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.
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.
Image segmentation is one of the most important problems in computervision. Recently, Fairfield proposed an interesting approach to image segmentation using toboggan enhancement followed by naive contrast segmentatio...
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ISBN:
(纸本)0819407445
Image segmentation is one of the most important problems in computervision. Recently, Fairfield proposed an interesting approach to image segmentation using toboggan enhancement followed by naive contrast segmentation, which is a noniterative, linear execution time method. The way it operates can be thought of as a man tobogganing in the first derivative terrain, i.e., the graph surface of a discontinuity measure computed by the first derivative of the image intensity. The segmentation results it produced appeared equal in quality to that of other complex optimal region growing methods. In this paper, an improved version of Fairfield's method, called keep-sliding toboggan segmentation, is presented. With our method, the toboggan will keep sliding on a plane in the derivative terrain, where the original toboggan method will stop sliding. Therefore, our method produces far less regions than the original. Other improvements achieved are as follows: Instead of being followed by contrast segmentation post-process, our keep-sliding tobogganing process is preceded by a prefiltering process which suppresses small fluctuations in the first derivative terrain. Because of this prefiltering operation, our tobogganing process can automatically merge the regions having small intercontrast. Also, a new discontinuity measure is proposed to allow the detection of small target regions without ever-segmenting the images. Experimental results indicate that the segmentations produced by the keep-sliding toboggan method are less noisy, and, therefore, it is more appropriate to use them as initial segmentations for higher level image segmentation techniques.
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.
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.
A main goal of robotics is to impart in machines an ability to intelligently interact with their environments. In this study we present a system (and an implementation of it) which evaluates the compatibility between ...
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ISBN:
(纸本)0819407445
A main goal of robotics is to impart in machines an ability to intelligently interact with their environments. In this study we present a system (and an implementation of it) which evaluates the compatibility between objects and specific goal oriented action requirements for carrying out hand-actions. The system is an extension in the framework of fuzzy sets and possibility theory of our model of functional recognition of objects. The system operates on a hierarchical description of objects and action requirements which are mapped into a functional compatibility domain. We show that what computations are actually carried out by the algorithm depends on the application. When the system is used for inspection, it probably knows the identity of the object and its task is only to verify whether the object is in a state that allows its use in the prototypical action for which it has been designed. When the system is used for categorization purposes it needs to identify the existence of features compatible with the action requirements and it verifies that features which prevent carrying out the action cannot be identified. This latter case is particularly interesting and computationally challenging since the system is asked to compute the auxiliary, or possible functions of an object in addition to the prototypical function. The computation of the auxiliary functions relies on the description of the object's parts and subparts.
To overcome the lack of flexibility and inadequacy in performance speed of perception systems for use in real-time tasks, the authors have applied integrated learning techniques to a perception system that is based on...
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To overcome the lack of flexibility and inadequacy in performance speed of perception systems for use in real-time tasks, the authors have applied integrated learning techniques to a perception system that is based on a selective sensing paradigm. The incorporation of multiple learning algorithms at different levels provides a great deal of flexibility and robustness when different perceptual task are performed. Using a selective sensing paradigm allows the system to eliminate a large amount of nonpertinent sensory data so that processing speed is greatly increased. Such a perception system is being implemented on an autonomous mobile agent. The methodology and a preliminary example of learning within the perception system are presented.< >
We describe the least median of squares (LMedS) robust estimator which identifies the surface corresponding to the absolute majority of the data points. However when all the data points are corrupted by noise LMedS ma...
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ISBN:
(纸本)0819404489
We describe the least median of squares (LMedS) robust estimator which identifies the surface corresponding to the absolute majority of the data points. However when all the data points are corrupted by noise LMedS may fail. This is the case in computervision applications and we have developed a new approach which preserves the robustness of LMedS but avoids its artifacts in the presence of noise.
This paper presents a new fuzzy validity function which is mathematically justified via its relationship to the separation index a well defmed hard clustering validity function. The condition for existence of a unique...
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ISBN:
(纸本)0819404489
This paper presents a new fuzzy validity function which is mathematically justified via its relationship to the separation index a well defmed hard clustering validity function. The condition for existence of a unique globally optimal fuzzy c-partition has been found. The performance of this function compares well with other validity measures.
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