DESC:This application is based on and derives the benefit of Indian Provisional Application 5239/CHE/2015, the contents of which are incorporated herein by reference.

TECHNICAL FIELD
[001] Embodiments disclosed herein relate to the field of electrical energy consumption in vehicles and more particularly the present invention relates to the field of optimizing the electrical energy consumption and reducing emissions in vehicles.

BACKGROUND
[002] The radiator fan and blower motors are major electrical energy consumers in a vehicle. As shown in FIG. 1, the radiator fan motor can be operated only in two speeds, high speed and low speed, according to engine coolant temperature and AC (Air Conditioning) pressure switch status. According to engine coolant temperature range with AC on condition, the radiator fan runs in low speed and if the AC pressure switch goes high, the radiator fan motor runs in high speed. According to defined temperature ranges in the EMS (Engine Management System) ECU (Electronic Control Unit), the EMS ECU gives signals to low speed and high-speed relays of the radiator fan motor. The low speed of radiator fan motor is achieved through voltage drop across high wattage series resister. This configuration consumes a significant amount of electrical energy, which can reduce the fuel economy of the vehicle and increase CO2 emissions from the vehicle.

OBJECTS
[003] The principal object of embodiments herein is to disclose methods and systems for optimization of speed control logic of a radiator fan motor of a vehicle, according to factors such as vehicle speed and airflow though the radiator.
[004] Another object of embodiments herein is to disclose use of a brushless DC motor in the radiator fan motor and the blower fan motor of the vehicle.
[005] Another object of embodiments herein is to disclose methods and systems for regeneration of energy from the radiator fan motor of the vehicle, when the vehicle is performing actions such as deceleration, freewheeling, braking and so on.

BRIEF DESCRIPTION OF FIGURES
[006] Embodiments disclosed herein are illustrated in the accompanying drawings, through out 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:
[007] FIG. 1 depicts the current method of operating the radiator fan in vehicles;
[008] FIG. 2 depicts a system for controlling a radiator fan motor in a vehicle, according to embodiments as disclosed herein;
[009] FIG. 3 depicts a plot of airflow through the radiator in cubic meter/hour against the vehicle speed in km/hour, according to embodiments as disclosed herein;
[0010] FIG. 4 depicts a system for regenerating energy from the radiator fan motor, according to embodiments as disclosed herein;
[0011] FIG. 5 shows the logic of the radiator fan control, according to embodiments as disclosed herein;
[0012] Fig. 6 depicts the soft-starting of the BLDC motor compared to the BDC motor, according to embodiments as disclosed herein;
[0013] FIG. 7 depicts an example comparison of power consumed by a 380W BLDC motor and a 500W BDC motors for same performance and output, according to embodiments as disclosed herein; and
[0014] FIG. 8 shows an example comparison of 190 W BLDC motor with 320 W resistive controlled BDC motor for AC blower application, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0015] 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. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0016] The embodiments herein disclose methods and systems for optimization of speed control logic of a radiator fan motor in a vehicle according to factors such as vehicle speed and airflow though the radiator. Referring now to the drawings, and more particularly to FIGS. 1 through 8, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0017] The vehicle as disclosed herein may be a vehicle that comprises of a radiator fan, such as a car, van, bus, truck, or any other vehicle.
[0018] Embodiments herein disclose methods and systems for optimization of speed control logic of a radiator fan motor in the vehicle according to the speed of the vehicle and airflow though the radiator. The rotational velocity of the radiator fan in low speed and high speed can be decided according to the amount of airflow needed to cool the radiator. Embodiments herein further disclose use of brushless DC (Direct Current) motor (BLDC) in the radiator fan motor and the blower motor of the vehicle. Embodiments herein further disclose regeneration of energy from the radiator fan; when the vehicle is performing actions such as deceleration, free wheeling, braking and so on.
[0019] FIG. 2 depicts a system for controlling a radiator fan motor in a vehicle. The system as depicted comprises of an ECU (Engine Control Unit) 201 connected to the radiator fan motor 202 in the vehicle. The ECU 201 can be connected to a plurality of vehicle systems and sensors such as an engine temperature sensor, AC pressure sensor, vehicle speed sensor, brake switch input, accelerator pedal input, and ambient temperature sensor input. The radiation fan motor 202 can communicate with vehicle systems such as the alternator, the battery vehicle loads, and so on. In an embodiment herein, the radiator fan motor 202 can comprise of a brushed DC motor (BDC). In an embodiment herein, the radiator fan motor 202 can comprise of a brushless DC motor (BLDC), wherein the BLDC can run on DC voltage supply and DC voltage can be converted in to AC voltage using an integrated controller circuit with motor.
[0020] The radiator fan motor 202 can control the rotational velocity of the radiator fan through a motor controller. In an embodiment herein, the motor controller can be integrated with the radiator fan motor 202. In an embodiment herein, the motor controller is separate from the radiator fan motor 202 and can communicate with the radiator fan motor 202 using a suitable means. The ECU 201 can determine a rotational velocity at which the radiator fan can rotate. The rotational velocity can have multiple levels (more than two levels). The ECU 201 can determine the rotational velocity of the radiator fan based on factors such as air flow through the radiator, current speed of the vehicle, engine coolant temperature, AC (air conditioning) status, AC pressure switch status, current state of the vehicle (such as deceleration, free running, braking, and so on) and so on. The rotational velocity of the radiator fan can also depend on the vehicle characteristics such as radiator area, front grill area, and so on. The ECU 201 can be configured to determine the rotational velocity of the radiator fan, based on a pre-determined logic, which can be programmed by an authorized person.
[0021] The pre-determined logic can be determined by performing the following steps:
- The airflow through the radiator is measured when the vehicle is not in motion, when the radiator fan is rotating at low speeds and high speeds. A suitable means such as an anemometer can be used to measure the airflow. The radiator can be divided into a grid comprising of a plurality of equal areas and each of the areas has a means to measure the airflow.
- The airflow through the radiator is measured when the vehicle is in motion or the vehicle motion is simulated (using a means such as wind tunnel), when the radiator fan is off. The vehicle is simulated or moved at pre-defined levels of speeds to the maximum speed of the vehicle, such as 5 km/hr, 10 km/hr, …., 25 km/hr, 30 km/hr, and so on. The airflow is measured at each speed level.
- Airflows measured in the above two steps are compared. As depicted in FIG. 3, this comparison will result in vehicle speed values S1 and S2, at which airflow through radiator are equal in static measurement (as in the first step) and dynamic measurement (as in the second step) respectively. S1 indicates vehicle speed at which airflow through radiator is equal to airflow through radiator when fan is running in low speed when the vehicle is not in motion. S2 indicates vehicle speed at which airflow through radiator is equal to airflow through radiator when fan is running in high speed when the vehicle is not in motion. S1 and S2 can depend on factors such as front grill opening and radiator size. It can be inferred that radiator will get natural airflow equivalent to low speed and high speed of radiator fan, when vehicle is running above S1 and S2 speed respectively. Thus, the low speed fan can be turned off, if the speed of the vehicle is above S1 and the high speed fan can be turned off if the speed of the vehicle is above S2.
Considering an example wherein the radiator area is 550mm x 582 mm, S1 was determined to be 25 km/h and S2 was 65 km/h. It can be interpreted that air flow through radiator at 25 km/h vehicle speed is equal to air flow through radiator when fan is running in low speed, and air flow through radiator at 65 km/h vehicle speed is equal to air flow through radiator when fan is running in high speed. It can be inferred that radiator will get natural airflow equivalent to low speed and high speed of radiator fan, when vehicle is running above 25km/h and 65 km/h speed respectively. Thus, the low speed fan can be turned off, if the speed of the vehicle is above 25 km/h and the high speed fan can be turned off if the speed of the vehicle is above 65 km/h.
[0022] In an embodiment herein, the ECU 201 can activate a regeneration mode of the radiator fan motor, on the ECU 201 depending on factors such as accelerator pedal, brake switch, rate of change in vehicle speed, engine coolant temperature and AC pressure switch status. The ECU 201 can activate the regeneration mode, on detecting that the vehicle is at least one of decelerating, freewheeling or braking. In the regeneration mode, the output voltage of the radiator fan motor 202 can be equal to the vehicle charging system line voltage. In regeneration mode, the energy from the radiator fan motor is reused by other systems present in the vehicle. As depicted in an example in FIG. 4, output voltage from the radiator fan is connected to an inverter 402 and a Hall element 403. A switch 401 is also provided, wherein the switch 401 is closed if the output voltage is not equal to the vehicle charging system line voltage. The inverter 402 can be used a converter by changing the firing angle.
[0023] FIG. 5 shows the logic of the radiator fan control. FIG. 5 indicates that electrical energy consumed by radiator fan motor at low speed and high speed can be saved after S1 and S2 respectively. However, the radiator fan motor has to be turned on at high speed as fail-safe strategy, if engine coolant temperature rises beyond a pre-defined threshold (T3oC ) irrespective of the speed of the vehicle.
[0024] Embodiments herein disclose use of a BLDC motor, wherein the power required for the BLDC motor is 75% less in low speed performance and 25% less in high speed performance than the BDC motor for the same rating, due to high torque to weight ratio and increased efficiency. Furthermore, the BLDC motor does not have starting inrush current, as in BDC motor. As shown in FIG. 6, the BLDC motor is gradually started and the motor controller can control the starting time. Fig. 6 depicts the soft-starting of the BLDC motor compared to the BDC motor. FIG. 6 shows the overlapping of both BDC and BLDC starting currents. FIG. 7 depicts an example comparison of power consumed by a 380W BLDC motor and a 500W BDC motors for same performance and output.
[0025] Similarly for AC blower motor application, use of BLDC motor instead of resistive controlled BDC motor will result in 37 % electrical power saving for same performance. FIG. 8 shows an example comparison of 190 W BLDC motor with 320 W resistive controlled BDC motor for AC blower application. It can be inferred from the FIG. 8 that use of BLDC blower motor gives comparable saving of electrical power ranging from 49W to 130W correspondence to blower position 1 to position 4.
[0026] Consider a vehicle with the specifications as depicted in table 1:
Displaced volume 1480 cc
Fuel Diesel
Seating Capacity 7
Radiator area 550mm x 582 mm
Curb weight 1620 Kg
Table 1
[0027] First, Fuel economy trial with conventional systems as depicted in FIG. 1, and BDC radiator fan motor and BDC blower motors was performed on chassis dyno with NEDC driving cycle. Fuel economy measured was 13.60 kmpl. Second, Fuel economy with new fan control logic as depicted in FIGs. 2 and 5, and using BLDC radiator blower motor was performed on chassis dyno with NEDC driving cycle. Fuel economy measured was 14.11 kmpl, which gave 3.75% improvement compared to first trial. This is depicted in table 2.
Fuel economy measurement with AC on condition (Kmpl)
NEDC chassis dyno cycle Highway driving cycle City driving cycle
Conventional systems (FIG. 1) 13.6 17.36 14.00
BLDC radiator and blower motor with fan control logic according to vehicle speed and airflow through radiator 14.11 18.1 14.51
Fuel economy improvement 3.75% 4.1% 3.64%
Table 2
[0028] Table 3 shows the net reduction of 558 Watt-hour, which is just 30 % of total vehicle electrical load, when BDC radiator and blower motors are replaced with BLDC motors.
% Percentage consumption of total vehicle electrical loads Net saving of energy (Whr)
Using BDC radiator and blower motor Using BLDC radiator and blower motor
Radiator fan motor and blower motor load 47% (1104 Whr) 30% (546 Whr) 558
Other Vehicle Loads 53% (1273Whr) 70% (1273Whr)
Total Vehicle Loads 100% (2377Whr) 100% (1820Whr)
Table 3
[0029] Table 4 shows the CO2 reduction achieved by embodiments as disclosed herein.
CO2 emission comparison
CO2 emitted by the vehicle during NEDC chassis dyno cycle (grams/km)
BDC radiator and blower motor with conventional fan control logic 150
BLDC radiator and blower motor with fan control logic according to vehicle speed and airflow through radiator 137.7
CO2 reduction 8.2% reduction
Table 4
[0030] The embodiment disclosed herein describes methods and systems for optimization of speed control logic of a radiator fan motor in a vehicle according to factors such as vehicle speed and airflow though the radiator. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in a preferred embodiment through or together with a software program written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs.
[0031] 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 spirit and scope of the embodiments as described herein.

,CLAIMS:CLAIMS
We claim:
1. A system in a vehicle comprising of an Engine Control Unit (ECU) (201) and a radiator fan motor (202), wherein the ECU (201) is configured to control rotational velocity of a radiator fan connected to the radiator fan motor (202) based on a plurality of factors comprising of air flow through a radiator, and current speed of the vehicle.
2. The system, as claimed in claim 1, wherein the radiator fan motor (202) comprises of a brushed DC (Direct Motor) (BDC) motor.
3. The system, as claimed in claim 1, wherein the radiator fan motor (202) comprises of a brushless DC (Direct Motor) (BLDC) motor.
4. The system, as claimed in claim 1, wherein a logic used by the ECU (201) to control rotational velocity of the radiator fan can be generated by
determining airflow through the radiator when the vehicle is not in motion and the radiator fan is rotating at low speeds and high speeds;
determining airflow through the radiator when the vehicle is in motion or the vehicle motion is simulated at different levels of speed when the radiator fan is off; and
determining speeds S1 and S2 by comparing the determined airflows, wherein S1 is the vehicle speed at which airflow through the radiator is equal to airflow through radiator when the radiator fan is running in low speed when the vehicle is not in motion and S2 is the vehicle speed at which airflow through the radiator is equal to airflow through the radiator when the fan is running at high speed when the vehicle is not in motion.
5. The system, as claimed in claim 4, wherein the ECU (201) is configured for
turning off a low speed radiator fan, on the ECU (201) detecting that the speed of the vehicle is above S1; and
turning off a high speed radiator fan, on the ECU (201) detecting that the speed of the vehicle is above S2.
6. The system, as claimed in claim 5, wherein the ECU (201) turns on the radiator fan at high speed, if temperature of engine coolant rises beyond a pre-defined threshold, irrespective of the speed of the vehicle.
7. The system, as claimed in claim 1, wherein the plurality of factors further comprise of status of the air conditioning (AC), AC pressure switch status, and current state of the vehicle.
8. The system, as claimed in claim 1, wherein the ECU (201) is further configured for activating a regeneration mode, on the ECU (201) detecting that the current state of the vehicle is at least one of decelerating, freewheeling, and braking.
9. The system, as claimed in claim 8, wherein the regeneration mode comprises of reusing energy from the radiator fan motor (202).
10. The system, as claimed in claim 8, wherein output voltage of the radiator fan motor (202) is equal to charging system line voltage of the vehicle, in the regeneration mode.
11. A method for controlling the radiator fan speed in a vehicle, the method comprising controlling rotational velocity of a radiator fan connected to a radiator fan motor (202) by an Engine Control Unit (ECU) (201) based on a plurality of factors comprising of air flow through a radiator, and current speed of the vehicle.
12. The method, as claimed in claim 11, wherein the radiator fan motor (202) comprises of a brushed DC (Direct Motor) (BDC) motor.
13. The method, as claimed in claim 11, wherein the radiator fan motor (202) comprises of a brushless DC (Direct Motor) (BLDC) motor.
14. The method, as claimed in claim 11, wherein the method further comprises of generating a logic used by the ECU (201) to control rotational velocity of the radiator fan by
determining airflow through the radiator when the vehicle is not in motion and the radiator fan is rotating at low speeds and high speeds;
determining airflow through the radiator when the vehicle is in motion or the vehicle motion is simulated at different levels of speed when the radiator fan is off; and
determining speeds S1 and S2 by comparing the determined airflows, wherein S1 is the vehicle speed at which airflow through the radiator is equal to airflow through radiator when the radiator fan is running in low speed when the vehicle is not in motion and S2 is the vehicle speed at which airflow through the radiator is equal to airflow through the radiator when the fan is running at high speed when the vehicle is not in motion.
15. The method, as claimed in claim 14, wherein the method further comprises of
turning off a low speed radiator fan by the ECU (201), on the ECU (201) detecting that the speed of the vehicle is above S1; and
turning off a high speed radiator fan by the ECU (201), on the ECU (201) detecting that the speed of the vehicle is above S2.
16. The method, as claimed in claim 15, wherein the method further comprises of turning on the radiator fan at high speed by the ECU (201), if temperature of engine coolant rises beyond a pre-defined threshold, irrespective of the speed of the vehicle.
17. The method, as claimed in claim 11, wherein the plurality of factors further comprise of status of the air conditioning (AC), AC pressure switch status, and current state of the vehicle.
18. The method, as claimed in claim 11, wherein method further comprises of activating a regeneration mode by the ECU (201), on the ECU (201) detecting that the current state of the vehicle is at least one of decelerating, freewheeling, and braking.
19. The method, as claimed in claim 18, wherein the regeneration mode comprises of reusing energy from the radiator fan motor (202).
20. The method, as claimed in claim 18, wherein output voltage of the radiator fan motor (202) is equal to charging system line voltage of the vehicle, in the regeneration mode.
21. A radiator fan motor (202) in a vehicle, wherein the radiator fan motor (202) comprises of a brushless DC (Direct Motor) (BLDC) motor.