FORM 2
The Patent Act 1970
(39 OF 1970)
AND
The Patent Rules, 2005
COMPLETE SPECIFICATION (See Section 10; Rule 13)
TITLE OF THE INVENTION
AUTOMATICALLY CONTROLLING POWER SUPPLIED TO AN AIR CONDITIONER OF A VEHICLE
APPLICANT(S)
TATA MOTORS LIMITED
an Indian company
Bombay house, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001,
Maharashtra, India.
and
TATA MOTORS EUROPEAN TECHNICAL CENTRE Plc
an United Kingdom company
18 Grosvenor Place, London, SW1X 7HS, London
United Kingdom.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present disclosure relates to an air conditioner controlling system, and more particularly to the air conditioner controlling system and method thereof for automatically controlling power supplied to an air conditioner of a vehicle.
BACKGROUND OF THE INVENTION
[0002] The evaporator cut off temperature is set to avoid evaporator icing in an air conditioner of a vehicle. A cooling capacity is used for sensible heat removal, which causes reduction in cabin air temperature of the vehicle and latent heat removal, which is utilized to condensate a moisture in cabin air and form condensate. The energy utilized to remove latent heat is very high as compared to sensible heat and is not useful except in high cabin humidity. Thus, there remain a need of a system and method for efficient air conditioning system for reducing power supplied to the air conditioner of the vehicle.
OBJECT OF THE INVENTION
[0003] The principal object of the embodiments herein is to provide an air conditioner controlling system and method for automatically controlling power supplied to an air conditioner of a vehicle.
[0004] Another object of the embodiments herein is to determine dew point temperature of a passenger compartment of the vehicle based on a temperature of a cabin of the vehicle and a humidity condition of the cabin of the vehicle.
[0005] Another object of the embodiments herein is to automatically reduce an amount of the power supplied to the compressor of the air conditioner in response

to determining that the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment.
SUMMARY OF THE INVENTION
[0006] In one aspect, an object is satisfied by providing a method for automatically controlling power supplied to an air conditioner of a vehicle. The method comprises measuring, by a plurality of sensors, a plurality of parameters of the vehicle, determining, by an air conditioner controller, a dew point temperature of a passenger compartment of the vehicle based on a plurality of parameter of the vehicle, and controlling, by an air conditioner controller, the power supplied to a compressor the air conditioner based on the dew point temperature.
[0007] In an embodiment, controlling the power supplied to the compressor the air conditioner based on the dew point temperature comprises measuring a surface temperature of an evaporator of the air conditioner, determining whether the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment, and automatically reducing an amount of the power supplied to the compressor of the air conditioner in response to determining that the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment.
[0008] In an embodiment, the plurality of parameters is a temperature of a cabin of the vehicle and a humidity condition of the cabin of the vehicle.
[0009] In an embodiment, the temperature of the cabin of the vehicle is measured using a cabin senor, and the humidity condition of the cabin of the vehicle is measured using a humidity sensor.

[0010] In an embodiment, the surface temperature of the evaporator is measured using an evaporator surface temperature sensor placed on the evaporator of the air conditioner.
[0011] In an embodiment, the dew point temperature indicates a temperature at which a water vapor in air start condensing.
[0012] Another aspect of the invention discloses an air conditioner controlling system for automatically controlling power supplied to an air conditioner of a vehicle. The air conditioner controlling system comprises at least one sensor and an air conditioner controller connected to the at least one sensor.
[0013] The at least one sensor measures a plurality of parameters of the vehicle. The air conditioner controller receives the plurality of parameters measured by the at least one sensor, determines a dew point temperature of a passenger compartment of the vehicle based on a plurality of parameter of the vehicle, and controls the power supplied to a compressor of the air conditioner based on the dew point temperature.
[0014] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0015] The system and method are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0016] FIG. 1 illustrates a block diagram of an air conditioner controlling system, according to an embodiment as disclosed herein; and
[0017] FIG. 2 illustrates a flowchart representing a method for automatically controlling power supplied to an air conditioner of a vehicle, according to an embodiment as disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0019] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments

presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those, which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0020] Referring now to the drawings, and more particularly to FIGS. 1 through 2, there are shown preferred embodiments.
[0021] FIG. 1 illustrates a block diagram of an air conditioner controlling system (100), according to an embodiment as disclosed herein. The air conditioner controlling system (100) comprises at least one sensor (110) and an air conditioner controller (120) connected to the at least one sensor (110). The at least one sensor (110) measures a plurality of parameters of the vehicle.
[0022] In an embodiment, the plurality of parameters may be a temperature of a cabin of the vehicle and a humidity condition of the cabin of the vehicle.
[0023] In an embodiment, the plurality of sensors (110) may comprise a cabin senor (101), a humidity sensor (102) and an evaporator surface temperature sensor (103) placed on a surface of an evaporator of the air conditioner of the vehicle. The cabin senor (101) is used to measure the temperature of the cabin of the vehicle. The humidity sensor (102) is used to measure the humidity condition of the cabin of the vehicle. Further, the evaporator surface temperature sensor (103) is used to measure the surface temperature of the evaporator of the air conditioner.
[0024] Further, the air conditioner controller (120) receives the plurality of parameters measured by the at least one sensor, determines a dew point temperature of a passenger compartment of the vehicle based on a plurality of parameters of the

vehicle, and controls the power supplied to a compressor of the air conditioner based on the dew point temperature. In an embodiment, the dew point temperature indicates a temperature at which a water vapor in air starts condensing. In an embodiment, the power supplied to the compressor of the air conditioner is controlled based on the dew point temperature. A surface temperature of an evaporator of the air conditioner is measured, and thereupon determining whether the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment, and automatically reducing an amount of power supplied to the compressor of the air conditioner in response to determining that the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment. Unlike the conventional air condition systems or air condition control systems, cooling capacity of the proposed air conditioner controlling system (100) is used to remove only sensible heat and saving energy utilized to remove latent heat content (resulting into condensate formation).
[0025] FIG. 2 is a flow chart (200) illustrating a method for automatically controlling power supplied to an air conditioner of a vehicle, according to an embodiment as disclosed herein. At step 202, a plurality of parameters of the vehicle are measured. The plurality of parameters may comprise a temperature of a cabin of the vehicle measured using the cabin sensor (101) and a humidity condition of the cabin of the vehicle measured using the humidity sensor (102). At step 204, a dew point temperature of a passenger compartment of the vehicle is determined based on a plurality of parameter of the vehicle. The dew point temperature indicates a temperature at which a water vapor in air start condensing. The step 206, a surface temperature of an evaporator of the air conditioner is measured. The step 208, it is determined whether the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment. At step 210, an amount of the power supplied to the compressor of the air conditioner is automatically reduced in response to determining that the surface temperature of

the evaporator is less than or equal to the dew point temperature of the passenger compartment. The dew point temperature is then set as cut off temperature for the temperature detected at the evaporator. The evaporator surface temperature is maintained above dew point temperature during the system operation, thereby reducing the amount of power supplied to a compressor. The compressor cut off point is set above condensation temperature to allow removal of only sensible heat and not the latent heat.
[0026] In an embodiment, the proposed air conditioner controlling system (100) works on thermodynamic principle to avoid formation of condensate, which is drained out and is not contributing to cabin pull down. The proposed air conditioner controlling system (100) avoids use of AC power for removal of latent heat, which is very high as compared to sensible heat, thus saves cooling capacity. The saving in AC power consumption will mean improved fuel economy and operating cost to a customer.
[0027] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

We Claim:
1. A method for automatically controlling power supplied to an air conditioner of
a vehicle, the method comprising:
measuring, by a plurality of sensors (110), a plurality of parameters of the vehicle;
determining, by an air conditioner controller (120), a dew point temperature of a passenger compartment of the vehicle based on the plurality of parameters of the vehicle; and
controlling, by the air conditioner controller (120), the power supplied to a compressor of the air conditioner based on the dew point temperature.
2. The method as claimed in claim 1, wherein controlling the power supplied to
the compressor of the air conditioner based on the dew point temperature
comprises:
measuring a surface temperature of an evaporator of the air conditioner;
determining whether the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment; and
automatically reducing an amount of the power supplied to the compressor of the air conditioner in response to determining that the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment.
3. The method as claimed in claim 1, wherein the plurality of parameters is a temperature of a cabin of the vehicle and a humidity condition of the cabin of the vehicle.
4. The method as claimed in claim 3, wherein the temperature of the cabin of the vehicle is measured using a cabin senor (101), and wherein the humidity condition of the cabin of the vehicle is measured using a humidity sensor (102).

5. The method as claimed in claim 2, wherein the surface temperature of the evaporator is measured using an evaporator surface temperature sensor (103) placed on the evaporator of the air conditioner.
6. The method as claimed in claim 1, wherein the dew point temperature indicates a temperature at which a water vapor in air start condensing.
7. An air conditioner controlling system (100) for automatically controlling power supplied to an air conditioner of a vehicle, the system (100) comprising:
at least one sensor (110) for measuring a plurality of parameters of the vehicle; and
an air conditioner controller (120) connected to the at least one sensor for:
receiving the plurality of parameters measured by the at least one sensor (110),
determining a dew point temperature of a passenger compartment of the vehicle based on the plurality of parameter of the vehicle; and
controlling the power supplied to a compressor of the air conditioner based on the dew point temperature.
8. The air conditioner controlling system (100) as claimed in claim 7, wherein
controlling the power supplied to the compressor the air conditioner based on
the dew point temperature comprises:
measuring a surface temperature of an evaporator of the air conditioner;
determining whether the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment; and
automatically reducing an amount of power supplied to the compressor of the air conditioner in response to determining that the surface temperature of the evaporator is less than or equal to the dew point temperature of the passenger compartment.

9. The air conditioner controlling system (100) as claimed in claim 7, wherein the plurality of parameters is a temperature of a cabin of the vehicle and a humidity condition of the cabin of the vehicle.
10. The air conditioner controlling system (100) as claimed in claim 9, wherein the at least one sensors comprises a cabin senor (101) for measuring the temperature of the cabin of the vehicle, a humidity sensor (102) for meaning the humidity condition of the cabin of the vehicle.
11. The air conditioner controlling system (100) as claimed in claim 8, wherein the surface temperature of the evaporator is measured using an evaporator surface temperature sensor (103) placed on the evaporator of the air conditioner.
12. The air conditioner controlling system (100) as claimed in claim 7, wherein the dew point temperature indicates a temperature at which a water vapor in air starts condensing.