose is to construct expert knowledge for efficient and better piloting of the AMRs, is presented and the effectiveness of the established rules and the effect of fuzzy control on AMR navigation are discussed on the basis of simulations.
Abstract: In the design of an autonomous mobile robot (AMR), it is necessary to describe schemes of monitoring the status of the robot and suitable procedures of handling various situations. this paper presents a sensor-based navigation method using fuzzy control, whose purpose is to construct expert knowledge for efficient and better piloting of the AMRs. This method provides a function for tracing a planned path by sensing the distance of an AMR from its planned path and the difference between its angle and that of the planned path, and another function that allows an AMR to avoid stationary and moving obstacles by sensing how far an open area extends ahead of it. Fuzzy control is also used to select suitable rules for tracing a path or avoiding obstacles according to the situation, which is determined from sensor information by using fuzzy control. The effectiveness of the established rules and the effect of fuzzy control on AMR navigation are discussed on the basis of simulations. >
TL;DR: A novel navigation strategy is described that employs a time- of-flight sonar system to guide an autonomous vehicle through an unstructured environment composed of specular surfaces by employing a scanning procedure that exploits the physics of sound propagation to detect objects.
Abstract: A novel navigation strategy is described that employs a time- of-flight sonar system to guide an autonomous vehicle through an unstructured environment composed of specular surfaces. Collisions are...
09 Apr 1991
TL;DR: The concept of ACTRESS is introduced, and the communication framework between robotic agents that compose the robot system is proposed, and an algorithm for static path planning and a strategy for dynamic path planning are proposed.
Abstract: An autonomous and decentralized robot system, ACTRESS, is being developed as an intelligent robot system which can execute high level tasks. The concept of ACTRESS is introduced, and the communication framework between robotic agents that compose the robot system is proposed. Taking a task of pushing objects by multiple mobile robots in a certain working environment as a case study of ACTRESS, the strategy for organizing the robot system is discussed, and the required functions for the robot system are introduced. The optimal distribution of the functions is designed based on communication evaluation. An algorithm for static path planning and a strategy for dynamic path planning are proposed. >
Proceedings Article•
14 Jul 1991TL;DR: A fast path planner for a car-like indoor mobile robot that can be modelled as a 2D object translating and rotating in the horizontal plane among well-defined obstacles that is one to two orders of magnitude faster than previously implemented planners for the same type of robot.
Abstract: A car-like indoor mobile robot is a kinematically constrained robot that can be modelled as a 2D object translating and rotating in the horizontal plane among well-defined obstacles. The kinematic constraints impose that the linear velocity of the robot point along its main axis (no sidewise motion is possible) and restrict the range of admissible values for the steering angle. In this paperl we describe a fast path planner for such a robot. This planner is one to two orders of magnitude faster than previously implemented planners for the same type of robot. In addition, it has an anytime flavor that allows it to return a path in a short amount of time, and to improve that path through iterative optimization according to the amount of time that is devoted to path planning. The planner is essentially a combination of preexisting ideas. Its efficiency derives from the good match between these ideas and from various technical improvements brought to them.
03 Jun 1991
TL;DR: The COPIS (conic projection image sensor) system acquires an omnidirectional view around the robot in real-time by using a conic mirror and generates an environmental map of an indoor scene while it is moving in the environment.
Abstract: An omnidirectional image sensor COPIS (conic projection image sensor) is proposed for guiding navigation of a mobile robot. It features passive sensing of the omnidirectional environment in real-time using a conic mirror. Because the conic mirror is used, its image is under conic projection; where the azimuth of each point in the scene appears in the image as its direction from the image center. The authors describe COPIS and its application to guide the navigation of a mobile robot. The COPIS system acquires an omnidirectional view around the robot in real-time by using a conic mirror. Under the assumption of constant motion of the robot, locations of objects around the robot can be estimated by detecting their azimuth changes in the omnidirectional image. Using this method, the robot generates an environmental map of an indoor scene while it is moving in the environment. A method to avoid collision against objects by detecting their azimuth changes is presented. >
TL;DR: An architecture for controlling autonomous mobile robots based on control of continuous activities (processes) rather than discrete actions is presented, and it is argued that different levels of activities require different sorts of computational mechanisms to control them.
Abstract: We present an architecture for controlling autonomous mobile robots based on control of continuous activities (processes) rather than discrete actions. We define a hierarchy of activity, and argue that different levels of activities require different sorts of computational mechanisms to control them. Many controversial issues concerning the use of persistent internal state and higher levels of abstraction can be better understood in terms of this hierarchy. Two experiments using the architecture to control mobile robots performing complex navigation tasks are described.
03 Nov 1991
TL;DR: The authors present a fast and exact planner based upon recursive subdivisions of a collision-free path generated by a lower-level geometric planner which ignores the motion constraints.
Abstract: Deals with the problem of motion planning for a car-like robot (i.e. a nonholonomic mobile robot whose turning radius is lower bounded). The authors present a fast and exact planner based upon recursive subdivisions of a collision-free path generated by a lower-level geometric planner which ignores the motion constraints. The resultant trajectory is optimized to give a path which is of near-minimal length in its homotopy class. The claims of high speed are supported by experimental results for several implementations which assume different geometric models of the robot. >
09 Apr 1991
TL;DR: In this article, several schemes for obstacle detection for autonomous vehicles traveling at high speeds (about 5 m/s) are presented. But they make a globally flat-world assumption and ignore vehicle pitch motion.
Abstract: Several schemes are presented for obstacle detection for autonomous vehicles traveling at high speeds (about 5 m/s). In particular, the authors discuss schemes that make a globally flat-world assumption and ignore vehicle pitch motion. They examine methods that relax the above assumptions. In each case the strengths and weaknesses of the solutions proposed are discussed. Experimental and simulation results are presented. >
09 Apr 1991
TL;DR: A conic projection image sensor (COPIS) and its application to guide the navigation of a mobile robot are described and judgment as to whether each object is static or moving and estimation of its location and velocity are possible by the change of the robot's velocity.
Abstract: A conic projection image sensor (COPIS) and its application to guide the navigation of a mobile robot are described. The COPIS system acquires an omnidirectional view around the robot in real-time by using a conic mirror. Under the assumption of constant linear motion of the robot and moving objects, objects moving along collision paths are found by monitoring their azimuth changes. If such objects are found, the robot changes its velocity to avoid collision. Judgment as to whether each object is static or moving and estimation of its location and velocity are possible by the change of the robot's velocity. >
03 Nov 1991
TL;DR: A type of contingency-tolerant navigation system for an autonomous mobile robot performing transportation tasks in an office-like environment that combines a planning component that makes use of the available knowledge to plan a lesser-committed motion plan and a reaction component that pilots the robot according to this plan through the unexpected obstacles detected by the robot's sensors.
Abstract: This paper describes a type of contingency-tolerant navigation system for an autonomous mobile robot performing transportation tasks in an office-like environment. A prior model of the environment is available, but this model is incomplete. The system combines a planning component that makes use of the available knowledge to plan a lesser-committed motion plan and a reaction component that pilots the robot according to this plan through the unexpected obstacles detected by the robot's sensors. These two components embody practical answers to several important questions such as what a lesser-committed motion plan is, how it can be represented and used; and how computations should be organized so that the most common situations are handled quickly. The navigation system described has been implemented and a robot called GOFER tested on. >
19 Jun 1991
TL;DR: The types of locomotion in mobile robots, the fundamental problem in the design of mobile robot, is discussed and it is pointed out that there are three fundamental configurations in the mobile robot: wheels and crawler track; legs; and an articulated body as discussed by the authors.
Abstract: The types of locomotion in mobile robots, the fundamental problem in the design of mobile robot, are discussed and it is pointed out that there are three fundamental configurations in the mobile robot: wheels and crawler track; legs; and an articulated body The characteristics of these configurations are discussed Some of the examples of mobile robot are given >
09 Apr 1991
TL;DR: The authors attempt to show that the integration of reflexive and planning capabilities is feasible, and a novel generic architecture, composed of three levels, functional, control, and planner, is proposed, which provides important features such as progressive and programmable reactivity, robustness, and versatility.
Abstract: It is pointed out that the purpose of an autonomous mobile robot is to achieve various tasks while adapting its behavior to the variations of its environment. Therefore, such a robot needs both reflexive and planning capabilities. It appears that combining these is difficult; indeed, some robot architectures exhibit a high degree of reactivity, but poor planning abilities, or vice versa. The authors attempt to show that the integration of reflexive and planning capabilities is feasible. A novel generic architecture, composed of three levels, functional, control, and planner, is proposed. It provides important features such as progressive and programmable reactivity, robustness, and versatility. All these features are described at each level. A complete implementation in an experimental mobile robot is described, and an actual example is presented. >
01 Jan 1991
TL;DR: Some initial experiments using self-organising feature maps are explained, and how those maps can be used by a mobile robot to recognise locations in its environment without using sensory information.
Abstract: Self-organising structures are a dominant feature of the experimental mobile robots built in our \Really Useful Robots" project. This paper continues where Nehmzow & Smithers 90] nished. It explains some initial experiments using self-organising feature maps, and how those maps can be used by a mobile robot to recognise locations in its environment. This location recognition capability is achieved without using sensory information. Instead information derived from the motor actions of the robot is used, and shown to be suucient.
09 Apr 1991
TL;DR: The mobile two-arm robot system KAMRO, which is capable of navigating within an assembly cell, of docking at a work table, and of executing an assembly according to a given plan, is described.
Abstract: As an example of an autonomous assembly robot, the mobile two-arm robot system KAMRO, is described. The system is capable of navigating within an assembly cell, of docking at a work table, and of executing an assembly according to a given plan. A series of successful experiments has demonstrated the completely autonomous operation of the system. >
09 Apr 1991
TL;DR: A very compact optical range sensor is described which is to be used for the acquisition of the range information for the navigation of a mobile platform and its real-time implementation on a commercially available image processing system and its performance are presented.
Abstract: A very compact optical range sensor is described which is to be used for the acquisition of the range information for the navigation of a mobile platform. A short review of the techniques currently used to acquire range data for a mobile vehicle is included. Some advantages and disadvantages of the different methods are presented. Emphasis is placed on a possible short-to-medium-term solution of the problem of robot navigation. A short description of the optical principle of the range sensor BIRIS, its real-time implementation on a commercially available image processing system, and its performance are presented. The high immunity of the sensor to ambient illumination and external perturbations is also demonstrated. Experimental results and a technique for the detection of the free space surrounding the vehicle using the range data are given. >
01 Mar 1991
TL;DR: A hall-following robot is presented based on a model-driven system for a real-time indoor mobile robot which combines sensing action and cognition which are the major building blocks for any autonomous system.
Abstract: An autonomous mobile robot must be able to combine uncertain sensory information with prior knowledge of the world. Moreover these operations have to be performed fast enough to be able to react to the changes in the world. This paper presents a model-driven system for a real-time indoor mobile robot. As the robot is constantly in motion information from an Environment Model is used to anticipate information-rich features and to direct selective sensing. Uncertain sensor information is combined with prior World Model knowledge to reduce uncertainty and the remaining uncertainty is directly represented by flexible ranges of values. We present a hall-following robot based on this system which exhibits real-time navigation performance. It does this despite primitive and relatively slow sensing motor control and communications capabilities. This system combines sensing action and cognition which are the major building blocks for any autonomous system.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: The Travelpilot IDS, a second-generation automotive drive-guidance system that uses dead reckoning and map matching for navigation, is described, covering its hardware, software, and navigation method, the maps it produces, and its expandability.
Abstract: The Travelpilot IDS, a second-generation automotive drive-guidance system that uses dead reckoning and map matching for navigation, is described, covering its hardware, software, and navigation method, the maps it produces, and its expandability. The system can also find destinations and display them to the driver. >
Proceedings Article•
14 Jul 1991TL;DR: This paper describes a system which processes local sensor data in such a way as to allow efficient, reactive local navigation, and experiments with this system, both in simulation, and with a real robot operating in natural terrain.
Abstract: In order to navigate autonomously, most robot systems are provided with some sort of global terrain map. To make storage practical, these maps usually have a high-level symbolic representation of the terrain. The robot's symbolic map is then used to plan a local path. This paper describes a system which uses the reverse (and perhaps more natural) process. This system processes local sensor data in such a way as to allow efficient, reactive local navigation. A byproduct of this navigation process is an abstraction of the terrain information which forms a global symbolic terrain map of the terrain through which the robot has passed. Since this map is in the same format as that used by the local navigation system, the map is easy for the system to use, augment, or correct. Compared with the data from which the maps are created, the maps are very space efficient, and can be modified, or used for navigation in real-time. Experiments with this system, both in simulation, and with a real robot operating in natural terrain, are described.