Magnetorheological suspension suitable for unmanned drive-by-wire skateboard chassis

Abstract

This invention discloses a magnetorheological suspension suitable for an unmanned drive-by-wire skateboard chassis, comprising a magnetorheological damper and a central computing platform. The magnetorheological damper includes an outer cylinder, a stepped inner cylinder, a piston assembly, a modular magnetic pole group, an excitation coil, a magnetorheological fluid channel, an end cap assembly, seals, and connecting fasteners. The central computing platform receives sensor signals and executes the control algorithm for the magnetorheological suspension. This invention features fast response, convenient maintenance, high control precision, and good sealing. By utilizing the magnetorheological suspension to reshape "road feel," on non-bumpy roads, the algorithm actively simulates the subtle road surface excitations of a traditional chassis, avoiding claustrophobia and discomfort experienced by occupants due to complete loss of road feedback.

Description

Technical Field

[0001] This invention belongs to the field of automotive suspension technology, specifically relating to a magnetorheological suspension suitable for an unmanned drive-by-wire skateboard chassis. Background Technology

[0002] With the development of autonomous driving technology, especially the rise of L4 and above unmanned skateboard chassis, the chassis and the upper body passenger compartment have achieved physical and functional decoupling. Specifically, the skateboard chassis integrates the power, steering, braking and suspension systems, and uses a central computing platform for domain control.

[0003] However, the existing technology has the following pain points: 1) Lack of road feel: Due to the elimination of the mechanical steering column and brake pedal, there is no rigid connection between the passenger compartment and the chassis, resulting in the occupants completely losing road feedback, which can easily lead to claustrophobia and discomfort. 2) Computing power and latency bottlenecks: Traditional distributed electronic control unit (ECU) architectures have limited computing power and high communication latency, making it difficult to meet the real-time requirements of complex suspension algorithms; 3) Excessive unsprung mass: The unsprung mass of the skateboard chassis using hub motors is significantly increased, which aggravates wheel bounce and reduces tire grip.

[0004] Based on the above shortcomings, existing magnetorheological dampers mostly adopt an integrated design with fixed magnetic circuit and damping gap, resulting in poor versatility, limited damping force adjustment range, and a single control method. They cannot be deeply integrated with the central computing platform and are difficult to meet the needs of autonomous driving chassis for road feel reshaping, rapid response, and complex working condition control. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the background art and to provide a magnetorheological suspension suitable for unmanned drive-by-wire skateboard chassis.

[0006] The present invention achieves the above objectives through the following technical solution: a magnetorheological suspension suitable for an unmanned drive-by-wire skateboard chassis, comprising a magnetorheological damper; Magnetorheological dampers include: The outer cylinder has a cylindrical hollow structure, with both ends fixedly connected to the end cap assembly to form a sealed cavity; A stepped inner cylinder is coaxial with the outer cylinder and fixed inside the outer cylinder, and the inner wall of the stepped inner cylinder is provided with at least 3 stepped surfaces along the axial direction. Piston assembly, which includes piston base and modular mounting base, piston base is clearance fit with stepped inner cylinder, and modular mounting base is fixed to the outer peripheral surface of piston base; Modular magnetic pole assembly, comprising at least two magnetic pole modules, wherein the magnetic pole modules are assembled on a modular mounting base by connecting fasteners, and the outer peripheral surface of the magnetic pole modules is provided with stepped protrusions that are adapted to the stepped surface of the stepped inner cylinder. The excitation coil is wound inside the coil slot of the magnetic pole module; The magnetorheological fluid flow channel consists of an outer cylinder, a stepped inner cylinder, and an annular space between the piston assembly. Seals are provided at the mating surfaces of the end cap assembly, outer cylinder, and piston assembly; In addition, the magnetorheological suspension also includes a central computing platform, which is electrically connected to the excitation coil and the sensor group set on the skateboard chassis, respectively, to receive sensor signals and execute the control algorithm of the magnetorheological suspension.

[0007] As a further embodiment of the present invention: the number of magnetic pole modules in the modular magnetic pole group is 2-4, and each magnetic pole module is arranged in series along the axial direction; The end faces of adjacent magnetic pole modules are respectively provided with bosses and grooves, and the bosses and grooves are fitted and positioned. The magnetic poles of each magnetic pole module are arranged alternately along the axial direction, forming an N-S-N arrangement.

[0008] As a further embodiment of the present invention: the magnetic pole module is fixed to the modular mounting base by a clamping nut and an anti-rotation pin.

[0009] As a further embodiment of the present invention: adjacent magnetic pole modules are electrically connected through elastic pins and sockets on the end face, and each excitation coil is arranged in series circuit; The magnetic pole module is made of laminated silicon steel sheets with a permeability ≥1.5×10⁻⁶. 4 H / m.

[0010] As a further embodiment of the present invention: the inner wall of the stepped inner cylinder is provided with 3-5 stepped surfaces, and the stepped protrusions are provided with 2-4 levels.

[0011] As a further aspect of the present invention, the radial clearance of the magnetorheological fluid channel is adjustable in the range of 0.5mm-2mm.

[0012] As a further aspect of the present invention: the control algorithm is integrated into a central computing platform, including: Road feel simulation steps: On non-bumpy road sections, the central computing platform controls the current of the excitation coil, causing the magnetorheological damper to actively generate small damping force changes that simulate the road surface excitation of a traditional chassis. Virtual quality control steps: For the unsprung mass brought by the hub motor, the central computing platform controls the current of the excitation coil, so that the magnetorheological fluid performs a rapid three-stage switching of "soft-hard-soft" in a short time to generate negative damping characteristics. Collaborative control steps: The central computing platform coordinates and adjusts the module status of the modular magnetic pole group, the gap size of the magnetorheological fluid flow channel, and the current of the excitation coil based on the real-time collected operating parameters.

[0013] As a further aspect of the present invention: the magnetorheological damper adopts a radially eccentric adjustable structure to achieve variable gap; The magnetic pole module has an eccentric ring structure, with an eccentricity between its central axis and the central axis of the piston assembly; the modular mounting base is equipped with a ring gear; the end face of the magnetic pole module is equipped with a gear structure that meshes with the gear ring, and by rotating the magnetic pole module, its radial distance from the inner wall of the stepped inner cylinder is changed.

[0014] As a further aspect of the present invention: the magnetorheological damper adopts an axial sliding adjustment structure to achieve variable clearance; The stepped inner cylinder is an axially sliding sleeve structure, and its positioning with the outer cylinder is achieved through positioning pins and positioning holes. The magnetic pole module of the modular magnetic pole group is a ring structure with equal diameter. The axial overlap length between the module and the modular magnetic pole group is changed by axially sliding the stepped inner cylinder.

[0015] As a further aspect of the present invention: the magnetorheological damper adopts an elastic adaptive adjustment structure to achieve variable gap; The magnetic pole module includes a fixing part and an elastic adjusting part connected by a spring; The modular mounting base of the piston assembly is equipped with a pressure sensor; when the pressure inside the magnetorheological fluid flow channel changes, the elastic adjustment part compresses or extends the spring under pressure, adaptively changing the radial clearance with the inner wall of the stepped inner cylinder.

[0016] The beneficial effects of this invention are: (1) Fast response speed: The alternating polarity design and variable gap structure of the modular magnetic pole group optimize the magnetic circuit, increasing the magnetic field utilization rate by 30%-50%, and the response speed of the magnetorheological fluid is ≤10ms; Convenient maintenance: Individual magnetic pole modules can be disassembled and replaced independently without the need to disassemble the damper as a whole, reducing maintenance costs by 50%; High control accuracy: The multi-parameter linkage control method, combined with the dynamic adjustment of gap status and working condition parameters, improves the vibration reduction effect by more than 25%, adapting to complex and changing driving conditions; Good sealing performance: O-ring seals are used between magnetic pole modules, ensuring reliable flow channel sealing and effectively preventing magnetorheological fluid leakage.

[0017] (2) This invention solves the problem of lack of rigid road feel feedback and support in the passenger cabin after the decoupling of the upper and lower body of the unmanned skateboard chassis: For L4 level and above skateboard chassis that completely eliminate mechanical steering column and brake pedal, the "road feel" is reshaped by magnetorheological suspension. On non-bumpy road sections, the algorithm actively simulates the small road surface excitation of the traditional chassis to avoid the passenger from feeling claustrophobic and uncomfortable due to the complete loss of road feedback.

[0018] (3) This invention solves the pain points of traditional distributed ECU computing power bottleneck and communication delay: abandoning the independent suspension controller, the magnetorheological suspension control algorithm is fully coded in C and integrated into the central computing platform of the skateboard chassis (such as based on NVIDIA Thor or Qualcomm Snapdragon Ride platform), realizing the integration of "perception-decision-execution", and compressing the suspension control loop cycle from the traditional 10ms to less than 1ms.

[0019] (4) This invention solves the problem of excessive unsprung mass of the hub motor of the skateboard chassis causing the wheel to bounce more. For the extra unsprung mass brought by the hub motor of the four-wheel independent drive, a virtual mass control algorithm with negative damping characteristics is designed. Through the rapid three-stage "soft-hard-soft" switching of the magnetorheological fluid in a very short time, the motion inertia of the hub motor is actively counteracted, and the wheel's ground contact is improved by 40%. Attached Figure Description

[0020] Figure 1 This is a front view of the magnetorheological damper in this invention; Figure 2 This is an attached view of the magnetorheological damper in this invention; Figure 3 This is the present invention. Figure 2 Sectional view at point AA; In the diagram: 1. Outer cylinder, 2. Stepped inner cylinder, 3. Piston assembly, 4. Modular magnetic pole assembly, 5. Excitation coil, 6. Magnetorheological fluid flow channel, 7. End cap assembly, 8. Seal, 9. Connecting fasteners. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1, as Figures 1 to 3As shown, this embodiment provides a magnetorheological suspension suitable for an unmanned drive-by-wire skateboard chassis, including a magnetorheological damper. The magnetorheological damper includes an outer cylinder 1, a stepped inner cylinder 2, a piston assembly 3, a modular magnetic pole group 4, an excitation coil 5, a magnetorheological fluid channel 6, an end cap assembly 7, a seal 8, and connecting fasteners 9.

[0023] The outer cylinder 1 is a cylindrical hollow structure, and its two ends are fixedly connected to the end cap assembly 7 by bolts to form a sealed cavity.

[0024] The stepped inner cylinder 2 is coaxially fixed inside the outer cylinder 1. Its inner wall has at least 3 stepped surfaces along the axial direction, and the stepped protrusions have 2-4 levels; generally, there are 3-5 stepped surfaces. The inner diameter of the stepped inner cylinder 2 is in the range of 80-120mm; the height of the stepped protrusions is generally in the range of 0.5-2mm, which is adapted to the stepped surfaces of the stepped inner cylinder 2.

[0025] The piston assembly 3 includes a piston base and a modular mounting base. The piston base is clearance-fitted with the stepped inner cylinder 2, and the modular mounting base is fixed to the outer circumferential surface of the piston base.

[0026] The modular magnetic pole group 4 consists of at least two independent magnetic pole modules. Each magnetic pole module is assembled on the modular mounting base by connecting fasteners 9, and the outer peripheral surface of the magnetic pole module is provided with stepped protrusions that are adapted to the stepped surface of the stepped inner cylinder 2. Each magnetic pole module includes a magnetic pole body, a coil slot, an elastic pin, a socket, a stepped protrusion, and a sealing groove.

[0027] In this embodiment, the magnetic pole module is fixed to the modular mounting base by a clamping nut and an anti-rotation pin. The clamping nut and anti-rotation pin can be removed to replace any magnetic pole module individually.

[0028] In this embodiment, each magnetic pole module is arranged in series along the axial direction; the end faces of adjacent magnetic pole modules are respectively provided with bosses and grooves, and the bosses and grooves are fitted and positioned; the magnetic pole polarities of each magnetic pole module are arranged alternately along the axial direction to form an N-pole-S-pole-N-pole arrangement.

[0029] In this embodiment, the magnetic pole body is made of laminated silicon steel sheets with a permeability ≥1.5×10⁻⁶. 4 H / m; 4-8 coil slots are evenly distributed around the circumference of the magnetic pole body.

[0030] In this embodiment, adjacent magnetic pole modules are positioned by bosses and grooves, sealed by O-rings, and electrically connected by elastic pins and sockets on their end faces.

[0031] The excitation coil 5 is wound in the coil slot of each magnetic pole module; the coil of each magnetic pole module is independently wired and connected in series with the adjacent magnetic pole modules through flexible pins; the excitation coil 5 is wound with copper enameled wire with 500-1500 turns.

[0032] The magnetorheological fluid flow channel 6 is composed of an outer cylinder 1, a stepped inner cylinder 2, and an annular space between the piston assembly 3; the magnetorheological fluid flow channel 6 includes an axial flow channel and a radial flow channel, and is filled with magnetorheological fluid; the radial clearance of the magnetorheological fluid flow channel 6 is adjustable from 0.5 mm to 2 mm.

[0033] The end cap assembly 7 includes end cap I and end cap II, wherein end cap I is provided with wiring holes and end cap II is provided with mounting hinge holes.

[0034] The sealing element 8 is located at the mating surfaces of the end cap assembly 7, the outer cylinder 1, and the piston assembly 3.

[0035] In addition, the magnetorheological suspension also includes a central computing platform, which is electrically connected to the excitation coil 5 and the sensor group set on the skateboard chassis, respectively, to receive sensor signals and execute the control algorithm of the magnetorheological suspension.

[0036] The control algorithm for receiving sensor signals and executing the magnetorheological suspension is integrated into the central computing platform, and specifically includes: Road feel simulation steps: On non-bumpy road sections, the central computing platform controls the current of the excitation coil 5, so that the magnetorheological damper actively generates a small damping force change that simulates the road surface excitation of a traditional chassis. Virtual quality control steps: For the unsprung mass brought by the hub motor, the central computing platform controls the current of the excitation coil 5, so that the magnetorheological fluid performs a three-stage rapid switching of "soft-hard-soft" in a very short time to generate negative damping characteristics. Collaborative control steps: The central computing platform coordinates the module status of the modular magnetic pole group 4, the gap size of the magnetorheological fluid flow channel 6, and the current of the excitation coil 5 based on the real-time collected operating parameters.

[0037] Magnetorheological dampers can achieve three types of variable gaps: First, the magnetorheological damper adopts a radially eccentric adjustable structure to achieve variable clearance. The magnetic pole module is an eccentric ring structure, and its central axis is eccentric to the central axis of the piston assembly 3. The modular mounting base is provided with a ring gear, and the end face of the magnetic pole module is provided with a gear structure that meshes with the gear. By rotating the magnetic pole module, the radial distance between it and the inner wall of the stepped inner cylinder 2 is changed, or the magnetic pole module with different protrusion heights is replaced, so that the radial clearance can be adjusted within the range of 0.5-2mm.

[0038] Secondly, the magnetorheological damper adopts an axial sliding adjustment structure to achieve variable clearance. The stepped inner cylinder 2 is an axially sliding sleeve structure, which is positioned in stages with the outer cylinder 1 through positioning pins and multiple positioning holes. The magnetic pole modules of the modular magnetic pole group 4 are equal-diameter annular structures. By axially sliding the stepped inner cylinder 2, the axial overlap length between it and the modular magnetic pole group 4 is changed, so that the effective length of the axial flow channel can be adjusted within the range of 50-200mm.

[0039] Third, the magnetorheological damper adopts an elastic adaptive adjustment structure to achieve variable clearance. The magnetic pole module includes a fixed part and an elastic adjustment part connected by a spring. The modular mounting seat of the piston assembly 3 is equipped with a pressure sensor. When the pressure inside the magnetorheological fluid channel 6 changes, the elastic adjustment part compresses or extends the spring under pressure, adaptively changing the radial clearance with the inner wall of the stepped inner cylinder 2.

[0040] In addition, the magnetorheological suspension also includes a control unit, including a vehicle speed sensor, an acceleration sensor, a Hall sensor, an actuator, and a controller, for coordinating the adjustment of the magnetic pole module status, the gap size, and the excitation coil current.

[0041] The control unit drives the micro motor, loosens the clamping nut, pulls out the anti-rotation pin, and locks it in place after the magnetic pole module is added, removed, or rotated. Its active collaborative control method includes the following steps: S1: Initialization settings, preset the number of magnetic pole modules, initial gap, and initial current according to the compatible vehicle model; S2: Real-time acquisition of operating parameters such as vehicle speed, vibration acceleration, and magnetic field strength; S3: Determine the clearance adjustment requirement based on the operating parameters and determine the target clearance state; S4: Drive the actuator to adjust the clearance to the target state; S5: Dynamically adjust the current of excitation coil 5 according to the gap status and operating parameters; S6: Real-time feedback monitoring to correct gap and current parameters.

[0042] This invention is highly versatile: the modular magnetic pole assembly 4 can be adapted to various vehicle types such as sedans, SUVs, and commercial vehicles by increasing or decreasing the number of modules or replacing modules of different specifications. One set of hardware can meet the needs of multiple scenarios, reducing production and R&D costs by more than 30%.

[0043] This invention features a wide damping adjustment range: the combined variable gap structure works in conjunction with current adjustment, allowing for a damping force adjustment range of up to 16 times (500-8000N), which can be flexibly switched according to road conditions, balancing comfort and stability.

[0044] This invention features a fast response speed: the alternating polarity design of the modular magnetic pole group 4 and the optimized magnetic circuit with a variable gap structure improve the magnetic field utilization rate by 30%-50%, and the magnetorheological fluid response speed is ≤10ms.

[0045] This invention offers convenient maintenance: individual magnetic pole modules can be independently disassembled and replaced without the need to disassemble the entire damper, reducing maintenance costs by 50%.

[0046] This invention features high control precision: a multi-parameter linkage control method that combines gap state and dynamic adjustment of operating parameters, improving vibration reduction by more than 25% and adapting to complex and ever-changing driving conditions.

[0047] This invention has good sealing performance: O-rings are used to seal between magnetic pole modules, ensuring reliable flow channel sealing and effectively preventing leakage of magnetorheological fluid.

[0048] Example 2: In practical use, a magnetorheological damper is adapted to an unmanned drive-by-wire skateboard chassis.

[0049] Structural parameters: Outer cylinder 1 has an inner diameter of 100mm; stepped inner cylinder 2 has 3 stepped surfaces (inner diameters of 80mm, 90mm, and 100mm); modular magnetic pole group 4 uses 2 magnetic pole modules, with each magnetic pole module having a stepped protrusion height of 0.8mm and 1.2mm; initial axial flow channel length of 100mm and initial radial clearance of 1.2mm. Assembly process: Position the magnetic pole module using the slot, fix it with the anti-rotation pin, connect the elastic pin to form an electrical path, and tighten the nut to lock it; inject magnetorheological fluid, install the end cap assembly 7 and seal it; Control parameters: initial current 0.5A, acceleration coefficient k=0.3A / g, gap coefficient m=0.2A / mm; Working process: On a smooth road surface (a≤0.5g), maintain a radial clearance of 1.2mm and a current of 0.5-1A; on a bumpy road surface, switch to a radial clearance of 0.8mm and a current of 1.5-2.5A.

[0050] Example 2: In practical use, the present invention is adapted to a magnetorheological damper for SUVs.

[0051] Structural parameters: Outer cylinder 1 has an inner diameter of 120mm; stepped inner cylinder 2 has 4 stepped surfaces (inner diameters of 90mm, 100mm, 110mm, and 120mm); modular magnetic pole group 4 uses 3 magnetic pole modules, with each module having a stepped protrusion height of 0.5mm, 1.0mm, and 1.5mm; initial axial flow channel length is 150mm, and initial radial clearance is 1.0mm. Assembly process: Add a new magnetic pole module, position it with the original module through the boss-groove positioning, connect it with the plug for electrical connection, and tighten the nut to lock it; Control parameters: initial current 0.6A, acceleration coefficient k=0.4A / g, gap coefficient m=0.3A / mm; Working process: When switching between off-road conditions, the radial clearance is 0.5mm, the current is 2-3A, and the damping force reaches 6000-8000N.

[0052] The replacement and maintenance of modular magnetic pole assembly 4 includes the following steps: Disassembly steps: Loosen end cover assembly 7, pull out piston assembly 3, loosen clamping nut, pull out anti-rotation pin, and pull out faulty magnetic pole module; Replacement steps: Insert the new magnetic pole module into the slot, align the pins, insert the anti-rotation pin, and tighten the clamping nut; Testing steps: Test the magnetic field strength and circuit connectivity by energizing the circuit, and test the sealing performance after injecting magnetorheological fluid.

[0053] Example 4: This example provides a specific implementation of an active collaborative control method.

[0054] Hardware configuration: The sensor module includes a vehicle speed sensor (range 0-150km / h), a triaxial accelerometer (range 0-10g), and a Hall sensor (range 0-2T); the actuator is a micro stepper motor (torque ≥0.5N・m); Software flow: The controller uses an STM32 microcontroller with a sampling frequency of 100Hz and a control cycle of 20ms; Test results: On bumpy roads, the gap adjustment response time is ≤50ms, the current adjustment response time is ≤10ms, and the damping force is increased from 1000N to 7500N, with a significant vibration reduction effect.

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A magnetorheological suspension for an unmanned drive-by-wire skateboard chassis, comprising a magnetorheological damper, characterized in that, The magnetorheological damper includes: The outer cylinder (1) has a cylindrical hollow structure, and its two ends are fixedly connected to the end cap assembly (7) to form a sealed cavity; A stepped inner cylinder (2) is coaxial with the outer cylinder (1) and fixed inside the outer cylinder (1), and the inner wall of the stepped inner cylinder (2) is provided with at least 3 stepped surfaces along the axial direction. Piston assembly (3), the piston assembly (3) includes a piston base and a modular mounting base, the piston base is clearance-fitted with the stepped inner cylinder (2), and the modular mounting base is fixed to the outer peripheral surface of the piston base; Modular magnetic pole group (4), the modular magnetic pole group (4) includes at least two magnetic pole modules, the magnetic pole modules are assembled on the modular mounting base by connecting fasteners (9), and the outer peripheral surface of the magnetic pole modules is provided with stepped protrusions that are adapted to the stepped surface of the stepped inner cylinder (2); The excitation coil (5) is wound in the coil slot of the magnetic pole module; The magnetorheological fluid flow channel (6) is composed of the annular space between the outer cylinder (1), the stepped inner cylinder (2) and the piston assembly (3); A sealing element (8) is disposed at the mating surfaces of the end cap assembly (7), the outer cylinder (1), and the piston assembly (3); In addition, the magnetorheological suspension also includes a central computing platform, which is electrically connected to the excitation coil (5) and the sensor group set on the skateboard chassis, respectively, for receiving sensor signals and executing the control algorithm of the magnetorheological suspension.

2. The magnetorheological suspension according to claim 1, characterized in that: The modular magnetic pole group (4) has 2-4 magnetic pole modules, and each of the magnetic pole modules is arranged in series along the axial direction. The end faces of adjacent magnetic pole modules are respectively provided with bosses and grooves, and the bosses and grooves are fitted and positioned. The magnetic poles of each of the magnetic pole modules are arranged alternately along the axial direction, forming an N-pole-S-pole-N-pole arrangement.

3. The magnetorheological suspension according to claim 1, characterized in that: The magnetic pole module is fixed to the modular mounting base by a clamping nut and an anti-rotation pin.

4. The magnetorheological suspension according to claim 1, characterized in that: The adjacent magnetic pole modules are electrically connected through the elastic pins and sockets on the end face, and the excitation coils (5) are arranged in series. The magnetic pole module is made of laminated silicon steel sheets with a magnetic permeability ≥1.5×10⁻⁶. 4 H / m.

5. The magnetorheological suspension according to claim 1, characterized in that: The inner wall of the stepped inner cylinder (2) is provided with 3-5 stepped surfaces, and the stepped protrusions are provided with 2-4 levels.

6. The magnetorheological suspension according to claim 1, characterized in that: The radial clearance adjustment range of the magnetorheological fluid channel (6) is 0.5mm-2mm.

7. The magnetorheological suspension according to claim 1, characterized in that: The control algorithm is integrated into the central computing platform and includes: Road feel simulation steps: On non-bumpy road sections, the central computing platform controls the current of the excitation coil (5) so that the magnetorheological damper actively generates a small damping force change that simulates the excitation of the traditional chassis road surface. Virtual quality control steps: For the unsprung mass brought by the hub motor, the central computing platform controls the current of the excitation coil (5) so that the magnetorheological fluid performs a three-stage rapid switching of "soft-hard-soft" in a short time to generate negative damping characteristics; Collaborative control steps: The central computing platform coordinates the module status of the modular magnetic pole group (4), the gap size of the magnetorheological fluid channel (6), and the current of the excitation coil (5) based on the real-time collected operating parameters.

8. The magnetorheological suspension according to claim 1, characterized in that: The magnetorheological damper adopts a radially eccentric adjustable structure to achieve variable clearance. The magnetic pole module is an eccentric ring structure, and its central axis is eccentric to the central axis of the piston assembly (3). The modular mounting base is provided with an annular toothed ring; The end face of the magnetic pole module is provided with a gear structure that meshes with the gear ring, and by rotating the magnetic pole module, the radial distance between it and the inner wall of the stepped inner cylinder (2) is changed.

9. The magnetorheological suspension according to claim 1, characterized in that: The magnetorheological damper adopts an axial sliding adjustment structure to achieve variable clearance; The stepped inner cylinder (2) is an axially sliding sleeve structure, and it is positioned in stages with the outer cylinder (1) through positioning pins and positioning holes; The magnetic pole module of the modular magnetic pole group (4) is an equal diameter ring structure. By axially sliding the stepped inner cylinder (2), the axial overlap length between it and the modular magnetic pole group (4) is changed.

10. The magnetorheological suspension according to claim 1, characterized in that: The magnetorheological damper adopts an elastic adaptive adjustment structure to achieve variable gap; The magnetic pole module includes a fixing part and an elastic adjusting part connected by a spring; The modular mounting base of the piston assembly (3) is equipped with a pressure sensor; when the pressure inside the magnetorheological fluid channel (6) changes, the elastic adjustment part compresses or extends the spring under pressure, adaptively changing the radial clearance with the inner wall of the stepped inner cylinder (2).

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