Active and passive hybrid suspension and ground shed negative inerter control method thereof

Abstract

The invention discloses an active and passive hybrid suspension and a ground shed negative inerter control method thereof, and relates to the technical field of active suspensions.The active and passive hybrid suspension is characterized in that a main spring, a main damper and an active and passive hybrid damping device are connected in parallel, and the active and passive hybrid damping device comprises an auxiliary spring, an auxiliary damper, a vibrator mass and an active actuator; wherein the auxiliary spring and the auxiliary damper are connected in parallel, and the auxiliary spring and the auxiliary damper are connected in series through the vibrator mass and the active actuator. The active actuator executes ground shed negative inerter control, the control effect is equivalent to reduction of unsprung mass, and the purposes of improving the ground gripping performance of tires and greatly improving the operation stability of a vehicle are achieved. Meanwhile, the active actuator in the active and passive hybrid vibration damping device is connected with the sprung mass through the passive vibration damping part, the adverse effects that the active actuator is directly connected with the sprung mass to increase the acceleration of a vehicle body and the riding comfort is worsened are overcome, the riding comfort is improved, the operation stability is improved, and the service life of the vehicle is prolonged. The purpose of improving the comprehensive performance of the suspension is achieved.

Description

Technical Field

[0001] This invention relates to the field of active suspension technology, and in particular to a hybrid active-passive suspension and its ground cover negative inertia control method. Background Technology

[0002] In-wheel motor (IWM) cars offer advantages such as superior dynamic performance, precise wheel control, and expanded interior space. However, the introduction of in-wheel motors causes a significant deterioration in handling and ride comfort compared to traditional cars due to the increased unsprung mass.

[0003] The introduction of IWM (Inductively Coupled Motor) deteriorates vehicle performance, and there are currently three different technical approaches to overcome this disadvantage. The first is to design lightweight motors using various methods, but due to high manufacturing costs and unstable material properties, lightweight IWMs have not been widely adopted. The second is to optimize the motor layout and combine it with IWMs by utilizing the characteristics of Dynamic Vibration Absorbers (DVAs), resulting in better suppression of vehicle vibration; however, the design of such structures is generally quite complex. The third is to fully utilize the suspension system, for example, by using improved LQR (Limited-Quickness Reduction), adaptive sliding mode control, finite-frequency H∞ (FQR), and advanced PID (PID) control schemes to study the negative vertical vibration effects of IWMs. However, most current suspension control methods for addressing the negative vertical effects of IWMs are computationally complex and cannot effectively solve the problem.

[0004] Professor Smith proposed the concept of an inerter (also known as an inertial mass accumulator or inertial energy storage device) in 2001 and applied it to vehicle suspension in 2004, developing the "Inerter-Spring-Damper" (ISD) suspension system. Chinese patent 201610300526 proposes a semi-active suspension system with ceiling-mounted inerter control. The idea behind ceiling-mounted inerter control is to connect the inertial reference frame and the sprung mass using an ideal inerter. The ideal inerter provides a positive gain force based on the sprung mass acceleration to suppress the acceleration vibration of the sprung mass, effectively increasing the sprung mass and thus improving vehicle ride comfort. However, the technical principle of this control method is to "increase" the sprung mass, not to "decrease" the unsprung mass. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a hybrid active-passive suspension and its method for controlling the negative inertia capacity of the floor. The negative inertia capacity of the floor is controlled through the active damping device of the hybrid active-passive damping system. This control effect is equivalent to reducing unsprung mass, thereby improving tire grip and significantly enhancing vehicle handling stability. Simultaneously, the active actuator in the hybrid active-passive damping system is connected to the sprung mass through the passive damping device, overcoming the adverse effects of directly connecting the active actuator to the sprung mass, which increases vehicle acceleration and degrades ride comfort. Therefore, this invention improves both ride comfort and handling stability, ultimately enhancing the overall performance of the suspension.

[0006] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0007] An active-passive hybrid suspension includes a sprung mass, a main spring, a main damper, an unsprung mass, a tire equivalent spring, an active-passive hybrid damping device, an actuator, an ECU, and an acceleration sensor; the main spring, the main damper, and the active-passive hybrid damping device are disposed between the sprung mass and the unsprung mass; an acceleration sensor is mounted on the unsprung mass, the acceleration sensor is connected to the ECU, and the ECU is connected to the active-passive hybrid damping device through the actuator.

[0008] In the above scheme, the active-passive hybrid vibration damping device includes an active vibration damping device and a passive vibration damping device. The passive vibration damping device includes a secondary damper, a secondary spring, and an oscillator mass. The secondary damper and the secondary spring are connected in parallel, and the oscillator mass is connected in series with the secondary damper and the secondary spring. The active vibration damping device includes an active actuator, wherein the active actuator is connected in series with the oscillator mass.

[0009] In the above scheme, the active-passive hybrid vibration damping device includes an active vibration damping device and a passive vibration damping device. The passive vibration damping device includes a secondary damper and a secondary spring, which are connected in parallel. The active vibration damping device includes an active actuator, which is connected in series with the secondary damper and the secondary spring. The active actuator includes an actuator stator and an actuator mover. The actuator stator is connected in series with the secondary spring and the secondary damper, and the actuator mover is connected in series with the unsprung mass, wherein the mass of the actuator stator is equivalent to the mass of the oscillator; or the actuator mover is connected in series with the secondary spring and the secondary damper, and the actuator stator is connected in series with the unsprung mass, wherein the mass of the actuator mover is equivalent to the mass of the oscillator.

[0010] A method for controlling the negative inertia capacity of the ground cover in a hybrid active-passive suspension system, characterized by the following steps:

[0011] Step 1: Select the proportion coefficient in the active-passive hybrid suspension. Thus, the negative inertia coefficient b of the ground shed is determined. ngnd The value of can be selected according to the following formula:

[0012]

[0013] In the formula, m e It refers to the mass of the hub motor, m w For the mass of the wheel;

[0014] Step 2: Obtain the unsprung mass acceleration using an accelerometer. Transmitted to the ECU;

[0015] Step 3: The ECU uses the acquired unsprung mass acceleration... The value is calculated based on the following formula to determine the magnitude of the active force of the active-passive hybrid vibration damping device:

[0016]

[0017] Step 4: The ECU adjusts the negative inertia coefficient b of the floor according to the selected size. ngnd This allows for the control of the actuator to drive and adjust the active-passive hybrid vibration damping device, effectively simulating and realizing the negative inertia capacity of the ground shed.

[0018] The beneficial effects of this invention are as follows: This invention proposes an active-passive hybrid suspension and its ground cover negative inertia control method. The ground cover negative inertia control is achieved through the active damping device of the active-passive hybrid damping device. Its control effect is equivalent to reducing unsprung mass, thereby improving tire grip performance and significantly improving vehicle handling stability. At the same time, the active actuator in the active-passive hybrid damping device is connected to the sprung mass through the passive damping device, overcoming the adverse effects of the active actuator being directly connected to the sprung mass, which increases vehicle acceleration and deteriorates ride comfort. Thus, it improves both ride comfort and handling stability, thereby improving the overall performance of the suspension. Attached Figure Description

[0019] Figure 1 For ideal ground-mounted negative inertia suspension systems;

[0020] Figure 2 It is a hybrid active and passive suspension system;

[0021] Figure 3 This is a schematic diagram of a hybrid active and passive vibration damping device;

[0022] Figure 4 This is a structural diagram of a hybrid active and passive vibration damping device;

[0023] Figure 5 This is a time-domain comparison chart of the suspension dynamic deflection when the scaling factor is 0.6;

[0024] Figure 6 This is a time-domain comparison of the tire dynamic load of the suspension when the scaling factor is 0.6;

[0025] Figure 7 This is a time-domain comparison chart of suspension body acceleration when the scaling factor is 0.6;

[0026] Figure 8 This is a time-domain comparison of vehicle acceleration for a direct-connected ground-mounted negative inertia suspension with a scaling factor of 0.6.

[0027] Figure 9 This is a time-domain comparison of vehicle body acceleration for a non-directly connected floor negative inertia suspension with a scaling factor of 0.6.

[0028] Figure label:

[0029] 1-Sprung mass; 2-Main spring; 3-Unsprung mass; 4-Ideal negative inertia container; 5-Main damper; 6-Wheel mass; 7-Wheel hub motor mass; 8-Tire equivalent spring; 9-Hybrid active and passive damping device; 10-Actuator; 11-ECU; 12-Acceleration sensor; 13-Secondary spring; 14-Oscillator mass; 15-Active actuator; 16-Secondary damper; 17-Actuator stator; 18-Actuator mover. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" 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 defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 this invention according to the specific circumstances.

[0033] Figure 1 This is an ideal ground-mounted negative inertia capacity suspension system, comprising a sprung mass 1, a main spring 2, a unsprung mass 3, an ideal negative inertia container 4, a main damper 5, a wheel mass 6, a hub motor mass 7, and a tire equivalent spring 8. The main spring 2 and the main damper 5 are positioned between the unsprung mass 3 and the sprung mass 1. The ideal negative inertia container 4 is positioned between the inertial reference frame and the unsprung mass 3. The ideal negative inertia container 4 generates a negative inertia capacity force opposite to the direction of the unsprung mass's acceleration. The magnitude of this force is equal to the product of the ground-mounted negative inertia capacity coefficient and the unsprung mass's acceleration. This negative inertia capacity force acts directly on the unsprung mass and is independent of the absolute acceleration of the sprung mass 1. Therefore, the ground-mounted negative inertia capacity can effectively "reduce" the unsprung mass during motion, thereby reducing the displacement difference between the unsprung mass and the ground, improving tire contact with the ground, and thus improving handling stability.

[0034] Figure 2 It is a hybrid active-passive suspension, also known as a negative inertia capacity suspension, comprising sprung mass 1, main spring 2, unsprung mass 3, main damper 5, wheel mass 6, hub motor mass 7, tire equivalent spring 8, hybrid active-passive damping device 9, actuator 10, ECU 11, and acceleration sensor 12; the main spring 2, main damper 5, and hybrid active-passive damping device 9 are disposed between sprung mass 1 and unsprung mass 3; the acceleration sensor 12 is disposed on unsprung mass 3, collects unsprung mass acceleration signals and transmits them to ECU 11, ECU 11 controls drive mechanism 10 to drive and adjust hybrid active-passive damping device 9 according to the negative inertia capacity control method, thereby simulating negative inertia capacity.

[0035] Figure 3(a) is a schematic diagram of a hybrid active-passive vibration damping device, including a passive vibration damping device and an active vibration damping device. The passive vibration damping device includes a secondary damper 16, a secondary spring 13, and an oscillator mass 14, wherein the secondary damper 16 and the secondary spring 13 are connected in parallel, and the oscillator mass 14 is connected in series with the above structure. The active vibration damping device includes an active actuator 15, wherein the active actuator 15 is connected in series with the oscillator mass 14. The upper end of the hybrid active-passive vibration damping device 9 is connected to the sprung mass 1, and the lower end is connected to the unsprung mass 3. The active force of the active actuator 15 acts on both the unsprung mass 3 and the oscillator mass 14. Under the action of the secondary spring 13, the secondary damper 16, and the oscillator mass 14 (the damping value of the secondary damper 16 is selected within a certain range), the negative impact of the force generated by the active actuator 15 on the sprung mass 1 is reduced, and at the same time, it plays a role in re-damping the sprung mass 1, thereby simulating the negative inertia of the ground while reducing the vibration of the sprung mass 1, improving ride smoothness, and improving ride comfort.

[0036] Figure 3 (b) and (c) are configurations of a hybrid active-passive vibration damping device. The active actuator 15 includes an actuator stator 17 and an actuator mover 18. The actuator stator 17 or the actuator mover 18 is connected to the secondary spring 13 and the secondary damper 16, and the actuator mover 18 or the actuator stator 17 is connected to the unsprung mass 3. The mass of the actuator stator 17 or the mass of the actuator mover 18 is equivalent to the oscillator mass 14, thereby achieving... Figure 3 The effect of the active-passive hybrid vibration damping device in (a) is to reduce the space occupied by the actuator.

[0037] Figure 4 This is a simplified structural diagram of a hybrid active and passive vibration damping device, corresponding to... Figure 3 The different configurations of (b) and (c) provide two structural forms, including generator mover 18, generator stator 17, auxiliary damper 16 and auxiliary spring 13; in both devices, the left end is connected to unsprung mass 3 and the right end is connected to sprung mass 1, and they are connected in parallel with main spring 2.

[0038] The ground-mounted negative inertia suspension uses a single mechanism to dynamically adjust the ground-mounted negative inertia; in this embodiment, it is a hybrid active-passive damping device. The active actuator control strategy is as follows:

[0039]

[0040] In the formula, F max The maximum force that the active actuator can output is used. To compare and analyze the control effect of the ground-mounted negative inertia capacity suspension, the lower cutoff spatial frequency n1 is set to 0.01m. -1The vehicle speed was 20 m / s, and a random Class B road surface simulated by white noise was used as the road displacement input. The results were compared with a traditional hub motor-driven passive suspension and an ideal floor-mounted negative inertia suspension. The sprung mass m of these three suspensions was... s Unsprung mass m t Spring stiffness k, damping coefficient c, and tire equivalent stiffness k t They are all equal.

[0041] Depend on Figures 5-6 It can be seen that the suspension dynamic travel and tire dynamic load index curves of the ground negative inertia capacity are consistent with those of the ideal ground negative inertia capacity. This indicates that the ideal ground negative inertia capacity control effect has been successfully achieved in an active manner through the active and passive hybrid damping device, which effectively "reduces" the unsprung mass and thus improves handling stability.

[0042] Depend on Figures 5-7 It can be seen that, compared with the passive suspension, the suspension dynamic travel of the negative inertia capacity suspension is almost unchanged, while the tire dynamic load and vehicle acceleration are improved to varying degrees. This indicates that while the negative inertia capacity control method optimizes handling stability, the active and passive hybrid damping device also plays a certain role in suppressing the vibration of the sprung mass, thereby giving the negative inertia capacity suspension good ride comfort.

[0043] As shown in the table below, compared to passive suspension, the root mean square value of vehicle acceleration of the negative inertia volume suspension is reduced by 24.86%, and the root mean square value of tire dynamic load is reduced by 25.27%. The root mean square value of suspension dynamic travel is similar to that of passive suspension. This indicates that the negative inertia volume suspension not only has good handling stability but also excellent ride comfort. Unlike most other suspensions that can only meet the requirements of handling stability or ride comfort, the negative inertia volume suspension innovatively solves this problem.

[0044] RMS Table of Automotive Suspension Evaluation Indicators

[0045]

[0046] Figure 8 and Figure 9 The figures show a time-domain comparison of vehicle acceleration for a ground-mounted negative-inertia suspension equipped with a hybrid active-passive damping system and a ground-mounted negative-inertia suspension where the active actuator is directly connected to the sprung and unsprung masses. As can be seen from the figures, the active actuator in the hybrid active-passive damping system is connected to the sprung mass through the passive damping system, overcoming the adverse effects of directly connecting the active actuator to the sprung mass, which increases vehicle acceleration and degrades ride comfort.

[0047] This invention provides a hybrid active-passive suspension and its method for controlling negative inertia capacity of the floor. It introduces a hybrid active-passive damping device, which achieves negative inertia capacity control of the floor through the active damping component. This control effect is equivalent to reducing unsprung mass, thereby improving tire grip and significantly enhancing vehicle handling stability. Simultaneously, the active actuator in the hybrid active-passive damping device is connected to the sprung mass through the passive damping component, overcoming the adverse effects of directly connecting the active actuator to the sprung mass, which increases vehicle acceleration and degrades ride comfort. This improves both ride comfort and handling stability, ultimately enhancing the overall performance of the suspension.

[0048] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A hybrid active-passive suspension, characterized in that, It includes a sprung mass (1), a main spring (2), a main damper (5), a unsprung mass (3), a tire equivalent spring (8), a hybrid active-passive damping device (9), an actuator (10), an ECU (11), and an acceleration sensor (12); the main spring (2), the main damper (5), and the hybrid active-passive damping device (9) are arranged in parallel between the sprung mass (1) and the unsprung mass (3); the unsprung mass (3) is provided with an acceleration sensor (12), the acceleration sensor (12) is connected to the ECU (11), and the ECU (11) is connected to the hybrid active-passive damping device (9) through the actuator (10).

2. The active-passive hybrid suspension according to claim 1, characterized in that, The active-passive hybrid vibration damping device (9) includes an active vibration damping device and a passive vibration damping device. The passive vibration damping device includes a secondary damper (16), a secondary spring (13), and an oscillator mass (14). The secondary damper (16) and the secondary spring (13) are connected in parallel, and the oscillator mass (14) is connected in series with the secondary damper (16) and the secondary spring (13). The active vibration damping device includes an active actuator (15), wherein the active actuator (15) is connected in series with the oscillator mass (14).

3. The active-passive hybrid suspension according to claim 1, characterized in that, The active-passive hybrid vibration damping device (9) includes an active vibration damping device and a passive vibration damping device. The passive vibration damping device includes a secondary damper (16) and a secondary spring (13), which are connected in parallel. The active vibration damping device includes an active actuator (15), which is connected in series with the secondary damper (16) and the secondary spring (13). The active actuator (15) includes an actuator stator (17) and an actuator mover (18). 8); The actuator stator (17) is connected in series with the auxiliary spring (13) and the auxiliary damper (16), and the actuator mover (18) is connected in series with the unsprung mass (3), wherein the mass of the actuator stator (17) is equivalent to the oscillator mass (14); or the actuator mover (18) is connected in series with the auxiliary spring (13) and the auxiliary damper (16), and the actuator stator (17) is connected in series with the unsprung mass (3), wherein the mass of the actuator mover (18) is equivalent to the oscillator mass (14).

4. The method for controlling the ground cover negative inertia capacity of a hybrid active-passive suspension according to any one of claims 2-3, characterized in that, Includes the following steps: Step 1: Select the proportion coefficient in the active-passive hybrid suspension. Thus, the negative inertia coefficient b of the ground shed is determined. ngnd The value of is selected according to the following formula: In the formula, m e The mass of the hub motor (7), m w For the mass of the wheel (6); Step 2: Obtain the unsprung mass acceleration using the accelerometer (12) Transmitted to ECU (11); Step 3: ECU (11) calculates the unsprung mass acceleration based on the obtained data. The value is calculated based on the following formula to determine the magnitude of the main driving force of the active-passive hybrid vibration damping device (9): In the formula, F max The maximum force that the main actuator can output; Step 4: ECU (11) adjusts the negative inertia coefficient b of the ground cover according to the selected size. ngnd This allows the actuator (10) to drive and adjust the active and passive hybrid vibration damping device (9), effectively simulating the negative inertia capacity of the shed.

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