Description:SYSTEM AND METHOD OF CONTROLLING WHEEL SLIP CONDITION OF VEHICLES
Field of the Invention
[0001] The present invention relates to vehicle management and particularly to a system and a method of controlling wheel slip condition of vehicles.

Background
[0002] The description in the Background section includes general information related to the field of the present application. The background is only meant to provide context to a reader in understanding the present invention. It is neither to be taken as an admission that any of the provided information relates to prior art for the presently claimed invention nor that any publication explicitly or implicitly referenced within this section relates to prior art. The background section is merely meant to be illustrative rather than exhaustive and is primarily intended to identify problems associated with the present state of the art.
[0003] Generally, in vehicle powertrains, the power source fulfils user commands through designated inputs. Further, the subsequent transmission of the generated power via a power delivery system, such as a transmission system assembly, to the tyres of the vehicle that contact the ground underneath the vehicle is critical for operation of the vehicle. The determination of the optimal power that can be transmitted through the transmission system assembly hinges on frictional forces between the ground and the tyre through the contact between the ground and the tyre.
[0004] However, during operation of the vehicle, the power transmitted to the rear wheel of the vehicle may surpass a frictional threshold associated with the corresponding tyre, thereby, causing a loss of surface grip between the tyre and the ground (referred to as “traction loss”). Such traction loss is frequently encountered on wet surfaces during unfavourable weather (such as, during or after a rainstorm), in cold environments, or on dusty roads. It will be appreciated that owing to the operation of the vehicle in diverse environmental conditions, the fluctuating power transmission can significantly impact the operation of the vehicle. Consequently, dynamic regulation of the maximum power transmitted to the tyre, or the rear wheels is important to ensure secure transmission of power without compromising vehicle stability.
[0005] In light of the above discussion, it can be readily understood that there is an urgent need for systems and/or methods that address the issue of traction loss in vehicles and unstable power transmission of powertrain systems of vehicles.
Objectives of the Invention
[0006] The following paragraphs briefly describe the various objectives sought to be achieved by the various embodiments of the present invention.
[0007] An object of the present invention is to provide an improved method or system capable of effectively regulating the power transmission to the tyres or rear wheels of vehicles based on the pre-existing frictional limits.
[0008] Another object of the present invention is to ensure optimal power transmission from the power source to the tyres of the vehicle in challenging driving conditions such as wet surfaces, cold environments and dusty roads.
[0009] Yet another object of the present invention is to substantially overcome the occurrence of traction loss of wheels of the vehicle resulting from the excessive power transmitted to the rear wheels.
[00010] Still another object of the present invention is to improve grip of the tyres with the ground during driving of the vehicle.

Summary
[00011] The following Summary section provides only a brief introduction to the various embodiments of the present invention. It is to be understood that the following paragraphs are neither meant to constitute a complete and thorough description of the claimed subject matter nor is it intended to define the technical features or the scope of the claimed subject matter. Thus, the description in the Summary section is neither intended to identify only the essential features of the present invention nor limit the scope of the claimed subject matter in any manner.
[00012] The present invention relates to vehicles and particularly to a system and a method of controlling wheel slip condition of vehicles.
[00013] In a first aspect, the present disclosure provides a method of controlling a wheel slip condition of a vehicle. The method comprises determining, at least one operating parameter of the vehicle. The operating parameter is selected from a motor speed, a motor torque, an acceleration and an angular velocity. The method further comprises calculating a load of the vehicle, determining a tyre force based on the determined at least one operating parameter l, determining a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load using a tyre mode, and controlling supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.
[00014] In a first embodiment, the tyre force is selected from a longitudinal force and a lateral force.
[00015] In a second embodiment, the load is selected from a normal load, a dead load, a live load, an impact load, a wind load, and a thermal load.
[00016] In a third embodiment, the wheel slip condition is selected from a longitudinal slip and a lateral slip.
[00017] In a fourth embodiment, controlling power supply of power to the wheel is dependent on at least one parameter selected from a current ride mode and a predefined current limit corresponding to the current ride mode.
[00018] In a fifth embodiment, controlling power supply to the wheels of the vehicle comprises adjusting the output of a traction motor to reduce the level of the wheel slip condition.
[00019] In a sixth embodiment, controlling power supply to the wheels of the vehicle comprises activating a lock braking unit.
[00020] In a seventh embodiment, controlling power supply to the wheels of the vehicle comprises regulating operation of an electronically controlled differential.
[00021] In an eighth embodiment, the predefined threshold is adjusted based on a parameter selected from: tyre pressure, tyre temperature, forces on the tyre, tyre rotational speed and tyre inclination angle.
[00022] In a ninth embodiment, the longitudinal slip is determined based on a comparison between a wheel speed and a vehicle speed.
[00023] In a second aspect, the present disclosure provides a system to control a wheel slip condition of a vehicle. The system comprises a sensor unit which detects at least one operating parameter of the vehicle. The operating parameter is selected from: a motor speed, a motor torque, an acceleration, and an angular velocity. The system comprises a vehicle control unit (VCU) communicatively coupled to the sensor unit. The VCU: calculates a load of the vehicle, determines a tyre force based on the determined at least one operating parameter, determines a level of the wheel slip condition based the determined tyre force and the calculated vehicle load using a tyre model, and controls supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.
[00024] The various objects, features, and advantages of the claimed invention will become clear when reading the following Detailed Description along with the Drawings.
Brief Description of the Drawings
[00025] The following Brief Description of Drawings section will be better understood when read in conjunction with the appended drawings. Although exemplary embodiments of the present invention are illustrated in the drawings, the embodiments are not limited to the specific features shown in the drawings. The drawings illustrate simplified views of the claimed invention and are therefore, not made to scale. Identical numbers in the drawings indicate like elements in the drawings.
[00026] The embodiments of the present invention will now be briefly described by way of example only with reference to the drawings in which:
[00027] FIG. 1 shows a flowchart of a method of controlling a wheel slip condition of a vehicle as per one embodiment of the present disclosure; and
[00028] FIG. 2 shows a block diagram of a system to control a wheel slip condition of a vehicle as per one embodiment of the present disclosure.
[00029] Fig. 3 depicts a flowchart describing a traction control subsystem for a vehicle, in accordance with an embodiment of the present disclosure.
Detailed Description
[00030] The following is a detailed description of exemplary embodiments to illustrate the principles of the invention. The embodiments are provided to illustrate aspects of the invention, but the invention is not limited to any single embodiment. The scope of the invention encompasses without limitation numerous alternatives, modifications and combinations.
[00031] It shall be noted that as used within the current section as well as in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Further, the use of words such as “first”, “second”, “third” and the like does not represent any particular order. Such words have been merely employed to distinguish one individual component from another. Moreover, “each” refers to each member of a set or each member of a subset of a set.
[00032] An arrangement of two or more components, unless stated specifically, can be done without limitation in any manner relative to a three-dimensional coordinate system. Thus, a second component arranged underneath a first component may also be taken to mean that the first component is arranged underneath the second component.
[00033] The phrase “configured to” as used through the Detailed Description as well as the appended Claims is to be taken to mean that the particular component that is configured to perform a specific action is specially conceived, designed and subsequently manufactured to enable the particular component to be employed for conveniently performing the specific action. However, this should not be taken to mean that the particular component is only capable of performing one specific action that the particular component is configured to do. It may perform a variety of different actions in addition to the specific action that the particular component has been configured to do.
[00034] The phrase “operably coupled” as used throughout the Detailed Description as well as the appended Claims is to be understood to refer to a coupling between two or more components that such an action performed by or on a first of the components is transferable as an equivalent action of or on a second of the component that is operably coupled to the first component. It will be appreciated that more than two components may be operably coupled to each other.
[00035] It will be appreciated that various components of the system may be permanently or temporarily (such as, detachably) coupled to each other using various permanent or temporary means, including but not limited to, welding the components together, using screws, nuts, bolts and the like to join the components together, attaching the components using magnets and the like. Such details are commonly available in the art and have therefore been omitted throughout the Detailed Description and the appended Claims for the sake of conciseness.
[00036] It will also be appreciated that modifications, additions, or omissions may be made to the systems and apparatuses described hereinafter without departing from the scope of the Claims. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components.
[00037] The present invention relates to vehicles and particularly to a system and a method of controlling wheel slip condition of vehicles.
[00038] Referring to FIG. 1, there is shown a flowchart 100 of a method of controlling a wheel slip condition of a vehicle as per one embodiment of the present disclosure. The method enables to effectively manage the wheel slip condition of a vehicle, such as an electric vehicle. At a step 102, at least one operating parameter of the vehicle is determined. The operating parameter is selected from a motor speed, a motor torque, an acceleration and an angular velocity. Such a determination of the at least one parameter enables to provide a comprehensive understanding of the current operating state and dynamics associated with the vehicle. The operating parameters can be determined using a set of sensors, for instance: a speed sensor (mounted on the wheels or the motor shaft) to measure the rotational speed of the wheels or the motor, a torque sensors (installed on the drivetrain to measure the force exerted by the motor), an accelerometer can be positioned on the vehicle's chassis to measure acceleration in different directions, and a gyroscope can measure the angular velocity, providing insights into the vehicle's stability and handling.
[00039] At a step 104, a load of the vehicle is calculated. Such a calculation of the load of the vehicle enables determination of moment of inertia and other relevant parameters associated with the vehicle, thereby, enabling accurate assessment of the dynamic load acting on the vehicle during operation of the vehicle. To calculate load of the vehicle various sensors (e.g., load sensor, tyre pressure monitoring sensors, suspension sensor) can be utilized. For example, weight sensors/load cells can be placed at various points of the vehicle, such as under the seats, within the suspension unit, or at the points where the vehicle's chassis meets the wheels. Load cells can measure the weight of passengers and cargo, as well as the force exerted on each wheel, which can be critical in assessing the vehicle's overall load. Suspension sensor can measure the displacement of the suspension, which can provide information about the load. For example, a heavily loaded vehicle will cause more compression in the suspension. Tyre pressure monitoring sensors (TPMS) can also indirectly provide insight about vehicle load. A change in tyre pressure might indicate a change in load, which can be correlated with other sensor data for more accurate load determination.
[00040] At a step 106, a tyre force is determined based on the determined at least one operating parameter. For example, factors such as acceleration, angular velocity and motor speed are considered for the determination of the tyre force. The process of determining tyre force involves utilization of several operating parameters, such as acceleration, angular velocity, and motor speed, to calculate the forces acting on the tyres. The operating parameters are analyzed to understand the forces acting on the tyres, considering aspects such as traction force during acceleration, centrifugal force during turns, and the distribution of vehicle weight on the tyres (load transfer). For example, in an electric vehicle (e.g., electric scooter) navigating a sharp turn at high speed, the sensing device can sense acceleration before the turn, the angular velocity of the wheels during the turn, and the motor speed. The vehicle control unit calculates the force on each tyre based on sensed operating parameters. Based on the sensed operating parameters the vehicle control unit assesses lateral acceleration to determine the lateral force on the tyres, crucial for maintaining grip and trajectory. Further, the vehicle control unit also evaluates longitudinal force, which is tied to acceleration and braking, influencing the vehicle's forward or backward movement. Furthermore, the vehicle control unit considers the dynamic vertical load on each tyre, which shifts as the vehicle manoeuvres. Through the aforesaid calculations, the vehicle control unit offers an in-depth understanding of tyre grip and traction. For example, excessive lateral forces might indicate a loss of grip, risking skidding, while extreme longitudinal force could cause tyre spin or locking during braking.
[00041] At a step 108, a level of the wheel slip condition is determined based on the determined tyre force and the calculated vehicle load using a tyre model. Such a determination of the wheel slip condition, for example, by evaluating slip percentage for the rear tyres, enables accurate determination of a level of traction and further identification of any potential instances of excessive slip that compromises stability and safety of the vehicle. Wheel slip occurs when the force transmitted through tyre exceeds the frictional grip available from the road surface, causing the wheel to lose traction and either spin or lock up. The wheel slip can be quantified as a percentage that represents the difference between the wheel's rotational speed and the vehicle's actual speed over the ground. Alternatively, wheel slip can be defined in terms of lateral slip, which refers to the difference between the direction a tyre is pointing and the actual direction in which the tyre is moving laterally. In simpler terms, when the vehicle turns, the tyres are pointed in the direction of the turn. However, due to various factors like speed, road surface, tyre condition, and vehicle dynamics, the tyres might not move exactly along the path they are pointing. Instead, they might slide sideways to some degree, which can be referred to as lateral slip. The degree of lateral slip is influenced by factors such as the tyre's grip on the road surface, the speed of the vehicle, and the sharpness of the turn. Lateral slip is a crucial parameter in vehicle handling and stability, as excessive lateral slip can lead to loss of control, such as in understeering or oversteering situations. Monitoring and controlling lateral slip is therefore important for safe vehicle operation, especially in high-speed or challenging driving conditions. By determining the level of wheel slip, the traction control system can be more responsive and precise. For instance, if excessive slip is detected at the rear tyres, the traction control system can intervene by adjusting engine power, applying brakes, or modifying torque distribution to regain traction. By identifying instances of excessive slip, the control subsystem can proactively make adjustments to avert potential skidding or loss of control, thereby enhancing the overall stability and safety of the vehicle and/or rider. Furthermore, determining the level of wheel slip allows for dynamic adjustments to driving modes and suspension settings, ensuring that the vehicle can adapt to different driving conditions while maximizing performance and safety. Moreover, advanced driver-assistance systems (ADAS) can leverage the data of wheel slip conditions to predict potential loss of control scenarios and initiate pre-emptive safety measures such as tightening seat belts, adjusting

headrests, or even deploying safety systems in anticipation of a possible collision.
[00042] At a step 110, supply of a power to the wheel is controlled if the detected level exceeds a predefined threshold, to control the wheel slip condition. Such controlling of the motor output based on current limits enables to actively minimize wheel slip, ensuring that the tyre remains within adhesion limits, thereby preventing wheel spin and maintaining optimal traction and stability. Optionally, such a controlling of the motor output is gradually reduced as the wheel slip decreases and traction is regained, ensuring a seamless transition to normal driving conditions. Thus, the method enables effective management of the wheel slip condition of the vehicle, thereby enhancing overall safety, stability, and efficiency of the vehicle during operation.
[00043] In a first embodiment, the tyre force is selected from a longitudinal force and a lateral force. Such a strategic selection of the tyre force enables a comprehensive assessment of the forces acting on the tyres, thereby facilitating an improved understanding of the grip and traction associated with the tyres. Further, a precise analysis of such forces enables to ensure an optimized control mechanism that effectively mitigates potential slip conditions, thereby enhancing overall vehicle stability and safety during operation. By isolating longitudinal (i.e., along the direction of travel) and lateral (i.e., perpendicular to the direction of travel) forces, vehicle control system can more accurately predict and respond to tyre behaviour under various conditions. Further, information about longitudinal and lateral forces, vehicle control systems such as anti-lock braking systems (ABS), traction control systems (TCS), and electronic stability programs (ESP) can be finely tuned to prevent or correct slip conditions by modulating brake pressure, engine/motor power, or even applying differential braking. By mitigating potential slip conditions through optimized control mechanisms, the risk of accidents due to loss of control can be significantly reduced to protect the vehicle user or other road users.
[00044] In a second embodiment, the load is selected from a normal load, a dead load, a live load, an impact load, a wind load, and a thermal load. Such a comprehensive evaluation of the various crucial factors enables to provide an improved understanding of the various loads acting on the vehicle, thereby contributing to an enhanced assessment of the operational dynamics of the vehicle. Further, the consideration of the various loads enables to optimize the control of the wheel slip, ensuring an effective and efficient management of the power supply of the vehicle, and enhancing the overall performance and safety of the vehicle.
[00045] In a third embodiment, the wheel slip condition is selected from a longitudinal slip and a lateral slip. Such a differentiation between the distinct slip conditions, facilitates a targeted and adaptive control that effectively addresses the specific challenges associated with each slip type. Further, the categorization enhances a capacity to optimize the power supply to the wheels, thereby ensuring improved traction and stability, thus significantly enhancing the overall safety and performance of the vehicle.
[00046] In a fourth embodiment, controlling power supply of power to the wheel is dependent on at least one parameter selected from a current ride mode and a predefined current limit corresponding to the current ride mode. For example, the vehicle is capable of operating in multiple ride modes, including but not limited to, an Eco mode corresponding to economization of power delivery to the motor and a Rush mode associated with delivery of high-power delivery for driving of the vehicle at increased speeds. Further, in the Eco mode, the current limit for 100% state of charge (SoC) of the battery is 60 A and for 50% SoC is 50A. Consequently, if slip is detected under the current ride mode, the power delivery (such as, the current provided by the battery) to the motor is limited compared to the preset current limits for each of the ride modes. Such an integration of crucial parameters corresponding to the ride mode of the vehicle enables a sophisticated and adaptive power management strategy that effectively aligns with diverse driving conditions and modes. Further, the adaptive control optimizes the power supply to the wheels, ensuring enhanced efficiency and stability, thereby significantly improving the overall performance and safety during operation of the vehicle.
[00047] In a fifth embodiment, controlling power supply to the wheels of the vehicle comprises adjusting an output of a traction motor to reduce the level of the wheel slip condition. The control of power is achieved by dynamically controlling the current supplied from the power source (such as a battery pack) to the electric motor. Such an adjustment enables refined control, ensuring an optimized adhesion mechanism, thereby enhancing overall traction and stability and contributing to an improved and safer driving experience of the vehicle.
[00048] In a sixth embodiment, controlling power supply to the wheels of the vehicle comprises activating a lock braking unit. Such a strategic activation serves as an additional safety feature, enhancing the efficacy of wheel slip control, particularly during critical driving scenarios. Further, the incorporation of the additional control mechanism enables to further improve the safety associated with the vehicle, minimizing potential risks and hazards during operation.
[00049] In a seventh embodiment, controlling power supply to the wheels of the vehicle comprises regulating the operation of an electronically controlled differential. The strategic regulation further enhances the adaptability of the vehicle to diverse driving terrains and conditions, ensuring improved traction and stability during vehicle operation. Moreover, the integration of such sophisticated regulation enables to significantly enhance the overall performance and safety of the vehicle across varying driving conditions.
[00050] In an eighth embodiment, the predefined threshold is adjusted based on a parameter selected from:tyre pressure, tyre temperature, forces on the tyre, tyre rotational speed and tyre inclination angle. The incorporation of such critical factors ensures an adaptable control with respect to diverse environmental conditions, thus ensuring optimal traction control under varying scenarios. Further, the dynamic adjustment of the predefined threshold significantly enhances the safety and stability of the vehicle across diverse operating conditions.
[00051] In a ninth embodiment, the longitudinal slip is determined based on a comparison between a wheel speed and a vehicle speed. The strategic comparison between the wheel speed and the vehicle speed enables a comprehensive assessment of the longitudinal slip, contributing to the implementation of targeted control measures that enhance the overall stability and safety of the vehicle during operation.
[00052] Referring to FIG. 2, there is shown a block diagram of a system 200 to control a wheel slip condition of a vehicle as per one embodiment of the present disclosure. The system 200 comprises a sensor unit 202 that detects at least one operating parameter of the vehicle. The sensor unit 202 can comprise various sensors such as speed sensor, torque sensor, accelerometer, gyroscope, and the like to measure various operating parameters selected from a motor speed, a motor torque, an acceleration, and an angular velocity. The sensor unit 202 detects the at least one operating parameter and subsequently, provides the operating parameter associated with the tyres of the vehicle, such as acceleration and angular velocity 206 to the vehicle state estimator 212. The system 200 further comprises a vehicle control unit (VCU) 204 communicatively coupled to the sensor unit 202. Optionally, the VCU 204 comprises the vehicle state estimator 212. The VCU 204 calculates a load of the vehicle. For example, the VCU 204 determines the rotational torque 208 and rotational speed 210 demanded from a motor of the vehicle. Subsequently, the VCU 204 provides the calculated rotational torque 208 and rotational speed to the vehicle state estimator 212 such that the vehicle state estimator 212 calculates the load of the vehicle based on the provided rotational torque 208 and rotational speed. Further, VCU 204 determines a tyre force based on the determined at least one operating parameter. The vehicle state estimator 212 employs the provided values to estimate the instantaneous forces on the tyre and the instantaneous normal load on the tyres. The vehicle state estimator 212 transmits the estimated instantaneous forces on the tyre and the instantaneous normal load on the tyres to the tyre model 214. Optionally, the VCU 204 stores the tyre model 214. The tyre model 214 performs testing of the tyre and data fitting by employing values for the coefficient that determines the shape of the curves that are stored by the model (for example, lateral force vs tyre slip at different normal loads and longitudinal force vs tyre slip at different normal loads). The VCU 204 determines a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load. The tyre model 214 employs the longitudinal forces, lateral forces and normal load to predict a value of slip associated with the tyre during current operation of the tyre. The VCU 204 controls supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition. Such a predicted value of slip is provided to the longitudinal and cornering traction control 216 (optionally, the longitudinal and cornering traction control 216 is part of the VCU 204) that determines if the slip of the tyre has exceeded a certain threshold. It will be appreciated that such exceeding of the slip of the tyre can happen in events where the road is wet and the coefficient of friction between the road and the tyre has reduced or if the rider of the vehicle pushes the vehicle beyond the cornering capability of the tyres while cornering. Further, upon detection of excessive slip, the current limits 218 that are sent to the rear wheel of the vehicle is managed. The system 200 can adjust the motor output to reduce the slip and restore the tyre back to adhesion limits. Consequently, the system prevents tyre slip while maintaining traction and stability and as the tyre slip decreases and traction is regained, the longitudinal and cornering traction control 216 gradually reduces the intervention.
[00053] Fig. 3 depicts a flowchart describing a traction control subsystem for a vehicle, in accordance with embodiment of present disclosure. The subsystem may comprise a motor controller, an inertial measurement unit (IMU), a vehicle state estimator and other known components. The motor controller adjusts the motor's speed and torque based on various inputs (such a throttle). The IMU measures a vehicle’s acceleration and angular position to provide information related to the vehicle's dynamics. The inputs from the motor controller and the IMU can be provided to the vehicle state estimator, which assess the vehicle's behaviour and interaction with the road. The vehicle state estimator calculates the forces acting on the tyres, including the normal load - the force exerted perpendicularly by the road. The determined load and force can be used by the tyre model to simulate tyre behaviour. The tyre model determines how the tyres are adhering to the road surface and how they respond to the commands from the motor controller. Upon detecting tyre slip, the sub-system activates the traction controller that adjusts electric current supplied to the motor based on ride modes and battery charging level, such as an Eco mode that conserves power or a Rush mode that allows for higher performance. These limits ensure that the power supplied to the motor is appropriate for the grip level of the tyres, preventing slip and ensuring stability. For example, in Eco mode at 100% battery state of charge (SoC), the current limit might be set to 60A, which is reduced to 50A at 50% SoC to prolong battery life and enhance safety.
Advantages of the Invention
[00054] The following paragraphs briefly describe the different advantages that are possible to be achieved through implementation of the present invention, including but not limited to, overcoming various drawbacks associated with conventional systems and methods known in the art.
[00055] An advantage of the present invention is that the proposed method and system consider factors associated with the vehicle such as the load of the vehicle to dynamically and effectively regulate the power transmission to the tyres or rear wheels, thereby ensuring proper operation of the vehicle corresponding to varying frictional limits.
[00056] Another advantage of the present invention is that the method and the system adaptively regulate the transmission of power from the power source to the tyres based on varying environmental conditions, thereby ensuring driving convenience and stability during challenging driving conditions such as wet surfaces, cold environments and dusty roads.
[00057] Yet another advantage of the present invention is that the method and system properly manage the power transmitted to the rear wheels, thereby enhancing the overall stability and safety of the vehicle during operation.
[00058] Still another advantage of the present invention is that the method and system enable to dynamically adjust the maximum power allocation to the tyres, thereby preventing improving the grip of the tyres with the ground surface.

Claims
1. A method of controlling a wheel slip condition of a vehicle, the method comprising:
determining, at least one operating parameter of the vehicle, wherein the operating parameter is selected from a motor speed, a motor torque, an acceleration and an angular velocity;
calculating a load of the vehicle;
determining, a tyre force based on the determined at least one operating parameter;
determining, a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load using a tyre model; and
controlling, supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.
2. The method as claimed in claim 1, wherein the tyre force is selected from a longitudinal force and a lateral force.
3. The method as claimed in claim 1, wherein the load is selected from a normal load, a dead load, a live load, an impact load, a wind load, and a thermal load.
4. The method as claimed in claim 1, wherein the wheel slip condition is selected from a longitudinal slip and a lateral slip.
5. The method as claimed in claim 1, wherein controlling power supply of power to the wheel is dependent on at least one parameter selected from a current ride mode and a predefined current limit corresponding to the current ride mode.
6. The method as claimed in claim 5, wherein controlling power supply to the wheels of the vehicle comprises adjusting an output of a traction motor to reduce the level the wheel slip condition.
7. The method as claimed in claim 6, wherein controlling power supply to the wheels of the vehicle comprises activating a lock braking unit.
8. The method as claimed in claim 1, wherein controlling power supply to the wheels of the vehicle comprises regulating an operation of an electronically controlled differential.
9. The method as claimed in claim 1, wherein the predefined threshold is adjusted based on a parameter selected from: tyre pressure, tyre temperature, forces on the tyre, tyre rotational speed and tyre inclination angle.
10. The method as claimed in claim 4, wherein the longitudinal slip is determined based on a comparison between a wheel speed and a vehicle speed.
11. A system to control a wheel slip condition of a vehicle, the system comprising:
a sensor unit detects at least one operating parameter of the vehicle, wherein the operating parameter is selected from: a motor speed, a motor torque, an acceleration, and an angular velocity;
a vehicle control unit (VCU) communicatively coupled to the sensor unit, wherein the VCU:
calculates a load of the vehicle;
determines a tyre force based on the determined at least one operating parameter using a tyre model;
determines a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load; and
controls supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.

Abstract
SYSTEM AND METHOD OF CONTROLLING WHEEL SLIP CONDITION OF VEHICLES

The present invention relates to a system to control a wheel slip condition of a vehicle. The system comprises a sensor unit that detects at least one operating parameter of the vehicle. The operating parameter is selected from: a motor speed, a motor torque, an acceleration, and an angular velocity. The system comprises a vehicle control unit (VCU) communicatively coupled to the sensor unit. The VCU calculates a load of the vehicle, determines a tyre force based on the determined at least one operating parameter using a tyre model, determines a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load and controls supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.
Fig. 1
, Claims:Claims
1. A method of controlling a wheel slip condition of a vehicle, the method comprising:
determining, at least one operating parameter of the vehicle, wherein the operating parameter is selected from a motor speed, a motor torque, an acceleration and an angular velocity;
calculating a load of the vehicle;
determining, a tyre force based on the determined at least one operating parameter;
determining, a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load using a tyre model; and
controlling, supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.
2. The method as claimed in claim 1, wherein the tyre force is selected from a longitudinal force and a lateral force.
3. The method as claimed in claim 1, wherein the load is selected from a normal load, a dead load, a live load, an impact load, a wind load, and a thermal load.
4. The method as claimed in claim 1, wherein the wheel slip condition is selected from a longitudinal slip and a lateral slip.
5. The method as claimed in claim 1, wherein controlling power supply of power to the wheel is dependent on at least one parameter selected from a current ride mode and a predefined current limit corresponding to the current ride mode.
6. The method as claimed in claim 5, wherein controlling power supply to the wheels of the vehicle comprises adjusting an output of a traction motor to reduce the level the wheel slip condition.
7. The method as claimed in claim 6, wherein controlling power supply to the wheels of the vehicle comprises activating a lock braking unit.
8. The method as claimed in claim 1, wherein controlling power supply to the wheels of the vehicle comprises regulating an operation of an electronically controlled differential.
9. The method as claimed in claim 1, wherein the predefined threshold is adjusted based on a parameter selected from: tyre pressure, tyre temperature, forces on the tyre, tyre rotational speed and tyre inclination angle.
10. The method as claimed in claim 4, wherein the longitudinal slip is determined based on a comparison between a wheel speed and a vehicle speed.
11. A system to control a wheel slip condition of a vehicle, the system comprising:
a sensor unit detects at least one operating parameter of the vehicle, wherein the operating parameter is selected from: a motor speed, a motor torque, an acceleration, and an angular velocity;
a vehicle control unit (VCU) communicatively coupled to the sensor unit, wherein the VCU:
calculates a load of the vehicle;
determines a tyre force based on the determined at least one operating parameter using a tyre model;
determines a level of the wheel slip condition based on the determined tyre force and the calculated vehicle load; and
controls supply of a power to the wheel if the detected level exceeds a predefined threshold, to control the wheel slip condition.