Field of the Invention:
The invention generally related to method and device for indicating illuminating unit failure
condition. In particular, the invention relates to method and device for monitoring failure of
illuminating unit(s) provided in automotive vehicles.
Background of the Invention:
Various types of illuminating unit failure indicating circuits have heretofore been proposed.
By way of example, U.S. Patent No. 4,667,187 discloses a system for monitoring the integrity
of a series circuit containing a single incandescent lamp and associated conductors between a
source of DC voltage and a switching device controllable to either an opened or closed
condition, comprising: means for periodically cycling said switching device between its
opened and closed conditions; means for correspondingly sensing periodic current flow in
one of said lamp conductors; means for indicating a failure of circuit continuity when said
circuit sensing means fails to sense periodic current flow in said one conductor; and wherein
said switching device is a power transistor that is independently controlled to either its
conducting or non-conducting state and said cycling means periodically changes the biasing
of said power transistor from its independently controlled state to its opposite state and back
again.
In yet another example, U.S. Patent 5,680,098 discloses as part of a lighting system for use in
automotive vehicle a system that comprises a controller connected to a first and a second
light sources, for detecting a current to the first light source. Upon detection of a failure of the
first light source, the controller modulates the second light source to provide the function of
the first light source with substantially the first intensity.
The teachings of the aforesaid patents are applicable in case the incandescent lamp or the
lighting system is connected to a source of DC voltage. However, in many instances in a
vehicle, an illuminating unit such as a headlight unit is not powered directly by a DC voltage.
In particular, in many instances, a regulator-rectifier circuit connected to an output of an
alternating current generator (as provided in a vehicle) powers the headlight unit and hence, it
is not possible to adopt the teachings of the aforesaid patents.
While there may be many other documents describing illumination unit failure detection
method and devices, there is still a need to provide a method and a device for detecting
failure of an illumination unit which is powered by regulator-rectifier circuit connected to an
3
output of an alternating current generator. Also in relation to automotive vehicles, such
method should be robust as well as easy to implement. The device should be cost effective.
Summary of the Invention:
Accordingly, the present invention provides a method for detecting failure of an illuminating
unit provided in a vehicle, said method comprising the steps of:
• receiving a current engine speed;
• counting a number of pulses of a first type flowing through a current detection path in
one rotation of the engine, the current detection path being parallel to the illuminating
unit;
• counting a number of pulses of a second type flowing through the current detection
path in one rotation of the engine; and
• detecting an illuminating unit failure condition if:
o the current engine speed is in excess of a predetermined level;
o the number of pulses of the first type is less than a first preset value; and
o the number of pulses of the second type is equal to or greater than a second
preset value.
The present invention also provides a device for detecting failure of an illuminating unit
provided in a vehicle, said device comprising:
• a first means for counting a number of pulses of a first type flowing through a current
detection path in one rotation of the engine, the current detection path being parallel
to the illuminating unit;
• a second means for counting a number of pulses of a second type flowing through the
current detection path in one rotation of the engine; and
• a detection unit coupled to the first means and the second means for receiving inputs
there from, the detection unit being further adapted to receive a current engine speed
and detect an illuminating unit failure condition if:
o the current engine speed received is in excess of a predetermined level;
o the number of pulses of the first type is less than a first preset value; and
o the number of pulses of the second type is equal to or greater than a second
preset value.
4
The present invention furthermore provides a vehicle comprising an illuminating unit adapted
to receive electrical power from a regulator–rectifier circuit, the regulator-rectifier circuit
being adapted to receive electrical power from an alternating current generator that is driven
by an engine of the vehicle; and a device for detecting failure of the illuminating unit
provided in the vehicle, said device comprising:
• a first means for counting a number of pulses of a first type flowing through a current
detection path in one rotation of the engine, the current detection path being parallel
to the illuminating unit;
• a second means for counting a number of pulses of a second type flowing through the
current detection path in one rotation of the engine; and
• a detection unit coupled to the first means and the second means for receiving inputs
there from, the detection unit being further adapted to receive a current engine speed
and detect an illuminating unit failure condition if:
o the current engine speed received is in excess of a predetermined level;
o the number of pulses of the first type is less than a first preset value; and
o the number of pulses of the second type is equal to or greater than a second
preset value.
The present invention further provides a method for detecting failure of a plurality of
illuminating units provided in a vehicle, said method comprising the steps of:
• receiving a current engine speed;
• counting a number of pulses of a first type flowing through a first current detection
path in one rotation of the engine, the first current detection path being parallel to a
first illuminating unit;
• counting a number of pulses of a second type flowing through the first current
detection path in one rotation of the engine;
• counting a number of pulses of a first type flowing through a second current detection
path in one rotation of the engine, the second current detection path being parallel to a
second illuminating unit;
• counting a number of pulses of a second type flowing through the second current
detection path in one rotation of the engine; and
• detect a failure condition pertaining to at least one of the plurality of illuminating
units based on a plurality of:
o the current engine speed,
5
o the number of pulses of the first type flowing through the first current
detection path,
o the number of pulses of the second type flowing through the first current
detection path,
o the number of pulses of the first type flowing through the second current
detection path, and
o the number of pulses of the second type flowing through the second current
detection path.
The present invention further provides a device for detecting failure of a plurality of
illuminating units provided in a vehicle, said device:
• a first means for counting a number of pulses of a first type flowing through a first
current detection path in one rotation of the engine, the first current detection path
being parallel to a first illuminating unit;
• a second means for counting a number of pulses of a second type flowing through the
first current detection path in one rotation of the engine;
• a third means for counting a number of pulses of a first type flowing through a second
current detection path in one rotation of the engine, the second current detection path
being parallel to a second illuminating unit;
• a fourth means for counting a number of pulses of a second type flowing through the
second current detection path in one rotation of the engine; and
• a detection unit being in operational interconnection with the first means, the second
means, the third means and the fourth means, the detection unit being adapted to
receive a current engine speed and receive inputs from the first, second, third and
fourth means and detect a failure condition pertaining to at least one of the plurality of
illuminating units.
A vehicle comprising:
• a first illuminating unit and a second illuminating unit, each of the first and the second
illuminating units being adapted to receive electrical power from a regulator–rectifier
circuit, the regulator-rectifier circuit being adapted to receive electrical power from an
alternating current generator that is driven by an engine of the vehicle;
• a first and a second means provided in relation to a first current detection path, the
first current detection path being parallel to the first illuminating unit, the first means
6
being adapted for counting a number of pulses of a first type flowing through the first
current detection path in one rotation of the engine and the second means being
adapted for counting a number of pulses of a second type flowing through the first
current detection path in one rotation of the engine;
• a third and a fourth means provided in relation to a second current detection path, the
second current detection path being parallel to the second illuminating unit, the third
means being adapted for counting a number of pulses of a first type flowing through
the second current detection path in one rotation of the engine and the fourth means
being adapted for counting a number of pulses of a second type flowing through the
second current detection path in one rotation of the engine; and
• a detection unit being in operational interconnection with the first means, the second
means, the third means and the fourth means, the detection unit being adapted to
receive a current engine speed and receive inputs from the first, second, third and
fourth means and detect a failure condition pertaining to at least one of the plurality of
illuminating units.
The foregoing, along with additional features, advantages, and benefits of the invention, will
be seen in the ensuing description and claims which should be considered in conjunction with
the accompanying drawings. The drawings disclose preferred embodiments of the present
invention in accordance with the best mode contemplated at the present time for carrying out
the invention.
Brief Description of Figures:
These and other features, aspects, and advantages of the present invention will become better
understood when the following detailed description is read with reference to the
accompanying drawings in which like characters represent like parts throughout the
drawings, wherein:
Figure 1 illustrates a flow chart of a method for detecting failure of an illuminating unit
provided in a vehicle in accordance with an embodiment of the invention;
Figure 2 illustrates a block diagram of a vehicle incorporating a device for detecting failure of
an illuminating unit provided in the vehicle in accordance with an embodiment of the
invention;
7
Figure 3 illustrates a flow chart of a method for detecting failure of at least one of a plurality
of illuminating units provided in a vehicle in accordance with an embodiment of the
invention; and
Figure 4 illustrates a block diagram of a vehicle incorporating a device for detecting failure of
at least one of a plurality of illuminating units provided in a vehicle in accordance with an
embodiment of the invention.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and may not have been necessarily been drawn to scale. For example, the flow
charts illustrate the method in terms of the most prominent steps involved to help to improve
understanding of aspects of the present invention. Furthermore, in terms of the construction
of the device, one or more components of the device may have been represented in the
drawings by conventional symbols, and the drawings may show only those specific details
that are pertinent to understanding the embodiments of the present invention so as not to
obscure the drawings with details that will be readily apparent to those of ordinary skill in the
art having benefit of the description herein.
Detailed Description:
For the purpose of promoting an understanding of the principles of the invention, reference
will now be made to the embodiment illustrated in the drawings and specific language will be
used to describe the same. It will nevertheless be understood that no limitation of the scope of
the invention is thereby intended, such alterations and further modifications in the illustrated
system, and such further applications of the principles of the invention as illustrated therein
being contemplated as would normally occur to one skilled in the art to which the invention
relates.
It will be understood by those skilled in the art that the foregoing general description and the
following detailed description are exemplary and explanatory of the invention and are not
intended to be restrictive thereof.
Reference throughout this specification to “an aspect”, “another aspect” or similar language
means that a particular feature, structure, or characteristic described in connection with the
embodiment is included in at least one embodiment of the present invention. Thus,
appearances of the phrase “in an embodiment”, “in another embodiment” and similar
8
language throughout this specification may, but do not necessarily, all refer to the same
embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a
non-exclusive inclusion, such that a process or method that comprises a list of steps does not
include only those steps but may include other steps not expressly listed or inherent to such
process or method. Similarly, one or more devices or sub-systems or elements or structures or
components proceeded by "comprises a" does not, without more constraints, preclude the
existence of other devices or other sub-systems or other elements or other structures or other
components or additional devices or additional sub-systems or additional elements or
additional structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skill in the art to which this invention
belongs. The system, methods, and examples provided herein are illustrative only and not
intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the
accompanying drawings.
Referring to Figure 1, there is illustrated a flow chart of a method 100 for detecting failure of
an illuminating unit as provided in a vehicle. The method 100 comprises a step of receiving
102 a current engine speed, a step of counting 104 a number of pulses of a first type flowing
through a current detection path in one rotation of the engine; and a step of counting 106 a
number of pulses of a second type flowing through the current detection path in one rotation
of the engine. In an embodiment of the invention, the current detection path is formed so as to
be parallel to the illuminating unit. In an embodiment of the invention, the step of receiving
102 the current engine speed, the step of counting 104 the number of pulses of the first type
and the step of counting 106 the number of pulses of the second type can be performed in any
sequence.
The method further comprises detecting an illumination unit failure condition if:
o the current engine speed is in excess of a predetermined level;
o the number of pulses of the first type is less than a first preset value; and
9
o the number of pulses of the second type is equal to or greater than a second
preset value.
In this regard, referring to figure 1, the method 100 comprises a step of detecting 108 whether
the current engine speed is in excess of a predetermined level. In case the current engine
speed (which may be represented in terms of rotations per minute (rpm)) is in excess of the
predetermined level, the method 100 proceeds to performing a step of detecting 110 whether
the number of pulses of the first type is less than a first preset value. In case the number of
pulses of the first type is less than the first preset value, the method 100 proceeds to
performing a step of detecting 112 whether the number of pulses of the second type is equal
to or greater than a second preset value. In case the number of pulses of the second type is
equal to or greater than the second preset value, the method 100 detects 114 an illumination
unit failure condition.
If it is detected in step 108 that the current engine rpm is not in excess of the predetermined
level, the method 100 may not proceed to performing the step of detecting 110 whether the
number of pulses of the first type is less than a first preset value. By way of a non-limiting
example, the method may re-perform the step of detecting 108 whether the current engine
speed is in excess of a predetermined level after a predetermined amount of time period
instead of performing the step of detecting 110 whether the number of pulses of the first type
is less than a first preset value.
If it is detected in step 110 that the number of pulses of the first type is equal to or more than
the first preset value, the method 100 detects 116 an illumination unit OK condition. If it is
detected in step 112 that the number of pulses of the second type is less than the second
preset value, the method 100 detects 118 an illumination unit OK condition.
In an embodiment of the invention, the pulses of the first type have a first voltage value and
the pulses of the second type have a second voltage value, the second voltage value being at
least 30% greater than the first voltage value. In another embodiment of the invention, the
second preset value is one. In yet another embodiment of the invention, the first preset value
is provided by the equation:
= ∗
wherein N is the number of poles present in the alternating current generator provided in the
vehicle;
10
F is a fraction having a value in the range of 0.25 to 0.8; and
V is the first preset value, which is rounded off to an integer value.
In an embodiment of the invention, in response to detecting an illumination unit failure
condition 114 the method 100 may further comprise a step of generating 120 an illumination
unit failure indicating signal for providing to an output device for output there-from. The
output device may be preferably placed on the vehicle. The output device may provide a
visual output or an audio output or a combination thereof. By way of example, the output
device may be in the form of a visual indicator and the illumination unit failure indicating
signal may illuminate the visual indicator.
In an embodiment of the invention, in response to detecting an illumination unit failure
condition 114, the method 100 may further comprise transmitting 122 the illumination unit
failure indicating signal to one or more remote devices.
Referring to figure 2, the present invention furthermore provides a vehicle 200 comprising:
an illumination unit 202 adapted to receive electrical power from a regulator–rectifier circuit
204 through a switch 206, the regulator-rectifier circuit 204 being adapted to receive
electrical power from an alternating current generator (ACG) 208 that is driven by an engine
210 of the vehicle 200; and a device 212 for detecting failure of the illumination unit 202
provided in the vehicle 200. There is provided a current detection path 214 which is parallel
to the illumination unit 202 and the device 212 is adapted to sense characteristics of current
flowing through said current detection path 214.
In an embodiment of the invention the device 212 comprises a first means 216 for counting a
number of pulses of a first type flowing through the current detection path 214 in one rotation
of the engine 208 and a second means 218 for counting a number of pulses of a second type
flowing through the current detection path 214 in one rotation of the engine.
The device 212 further comprises a detection unit 220 coupled to the first means 216 and the
second means 218 for receiving inputs there-from. The detection unit 220 is further adapted
to receive a current engine speed and detect an illumination unit failure condition if: the
current engine speed received is in excess of a predetermined level; the number of pulses of
the first type is less than a first preset value; and the number of pulses of the second type is
equal to or greater than a second preset value.
11
In response to detecting an illumination unit failure condition, the device 212 may be further
adapted to generate an illumination unit failure indicating signal. The device 212 may
comprise a signal generating unit 222 for generating the illumination unit failure indicating
signal. The illumination unit failure indicating signal thus generated may be given to an
output device 224 that is preferably placed on the vehicle 200 for output there-from.
The device 210 may be further adapted enable transmission of the illumination unit failure
indicating signal to one or more remote devices (not shown). In this regard, there may be
provided a transmitting unit 226. The transmission unit 226 may either form part of the
device 212 or may form part of the vehicle 200 but is external to the device 212 (as shown in
Figure 2).
In an embodiment of the invention, the first means, the second means, the detecting unit, the
signal generating unit can all be all be implemented within a microprocessor. Alternatively,
some, but NOT all of the aforesaid means/units can be implemented within a micro-processor
and the remaining means/units can be implemented as discrete components that are operably
connected to the micro-processor. In yet another alternative, all of the aforesaid means/units
can be implemented as discrete components, which are appropriately interconnected.
In an embodiment, if the vehicle 200 already comprises a current engine speed calculating
section (or alternatively a RPM calculating section) 228, the device 212 may receive the
current engine speed thus calculated by the RPM calculating section 228. If the vehicle 200
does not comprise a RPM calculating section or if it becomes practically difficult for the
device 212 to receive the current engine speed from the RPM calculating section, then the
device 212 may receive from a sensor disposed on the vehicle information for calculating the
current engine speed. By way of a non-limiting example, the device 212 may receive signals
as produced by a crank position sensor 230 and may calculate the current engine speed therefrom.
Based on the signals received from the crank position sensor 230 the device 212 (and more
particularly, the first means 216 and the second means 218) may demarcate the pulses
received during a first rotation of the engine from the pulses received during a second
rotation of the engine. By way of example, based on the signals received from the crank shaft
position sensor, the device 212 may demarcate the pulses of the first type received during a
12
first rotation of the engine from the pulses of the first type received during a second rotation
of the engine. By way of another example, based on the signal received from the crank shaft
position sensor, the device 212 may demarcate the pulses of the second type received during
a first rotation of the engine from the pulses of the second type received during a second
rotation of the engine. Thus, the first means 216 counts the number of pulses of the first type
received between two consecutive crank position signals and treats this value as the number
of pulses of the first type received during one rotation of the engine. Likewise, the second
means 218 counts the number of pulses of the second type received between two consecutive
crank position signals and treats this value as the number of pulses of the second type
received during one rotation of the engine.
The method and the device as explained in relation to figures 1 and 2, is specifically provided
to cater to detecting failure of an illumination unit which is powered by a regulator-rectifier
circuit connected to an output of an alternating current generator (as provided in a vehicle).
In a vehicle, there may be plurality of illuminating units that are powered by a regulatorrectifier
circuit connected to an output of an alternating current generator (as provided in a
vehicle). In scenarios where the vehicle has plurality of illuminating units that are powered
by a regulator-rectifier circuit connected to an output of an alternating current generator, it
becomes desirable to detect failure of at least one of the plurality of illuminating units thus
provided in the vehicle. One example of the above scenario is a headlamp that includes a first
illuminating unit for providing a high-beam function and a second illuminating unit for
providing a low-beam function. In relation to such a headlamp, it is desirable to detect failure
of the first illuminating unit as well as to detect failure of the second illuminating unit.
Referring to Figure 3, there is illustrated a flow chart of a method 300 for detecting failure of
at least one of a plurality of illuminating units as provided in a vehicle. The method 300
comprises a step of receiving 302 a current engine speed. The method further comprises a
step of counting 304 a number of pulses of a first type flowing through a first current
detection path in one rotation of the engine; and a step of counting 306 a number of pulses of
a second type flowing through the first current detection path in one rotation of the engine. In
an embodiment of the invention, the first current detection path is formed so as to be parallel
to the first illuminating unit. The method further comprises a step of counting 308 a number
of pulses of a first type flowing through a second current detection path in one rotation of the
engine; and a step of counting 310 a number of pulses of a second type flowing through the
13
second current detection path in one rotation of the engine. In an embodiment of the
invention, the second current detection path is formed so as to be parallel to the second
illuminating unit.
The method further comprises detecting 312 a failure condition pertaining to at least one of
the plurality of illuminating units based on a plurality of:
o the current engine speed,
o the number of pulses of the first type flowing through the first current
detection path,
o the number of pulses of the second type flowing through the first current
detection path,
o the number of pulses of the first type flowing through the second current
detection path, and
o the number of pulses of the second type flowing through the second current
detection path.
In particular, a failure condition corresponding to the first illuminating unit is detected if:
• the current engine speed received is in excess of a predetermined level;
• the number of pulses of the first type flowing through the first current detection path
is less than a first preset value; and
• the number of pulses of the second type flowing through the first current detection
path is equal to or greater than a second preset value.
Likewise, a failure condition pertaining to the second illuminating unit is detected if:
• the current engine speed received is in excess of a predetermined level;
• the number of pulses of the first type flowing through the second current detection
path is less than a first preset value; and
• the number of pulses of the second type flowing through the second current detection
path is equal to or greater than a second preset value.
Referring to figure 4, the present invention furthermore provides a vehicle 400 comprising: a
first illumination unit 402 for a high-beam function and a second illumination unit 404 for a
low-beam function. There are provided two current detection paths 406 and 408, with a first
current detection path 406 being parallel to the first illumination unit 402 and a second
current detection path 408 being parallel to the second illumination unit 404.
14
The first illumination unit 402 is adapted to receive electrical power from a regulator–
rectifier circuit 410 through a switch 412, the regulator-rectifier circuit 410 being adapted to
receive electrical power from an alternating current generator 414 that is driven by an engine
416 of the vehicle 400. Likewise, the second illumination unit 404 is adapted to receive
electrical power from the regulator–rectifier circuit 410, the regulator-rectifier circuit 410
being adapted to receive electrical power from an alternating current generator 414 that is
driven by an engine 416 of the vehicle 400.
There is further provided a first means 418 and a second means 420. The first means is
adapted for counting a number of pulses of a first type flowing through the first current
detection path 406 in one rotation of the engine 416. The second means 420 is adapted for
counting a number of pulses of a second type flowing through the first current detection path
406.
There is further provided a third means 422 and a fourth means 424. The third means 420 is
adapted for counting a number of pulses of a first type flowing through the second current
detection path 408 in one rotation of the engine 416. The fourth means 424 is adapted for
counting a number of pulses of a second type flowing through the second current detection
path 408.
There is further provided a detection unit 426 coupled to the first means 418, the second
means 420, the third means 422 and the fourth means 424 for receiving inputs there-from.
The detection unit 426 being further adapted to receive a current engine speed and receive
inputs from the first, second, third and fourth means and detect a failure condition pertaining
to at least one of the plurality of illuminating units.
By way of a non-limiting example, the detection unit 426 is adapted to detect a first
illuminating unit failure condition if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the first current detection path is less
than a first preset value; and
the number of pulses of the second type flowing through the first current detection path is
equal to or greater than a second preset value.
15
By way of a non-limiting example, the detection unit is adapted to detect a second
illuminating unit failure condition if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the second current detection path is less
than a first preset value; and
the number of pulses of the second type flowing through the second current detection path is
equal to or greater than a second preset value.
In an embodiment, if the vehicle 400 already comprises a current engine speed calculating
section (or alternatively a RPM calculating section) 428, the detection unit 426 may receive
the current engine speed thus calculated by the RPM calculating section 428. If the vehicle
400 does not comprise a RPM calculating section or if it becomes practically difficult for the
detection unit 426 to receive the current engine speed from the RPM calculating section, then
the detection unit 426 may receive from a sensor disposed on the vehicle information for
calculating the current engine speed. By way of a non-limiting example, the detection unit
426 may receive signals as produced by a crank position sensor 430 and may calculate the
current engine speed there-from.
Based on the signals received from the crank position sensor 430 the first means 418, the
second means 420, the third means 422 and the fourth means 424 may demarcate the pulses
received during a first rotation of the engine from the pulses received during a second
rotation of the engine. By way of example, based on the signals received from the crank shaft
position sensor, the first means 418 may demarcate the pulses of the first type received during
a first rotation of the engine from the pulses of the first type received during a second rotation
of the engine. By way of another example, based on the signal received from the crank shaft
position sensor, the second means 420 may demarcate the pulses of the second type received
during a first rotation of the engine from the pulses of the second type received during a
second rotation of the engine.
Likewise, based on the signals received from the crank shaft position sensor, the third means
422 may demarcate the pulses of the first type received during a first rotation of the engine
from the pulses of the first type received during a second rotation of the engine. By way of
another example, based on the signal received from the crank shaft position sensor, the fourth
means 424 may demarcate the pulses of the second type received during a first rotation of the
engine from the pulses of the second type received during a second rotation of the engine.
16
Thus, the first means 418 counts the number of pulses of the first type received between two
consecutive crank position signals and treats this value as the number of pulses of the first
type received during one rotation of the engine. Likewise, the second means 420 counts the
number of pulses of the second type received between two consecutive crank position signals
and treats this value as the number of pulses of the second type received during one rotation
of the engine.
Similarly, the third means 422 counts the number of pulses of the first type received between
two consecutive crank position signals and treats this value as the number of pulses of the
first type received during one rotation of the engine. Similarly, the fourth means 424 counts
the number of pulses of the second type received between two consecutive crank position
signals and treats this value as the number of pulses of the second type received during one
rotation of the engine.
Although not illustrated, there may be provided a signal generating unit for generating an
illumination unit failure indicating signal. The illumination unit failure indicating signal thus
generated may be given to an output device (not illustrated) that is preferably placed on the
vehicle 400 for output there-from.
Also, the illumination unit failure indicating signal may be sent to one or more remote
devices (not shown). To enable the above, there may be provided a transmitting unit (not
shown), which may either form part of the vehicle 400 or any sub-component thereof.
In an embodiment of the invention, the first means, the second means, the third means, the
fourth means, the detecting unit and the signal generating unit can all be implemented within
a microprocessor. Alternatively, some, but NOT all of the aforesaid means/units can be
implemented within a micro-processor and the remaining means/units can be implemented as
discrete components that are operably connected to the micro-processor. In yet another
alternative, all of the aforesaid means/units can be implemented as discrete components,
which are appropriately interconnected.
While specific language has been used to describe the disclosure, any limitations arising on
account of the same are not intended. As would be apparent to a person in the art, various
working modifications may be made to the method in order to implement the inventive
concept as taught herein.
17
The figures and the forgoing description give examples of embodiments. Those skilled in the
art will appreciate that one or more of the described elements may well be combined into a
single functional element. Alternatively, certain elements may be split into multiple
functional elements. Elements from one embodiment may be added to another embodiment.
For example, orders of processes described herein may be changed and are not limited to the
manner described herein. Moreover, the actions of any flow diagram need not be
implemented in the order shown; nor do all of the acts necessarily need to be performed.
Also, those acts that are not dependent on other acts may be performed in parallel with the
other acts. The scope of embodiments is by no means limited by these specific examples.
Numerous variations, whether explicitly given in the specification or not, such as differences
in structure, dimension, and use of material, are possible. The scope of embodiments is at
least as broad as given by the following claims.

WE CLAIM:
1. A method for detecting failure of an illuminating unit provided in a vehicle, said
method comprising the steps of:
a. receiving a current engine speed;
b. counting a number of pulses of a first type flowing through a current detection
path in one rotation of the engine, the current detection path being parallel to
the illuminating unit;
c. counting a number of pulses of a second type flowing through the current
detection path in one rotation of the engine; and
d. detecting an illuminating unit failure condition if:
i. the current engine speed is in excess of a predetermined level;
ii. the number of pulses of the first type is less than a first preset value;
iii. the number of pulses of the second type is equal to or greater than a
second preset value.
2. The method as claimed in claim 1, wherein the pulses of the first type have a first
voltage value and the pulses of the second type have a second voltage value, the
second voltage value being at least 30% greater than the first voltage value.
3. The method as claimed in claim 1, wherein the second preset value is one.
4. The method as claimed in claim 1, wherein the first preset value is provided by the
equation:
= ∗
wherein N is the number of poles present in the alternating current generator provided
sin the vehicle;
F is a fraction having a value in the range of 0.25 to 0.8; and
V is the first preset value, which is rounded off to an integer value.
5. The method as claimed in claim 1, wherein in response to detecting an illuminating
unit failure condition, the method further comprises generating an alarm signal for
output by an alarm output device provided in the vehicle.
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6. The method as claimed in claim 1, wherein in response to detecting an illuminating
unit failure condition, the method further comprises transmitting a illuminating unit
failure indicating signal to one or more remote devices.
7. A device for detecting failure of a illuminating unit provided in a vehicle, said device:
a. a first means for counting a number of pulses of a first type flowing through a
current detection path in one rotation of the engine, the current detection path
being parallel to the illuminating unit;
b. a second means for counting a number of pulses of a second type flowing
through the current detection path in one rotation of the engine; and
c. detection unit coupled to the first means and the second means for receiving
inputs there from, the detection unit being further adapted to receive a current
engine speed and detect an illuminating unit failure condition if:
i. the current engine speed received is in excess of a predetermined level;
ii. the number of pulses of the first type is less than a first preset value;
iii. the number of pulses of the second type is equal to or greater than a
second preset value.
8. The device as claimed in claim 7, comprising a signal generation unit for generating
illuminating unit failure indicating signal.
9. The device as claimed in claim 8 further comprising a signal transmitting unit for
transmitting the illuminating unit failure indicating signal.
10. A vehicle comprising:
an illuminating unit adapted to receive electrical power from a regulator–rectifier
circuit, the regulator-rectifier circuit being adapted to receive electrical power from an
alternating current generator that is driven by an engine of the vehicle; and
a device for detecting failure of the illuminating unit provided in the vehicle, said
device comprising:
a. a first means for counting a number of pulses of a first type flowing through a
current detection path in one rotation of the engine, the current detection path
being parallel to the illuminating unit;
b. a second means for counting a number of pulses of a second type flowing
through the current detection path in one rotation of the engine; and
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c. detection unit coupled to the first means and the second means for receiving
inputs there from, the detection unit being further adapted to receive a current
engine speed and detect an illuminating unit failure condition if:
i. the current engine speed received is in excess of a predetermined level;
ii. the number of pulses of the first type is less than a first preset value;
iii. the number of pulses of the second type is equal to or greater than a
second preset value.
11. The vehicle as claimed in claim 10, wherein the device for detecting failure of the
illuminating unit further comprises a signal generation unit for generating illuminating
unit failure indicating signal.
12. The vehicle as claimed in claim 11, further comprising an output device for outputting
the illuminating unit failure indicating signal.
13. A method for detecting failure of a plurality of illuminating units provided in a
vehicle, said method comprising the steps of:
a. receiving a current engine speed;
b. counting a number of pulses of a first type flowing through a first current
detection path in one rotation of the engine, the first current detection path
being parallel to a first illuminating unit;
c. counting a number of pulses of a second type flowing through the first current
detection path in one rotation of the engine;
d. counting a number of pulses of a first type flowing through a second current
detection path in one rotation of the engine, the second current detection path
being parallel to a second illuminating unit;
e. counting a number of pulses of a second type flowing through the second
current detection path in one rotation of the engine; and
f. detect a failure condition pertaining to at least one of the plurality of
illuminating units based on a plurality of:
i. the current engine speed,
ii. the number of pulses of the first type flowing through the first current
detection path,
iii. the number of pulses of the second type flowing through the first
current detection path,
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iv. the number of pulses of the first type flowing through the second
current detection path, and
v. the number of pulses of the second type flowing through the second
current detection path.
14. The method as claimed in claim 13, wherein a first illuminating unit failure condition
is detected if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the first current detection path
is less than a first preset value; and
the number of pulses of the second type flowing through the first current detection
path is equal to or greater than a second preset value.
15. The method as claimed in claim 13, wherein a second illuminating unit failure
condition is detected if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the second current detection
path is less than a first preset value; and
the number of pulses of the second type flowing through the second current detection
path is equal to or greater than a second preset value.
16. A device for detecting failure of at least one of a plurality of illuminating units
provided in a vehicle, said device:
a. a first means for counting a number of pulses of a first type flowing through a
first current detection path in one rotation of the engine, the first current
detection path being parallel to a first illuminating unit;
b. a second means for counting a number of pulses of a second type flowing
through the first current detection path in one rotation of the engine;
c. a third means for counting a number of pulses of a first type flowing through a
second current detection path in one rotation of the engine, the second current
detection path being parallel to a second illuminating unit;
d. a fourth means for counting a number of pulses of a second type flowing
through the second current detection path in one rotation of the engine; and
e. a detection unit being in operational interconnection with the first means, the
second means, the third means and the fourth means, the detection unit being
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adapted to receive a current engine speed and receive inputs from the first,
second, third and fourth means and detect a failure condition pertaining to at
least one of the plurality of illuminating units.
17. The device as claimed in claim 16, wherein the detection unit is adapted to detect a
first illuminating unit failure condition if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the first current detection path
is less than a first preset value; and
the number of pulses of the second type flowing through the first current detection
path is equal to or greater than a second preset value.
18. The device as claimed in claim 16, wherein the detection unit is adapted to detect a
second illuminating unit failure condition if:
the current engine speed received is in excess of a predetermined level;
the number of pulses of the first type flowing through the second current detection
path is less than a first preset value; and
the number of pulses of the second type flowing through the second current detection
path is equal to or greater than a second preset value.
19. A vehicle comprising:
a first illuminating unit and a second illuminating unit, each of the first and the second
illuminating units being adapted to receive electrical power from a regulator–rectifier
circuit, the regulator-rectifier circuit being adapted to receive electrical power from an
alternating current generator that is driven by an engine of the vehicle;
a first and a second means provided in relation to a first current detection path, the
first current detection path being parallel to the first illuminating unit, the first means
being adapted for counting a number of pulses of a first type flowing through the first
current detection path in one rotation of the engine and the second means being
adapted for counting a number of pulses of a second type flowing through the first
current detection path in one rotation of the engine;
a third and a fourth means provided in relation to a second current detection path, the
second current detection path being parallel to the second illuminating unit, the third
means being adapted for counting a number of pulses of a first type flowing through
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the second current detection path in one rotation of the engine and the fourth means
being adapted for counting a number of pulses of a second type flowing through the
second current detection path in one rotation of the engine; and
a detection unit being in operational interconnection with the first means, the second
means, the third means and the fourth means, the detection unit being adapted to
receive a current engine speed and receive inputs from the first, second, third and
fourth means and detect a failure condition pertaining to at least one of the plurality of
illuminating units.