This paper presents an evaluation of a stereo vision system using a unique wide-angle imaging device. Because of the extremely wide field of view, the use of such optics is potentially useful to stereo applications wh...
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ISBN:
(纸本)0819426407
This paper presents an evaluation of a stereo vision system using a unique wide-angle imaging device. Because of the extremely wide field of view, the use of such optics is potentially useful to stereo applications where large scenes or close-up features are of interest. A general problem and deterrent for the use of wide-angle optics has been the large amount of distortion which makes processing of the warped image features and modeling of the lens difficult when using conventional camera models. However, this research attempts to use a unique digital orientation and viewing apparatus, OMNIview, to eliminate this problem. The OMNIview Motionless Camera Orientation System provides a method for video pan, tilt, zoom, rotation, and distortion correction without moving parts. The incentive for using such a device within a stereo vision system is the wide field of measurement which can be achieved without physical scanning of the camera. This research will show that use of OMNIview for acquisition and correction of a stereo pair of wide-angle images results in limitations to the accuracy of the system.
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of an obstacle avoidanc...
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ISBN:
(纸本)0819426407
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of an obstacle avoidance system using sonar sensors for a modular autonomous mobile robot controller. The advantages of a modular system are related to portability and the fact that any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. The obstacle avoidance system is based on a micro-controller interfaced with multiple ultrasonic transducers. This micro-controller independently handles all timing and distance calculations and sends a distance measurement back to the computer via the serial line. This design yields a portable independent system. Testing of these systems has been done in the lab as well as on an outside test track with positive results that show that at five mph the vehicle can follow a line and at the same time avoid obstacles. This design, in its modularity, creates a portable autonomous obstacle avoidance controller applicable for any mobile vehicle with only minor adaptations.
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research an the design of a modular autonomous...
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ISBN:
(纸本)0819426407
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research an the design of a modular autonomous mobile robot controller. The controller incorporates a fuzzy logic approach Ear steering and speed control, a neuro-fuzzy approach for ultrasound sensing (not discussed in this paper) and an overall expert system. The advantages of a modular system are related to portability and transportability, i.e. any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. This cart has full speed control with guidance provided by a vision system and obstacle avoidance using ultrasonic sensors. The speed and steering fuzzy logic controller is supervised by a 486 computer through a multi-axis motion controller. The obstacle avoidance system is based on a micro-controller interfaced with six ultrasonic transducers. This micro-controller independently handles all timing and distance calculations and sends a steering angle correction back to the computer via the serial line. This design yields a portable independent system in which high speed computer communication is not necessary. vision guidance is accomplished with a CCD camera with a zoom lens. The data is collected by a vision tracking device that transmits. the X,Y coordinates of the lane marker to the control computer. Simulation and resting of these systems yielded promising results. This design, in its modularity, creates a portable autonomous fuzzy logic controller applicable to any mobile vehicle with only minor adaptations.
This paper examines a novel approach for extracting motion information to allow the autonomous navigation of an intelligent mobile robot using computervision in a moving camera, moving object environment. The approac...
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ISBN:
(纸本)0819426407
This paper examines a novel approach for extracting motion information to allow the autonomous navigation of an intelligent mobile robot using computervision in a moving camera, moving object environment. The approach begins by extracting low-level scene feature information using algorithms such as the SUSAN corner and edge detector. A routine is described for converting the information obtained from these stable features to initialisation information for creating active contour models or 'snakes'. Multiple open and closed active contours are identified in an initialisation frame from this primary feature extraction. These contours are allowed to converge more closely to the features to which they are attached. These contours are then allowed to converge to the features within each frame through image sequences, with criteria for the re-initialisation of new contours when motion information in the sequence or a region becomes sparse. The information received from these contour models is then used to determine. the motion information in the scene. Reasons for this approach are outlined and justified. This theoretical approach is then applied to the practical cases of a mobile robot navigating indoor scenes. Large sections of this approach have been implemented in the Khoros environment, with new routines written for this approach. Promising results are already available and this approach is being examined to allow the extraction of depth information in the scene for assisting navigation using a form of '3-D snakes'.
Machine vision systems based on a colour camera are increasingly used for colour measurements under industrial conditions. An important problem in the measurement of small colour differences is related to metamerism. ...
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ISBN:
(纸本)0819426407
Machine vision systems based on a colour camera are increasingly used for colour measurements under industrial conditions. An important problem in the measurement of small colour differences is related to metamerism. But because colour cameras and human vision have slightly different response functions, they produce different sets of ''tristimulus values'' for the same object viewed under the same illumination conditions, and it can happen that metameric pairs for a human are discriminated very well by a colour camera and vice versa. The purpose of the present research was to evaluate the performance of colour camera for measuring small colour differences. The tests were performed for the whole collection of the NCS COLOUR BLOCK' viewed under three different illuminants: Standard illuminant A, Standard Illuminant D-65 and illuminant F11, and for two options of colour camera, g-bit and 12-bit. The results show some limitations with lower bit camera for accurate colorimetric measurements and good performance with the 12-bit camera in discrimination of very similar colours.
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of the remote controlle...
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ISBN:
(纸本)0819426407
Automated Guided Vehicles (AGV's) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of the remote controlled emergency stop and vision systems for an autonomous mobile robot. The remote control provides human supervision and emergency stop capabilities for the autonomous vehicle. The vision guidance provides automatic operation. A mobile robot test-bed has been constructed using a golf cart base. The mobile robot (Bearcat) was built for the Association far Unmanned Vehicle Systems (AUVS) 1997 competition. The mobile robot bar;full speed control with guidance provided by a vision system and an obstacle avoidance system using ultrasonic sensors systems. vision guidance is accomplished using two CCD cameras with zoom lenses. The vision data is processed bq a high speed tracking device, communicating with the computer the X, Y coordinates of blobs along the lane markers. The system also has three emergency stop switches and a remote controlled emergency stop switch that can disable the traction motor and set the brake. Testing of these systems has been done in the lab as well as on an outside test track with positive results that show that at five mph the vehicle can follow a line and at the same time avoid obstacles.
This paper describes the development of a Robot Fault Diagnosis System (RFDS). Though designed ostensibly for the University of Cincinnati's autonomous, unmanned, mobile robot for a national competition, it has th...
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ISBN:
(纸本)0819426407
This paper describes the development of a Robot Fault Diagnosis System (RFDS). Though designed ostensibly for the University of Cincinnati's autonomous, unmanned, mobile robot for a national competition, it has the flexibility to be adapted for industrial applications as well. Using a top-down approach the robot is sub-divided into different functional units, such as the vision guidance system, the ultrasonic obstacle avoidance system, the steering mechanism, the speed control system, the braking system and the power unit. The techniques of Potential Failure Mode and Effects Analysis (PFMEA) are used to analyze faults, their visible symptoms, and probable causes and remedies. The relationships obtained therefrom are mapped in a database framework. This is then coded in a user-friendly interactive Visual Basic((TM)) program that guides the user to the likely cause(s) of failure through a question-answer format. A provision is made to ensure better accuracy of the system by incorporating historical data on failures as it becomes available. The RFDS thus provides a handy trouble-shooting tool that cuts down the time involved in diagnosing failures in the complex robot consisting of mechanical, electric, electronic and optical systems. This has been of great help in diagnosing failures and ensuring maximum performance from the robot during the contest in the face of pressure of the competition and the outdoor conditions.
Earlier(13,18,19), the biologically plausible active vision,model for Multiresolutional Attentional Representation and Recognition (MARR) has been developed. The model is based on the scanpath theory of Noton and Star...
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ISBN:
(纸本)0819426407
Earlier(13,18,19), the biologically plausible active vision,model for Multiresolutional Attentional Representation and Recognition (MARR) has been developed. The model is based on the scanpath theory of Noton and Stark(17) and provides invariant recognition of gray-level images. In the present paper, the algorithm of automatic image viewing trajectory formation in the MARR model, the results of psychophysical experiments, and possible applications of the model are considered, Algorithm of automatic Image viewing trajectory formation is based on imitation of the scanpath formed by operator Several propositions about possible mechanisms for a consecutive selection of fixation points in human visual perception inspired by computer simulation results and known psyhophysical data have been tested and confirmed in our psychophysical experiments, in particular, we have found that gaze switch may be directed (i) to a peripheral part of the vision field which contains an edge oriented orthogonally to the edge in the point of fixation, and (ii) to a peripheral part of the vision field containing crossing edges, Our experimental results have been used to optimize automatic algorithm of image viewing in the MARR model, The modified model demonstrates an ability to recognize complex real world images invariantly with respect to scale, shift, rotation, illumination conditions, and, in part, to point of view and can be used to solve some robot vision tasks.
We describe an integrated system developed for use onboard a moving work machine. The machine is targeted to such applications as e.g. automatic container handling at loading terminals. The main emphasis is on the var...
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ISBN:
(纸本)0819426407
We describe an integrated system developed for use onboard a moving work machine. The machine is targeted to such applications as e.g. automatic container handling at loading terminals. The main emphasis is on the various environment perception duties required by autonomous or semi-autonomous operation. These include obstacle detection, container position determination, localization needed for efficient navigation and measurement of docking and grasping locations of containers. Practical experience is reported on the use of several different types of technologies for the tasks. For close distance measurement, such as container row following, ultrasonic measurement was used, with associated control software. For obstacle and docking position detection, 3D active visiontechniques were developed with structured lighting, utilizing also motion estimation techniques. Depth from defocus-based methods were developed for passive 3D vision. For localization, fusion of data from several sources was carried out. These included dead-reckoning data from odometry, an inertial unit, and several alternative external localization devices, i.e. real-time kinematic GPS, inductive and. optical transponders. The system was integrated to run on a real-time operating system platform, using a high-level software specification tool that created the hierarchical control structure of the software. Testing of the integrated system included real outdoor task execution on a light tractor.
This paper deals with strategies for reliably obtaining the edges and the surface texture of metallic objects. Since illumination is a critical aspect regarding robustness and image quality, it is considered here as a...
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ISBN:
(纸本)0819426407
This paper deals with strategies for reliably obtaining the edges and the surface texture of metallic objects. Since illumination is a critical aspect regarding robustness and image quality, it is considered here as an active component of the image acquisition system. The performance of the methods presented is demonstrated -among other examples -with images of needles for blood sugar tests. Such objects show an optimized form consisting of several planar grinded surfaces delimited by sharp edges. To allow a reliable assessment of the quality of each surface, and a measurement of their edges, methods for fusing data obtained with different illumination constellations were developed. Tile fusion strategy is based on the minimization of suitable energy functions. First, an illumination-based segmentation of the object is performed. To obtain the boundaries of each surface, directional light-field illumination is used. By formulating suitable criteria, nearly binary images are selected by variation of the illumination direction. Hereafter, the surface edges are obtained by fusing the contours of the areas obtained before. Following, an optimally illuminated image is acquired for each surface of the object by varying the illumination direction. For this purpose, a criterion describing the quality of the surface texture has to be maximized, Finally, the images of all textured surfaces of the object are fused to an improved result, in which the whole object is contained with high contrast. Although the methods presented were designed for inspection of needles, they also perform robustly in other computervision tasks where metallic objects have to be inspected.
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