ACCESSORY FOR VEHICLES FOR AUTOMATING MAIN BEAMS COMPLETE WITH AN ELECTRONIC SYSTEM FOR REDUCING OPTICAL DISTURBANCES

Abstract

The electronic device described in the present patent application applies to the accessories used to automate the main beams that use sensors to detect the light coming from the vehicles met along roads. The device reduces or even suppresses the undesired effects produced by reflections, onto the surrounding objects, of the lights of the vehicle on which it is mounted, thus avoiding undesired main beam turn-off signals. Said device is particularly convenient to use if mounted after the vehicle is commissioned, being it compatible with wireless transmission systems which make its installation easier.

Claims

1-12. (canceled)

13. An accessory for vehicles to automate the turn-off and the turn-on of the main beams, comprising: one or several photo-detectors; a main beam turn-off and turn-on control circuit comprising a central processing unit which runs a program stored in a memory and controls a switch which makes said main beams turn on or off; an analysis circuit analyzing electrical signals generated by said one or several photo-detectors comprising a decision circuit, a central processing unit which runs a program stored in a memory, and a comparator which compares the signal coming from said one or several photo-detectors to a trigger signal, corresponding to the relative dark signal, generated by said central processing unit; a wireless transmit assembly connected to said analysis circuit which transmits the signal received by it; a wireless receive assembly, connected to said control circuit, which receives the signal from said wireless transmit assembly; and a battery which supplies power to said one or several photo-detectors, to said analysis circuit and to said transmit assembly; wherein said program of said main beam turn-off and turn-on control circuit and said program of said analysis circuit share a timing sequence, whose execution is coordinated via said wireless transmit assembly and said wireless receive assembly, so that the sequence of said trigger signal is synchronous with the main beam turn-on and turn-off sequence; wherein said comparator outputs a reflection or blank signal toward said central processing unit of said analysis circuit whenever the magnitude of said signal from said one or several photo-detectors is greater than the magnitude of said trigger signal; wherein in the presence of said reflection or blank signal, said central processing unit of said analysis circuit sends to said main beam turn-off and turn-on control circuit a reflection or blank signal and therefore causing the main beams to be turned-on again.

14. The accessory according to claim 13, wherein said program of said main beam turn-off and turn-on control circuit and said program of said analysis circuit start being run under the control of said decision circuit which activates said central processing unit of said analysis circuit which in turn starts the transmission of said wireless transmit assembly.

15. The accessory according to claim 14, wherein said timing sequence makes said main beam turn-off and turn-on control circuit turn-off said main beams at least two times.

16. The accessory according to claim 15, wherein said program of said main beam turn-off and turn-on control circuit and said program of said analysis circuit start being run thereafter in the presence of said signal sent by said decision circuit after a pre-determined delay time.

17. The accessory according to claim 16, wherein said pre-determined delay time is one second.

18. The accessory according to claim 15, wherein said main beam turn-off and turn-on control circuit, in the absence of said reflection or blank signal, makes the main beams turn-on again after three seconds.

19. The accessory according to claim 14, wherein said main beam turn-off and turn-on control circuit, in the absence of said reflection or blank signal, makes the main beams turn-on again after three seconds.

20. The accessory according to claim 14, wherein said program of said main beam turn-off and turn-on control circuit and said program of said analysis circuit start being run thereafter in the presence of said signal sent by said decision circuit after a pre-determined delay time.

21. The accessory according to claim 20, wherein said pre-determined delay time is one second.

22. The accessory according to claim 20, wherein said main beam turn-off and turn-on control circuit, in the absence of said reflection or blank signal, makes the main beams turn-on again after three seconds.

23. The accessory according to claim 13, wherein one of said one or several photo-detectors is dedicated to detecting all or some of the light emissions comprised in the range of the wavelengths from 620 to 700 nm.

24. The accessory according to claim 23, wherein upstream said photo-detector dedicated to all or some of the light emissions comprised in the range of the wavelengths from 620 to 700 nm there is installed a filter of a type that lets at least some of the light emissions comprised in the range of the wavelengths from 620 to 700 pass through.

25. The accessory according to claim 24, wherein said filter is an optical filter.

26. The accessory according to claim 13, wherein said timing sequence makes said main beam turn-off and turn-on control circuit turn-off said main beams at least two times.

27. The accessory according to claim 13, wherein said program of said main beam turn-off and turn-on control circuit and said program of said analysis circuit start being run thereafter in the presence of said signal sent by said decision circuit after a pre-determined delay time.

28. The accessory according to claim 27, wherein said pre-determined delay time is one second.

29. The accessory according to claim 13, wherein said analysis circuit comprises an equalizer filter which suppresses one or several frequency components of the signal coming from said one or several photo-detectors before it is input to said comparator.

30. The accessory according to claim 13, wherein said central processing unit and said program memory of said analysis circuit are contained in a microcontroller.

31. The accessory according to claim 13, wherein said processing unit and said program memory of said main beam turn-off and turn-on control circuit are contained in a microcontroller.

32. The accessory according to claim 13, wherein said main beam turn-off and turn-on control circuit, in the absence of said reflection or blank signal, makes the main beams turn-on again after three seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows a typical installation on a vehicle (A) of an accessory for automating the turning off and on of full beam headlights in the presence of a vehicle that meets it. The figure shows a box (20) housing an analysis circuit (1) and boxes (21, 22) accommodating the control circuits (2) relevant to the right and left headlights.

[0044] FIG. 2 shows an example of how can the objects surrounding the vehicle (A), and in particular the reflecting road sign (C), interfere with the operation of the analysis circuit located inside the box (20).

[0045] FIG. 3 shows a particularly compete embodiment of the analysis circuit (1) usually housed inside said box (20), in the case of a single photo-detector. The light beam, represented by an arrow, is incident on a photo-detector (3) which emits a signal which is processed by a decision circuit (4) and compared by a comparator (7). The figure also shows an equalizer filter (6), a microcontroller (5), and a wireless transmit assembly (8).

[0046] FIG. 4 shows the functional diagram of an embodiment of the control circuit (2) which is usually placed inside either of said boxes (21, 22). The figure also shows a wireless receive assembly (9), a microcontroller (10), a switch (11), and a full-beam headlight or shortly main beam (12) which emits a light beam represented by an arrow. The figure does not show the source used to supply power to the component elements, which is usually the 12 V or 24 V battery of the vehicle, nor other signals, including, for instance, that used by the driver to activate or deactivate the accessory manually. In a convenient embodiment, should the driver wish to bypass the operation of the accessory, appropriate signals can be sent via the power supply circuit.

[0047] FIG. 5 shows the operation of the analysis circuit (1). In the first line there is the signal coming from the decision circuit (4), in the second line the signal from the photo-detector, also via an equalizer filter, in the third line the trigger signal whose sequence is determined by the microcontroller (5), and in the last line the outcome of the comparison carried out to check for the presence of a reflection possibly determined by surrounding objects. In the second line a horizontal line indicates the value for the relative dark condition.

[0048] FIG. 6 shows the operation of the control circuit (2). In the first line there is the signal input from the wireless receive assembly, in the second line the control signal sent to the switch, whereas the last line highlights the reflection cases which determine an extension of the transmission time, as apparent from a comparison to the first line. In the second line the main beams turn off as soon as the value is in the upper position.

[0049] FIG. 7 shows a flow chart of the operating logic of an embodiment of the microcontroller (5) of the analysis circuit which comprises the following operations: [0050] (51) microcontroller operation triggered by the decision circuit (4); [0051] (52) turn on and off sequence transmission control sent to the wireless transmit assembly (8); [0052] (53) trigger signal sent to the threshold comparator (7); [0053] (54) checking for the presence of a reflection or blank signal from the threshold comparator (7); [0054] (55) blank signal sent to the threshold comparator; [0055] (56) wait; [0056] (57) stand-by.

[0057] FIG. 8 shows a flow chart of the operating logic of an embodiment of the microcontroller (10) of the control circuit which comprises the following operations: [0058] (101) check for the presence of a turn on and off sequence start signal from the wireless receive assembly (9); [0059] (102) sequence start command sent to the switch (11); [0060] (103) check for the presence of a blank signal from the wireless receive assembly (9) [0061] (104) 3 seconds wait, while the headlights are turned off; [0062] (105) headlight turn on control signal sent to the switch (11).

[0063] FIG. 9 shows a functional diagram of a Schmitt comparator (12) which compares the signal from the photo-detector to the relative dark during the sequence set by the central processing unit.

[0064] FIG. 10 shows an embodiment of the analysis circuit (1) complete with a red sensor (32), i.e. with a photo-detector dedicated to the light emissions whose wavelengths range from 620 to 700 nm.

[0065] Installed upstream the red sensor (32) is an optical filter (31), whose function is to let the radiations corresponding to the red tone pass through while rejecting the others.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0066] In a particularly complete and cost-effective embodiment that makes use of microcontrollers, the accessory with an electronic system for deleting disturbances according to the present patent application comprises two silicon photodiodes housed in a box (20) with two holes facing the same side. An optical concentration system is applied to either of these holes, whereas a filter is applied to the other. Said box (20) includes appropriate means for being secured to the inside of the windscreen of a vehicle or to another appropriate position.

[0067] The box accommodates inside an analysis circuit (1) which analyses the electrical signals produced by said two photodiodes, which comprises a decision circuit (4) which outputs a signal whenever such a light beam is incident on the photo-detectors so as to indicate the presence of another vehicle coming from the opposite direction.

[0068] The mode of use whereby two photodiodes are used instead of one detector is known in the present status of the art, for instance that described in ITFI20130072.

[0069] In the embodiment here described said analysis circuit also comprises a microcontroller (5) equipped with a transmit firmware resident in the indelible internal storage, and an equalizer filter (6) which suppresses the alternating component produced by the public lighting, which usually receives power from the 50 Hz or 60 Hz public distribution networks, and a threshold comparator (7).

[0070] Said analysis circuit (1) receives power from a battery which also supplies power to said one or several photo-detectors and to said transmit assembly.

[0071] The central processing unit of said microcontroller (5) performs the instructions stored in the transmit firmware and at least generates a signal output to a transmit assembly (8) and a signal output to said threshold comparator (7). The signal output from the latter is fed back as an input to the same microcontroller (5).

[0072] The signal output from the microcontroller (5) to the wireless transmit assembly (8) is sent to a wireless receive assembly (9) connected to a main beam turn off and on control circuit.

[0073] Said control circuit (2) comprises a microcontroller (10) equipped with a receive firmware resident in the indelible internal storage and an electronic switch which, in a preferred embodiment, is of the MOSFET type.

[0074] Both firmwares contain one and the same sequence which, in the case of the receive firmware, causes the headlights to turn on and off whereas, in the case of the transmit firmware, it determines the trigger signal that is sent to said comparator (7) by said microcontroller (5).

[0075] In other words, said comparator (7), which is a Schmitt trigger in a preferred embodiment, compares the signal from said photodiodes to a trigger signal that represents a synchronized dark signal, corresponding to the programmed main beam turn off and on sequence. Since the trigger signal sequence is equal to the main beam turn off and on sequence, said comparator (7) checks whether a light beam remains in the absence of the reflected light beam of the full beam read lights of its own vehicle.

[0076] If, the full beam headlights not being turned on, the photodiodes indicate the presence of a light beam, then it is assumed that this is produced by a vehicle that is going to be met, otherwise it is a matter of a reflection or blank due to a reflection onto surrounding objects.

[0077] So this condition is detected by the comparator which sends a reflection signal to the microcontroller which inserts it into the output signal addressed to said wireless transmit assembly (8) which sends it to the wireless receive assembly (9). Having been received by the microcontroller (10), the reflection signal causes the headlights to immediately turn on again. In the absence of a reflection signal, the receive microcontroller holds the turn off condition for a given period of time. The latter can vary from two seconds to five seconds and preferably equals three seconds.

[0078] The activation of the transmit microcontroller is controlled by said decision circuit (4), immediately upon detecting a condition whereby there is a risk of dazzling an incoming vehicle. This progressive activation of the different elements of the accessory results in an important energy saving which safeguards the battery used to supply power to the circuit contained in said box (20).

[0079] In a preferred embodiment the time sequence of the receive firmware features a turn off duration ranging from 10 to 100 ms alternating to equal turn on intervals. In the embodiment here described, both said turn off duration and said interval last 20 milliseconds.

[0080] Conveniently can the sequence include some repetitions of the turn off and on sequence so as to prevent inaccurate detections due to objects that determined a temporary darkening, be they external to or part of the vehicle. A preferred embodiment of said sequence features three turnings off.

[0081] Further, in order to limit the use of the device and its power consumption to those cases in which it is really needed, a pause is introduced between the start of a main beam turn off and on sequence and the next one.

[0082] Advantageously can this pause be provided after a reflection signal is sent, or not, by said microcontroller (5), before checking again whether the decision circuit (4) requests a new analysis cycle to be repeated.

[0083] Conversely, if no reflection signal has been produced, then the control circuit (2) keeps the main beams turned off for a given period of time, for instance three seconds.

[0084] Reference is made to the description of FIGS. 5 and 6 for further details on the operation of the analysis and control circuits in a particular embodiment.

[0085] In a particularly complete embodiment of the invention a sensor (32), also called red sensor, dedicated to detecting the 660 nm±40 nm spectrum, corresponding to the red color, is also equipped; an optical filter (31) installed upstream the red sensor operates in such a way as to let the radiations corresponding to the red color only pass through, while rejecting the others, present in the artificial light sources, thus enhancing the selective sensitivity of the red sensor.

[0086] The signal detected by the red sensor is sent to the decision circuit together with the signal detected by the main light sensor, hence both sensors are in a position to activate, independently of each other, the start of the transmission procedure to the receive assembly which in turn drives the main beams electronic switches.