Description:FIELD OF THE INVENTION
[001] The present invention relates to stabilisation of a vehicle. More particularly, the present invention relates to a system and method for stabilisation of a vehicle.

BACKGROUND OF THE INVENTION
[002] With the advancement in vehicle technologies, there is greater focus on enhancement of driver assistance, and on improving the overall driving experience. Even with the evolving nature of the vehicles, and specifically two-wheeled vehicles, stability control of the vehicle at low-speeds remains a primarily manual process. For stability control at low speeds, the rider of the vehicle has to continuously provide steering inputs and brake inputs to keep the vehicle stable, so as to prevent the vehicle from rolling over. Further, especially in motorcycle type vehicles, where riding the motorcycle over bends or low-speed corners, braking and accelerating through the corner is very crucial. The difficulty in braking and accelerating through corners especially increases in conditions such as a slippery road surface, poor road condition and traffic situations.
[003] A few modern-day vehicles, especially two-wheeled vehicles are provided with some form or rider assist for low speed stability control. However, in conventional systems of brake-throttle assist devices for low speed stabilisation, stabilisation of vehicle at low speed is controlled by taking responses from mainly two variables, namely roll rate, i.e. rate of roll or incline of the vehicle, and steering angle, i.e. the angle of rotation of the handlebar. However, the effect of slip ratios and slip angle under complicated road conditions is not accounted for in brake-throttle assist. It is known that high slip ratios & slip angle adversely affect the stability and driving performance of the vehicle.
[004] When the conventional braking-throttle assist stabilisation control system is operated only with the consideration of roll rate and steering angle as the only control input, the low-speed stabilisation of the vehicle is configured only for one type of road surface. The conventional systems remain unable to provide low-speed stabilisation control over a range of different road surfaces.
[005] Thus, there is a need in the art for a system and method for stabilisation of a vehicle, which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[006] In one aspect, the present invention relates to a system for stabilisation of a vehicle. The system has a wheel speed sensor being configured for measuring a speed of a wheel of the vehicle. The system further has an Inertial Measurement Unit being configured for measuring a roll rate of the vehicle and a speed of the vehicle. The system further has a steering angle sensor being configured for measuring an angle of rotation of a handlebar of the vehicle. The system further a traction unit being connected to a powered wheel of the vehicle and a brake unit being connected to the wheel of the vehicle. A control unit is in communication with the wheel speed sensor, the Inertial Measurement Unit and the steering angle sensor. The control unit is configured to: detect whether the speed of the vehicle is lower than a first predetermined value; determine a value of wheel slip based on the inputs received from the wheel speed sensor, the Inertial Measurement Unit and the steering angle sensor; detect whether the value of wheel slip is greater than a second predetermined value; detect whether the roll rate of the vehicle is greater than a third predetermined value; detect whether the steering angle of the handlebar is greater than a fourth predetermined value; and control the operation of a throttle input of the traction unit and the operation of the brake unit of the vehicle, to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle.
[007] In an embodiment of the invention, the control unit is configured to determine a direction of a fall of the vehicle based on at least one of said inputs from Inertial Measurement Unit or rotation angle of the handlebar; and control the operation of the throttle input of the traction unit and the operation of the brake unit, to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle.
[008] In an embodiment of the invention, the control unit is configured to estimate the intended wheel slip, and to detect the roll rate and steering angle, and control the operation of the throttle input of the traction unit and the operation of the brake unit to achieve the intended values of the wheel slip to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle.
[009] In a further embodiment of the invention, the vehicle has a drive gear attached to a steering shaft of the vehicle, and a driven gear configured to mesh with the drive gear. Further, the steering angle sensor has a potentiometer connected to the driven gear, wherein angle of rotation of the driven gear is measured by the potentiometer, thereby measuring the steering angle of the handlebar.
[010] In another embodiment of the invention, the system has a motor actuator connected to the control unit, and the motor actuator is configured to operate the brake unit, wherein the motor assembly actuator being connected to a brake wire by means of a gear assembly.
[011] In a further embodiment of the invention, the motor actuator is a part of an ABS unit of the brake unit.
[012] In a further embodiment of the invention, the system has a throttle position sensor for sensing the amount of opening of the throttle input to the traction unit, and the control unit is configured to operate the brake unit based on the sensed amount of opening of the throttle input to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle.
[013] In another aspect, the present invention relates to a method for stabilising of a vehicle. The method has the steps of: receiving, by the control unit, a speed of a wheel from a wheel speed sensor, a roll angle and a speed of the vehicle from an Inertial Measurement Unit and a rotation angle of a handlebar from a steering angle sensor; detecting, by the control unit, whether the speed of the vehicle is lower than a first predetermined value; determining, by the control unit, a value of wheel slip based on the inputs received from the wheel speed sensor, the Inertial Measurement Unit and the steering angle sensor; detecting, by the control unit, whether the value of wheel slip is greater than a second predetermined value; detecting, by the control unit, whether the roll rate of the vehicle is greater than a third predetermined value; detecting, by the control unit, whether the steering angle of the handlebar is greater than a fourth predetermined value; and controlling, by the control unit, the operation of a throttle input of a traction unit and the operation of a brake unit of the vehicle, to generate at least one of balancing lateral force or a longitudinal balancing force, thereby stabilising the vehicle.
[014] In an embodiment of the invention, the method has the steps of: determining, by the control unit, a direction of a fall of the vehicle based on at least one of said inputs from said Inertial Measurement Unit or the rotation angle of the handlebar; and controlling, by the control unit, the operation of the throttle input of the traction unit and the operation of the brake unit, to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle.
[015] In an embodiment of the invention, the method has the steps of: estimating, by the control unit, the intended wheel slip; detecting, by the control unit, roll rate and steering angle; and controlling, by the control unit, the operation of the throttle input of the traction unit and the operation of the brake unit to achieve the intended values of the wheel slip, roll rate and steering angle to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS
[016] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a system for stabilisation of a vehicle, in accordance with an embodiment of the present invention.
Figure 2 illustrates method steps involved in a method for stabilisation of the vehicle, in accordance with an embodiment of the present invention.
Figure 3 illustrates a perspective view of the vehicle, in accordance with an embodiment of the present invention.
Figure 4A and 4B illustrates a perspective and an exploded view, respectively of a motor actuator of the system, in accordance with an embodiment of the invention.
Figure 5 illustrates a magnified view of a drive gear and a driven gear of the system, in accordance with an embodiment of the invention.
Figure 6 illustrates an exploded view of the drive gear and the driven gear, in accordance with an embodiment of the invention.
Figure 7 illustrates a front perspective view of the vehicle, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[017] The present invention relates to stabilisation of a vehicle. More particularly, the present invention relates to system and method for stabilisation of a vehicle. The system and method of the present invention are typically used in a vehicle such as a two wheeled vehicle, or other multi-wheeled vehicles as required.
[018] Figure 1 illustrates a system 100 for stabilisation of a vehicle 10 (shown in Figure 3). As illustrated, the system 100 comprises a wheel speed sensor 110. The wheel speed sensor 110 is configured for measuring a speed of a wheel 14 (shown in Figure 3) of the vehicle 10. In an embodiment, the wheel 14 is a front wheel of the vehicle 10. Further, the system 100 comprises an Inertial Measurement Unit 120 that is configured for measuring a roll rate of the vehicle 10 along with and a speed of the vehicle 10. Herein, the vehicle speed is the longitudinal speed of the vehicle 10. In an embodiment, the Inertial Measurement Unit 120 includes one or more gyroscopes and accelerometers for detecting specific angular rates and specific speeds and accelerations of the vehicle.
[019] The system 100 further comprises a steering angle sensor 130. The steering angle sensor 130 is configured for measuring an angle of rotation of a handlebar 50 (shown in Figure 3) of the vehicle 10. The system 100 further has a traction unit 20 (shown in Figure 3) being connected to a powered wheel 16 (shown in Figure 3) of the vehicle 10. In an embodiment, the traction unit 20 is an internal combustion engine or a traction motor, and the powered wheel 16 is a rear wheel of the vehicle 10. Further, the system 100 has a brake unit 30 (shown in Figure 3) that is connected to the wheel 14 of the vehicle 10.
[020] As further illustrated in Figure 1, the system 100 has a control unit 140. As illustrated, the control unit 140 is in communication with the wheel speed sensor 110, the Inertial Measurement Unit 120 and the steering angle sensor 130. Herein, the control unit is configured to detect whether the speed of the vehicle 10 is lower than a first predetermined value. In an embodiment, the first predetermined value of the speed of the vehicle 10 is 7Kmph. A low speed of the vehicle 10 is where the stabilisation is required by means of brake-throttle inputs. The control unit 140 is further configured to determine a value of wheel slip based on the inputs received from the wheel speed sensor 110, the Inertial Measurement Unit 120 and the steering angle sensor 130. Wheel slip is defined as the difference between the rotation speed of the wheel 14 and the longitudinal speed of the vehicle 16. Further, the control unit 10 is configured to detect whether the value of wheel slip is greater than a second predetermined value. Wheel slip is indicative of the slipping behaviour of the wheel 14, and a high value of wheel slip indicates that there is a high difference between the longitudinal speed of the vehicle 10 and the speed of the wheel 14, thus a greater chance of slipping of the wheel 14 on the road surface.
[021] The control unit 140 is further configured to detect whether the roll rate of the vehicle 10 is greater than a third predetermined value. Roll rate is the measure of the change in sideways roll or inclination of the vehicle 10, and a high roll rate indicates that the sideways roll of the vehicle 10 is increasing rapidly, thus high likeliness of vehicle rolling or falling. Further, the control unit 140 is configured to detect whether the steering angle of the handlebar 50 is greater than a fourth predetermined value. Steering angle is indicative of the angle of rotation of the handlebar 50 wherein a high steering angle indicates that a sharp corner is to be traversed by the vehicle 10 or a sharp steering input by the rider, thus requiring stabilisation.
[022] On satisfaction of all the aforementioned preconditions, i.e. speed of the vehicle 10 being lower than the first predetermined value, value of wheel slip being greater than the second predetermined value, roll rate of the vehicle 10 being greater than the third predetermined value, and the steering angle of the handlebar 50 being greater than the fourth predetermined value, the control unit 140 is configured to control the operation of a throttle input 22 (shown in Figure 3) of the traction unit 20 and the operation of the brake unit 30 of the vehicle 10, to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle 10. Thus, in operation, the control unit 140 on detection low vehicle speed, high possibility of wheel slip and vehicle roll, detects that stabilisation assist is required for the vehicle 10, and thus operates the traction unit 20 and the brake unit 30 to provide balancing force for preventing the vehicle from falling over or slipping.
[023] In an embodiment, the control unit 140 is configured to determine a direction of a fall of the vehicle 10 based on at least one of the inputs from Inertial Measurement Unit 120 or rotation angle of the handlebar 50. Generally, if the vehicle 10 is rolling or falling over on one side, the rider of vehicle 10, to provide balancing force, rotates the handlebar 50 in the direction of the roll or fall of the vehicle 10. Alternatively, if the vehicle 10 has to take a right turn, the handlebar 50 is rotated towards the right side and the vehicle 10 is likely to fall over on the right side. Further, the control unit 140 is configured to control the operation of the throttle input 22 of the traction unit 20 and the operation of the brake unit 30, to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle 10.
[024] In an embodiment, the control unit 140 is configured to estimate the intended wheel slip, and to detect the roll rate and steering angle. In that, since, different wheel slip values are appropriate for different road surfaces and turning operations, the control unit 140 estimates target control parameters in respect of the intended wheel slip and the detected roll rate and steering angle. Thereafter, the control unit 140 is configured to control the operation of the throttle input 22 of the traction unit 20 and the operation of the brake unit 30 to achieve the intended values of the wheel slip to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle 10.
[025] Reference is made to Figure 5, Figure 6 and Figure 7, wherein as illustrated, to measure the steering angle of the handlebar 50, the vehicle 10 comprises a drive gear 62 attached to a steering shaft 24 of the vehicle 10. Further, a driven gear 64 is configured to mesh with the drive gear 62. In that, the steering angle sensor 130 comprises a potentiometer connected to the driven gear 64. Herein, angle of rotation of the driven gear 64 is measured by the potentiometer, thereby measuring the steering angle of the handlebar 50.
[026] Reference is made to Figure 4A and Figure 4B, wherein as illustrated, for controlling of the operation of the brake unit 30, the system 100 has a motor actuator 70 connected to the control unit 140. The motor actuator 70 is configured to operate the brake unit 30 facilitated by the motor actuator 70 being connected to a brake wire 72 by means of a gear assembly 74. The rotation of the motor actuator 74 is transmitted to the brake wire 72 by means of the gear assembly, and the resultant actuation of the brake wire 72 operates the brake unit 30. The control unit 140 also controls the degree of actuation of the motor actuator 70, thereby controlling the quantum of actuation of the brake wire 72 and thus, operation of the brake unit 30. In an embodiment, the motor actuator 70 is integrated or incorporated as a part of the Anti Lock Braking System (ABS) unit for the brake unit 30 of the vehicle 10.
[027] In a further embodiment, the system 100 has a throttle position sensor 150 for sensing the amount of opening of the throttle input 22 to the traction unit 20. The control unit 140 is configured to control the traction unit 20 and the brake unit 30 in unison, meaning that the brake unit 30 is operated based on the operation of the traction unit 20. In that, the control unit 140 is configured to operate the brake unit 30 based on the sensed amount of opening of the throttle input 22 to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle 10.
[028] In another aspect, the present invention relates to a method 200 for stabilising a vehicle 10. Figure 2 illustrates the method steps involved in the method 200 for stabilising the vehicle 10. As illustrated, at step 202, a speed of a wheel 14 from a wheel speed sensor 110, a roll angle and a speed of the vehicle 10 from an Inertial Measurement Unit 120 and a rotation angle of a handlebar 50 from a steering angle sensor 130, are received by the control unit 140. At step 204, whether the speed of the vehicle 10 is lower than a first predetermined value is detected by the control unit 140. If the speed of the vehicle 10 is higher than the first predetermined value, then the method 200 concludes and no assist is provided in the stabilisation of the vehicle 10. If the speed of the vehicle 10 is lower than the first predetermined value, then the method 200 moves to step 210.
[029] Thereafter, at step 206, a value of wheel slip is determined by the control unit 140 based on the inputs received from the wheel speed sensor 110, the Inertial Measurement Unit 120 and the steering angle sensor 130. At step 208, whether the value of wheel slip is greater than a second predetermined value is detected by the control unit 140. If the wheel slip is greater than the second predetermined value, the method 200 moves to step 210, otherwise, the method 200 concludes and no assist is provided.
[030] At step 210, whether the roll rate of the vehicle 10 is greater than a third predetermined value is detected by the control unit 140. If the roll rate is greater than the third predetermined value, the method 200 moves to step 212, otherwise, the method 200 concludes and no assist is provided. Thereafter, at step 212, whether the steering angle of the handlebar 50 is greater than a fourth predetermined value is detected by the control unit. If the steering angle is greater than the fourth predetermined value, the method 200 moves to step 214, otherwise, the method 200 concludes and no assist is provided.
[031] At step 214, the operation of a throttle input 22 of a traction unit 20 and the operation of a brake unit 30 of the vehicle 10 are controlled by the control unit 140, to generate at least one of balancing lateral force or a longitudinal balancing force, thereby stabilising the vehicle 10. As a result, at step 216, the vehicle 10 is stabilised.
[032] In an embodiment, the method 200 further has the steps of determining a direction of a fall of the vehicle 10 by the control unit 140 based on at least one of said inputs from said Inertial Measurement Unit 120 or the rotation angle of the handlebar 50. The method 200 further has the steps of controlling the operation of the throttle input 22 of the traction unit 20 and the operation of the brake unit 30 by the control unit 140, to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle 10.
[033] In a further embodiment, the method 200 has the steps of estimating the intended wheel slip by the control unit 140; detecting roll rate and steering angle by the control unit 140; and controlling the operation of the throttle input 22 of the traction unit 20 and the operation of the brake unit 30 by the control unit 140, to achieve the intended values of the wheel slip to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle 10.
[034] Advantageously, the present invention provides a system and method for stabilising a vehicle, that provides operation of traction unit and the brake unit of the vehicle to provide a balancing force, thereby stabilising the vehicle. The operation of the traction unit and the brake unit is controlled based upon the wheel slip in addition to the roll rate and the steering angle, thereby allowing the present invention to provide low-speed stabilisation for the vehicle under all road conditions.
[035] Further, the present invention allows for low-speed stabilisation assist for a vehicle, especially on slippery road surfaces or bad road conditions, thereby ensuring prevention of the rolling or falling of the vehicle at low speeds, thus enhancing rider safety. The present invention allows for reduced instability and reduced requirement of throttle and brake by the rider, which also reduces rider fatigue.
[036] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

List of Reference Numerals
10: Vehicle
14: Wheel
16: Powered Wheel
20: Traction Unit
22: Throttle Input
24: Steering Shaft
30: Brake Unit
50: Handlebar
62: Drive Gear
64: Driven Gear
70: Motor Actuator
72: Brake Wire
74: Gear Assembly
100: System for Stabilising a Vehicle
110: Wheel Speed Sensor
120: Inertial Measurement Unit
130: Steering Angle Sensor
140: Control Unit
200: Method for Stabilising a Vehicle
, Claims:WE CLAIM:
1. A system (100) for stabilisation of a vehicle (10), the system (100) comprising:
a wheel speed sensor (110) being configured for measuring a speed of a wheel (14) of the vehicle (10);
an Inertial Measurement Unit (120) being configured for measuring a roll rate of the vehicle (10), and a speed of the vehicle (10);
a steering angle sensor (130) being configured for measuring an angle of rotation of a handlebar (50) of the vehicle (10);
a traction unit (20) being connected to a powered wheel (16) of the vehicle (10);
a brake unit (30) being connected to the wheel (14) of the vehicle (10); and
a control unit (140), the control unit (140) being in communication with the wheel speed sensor (110), the Inertial Measurement Unit (120) and the steering angle sensor (130), the control unit (140) being configured to:
detect whether the speed of the vehicle (10) is lower than a first predetermined value;
determine a value of wheel slip based on the inputs received from the wheel speed sensor (110), the Inertial Measurement Unit (120) and the steering angle sensor (130);
detect whether the value of wheel slip is greater than a second predetermined value;
detect whether the roll rate of the vehicle (10) is greater than a third predetermined value;
detect whether the steering angle of the handlebar (50) is greater than a fourth predetermined value; and
control the operation of a throttle input (22) of the traction unit (20) and the operation of the brake unit (30) of the vehicle (10), to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle (10).

2. The system (100) as claimed in claim 1, wherein the control unit (140) is configured to:
determine a direction of a fall of the vehicle (10) based on at least one of said inputs from Inertial Measurement Unit (120) or rotation angle of the handlebar (50); and
control the operation of the throttle input (22) of the traction unit (20) and the operation of the brake unit (30), to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle (10).

3. The system (100) as claimed in claim 1, wherein the control unit (140) is configured to estimate the intended wheel slip, and to detect the roll rate and steering angle, and control the operation of the throttle input (22) of the traction unit (20) and the operation of the brake unit (30) to achieve the intended values of the wheel slip to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle (10).

4. The system (100) as claimed in claim 1, wherein the vehicle (10) comprises a drive gear (62) attached to a steering shaft (24) of the vehicle (10); and a driven gear (64) configured to mesh with the drive gear (62); and the steering angle sensor (130) comprises a potentiometer connected to the driven gear (64), wherein angle of rotation of the driven gear (64) is measured by the potentiometer, thereby measuring the steering angle of the handlebar (50).

5. The system (100) as claimed in claim 1, comprising a motor actuator (70) connected to the control unit (140), the motor actuator (70) being configured to operate the brake unit (30) wherein the motor actuator (70) being connected to a brake wire (72) by means of a gear assembly (74).

6. The system as claimed in claim 5, wherein the motor actuator (70) is a part of an ABS unit of the brake unit (30).

7. The system (100) as claimed in claim 1, comprising a throttle position sensor (150) for sensing the amount of opening of the throttle input (22) to the traction unit (20), and the control unit (140) being configured to operate the brake unit (30) based on the sensed amount of opening of the throttle input (22) to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle (10).

8. A method (200) for stabilisation of a vehicle (10), the method (200) comprising the steps of:
receiving, by the control unit (140), a speed of a wheel (14) from a wheel speed sensor (110), a roll angle and a speed of the vehicle (10) from an Inertial Measurement Unit (120) and a rotation angle of a handlebar (50) from a steering angle sensor (130);
detecting, by the control unit (140), whether the speed of the vehicle (10) is lower than a first predetermined value;
determining, by the control unit (140), a value of wheel slip based on the inputs received from the wheel speed sensor (110), the Inertial Measurement Unit (120) and the steering angle sensor (130);
detecting, by the control unit (140), whether the value of wheel slip is greater than a second predetermined value;
detecting, by the control unit (140), whether the roll rate of the vehicle (10) is greater than a third predetermined value;
detecting, by the control unit (140), whether the steering angle of the handlebar (50) is greater than a fourth predetermined value; and
controlling, by the control unit (40), the operation of a throttle input (22) of a traction unit (20) and the operation of a brake unit (30) of the vehicle (10), to generate at least one of balancing lateral force or a longitudinal balancing force, thereby stabilising the vehicle (10).

9. The method (200) as claimed in claim 8, comprising the steps of:
determining, by the control unit (140), a direction of a fall of the vehicle (10) based on at least one of said inputs from said Inertial Measurement Unit (120) or the rotation angle of the handlebar (50); and
controlling, by the control unit (140), the operation of the throttle input (22) of the traction unit (20) and the operation of the brake unit (30), to generate at least one of balancing lateral force or balancing longitudinal force in a direction opposite to the direction of the fall, thereby stabilising the vehicle (10).

10. The method (200) as claimed in claim 8, comprising the steps of:
estimating, by the control unit (140), the intended wheel slip;
detecting, by the control unit (140), roll rate and steering angle; and
controlling, by the control unit (140), the operation of the throttle input (22) of the traction unit (20) and the operation of the brake unit (30) to achieve the intended values of the wheel slip to generate at least one of balancing lateral force or balancing longitudinal force, thereby stabilising the vehicle (10).

Dated this 09 day of May 2023

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471