Showing papers on "Mobile robot navigation published in 1989"
TL;DR: An approach to robot perception and world modeling that uses a probabilistic tesselated representation of spatial information called the occupancy grid, a multidimensional random field that maintains stochastic estimates of the occupancy state of the cells in a spatial lattice is reviewed.
Abstract: An approach to robot perception and world modeling that uses a probabilistic tesselated representation of spatial information called the occupancy grid is reviewed. The occupancy grid is a multidimensional random field that maintains stochastic estimates of the occupancy state of the cells in a spatial lattice. To construct a sensor-derived map of the robot's world, the cell state estimates are obtained by interpreting the incoming range readings using probabilistic sensor models. Bayesian estimation procedures allow the incremental updating of the occupancy grid, using readings taken from several sensors over multiple points of view. The use of occupancy grids from mapping and for navigation is examined. Operations on occupancy grids and extensions of the occupancy grid framework are briefly considered. >
2,328 citations
01 Jan 1989
TL;DR: A real-time obstacle avoidance approach for mobile robots that permits the detection of unknown obstacles simultaneously with the steering of the mobile robot to avoid collisions and advance toward the target.
Abstract: A real-time obstacle avoidance approach for mobile robots has been developed and implemented. It permits the detection of unknown obstacles simultaneously with the steering of the mobile robot to avoid collisions and advance toward the target. The novelty of this approach, entitled the virtual force field method, lies in the integration of two known concepts: certainty grids for obstacle representation and potential fields for navigation. This combination is especially suitable for the accommodation of inaccurate sensor data as well as for sensor fusion and makes possible continuous motion of the robot with stopping in front of obstacles. This navigation algorithm also takes into account the dynamic behavior of a fast mobile robot and solves the local minimum trap problem. Experimental results from a mobile robot running at a maximum speed of 0.78 m/s demonstrate the power of the algorithm. >
1,171 citations
TL;DR: A variant of the potential field method is used to produce the appropriate velocity and steering commands for the robot and demonstrates the feasibility of this approach.
Abstract: Motor schemas serve as the basic unit of behavior specifica tion for the navigation of a mobile robot. They are multiple concurrent processes that operate in conjunction with asso ciated perceptual...
1,072 citations
01 Sep 1989
TL;DR: The issues involved in integrating multiple sensors into the operation of a system are presented in the context of the type of information these sensors can uniquely provide, along with proposed high-level multisensory representations suitable for mobile robot navigation and control.
Abstract: The issues involved in integrating multiple sensors into the operation of a system are presented in the context of the type of information these sensors can uniquely provide. A survey is provided of the variety of approaches to the problem of multisensor integration and fusion that have appeared in the literature in recent years ranging from general paradigms, frameworks, and methods for integrating and fusing multisensory information to existing multisensor systems used in different areas of application. General multisensor fusion methods, sensor selection strategies, and world models are examined, along with approaches to the integration and fusion of information from combinations of different types of sensors. Short descriptions of the role of multisensor integration and fusion in the operation of a number of existing mobile robots are provided, together with proposed high-level multisensory representations suitable for mobile robot navigation and control. Existing multisensor systems for industrial and other applications are considered. >
800 citations
Patent•
06 Sep 1989
TL;DR: In this article, the authors describe a vision system for a mobile robot which includes at least one radiation projector (14, 16) projecting a structured beam of radiation into the robot's environment.
Abstract: A vision system for a vehicle, such as a mobile robot (10) includes at least one radiation projector (14, 16) which projects a structured beam of radiation into the robot's environment. The structured beam of radiation (14a, 16a) preferably has a substantially planar pattern of sufficient width to encompass the immediate forward path of the robot and also to encompass laterally disposed areas in order to permit turning adjustments. The vision system further includes an imaging (12) sensor such as a CCD imaging device having a two-dimensional field of view which encompasses the immediate forward path of the robot. An image sensor processor (18) includes an image memory (18A) coupled to a device (18D) which is operable for accessing the image memory. Image processing is accomplished in part by triangulating the stored image of the structured beam pattern to derive range and bearing, relative to the robot, of an object being illuminated. A navigation control system (20) of the robot inputs data from at least the vision system and infers therefrom data relating to the configuration of the environment which lies in front of the robot. The navigation control system generates control signals which drive propulsion and steering motors in order to navigate the robot through the perceived environment.
309 citations
Patent•
07 Jun 1989
TL;DR: In this paper, an approach for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of a retroreflective ceiling feature is presented.
Abstract: Apparatus and method which provides for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of a retroreflective ceiling feature. A mobile robot 10 includes a light source 28 and a camera 12 that are pitched up obliquely at an intermediate angle between a horizon and a zenith. The camera views a ceiling having one or more strip-like retroreflective features 16 which are preferably aligned with an axis of the hallway. In that the feature presents a pattern or alignment which is substantially parallel to a long axis of the hallway the pattern is detected and processed to derive robot navigation information therefrom.
184 citations
01 Feb 1989
TL;DR: An appropriate model to represent the extended world for the path planning task is investigated, and a time-optimal solution is given using this model.
Abstract: A method is presented for planning a path in the presence of moving obstacles. Given a set of polygonal moving obstacles, the authors focus on generating a path for a mobile robot that navigates in the two-dimensional plane. Their methodology is to include time as one of the dimensions of the model world. This enables the authors to regard the moving obstacles as being stationary in the extended world. For a solution to be feasible, the robot must not collide with any other moving obstacles, and, also, it must navigate without exceeding the predetermined range of velocity, acceleration, and centrifugal force. The authors investigate an appropriate model to represent the extend world for the path-planning task, and give a time-optimal solution using this model. >
173 citations
14 May 1989
TL;DR: A general methodology is described which extends the construction of navigation functions on sphere worlds to any smoothly deformable space and yields automatically a bounded torque feedback control law which is guaranteed to guide the robot to destination point from almost every initial position without hitting any obstacle.
Abstract: The authors consider the construction of navigation functions on configuration spaces whose geometric expressiveness is rich enough for navigation amidst real-world obstacles. They describe a general methodology which extends the construction of navigation functions on sphere worlds to any smoothly deformable space. According to this methodology, the problem of constructing a navigation function is reduced to the construction of a transformation mapping a given space into its model sphere world. The transformation must satisfy certain regularity conditions guaranteeing invariance of the navigation function properties. The authors demonstrate this idea by constructing navigation functions on star worlds: n-dimensional star shaped subsets of E/sup n/ punctured by any finite number of smaller disjoint n-dimensional stars. This construction yields automatically a bounded torque feedback control law which is guaranteed to guide the robot to destination point from almost every initial position without hitting any obstacle. >
155 citations
19 Jun 1989
TL;DR: It is shown how sensors data inaccuracies can be processed to produce a consistent environment model and an as precise as possible robot positioning.
Abstract: Incremental map-making is a necessary function of an autonomous mobile robot Sensor data are always imprecise, and in the case of a mobile robot, sensor location is itself imprecise and even sometimes false (eg in case of slippage) We show how sensors data inaccuracies can be processed to produce a consistent environment model and an as precise as possible robot positioning The experimental system (a mobile robot with a laser range finder and odometry) is presented and the theoretical approach is applied on actual data
154 citations
Patent•
03 Oct 1989
TL;DR: In this paper, an approach for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of ceiling lights is presented. But this approach requires a mobile robot that is pitched up obliquely at an intermediate angle between a horizon and a zenith.
Abstract: Apparatus and method which provides for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of ceiling lights. A mobile robot 10 includes a camera 12 that is pitched up obliquely at an intermediate angle between a horizon and a zenith. The camera views a ceiling having one or more ceiling lights 16 which may be of rectangular shape and which are preferably aligned with an axis of the hallway. In that the lights present a pattern or alignment which is substantially parallel to or perpendicular to a long axis of the hallway the pattern is detected and processed to derive robot navigation information therefrom.
123 citations
04 Sep 1989
TL;DR: The position estimation system for an autonomous robot vehicle called Blanche, which is designed for use in structured office or factory environments, consists of odometry supplemented with a fast, robust matching algorithm which determines the congruence between the range data and a 2D map of its environment.
Abstract: This paper describes the position estimation system for an autonomous robot vehicle called Blanche, which is designed for use in structured office or factory environments. Blanche is intended to be low cost, depending on only two sensors, an optical rangefinder and odometry. Briefly, the position estimation system consists of odometry supplemented with a fast, robust matching algorithm which determines the congruence between the range data and a 2D map of its environment. This is used to correct any errors existing in the odometry estimate. The integration of odometry with fast, robust matching allows for accurate estimates of the robot’s position and accurate estimates of the robot’s position allow for fast, robust matching. That is, the system is self sustaining.
TL;DR: A framework is presented that uses the same strategy to solve both the learned navigation and terrain model acquisition and it is shown that any abstract graph structure that satisfies a set of four properties suffices as the underlying structure.
Abstract: A framework is presented that uses the same strategy to solve both the learned navigation and terrain model acquisition. It is shown that any abstract graph structure that satisfies a set of four properties suffices as the underlying structure. It is also shown that any graph exploration algorithm can serve as the searching strategy. The methods provide paths that keep the robot as far from the obstacles as possible. In some cases, these methods are preferable to visibility graph methods that require the robot to navigate arbitrarily close to the obstacles, which is hard to implement if the robot motions are not precise. >
04 Sep 1989
TL;DR: The logical structure of robot vision systems is analyzed as a basis for designing such systems and both sensor data fusion and knowledge representation in a vision system may be broken down into four hierarchical levels.
Abstract: . the architecture of multi-processor computer systems The logical structure of robot vision systems is analyzed as a basis for designing such systems. Both sensor data fusion and knowledge representation in a vision system may be broken down into four hierarchical levels where at each level knowledge represen- .
TL;DR: The task of navigational path-planning is addressed, which provides the robot with a path guaranteed to be free of collisions with any modeled obstacles, and consideration is given to just what constitutes an “optimal” path.
Abstract: The Autonomous Robot Architecture (AuRA) provides multi-level representation and planning capabilities. This paper addresses the task of navigational path-planning, which provides the robot with a path guaranteed to be free of collisions with any modeled obstacles. Knowledge supporting visual perception can also be embedded, facilitating the actual path traversal by the vehicle.A multi-level representation and architecture to support multi-sensor navigation (predominantly visual) are described. A hybrid vertex-graph free-space representation based upon the decomposition of free space into convex regions capable for use in both indoor and limited outdoor navigation is discussed. This “meadow map” is produced via the recursive decomposition of the initial bounding area of traversability and its associated modeled obstacles. Of particular interest is the ability to handle diverse terrain types (sidewalks, grass, gravel, etc.) “Transition zones” ease the passage of the robot from one terrain type to another.The navigational planner that utilizes the data available in the above representational scheme is described. An A* search algorithm incorporates appropriate cost functions for multi-terrain navigation. Consideration is given to just what constitutes an “optimal” path in this context.
TL;DR: An autonomous mobile robot, HERMIES-IIB intelligence experiment series, is described, a self-powered, wheel-driven platform containing an onboard 16-node Ncube hypercube parallel processor interfaced to effectors and sensors through a VME-based system.
Abstract: Research focused on the development and experimental validation of intelligent control techniques for autonomous mobile robots able to plan and perform a variety of assigned tasks in unstructured environments is presented. In particular, an autonomous mobile robot, HERMIES-IIB intelligence experiment series, is described. It is a self-powered, wheel-driven platform containing an onboard 16-node Ncube hypercube parallel processor interfaced to effectors and sensors through a VME-based system containing a Motorola 68020 processor, a phased sonar array, dual manipulator arms, and multiple cameras. Research on navigation and learning is examined. >
Patent•
30 Oct 1989TL;DR: In this paper, a method for communicating the need to move a mobile robot, such as an AGV, from one location (node) to another, on a node-by-node basis, incrementally, among the nodes established in a physical environment such as a factory, is presented.
Abstract: The invention provides a method for communicating the need to move a mobile robot, such as an AGV¹, from one location (node) (2,4,6-10) to another, on a node-by-node basis, incrementally, among the nodes established in a physical environment such as a factory. The invention also provides the means to generate the commands necessary to accomplish this motion, by providing specific steering and drive information such as angle and speed to the mobile robot or AGV¹. The invention accomplishes these tasks in response to direct commands from a stationary controller as well as in response to continuous node-by-node position updates provided by an external navigation system, such as a visual navigation system, or an internal dead-reckoning navigation system, or both.
04 Sep 1989
TL;DR: This paper first clarifies the design of a mechanism and a method for avoiding obstacles and transferring the robot to a branch wire and shows experimental results using a prototype of mobile robot with an ultrasonic sensing system.
Abstract: This paper proposes a mechanism and a control system for a wire mobile robot with a multi-unit structure The mobile robot has an ultrasonic sensing system for environment recognition enabling it to move autonomously With this mechanism, control and sensing system, the robot can transfer to a branch wire and avoid obstacles on the wire This paper first clarifies the design of a mechanism and a method for avoiding obstacles and transferring the robot to a branch wire Then it shows experimental results using a prototype of mobile robot with an ultrasonic sensing system
04 Sep 1989
TL;DR: This paper offers a solution to the mobile robot navigation problem, which relies on the concept of a ugeneralized geometric beacon - a feature which can be reliably observed in successive sensor measurements (a beacon), andWhich can be described in terms of some small number of geometric objects.
Abstract: A continuing problem in mobile robotics is that of achieving reliable autonomous navigation based only on information obtained from the sensors of a mobile vehicle. The basic navigation problem based on the observation of navigation beacons has been studied extensively over many hundreds of years, and is in general well-understood. The application of these techniques in robotics has faltered on the problem of reliably extracting beacons from sensor data and utilizing them in automating the navigation process. In this paper we offer a solution to the mobile robot navigation problem, which relies on the concept of a ugeneralized geometric beaconn - a feature which can be reliably observed in successive sensor measurements (a beacon), and which can be described in terms of some small number of geometric objects. This navigation algorithm is based around a simple Kalman-filter which is employed to maintain a map of these observed geometric beacons, and into which new sensor measurements can be matched. We describe three different implementations of this navigation algorithm, the first on a vehicle with only one rotating sonar, the second on a vehicle with six static sonars, and the third on a vehicle equipped with both a sonar and an active infra-red sensor. These implementations demonstrate how different geometric beacons extracted from different sensors and algorithms can be used to provide a robust and reliable estimate of mobile robot location.
01 Jan 1989
TL;DR: A mobile robot path execution system has been developed that strongly correlates with a model for detour behavior in the frog and the robot’s motor schema based navigation system draws on potential field methodology to produce “intelligent” behavior based on environmental perception.
Abstract: Theories for path planning behavior in animals can be of great value in providing significant insights into the design of functioning mobile robot systems. A mobile robot path execution system has been developed that strongly correlates with a model for detour behavior in the frog. The robot’s motor schema based navigation system draws on potential field methodology to produce “intelligent” behavior based on environmental perception. Both simulation and actual experimental results are presented.
04 Sep 1989
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.
TL;DR: The basic concepts needed for a simulation environment capable of supporting the design of robot organizations for managing chemical, or similar, laboratories on the planned U.S. Space Station are described.
Abstract: This paper describes the basic concepts needed for a simulation environment capable of supporting the design of robot organizations for managing chemical, or similar, laboratories on the planned U.S. Space Station. The environment should facilitate a thorough study of the problems to be encountered in assigning the responsibility of managing a nonlife-critical, but mission valuable, process to an organized group of robots. In the first phase of the work, we seek to employ the simulation environment to develop robot cognitive systems and strategies for effective multi-robot management of chemical experiments. Later phases will explore human-robot interaction and development of robot autonomy.
31 Jan 1989
TL;DR: A new approach to robot perception is presented that addresses such scenarios using a probabilistic tesselated representation of spatial information called the Occupancy Grid, a multi-dimensional random field that maintains stochastic estimates of the occupancy state of each cell in the grid.
Abstract: The ability to recover robust spatial descriptions from sensory information and to efficiently utilize these descriptions in appropriate planning and problem-solving activities are crucial requirements for the development of more powerful robotic systems. Traditional approaches to sensor interpretation, with their emphasis on geometric models, are of limited use for autonomous mobile robots operating in and exploring unknown and unstructured environments. Here, researchers present a new approach to robot perception that addresses such scenarios using a probabilistic tesselated representation of spatial information called the Occupancy Grid. The Occupancy Grid is a multi-dimensional random field that maintains stochastic estimates of the occupancy state of each cell in the grid. The cell estimates are obtained by interpreting incoming range readings using probabilistic models that capture the uncertainty in the spatial information provided by the sensor. A Bayesian estimation procedure allows the incremental updating of the map using readings taken from several sensors over multiple points of view. An overview of the Occupancy Grid framework is given, and its application to a number of problems in mobile robot mapping and navigation are illustrated. It is argued that a number of robotic problem-solving activities can be performed directly on the Occupancy Grid representation. Some parallels are drawn between operations on Occupancy Grids and related image processing operations.
04 Sep 1989
TL;DR: Combining data from several sensors and from a pre-stored model of the domain provides a way to enhance the reliability of a perception system by integrating range measurements into a geometric model ofThe local environment.
Abstract: Unfortunately, the sensing devices which are available for mobile robots often fail in a variety of circumstances. This is especially true of the less expensive devices such as ultrasonic and infrared range sensors. Combining data from several sensors and from a pre-stored model of the domain provides a way to enhance the reliability of a perception system. Such combination may be accomplished by integrating range measurements into a geometric model of the local environment.
01 Jan 1989
TL;DR: This paper focuses on the problems associated with capturing a free-floating object that is initially out of reach of the robot and a set of rules is presented for generating an appropriate intercept trajectory.
Abstract: This paper reviews initial work at the Stanford University Aerospace Robotics Laboratory (ARL) in developing and controlling a free-flying space robot. The objective of this project is to develop a laboratory version of a space robot that is capable of performing target tracking, acquisition, and manipulation. In particular, this paper focuses on the problems associated with capturing a free-floating object that is initially out of reach of the robot. A set of rules is presented for generating an appropriate intercept trajectory. A controller architecture suitable for carrying out these motions is also described. Finally the results of computer simulations illustrating the behavior of these algorithms are shown along with a description of the physical hardware on which they will be tested.
TL;DR: The global dynamic behavior of multiple interacting autonomous mobile robots with simple navigation strategies is studied and various simple homing and collision-avoidance navigation strategies are derived.
Abstract: The global dynamic behavior of multiple interacting autonomous mobile robots with simple navigation strategies is studied. Here, the effective spatial domain of each robot is taken to be a closed ball about its mass center. It is assumed that each robot has a specified cone of visibility such that interaction with other robots takes place only when they enter its visibility cone. Based on a particle model for the robots, various simple homing and collision-avoidance navigation strategies are derived. Then, an analysis of the dynamical behavior of the interacting robots in unbounded spatial domains is made. The article concludes with the results of computer simulations studies of two or more interacting robots.
Patent•
08 Feb 1989TL;DR: In this article, the origin of a robot layout is determined by displaying the range of robot motion at the robot's origin, and obstacles within this range of motion are displayed in a color different from that of obstacles outside of the robot motion.
Abstract: In a method of deciding robot layout according to the present invention, the origin (P i ) of a robot layout is entered, the range (1) of robot motion at the origin of robot layout is displayed, obstacles (2, 3) within this range of motion are displayed in a color different from that of obstacles outside the range of robot motion, and the origin of robot layout is decided, while reference is made to the display, in such a manner that the robot will not interfere with the obstacles and will be capable of performing motions with respect to a workpiece.
11 Sep 1989
TL;DR: It is confirmed that accurate and continuous car location is achievable by a method combining dead-reckoning via the geomagnetic sensor, map-matching, and signpost navigation, which is highly feasible in a small country like Japan.
Abstract: The use of signpost navigation, map-matching, and satellite navigation as methods for correcting the accumulated errors of dead-reckoning is described. Also considered are ways to obtain accurate and continuous car location by combining those methods with dead-reckoning. The merits, demerits and feasibility of each method are discussed. It is confirmed that accurate and continuous car location is achievable by a method combining dead-reckoning via the geomagnetic sensor, map-matching, and signpost navigation. This combination is highly feasible in a small country like Japan. A method combining dead-reckoning via terrestrial magnetism and GPS (Global Positioning System) is expected to make accurate and continuous car location possible even in a large country and areas where signposts are not yet installed. >
04 Sep 1989
TL;DR: Four dicerent visual strategies for use in docking operations for a mobile robot in a manufacturing environment include temporal activity (motion) detection, Hough transform-based recognition, adaptive fast region segmentation, and edge-based texture niethods.
Abstract: This paper presents four dicerent visual strategies for use in docking operations for a mobile robot in a manufacturing environment. The algorithms developed include temporal activity (motion) detection, Hough transform-based recognition, adaptive fast region segmentation, and edge-based texture niethods. These algorithms are to be sequenced in a manner that is consistent wit11 our robot’s motor behavior (schema) for docking, exploiting aspects of ballistic and controlled motion a8 the robot moves towards a workstation.
04 Sep 1989
TL;DR: The problem of terrain acquisition presents one aspect of the more general problem of automatic motion planning in the presence of obstacles and the proposed algorithm guarantees convergence and exhibits an upper bound performance quadratic in the perimeters of obstacles in the terrain.
Abstract: The problem of terrain acquisition presents one aspect of the more general problem of automatic motion planning in the presence of obstacles. In turn, there is a number of ways to formulate the terrain acquisition problem. We consider a case whereby a mobile robot is required to cover all reachable areas of a finite-size planar terrain populated with a finite number of obstacles of arbitrary shape. The robot is equipped with a “vision” which delivers coordinates of all visible obstacles within a limited radius (radius of vision). The proposed algorithm guarantees convergence and exhibits an upper bound performance quadratic in the perimeters of obstacles in the terrain.
13 Dec 1989
TL;DR: The terrain acquisition problem is formulated as that of continuous motion planning, and an algorithm that allows obstacles to be of arbitrary shape is presented, and the upper bound on the algorithm's performance is estimated in terms of the length of the generated paths.
Abstract: Concerns a special case of the problem of robot motion planning, in which a mobile robot is required to build a complete map of an unfamiliar scene populated with a finite number of unknown objects (obstacles). The robot has a sort of sensory feedback equivalent to stereo vision or a range finder, and is expected to generate a reasonably short path during the operation. The terrain acquisition problem is formulated as that of continuous motion planning, and an algorithm that allows obstacles to be of arbitrary shape is presented. The upper bound on the algorithm's performance is estimated in terms of the length of the generated paths and is shown to be linear in the perimeters of the obstacles in the scene. >