scholarly journals Fiber optic coherent laser radar 3D vision system

1994 ◽  
Author(s):  
Richard L. Sebastian ◽  
Robert B. Clark ◽  
Dana L. Simonson ◽  
Anthony R. Slotwinski
Keyword(s):  
Fiber Optic ◽  
Vision System ◽  
Laser Radar ◽  
3D Vision ◽  
Coherent Laser Radar

Development of an All-Fiber Coherent Laser Radar for Precision Range and Velocity Measurements

2005 ◽  
Vol 883 ◽  
Author(s):  
Diego Pierrottet ◽  
Farzin Amzajerdian ◽  
Frank Peri
Keyword(s):  
Fiber Optic ◽  
Radar System ◽  
Space Environment ◽  
Laser Radar ◽  
Doppler Velocity ◽  
Velocity Measurements ◽  
Soft Landing ◽  
Highly Efficient ◽  
Laser Altimeters ◽  
Coherent Laser Radar

AbstractAn all-fiber coherent laser radar system capable of high-resolution range and line of sight velocity measurements is under development with a goal to aid NASA's new Space Exploration initiative for manned and robotic missions to the Moon and Mars. Precision range and velocity data are key parameters to navigating planetary landing pods to the pre-selected site and achieving autonomous safe soft-landing. By employing a combination of optical heterodyne and linear frequency modulation techniques [1-3] and utilizing state-of-the-art fiber optic technologies, highly efficient, compact and reliable laser radar suitable for operation in a space environment is being developed.The all-fiber coherent laser radar has several important advantages over more conventional pulsed laser altimeters or range finders. One of the advantages of the coherent laser radar is its ability to directly measure the platform velocity by extracting the Doppler shift generated by the platform motion. The Doppler velocity measurement is about two orders of magnitude more accurate than the velocity estimates obtained by laser altimeters using the rate of change in range [4]. Another advantage is continuous-wave operation that allows the use of highly efficient and reliable commercial off-the-shelf fiber optic telecommunication components. This paper will describe the design and operation of this laser radar sensor and discuss its projected performance. A laboratory breadboard system has already been developed as a step toward a flight prototype. The experimental data representing the potentials of this laser radar system will be reported.

Real-Time Sensing of Sag Geometry During GTA Welding

1997 ◽  
Vol 119 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Y. M. Zhang ◽  
R. Kovacevic
Keyword(s):  
Real Time ◽  
Vision System ◽  
Structured Light ◽  
Gta Welding ◽  
Seam Tracking ◽  
Image Processing Algorithm ◽  
3D Vision ◽  
Full Penetration ◽  
Laser Stripe ◽  
Penetration Control

Seam tracking and weld penetration control are two fundamental issues in automated welding. Although the seam tracking technique has matured, the latter still remains a unique unsolved problem. It was found that the full penetration status during GTA welding can be determined with sufficient accuracy using the sag depression. To achieve a new full penetration sensing technique, a structured-light 3D vision system is developed to extract the sag geometry behind the pool. The laser stripe, which is the intersection of the structured-light and weldment, is thinned and then used to acquire the sag geometry. To reduce possible control delay, a small distance is selected between the pool rear and laser stripe. An adaptive dynamic search for rapid thinning of the stripe and the maximum principle of slope difference for unbiased recognition of sag border were proposed to develop an effective real-time image processing algorithm for sag geometry acquisition. Experiments have shown that the proposed sensor and image algorithm can provide reliable feedback information of sag geometry for the full penetration control system.

scholarly journals Low-cost and home-made immersive systems

2012 ◽  
Vol 11 (3) ◽  
pp. 9-17 ◽  
Author(s):  
Sébastien Kuntz ◽  
Ján Cíger
Keyword(s):  
Virtual Reality ◽  
Vision System ◽  
Low Cost ◽  
Immersive Virtual Reality ◽  
Simple Application ◽  
3D Vision ◽  
Head Mounted Display ◽  
Good Level ◽  
Application Sharing ◽  
Immersive Systems

A lot of professionals or hobbyists at home would like to create their own immersive virtual reality systems for cheap and taking little space. We offer two examples of such "home-made" systems using the cheapest hardware possible while maintaining a good level of immersion: the first system is based on a projector (VRKit-Wall) and cost around 1000$, while the second system is based on a head-mounted display (VRKit-HMD) and costs between 600� and 1000�. We also propose a standardization of those systems in order to enable simple application sharing. Finally, we describe a method to calibrate the stereoscopy of a NVIDIA 3D Vision system.

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