The present invention refers to a system and to a method for detecting anomalous overheating in moving road transport vehicles, like for example lorries, buses, auto mobiles and/or motor vehicles.

In order to prevent fires from starting inside substantially closed environments in which vehicles can transit, like for example particularly long tunnels, it is wished to be able to detect anomalous overheating in transiting vehicles before they enter into such environments .

It can indeed happen, in particular in heavy vehicles like lorries or buses, that the brake group is overheated due for example to an accidental locking thereof .

As long as the vehicle is moving out in the open air, the overheating effect is mitigated, but once in the tunnel, and possibly forced to stop in it due to traffic, the overheating of the brake group can lead to fire. Such a phenomenon is promoted by the fact that inside the tunnel the temperature is greater than outside, since there can also be no ventilation given by movement.

Analogous phenomena can occur in closed or underground garages or warehouses in which, when stopping, therefore when the overheated parts of the vehicle are still at high temperature, there is no ventilation from movement .

Nowadays, it is known to detect the overall temperature of the moving vehicles through the use of infrared video cameras also known as thermal cameras, at the entrance of tunnels, arranged at the sides of the lane where the vehicle is moving.

Through the continuous capture of images carried out by- thermal cameras there is a brief inspection of the side thermal image of the transiting vehicle so as to prevent vehicles in danger from accessing the tunnel. The detection of the thermal image is generally associated with a digital processing of the image that makes it possible to recognise hot spots in the photograph and, therefore, to identify overheating.

The detecting systems used today are unfortunately not very accurate .

On one hand, the thermal cameras available on the market today have difficulties detecting moving objects in a precise manner.

On the other hand in known systems the image of the entire vehicle is captured detecting also areas that are necessarily hot but not dangerous, like for example at the exhaust .

If operated automatically, such a system tends to therefore generate different false alarms, making it practically impossible to create algorithms that make it possible to correctly discriminate dangerous overheating from safe overheating. The supervision by a worker is thus essential.

The purpose of the present invention is that of avoiding the aforementioned drawbacks and in particular that of conceiving a system and a method for detecting anomalous overheating in moving road transport vehicles that offer measurements that are much more accurate with respect to those obtained today with known systems, making it possible to identify actual dangerous overheating, like that generated by a locking of the brake group .

Another purpose of the present invention is that of providing a system for detecting anomalous overheating in moving road transport vehicles that does not substantially generate false alarms.

A further purpose of the present invention is that of making a method for detecting anomalous overheating in moving road transport vehicles that can be made automatic requiring minimum intervention by workers. These and other purposes according to the present invention are achieved by making a system and a method for detecting anomalous overheating in moving road transport vehicles like outlined in the independent claims .

Further characteristics of the system and of the method for detecting anomalous overheating in moving road transport vehicles are object of the dependent claims. The characteristics and the advantages of a system and of a method for detecting anomalous overheating in moving road transport vehicles according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, with reference to the attached schematic drawings, in which:

figure 1 is an elevation schematic view of one embodiment of the system for detecting anomalous overheating in moving road transport vehicles according to the present invention;

- figure 2 is a schematic perspective view highlighting the area of the road transport vehicle of which the temperature is detected;

- figure 3 is a top schematic view of a vehicle moving through the system for detecting anomalous overheating in moving road transport vehicles of figure 1;

figure 4 is a graph representing synchronising signals of the detection that make it possible to identify the exact transit of the area to be detected at the sensors;

- figure 5 is a block diagram of one embodiment of the method for detecting anomalous overheating in moving road transport vehicles according to the present invention.

With reference to the figures, a system for detecting anomalous overheating in moving road transport vehicles is shown wholly indicated with reference numeral 10. The detecting system 10 according to the present invention comprises a path for the forward movement 11 of a road transport vehicle 20 (hereafter in brief also only vehicle 20) in which at least one seat 17 is formed, preferably arranged in a central portion 11a of the path of forward movement 11, inside which at least one infrared temperature sensor 12 is housed.

The at least one temperature sensor 12 can be arranged partially protruding, recessed or flush with respect to the road surface defined by the path of forward movement 11.

In a preferred manner, the at least one temperature sensor 12 is arranged substantially flush or slightly recessed with respect to the road surface defined by the path of forward movement 11 so as to minimise possible damage to the sensor 12 due to collisions.

Preferably, two infrared sensors 12 are foreseen so as to be able to simultaneously detect overheating on both sides of the vehicle 20.

Each temperature sensor 12 is provided with an optical group 13 oriented so as to receive a beam of infrared radiation emitted by a wheel-brake group 21 of a vehicle 20 moving along the path 11 and to direct it, directly or indirectly, towards an infrared detector

(not illustrated) . The amount of radiation emitted by a particular area is indicative of its temperature.

In the advantageous embodiment in which the sensors 12 are arranged in the central portion 11a of the path of forward movement 11, the optical group 13 is oriented so as to receive a beam of infrared radiation emitted by the inner side of the wheel-brake group 21.

Preferably, the optical group 13 of a first left sensor 12 is oriented so as to receive a beam of infrared radiation emitted by the inner side of the right wheel- brake group 21 of the vehicle 20 and, vice versa, the optical group 13 of a second right sensor 12 is oriented so as to receive a beam of infrared radiation emitted by the inner side of the left wheel-brake group 21 of the vehicle 20.

In particular, the optical groups 13 are oriented so as to receive the infrared radiation emitted by an area 14 of the inner side of the wheel-brake group 21 located below the corresponding axle 22 of the vehicle 20 and that covers at least one portion of the brake group 21a and at least one portion of tyre 21b.

Preferably, infrared sensors 12 of the mercury-cadmium- tellurium type are used having high sensitivity even for distant heat sources detecting wavelengths of between 3-5 μm.

The infrared sensors 12 are also connected to a processing unit of the received radiation, arranged for example inside a control panel 15, suitable for processing the temperature of the detected area 14 and for identifying possible overheating.

In order to ensure that the infrared sensors 12 are activated at the transit of each wheel-brake group 21, means 16 for detecting the transit and the speed of such a group 21 are also provided.

The detection means 16 are arranged along the path 11 of the passing vehicle 20 upstream of the sensors 12 with respect to the forward movement of the vehicle 20. Once the transit of a wheel-brake group 21 has been detected and its speed has been calculated, the time T necessary for the wheel-brake group 21 to reach the position at the temperature sensors 12 is determined. Once the calculated time T has passed, the sensors 12 are consequently activated.

Otherwise, the sensors can always be active and the calculated time T is used for determining within the detection which measurements relate to the transit of the wheel-brake group 21.

The transit detection means 16 are preferably two optical barriers 16a, 16b arranged at a height from the ground such as to be interrupted only when a wheel- brake group 21 passes.

The optical barriers 16a, 16b can be of the infrared or laser type or of the type with other technology suitable for particular applications.

Preferably, a first optical barrier 16a is arranged at about 10m upstream of the infrared sensors 12 along the direction of forward movement of the vehicle 20, whereas a second optical barrier 16b is arranged at only a few centimetres upstream of such sensors 12.

Based upon the two measurements arranged at a short distance apart, it is possible to determine the speed at which the vehicle 20 is travelling and, consequently, to calculate the time necessary to reach the temperature sensors 12.

In particular, the means 16 for detecting the transit are implemented so as to correctly drive the activation of the temperature sensors 12 for each vehicle 20 that passes along the path at a speed of between 5 km/h and 50 km/h, and preferably between 5 km/h and 100 km/h. Moreover, the detecting means 16 are capable of correctly driving the activation of the temperature sensors 12 even when there is an acceleration of the vehicle 20 between the two measurements carried out, as long as the acceleration remains constant during the measurement time period.

Thanks to the particular arrangement of the temperature sensors 12 and to the transit detection means 16 it is ensured that exclusively the temperature of the areas the overheating of which can really be dangerous is precisely detected.

In such a way different false alarms are avoided, since each overheating detected indeed refers to a situation of possible emergency.

The operation of the system 10 for detecting the anomalous overheating in moving vehicles is as follows. First of all the approach of a wheel-brake group 21 of a vehicle 20 is detected (step 110) and the point in time of transit of such a group 21 is determined (step 120) at at least one infrared temperature sensor 12. Preferably, the approaching of the wheel-brake group 21 is detected through a first optical barrier 16a that generates a first signal 50 and a second optical barrier 16b arranged at a short distance from the first 16a along the direction of forward movement of the vehicle 20, which generates a second signal 51.

The time difference ΔT between the generation of the two signals 50, 51 is used to determine the speed of the forward movement of the vehicle 20 based upon the fixed and known distance between the two optical barriers 16a, 16b.

In turn, the speed of the forward movement of the vehicle 20 is used to determine the point in time in which the wheel-brake group 21 passes the at least one infrared temperature sensor 12 arranged at a known distance from the optical barriers 16a, 16b along the direction of forward movement of the vehicle 20.

At the determined point in time of transit, the at least one infrared temperature sensor 12 is activated and the infrared radiation emitted by the area 14 of the inner side of the wheel-brake group 21 located below the corresponding axle 22 of the vehicle 20 and that covers at least one portion of the brake group 21a and at least one portion of tyre 21b, are received (step 130) .

Otherwise, in the case in which the sensors 12 are always active, the determined point in time of transit is used to identify, inside the entire detection, which measurements refer to the passing of the wheel-brake group 21.

The received radiations are processed (step 140) to generate a temperature signal 53 that, through the comparison with a threshold temperature value, makes it possible to correctly and reliably identify overheating.

The comparison (step 150) of the detected temperature can lead to different types of alarms.

As an example, an absolute temperature threshold can be defined beyond which an absolute alarm signal is generated. Otherwise, it is possible to define a relative temperature threshold, in order to take into account the influence of the surrounding temperature on the seriousness of the overheating.

Finally, it is also possible to evaluate the difference between the detected temperature and an average temperature value comparing it with a specially defined temperature threshold, beyond which a relative alarm is generated.

From the description made the characteristics of the system and the method for detecting anomalous overheating in moving road transport vehicles object of the present invention should be clear, just as the relative advantages should also be clear.

Indeed, the system for detecting anomalous overheating in moving road transport vehicles according to the present invention focuses the detection only in those areas the overheating of which could actually be dangerous, offering in such a way very accurate results .

False alarms generated by the system are thus substantially reduced, thus allowing reliable automation of the system and requiring minimal intervention by a worker.

Finally, it should be clear that the system and the method for detecting anomalous overheating in moving road transport vehicles thus conceived may undergo numerous modifications and variants, all covered by the invention; moreover, all the details can be replaced by technically equivalent elements. In practice the materials used, as well as the sizes, can be any according to the technical requirements .