Anti-roll torque distribution control method and system

Abstract

The invention relates to the technical field of vehicle active safety, and provides an anti-roll moment distribution control method, which specifically comprises the following steps of: in a vehicle driving process, detecting a lateral acceleration ay of a vehicle in real time; an ideal roll angle # imgabs0 # under the current lateral acceleration ay is determined, the current vehicle body roll angle # imgabs1 # of the vehicle is detected, the difference value between the ideal roll angle # imgabs2 # and the current vehicle body roll angle # imgabs3 # serves as the input of a PID controller, the PID controller outputs the anti-roll torque # imgabs4 # currently needed by the vehicle, and the vertical load transfer amount delta Wf of a front suspension and the vertical load transfer amount delta Wr of a rear suspension are calculated; the anti-roll moment # imgabs5 is distributed to the front suspension and the rear suspension based on the vertical load transfer amount of the front suspension and the rear suspension. According to the vehicle suspension vertical load transfer amount, an anti-roll moment distribution method is designed, and roll stiffness of the front suspension and the rear suspension is further adjusted through stabilizer bars of the front suspension and the rear suspension, so that excessive steering amount of a vehicle is reduced, insufficient steering amount is increased, and active safety of vehicle driving is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle active safety, and provides an anti-roll moment distribution control method and system. Background Art

[0002] During the turning process of the car, the car body rolls due to centrifugal force, load transfer, etc. The body roll angle will affect the steady-state response and transient response of the car's yaw rate. Excessive body roll angle will not only reduce the stability and safety of the car, but also reduce the smoothness of the vehicle's driving, thus affecting the riding comfort of passengers.

[0003] By increasing the suspension roll stiffness to reduce the body roll angle, the impact force of the car's vibration and bumps will increase when the car is driving on uneven roads, and the smoothness of the whole vehicle will deteriorate. In order to improve the car's anti-roll ability, the vehicle's suspension roll stiffness can be increased by using a stabilizer bar.

[0004] Stabilizer bars are divided into active stabilizer bars and passive stabilizer bars. Currently, most vehicles use passive stabilizer bars. The stiffness of the vehicle suspension corresponding to the passive stabilizer bar is a set value. The stiffness of the vehicle suspension cannot be adaptively adjusted, and the vehicle may still experience excessive roll angles. Summary of the invention

[0005] In view of this, the present application provides an anti-roll moment distribution control method, aiming to improve the above-mentioned problem.

[0006] Specifically, the following technical solutions are included:

[0007] On the one hand, an embodiment of the present application provides an anti-roll moment distribution control method, and the method is specifically as follows:

[0008] (1) During vehicle driving, the lateral acceleration a of the vehicle is detected in real time y , determine the current lateral acceleration a y Ideal roll angle

[0009] (2) Detect the vehicle's current body roll angle , the ideal roll angle With the current body roll angle The difference is used as the input of the PID controller, and the PID controller outputs the anti-roll moment currently required by the vehicle.

[0010] (3) Calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , based on the vertical load transfer of the front and rear suspensions, the anti-roll moment Assigned to front and rear suspension.

[0011] In some embodiments of the present invention, the current lateral acceleration a y Ideal roll angle The acquisition process is as follows:

[0012] The front lateral acceleration a y Input the ideal roll angle calculation model, and the ideal roll angle calculation model calculates the current lateral acceleration a y Corresponding ideal roll angle , the method for forming the ideal roll angle calculation model is as follows:

[0013] The maximum roll angle that will not occur under different lateral accelerations is calibrated, and multiple sets of lateral accelerations and their corresponding maximum roll angles are modeled to form an ideal roll angle calculation model.

[0014] In some embodiments of the present invention, the ideal roll angle calculation model is specifically expressed as follows:

[0015]

[0016] Among them, A, B, and E are fitting coefficients.

[0017] In some embodiments of the present invention, at the current lateral acceleration a y satisfy: The vehicle will not roll over.

[0018] In some embodiments of the present invention, based on the current lateral acceleration a y To calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , the vertical load transfer of the front suspension ΔW f , vertical load transfer of the suspension ΔW r The calculation formula is as follows:

[0019]

[0020] Among them, h s is the distance between the center of mass of the vehicle body and the roll axis, h 0 is the distance between the center of the vehicle's roll axis and the ground, B t is the wheelbase of the front or rear wheels, L f , L r are the distances from the vehicle's center of mass to the front axle and rear axle, respectively, h f is the distance from the front suspension roll center to the ground, h r is the distance from the rear suspension roll center to the ground, m s is the vehicle body mass, mu is the unsprung mass, k f , k r are the equivalent roll stiffness of the front suspension spring and the rear suspension spring respectively, r is the wheel radius, and L is the wheelbase between the front axle and the rear axle.

[0021] In some embodiments of the present invention, the vertical load transfer ΔW of the front suspension is calculated according to f , vertical load transfer of the suspension ΔW r Determine the roll moment distribution method.

[0022] In some embodiments of the present invention, if ΔW f <ΔW r , the anti-rolling moment All applied to the rear suspension.

[0023] In some embodiments of the present invention, if ΔW f ≥ΔW r , the anti-rolling moment Distributed to the front suspension and rear suspension, the anti-roll moment distributed to the front suspension and rear suspension The allocation is based on the following formula:

[0024]

[0025] In some embodiments of the present invention, the ideal roll angle The actual roll angle of the vehicle The difference As the input of PID controller , the PID controller calculates the anti-roll moment currently required by the vehicle based on the following formula :

[0026]

[0027] Among them, K P is the proportionality coefficient, K I is the integration coefficient, K D is the differential coefficient.

[0028] On the other hand, an embodiment of the present application provides an anti-roll moment distribution control system, the system comprising:

[0029] A collection unit, and a controller connected to the collection unit;

[0030] The acquisition unit collects the vehicle's current lateral acceleration a in real time y and body roll angle , and sent to the controller, which allocates the anti-roll moment currently required by the vehicle based on the above anti-roll moment distribution control method. Assigned to front suspension and rear suspension.

[0031] The present invention proposes an anti-roll moment distribution control strategy for vehicle active safety, which has a simple calculation process and is easy to apply. , using PID control to obtain the vehicle anti-roll moment ; The anti-roll moment distribution method is designed according to the vertical load transfer of the vehicle suspension, and the roll stiffness of the front and rear suspensions is further adjusted through the stabilizer bars of the front and rear suspensions, so as to reduce the excessive steering amount of the vehicle, increase the understeering amount, and effectively improve the active safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A flow chart of the anti-roll moment distribution control method provided by an embodiment of the present invention;

[0034] Figure 2 A side view schematic diagram of a vehicle rollover provided by an embodiment of the present invention;

[0035] Figure 3 A rear view diagram of a vehicle rollover provided by an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of the structure of an anti-roll moment distribution control system provided by an embodiment of the present invention;

[0037] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical terms used in the embodiments of the present application have the same meanings as commonly understood by those of ordinary skill in the art.

[0040] Figure 1 A flow chart of an anti-roll moment distribution control method provided by an embodiment of the present invention, the method comprising the following steps:

[0041] (1) During vehicle driving, the lateral acceleration a of the vehicle is detected in real time y , determine the current lateral acceleration a y Ideal roll angle , ideal roll angle is the current lateral acceleration a y The maximum roll angle at which rollover does not occur;

[0042] In this embodiment of the present invention, the current lateral acceleration a y Ideal roll angle The acquisition process is as follows:

[0043] The front lateral acceleration a y Input the ideal roll angle calculation model, and the ideal roll angle calculation model calculates the current lateral acceleration a y Corresponding ideal roll angle , the method for forming the ideal roll angle calculation model is as follows:

[0044] The maximum roll angle that will not occur under different lateral accelerations is calibrated, and multiple sets of lateral accelerations and their corresponding maximum roll angles are modeled to form an ideal roll angle calculation model. The ideal roll angle calculation model is specifically expressed as follows:

[0045]

[0046] Among them, A, B, and E are fitting coefficients.

[0047] In the embodiment of the present invention, when the vehicle satisfies formula (2), the vehicle will roll over. Formula (2) is specifically as follows:

[0048]

[0049] Among them, h 0 is the distance between the vehicle's roll center and the ground, h g is the distance between the center of mass of the vehicle and the ground, B t is the vehicle wheelbase, R φ is the vehicle roll rate, g is the gravitational acceleration, in order to ensure that the vehicle does not roll over, the current lateral acceleration a y The following formula (3) is satisfied. The specific formula (3) is as follows:

[0050]

[0051] (2) Detect the vehicle's current body roll angle , the ideal roll angle With the current body roll angle The difference is used as the input of the PID controller, and the PID controller outputs the anti-roll moment currently required by the vehicle. ;

[0052] In the embodiment of the present invention, the ideal roll angle is first calculated The actual roll angle of the vehicle The difference , the difference As the input of PID controller , the PID controller can calculate the anti-roll moment currently required by the vehicle based on formula (4): , formula (4) is as follows:

[0053]

[0054] Among them, K P is the proportionality coefficient, K I is the integration coefficient, K D is the differential coefficient.

[0055] (3) Calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , based on the vertical load transfer of the front and rear suspensions, the anti-roll moment Assigned to front and rear suspension.

[0056] In the embodiment of the present invention, based on the current lateral acceleration a y To calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , combined with Figure 2 and Figure 3 To illustrate the vertical load transfer ΔW of the front suspension f , vertical load transfer of the suspension ΔW r Calculation of the vertical load transfer of the suspension ΔW f , vertical load transfer of the suspension ΔW r The calculation formulas are shown in formula (5) and formula (6) respectively:

[0057]

[0058] Among them, h s is the distance between the center of mass of the vehicle body and the roll axis, h 0is the distance between the center of the vehicle's roll axis and the ground, B t is the wheelbase of the front or rear wheels, L f , L r are the distances from the vehicle's center of mass to the front axle and rear axle, respectively, h f is the distance from the front suspension roll center to the ground, h r is the distance from the rear suspension roll center to the ground, m s is the vehicle body mass, m u is the unsprung mass, k f , k r are the equivalent roll stiffness of the front suspension spring and the rear suspension spring respectively, r is the wheel radius, and L is the wheelbase between the front axle and the rear axle.

[0059] In the embodiment of the present invention, the vertical load transfer amount ΔW of the front suspension is calculated according to f , vertical load transfer of the suspension ΔW r Determine the roll moment distribution method. The roll moment distribution method is divided into the following two cases:

[0060] Case 1: If ΔW f <ΔW r , the anti-rolling moment All work on the rear suspension;

[0061] In the second case, if ΔW f ≥ΔW r , the anti-rolling moment Distributed to the front suspension and rear suspension, the anti-roll moment distributed to the front suspension and rear suspension The calculation is performed based on formula (7), which is as follows:

[0062]

[0063] When necessary, the anti-roll moment It acts on the active stabilizer bar of the front suspension and rear suspension respectively. The active stabilizer bar will be based on the anti-roll moment Further adjust the roll stiffness of the front and rear suspension.

[0064] The present invention proposes an anti-roll moment distribution control strategy for vehicle active safety, which has a simple calculation process and is easy to apply. , using PID control to obtain the vehicle anti-roll moment ; The anti-roll moment distribution method is designed according to the vertical load transfer of the vehicle suspension, and the roll stiffness of the front and rear suspensions is further adjusted through the stabilizer bars of the front and rear suspensions, so as to reduce the excessive steering amount of the vehicle, increase the understeering amount, and effectively improve the active safety of the vehicle.

[0065] Figure 4 The structure diagram of the anti-roll moment distribution control system provided by the embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown. The system includes:

[0066] A collection unit, and a controller connected to the collection unit;

[0067] The acquisition unit collects the vehicle's current lateral acceleration a in real time y and body roll angle , and sent to the controller, which allocates the anti-roll moment currently required by the vehicle based on the above anti-roll moment distribution control method. Assigned to the active stabilizer bars on the front and rear suspensions, the active stabilizer bars will be based on the anti-roll moment Further adjust the roll stiffness of the front and rear suspension.

[0068] The present invention utilizes a controller to control the roll angle of a vehicle body in a driving state, thereby preventing an excessively large roll angle of the vehicle body from reducing the driving stability and safety of the vehicle. By utilizing the distribution of the anti-roll moment and further adjusting the roll stiffness of the front and rear suspensions through the stabilizer bars of the front and rear suspensions, the over-steering characteristic of the vehicle is reduced, the under-steering characteristic is increased, and the active safety of the vehicle driving is increased.

[0069] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the present application disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only.

[0070] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for controlling the distribution of anti-roll moment, characterized in that: The method is specifically as follows: (1) During vehicle driving, the lateral acceleration a of the vehicle is detected in real time y , determine the current lateral acceleration a y Ideal roll angle (2) Detect the vehicle's current body roll angle The ideal roll angle With the current body roll angle The difference is used as the input of the PID controller, and the PID controller outputs the anti-roll moment currently required by the vehicle. (3) Calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , based on the vertical load transfer of the front and rear suspensions, the anti-roll moment Assigned to front and rear suspension.

2. The anti-roll moment distribution control method according to claim 1, characterized in that: Current lateral acceleration a y Ideal roll angle The acquisition process is as follows: The front lateral acceleration a y Input the ideal roll angle calculation model, and the ideal roll angle calculation model calculates the current lateral acceleration a y Corresponding ideal roll angle The method for forming the ideal roll angle calculation model is as follows: The maximum roll angle that will not occur under different lateral accelerations is calibrated, and multiple sets of lateral accelerations and their corresponding maximum roll angles are modeled to form an ideal roll angle calculation model.

3. The anti-roll moment distribution control method according to claim 2, characterized in that: The ideal roll angle calculation model is expressed as follows: Among them, A, B, and E are fitting coefficients.

4. The anti-roll moment distribution control method according to claim 3, characterized in that: At the current lateral acceleration a y satisfy: The vehicle will not roll over.

5. The anti-roll moment distribution control method according to claim 1, characterized in that: Based on the current lateral acceleration a y To calculate the vertical load transfer ΔW of the front suspension f and the vertical load transfer of the rear suspension ΔW r , the vertical load transfer of the front suspension ΔW f , vertical load transfer of the suspension ΔW r The calculation formula is as follows: Among them, h s is the distance between the center of mass of the vehicle body and the roll axis, h0 is the distance between the center of the vehicle roll axis and the ground, B t is the wheelbase of the front or rear wheels, L f , L r are the distances from the vehicle's center of mass to the front axle and rear axle, respectively, h f is the distance from the front suspension roll center to the ground, h r is the distance from the rear suspension roll center to the ground, m s is the vehicle body mass, m u is the unsprung mass, k f , k r are the equivalent roll stiffness of the front suspension spring and the rear suspension spring respectively, r is the wheel radius, and L is the wheelbase between the front axle and the rear axle.

6. The anti-roll moment distribution control method according to claim 5, characterized in that: According to the calculation of the vertical load transfer of the front suspension ΔW f , vertical load transfer of the suspension ΔW r Determine the roll moment distribution method.

7. The anti-roll moment distribution control method according to claim 6, characterized in that: If ΔW f <ΔW r , the anti-rolling moment All applied to the rear suspension.

8. The anti-roll moment distribution control method according to claim 6, characterized in that: If ΔW f ≥ΔW r , the anti-rolling moment Distributed to the front suspension and rear suspension, the anti-roll moment distributed to the front suspension and rear suspension The allocation is based on the following formula:

9. The anti-roll moment distribution control method according to claim 1, characterized in that: The ideal roll angle The actual roll angle of the vehicle The difference As the input of PID controller The PID controller calculates the anti-roll moment currently required by the vehicle based on the following formula: Among them, K P is the proportionality coefficient, K I is the integration coefficient, K D is the differential coefficient.

10. An anti-roll moment distribution control system, characterized in that: The system comprises: A collection unit, and a controller connected to the collection unit; The acquisition unit collects the vehicle's current lateral acceleration a in real time y and body roll angle and sent to the controller, which allocates the anti-roll moment currently required by the vehicle based on the anti-roll moment distribution control method according to any one of claims 1 to 9. Active stabilizer bars assigned to the front and rear suspensions.

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