A system for detecting the presence of rain droplets on a windshield (17) employs a source of light, such as an LED (11), and a photodetector (12) installed on the dashboard (13) of a vehicle. The LED (11) and the photodiode (12) are arranged with respect to one another such that light from the LED (11) cannot reflect directly off the windshield into the photodiode (12). Only when the light from the LED is backscattered by an environmental condition, such as the raindrops (25) on the exterior of the windshield (17), the condensation of moisture on the interior of the windshield (17), or the presence of smoke in the cabin, will the photodiode (12) receive the light from the LED (11). Each of these environmental conditions has a predeterminable characteristic signature which permits the processing of data to detect same. An ambient light signal is subtracted from the combination of the rain and ambient light signals by pulsed operation of the LED (11) and subtracting the ambient light signal, which is detected when the LED (11) is dark, from the combined LED (11) and ambient light signal which is present when the LED (11) is illuminated.

Multi-function light sensor for vehicle

A control system is employed in a vehicle to assist a user to operate the vehicle effectively and safely. In accordance with the invention, the system provides driving assistance to the user by taking into account the user's physical condition, the vehicle condition and the surrounding conditions. The surrounding conditions include, e.g., road, weather and traffic conditions, external to the vehicle. The vehicle condition concerns the conditions of the brakes, steering, tires, radiator, etc. of the vehicle. Signs of fatigue, stress and illness of the user are monitored by the control system to assess the user's physical condition.

Technique for operating a vehicle effectively and safely

The initiation and subsequent propagation of flame fronts by breakdown, are and glow discharge ignition devices have been investigated by time resolved interferometry in CH4-air mixtures (1/Ф=1.0, 1.11, 1.25, 1.4) at 4 bar. Based on size, effective expansion velocity, and radial temperature profiles across the flame fronts as functions of time after spark onset, it is shown that the breakdown controls the inflammation process up to ≈1 ms. The breakdown is far better suited for inflaming combustible mixtures than are or glow discharge due to very high energy transfer efficiency (≈95%), large double sided contact areas with the unburnt mixture, very steep gradients of temperature and particle density, and reignition capabilities at ≈300 μs. Thus extremely lean (1/Φ≈1.6) mixtures ignited at high flow velocities with high inflammation probabilities.

Initiation and propagation of flame fronts in lean CH4-air mixtures by the three modes of the ignition spark

Application of high energy ignition systems to engines

A Fundamental Model for Flame Kernel Formation in S. I. Engines

The device for visibility measurement is designed primarily for use in motor vehicles. A light emitter is arranged inside the driver's compartment preferably on the rear view mirror in front of the windshield. The light emitter generates light pulses or flashes radiating through the windshield. The light scattered back due to soiling on the inside and outside of the windshield or in scatter zones, formed by fog or smoke or the like, in front of the windshield, impinges a light sensor, preferably likewise arranged on the rear view mirror inside the driver's compartment. By utilizing light pulses of various wavelengths and processing of the output signals of the light sensor in predetermined or predeterminable time windows or intervals, not only the respective visibility but also the type of viewing impairment can be determined.

Device for visibility measurement for a motor vehicle

Fundamental investigations have been made on processes in common spark plugs useful for ignition of fuel-air mixtures. Development of spark discharge from the early beginnings as well as the initiation of chemical reaction have been studied experimentally by using very high frequency measuring technique, radiation measurements, spectroscopic methods and interferometry by a nitrogen laser (about 300 ps). The measurements have been carried out in non-reacting gases (N2, air) as well as in inflammable mixtures. A complete description will be given of the total process from the spark breakdown to the arc and glow-phase, resp., in the millisecond range including temperature, local dimensions, energy distribution and radicals which can be formed. /SASI/

New Aspects on Spark Ignition

Vorrichtung zur sichtweitenmessung

An arrangement for the ignition of ignitable mixtures, especially a spark plug for producing sparks in otto-engines, which is constructed according to high-frequency standpoints and in which at least one condenser arranged in the spark plug is adapted to be charged to a high voltage and is adapted to be discharged as much as possible exclusively in the breakdown phase of the starting phase of the ignition spark by way of a booster gap also arranged in the spark plug and a main gap formed by an ignition electrode with respect to a ground electrode, whereby the breakdown voltage of the booster is higher than the breakdown voltage at the main gap. In particular, for achieving a compact constructive form, satisfactory from a manufacturing point of view, and for optimizing the ignition and flame development, the condenser and the main gap are connected in a series circuit in a preferred embodiment of the invention, with respect to which the booster gap is connected in parallel.

Arrangement for the ignition of ignitable mixtures

Die vor allem fur den Einbau in Kraftfahrzeuge konzipierte Vorrichtung besitzt einen Lichtemitter (1), welcher innerhalb der Fahrerkabine, vorzugsweise am Ruckspiegel, vor der Windschutzscheibe (3) angeordnet ist und die Windschutzscheibe durchstrahlende Lichtimpulse bzw. -blitze erzeugt. The designed especially for installation in motor vehicles apparatus has a light emitter (1) which is arranged inside the driver's cab, preferably at the rear-view mirror, in front of the windshield (3) and generates the windshield by radiating light pulses or Flashes. Das aufgrund von Verschmutzungen an der Windschutzscheibe (3) innen und ausen oder in durch Nebel oder Rauch od.dgl. The result of dirt on the windshield (3) inside and out or in through fog or smoke, or the like. gebildete Streuzonen (7) vor der Windschutzscheibe zuruckgestreute Licht beaufschlagt einen vorzugsweise ebenfalls am Ruckspiegel innerhalb der Fahrerkabine angeordneten Lichtsensor (2). Scatter zones (7) formed in front of the windshield back-scattered light is applied to a preferably likewise arranged on the rear-view mirror inside the driver's cab light sensor (2). Durch Lichtimpulse verschiedener Wellenlange und Verarbeitung der Ausgangssignale des Lichtsensors (2) in vorgegebenen bzw. vorgebbaren Zeitfenstern bzw. -intervallen last sich neben der jeweiligen Sichtweite auch die Art der Sichtbeeintrachtigung ermitteln. By light pulses of different wavelengths, and processing the output signals of the light sensor (2) in predetermined or predeterminable time windows or intervals can be next to each sight and the type of visual impairment determined.

Hans Prof Dr Albrecht

Papers

Device for visibility measurement for a motor vehicle

New Aspects on Spark Ignition

Vorrichtung zur sichtweitenmessung

Arrangement for the ignition of ignitable mixtures

Device for measurement of visual range