Wheel spin control in a vehicle

Abstract

A computer-implemented method for wheel spin control in a vehicle (102) comprising a powertrain (104) having at least one electric machine (106) configured to provide propulsion power to a first subset (108) of wheels (108a,b) of the vehicle, the method comprising: estimating, by processing circuitry (116) of a computer system (100), a vehicle speed (121) over a time period (120) based on an effective wheel speed (Ef) associated with a second subset (110) of wheels (110a,b) of the vehicle, the second subset of wheels (110a,b) being subject to less torque variation compared to the first subset of wheels (108a,b) over the time period; determining, by the processing circuitry, a speed criterion (124) based on the estimated vehicle speed and an offset speed (122); and providing, by the processing circuitry, control instructions (C) to the electric machine to limit output torque to the first subset of wheels (108a,b) in accordance with the determined speed criterion.

Description

Technical Field

[0001] This disclosure relates to a computer-implemented method for wheel spin control in a vehicle. This disclosure also relates to a computer system, a vehicle, a computer program product, and a non-transitory computer-readable storage medium. Background Technology

[0002] For wheels connected to propulsion actuators, excessive wheel slip can occur when the corresponding actuator applies too much propulsion torque to the wheel, negatively impacting vehicle stability or steering. Traditional traction control systems manage wheel slip by limiting the output engine torque. However, the effectiveness of wheel slip control depends to some extent on the responsiveness of torque control. This is particularly pronounced with electric actuators, as they can build up torque at the wheels much faster than traditional internal combustion engines. Summary of the Invention

[0003] Overall, the disclosed subject matter relates to improved wheel slip control. In particular, the disclosed subject matter provides instructions for determining the limits of the vehicle's motor output torque in a more efficient manner with reduced latency.

[0004] According to a first aspect of this disclosure, a computer-implemented method for wheel idling control in a vehicle is provided, the vehicle including a powertrain system having at least one motor configured to provide propulsion power to a first subset of wheels of the vehicle (or a first subset of wheels), the method comprising: estimating a vehicle speed by a processing circuit of a computer system over a time period based on an effective wheel speed associated with a second subset of wheels of the vehicle (or a second subset of wheels), the second subset of wheels experiencing a smaller torque variation compared to the first subset of wheels during the time period; determining a speed criterion by the processing circuit based on the estimated speed and offset speed; and providing control commands by the processing circuit to the motor to limit the output torque to the first subset of wheels according to the determined speed criterion.

[0005] The technical problem addressed by the disclosed subject matter involves managing the output torque of an electric motor to avoid excessive wheel slippage that could lead to vehicle instability. Electric motors tend to have high responsiveness, which allows torque to accumulate rapidly at the wheels. If the responsiveness of limiting the output torque is not fast enough, the vehicle may suffer from instability and / or steering problems.

[0006] This disclosure addresses at least in part the aforementioned and other problems by using a simplified vehicle speed estimate based on the effective wheel speed associated with a second subset of the vehicle's wheels, which experiences less torque responsiveness compared to the first subset of wheels propelled by an electric motor.

[0007] The proposed method does not rely on previous, more complex vehicle speed calculations that typically involve multiple electronic control units or vehicle systems, allowing for faster response to wheel spin control using the examples disclosed herein. It also allows for placing the processing circuitry closer to the motor, reducing latency in communication with the motor and further improving responsiveness.

[0008] Effective wheel speed can be a value measured directly at the wheel or an estimated value based on rotating components connected to the wheel, such as the wheel's drive shaft or actuator.

[0009] Offset speed is a value that can be combined with the vehicle's estimated speed to determine a speed standard that allows acceleration or deceleration without the risk of excessive wheel slippage (e.g., slippage that could lead to instability and / or steering problems). For example, offset speed can be added to or subtracted from the vehicle's estimated speed based on the driving scenario to determine a speed standard that allows reasonable acceleration or deceleration without the risk of excessive slippage.

[0010] Speed ​​standards can be implemented in various ways, such as threshold speed, speed limit, speed range, and average speed over a time period. Estimated speed and offset speed can be used as inputs to determine the speed standard in the algorithm. That is, control commands can instruct the motor to limit the permissible torque according to the target level, ensuring the vehicle does not exceed the threshold speed or speed limit, remains within the speed range, or does not exceed the average speed over a time period.

[0011] Wheel slip in vehicle dynamics refers to the relative motion between a vehicle's tires and the road. While lateral slip can be partially addressed in some cases, longitudinal slip is the primary type of slip addressed in this disclosure. Longitudinal slip is the difference between the wheel's rotational speed and the vehicle's actual speed in the longitudinal direction of travel, and typically occurs during acceleration or braking.

[0012] In one example, the offset speed can depend on the current driving conditions. Advantageously, this allows for better adjustment of the offset speed to take into account the vehicle's current conditions that will affect wheel slippage trends. Driving conditions can include one or more of estimated speed, measured acceleration, and estimated wheel friction. Friction estimates can be calculated based on measured acceleration. Friction can also be estimated using a combination of wheel torque and speed, as well as wheel acceleration. Additional parameters that can be part of the driving conditions include vehicle motion parameters such as yaw rate, curvature, steering, and oversteer / understeer trends, or one or more of these.

[0013] In other examples, the offset rate can be constant.

[0014] In one example, the method may include: obtaining, by processing circuitry, the permissible amount of wheel slip based on the current driving conditions, and determining, by processing circuitry, an offset speed based on the permissible amount of wheel slip. By correlating the offset speed with the permissible wheel slip, an accurate limit output torque can be determined, directly reflecting the permissible wheel slip.

[0015] In one example, the processing circuitry may be included in either the motor's inverter or an engine control module connected to the motor. Advantageously, for example, a less complex calculation of vehicle speed allows the processing circuitry to be located as close to the motor as possible, thereby minimizing time delays in communication with the motor.

[0016] In one example, the powertrain may include an actuator configured to provide propulsion power to a second subset of wheels, wherein during the said time period, the torque responsiveness of the electric motor may be greater than that of the actuator. The actuator may be an internal combustion engine, thus the vehicle is a hybrid vehicle.

[0017] In some examples, the second wheel subset may not be propelled in the vehicle's first driving mode, but may be propelled by an actuator in the vehicle's second driving mode. For example, in ECO mode, the actuator may be disabled or disconnected from the second wheel subset, and in power mode it may be enabled or coupled to the second wheel subset.

[0018] In some examples, the torque response of the actuator can vary depending on the vehicle's driving mode.

[0019] In some examples, the second wheel subset can be on the non-propulsion axle of the vehicle.

[0020] In one example, the method may include determining, by processing circuitry, that the vehicle is in an acceleration scenario, wherein the offset speed is set such that a speed criterion allows the vehicle to accelerate during that time period. In other words, the offset is advantageously configured such that, for example, by setting the speed criterion to the sum of the offset speed and the estimated speed, the vehicle accelerates but does not accelerate excessively, resulting in excessive wheel slippage.

[0021] In one example, the method may include determining, by processing circuitry, that the vehicle is in a deceleration scenario, wherein the offset speed is set such that a speed criterion limits the regenerative braking torque on a first subset of wheels. In other words, the offset is advantageously configured such that, for example, by setting the speed criterion to the difference between the estimated speed and the offset speed, regenerative charging allows the vehicle to decelerate without excessively causing excessive wheel slippage.

[0022] However, it is conceivable that regardless of whether the vehicle is accelerating, decelerating, or rolling, it can always continuously determine and follow the acceleration and deceleration targets.

[0023] In one example, this method can be executed in parallel with the operation of a propulsion torque limiting system that operates in the braking control module based on inertial measurement unit data, wheel speed data, and driving condition data. In other words, this method can advantageously operate in parallel with conventional torque limiting systems.

[0024] In the example, the wheel speed of the second wheel subset can be determined from wheel speed sensors or based on the operating speed of the actuators connected to the second wheel subset.

[0025] According to a second aspect of this disclosure, a computer system for wheel idling control in a vehicle is provided, the vehicle including a powertrain having at least one motor configured to provide propulsion power to a first subset of wheels of the vehicle, the computer system including processing circuitry configured to: estimate a vehicle speed over a time period based on an effective wheel speed associated with a second subset of wheels of the vehicle, the second subset of wheels experiencing a smaller torque variation compared to the first subset of wheels during the time period; determine a speed criterion based on the estimated speed and offset speed; and provide control commands to the motor to limit the output torque to the first subset of wheels according to the determined speed criterion.

[0026] The effects, features, and examples of this second aspect are highly similar to those described with reference to the first aspect.

[0027] In one example, a vehicle is also provided, the vehicle comprising: a powertrain having an electric motor coupled to a first subset of wheels of the vehicle, a second subset of wheels subjected to a smaller torque variation compared to the first subset of wheels, and a computer system according to any example of the second aspect.

[0028] In one example, a computer program product is also provided, which includes program code for performing methods of any of the examples disclosed herein when executed by processing circuitry.

[0029] In one example, a non-transitory computer-readable storage medium comprising instructions that, when executed by processing circuitry, cause the processing circuitry to perform any of the examples disclosed herein.

[0030] Further features and advantages of the examples of this disclosure will become apparent when examined in light of the appended claims and the following description. Those skilled in the art will recognize that different features of this disclosure can be combined to create examples other than those described below, without departing from the scope of this disclosure. Attached Figure Description

[0031] These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate examples, wherein: Figure 1 This is a block diagram of a computer system according to an example of this disclosure.

[0032] Figure 2 This is a block diagram of a computer system according to an example of this disclosure.

[0033] Figure 3 This is a schematic diagram of a vehicle according to an example of this disclosure.

[0034] Figure 4 This is a flowchart of method steps for wheel idling control according to an example of this disclosure.

[0035] Figure 5 This is a flowchart of method steps for wheel idling control according to an example of this disclosure.

[0036] Figure 6 This is a flowchart of method steps for wheel idling control according to an example of this disclosure.

[0037] Figure 7 This is a schematic diagram of a computer system used to implement the examples disclosed herein. Detailed Implementation

[0038] In this detailed description, various embodiments of the present disclosure are described with reference to specific implementations. Specific terminology is used in the description of examples for clarity. However, this disclosure is not intended to be limited to the specific terminology chosen so far. While specific examples are discussed, it should be understood that this is done merely for illustrative purposes. Those skilled in the art will recognize that other components and configurations can be used without departing from the scope of this disclosure.

[0039] Typical systems and algorithms for limiting torque to prevent wheel slippage involve several modules and steps. These include wheel speed and inertial measurement unit (IMU) sensor information for speed estimation and driving condition identification, a brake control module for speed estimation and coordination with brake traction control, and a propulsion controller that limits the permissible torque based on a determined target level. While this is a promising approach, there is still room for improvement. For example, the involvement of multiple modules and electronic control units (ECUs) means that a significant delay can occur between the moment a driving scenario occurs and the moment the desired limit from the propulsion controller is reached. This is particularly pronounced in vehicles with wheels propelled by electric motors, which accumulate torque at the wheels much faster than, for example, wheels propelled by internal combustion engines, meaning a higher slip level can be reached before the desired propulsion torque limit is achieved.

[0040] The examples presented in this article address the shortcomings of existing technologies by proposing simpler speed estimation methods that allow for reduced time delays. In this way, wheel spin can be better controlled, and vehicle stability and maneuverability can be improved.

[0041] Figure 1 This is a block diagram of an example computer system 100. The computer system 100 is configured for wheel idling control in a vehicle 102. The vehicle 102 includes a powertrain 104 having at least one motor 106 configured to provide propulsion power to a first subset 108 of wheels 108a-b of the vehicle 102. The motor may be powered by the vehicle's propulsion battery 132 or, for example, by a fuel cell. The motor 106 is coupled to the first subset 108 of wheels 108a-b via a drive axle 109. The computer system also includes a digital memory 111.

[0042] Vehicle 102 also includes a second subset 110 of wheels 110a-b. This second subset of wheels may be non-propelled, meaning no actuator or engine is connected to it. More precisely, the second subset of wheels may be on the non-propelled axle of vehicle 102. Typically, the second subset 110 of wheels 110a-b experiences smaller torque variations compared to the first subset 108 of wheels 108a-b.

[0043] In other examples, the powertrain 104 includes an actuator 112 configured to provide propulsive power to a second subset 110 of wheels 110a-b. During a given time period, the torque responsiveness of the motor 106 is greater than that of the actuator 112. In some examples, the actuator 112 is an internal combustion engine.

[0044] In other examples, the axle 114 of the second subset 110 of wheels 110a, 110b is non-propulsed in a first driving mode of vehicle 102 and propulsed by actuator 112 in a second driving mode of vehicle 102. In other words, the torque responsiveness of actuator 112 can vary depending on the driving mode of vehicle 102. For example, the vehicle may have an ECO mode and a Power mode, where the torque responsiveness of actuator 112 is higher in Power mode than in ECO mode. In practice, the actuator can disengage from axle 114 in less responsive modes, effectively preventing axle 114 from being propulsed. In any case, during the time period mentioned herein, the second subset 110 of wheels 110a-b experiences smaller torque variations compared to the first subset 108 of wheels 108a-b.

[0045] Computer system 100 includes processing circuitry 116 configured to estimate vehicle speed 121 within time period 120 based on the effective wheel speed Ef associated with a second subset 110 of wheels 110a-b of vehicle 102. As discussed, during time period 120, the second subset 110 of wheels 110a-b experiences smaller torque variations compared to the first subset 108 of wheels 108a-b.

[0046] Time period 120 is the period during which the first subset 108 of wheels 108a-b experiences high torque variability or variation. The second subset 110 of wheels 110a-b experiences less torque variability or no torque variability during the same time period 120. Time period 120 can be a sampling time period for the torque limiting process described herein. The time period is sufficient to detect wheel dynamics, such as slippage. The time period is short enough that the output torque of the first subset 108 of wheels 108a, 108b is temporally limited before potential instability problems occur.

[0047] The term "effective wheel speed" refers to a parameter representing the rotational speed of a wheel. This parameter can correspond to a direct measurement of the wheel's rotational speed or an indirect estimate based on measurements obtained from components mechanically connected to the wheel, such as electric motors, drive shafts, axles, or gearboxes. Effective wheel speed can be derived using sensor data, control signals, or a combination thereof, and can be combined with signal processing or estimation techniques (e.g., filtering, observer models, or values ​​inferred from torque and acceleration).

[0048] The wheel speed of the second subset 110 of wheels 110a-b can be measured from wheel speed sensor 118 or determined based on the operating speed of actuator 112 connected to the second subset 110 of wheels 110a-b.

[0049] The processing circuit 116 is configured to determine the speed standard 124 based on the estimated speed 121 and the offset speed 122.

[0050] Furthermore, the processing circuit 116 is configured to provide control command C to the motor 106 to limit the output torque of a first subset 108 of wheels 108a-b according to a determined speed standard 124.

[0051] The offset speed of 122 can be a fixed value.

[0052] However, in other examples, the offset speed is a variable offset value that depends on at least one other parameter. Typically, the offset speed 122 depends on the current driving condition 126.

[0053] Current driving conditions refer to, for example, the vehicle's estimated speed or current acceleration or deceleration. In other examples, driving conditions may alternatively or additionally refer to one or more of the following: the friction between the wheels and the ground, the vehicle's yaw rate, curvature, steering, or oversteer / understeer tendency. For example, lower friction may result in lower offset. Oversteer may result in less offset on the rear axle coupled to the high-response motor.

[0054] Friction can be estimated using a combination of wheel torque, speed, and wheel acceleration.

[0055] Processing circuitry 116 can be configured to acquire an allowable wheel slip 128 based on the current driving condition 126. The allowable wheel slip can set limits for slippage that could cause instability and / or reduced stability in the vehicle. This depends on the current driving condition 126. Processing circuitry 116 can determine a deflection speed 122 based on the allowable wheel slip 128. The allowable wheel slip 128 can be an allowable longitudinal wheel slip. The longitudinal wheel slip is calculated based on the difference between the speed at the tire-road contact surface and the vehicle speed.

[0056] Based on the permissible slip, the permissible vehicle speed can be found and compared with the vehicle's current speed, and the offset can be determined based on this comparison. For example, it can be expressed as the difference between the vehicle's permissible speed and its current speed.

[0057] Vehicle 102 can be in different scenarios where the speed standard can be adjusted accordingly. For example, processing circuitry 116 can determine that the vehicle is in or approaching an acceleration scenario. In this case, reasonable acceleration is expected to be allowed. Therefore, the offset speed is set such that the speed standard allows the vehicle to accelerate during that time period without causing wheel slippage.

[0058] As another example, the processing circuitry can determine that the vehicle is in a deceleration scenario. That is, the vehicle is decelerating, allowing regenerative braking and charging of the energy storage device 132 via motor 106. In this case, the offset speed 122 is set such that the speed criterion limits the regenerative braking torque on a first subset 108 of wheels 108a-b. In other words, regenerative braking should not be excessive to the point of causing wheel slippage.

[0059] Typically, an electric motor can operate as a motor to generate propulsive torque and as a generator to generate braking torque for charging the battery.

[0060] It can be envisioned that regardless of whether the vehicle is accelerating, decelerating, or rolling, it can continuously and simultaneously provide and follow acceleration and deceleration offsets.

[0061] Computer system 100 can set different offsets for propulsion and regeneration limits.

[0062] Acceleration can be determined based on a combination of the sign of the vehicle speed and the sign of the applied / requested torque. Acceleration and deceleration can also be distinguished based on the derivative of the absolute value of the estimated vehicle speed, where a positive derivative represents acceleration and a negative derivative represents deceleration.

[0063] Optionally, the computer system 100 can operate in parallel with the propulsion torque limiting system 150, which operates in the braking control module 152 based on inertial measurement unit data, wheel speed data, and driving condition data.

[0064] Figure 2 Another example, referred to as the preferred example, is shown. Here, the processing circuitry 116 and optionally the memory 111 are included in one of the inverter 140 for the motor 106 (or the inverter 140 for the motor 106) or the engine control module (ECM) 142 connected to the motor 106.

[0065] Figure 3 This is a schematic diagram of a vehicle 102 (such as an automobile including a powertrain 104), wherein a motor 106 is coupled to a first subset of wheels 108a, 108b of the vehicle 102. The vehicle 102 also includes a second subset of wheels 110a, b that experience smaller torque variations compared to the first subset of wheels 108a, b. The second subset 110 of wheels 110a, 110b can be propelled by an actuator 112 or non-propelled. The vehicle 102 includes a computer system 100; however, processing circuitry 116 can be arranged in either an inverter 140 or an ECM 142, as close as possible to the motor 106 coupled to the axle 109. Figure 3 Two options are shown: the processing circuit 116 may be included in the inverter 140 or the ECM 142.

[0066] Furthermore, the processing circuitry 116 can be separated between the inverter 140 and the ECM 142. For example, the vehicle speed 121 can be determined by the processing circuitry 116 in the ECM 142 based on the effective wheel speed, and the offset 122 can be determined and included by the processing circuitry 116 in the inverter 140.

[0067] ECM 142 can provide control signals c1 To indicate the torque and speed limits of inverter 140, thereby inverter 140 provides control signals. c2 To control the torque output of motor 106.

[0068] Figure 4 This is a flowchart of method steps for wheel idling control in a vehicle according to an example of this disclosure. The vehicle 102 includes a powertrain 104 having at least one motor 106 configured to provide propulsion power to a first subset 108 of wheels 108a-b of the vehicle 102.

[0069] In step S102, the processing circuit 116 of the computer system 100 estimates the vehicle speed 121 within time period 120 based on the effective wheel speed Ef associated with a second subset 110 of the wheels 110a, 110b of the vehicle 102. The second subset 110 of the wheels 110a, b experiences smaller torque variations during this time period compared to the first subset 108 of the wheels 108a, b.

[0070] In step S105, the processing circuit 116 determines the speed standard 124 based on the estimated speed and the offset speed 122.

[0071] In step S106, the processing circuit 116 provides a control command C to the motor 106 to limit the output torque of the first subset 108 of the wheels 108a, 108b according to the determined speed standard 124.

[0072] Figure 5 This is a flowchart of the method steps for wheel spin control in a vehicle, according to an example of this disclosure.

[0073] Besides about Figure 4 In addition to the described steps S102, S105, and S106, the method further includes step S103a: obtaining, by the processing circuit 116, the permissible wheel slip amount 128 based on the current driving condition 126. The current driving condition 126 is determined or obtained prior to step S103a. In step S103b, the processing circuit 116 determines the offset speed 122 based on the obtained permissible wheel slip amount 128.

[0074] Figure 6 This is a flowchart of the method steps for wheel spin control in a vehicle, according to an example of this disclosure.

[0075] The method further includes step S104a, to determine by the processing circuit whether the vehicle is in an acceleration scenario or a deceleration scenario.

[0076] If vehicle 102 is in an acceleration scenario, the offset speed in step S104b is set so that the speed standard allows the vehicle to accelerate during that time period.

[0077] If the vehicle is in a deceleration scenario, the offset speed in step S104b is set such that the speed standard limits the regenerative braking torque on the first subset of wheels.

[0078] Both acceleration and deceleration targets can be determined and provided simultaneously by the processing circuit, enabling the motor to simultaneously comply with acceleration and deceleration speed standards.

[0079] Figure 7 A computer system 700 according to one embodiment is illustrated. The steps of the method executed by the computer system 700 are actually performed by a processing circuit 711, which is embodied in the form of one or more microprocessors arranged to execute a computer program 712 downloaded to a non-transitory computer-readable storage medium 713 (such as random access memory (RAM), flash memory, or hard disk drive) associated with the microprocessor. The processing circuit 711 is arranged to cause the computer system 700 to execute the method according to the embodiment when a suitable computer program 712, including computer-executable instructions, is downloaded to the storage medium 713 and executed by the processing circuit 711. The storage medium 713 may also be a computer program product including the computer program 712. Alternatively, the computer program 712 may be transferred to the storage medium 713 by means of a suitable computer program product (such as a digital multifunction disc (DVD) or memory stick). As another alternative, the computer program 712 may be downloaded to the storage medium 713 via a network. The processing circuitry 711 may alternatively be implemented as a digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), complex programmable logic device (CPLD), etc. The computer system 100 also includes a communication interface 714 (wired or wireless), which is configured to send and receive data through the communication interface 714.

[0080] Example 1: A computer-implemented method for wheel idling control in a vehicle, the vehicle including a powertrain system having at least one motor configured to provide propulsion power to a first subset of the vehicle's wheels, the method comprising: estimating a vehicle speed by a processing circuit of a computer system over a time period based on an effective wheel speed associated with a second subset of the vehicle's wheels, the second subset of wheels experiencing a smaller torque variation compared to the first subset of wheels during the time period; determining a speed criterion by the processing circuit based on the estimated speed and offset speed; and providing control commands by the processing circuit to the motor to limit the output torque to the first subset of wheels according to the determined speed criterion.

[0081] Example 2: The method described in Example 1, wherein the offset speed depends on the current driving conditions.

[0082] Example 3: Based on any of the methods in Examples 1-2, including: The processing circuit obtains the permissible wheel slip based on the current driving conditions and determines the offset speed based on the permissible wheel slip.

[0083] Example 4: The method according to any one of Examples 1-3, wherein the processing circuitry is included in either the inverter of the motor or the engine control module connected to the motor.

[0084] Example 5: The method according to any one of Examples 1-4, wherein the power transmission system includes an actuator configured to provide propulsion power to the second subset of wheels, wherein during the time period, the torque responsiveness of the motor is greater than the torque responsiveness of the actuator.

[0085] Example 6: According to the method of Example 5, the actuator is an internal combustion engine.

[0086] Example 7: The method according to any one of Examples 5-7, wherein the second subset of wheels is non-propulsory in a first driving mode of the vehicle and is propulsed by the actuator in a second driving mode of the vehicle.

[0087] Example 8: The method according to any one of Examples 5-7, wherein the torque responsiveness of the actuator varies according to the driving mode of the vehicle.

[0088] Example 9: The method of any one of Examples 1-4, wherein the second set of wheels is on the non-propulsion axle of the vehicle.

[0089] Example 10: The method according to any one of Examples 1-9 includes: determining by processing circuitry that the vehicle is in an acceleration scenario, wherein the offset speed is set such that a speed standard allows the vehicle to accelerate during the time period.

[0090] Example 11: A method according to any one of Examples 1-10, comprising: determining by processing circuitry that the vehicle is in a deceleration scenario, wherein the offset speed is set such that a speed criterion limits the regenerative braking torque on a first subset of wheels.

[0091] Example 12: The method according to any one of Examples 1-11 is performed in parallel with the operation of a propulsion torque limiting system operating in a braking control module based on inertial measurement unit data, wheel speed data, and driving condition data.

[0092] Example 13: The method according to any one of Examples 1-12, wherein the wheel speed of the second wheel subset is measured from a wheel speed sensor or determined based on the operating speed of the actuator connected to the second wheel subset.

[0093] Example 14: A computer system for wheel idling control in a vehicle, the vehicle including a powertrain having at least one motor configured to provide propulsion power to a first subset of the vehicle's wheels, the computer system including processing circuitry configured to: estimate a vehicle speed over a time period based on an effective wheel speed associated with a second subset of the vehicle's wheels, the second subset of wheels experiencing a smaller torque variation compared to the first subset of wheels during the time period; determine a speed criterion based on the estimated speed and offset speed; and provide control commands to the motor to limit the output torque to the first subset of wheels according to the determined speed criterion.

[0094] Example 15: The computer system according to Example 14, where the offset speed depends on the current driving conditions.

[0095] Example 16: According to any one of Examples 14-15, the processing circuit is configured to: acquire an allowable amount of wheel slip based on the current driving conditions, and determine an offset speed based on the allowable amount of wheel slip.

[0096] Example 17: A computer system according to any one of Examples 14-16, wherein the processing circuitry is included in either the inverter of the motor or an engine control module connected to the motor.

[0097] Example 18: A computer system according to any one of Examples 14-17, wherein the power transmission system includes an actuator configured to provide propulsion power to a second subset of wheels, wherein during the time period, the torque responsiveness of the motor is higher than the torque responsiveness of the actuator.

[0098] Example 19: The computer system of Example 18, wherein the actuator is an internal combustion engine.

[0099] Example 20: A computer system of any of Examples 18-19, wherein the axles of the second subset are non-propulsory in a first driving mode of the vehicle and propulsory by actuators in a second driving mode of the vehicle.

[0100] Example 21: A computer system of any of Examples 18, wherein the torque responsiveness of the actuator varies depending on the driving mode of the vehicle.

[0101] Example 22: A computer system according to any one of Examples 14-17, wherein the second subset of wheels is on the non-propulsion axle of the vehicle.

[0102] Example 23: In any one of Examples 18-22, the processing circuitry is configured to determine that the vehicle is in an acceleration scenario, wherein the offset speed is set such that a speed standard allows the vehicle to accelerate during that time period.

[0103] Example 24: According to any one of Examples 14-23, the processing circuit is configured to determine that the vehicle is in a deceleration scenario, wherein the offset speed is set such that a speed criterion limits the regenerative braking torque on a first subset of wheels.

[0104] Example 25: A computer system according to any one of Examples 14-24 operates in parallel with a propulsion torque limiting system that operates in a braking control module based on inertial measurement unit data, wheel speed data, and driving condition data.

[0105] Example 26: A computer system according to any one of Examples 14-25, wherein the wheel speed of the second wheel subset is measured from a wheel speed sensor or determined based on the operating speed of an actuator connected to the second wheel subset.

[0106] Example 27: A vehicle includes: a powertrain having an electric motor coupled to a first subset of wheels of the vehicle, a second subset of wheels subjected to a smaller torque variation compared to the first subset of wheels, and a computer system according to any one of Examples 14-26.

[0107] Example 28: A computer program product comprising program code for performing the method described in any one of Examples 1-13 when executed by processing circuitry.

[0108] Example 29: A non-transitory computer-readable storage medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform any one of Examples 1-13.

[0109] Various examples have been described. These and other examples are within the scope of the appended claims.

Claims

1. A computer-implemented method for wheel idling control in a vehicle (102), the vehicle (102) including a powertrain (104) having at least one motor (106) configured to provide propulsion power to a first subset (108) of wheels (108a, b) of the vehicle, the method comprising: The processing circuit (116) of the computer system (100) estimates (S102) the vehicle speed (121) within a time period (120) based on the effective wheel speed (Ef) associated with a second subset (110) of the wheels (110a, b) of the vehicle. Compared with the torque change of the first subset (108) of the wheels (108a, b) during the time period, the second subset (110) of the wheels (110a, b) experiences a smaller torque change. The processing circuit (116) determines (S105) the speed standard (124) based on the estimated vehicle speed (121) and offset speed (122), and The processing circuit (116) provides (S106) control command (C) to the motor (106) to limit the output torque to the first subset (108) (108a, b) of the wheels according to the determined speed standard.

2. The method according to claim 1, wherein, The deflection speed depends on the current driving conditions.

3. The method according to any one of claims 1-2, comprising: The processing circuit obtains the permissible wheel slip based on the current driving conditions, and The offset speed is determined based on the allowable amount of wheel slippage.

4. The method according to any one of claims 1-3, wherein, The processing circuitry is included in either the inverter of the motor or the engine control module connected to the motor.

5. The method according to any one of claims 1-4, wherein, The powertrain includes an actuator configured to provide propulsion power to a second subset of the wheels, wherein, during the time period, the torque responsiveness of the motor is greater than that of the actuator.

6. The method according to claim 5, wherein, The actuator is an internal combustion engine.

7. The method according to any one of claims 5-7, wherein, The second subset of wheels is not propelled in the first driving mode of the vehicle, but is propelled by the actuator in the second driving mode of the vehicle.

8. The method according to any one of claims 5-7, wherein, The torque responsiveness of the actuator varies depending on the driving mode of the vehicle.

9. The method according to any one of claims 1-4, wherein, The second subset of wheels is on the non-propulsion axle of the vehicle.

10. The method according to any one of claims 1-9, comprising: The processing circuit determines that the vehicle is in an acceleration scenario, wherein the offset speed is set such that the speed standard allows the vehicle to accelerate during the time period.

11. The method according to any one of claims 1-10, comprising: The processing circuit determines that the vehicle is in a deceleration scenario, wherein the offset speed is set such that the speed criterion limits the regenerative braking torque on the first subset of the wheels.

12. A computer system (100) for wheel idling control in a vehicle, the vehicle including a powertrain (104) having at least one motor (106) configured to provide propulsion power to a first subset (108) of wheels (108a, b) of the vehicle (102), the computer system including a processing circuit (116) configured to: The vehicle speed (121) is estimated within time period (120) based on the effective wheel speed (Ef) associated with a second subset (110) of the wheels (110a, b) of the vehicle (102), the second subset (110) of the wheels (110a, b) experiencing a smaller torque variation compared to the first subset of the wheels within the time period. The velocity criterion (124) is determined based on the estimated velocity and the offset velocity, and A control command (C) is provided to the motor (106) to limit the output torque of the first subset (108) of the wheels (108a, b) according to a determined speed standard.

13. A vehicle comprising: A powertrain system having motors connected to a first subset of the wheels of the vehicle. The second subset of wheels that experience smaller torque variations compared to the first subset of wheels, and The computer system according to claim 12.

14. A computer program product comprising program code for performing the method of any one of claims 1-11 when executed by processing circuitry.

15. A non-transitory computer-readable storage medium comprising instructions that, when executed by the processing circuitry, cause the processing circuitry to perform the method according to any one of claims 1-11.

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