FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and Rule 13]
TITLE: “METHOD AND SYSTEM FOR OPERATING DRIVE MODE WITH MULTIPLE DRIVE AXLE ASSEMBLY IN A VEHICLE”
Name and Address of the Applicant: TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed

TECHNICAL FIELD
Present disclosure relates to the field of automobile engineering. Particularly, but not exclusively, the present disclosure relates to multi-drive mode vehicles. Further embodiments of the present disclosure, disclose a method and a system for operating a multiple drive axle assembly in a vehicle.
BACKGROUND OF THE DISCLOSURE
The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s).
In a modern vehicle, a plurality of functions are provided to comfort occupants of the vehicle. Additional functions may be implemented to provide comfort to the occupants or to enrich the driving experience. One such function is the inclusion of driving modes. Driving modes are present in the vehicle to improve the driving experience and/ or to improve vehicle performance. There are several driving modes known in the art such as economy mode, balance mode, power mode, etc. Generally, switches or knobs are provided on an instrument cluster of the vehicle or on a dashboard of the vehicle to select the different driving modes. An operator generally selects the required driving mode based on the requirements by actuating switches or knobs. When the driving mode is selected, various system/units associated with the vehicle responds accordingly, and the vehicle is driven according to the selected driving mode.
Recently, industry trends for commercial vehicles having multiple drive axle assembly is in focus and the aspect is to improve vehicle efficiency and performance. One of the ways in which efficiency and performance can be improved is through refinements made to a tandem axle system forming a portion of the driveline of the vehicle.
The drive axle of trucks and tractors are often referred to as 4x2, 6x2, 6x4, 6x6, 8x8, 10x8, or 10x10 configurations based on the number of wheels and the number

of driven wheels. A 6x4 configuration, for example, has three axles of at least two wheels each. Two of the axles (at least 4 wheels) are driven axles. Conventionally, some features that may be offered in the tandem axle system are a selectable operating mode, such as a 6×2 operating mode and a 6×4 operating mode. In the 6×2 operating mode, a single axle of the tandem axle assembly is engaged to improve vehicle performance and fuel efficiency. The selection of minimum drive axles produces less rolling resistance and torque delivery to all axles is also limited thereby improving fuel consumed during vehicle operation. In the 6×4 operating mode, both axles of the tandem axle assembly are engaged to increase tractive effort/traction of the vehicle. This feature is termed the “Traction on demand”. In order to improve the overall fuel economy of the vehicle by providing operating mode options between 6×4 and 6×2, based on the vehicle operating duty cycle.
However, in the existing vehicles, the driver has to manually select from a plurality of switches, to shift a drive axle system from a first operating mode to a second operating mode as shown in Figure 1. Also, the driver has to frequently change the switches during the journey. Further, once the switch is selected, the vehicle is driven in the same operating mode (i.e., 6×2 operating mode or 6×4 operating mode) even when the road conditions are changed. Current tandem axle systems do not offer an operator of a vehicle a selectable axle mode shift schedule with extensive control over a pattern of engagement for the tandem axle system. Thus, there is always a compromise either towards the performance of the engine or towards the fuel efficiency of the engine.
The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior art.
SUMMARY OF THE DISCLOSURE
One or more shortcomings of the conventional systems are overcome by system and method as claimed and additional advantages are provided through the provision of system and method as claimed in the present disclosure. Additional

features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure a method for operating a multiple drive axle assembly in a vehicle. The method comprises sensing one or more operating parameters of the vehicle by one or more sensors. The method further comprises receiving, by a control unit, data related to one or more operating parameters associated with the vehicle. Thereafter, the method comprises comparing, by the control unit, the data with one or more threshold values. Further, the method comprises detecting, by the control unit, corresponding drive mode engaged from a plurality of pre-set drive modes for operating the vehicle. The control unit selects one or more drive axles from the multiple drive axle assembly based on the one or more operating parameters and the corresponding engaged drive mode.
In an embodiment of the present disclosure, the one or more operating parameters is at least one of speed of the vehicle and the engine load of the vehicle.
In an embodiment of the present disclosure, the one or more sensors is at least one of a speed sensor, a load sensor, an accelerator pedal position (APP) sensor, a brake pedal position (BPP) sensor, a clutch pedal position (CPP) sensor, and a gear position (GP) sensor.
In an embodiment of the present disclosure, the selection of the one or more drive axles from multiple drive axles is at least one of a two-axle drive and a single axle drive.
In an embodiment of the present disclosure, the plurality of pre-set drive modes is at least one of an economy mode, a balance mode, and a power mode.
In an embodiment of the present disclosure, the two-axle drive is selected when the vehicle speed is 0 kmph.

In an embodiment of the present disclosure, the threshold value of the speed of the vehicle is in the range of 40kmph – 80 kmph.
In an embodiment of the present disclosure, the method of selecting the drive axle from the multiple drive axle assembly comprises selecting the two-axle drive when, the speed of the vehicle is less than the threshold value, and the drive mode is engaged in power mode. The method further comprises selecting the single axle drive when, the speed of the vehicle is less than the threshold value, and the drive mode is engaged either in economy mode or in balance mode.
In an embodiment of the present disclosure, an override switch is configured to override the corresponding drive mode and selects the two-axle drive in the vehicle
In one non-limiting embodiment of the present disclosure, a multiple drive axle assembly of a vehicle is disclosed. The multiple drive axle assembly comprises at least two driven axles mounted to a chassis of the vehicle, a driveshaft connected to each driven axle via a differential, and a control unit. The control unit comprises one or more sensors to measure one or more operating parameters of the vehicle. The control unit is configured to receive one or more operating parameters of the vehicle sensed by one or more sensors, and then compare the data of one or more operating parameters with one or more threshold values. The control unit is further configured to detect the corresponding drive mode from a plurality of pre-set drive modes for operating the vehicle. The control unit selects a drive axle from the multiple drive axle assembly based on one or more operating parameters and the drive mode.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
Figure 1 [Prior Art] is an exemplary illustration of a flowchart for selecting a drive axle from the multiple drive axle manually, in accordance with prior art.
Figure 2 illustrates a flowchart for selecting the drive axle from the multiple drive axle in a vehicle in real-time, in accordance with an embodiment of the present disclosure.
Figure 3 is an exemplary illustration of a flowchart for selecting the drive axle from the multiple drive axle in a vehicle, in accordance with an embodiment of the present disclosure.
Figure 4 illustrates a block diagram of a control unit to engage the single axle drive in a vehicle, in accordance with an embodiment of the present disclosure.
Figure 5 illustrates a block diagram of the control unit to engage the two-axle drive in a vehicle, in accordance with an embodiment of the present disclosure.
It should be appreciated by those skilled in the art that any block diagram herein represents conceptual views of illustrative systems embodying the principles of the present subject matter. The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the assemblies and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the system or method, without departing from the scope of the disclosure. Therefore, such modifications are considered to be a part of the disclosure.
Accordingly, the drawings only show those specific details that are pertinent to understanding the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those ordinary skilled in the art having the benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a system and method that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or the device.
Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Embodiments of the disclosure are described in the following paragraphs with reference to FIGS. 2 to 5.

Conventionally, vehicles are equipped with multiple axles for transferring torque for various load and traction requirements. However, such selection of multiple axles needs to be manually chosen based on the need of an operator. This can sometimes be cumbersome to the operator and may also be dangerous, as the operator has to concentrate away from driving and road conditions ahead. Switches on the dashboard had to be manually chosen in order to comply with the road conditions and the load-carrying capacity of the vehicle. In many situations, the operator would wrongly or erroneously select different driving modes or axles during the operation of the vehicle leading to inefficient performance of the vehicle as well as high fuel consumption. Embodiments of the present disclosure relate to operating a multiple drive axle assembly in a vehicle. A control unit of the vehicle receives data related to one or more operating parameters associated with the vehicle. Further, the control unit detects the corresponding drive mode engaged from a plurality of pre-set drive modes for operating the vehicle. The control unit selects one or more drive axles from the multiple drive axle assembly based on the one or more operating parameters and the corresponding engaged drive mode. Essentially, the system of the present disclosure aims to provide features that contribute to significant improvement of the overall performance of the vehicle and to reap maximum benefits out of a multi-drive mode vehicle over a conventional vehicle.
The present disclosure generally relates to a method and a system for operating a multiple drive axle assembly (102) in a vehicle. The system of the multiple drive axle assembly (102) for a vehicle includes a differential, and at least two driven axles (not shown in figures) mounted to a chassis of the vehicle. In a preferred embodiment, at least two driven axles comprise a first axle assembly and a second axle assembly. A driveshaft is connected to each driven axle via the differential. The multiple drive axle assembly (102) is engaged with a power train. The power train is engaged with an input shaft of the differential and supplies required torque thereto. In a preferred embodiment, the power train may be an internal combustion

engine. However, it may be understood that the power train may include an electric motor.
The system may further include a control unit (106), one or more switches for selecting a plurality of pre-set drive modes for operating the vehicle. In an embodiment, the one or more switches can include a selection of drive modes from a group of drive modes i.e. an economy mode, a balance mode, and a power mode. In an example, the economy mode relates to pre-set values such that, the engine response and other factors such as air conditioning are altered to produce the best fuel economy the vehicle can offer. Whereas, the power mode relates to the pre¬set values such that powertrain components are controlled to attain an engaging drive during the start of the vehicle or during the increase in load or torque demands as per the terrain conditions of the road. The balance mode relates to a balance between the economy mode and the power mode. A person skilled in the art will appreciate that the drive modes are not limited to the economy mode, the balance mode, and the power mode and can include several other modes.
The system further comprises one or more sensors (104) to measure one or more operating parameters of the vehicle. In an embodiment, the one or more operating parameters are at least one of speed of the vehicle, load of the vehicle, acceleration of vehicle, braking application values, clutch application values and current gear selection. In a preferred embodiment, the one or more sensors is at least one of a speed sensor, a load sensor, an accelerator pedal position (APP) sensor, a brake pedal position (BPP) sensor, a clutch pedal position (CPP) sensor, and a gear position (GP) sensor. The control unit (106) is configured to receive one or more operating parameters of the vehicle sensed by one or more sensors (104).
In some embodiments, the control unit (106) may comprise one or more threshold values with which the data of one or more operating parameters are compared. For example, a first threshold value can indicate a first speed of the vehicle, a second threshold value can indicate a second speed of the vehicle. In an embodiment, the first speed may be the speed of the vehicle at a given time ‘x’ and the second speed

is the speed of the vehicle at another time ‘y’. In an embodiment, the threshold value of the speed of the vehicle is in the range of 40kmph - 80 kmph. In another embodiment, the threshold value of the speed of the vehicle is in the range of 30kmph - 90 kmph. In another embodiment, the threshold value of the speed of the vehicle is in the range of 0 kmph - 120 kmph. In an embodiment, the control unit is programmed with the pre-fed threshold parameters depending on the vehicle requirements. In an embodiment, the one or more threshold values may be set during the assembly line of the vehicle in a factory, or the control unit (106) may be programmed to set the one or more threshold values based on the driving pattern of the operator. The control unit (106) is further configured to detect the corresponding drive mode from the plurality of pre-set drive modes for operating the vehicle. Accordingly, the control unit (106) dynamically selects a drive axle from the multiple drive axle assembly based on one or more operating parameters and the drive mode.
In an exemplary embodiment, the vehicle operated with multiple drive modes is disclosed in the present disclosure which includes the plurality of pre-set drive modes (108). As an example, the multiple drive modes may be broadly classified into economy mode, balance mode, and power mode. Each of the above-mentioned modes i.e. economy mode, power mode, and balance mode may further include the plurality of pre-set drive modes (108). These drive modes may be configured to accommodate the different needs of the vehicle operator. These drive modes allow the vehicle to have multiple characteristics accordingly to the driving pattern of the operator as opposed to a single set of characteristics in the conventional vehicles.
Generally, the vehicle may be configured to operate in a single drive mode during operation. For example, a vehicle with multiple drive modes such as economy mode, sports mode may be operated in any of these modes based on the requirement. However, some vehicles are not equipped with drive modes but are operated in a single mode in any circumstance. Whereas, vehicles with multiple

drive modes allow the operator of the vehicle to experience and utilize the required drive mode based on various parameters.
Figure 2 shows a flow chart illustrating a method (200) for operating the multiple drive axle assembly (102) in the vehicle in real-time, in accordance with the embodiments of the present disclosure. As illustrated, the method (200) may comprise one or more steps. The method (200) may be described in the general context of computer-executable instructions. Generally, computer-executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.
The order in which the method (200) is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.
At step (201), one or more sensors (104) may receive measurements of one or more operating parameters. Further, the measurements of one or more operating parameter is made using various sensors (104) for measuring different vehicle parameters.
At step (202), the control unit (106) compares the rate of change of one or more operating parameters with one or more threshold values. The control unit (106) receives the measurements in real-time and these measurements can be used to determine the rate of change of one or more parameters. For example, the control unit (106) receives inputs on the speed of the vehicle and determines particular actions based on the speed of the vehicle. Likewise, the control unit (106) may receive inputs on the rate of change of load of the vehicle, braking application values, clutch application values, and the current gear selection by receiving

measurements from respective one or more sensors (104) and determines particular action based on these parameters.
At step (203), the control unit (106) detects the corresponding drive mode engaged from the plurality of driving modes, and finally, at step (204), the control unit (204) selects one or more drive axles based on the comparison and the corresponding engaged drive mode as detected at step (203). The steps of selecting one or more drive axles are described in detail in Figure 3. In an embodiment, the selection of the one or more drive axles from multiple drive axles is at least one of a two-axle drive (6×4 mode) and a single axle drive (6×2 mode). In an embodiment, the present disclosure can be utilized in 8x2, 8x4, 10x2, 10x4, or even larger configuration of commercial vehicle without deviating from the scope of the present disclosure.
FIG.3 is an exemplary embodiment of the present disclosure, which illustrates the operation of the control unit (106) to select one or more drive axles from the multiple drive axle assembly (102). As shown, when the ignition is ON (301), the control unit (106) of the vehicle measures the speed of the vehicle using the speed sensor. If the vehicle speed is at 0 kmph (302), the control unit (106) engages the two-axle drive (i.e. 6×4 mode) at (303), else the control unit moves to the next logic block (304) to check the engagement of the corresponding pre-set drive modes (i.e. economy mode, balance mode, or power mode).
If the pre-set drive mode is engaged as economy mode or balance mode (305) then the control unit (106) compares the vehicle speed with the set threshold value of the speed (306).
If the vehicle speed is less than the set threshold value, the control unit engages the single axle drive (i.e. 6×2 mode) at (307), else the vehicle remains on the same drive axle (308). Further, if the pre-set drive mode is not at economy mode or balance mode (305) i.e. it is at power mode then the control unit (106) compares the vehicle speed with the set threshold value of the speed (310).

If the vehicle speed is less than the set threshold value, the control unit (106) engages the two-axle drive (i.e. 6×4 mode) at (303), else the vehicle remains on the same drive axle (308). In an embodiment, an override switch is configured to override the corresponding drive mode (309) and selects the two-axle drive (i.e. 6×4 mode) in the vehicle. Finally, the control unit (106) indicates the operator through a tell-tale indicator for selecting the corresponding axle drive (311). In an embodiment, the indication to the operator is at least one of a visual indication or an audio indication or a combination of both.
The illustrated operations of Figure 3 show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above-described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single control unit or by distributed control units.
Figure 4 and Figure 5 of the present disclosure illustrate a block diagram representation of the control unit (106) using which the control unit (106) selects one or more drive axles from the multiple drive axle assembly (102). The block diagram representation is illustrated with respect to the embodiment illustrated in Figure 3. In order to select one or more drive axles, the system comprises a plurality of solenoid valves mounted on the drive axle assembly (102).
In an embodiment, the plurality of solenoid valves comprises a synchro solenoid valve (110), an inter-axle solenoid valve (112), and an axle shaft solenoid valve (114). Further, the system also comprises an air reservoir (116) configured to supply pneumatic energy to the plurality of solenoid valves in order to select one or more drive axles. In an embodiment, the air reservoir (116) is configured to store compressed air which comprises an air compressor to maintain the pneumatic reservoir (116) under required pressure. When an electrical signal is sent from the control unit (106) to the plurality of solenoid valves as per the requirements, the

respective solenoid valves get opened or closed. Accordingly, the pneumatic energy flows through the solenoid valve, and one or more drive axles are engaged or disengaged. In an embodiment, the system further comprises a plurality of limit switches configured to actuate the plurality of solenoid valves respectively.
Figure 4 shows the block diagram of the control unit (106) to engage the single axle drive (i.e. 6×2 mode) in accordance with an embodiment of the present disclosure. The control unit (106) receives input from speed sensors (104). Also, the control unit (106) detects the corresponding drive mode engaged. If the detected drive mode is in the economy mode or balance mode, then the control unit (106) actuates the inter-axle solenoid valve (112). During this, the synchro solenoid valve (110) and the axle shaft solenoid valve (114) remain closed. Once the inter-axle solenoid valve (112) gets actuated, the control unit (106) engages the single axle drive (i.e. 6×2 mode) by supplying the pneumatic energy to the inter axle actuator respectively.
Figure 5 shows the block diagram of the control unit (106) to engage the two-axle drive (i.e. 6×4 mode) in accordance with an embodiment of the present disclosure. The control unit (106) receives input from speed sensors (104). Also, the control unit (106) detects the corresponding drive mode engaged. If the detected drive mode is power mode, then the control unit (106) sends electrical signals to actuate the synchro solenoid valve (110) and the axle shaft solenoid valve (114). At this stage, the inter-axle solenoid valve (112) remains closed. Once the synchro solenoid valve (110) and the axle shaft solenoid valve (114) are actuated, the control unit (106) engages two-axle drive (i.e. 6×4 mode) by supplying the pneumatic energy to the synchro gear and axle shaft actuator respectively.
The present disclosure enables automatic selection of one or more drive axles from the multiple drive axle assembly (102) thus providing a seamless driving experience to occupants. Also, the performance of the vehicle is improved as drive axles are selected automatically according to driving conditions. The system can be retrofitted into existing vehicles.

In light of the above-mentioned advantages and the technical advancements provided by the disclosed method and system, the claimed steps as discussed are not routine, conventional, or well understood in the art, as the claimed steps enable the following solutions to the existing problems in conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the device itself as the claimed steps provide a technical solution to a technical problem.
It is to be understood that a person of ordinary skill in the art may develop a system and a method of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation, no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to

introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general, such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and

embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
Reference numerals:

Reference Number Description
102 Drive axle assembly
104 Sensors
106 Control unit
108 Drive mode switch
110 Synchro solenoid valve
112 Inter axle solenoid valve
114 Axle shaft solenoid valve
116 Air reservoir
201 to 204 Flowchart blocks for selecting drive axle
301 to 311 Logic blocks for the operation of the control unit

We claim:
1. A method for operating a multiple drive axle assembly (102) in a vehicle,
the method comprising:
sensing one or more operating parameters of the vehicle by one or more sensors (104);
receiving, by a control unit (106), data related to one or more operating parameters associated with the vehicle;
comparing, by the control unit (106), the data with one or more threshold values;
detecting, by the control unit (106), corresponding drive mode engaged from a plurality of pre-set drive modes for operating the vehicle;
wherein the control unit (106) selects one or more drive axles from the multiple drive axle assembly (102) based on the one or more operating parameters and the corresponding engaged drive mode.
2. The method as claimed in claim 1, wherein the one or more operating parameters is at least one of speed of the vehicle, and engine load of the vehicle.
3. The method as claimed in claim 1, wherein the one or more sensors is at least one of a speed sensor, a load sensor, an accelerator pedal position (APP) sensor, a brake pedal position (BPP) sensor, a clutch pedal position (CPP) sensor, and a gear position (GP) sensor.
4. The method as claimed in claim 1, wherein the selection of the one or more drive axles from multiple drive axle is at least one of a two-axle drive and a single axle drive.

5. The method as claimed in claim 1, wherein the plurality of pre-set drive modes is at least one of an economy mode, a balance mode, and a power mode.
6. The method as claimed in claim 4, wherein the two-axle drive is selected when the vehicle speed is 0 kmph.
7. The method as claimed in claim 1, wherein the threshold value of the speed of the vehicle is in the range of 40kmph – 80 kmph.
8. The method as claimed in claim 1 and claim 7, wherein selecting the drive axle from the multiple drive axle assembly comprises:
selecting the two-axle drive when the speed of the vehicle is less than the threshold value, and the drive mode is engaged in power mode; and
selecting the single axle drive when the speed of the vehicle is less than the threshold value, and the drive mode is engaged either in economy mode, or in balance mode.
9. The method as claimed in claim 7, wherein an override switch is configured to override the corresponding drive mode and selects the two-axle drive in the vehicle.
10. A multiple drive axle assembly of a vehicle, comprising:
at least two driven axles mounted to a chassis of the vehicle; a driveshaft connected to each driven axle via a differential; a control unit (106) comprising:
one or more sensors (104) to measure one or more operating parameters of the vehicle; and the control unit (106) configured to:
receive one or more operating parameters of the vehicle sensed by one or more sensors (104);

compare the data of one or more operating parameters with one or more threshold values;
detect corresponding drive mode from a plurality of pre-set drive modes for operating the vehicle;
wherein the control unit (106) dynamically selects a drive axle from the multiple drive axle assembly based on the one or more operating parameters and the drive mode.