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Showing papers on "Mobile robot published in 1993"


Book
01 Mar 1993
TL;DR: Control of robot manipulators , Control of robot Manipulators , مرکز فناوری اطلاعات و £1,000,000; اوشاوρز رسانی, کسورزی;
Abstract: Control of robot manipulators , Control of robot manipulators , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

1,146 citations


Journal ArticleDOI
02 May 1993
TL;DR: The structure of the kinematic and dynamic models of wheeled mobile robots is analyzed and it is shown that, for a large class of possible configurations, they can be classified into five types, characterized by generic structures of the model equations.
Abstract: The structure of the kinematic and dynamic models of wheeled mobile robots is analyzed. It is shown that, for a large class of possible configurations, they can be classified into five types, characterized by generic structures of the model equations. For each type of model the following questions are addressed: (ir)reducibility and (non)holonomy, mobility and controllability, configuration of the motorization, and feedback equivalence.

1,066 citations


Journal ArticleDOI
TL;DR: It is argued that knowledge transfer is essential if robots are to learn control with moderate learning times in complex scenarios and two approaches which both capture invariant knowledge about the robot and its environments are presented.

600 citations


Book
31 Jul 1993
TL;DR: This book describes a connectionist system called ALVINN (Autonomous Land Vehicle In a Neural Network) that overcomes difficulties and can learn to control an autonomous van in under 5 minutes by watching a person drive.
Abstract: From the Publisher: Vision based mobile robot guidance has proven difficult for classical machine vision methods because of the diversity and real time constraints inherent in the task. This book describes a connectionist system called ALVINN (Autonomous Land Vehicle In a Neural Network) that overcomes these difficulties. ALVINN learns to guide mobile robots using the back-propagation training algorithm. Because of its ability to learn from example, ALVINN can adapt to new situations and therefore cope with the diversity of the autonomous navigation task. But real world problems like vision based mobile robot guidance present a different set of challenges for the connectionist paradigm. Among them are: how to develop a general representation from a limited amount of real training data, how to understand the internal representations developed by artificial neural networks, how to estimate the reliability of individual networks, how to combine multiple networks trained for different situations into a single system, and how to combine connectionist perception with symbolic reasoning. Neural Network Perception for Mobile Robot Guidance presents novel solutions to each of these problems. Using these techniques, the ALVINN system can learn to control an autonomous van in under 5 minutes by watching a person drive. Once trained, individual ALVINN networks can drive in a variety of circumstances, including single-lane paved and unpaved roads, and multi-lane lined and unlined roads, at speeds of up to 55 miles per hour. The techniques also are shown to generalize to the task of controlling the precise foot placement of a walking robot.

508 citations


Book ChapterDOI
28 Oct 1993
TL;DR: The interaction of an autonomous mobile robot with the real world critically depends on the robots morphology and on its environment Building a model of these aspects is extremely complex, making simulation insufficient for accurate validation of control algorithms as mentioned in this paper.
Abstract: The interaction of an autonomous mobile robot with the real world critically depends on the robots morphology and on its environment Building a model of these aspects is extremely complex, making simulation insufficient for accurate validation of control algorithms

446 citations


01 Jan 1993
TL;DR: In this paper, two general controllers for unicycle-type and two-steering-wheels mobile robots are proposed and conditions for asymptotical convergence to a predefined path are established and simulation results are presented.
Abstract: Through two different approaches, this report proposes two general controllers for unicycle-type and two-steering-wheels mobile robots. For both systems, conditions for asymptotical convergence to a predefined path are established and simulation results are presented. Rather than writing the systems' equations with respect to a fixed reference frame, the robot state is here parametrized relative to the followed path, in terms of distance and orientation.

353 citations


Journal ArticleDOI
TL;DR: The mechanisms, used to invoke the group behavior, allow the system of robots to perform tasks without centralized control or explicit communication and suggest that decentralized control without explicit communication can be used to perform cooperative tasks requiring a collective behavior.
Abstract: Achieving tasks with multiple robots will require a control system that is both simple and scalable as the number of robots increases. Collective behavior as demonstrated by social insects is a form of decentralized control that may prove useful in controlling multiple robots. Nature's several examples of collective behavior have motivated our approach to controlling a multiple robot system using a group behavior. Our mechanisms, used to invoke the group behavior, allow the system of robots to perform tasks without centralized control or explicit communication. We have constructed a system of five mobile robots capable of achieving simple collective tasks to verify the results obtained in simulation. The results suggest that decentralized control without explicit communication can be used to perform cooperative tasks requiring a collective behavior.

350 citations


Book
01 Jan 1993
TL;DR: The goal function in robot architecture and robot learning conclusions are discussed in this article, where intelligent behaviour rational behaviour utility state and cost design and decision motivation and autonomy goals and behaviour accomplishing tasks are prerequisites for an autonomous robot.
Abstract: Intelligent behaviour rational behaviour utility state and cost design and decision motivation and autonomy goals and behaviour accomplishing tasks prerequisites for an autonomous robot the goal function in robot architecture animal and robot learning conclusions.

331 citations


Journal ArticleDOI
TL;DR: This work analyzes the controllability of nonholonomic multibody mobile robots and shows that the well-known Controllability Rank Condition Theorem is applicable to these robots even when there are inequality constraints on the velocity.
Abstract: We consider mobile robots made of a single body (car-like robots) or several bodies (tractors towing several trailers sequentially hooked). These robots are known to be nonholonomic, i.e., they are subject to nonintegrable equality kinematic constraints involving the velocity. In other words, the number of controls (dimension of the admissible velocity space), is smaller than the dimension of the configuration space. In addition, the range of possible controls is usually further constrained by inequality constraints due to mechanical stops in the steering mechanism of the tractor. We first analyze the controllability of such nonholonomic multibody robots. We show that the well-known Controllability Rank Condition Theorem is applicable to these robots even when there are inequality constraints on the velocity, in addition to the equality constraints. This allows us to subsume and generalize several controllability results recently published in the Robotics literature concerning nonholonomic mobile robots, and to infer several new important results. We then describe an implemented planner inspired by these results. We give experimental results obtained with this planner that illustrate the theoretical results previously developed.

304 citations


Journal ArticleDOI
TL;DR: A set of stabilizing smooth time-varying feedbacks is derived, and simulation results are given.
Abstract: Many nonholonomic mechanical systems, such as common wheeled mobile robots, are controllable but cannot be stabilized to given positions and orientations bv using smooth pure-state feedback control...

297 citations


01 Aug 1993
TL;DR: The task of planning trajectories for a mobile robot has received considerable attention in the research literature, but less attention has been paid to the problem of unknown or partially-known environments.
Abstract: : The task of planning trajectories for a mobile robot has received considerable attention in the research literature. Algorithms exist for handling a variety of robot shapes, configurations, motion constraints, and environments. Most of the work assumes the robot has a complete and accurate model of its environment before it begins to move; less attention has been paid to the problem of unknown or partially-known environments. This situation occurs for an exploratory robot or one that must move to a goal location without the benefit of a floorplan (indoor) or terrain map (outdoor). Existing approaches plan an initial global path or route based on known information and then modify the plan locally as the robot discovers obstacles with its sensors. While this strategy works well in environments with small, sparse obstacles, it can lead to grossly suboptimal and incomplete results in cluttered spaces. An alternative approach is to replan the global path from scratch each time a new obstacle is discovered.

Journal ArticleDOI
01 Aug 1993-Leonardo
TL;DR: Using photographs, illustrations, and informative text, Mobile Robots guides the reader through the step-by-step process of constructing two different and inexpensive yet fully functional robots.
Abstract: Revised and updated, the second edition includes several new chapters with projects and applications. The authors keep pace with the ever-growing and rapidly expanding field of robotics. The new edition reflects technological developments and includes programs and activities for robot enthusiasts. Using photographs, illustrations, and informative text, Mobile Robots guides the reader through the step-by-step process of constructing two different and inexpensive yet fully functional robots.

Proceedings ArticleDOI
26 Jul 1993
TL;DR: An image sensor with a hyperboloidal mirror for vision based navigation of a mobile robot and this sensing system can acquire an omnidirectional view around the robot, in real-time, with use of aHyperOmni Vision.
Abstract: Described here is an image sensor with a hyperboloidal mirror for vision based navigation of a mobile robot. Its name is HyperOmni Vision. This sensing system can acquire an omnidirectional view around the robot, in real-time, with use of a hyperboloidal mirror.

Proceedings ArticleDOI
02 May 1993
TL;DR: A decentralized method for controlling a homogeneous swarm of autonomous mobile robots that collectively transport a single palletized load is proposed, and the resulting stable behavior of the system is verified by computer simulation.
Abstract: A decentralized method for controlling a homogeneous swarm of autonomous mobile robots that collectively transport a single palletized load is proposed. The small tank-like robots have no advanced sensory or communications capabilities. They have no information on the position or number of other robots transporting the small pallet. Instead, all information needed by the robots is derived from the dynamics inherent when the system of robots is contacting a common rigid body. Each robot derives the required local information from a force sensor mounted at the point at which it contacts the pallet. A distributed control law is derived, and the resulting stable behavior of the system is verified by computer simulation. >

Journal ArticleDOI
01 Feb 1993
TL;DR: The problem of generating collision-free motion in an operator-assisted teleoperated robot arm manipulator system is discussed and the suggested methodology draws on recent work on motion planning with incomplete information for whole-sensitive robots.
Abstract: The problem of generating collision-free motion in an operator-assisted teleoperated robot arm manipulator system is discussed. The concentration is on several system requirements: a real real-time operation, a guarantee of collision-free motion for the entire body of the arm manipulator, and an ability to handle obstacles of arbitrary shapes. The suggested methodology draws on recent work on motion planning with incomplete information for whole-sensitive robots. >

Proceedings ArticleDOI
02 May 1993
TL;DR: The kinematics of a form of hyper-redundant mobile robot locomotion which is analogous to the sidewinding locomotion of desert snakes are considered and algorithms are developed which enable travel in a uniform direction as well as changes in direction.
Abstract: The kinematics of a form of hyper-redundant mobile robot locomotion which is analogous to the sidewinding locomotion of desert snakes are considered. This form of locomotion can be generated by a repetitive traveling wave of mechanism bending. Using a continuous backbone curve model, algorithms are developed which enable travel in a uniform direction as well as changes in direction. >

Journal ArticleDOI
01 Dec 1993
TL;DR: The authors shows that four different control systems correspond to a same differential model, which presents a proof of controllability for four distinct multibody mobile robot systems.
Abstract: This paper presents a proof of controllability for a multibody mobile robot (e.g., a car pulling and pushing trailers like a luggage carrier in an airport). Such systems appear as canonical systems to illustrate the tools from differential geometric control theory required by nonholonomic motion planning. Three modeling steps are considered: geometric, differential, and control steps. The author derives the kinematic equations for four distinct multibody mobile robot systems: a convoy driven by 1) a unicycle, 2) a two-driving wheels vehicle, 3) a real car and 4) the first two bodies. He shows that these four control systems correspond to the same differential model, which is then used to give the same proof of controllability. Previous work proved the controllability of two-body systems and three-body systems. The main result of this paper is prove the controllability for a general n-body system. >

Journal ArticleDOI
Fabrice Noreils1
TL;DR: This architecture exhibits important benefits such as mod ularity, robustness, and robustness (although some modules on the robot fail, it is still able to perform useful tasks), and programmability.
Abstract: This article describes an architecture for cooperative and au tonomous mobile robots. The architecture is composed of three levels: functional, control, and planner levels. The functional and contr...

Proceedings ArticleDOI
26 Jul 1993
TL;DR: This paper presents a taxonomy of the different ways in which a collection of autonomous robotic agents can be structured, and it is shown that certain swarms provide little or no advantage over having a single robot, while other swarms can obtain better than linear speedup over a single robots.
Abstract: In many cases several mobile robots (autonomous agents) can be used together to accomplish tasks that would be either more difficult or impossible for a robot acting alone. Many different models have been suggested for the makeup of such collections of robots. In this paper the authors present a taxonomy of the different ways in which such a collection of autonomous robotic agents can be structured. It is shown that certain swarms provide little or no advantage over having a single robot, while other swarms can obtain better than linear speedup over a single robot. There exist both trivial and non-trivial problems for which a swarm of robots can succeed where a single robot will fail. Swarms are more than just networks of independent processors - they are potentially reconfigurable networks of communicating agents capable of coordinated sensing and interaction with the environment.

Proceedings ArticleDOI
02 May 1993
TL;DR: An attitude estimation system based on inertial measurements for a mobile robot is described and experimental results show that the resulting system is very sensitive and accurate.
Abstract: An attitude estimation system based on inertial measurements for a mobile robot is described. Five low-cost inertial sensors are used: two accelerometers and three gyros. The robot's attitude, represented by its roll and pitch angles, can be obtained using two different methods. The first method is based on accelerometric measurements of gravity. The second one proceeds by integration of the differential equation relating the robot's attitude and its instantaneous angular velocity which is measured by the gyrometers. The results of these two methods are fused, using an extended Kalman filter. Experimental results show that the resulting system is very sensitive and accurate. >

Journal ArticleDOI
TL;DR: In this paper, a cross-coupling motion controller for a differential-drive mobile robot is described, which directly minimizes the most significant error by coordinating the motion of the two drive wheels.
Abstract: The design and implementation of a cross-coupling motion controller for a differential-drive mobile robot is described. A new concept, the most significant error, is introduced as the control design objective. Cross-coupling control directly minimizes the most significant error by coordinating the motion of the two drive wheels. The cross-coupling controller has excellent disturbance rejection. This is advantageous when the robot is not loaded symmetrically or has large friction in its drive mechanism, and especially when it is instructed to follow curved paths. Experimental results show that cross-coupling control yields substantially smaller position and orientation errors than conventional methods. >

Proceedings ArticleDOI
28 Mar 1993
TL;DR: A fuzzy controller for such a mobile robot that can take abstract goals into consideration is described that has been implemented in the SRI mobile robot Flakey, resulting in extremely smooth and reliable movement.
Abstract: Controlling the movement of an autonomous mobile robot requires the ability to pursue strategic goals in a highly reactive way. The authors describe a fuzzy controller for such a mobile robot that can take abstract goals into consideration. Through the use of fuzzy logic, reactive behavior, e.g., avoiding obstacles on the way, and goal-oriented behavior, e.g., trying to reach a given location, are smoothly blended into one sequence of control actions. The technique proposed has been implemented in the SRI mobile robot Flakey, resulting in extremely smooth and reliable movement. >

Book
02 Jan 1993
TL;DR: How the Soar architecture supports planning, execution, and learning in unpredictable and dynamic environments is described and capabilities are demonstrated on two robotic systems controlled by Soar.
Abstract: Three key components of an autonomous intelligent system are planning, execution, and learning. This paper describes how the Soar architecture supports planning, execution, and learning in unpredictable and dynamic environments. The tight integration of these components provides reactive execution, hierarchical execution, interruption, on demand planning, and the conversion of deliberate planning to reaction. These capabilities are demonstrated on two robotic systems controlled by Soar, one using a Puma robot arm and an overhead camera, the second using a small mobile robot with an arm.

Proceedings ArticleDOI
W.D. Rencken1
26 Jul 1993
TL;DR: This paper presents an approach where the boot-strapping problem of concurrent localization and map building is solved by estimating the respective errors introduced by each of the processes and correcting them accordingly.
Abstract: Successful autonomous navigation by a mobile robot depends on its ability to map its environment and to accurately determine its position within this environment. In complex environments, where no additional navigational aids are present, the localization and map-building processes are not independent of each other. This paper presents an approach where the boot-strapping problem of concurrent localization and map building is solved by estimating the respective errors introduced by each of the processes and correcting them accordingly. The algorithms were tested in simulation, and results showed that the robot stably navigated in its environment.

Proceedings Article
09 Aug 1993
TL;DR: A mobile robots engaged in a cooperative task that requires communication is described, initially given a but uninterpreted vocabulary for communication and attempting to perform their task the robots learn a private communication lan guage.
Abstract: We describe mobile robots engaged in a cooperative task that requires communication The robots are initially given a xed but uninterpreted vocabulary for communication In attempting to perform their task the robots learn a private communication lan guage Di erent meanings for vocabulary elements are learned in di erent runs of the experiment As circumstances change the robots adapt their lan guage to allow continued success at their task

Proceedings ArticleDOI
01 Jan 1993
TL;DR: The first results on COLUMBUS, an autonomous mobile robot, are presented, which aims to explore and model the environment efficiently while avoiding collisions with obstacles using an instance-based learning technique for modeling its environment.
Abstract: The first results on COLUMBUS, an autonomous mobile robot, are presented. COLUMBUS operates in initially unknown structured environments. Its task is to explore and model the environment efficiently while avoiding collisions with obstacles. COLUMBUS uses an instance-based learning technique for modeling its environment. Real-world experiences are generalized via two artificial neural networks that encode the characteristics of the robot's sensors, as well as the characteristics of typical environments which the robot is assumed to face. Once trained, these networks allow for the transfer of knowledge across different environments the robot will face over its lifetime. Exploration is achieved by navigating to low confidence regions. A dynamic programming method is employed in background to find minimal-cost paths that, when executed by the robot, maximize exploration. >

Journal ArticleDOI
02 May 1993
TL;DR: This paper addresses the problem of smoothing mobile robot motions when cusps, i.e., changes of motion direction along the trajectory, are imposed by pinpointing some special curves that are called "anticlothoids" and discussing how they can be used together with clothoids in order to smooth a predefined trajectory.
Abstract: Clothoids are very useful for smoothing the motion of a mobile robot moving along a trajectory. This paper addresses the problem of smoothing mobile robot motions when cusps, i.e., changes of motion direction along the trajectory, are imposed. We pinpoint some special curves (that we call "anticlothoids") and we discuss how they can be used together with clothoids in order to smooth a predefined trajectory. >

Book
01 Jan 1993

Proceedings ArticleDOI
02 May 1993
TL;DR: A mechanism and a control method is described for a two-link brachiation robot, a mobile robot that moves using its arms much like a gibbon moving from branch to branch, and achieves locomotion with trajectory and arm-direction feedback control.
Abstract: A mechanism and a control method of a two-link brachiation robot are described. The robot can generate motions by a heuristic method and locomotes with the trajectory and arm-direction feedback control. It controls the switching amplitude by a method based on parametric excitation. Experimental results of the swing and locomotion control of the robot using these methods are given. They enable the robot to catch its target and to continue locomotion from any initial states. >

Proceedings ArticleDOI
02 May 1993
TL;DR: It is shown that the addition of a local spatial memory that allows a robot to avoid areas that have already been visited offers a solution to the box canyon and other navigational problems.
Abstract: Reactive navigation methods, which eliminate or minimize the use of memory, are considered, focusing on problems that still present a challenge to reactive strategies (box canyons, for example). It is shown that the addition of a local spatial memory that allows a robot to avoid areas that have already been visited offers a solution to the box canyon and other navigational problems. Such a strategy has been implemented using a spatial memory within a schema-based motor control model. Experiments have produced promising results in simulation and on mobile robots. >