Angle module with active torsion bar spring and method for controlling torsion bar spring

Abstract

The invention relates to the technical field of vehicles, in particular to an angle module with an active torsion bar spring and a control method of the torsion bar spring, the angle module comprises a wheel assembly, a steering knuckle, a steering mechanism, a lower control arm and a torsion bar spring mechanism, and the steering mechanism is connected with the wheel assembly through the steering knuckle; the lower control arm comprises a lower control arm body, a first connecting part, a second connecting part and a third connecting part, the torsion rod spring mechanism comprises a driving device and a torsion rod spring, the torsion rod spring penetrates through the second connecting part and the third connecting part, one end of the torsion rod spring is in spline fit with the second connecting part, and the other end of the torsion rod spring is connected with the driving device; the driving device is used for being connected with a frame so as to drive the torsion rod spring to rotate. The torsion bar spring mechanism has the advantages that through the driving motor of the torsion bar spring mechanism, the torsion moment of the torsion bar spring can be adjusted in real time, the wheel posture can be actively adjusted, vehicle heeling and pitching are effectively restrained, and the vehicle handling stability and riding comfort are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to an angle module with an active torsion bar spring and a control method for the torsion bar spring. Background Technology

[0002] Torsion bar spring suspensions are widely used in the suspension systems of various vehicles due to their simple structure, high reliability, and low cost. Traditional torsion bar spring suspensions are passive structures, with a fixed torsional stiffness of the torsion bar spring. They can only absorb road impacts and suppress changes in vehicle posture by relying on their own elastic deformation. They cannot actively adjust the wheel posture according to driving conditions such as steering, braking, and bumpy roads, resulting in limitations in vehicle driving stability and comfort.

[0003] Meanwhile, traditional torsion bar springs are often connected to the lower control arm via direct end hinges or bracket connections. This results in the torsion bar spring occupying a significant amount of longitudinal space in the vehicle body, limiting the span design of the lower control arm. This not only reduces the overall layout flexibility of the suspension system but also makes it prone to interference with other vehicle components, restricting the integrated design of the vehicle chassis. Furthermore, if the connection between the existing torsion bar spring and the lower control arm is poorly designed, it is prone to wear and loosening, which in turn affects the service life of the suspension system and vehicle driving safety.

[0004] With the development of vehicle intelligence and chassis integration, users have placed higher demands on vehicle driving stability, comfort, and space utilization. Existing passive torsion bar spring suspensions are no longer suitable for complex and changing driving conditions, and their structural layout and connection reliability defects also restrict further improvement in chassis performance. Summary of the Invention

[0005] Based on this, the present invention aims to provide an angle module with an active torsion bar spring and a torsion bar spring control method. By setting a torsion bar spring mechanism, active control of the torsion bar spring and active adjustment of wheel posture are realized, thereby optimizing the suspension space layout. At the same time, a spline connection is used to achieve a reliable connection between the torsion bar spring and the second connection part, thereby improving connection reliability and service life.

[0006] To achieve the above objectives, the technical solution of this invention is implemented as follows: an angle module with an active torsion bar spring, comprising: a wheel assembly; a steering knuckle connected to the wheel assembly; the steering knuckle including an upper mounting base and a lower mounting base; a steering mechanism, the output end of which is connected to the upper mounting base to drive the steering knuckle to turn, thereby causing the wheel assembly to rotate; a lower control arm, the lower control arm including a lower control arm body, a first connecting portion, a second connecting portion, and a third connecting portion. The first connecting portion is disposed at the end of the lower control arm body near the steering knuckle and is used for hinged to the lower mounting base; the second connecting portion and the third connecting portion are spaced apart at the end of the lower control arm body away from the steering knuckle; a torsion bar spring mechanism, the torsion bar spring mechanism including a drive device and a torsion bar spring, the torsion bar spring passing through the second connecting portion and the third connecting portion, one end of the torsion bar spring forming a torque transmission connection with the second connecting portion, and the other end of the torsion bar spring being connected to the drive device, the drive device being connected to the vehicle frame to drive the torsion bar spring to rotate.

[0007] Furthermore, the torsion bar spring is arranged longitudinally along the vehicle, and the torsion bar spring is rotatably engaged with the third connecting part; one end of the torsion bar spring is provided with a spline, and the second connecting part is provided with a spline hole that matches the spline, and the spline and the spline hole are engaged and connected.

[0008] Furthermore, the relationship between the diameter, length, and torsional stiffness of the torsion bar spring is as follows:

[0009] ;

[0010] ;

[0011] Where d represents the diameter of the torsion bar spring, k_t represents the torsional stiffness of the torsion bar spring, Lt represents the effective working length of the torsion bar spring, G represents the shear modulus of the torsion bar spring material, k represents the vertical stiffness of the single wheel, L represents the effective lever arm of the lower control arm, and α represents the angle between the rotation plane of the lower control arm and the horizontal plane.

[0012] Furthermore, the steering mechanism includes a steering motor, a first reducer, and an adapter. The output end of the steering motor is connected to the input end of the first reducer, the output end of the first reducer is rotatably connected to the upper mounting base, and the adapter is connected to the side of the reducer near its output end.

[0013] Furthermore, it also includes an upper control arm and a shock absorption mechanism. One end of the upper control arm is hinged to the adapter, and the other end of the upper control arm is connected to the vehicle frame. One end of the shock absorption mechanism is connected to the lower control arm, and the other end of the shock absorption mechanism is connected to the vehicle frame.

[0014] A control method for an active torsion bar spring, applied to a vehicle including four of the aforementioned corner modules, includes the following steps:

[0015] S1: Collect vehicle operating status signals.

[0016] S2: Determine whether to enter active control mode based on preset active control intervention conditions.

[0017] S3: When the intervention conditions are met and the active control mode is entered, the vehicle state is estimated and it is determined whether the vehicle is in a combined roll-pitch condition or a single condition.

[0018] S4: When the condition is determined to be a single working condition, single attitude control is executed; when the condition is determined to be a combined working condition, roll-pitch joint control is executed to generate anti-roll target torque and anti-pitch target torque, and torque is distributed to the drive devices of the four corner modules.

[0019] S5: Perform constraint processing on the allocated target torque and output control commands to the drive motors of each corner module.

[0020] Furthermore, the preset active control intervention conditions are: the vehicle speed is greater than or equal to the vehicle speed intervention threshold, and the absolute value of at least one of the steering angle, braking input, roll angle, and pitch angle is greater than or equal to their respective preset thresholds; the judgment conditions for the roll-pitch composite condition are: the absolute value of the vehicle's lateral acceleration is greater than or equal to the vehicle's lateral acceleration threshold, and the absolute value of at least one of the vehicle's longitudinal acceleration, vehicle roll rate, and vehicle pitch rate is greater than or equal to their respective thresholds.

[0021] Furthermore, in step S4, the single attitude control includes anti-roll control and anti-pitch control; anti-roll control calculates the anti-roll target torque based on the roll angle, roll angular velocity and lateral acceleration, and distributes the anti-roll target torque to the drive motors of each corner module according to the distribution coefficient; anti-pitch control calculates the anti-pitch target torque based on the pitch angle, pitch angular velocity and longitudinal acceleration, and distributes the anti-pitch target torque to the drive motors of each corner module according to the distribution coefficient.

[0022] Furthermore, the combined roll-pitch control in step S4 includes:

[0023] Simultaneously generate anti-roll target moment and anti-pitch target moment;

[0024] Obtain the reference pre-torque of the drive motor of each corner module;

[0025] The anti-roll target torque and anti-pitch target torque are distributed to the execution units of the four corner modules (left front, right front, left rear, and right rear) according to the coupling distribution relationship. Combined with the reference pre-torque torque corresponding to each corner module, the target control torque of the drive device of each corner module is obtained.

[0026] Furthermore, in step S5, the constraint processing includes at least one of the following:

[0027] Torque limiting: Limits the target torque of each corner module to between the preset minimum torque and maximum torque;

[0028] Torque change rate limiting: Limits the torque change rate of each corner module at adjacent time points to a preset change rate range;

[0029] Pre-torsion angle limiting: Limits the rotation angle of the torsion bar spring in each corner module to between the preset minimum and maximum rotation angles.

[0030] Compared with existing technologies, inventions and creations can achieve the following beneficial effects:

[0031] 1) The wheel assembly, steering knuckle, upper and lower control arms, torsion bar spring mechanism, and braking unit are integrated into one unit, achieving a compact layout of chassis components, reducing space occupation, and adapting to new architectures such as drive-by-wire chassis and hub motors. Through the drive motor of the torsion bar spring mechanism, the torsional torque of the torsion bar spring can be adjusted in real time, actively adjusting the wheel attitude, effectively suppressing vehicle roll and pitch, and significantly improving vehicle handling stability and ride comfort. A spline connection is used to achieve torque transmission between the torsion bar and the drive motor, resulting in high transmission efficiency and small backlash, ensuring accurate and timely control response. Bushing and sealing sleeve designs effectively reduce wear, isolate dust and impurities, extend the service life of the mechanism, and improve system reliability.

[0032] 2) By employing vehicle speed thresholds and multi-condition triggering mechanisms, control is ensured to activate only when there is a risk of instability, balancing energy efficiency and smoothness. Single and compound operating conditions are precisely distinguished based on lateral acceleration, longitudinal acceleration, and attitude angular velocity to avoid insufficient control under complex conditions. Torque is calculated independently under single operating conditions, resulting in simple logic and convenient debugging. Under compound operating conditions, torque is jointly generated and coupled for distribution, simultaneously suppressing roll and pitch to address the complexity of multi-attitude coupling. A reference pre-torque torque is introduced to eliminate control idle travel, improving response speed and accuracy. Target torque is distributed by using left-right wheel torque difference to resist roll and front-rear wheel torque difference on the same side to resist pitch. Combining torque limiting, rate of change limiting, and angle limiting three layers of execution constraints ensures that control commands remain within physically feasible limits, effectively improving system safety and durability. Attached Figure Description

[0033] The accompanying drawings, which form part of the invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0034] Figure 1This is a schematic diagram of the structure of an angle module with an active torsion bar spring according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the steering knuckle provided according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of the lower control arm provided according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the structure of a torsion bar spring mechanism provided according to an embodiment of the present invention;

[0038] Figure 5 This is a flowchart illustrating the control method for an active torsion bar spring according to an embodiment of the present invention.

[0039] The reference numerals in the accompanying drawings include: 1. Wheel assembly; 2. Steering knuckle; 21. Steering knuckle body; 22. Lower mounting base; 23. Upper mounting base; 3. Steering mechanism; 4. Upper control arm; 5. Lower control arm; 51. Lower control arm body; 52. First connecting part; 53. Second connecting part; 531. Spline hole; 54. Third connecting part; 6. Torsion bar spring mechanism; 61. Drive unit; 62. Torsion bar spring; 621. Spline; 7. Shock absorption mechanism; 8. Braking unit. Detailed Implementation

[0040] To make the purpose, technical solution, and advantages of the invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and do not constitute a limitation on the invention.

[0041] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of the invention can be combined with each other.

[0042] In the description of an invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature specified with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of an invention, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the invention based on the specific circumstances.

[0044] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] like Figures 1 to 4 As shown in the figure, an embodiment of the present invention provides an angle module with an active torsion bar spring, including: a wheel assembly 1, a steering knuckle 2, a steering mechanism 3, an upper control arm 4, a lower control arm 5, a torsion bar spring mechanism 6, a shock absorption mechanism 7, and a braking unit 8.

[0046] Wheel assembly 1 includes a wheel and a hub motor, the hub motor being disposed within the wheel. Steering knuckle 2 is connected to the hub motor. In some embodiments, wheel assembly 1 includes a wheel and a hub bearing, the steering knuckle 2 being connected to the hub bearing.

[0047] The steering knuckle 2 includes a steering knuckle body 21, a lower mounting base 22, and an upper mounting base 23. The upper mounting base 23 extends from the upper part of the steering knuckle body 21 toward the side away from the wheel, and the upper mounting base 23 is provided with a shaft hole for connection with the steering mechanism 3.

[0048] The lower mounting base 22 includes a first extension and a second extension. The first extension is connected to one side of the steering knuckle body 21 through the second extension, and the first extension extends toward the center of the steering knuckle body 21, making the outer contour of the lower mounting base 22 L-shaped. The first extension is located below the steering knuckle body 21, and the upper mounting base 23 and the lower mounting base 22 are spatially intersecting.

[0049] The steering knuckle body 21 has two outwardly extending connecting parts on one side, the two connecting parts are arranged at intervals, and each connecting part has a caliper hole for connecting the caliper.

[0050] The first extension is provided with a first pin hole, and the ball head passes through the lower control arm 5 and the first pin hole in sequence to hinge the lower control arm 5 to the lower mounting base 22.

[0051] In this embodiment, the steering knuckle 2 is bolted to the hub motor. The steering knuckle 2 can rotatably support the rotor of the hub motor by means of a bearing (not shown) inside the hub motor. The detailed shape of the steering knuckle 2 is not limited to... Figure 2 The shape shown is sufficient to enable the steering mechanism 3 to steer the wheels by driving the steering knuckle 2.

[0052] The steering mechanism 3 includes a steering motor, a first reducer, and an adapter. The output end of the steering motor is connected to the input end of the first reducer, and the output end of the first reducer is rotatably connected to the shaft hole of the upper mounting base 23 for driving the steering knuckle 2 to turn, thereby driving the wheel assembly 1 to rotate.

[0053] One end of the adapter is connected to the side of the first reducer near its output end. One end of the upper control arm 4 is hinged to the other end of the adapter, and the other end of the upper control arm 4 is connected to the vehicle frame. The upper control arm 4 is used to absorb the load transmitted by the wheels when the vehicle is in motion, and connects the wheels to the vehicle frame through the steering mechanism 3, while using its own rigidity to adjust the movement of the wheels.

[0054] One end of the lower control arm 5 is hinged to the lower mounting base 22 via a ball joint, and the other end of the lower control arm 5 is connected to the torsion bar spring mechanism 6. The lower control arm 5 is spaced apart from the upper control arm 4. The lower control arm 5 is provided with a hinge part, one end of the shock absorption mechanism 7 is hinged to the hinge part, and the other end of the shock absorption mechanism 7 is hinged to the vehicle frame.

[0055] Specifically, the lower control arm 5 includes a lower control arm body 51, a first connecting portion 52, a second connecting portion 53, and a third connecting portion 54. The first connecting portion 52 is located at the end of the lower control arm body 51 near the steering knuckle 2, and has a second pin hole. A ball joint passes through the first pin hole and the second pin hole to hinge the lower control arm 5 to the lower mounting base 22. The second connecting portion 53 and the third connecting portion 54 are spaced apart at the ends of the lower control arm body 51 away from the steering knuckle 2. The second connecting portion 53 has a spline hole 531, and the third connecting portion 54 has a through hole.

[0056] The torsion bar spring mechanism 6 includes a drive unit 61 and a torsion bar spring 62. The torsion bar spring 62 is arranged longitudinally along the vehicle and passes through the second connecting portion 53 and the third connecting portion 54, with the third connecting portion 54 located between the drive unit 61 and the second connecting portion 53. The torsion bar spring 62 rotatably engages with the through hole of the third connecting portion 54. One end of the torsion bar spring 62 forms a torque transmission connection with the second connecting portion 53, and the other end of the torsion bar spring 62 is connected to the drive unit 61. The drive unit 61 is connected to the vehicle frame to drive the torsion bar spring 62 to rotate.

[0057] Specifically, a wear-resistant bushing is installed inside the through hole of the third connecting part 54. The bushing is made of high-strength copper alloy or engineering plastic, possessing good wear resistance and self-lubricating properties. The inner diameter of the bushing matches the outer diameter of the torsion bar spring 62, ensuring that the torsion bar spring 62 can rotate freely within the bushing, while preventing direct contact between the torsion bar spring 62 and the through hole of the lower control arm 5, thus reducing wear. A clearance of 0.1 to 0.3 mm is reserved between the bushing and the torsion bar spring 62 to compensate for the thermal expansion and contraction of the torsion bar spring 62 during operation, while ensuring the smooth rotation of the torsion bar spring 62 and preventing jamming. This clearance can be finely adjusted by selecting bushings with different wall thicknesses to adapt to the usage requirements under different working conditions.

[0058] One end of the torsion bar spring 62 is provided with a spline 621 that is adapted to the spline hole 531. The spline 621 and the spline hole 531 are connected to form a fixed connection end; the other end of the torsion bar spring 62 is connected to the drive device 61. The drive device 61 is fixed to the frame to drive the torsion bar spring 62 to twist. The self-torsion angle of the torsion bar spring 62 (i.e., the relative torsion angle between the two end sections) ranges from -8° to 8°.

[0059] In some embodiments, one end of the torsion bar spring 62 and the second connecting part are connected by a key, a pin-groove, or an interference fit to achieve torque transmission.

[0060] In this embodiment, a sealing sleeve is also provided at the junction of the torsion bar spring 62 and the third connecting part 54 to prevent dust, mud and other impurities from entering the through hole of the third connecting part 54, avoid wear on the bushing and the torsion bar spring 62, and improve the service life of the connecting part.

[0061] The torsion bar spring 62 achieves reliable torque transmission through the spline 621 and spline hole 531, while significantly shortening the span of the lower cross arm, reducing the space occupied by the torsion bar spring 62 in the longitudinal direction of the vehicle body, and avoiding interference with other parts of the vehicle body.

[0062] In this embodiment, the drive device 61 includes a drive motor and a second reducer. The output end of the drive motor is connected to the input end of the second reducer, and the output end of the second reducer is connected to the end of the torsion bar spring 62 away from the spline 621 via a coupling.

[0063] The drive motor is fixedly connected to the frame, and the output shaft of the motor is rigidly connected to the torsion bar spring 62 on the same axis. The drive motor is controlled by the vehicle control system (such as ECU) and can output corresponding torque according to the vehicle driving conditions (such as steering angle, vehicle speed, road surface smoothness, vehicle posture feedback, etc.) to drive the torsion bar spring 62 to rotate around its own axis, thereby driving the lower control arm 5 to rotate around the hinge point, realizing the active adjustment of wheel posture (such as camber, toe), and optimizing the vehicle driving stability and comfort.

[0064] The relationship between the diameter, length, and torsional stiffness of the torsion spring 62 is as follows:

[0065] ;

[0066] ;

[0067] Where d represents the diameter of the torsion bar spring 62; k_t represents the torsional stiffness of the torsion bar spring 62; Lt represents the effective working length of the torsion bar spring 62; G represents the material shear modulus of the torsion bar spring 62; k represents the vertical stiffness of a single wheel, which refers to the change in vertical load corresponding to a unit vertical displacement of a single wheel in the direction perpendicular to the ground, used to characterize the vertical stiffness characteristics of the wheel and suspension system; L represents the effective lever arm of the lower control arm 5; α represents the angle between the rotation plane of the lower control arm 5 and the horizontal plane, the rotation plane of the lower control arm 5 being the plane determined by the centerline of the ball head and the axis of the torsion bar spring 62.

[0068] The braking unit 8 includes a brake disc and a caliper. The caliper is connected to the caliper hole of the steering knuckle 2, and the brake disc is connected to the hub motor rotor and the hub bearing. The caliper is used to clamp or release the brake disc, thereby increasing the braking effect of the device through the arrangement of the brake and the brake disc.

[0069] In summary, the corner module with active torsion bar spring of this invention integrates wheel assembly 1, steering knuckle 2, upper and lower control arms, torsion bar spring mechanism 6, and braking unit 8 into one unit, achieving a compact layout of chassis components, reducing space occupation, and adapting to new architectures such as drive-by-wire chassis and hub motors. Through the drive motor of torsion bar spring mechanism 6, the torsional torque of torsion bar spring 62 can be adjusted in real time, actively adjusting wheel attitude, effectively suppressing vehicle roll and pitch, and significantly improving vehicle handling stability and ride comfort. The spline connection 621 achieves torque transmission between torsion bar spring 62 and drive motor, resulting in high transmission efficiency and small backlash, ensuring accurate and timely control response. The bushing and sealing sleeve structural design effectively reduces wear, isolates dust and impurities, extends the service life of the mechanism, and improves system reliability.

[0070] like Figure 5 As shown, a control method for an active torsion bar spring, applied to a vehicle including four corner modules as described above, includes the following steps:

[0071] S1: Collect vehicle operating status signals.

[0072] Vehicle operating status signals include vehicle speed v, steering wheel angle δ, brake input b, and vehicle longitudinal acceleration. lateral acceleration of the vehicle Vehicle roll angle φ, vehicle pitch angle θ. Brake input b is the brake pedal opening signal (0~100%), collected by the brake pedal position sensor, used to characterize the driver's braking intention.

[0073] By collecting multi-dimensional signals such as vehicle speed, steering wheel angle, braking input, attitude angle, and acceleration, a complete input basis is provided for subsequent control decisions, ensuring the robustness of the control strategy.

[0074] S2: Determine whether to enter active control mode based on preset active control intervention conditions.

[0075] The preset active control intervention conditions are: the vehicle speed is greater than or equal to the vehicle speed intervention threshold, and the absolute value of at least one of the steering angle, braking input, roll angle, and pitch angle is greater than or equal to their respective preset thresholds.

[0076] When any of the above conditions are met, the intervention condition is denoted as: =1, enter active control mode. =1 can be quantized as: v≥ and( ≥ or ≥ or ≥ or ≥ ),in, Indicates the vehicle speed intervention value. Indicates the threshold for the turn input. Indicates the braking input threshold. Indicates the roll angle threshold. This represents the pitch angle threshold.

[0077] When intervention conditions When =0, maintain the reference pre-torque state.

[0078] By setting a vehicle speed threshold as a prerequisite, unnecessary control intervention is avoided under low-speed conditions, balancing energy saving and ride smoothness; combined with multiple triggering conditions such as steering, braking, and attitude angle, active control is ensured to be activated only when there is a risk of vehicle attitude instability.

[0079] S3: When the intervention conditions are met and the active control mode is entered, the vehicle state is estimated and it is determined whether the vehicle is in a combined roll-pitch condition or a single condition.

[0080] Based on the vehicle's lateral acceleration, longitudinal acceleration, roll rate, and pitch rate, determine whether the vehicle has entered a combined roll-pitch condition.

[0081] The vehicle state assessment conditions for the pre-set roll-pitch composite condition are: the absolute value of the vehicle's lateral acceleration is greater than or equal to the vehicle's lateral acceleration threshold, and the absolute value of at least one of the vehicle's longitudinal acceleration, roll rate, and pitch rate is greater than or equal to its respective threshold.

[0082] When the above-mentioned roll-pitch combined operating conditions are met, the intervention condition is denoted as: =1, the vehicle enters a combined roll-pitch control mode. =1 can be quantized as: ≥ and( ≥ or ≥ or ≥ ),in, Indicates the lateral acceleration of the vehicle. This indicates the vehicle's lateral acceleration threshold. Indicates the longitudinal acceleration of the vehicle. Indicates the vehicle's longitudinal acceleration threshold. Indicates the vehicle's roll rate. Indicates the vehicle roll rate threshold. Indicates the vehicle's pitch rate. This indicates the vehicle pitch rate threshold.

[0083] When intervention conditions When =0, the vehicle enters single-condition control.

[0084] Based on lateral acceleration, longitudinal acceleration, roll rate, and pitch rate, the system distinguishes between single operating conditions and roll-pitch composite operating conditions, avoiding insufficient control by a single control strategy under complex conditions. This provides a basis for subsequent hierarchical control, enabling precise responses to different driving scenarios and improving vehicle attitude control capabilities under complex conditions.

[0085] S4: When the condition is determined to be a single working condition, single attitude control is executed; when the condition is determined to be a complex working condition, roll-pitch joint control is executed to generate anti-roll target torque and anti-pitch target torque, and torque is distributed to the drive devices 61 of the four corner modules.

[0086] Specifically, single attitude control includes anti-roll control and anti-pitch control; anti-roll control calculates the anti-roll target torque based on the roll angle, roll angular velocity and lateral acceleration, and distributes the anti-roll target torque to the drive motors of each torsion bar spring mechanism 6 according to the distribution coefficient; anti-pitch control calculates the anti-pitch target torque based on the pitch angle, pitch angular velocity and longitudinal acceleration, and distributes the anti-pitch target torque to the drive motors of each corner module according to the distribution coefficient.

[0087] The target anti-roll moment is:

[0088] ;

[0089] The additional tilt torque of the drive motor corresponding to the i-th corner module is:

[0090] ;

[0091] in, Indicates the target moment for anti-roll. , , These are coefficients corresponding to the roll angle, roll rate, and vehicle lateral acceleration, respectively. These three coefficients can be determined through setting or actual vehicle calibration. This indicates the additional tilt torque of the drive motor. The distribution coefficients for the anti-roll target moment are represented by i=1, 2, 3, 4, which correspond to the four corner modules: left front, right front, left rear, and right rear, respectively.

[0092] The anti-pitch target moment is:

[0093] ;

[0094] The additional pitch torque of the drive motor corresponding to the i-th angle module is:

[0095] ;

[0096] in, Indicates the anti-pitch target moment. , , These are coefficients corresponding to pitch angle, pitch rate, and vehicle longitudinal acceleration, respectively. These three coefficients can be determined through setting or actual vehicle calibration. This indicates the additional pitch torque of the drive motor. This represents the distribution coefficient of the anti-pitch target moment.

[0097] The combined roll-pitch control includes: simultaneously generating anti-roll target torque and anti-pitch target torque; obtaining the reference pre-torque torque of the drive motor of each corner module; distributing the anti-roll target torque and anti-pitch target torque to the execution units of the four corner modules (left front, right front, left rear, and right rear) according to the coupling distribution relationship, and combining the reference pre-torque torque of each corner module to obtain the target control torque of the drive motor of each corner module.

[0098] Once the roll-pitch combined operating condition is determined, anti-roll target moment and anti-pitch target moment are generated simultaneously:

[0099] ;

[0100] ;

[0101] The reference pre-torque of each drive motor is mainly used to compensate for mechanism backlash and assembly errors, and to keep the drive motor within the target operating range. The reference offset torque of the i-th drive motor is expressed as:

[0102]

[0103] Subsequently, the aforementioned anti-roll target moment and anti-pitch target moment are distributed to the drive motors of the four corner modules (left front, right front, left rear, and right rear) using the following coupling distribution relationship:

[0104] ;

[0105] ;

[0106] ;

[0107] ;

[0108] in, , , , The target additional torques for the left front, right front, left rear, and right rear drive motors are respectively. , , , These are the reference bias torques for the left front, right front, left rear, and right rear drive motors, respectively. Let represent the equivalent torsional stiffness of the i-th torsion bar spring 62. This indicates the reference torsion angle of the torsion bar spring 62.

[0109] As can be seen from the above formula, the torque difference between the drive motors corresponding to the left and right wheels is used to generate anti-roll torque, and the torque difference between the front and rear drive motors is used to generate anti-pitch torque.

[0110] By calculating anti-roll and anti-pitch moments independently, the logic is simple and debugging is convenient, ensuring control reliability under a single operating condition. Anti-roll and anti-pitch moments are jointly generated and coupled for distribution, simultaneously suppressing roll and pitch movements and resolving the complexity of multi-attitude coupling. A reference pre-torque torque is introduced to compensate for mechanism backlash and assembly errors, eliminating control idle travel and improving system response speed and control accuracy. The target torque is distributed to each corner module according to coefficients, achieving anti-roll based on the torque difference between the left and right wheels and anti-pitch based on the torque difference between the front and rear wheels.

[0111] S5: Perform constraint processing on the allocated target torque and output control commands to the drive motors of each corner module.

[0112] In step S5, the constraint processing includes at least one of the following methods:

[0113] Torque limiting: Limits the target torque of each corner module to between the preset minimum torque and maximum torque.

[0114] ;

[0115] in, This indicates the target torque after amplitude limiting. This represents the target torque of the i-th corner module. This indicates the minimum permissible torque for the angle module. This indicates the maximum permissible torque of the angle module; sat() represents the standard saturation function (limiting function), which restricts the input value between the upper and lower limits.

[0116] Torque change rate limiting: Limits the torque change rate of each corner module at adjacent time points to a preset change rate range.

[0117] ;

[0118] in, This indicates the torque change rate limit. This represents the torque of the i-th corner module at the current moment; This represents the torque of the i-th corner module at the previous moment; Indicates the control period (time difference). This indicates the minimum permissible rate of torque change for the angle module. This indicates the maximum permissible rate of torque change for the corner module.

[0119] Pre-torsion angle limiting: Limits the rotation angle of the torsion bar spring 62 in each corner module to between the preset minimum and maximum rotation angles.

[0120] ;

[0121] in, This indicates the pre-torsion angle of the torsion bar spring after amplitude limiting (62). This represents the target torsion angle of the i-th corner module. This indicates the minimum permissible torsion angle of the torsion bar spring 62. This indicates the maximum permissible angle of twist.

[0122] Limiting the target torque within the motor's allowable range prevents overload and protects the actuator. Limiting the rate of torque change avoids shocks, improves ride comfort, and protects suspension and transmission components. Limiting the torsion bar spring's rotation angle to 62 degrees prevents overload failure and extends the mechanism's lifespan. By implementing constraints, control commands are ensured to remain within physically feasible limits, enhancing system safety and durability.

[0123] In summary, the active torsion bar spring control method provided by this invention ensures that control is activated only when there is a risk of instability through vehicle speed thresholds and multi-condition triggering mechanisms, balancing energy saving and smoothness. It accurately distinguishes between single and compound operating conditions based on lateral acceleration, longitudinal acceleration, and attitude angular velocity, avoiding insufficient control under complex conditions. Torque is calculated independently under single operating conditions, resulting in simple logic and convenient debugging. Under compound operating conditions, torque is jointly generated and coupled for distribution, simultaneously suppressing roll and pitch, thus resolving the complexity of multi-attitude coupling. A reference pre-torque torque is introduced to eliminate control idle travel, improving response speed and accuracy. Target torque is distributed by using the torque difference between the left and right wheels to resist roll and the torque difference between the front and rear wheels to resist pitch. Combining three layers of execution constraints—torque limiting, rate of change limiting, and angle limiting—ensures that control commands are within physically feasible limits, effectively improving system safety and durability.

[0124] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An angle module with an active torsion bar spring, characterized in that, include: Wheel assembly; A steering knuckle, which is connected to the wheel assembly; the steering knuckle includes an upper mounting base and a lower mounting base; A steering mechanism, the output end of which is connected to the upper mounting base to drive the steering knuckle to turn, thereby causing the wheel assembly to rotate; The lower control arm includes a lower control arm body, a first connecting portion, a second connecting portion, and a third connecting portion; the first connecting portion is disposed at one end of the lower control arm body near the steering knuckle and is used to hinge with the lower mounting seat; the second connecting portion and the third connecting portion are spaced apart at one end of the lower control arm body away from the steering knuckle. A torsion bar spring mechanism includes a drive device and a torsion bar spring. The torsion bar spring passes through the second connecting part and the third connecting part. One end of the torsion bar spring is connected to the second connecting part to transmit torque, and the other end of the torsion bar spring is connected to the drive device. The drive device is connected to the vehicle frame to drive the torsion bar spring to rotate.

2. The angle module with an active torsion bar spring according to claim 1, characterized in that, The torsion bar spring is arranged along the longitudinal direction of the vehicle, and the torsion bar spring is rotatably engaged with the third connecting part; one end of the torsion bar spring is provided with a spline, and the second connecting part is provided with a spline hole adapted to the spline, and the spline is engaged with the spline hole.

3. The angle module with an active torsion bar spring according to claim 1, characterized in that, The relationship between the diameter, length, and torsional stiffness of the torsion bar spring is as follows: ； ； Where d represents the diameter of the torsion bar spring, k_t represents the torsional stiffness of the torsion bar spring, Lt represents the effective working length of the torsion bar spring, G represents the shear modulus of the torsion bar spring material, k represents the vertical stiffness of the single wheel, L represents the effective lever arm of the lower control arm, and α represents the angle between the rotation plane of the lower control arm and the horizontal plane.

4. The angle module with an active torsion bar spring according to claim 1, characterized in that, The steering mechanism includes a steering motor, a first reducer, and an adapter. The output end of the steering motor is connected to the input end of the first reducer, and the output end of the first reducer is rotatably connected to the upper mounting base. The adapter is connected to the side of the reducer near its output end.

5. The angle module with an active torsion bar spring according to claim 4, characterized in that, It also includes an upper control arm and a shock absorption mechanism. One end of the upper control arm is hinged to the adapter, and the other end of the upper control arm is connected to the vehicle frame. One end of the shock absorption mechanism is connected to the lower control arm, and the other end of the shock absorption mechanism is connected to the vehicle frame.

6. A control method for an active torsion bar spring, applied to a vehicle comprising four corner modules as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Collect vehicle operating status signals; S2: Determine whether to enter active control mode based on preset active control intervention conditions; S3: When the intervention conditions are met and the active control mode is entered, the vehicle state is estimated and it is determined whether the vehicle is in a combined roll-pitch condition or a single condition. S4: When the condition is determined to be a single working condition, single attitude control is executed; when the condition is determined to be a complex working condition, roll-pitch joint control is executed to generate anti-roll target torque and anti-pitch target torque, and torque is distributed to the drive devices of the four corner modules. S5: Perform constraint processing on the allocated target torque and output control commands to the drive motors of each corner module.

7. The control method for the active torsion bar spring according to claim 6, characterized in that, The preset active control intervention conditions are: the vehicle speed is greater than or equal to the vehicle speed intervention threshold, and the absolute value of at least one of the steering angle, braking input, roll angle, and pitch angle is greater than or equal to their respective preset thresholds. The criteria for determining the roll-pitch composite condition are: the absolute value of the vehicle's lateral acceleration is greater than or equal to the vehicle's lateral acceleration threshold, and the absolute value of at least one of the vehicle's longitudinal acceleration, roll rate, and pitch rate is greater than or equal to its respective threshold.

8. The control method for the active torsion bar spring according to claim 6, characterized in that, The single attitude control mentioned in step S4 includes anti-roll control and anti-pitch control; The anti-roll control calculates the anti-roll target torque based on the roll angle, roll angular velocity and lateral acceleration, and distributes the anti-roll target torque to the drive motors of each corner module according to the distribution coefficient; The anti-pitch control calculates the anti-pitch target torque based on the pitch angle, pitch angular velocity, and longitudinal acceleration, and distributes the anti-pitch target torque to the drive motors of each corner module according to the distribution coefficient.

9. The control method for the active torsion bar spring according to claim 6, characterized in that, The roll-pitch joint control described in step S4 includes: Simultaneously generate anti-roll target moment and anti-pitch target moment; Obtain the reference pre-torque of the drive motor of each corner module; The anti-roll target torque and the anti-pitch target torque are distributed to the execution units of the four corner modules (left front, right front, left rear, and right rear) according to the coupling distribution relationship. Combined with the reference pre-torque torque corresponding to each corner module, the target control torque of the drive device of each corner module is obtained.

10. The control method for the active torsion bar spring according to claim 6, characterized in that, In step S5, the execution constraint processing includes at least one of the following: Torque limiting: Limits the target torque of each corner module to between the preset minimum torque and maximum torque; Torque change rate limiting: Limits the torque change rate of each corner module at adjacent time points to a preset change rate range; Pre-torsion angle limiting: Limits the rotation angle of the torsion bar spring in each corner module to between the preset minimum and maximum rotation angles.

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