GB2332551A

GB2332551A - Lighting system

Info

Publication number: GB2332551A
Application number: GB9828029A
Authority: GB
Inventors: Hans-Heinrich Schussler
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1997-12-19
Filing date: 1998-12-18
Publication date: 1999-06-23
Anticipated expiration: 2018-12-18
Also published as: GB2332551B; FR2772960A1; IT1302930B1; ITRM980780A1; DE19756698A1; GB9828029D0

Abstract

A lighting system for a vehicle lighting system or traffic light system has at least one light source 3a, 3b, 4a, 4b, 5a, 5b, 6, 7, 20a, 20b, 102-104, 106-108 and 201-203 for emitting light in a visible wavelength region for illuminating or signalling purposes, and a lighting system controller 2, 300, for activating the at least one light source, in such a way that the light emitted by it also contains an extra-visual code information signal.

Description

1 Lighting system 2332551 The invention relates to a lighting system

particularly but not exclusively, for a vehicle or one or more traffic lights.

Offenlegungsschrift DE 196 25 960 Al has disclosed a device for transmitting data between vehicles, in which a customary signalling system is equipped with light-emitting diodes via which the coded light signals are emitted. The signal transmission can be performed both in the wavelength region visible to the human eye, and in the wavelength region invisible to the human eye. Coding can be performed in a simple modulation such as, for example, clocking the light-emitting diodes with clock frequencies of a few kilohertz. It is, in particular, information on the way a vehicle driving in front is being handled, such as the intensity of a braking operation or the ABS response of the vehicle which is transmitted as data to a following vehicle, which is equipped for this purpose with a correspondingly configured receiver.

Offenlegungsschrift DE 39 02 627 Al has disclosed an IR sensor, in particular a CCD sensor, for a motor vehicle, which serves to detect the IR radiation for an IR transmitter arranged on a vehicle driving in front. Rear lights, brake lights or rear fog lights equipped with conventional illuminating means, such as incandescent lamps, of a known motor vehicle and/or a separate IR transmitter are provided, for example, as IR transmitter. The light emissions from the IR transmitters which come into consideration can be modulated with a frequency or pulse train, with the result that coded data, for example on dangerous situations in the surroundings of the vehicle driving in front,'can be transmitted from the vehicle driving in front to the following vehicle. Furthermore, the following vehicle can measure spacings between the vehicles by at least two IR sensors.

Patent Specification DE 42 13 516 C I has disclosed a signalling device for a motor vehicle, which has a transducing sensor, in particular a flash tube with an IR filter, which is arranged in a mobile fashion on the rear of a motor vehicle or in a stationary fashion at a danger spot on a roadway, as well as, on the vehicle side, a receiving device with an IR sensor and a detector stage. In the case of a transducing sensor accommodated in a mobile fashion in a motor vehicle, said sensor is preferably integrated into the rear lights. The aim is to use pulsed signals for a coded transmission to a following vehicle of traffic information such as, for example, data relating to a braking operation of a vehicle travelling in front.

Offenlegungsschrift DE 1 815 671 has disclosed a conununications lighting system for motor vehicles by means of which a bidirectional voice traffic is implemented between two vehicle drivers via visible or non-visible light, in particular IR light. In addition to the customary vehicle lamps, there is additionally provided especially for this purpose on each vehicle a light transmitter which emits light which contains the voice information and can be received by a receiver located on a further vehicle.

Furthermore, Offenlegungsschrift DE 40 14 916 Al has disclosed a brake light system which makes a visual code information signal on the braking intensity of the vehicle equipped with this system available to the driver of a following vehicle. For this purpose, a brake light is provided with a plurality of light sources which are suitable for outputting a variable luminosity and/or a variable light intensity pattern, the visual code information signal being formed as a result.

Auslegeschrift DE 1036 720 has disclosed an alarm system for motor vehicle traffic which has a separate spark flash light source which is suitable for responding to a photoelectric receiver in another motor vehicle.

Patent Specification DE 44 13 886 Cl has disclosed an optical transmitting system for traffic information which has bidirectional communication between transmitting/receiving units provided especially for this purpose on the vehicle and along the route.

Offenlegungsschrift DE 38 36 095 A 1 has disclosed a device for emitting and receiving an IR recognition signal, the IR recognition signal serving to mark specific motor vehicles, and a mutual recognition of two vehicles equipped in such a way triggering a specific control action inside these vehicles.

In conventional vehicle lighting systems, it has so far been possible to distinguish the lamps only roughly by their colour, for example white for he.adlamps and reversing lamps and, in part, fog lamps, red for brake lights, rear lights and rear fog lights, amber for direction indicators, left or right at the front, at the side and/or at the rear and, in part, for fog lamps. All direction indicators also serve together as a hazard warning system. Since the lamps are fitted at different sites on the vehicle, 3 and there are, in part, several of them present, are of different configuration and at different spacings from one another, depending on make, and also are fitted at different heights depending on the vehicle type, it is possible only with difficulty automatically to identify the lamps with the aid of a visible light they have emitted. In addition, although in the case of lamps of the same colour, such as brake lights and rear lights, a differing luminosity is provided, the latter decreases with the square of the visual distance and can be impaired by aging of the lamp or external contamination as well as dust particles in the air or fog, with the result that they can no longer be distinguished visually at a distance by the following driver. Moreover, the luminosities fluctuate from vehicle to vehicle.

In conventional traffic light systems, it is the case, inter alia, that lamps of red, amber, green colour are arranged one above another in a signal unit. They may have arrow symbols for specific driving directions. In the case of multi-lane traffic management, it is the case, furthermore, that a plurality of traffic lights are arranged next to one another for different lanes. Under unfavourable (sun) light conditions, the colours or their signalling function are difficult to detect. Flashing traffic beacons with amber lamps are used, for example, on construction sites for traffic management. Colour-blind people can orientate themselves only from the arrangement of the respectively shining lamp.

In all cases, there is a need for automatic identification of respectively activated lamps, for example in the case of vehicles for the purpose of automatically initiating a suitable driving manoeuvre of a respective vehicle when specific vehicle lamps are activated on a vehicle driving in front or following or driving alongside on the left or right, and/or to indicate to the driver such a lamp activation on a vehicle driving in front, approaching, following or driving alongside, so that said driver can initiate suitable reactions on the basis of reliable information.

The present invention seeks to provide a lighting system of the type mentioned at the beginning and having an extended range of light source functions, and at the same time, for example, to permit automatic light source identification.

According to one aspect of the present invention there is provided a lighting system having - one or more traffic lights with light sources for emitting light in a visible wavelength 4 region, and - a lighting system controller for activating the light sources, wherein at least one of the light sources is adapted to be activated by the lighting system controller in such a way that the light emitted by said at least one of the light sources contains an extra-visual code information signal.

According to a second aspect of the present invention there is provided a lighting system for a vehicle lighting system or traffic light system, having - at least one light source for emitting light in a visible wavelength region for illuminating and/or signalling purposes, and - a lighting system controller for activating the at least one light source which can be activated by the lighting system controller in such a way that the light emitted by the at least one light source contains an extra-visual code information signal, wherein the code information signal contains information on the function and/or the fitting site of the light source.

In these systems, there is superimposed in a supplementary fashion on the light which is emitted from one or more associated light sources and is provided primarily for illuminating or signalling purposes, an extravisual code information signal, that is to say a signal which the human eye cannot perceive or can scarcely perceive.

For the case of application of a traffic light system, in particular for road traffic or a railway traffic or waterway traffic, the visible light emitted by these lighting fittings are superimposed with ftniher code information, for example relating to function andlor traffic, which can be detected by suitable sensors in vehicles or in a traffic management system. In addition to the conventional signalling function, the emitted light thereby functions as a carrier for an extra-visual code information signal. For the case of application of a vehicle lighting system according to the second aspect, it is the brake lights, rear lights, rear fog lights, direction indicators or headlamps which come into consideration as such light sources.

For the case of application of a vehicle lighting system according to the second aspect, it is lamps arranged one above another in the colours of red, amber and green which come into consideration as such light sources. According to the invention, the visible light emitted by these lighting fittings is superimposed with further code information which is related to function and/or position with regard to the light source and can be detected by suitable sensors in vehicles or in a traffic management system. A respective receiver thereby receives clear information on the light source itself.

Preferably, the lighting system has at least one receiver unit for detecting a received code information signal and for extracting the information contained. This arrangement permits the reception of code information signals from other, similar lighting systems in vehicles, traffic lights or luminous traffic signs, and evaluation with regard to the information contained, and thus direct communication with other such lighting systems.

Preferably, the lighting system is a vehicle lighting system or traffic light system and outputs to a display and/or function control unit of the vehicle a signal dependent on the extracted information. This arrangement permits the information obtained via the code information signal to be relayed to a display and/or function control unit of the corresponding vehicle. As a result, the vehicle driver and/or the function control unit of the vehicle is placed in the position of being able to react to the information received. In the case of automatic lamp identification, in particular, this can be performed virtually without delay, that is to say without time for the driver to be shocked and react, with the result that automatic measures can be initiated at once. This gain in time yields a substantial gain in driving safety and traffic safety.

Preferably, the code information signal is implemented as an amplitude, frequency and/or pulse-code modulation signal which can be modulated on to the emitted light with simple means and cannot be perceived by the human eye.

A preferred embodiment of the lighting system comprises a vehicle lighting system which emits a code information signal which contains information on the state of the vehicle and/or its functional units as well as the vehicle surroundings. In this case, information on the specific functional units of the vehicle, for example the brake unit, functionally associated light sources, can be assigned, for example, to the brake lights for the purpose of emission.

A preferred embodiment of the invention is represented in the drawing and is described below. The sole figure shows a diagram of the arrangement of important components of a vehicle lighting system and a traffic light system.

The lighting system represented in Figure 1 for a motor vehicle 1 has 6 a plurality of light sources which can be activated by a central lighting system controller 2. The light sources are driving headlamps 3a, 3b, rear lights 4a, 4b, brake lights 5a, 5b, side-mounted turn indicators 20a, 20b, a reversing light 6 and a rear fog light 7. In modified embodiments, the number of the said light sources serving as illuminating means can be varied at will. Furthermore, it is also possible for other light sources such as, for example, front fog lamps, side-mounted clearance lamps and/or direction indicators, to be activated by the lighting system controller 2. The number, configuration and positioning of the said light sources on the vehicle vary depending on the make and type of the vehicle. Instead of conventional incandescent lamps, it is preferable to provide laser diode systems of flat design as light sources.

The said light sources 3a, 3b, 4a, 4b, 5a, 5b, 6, 7, 20a, 20b can be activated conventionally via the lighting system controller in such a way that they fulfil their normal lighting or signalling function. For example, the brake lights 5a, 5b are switched on upon actuation of the vehicle brake unit, with the result that they emit visible light with a red colour of a specific intensity. All the other illuminating means similarly fulfil their illuminating and/or signalling functions demanded by the road traffic conditions and regulations, and this need not be set forth further.

The lighting system controller 2 is fed an information signal 8 which can constitute data on the function and position of the respectively activated vehicle lighting fitting, measured or stored vehicle data, roadway data, and/or data input by the vehicle driver. The information signal 8 is detected by a coder unit 9 and converted into a code information signal which is modulated by a light source controller 10 on to the visible light, emitted for illuminating and/or signalling purposes, of an assigned light source. This is performed in the form of amplitude modulation, frequency modulation or pulsecode modulation in such a way that the code information signal modulated on to the visible illuminating light cannot be perceived by the human eye, and therefore does not disturb the actual illuminating function of the light source. The use of laser diode systems renders it possible in this case to carry out modulations in a range of high frequencies which is not accessible to conventional incandescent lamps, because of their thermal inertia. The light source controller can also be integrated into the individual lamp, in particular when the coding serves only to identify.

Information on the type of the respective vehicle lighting fitting and its 7 positioning on the vehicle can be provided as information which is modulated on to the light, in order to permit automatic identification of lighting fittings such as brake light, rear light on the left, direction indicator on the right, etc. It is possible alongside this to provide further vehicle-related information which refers, for example, to the brake pressure, the vehicle speed and the vehicle deceleration, which are output, for example, via the brake light 5.

The vehicle lighting system further has a receiver 11 on the front side of the motor vehicle 1 with a wide cone of coverage 12, for example a wide-angle photosensor. The receiver 11 is capable of intercepting, via a vehicle lighting system acting in a similar way, light which is emitted in particular by vehicles driving in front or approaching. An evaluation unit 13 serves to evaluate received light with respect to any code information signals possibly contained, and to extract the information contained and, together with the receiver 11, forms a receiver unit which outputs the received information as a corresponding information signal 14 to a display and/or function control unit (not shown) of the motor vehicle 1. The extracted information can be displayed via the display unit to the driver of the motor vehicle 1, with the result that the driver can react suitably, ' if required. If the information is transmitted to a function control unit, the latter can act directly on units of the vehicle, in particular the brake unit or the lighting system controller 2 itself. It is possible thereby, for example, to use the code information signal transmitted by means of the lit-up brake light of a vehicle driving in front to detect this brake light activation automatically, and to conclude from this that the relevant vehicle is just braking, for example, or is carrying out an emergency stop. If required, this information which has been fed can be used by the brake system of the following vehicle automatically to trigger an appropriate braking manoeuvre in order to avoid danger, doing so without having to wait for the reaction of the driver.

In addition to a front receiver 11, the lighting system controller preferably also has one or two side-mounted receivers, of which one receiver 1 la is shown in a representative fashion in the figure, and a rear receiver, via which information signals from vehicles which are driving alongside or following can be detected. This yields the possibility of reciprocal communication between successive vehicles, for example on the state of the roadway or an impending driving manoeuvre 8 by the respective vehicle driver, without radio contact being required for this purpose. This avoids additional electromagnetic fields and biological environmental stresses or technical disturbances caused thereby.

By contrast with radio contact, optical means render it possible to select direction simply, for example by selecting the cone of coverage 12, with the result that the vehicle driving directly in front can preferably be detected and/or observed. It can be expedient for the purpose of distinguishing further vehicles driving in front to use three different receivers for front left, front centre and front right in order to increase the directional resolution.

The receiver(s) (11, Ila,...) can alternatively also be constructed as CCD cameras. This permits a further spatial resolution of the location of the lamp in the visual range of the receiver, for which purpose a relatively low number of pixels of, for example, a 3 X 3 or 5 x 5 pixel matrix is sufficient. If a vehicle already has a CCD camera system, for example for the purpose of automatic traffic management along lane markings and/or of detecting obstacles and/or other vehicles, the task of larnp detection can, if appropriate, be taken over by this camera with a higher spatial resolution, while the lamp identification is performed in the evaluation unit 13.

Represented in the upper part of Figure 1 are two forms of fixed traffic lights, specifically a single signal unit 200 and a double single unit 100, in the visual range of the receiver 11. The signal units 100, 200 are part of the lighting system and can be activated in a similar way to that described in relation to the various vehicle lighting fittings by an associated lighting system controller 300 for the purpose of outputting corresponding code information signals which can then be evaluated by the lighting system controller 2 on the vehicle side. As usual, the single signal unit 200 contains three coloured lamps 201, 202, 203. The double signal unit 100 comprises two signal units 101, 105 with in each case three coloured lamps 102, 103, 104; 106, 107, 108. Depending on the traffic management, the signal unit 101 can operate on the right-hand side of the road in synchronism with the single signal unit 200 on the lefthand side of the road, or they control different road lanes. These and further special cases can be identified directly by different standardized lamp codes.

Thus, the vehicle lighting system described makes available a communication system which uses the conventional light sources of motor vehicles to 9 permit exchange of information between different motor vehicles and traffic lights, in particular with regard to automatic detection, independent of the driver, of the activation of respective lighting fittings. Since use is made only of lighting fittings which are present in any case, the outlay on implementation is low and the vehicle configuration remains uncompromised. Conventional vehicle lighting systems can be rebuilt into a system according to the invention by simple retrofitting, in particular with a suitable lighting system controller. In order to enhance traffic safety, it is possible to implement between the inventive lighting system controllers of different vehicles a rapid and reliable exchange of information which permits automatic reaction to dangerous situations by relaying the information directly to appropriate functional control units of the respective vehicles. This makes an important contribution to raising the level of traffic safety. It is expedient in this case to standardize the lamp coding relating to function, type of fitting and, if appropriate, colour.

It goes without saying that inventive lighting systems can be used not only in vehicles for road, railway and waterway traffic, but also in other sectors where there is a need for automatic identification of activated light sources.

1.

Claims

Claims

A lighting system having one or more traffic lights with light sources for emitting light in a visible wavelength region, and a lighting system controller for activating the light sources, wherein at least one of the light sources is adapted to be activated by the lighting system controller in such a way that the light emitted by said at least one of the light sources contains an extra-visual code information signal.
2. having A lighting system for a vehicle lighting system or traffic light system, at least one light source for emitting light in a visible wavelength region for illuminating and/or signalling purposes, and a lighting system controller for activating the at least one light source which can be activated by the lighting system controller in such a way that the light emitted by the at least one light source contains an extra-visual code information signal, wherein the code information signal contains information on the function and/or the fitting site of the light source.
A lighting system according to Claim 1 or 2, wherein the lighting system has at least one receiver unit for detecting a received code information signal and for extracting the information contained.
4. A lighting system according to Claim 3, wherein the lighting system is a vehicle lighting system or traffic light system and outputs to a display and/or function control unit of the vehicle a signal dependent on the extracted information.
5. A lighting system according to any one of Claims 1 to 4, wherein the code information signal is an amplitude, frequency and/or pulse-code modulation signal modulated on to the emitted light.

A lighting system according to any one of Claims 2 to 5, comprising a vehicle lighting system in which the code information signal contains information on the state of the vehicle and/or of the vehicle surroundings.
6.

A lighting system substantially as described herein with reference to and as illustrated in the accompanying drawing.
7.