Showing papers on "Mobile robot published in 1985"

High resolution maps from wide angle sonar

Abstract: We describe the use of multiple wide-angle sonar range measurements to map the surroundings of an autonomous mobile robot. A sonar range reading provides information concerning empty and occupied volumes in a cone (subtending 30 degrees in our case) in front of the sensor. The reading is modelled as probability profiles projected onto a rasterized map, where somewhere occupied and everywhere empty areas are represented. Range measurements from multiple points of view (taken from multiple sensors on the robot, and from the same sensors after robot moves) are systematically integrated in the map. Overlapping empty volumes re-inforce each other, and serve to condense the range of occupied volumes. The map definition improves as more readings are added. The final map shows regions probably occupied, probably unoccupied, and unknown areas. The method deals effectively with clutter, and can be used for motion planning and for extended landmark recognition. This system has been tested on the Neptune mobile robot at CMU.

Real-time obstacle avoidance for manipulators and mobile robots

Abstract: This paper presents a unique real-time obstacle avoidance approach for manipulators and mobile robots based on the "artificial potential field" concept. In this approach, collision avoidance, traditionally considered a high level planning problem, can be effectively distributed between different levels of control, allowing real-time robot operations in a complex environment. We have applied this obstacle avoidance scheme to robot arm using a new approach to the general problem of real-time manipulator control. We reformulated the manipulator control problem as direct control of manipulator motion in operational space-the space in which the task is originally described-rather than as control of the task's corresponding joint space motion obtained only after geometric and kinematic transformation. This method has been implemented in the COSMOS system for a PUMA 560 robot. Using visual sensing, real-time collision avoidance demonstrations on moving obstacles have been performed.

Position referencing and consistent world modeling for mobile robots

Abstract: In order to understand its environment, a mobile robot should be able to model consistently this environment, and to locate itself correctly. One major difficulty to be solved is the inaccuracies introduced by the sensors. The approach proposed in this paper to cope with this problem relies on 1) defining general principles to deal with uncertainties : the use of a multisensory system, favo ring of the data collected by the more accurate sensor in a given situation, averaging of different but consistent measurements of the same entity weighted with their associated uncertainties, and 2) a methodology enabling a mobile robot to define its own reference landmarks while exploring its environment. These ideas are presented together with an example of their application on the mobile robot HILARE.

Navigation for an intelligent mobile robot

Abstract: A navigation system is described for a mobile robot equipped with a rotating ultrasonic range sensor. This navigation system is based on a dynamically maintained model of the local environment, called the composite local model. The composite local model integrates information from the rotating range sensor, the robot's touch sensor, and a pre-learned global model as the robot moves through its environment. Techniques are described for constructing a line segment description of the most recent sensor scan (the sensor model), and for integrating such descriptions to build up a model of the immediate environment (the composite local model). The estimated position of the robot is corrected by the difference in position between observed sensor signals and the corresponding symbols in the composite local model. A learning technique is described in which the robot develops a global model and a network of places. The network of places is used in global path planning, while the segments are recalled from the global model to assist in local path execution. This system is useful for navigation in a finite, pre-learned domain such as a house, office, or factory.

Visual map making for a mobile robot

Abstract: Mobile robots sense their environment and receive error laden readings. They try to move a certain distance and direction, and do so only approximately. Rather than try to engineer these problems away it may be possible, and may be necessary, to develop map making and navigation algorithms which explicitly represent these uncertainties, but still provide robust performance. The key idea is to use a relational map, which is rubbery and stretchy, rather than try to place observations in a 2-d coordinate system.

Walking machines : an introduction to legged robots

Abstract: Advantages of legs- Terminology- 1 A brief history of walking machines- Rough-terrain transport- Bipeds: medical applications and man-amplifiers- The modern era: computer control- Alternative mechanisms of locomotion- 2 General principles of legged locomotion- The theory of land locomotion in general- The soil mechanics of wheels- Locomotion using levers- Soil mechanics and the difference between feet and wheels- The energetics of legged locomotion- Other properties of legs- Mechanisms other than legs- Aids to locomotion- Non-locomotory uses of appendages- Description and classification of gaits- 3 The mechanics of legged vehicles- Animal structures and their applications to robots- Leg number and arrangement- Leg design- Structure- Actuation methods- 4 The analysis and control of legged systems- Purpose of analysis and control- The objectives of control in legged locomotion- Dynamics- Multipod control- 5 Computing: hardware and software requirements- Computer architectures- Sensing methods- The design of algorithms for multipod walking- Programming languages for legged robots- 6 Current developments- The Ohio State University hexapod and adaptive suspension vehicle- ReCUS: the Komatsu underwater octopod- Sutherland's hexapod- The Odetics ODEX I- Quadruped research at the Tokyo Institute of Technology- Walking robots in France- Jurassic Robots- Current research on bipeds- Research on hopping at Carnegie-Mellon University- Conclusions- 7 Applications of walking machines- Military transport- Mining- Nuclear engineering and other cases of remote handling- Prosthetics and orthotics: walking chairs- Planetary exploration- Construction and related activities- Agriculture and forestry- Mobile robots in artificial intelligence- Fire-fighting and rescue robots- Applications unlikely to be suitable for walking machines- The study of locomotion (zoology and engineering)- Education, art and entertainment- References and bibliography

Redefinition of the robot motion-control problem

Abstract: The objective of this paper is a redefinition of the robot control problem, based on (1) realistic models for the industrial robot as a controlled plant, (2) end-effector trajectories consistent with manufacturing applications, and (3) the need for end-effector sensing to compensate for uncertainties inherent to most robotic manufacturing applications. Based on extensive analytical and experimental studies, robot dynamic models are presented that have been validated over the frequency range 0 to 50 Hz. These models exhibit a strong influence of drive system flexibility, producing lightly damped poles in the neighborhood of 8 Hz, 14 Hz, and 40 Hz, all unmodeled by the conventional rigid-body multiple-link robot dynamic approach. The models presented also quantify the significance of non-linearities in the drive system, in addition to those well known in the linkage itself. Simulations of robot dynamics and motion controls demonstrate that existing controls coupled with effective path planning produce dynamic path errors that are acceptable for most manufacturing applications. Major benefits are projected, with examples cited, for use of end-effector sensors for position, force, and process control.

Navigation system and method for a mobile robot

Abstract: An opto/acoustic navigation system allows a mobile robot to detect and mate with a floating plug-equipped charging unit upon detection of the need for recharging of the robot's storage battery. A plurality of infrared (IR) emitters and sensors located on the robot and adjacent to the charger in combination with the robot's acoustic sensors allow the robot to locate the charger, move to within a predetermined distance of the charger, maneuver to a position directly in front of the charger, and then back into engagement with the charger's floating plug.

Remotely controlled and/or powered mobile robot with cable management arrangement

Abstract: A mobile robot remotely controlled and/or powered through a cable from a stationary console is provided. The robot carries a cable management arrangement which stores the cable and dispenses and retracts it as needed. The arrangement lays down the cable under zero tension when the robot is outbound and reels it in as the robot returns to allow the robot to follow a tortuous path without entangling the cable under or around obstacles. The robot can have numerous configurations such as a simple configuration for use as a transporter for mail in an office and parts in a factory, to a complex configuration with robotic arms and sensors for use in remote surveillance and security work. The robot is especially usable in hostile environments such as nuclear power plants and has a containment box permitting it to be moved to numerous locations without contaminating other areas.

Robotics for Engineers

Abstract: Robotics for engineers , Robotics for engineers , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Dynamic world modeling for an intelligent mobile robot using a rotating ultra-sonic ranging device

Abstract: A system which performs task-oriented navigation for an intelligent mobile robot is described in this paper. This navigation system is based on a dynamically maintained model of the local environment, called the "Composite Local Model." The Composite Local Model integrates information from a rotating sonar sensor, the robot's touch sensor and a pre-learned Global Model as the robot moves through its environment. Techniques are described for constructing a line segment description of the most recent sensor scan (the Sensor Model), and for integrating such descriptions to build up a model of the immediate environment (the Composite Local Model). Model integration is based on a process of reinforcing the confidence in consistent information while decaying the confidence in inconsistent information. The estimated position of the robot is corrected by the difference in position between observed sensor signals and the corresponding symbols in the Composite Local Model. This system is useful for navigation in a finite, pre-learned domain such as a house, office, or factory.

Some Heuristics for the Navigation of a Robot

Abstract: A mobile robot is required to navigate around barriers in an unexplored environment. Some heuristic strategies to aid such navigation are discussed here. Being heuristic, these methods can be neither exhaustively tested nor proved effec tive in all cases. However, examples are given to demonstrate their usefulness in obstacle avoidance. In a simple case of sufficient generality, the heuristics are shown to be effective.

Minimum-time path planning for robot arms and their dynamics

Abstract: Despite its close relationship to robot arm dynamics, conventional path planning does not take it into account, leading to the possible underutilization of the robot's capabilities. The authors have developed a minimum-time path-planning method in joint space taking into consideration robot arm dynamics as well as other realistic constraints. The main differences between this method and others are: (1) an absolute tolerance in the path deviation at each corner point can be specified; (2) local upper bounds on joint accelerations are derived from the arm dynamics so as to nearly fully utilize robot's capabilities; and (3) a set of local optimization problems, one at every local corner point, replaces the global minimum-time problem, thus making the minimum-time path-planning problem simpler and easier to solve. The method is applied to the path planning of the first three joints of the Unimation PUMA 600 series robot arm, using its simulator on a DEC VAX-11/780. The results show significant improvements in the total traveling time in addition to the ease and simplicity obtained from the decomposition of the global problem into a set of local optimization problems.

A Mobile Platform for Nursing Robots

Abstract: This paper describes a computer-controlled vehicle which is part of a nursing robot system currently under development at the Technion-Israel Institute for Technology. The platform of this vehicle can also be used for household robots. Design considerations, control algorithms, and the necessary sensory devices are discussed. The vehicle applies a motion control strategy which avoids slippage and minimizes position errors. Experimental results, performed on a prototype vehicle, are described as well.

A spatial representation system for mobile robots

Abstract: A two dimensional spatial representation system is presented which makes efficient use of distance information for accomplishing common mobile robot tasks. Ways to use the representation for route planning, positioning, and execution monitoring are presented. The representation is very space efficient, and all the transformations to be performed on it are computationally tractable.

Method for predicting tracking cameras for free-roaming mobile robots

Abstract: In a manufacturing environment, a controllable mobile apparatus such as a mobile robot is guided through the manufacturing environment by a navigation system that utilizes fixed overhead cameras having a predefined viewing area. As the robot leaves a first viewing area there is an uncertainty as to which viewing area the robot will go into so that that camera may be monitored. The uncertainty is minimized by using a plurality of rings of uncertainty which overlap the surrounding areas. The uncertainty is continuously eliminating by drawing the circle of uncertainty into smaller and smaller area.

Industrial robots: Computer interfacing and control

Abstract: Preparing the books to read every day is enjoyable for many people. However, there are still many people who also don't like reading. This is a problem. But, when you can support others to start reading, it will be better. One of the books that can be recommended for new readers is industrial robots computer interfacing and control. This book is not kind of difficult book to read. It can be read and understand by the new readers.

Robot Modelling: Control and Applications With Software

Abstract: This book provides a ''picture'' of robotics covering both the theoretical aspect of modeling as well as the practical and design aspects of: robot programming; robot tooling and automated hand changing; implementation planning; testing; and software design for robot systems. The authors present an introduction to robotics with a systems approach. They describe not only the tasks relating to a single robot (or arm) but also systems of robots working together on a product or several products.

Redundant Sensors for Mobile Robot Navigation

Abstract: : Redundant sensors are needed on a mobile robot so that the accuracy with which it perceives its surroundings can be increased. Sonar and infrared sensors are used here in tandem, each compensating for deficiencies in the other. The robot combines the data from both sensors to build a representation which is more accurate than if either sensor were used alone. Another representation, the curvature primal sketch, is extracted from this perceived workspace and is used as the input to two path planning programs: one based on configuration space and one based on a generalized cone formulation of free space. (Author).

Optimal compliance design for grinding robot tool holders

Abstract: A simple and effective solution to the robot grinding problem is introduced, which significantly reduces vibrations during grinding without additional actuators or active control. The objective is to determine the optimal compliance design for grinding robot tool holders. It is found that the degree of correlation between the dynamic behavior of the wheel in the directions normal and tangent to the desired workpiece surface has a direct effect on the grinding performance. This fact is utilized to determine the optimal tool holder compliance design through analysis, simulation and experimentation. The resulting design conclusions have been incorporated in an end-effector which was successfully tested for the grinding of weld seams.

Visual navigation system for mobile robots

Abstract: A visual navigation system navigates an electrically controllable apparatus such as a mobile robot. Navigation commands are generated to move the mobile apparatus based upon the location of the mobile apparatus. Once the location of the mobile apparatus is determined and the coordinates of a new position are provided, then the commands are transmitted to the mobile apparatus to relocate to the new position. The repetitive update of the location and move commands ensure the movement of the mobile apparatus without wire or rails.

Robot system safety method

Abstract: A safety method in a robot system including at least a robot (1), peripheral equipment (2-5) serviced by the robot, a robot control unit (6) which causes the robot to execute predetermined services for the peripheral equipment, and a teach control panel (9). A door (11) is provided at the entrance to a robot operating zone, and the door is provided with a safety switch (12) for terminating automatic operation of the robot when the robot is in an automatic operating state. When the safety switch is actuated by opening the door, robot motion in the automatic operating state is decelerated and stopped. During the time that the safety switch is in the actuated state, the robot is placed in a playback operation state to enable control that is performed through the teach control panel.

Multi-goal real-time global path planning for an autonomous land vehicle using a high-speed graph search processor

Abstract: This paper presents a fast and powerful global path planning subsystem for an autonomous land vehicle (ALV). It addresses its relation with a complete hierarchical planner and describes its real-time implementation.

Dynamic scene analysis for a mobile robot in a man-made environment

Abstract: Analysis of scene viewed continuously from a robot moving in a man-made environment, such as a building or a plant, yields useful information for the navigation. The knowledge on the environment, richness of the scene in vertical edges and the flatness of the floor, is arranged in constraints for the dynamic scene analysis. The rotational component of camera motion is estimated first from image points invarient from translation. After compensating for movements by the rotation between the consecutive images, the foci of expansion of translational motion of both the robot and moving objects are determined.

The role of knowledge in the architecture of a robust robot control

Abstract: We would like robots to recognize and handle situations that do not conform with normal operating conditions. We want to be able to do this without having to consider explicitly errors caused by missing or defective parts, or by malfunctioning. To this end we present the detailed design of a system in which the controller of the robot takes advantage of large knowledge bases to ensure proper execution of the robot task. Real time considerations played a large role in our design.

Sensing Error for a Mobile Robot Using Line Navigation

Abstract: The use of a contrasting line for the visual navigation of autonomous mobile robots in a factory environment is developed. Minimum and maximum linewidths are determined analytically by considering sensor geometry, field of view, and error conditions present in the system. The effects of these error conditions on the width of the line, as seen in the image plane, determines the optimal linewidth. Numerical examples using typical sensor parameters are given.

Internally Balanced Magnetic Unit

Abstract: 建物や大型構造物の壁や天井面を動きまわるようなロボットを構成するためには, まず初めにそれを可能にするだけの強力な吸着力を生成し得る信頼性の高い吸着装置を実現しなければならない.本論文は原子炉や船舶などの鋼板上を動くロボットのための磁気吸着ユニットに関するものである.まず初めに従来からある磁気吸着ユニットの比較検討を行い, ついでIBマグネットと呼ぶ磁気吸着ユニットを提案する.これは永久磁石による強力な吸着力を生ずると同時に, 内部力をバネユニットで打ち消す構造を持たせることにより, 容易に脱離を可能にする装置である.本IBマグネットを構成する上で必要となる磁気吸着ユニットの設計手法, さらにそれとバランスする非線形バネユニットの設計手法を論ずる.最後に, 人間がこのIBマグネット装置4台を両手両足に装着し, 鋼板壁面と天井面を歩行する実験を行うことにより, 本装置が移動ロボットの吸着ユニットとして応用可能であることを示した.