Vehicle stability control platform and actuation architecture

Abstract

A vehicle stability control platform for a vehicle including a drivetrain having a differential that distributes driving torque to left and right outputs is disclosed. The platform manages operational states of the differential outputs according to a vehicle driving condition, wherein at least one output is selectively assigned to a torque transmission state, a power interruption state, or a braking intervention state. The platform includes a disconnect control unit configured to selectively interrupt torque transmission of a differential output, a braking control unit configured to selectively apply a braking resistance to the same output, and an actuation architecture configured to operate the disconnect control unit and the braking control unit in a coordinated or sequential manner. By managing the operational states, a rotational behavior of an opposite output of the same differential is indirectly controlled based on a mechanical operating characteristic of the differential thereof.

Description

[0001] 1) DESCRIPTION

[0002] Title of the Invention

[0003] Vehicle Stability Control Platform and Actuation Architecture

[0004] Technical Field

[0005] The present disclosure relates to a vehicle stability control platform for managing drivetrain behavior of a vehicle.

[0006] More particularly, the disclosure relates to a platform configured to manage operational states of left and right outputs of a differential, wherein each output is selectively assigned to a torque transmission state, a power interruption state, or a braking intervention state according to a vehicle driving condition, thereby improving vehicle stability and cornering performance.

[0007] The disclosure further relates to actuation architectures capable of implementing said operational states at a differential output level.

[0008] Background Art

[0009] In four-wheel-drive (4WD) or all-wheel-drive (AWD) vehicles, a differential positioned in an axle distributes input torque to left and right outputs and is essential for absorbing rotational radius differences between wheels during steering. However, under low-speed and large steering angle conditions, such as U-turns, a tight corner braking phenomenon may occur. In addition, when wheel slip occurs at one wheel, a mechanical operating characteristic of the differential may cause driving force to be biased toward an output side with lower resistance, resulting in insufficient driving force being delivered to the opposite output of the same differential.

[0010] Conventional torque vectoring technologies typically rely on direct wheel braking using a vehicle braking system. In low-speed driving or in situations requiring recovery of driving force, such wheel-based braking approaches may suffer from reduced control efficiency. Furthermore, limited-slip devices applied to certainvehicles may not sufficiently resolve output interference issues occurring under steering conditions.

[0011] Accordingly, there is a demand for a vehicle-level control concept capable of managing differential output behavior beyond conventional wheel-based braking approaches.

[0012] As used herein, the term "torque vectoring" includes:

[0013] (i) conventional wheel (tire) direct braking-based methods; and

[0014] (ii) output-side braking-based methods in which braking torque or resistance is applied to a differential output, thereby controlling a rotational speed or driving state of an opposite output of the same differential according to a mechanical operating characteristic of the differential.

[0015] 2) SUMMARY OF THE INVENTION

[0016] Problem to be Solved

[0017] The present disclosure provides a vehicle stability control platform capable of managing differential output behavior under various driving conditions, including tight corner braking and wheel slip, without relying solely on direct wheel braking.

[0018] Solution

[0019] To achieve the above objective, the disclosure provides a vehicle stability control platform for a vehicle including a drivetrain having a differential that distributes driving torque to left and right outputs through an axle.

[0020] The platform is configured to manage operational states of the left and right outputs of the differential such that, according to a vehicle driving condition, at least one of the left and right outputs is selectively assigned to an operational state selected from:

[0021] (a) a torque transmission state in which driving torque is transmitted to acorresponding wheel;

[0022] (b) a power interruption state in which torque transmission to the corresponding wheel is interrupted; and

[0023] (c) a braking intervention state in which a braking resistance is applied to the corresponding output.

[0024] By selectively managing said operational states, a rotational behavior of an opposite output of the same differential is indirectly controlled based on a mechanical operating characteristic of the differential.

[0025] 3) ADVANTAGEOUS EFFECTS

[0026] According to the present disclosure, differential output behavior is managed at a drivetrain system level, thereby reducing output interference during tight corner braking and improving vehicle stability.

[0027] Further, by applying braking intervention at a differential output side rather than directly braking wheels, degradation of torque vectoring performance at low vehicle speeds can be mitigated.

[0028] In addition, when wheel slip occurs, driving force loss to a slipping wheel can be prevented by managing an operational state of a corresponding differential output, thereby improving driving force delivery to a non-slipping wheel even without an additional limited-slip device.

[0029] System Composition (HW / SW Hybrid Platform)

[0030] In the present disclosure, the vehicle stability control platform comprises a combination of hardware components and software -based control logic.

[0031] The hardware components may include at least one electronic control unit, actuators, hydraulic control units, and sensors, while the software-based control logic is configured to determine vehicle driving conditions and to manage transitions between operational states of differential outputs based on sensor inputs.

[0032] This hybrid configuration enables system-level coordination between front and reardifferentials as well as left and right output actuators under various vehicle dynamics scenarios.

[0033] The software-based control logic may be stored as executable instructions in a non-transitory computer-readable medium and executed by the electronic control unit.

[0034] 4) BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 is an overall configuration illustrating an axle including a differential and an apparatus implementing the platform, with an actuator mounted thereto.

[0036] FIG. 2 illustrates a coupled state of a dog clutch set of a disconnect control unit. FIG. 3 illustrates a separated state of the dog clutch set, showing interruption of power transmission of one differential output.

[0037] FIG. 4 is an exploded view of one side of an actuator.

[0038] FIG. 5 is a cross-sectional view of an actuator corresponding to one of the left / right differential outputs; actuators for left and right outputs are independently controlled by separate ports.

[0039] FIG. 6 illustrates an example wheel slip condition in which torque escapes through a slipping wheel.

[0040] FIG. 7 illustrates a state where the outer piston presses a pressure plate to actuate a multi-disc brake set after the dog clutch is disconnected, thereby changing the opposite output speed according to differential gear behavior.

[0041] FIG. 8 illustrates an Ackermann steering geometry example.

[0042] FIG. 9 illustrates an installation relationship among the differential, multi-disc brake set, coupling, actuator, and HECU.

[0043] FIG. 10 is a perspective view of an external appearance of the actuator.

[0044] FIG. 11 is an exploded view illustrating the dog clutch set, multi-disc brake set, andcoupling.

[0045] 5) DETAILED DESCRIPTION

[0046] In the present disclosure, power interruption and braking torque application are treated as operational states of a drivetrain managed by the vehicle stability control platform, rather than as isolated actuator functions.

[0047] Because left and right outputs of a differential are mechanically linked through internal gears, when braking resistance is applied to one output, the opposite output automatically changes its rotational speed or driving state according to the mechanical operating characteristic of the differential.

[0048] In one embodiment, when a vehicle enters a tight corner braking condition, the platform assigns a power interruption state to a differential output corresponding to an inner wheel. Thereafter, a braking intervention state is assigned to the same output such that the opposite output of the same differential is controlled to rotate at a speed corresponding to a turning radius.

[0049] In another embodiment, when wheel slip occurs, the platform assigns a power interruption state to a differential output associated with a slipping wheel, thereby preventing driving force from being lost to the slip side. Thereafter, a braking intervention state is assigned to the same output so that driving force is delivered to the opposite output of the same differential.

[0050] Implementation Example

[0051] In one implementation example, the operational states are implemented using an actuation architecture including a disconnect control unit and a braking control unit. The disconnect control unit may include a dog clutch coupled to a differential output.

[0052] The braking control unit may include a multi-disc brake set configured to apply braking resistance to the same output.

[0053] An inner piston and an outer piston may be arranged within a single actuatorhousing and hydraulically separated by a partition structure, such as a center cone, to selectively implement said operational states without hydraulic interference. The disconnect control unit and the braking control unit may be operated in a mutually exclusive manner such that actuation of one prevents simultaneous actuation of the other.

[0054] Alternative Implementations (Hydraulic / Electric Actuation)

[0055] While the foregoing embodiments illustrate a hydraulic actuation system using a multi-disc brake and piston units, the present disclosure is not limited thereto. In alternative embodiments, the braking resistance may be implemented using an electrically actuated braking device, an electromagnetic resistance mechanism, or a motor-driven friction unit configured to apply controllable resistance to a differential output.

[0056] Such variations enable the platform to be integrated into next-generation e-Axle and electronic torque vectoring systems for electric or hybrid vehicles.

[0057] Re-engagement Control

[0058] Re-engagement after power interruption may be performed through a synchronization process.

[0059] A reference speed may be set as a rotational speed of an opposite output of the same differential or an output belonging to a same axle group.

[0060] Braking resistance may be controlled to reduce a speed difference below a threshold, after which the interrupted output is reassigned to the torque transmission state.

[0061] Vehicle State Determination

[0062] Vehicle driving conditions may be determined based on vehicle state information received from at least one of wheel speed sensors, a steering angle sensor, and a yaw rate sensor.

[0063] Based on the determined driving condition, the platform manages transitions between operational states.) List of Reference Numerals

[0064] • 10A: differential

[0065] • 10: front differential

[0066] • 20: rear differential

[0067] • 30: front-left control unit

[0068] • 40: front-right control unit

[0069] • 50: rear-left control unit

[0070] • 60: rear-right control unit

[0071] • 70: transfer case

[0072] • 80: propeller shaft

[0073] • 500: differential ring gear

[0074] • 500e: differential pinion gear

[0075] • 510: differential side gear coupling

[0076] • 600: disconnect control port

[0077] • 600L: disconnect control port (left actuator)

[0078] • 600R: disconnect control port (right actuator)

[0079] • 610: inner piston

[0080] • 612: disconnect control lever

[0081] • 614: inner shaft

[0082] • 618: disconnect fork

[0083] • 620: dog clutch set (622 + 624)

[0084] • 622: dog A

[0085] • 624: dog B

[0086] • 700: torque vectoring control port

[0087] • 700L: torque vectoring control port (left actuator)• 700R: torque vectoring control port (right actuator) • 710: outer piston

[0088] • 720: torque vectoring control lever

[0089] • 730: outer shaft

[0090] • 740: torque vectoring control fork

[0091] • 750: pressure plate

[0092] • 760: multi-brake set (762 + 764)

[0093] • 762: first brake disc

[0094] • 764: second brake disc

[0095] • 770: multi-brake housing

[0096] • 780: coupling

[0097] • 800: actuator

[0098] • 810: center cone (central partition member)

[0099] • 820: cover

[0100] • 830: housing

[0101] • 840: HECU (Hydraulic Electronic Control Unit)

[0102] • 850: first packing

[0103] • 860: second packing

[0104] • 870: third packing

[0105] • 900: axle

[0106] • A1: first hydraulic space

[0107] • A2: second hydraulic space

[0108] • a: steering angle

[0109] • b: steering angle on inner turning radius

[0110] • O: center of rotation (low-speed condition)• O': center of rotation (high-speed condition)

[0111] • Description of single-side actuator configuration: use of ports 600 and 700 • Independent left / right application: use of ports 600L / 600R and 700L / 700R

Claims

AMENDED CLAIMSreceived by the International Bureau on 16 May 2026 (16.05.2026)

1. [Amended] A differential-output actuation apparatus for a vehicle drivetrain including a differential configured to distribute driving torque to left and right differential outputs, the apparatus being configured to be coupled to one of the differential outputs, the apparatus comprising:a dog clutch set configured to selectively connect and disconnect the differential output from torque transmission;a multi-disc brake set configured to selectively apply braking resistance to the same differential output;an actuator housing;an inner piston arranged in the actuator housing and operatively connected to the dog clutch set;an outer piston arranged in the actuator housing and operatively connected to a pressure plate of the multi-disc brake set;a central partition member arranged in the actuator housing and configured to hydraulically separate a first hydraulic space for actuating the inner piston from a second hydraulic space for actuating the outer piston;a disconnect control port communicating with the first hydraulic space; anda torque- vectoring control port communicating with the second hydraulic space,wherein the apparatus is configured to selectively implement, at the same differential output, a power interruption state by actuating the dog clutch set and a braking intervention state by actuating the multidisc brake set, without hydraulic interference between actuation of the inner piston and actuation of the outer piston.

2. [Amended] The differential-output actuation apparatus according to claim 1, wherein the central partition member comprises a center cone disposed between the inner piston and the outer piston.

3. [Amended] The differential-output actuation apparatus according to claim 1, wherein the first hydraulic space and the second hydraulic space are formed within the actuator housing and are isolated from each other by the central partition member.

4. [Amended] The differential-output actuation apparatus according to claim 1, wherein the dog clutch set comprises a first dog member and a second dog member configured to be selectively coupled and separated.

5. [Amended] The differential-output actuation apparatus according to claim 1, wherein the inner piston is operatively connected to the dog clutch set through a disconnect control lever, an inner shaft, and a disconnect fork.

6. [Amended] The differential-output actuation apparatus according to claim 1, wherein the outer piston is operatively connected to the pressure plate through a torque- vectoring control lever, an outer shaft, and a torque- vectoring control fork.

7. [Amended] The differential-output actuation apparatus according to claim 1, wherein the multi-disc brake set comprises a first brake disc and a second brake disc configured to generate braking resistance when pressed by the pressure plate.

8. [Amended] The differential-output actuation apparatus according to claim 1, wherein the dog clutch set and the multi-disc brake set are arranged as an integrated output-side module for the same differential output.

9. [Added] The differential-output actuation apparatus according to claim 1, wherein actuation of the dog clutch set and actuation of the multidisc brake set are controlled in a mutually exclusive manner such that actuation of one prevents simultaneous actuation of the other.

10. [Added] The differential-output actuation apparatus according to claim 1, wherein the apparatus is configured to actuate the multi-disc brake set after torque transmission through the same differential output has been interrupted by the dog clutch set.

11. [Added] The differential-output actuation apparatus according to claim 1, wherein the braking resistance applied to the differential output changes a rotational behavior of an opposite output of the same differential according to a mechanical operating characteristic of the differential.

12. [Added] The differential-output actuation apparatus according to claim 1, wherein the apparatus is one of a left- side actuator and a right-side actuator, and wherein the left-side actuator and the right-side actuator are configured to be independently controlled by separate disconnect control ports and separate torque- vectoring control ports.

13. [Added] The differential-output actuation apparatus according to claim 1, wherein the apparatus is configured to reduce a rotational speed difference between a disconnected differential output and a reference output before the disconnected differential output is reconnected by the dog clutch set.

14. [Added] A vehicle drivetrain control system comprising:a differential configured to distribute driving torque to a left differential output and a right differential output;a left differential-output actuation apparatus coupled to the left differential output;a right differential-output actuation apparatus coupled to the right differential output; anda hydraulic electronic control unit configured to independently control the left differential-output actuation apparatus and the right differentialoutput actuation apparatus,wherein each of the left and right differential-output actuation apparatuses comprises:a dog clutch set configured to selectively interrupt torque transmission through a corresponding differential output;a multi-disc brake set configured to selectively apply braking resistance to the corresponding differential output;an inner piston configured to actuate the dog clutch set;an outer piston configured to actuate the multi-disc brake set;a center cone configured to hydraulically separate a first hydraulic space for the inner piston from a second hydraulic space for the outer piston;a disconnect control port connected to the first hydraulic space; and a torque- vectoring control port connected to the second hydraulic space.

15. [Added] The vehicle drivetrain control system according to claim 14, wherein the hydraulic electronic control unit is configured to independently control the disconnect control ports of the left and right differential-output actuation apparatuses.

16. [Added] The vehicle drivetrain control system according to claim 14, wherein the hydraulic electronic control unit is configured to independently control the torque- vectoring control ports of the left and right differential-output actuation apparatuses.

17. [Added] The vehicle drivetrain control system according to claim 14, wherein the system is applied to at least one of a front differential and a rear differential of a four-wheel-drive vehicle.

18. [Added] A method of controlling a differential output of a vehicle drivetrain including a differential, the method comprising: providing an actuation apparatus coupled to one differential output of the differential, the actuation apparatus including a dog clutch set, a multi-disc brake set, an inner piston, an outer piston, an actuator housing, a central partition member separating a first hydraulic space from a second hydraulic space, a disconnect control port communicating with the first hydraulic space, and a torque- vectoring control port communicating with the second hydraulic space; detecting a vehicle driving condition based on vehicle state information;supplying hydraulic pressure to the disconnect control port to move the inner piston and actuate the dog clutch set, thereby interrupting torque transmission through the one differential output; andsupplying hydraulic pressure to the torque-vectoring control port to move the outer piston and press a pressure plate of the multi-disc brake set, thereby applying braking resistance to the same differential output.

19. [Added] The method according to claim 18, wherein the vehicle driving condition includes at least one of a wheel slip condition, a tight corner braking condition, a low- speed steering condition, and a high yaw-rate condition.

20. [Added] The method according to claim 18, further comprising reducing a rotational speed difference between the one differential output and a reference output before reconnecting the dog clutch set, wherein the reference output is an opposite output of the same differential or an output belonging to a same axle group.STATEMENT UNDER ARTICLE 19 (1)The claims have been amended to more particularly define the actuation architecture disclosed in the application as filed.The originally filed claims were directed to a vehicle stability control platform for managing operational states of left and right outputs of a differential. The amended claims are now directed primarily to a differential-output actuation apparatus including a dog clutch set, a multi-disc brake set, an actuator housing, an inner piston, an outer piston, a central partition member, first and second hydraulic spaces, a disconnect control port, and a torque-vectoring control port.The amended independent apparatus claim defines a specific integrated output-side module in which a power interruption state and a braking intervention state are selectively implemented at the same differential output. The hydraulic spaces for actuating the inner and outer pistons are separated by a central partition member, such as a center cone, thereby allowing the disconnect function and the braking intervention function to be implemented without hydraulic interference. The amended claims also include a vehicle drivetrain control system having left and right differential-output actuation apparatuses independently controlled by a hydraulic electronic control unit, and a method of controlling a differential output using the disclosed actuation apparatus.The amendments are based on the description and drawings as originally filed, including the disclosed dog clutch set, multi-disc brake set, inner and outer pistons, actuator housing, center cone, first and second hydraulic spaces, disconnect control ports, torque-vectoring control ports, and left / right independent control port arrangement. No new matter is introduced by these amendments.

Images