Traffic control system for signaling on time any obstruction on a road network

Abstract: Traffic control system for signalling timely any obstruction on the road determined by accidents, ja ns etc., in order to signal the presence of still motor-vehicles to the vehicles being arriving. Control system comprising a plurality of autonomous detecting units (10), co-operating with analogous units distributed along the road, and each comprising a control plant (11) formed by sensor means (13,14) of the presence of motor-vehicles, a timer unit (15) receiving the signals provided by the sensor means when the vehicles are passing and letting only a signal longer than a pre-established time to pass, in the case in which a vehicle column has been formed, and a central control unit (16) receiving the signals from the sensor means (13,14) and the timer unit (15) and adapted to control alarm means (17,18) when the column is formed and radio-transmitter units (19,20) and radio-receiver units (21,22) The system is housed inside an envelope (27) shaped preferably like a kerbstone¸

Description: The invention concerns a control system for roads and motorways adapted to signal timely to the arriving motor vehicles the presence of any obstructions still along the roads, which system therefore is particularly suitable in the case of accidents on fog or inside tunnels, jams etc.. From FR-A-2693582 is known a safety warning system comprising a plurality of vehicle detecting units shaped as kerbstones, disposed spaced away along the road and each comprising a control plant with an electric supply voltage, which is co-operating with the other detecting units and is composed of sensor means of the presence of motor-vehicles, adapted to generate signals in presence of motor-vehicles, and of timer means, adapted to measure the time in which a vehicle has passed the distance between one detecting unit and the next one along the road, which measure is transmitted as a signal along a cable to the subsequent detecting units. In this manner, if this vehicle arrives in front of the subsequent detecting unit within the time measured by the preceding detecting unit, this means that such vehicle is regularly running on the road. On the contrary, if this vehicle isn't detected by this subsequent detecting unit, after that the measured time has lapsed, this means that such vehicle is no more running on the road and therefore has stopped to run, and represents a dangerous obstacle (traffic jam) for the other vehicles running on the same road, and such situation is detected and transmitted as signals along the cable to the preceding detecting units, by activating also their alarm systems. The object of the invention is to provide a traffic control system made in a manner different that that disclosed by the FR-A- 2693582, having the scope defined by the appended claims. This object is attained with a traffic control system made with the constructive characteristics described in the patent claims. The invention will be better understood from the following description, given solely by way of not-limiting example and with reference to the attached drawings, wherein : Fig. 1 shows the block diagram of the component parts of an unit of the present control system; Fig. 2 shows a perspective view of front part of an unit included in the present traffic control system; Fig. 3 shows a perspective view of the back part of the unit of Fig. 2; Fig. 4 shows a perspective view of a portion of motorway equipped with the system according to the invention. The present invention which will be described hereinafter concerns a system 8 (see Fig. 4) for signalling and detecting timely any traffic obstruction caused both to an accident or a jam of motor-cars so as to determine anyway a speed reduction of the same cars on the road stretch controlled by the same system. Such system 8 for detecting almost still cars 9 is constituted by a plurality of autonomous detecting units 10 having an electric supply voltage therein, each one of which is provided with at least a control plant 11 (see Figs. 1 and 2) composed of a plurality of electric and electronic component parts, each of which performs a specific function and contemporaneously, by interacting both directly with the other component parts of the same control plant and with similar control plants 11 of further detecting units 10, permits to signal the detected situation to the cars being arriving on the controlled road stretch, thereby allowing the timely speed reduction and/or stopping of these cars. As evident from Fig. 1, the control plant 11 is included in an envelope shaped housing preferably like a kerbstone 12 having a vertical extent (figs. 2 and 3), and comprises substantially a car sensor for detecting the presence of cars, which is normally formed by an emitting unit 13 and a receiving unit 14 of electromagnetic, luminous or sound or the like signals (i.e. a photoelectric cell, a radar, a laser unit etc..) adapted to detect the presence of motor-cars between the emitting unit 13 and a possible bounce screen 28 situated along the road and the opposite receiving unit 14, or also to detect a reduction of the free spaces in front of the motor-vehicles (Fig. 4). These sensors have a very low hysteresis and therefore are able to reset themselves in a very short time in the case of too intensive traffic, since between the passage of a car and a subsequent one it exists an interval which will be called blank interval, namely without traffic, in which the sensor does not detect obstacles and leaves off transmitting signals and resets itself namely zeroizes its function. The control plant also comprises a timer unit 15 acting as a filter adapted to receive all the signals coming from the sensor and to let pass only a signal coming from the sensor and of continuous type and longer than a pre-established time, for example 5 sec. In turn, the unit 15 is interfaced with a component part acting as a general control and managing central unit 16. Such general control and managing central unit 16, when the signal coming from the units 13, 14 and 15 arrives, provides to supply the optical alarm device 17 which is constituted for example by a yellow blinking lamp suitable for the fog, and which will emit a luminous beam in the direction of the coming motor-cars. A possible sound alarm device 18 will provide to inform the near car drivers that the system is operating. The central control unit 16 is additionally connected to radio-transmitter and receiver units, in the example constituted by four radio units 19, 20, 21 and 22, of which the units 19,20 are constituted by a radio-transmitter units respectively with low and high range of diffusion and the units 21 and 22 are constituted by radio-receiver units all provided with suitable antenna and respectively with high and low range of diffusion. In particular, in the case of traffic jam, detected by the traffic presence sensor, the central control unit 16 will receive such traffic jam information through the sensor and the timer unit 15, and as response thereof will generate a corresponding control signal which will be transmitted to the radio-transmitter unit 19, which therefore will transmit an electromagnetic signal with low (namely limited) range of diffusion (for example 200 m), which will be received from the next detecting units 10 in the manners and with the consequences which will be described. In turn, the radio-receiver unit 22 has the object, when a signal coming from other detecting units 10 arrives, to transmit an impulse to the general control central unit 16, which provides to activate the optical alarm device 17 connected thereto, in which condition such optical alarm device 17 is therefore activated only when receiving the radio signal and not the signals coming from such traffic presence sensors. Moreover, in this case the central unit 16 does not provide to generate radio signals and sound alarm signals, except in the condition, for example in the tunnel, which will be considered later on. Consequently, all the optical alarm devices of the system are activated (in the example in the 200 m. range), whose radio receiver units 22 are syntonized on the frequency of the radio-transmitter units 19, and therefore it is determined a situation of danger warning for the drivers being passing along all the way and on the same running direction. This is made possible also by the fact that all the radio units are provided with a band selector, not shown, and in particular the radio units 19 and 22 operate with at least two different radio frequencies, which are utilized for the two different running directions provided in the same road way. In the case in which the control system according to the invention be arranged inside tunnels, in order to avoid any car jam inside such tunnels, it is necessary that the emergency luminous signal reaches not only the detecting units situated in the next neighbourhoods (namely 200 m. as stated previously) but also other detecting units which are placed at the tunnel inlet, thereby avoiding the danger that additional cars enter the same tunnel when it is already jammed. To this purpose, the central unit 16 comprises a selector, not shown, which is operable in the case of arrangement of detecting units inside tunnels, which is adapted to determine, in the case in which it receives a radio signal from a further detecting unit, not only the activation of the optical alarm device, but also the emission of the radio signal with the radio-transmitter unit 19, so as to diffuse such signal up to the desired distance. The detecting units disposed inside tunnels are supplied directly by the electric circuit included therein, through adequate adapter circuits. In the case in which the central unit 16 receives a signal through the sensor and the unit 15, such central unit causes the radio-transmitter unit 20 to emit a radio signal with long range of diffusion, which is syntonized with the official road checking boards such as police, motorway society etc.., thereby informing them of the emergency condition which has been determined. These official boards can transmit a pre-established radio signal to the radio-receiver units 21 which, upon recognizing such signal interact with the central unit 16, and therefore are able to interrupt the emission of the signal by the unit 20. The central unit 16 is also connected with an outer control unit such as a selector 23, which can be attained from the outside by means of skilled personnel and suitable means, and said selector has the function either to activate or de-activate the relative electronic control plant 11 in the case of failure thereof, or also to activate the control system for the distance respectively affected, for example in the case of works being carried out. Such selector can be constituted also by a remote control which is active on the central unit 16, performing the same function of the same selector. Besides, the control plant 11 is provided preferably with an autonomous supply voltage unit composed for example of a photosensitive cells panel 24 which, by interacting with a storage battery charge control unit 25, which is connected thereto, provides to guarantee a steady maximum charge to the supply batteries 26 included in the control plant, thereby keeping the detecting unit 10 always under voltage. Furthermore, such control plant 11 may be supplied also from outer and separated electric supply voltages. When the signals coming from the sensor and the units 15 and 22 are ceased, when the car jamming situation has been eliminated, the central unit 16 of each control plant resets itself, and arrange itself again to perform the function of traffic watch. In the Figs. 2 and 3 it can be seen a possible embodiment of the detecting unit 10, in each one of which the electronic assembly composing the control plant 11 is housed, wherein the receiving unit 14 and the emitting unit 13 are housed on the kerbstone upper part, turned toward the road, at such a position as to be able to check the area in front thereto, while the blinking light or the optical alarm device 17, possibly paired with the reflex reflector 26', are housed on the part of the kerbstone turned toward the passing cars. In turn, the sound alarm unit 18 can be housed inside the kerbstone envelope 27. As visible from the Fig. 3, the safety selector 23 and the photosensitive cells panel 24 are housed on the back side of the envelope 27, while also a lid (not shown) is provided, permitting the access therein, before arranging the detecting unit 10 in a definitive manner, for selecting the radio frequencies to be used in the control system and in particular for selecting the signal used for a specific car running direction and for the possible return of the possible existing radio signal in the case in which the system is arranged inside tunnels. In the Fig. 4 it can be seen a portion of the control system 8 during the step of alarm condition signalling (road with running direction right to left) and a portion of control system 8' during the step of normal signalling (road with running direction left to right), and in this case such systems are provided operating with infrared sensors by way of not-limiting example only. The Figure shows only a control system portion, which can be constituted by at least two and also further detecting and control units 10 which are installed and formed as described previously, which are positioned spaced more or less regularly along the road, and have the emitting units 13 and the receiving units 14 turned toward the road center, while on the opposite side of the road there are placed the reflecting or bouncing screens which, in the case of absence of obstacles, return the signal coming from the emitting unit 13 back to the receiving unit 24, while they do not return back more such signal in the case of presence of obstacle, in which condition after the pre-established time of some sec. is lapsed the alarm signal is activated. Therefore, if for example the cars 29 and 30 have caused an accident, so as to form an obstacle situated in a position coinciding with the control unit 10' and therefore with the relative sensor 13, this latter as soon as the pre-established time is lapsed (for example 5 sec.) provides to start the process with consequent : voltage supply of the associated blinker 17, the associated sound alarm device 18 and emission of radio signals from the relative transmitting unit 19, which causes all the optical alarm devices provided on the operation range of such emitting unit to be activated, which devices are represented in the exemplifying drawing by the control units 10", 10"', 10iv, which are syntonized on the same frequency and concern only the running direction on which the obstruction is happened, while on the other running direction the traffic is normal. When a queue is formed, also the control units 10'', 10''' etc.. will be activated by signalling progressively and timely in advance the alarm condition corresponding to the column of cars being stopped to the cars being arriving. A possible control unit such for example the unit 10v which might not signal the jamming condition since it is operating among still motor-vehicles or since it is not operating owing to a failure, will not prejudice excessively the system since in such case its function will be performed by the subsequent control unit, indicated with the number 10iv in our example, which unit therefore will provide to signal timely the danger situation to the car 33 being arriving, which will be able to brake timely. Finally, thanks to the fact of being able to be interfaced through the receiving units 22 and the transmitting units 20 with the checking boards such as police and motorway society etc.., and to be able to be identified on sets, the control system 8 can be activated per unit sets by these checking boards such for example in the case of dense fog, in a manner to let the blinkers 14 performing not only the deterrent function but also the function of making visible the road references such the road side.

Claims: Traffic control system for roads and motorways, adapted to signal timely to the arriving vehicles any traffic obstruction caused by either an accident or a jam of motorcars, comprising a plurality of autonomous vehicle detecting units (10) disposed spaced away along the road and each comprising at least a control plant (11) having an electric supply voltage, a charge control unit (25) and batteries (25), said control plant (11) being included in a housing having a vertical extent, and including sensor means (13,14) detecting the presence of motor vehicles, said sensor means being formed by an emitting unit (13) and a receiving unit (14) of electromagnetic, luminous or sound signals. The vehicle detecting units (10) further comprising a timer unit (15) adapted to receive all the signals coming from said sensor means (13,14), a control central unit (16) and alarm means (17,18) comprising an optical alarm device (17) and/or a sound alarm device (18). The vehicle detecting units (10) further comprising radio transmitter units (19,20) and radio receiver units (21,22) connected to said central control unit (16), characterized in that said timer unit (15) is interfaced with said central control unit (16) and is adapted to let pass only a signal coming from said sensor means (13,14) and of continuous type and longer than a pre-established time on the condition of traffic jam, and said control central unit (16) will receive, in the case of traffic jam detected by said sensor means (13,14), a traffic jam notification through said sensor means (13,14) and said timer unit (15), and as response thereof will generate a corresponding control signal which will be transmitted as electromagnetic signal to said radio-transmitter units (19,20), whose signal is transmitted to the radio-receiver units (21,22) of a next detecting unit (10), which in turn transmit a corresponding impulse to the associated central control means (16) for activating their own alarm means (17,18). Traffic control system according to claim 1, characterized in that said sensor means (13,14) have a very low hysteresis and are able to reset themselves in a very short time in the case of too intensive traffic. Traffic control system according to claim 1, characterized in that said control unit (16) comprises selector means, which can be operated in the case in which said detecting units (10) are disposed inside tunnels, and which are adapted to activate not only said alarm means (17,18) but also said radio-transmitter units (19,20) and said radio-receiver units (21,22). Traffic control system according to claim 1, characterized in that said central control unit (16) is also connected to an outer control unit (selector 23), which can be operated by means of skilled personnel and suitable means, or also by a remote control, so as to activate or deactivate the relative electronic control plant (11) in the case of failure thereof or also to activate the control system solely for the affected distance, for example in the case of works being carried out. Traffic control system according to claim 1 and 3, characterized in that each vehicle detecting unit comprises two radio-transmitter units (19,20), one with a low range of diffusion and the other with a high range of diffusion, and two radio-receiver units, one with a low range of diffusion and the other with a high range of diffusion.

Inventors: REGAZZO OLINDO, SOMMA FAUSTO, REGAZZO, OLINDO, SOMMA, FAUSTO
Applicants: REGAZZO OLINDO, SOMMA FAUSTO, REGAZZO, OLINDO, SOMMA, FAUSTO
Application year: 2001
Main classification: G08G1
IPC codes: G08G1