James W. Roberts

PC-based real-time defect imaging system for high-speed web inspection

PC-based inspection systems for wide web materials have been unable to effectively image fine defects as they are detected. The amount of data produced by highly parallel video inspection cameras can exceed 400 MBytes/sec. The system described in this paper is capable of analyzing and displaying a detected image within seconds of the even using a single frame grabber and a 386 computer. The system can operate at processing speeds of greater than 400 MBytes/sec since it makes use of a novel post processing algorithm within the camera itself. The video cameras are based on TDI (Time Delay and Integration) technology to provide high grey scale resolution at high data rates and low light levels. The system has an adjustable resolution ranging from 2000 to 24,000 pixels per line scanned. The scanning rate is adjustable to a maximum of 20,000 line scans per second.

An In-Camera Data Stream Processing System for Defect Detection in Web Inspection Tasks

One of the aims of industrial machine vision is to develop computer and electronic systems to replace human vision in quality control of industrial production. Traditionally these systems consist of a line scan camera, host computer, frame grabber and one or more dedicated processing boards. In this paper we discuss the development of a new integrated design environment, developed for real-time defect detection, that eliminates the need for an external frame grabber and other associated host computer peripheral systems. The processing board contains a reconfigurable field programmable gate array FPGA inside a DALSA CCD camera. The FPGA is directly connected to the video data-stream and outputs data to a low bandwidth output bus. The system is targeted for web inspection but has the potential for broader application areas. We describe and show test results of the in-camera prototype system board and discuss some of the algorithms currently simulated and implemented for web inspection applications.

New design environment for defect detection in web inspection systems

One of the aims of industrial machine vision is to develop computer and electronic systems destined to replace human vision in the process of quality control of industrial production. In this paper we discuss the development of a new design environment developed for real-time defect detection using reconfigurable FPGA and DSP processor mounted inside a DALSA programmable CCD camera. The FPGA is directly connected to the video data-stream and outputs data to a low bandwidth output bus. The system is targeted for web inspection but has the potential for broader application areas. We describe and show test results of the prototype system board, mounted inside a DALSA camera and discuss some of the algorithms currently simulated and implemented for web inspection applications.

In-camera video-stream processing for bandwidth reduction in web inspection

Automated machine vision systems are now widely used for industrial inspection tasks where video-stream data information is taken in by the camera and then sent out to the inspection system for future processing. In this paper we describe a prototype system for on-line programming of arbitrary real-time video data stream bandwidth reduction algorithms; the output of the camera only contains information that has to be further processed by a host computer. The processing system is built into a DALSA CCD camera and uses a microcontroller interface to download bit-stream data to a XILINXTM FPGA. The FPGA is directly connected to the video data-stream and outputs data to a low bandwidth output bus. The camera communicates to a host computer via an RS-232 link to the microcontroller. Static memory is used to both generate a FIFO interface for buffering defect burst data, and for off-line examination of defect detection data. In addition to providing arbitrary FPGA architectures, the internal program of the microcontroller can also be changed via the host computer and a ROM monitor. This paper describes a prototype system board, mounted inside a DALSA camera, and discusses some of the algorithms currently being implemented for web inspection applications.

High-speed web inspection using intelligent TDI cameras

Inspection systems for wide web materials have been unable to effectively image fine defects as they are detected. The amount of data produced by highly parallel video inspection cameras can exceed 400 MBytes/sec. The system described in this paper is capable of analyzing and displaying a detected image within seconds of the event using a single frame grabber and a 386 computer. The system can operate at processing speeds of greater than 400 MBytes/sec since it makes use of a novel post processing algorithm within the camera itself. The video cameras are based on TDI (Time Delay and Integration) technology to provide high grey scale resolution at high data rates and low light levels. The system has an adjustable resolution ranging from 256 to 24,000 pixels per line scanned. The scanning rate is adjustable to a maximum of 20,000 lines scans per second.

Examining the effect of state anxiety on compensatory and strategic adjustments in the planning of goal-directed aiming

The anxiety-perceptual-motor performance relationship may be enriched by investigations involving discrete manual responses due to the definitive demarcation of planning and control processes, which comprise the early and late portions of movement, respectively. To further examine the explanatory power of self-focus and distraction theories, we explored the potential of anxiety causing changes to movement planning that accommodate for anticipated negative effects in online control. As a result, we posed two hypotheses where anxiety causes performers to initially undershoot the target and enable more time to use visual feedback (play-it-safe), or fire a ballistic reach to cover a greater distance without later undertaking online control (go-for-it). Participants were tasked with an upper-limb movement to a single target under counter-balanced instructions to execute fast and accurate responses (low/normal anxiety) with non-contingent negative performance feedback (high anxiety). The results indicated that the previously identified negative impact of anxiety in online control was replicated. While anxiety caused a longer displacement to reach peak velocity and greater tendency to overshoot the target, there appeared to be no shift in the attempts to utilise online visual feedback. Thus, the tendency to initially overshoot may manifest from an inefficient auxiliary procedure that manages to uphold overall movement time and response accuracy.

The effect of modeled absolute timing variability and relative timing variability on observational learning

There is much evidence to suggest that skill learning is enhanced by skill observation. Recent research on this phenomenon indicates a benefit of observing variable/erred demonstrations. In this study, we explore whether it is variability within the relative organization or absolute parameterization of a movement that facilitates skill learning through observation. To do so, participants were randomly allocated into groups that observed a model with no variability, absolute timing variability, relative timing variability, or variability in both absolute and relative timing. All participants performed a four-segment movement pattern with specific absolute and relative timing goals prior to and following the observational intervention, as well as in a 24h retention test and transfers tests that featured new relative and absolute timing goals. Absolute timing error indicated that all groups initially acquired the absolute timing, maintained their performance at 24h retention, and exhibited performance deterioration in both transfer tests. Relative timing error revealed that the observation of no variability and relative timing variability produced greater performance at the post-test, 24h retention and relative timing transfer tests, but for the no variability group, deteriorated at absolute timing transfer test. The results suggest that the learning of absolute timing following observation unfolds irrespective of model variability. However, the learning of relative timing benefits from holding the absolute features constant, while the observation of no variability partially fails in transfer. We suggest learning by observing no variability and variable/erred models unfolds via similar neural mechanisms, although the latter benefits from the additional coding of information pertaining to movements that require a correction.

Programmable CCD camera equipped with user-configurable video rate digital video processing for use in industrial inspection

A new high performance CCD camera family is presented. The camera incorporates a micro-controller/PLD combination to provide users with computer control of image acquisition, image processing and analysis. User control of image acquisition includes adjustable gain and offset, data rate and timing.Image processing and analysis algorithms are implemented within PLDs and regulated via the microcontroller. A variety of image processing algorithms are discussed including gray scale thresholding, RLE, edge detection and gauging. Parameters that govern the nature of the image processing algorithm can be computer controlled and randomly accessed. The camera transmits a combination of high speed digital video for frame grabber acquisition and low speed serial analysis and status information to a PC serial prot. Pixel rates at up to 20Mbyte/sec/channel for up to 8 channels combine for data throughputs of up to 160Mbytes/sec/camera. Camera configurations include single and multi-tap, linescan, TDI and area array formats. Up to 15 cameras can be easily integrated together to form a single network through the use of a programmable communication HUB unit. An even larger number of cameras can be linked together by combining several networks into a web. Applications for the programmable camera/HUB technology include web and parts inspection, template matching and gauging.

An experimental procedure for measuring silicon lattice heating due to hot carriers in MOSFETs

Abstract The presence of hot carriers within the pinch-off region of a MOSFET can result in a localised increase in the silicon lattice temperature. The amount of heating is dependent on the density and energy of the carriers. In small devices thermal conduction results in an elevated temperature across the entire device. By using the source-substrate p - n junction diode, changes in the silicon lattice temperature can be measured. The procedure makes use of the temperature effect on the forward bias diode current. The silicon temperature in the immediate vicinity of the pinchoff region can be determined from steady-state current-voltage measurements using an HP parameter analyzer. As a test, this new procedure has been applied to a number of small geometry MOSFETs. The silicon temperatures correlated well with impact ionization substrate current. Combined with a knowledge of the hot carrier density, this experimental procedure may allow estimates of the average carrier energies to be made. The procedure may also be used as a calibration tool for hydrodynamic models used in numerical device simulation.

Two-poly 128x128-element area array with lateral antiblooming

An image sensor with lateral antiblooming for overillumination protection is discussed. The device is implemented using a double poly, NMOS buried channel CCD process with a buried drain that runs adjacent to the channel stops. The antiblooming barrier is formed by a surface channel region adjacent to the buried data. Typically these devices are implemented using a three poly process but by eliminating the exposure control requirement, a two poly process technology can be used. The area array pixels are built using four phase CCD technology maximizing charge handling capacity. The surface channel antiblooming barrier confines the charge to buried channel operation.