Technical Field r#
[0001] The present invention generally relates to a control system
for a vehicle and particularly relates to an electronic control system for a
lighting assembly of the vehicle.
Background
[0002] In automobiles, typically, a front lighting assembly including a
headlamp device serves to function in dual lighting mode, i.e. either in a
high beam mode or in a low beam mode. Particularly, the front lighting
assembly includes a headlamp beam control switch, for manual selection
of said high beam mode or said low beam mode, thereby permitting a
driver to switch between the high beam mode and the low beam mode
depending on driving conditions on the road.
[0003] Typically, the energy required to power said headlamp
device is drawn either from a battery or an alternating current (AC).
generator (also caHed a magneto) connected with the engine. The battery
is charged through a regulator-rectifier unit which converts the alternating
current generated into regulated direct current. The regulator-rectifier unit
can also provide regulated AC voltage for supplying to AC loads. At low
engine speeds, the voltage generated by the magneto is low and if the
headlamp device is only connected with the regulated AC voltage then the
intensity of the headlamp device will be less. To provide constant
illumination even during low engine speeds, the headlamp is generally
powered from the battery which in turn is charged through the rectified and
regulated AC voltage.

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[0004] At high engine speeds, the magneto generates sufficient
voltage for charging the battery and for supplying to the headlamp device.
But at low engine speeds, particularly during engine idling condition, the
headlamp device draws power from the battery to maintain light intensity
and the magneto voltage is insufficient to charge the battery, thereby
leading to draining of battery charge. It is therefore desirable to disallow
the battery from discharging high currents in such conditions.
[0005] Conventional arts teach controlling the lighting mode and
intensity of lighting of the headlamp device with the aid of signals based on inputs from multiple sensors such as speed sensor, illumination sensor, steering sensor, weather sensor and the like. However, use of multiple sensors for controlling the lighting mode of the headlamp device, not only involves increased costs but also increases design complexities in the vehicle.
[0006]. Besides the headlamp beam control switch, the front lighting
assembly also includes a pass-by, the manual selection of which causes light produced by the headlamp device to switch to high beam so as to enable the driver to give a crossing signal or a pass signal to a rider riding ahead. However, conventionally in vehicles, a pass mode of the headlamp device is not useful in all conditions. For example, when the headlamp device is functioning in the high beam mode, especially in vehicles operating in full DC systems, selection of the pass-by does not result in any discernible intensity variation which the other rider can recognize. In

other words, despite the manual selection of the pass-by, the headlamp device continues to function in the high beam mode, and thereby failing to give a pass indication to the rider riding ahead. There is therefore a need to aJso control the pass mode of the headlamp device and ensure functioning of the pass mode in all driving conditions. Summary of the Invention
[0007] The present invention has been made in view of the above
circumstances.
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[0008] It is an object of the present invention to provide a vehicle
including an electronic control system which is adapted to control
operation of a lighting assembly including a headlamp device.
[0009] It is another object of the present invention to provide a
vehicle including an electronic control system which is adapted to control
operation of the headlamp device during engine idling conditions.
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[0010] It is yet another object of the present invention to provide a
vehicle including an electronic control system which is adapted to control operation of the headlamp device based on inputs received from a pulser coil, a headlamp switch, a headlamp beam control switch, a pass-by, and an ignition switch.
[0011] It is still another object of the present invention to provide a
vehicle including an electronic control system which aids in ensuring functioning of a pass mode of the headlamp device in all conditions.

[0012] With the above and other objects in view, the present
invention provides a vehicle including an electronic control system . comprising an electronic control unit for controlling an operation of a lighting assembly including a headlamp device. As per an embodiment of the present invention, in order to control the operation of the headlamp device, the electronic control unit is adapted to be responsive to a headlamp switch position, a headlamp beam control switch position, and a pass-by switch position, of the headlamp switch, the headlamp beam control switch, and the pass-by switch respectively of the lighting assembly, besides being responsive to inputs from a pulser coil operatively connected to an engine of the vehicle.
[0013] In one embodiment, a method of operation of the electronic
control unit for controlling operation of the headlamp device during engine idling conditions is described. The method includes detecting engine speed of the vehicle at all points in time based on inputs from the pulser coil, and taking inputs about the.headlamp beam control switch position; activating operation of the headlamp device by pulse width modulation (hereinafter 'PWM') for a predetermined duration if the engine speed is below a predetermined threshold value. In other words, the headlamp device will produce light with maximum intensity either in the high beam mode or in the low beam mode for a predetermined duration after which the effective voltage supplied to the headlamp device is reduced so that the headlamp device glows with reduced brightness. Thus, by reducing

the effective voltage supplied to the headlamp device by performing PWM,
the electronic control unit aids in reducing energy consumption from the
battery.
[0014] Further, the embodiment also describes a method of
operation of the electronic control unit for controlling operation of the
headlamp device when the pass-by switch is selected in different riding
conditions.
[0015] Summary provided above explains the basic features of the
invention and does not limit the scope of the invention. The nature and
further characteristic features of the present invention will be made clearer
from the following descriptions made with reference to the accompanying
drawings.
Brief Description of Drawings
[0016] The above and other features, aspects, and advantages of
the subject matter will be better understood with regard to the following
description and accompanying drawings where:
[0017] FIG.1 is a schematic representation of a circuit of the
electronic control system in accordance with an embodiment of the
present invention.
[0018] FIG.2 illustrates a flow chart depicting steps of.a method of
operation of the electronic control system controlling operation of a lighting
assembly in accordance with an embodiment of the present invention.

Detailed Description of the Preferred Embodiments
[0019] The present subject matter described herein provides for an
electronic control system for controlling operation of a lighting assembly of
a vehicle, said lighting assembly including a headlamp device. Particularly,
the electronic control system includes ah electronic control unit for
controlling operation of the headlamp device during engine idling
conditions. Besides, according to an aspect of the invention, the electronic
control unit also controls operation of the headlamp device in relation to
operation of a headlamp switch, a headlamp beam control switch, and a
pass-by switch of the lighting assembly during different driving conditions.
[0020] Exemplary embodiments detailing features of the electronic
control system, in accordance with the present invention will be described
hereunder. The embodiments described herein apply to a vehicle powered
by an engine and a voltage source such as a battery, wherein said engine
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is operatively connected to a pulser coil. Further, for the engine to operate,
an ignition switch is provided in the vehicle. The vehicle further comprises
. a lighting assembly energized by the battery, said lighting assembly
including a headlamp device, a headlamp switch, a headlamp beam
control switch and a pass-by switch. The electronic control system
includes an electronic control unit operatively connected to the lighting
assembly and the pulser coil.
[0021]. Referring to FIG.1, a description is made of a schematic
representation of the electronic control system A as per an embodiment of

the present invention. As may be seen, the electronic control system A includes a magneto assembly 1 which generates an alternating current due to a rotating magnetic field. Alternating current from the magneto assembly 1 is rectified and regulated by a Regulator and Rectifier (hereinafter 'RR') unit 2 into direct current. The RR unit 2 maintains a direct current voltage within strict tolerances to ensure optimum charging of the battery 3 and satisfactory performance of all vehicle loads. A fuse 4 protects the battery 3 against short circuit conditions. When an ignition switch 5 in the vehicle is turned ON, the battery 3 supplies direct current to an electronic control unit 6. The electronic control unit 6 is adapted to receive inputs from various manually controlled switches of the lighting assembly including the headlamp switch 7, the headlamp beam control switch 8, and the pass-by 9. Particularly, the electronic control unit 6 drives the headlamp device in a low beam mode, a high beam mode, and a toggle mode in which the headlamp device toggles between the high beam mode and the low beam mode or vice versa based on the headlamp beam control switch position and the pass-by switch position. Particularly, the electronic control unit 6 drives the toggle mode from high beam to low beam and back to high beam when the position of the headlamp beam control switch is in high beam mode and correspondingly the pass-by switch has been selected. Similarly, the electronic control unit 6 drives the toggle mode from low beam to high beam and back to low beam when the position of the headlamp beam control switch is in low beam mode and

correspondingly the pass-by switch has been selected. Besides the above mentioned manual switches, the electronic control unit 6 also receives inputs from a pulser coil 10 for calculating engine speed from a pulser coil signal. In the present embodiment, the electronic control unit 6 also controls spark ignition by driving an ignition coil.
[0022] As per an embodiment of the present invention, the
electronic control unit 6 controls operation of the headlamp device in engine idling conditions based on inputs received from the pulser coil 10 operatively connected to the engine. The electronic control unit 6 includes a microcomputer which calculates engine speed from an input given in the form of pulser coil signal and processes the same based on predetermined engine speed values stored therein. Information processed by the microcomputer is sent as an input signal to a headlamp driver encompassed in the electronic control unit 6, which in turn causes the headlamp device to operate with a reduced intensity during engine idling conditions, iri other words, the headlamp driver reduces the effective voltage supplied from the voltage source such as the battery to the headlamp device during engine idling conditions and causes the headlamp device to operate at a reduced operating voltage.
[0023] As per another embodiment of the present invention, battery
voltage may be used as an input instead of engine speed by the electronic control unit 6, based on which intensity of light produced by the headlamp device can be controlled; When the battery is in a good state of charge,

the headlamp device can be operated at a high duty cycle and the duty
cycle can be reduced based on battery voltage deterioration.
[0024] As per an aspect of the present invention, the electronic
control unit 6 is also responsive to the operation of the headlamp beam
control switch 8, and to the pass-by switch 9 for causing operation of the
headlamp device in a toggle mode. For example, when a rider riding in
the high beam mode operates the pass-by switch 9 to give a crossing
signal to a driver riding ahead, the headlamp device automatically toggles
between the high beam mode to the low beam mode and back to the high
beam mode rather than continuing to glow in the high beam mode as
observed in conventional vehicles, thereby activating the pass functionality
even when the headlamp device is operating in the high beam mode.
[0025] FIG.2 represents a flow chart which represents the steps of
operation of the electronic control unit 6 for operating the headlamp device under different conditions.. In a first step of its operation, the electronic control unit 6 determines engine operating conditions based on input from the pulser coil 10. Further, in the first step of its operation, the electronic control unit 6 also takes input regarding the headlamp beam control switch 8 position. Based on the engine operating conditions, the electronic control unit 6 causes the headlamp device to function with headlamp output duty cycle either at 50% or 100% by performing pulse width modulation (PWM) when the engine speed is lesser than or greater than a predetermined engine rpm. For example, if the engine operating condition is ON, and the

engine speed is less than 800 rpm (idling condition, for example) for 20s,
the headlamp device is made to operate with headlamp output duty cycle
at 50%. However, if the engine operating condition is ON, and the engine
speed is greater than 800 rpm for 20s, the headlamp device is made to
operate with headlamp output duty cycle at 100%. Particularly, when the
electronic control unit 6 is performing PWM dimming operation and the
engine speed is raised above 800 rpm, then the PWM dimming operation
is stopped and the electronic control unit 6 allows the headlamp device to
glow with maximum brightness either in the high beam mode or in the low
beam mode based on the headlamp beam control switch 8 position. In
other words, the electronic control unit 6 causes the headlamp device to
glow with reduced intensity irrespective of whether the headlamp beam
control switch position is in high beam or low beam, if the engine rpm is
below the predetermined engine rpm. Further, in conditions where the
engine speed exceeds 800 rpm substantially, the magneto assembly 1
supplies required current to the electronic control unit 6 through the RR
unit 2, thereby ensuring that the battery 3 heed not discharge, high
. currents. <• r
[0026] Thus, if the engine is in idling condition for more than 20s,.
the headlamp device operates with reduced intensity since the voltage supplied to the headlamp device is reduced. As a result, energy consumption from battery is reduced.

[0027] In a second step of its operation, the electronic control unit 6
controls operation of the headlamp device based on operation of the pass-by switch 9 in relation to the headlamp switch 7 position and the headlamp beam control switch 8 position, in an engine operating condition. For example, if the pass-by switch 9 is activated when the headlamp switch is ON and the headlamp beam control switch 8 is positioned to function in the low beam mode, then the electronic control unit 6 causes the headlamp device to function in the toggle mode, wherein the headlamp device toggles from the low beam mode to the high beam mode and back to the low beam mode when the pass-by switch 9 is deactivated. Similarly, if the pass-by switch 9 is activated when the headlamp switch is ON and the headlamp beam control switch 8 is positioned to function in the high beam mode, then the electronic control unit 6 causes the headlamp device to function in the toggle mode, wherein the headlamp device toggles from the high beam mode to the low beam mode and back to the high beam mode when the pass-by switch 9 is deactivated: Thus, the electronic control unit 6 aids in generating a discernible change in the headlamp lighting, due to which passing intention can be clearly communicated to an oncoming rider. Therefore, the driver can give a crossing signal or a pass to the rider riding ahead in night driving conditions even when the headlamp device is being operated in the high beam mode. Thus, the automatic toggling of the headlamp device when the pass-by switch 9 is activated does away with the need of performing a highly repetitive action

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of manually switching between the high beam mode and the low beam mode, thus facilitating driver convenience.
[0028] Further, the electronic control unit 6 also enables the driver
to communicate the pass signal effectively even during day conditions. For example, during day conditions when the headlamp switch is OFF, and the pass-by switch 9 is activated to signal crossing/over taking, the electronic control unit 6 causes the headlamp device to function in 100% output duty cycle, thereby causing it to glow with full brightness in the high beam mode. Moreover, in an engine non-operating condition but where the ignition switch is ON, a condition which is commonly observed when the vehicle is standing at a traffic signal; the driver may switch on the pass-by switch 9 to indicate that he/she is about to pass or over-take a vehicle waiting ahead. In such a situation, when the pass-by switch position is ON,
the electronic control unit 6 causes the headlamp device to function in the
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high beam mode at 50% output duty cycle. In other words, in a condition when the engine rpm is less than the predetermined engine rpm, and the headlamp switch position is OFF; the driver selects the pass-by switch 9 to indicate that he/she is about to pass or over-take a vehicle waiting ahead, the electronic control unit 6 causes the headlamp device to operate in high beam mode at 50% output duty cycle. Thus, safety feature of the vehicle is ensured completely while ensuring that battery is not unnecessarily discharged.

[0029] In the present embodiment, the headlamp device is provided
with halogen filled tungsten filament bulbs for operation in the high beam mode and the low beam mode. However, instead of halogen filled tungsten filament bulbs, the headlamp device can also be provided with LED bulbs or high intensity discharge lamps.
[0030] These and other modifications are possible without departing
from the spirit and. scope of the invention.
[0031] While the present invention has been shown and described
with reference to the foregoing preferred embodiments, it will be apparent
to those skilled in the art that changes in form, connection, and detail may
be made therein without departing from the spirit and scope of the
invention as defined in the appended claims.