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TECHNICAL FIELD

The present invention refers to an anti-collision system for vehicles.

In particular, the present invention is referred to a system that can avoid collision between road vehicles going in converging directions, for example at intersections.

The invention finds its main application in the automobile field.

BACKGROUND ART It is known that vehicle traffic is seriously penalised, especially in poor visibility conditions, from accidents that cause big impediments to the traffic, and also serious damage to the vehicles and people that are involved.

A great number of accidents happen at intersections in which, especially but not exclusively in built-up areas, the visibility conditions are hardly ever optimal because of the presence of buildings that do not allow the driver to realise if another vehicle is going to cross from another direction the intersection in question.

At the moment their is no device that can intervene in a automatic way to avoid these accidents.

DESCRIPTION OF THE INVENTION The main purpose of the present invention is to supply a simple and economical solution to the problem mentioned above, and to provide in a secure way a system that can avoid accidents between vehicles at intersections.

This is obtained with a system that has the features described in the main claim.

The dependent claims outline the particularly advantageous forms of embodiment of the system according to the invention. The system according to the invention is carried out in two

parts, and more particularly, a fixed part installed at the intersection, and a mobile part which is in the vehicle.

The fixed part uses detectors to survey the passing of a vehicle, for example, these detectors can be represented by metallic conductors buried in the ground, like the ones already in use at the stoplights for the automatic regulation of traffic, modified in a way to signal the presence of a vehicle in movement at least twenty metres before the intersection, the distance of twenty metres represents a minimum distance for the success of our intention, best results are obtained with detectors placed at least fifty metres from the intersection.

According to a feature of the invention, each conductor is buried under the road in a way to obtain a path that has a plurality of tracts parallel between themselves and perpendicular to the direction of movement of the vehicle; in practice, these tracts are disposed transversally to the lane.

In these conductors, in function, electricity passes and forms a electromagnetic field that is influenced by the metallic mass of the vehicles in transit on top of them. This allows the system to reveal not only vehicles stopped at the intersection or the stoplight, but even the variation in the engagement of the conductors and so reveal a vehicle in movement.

This information is elaborated by a central unit, positioned by the intersections, and sent through an adequate transmitter (infrared, radio waves, induction by conductor means) to a receiver positioned in the vehicle coming from another direction.

The part of the system present in the vehicle discriminates the signal that arrives and visualises through an adequate optical and/or acoustic indicator the engagement of the intersection created by other vehicles.

If no vehicle is signalled at the moment of the engagement of the intersection, a signal of clear road will be given to the driver, for example a green light.

According to an advantageous feature of the invention, when a driver is nearing a intersection when the device installed on the vehicle is connected to the device installed at the intersections, a red light and the acoustic signal both activate giving a quick information of engaged intersection as a test of correct functioning of the system.

ILLUSTRATION OF THE DRAWINGS Other features and advantages of the invention will become apparent by reading the following description, given a non- limiting example, with the help of attached drawings in which:

Figure 1 shows a schematic system of the invention installed at an intersection; Figure 2 shows a way of realisation of the mobile part of the system installed in a vehicle; Figure 3 shows a way of realisation of the fixed part of the system installed at an intersection. DESCRIPTION OF A FORM OF EMBODIMENT In the figures, the fixed part of the anti-collision system 10 is provided with a series of electric conductors 11, 12, 13, 14 disposed in a predeterminated draft along the access roads to the crossing in a way to reveal the vehicles 15, 16 in movement; both of the conductors are connected to a electronic system 17, 18, 19, 20 that electrically feeds the conductors and reveals the vehicle. Besides, the system 10 includes a microprocessor 21 that collects the information and codifies it in a way to give the mobile system the information about which road at the intersection is going to be engaged, and a device 22 of transmission to the vehicle of the information of engagement of the intersection.

Figure 2 shows a scheme in blocks of the device installed in the vehicle.

It is made of an adequate receiver 23 that receives the information transmitted from the intersection, an electronic system 24 that decodes the information transmitted and a system

of visualisation 25 of the present situation at the intersection, that includes a couple of optical-acoustic advisors 26, 27.

The alimentation is given by a alimentator 28 connected to the battery 29 of the vehicle.

In figure 1 an intersection is drawn in which the system is installed according to the invention, that works in the following way.

Imagine a vehicle 16 has installed a board a mobile unit that cooperates with the fixed unit placed at the intersection.

The presence of the vehicle 16 in signalled to the central unit 10 which sends the mobile unit a signal that represents the activation of the central unit.

Once a vehicle 15, coming from a different direction of vehicle 16, transits in correspondence of a detector 13, this sends to unit 10 a signal that represents the presence of a vehicle that is approaching the intersection.

At this point, the unit 10 sends a signal that is received from the mobile unit that signals, though the optical-acoustic advisors 26, 27 on board vehicle 16, the arrival of vehicle 15 so the driver of vehicle 16 can take precautions.

When the intersection is not engaged, the central unit sends to vehicle 16 a signal that represents this situation, that can be visualised on board the vehicle 16 through a green light.

The disposition of the conductors can be varied from those represented in the figures, because the information that is represented by variations of the electromagnetic field can be used even as speed detectors of the vehicles approaching. In this case, the information about the speed can be sent through mobile devices installed in vehicles as supplement information, or as automatism of the management of the stoplights or as a trigger for an eventual device that notices speed like the autovelox, or again for other information that can be useful.

As to the use of this system in the extra-urban routes, the problem of the energy feed can be solved with a solar cell, because of the low consumption.

In the case in which the system according to the invention is installed at an intersection managed by a stoplight, it will automatically be operative in case of failure, non-operativity of the stoplight or when the yellow blinking lights are on, instead it will be deactivated when the stoplight functions normally. According to an advantageous form of embodiment of the invention, the system can be equipped with an antisabotage device that can prevent tampering by hooligans or bad- intentioned people.

In case of malfunction of the system, on the mobile device of the oncoming vehicle there will be a signal of ENGAGED INTERSECTION and there will be no blinking (with a short "beep") that indicates that the intersection is equipped with an anti- collision device and that it is efficient, so the driver will have to check, himself, if the intersection is engaged. The invention has been previously described referring to a preferable form of embodiment thereof.

Yet the invention is susceptible to several variants that fall within its scope.

Therefore, the invention comprises forms of embodiment according to which the detectors of the passing vehicle are made of different devices than the buried conductors; for example, these detectors can be electro-optical devices, magnetic, radio frequency, infrared, radar, photoelectric barriers, mechanic and/or hydraulic pressure sensors. In the same way the transmission system of the data to the vehicle can use radio waves, infrared, or other adequate systems for this purpose using electromagnetic waves.

The system according to the invention is described according to a preferential form of embodiment, in compliance that the intersection taken in consideration is of two roads.

Of course, the system can be used even in correspondence to other types of intersections, for example when a road crosses a railroad, in this case the detectors are positioned along the rails and the signal of train arriving can be eventually used for the automatic lowering of the railroad crossing bars.