DESC:FIELD OF TECHNOLOGY
[0001] The present invention relates to lighting system of vehicle and, more particularly, to controlling switching of lighting loads of the vehicle.
BACKGROUND
[0002] In many vehicles lighting system such as headlight, position light etc., is energized by a battery power. In such vehicles, at the time of starting of internal combustion engine, a starter motor is energized, by the battery power mounted on the vehicle, which is mechanically engaged to start the engine. During this phase, a lighting system also gets energized by the battery power. As the lighting system is energized by the battery power i.e. Direct Current (DC) power, bulbs of the lighting system do not exhibit any flickering. However, there are also other types of vehicles in which the lighting system is energized by the power generator i.e. alternator or Alternating Current Generator (ACG) which is mounted on the vehicle. The alternator is mechanically connected to the engine and is synchronously driven therewith. The alternator provides an output current that is used to recharge the battery and to supply current to some electrical loads such as headlight, position lights etc., if the headlight switch, position light switch are in ON state. While usage, issues of flickering of electric bulb (of the lighting system) may be observed during starting of the engine, as the current is supplied by the alternator to charge the battery and to other electrical loads. Further, over a prolonged use, due to temperature and operational conditions, the alternator or ACG power generation capacity may differ due to which the reference values of the alternator output voltage of the alternator for particular engine RPM may differ. Electric bulb flickering reduces electric bulb life. Further, in the case when battery is low (or battery less condition) and if the headlight switch is in the ON state, then power required to start the engine will be more which may lead to the situation where the number of cranks required for starting the engine may be more than the situation when the headlight switch is in the OFF state. In the vehicles, where the headlight is desired to be always kept ON, this problem may become more severe and the bulb life may be reduced. Hence, it is desirable to energize the headlight at such a state so that the flickering of the electric bulb is reduced if not completely eliminated.
[0003] In order to achieve stable alternator output voltage it requires additional circuitry made up of components such as diode, capacitor, resistor or combination of all or any average voltage measurement intelligent circuit. However, introduction of such additional circuitry increases the cost.
SUMMARY

[0004] In an embodiment, a lighting system of a vehicle comprises an alternator for generating alternating current, a regulating device to provide regulated current in response to the alternating current, and a switch for operating at least one lighting load. The lighting system further comprises an electronic control unit electrically coupled to the regulating device, the switch and an ignition switch. The electronic control unit is configured to determine a frequency of the regulated current, and enable the switch to provide the regulated current to the at least one lighting load upon determining the frequency being greater than a threshold frequency.
[0005] In an embodiment, the at least one lighting load is at least one of a headlight, a tail light, an indicator and a position lamp.
[0006] In an embodiment, the electronic control unit is configured to enable the switch to provide the regulated current to the at least one lighting load when the ignition switch is in ON state.
[0007] In an embodiment, the switch is turned into a default position when the ignition switch is in OFF state.
[0008] In another embodiment, a lighting system of a vehicle, comprises an alternator for generating alternating current; a regulating device, a switch of operating at least one lighting load, and an electronic control unit. The regulating device is electrically coupled to the alternator to provide regulated current in response to the alternating current received from the alternator. The electronic control unit is electrically coupled to the alternator, the switch and an ignition switch. The electronic control unit is configured to determine a frequency of the alternating current received from the alternator, determine an ON state of the ignition switch, and enable the switch to provide the regulated current to the at least one lighting load upon determining the ON state of the ignition switch, and determining the frequency being greater than a threshold frequency
[0009] In yet another embodiment, a vehicle is provided. The vehicle comprises an ignition switch, at least one lighting load and a lighting system. The lighting system comprises an alternator for generating alternating current, a regulating device to provide regulated current in response to the alternating current, and a switch for operating at least one lighting load. The lighting system further comprises an electronic control unit electrically coupled to the regulating device, the switch and the ignition switch. The electronic control unit is configured to determine a frequency of the regulated current, and enable the switch to provide the regulated current to the at least one lighting load upon determining the frequency being greater than a threshold frequency. The lighting system precludes flickering in the at least one lighting load at start of engine of the vehicle
[0010] In still another embodiment, a method of operating at least one lighting load is provided. The method comprises determining an ON state of an ignition switch, determining a frequency of a regulated current if the ignition switch is in ON state and enabling a switch to disconnect the regulated current to the at least one lighting load upon determining the frequency smaller than a threshold frequency, and connect the regulated current to the at least one lighting load upon determining the frequency greater than the threshold frequency.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention itself, together with further features and attended advantages, will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments of the present invention are now described, by way of example only wherein like reference numerals represent like elements and in which:
[0012] Figure 1 depicts an example representation of a two-wheeled vehicle;
[0013] Figure 2 depicts a block diagram of a lighting system including electrical loads and the power storage unit, according to an embodiment of the present invention;
[0014] Figure 3 depicts a block diagram of a lighting system according to another embodiment of the present invention;
[0015] Figure 4 depicts a block diagram of a lighting system according to another embodiment of the present invention; and
[0016] Figure 5 depicts a flow diagram of a method of operating at least one lighting load according to another embodiment of the present invention.
[0017] The drawings referred to in this description are not to be understood as being drawn to scale except if specifically noted, and such drawings are only exemplary in nature. The coloured drawings, if provided along with this description are only meant to make the details of invention clear and have no effect whatsoever on the scope of the invention.
DETAILED DESCRIPTION
[0018] While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention.
[0019] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
[0020] The “Vehicle control unit” as described in the description, can take form of either a microprocessor or any similar programmable devices. For example, the “Vehicle control unit” or “electronic control unit (ECU)” may be embodied as one or more of various processing devices, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. The “Vehicle control unit” can comprise either single control unit or multiple control units as each of the control units being electronically connected with each other using serial bus to transmit the data there between.
[0021] Various embodiments of lighting system are described herein with reference to Figures 1 to 5. For better understanding of this invention, reference would now be made to the embodiments in the accompanying figures and description below, further, in the following figures, the same reference numerals are used to identify the same components in various views.
[0022] Figure 1 illustrates side view of a vehicle for example a two-wheeled vehicle (100) according to an embodiment of the present invention. The two-wheeled vehicle (100) comprises, inter-alia, a front fork (121), a head pipe (122), a front fender (172), a front wheel (123), a headlight (128), a position light (132), a steering handlebar (124), a fuel tank (125), an engine unit (126), a rear suspension (129), a swing arm (173), an indicator (118), a dress guard (111), a rear wheel (127), a rear fender (116), a tail light (117), and a seat (130). It may be noted that the two-wheeled vehicle (100) is shown to have include above stated parts, however, those ordinarily skilled in the art would appreciate that the two-wheeled vehicle (100) includes other parts which may not be relevant for explaining embodiments of the present invention and hence are not shown and described.
[0023] As depicted in Figure 1, the body frame of the two-wheeled vehicle (100) comprises a main frame (102), the head pipe (122), a pair of seat rail members comprising a left seat rail member (103) and a right seat rail member (not visible in Figures), a pair of sub-frame members comprising a left sub-frame member (109) and a right sub-frame member (not visible in Figures), a down frame member (105) and one or more brackets. The main frame (102) comprises a front portion (102a) that extends obliquely in the rearward and downward direction from the head pipe (122) and a rear portion (102b) changing the direction and thereafter extending further downward. The pair of seat rails comprising the left seat rail member (103) and the right seat rail member (not visible in drawings) extends from a rear end of the front portion (102a) of the main frame (102). The down frame member (105) obliquely extends in the downward direction from the lower portion of the head pipe (122). The left sub-frame member (109) and the right sub-frame member connect the rear portion (102b) of the main frame (102) and the respective seat-rail, for example, the left seat-rail (103) or the right seat-rail, through a bracket.
[0024] As illustrated in Figure 1, the front fork (121) is rotatably attached to the head pipe (122) enabling free steering. The front fork (121) supports the front wheel (123) at lower end thereof and the steering handlebar (124) at upper end thereof. A front fender (172) is provided above to the rear of the front wheel (123) for shielding the operator from mud.
[0025] The left seat rail member (103) and the right seat rail member primarily intended to support the seat (130) for a rider and/or pillion, are disposed above the rear wheel (127). The dress guard (111) is connected to the left seat rail member (103), and the dress guard (111) is intended to cover the left side of the rear wheel (127). The rear wheel (127) is covered from above by the rear fender (116) which is mounted onto the rear end portions of the left seat rail member (103) and the right seat rail member. The rear wheel suspension section includes the swing arm (173) supporting the rear wheel (127) and at least one rear suspension (129) attached between the swing arm (173) and the left seat rail member (103) or the right seat rail member. The tail light (117) is mounted on the rear fender (116).
[0026] Figure 2 illustrates block diagram of a lighting system (200), according to an embodiment of the present invention. The lighting system (200) can be implemented in a vehicle such as the two-wheeled vehicle (100).
[0027] In an embodiment, the lighting system (200) includes an alternator (202), an alternating current regulating means such as a regulating device (204), a power storage unit (206), an ignition switch (208), an electronic control unit (ECU) (220), a power supply module (214), a switch (212), and at least one lighting load (210). The examples of the lighting load (210) may be the headlight (128), the position light (132), the tail light (117), and/or any other lighting system incorporated in the two-wheeled vehicle (100). The alternator (202), which is mechanically connected to the engine (e.g., the engine unit 126), is synchronously driven therewith and provides an output alternating current that is used to recharge the power storage unit (206) and to supply current to other electrical loads that are turned on.
[0028] In an embodiment, the alternator (202) is connected to the power storage unit (206) through the regulating device (204). In a non-limiting embodiment, the power storage unit (206) is a 12 volt battery of the vehicle. In an embodiment, the power storage unit (206) serves as a source of electric power for energization of the ECU (220) and one or more DC electrical loads connected thereto. For the purposes of explanation, it will be assumed that the power storage unit (206) is a storage battery which is charged when the vehicle engine is running. In an embodiment, one or more electrical loads (e.g., winker light, horn of the vehicle etc.) are connected to the power storage unit (206) through the ignition switch (208).
[0029] In an embodiment, as shown in Figure 2, the ECU (220) is electrically coupled to the regulating device (204) through the ignition switch (208) and is configured to receive a regulated electric current from the regulating device (204). The regulated electric current from the regulating device (204) comprises regulated –ve and + ve components of the alternating electric current generated by the alternator (202). At least one lighting load (210) is electrically coupled to the AC output line (L1) of the regulating device (204) through the switch (212). The switch (212) is also coupled to the ECU (220) and is controlled by the ECU (220). In an embodiment, the ECU (220) is coupled to the output of the regulating device (204). In an embodiment, the ECU (220) is configured to receive a first signal from the output (e.g., AC output line (L1)) of the regulating device (204). The first signal from the output of the regulating device (204) represents the value of the alternator frequency. Further, the ECU (220) is configured to receive a second signal from the ignition switch (208). The second signal from the ignition switch (208) represents the status of ignition switch (208). The receipt of the first signal and the second signal are shown by input (216) in the ECU (220).
[0030] In operation, when the ignition switch (208) is in “ON” condition and when the engine is put in the motion by the starter motor or by the kickstart, the alternator (202) generates alternating electric current which is Alternating Current (AC) and which is further regulated by the regulating device (204) and the regulated current is supplied to the power storage unit (206) for the charging the power storage unit (206).
[0031] In an embodiment, as shown in Figure 2, the ECU (220) receives the regulated current from the regulating device (204) when the engine is put in motion. A regulated AC component of the electric current is supplied to the at least one lighting load (210) through the AC output line (L1). The switch (212) provided on the AC component line (L1) controls the supply of the regulated current to the lighting load (210). The ECU (220) is configured to receive the first signal which represents value of the frequency of regulated AC provided in the AC output line (L1). In an embodiment, an electronic circuitry is provided in the ECU (220) to determine the value of alternator frequency at the output of the regulating device (204) or the AC output line (L1). The ECU (220) operates the switch (212) based on the first signal and the second signal received from the AC output line (L1) and the ignition switch (208), respectively.
[0032] For example, the ECU (220) determines the status of the ignition switch (208), and determines the frequency of the regulated current provided in the AC output line (L1). In an embodiment, if the ignition switch (208) is in the ‘ON’ state and the value of the frequency is above a threshold frequency (e.g., FT), then the ECU (220) enables the switch (212) to electrically connect the lighting load (210) to the AC output line (L1). However, even if the ignition switch (208) is in the ON state, but the value of the frequency is below the threshold frequency (FT), then the ECU (220) disables the switch (212) to electrically disconnect the lighting load (210) to the AC output line (L1). In an embodiment, the switch (212) is preferably an electronic switch such as a thyristor. It should be noted that the ON state of the ignition switch (208) may be configured in a variety of ways, for example, by manually pressing ON the ignition switch (208) by the operator, or by turning ON the ignition switch through any automatic or semi-automatic means.
[0033] In some embodiments, the ECU (220) may operate the switch (212) based only on the first signal representing the value of the alternator frequency determined from output of the regulating device (204). In such embodiments, the vehicle (100) may have a secondary power source such as battery connected to the ECU (220), and when the ECU (220) determines that the alternator frequency (determined from the output of the regulating device (204)) becomes greater than the FT, the ECU (220) enables the switch (212) to electrically connect the lighting load (210) to the AC output line (L1).
[0034] The ECU (220) controls the operation of switch (212) such that AC output line (L1) is connected or disconnected to the lighting load (210) based on an output (see, 218) provided by the ECU (220). For example, even if the ignition switch (208) is in ON state, the ECU (220) controls the operation of the switch (212) such that the regulated current is not provided (or disconnected) to the lighting load (210) as long as the frequency of the regulated current is below the FT. Further, even if the switch (212) is in the OFF state, the ignition switch (208) in the ON state and the frequency of the regulated current is more than the FT, the ECU (220) controls the operation of the switch (212) such that AC output line (L1) is connected to the lighting load (210) (i.e. regulated current is provided to the lighting load (210)).
[0035] It should be appreciated that in the embodiment shown in Figure 2, the regulated current is not provided to the lighting load (210) by disabling the switch (212), if the frequency of the regulated current is less than the FT, and hence the flickering of the lighting load (210) for example, the headlight (128) is precluded.
[0036] The present invention may have one or more variations, for example, lighting systems (300) and (400) as shown in Figures 3 and 4, respectively.
[0037] In the embodiment of lighting system (300) shown in Figure 3, the first signal is received from the output of the alternator (202) and the second signal is received from the ignition switch (208). Hence, the ECU (220) is configured to determine the frequency of the AC output of the alternator (202) and the status of the ignition switch (208), and is configured to control the operation of the switch (212) to electrically connect/disconnect the AC output line (L1) to the lighting load (210) based on comparison of the frequency to FT. In another configuration, the ECU (220) may only determine the frequency of the AC output of the alternator (202) and is configured to control the operation of the switch (212) to electrically connect/disconnect the AC output line (L1) to the lighting load (210) based on comparison of the frequency to FT.
[0038] In the embodiment of lighting system (400) shown in Figure 4, the power source (206) may not be present and the power supply module (214) may receive the power from the regulating device (204) to power the ECU (220). In this embodiment, the ECU (220) is configured to determine the frequency of the regulated current of the regulating device (204) and the status of the ignition switch (208), and is configured to control the operation of the switch (212) to electrically connect/disconnect the AC output line (L1) to the lighting load (210).
[0039] Figure 5 illustrates a flow diagram of a method 500 for operating a lighting load (210), in accordance with an embodiment of the present invention.
[0040] At 505, a vehicle for example, the two-wheeled vehicle (100) is started by turning ON the ignition switch (208). At 510, status of the ignition switch (208) is checked (e.g., by the ECU (220)) to determine whether the ignition switch (208) is in ON state or in OFF state.
[0041] If the ignition switch (208) is in the ON state, at 515, the method 500 includes determining a frequency of a regulated current. The regulated current is received from output of the regulating device (204).
[0042] At 520, the method 500 includes checking whether the frequency of the regulated current is greater than the threshold frequency (FT). The threshold frequency (FT) may be a predetermined value which may be a preconfigured value or customisable by the operator. If the frequency is greater than FT, the switch (212) is enabled to electrically connect the AC output line (L1) to the lighting load (210) at 525, i.e. regulated current is supplied to the lighting load (210). As shown in the method (500), the ECU (220) waits until the frequency of the regulated current becomes greater than FT, and thereafter the regulated current is provided to the lighting load (210).
[0043] As described in the aforementioned description, the lighting systems (200 or 300 or 400) are operated at a predetermined value (FT) of the alternator frequency which is above the value of the alternator frequency when the engine starts, therefore, there is less chance of the flickering of the lighting loads (210) such as headlight or any other bulb or lamp. In an embodiment, the switch (212) is turned into a default position (e.g., disabled) when the ignition switch (208) is brought back into OFF state.
[0044] As described in the aforementioned description, the ECU operates the switch means based on the alternator frequency (i.e. frequency of the AC output of the alternator) and not on the alternator output voltage, therefore, the switch means can be reliably operated to control the lighting system as there is less chance of variation of the alternator frequency during the starting of the engine.
[0045] While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
,CLAIMS:We claim:
1. A lighting system (200) of a vehicle (100), comprising:
an alternator (202) for generating alternating current;
a regulating device (204) electrically coupled to the alternator (202) to provide regulated current in response to the alternating current received from the alternator (202);
a switch (212) for operating at least one lighting load (210); and
an electronic control unit (220) electrically coupled to the regulating device (204), the switch (212) and an ignition switch (208), the electronic control unit (220) configured to:
determine a frequency of the regulated current; and
enable the switch (212) to provide the regulated current to the at least one lighting load (210) upon determining the frequency being greater than a threshold frequency.
2. The lighting system (200) as claimed in claim 1, wherein the at least one lighting load (210) is at least one of a headlight (128), a tail light (117), an indicator (118) and a position lamp (132).

3. The lighting system (200) as claimed in claim 1, wherein the electronic control unit (220) is configured to enable the switch (212) to provide the regulated current to the at least one lighting load (210) when the ignition switch (208) is in an ON state.

4. The lighting system (200) as claimed in claim 3, wherein the switch (212) is turned into a default position when the ignition switch (208) is in an OFF state.
5. A lighting system (300) of a vehicle (100), comprising:
an alternator (202) for generating alternating current;
a regulating device (204) electrically coupled to the alternator (202) to provide regulated current in response to the alternating current received from the alternator (202);
a switch (212) for operating at least one lighting load (210); and
an electronic control unit (220) electrically coupled to the alternator (202), the switch (212) and an ignition switch (208), the electronic control unit (220) configured to:
determine a frequency of the alternating current received from the alternator (202);
determine an ON state of the ignition switch (208); and
enable the switch (212) to provide the regulated current to the at least one lighting load (210) upon determining the ON state of the ignition switch (208), and determining the frequency being greater than a threshold frequency.
6. The lighting system (300) as claimed in claim 5, wherein the at least one lighting load (210) is at least one of a headlight (128), a tail light (117), an indicator (118) and a position lamp (132).
7. A vehicle (100), comprising:
an ignition switch (208);
at least one lighting load (210); and
a lighting system (200) comprising:
an alternator (202) for generating alternating current;
a regulating device (204) electrically coupled to the alternator (202) to provide regulated current in response to the alternating current received from the alternator (202);
a switch (212) for operating the at least one lighting load (210); and
an electronic control unit (220) electrically coupled to the regulating device (204), the switch (212) and the ignition switch (208), the electronic control unit (220) configured to:
determine a frequency of the regulated current; and
enable the switch (212) to provide the regulated current to the at least one lighting load (210) upon determining the frequency being greater than a threshold frequency.

8. The vehicle (100) as claimed in claim 7, wherein the electronic control unit (220) is configured to enable the switch (212) to provide the regulated current to the at least one lighting load (210) when the ignition switch (208) is in an ON state.
9. The vehicle (100) as claimed in claim 7, wherein the at least one lighting load (210) is at least one of a headlight (128), a tail light (117), an indicator (118) and a position lamp (132).
10. A method (500) of operating at least one lighting load (210), the method (500) comprising:
determining an ON state of an ignition switch (208) by an electronic control unit (220);
determining, by the electronic control unit (220), a frequency of regulated current if the ignition switch (208) is in an ON state; and
enabling, by the electronic control unit (220), a switch (212) to:
disconnect the regulated current to the at least one lighting load (210) upon determining the frequency smaller than a threshold frequency; and
connect the regulated current to the at least one lighting load (210) upon determining the frequency greater than the threshold frequency.