Showing papers on "Mobile robot published in 1984"

Autonomous mobile robot

Abstract: A vision system for a mobile robot employs at least two arrays of sensors for obtaining data on the position and distance of objects in a workspace. One of the sensor arrays is used principally to see near objects and the other array is used principally to see far objects. The two arrays are symmetric about an axis that extends through the body of the robot. The robot carries a computer which controls the sequence in which the sensors are serially polled for information. Data received from the sensors is stored and provides a representation of the space and objects seen by the sensors. A software program causes the computer to manipulate data from the sensors to simulate rotation of the robot around the axis of symmetry and control behavior of the robot to complete goals set by input commands from a natural language processor.

Path Relaxation: Path Planning for a Mobile Robot

Abstract: Path Relaxation is a method of planning safe paths around obstacles for mobile robots. It works in two steps: a global grid search that finds a rough path, followed by a local relaxation step that adjusts each node on the path to lower the overall path cost. The representation used by Path Relaxation allows an explicit tradeoff among length of path, clearance away from obstacles, and distance traveled through unmapped areas.

Multiple robot control system using grid coordinate system for tracking and completing travel over a mapped region containing obstructions

Abstract: A control system for a mobile robot calculates the instantaneous position of the robot, and sequentially stores data representative of the respective robot positions. The system studies and stores a range which the robot is to travel, and calculates a running pattern of the robot in the specific range. The robot is allowed to travel within the range without leaving any region untravelled in spite of the presence of obstructions which alters its path, while checking its own position. Also, the robot compensates for dislocations caused by slippage of its drive wheels or errors in the operation of its motors.

Coordinated control of two robot arms

Abstract: A computer control structure has been designed and implemented to enable two robot arms to function in a coordinated manner. One algorithm has been derived and implemented but not tested for a closed-loop configuration. Errors for the open-loop operation are given in the report.

Determining the position of a robot using a single calibration object

Abstract: A procedure for determining the position uniquely, of a mobile robot in a three-dimensional space is presented. The method consists of viewing a single sphere with horizontal and vertical calibration great circles and computing distance and elevation and azimuth angles with respect to the sphere. The method is simple and provides good results as long as the sphere is projected onto a large portion of the image plane. Results using simulated and actual data are presented.

Path relaxation: path planning for a mobile robot

Abstract: Path Relaxation is a method of planning safe paths around obstacles for mobile robots It works in two steps: a global grid search that finds a rough path, followed by a local relaxation step that adjusts each node on the path to lower the overall path cost The representation used by Path Relaxation allows an explicit tradeoff among length of path, clearance away from obstacles, and distance traveled through unmapped areas

Mobile robot calling system

Abstract: A mobile robot calling system has a mobile robot normally waiting at a home position and connected to an AC power supply such that its battery is charged by the AC power supply in the wait status, and a calling oscillator for generating a calling signal to the mobile robot. The calling signal is supplied from the calling oscillator to the mobile robot through indoor AC power supply wiring. Relay transmitters are respectively arranged for a plurality of AC receptacles to relay the calling signal. A controller is arranged to control a plurality of calling devices and robot waiting stations. The controller cyclically checks the robot calling states of the calling devices and robot wait status in the waiting stations. The controller generates a robot calling command to the waiting stations in accordance with the robot wait status in the waiting stations when the robot calling signals are generated from the calling devices.

Control system for mobile robot

Abstract: A control system for a mobile robot includes operation means for calculating an instantaneous position of the robot, storage means for sequentially storing data representative of the respective robot positions, means for studying and storing a rangewhich the robot is to travel, and means for calculating a running pattern of the robot in the specific range. The robot is allowed to travel thrpughly in the range without leaving any region non-travelled, while checking its own position.

Improving the precision of a robot

Abstract: Least square error methods are employed to improve the precision of a robot world coordinate system model. A solution which reduces the large scale errors of the robot is presented. This method is then applied to the task of vision directed workpiece reorientation.

Algorithm of navigation for a mobile robot

Abstract: This study describes the theoretical and practical aspects of the design and computer simulation of a heuristic based navigation algorithm. An algorithm is developed which provides a convenient testing system for generalized navigation strategies on a fixed map which may be known or unknown to a system. A variety of maps are simulated and the navigation results are compared.

Servoed world models as interfaces between robot control systems and sensory data

Abstract: A hierarchical robot sensory system being developed for industrial robotics is described. At each level of the hierarchy, sensory interpretative processes are guided by expectancy-generating modeling processes. The modeling processes are driven by a priori knowledge (object prototypes), by knowledge of the robot's movements (feed-forward from the control system), and by feedback from the interpretative processes (prior state of the sensory world). At the lowest level, the senses (vision, proximity, tactile, force, joint angle, etc.) are handled separately; above this level, they are integrated into a multi-model world model. At successively higher levels, the interpretative and modeling processes describe the world with successively higher order constructs, and over successively longer time periods. Each level of the modeling hierarchy provides output, in parallel, to guide the corresponding levels of a hierarchical robot control system.

Cellular type robot apparatus

Abstract: This invention relates to a cellular type robot apparatus consisting of a plurality of cellular robots (11-34) each having intelligence wherein each cellular robot controls the operation of its own on the basis of information exchange with adjacent cellular robots, the operations of the cellular robots are as a whole coordinated, and each cellular robot can be controlled without the necessity of change of hard- and softwares even when a part of cellular robots is out of order or is expanded. Each cellular robot can be increased or decreased in a building block arrangement. More definitely, each cellular robot has arms corresponding to hands and feet, can control the operation by itself. As the cellular robots are connected and combined through transmission routes so as to exchange information, they can operate cooperatively as a group of cellular robots. The operation of the group of cellular robots is to constitute the shape of a predetermined pattern besides the operations of entwining an object, and gripping and moving the object.

Collision avoidance for industrial robots with arbitrary motion

Abstract: For effective application of industrial robots in flexible manufacturing systems and in automatic assembly, guided automatic collision avoidance is an important and—in spite of many applications—so far unsolved problem. The basis is unconstrained path control of each robot controlled, for example, by optical sensors in connection with different priority levels assigned to the robots. Iterative, time-consuming, hierarchical control methods are not applicable due to the complexity and the real-time constraints of this task. As a new and successful approach the application of various hierarchical decision strategies in connection with extremely time-efficient evaluation of decision tables is presented. This concept is based on a suitable description of the actual possible collision spaces.

Robot Vision Using A Projection Method

Abstract: A dramatic increase in the use of industrial robots is expected in the United States within this decade. This increase increase will require robot vision systems so that the machines can respond and adapt to their environment, i.e., be intelligent. These advances can lead to new methods for use in flexible manufacturing systems and automated factories. The purpose of this paper is to describe a technique for three dimensional robot vision using a single projected image. The method involves automatic location of projected vertex points to determine the three dimensional surface characteristics of an object. The method is robust enough to permit measurement of featureless curved objects. Examples are given which demonstrate the simplicity of the technique. The significance of this method is that it is simple enough for use in robot control or inspection applications.

A functional vehicle for autonomous mobile robot research

Abstract: : Neptune is a tethered vehicle built for autonomous mobile robot research. Included are: the design considerations, the resulting design, and details of the mechanical structure and electrical control system. Detail is sufficient to enable replication or adaptation by others. A discussion of the performance with respect to the design considerations is also included. (Author).

Educational and laboratory work cell for a robotic device

Abstract: A robotic cell, or work area, especially useful for education. The cell has a plurality of interchangable work surfaces for mounting objects that the robot manipulates. Students, researchers, or other workers can thus set up separate experiments that need not be torn down each time a different user begins work with the cell. The cell has safety switches that encourage a user, when near the robot, to keep a hand on the robot so as not to be accidentally injured by the robot's motion. There is also a dead man switch effective to disenable the robot entirely, after a short time delay. The cell has a pneumatic control circuit that enables a user to position the robot's gripper arm at positions intermediate of fully up and fully down.

Design and implementation of a compliant robot with force feedback and strategy planning software

Abstract: Force-feedback robotics techniques are being developed for automated precision assembly and servicing of NASA space flight equipment. Design and implementation of a prototype robot which provides compliance and monitors forces is in progress. Computer software to specify assembly steps and makes force feedback adjustments during assembly are coded and tested for three generically different precision mating problems. A model program demonstrates that a suitably autonomous robot can plan its own strategy.

Experience with Visual Robot Navigation

Abstract: The CMU Mobile Robot Lab is studying issues in the development of autonomous vehicles, including path planning, motion determination, and obstacle detection from video and sonar data We have built a simple testbed vehicle and a visual navigation system designed to maneuver to a pre-defined location in a static environment The visual system is based on algorithms developed by Moravec for the Stanford Cart [10] At each Cart position, these algorithms used stereo correspondence in nine camera images to triangulate the distance to potential obstacles Motion of the vehicle was determined by tracking these obstacles over time This paper discusses several issues in the on-going evolution from the Cart to our present system These issues have led to the use of fewer images per step, to the use of more constraint in the correspondence process, and toward the use of a different motion solving algorithm that better embodies the rigidity property inherent in the problem

Road map production system for intelligent mobile robot

Abstract: This paper proposed a road map production system model using bidirectional search algorithm. The model enable a mobile robot to navigate an environment effectively and be able to execute a high level command such as "go from station I (STI) to station 2 (ST2)". The search algorithm yields the shortest path solution. In the event of unexepeted occurrences such as obstruction of the shortest path, the model would enable the robot to quickly search for the shortest alternative path from its current position to its destination. The system can readily adapt to a dynamically changing road map.

Structures for Sensor-Based Robot Motion Control

Abstract: Feedback of end-effector position to robot controllers provides an effective means for compensating for manipulator path errors and variations in workpiece geometry. Most current robot controllers do not provide the facility for real-time path correction using sensor feedback; this capability will be an essential element of future robot control systems. This paper presents a comparison of two alternative control structures, as applied to realistic models of robot mechanical and microelectronic control systems.