Intelligent robotic systems should be capable of performing a range of complex tasks in unstructured and dynamic environments. This chapter discusses a number of important items associated with intelligent robots, rol...
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Intelligent robotic systems should be capable of performing a range of complex tasks in unstructured and dynamic environments. This chapter discusses a number of important items associated with intelligent robots, role of vision sensing in intelligent robotics, and architecture for the design of an intelligent robot. The chapter also describes the computational task hierarchy that governs a model-based robot vision system, and presents a detailed tutorial on two important components of this hierarchy: image segmentation and matching. The main capabilities that intelligent robotic systems should possess include ability for perception of their environment, planning of their actions, and execution of the planned action. The two important components of a model-based vision system are image segmentation and the matching module. A procedure that allows transformation of 2D image coordinates into 3D world coordinates is also discussed in the chapter. The architecture and control aspects of an integrated sensor-based robotic system consist of six modules: supervisor, task planner, perception, motor, user interface, and knowledge-base. Intelligent, sensor-driven systems pose many challenging basic-research problems from a broad range of scientific and technological disciplines; however, there are many important application areas where such systems would be of significant value and utility, including hazardous environments such as nuclear plants, underwater, and space as well as many industrial-automation tasks. Recent advancements in the VLSI, computer-architectures, sensor-and robot-hardware, and artificial-intelligence fields may aid to the development of robust, practical, and cost-effective intelligent robotic systems for a wide variety of applications.
In this paper we present a computational approach for extracting three-dimensional structure of controllable resolution, depth of field, and accuracy, all made available at real-time speeds, This approach utilizes the...
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In this paper we present a computational approach for extracting three-dimensional structure of controllable resolution, depth of field, and accuracy, all made available at real-time speeds, This approach utilizes the spatial and the temporal gradients of the streams of images acquired using an actively controlled camera, Depending on the requirements of a particular task, appropriate parameters such as disparity value sought, interframe camera displacement, and number of frames in a stream are chosen to control the resolution, depth of field, and accuracy, The acquisition and processing of the image stream are done in real time on a pipeline architecture based processor. Extensive experiments are presented to demonstrate the system's accuracy, controllability of depth of field and resolution, and ability to perform successfully in a variety of scenes. The system operated with no latency between image acquisition and processing. The total acquisition and processing time in these experiments is in the range from 0.27 to 1.56 s. The depth results have an accuracy of 85% to 92%. (C) 1996 Academic Press, Inc.
In the emerging paradigm of animate vision, the visual processes are not thought of as being independent of cognitive or motor processing, but as an integrated system within the context of visual behavior. Intimate co...
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In the emerging paradigm of animate vision, the visual processes are not thought of as being independent of cognitive or motor processing, but as an integrated system within the context of visual behavior. Intimate coupling of sensory and motor systems have found to improve significantly the performance of behavior based vision systems. In order to study active vision systems one requires sensory-motor systems. Designing, building, and operating such a test bed is a challenging task. In this paper we describe the status of on-going work in developing a sensory-motor robotic system, R2H, with ten degrees of freedoms (DOF) for research in active vision. To complement the R2H system a Graphical Simulation and Animation (GSA) environment is also developed. The objective of building the GSA system is to create a comprehensive design tool to design and study the behavior of active systems and their interactions with the environment. GSA system aids the researchers to develop high performance and reliable software and hardware in a most effective manner. The GSA environment integrates sensing and motor actions and features complete kinematic simulation of the R2H system, it's sensors and it's workspace. With the aid of the GSA environment a Depth from Focus (DFF), Depth from Vergence, and Depth from Stereo modules are implemented and tested. The power and usefulness of the GSA system as a research tool is demonstrated by acquiring and analyzing images in the real and virtual worlds using the same software implemented and tested in the virtual world.
There is no standard representation scheme that is followed by different groups of robot designers to describe the orientation of a rotating rigid body. For a sensor-based robot, the particular rotation representation...
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There is no standard representation scheme that is followed by different groups of robot designers to describe the orientation of a rotating rigid body. For a sensor-based robot, the particular rotation representation scheme used by the robot affects not only the specification of the positioning of the arm and end-effector, but also the specification of the placement of the sensors and the method of computing the sensory-to-world transformation. Thus the need for finding the transformation between different rotation representations is obvious for one involved in the development of high-level software systems that need to be transported to different robots utilizing different rotation representation schemes. Among those representation schemes, Euler angle representations are widely used in commercial robots as well as in researchlaboratory robots. Typically, there are three different Euler angle representation systems, and each system describes a particular orientation of a rigid body in a reference coordinate frame by specifying three angles. Mathematical derivations of the transformation relationships underlying the parameters from two most commonly utilized representation schemes are presented. These relationships are derived in two different ways. One is based upon the solution of the inverse transform for Euler angles and the other is based upon the Napier's rules associated with spherical trigonometry.
Robot tasks have come to demand flexible sensory-based "intelligent" behavior. The single robot has given way to multiple robots cooperating in three-dimensional dynamic environments which allow them to acco...
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Robot tasks have come to demand flexible sensory-based "intelligent" behavior. The single robot has given way to multiple robots cooperating in three-dimensional dynamic environments which allow them to accomplish complex and intricate tasks. Because of the complex nature of the tasks performed, centralized control is no longer practical; workcells have become centers of distributed computing. This motivates the need for an interprocess communication (IPC) facility which would integrate the individual elements both within and between workcells. A survey of IPC is presented in the context of distributed robotics. To make the survey more meaningful, it is introduced by some remarks about general approaches to communication within a distributed computing environment. A discussion of the main IPC design issues for distributed robotics is included.
Texture is an important cue in region-based segmentation of images. In this paper, we provide insight into the development of a new set of distortion-invariant texture operators. These ''circular-Mellin'...
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Texture is an important cue in region-based segmentation of images. In this paper, we provide insight into the development of a new set of distortion-invariant texture operators. These ''circular-Mellin'' operators are invariant to both scale and orientation of the target and represent the spectral decomposition of the image scene in the polar-log coordinate system. Coupled with the unique shift invariance property of the correlator architecture, we show that these circular-Mellin operators can be used for rotation-and scale-invariant feature extraction. We note that while these feature extractors have a functional form that is similar to the Gabor operators, they have distortion-invariant characteristics unlike the Gabor functions that make them more suitable for texture segmentation. A detailed analytical description of these operators and segmentation results to highlight their salient properties are presented.
A necessary goal in the calibration of any instrument is an indication of how well the particular device performs. In the specific case where a camera system is used in the process of three-dimensional reconstruction ...
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A necessary goal in the calibration of any instrument is an indication of how well the particular device performs. In the specific case where a camera system is used in the process of three-dimensional reconstruction or stereopsis, geometric measures of the accuracy, precision, and repeatability of 3-D point measurements give a quantitative evaluation of the success of that algorithm. This paper presents an experimental performance analysis of a traditional calibration algorithm as applied to the problem of three-dimensional vision. The study begins with an analysis of the algorithm in a single camera or monocular system. Monocular analysis concludes with a derivation of error boundaries under different. geometric constraints. Showing how this residual error propagates from the component monocular systems into a three-dimensional reconstruction, a binocular analysis derives the desired performance monitors. The paper concludes with a geometric interpretation of the results.
We present an efficient method for detecting straight line segments in digital pictures using a hypothesis prediction/verification paradigm. In this paradigm, a straight line segment of predefined length is predicted ...
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We present an efficient method for detecting straight line segments in digital pictures using a hypothesis prediction/verification paradigm. In this paradigm, a straight line segment of predefined length is predicted to exist at some particular pixel location. The orientation of this predicted line segment is based on the edge orientation at the pixel location. This prediction is then verified against statistical tests performed on the line. As a result, the predicted line is either validated as being a line segment, or it is rejected. An extension of this algorithm for the detection of lines at different lengths is also presented, and a criterion is defined in order to evaluate the significance of the detected line segments.
Optical flow can be thought of as a generalization of orientation selection to include time, and this is a first attempt to develop this generalization. This paper is informal, and begins with an overview of a computa...
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Optical flow can be thought of as a generalization of orientation selection to include time, and this is a first attempt to develop this generalization. This paper is informal, and begins with an overview of a computational theory of orientation selection that has been developed in our laboratory during the past few years. A theory of optical flow computations is then sketched on the basis of this background, and a number of consequences important for both computational modeling and psychophysics are discussed. We concentrate in particular on two notions—dimensionality and structure—and describe a series of experiments that demonstrate that sensitivity to discontinuities in optical flow patterns has significant similarities to those in orientation patterns. Such similarities lend strong support to the analogy.
Intelligent robotic workcell activities have come to require a database framework for arranging, storing and accessing information in real-time about the workcell environment in a standard way. After a brief introduct...
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Intelligent robotic workcell activities have come to require a database framework for arranging, storing and accessing information in real-time about the workcell environment in a standard way. After a brief introduction to the theory of databases (DB), we examine the general topic of robotic workcells, identify characteristics typical of robotic applications, and then present a survey of DB-related work in the robotics domain. We then construct a set of design constraints based on our analysis of robotic applications, and describe a suitable software architecture. The paper concludes with a discussion of experience gained with two generations of DB implementations.
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