EP0104437A2 - Equipment for detecting and recording offences against the highway code using light energy in the near-visible field - Google Patents

Abstract

The appts. (1) at the roadside or in a law-enforcement vehicle takes a photograph (f1) using ultraviolet or near infrared light for illuminating the registration number plate of the infringing vehicle (V), and simultaneously recording data of the infringement. When a speed limit is exceeded the rear number plate is photographed. When main-beam headlamps are used illegally the appts. photographs the front of the offending vehicle (V2) automatically under the control of a threshold photodetector and integrator, which discriminate between sustained main-beam illumination and transient flashing or dipped-headlamp illumination and also allow for the variation of distance. The wavelength used for the photograph does not distract the driver, nor dazzle occupants of an oncoming vehicle, nor give warning of the presence of the law-enforcement appts.

Description

Apparatuses are known which carry out surveys of traffic offenses by means of photographs taken at the appropriate time and in which data relating to an offense can be stored at the same time. Apparatuses of this kind currently have limited possibilities for night-time surveys, owing to difficulties in recovery and registration. Indeed, it has been observed that the light from the headlights of vehicles in circulation can disturb recovery; in addition, the flash or intense flash required for certain photographic recordings can annoy the drivers of vehicles in the vicinity of the bearing area. These drawbacks have limited the possibilities of benefiting from currently known devices and have damaged their credibility and their employment possibilities.

The object of the invention is to eliminate the current limitations and drawbacks. In essence, the invention provides that one operates with the apparatus in question in the energy frequencies of the light type at the margins of the visible band, including in the low infrared or ultraviolet band with limited extensions. in the visible area. In this way, both the disturbances in the photographic recordings caused by the light of the headlights of the vehicles in circulation and the glare of the drivers of these vehicles by the flash necessary for carrying out photographic surveys are avoided.

According to the invention, it is possible to operate in the range of ultraviolet or, advantageously, in the low infrared range, for which the necessary photographic and filtering materials are particularly easy to obtain.

More particularly, provision may be made for the use of filters for said ranges on the objective of the camera intended for surveys and on the flash generator. The light energy of the flash, which is used for recording, remains in the region of black light or almost and, in any case, does not disturb, by its intensity or its color, the vision of the drivers of the vehicles in circulation and cannot remotely warn of the presence of a checkpoint. On the other hand, the use of filters on the camera makes it possible to detect all that is illuminated with invisible light, while preserving the film of undesirable images due, for example, to the light of the headlights of motor vehicles in circulation.

Apparatus of this kind can be used for lifting. the image of a vehicle and its rear registration plate when this vehicle is traveling at a speed exceeding the authorized limit and pre-established by the apparatus, the photographic recording taking place at the margins and beyond the margins of the field visible, and therefore with attenuation of various light disturbances.

Apparatus fitted as above can also be used to identify offenses for the improper use of high beams. In this case, the apparatus is provided with selection filters to operate at the margins of the visible range, in particular in the low infrared band, and means of signal integration for the evaluation of the longer or shorter incorrect use of the headlights, in the presence, for example, of a trap car arranged in the opposite lane and whose presence requires not to use the headlights. In this case also the recording with flash is necessary or flash to photograph the vehicle which is committing the offense and in particular its front part, and also its rear part; in both cases, the use of normal white light may constitute discomfort and this is why it is advisable to provide for the use of the filtering means according to the invention.

The arrangement according to the invention makes it possible to install the recovery and recording members on the edges of a road even with a double track, thus avoiding having to place an installation in the central strip separating the traffic lanes in both directions. . This simplifies the use of the equipment and also makes it possible to carry out several types of checks with the same equipment.

Advantageously, provision may be made for a prolonged increase in the offense constituted by the improper and prolonged use of headlights - which is necessary for signal integration - with an optical type system comprising a photoelectric cell positioned at the focus the optical system which explores the lane of traffic, to control the use of the headlights by the vehicles which occur; the arrangement is designed so that the light is concentrated on the photocell as long as the vehicle is distant, while this light is defocused and therefore attenuated as the vehicle approaches. It follows that - with an adequate selection threshold - it is possible to collect only the signal from a distant main beam, since the low beams do not reach the pre-established sensitivity threshold, whereas as the lighthouse approaches the image of it is attenuated by defocusing and, therefore, the energy of a main beam is always recordable, while the energy emitted by a low beam is insufficient.

The use of filters for the low infrared and at the margins of the visible range also allows, in this case, take readings and recordings without risk of causing disturbances and signaling the presence of a checkpoint.

The invention will be better understood thanks to the description given below and to the attached drawing, which represents a practical, non-limiting example, of embodiment of the invention.

• - les figures 1 et 2 représentent schématiquement deux manières possibles d'opérer pour un appareillage selon l'invention;
• - la figure 3 représente schématiquement un mode de fonctionnement d'un détecteur optique pour l'évaluation de l'emploi incorrect des phares par un véhicule qui survient;
• - la figure 4 représente un exemple d'installation sur un véhicule automobile.

On this drawing :

• - Figures 1 and 2 schematically represent two possible ways of operating for an apparatus according to the invention;
• - Figure 3 schematically shows an operating mode of an optical detector for the evaluation of the incorrect use of headlights by a vehicle which occurs;
• - Figure 4 shows an example of installation on a motor vehicle.

As already indicated, an apparatus according to the invention for the specified purposes, mainly comprises a camera intended to photograph and therefore memorize the image of a vehicle - including its license plate - and further comprises , a generator of flashes of light or generator of flash, designed to allow a strong instantaneous illumination to impress the film with the desired image. The emission of the generator and the objective of the camera are equipped with a filter designed to exclude most of the visible range of light, but also designed to allow the passage of energy of light type in at least one of the ranges adjacent to the visible range with limited extensions in the visible and therefore in a range close to the ultraviolet and in the low infrared region; the latter seems to be preferable because it is easier to find on the market both the filters and the photographic equipment which must be used in the camera.

In this way, the disturbances due to the production of a particularly intense flash to ensure good photographic capture.

With reference to FIG. 1, an apparatus 1 for taking photographs and producing a flash of light (flash) in the direction of the arrow f ₁ must be able to be activated, for example, to take data from a vehicle V by photographing its rear part, vehicle V moving along the arrow f _V. Under the conditions shown in FIG. 1, a flash of light can hinder or distract the driver of vehicle V and can dazzle the driver of a vehicle V2 occurring in the opposite direction; moreover, a flash of light which can be perceived from a distance constitutes an obvious sign of the presence of control equipment, which then makes much of the function of such apparatus useless, since it exercises a role of deterrence especially when we do not know its presence. By using light energy at the margins of the visible range, direct light is not detectable insofar as it is at least attenuated in the visible field, while the use of specific material for the range of chosen frequencies allows to obtain absolutely complete photographs.

The equipment in question also makes it possible to identify a specific offense, namely the improper use of high beams. In order to identify this offense, it is necessary to assess the intensity of the driving beam and the period of use of the driving beam, and account must be taken of variations in the distance between the vehicle and the detection equipment.

This switchgear must be able to distinguish the dazzling light from the headlights from the less intense and non-annoying light from the low beams. Of course, rational positioning must be provided at the necessary level in relation to the traffic lane to be brought under control; it is necessary to select by intensity with an adequate threshold and an integration of the quantities of energy received by the sensitive element in order to assess whether the incorrect use of the headlights has extended beyond a tolerable limit. The apparatus will therefore include an integrator of the signal received during a predetermined period, an intensity threshold below which the energy received is not counted, and a means which allows compensation as a function of the distance gradually reducing between vehicle and sensitive element. Everything must be accompanied by the data collection system for the identification of the vehicle and even for the proof of the offense, as explained above. It is therefore necessary - as in other cases - to avoid raising with flashes of visible light for the same reasons indicated above, but in the case studied now is also necessary the presence of filters which exclude at least in good part of the visible range, since the taking of photographs must bear on the front of the vehicle so as to also photograph the switched on headlights, which, with their luminous power, could prevent the visibility of the license plate and other details of the front of the vehicle; on the other hand, with the use of the wavelengths of the low infrared, and possibly of the ultraviolet, the illumination of the plate is obtained and of the other details, the direct driver glare, remote reporting is avoided and, in addition, the light beam from the headlights is attenuated while maintaining their recording on the photographic image with an intensity which varies depending on whether the s main beam or dipped beam (which is clearly differentiated at close range).

With regard to the need to compensate for variations in the light intensity of the headlights with respect to the distance from which the vehicle is located and to ensure a selection between the energy of the main beam and the energy of the low beam, a system can be used. associated optics to the sensitive element that takes the signal to send it to development and integration. FIG. 3 shows an optical system 6 with a lens optic 8 placed before the photoelectric sensitive element 10. The device is designed so that the rays of a parallel or quasi-parallel beam F are concentrated on the sensitive element 10 which is at the focus of the optical system; therefore, the energy of distant driving headlights is sufficiently concentrated and high to exceed the threshold provided for the assessment, while the rays of distant passing headlights have no influence. A beam of non-parallel rays Fd, passing through the optical system 8, strikes the sensitive element 10 not with a maximum concentration, but with an energy which is diffused in a section frankly larger than the surface of the sensitive element, and this diffusion is all the more important as the vehicle is closer. It follows that the more intense energy of the headlights of a nearer vehicle is attenuated, but the energy of the low beams is even more attenuated, so that the signal of the high beams remains above of the discrimination threshold and the low beam signal below this threshold.

We can thus obtain an evaluation of the correct and incorrect use of the vehicle's headlight system, taking into account and the duration of the use of the headlights (thanks to the integration of the signal) and of the distances gradually reducing since the beginning of the bearing, without risking having an incorrect assessment influenced by the use of the low beams. Photographic recording can be carried out (FIG. 2) when the vehicle is in position V3 close to switchgear 1 or when it is in position V4 having passed switchgear l, and in both conditions, while that the start of the evaluation can take place at a considerable distance from the apparatus 1, possibly using a control system also automated with range finder, detector, time or other.

FIG. 4 shows an installation diagram (produced in the form of a block diagram) which can also be provided on board a motor vehicle. In MF is indicated the camera, in So the optical sensitive element, in FS the flash or lightning generator; in ST is indicated a means used to signal the presence of a vehicle likely to be dazzled by the headlights of another vehicle occurring in the track under control. In the block diagram, CV designates a converter, TM a timer and AT an amplifier with trigger.

It is understood that the drawing represents only an example given only as a practical demonstration of the invention, this invention being able to vary with regard to the forms and the arrangements, without however departing from the framework of principle on which is based. said invention.

Claims (7)

1. Apparatus for readings and recordings of traffic offenses, by means of photographs taken at the appropriate time and in which data relating to an offense can also be stored, apparatus designed to carry out readings at night and characterized by fact that it includes means for operating with light-type energy in the margins of the visible band. 2. Apparatus according to claim l, characterized in that it comprises means for operating in the frequency band of the low infrared, with limited extension in the region of the visible bands of red. 3. Apparatus according to claim 1, characterized in that it comprises means for operating in the frequency band of the ultraviolet with limited extensions in the visible range. 4. Apparatus according to any one of the preceding claims, characterized in that it comprises filters for selecting the low infrared or ultraviolet respectively on the objective of a camera intended for surveys and on the lightning generator (flash) which is used for photographic recording of the image. 5. Apparatus according to any one of the preceding claims, equipped for the reporting of offenses for misuse of high beams, characterized in that it can include means for integrating the signal for the evaluation of the most or shorter duration of incorrect use of the headlights. 6. Apparatus according to claim 5, characterized in that it comprises a photoelectric cell positioned at the focus of the optical system which explores the lane of the vehicles which arise, to control the use of the headlights, with the particularity that the illumination is concentrated on the photocell as long as the vehicle is distant, while it is defocused and therefore attenuated as the vehicle approaches and the device is capable of discriminating the main beam from the low beam. 7. Apparatus for surveying and recording traffic violations, all as described above and shown by way of example in the attached drawing.

Images