Device for modifying a road traffic light using a combined light / camera bulb connected in place of the traditional light source

Abstract

The invention relates to a road or pedestrian traffic light comprising at least one light system provided with a red, orange or green light source, characterised in that it comprises a combined light (103; 305) / camera (104; 306) bulb (202) for continuously illuminating and filming its environment, using the video data itself or transmitting the data for road traffic optimisation or video surveillance purposes, wherein the combined light / camera bulb is connected in place of the light system of the traffic light, and wherein the camera (104; 306) operates continuously even when the light source of the light system is turned off.

Description

Description Title of the invention: Device for modifying a road traffic light using a mixed light / camera bulb connected in place of the traditional light source Technical field of the invention

[0001] The innovation is part of the technical field of the smart connected city, which includes road and pedestrian traffic lights, the search for their optimal synchronization, including through artificial intelligence, public road surveillance cameras, automatic detection of traffic violations, etc. Prior art

[0002] Traffic lights are equipped with incandescent light sources or LEDs (Light Emitting Diodes) capable of generating only light. The switching on or off of each red, orange or green light source is generally controlled by a switch allowing the opening or closing of the electrical supply circuit of said light sources. The instruction to open or close the switches is given locally by a program located in the traffic light, or remotely by a centralized control system for all the traffic lights in the same area, with communication between the centralized system and each traffic light most often taking place via a wired communication network.

[0003] Traffic lights are subject to very strict standards, particularly in terms of light intensity, lighting time of each red / orange / green light source, failure rate, latency time between the order of switching on / off the light sources and the actual switching on / off of said sources, etc.

[0004] Intelligently adjusting traffic lights to reduce braking and vehicle waiting times is an effective way to reduce pollution and energy consumption from road traffic. Many traffic control systems Traffic lights have been invented and implemented around the world to regulate road traffic by combining traffic lights, road traffic sensors, as well as computer programs possibly coupled with artificial intelligence.

[0005] An example of such systems is the American patent US2005 / 0206728A1 Al dated 2003 which improves the triggering of a camera when the light is red and a vehicle is nevertheless on the road, thus allowing the user to be fined.

[0006] Another example of such control systems is patent US2005 / 0156757 Al dated 2005, which describes an intelligent red light equipped with a camera and capable of adapting its behavior according to road traffic.

[0007] Another example is the US patent US9805595B1 dated 2016 which proposes in particular a method for centralized synchronization of traffic lights in an area equipped with traffic lights and traffic sensors.

[0008] The widespread use of these systems, however, is hampered by the very high cost of installing these road and pedestrian traffic sensors. The first type of sensor used is an electromagnetic loop system buried under the roadway, which is particularly expensive. The other possible sensor is a digital camera which, combined for example with artificial intelligence, is capable of measuring traffic. The installation cost of these cameras is nevertheless high because they require a specific power supply, a specific physical support (adaptation to an existing pole on the public highway or addition of a new pole on the roadway), and the creation of a secure communication network to transmit the video data to a centralized server capable of interpreting it.

[0009] State of the art of video surveillance on public roads:

[0010] Some cities are installing video surveillance systems on their public roads that can transmit video data either by wire or by electromagnetic waves. These cameras are installed on dedicated poles or on existing poles intended for also for other uses (street lighting, traffic lights, etc.). The development of video surveillance systems in cities is hampered in particular by the very high cost of physically installing cameras on poles, installing permanent power supplies for said cameras, and installing a communications network connecting these cameras to a centralized control server.

[0011] State of the art of camera bulbs and other all-in-one mixed systems capable of producing light and illuminating:

[0012] The miniaturization of electronic circuits and the emergence of LEDs have recently made it possible to manufacture all-in-one combined light bulb / camera devices capable of emitting light and filming. These devices, the size of a conventional light bulb, are mainly used for video surveillance purposes and have the advantage of requiring very low installation costs.

[0013] Camera bulbs sold to individuals are, for example, devices that resemble conventional light bulbs that only generate light, that plug into a socket like conventional bulbs, and that, when supplied with electricity, can detect movements, film, record sounds, emit sounds, possibly produce light, and communicate with the outside world via electromagnetic waves (wifi, 4G, 5G, ■■■) in order to be controlled and transmit video data. For the camera function to work continuously, these camera bulbs must be supplied with electricity at all times. Thus, the normal operation of these bulbs is to be supplied with electricity at all times. For this reason, these camera bulbs are equipped with a wireless communication system (often wifi and 5G technology) capable of controlling the lighting function.However, these wireless communication systems have at least two major drawbacks. First, the latency between the on / off command and the actual on / off of the light source is relatively long. Furthermore, the failure rate of the on / off function of the light source due to a poor wireless connection of the bulb-camera is high. Presentation of the invention

[0014] The present invention proposes that the road or pedestrian traffic signal light can both operate its lighting device normally and continuously film its environment in order to use the video data itself or transmit it to centralized systems so that it can be used for the purposes of intelligent road traffic management or public safety.

[0015] To this end, the present invention relates to a road or pedestrian traffic signal light comprising at least one lighting system provided with a red, orange or green light source, characterized in that it comprises a mixed light / camera bulb making it possible to continuously illuminate and film its environment and to use the video data itself or to transmit them for the purposes of optimizing road traffic or video surveillance, said mixed light / camera bulb being connected in place of the lighting system of said traffic light, the camera operating continuously even when the light source of the lighting system is switched off.

[0016] The present invention is thus based on the use of a mixed light / camera bulb capable of both emitting light and filming. This bulb is installed in the location normally reserved for the red, orange or green light source of the traffic light.

[0017] Preferably, the switching on or off of the light source of the combined light / camera bulb is carried by the electric current supplying said bulb which, in order to be able to film and transmit the video signal permanently, is permanently supplied with electricity.

[0018] The technical problem to be solved is the fast and reliable switching on / off of the light source of the combined light / camera bulb when the signal light switching on / off instruction is transmitted by the traffic light. The fast and reliable transmission of the switching on / off instruction cannot be managed via wireless communication by electromagnetic waves because the latency time is too high and the risks of cutting off or jamming the wireless connection are too great.

[0019] In order to control the switching on / off function of the light source of the mixed light / camera bulb with minimal latency and failure rate, and thus to have a system that complies with the safety standards for road traffic lights, the present invention uses the existing wired system for supplying electrical current to said bulb. More specifically, the transmission of the switching on / off instruction is ensured by a variation in the supply voltage of the mixed light / camera bulb.

[0020] Advantageously, the light source of the mixed light / camera bulb turns on or off depending on the voltage of the electric current supplying said bulb, while the camera operates continuously even in the event of a variation in the voltage of the electric current supplying said bulb, and said light further comprises a switch which opens or closes an electric circuit supplying the red, orange or green light source to which the mixed light / camera bulb is connected, allowing on the one hand a permanent electrical supply of said bulb, whether the switch is open or closed, and on the other hand a modification of the voltage of the current supplying said bulb depending on whether the switch is open or closed.

[0021] In particular, the switch for opening or closing the electrical circuit supplying the red, orange or green light source of said light to which the mixed light / camera bulb is connected comprises an electrical resistor connected in parallel with said switch so that, when the switch is in the closed position, the electrical current passes through the switch without passing through the resistor and supplies the mixed light / camera bulb with a certain voltage and, when the switch is in the open position, the electrical current passes through the resistor and supplies the mixed light / camera bulb with a reduced voltage.

[0022] The addition of an electrical component having a relatively stable resistance R regardless of its operation and electrically connected in parallel with the switch allows the current to bypass the latter when it is open and to continue to supply the mixed bulb light / camera with a weakened voltage. On the other hand, when the switch is closed, the current flows through the switch without passing through the resistor and supplies the combined light / camera bulb with a higher voltage.

[0023] According to a preferred embodiment of the present invention, the mixed light / camera bulb has the dimensions of a conventional light bulb for signaling lights and has both a light system and a camera system, said mixed bulb further comprising a voltage sensor for measuring in real time the voltage of the electric supply current at its terminals and a microcontroller connected to said voltage sensor making it possible to turn on or off its light system depending on the voltage of the electric current at its terminals.

[0024] According to an additional characteristic, the mixed light bulb also includes a Hall effect current intensity sensor to measure in real time the intensity of the current circulating in its lighting system and a microcontroller, connected in particular to said voltage sensor and making it possible to open a general switch integrated into the bulb when the intensity of the current circulating through its lighting system is abnormal, in order to cut off all circulation of electric current within said bulb.

[0025] Using the location normally reserved for the orange light to connect the mixed light / camera bulb is particularly relevant because it allows you to capture, most of the time, a video signal that is not disturbed by the light emitted by the traffic light (the orange light being off most of the time).

[0026] A modification of the light source protection and diffusion porthole of the light source may be necessary in order to allow both good diffusion of the brightness of the light source of the mixed light / camera bulb, and good quality of the video captured by the bulb's camera.

[0027] The combined light / camera bulb may also contain a recording and / or sound emission device. Brief description of the figures

[0028] Other advantages, aims and characteristics of the present invention emerge from the following description, given for explanatory and non-limiting purposes, with reference to the appended drawings, in which:

[0029] [Fig. 1] is a cross-sectional view of the combined light / camera bulb.

[0030] [Fig. 2] is the electrical diagram of the modification, at the traffic light, of the power supply switch for the red, orange or green light source replaced by the mixed light / camera bulb.

[0031] [Fig. 3] is a possible electrical diagram of the combined light / camera bulb.

[0032] [Fig. 4] is another possible electrical diagram of the combined light / camera bulb to protect both the camera components and the data transmission system components from supply voltage variations. Description of the embodiments

[0033] Figure 1 is a sectional view of the combined light / camera bulb with a stud 101 and a base 102 as well as a lighting system 103 and a digital camera 104 capable of transmitting the video signal 104.

[0034] Figure 2 is the electrical diagram of the modification, at the traffic light, of the power supply switch for the red, orange or green light source replaced by a mixed light / camera bulb 202. A switch 204 is placed in series on the circuit supplying the power supply to the mixed light / camera bulb 202. A resistor 203 with a value of R ohms is placed in parallel with the switch 204. This circuit allows, when the switch 204 is open, a power supply to the mixed light / camera bulb 202 thanks to a current which passes through the resistor R. The electrical voltage of the power supply current to the mixed light / camera bulb is then weakened. This system also allows, when the switch 204 is closed, a power supply to the mixed light / camera bulb 202 thanks to a current which passes through the switch without passing through the resistor.The electrical voltage of the power supply current of the combined light / camera bulb is then higher.

[0035] Figure 3 is a possible electrical diagram of the combined light / camera bulb 202. The bulb 202 is composed of an LED type light system 305 and a digital camera system 306 equipped with a system 307 for transmitting the video signal by electromagnetic waves.

[0036] A possible electrical and electronic connection of the various components of the mixed light / camera bulb is explained in Figure 3 in which a Hall effect sensor 301 is optional. In the configuration in which there is no inverse of the ON / OFF instruction of the ignition switch, the microcontrollers of the mixed light / camera bulb connected according to the principles of Figure 3 are programmed to behave in the following way.

[0037] A microcontroller 303 of the combined light / camera bulb closes a switch 304 to turn on the LED lighting system when a sudden increase in the current voltage is detected in a voltage sensor 302 of a value approximately equal to (+R) / Rcam where R is the value in ohms of the resistor connected in parallel with the traffic light switch according to Figure 2 and where Ream is the value of the intrinsic resistance of the digital camera 306 and its data transmission system 307.

[0038] The following two methods can be used to characterize this voltage increase precisely and thus program the 303 microcontroller precisely:

[0039] First method: the microcontroller memorizes the voltage at time t minus a few milliseconds captured by the voltage sensor 302 (denoted U(t-ms) hereafter). Then, the microcontroller compares this voltage to the voltage at time t (denoted U(t) hereafter), by calculating the value [U(t)-U(t-ms)] / [U(t-ms)]. The microcontroller closes the switch 304 when the value [U(t)-U(t-ms)] / [U(t-ms)] is close to the value (+R) / Rcam, where R is the value in ohms of the resistor connected in parallel with the traffic light switch and where Ream is the value in ohms of the intrinsic resistance of the camera 306 and the data transmission system 307 incorporated inside the mixed light / camera bulb.

[0040] Second method: the microcontroller is connected to a Hall effect current sensor 301 and stores the current captured at time t minus a few milliseconds (hereinafter denoted l(t-ms). Then the microcontroller calculates the value R * l(t-ms), where R is the value in ohms of the resistor connected in parallel with the traffic light switch. In addition, the microcontroller stores the voltage at time t minus a few milliseconds captured using the voltage sensor 302 (hereinafter denoted U(t-ms). Then, the microcontroller compares this voltage to the voltage at time t captured by the sensor 302 (hereinafter denoted U(t)) by calculating the value [U(t)-U(t-ms)]. The microcontroller closes switch 304 when the value [U(t)-U(t-ms)] is close to the value R * l(t-ms).

[0041] The microcontroller 303 opens the switch 304 when a sudden drop in the current voltage is detected in the voltage sensor 302 by a value approximately equal to (-R) / (R+Rcam) where R is the value in ohms of the resistance connected in parallel with the traffic light switch according to Figure 2 and where Ream is the value of the intrinsic resistance of the camera 306 and its data transmission system 307.

[0042] In the same way as before, the following two methods can be used to characterize this voltage decrease precisely and thus program the microcontroller 303 precisely:

[0043] First method: the microcontroller memorizes the voltage at time t minus a few milliseconds captured by the voltage sensor 302 (denoted U(t - ms) hereafter). Then the microcontroller compares this voltage to the voltage at time t (denoted U(t) hereafter) by calculating the value [U(t)-U(t-ms)] / [U(t-ms)]. The microcontroller opens the switch 304 when the value [U(t)-U(t-ms)] / [U(t-ms)] is close to the value (- R) / (R+Rcam), where R is the value in ohms of the resistor connected in parallel with the traffic light switch and where Ream is the intrinsic resistance of the camera 306 and the data transmission system 307 incorporated inside the mixed light / camera bulb.

[0044] Second method: the microcontroller is connected to a Hall effect current sensor 301 and captures the value of the current measured at time t (hereinafter denoted l(t). Then the microcontroller calculates the value R * I (t), where R is the value in ohms of the resistor connected in parallel with the traffic light switch. In addition, the microcontroller stores the voltage at time t minus a few milliseconds captured using the voltage sensor 302 (hereinafter denoted U(t-ms). Then the microcontroller compares this voltage to the voltage at time t captured by the sensor 302 (hereinafter denoted U(t)) by calculating the value [U (t)- U(t-ms)]. The microcontroller opens the switch 304 when the value [U(t)-U(t-ms)] is close to the value -R * l(t).

[0045] The combined light / camera bulb also has an electronic safety system that automatically cuts off the overall electrical circuit supplying the entire bulb when an anomaly in the bulb's lighting function is detected. Thus, no current flows into the combined light / camera bulb if the lighting function is defective. The combined light / camera bulb then behaves as if the light bulb were blown. This allows the centralized traffic light safety system to detect the anomaly, either because this system is capable of detecting that a bulb is blown thanks to sensors within the light, or because this system is capable of detecting that the camera is not working and is not emitting a video signal.

[0046] Figure 3 shows a possible electrical diagram of the mixed light / camera bulb. In this diagram, the detection of an anomaly in the light function is carried out by a Hall effect sensor type current intensity sensor 308 to measure the intensity or at least the variation in intensity of the electric current flowing in the light system of the bulb. The automatic cut-off of the power supply current to the entire bulb is carried out by a microcontroller 309 connected to said Hall effect intensity sensor 308, to the microcontroller 303 which controls in particular the opening and closing of the power supply circuit of the light function, and to a general switch 310 which allows the opening or closing of the entire power supply circuit of the mixed light / camera bulb.

[0047] Thus, the microcontroller 309 opens the general switch 310 if it detects an abnormally low intensity at the Hall effect intensity sensor 308 while the microcontroller 303 has given the order to close the power switch 304 of the light function.

[0048] This is a safety system to place the combined light / camera bulb in "burned out" mode when the light function is faulty.

[0049] It should be noted that the electrical connections of the components of the mixed light / camera bulb as described in Figure 3 allow the camera to be powered even in the event of a variation in the supply voltage of said bulb. This voltage variation must be relatively low so as not to damage the camera and its data transmission system and it is therefore advisable to carefully choose the R and Ream values ​​so that a relative variation in the voltage across the camera terminals [U (t)-U (t-ms)] / [U (t-ms)] having a value of (+R) / Rcam or (-R) / (R+Rcam) is low enough to be supported by the electrical circuits of said camera and said data transmission system.

[0050] Figure 4 is another possible electrical diagram of the combined light / camera bulb to protect both the camera components and the data transmission system components from supply voltage variations.

[0051] In this diagram, a switch 311 is placed in series with the camera power supply circuit just before the camera. In addition, an electrical device 312 having a resistance or intrinsic resistance equal to R ohms is placed in parallel with this switch - the value R is here exactly the same as the value of the resistance placed in parallel with the traffic light switch as described previously. Finally, the microcontroller 303 controls the switch 311 according to the following rule: the microcontroller 303 opens the switch 311 when it closes the switch 304, and vice versa.

[0052] The traffic light modification device also allows the transmission of video data and several technologies can be used:

[0053] The first technology involves equipping the combined light / camera bulb with an electromagnetic wave transmitter. Depending on the system chosen, the combined light / camera bulb can transmit the data either to a telecom network outside the traffic light network (for example, in the case of a 4G or 5G transmitter), or transmit the data to a receiver located nearby, for example, in the traffic light, and capable of subsequently transmitting the information via the existing communication network between the different traffic lights and their control center. The choice of system depends on the existing infrastructure and security constraints.

[0054] The other usable technology is to equip the mixed light / camera bulb with a wired data transmission system via electric current, using for example LPG (Power Line Communication) technology or a similar technology.

[0055] The present invention, which makes it possible to safely create a network of road traffic sensors and surveillance cameras, has the great advantage of allowing the creation of this network at a lower cost. Indeed, it is not necessary to create very expensive devices for fixing, powering and communicating cameras. Thanks to this invention, a reduction in pollution and energy consumption caused by road traffic can be achieved by connecting all these road traffic video sensors to a road traffic management system by synchronizing the lights in a geographical area. It is also possible thanks to this invention to create a video surveillance system for public roads at a lower cost.

[0056] It should be clearly understood that the detailed description of the subject matter of the invention, given solely by way of illustration, does not constitute a limitation in any way, technical equivalents also being included within the scope of the present invention.

Claims

Claims Claim 1. Road or pedestrian traffic signal light comprising at least one lighting system provided with a red, orange or green light source, characterized in that it comprises a mixed light bulb (202) (103; 305) / camera (104; 306) making it possible to continuously illuminate and film its environment and to use the video data itself or to transmit them for the purposes of optimizing road traffic or video surveillance, said mixed light bulb / camera being connected in place of the lighting system of said traffic light, the camera (104; 306) operating continuously even when the light source of the lighting system is switched off. Claim 2. Signaling light according to claim 1, characterized in that the switching on or off of the light source of the mixed light / camera bulb is carried by the electric current supplying said bulb which, in order to be able to film and transmit the video signal permanently, is permanently supplied with electricity. Claim 3. Signaling light according to claim 1 and 2, characterized in that: a) The light source (103; 305) of the mixed light / camera bulb turns on or off depending on the voltage of the electric current supplying said bulb, while the camera operates continuously even in the event of variation in the voltage of the electric current supplying said bulb, and b) said light further comprises a switch (204; 304) which opens or closes an electric circuit (202) supplying the red, orange or green light source to which the mixed light / camera bulb is connected, allowing on the one hand a permanent electrical supply of said bulb, whether the switch is open or closed, and on the other hand a modification of the voltage of the current supplying said bulb depending on whether the switch is open or closed. Claim 4. Signaling light according to claim 3, characterized in that the switch (204; 304) making it possible to open or close the electrical circuit (202) supplying the red, orange or green light source of said light to which the mixed light / camera bulb is connected comprises an electrical resistor (203) connected in parallel with said switch (204; 304) so ​​that, when the switch (204; 304) is in the closed position, the electric current passes through the switch (204; 304) without passing through the resistor (203) and supplies the mixed light / camera bulb with a certain voltage and, when the switch (204; 304) is in the open position, the electric current passes through the resistor (203) and supplies the mixed light / camera bulb with a reduced voltage. Claim 5. Signaling light according to claim 4, characterized in that the mixed light / camera bulb has the dimensions of a conventional light bulb for signaling lights and has both a light system (305) and a camera system (104; 306), said mixed bulb further comprising a voltage sensor (302) for measuring in real time the voltage of the electric supply current at its terminals and a microcontroller (303) connected to said voltage sensor (302) making it possible to turn on or off its light system (305) depending on the voltage of the electric current at its terminals. Claim 6. Signaling light according to claim 5, characterized in that the mixed light bulb also comprises a Hall effect current intensity sensor (301; 308) for measuring in real time the intensity of the current flowing in its lighting system (305) and a microcontroller (309), connected in particular to said voltage sensor (302) and making it possible to open a general switch (310) integrated in the bulb (202) when the intensity of the current flowing through its lighting system (305) is abnormal, in order to cut off all circulation of electric current within said bulb.

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