FORM 2
THE PATENTS ACT 1970 (as amended) [39 OF 1970] & The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE OF THE INVENTION A HILL-ASSIST SYSTEM
APPLICANT
TATA MOTORS LIMITED
Of Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, INDIA;
An Indian Company
INVENTORS
MR. CHINMAYANANDA KHANDAI, MR. VIVEK M KOLHE
AND MR. TUSHAR SAHU all are TATA MOTORS LIMITED
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, INDIA;
An Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
The present disclosure generally relates to field of vehicle operation on a gradient or a slope. Particularly but not exclusively, the present disclosure relates to a hill assist system for improving re-start ability of vehicles on a gradient or slope. However, the feature is not limited to automotive applications alone and can be used in other applications as well.
Definition
“low idle speed” - It is the lowest possible speed / set speed for an engine.
BACKGROUND OF THE INVENTION
Driving a vehicle in a hilly terrain, consisting of steep slopes and sharp turns, is cumbersome, tiring and a tricky affair for any driver. If the engine stalls, while negotiating slopes and turns, then vehicle maneuvering becomes difficult. Restarting loaded vehicle on slope, after engine has stalled (or vehicle has stopped) becomes more challenging if the vehicle is fitted with a manual transmission. Because the driver has to simultaneously manipulate three separate control pedals (Accelerator, clutch and brake pedals) with two legs. It is difficult to manipulate three pedals simultaneously, it requires lot of skill. Inability to control three pedals at slope for maneuvering the vehicle while negotiating slopes on zigzag path are risky and unsafe. At times, it can cause accident and subsequent damages.
To ease out the stated situation, there is a need for a Hill assist system and method for improving re-start ability of vehicles on a gradient or a slope. The methodology needs to be simple to operate (irrespective of skill level) and should be reliable. Furthermore, there is a need for a Hill assist system and method for improving re-start ability of vehicles that facilitates quick and convenient maneuvering of the vehicle on a gradient or a slope. Still further, there is a need for a Hill assist system and method for improving re-start ability of vehicles on a gradient or a slope that improves vehicle safety and driver comfort, and

makes vehicle restarting on slopes, an effortless affair. Furthermore, there is a need for a Hill assist system that can be easily retrofitted in the present vehicles, without much modification.
OBJECTS OF THE INVENTION
One object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle on a gradient or a slope that involves simple operation and is reliable.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that relieves the driver from tedious task of simultaneously controlling accelerator pedal along with brake and clutch pedal, while maneuvering the vehicle on slopes.
Still another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that improves vehicle safety and driver comfort.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that prevents accidents.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that enables the vehicle to be handled by even moderately skilled driver as the driver needs to manipulate only clutch and brake pedals for maneuvering the vehicle on slopes.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that enables quick and convenient maneuvering of the vehicle on a gradient or a slope.

Yet another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that improves fuel efficiency and performance of the vehicle.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that adds a user-friendly feature to the vehicle.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that is inexpensive and efficient.
Still another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that enhances maneuverability of the vehicle on a gradient or a slope.
Yet another object of the present disclosure is to provide a hill assist system that reduces clutch wear and enhances clutch life.
Another object of the present disclosure is to provide a hill assist system and a method for improving re-start ability of a vehicle that can be easily retrofitted in the present vehicles, without much modification.
Another object of the present disclosure is maximizing the use of engine torque at given condition.
Another object of the present disclosure is to protect methodology of the novel method which eases the difficult maneuverability of the vehicle (automobile / not automobile) due to multiple controls needed simultaneously
SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome and additional advantages are provided through 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 an embodiment of the present disclosure a hill assist system for a vehicle is disclosed. The system includes a switch and an engine control unit. The switch changes operating mode of an engine of the vehicle from a normal mode to either one of a plurality of booster modes, wherein mode selection is based on terrain on which the vehicle is traversing. The engine control unit elevates engine speed from a first pre-determined engine speed to elevated second pre-determined engine speed corresponding to selected booster mode, and also governs the elevated second pre-determined engine speed by regulating fuel intake quantity as long as accelerator pedal travel is zero, as the operating mode is changed from the normal mode to the booster mode, thereby enabling the driver to manipulate only clutch and brake pedals for maneuvering the vehicle on a slope. The engine control unit further lowers the engine speed from the elevated second pre-determined engine speed to the first pre-determined engine speed, as the operating mode is changed from the booster mode to the normal mode.
Typically, the engine control unit is an engine Management System of the vehicle.
Generally, the first pre-determined engine speed is “low idle speed” of the engine that is the set lowest speed of the engine. ...
Specifically but not exclusively, the second pre-determined engine speed is the next desired engine speed at which maximum torque can be utilized.
In accordance with an embodiment, the engine control unit is an electronic engine control unit comprising a Proportional Integral Derivative (PID) controller that governs engine speed by regulating fuel quantity.

In accordance with another embodiment, the engine control unit is an electronic engine control unit comprising a non-linear controller adapted to govern engine speed by regulating fuel quantity.
Alternatively, the controller is a mechanical engine control system comprising a fly-ball type governor adapted to govern engine speed by regulating fuel quantity.
Typically, the switch is disposed on the dashboard of the vehicle.
In accordance with an embodiment, the accelerator pedal is disabled in the booster mode.
In accordance with another embodiment, the accelerator pedal remains operative in the booster mode.
Further, the hill assist system includes an indicator for alerting the driver when the booster mode is switched on.
In accordance with an embodiment of the present disclosure, the indicator is a visual indicator.
In accordance with another embodiment, the indicator is an audio indicator.
Optionally, the hill assist system also includes a torque reduction module that reduces torque incase the elevated second pre-determined engine speed crosses a pre-determined speed.
In accordance with an embodiment, the switch is either one of single-step and multi-step selection knob that selects different booster modes, wherein a corresponding elevated second pre-determined engine speed is defined for each booster mode.

A method for improving re-start ability of a vehicle on a gradient is disclosed in accordance with an embodiment of the present disclosure. The method includes the steps of switching operating mode of the engine from a normal mode to either one of a plurality of booster modes based on terrain on which the vehicle is traversing, elevating engine speed from a first pre-determined engine speed to an elevated second pre¬determined engine speed corresponding to the selected booster mode, as the operating mode is changed from the normal mode to the booster mode and governing the elevated second pre-determined engine speed by regulating fuel quantity/intake, as long as accelerator pedal travel is zero, thereby enabling the driver to manipulate only clutch and brake pedals for maneuvering the vehicle on a slope, the method further includes the step of lowering the engine speed from the elevated second pre-determined engine speed to the first pre-determined engine speed, as the operating mode is changed from the booster mode to the normal mode.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 illustrates the schematic block diagram representation of a hill assist system (100) for a vehicle in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described

hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
The hill assist system is a methodology which is not limited to only hill assist or grade / slope maneuvering with ease but may be extended to the situations where the maneuvering of the accelerator, brake and clutch controls are needed simultaneously.
The present disclosure generally relates to a hill assist system and a method for improving re-start ability of a vehicle that is fitted with internal combustion engines with either electronic or mechanical engine control system. In accordance with an embodiment of the present disclosure the engine is a spark ignition engine. In accordance with another embodiment, the engine is a compression ignition engine. However, the hill assist system of the present disclosure is not limited to any particular configuration of engine or vehicle type and is applicable to any engine configuration and vehicle type. Particularly, although the hill assist system of the present disclosure is explained w.r.t vehicles for on-road applications and automotive applications, however, the hill assist system is not limited to on-road vehicle applications can also be applicable in vehicles for off-road applications, particularly, tractors used in farm applications and tippers used in mine applications and or earth moving machinery. The hill assist system includes a switch and an engine control unit. The switch changes operating mode of an engine of the vehicle from a normal mode to either one booster mode from a plurality of booster modes, wherein mode selection is

based on terrain on which the vehicle is traversing. Upon activation of booster mode, engine control system elevates engine speed from a first pre-determined engine speed i.e. from “low idle speed” of the engine, to a second pre-determined higher engine speed corresponding to the booster mode selected and continues to govern this elevated engine speed as long as accelerator pedal travel is zero. In accordance with an embodiment, switch is either one of single-step and multi-step selection knob that selects different booster modes, wherein a corresponding elevated second pre-determined engine speed is defined for each booster mode. In accordance with an embodiment of the present disclosure, the booster mode is manually actuated by actuating a switch that is ergonomically disposed within reach of the driver so that the switch is conveniently accessible while driving. In accordance with another embodiment of the present disclosure, the booster mode is automatically actuated based on inputs received from a gradient sensor/detector, that may be inbuilt in the vehicle. Upon actuation of the booster mode, the accelerator pedal control is taken over by the ECU, and the driver may or may not operate the accelerator physically.
Upon deactivation of the switch, engine speed falls back to the second pre-determined engine speed or the normal low idle speed of the engine. In accordance with an embodiment of the booster mode is manually deactivated by using the switch. However, the present disclosure is not limited to use of switch for deactivating the booster mode and the booster mode can also be deactivated by using other provisions such as tapping of the accelerator pedal. In accordance with an embodiment of the present disclosure, the hill assist system has provision for automatically returning the engine to the normal low idle speed once the gradient has been traversed based on inputs received from the gradient sensor. In accordance with an embodiment, the first pre-determined engine speed i.e. “low idle speed” of the engine / minimum set speed. In accordance with another embodiment, the second pre-determined engine speed is higher speed capable to maneuver the concern grade. By increasing the low idle speed to a little higher rpm, to get suitable torque, the reserve torque that is not available at low ideal speed becomes available and can be utilized. Moreover, higher low idle speed results in higher marching speed, thereby causing inconvenient to drive the vehicle bumper to bumper driving

condition. Also, clutch engagement at a higher engine speed, during restart results in higher clutch wear. Considering these factors, in the booster mode, the engine speed is raised from the first pre-determined engine speed i.e. “low idle speed” to the second pre-determined engine speed. However, the present disclosure is not limited to increasing the engine speed to any particular speed when in the booster mode, and raising the engine speed to any value over and above the “low ideal speed” depending upon the different engine configurations is within the scope and ambit of the present disclosure. Further, in accordance with an embodiment of the present disclosure, as the switch is actuated for actuating the booster mode, the engine rpm can be raised to any one of a plurality of engine speeds above the “low ideal speed”, wherein for each booster mode selected there is a corresponding pre-defined engine speed.
Switching between the normal mode and the booster mode is possible on the go, without any necessity to stop the engine and then re-start. In accordance with an embodiment, the accelerator pedal behavior remains unchanged, irrespective of whether the engine is operating in normal mode or booster mode. In accordance with an embodiment of the present disclosure, the accelerator pedal is disabled in the booster mode. In accordance with another embodiment, the accelerator pedal remains operative in the booster mode.
Low idle speed governor maintains (i.e. holds constant) a pre-determined engine speed, by adjusting fuel/charge quantity. The rate of change (rise/ fall) of fuel/charge quantity, with respect to change (rise/ fall) of engine speed is based on a pre-determined set of rules or pre-define protocol that is followed by a controller. In accordance with an embodiment of the present disclosure, for electronically controlled engines, the controller is a Proportional Integral Derivative (PID) controller that govern engine speed by regulating fuel quantity. Alternatively, the controller is a non-linear controller etc. The present disclosure is not limited to any particular type and configuration of the controller and any controller that can govern engine speed can be used. Further, in case of mechanically controlled engines, fly-ball type governor is employed for governing engine speed by regulating fuel quantity. However, the present disclosure is not limited to any particular type of governor and any other type of governor can be used.

Such configuration, relieves the driver from tedious task of simultaneously controlling accelerator pedal along with brake and clutch pedal, while maneuvering the vehicle on slopes. Particularly, while maneuvering or operating the vehicles on slopes or re-starting the vehicle on slopes, the hill assist system relieves the driver from controlling accelerator pedal, as the Electronic Control Unit (ECU) takes over the control of accelerator pedal, leaving only clutch and brake pedal for the driver to take care off. Accordingly, leaving only clutch and brake pedals for the driver to manipulate while maneuvering the vehicle on slopes, thereby improving vehicle safety and driver comfort, and makes vehicle restarting on slopes, an effortless affair. Further, such configuration of the system is not limited to use in hill assist applications and the same feature, wherein the driver has to control only clutch and brakes for maneuvering the vehicle can be used by the driver for any other applications based on convenience and terrain conditions, wherein the system can assist the handling of the vehicle without the maneuvering of the pedals. Such configuration of the Hill assist system enables the driver to easily maneuver the vehicle on slopes and substantially improves the restart-ability of a loaded vehicle on a slope, after engine has stalled or the vehicle has stopped, thereby enabling even a moderately skilled driver to convenient handle, maneuver vehicles on hilly terrain, consisting of steep slopes and sharp turns.
FIG. 1 illustrates the schematic block diagram representation of a hill assist system (100) for a vehicle in accordance with an embodiment of the present disclosure. In an embodiment of the present disclosure a hill assist system (100) for a vehicle is disclosed. The system (100) includes a switch (10) and an engine control unit (20). The switch (10) is disposed on the dashboard of the vehicle. The switch (10) changes operating mode of the engine from a normal mode to a booster mode, wherein mode selection is based on terrain on which the vehicle is traversing. The engine control unit (20) elevates engine speed from a first pre-determined engine speed to an elevated second pre-determined engine speed, governs the elevated second pre-determined engine speed by regulating fuel quantity as long as accelerator pedal travel is zero, as the operating mode is changed from the normal mode to the booster mode. The engine control unit (20) further lowers

the engine speed from the elevated second pre-determined engine speed to the first pre-determined engine speed, as the operating mode is changed from the booster mode to the normal mode.
The vehicle equipped with the hill assist system (100) of the present invention exhibits marginally better fuel efficiency on hilly terrain as compared to conventional vehicles without hill assist system. Specifically, in the absence of hill assist feature, the driver has to engage the clutch at engine fly up rpm. Therefore, the engine will consume more fuel. With hill assist feature of the present invention, the clutch engagement happens at pre-determined speed (much lesser than engine fly up). Hence fuel economy will be better during restart operations.
A method for improving re-start ability of a vehicle on a gradient is disclosed in accordance with an embodiment of the present disclosure. The method includes the steps of switching operating mode of the engine from a normal mode to a booster mode based on terrain on which the vehicle is traversing by suing a switch (10), elevating engine speed from a first pre-determined engine speed to an elevated second pre-determined engine speed, as the operating mode is changed from said normal mode to said booster mode and governing the elevated second pre-determined engine speed by regulating fuel quantity, as long as accelerator pedal travel is zero, lowering the engine speed from the elevated second pre-determined engine speed to the first pre-determined engine speed, as the operating mode is changed from the booster mode to the normal mode.
Such hill assist system offers further various advantages such as, with such a feature, clutch is engaged at a much lower engine speed during re-start, thus reducing clutch wear unlike in conventional vehicles wherein clutch is engaged by keeping engine at fly-up speed, thereby drastically reducing the clutch life.
Further, the hill assist system includes an indicator for alerting the driver when the booster mode is switched on. In accordance with an embodiment of the present disclosure, the indicator is a visual indicator. In accordance with another embodiment, the

indicator is an audio indicator. Typically, the hill assist system also includes a torque reduction module that reduces torque incase the elevated second pre-determined engine speed crosses a pre-determined speed. Such feature dissuades the driver to drive vehicle with booster mode on plane road. Further, higher marching speed in booster mode due to higher idle speed also makes it inconvenient to continuously drive with booster mode active.
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.
Advantages:
The present disclosure provides a hill assist system and a method for improving re-start ability of a vehicle on a gradient or a slope, however, the system is not limited to hill assist system but can be any other such feature which uses such methodology, and that: ()
• involves simple operation and is reliable;
• relieves the driver from tedious task of simultaneously controlling accelerator pedal along with brake and clutch pedal, while maneuvering the vehicle on slopes;
• improves vehicle safety and driver comfort;
• prevents accidents and subsequent damages;
• enables the vehicle to be handled by even moderately skilled driver, as the driver needs to manipulate only clutch and brake pedals for maneuvering the vehicle on slopes;

• enables quick and convenient maneuvering of the vehicle on a gradient or a slope;
• improves fuel efficiency and performance of the vehicle;
• adds a user-friendly feature to the vehicle;
• is inexpensive and efficient;
• reduces clutch wear and enhances clutch life;
• enhances maneuverability of the vehicle on a gradient or a slope; and
• can be easily retrofitted in the present vehicles, without much modification.
Reference Numerals:

Reference Number Description
(100) a hill assist system
(10) an actuation switch
(20) an engine control unit
“G” Governor
“E” Engine

We Claim:
1. A hill assist system (100) for a vehicle, said system comprising:
• a switch (10) adapted to change operating mode of an engine of the vehicle from a normal mode to either one of a plurality of booster modes, wherein mode selection is based on terrain on which the vehicle is traversing; and
• an engine control unit (20) adapted to elevate engine speed from a first pre-determined engine speed to elevated second pre-determined engine speed corresponding to said selected booster mode, govern said elevated second pre-determined engine speed by regulating fuel quantity/intake as long as accelerator pedal travel is zero, as the operating mode is changed from said normal mode to said booster mode, thereby enabling the driver to manipulate only clutch and brake pedals for maneuvering the vehicle on a slope, said engine control unit (20) further adapted to lower said engine speed from said elevated second pre-determined engine speed to said first pre-determined engine speed, as the operating mode is changed from said booster mode to said normal mode.

2. The system (100) as claimed in claim 1, wherein said engine control unit is an engine Management System of said vehicle.
3. The system (100) as claimed in claim 1, wherein said first pre-determined engine speed is “low idle speed” of the engine / that is the set lowest speed of the engine.
4. The system (100) as claimed in claim 1, wherein said second pre-determined engine speed is a desired optimized torque delivering speed of the engine.
5. The system (100) as claimed in claim 1, wherein said engine control unit (20) is an electronic engine control unit comprising a Proportional Integral Derivative (PID) controller adapted to govern engine speed by regulating fuel quantity.

6. The system (100) as claimed in claim 1, wherein said engine control unit (20) is an electronic engine control unit comprising a non-linear controller adapted to govern engine speed by regulating fuel quantity.
7. The system (100) as claimed in claim 1, wherein said controller (20) is a mechanical engine control system comprising a fly-ball type governor adapted to govern engine speed by regulating fuel intake/ quantity.
8. The system (100) as claimed in claim 1, wherein the switch is disposed on the dashboard of the vehicle.
9. The system (100) as claimed in claim 1, wherein the accelerator pedal is disabled in the booster mode.
10. The system (100) as claimed in claim 1, wherein the accelerator pedal remains operative in the booster mode.
11. The system (100) as claimed in claim 1, further comprising an indicator for alerting the driver when the booster mode is switched on.
12. The system (100) as claimed in claim 11, wherein the indicator is a visual indicator.
13. The system (100) as claimed in claim 11, wherein the indicator is an audio indicator.
14. The system (100) as claimed in claim 1, further comprising a torque reduction module adapted to reduce torque incase said elevated second pre-determined engine speed crosses a pre-determined speed.
15. The system (100) as claimed in claim 1, wherein said switch is either one of single-step and multi-step selection knob adapted to select different booster

modes, wherein a corresponding elevated second pre-determined engine speed is defined for each booster mode.
16. A method for improving re-start ability of a vehicle on a gradient, said method comprising the steps of:
• switching operating mode of the engine from a normal mode to either one of a plurality of booster modes based on terrain on which the vehicle is traversing;
• elevating engine speed from a first pre-determined engine speed to elevated second pre-determined engine speed corresponding to said selected booster mode, as the operating mode is changed from said normal mode to said either one booster mode and governing said elevated second pre-determined engine speed by regulating fuel quantity intake, as long as accelerator pedal travel is zero, thereby enabling the driver to manipulate only clutch and brake pedals for maneuvering the vehicle on a slope, lowering said engine speed from said elevated second pre-determined engine speed to said first pre-determined engine speed, as the operating mode is changed from said booster mode to said normal mode.