Braking strategy for electric propulsion vehicles

Abstract

This disclosure relates to braking strategies for electrically propelled vehicles, and more particularly to a computer system comprising: a processing circuit configured to: obtain a target deceleration level of a vehicle, the vehicle including a plurality of motors, each motor operatively connected to at least one wheel of the vehicle; control each of the plurality of motors according to a braking torque distribution scheme to obtain the target deceleration level; after applying braking torque according to the braking torque distribution scheme, determine that a first wheel operable by a first motor of the plurality of motors has reached a predefined wheel slip limit of the first wheel; and in response to the first wheel reaching the predefined wheel slip limit: update the braking torque distribution scheme by increasing the braking torque on at least one second motor operatively connected to at least one second wheel of the vehicle.

Description

Technical Field

[0001] This disclosure generally relates to a system and method for controlling braking operations in a vehicle. In a particular aspect, this disclosure relates to a braking strategy for an electrically propelled vehicle. This disclosure is applicable to heavy vehicles, such as trucks, buses, and construction equipment, as well as other vehicle types. Although this disclosure may be described with respect to a particular vehicle, it is not limited to any particular vehicle. Background Technology

[0002] Vehicle braking systems play a crucial role in ensuring safety and stability under various driving conditions. Technological advancements have introduced systems that can utilize electric motors to improve braking performance and energy efficiency. However, achieving consistent and reliable braking performance can be challenging in certain scenarios, such as when the road surface is slippery or when the vehicle suddenly needs to brake. In such situations, maintaining stability and achieving the required deceleration level is essential to preventing accidents such as collisions, skidding, or loss of control during sharp turns or downhill driving. Summary of the Invention

[0003] According to a first aspect of this disclosure, a computer system is provided, the computer system including processing circuitry configured to: obtain a target deceleration level of a vehicle including a plurality of motors, each motor operatively connected to at least one wheel of the vehicle; control each of the plurality of motors according to a braking torque distribution scheme to obtain the target deceleration level; after applying braking torque according to the braking torque distribution scheme, determine that a first wheel operable by a first motor of the plurality of motors has reached a predefined wheel slip limit of the first wheel; and in response to the first wheel reaching the predefined wheel slip limit: update the braking torque distribution scheme by increasing the braking torque on at least one second motor operatively connected to at least one second wheel of the vehicle. The first aspect of this disclosure seeks to optimize the regeneration of electrical energy during braking while maintaining the desired overall braking performance of the vehicle. Technical advantages may include: the overall braking performance of the vehicle can be obtained even when the first wheel reaches the predefined wheel slip limit. Therefore, the computer system can employ an updated braking torque distribution scheme to effectively redistribute braking torque such that when the first motor is unable to apply its expected braking torque due to the first wheel reaching the predefined wheel slip limit, the second motor can apply increased braking torque. By achieving sufficient braking torque, further technological advantages may include enhanced safety and stability. Further technological advantages may include improved regenerative braking efficiency by redistributing braking torque between motors, reducing reliance on mechanical service brakes, and increasing energy recovery.

[0004] Optionally, in some examples, including at least one preferred example, when the first wheel reaches the predefined wheel slip limit at the first braking torque level of the first motor, the processing circuit is further configured to update the braking torque distribution scheme by maintaining the braking torque of the first motor at the first braking torque level. Technical advantages may include: the first motor operates at its maximum braking performance, thereby facilitating the overall deceleration of the vehicle. Further technical advantages may include: by maintaining the braking torque of the first motor at a predefined safe level, excessive instability or wheel slippage can be prevented, thereby avoiding sudden or unnecessary torque reductions that could jeopardize vehicle deceleration.

[0005] Optionally, in some examples, including at least one preferred example, the processing circuitry is further configured to: after increasing the braking torque on the second motor, determine that the second wheel has reached a predefined wheel slip limit, and in response to the second wheel reaching the predefined wheel slip limit: update the braking torque distribution scheme by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, control the vehicle's service brakes to apply braking torque to achieve the target deceleration level. Technical advantages may include: even if an additional wheel reaches its slip limit, the target deceleration level can be achieved by redistributing torque to other motors or seamlessly transitioning to the service brakes without further regenerative braking.

[0006] Optionally, in some examples, including at least one preferred example, the service brake is operatively coupled to the non-drive wheels of the vehicle. Technical advantages may include improved braking control and stability by utilizing the service brake on the non-drive wheels.

[0007] Optionally, in some examples, including at least one preferred example, the braking torque distribution scheme includes a braking torque application sequence, wherein the braking torque is first applied to the first motor and then to the second motor in response to the first wheel reaching its predefined wheel slip limit. Technical advantages may include achieving a predictable and efficient braking torque application sequence, which can improve system response and ensure stable control as each wheel approaches its slip limit. Furthermore, steering action is not compromised during braking.

[0008] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to determine that the wheel slip level of the second wheel is below a predefined wheel slip limit of the second wheel before updating the braking torque distribution scheme. Technical advantages may include: by ensuring that only wheels below their slip limits receive the increased torque, unnecessary adjustments to the braking torque distribution scheme can be avoided, thus maintaining braking consistency and stability.

[0009] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to monitor the yaw rate of the vehicle and update the braking torque distribution scheme in response to the yaw rate exceeding a predetermined yaw rate threshold. Technical advantages may include: by monitoring and responding to changes in yaw rate, vehicle stability during braking can be improved. This can prevent excessive yaw moment, which could otherwise lead to lateral instability or loss of control.

[0010] Optionally, in some examples, including at least one preferred example, the predefined wheel slip limits for each wheel are dynamically updated in response to road conditions, vehicle speed, and / or wheel load distribution. Technical advantages may include improved braking performance on wet or low-friction surfaces because the processing circuitry dynamically adjusts the wheel slip limits to maintain consistent deceleration. Further technical advantages may include improved adaptability to changing driving conditions by dynamically adjusting the slip limits based on road surface, speed, and wheel load. Therefore, optimal braking performance can be achieved across a wide range of environments.

[0011] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: determine the maximum regenerative braking capability of each of the plurality of motors, and assign the motor with the highest maximum regenerative braking capability as the second motor. Further technical advantages may include: by preferentially selecting a motor with higher regenerative capability, regenerative braking efficiency can be improved, thereby increasing energy recovery. The highest maximum regenerative braking capability may be the lowest level of energy loss the motor experiences under the current braking action.

[0012] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: determine the desired trajectory during braking and assign the motor that enables the vehicle to follow the desired trajectory to the second motor.

[0013] Optionally, in some examples, including at least one preferred example, the processing circuitry is further configured to: determine that all wheels driven by the motors have reached their respective predefined wheel slip limits, and control the braking of the non-drive wheels in conjunction with the applied torque on each of the plurality of motors to apply braking torque to achieve the target deceleration level. Technical advantages may include: maintaining effective braking even when all drive wheels have reached their slip limits. This can be achieved by seamlessly integrating service brakes on the non-drive wheels, thereby ensuring that the target deceleration level is always achieved.

[0014] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to detect a fault in one of the plurality of motors and update the braking torque distribution scheme based on the fault. Technical advantages may include: the braking torque distribution scheme can be adapted to compensate for faults in one or more motors, thereby ensuring uninterrupted braking function.

[0015] Optionally, in some examples, including at least one preferred example, the braking torque distribution scheme is based on at least one of real-time data from multiple wheel slip controllers associated with the respective wheels, the vehicle's lateral acceleration, and a predicted vehicle trajectory. Technical advantages may include: precise torque distribution adjustments can be achieved to maintain stability and control.

[0016] According to the second aspect, a vehicle is provided that includes a computer system comprising any of the examples described above with respect to the first aspect. The effects and features of the second aspect are therefore largely similar to those described with respect to the first aspect.

[0017] According to a third aspect, a computer-implemented method is provided, comprising: obtaining a target deceleration level of a vehicle, the vehicle including a plurality of motors, each operatively connected to at least one wheel of the vehicle, by a processing circuit of a computer system; controlling each of the plurality of motors according to a braking torque distribution scheme to obtain the target deceleration level; after applying braking torque according to the braking torque distribution scheme, determining by the processing circuit that a first wheel operable by a first motor of the plurality of motors has reached a predefined wheel slip limit of the first wheel; and in response to the first wheel reaching the predefined wheel slip limit: updating the braking torque distribution scheme by the processing circuit by increasing the braking torque on at least one second motor operatively connected to at least one second wheel of the vehicle. The third aspect of this disclosure seeks to optimize the regeneration of electrical energy during braking while maintaining the desired overall braking performance of the vehicle. Technical advantages may include: achieving the vehicle's overall braking performance even when the first wheel reaches the predefined wheel slip limit. Therefore, the computer system can employ an updated braking torque distribution scheme to effectively redistribute braking torque, allowing the second motor to apply increased braking torque when the first motor is unable to apply its intended braking torque due to the first wheel reaching a predefined wheel slip limit. Further technical advantages of achieving sufficient braking torque include enhanced safety and stability. Further technical advantages may include improved regenerative braking efficiency, reduced reliance on mechanical service brakes, and increased energy recovery through the redistribution of braking torque between motors.

[0018] Optionally, in some examples, including at least one preferred example, the method further includes: after increasing the braking torque on the second motor, determining by the processing circuit that the second wheel has reached a predefined wheel slip limit; and in response to the second wheel reaching the predefined wheel slip limit: updating the braking torque distribution scheme by the processing circuit by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, controlling the vehicle's service brake to apply braking torque to achieve the target deceleration level. Technical advantages may include: even if an additional wheel reaches its slip limit, the target deceleration level can be achieved by redistributing torque to other motors or seamlessly transitioning to the service brake without further regenerative braking.

[0019] Optionally, in some examples, including at least one preferred example, the method further includes: determining, by the processing circuit, that the wheel slip level of the second wheel is below a predefined wheel slip limit of the second wheel before updating the braking torque distribution scheme. Technical advantages may include: by ensuring that only wheels below their slip limits receive the increased torque, unnecessary adjustments to the braking torque distribution scheme can be avoided, thus maintaining braking consistency and stability.

[0020] Optionally, in some examples, including at least one preferred example, the method further includes: monitoring the yaw rate of the vehicle by the processing circuit; and updating the braking torque distribution scheme by the processing circuit in response to the yaw rate exceeding a predetermined yaw rate threshold. Technical advantages may include: by monitoring and responding to changes in yaw rate, vehicle stability during braking can be improved. This can prevent excessive yaw moment, which could otherwise lead to lateral instability or loss of control.

[0021] Optionally, in some examples, including at least one preferred example, the method further includes: determining the maximum regenerative braking capability of each of the plurality of motors by the processing circuit; and assigning the motor with the highest maximum regenerative braking capability as the second motor by the processing circuit. Further technical advantages may include: by preferentially selecting a motor with higher regenerative capability, regenerative braking efficiency can be improved, thereby increasing energy recovery.

[0022] The other effects and characteristics of the third aspect are largely similar to those described above regarding the first aspect.

[0023] According to a fourth aspect, a computer program product is provided, the computer program product including program code that, when executed by the processing circuitry, performs any of the methods described above with respect to the third aspect.

[0024] According to a fifth aspect, a non-transitory computer-readable storage medium is provided, which, when executed by the processing circuitry, causes the processing circuitry to perform any of the methods described above with respect to the third aspect.

[0025] The effects and characteristics of the fourth and fifth aspects are largely similar to those described above regarding the first and third aspects.

[0026] Those skilled in the art will understand that the disclosed aspects, examples (including any preferred examples), and / or appended claims can be appropriately combined with each other. Additional features and advantages are disclosed in the following description, claims, and drawings, and will be apparent in part to those skilled in the art or recognized by practicing this disclosure as described herein.

[0027] This document also discloses computer systems, control units, code modules, computer-implemented methods, computer-readable media, and computer program products related to the technical advantages discussed above. Attached Figure Description

[0028] The example is described in more detail below with reference to the accompanying drawings.

[0029] Figure 1 This is an exemplary illustration based on the example vehicle.

[0030] Figure 2 This is an exemplary illustration of the drivetrain of an example vehicle.

[0031] Figure 3 This is an exemplary illustration of a braking torque distribution scheme based on an example.

[0032] Figure 4 This is an exemplary illustration based on a flowchart of an example.

[0033] Figure 5 This is a schematic diagram of an exemplary computer system for implementing the examples disclosed herein, based on one example. Detailed Implementation

[0034] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice this disclosure.

[0035] The following disclosure aims to optimize the regeneration of electrical energy during braking while maintaining the vehicle's desired overall braking performance. Technical advantages may include achieving the vehicle's overall braking performance even when the first wheel reaches a predefined wheel slip limit.

[0036] refer to Figure 1 The figure is an exemplary illustration based on the example vehicle 1. Figure 1 The vehicle 1 depicted is preferably a battery electric vehicle, also commonly referred to as a BEV. Alternatively, the vehicle may be a fuel cell electric vehicle, also commonly referred to as a FCEV. In both examples, vehicle 1 includes a plurality of motors 102, 102', 104, 104' operable to propel vehicle 1. Vehicle 1 also includes a traction battery 106 from which power is fed to the plurality of motors 102, 102', 104, 104' during propulsion. The motors 102, 102', 104, 104' are also arranged to generate power during braking, which may be referred to as regenerative braking or reconstitution braking.

[0037] Each of motors 102, 102', 104, and 104' is operatively connected to the corresponding wheel 108 or 110 of vehicle 1. Figure 1 In the example depicted, motors 102, 102', 104, and 104' are arranged as hub motors. Therefore, each motor is connected to the corresponding wheel of vehicle 1. Figure 1 For example, vehicle 1 has a pair of front wheels 108 (also referred to as the first wheels), a pair of rear rear wheels 110 (also referred to as the second wheels), and a pair of front rear wheels 112 (also referred to as the third wheels). Figure 1 In the example depicted, each wheel of the front wheel pair 108 is equipped with a motor 102 (hereinafter referred to as the first motor 102 and the third motor 102'), and each wheel of the rear wheel pair 110 is equipped with a motor 104 (hereinafter referred to as the second motor 104 and the fourth motor 104'). In this example, the wheels of the front rear wheel pair 112 are not equipped with motors. Each wheel of the front rear wheel pair 112 has a service brake 114. Although Figure 1 Although not depicted in the text, service brakes may also be provided for the front wheel 108 and the rear wheel 110.

[0038] Vehicle 1 further includes a computer system 500. The computer system 500 includes processing circuitry 502 configured to operate as described below. The computer system 500 and processing circuitry 502 are operatively connected to motors 102 and 104, and optionally also operatively connected to a service brake 114. Reference will also be made below. Figure 5 The description presents details of computer system 500.

[0039] refer to Figure 2 This is an exemplary illustration based on the drivetrain 200 of an example vehicle 1. Specifically, Figure 2 This is a top view showing details of a drivetrain 200 according to an example. The drivetrain 200 includes the aforementioned plurality of motors 102, 104. Figure 2In the example depicted, a single first motor 102 is connected to the pair of front wheels 108 via a first axle 202. Similarly, a single second motor 104 is connected to the pair of rear wheels 110. Figure 1 Similar examples exist. Figure 2 The exemplary vehicle 1 does not include a motor connected to the pair of front rear wheels 112. The pair of rear rear wheels 112 are connected to a third wheel axle 206.

[0040] During the operation of vehicle 1, especially during braking operations, the processing circuit controls multiple motors 102, 104, and optionally also the service brake 114, according to a braking torque distribution scheme, to achieve a target deceleration level for vehicle 1. (Reference) Figure 3 A braking torque distribution scheme 300 according to an example will be described in more detail. The braking torque distribution scheme 300 is depicted as a braking torque distribution manager arranged separately from the processing circuitry 502, but should also be understood as constituting part of the processing circuitry 502. The target deceleration level can be obtained by the processing circuitry 502 in various ways. For example, the target deceleration level can be obtained by the operator pressing the brake pedal or by the operator releasing the accelerator pedal, or by deceleration command data from the autonomous control propulsion system. The processing circuitry 502 can instruct the first motor 102 to apply a first braking torque on the first wheel, instruct the second motor 104 to apply a braking torque on the second wheel, and optionally also instruct the service brake 114 to apply a braking torque on the third wheel. The braking torque distribution can vary depending on, for example, the load distribution of vehicle 1, whether vehicle 1 is loaded, the tire pressure of each wheel of vehicle 1, etc. Therefore, the braking torque distribution scheme can be changed in response to specific parameters of the vehicle, such as weight, load distribution, tire pressure, etc. In addition, the braking torque distribution scheme can also be based on at least one of real-time data from multiple wheel slip controllers associated with the respective wheels, the vehicle's lateral acceleration, and the predicted vehicle trajectory.

[0041] More specifically, the processing circuit 502 can transmit: first braking torque data 302, instructing the first motor 102 to apply braking torque at a first braking torque level; second braking torque data 304, instructing the second motor 104 to apply braking torque at a second braking torque level; third braking torque data 302', instructing the third motor 102' to apply braking torque at a third braking torque level; and fourth braking torque data 304', instructing the fourth motor 104' to apply braking torque at a fourth braking torque level. As indicated above, the first braking torque data 302 can instruct the first motor 102 to apply only braking torque. In this case, the second braking torque data 304, the third braking torque data 302', and the fourth braking torque data 304' instruct the corresponding motors not to apply torque. Alternatively, and also as indicated above, the first braking torque level, the second braking torque level, the third braking torque level, and the fourth braking torque level can each correspond to a specific proportion of the total braking torque, and these proportions, when added together, can correspond to the desired total braking torque.

[0042] Wheels 108, 110, and 112 of vehicle 1 can be controlled to prevent exceeding predefined wheel slip limits. These predefined wheel slip limits can be the same for all wheels, or they can be set uniquely for each wheel. Wheel slip should be understood as the difference between the ground-based wheel speed and the actual wheel speed. As a non-limiting example, a tire model can be used to convert between maximum braking torque and wheel slip. As stated, wheel slip is related to the difference between wheel speed and ground-based wheel speed. Wheel speed is the rotational speed of the wheel, given in units such as revolutions per minute (rpm), or angular velocity in radians per second (rad / s) or degrees per second (deg / s). Therefore, a wheel subjected to braking torque may reach its wheel slip limit when a certain braking torque level is reached. Each wheel of vehicle 1 can be associated with a corresponding wheel slip controller that sets or determines the predefined wheel slip limit for its corresponding wheel.

[0043] Predefined wheel slip limits can be dynamically updated in response to various wheel-specific parameters or various environmental conditions. Based on some non-limiting examples, wheel slip limits can be dynamically updated in response to road conditions, vehicle speed, and / or wheel load distribution.

[0044] For further reference Figure 4This is an exemplary illustration based on a flowchart of an example. During the operation of vehicle 1, particularly during braking operations of vehicle 1, processing circuit 502 obtains a target deceleration level, S1, i.e., the desired deceleration of the vehicle. The target deceleration can advantageously be expressed as the desired deceleration in meters per square second. Based on a specific braking torque distribution scheme illustrated above, processing circuit 502 controls S2 to control the first motor 102, the second motor 104, the third motor 102', and the fourth motor 104' to apply braking torque. As illustrated above, the first motor 102 can apply braking torque alone, and in this case, processing circuit 502 controls the second motor 104, the third motor 102', and the fourth motor 104' to apply zero braking torque. Alternatively, the first motor 102 can apply, for example, 40% of the total braking torque, the second motor 30%, the third motor 20%, and the fourth motor 10%. The latter ratios should be interpreted as examples provided only for further understanding by experienced readers.

[0045] When the processing circuit 502 controls the motor to apply braking torque according to the braking torque distribution scheme 300, the processing circuit 502 determines whether the first wheel 108 has reached the predefined wheel slip limit in S3. Therefore, the first wheel 108 can reach the predefined wheel slip limit at a torque level lower than the torque level of the braking torque distribution scheme 300 for the first motor 102. For example, in the braking torque distribution scheme 300, the desired torque of the first motor 102 is 2500 Nm, but the first wheel reaches the predefined slip limit at 2000 Nm. If or when the first wheel 108 reaches the predefined wheel slip limit at a braking torque level lower than the expected braking torque of the first motor 102, i.e., when the first wheel 108 reaches the predefined wheel slip limit, the processing circuit 502 updates the braking torque distribution scheme 300 in S4 by increasing the braking torque of one or more of the remaining motors 102', 104, and 104' of the vehicle 1. According to the above non-limiting example, the braking torque of the second motor can be increased by 500 Nm. Clearly, the 500 Nm braking torque can be distributed among the second motor 104, the third motor 102', and the fourth motor 104'. Alternatively or supplementarily, before updating the braking torque distribution scheme, the processing circuit 502 can determine that the wheel slip level of the second wheel is below a predefined wheel slip limit for the second wheel. If the second wheel has reached the predefined wheel slip limit by the braking torque applied by the second motor, the braking torque distribution scheme can be updated by increasing the braking torque of the third motor. The processing circuit 502 can also determine the maximum regenerative braking capacity of each of the multiple motors, i.e., the maximum regenerative braking capacity of each of the second motor 104, the third motor 102', and the fourth motor 104'. If the first wheel reaches the predefined wheel slip limit, the processing circuit 502 can update the braking torque distribution scheme by increasing the braking torque of the motor with the highest maximum braking torque capacity. Therefore, the motor with the highest braking torque capacity is assigned as the second motor, i.e., the next motor to have its torque increased.

[0046] If the first wheel does not reach the predefined wheel slip limit, then the S5 braking torque distribution scheme 300 will obviously be maintained.

[0047] When updating the braking torque distribution scheme 300, the braking torque of the first motor 102 is maintained at a level that allows the first wheel to reach a predefined wheel slip limit. According to the above non-limiting example, if the first wheel reaches the predefined wheel slip limit at a braking torque of 2000 Nm, the updated braking torque distribution scheme sets the braking torque at 2000 Nm to the first motor. The first motor 102 can be defined here as a saturated motor. Saturation refers to a situation where the first motor cannot apply additional torque due to the wheel slip limit.

[0048] If the updated braking torque distribution scheme 300 causes the braking torque of the second motor 104 to cause the second wheel 110 to also reach the predefined wheel slip limit, then the braking torque distribution scheme 300 is updated by increasing the braking torque on the third motor 102' to achieve the target deceleration level. Figure 2 In the example depicted with two motors, the processing circuit 502 updates the braking torque distribution scheme 300 by transmitting service braking torque data 314 to the service brake 114, which instructs the service brake to apply braking torque to achieve a target deceleration level.

[0049] Therefore, the braking torque distribution scheme 300 is preferably updated to preferentially select motors 102, 102', 104, and 104' to apply braking torque, as this optimizes total energy recovery during braking. However, if all wheels operable by the motors reach their respective predefined wheel slip limits, the processing circuit 502 controls the service brakes to apply braking torque to achieve the target deceleration level. Thus, the vehicle speed is reduced by combining the braking torque of the service brakes with the braking torque of the motors. The anti-lock braking system (ABS) can also intervene to prevent wheel lock-up with the service brakes engaged. In this case, the processing circuit 502 can transmit data to the ABS controller 320.

[0050] Furthermore, the processing circuit 502 can also be configured to detect whether one or more of the motors are not operating as expected, i.e., whether a motor malfunctions. If this occurs, the braking torque distribution scheme is updated based on the malfunction. Thus, the operating motor receives a command to increase torque. Additionally, the processing circuit 502 can monitor the vehicle's yaw rate. To avoid excessive yaw, the processing circuit 502 can update the braking torque distribution scheme 300 in response to the yaw rate exceeding a predetermined yaw rate threshold. The predetermined yaw rate threshold can be a dynamic threshold. This dynamic threshold can be based on the current or desired vehicle trajectory. The dynamic threshold can also be derived from the steering wheel angle. Therefore, the updated braking torque distribution scheme 300 can ensure that excessive yaw is prevented.

[0051] Figure 5This is a schematic diagram of a computer system 500 for implementing the examples disclosed herein. The computer system 500 is adapted to execute instructions from a computer-readable medium to perform these and / or any of the functions or processes described herein. The computer system 500 may be connected (e.g., networked) to other machines in a LAN (Local Area Network), LIN (Local Internet Protocol), automotive network communication protocols (e.g., FlexRay), intranet, extranet, or the Internet. Although only a single device is shown, the computer system 500 may include any collection of devices that individually or jointly execute a set of instructions (or more sets of instructions) to perform any one or more of the methods discussed herein. Therefore, any reference in this disclosure and / or claims to computer systems, computing systems, computer devices, computing apparatuses, control systems, control units, electronic control units (ECUs), processor devices, processing circuitry systems, etc., includes references to one or more such devices to individually or jointly execute a set of instructions (or more sets of instructions) to perform any one or more of the methods discussed herein. For example, a control system may include a single control unit or multiple control units connected to or otherwise communicatively coupled to each other, such that any functions performed can be distributed among the control units as needed. Furthermore, such devices can communicate with each other or with other devices through various system architectures, such as directly or via a controller area network (CAN) bus.

[0052] Computer system 500 may include at least one computing device or electronic device capable of including firmware, hardware, and / or executing software instructions to implement the functionality described herein. Computer system 500 may include a processing circuitry system 502 (e.g., a processing circuitry system including one or more processor devices or control units), memory 504, and system bus 506. Computer system 500 may include at least one computing device having processing circuitry system 502. System bus 506 provides interfaces for system components including, but not limited to, memory 504 and processing circuitry system 502. Processing circuitry system 502 may include any number of hardware components for performing data or signal processing or for executing computer code stored in memory 504. Processing circuitry system 502 may, for example, include a general-purpose processor, a special-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), circuitry containing processing components, a set of distributed processing components, a set of distributed computers configured to perform processing, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Processing circuitry system 502 may further include computer-executable code controlling the operation of the programmable device.

[0053] System bus 506 can be any of several types of bus architectures, which can further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and / or a local bus using any of a variety of bus architectures. Memory 504 can be one or more means for storing data and / or computer code to perform or facilitate the methods described herein. Memory 504 may include database components, object code components, script components, or any type of information structure for supporting the various activities described herein. Any distributed or local memory device may be used in conjunction with the systems and methods described herein. Memory 504 may be communicatively connected to processing circuitry system 502 (e.g., via circuitry or any other wired, wireless, or network connection) and may include computer code for performing one or more processes described herein. Memory 504 may include non-volatile memory 508 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.) and volatile memory 510 (e.g., random access memory (RAM)), or any other medium that may be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a computer or other machine having processing circuitry system 502. Basic Input / Output System (BIOS) 512 may be stored in non-volatile memory 508 and may include basic routines that facilitate the transfer of information between elements within computer system 500.

[0054] Computer system 500 may further include or be coupled to a non-transitory computer-readable storage medium, such as storage device 514, which may include, for example, internal or external hard disk drives (HDDs) (e.g., Enhanced Integrated Drive Electronics (EIDE) or Serial Advanced Technology Accessories (SATA)), HDDs for storage (e.g., EIDE or SATA), flash memory, etc. Storage device 514 and other drives associated with computer-readable and computer-usable media can provide non-volatile storage of data, data structures, computer-executable instructions, etc.

[0055] Hard-coded or soft-coded computer code may be provided in the form of one or more modules. Modules may be implemented as software and / or hard-coded in a circuit system to fully or partially implement the functionality described herein. These modules may be stored in a storage device 514 and / or volatile memory 510, which may include an operating system 516 and / or one or more program modules 518. All or part of the examples disclosed herein may be implemented as a computer program 520 stored on a transient or non-transitory computer-usable or computer-readable storage medium (e.g., a single medium or multiple media) such as storage device 514, the computer program including complex programming instructions (e.g., complex computer-readable program code) that cause the processing circuit system 502 to perform the actions described herein. Thus, the computer-readable program code of computer program 520 may include software instructions for implementing the functionality of the examples described herein when executed by the processing circuit system 502. In some examples, storage device 514 may be a computer program product (e.g., a readable storage medium) on which computer program 520 is stored, wherein at least a portion of computer program 520 may be loadable (e.g., loaded into a processor) for implementing the functionality of the examples described herein when executed by processing circuitry system 502. Processing circuitry system 502 may serve as a controller or control system for computer system 500 for implementing the functionality described herein.

[0056] Computer system 500 may include an input device interface 522 configured to receive input and selections to be transmitted to computer system 500, such as from a keyboard, mouse, touch-sensitive surface, etc., when executing instructions. Such input devices may be connected to processing circuitry system 502 via input device interface 522 coupled to system bus 506, but may also be connected via other interfaces, such as parallel ports, IEEE 1394 serial ports, Universal Serial Bus (USB) ports, IR interfaces, etc. Computer system 500 may include an output device interface 524 configured to forward output to, for example, a display, video display unit (e.g., liquid crystal display (LCD) or cathode ray tube (CRT)). Computer system 500 may include a communication interface 526 suitable for communicating with a network, as appropriate or as required.

[0057] Operational actions described in any of the exemplary aspects herein are described to provide examples and discussion. These actions may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform these actions, or may be performed by a combination of hardware and software. Although a particular order of method actions may be shown or described, the order of actions may differ. Furthermore, two or more actions may be performed simultaneously or partially simultaneously.

[0058] Example list

[0059] Example 1. A computer system comprising: a processing circuit configured to: obtain a target deceleration level of a vehicle including a plurality of motors, each motor operatively connected to at least one wheel of the vehicle; control each of the plurality of motors according to a braking torque distribution scheme to obtain the target deceleration level; after applying braking torque according to the braking torque distribution scheme, determine that a first wheel operable by a first motor of the plurality of motors has reached a predefined wheel slip limit of the first wheel; and in response to the first wheel reaching the predefined wheel slip limit: update the braking torque distribution scheme by increasing the braking torque on at least one second motor operatively connected to at least one second wheel of the vehicle.

[0060] Example 2. A computer system as described in Example 1, wherein the first wheel reaches the predefined wheel slip limit at the first braking torque level of the first motor, the processing circuit is further configured to update the braking torque distribution scheme by maintaining the braking torque of the first motor at the first braking torque level.

[0061] Example 3. The computer system as described in any one of Examples 1 or 2, wherein the processing circuitry is further configured to: determine that the second wheel has reached a predefined wheel slip limit after increasing the braking torque on the second motor, and in response to the second wheel reaching the predefined wheel slip limit: update the braking torque distribution scheme by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, control the vehicle's service brakes to apply braking torque to achieve the target deceleration level.

[0062] Example 4. A computer system as described in Example 3, wherein the service brake is operatively coupled to the non-drive wheels of the vehicle.

[0063] Example 5. A computer system as described in any of the preceding examples, wherein the braking torque distribution scheme includes a braking torque application sequence, wherein the braking torque is first applied to the first motor and then applied to the second motor in response to the first wheel reaching the predefined wheel slip limit.

[0064] Example 6. A computer system as described in any of the preceding examples, wherein the processing circuitry is further configured to: determine, before updating the braking torque distribution scheme, that the wheel slip level of the second wheel is below a predefined wheel slip limit of the second wheel.

[0065] Example 7. A computer system as described in any of the preceding examples, wherein the processing circuitry is further configured to: monitor the yaw rate of the vehicle and update the braking torque distribution scheme in response to the yaw rate exceeding a predetermined yaw rate threshold.

[0066] Example 8. A computer system as described in any of the preceding examples, wherein the predefined wheel slip limits for each wheel are dynamically updated in response to road conditions, vehicle speed, and / or wheel load distribution.

[0067] Example 9. A computer system as described in any of the preceding examples, wherein the processing circuitry is further configured to: determine the maximum regenerative braking capability of each of the plurality of motors, and assign the motor having the highest maximum regenerative braking capability as the second motor.

[0068] Example 10. A computer system as described in any of the preceding examples, wherein the processing circuitry is further configured to: determine that all wheels driven by the motors have reached their respective predefined wheel slip limits, and control the braking of the non-driven wheels in conjunction with the applied torque on each of the plurality of motors to apply braking torque to achieve the target deceleration level.

[0069] Example 11. A computer system as described in any of the preceding examples, wherein the processing circuitry is further configured to: detect a fault in one of the plurality of motors and update the braking torque distribution scheme based on the fault.

[0070] Example 12. A computer system as described in any of the preceding examples, wherein the braking torque distribution scheme is based on at least one of real-time data from a plurality of wheel slip controllers associated with the respective wheels, the lateral acceleration of the vehicle, and the predicted vehicle trajectory.

[0071] Example 13. A vehicle comprising a computer system as described in any one of Examples 1 to 12.

[0072] Example 14. A computer-implemented method comprising: obtaining a target deceleration level of a vehicle by a processing circuit of a computer system, the vehicle including a plurality of motors, each motor operatively connected to at least one wheel of the vehicle; controlling each of the plurality of motors by the processing circuit according to a braking torque distribution scheme to obtain the target deceleration level; after applying braking torque according to the braking torque distribution scheme, determining by the processing circuit that a first wheel operable by a first motor of the plurality of motors has reached a predefined wheel slip limit of the first wheel; and in response to the first wheel reaching the predefined wheel slip limit: updating the braking torque distribution scheme by the processing circuit by increasing the braking torque on at least one second motor operatively connected to at least one second wheel of the vehicle.

[0073] Example 15. The method of Example 14, further comprising: after increasing the braking torque on the second motor, determining by the processing circuit that the second wheel has reached a predefined wheel slip limit of the second wheel; and in response to the second wheel reaching the predefined wheel slip limit: updating the braking torque distribution scheme by the processing circuit by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, controlling the service brake of the vehicle to apply braking torque to achieve the target deceleration level.

[0074] Example 16. The method as described in any one of Examples 14 or 15, further comprising: determining by the processing circuit that the wheel slip level of the second wheel is below a predefined wheel slip limit of the second wheel before updating the braking torque distribution scheme.

[0075] Example 17. The method of any one of Examples 14 to 16, further comprising: monitoring the yaw rate of the vehicle by the processing circuit; and updating the braking torque distribution scheme by the processing circuit in response to the yaw rate exceeding a predetermined yaw rate threshold.

[0076] Example 18. The method of any one of Examples 14 to 17, further comprising: determining by the processing circuit the maximum regenerative braking capability of each of the plurality of motors; and assigning by the processing circuit the motor having the highest maximum regenerative braking capability as the second motor.

[0077] Example 19. A computer program product comprising program code for performing, when executed by processing circuitry, a method as described in any one of Examples 14 to 18.

[0078] Example 20. A non-transitory computer-readable storage medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform the method as described in any one of Examples 14 to 18.

[0079] The terminology used herein is for descriptive purposes only and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” are intended to also include the plural forms. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms “comprising” and / or “including”, when used herein, indicate the presence of the stated features, integers, actions, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and / or groups thereof.

[0080] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0081] In this document, relative terms such as “below,” “above,” “upper,” “lower,” “horizontal,” or “vertical” may be used to describe the relationship between one element and another, as illustrated in the figures. It should be understood that these terms, along with those discussed above, are intended to cover different device orientations in addition to those depicted in the figures. It should be understood that when an element is referred to as “connected” or “coupled” to another element, the element may be directly connected or coupled to the other element, or there may be intermediate elements present. In contrast, when an element is referred to as “directly connected” or “directly coupled” to another element, there are no intermediate elements present.

[0082] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that, unless expressly defined herein, terms used herein shall be interpreted as having the same meaning as they have in the context of this specification and the relevant field, and not in an idealized or overly formal sense.

[0083] It should be understood that this disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of this disclosure and the appended claims. Aspects have been disclosed in the drawings and description for illustrative purposes only and not for limiting purposes, and the scope of this disclosure is set forth in the appended claims.

Claims

1. A computer system comprising processing circuitry, the processing circuitry being configured to: To obtain a target deceleration level for a vehicle, the vehicle includes multiple motors, each operatively connected to at least one wheel of the vehicle. Each of the plurality of motors is controlled according to the braking torque distribution scheme to achieve the target deceleration level. After applying braking torque according to the braking torque distribution scheme, it is determined that the first wheel, which can be operated by the first motor among the plurality of motors, has reached a predefined wheel slip limit of the first wheel, and in response to the first wheel reaching the predefined wheel slip limit: The braking torque distribution scheme is updated by increasing the braking torque on at least one second motor operably connected to at least one second wheel of the vehicle.

2. The computer system of claim 1, wherein the first wheel reaches the predefined wheel slip limit at the first braking torque level of the first motor, and the processing circuit is further configured to: The braking torque distribution scheme is updated by maintaining the braking torque of the first motor at the first braking torque level.

3. The computer system as claimed in any one of claims 1 or 2, wherein the processing circuitry is further configured to: After increasing the braking torque on the second motor, it is determined that the second wheel has reached a predefined wheel slip limit, and in response to the second wheel reaching the predefined wheel slip limit: The braking torque distribution scheme is updated by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, the vehicle's service brakes are controlled to apply braking torque to achieve the target deceleration level.

4. The computer system of claim 3, wherein the service brake is operatively coupled to the non-drive wheels of the vehicle.

5. The computer system of any of the preceding claims, wherein the braking torque distribution scheme includes a braking torque application sequence, wherein the braking torque is first applied to the first motor and then applied to the second motor in response to the first wheel reaching the predefined wheel slip limit.

6. The computer system as claimed in any of the preceding claims, wherein the processing circuitry is further configured to: Before updating the braking torque distribution scheme, it is determined that the wheel slip level of the second wheel is lower than the predefined wheel slip limit of the second wheel.

7. The computer system as claimed in any of the preceding claims, wherein the processing circuitry is further configured to: Monitor the yaw rate of the vehicle, and The braking torque distribution scheme is updated in response to the yaw rate exceeding a predetermined yaw rate threshold.

8. The computer system as claimed in any of the preceding claims, wherein the predefined wheel slip limit for each wheel is dynamically updated in response to road conditions, vehicle speed and / or wheel load distribution.

9. The computer system as claimed in any of the preceding claims, wherein the processing circuitry is further configured to: Determine the maximum regenerative braking capacity of each of the plurality of motors, and The motor with the highest maximum regenerative braking capacity is assigned as the second motor.

10. The computer system as claimed in any of the preceding claims, wherein the processing circuitry is further configured to: It is determined that all wheels driven by the motor have reached their respective predefined wheel slip limits, and The braking of the non-drive wheels is controlled by combining the applied torque on each of the plurality of motors to apply braking torque to achieve the target deceleration level.

11. The computer system as claimed in any of the preceding claims, wherein the processing circuitry is further configured to: Detect a fault in one of the plurality of motors, and The braking torque distribution scheme is updated based on the fault.

12. The computer system as claimed in any of the preceding claims, wherein the braking torque distribution scheme is based on at least one of real-time data from a plurality of wheel slip controllers associated with the respective wheels, the lateral acceleration of the vehicle, and the predicted vehicle trajectory.

13. A vehicle comprising a computer system as claimed in any one of claims 1 to 12.

14. A computer-implemented method, comprising: The target deceleration level of the vehicle is obtained by the processing circuitry of a computer system. The vehicle includes multiple motors, each operatively connected to at least one wheel of the vehicle. The processing circuit controls each of the plurality of motors according to a braking torque distribution scheme to achieve the target deceleration level; After applying braking torque according to the braking torque distribution scheme, the processing circuit determines that the first wheel, which can be operated by the first motor among the plurality of motors, has reached the predefined wheel slip limit of the first wheel. And in response to the first wheel reaching the predefined wheel slip limit: The braking torque distribution scheme is updated by the processing circuit by increasing the braking torque on at least one second motor operably connected to at least one second wheel of the vehicle.

15. The method of claim 14, further comprising: After increasing the braking torque on the second motor, the processing circuit determines that the second wheel has reached the predefined wheel slip limit of the second wheel; And in response to the second wheel reaching the predefined wheel slip limit: The processing circuit updates the braking torque distribution scheme by increasing the braking torque on a third motor operably connected to at least one third wheel of the vehicle, or, in the absence of a third motor, controls the vehicle's service brakes to apply braking torque to achieve the target deceleration level.

16. The method of any one of claims 14 or 15, further comprising: Before updating the braking torque distribution scheme, the processing circuit determines that the wheel slip level of the second wheel is lower than the predefined wheel slip limit of the second wheel.

17. The method of any one of claims 14 to 16, further comprising: The yaw rate of the vehicle is monitored by the processing circuit. as well as The braking torque distribution scheme is updated by the processing circuit in response to the yaw rate exceeding a predetermined yaw rate threshold.

18. The method of any one of claims 14 to 17, further comprising: The processing circuit determines the maximum regenerative braking capability of each of the plurality of motors; as well as The processing circuit assigns the motor with the highest maximum regenerative braking capability as the second motor.

19. A computer program product comprising program code that, when executed by processing circuitry, performs the method as described in any one of claims 14 to 18.

20. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing circuitry system, cause the processing circuitry system to perform the method as described in any one of claims 14 to 18.

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