Showing papers on "Mobile robot published in 1983"

The Stanford Cart and the CMU Rover

Abstract: The Stanford Cart was a remotely controlled TV-equipped mobile robot. A computer program was written which drove the Cart through cluttered spaces, gaining its knowledge of the world entirely from images broadcast by an on-board TV system. The CMU Rover is a more capable, and neatly operational, robot being built to develop and extend the Stanford work and to explore new directions. The Cart used several kinds of stereopsis to locate objects around it in three dimensions and to deduce its own motion. It planned an obstacle-avoiding path to a desired destination on the basis of a model built with this information. The plan changed as the Cart perceived new obstacles on its journey. The system was reliable for short runs, but slow. The Cart moved 1 m every 10 to 15 min, in lurches. After rolling a meter it stopped, took some pictures, and thought about them for a long time. Then it planned a new path, executed a little of it, and paused again. It successfully drove the Cart through several 20-m courses (each taking about 5 h) complex enough to necessitate three or four avoiding swerves; it failed in other trials in revealing ways. The Rover system has been designed with maximum mechanical and control system flexibility to support a wide range of research in perception and control. It features an omnidirectional steering system, a dozen on-board processors for essential real-time tasks, and a large remote computer to be helped by a high-speed digitizing/data playback unit and a high-performance array processor. Distributed high-level control software similar in organization to the Hearsay II speech-understanding system and the beginnings of a vision library are being readied. By analogy with the evolution of natural intelligence, we believe that incrementally solving the control and perception problems of an autonomous mobile mechanism is one of the best ways of arriving at general artificial intelligence.

Conventional controller design for industrial robots — A tutorial

Abstract: Industrial robots are serial link manipulators whose dynamic characteristics are highly nonlinear. By controlling each link or joint individually, employing the conventional technique to design linear feedback controllers for the robot is possible. The gravitational force and force interactions between joints are suppressed by precalculated feedforward compensation. To ease the computational burden, the compensating signals are either approximated or their computational formulas are simplified.

An anatomy of industrial robots and their controls

Abstract: In the United States, commercially available industrial robots perform very well in limited areas of industrial tasks such as arc welding, paint spraying, etc. These tasks mainly involve synchronization but no task interaction. A close examination of the basic structure and controls of the robots reveals their resulting limitations which lead to unnatural specifications and inefficient performance of task interactions. It is our opinion that, to expand the range of robot tasks to include labor intensive jobs such as product assembly, sensors of multiple purposes must be added onto the robots and integrated into their control systems. Computer command language must be developed to enable nonexpert users to operate the robots, and a work-method must be available for analyzing robot time-motion so that the robots can be programmed to achieve best efficiency with least production cost.

The Industrial Robot

Abstract: Since the development of the first articulated arm in the 1950’s and subsequent developments in computer technology, robots have become more widely used and are now available in a variety of types, styles and sizes. Robots are capable of performing a wide variety of tasks and have become an integral part of automated manufacturing systems. An industrial robot consists of a number of rigid links connected by joints of different types, controlled and monitored by a computer. To a large extent, the physical construction of a robot resembles a human arm. The link assembly mentioned above is connected to the body, which is usually mounted on a base. Advertisement from 1986

A System for Programming and Controlling Sensor-Based Robot Manipulators

Abstract: This paper describes an approach to programming and controlling robot manipulators which facilitates the use of sensory information. Robot actions are specified by declaring software servo processes which control the robot's various degrees of freedom. These servo processes can involve position, orientation, force, and torque information from the robot itself, or data from external sensors. Robot tasks are programmed by dynamically modifying the servo processes or by changing set points to these processes. Condition monitors, which have access to program and sensory information, detect the completion of program steps.

Model structuring and concept recognition: two aspects of learning for a mobile robot

Abstract: We present here a method for providing a mobile robot with learning capabilities. The method is based on a model of the environment with several hierarchical levels organized by degree of abstraction. The mathematical structuring tool used is the decomposition of a graph into its k-connected components (k=2 and k=3). This structure allows the robot to improve navigation procedures and to recognize some concepts, such as a door, a room, or a corridor.

A distributed control system for the CMU rover

Abstract: This paper describes a distributed software control structure developed for the CMU Rover, an advanced mobile robot equipped with a variety of sensors. Expert modules are used to control the operation of the sensors and actuators, interpret sensory and feedback data, build an internal model of the robot's environment, devise strategies to accomplish proposed tasks and execute these strategies. Each expert module is composed of a master process and a slave process, where the master process controls the scheduling and working of the slave process. Communication among expert modules occurs asynchronously over a blackboard structure. Information specific to the execution of a given task is provided through a control plan. The system is distributed over a network of processors. Real-time operating system kernels local to each processor and an interprocess message communication mechanism ensure transparency of the underlying network structure. The various parts of the system are presented in this paper and future work to be performed is mentioned.

Concurrent programming of intelligent robots

Abstract: Real time intelligent robots usually consist of more than one processing unit (pu) to ensure parallel operation of several functions. Each pu in a robot executes repetitive monitoring and controlling operations as well as information exchange to and from other pu's. Since timing of each operation is independent of others, if the robot operating software supports concurrent process facilities, it would be helpful in robot programming. A self-contained robot "Yamabico 9" has been constructed to be a tool for investigating how a mobile robot understands the outer world. In order to support software production on the robot, Robot Control System (RCS) has been implemented, including simple job commands and a supervisor call (SVC) system. The concurrent process monitor is a part of RCS and some of SVC's are for these facilities. The monitor adopts a "message sending" method to synchronize execution of two processes and to exchange information between processes and pu's. An example of a concurrent process program, "walk along left walls", is given to demonstrate the describing power of our system.

Simulating Motion Elements of General-Purpose Robot Arms

Abstract: Robot arm displacement curves are constructed, assuming that all links in the arm are rigid. This can be accomplished by using familiar, cam-motion profile techniques whenever possible. The benefits of these considerations can help achieve smoother motion while minimizing wear on and effort by the robot actuators. A set of motion primitives within the General Robot Arm Simulation Program (GRASP) are presented as examples.

A parallel processor algorithm for robot route planning

Abstract: This paper presents a fast, uniform, parallel search algorithm for robot route planning and obstacle avoidance. The algorithm is equally applicable to real or synthetic data and overcomes many problems associated with other route finding methods. The time taken to generate a route through a an arbitrarily complex environment has been reduced to an insignificant fraction of the time taken for the robot to traverse the route. Furthermore the time taken to create the route is independent of environment complexity and only linearly proportional to route length. Actual results and timings from running the algorithm on the ICL Distributed Array Processor and executing the resultant path on a mobile robot are presented.

Hypothesizing Channels through Free-Space in Solving the Findpath Problem

Abstract: : Channels are an encoding of free-space corresponding to the classes of paths within an environment. An implementation exploiting this global model of the connectivity of free-space has been able to solve 2-dimensional find-path problems in several minutes which formerly took many hours. The author's algorithm is essentially a problem-solving strategy using a homeomorphic reduction of the search space. Given a polyhedral environment, a technique is presented for hypothesizing a channel volume through the free space containing a class of successful collision-free paths. A set of geometric constructions between obstacle faces is proposed, and defined is a mapping from a field of view analysis to a direct local construction of free space. The algorithm has the control structure of a search which propagates construction of a connected channel towards a goal along a frontier of exterior free faces. Thus a channel volume starts out by surrounding the moving object in the initial configuration and grows towards the goal. Finally, techniques for analyzing the channel decomposition of free space and suggesting a path are shown. This paper addresses issues in the find-path or piano mover's problem in robotics and spatial planning: the problem involves finding a path for a solid object in an environment containing obstacles. In robotics we are typically interested in motion planning for a mobile robot or manipulator. In Computer-Aided Design, the problem of automated structural design for n structural members is also an instance of the most general form of the mover's problem.

Work instructing system of robot and its using

Abstract: PURPOSE:To perform work safely for a short time by displaying macro-check of a working procedure or the like on a graph by using a three-dimensional robot simulator. CONSTITUTION:A robot work instructing system is constituted of a display 19, a graphic processor, etc. An operator 20 writes the working procedure and working environment of the robot 25. On the basis of said descriptions, the system executes preprocessing 12, simulates the movement of the robot 25 by a robot operation command or the like and then animations based upon three-dimensional movement are displayed on a display 19. If there is no fault, robot operation data 17 are converted 22 into a control command to actuate the robot 25. Fine adjustment at the catch or the like of parts by the robot 25 is performed by processing picture information 29 through a television camera 26 and obtaining sensor information 27 compensated at the catching position. Control calculation 28 is performed on the basis of such information to control the robot 25.

Safety system for robot

Abstract: A safety system for industrial robots has a photoelectric detection means (9, 9a-9d) having a field of vision covering the area of reach of the robot. The data concerning the sight obtained through the photo-electric detection means in each of predetermined operation positions is compared with the data concerning the normal or correct sight in the same operation position. The movement of the robot to the next operation position is prohibited when a difference of a level exceeding a predetermined level is found during the comparison.

Intelligent Assembly Robot

Abstract: An experimental intelligent assembly robot comprising two articulated robots and a vision system has been developed. The pilot system is capable of visual recognition of location and orientation of parts which are randomly placed, and of performing coordinated motions of two arms. A new robot mechanism in which various configuration of joints can be built from a basic model with six degrees of freedom has been developed. In order to carry out such advanced control of the robot as vision interaction and multi-robot coordination, a control technique employing hierarchical structure of two microprocessors has been applied. A new robot language has been developed for easy description of robot programs involving such advanced control. A vision system using a partial pattern matching technique has proven to be well suited for robot vision.

Cellular robot device

Abstract: PURPOSE: To increase the number of degrees of freedom of operation and to attain a quick responsiveness by allowing individual cellular robots to control operations of themselves and perform an operation as the whole on the basis of information exchange between adjacent cellular robots. CONSTITUTION: The whole of a robot consists of plural cellular robots 11,12W, and these cellular robots are connected to adjacent cellular robots by arms 111, 121W112, 212W. An arm driving device and a controller for arm driving are stored in each cellular robot. Each controller is connected to the controller in the adjacent cellular robot by a transmission line, and information exchange is performed. Individual cellular robots control operations of themselves on the basis of this information exchange between adjacent cellular robots. The operation as the whole is performed also on the basis of this information exchange, and they can control themselves without changing hardware and software even in case of trouble and extension of partial cellular robots. COPYRIGHT: (C)1985,JPO&Japio