Night Vision System Research Articles

Properties of light reflected from road signs in active imaging

Night vision systems in vehicles are a new emerging technology. A crucial problem in active (laser-based) systems is distortion of images by saturation and blooming due to strong retroreflections from road signs. We quantify this phenomenon. We measure the Mueller matrices and the polarization state of the reflected light from three different types of road sign commonly used. Measurements of the reflected intensity are also taken with respect to the angle of reflection. We find that different types of sign have different reflection properties. It is concluded that the optimal solution for attenuating the retroreflected intensity is using a linear polarized light source and a linear polarizer with perpendicular orientation (with regard to the source) at the detector. Unfortunately, while this solution performs well for two types of road sign, it is less efficient for the third sign type.

Properties of light reflected from road signs in active imaging

Night vision systems in vehicles are a new emerging technology. A crucial problem in active (laser-based) systems is distortion of images by saturation and blooming due to strong retroreflections from road signs. We quantify this phenomenon. We measure the Mueller matrices and the polarization state of the reflected light from three different types of road sign commonly used. Measurements of the reflected intensity are also taken with respect to the angle of reflection. We find that different types of sign have different reflection properties. It is concluded that the optimal solution for attenuating the retroreflected intensity is using a linear polarized light source and a linear polarizer with perpendicular orientation (with regard to the source) at the detector. Unfortunately, while this solution performs well for two types of road sign, it is less efficient for the third sign type.

Pedestrian Detection with near and far Infrared Night Vision Enhancement

Current headlighting and road lighting are only partly effective in reducing the risk of driving at night. To further reduce this risk, two major sensing technologies for night vision systems have been receiving particular development interest: near infrared (NIR) systems, which actively illuminate the scene in the near infrared spectrum and capture the reflected radiation, and far infrared (FIR) systems, which generate images by passively detecting thermal emissions. To compare pedestrian detection with night vision systems, a test vehicle equipped with an NIR and an FIR system was driven at night on several roads with pedestrians standing along the route. Video clips, recorded from both systems simultaneously, were later shown in a laboratory to 16 subjects (eight younger than 30 years and eight older than 64 years). Subjects pressed a button as soon as they saw each pedestrian. Detection distances with FIR were, on average, three times greater than with NIR. For both systems, detection distances of younger subjects were about 1.7 greater than of older drivers. The effectiveness of night vision systems can be expected to depend on inherent advantages of either technology as well as the details of implementation. To the extent that the two systems used in this experiment reasonably represent the respective technologies, the results support the expected enhancement of pedestrian detection in FIR systems.

Night vision 2 — The first night-vision system to recognize pedestrians and cyclists

Autoliv has produced a night-vision system for automotive applications, operating in the far infra-red. With the aid of a thermal imaging camera, this shows up humans and animals beyond the range of the headlights. The second generation of Night Vision is still under development, but includes many innovations. For example, it classifies objects as ‘pedestrian’ or ‘cyclist’ and warns the driver. The camera also has some decisive new features. The image processing now takes place in a separate electronic unit with a processor that is also new.

Pedestrian tracking routine for passive automotive night vision systems

Purpose – This paper aims to present a new approach to implement a pedestrian tracking algorithm for a passive automotive night vision application.Design/methodology/approach – First, the basic information of passive and active night vision systems is presented, with implementation methods adopted in previous work. The proposed thermal‐image processing is a combination of seed detection, boundary detection and seed growth computations, based on a temperature thresholding scheme.Findings – The processing routine performance is assessed when implemented to a continuous sequence of thermal acquisitions, from a commercial automotive night vision module. Experimental results show good tracking performance for both pedestrians and passing vehicles.Research limitations/implications – A strategy of multi‐seed growth, directional seed growth and image fusion is proposed to improve the current tracking algorithm.Originality/value – New thermal image processing routines are applied to commercial, automotive night vi...

Car makers launch new generations of night vision systems

Car makers launch new generations of night vision systems

Camera position and presentation scale for infrared night vision systems in cars

AbstractPrinciples of an infrared night vision system in cars were studied in a stationary car simulator. The 20 participants drove for about 45 min on a rural route in night conditions where four objects were placed in or next to the road. When the camera was mounted on the grill of the car and the scale was true size, that is, 1:1, the time to collision was the longest. Changing the scale to a wide‐angle view of 1:2 decreased this time. When the camera was mounted on the roof of the car, the scale change produced an increase of the time to collision. Principal components analysis indicated that the speed and the lateral position of the car were independent. The results were explained partly in terms of differences between the optic arrays presented to the drivers and to motion adaptation. It is suggested that the camera for a night vision system should be placed at the level of the car grill and the presentation scale should be 1:1. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 457–473, 2007.

Study on Visibility of Night Vision System and Its Image Presentation Using Head-up Display

To assist night-time driving, night vision systems (NVSs) present the image of forward visual field taken with an infrared/near-infrared camera to a driver. We investigated whether such systems detect a visual target (i.e., a pedestrian, a road sign, or obstacles) faster than conventional low-beam forward lighting does. Our results showed the NVS is significantly faster. We also examined various sizes and positions of the HUD presenting the NVS image and determined the appropriate image size and position of the HUD for the NVS. An image, 6(H) × 4.7(V) degrees in visual angle, presented in the lower front of the driver showed the best scores in subjective evaluations.

Flight Tests of the KO-1 Aircraft at Night

The KO-1 aircraft which has the functionality of tactical observation, was successfully developed in August of 2004 in South Korea. It is important for the KO-1 aircraft to achieve successful missions at nighttime as well as during daytime. The aircraft, equipped with interior and exterior lighting systems and lighting control panel modified from those of the KT-1 basic trainer, provides improved safety, operational effectiveness, and situational awareness during operation at night when used with night-vision goggles (NVGs). KO-1 is the first domestic aircraft that utilizes the night-vision imaging system (NVIS) technology in Korea. KO-1 NVIS was developed with the goal of defining the components of NVIS and establishing test and evaluation procedures for both the subsystems and main system. In this paper, we present the establishment of a KO-1 NVIS lighting system, NVIS component development, and representative ground and flight test results.

Pedestrian Detection with Night Vision Systems Enhanced by Automatic Warnings

Pedestrian detection using far-infrared (FIR) and near-infrared (NIR) night vision systems was compared in this experiment, combined with automatic warnings at one of two distances (150 m and 75 m) or no warning at all. Sixteen subjects (eight younger than 30 years and eight older than 60 years) pressed a button as soon as they saw a pedestrian on a night vision system in the center console of a vehicle simulator. In addition, they performed a concurrent simulated steering task that required almost continuous viewing of the forward scene, similar to real driving. The automatic visual warning was a blue rectangle that zoomed in on the pedestrian in the video display. When the warning was presented 150 m ahead of the pedestrian, detection distance and accuracy for both night vision systems increased, but the effects were more prominent for the NIR system. In the 75 m condition, automatic warnings improved performance with NIR but worsened performance with FIR, possibly because in some trials subjects waited for the automatic warning before responding. Overall, automatic visual warnings based on image processing were effective in increasing accuracy and detection distance for pedestrians except when short-distance warnings were used with the FIR system.

Range gated active night vision system for automobiles

Night vision for automobiles is an emerging safety feature that is being introduced for automotive safety. We develop what we believe is an innovative new night vision system using gated imaging principles. The concept of gated imaging is described and its basic advantages, including the backscatter reduction mechanism for improved vision through fog, rain, and snow. Evaluation of performance is presented by analyzing bar pattern modulation and comparing Johnson chart predictions.

Continuous versus Situation-Dependent Night Vision Presentation in Automotive Applications

As the number of advanced driver assistance systems in modern cars increases the question of possible negative behavioral adaptation is raised. We have investigated this phenomenon for night vision systems in a driving simulator. One common opinion is that there is a risk for using the enhanced visual conditions that come with these systems to increase speed during nighttime driving and thereby eliminate the safety margins the system was designed to provide. In our study two system approaches were compared, one with continuous presentation and one with presentation only when dangerous objects were detected by the system. The latter approach was meant to minimize the risk of negative adaptation, which was partly confirmed in the study. Moreover, the results showed better and more consistent driver performance with the situation-dependent system and all subjects preferred this approach from a workload perspective.

Safer driving in the dead of night [infrared vision systems

One of the innovations that were showcased at the 2005 Detroit auto show was the night vision systems in high-end cars designed to improve driver safety during night time where there is inadequate illumination. This high-tech safety option is expected to be available in the 2006 models of the Mercedes Benz S Class and BMW's 7 series. The night vision systems use infrared sensors to let drivers see as much as three or four times farther ahead and help them quickly distinguish among objects. While night vision systems help reduce the chances of accidents, it is ultimately the driver's responsibility to recognize obstacles in the road.

Interference filters for innovative night vision systems

Even though night-time driving accounts for only 20 % of all traffic, around 40 % of all fatal accidents occur at night. In order to prevent these accidents, car manufacturers and their suppliers are developing new, intelligent headlight technology. Innovative night vision systems provide the driver with additional information on the road ahead, especially in the more distant areas in front of the vehicle, thus helping to avoid collisions. Schott AG has developed special interference filters to series production readiness for use in these night vision systems. This article describes the design, development and manufacturing of these filters.

72.1: Automotive Night Vision System with Picture Presentation

First generation Night vision enhancement systems with image presentation in the dashboard have been introduced on the market. Far Infrared and Near Infrared systems are currently competing technologies. The camera picture is presented either with a Head-up display on the windscreen or in the dashboard region. An arbitrarily configurable LC display located in the instrument cluster was found to meet best the requirements of a quick and distraction-free reading. A precondition for a quick recognition and identification of relevant obstacles is a highcontrast and brilliant picture quality. To achieve this, picture quality improvement means have been applied. Such a setup has been selected for the new Mercedes S-Class.

Integration of night-vision and head-up display in vehicles

Night vision enhancement based on electronics is a very recent development within the field of driver assistance solutions. Night vision systems, as they are usually called, support the driver in a borderline situation of human perception in order to lower the risk of accidents. The ergonomics of displaying the vision enhanced image are one of the key issues of night vision solutions. Siemens VDO Automotive has developed two night vision technologies to functional maturity and has tested various image display locations in the cockpits of a passenger car and a commercial vehicle. This paper gives a current status of the findings so far and focuses on explaining the potential that lies in integrating night vision solution and head-up display.

Focus on Photonics and Imaging

Focus on Photonics and Imaging

Night vision systems developed for series production

When visibility is still insufficient despite good headlamps in unclear traffic situations at night, the moment has come for a night vision system to be used. One glance at the display is enough to register the context of the traffic situation and be able to continue driving safely. Because the display shows information the driver cannot acquire with his natural visual abilities. This article explains how such innovative infrared systems work and describes some of the components currently being developed ready for series production by Hella under the product description ADILIS.

Pedestrian Detection Using Stereo Night Vision

A method is presented for pedestrian detection using a stereo night-vision system installed on the vehicle. Much of the work in this area makes use of shape information. The proposed method detects moving objects whose motions are not consistent with the movement of the background and is considered to be complementary to shape-based approaches. In this paper, two new techniques are introduced for this task for night vision, namely a two-stage method for stereo correspondence and motion detection without explicit ego-motion calculation. These techniques make use of characteristics of night-vision video data, in which humans appear as hotspots. This method works well in cases where the camera motion has a dominant translational motion with a small amount of rotational motion, which is suitable for the camera on the vehicle. Error analysis as well as experimental results are presented to validate our approach and comparisons have been carried out between our approach and frame-by-frame based pattern-recognition approaches.

Canadian helicopter verifies night vision system with Ascension's laserBIRD

Canadian helicopter verifies night vision system with Ascension's laserBIRD