[0001] The present invention relates to a vehicle headlamp, and more particularly relates to a headlamp control system that automatically controls and switches a high beam and a low beam state of both own and oncoming vehicles headlamp.
BACKGROUND OF THE INVENTION
[0002] Vehicles are generally fitted with headlamps to illuminate a driver's field of view at night. Each vehicle is provided with two beams, high beam and low beam. The high beam provides good illuminance of the field ahead. When the high beam from the headlamps is incident on a driver coming from opposite direction, it causes disability glare resulting in temporary blindness in effect causing numerous accidents while driving at night. Hence the high beam should be manually shifted to low beam whenever there is oncoming vehicle so that vision of the road ahead is available to both the drivers reducing the risk of an accident. However, this is not practiced by humans due to various factors like subjective thinking, physiological and psychological state of mind, and tiredness of driver among other factors. Therefore, a need to automate this process of shifting between the high beam and the low beam state based on various dynamic conditions is desired.
[0003] Majority of prior art systems to control the headlamp includes an auto dipper. In general, the headlamps are to be maintained in high beam if there is no oncoming vehicle. Similarly, the headlamps of the vehicle need to be maintained in low beam whenever the road is lit with street lights. The prior art systems are partially immune to street lamps, sunlight, moonlight and other reflected light. Their low immunity to the unwanted lights can result in unwanted dipping which in turn increases the probability of the accident. Additionally, the prior art system does not reduce the dazzle effect of glare to the oncoming driver and shifts the beam suddenly at higher speeds causing disturbance to the driver's vision which is quite dangerous at that speeds.
[0004] Such prior art systems simply switches headlamps to the low beam state on encountering light and switch back to the main beam in situation where no light is incident on

a sensor. However, in a situation where a vehicle is installed with the prior art systems, the headlamps of the vehicle are switched to the low beam state and the oncoming vehicle may maintain the high beam state, and the driver faces increasing level of glare while getting closer to the oncoming vehicle. Ideally, the device should switch back to the high beam state if the oncoming vehicle does not switch to the low beam state giving increased visibility to the driver facing the glare. This particular need was addressed in the Indian patent no. 174895.
[0005] The core issue prior solutions have not addressed is that the driver causing the glare is not initiating the action of shifting to the low beam state but the one having the detection device and facing the glare is shifting to the low beam state expecting the other to shift to the low beam state too. It is desired that the one causing glare shifts to the low beam first. Additionally, prior art systems do not distinguish between a discomfort glare, from a disability glare in a vehicle meeting situation. The disability glare is considered as the light intensity from the oncoming vehicle headlamp when the distance between two vehicles is less than or equal to a safe stopping distance.
[0006] Hence, there is a need for an improved automatic headlamp control system and method that automatically controls and switches a high beam and a low beam state of both own and oncoming vehicle's headlamp with respect to a number of operation modes based on the vehicle speed, as described in greater detail later in this document.
SUMMARY OF THE INVENTION
[0007] The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0008] It is, therefore, one aspect of the present invention to provide an improved automatic headlamp control system that automatically controls and switches between a high beam and a low beam state of both own and oncoming vehicle's headlamp.

[0009] It is another aspect of the present invention to provide an improved headlamp control system to differentiate the headlamp light signal from light signals of other artificial light sources.
[0010] It is further aspect of the present invention to provide an improved method for automatically controlling and switching between a high beam and a low beam state of both own and oncoming vehicle's headlamp with respect to a number of operation modes based on the vehicle speed.
[0011] In one aspect of the present invention, the automatic headlamp control system includes a light sensing unit having a number of light sensors each for sensing a desired range of wavelength in an electromagnetic spectrum to continuously detect a headlamp light signal of an oncoming vehicle. The light sensors of the light sensing unit are sensitive to detect and differentiate the headlamp light signal from light signals of other artificial light sources. A speed sensing unit is configured to capture and generate real-time vehicle movement information of its own vehicle. The automatic headlamp control system further includes at least one control unit communicating with the light sensing unit and the speed sensing unit to receive data indicative of the headlamp light signal and the vehicle movement information. While determining the presence of oncoming vehicle headlamp, the control unit processes the data from both the sensing units for automatically controlling and switching the beam states of the own vehicle headlamp and the oncoming vehicle headlamp based on a set of operation modes with respect to the real-time vehicle movement information.
[0012] The operation modes are selected based on real-time vehicle movement information. For example, the operation modes are divided into a low speed mode (first mode) when the vehicle speed is less than 20km/hr, an auto mode (second mode) when the vehicle speed is in the range between 20km/hr and lOOkm/hr, and a high speed mode (third mode) when the vehicle speed is higher than lOOkm/hr, where the above speeds are mentioned for the purpose of indication only and can be varied as per vehicle movement information and user requirements. The control unit transmits a control signal indicative to shift the beam state of the headlamp, to the oncoming vehicle through a wireless communication unit and indicates a real-time operational status of the headlamp control system to a vehicle driver. The light sensing unit further includes a first light sensor for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum

originating from the vehicle headlamp and a number of second light sensors for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum originating from the other artificial light sources in order to differentiate between the vehicle headlamp light signal and the other artificial light signals.
[0013] The control unit is in communication with the first and second light sensors of the light sensing unit for receiving the vehicle headlamp light spectrum from the first light sensor and the other artificial light spectrum from the second light sensors in order to determine the presence and light intensity of the oncoming vehicle headlamp and the presence of artificial lights on the road. The speed sensing unit captures and communicates the real-time vehicle movement information to and from the control unit, where the real-time vehicle movement information includes a signal of vehicle speed, vehicle direction of travel and vehicle geographical position or location. The control unit further comprises a status indicator that is electrically connected to the control unit to display the real time operational status related to power availability, the current headlamp beam, and the operation mode to the vehicle driver. The control unit is composed of a first control unit that is electrically connected to the light sensing unit to receive the light signal of the oncoming vehicle headlamp, and a second control unit that is electrically connected to the speed sensing unit to receive the real-time vehicle movement information, i.e. vehicle speed, vehicle direction of travel and vehicle geographical position, on a periodical basis and also to the communication unit to receive and send wireless communication signals.
[0014] In another aspect of the present invention, the control unit maintains the own vehicle headlamp in the low beam state independent of an external condition in the low speed mode and transmits the control signal to request the oncoming vehicle to shift the headlamp to the low beam state while detecting a glare from the oncoming vehicle headlamp. In the auto mode, the control unit detects the glare based on the light level of the headlamp of the oncoming vehicle, which shifts the vehicle headlamp causing the glare into the low beam state and subsequently maintains both the own and oncoming vehicle headlamps in the low beam state until the own and oncoming vehicles cross each other.
[0015] If the oncoming vehicle does not have a similar system installed, it will be the prior art systems or a driver who make that decision to shift to the low beam state or the high beam state. If the oncoming vehicle does not shift its headlamp to the low beam state, they

will cause disability glare to the driver of the own vehicle. As this increases the risk of accident again, the system will switch the headlamps of the own vehicle to the high beam state if it detects disability glare from the oncoming vehicle. The system distinguishes 'discomfort glare', from 'disability glare' in a vehicle meeting situation. The system also considers the glare from the oncoming vehicle as 'discomfort glare' when the longitudinal distance between two opposing vehicles is more than the safe stopping distance. Similarly, 'disability glare' is considered as the light intensity from the oncoming vehicle headlamp when the distance between two vehicles is less than or equal to safe stopping distance.
[0016] Additionally, the headlamps of the own vehicle are maintained in the low beam state if the light signals from other artificial light sources are lit. The control signal from the control unit can be manually overridden and intervened to obtain a reverse beam of the own vehicle based on various dynamic condition by a driver. In the high speed mode, the control unit maintains the headlamps of the own vehicle in the high beam state independent of the external conditions and transmits the control signal to request the oncoming vehicle to shift the headlamp to the low beam state while detecting a glare from the oncoming vehicle headlamp.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The disclosed embodiments may be better understood by referring to the figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0018] FIG. 1 illustrates a block diagram of an automatic headlamp control system that automatically controls and switches between a high beam and a low beam state of both own and oncoming vehicles headlamp based on a number of operation modes, in accordance with the present invention;
[0019] FIG. 2 illustrates a schematic diagram of a light sensing unit, in accordance with the present invention;

[0020] FIG. 3 illustrates a schematic diagram of a speed sensing unit, in accordance with the present invention;
[0021] FIG. 4 illustrates a schematic diagram of a first control unit having a status indicator, in accordance with the present invention;
[0022] FIG. 5 illustrates a schematic diagram of a second control unit, in accordance with the present invention;
[0023] FIG. 6 illustrates a schematic diagram of a wireless communication unit, in accordance with the present invention;
[0024] FIG. 7 illustrates a schematic diagram of a voltage regulator, in accordance with the present invention; and
[0025] FIG. 8 illustrates a flow chart illustrating a method for automatically controlling and switching between the high beam and the low beam state of both own and oncoming vehicles headlamp based on the operation modes, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
[0027] In the following, numerous specific details are set forth to provide a thorough description of various embodiments. Certain embodiments may be practiced without these specific details or with some variations in detail. In some instances, certain features are described in less detail so as not to obscure other aspects. The level of detail associated with each of the elements or features should not be construed to qualify the novelty or importance of one feature over the others.

[0028] The claimed subject matter has been provided here with reference to one or more features or embodiments. Those skilled in the art will recognize and appreciate that, despite of the detailed nature of the exemplary embodiments provided here; changes and modifications may be applied to said embodiments without limiting or departing from the generally intended scope. These and various other adaptations and combinations of the embodiments provided here are within the scope of the disclosed subject matter as defined by the claims and their full set of equivalents. Like numbers refer to like elements throughout.
[0029] The present invention is an automatic headlamp control system that automatically controls and switches between a high beam and a low beam state of both own and oncoming vehicles headlamp. The headlamp control system differentiates the headlamp light signal from light signals of other artificial light sources. The present invention is capable of controlling and switching both own and oncoming vehicles headlamp with respect to a number of operation modes based on the vehicle speed. The headlamp control system has high processing power and memory to make them suitable for speed sensing and wireless communication of a control signal to the oncoming vehicle.
[0030] FIG. 1 illustrates a block diagram of an automatic headlamp control system (10) that automatically controls and switches between a high beam state and a low beam state of both own and oncoming vehicles headlamp (34) and (44) based on a number of operation modes (60), in accordance with the present invention. Note that in FIGS. 1-8 identical parts or elements are generally indicated by identical reference numerals. The automatic headlamp control system (10) generally includes a light sensing unit (15), a speed sensing unit (40), at least one control unit (55), a wireless communication unit (80) and a status indicator (50). Note that the light sensing unit (15), the speed sensing unit (40), the control unit (55) and the wireless communication unit (80) is configured in a printed circuit board assembly and even can be implemented in ASIC/HMC or any integrated circuits, which contains all the necessary electronic components and interconnections to support operation of the automatic headlamp control system (10).
[0031] The light sensing unit (15) includes a number of light sensors (20) and (30) each for sensing a desired range of wavelength in an electromagnetic spectrum to continuously detect a headlamp light signal (25) of an oncoming vehicle (43). The light sensors (20) and (30) of the light sensing unit (15) are sensitive to detect and differentiate the

headlamp light signal (25) from light signals (35) (unwanted light signals) of other artificial or unwanted light sources. The light sensing unit (15) further includes a first light sensor (20) for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum originating from the oncoming vehicle headlamp (44) and a number of second light sensors (30) for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum originating from the other artificial light sources in order to differentiate between the vehicle headlamp light signal (25) and the other artificial light signals (35).
[0032] The speed sensing unit (40) is configured to capture speed of the vehicles (33) and (43) and to generate a vehicle speed signal (45) of the own vehicles (33) and (43) where the speed sensing unit (40) is fitted in. The speed sensing unit (40) is in communication with a satellite, and captures and communicates the real-time vehicle movement information to and from the control unit, where the real-time vehicle movement information includes a signal of vehicle speed, vehicle direction of travel and vehicle geographical position. In a preferred embodiment, the light sensing unit (15) and the speed sensing unit (40) collects data and sends it to the control unit (55) via wired/wireless communication, depending upon design consideration. The automatic headlamp control system (10) further includes at least one control unit (55) connected to the light sensing unit (15) and the speed sensing unit (40) to receive data indicative of the headlamp light signal (25) and the vehicle speed signal (45). The control unit (55) processes the data from both the sensing units (15) and (40) for automatically controlling and switching the beam states of the own vehicle headlamp (34) and the oncoming vehicle headlamp (44) with respect to the operation modes (60) based on the vehicle speed signal (45) while determining the presence of the oncoming vehicle headlamp (44).
[0033] The control unit (55) is composed of a first control unit (85) that is electrically connected to the light sensing unit (15) to receive the light signal (25) of the oncoming vehicle headlamps (44), and a second control unit (90) that is electrically connected to the speed sensing unit (40) to receive the vehicle speed signal (45) of the own vehicle (33) and also to the wireless communication unit to send and receive the control signals indicative to requesting a shift to low beam. The control unit (55) transmits a control signal (95) indicative to shift the beam state of the headlamp, to the oncoming vehicle (43) through a wireless communication unit (80) whenever the discomfort glare is detected, and indicates a real-time operational status of the headlamp control system (10) to a vehicle driver. In a preferred

embodiment, the communication module uses radio frequency waves as the mode of communication. However, communication can be achieved in multiple other ways.
[0034] The control unit (55) is in communication with the first and second light sensors (20) and (30) of the light sensing unit (15) for receiving the vehicle headlamp light spectrum from the first light sensor (20) and the other artificial light spectrum from the second light sensors (30) in order to determine the presence and light intensity of the oncoming vehicle headlamp and the presence of artificial lights on the road. The control unit (55) further comprises a status indicator (50) that is electrically connected to the control unit (55) to display the real time operational status related to power availability, the current headlamp beam, and the operation mode to the vehicle driver. In a preferred embodiment, the control unit (55) communicates with the light sensing unit (15) and the speed sensing unit (40) fitted in the own vehicle (33) and also transmits signal to the control unit (55) fitted in the oncoming vehicle (43) via the wireless communication unit (80). The wireless signal from the control unit (55) of the oncoming vehicle (43) is also considered as input to the control unit (55) of the own vehicle (33).
[0035] The operation modes are selected based on real-time vehicle movement information. For example, the operation modes are divided into a low speed mode when the vehicle speed is less than 20km/hr, an auto mode when the vehicle speed is in the range between 20km/hr and lOOkm/hr, and a high speed mode when the vehicle speed is higher than lOOkm/hr, where the above speeds are mentioned for the purpose of indication only and can be varied as per real-time vehicle movement information and user requirements. Additionally, the operation modes can also be divided into a non-auto mode (not shown in FIG. 1) and an over-ride mode (not shown in FIG. 1), in which all the functions are deactivated at the output level and the output remains static and latched in that mode though the automatic processes keep going to restore the appropriate beam immediately after restoration to the auto mode. Within the auto mode, the low speed and high speed modes can act as a OVERIRDE again. Here the device determines the over ride rather than a manually pushed over ride. The override can also be done manually by the driver at any time independent of the mode of operation. Once manually overridden, the headlamps stay in that position until the headlamp lever is brought back to its original position. The continuous process by sensor can be going on in the background when the lever is overridden in order to decide the output state when the lever is brought back to its original position restoring auto

mode. The control unit (55) maintains the own vehicle headlamp (34) in the low beam state independent of an external condition in the low speed mode (65) and transmits the control signal (95) to request the oncoming vehicle (43) to shift the headlamp (44) to the low beam state while detecting a glare from the oncoming vehicle headlamp (44).
[0036] In the auto mode (70), the control unit (55) detects the glare based on the light level (lux level) of the headlamps (44) of the oncoming vehicle (43), which shifts the vehicle headlamp causing the glare into the low beam state and subsequently maintains both the own and oncoming vehicle headlamps (34) and (44) in the low beam state until the own and oncoming vehicles (33) and (43) cross each other. If the oncoming vehicle (43) does not have the system (10) installed to receive wireless signal and process it, the headlamps (34) of own vehicle (33) transmits a wireless signal first and shift its own headlamps (34) to low beam on detecting 'discomfort glare'. If the oncoming vehicle (43) shifts its headlamps (44) to the low beam state, own vehicle's headlamps (34) will maintain headlamps in the low beam state until the vehicles cross each other. However, if the oncoming vehicle (43) does not switch to the low beam state even when the distance between the vehicles is at a safe stopping distance, the own vehicle (33) detects disability glare and will switch its headlamps (34) to the high beam state increasing the vision for the driver of the own vehicle (33).
[0037] Additionally, the headlamps (34) of the own vehicle (33) are maintained in the low beam state if the light signals (35) from other artificial light sources are detected. The control signal (95) from the control unit (55) can be manually overridden and intervened to obtain a reverse beam of the own vehicle (33) based on judgement of the driver. In the high speed mode (75), the control unit (55) maintains the headlamps (34) of the own vehicle (33) in the high beam state independent of the external condition and transmits the control signal (95) to request the oncoming vehicle (43) to shift the headlamp (44) to the low beam state while detecting a glare from the oncoming vehicle headlamp (44).
[0038] FIG. 2 illustrates a schematic diagram of the light sensing unit (15), in accordance with the present invention. The system (10) continuously detects the headlamp (44) of the oncoming vehicle (43), and the multiple light sensors (20) and (30) respond to only limited range of wavelength in the electromagnetic spectrum in order to detect the appropriate light spectrum originating from vehicular headlamp (44) and to differentiate

between other road light coming from street lamps, traffic light, reflection from road, building and other structures.
[0039] PD1 represents the light sensor (20) that is sensitive to only specific wavelength range of the electromagnetic spectrum. PD2, PD3 and PD4 represents the light sensors (30) again that are sensitive to specific wavelength range of the electromagnetic spectrum different form that of PD1. PD1 helps the system (10) detect oncoming headlamps while other light sensors PD2, PD3 and PD4 help detect street lights, road lights and other reflected lights to differentiate between vehicle headlamps and other artificial sources of light. In this circuit, VCC1 is the voltage provided to power the microcontroller U6. Resistors R17 and R18 are part of the design rules of microcontroller. R16 acts as a noise suppressor. R19 acts as a multiplier for conversion of photo current to voltage. Resistors R20, R24 are part of the design rules of microcontroller. Capacitor C10 acts as a DC filter. Resistors R21 and R22 help limit the current. R23 acts as a pull down resistor thus eliminating any chance of spurious voltage to be present on the line. Component D5 restricts the signal to contain only positive waves. SIG1 and SIG3 are outputs of the light sensing unit (15) which feed to first control unit (85). Based on the input received from the light sensing unit (15), the decision on headlamp beam is taken.
[0040] FIG. 3 illustrates a schematic diagram of the speed sensing unit (40), in accordance with the present invention. As stated above, the system (10) works in three different operation modes (60) based on the real-time vehicle movement information. The speed of the vehicles (33) and (43) is captured by the speed sensing unit (40) independently. This data is sent to the second control unit (90). Microcontroller U4 captures input signal from satellites and processes the vehicle speed. The data is then sent to the second control unit (90) using SIG9. Similarly, the speed sensing unit (40) can receive data from the second control unit (90) via SIG10. VCC2 is the supply voltage provided to U4. Capacitor C9 acts as a de-coupling capacitor. It minimizes fluctuations arising in VCC2 signal.
[0041] FIG. 4 illustrates a schematic diagram of the first control unit (85) having the status indicator (50), in accordance with the present invention. The core microcontroller gathers data from the light sensing unit (15) and the second control unit (90) and runs pre-defined algorithm and controls the status indicators (50) in addition to sending the decision to a relay sub-system (not shown) via SIG8. The status indicators (50) are connected to the first

control unit microcontroller (85) directly. The status indicators (50) are used to display the live operational status of the system (10) to the driver of the vehicle. This includes the display of power availability, current headlamp beam, operation mode among others. In a preferred embodiment the status indicators (50) includes light emitting diodes. However, any other way can be utilized for the same purpose of updating the user with real time operation status of the system (10).U2 represents the core microcontroller and Jl represents a connection for the programmer through which the microcontroller U2 can be loaded with a software program. Diode Zl ensures that the voltage level does not exceed a pre-defined value on that line thus protecting the electronic components. Capacitor C4 acts as a de-coupling capacitor stabilizing the signal. Resistors R2 and R3 form a resistor divider bridge to ensure voltage level of SIG8 is in the accepted range of relay sub-system. Capacitor C5, C6 and C8 act as decoupling capacitors minimizing any fluctuations in the voltage on that line.
[0042] SIG1 is an input from the light sensing unit (15) to the microcontroller U2. SIG3 is second input from the light sensing unit (15) of the system (10). Ul processes these inputs to calculate the presence of oncoming vehicle headlamps (44). Dl, D2, D3 and D4 are LEDs acting as the status indicators (50). Respective resistors R4, R5, R7 and R8 help limit current flowing through the LEDs. SIG5, SIG6, SIG7 are communication signals between first control unit (85) and the second control unit (90) to enable communication between the two control units (85) and (90). As Ul decides to send messages or read incoming messages, it interacts with second control unit (90) to access the communication unit (80).
[0043] FIG. 5 illustrates a schematic diagram of the second control unit (90), in accordance with the present invention. The second control unit (90) is a dedicated microcontroller that is connected to the speed sensing unit (40), the communication unit (80) and the first control unit (85). This microcontroller has high processing power and memory to make them suitable for speed sensing and wireless communication. As high traffic is expected with wireless communication signals in normal city environment, dedicated microcontroller is allocated for this function. In this circuit, J3 represents a physical connector used for programming the microcontroller, U3 with software. Resistor R12 acts as a pull down resistor eliminating the probability of any spurious charge being present. SIG5 is a communication port through which U3 sends signals to the first control unit (85). Resistor Rll limits the current flow in that path providing protection to the electronics. SIG13 is a

communication port between second control unit (90) and communication unit (80). SIG7 is another communication port of U3 that forms a connection with the first control unit (85).
[0044] Resistors R14 and R15 form a divider bridge that enables voltage level control during communication. SIG16, SIGH is a design rule demanded by the communication unit(80). They are kept at a constant voltage for smooth operation of the unit. SIG15 and SIG14 form the send and receive pair between second control unit (90) and communication unit. SIG9 and SIG10 enable communication between the second control unit (90) and the speed sensing unit (40). SIG6 is another communication port of U3 which enables communication between the second control unit (90) and the first control unit (85). Resistor R13 limits the current flow in this path protecting the electronics. SIG12 is another design rule demanded by manufacturer of the communication unit (80).
[0045] FIG. 6 illustrates a schematic diagram of the wireless communication unit (80), in accordance with the present invention. The wireless communication unit (80) enables the system (10) to send wireless signals to other vehicles. Whenever a message has to be sent, the first control unit (85) sends the command to the second control unit (90) which in turn sends it to the communication unit (80). The wireless communication unit (80) converts the message into an electromagnetic signal and transmits it over air via amplifier, El. In the circuit, U5 is the microcontroller that enables wireless communication. The commands, message and data is received via SIG15. SIG13, SIG14, SIGH, SIG12 and SIG16 are default pins of the communication unit (80) that need to be connected to pre-defined voltages as defined by the manufacturer. El acts as signal amplifier which enables the transmission of communication signals.
[0046] FIG. 7 illustrates a schematic diagram of a voltage regulator (96), in accordance with the present invention. Standard voltage regulator IC, Ul is used here to generate stable output voltage. As seen here, VCC1 is the voltage at input terminal of Ul while VCC2 is the voltage at output terminal of Ul. Capacitors CI, C2 and C3 act as decoupling capacitors. They minimize minor fluctuations in the voltage on this line.
[0047] FIG. 8 illustrates a flow chart illustrating a method (98) for automatically controlling and switching between the high beam and the low beam state of both own and oncoming vehicles headlamp (34) and (44) based on the operation modes (60), in accordance with the present invention. The headlamp light signal (25) of the oncoming vehicle (43) is

continuously detected by sensing a desired range of wavelength in an electromagnetic spectrum via the light sensors (20) and (30) of the light sensing unit (15), and the headlamp light signal (25) is differentiated from the light signals (35) of other artificial light sources, as shown at block (12). The real-time vehicle movement information of the own vehicle (33) is captured and generated by the speed sensing unit (40), as illustrated at block (22), where the real-time vehicle movement information (45) comprises a signal of vehicle speed, vehicle direction of travel and vehicle geographical position. While determining the presence of oncoming vehicle headlamp (44), the data received from both the sensing units (15) and (40) is processed by the control unit (55) for automatically controlling and switching the beam states of the own vehicle headlamp (34) based on a plurality of operation modes (60) with respect to the real-time vehicle movement information (45), as shown at block (32). The oncoming vehicle headlamp (44) is automatically controlled and switched subject to other conditions by wirelessly transmitting a control signal (95) requesting to shift the beam state of the headlamp, to the oncoming vehicle (43), and by indicating a real-time operational status of the headlamp control system (10) to a vehicle driver, as shown at block (32). The wireless control signals from the oncoming vehicle (43) is received and the data is processed to control the headlamp (34) of own vehicle (33), as indicated at block (37).
[0048] The plurality of operation modes (60) is divided into a first mode (65), a second mode (70), and a third mode (75) with respect to the real-time vehicle movement information (45). For example, a determination is made to identify the speed of the vehicle, as shown at block (42). If the speed of the vehicle is less than 20 km/hr, the low speed mode (65) is initiated to maintain the headlamps (34) in low beam state independent of external conditions. As indicated at block (52), the headlamps (34) of the own vehicle (33) are maintained in low beam regardless of the oncoming vehicle headlamp beam (44), If the glare is detected from the oncoming vehicle headlamp (44) and when the own vehicle (33) is in the low speed mode (65), a wireless signal is transmitted to the oncoming vehicle (43) requesting to shift the headlamp (44) to the low beam state, as shown at block (62). The control signal (95) from the control unit (55) can be manually overridden and intervened to obtain a reverse beam of the own vehicle (33) based on various dynamic condition by a driver (driver preference), as indicated at block (72).
[0049] If the speed of the vehicle is in the range between 20km/hr and lOOkm/hr, the auto mode (70) is initiated to detect the glare based on the light level of the headlamp (44) of

the oncoming vehicle (43), which shifts the vehicle headlamp causing the glare into the low beam state by transmitting the wireless signal, as shown at block (92). It is to be noted that the glare can be continuously detected by the control system independent of vehicle speed. When the light level, i.e. discomfort threshold lux level, is detected, a wireless control signal is sent requesting a shift to the low beam and the headlamps (34) of the own vehicle (33) is switched to the low beam position. If the oncoming vehicle (43) switches its headlamps (44) to low beam, system installed in own vehicle (33) will maintain headlamps (34) in low beam until the vehicles cross each other. Subsequently maintain both own and oncoming vehicle's headlamps (34) and (44) in low beam position until own and oncoming vehicles (33) and (43) cross each other if the oncoming vehicle (43) is fitted with the automatic headlamp control system (10), as indicated at block (93). If the oncoming vehicle (43) does not switch its headlamps (44) to low beam, system (10) in the own vehicle (33) will switch its headlamps (34) to high beam when the distance between both vehicles is equal to or less than the safe stopping distance while detecting the disability glare, as shown at block (94).
[0050] For example, assume two vehicles A and B, both fitted with the headlamp control system (10) that is travelling towards each other on an empty highway. Assuming the vehicles are at about 500 meters apart, the control system (10) maintains headlamps of both vehicles in high beam. As the headlamp intensity keeps varying for different vehicles and owners assume that the headlamps of vehicle B are 1.5x brighter than that of vehicle A. Therefore, when both vehicles are approaching each other, driver of vehicle A will face glare before the driver of vehicle B. Therefore, the headlamps of vehicle B have to be shifted to low beam in order to increase road safety. The control system (10) will detect the glare and send a wireless signal to vehicle B requesting it to shift its headlamps to low beam.
[0051] The control system (10) in vehicle B will receive the wireless signal and shift the headlamps to low beam based on the processing of speed, direction of travel and geographical location of both the vehicles. The control system (10) of vehicle B will process the wireless request from vehicle A and act if the other information justifies shifting to low beam. This is to ensure a shift to low beam on the basis of an actual need from a valid oncoming vehicle and not from other sources or from other vehicles which are not facing it's glare. This increases visibility to both drivers. As both vehicles approach each other, a point arises when vehicle A will cause glare to driver of vehicle B. At this point, the control system (10) in vehicle B will request the control system (10) in vehicle A to shift it's headlamps to

low beam. Now that both headlamps are in low beam, the vehicles will be able to safely cross each other. As soon as they cross each other, the headlamps of both vehicles will shift to high beam. The light sensing unit (15) continuously detects the headlamps of oncoming vehicles. Whenever the discomfort glare is detected that is not safe, the above explained procedure takes place. The control unit (90) that receives a wireless signal requesting it to shift to low beam will check the following conditions before shifting to low beam: If the headlamps are in high beam, if the vehicle is within 250 meters from the vehicle sending the signal and if the vehicle's movement is opposite to the vehicle from where the signal has originated. As the light sensing unit (15) continuously detects the headlamps of oncoming vehicles, whenever glare/high beam is detected that is not safe these checks ensures that only the vehicle causing the glare will shift to low beam and not others.
[0052] Now let us assume that vehicle B is fitted with a prior art system called 'autodipper'. When vehicle A receives glare and sends a wireless signal, vehicle B does not have the system to receive the wireless signal and act accordingly. The prior art system may now shift vehicle B's headlamps to low beam on detecting the headlamps of vehicle A. In this scenario, vehicle A will continuously detect headlamps of vehicle B in low beam and thus maintain vehicle A's headlamps in low beam until the vehicles cross each other.
[0053] In another event where vehicle B is not fitted with any automatic headlamp control system, vehicle A will send the wireless signal on detecting glare from vehicle B and shift its own headlamps (34) to low beam. If the driver of vehicle B recognizes vehicle A's headlamps switching from high beam to low beam and shifts vehicle B's headlamps to low beam, vehicle A will also maintain low beam until both vehicle cross each other. If the driver of vehicle B does not shift to low beam, it will cause disability glare to the driver of vehicle A causing temporary blindness. The system (10) installed in vehicle A will recognize the lux level of disability glare arising from the oncoming vehicle headlamps and shift its own headlamps to high beam giving increased vision of the road ahead to driver of vehicle A.
[0054] Additionally, the headlamps (34) of the own vehicle (33) is maintained in the low beam state if the light signals from other artificial light sources are lit. The control signal (95) from the control unit (55) can be manually overridden and intervened to obtain a reverse beam of the own vehicle (33) based on judgement of the driver (driver preference), as indicated at block (72). If the speed of the vehicle is higher than lOOkm/hr, the high speed

mode (75) is initiated to maintain the headlamps (34) of the own vehicle (33) in the high beam state independent of the external condition, and a wireless signal is transmitted to the oncoming vehicle (43) requesting to shift the headlamp (44) to the low beam state whenever the threshold lux level is detected., as shown at blocks (82) and (62). The control signal (95) from the control unit (55) can be manually overridden and intervened to obtain a reverse beam of the own vehicle (33) based on judgement of the driver (driver preference), as indicated at block (72). The automatic headlamp control system (10) can be implemented to control the vehicle's movement, headlamps, engine performance or physical structure (aerodynamics). The automatic headlamp control system (10) can also have access to accelerometer to determine the physical movement of own vehicle in x, y and z axis so that any abnormality can be detected and reported with the help of communication module fitted in it. The vehicles will always dip if the system (10) is used on all vehicles so that the glare from the headlamps will always be below the glare threshold leading to an improved safety.
[0055] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

1. An automatic headlamp control system (10) for controlling and switching a vehicle
headlamp between high and low beam states of both own and oncoming vehicles (33) and
(43), comprising:
a light sensing unit (15) having a plurality of light sensors (20) and (30) each for sensing a desired range of wavelength in an electromagnetic spectrum to continuously detect a headlamp light signal (25) of an oncoming vehicle (43), where at least one of the light sensors of the light sensing unit (15) is sensitive to detect and differentiate the headlamp light signal (25) from light signals (35) of other artificial light sources;
a speed sensing unit (40) configured to capture and generate real-time vehicle movement information (45) of its own vehicle; and
at least one control unit (55) communicating with the light sensing unit (15) and the speed sensing unit (40) to receive data indicative of the headlamp light signal (25) and the vehicle movement information (45), wherein while determining the presence of oncoming vehicle headlamp (44), the control unit (55) processes the data from both the sensing units (15) and (40) for automatically controlling and switching the beam states of the own vehicle headlamp (34) and the oncoming vehicle headlamp (44) based on a plurality of operation modes (60) with respect to the real-time vehicle movement information (45).
2. The headlamp control system of claim 1, wherein the control unit (55) transmits a control signal (95) indicative to shift the beam state of the headlamp, to the oncoming vehicle (43) through a wireless communication unit (80) and indicates a real-time operational status of the headlamp control system (10) to a vehicle driver.
3. The headlamp control system ofclaiml, wherein the light sensing unit (15) further comprises:
a first light sensor (20)(PD1) for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum originating from the oncoming vehicle headlamp (44); and
a plurality of second light sensors (30)(PD2, PD3 and PD4) for sensing the wavelength range of the electromagnetic spectrum indicative of a light spectrum originating from the other artificial light sources in order to differentiate between the vehicle headlamp light signal (25) and the other artificial light signals (35).

4. The headlamp control system of claim 3, wherein the control unit (55) is in communication with the first and second light sensors (20) and (30) of the light sensing unit (15) for receiving the vehicle headlamp light spectrum from the first light sensor (20) and the other artificial light spectrum from the second light sensors (30) in order to determine the presence and light intensity of the oncoming vehicle headlamp (44) and the presence of artificial lights on the road.
5. The headlamp control system of claim 1, wherein the control unit (55) further comprises a status indicator (50) that is electrically connected to the control unit (55) to display the real time operational status related to a power availability, the current headlamp beam, and the operation mode to the vehicle driver.
6. The headlamp control system of claim 1, wherein the plurality of operation modes (60) is divided into a first mode (65), a second mode (70), and a third mode (75) with respect to the real-time vehicle movement information (45).
7. The headlamp control system of claims 1, 2 and 6, wherein in the first mode (65), the control unit (55) maintains the own vehicle headlamp (34) in the low beam state independent of an external condition and transmits the control signal (95) to request the oncoming vehicle (43) to shift the headlamp (44) to the low beam state while detecting a glare from the oncoming vehicle headlamp (44).
8. The headlamp control system of claims 1, 2 and 6, wherein in the second mode (70), the control unit (55) detects the glare based on the light level of the headlamps (44) of the oncoming vehicle (43), which shifts the vehicle headlamp causing the glare into the low beam state and subsequently maintains both the own and oncoming vehicle headlamps (34) and (44) in the low beam state until the own and oncoming vehicles (33) and (43) cross each other.
9. The headlamp control system of claim 8, wherein the vehicle headlamp (34) of the own vehicle (33) is shifted to the high beam state if the system (10) detects the disability glare.
10. The headlamp control system of claims 1, 2 and 6, wherein in the third mode (75), the control unit (55) maintains the headlamps (34) of the own vehicle (33) in the high beam state

independent of the external condition and transmits the control signal (95) to request the oncoming vehicle (43) to shift the headlamp (44) to the low beam state while detecting the disability glare from the oncoming vehicle headlamp (44).
11. The headlamp control system of claim 1, wherein the control unit (55) is composed of a first control unit (85) that is electrically connected to the light sensing unit (15) to receive the headlamp light signal (25) of the oncoming vehicle headlamp (44), and a second control unit (90) that is electrically connected to the speed sensing unit (40) to receive the vehicle movement information (45) and also to the wireless communication unit (80) to send and receive wireless communication signals.
12. The headlamp control system of claims 1, 7 and 11, wherein the real-time vehicle movement information (45) is composed of a signal of vehicle speed, vehicle direction of travel and vehicle geographical position.
13. A method (98) for controlling and switching a vehicle headlamp between high and low beam states of both own and oncoming vehicles (33) and (43), comprising:
continuously detecting a headlamp light signal (25) of an oncoming vehicle (43) by sensing a desired range of wavelength in an electromagnetic spectrum by a light sensing unit (15) and differentiating the headlamp light signal (25) from light signals (35) of other artificial light sources;
capturing and generating real-time vehicle movement information (45) of its own vehicle by a speed sensing unit (40); and
while determining the presence of oncoming vehicle headlamp (44), processing, by a control unit (55), data indicative of the headlamp light signal (25) and the vehicle movement information (45) for automatically controlling and switching the beam states of the own vehicle headlamp (34) and the oncoming vehicle headlamp (44) based on a plurality of operation modes (60) with respect to the real-time vehicle movement information (45).
14. The method of claim 13, wherein the plurality of operation modes (60) is divided into a first mode (65), a second mode (70), and a third mode (75) with respect to the real-time vehicle movement information (45).
15. The method of claim 13 and 14, further comprising: wirelessly transmitting a control

signal (95) requesting to shift the beam state of the headlamp, to the oncoming vehicle (43), and indicating a real-time operational status of the headlamp control system (10) to the vehicle driver.
16. The method of claims 14 and 15, further comprising manually overriding and intervening the control signal (95) from the control unit (55) to obtain a reverse beam of the own vehicle (33) based on judgement of the driver.
17. The method of claims 13 to 16, wherein in the first mode (65), the method further comprises the steps of:
maintaining the own vehicle headlamp (34) in the low beam state independent of an external condition; and
transmitting the control signal (95) to request the oncoming vehicle (43) to shift the headlamp (44) to the low beam state while detecting a glare from the oncoming vehicle headlamp (44).
18. The method of claims 13 to 16, wherein if both vehicles are in the second mode (70),
the method further comprises the steps of:
detecting the glare based on the light level of the headlamps (44) of the oncoming vehicle and (43); and
after detecting the glare, shifting the vehicle headlamp causing the glare into the low beam state and subsequently maintaining both the own and oncoming vehicle headlamps (34) and (44) in the low beam state until the own and oncoming vehicles (33) and (43) cross each other.
19. The method of claims 13 to 16, the method further comprises the steps of:
Shifting the vehicle headlamp (34) of the own vehicle (33) to the high beam state if the system (10) detects the disability glare.
20. The method of claims 13 to 16, wherein in the third mode (75), the method further
comprises the steps of:
maintaining the headlamp (34) of the own vehicle (33) in the high beam state independent of the external condition; and
transmitting the control signal (95) to request the oncoming vehicle (43) to shift the

headlamp (44) to the low beam state while detecting a glare from the oncoming vehicle headlamp (44).
21. The method of claims 13 and 14, wherein the real-time vehicle movement information (45) is composed of a signal of vehicle speed, vehicle direction of travel and vehicle geographical position.