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 stabilising a vehicle.

BACKGROUND OF THE INVENTION
[002] Typically, while riding a saddle type vehicle such as motorcycles or a scooter type vehicle, user tends to provide more inputs for manoeuvring the vehicle, due to this a user interface is provided to assist the user at any type of terrain or road conditions. The current user interface is complex because of inbuilt architecture which requires complicated algorithms and advanced sensors and actuators. It becomes a challenge for OEMs and manufactures to provide a user friendly and straight forward user interface which can work efficiently with less user intervention. Without these assist systems, based on the terrain and riding conditions, there is a high requirement of inputs from the rider for riding the vehicle under different conditions.
[003] One specific problem that is faced during riding of the motorcycle type or scooter type vehicle, especially by elderly users or new users is during taking a turn (which can be close turn or U- turn) that requires a specific handling and manoeuvring sequence involving brakes as well as the throttle. Elderly users or new users find it challenging to handle all the processes required at the same time to take such turns. For example, while taking turns, a change in speed is required to be made) it can be increase in speed or decrease in speed) with a control on a braking system, and also sometimes requiring clutch and gear control. Controlling of such a large number of inputs by the user is difficult because user tends to focus on the turn path and also managing the path of other vehicles and may sometimes lead to accidents or other unwanted circumstances for the user, because there are chances of longitudinal slip which can occur due to differences in rotational speed between wheels and surface and lateral slip due to wheel’s direction of motion deviates from the direction it is pointing.
[004] There exist some conventional systems for turn assist, in which some assistance is provided to the user for taking a turn, but due to different types of segments in two wheelers, the parameters and variables of all these systems are different. Thus, a single system cannot be adapted to a variety of vehicles. Most conventional systems are complicated and rely on ABS control for controlling the braking, but these systems are limited only to vehicles that have ABS and cannot be applied to vehicles not having ABS. Further, other systems which use only a very limited number of inputs for stabilisation, stabilisation is not always possible at various road conditions because there exist various other factors that have a high impact on the stability of the vehicle, which are not considered.
[005] Thus, there is a need in the art for a system and method for stabilising 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 stabilising a vehicle. The system has one or more vehicle sensors configured to detect one or more vehicle parameters. The one or more vehicle parameters include a first parameter and a set of second parameters. Further, one or more actuators are configured to control one or more operating parameters of the vehicle. Further, control unit is configured to receive the one or more vehicle parameters from the one or more vehicle sensors; determine whether the first parameter is lower than a first predetermined value; determine whether the set of second parameters are greater than a set of second predetermined values, if the first parameter is lower than the first predetermined value; estimate a third parameter based on the set of second parameters, if the set of second parameters are greater than the set of second predetermined values; determine whether the third parameter is greater than a third predetermined value; and operate the one or more actuators for controlling the one or more operating parameters for stabilising the vehicle, if the third parameter is greater than the third predetermined value.
[007] In an embodiment of the invention, the one or more sensors includes a speed sensor of the vehicle, and the first parameter is a speed of the vehicle.
[008] In a further embodiment of the invention, the one or more sensors include one or more of a steering angle sensor, and an inertial measurement unit, and the set of second parameters include one or more of a lateral acceleration, a steering angle, a roll rate and a yaw rate of the vehicle.
[009] In a further embodiment of the vehicle, the third parameter is a side slip of the vehicle, and the control unit is configured to estimate the side slip of the vehicle based on at least a lateral velocity and the yaw rate of the vehicle.
[010] In a further embodiment of the invention, the one or more actuators include an engine management system with a throttle position sensor. The one or more operating parameters comprise a speed of the vehicle, wherein the control unit is configured to communicate with the engine management system to control a torque of an engine and the throttle position of the vehicle thereby controlling the speed of the vehicle.
[011] In another aspect, the present invention relates to a method for stabilising a vehicle. The method has the steps of: detecting, by one or more vehicle sensors, one or more vehicle parameters, the one or more vehicle parameters having a first parameter and a set of second parameters; receiving, by a control unit, the one or more vehicle parameters from the one or more vehicle sensors; determining, by the control unit, whether first parameter is lower than a first predetermined value; determining, by the control unit, whether the set of second parameters are greater than a set of second predetermined values, if the first parameter is lower than the first predetermined value; estimating, the control unit, a third parameter based on the set of second parameters, if the set of second parameters are greater than the set of second predetermined values; determining, the control unit, whether the third parameter is greater than a third predetermined value; and operating, by the control unit, one or more actuators for controlling the one or more operating parameters for stabilising the vehicle, if the third parameter is greater than the third predetermined value.
[012] In an embodiment of the invention, the one or more sensors includes a speed sensor of the vehicle, and the first parameter is a speed of the vehicle.
[013] In a further embodiment of the invention, the one or more sensors include one or more of a steering angle sensor, and an inertial measurement unit, and the set of second parameters include one or more of a lateral acceleration, a steering angle, a roll rate and a yaw rate of the vehicle.
[014] In a further embodiment of the vehicle, the third parameter is a side slip of the vehicle, and the method has the steps of: estimating, by the control unit, the side slip of the vehicle based on at least a lateral velocity and the yaw rate of the vehicle.
[015] In a further embodiment of the invention, the one or more actuators include an engine management system with a throttle position sensor, and the one or more operating parameters comprise a speed of the vehicle. The method comprises the step of: communicating, by the control unit with the engine management system to control a torque of an engine of the vehicle and a throttle position thereby controlling the speed of 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 stabilising a vehicle, in accordance with an embodiment of the present invention.
Figure 2 illustrates method steps involved in a method for stabilising a vehicle, in accordance with an embodiment of the present invention.
Figure 3 illustrates steps involved in a method for stabilising a vehicle, in accordance with an embodiment of the present 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 stabilising a vehicle. The system and method of the present invention are typically used in a vehicle such as a two wheeled vehicle, however, the system and method of the present invention is capable of being used in three-wheeled vehicles, or other multi-wheeled vehicles as required.
[018] Figure 1 illustrates a system 100 for stabilising a vehicle. The system 100 of the present invention is specifically configured to stabilise the vehicle, especially at low speeds and during cornering, such as when taking a U-turn. As illustrated, the system 100 has one or more vehicle sensors 110. The one or more vehicle sensors 110 are configured to detect one or more vehicle parameters. Specifically, the one or more vehicle parameters comprise a first parameter and a second parameter. In an embodiment, as illustrated in Figure 1, the one or more vehicle sensors 110 comprises a speed sensor 112 of a vehicle, and the first parameter comprises a speed of the vehicle.
[019] In a further embodiment, as illustrated in Figure 1, the one or more vehicle sensors 110 comprises one or more of a steering angle sensor 114 configured to detect a steering angle of the vehicle, and an inertial measurement unit 118 configured to detect a roll rate of the vehicle and a yaw rate of the vehicle, along with the lateral acceleration of the vehicle. Accordingly, the set of second parameters comprises one or more of the lateral acceleration of the vehicle, the steering angle of the vehicle, the roll rate of the vehicle and the yaw rate of the vehicle. Accordingly, in an embodiment, a combination of the lateral acceleration, the steering angle, the roll rate and the yaw rate of the vehicle are used as second parameters for stabilising the vehicle.
[020] The system 100 further has a control unit 120. The control unit 120 is configured to receive the one or more vehicle parameters from the one or more vehicle sensors 110 for further processing and stabilising the vehicle. The control unit 120 is configured to determine whether the first parameter is lower than a first predetermined value, based on which further processing is done. In an embodiment, the control unit 120 is configured to determine whether the speed of the vehicle is lower than the first predetermined value. The speed of the vehicle being lower than the first predetermined value indicates that the vehicle is slowing down, and there is a possibility of the user approaching a U-turn or a tight corner. In an embodiment, the first predetermined value of the speed of the vehicle ranges between 2kmph and 20kmph.
[021] If it is determined that the first parameter is lower than the first predetermined value, the control unit 120 is further configured to determine whether the set of second parameters are greater than a set of second predetermined values. In an embodiment, the control unit 120 determines whether each of the set of second parameters are greater than their corresponding predetermined values. In an embodiment, the control unit 120 determines whether the lateral acceleration of the vehicle is greater than its corresponding predetermined value, whether the roll rate of the vehicle is greater than its corresponding predetermined value, and whether the yaw rate of the vehicle is greater than its corresponding predetermined value. In an embodiment, the predetermined value of the lateral acceleration of the vehicle is 0.1-0.3m/s2 , the predetermined value of the roll rate of the vehicle is 10-20 degrees/second and the predetermined value of the yaw rate of the vehicle is 45-55 degrees/second. If the lateral acceleration, the roll rate and the yaw rate of the vehicle is greater than their corresponding predetermined values, it indicates that the vehicle is cornering.
[022] Further, in this embodiment, the control unit 120 determines whether the steering angle of the vehicle is greater than its corresponding predetermined value. In an embodiment, the second predetermined value of the steering angle ranges between 20 degrees and 60 degrees. If the steering angle is greater than its corresponding predetermined value from the set of second predetermined values, and the lateral acceleration, the roll rate and the yaw rate of the vehicle is greater than their corresponding predetermined values from the set of second predetermined values, it indicates that the vehicle is cornering and taking a U-turn and thus possibly requires assisting for stabilising the vehicle.
[023] To be certain about providing an assist for stabilisation of the vehicle, if the set of second parameters are greater than the set of second predetermined values as explained hereinbefore, the control unit 120 is configured to estimate a third parameter based on the set of second parameters, and whether the third parameters is greater than a third predetermined value. In an embodiment, the third parameter comprises a side slip of the vehicle, and the third predetermined value of the side slip of the vehicle is 2.3 degrees. If the side slip of the vehicle is greater than the predetermined value, it is ascertained that the vehicle is in a cornering state and is taking a tight turn/U-turn and requires assist to prevent rolling over.
[024] Side slip of the vehicle is defined as the ratio of lateral velocity of the vehicle Vy (along the width of the vehicle) to the ratio of longitudinal velocity of the vehicle Vx (along the length of the vehicle. However, while longitudinal velocity Vx of the vehicle is easily measured, it is not possible to measure the lateral velocity Vy of the vehicle, and thus for calculation of the side slip, the lateral velocity Vy of the vehicle is estimated by the control unit 120. For this, the control unit 120 estimates the lateral velocity of the vehicle Vy as a product of the yaw rate (?) of the vehicle with a specified length (l2). The specified length is the horizontal distance measured from the rear end of a rear tyre to the centre of gravity of the vehicle. A suitable proportional time gain value (for example 240ms) is also used to estimate the side slip value earlier than the actual event, so as to avoid collisions. Thus, the slide slip is measured using the below formula:
Side Slip = Gain*(?*l2/Vx)

[025] The system 100 further has one or more actuators 130 that are configured to control one or more operating parameters of the vehicle. Thus, for stabilising the vehicle, if the third parameter is greater than the third predetermined value, the control unit 120 is configured to operate the one or more actuators 130 for controlling the one or more operating parameters for stabilising the vehicle. Thus, by virtue of the provision of the system 100, based on determination of the parameters as explained hereinbefore, the control unit 120 controls the one or more actuators 130 so as to stabilise the vehicle when the vehicle is cornering or negotiating a tight bend, thus assisting the user.
[026] In an embodiment, the one or more actuators 130 comprise an engine management system 132 with a throttle position sensor 134, and the one or more operating parameters comprise a speed of the vehicle. Accordingly, the control unit 120 is configured to communicate with the engine management system 132 for controlling a torque of an engine of the vehicle and a throttle position thereby controlling the speed of the vehicle. The control of engine torque and throttle position ensures that the vehicle keeps running at a constant speed for the duration of the cornering or taking the U-turn. Accordingly, the system 100 of the present invention automates the throttle input and controls the torque of the engine so as to maintain a constant speed during cornering or taking a U-turn, thereby ensuring that the vehicle does not roll over during such a condition and eliminating the requirement of a large number of user inputs for maintaining constant speed of the vehicle.
[027] In an embodiment, the system 100 comprises a Proportional integral (PI) Controller that is in communication with the engine management system 132 for maintaining the constant speed of the vehicle at a desired level. In operation, for example, if the vehicle, during taking a U-turn is rolling over in the clockwise direction, the system 100 tends to maintain the speed of the vehicle by controlling the torque and throttle position such that the vehicle balanced is balanced by the user in the counterclockwise direction, thereby balancing the vehicle.
[028] In another aspect, the present invention relates to a method 200 for stabilising the vehicle. Figure 2 illustrates the method steps involved in the method 200 for stabilising the vehicle. At step 202, one or more vehicle parameters are detected by one or more vehicle sensors 110, wherein the one or more vehicle parameters comprise a first parameter and a set of second parameters. At step 204, the one or more vehicle parameters are received by the control unit 120 from the one or more vehicle sensors 110. At step 206, it is determined by the control unit 120 whether the first parameter is lower than the first predetermined value. If it is determined that the first parameter is lower than the first predetermined value, then the method moves to step 210, otherwise method 200 moves to step 208 and no assist is provided. At step 210, it is determined by the control unit 120 that whether the set of second parameters are greater than the set of second predetermined values. If at step 210, it is determined that the set of second parameters are greater than the set of second predetermined values, then the method moves to step 214, otherwise the method 200 moves to step 212 and no assist is provided.
[029] At step 214, the third parameter is estimated by the control unit 120 based on the set of second parameters. Thereafter, at step 216, it is determined by the control unit 120 whether the third parameter is greater than the third predetermined value. If at step 216, it is determined that the third parameter is greater than the third predetermined value, then the method 200 moves to step 220, otherwise the method 200 moves to step 218 and no assist is provided. At step 220, the one or more actuators 130 are operated by the control unit 120 for controlling one or more operating parameters for stabilising the vehicle.
[030] Figure 3 illustrates further method steps 300 involved in the method 200, in accordance with an embodiment of the invention. In an embodiment, the one or more vehicle sensors 110 comprises a speed sensor 112 of a vehicle, and the first parameter comprises a speed of the vehicle. Accordingly, at step 302, it is determined whether the speed of the vehicle is lower than the predetermined value, and if so, method moves to step 306, otherwise method moves to step 304, and no assist is provided.
[031] In a further embodiment, the set of second parameters comprise one or more of the lateral acceleration, the steering angle, the roll rate and the yaw rate of the vehicle. At step 306, it is determined whether the roll rate, the yaw rate and the lateral acceleration of the vehicle are greater than their corresponding predetermined values from the set of second predetermined values. If at step 306, it is determined that the roll rate, the yaw rate and the lateral acceleration of the vehicle are greater than their corresponding predetermined values, then the method moves to step 310, otherwise method moves to step 308, and no assist is provided. At step 310, it is determined by the control unit 120 that whether the steering angle of the vehicle is greater than its corresponding predetermined value from the set of second predetermined values. If at step 310, it is determined that the steering angle of the vehicle is greater than its corresponding predetermined value, the method moves to step 314, otherwise method moves to step 312 and no assist is provided. At step 314, the slide slip of the vehicle is determined as explained hereinbefore, and it is determined whether the value of the slide slip is greater than the third predetermined value. If at step 314, it is determined that the slide slip is greater than the third predetermined value, then the method moves to step 318, otherwise method moves to step 316, and no assist is provided. At step 318, the control unit 120 communicates with the engine management system 132 with the throttle position sensor 134 for controlling the torque of the engine and the throttle position for stabilising the vehicle. At step 320, it is determined whether the current speed of the vehicle is greater than or equal to a desired vehicle speed based on which, the PI controller maintains the constant vehicle speed. At step 318, it is also determined whether the engine management system torque control and throttle position control is below a predetermined value, and if so, method moves to step 322 wherein the vehicle is stabilised, otherwise method reverts to step 302.
[032] Advantageously, the present invention provides a system and a method for stabilising a vehicle which detects whether the vehicle is in the state of cornering or taking a U-turn and provides control of one or more operating parameters of the vehicle for stabilising the vehicle. The present invention provides for automatic operation of the one or more actuators for controlling the operating parameters of the vehicle, thereby reducing the rider input required for maintaining a constant speed during the vehicle U-turn or cornering, which is especially helpful for new or elderly riders.
[033] Further, in the present invention, the control of engine torque and throttle position ensures that the vehicle keeps running at a constant speed for the duration of the cornering or taking the U-turn. Accordingly, the system of the present invention automates the throttle input and controls the torque of the engine so as to maintain a constant speed during cornering or taking a U-turn, thereby ensuring that the vehicle does not roll over during such a condition and eliminating the requirement of a large number of user inputs for maintaining constant speed of the vehicle. This increases rider safety as well as vehicle performance.
[034] The present invention also ensures that the vehicle can be stabilised during U-turn or cornering conditions without requiring usage of complex ABS based systems, and thus can be applied to vehicles not having an ABS. The present invention also accounts for side slip for stabilising the vehicle, which ensures that the present invention is capable of stabilising the vehicle for a variety of road and operating conditions.
[035] 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
100: System for Stabilising a Vehicle
110: One or more Vehicle Sensors
112: Speed Sensor
114: Steering Angle Sensor
118: Inertial Measurement Unit
120: Control Unit
130: One or more Actuators
132: Engine Management System
134: Throttle Position Sensor
200: Method for Stabilising a Vehicle
, Claims:1. A system (100) for stabilising a vehicle, the system (100) comprising:
one or more vehicle sensors (110), the one or more vehicle sensors (110) configured to detect one or more vehicle parameters, the one or more vehicle parameters comprising a first parameter and a set of second parameters;
one or more actuators (130), the one or more actuators (130) being configured to control one or more operating parameters of the vehicle; and
a control unit (120), the control unit (120) being configured to:
receive the one or more vehicle parameters from the one or more vehicle sensors (110);
determine whether the first parameter is lower than a first predetermined value;
determine whether the set of second parameters are greater than a set of second predetermined values, if the first parameter is lower than the first predetermined value;
estimate a third parameter based on the set of second parameters, if the set of second parameters are greater than the set of second predetermined values;
determine whether the third parameter is greater than a third predetermined value; and
operate the one or more actuators (130) for controlling the one or more operating parameters for stabilising the vehicle, if the third parameter is greater than the third predetermined value.

2. The system (100) as claimed in claim 1, wherein the one or more vehicle sensors (110) comprises a speed sensor (112) of the vehicle, and the first parameter comprises a speed of the vehicle.

3. The system (100) as claimed in claim 1, wherein the one or more vehicle sensors (110) comprising a steering angle sensor (114), and a roll rate identifier (118), and the set of second parameters comprise one or more of a lateral acceleration, a steering angle, a roll rate and a yaw rate of the vehicle.

4. The system (100) as claimed in claim 3, wherein the third parameter comprises a side slip of the vehicle, and the control unit (120) is configured to estimate the side slip of the vehicle based on at least a lateral velocity and the yaw rate of the vehicle.

5. The system (100) as claimed in claim 1, wherein the one or more actuators (130) comprise an engine management system (132) with a throttle position sensor (134), and the one or more operating parameters comprise a speed of the vehicle, wherein control unit is configured to communicate with the engine management system (132) to control a torque of an engine and a throttle position of the vehicle thereby controlling the speed of the vehicle.

6. A method (200) for stabilising a vehicle, the method (200) comprising the steps of:
detecting, by one or more vehicle sensors (110), one or more vehicle parameters, the one or more vehicle parameters comprising a first parameter and a set of second parameters;
receiving, by a control unit (120), the one or more vehicle parameters from the one or more vehicle sensors (110);
determining, by the control unit (120), whether first parameter is lower than a first predetermined value;
determining, by the control unit (120), whether the set of second parameters are greater than a set of second predetermined values, if the first parameter is lower than the first predetermined value;
estimating, the control unit (130), a third parameter based on the set of second parameters, if the set of second parameters are greater than the set of second predetermined values;
determining, the control unit (120), whether the third parameter is greater than a third predetermined value; and
operating, by the control unit (120), one or more actuators (130) for controlling the one or more operating parameters for stabilising the vehicle, if the third parameter is greater than the third predetermined value.

7. The method (200) as claimed in claim 6, wherein the one or more vehicle sensors (110) comprises a speed sensor (112) of the vehicle, and the first parameter comprises a speed of the vehicle.

8. The method (200) as claimed in claim 6, wherein the one or more vehicle sensors (110) comprising a steering angle sensor (114), and an inertial measurement unit (118), and the set of second parameters comprise one or more of a lateral acceleration, a steering angle, a roll rate and a yaw rate of the vehicle.

9. The method (200) as claimed in claim 8, wherein the third parameter comprises a side slip of the vehicle, and the method (200) has the steps of:
estimating, by the control unit (120), the side slip of the vehicle based on at least a lateral velocity and the yaw rate of the vehicle.

10. The method (200) as claimed in claim 6, wherein the one or more actuators (130) comprise an engine management system (132) with a throttle position sensor (134), and the one or more operating parameters comprise a speed of the vehicle, and the method (200) comprises the step of:
communicating, by the control unit (120) with the engine management system (132) to control a torque of an engine of the vehicle and a throttle positions thereby controlling the speed of the vehicle.