A new set of collision checking and obstacle avoidance algorithms has been developed and implemented in both hardware and software. The method allows for unlimited vector checks against an unlimited set of objects. De...
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ISBN:
(纸本)0819407445
A new set of collision checking and obstacle avoidance algorithms has been developed and implemented in both hardware and software. The method allows for unlimited vector checks against an unlimited set of objects. Dependent upon the application, the single card hardware performance ranges from 1 million line sorts per second to hundreds of millions. Therefore, due to the high algorithm speed, the overall system performance only becomes limited by the choice of processor and the speed of the interface. The hardware is presently configured to process large blocks of objects and data (8K) at a sorting rate of one point against eight objects at a rate of 200 million points per second. The trade-off between choice of algorithm and performance is discussed.
This paper presents a vision-guided control system for an industrial robot capable of picking up an object, moving it to a goal, and placing it there. Tasks given to the control system are based on imperfect knowledge...
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ISBN:
(纸本)0819407445
This paper presents a vision-guided control system for an industrial robot capable of picking up an object, moving it to a goal, and placing it there. Tasks given to the control system are based on imperfect knowledge about the environment. The control system corrects the task parameters by matching them against range information gained from the environment. The control system is part of a larger system, which includes a high-level goal-oriented planner. The planner consists of hierarchically organized planning-executing-monitoring triplets, which execute given tasks by dividing them into subtasks, by sending the subtasks either to other triplets or to the control system described in this paper, and by monitoring the execution of the subtasks. The planner sees the robot and the control system as an intelligent robot capable of executing pick-and-place tasks in a dynamic, partly unknown environment. This paper presents the results of the testing of the control system with an industrial 6-axis robot and a structured light-based range sensor. Also the principle of calibrating the robot and the sensor is presented.
The role of features versus the whole in the learning of human facial expressions is explored. A pyramid-like modular network has been developed to learn and identify hand-drawn facial expressions. because of the natu...
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ISBN:
(纸本)0819407445
The role of features versus the whole in the learning of human facial expressions is explored. A pyramid-like modular network has been developed to learn and identify hand-drawn facial expressions. because of the nature of the network architecture, image size becomes less of an issue in network learning. The network exhibits a parallel learning capability which could be used to speed up the training process. An analysis of the hidden units of the network reveals that the features are used in learning when there is commonality of facial features in the training patterns. We have also demonstrated attention focusing in the network by masking off specific areas of the face during testing.
In this paper, we begin by describing a range image processing method developed to allow an autonomous robot to detect and locate objects. The procedure consists of taking a range image, filtering and preprocessing th...
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ISBN:
(纸本)0819407453
In this paper, we begin by describing a range image processing method developed to allow an autonomous robot to detect and locate objects. The procedure consists of taking a range image, filtering and preprocessing the image, calculating surface normals, obtaining edge maps from both range and surface normals, combining the edge maps into an initial scene segmentation map, and analyzing each object in the scene in order to detect and locate the desired objects. While this method is reasonably fast and robust, its surface characterization is fairly crude. More elaborate surface characterization on a serial computer would be considerably slower, which is not desirable for autonomous robot operations. We then discuss the development of parallel techniques for surface characterization using range data. By using parallel processing, the complexity and accuracy of the characterization can be increased without an unacceptable cost in processing time. The method explored is a parallel implementation of a least squares QR surface fitting technique using Givens transformations. We conclude by summarizing the work done and briefly listing some future extensions of the current research.
An object-oriented robot independent programming environment (RIPE) developed at Sandia National Laboratories is being used for rapid design and implementation of a variety of intelligent machine applications. A syste...
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ISBN:
(纸本)0819407445
An object-oriented robot independent programming environment (RIPE) developed at Sandia National Laboratories is being used for rapid design and implementation of a variety of intelligent machine applications. A system architecture based on hierarchies of distributed multiprocessors provides the computing platform for a layered programming structure that models work cell tasks as a set of software objects. These objects are designed to support model-based automated planning and programming, real-time sensor-based activity, and robust communication. The object-oriented paradigm provides mechanisms such as inheritance and polymorphism which allow the implementation of the system to satisfy the goals of software reusability, extensibility, reliability, and portability. By designing a hierarchy of generic parent classes and device-specific subclasses which inherit the same interface, a robot independent programming language (RIPL) is realized. Prototype systems for handling nuclear waste shipping casks, underground storage tank cleanup, nuclear weapons disassembly, and glove box access are successfully implemented using this object-oriented software environment.
Automatic recognition of human faces is a frontier topic in computervision. In this paper, a novel recognition approach to human faces is proposed, which is based on the statistical model in the optimal discriminant ...
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ISBN:
(纸本)0819407445
Automatic recognition of human faces is a frontier topic in computervision. In this paper, a novel recognition approach to human faces is proposed, which is based on the statistical model in the optimal discriminant space. Singular value vector has been proposed to represent algebraic features of images. This kind of feature vector has some important properties of algebraic and geometric invariance, and insensitiveness to noise. Because singular value vector is usually of high dimensionality, and recognition model based on these feature vectors belongs to the problem of small sample size, which has not been solved completely, dimensionality compression of singular value vector is very necessary. In our method, an optimal discriminant transformation is constructed to transform an original space of singular value vector into a new space in which its dimensionality is significantly lower than that in the original space. Finally, a recognition model is established in the new space. Experimental results show that our method has very good recognition performance, and recognition accuracies of 100 percent are obtained for all 64 facial images of 8 classes of human faces.
The Laboratory for Space Teleoperation and Robotics is developing a neutrally-buoyant robot for research into the automatic and teleoperated (remote human) control of unmanned robotic vehicles for use in space. The go...
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ISBN:
(纸本)0819407445
The Laboratory for Space Teleoperation and Robotics is developing a neutrally-buoyant robot for research into the automatic and teleoperated (remote human) control of unmanned robotic vehicles for use in space. The goal of this project is to develop a remote robot with maneuverability and dexterity comparable to that of a space-suited astronaut with a manned maneuvering unit, able to assume many of the tasks currently planned for astronauts during extravehicular activity (EVA). Such a robot would be able to spare the great expense and hazards associated with human EVA, and make possible much less expensive scientific and industrialization exploitation of orbit. Both autonomous and teleoperated control experiments will require the vehicle to be able to automatically control its position and orientation. The laboratory is developing vision-based vehicle navigation system that works by tracking features in video images from cameras mounted on the vehicle and trained at a special target fixed in the environment. The methods are adaptable to a variety of video-based tracking systems, and are based on a linearized vision model, receiving as inputs image feature coordinates at each time step This paper includes a description of the underwater vehicle and the vision system.
We present a new edge-based matching algorithm that can be applied for unstructured stereo images. We first review briefly a major recent development in establishing stereo correspondences and show that a great deal o...
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ISBN:
(纸本)0819410276
We present a new edge-based matching algorithm that can be applied for unstructured stereo images. We first review briefly a major recent development in establishing stereo correspondences and show that a great deal of research in stereo is needed in order to apply stereo techniques to solve more real-world problems. We then discuss why we use edges (without simplification and without linking) as primitives to be matched rather than other primitives (points, regions, ...) and what adequate edge detector should be used. We then argue that matching a whole parts of edges should be done rather than comparison of straight line segments. We then discuss the occlusion problem and some defects of the edge detector that possibly cut the edges to several pieces, and argue that partial matching of edges can be a solution to such problems. We then explain what best matching criteria are used, comprising both shape and gray level attributes. These criteria are chosen for their pertinence, representation and computation simplicity and for their similarity to those probably used in human vision system. Finally, complete quantitative experimental results are shown with various indoor and outdoor real world scenes.
A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end-effector. Such a manipulator has dexterity, flexibility, and...
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ISBN:
(纸本)0819407445
A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end-effector. Such a manipulator has dexterity, flexibility, and the ability to maneuver in the presence of obstacles. This paper presents a solution to the inverse kinematics problem for redundant manipulator based on artificial neural network (ANN). The ANN used is of the supervised type - multilayer feedforward neural network with back error propagation (BEP) training algorithm. The training set for the ANN is obtained by sampling the joint space trajectory of the redundant manipulator arm or from the joint angle encoders of the manipulator. These sampled values of the task space trajectory (end-effector coordinates) are used as the command input vectors to the ANN. By presenting the network with these training set cyclically during training time, the BEP algorithm will change the learning parameters of the ANN so that the sum of the squared difference between the actual joint coordinates and the desired output vectors is minimized.
robots operating in unstructured environments require continuous utilization of sensors and intelligence for adapting to changing situations. In this paper a control method to achieve this goal is described and prelim...
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ISBN:
(纸本)0819407445
robots operating in unstructured environments require continuous utilization of sensors and intelligence for adapting to changing situations. In this paper a control method to achieve this goal is described and preliminary experiments are discussed. The control scheme is based on a hierarchically organized set of planning-executing-monitoring (PEM) cycles. Every PEM cycle is a goal-oriented module, which consists of three generic activities - planning, executing, and monitoring - and a separate meta control mechanism, which takes care of the control of generic activities inside a PEM cycle. We present our design experiments beginning from the development of a PEM-based logical model for an autonomous machine, and continue to the development of an implementation model for a loading manipulator control system. The laboratory implementations in two industrial robot environments are also described as well as plans for PEM-control implementation for a heavy-duty manipulator designed for loading paper rolls in harbor sites.
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