Drift control unit, system and method for a vehicle

Abstract

The present invention provides a drift control unit, system and method for a vehicle. The drift control unit includes: an acquisition module configured to acquire a drift amount and a driver's steering operation that characterize the degree of drift of the vehicle; a processing module configured to determine the current drift level of the vehicle based on the acquired drift amount; a target torque distribution for the wheels or axles is adjusted based on the change trend of the drift amount and the driver's steering operation to perform slip control or torque control corresponding to the current vehicle drift level; and an output module that outputs the adjusted target torque distribution so that the vehicle's power system is controlled according to the adjusted target torque distribution. The current drift level is one of a plurality of predetermined drift levels, and the plurality of predetermined drift levels include: a drift start level, a first drift level, a second drift level, and a dangerous level with gradually increasing drift levels.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle drift control, and in particular to a drift control unit, a drift control system and a drift control method for a vehicle, and also to a corresponding machine-readable storage medium. Background Art

[0002] Drift is when the rear wheels of a vehicle lose grip, causing the vehicle to turn in a tail-swinging posture, which is opposite to the gripping cornering method (grip) that maintains wheel grip. The driver controls the vehicle so that a large angle is formed between the direction of the front of the vehicle and the actual direction of movement of the vehicle body. At this time, the vehicle will slide sideways through the corner and drift. Drifting is regarded as a "gorgeous driving skill" and is often seen in performances or racing events. However, it may happen that the driver cannot master the drifting technique well, in which case the vehicle needs to have a drift assist function to assist the driver in achieving vehicle drift. Summary of the invention

[0003] In this context, one aspect of the present invention provides a drift control unit for a vehicle, comprising: an acquisition module, configured to acquire a drift amount representing the degree of drift of the vehicle and a steering operation of a driver; a processing module, configured to determine a current drift level of the vehicle based on the acquired drift amount; adjust a target torque distribution for wheels or axles based on a changing trend of the drift amount and the steering operation of the driver to perform slip control or torque control corresponding to the current drift level of the vehicle; and an output module, outputting an adjusted target torque distribution so that a power system of the vehicle is manipulated according to the adjusted target torque distribution, wherein the current drift level is one of a plurality of predetermined drift levels, and the plurality of predetermined drift levels include gradually increasing drift levels: a start drift level, a first drift level, a second drift level, and a dangerous level.

[0004] Another aspect of the present invention provides a drift control system for a vehicle, comprising: a sensing unit for collecting information related to vehicle drift, including: a drift amount characterizing the degree of vehicle drift and a driver's steering operation; a driving unit for providing driving force for the vehicle's axles or wheels; and a drift control unit as described above, for controlling the driving unit based on the collected information to perform slip control or torque control.

[0005] Another aspect of the present invention provides a drift control method unit for a vehicle, optionally, the method is executed by the drift control unit as described above or the drift control system as described above, the method comprising: obtaining a drift amount characterizing the degree of drift of the vehicle and a steering operation of the driver; determining a current drift level of the vehicle based on the obtained drift amount; adjusting a target torque distribution for wheels or axles based on a changing trend of the drift amount and the steering operation of the driver to perform slip control or torque control corresponding to the current drift level of the vehicle; and outputting an adjusted target torque distribution so that a power system of the vehicle is manipulated according to the adjusted target torque distribution, wherein the current drift level is one of a plurality of predetermined drift levels, and the plurality of predetermined drift levels include gradually increasing drift levels: a starting drift level, a first drift level, a second drift level, and a dangerous level.

[0006] Yet another aspect of the present invention provides a machine-readable storage medium storing executable instructions, which, when executed, cause one or more processors to perform the torque control method as described above.

[0007] The above presents a summary of major aspects of the invention in order to provide a basic understanding of such aspects and as a prelude to the detailed description that is presented later. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The technical solution of the present invention will become clearer from the following detailed description in conjunction with the accompanying drawings. It is understood that these drawings are only used for exemplary description and are not intended to limit the scope of protection of the present invention.

[0009] Figure 1 is a schematic diagram of a drift braking control system for a vehicle according to an embodiment of the present invention.

[0010] Figure 2 A drift control unit for a vehicle according to an embodiment of the present invention.

[0011] Figures 3A-3C Shows Figure 1 The drift control system in the drive unit has three modes.

[0012] Figure 4 The drift control process according to one embodiment of the present invention is schematically shown.

[0013] Figure 5 is a flow chart of a drift control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0015] Figure 1 The drift control system 100 for a vehicle V according to an embodiment of the present invention is schematically shown, and is disposed on the vehicle V, so the drift control system 100 may also be referred to as a vehicle-mounted system. Figure 1 As shown, the drift control system 100 includes a sensing unit 10 , a drift control unit 20 , and a driving unit 30 .

[0016] The sensing unit 10 is used to collect information related to vehicle drift, which includes: a drift amount representing a degree of drift of the vehicle V and a steering operation of the driver of the vehicle V.

[0017] The drift amount characterizing the degree of drift of the vehicle V may include parameters related to the lateral motion of the vehicle V (i.e., lateral motion related parameters), for example, including: center of mass slip angle, rear wheel sideslip angle, body sideslip angle, body sideslip angle, yaw rate, yaw acceleration, lateral acceleration, and tire lateral force. Accordingly, the sensing unit 10 may include a sensor that directly or indirectly collects parameters related to the lateral motion of the vehicle V. The drift amount may also be a value that can characterize the degree of drift of the vehicle calculated based on one or more of the above-mentioned lateral motion related parameters. It is to be understood that the present invention does not limit how to measure the parameters related to lateral motion and how to calculate the drift amount based on the parameters related to lateral motion.

[0018] For the driver's steering operation, the steering direction, angle and speed of the steering wheel can be measured, thereby knowing the driver's steering operation intention, for example, whether to maintain the current drift posture of the vehicle V. Accordingly, the sensing unit 10 may include a sensor that directly or indirectly measures the driver's operation of the steering wheel. For example, the sensing unit 10 may include a sensor for measuring the hand torque applied by the driver to the direction. It is understandable that the present invention does not limit how to measure or calculate the driver's steering operation.

[0019] In addition, in addition to sensors for measuring parameters related to the lateral movement of the vehicle V and the driver's steering operation, the sensing unit 10 may also include sensors for receiving information from devices connected to the vehicle V, for example, receiving information such as vehicle speed, vehicle acceleration, and vehicle body yaw angle from a roadside unit (RSU) connected to the vehicle V, and then calculating parameters related to the lateral movement of the vehicle V based on the received information.

[0020] The drift control unit 20 includes a drift control strategy according to an embodiment of the present invention, that is, based on the drift degree of the vehicle V and the driver's steering operation, a target torque distribution adjustment scheme for the wheels and / or axles is determined to perform slip control or torque control.

[0021] It is understandable that during the driving process of the vehicle, the stability system controller or the power system controller of the vehicle V will always calculate the target slip or target torque for the axle and the wheel. According to the drift control strategy of the embodiment of the present invention, different adjustment schemes for the target slip or different adjustment schemes for the target torque are given for different situations, for example, adjusting: the target torque distribution for the front inner wheel and the front outer wheel; and the target torque distribution for the rear inner wheel and the rear outer wheel, so as to control the drift of the vehicle V.

[0022] According to an embodiment of the present invention, the degree of drift of the vehicle is divided into four levels according to the severity of the drift of the vehicle, that is, the drift degree increases successively: the starting drift level (L0), the first drift level (L1), the second drift level (L2), and the danger level (L3). The four levels are determined based on the drift amount. Each drift level has a corresponding drift amount range, that is, the upper and lower limits of the drift amount. For example, if the measured current drift amount of the vehicle V is within the range of the first drift level (L1), it is determined that the current drift level of the vehicle V is the first drift level. The range of each drift level is predetermined and can be adjusted according to different vehicle models, user needs, and application scenarios.

[0023] It is understandable that when determining the drift level of the vehicle or judging the change trend of the drift amount, one of the above-mentioned multiple lateral motion related parameters can be used as a standard, for example, the center of mass slip angle is used. If the measured center of mass slip angle is within the range of the second drift level and is increasing, the current drift level is determined to be the second drift level, and it indicates that the drift degree of the vehicle is increasing. When determining the drift level of the vehicle or judging the change trend of the drift amount, two or more of the above-mentioned multiple lateral motion related parameters can also be used to calculate according to a predetermined algorithm, and the calculated values ​​are used to determine the current drift level of the vehicle and judge the change trend of the drift amount.

[0024] Below, the relevant definitions of each drift level are listed in Table 1 below.

[0025] Table 1

[0026]

[0027] As shown in Table 1, in the drifting level (L0), slip control is adopted, and the stability system of the vehicle V does not intervene, because the vehicle is at the beginning stage of drifting at this time, and the driving stability is good. In the first drifting level (L1), torque control is adopted, and the stability system of the vehicle does not intervene, because the drift degree of the vehicle is not severe at this time, and the driving stability of the vehicle is good. In the second drifting level (L2), torque control is adopted, and the stability system of the vehicle intervenes, because the drift degree of the vehicle is severe at this time, and it is necessary to ensure the driving stability of the vehicle while maintaining the drift of the vehicle. In the dangerous drifting level (L3), torque control is adopted, and the stability system of the vehicle intervenes, because the drift posture of the vehicle is out of control at this time, and the stability system is needed to control the lateral stability of the vehicle to ensure the driving safety of the vehicle.

[0028] In the embodiments of the present invention, "slip amount" can be understood as a quantity indicating the degree of slippage of the vehicle, which can be expressed in a variety of ways. For example, the slip amount can be expressed by the difference between the vehicle's drive wheel speed or drive shaft speed and the vehicle speed. For example, the slip amount can also be expressed by the ratio between the above difference (i.e., the difference between the vehicle's drive wheel speed or drive shaft speed and the vehicle speed) and the vehicle speed. In addition, the slip amount can also be expressed by a numerical value calculated by the above difference and / or ratio.

[0029] In the embodiments of the present invention, "slip amount" may include so-called "slip amount", "slip amount", "slip amount", "slip ratio" and "slip amount". Accordingly, "slip amount control" should be understood to include control of the slip amount according to various embodiments.

[0030] In the embodiments of the present invention, "target slip amount" should also be understood similarly. Therefore, "increasing the target slip amount" should be understood to include increasing the target slip amount according to each embodiment. "Decreasing the target slip amount" should be understood to include decreasing the target slip amount according to each embodiment.

[0031] Figure 2 The drift control unit 20 according to one embodiment of the present invention is shown, which includes an acquisition module 21, a processing module 22 and an output module 23. The acquisition module 21 acquires information (INFO) including the drift amount and the driver's steering operation. The processing module 22 determines the target torque distribution adjustment scheme based on the acquired information. The output module 23 outputs the target torque distribution adjustment scheme (T Distribution In addition, the output module 23 can also output information such as the current drift level and whether the stability system intervenes.

[0032] It is understandable that these modules are named according to their functions, and are not intended to limit their physical locations and implementations. For example, these modules may be arranged in the same chip or circuit, or in different circuits or chips.

[0033] In one embodiment, the drift control unit 20 is provided in a traction control system (TCS) of the vehicle V, or in a controller of a power system of the vehicle V, or in a domain controller of the vehicle V. The drift control unit 20 exchanges information with a control unit of a stability system of the vehicle V via a vehicle bus.

[0034] It is understood that the drift control unit 20 can be implemented in hardware or software or a combination of software and hardware. For the part implemented in hardware, it can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic units designed to perform their functions, or combinations thereof. For the part implemented in software, it can be implemented with the aid of microcodes, program codes, or code segments, and they can also be stored in machine-readable storage media such as storage components.

[0035] In one embodiment, the drift control unit 20 comprises a memory and a processor. The memory comprises instructions, which, when executed by the processor, enable the processor to perform a drift control strategy / method according to an embodiment of the present invention.

[0036] The drive unit 30 includes a plurality of motors, which can realize the sub-wheel drive of the vehicle, and thus the embodiment of the present invention can realize the sub-wheel control of the vehicle by controlling the plurality of motors. The drive unit 30 can be realized in one of three modes, i.e., one of the first mode (1F2R), the second mode (2F1R), and the third mode (2F2R). Figures 3A-3C The three modes are shown. Embodiments of the present invention include a drift control strategy for each of the 3 modes separately.

[0037] Figure 3A The first mode (1F2R) is shown. Figure 3A As shown, the drive unit 30 includes three motors, namely, a motor M_F for driving the front axle of the vehicle, the output of which is transmitted to the front axle of the vehicle; a motor M_RI for driving the rear inner wheel RI of the vehicle, the output of which is transmitted to the rear inner wheel RI of the vehicle V; and a motor M_RO for driving the rear outer wheel RO of the vehicle, the output of which is transmitted to the rear outer wheel RO. Figure 3AIn the 1F2R mode, the target torque adjustment includes adjustments to the target torques for the front axle, rear inner wheel and rear outer wheel respectively.

[0038] Figure 3B The second mode (2F1R) is shown. Figure 3B As shown, the drive unit 30 includes three motors, namely, a motor M_R for driving the rear axle of the vehicle, the output of which is transmitted to the rear axle of the vehicle; a motor M_FI for driving the front inner wheel FI of the vehicle, the output of which is transmitted to the front inner wheel FI of the vehicle V; and a motor M_FO for driving the front outer wheel FO of the vehicle, the output of which is transmitted to the front outer wheel FO. Figure 3B In the 2F1R mode, the target torque adjustment includes adjustments to the target torques for the front inner wheel, front outer wheel and rear axle respectively.

[0039] Figure 3C The third mode (2F2R) is shown. Figure 3C As shown, the drive unit 30 includes four motors, namely, a motor M_FI for driving the front inner wheel of the vehicle, the output of which is transmitted to the front inner wheel of the vehicle; a motor M_FO for driving the front outer wheel of the vehicle, the output of which is transmitted to the front outer wheel of the vehicle; a motor M_RI for driving the rear inner wheel RI of the vehicle, the output of which is transmitted to the rear inner wheel RI of the vehicle V; and a motor M_RO for driving the rear outer wheel RO of the vehicle, the output of which is transmitted to the rear outer wheel RO. Figure 3C In the 2F2R mode, the target torque adjustment includes adjustments to the target torques for the front inner wheel, front outer wheel, rear inner wheel and rear outer wheel respectively.

[0040] It should be understood that the definition of inner wheels and outer wheels is related to the direction of the vehicle. For example, when the vehicle turns left, the left wheel is the inner wheel and the right wheel is the outer wheel. Conversely, when the vehicle turns right, the right wheel is the inner wheel and the left wheel is the outer wheel. Figures 3A-3C 3A-3C exemplarily shows a vehicle turning left (see the arrow directions in 3A-3C), and determines the inner and outer wheels based on the left turn.

[0041] Figure 4 The drift control process 400 according to one embodiment of the present invention is shown. The drift control process 400 is described below by taking the drift control unit 20 controlling the drift of the vehicle V as an example.

[0042] See also Figure 4 In box 402, the acquisition module 21 acquires the drift amount representing the degree of drift of the vehicle V and the driver's steering operation.

[0043] In block 404 , the processing module 22 determines the current drift level of the vehicle V based on the acquired drift amount. For example, the processing module 22 determines which drift level of four predetermined drift levels the acquired drift amount is within, thereby determining the current drift level.

[0044] In block 406, the processing module 22 determines the target torque distribution adjustment scheme according to the change trend of the drift amount and the driver's turning operation, so as to perform slip control or torque control corresponding to the current drift level. Next, for the current drift level of L0, L1, L2 and L3, and in combination with the three modes of 1F2R, 2F1R and 2F2R of the above-mentioned drive unit, the drift control strategies under various situations are specifically introduced.

[0045] Referring to block 4061, when the current drift level is the drift start level L0 and the drift amount is changing in a trend that the drift amount is increasing, the drift control unit 20 performs slip control for the front and rear axles of the vehicle V. The slip control includes: increasing the target slip (F↑) for the front axle of the vehicle and reducing the target slip (R↓) for the rear axle of the vehicle. In this case, such slip control is performed for the three modes of the drive unit, 1F2R, 2F1R and 2F2R.

[0046] Next, a PID operation is performed based on the target slip adjustment scheme described above, and a target torque adjustment scheme for the front and rear axles of the vehicle is calculated based on the PID operation. The PID operation can be performed by the processing module 22, or in other control units of the vehicle V, or even in a computing device outside the vehicle V. The present invention does not limit how to implement the PID operation.

[0047] It can be understood that when the current drift level is the starting drift level L0 and the drift amount has a decreasing trend, the drift control unit 20 enters a waiting state (ie, enters a Standby state).

[0048] Referring to block 4062, when the following conditions are met, the processing module 22 executes a first target torque distribution adjustment scheme related to the vehicle driving direction (see "①" in block 4062):

[0049] -The current drift level is the first drift level;

[0050] -The drift trend is increasing;

[0051] - The driver's steering operation is: the driver does not turn the steering wheel in the direction opposite to the direction the vehicle is turning; and

[0052] The yaw rate is greater than a predetermined yaw rate upper limit value corresponding to the first drift level.

[0053] It can be understood that if the current drift level is the first level L1, and the drift amount is increasing, this indicates that the vehicle's drift posture is intensifying. If the driver's steering operation at this time is: not steering the wheel in the direction opposite to the vehicle's steering direction, it means that the driver's intention of steering the wheel is: not maintaining the vehicle's current drift posture, because the vehicle's drift posture is intensifying at this time. In order to maintain the vehicle's current drift posture, the driver should steer the wheel in the direction opposite to the vehicle's steering direction, that is, against the direction of the vehicle's drift. If the driver does not steer the wheel in the direction opposite to the vehicle's steering direction, the vehicle's drift posture will continue to intensify until the vehicle's yaw angular velocity is greater than the predetermined yaw angular velocity upper limit value corresponding to the first drift level, thereby triggering the first target torque adjustment scheme.

[0054] It can be understood that the target torque distribution adjustment scheme related to the vehicle's driving direction means that the increase or decrease of the target torque of the inner and outer wheels is based on the vehicle's driving direction, that is, related to the vehicle's tail-swinging direction.

[0055] When the drive unit 30 is implemented as the first mode (1F2R), the first target torque distribution adjustment scheme includes: increasing the target torque for the front axle (F↑), reducing the target torque for the rear inner wheel (RI↓+), reducing the target torque for the rear outer wheel (RI↓++), and the degree of torque reduction of the rear inner wheel is less than that of the rear outer wheel.

[0056] In one embodiment, a first decrement unit is used to reduce the target torque for the rear inner wheel, and a second decrement unit is used to reduce the target torque for the rear outer wheel, and the first decrement unit is smaller than the second decrement unit, thereby achieving a greater reduction in the target torque for the rear outer wheel.

[0057] When the drive unit 30 is implemented in the second mode (2F1R), the first target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel (FI↑), reducing the target torque for the front outer wheel (FO↓), and reducing the target torque for the rear axle (R↓).

[0058] When the drive unit 30 is implemented as the third mode (2F2R), the first target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel (FI↑), reducing the target torque for the front outer wheel (FO↓), reducing the target torque for the rear inner wheel RI↓+, reducing the target torque for the rear outer wheel (RI↓++), and the degree of reduction in the target torque of the rear inner wheel is less than that of the rear outer wheel.

[0059] Similarly, in one embodiment, the target torque for the rear inner wheel is reduced by a first reduction unit, the target torque for the rear outer wheel is reduced by a second reduction unit, and the first reduction unit is smaller than the second reduction unit, thereby achieving a greater reduction in the target torque for the rear outer wheel.

[0060] Continuing to refer to block 4062, when the following conditions are met, the processing module 22 executes a second target torque distribution adjustment scheme related to the vehicle driving direction (see "②" in block 4062):

[0061] -The current drift level is the first drift level;

[0062] -The drift amount tends to decrease;

[0063] - The driver's steering operation is not to turn the steering wheel in the same direction as the vehicle is turning; and

[0064] The yaw rate is less than a predetermined yaw rate lower limit value corresponding to the first drift level.

[0065] It can be understood that if the current drift level is the first level L1, and the drift amount is decreasing, this indicates that the vehicle's drift posture is weakening. If the driver's steering operation at this time is: not steering in the same direction as the vehicle is turning, it means that the driver's intention of steering is: not maintaining the vehicle's current drift posture, because the vehicle's drift posture is weakening at this time. In order to maintain the vehicle's current drift posture, the driver should steer in the same direction as the vehicle is turning, that is, in a direction that intensifies the vehicle's drift. If the driver does not steer in the same direction as the vehicle is turning, the vehicle's drift posture will continue to weaken until the vehicle's yaw angular velocity is less than the predetermined yaw angular velocity lower limit corresponding to the first drift level, triggering the second target torque adjustment scheme.

[0066] When the drive unit 30 is implemented in the first mode (1F2R), the second target torque distribution adjustment scheme includes: reducing the target torque for the front axle (F↓), increasing the target torque for the rear inner wheel (RI↑+), increasing the target torque for the rear outer wheel (RI↑++), and the increase degree of the target torque for the rear inner wheel is less than the increase degree of the target torque for the rear outer wheel.

[0067] In one embodiment, the target torque for the rear inner wheel is increased by a first incremental unit, the target torque for the rear outer wheel is increased by a second incremental unit, and the first incremental unit is smaller than the second incremental unit, thereby achieving a greater increase in the target torque for the rear outer wheel.

[0068] When the drive unit 30 is implemented in the second mode (2F1R), the second target torque distribution adjustment scheme includes: reducing the target torque for the front inner wheel (FI↓), increasing the target torque for the front outer wheel (FO↑), and increasing the target torque for the rear axle (R↑).

[0069] When the drive unit 30 is implemented as the third mode (2F2R), the second target torque distribution adjustment scheme includes: reducing the target torque for the front inner wheel (FI↓), increasing the target torque for the front outer wheel (FO↑), increasing the target torque for the rear inner wheel (RI↑+), increasing the target torque for the rear outer wheel (RI↑++), and the increase degree of the target torque for the rear inner wheel is less than the increase degree of the target torque for the rear outer wheel.

[0070] Similarly, in one embodiment, the target torque for the rear inner wheel is increased by a first incremental unit, the target torque for the rear outer wheel is increased by a second incremental unit, and the first incremental unit is smaller than the second incremental unit, thereby achieving a greater increase in the target torque for the rear outer wheel.

[0071] Referring to block 4063, when the following conditions are met, the processing module 22 executes a third target torque distribution adjustment scheme related to the vehicle driving direction (see "③" in block 4063):

[0072] -The current drift level is the second drift level;

[0073] -The drift trend is increasing;

[0074] - The driver's steering operation is: not turning the steering wheel in the direction opposite to the direction in which the vehicle is turning; and

[0075] The yaw rate is greater than a predetermined yaw rate upper limit value corresponding to the second drift level.

[0076] It can be understood that if the current drift level is the second level L2, and the drift amount is increasing, this indicates that the vehicle's drift posture is intensifying. If the driver's steering operation at this time is: not steering the wheel in the direction opposite to the vehicle's steering direction, it means that the driver's intention of steering the wheel is: not maintaining the vehicle's current drift posture, because the vehicle's drift posture is intensifying at this time. In order to maintain the vehicle's current drift posture, the driver should steer the wheel in the direction opposite to the vehicle's steering direction, that is, against the direction of the vehicle's drift. If the driver does not steer the wheel in the direction opposite to the vehicle's steering direction, the vehicle's drift posture will continue to intensify until the vehicle's yaw angular velocity is greater than the predetermined yaw angular velocity upper limit value corresponding to the second drift level, thereby triggering the third target torque adjustment scheme.

[0077] When the drive unit 30 is implemented as the first mode (1F2R), the third target torque distribution adjustment scheme includes: increasing the target torque for the front axle to a peak value (F↑MAX) based on the maximum output of the motor, reducing the target torque for the rear inner wheel (RI↓), and reducing the target torque for the rear outer wheel to 0 (ROI↓0).

[0078] It is understandable that the motor has a maximum output power, that is, the limit of its driving capability. “Increasing the target torque to a peak value based on the maximum output of the motor” means setting the target torque to a torque value that can be reached by the maximum driving capability of the associated motor.

[0079] When the drive unit 30 is implemented in the second mode (2F1R), the third target torque distribution adjustment scheme includes: reducing the target torque for the rear axle to 0 (R↓0), reducing the target torque for the front outer wheel (FO↓), and increasing the target torque for the front inner wheel to a peak value based on the maximum output of the motor (FI↑MAX).

[0080] When the drive unit 30 is implemented as the third mode (2F2R), the third target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel to a peak value (FI↑MAX) based on the maximum output of the motor, reducing the target torque for the front outer wheel (FO↓), reducing the target torque for the rear inner wheel (RI↓), and reducing the target torque for the rear outer wheel to 0 (RO↓0).

[0081] Continuing with block 4063, when the following conditions are met, the current target torque distribution is maintained (HOLD ON):

[0082] -The current drift level is the second drift level;

[0083] -The drift amount tends to decrease;

[0084] - The driver's steering operation is not in the same direction as the vehicle is turning; and

[0085] The yaw rate is less than a predetermined yaw rate lower limit value for the second drift level.

[0086] It is understandable that the above lower limits of the horizontal angular velocity for the first and second drift levels are predetermined, and these thresholds can be obtained through actual vehicle testing and / or model calculation. Moreover, these thresholds can be adjusted based on actual application scenarios and user needs.

[0087] Referring to block 4064, when the current drift level is a dangerous level, the processing module 22 sets the target torque for all wheels or axles to 0. At this time, the drift posture of the vehicle V is out of control, and the stability system of the vehicle V controls the driving stability of the vehicle V to ensure vehicle safety.

[0088] In box 408, the output module 23 outputs the target torque distribution adjustment scheme so that the power system of the vehicle is controlled in turn. It can be understood that the process quantity can be controlled so that the torque provided to each axle or wheel meets the target torque distribution adjustment scheme.

[0089] In addition, there may be a situation where, although the target torque distribution adjustment scheme has been determined and the vehicle is operated in sequence, there is a difference between the actual drift posture of the vehicle and the drift posture that should be achieved according to the target torque distribution adjustment scheme due to various factors. In this regard, according to one embodiment of the present invention, the processing module 22 further calculates a correction torque to compensate for the difference between the actual drift posture of the vehicle and the drift posture that should be achieved according to the target torque distribution adjustment scheme.

[0090] Figure 5 A drift control method 500 according to an embodiment of the present invention is shown. The method 500 can be implemented by means of the above drift control system 100 or the above drift control unit 20, so the above description of the drift control system 100 and the drift control unit 20 is also applicable here.

[0091] See also Figure 5 In step S5102, the drift amount representing the degree of vehicle drift and the driver's steering operation are obtained.

[0092] In step S520, the current drift level of the vehicle is determined based on the acquired drift amount. The current drift level is one of a plurality of predetermined drift levels, wherein the plurality of predetermined drift levels include a drift start level, a first drift level, a second drift level, and a danger level with gradually increasing drift degrees.

[0093] In step S530, the target torque distribution for the wheels or axles is adjusted based on the change trend of the drift amount and the driver's steering operation to perform slip control or torque control corresponding to the current vehicle drift level.

[0094] In step S540 , the adjusted target torque distribution is output so that the power system of the vehicle is controlled according to the adjusted target torque distribution.

[0095] The present invention also provides a machine-readable storage medium storing executable instructions, which, when executed, enable the machine to perform the drift control method 500 as described above.

[0096] It is to be understood that all operations in the processes and methods described above are merely exemplary, and the present invention is not limited to any operations in the methods or the order of these operations, but should cover all other equivalent transformations under the same or similar concepts.

[0097] It is understood that the control unit described above can be implemented in various ways, for example, as hardware, software, or a combination thereof.

[0098] Control unit may include one or more processors. These processors may be implemented using electronic hardware, computer software or any combination thereof. Whether these processors are implemented as hardware or software will depend on specific application and the overall design constraints imposed on the system. As an example, the processor provided in the present invention, any part of the processor or any combination of the processor may be implemented as a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gate logic, a discrete hardware circuit and other suitable processing components configured to perform the various functions described in the present invention. The function of the processor provided in the present invention, any part of the processor or any combination of the processor may be implemented as software performed by a microprocessor, a microcontroller, a DSP or other suitable platforms.

[0099] Software can be broadly considered to represent instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, running threads, processes, functions, etc. Software can reside in a computer-readable medium. A computer-readable medium can include, for example, a memory, which can be, for example, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic stripe), an optical disk, a smart card, a flash memory device, a random access memory (RAM), a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, or a removable disk. Although the memory is shown as being separated from the processor in the various aspects provided by the present invention, the memory can also be located inside the processor (e.g., a cache or a register).

[0100] The above description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects are apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents of elements of the various aspects described herein that are known or to be known to those skilled in the art will be expressly included herein by reference and are intended to be covered by the claims.

Claims

1. A drift control unit for a vehicle, comprising: An acquisition module configured to acquire a drift amount representing a degree of drift of the vehicle and a steering operation of the driver; a processing module configured to determine a current drift level of the vehicle based on the acquired drift amount; Adjusting the target torque distribution for the wheels or axles based on the change trend of the drift amount and the driver's steering operation to perform slip control or torque control corresponding to the current vehicle drift level; as well as an output module, outputting an adjusted target torque distribution so that a power system of the vehicle is controlled according to the adjusted target torque distribution, The current drift level is one of a plurality of predetermined drift levels, wherein the plurality of predetermined drift levels include a drift start level, a first drift level, a second drift level, and a danger level with gradually increasing drift degrees. wherein, in the drifting level, the drift control unit performs slip amount control, and the drift control unit is not intervened by a stability system of the vehicle; In the first drift level, the drift control unit performs torque control and the drift control unit is not intervened by a stability system of the vehicle; and In the second drift level, the drift control unit performs torque control and the drift control unit is intervened by a stability system of the vehicle.

2. The drift control unit according to claim 1, wherein: The vehicle includes a drive unit, and the adjusted target torque distribution is provided to the drive unit to adjust the target torque for an axle or a wheel; and The driving unit is implemented in one of the following three modes: The first mode (1F2R) includes three motors for driving the front axle, one wheel connected to the rear axle, and another wheel connected to the rear axle; The second mode (2F1R) includes three motors for driving the rear axle, one wheel connected to the front axle, and another wheel connected to the front axle; The third mode (2F2R) includes four motors, which are respectively used to drive one wheel connected to the front axle, another wheel connected to the front axle, one wheel connected to the rear axle, and another wheel connected to the rear axle.

3. The drift control unit according to claim 1, wherein: In the danger level, the drift control unit sets the torque to zero for each wheel or axle and is intervened by the vehicle's stability system.

4. The drift control unit according to claim 1, wherein: The slip control comprises: When the current drift level is the starting drift level and the drift amount has an increasing trend, a target slip amount adjustment scheme is determined, which includes: increasing the target slip amount for the front axle of the vehicle and reducing the target slip amount for the rear axle of the vehicle.

5. The drift control unit according to claim 2, wherein: The torque control comprises: The first target torque distribution adjustment scheme related to the vehicle driving direction is executed when the following conditions are met: The current drift level is the first drift level; The drift amount tends to increase; The driver's steering operation is: not turning the steering wheel in the direction opposite to the direction the vehicle is turning; and The yaw rate is greater than a predetermined yaw rate upper limit value for a first drift level; and The second target torque distribution adjustment scheme related to the vehicle's driving direction is executed when the following conditions are met: The current drift level is the first drift level; The change trend of the drift amount is decreasing; The driver's steering operation is: not turning the steering wheel in the same direction as the vehicle is turning; and The yaw rate is less than a predetermined yaw rate lower limit value for the first drift level.

6. The drift control unit according to claim 5, wherein: When the drive unit is implemented in the first mode, the first target torque distribution adjustment scheme includes: increasing the target torque for the front axle, reducing the target torque for the rear inner wheel, reducing the target torque for the rear outer wheel, and the degree of reduction of the target torque of the rear inner wheel is less than the degree of reduction of the target torque of the rear outer wheel; When the drive unit is implemented in the second mode, the first target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel, reducing the target torque for the front outer wheel, and reducing the target torque for the rear axle; and When the drive unit is implemented in the third mode, the first target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel, reducing the target torque for the front outer wheel, reducing the target torque for the rear inner wheel, reducing the target torque for the rear outer wheel, and the degree of reduction in the target torque of the rear inner wheel is less than that of the target torque of the rear outer wheel.

7. The drift control unit according to claim 5 or 6, wherein: When the drive unit is implemented in the first mode, the second target torque distribution adjustment scheme includes: reducing the target torque for the front axle, increasing the target torque for the rear inner wheel, and increasing the target torque for the rear outer wheel, and the increase degree of the target torque for the rear inner wheel is less than the increase degree of the target torque for the rear outer wheel; When the drive unit is implemented in the second mode, the second target torque distribution adjustment scheme includes: reducing the target torque for the front inner wheel, increasing the target torque for the front outer wheel, and increasing the target torque for the rear axle; When the drive unit is implemented in the third mode, the second target torque distribution adjustment scheme includes: reducing the target torque for the front inner wheel, increasing the target torque for the front outer wheel, increasing the target torque for the rear inner wheel, increasing the target torque for the rear outer wheel, and the increase degree of the target torque for the rear inner wheel is less than the increase degree of the target torque for the rear outer wheel.

8. The drift control unit according to claim 2, wherein: The torque control comprises: The third target torque distribution adjustment scheme related to the vehicle's driving direction is executed when the following conditions are met: The current drift level is the second drift level; The drift amount tends to increase; The driver's steering operation is: not turning the steering wheel in the direction opposite to the direction the vehicle is turning; and The yaw rate is greater than a predetermined yaw rate upper limit value for a second drift level; and The current target torque distribution is maintained when the following conditions are met: The current drift level is the second drift level; The change trend of the drift amount is decreasing; The driver's steering operation is: not turning the steering wheel in the same direction as the vehicle is turning; and The yaw rate is less than a predetermined yaw rate lower limit value for the second drift level.

9. The drift control unit according to claim 8, wherein: When the drive unit is implemented in the first mode, the third target torque distribution adjustment scheme includes: increasing the target torque for the front axle to a peak value based on the maximum output of the motor, reducing the target torque for the rear inner wheel, and reducing the target torque for the rear outer wheel to 0; When the drive unit is implemented in the second mode, the third target torque distribution adjustment scheme includes: reducing the target torque for the rear axle to 0, reducing the target torque for the front outer wheel, and increasing the target torque for the front inner wheel to a peak value based on the maximum output of the motor; and When the drive unit is implemented in the third mode, the third target torque distribution adjustment scheme includes: increasing the target torque for the front inner wheel to a peak value based on the maximum output of the motor, reducing the target torque for the front outer wheel, reducing the target torque for the rear inner wheel, and reducing the target torque for the rear outer wheel to 0.

10. The drift control unit according to claim 1, wherein: The processing module is also configured to: The correction torque is calculated to compensate for the difference between the actual drift posture of the vehicle and the drift posture that should be achieved according to the target torque distribution adjustment scheme.

11. The drift control unit according to claim 1, wherein: The drift amount is: a parameter related to the lateral motion of the vehicle, or a value calculated based on the parameter related to the lateral motion of the vehicle and capable of characterizing the degree of drift of the vehicle; and The parameters related to the lateral motion of the vehicle include one or more of the following: center of mass slip angle, rear wheel sideslip angle, body sideslip angle, body sideslip angle, yaw rate, yaw acceleration, lateral acceleration, and tire lateral force.

12. The drift control unit according to claim 1, wherein: The drift control unit is arranged in a power system controller of the vehicle, or in a domain controller of the vehicle, or in a traction control system of the vehicle.

13. A drift control system for a vehicle, comprising: A sensing unit, used to collect information related to vehicle drift, including: a drift amount representing the degree of vehicle drift and a steering operation of the driver; A drive unit for providing driving force to the axles or wheels of the vehicle; and The drift control unit according to any one of claims 1 to 12, is used to control the drive unit based on the collected information to perform slip control or torque control.

14. The drift control system of claim 13, wherein: The drive unit is implemented in one of the following three modes: The first mode (1F2R) includes three motors for driving the front axle, one wheel connected to the rear axle, and another wheel connected to the rear axle; The second mode (2F1R) includes three motors for driving the rear axle, one wheel connected to the front axle, and another wheel connected to the front axle; The third mode (2F2R) includes four motors, which are respectively used to drive one wheel connected to the front axle, another wheel connected to the front axle, one wheel connected to the rear axle, and another wheel connected to the rear axle.

15. A drift control method for a vehicle, the method being executed by a drift control unit according to any one of claims 1 to 12 or a drift control system according to claim 13 or 14, the method comprising: Acquire the drift amount representing the degree of vehicle drift and the steering operation of the driver; Determining a current drift level of the vehicle based on the obtained drift amount; Adjusting the target torque distribution for the wheels or axles based on the change trend of the drift amount and the driver's steering operation to perform slip control or torque control corresponding to the current vehicle drift level; as well as outputting an adjusted target torque distribution so that the power system of the vehicle is controlled according to the adjusted target torque distribution, The current drift level is one of a plurality of predetermined drift levels, and the plurality of predetermined drift levels include a starting drift level, a first drift level, a second drift level, and a danger level with gradually increasing drift degrees. 16 . A machine-readable storage medium storing executable instructions, which, when executed, cause one or more processors to perform the drift control method of claim 15 .

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