阅读说明：本技术 用于控制配备有半主动悬架的车辆的稳定性的系统和方法 (System and method for controlling stability of a vehicle equipped with a semi-active suspension ) 是由 马泰奥·科尔诺 塞尔焦·马泰奥·萨瓦雷西 朱利奥·潘扎尼 奥尔加·加卢皮 雅各布·切科尼 于 2020-04-08 设计创作，主要内容包括：用于控制配备有半主动减振器(4)的车辆(1)的稳定性的系统(100)包括：致动器(5)、多个传感器(6C、6D)、低级控制单元(8L)、高级控制单元(8H)、以及适于执行算法(A)以计算阻尼水平(C-(ref))的中级控制单元(8M)。(System (100) for controlling the stability of a vehicle (1) equipped with a semi-active shock absorber (4) comprising: an actuator (5), a plurality of sensors (6C, 6D), a low level control unit (8L), a high level control unit (8H), and a processor adapted to execute an algorithm (A) to calculate a level of damping (C) ref ) The intermediate control unit (8M).)

1. A system (100) for controlling the stability of a vehicle (1) having a longitudinally extending axis (x), a transversely extending axis (y) and a vertically extending axis (z) and comprising a body (2), a plurality of wheels (3) and, for each wheel (3), at least one semi-active shock absorber (4) interposed between the respective wheel (3) and the body (2); the control system (100) comprises:

-at least one actuator (5) configured to continuously adjust a damping level (C) of said semi-active shock absorber (4)_ref)；

-at least a first sensor (6D) configured to measure at least one kinetic parameter of the vehicle (1) and to send at least a first signal (S1) containing an item of information about said kinetic parameter;

-at least a second sensor (6C) configured to measure an input entered by a driver of the vehicle (1) and to send at least a second signal (S2) containing an item of information about the input;

-a high-level control unit (8H) in communication with the first sensor (6D) and the second sensor (6C) and configured to receive the first signal (S1) and the second signal (S2);

-a medium-level control unit (8M) in communication with the high-level control unit (8H) and the first sensor (6D) to receive the first signal (S1);

-a low level control unit (8L) in communication with the actuator (5) and the medium level control unit (8M) and configured to send a drive signal to the actuator (5);

and characterized in that the advanced control unit (8H) is configured to parameterize an algorithm (A) according to the first signal (S1) and the second signal (S2), the algorithm (A) being executed by the intermediate unit (8M) to calculate the damping level (C) according to the first signal (S1)_ref)。

2. The system (100) according to the preceding claim, comprising a computerized calculation unit (7) communicating with said first sensor (6D), said second sensor (6C), said advanced control unit (8H) and said intermediate control unit (8M); the computerized computing unit (7) is configured to: -processing the first signal (S1) and the second signal (S2) and sending at least one quantity derived from the first signal (S1) and the second signal (S2) to the advanced control unit (8H) and the intermediate control unit (8M).

3. The system (100) according to any one of the preceding claims, wherein the first sensor (6D) comprises at least one of:

-an accelerometer (10) configured to measure the acceleration of the body (2) close to a respective wheel (3) along a direction parallel to the vertically extending axis (z);

-a potentiometer (11) configured to measure the compression of the shock absorber (4) along a direction parallel to the vertical extension axis (z);

and the second sensor (6C) comprises at least one of:

-a steering angle sensor (12) configured to measure a steering angle (δ) determined by a steering wheel (13);

-an accelerator sensor (14) configured to measure an action exerted by a command from the accelerator (15);

-a brake sensor (16) configured to measure an action exerted by a command from the brake (17).

4. System (100) according to claims 2 and 3, wherein said first sensor (6D) comprises at least said potentiometer (10) and said accelerometer (11), said computerized calculation unit (7) being configured to calculate a vertical speed (zj) of the body close to the wheel (3) from said first signal (S1) containing at least one item of information from said accelerometer (10) and said potentiometer (11)_c) And the compression velocity (z) of the damper_d)。

5. The system (100) according to the preceding claim, wherein the damping level (C) of the shock absorber (4)_ref) By the intermediate control unit (8M) based on the vertical speed (z) of the vehicle body_c) And the compression speed (z) of said damper_d) To calculate.

6. System (100) according to the preceding claim, wherein the damping water of the shock absorber (4)Flat (C)_ref) -calculating by said intermediate control unit (8M) using said algorithm (a) defined as:

wherein (C)_min) And (C)_max) Respectively, the applicable damping level (C)_ref) And wherein (K)_sky) And (C)_nom) Are two adjustable parameters representing the gain of the algorithm (A) and the speed (z) of the vehicle body in the absence of vertical_c) Or the compression speed (z) of the damper_d) Nominal damping level in the case of (2).

7. The system (100) according to the preceding claim, wherein the nominal damping level (C) is calculated by the advanced control unit (8H)_nom) The following were used:

C_nom＝C₀+C_lat+C_long，

wherein (C)₀) Is a default nominal damping level and wherein (C)_lat) And (C)_long) Respectively a first and a second addition factor, both calculated by the advanced control unit (8H) from the first signal (S1) and the second signal (S2).

8. The system (100) according to the preceding claim, wherein the first addition factor (C)_lat) Is calculated as follows:

C_lat＝K_latA_y,HP，

wherein (K)_lat) Is an adjustable gain factor, (A)_y,HP) Is the following amount A_yThe filtration form of (1):

wherein (v) is the speed of movement of the vehicle (1), (K)_us) Is thatA steering reference coefficient, (L) is a parameter describing a track length of the vehicle (1).

9. The system (100) according to claim 7 or 8, wherein the second addition factor (C)_long) Is calculated as follows:

C_long＝K_longA_x,HP，

wherein (K)_long) Is an adjustable gain factor, (A)_x,HP) Is the following amount A_xThe filtration form of (1):

wherein (ρ) is the air density, (S) is the front surface of the vehicle (1), (C)_x) Is the aerodynamic friction coefficient of the vehicle (1), (m) is the mass of the vehicle (1), (v) is the speed of movement of the vehicle (1), (k)_bk) Is the braking efficiency, (P)_bk) Is the pressure (k) on the brake control device (17) measured by the brake sensor (16)_pos) Is a first model parameter describing the efficiency of the propulsion unit, (k)_neg) Is a second model parameter describing the efficiency of the propulsion unit, (T)_eng,pos) Is a parameter describing the positive torque of the engine (T)_eng,neg) Is a parameter describing the negative torque of the engine, and (ω)_eng) Is a parameter describing the number of revolutions of the engine of the vehicle (1).

10. The system (100) according to any one of the preceding claims, wherein the damper (4) is a magnetorheological damper.

11. A method (200) for controlling the stability of a vehicle (1), said vehicle (1) having a longitudinally extending axis (x), a transversely extending axis (y) and a vertically extending axis (z) and comprising a body (2), a plurality of wheels (3) and at least one semi-active shock absorber (4) for each wheel (3) interposed between the respective wheel (3) and the body (2); the method (200) comprises the steps of:

-a first measurement step (201) for capturing at least one kinetic parameter of the vehicle (1);

-a second measurement step (202) for capturing at least one input entered by a driver of the vehicle (1);

-executing an algorithm (a) to calculate a damping level (C) of the shock absorber (4) as a function of the dynamic parameters and the inputs_ref) Step (203);

-implementing said level of damping (C) calculated by said algorithm (A) by means of an actuator (5) operatively connected to said shock absorber (4)_ref) Step (204).

12. Method (200) according to the preceding claim, wherein said first measurement step (201) for capturing at least one dynamic parameter of the vehicle (1) comprises at least one of the following sub-steps:

-measuring at least one acceleration of the body (2) close to the wheel (3) along a direction parallel to the vertical axis (z) of the vehicle (1);

-measuring at least one compression of the shock absorber (4) along a direction almost parallel to the vertical axis (z).

13. The method (200) according to the preceding claim, wherein said first measurement step (201) comprises at least a sub-step of measuring at least one acceleration of the body (2) and a sub-step of measuring at least one compression of the shock absorber (4), said first measurement step (201) comprising processing said dynamic parameters of the vehicle (1) to calculate a vertical speed (z) of the body close to the wheels (3)_c) And the compression speed (z) of said shock absorber_d) And (2) a substep of (a).

14. The method (200) according to any one of claims 11-13, wherein the second measuring step (202) for capturing input entered by a driver of the vehicle (1) comprises at least one of the following sub-steps:

-measuring a steering angle (δ) determined by a steering wheel (13);

-measuring an acceleration action exerted by a command from the accelerator (15);

-measuring the braking action applied by the command from the brake (16).

15. The method (200) according to claims 13 and 14, wherein performing step (203) comprises performing the algorithm (a) defined as:

wherein (C)_min) And (C)_max) Respectively, the applicable damping level (C)_ref) And wherein (K)_sky) And (C)_nom) Are two adjustable parameters representing the gain of the algorithm (A) and the speed (z) of the vehicle body in the absence of vertical_c) Or the compression speed (z) of the damper_d) Nominal damping level in the case of (2).

16. The method (200) according to the preceding claim, wherein said parameter (C) is calculated as a function of said kinetic parameter of the vehicle (1) captured during said first measurement step (201) and said input captured during said second measurement step (202)_nom)。

Technical Field

The present invention relates to a system and a method for controlling the stability of a vehicle, in particular a vehicle equipped with a semi-active suspension.

Background

Suspension systems have a great impact on the drivability and safety of the vehicle and the driver's comfort on uneven road surfaces.

Modern stability control systems are primarily concerned with two types of suspension: electro-pneumatic suspensions and semi-active suspensions.

These two types of suspensions differ in that: electro-pneumatic suspensions are active and capable of applying forces, while semi-active suspensions are passive and the resistance to contraction and expansion of the suspension is adjustable.

However, semi-active suspension has the following advantages: have a higher control frequency and are less bulky in terms of weight and space, and consume less energy because they are passive.

The control methods known so far implement skyhook-type algorithms designed to limit as much as possible the dynamics of the damped mass (i.e. the vehicle body) -compared to the substantially undamped mass in contact with the ground (i.e. the wheels).

Based on the vertical velocities of the body and wheels measured by specific sensors, the skyhook algorithm calculates the ideal level of damping that the shock absorbers must apply in order to ensure optimal ride quality.

Most suspension control methods developed are based on mathematical models of vehicle angle to locally attenuate the impact caused by road surface irregularities.

However, these systems fail to control the overall dynamics of the vehicle, such as left and right roll and pitch dynamics, as determined by steering, braking and acceleration commands given by the driver, which affect vehicle stability and driving enjoyment.

To control these dynamics, the prior art teaches the use of a hierarchical system, where low-level controllers are used to process individual vehicle dynamics, and high-level controllers are used to determine which low-level controllers have priority based on predetermined logic.

Thus, suspension control is managed in a sub-optimal manner, since one control system takes precedence over the other, and commands from the other are therefore ignored.

Thus, when higher priority is assigned to the right and left roll and pitch control systems, commands issued by the system controlling the damping of road irregularities are ignored, and vice versa.

Thus, these priority-based control systems do not ensure comprehensive, synchronized control of vehicle dynamics, which can adversely affect the driving comfort and grip of the vehicle.

Therefore, the need to provide an overall system is particularly strongly felt in the field of vehicle stability control: a system capable of simultaneously addressing both road surface irregularities and overall vehicle dynamics.

Disclosure of Invention

Against this background, the main object of the present invention is to overcome the above-mentioned drawbacks.

In particular, the object of the present disclosure is to propose a control system for the stability of a vehicle equipped with a semi-active shock absorber which allows to simultaneously handle the oscillations due to the road surface irregularities and the rolling and pitching dynamics of the vehicle due to the manoeuvre of the driver.

According to one aspect of the present disclosure, a control system for stability of a vehicle equipped with a semi-active shock absorber comprises:

-a plurality of actuators configured to continuously adjust a damping level of the semi-active shock absorber;

-a first set of sensors configured to detect at least one kinetic parameter of the vehicle;

-a second set of sensors configured to capture input from a driver of the vehicle;

-an advanced control unit configured to calculate, by means of a model, nominal damping parameters from the quantities detected by the two sets of sensors;

-at least one intermediate-level control unit configured to calculate, by means of a parameterized algorithm, the level of damping to be applied to each shock absorber by the intermediate-level control unit as a function of the quantities detected by the first set of sensors;

-at least one low level control unit configured to send a drive signal to an actuator of the shock absorber.

According to another aspect, the present disclosure relates to a method of controlling stability of a vehicle, comprising the steps of: capturing the dynamic parameters of the vehicle, capturing the input entered by the driver, executing an algorithm to calculate the optimal damping level to be applied to each shock absorber equipped to the vehicle and finally implementing the calculated damping levels.

Drawings

Further features and advantages of the invention will become clearer in the non-limiting description of a preferred but not exclusive embodiment of a control system for the stability of a vehicle, illustrated in the attached drawings, wherein:

figure 1 represents a schematic side view of a vehicle equipped with the stability control system of the present patent specification;

figure 2 schematically shows a detail of the stability control system of figure 1;

fig. 3 shows the matching between the dynamic parameters of the vehicle and the damping levels by means of a grey scale map.

Detailed Description

With particular reference to the figures, reference numeral 100 denotes a control system for the stability of the vehicle 1.

As shown, the vehicle 1 has a vehicle body 2 and a plurality of wheels 3, the plurality of wheels 3 being points of contact of the vehicle with the ground.

Preferably, the vehicle 1 has four wheels 3.

The vehicle 1 also has a longitudinally extending axis x, a transversely extending axis y and a vertically extending axis z.

The vehicle 1 further comprises at least one semi-active shock absorber 4 for each wheel 3 with which the vehicle 1 is equipped; since the semi-active damper 4 is preferably technically identical for each wheel, for the sake of simplicity only one damper 4 is mentioned below.

The shock absorbers 4 are interposed between the respective wheels 3 and the vehicle body 2 and are configured to damp oscillations of the vehicle body 2 along a vertically extending axis z of the vehicle 1.

Preferably, the shock absorber 4 has a damping at a minimum level C_minAnd maximum damping level C_maxBetween continuously adjustable damping levels C_ref。

In other words, possible damping level C_refIs not limited and predetermined, but may be represented by C_minAnd C_maxThe defined range is set as required.

Advantageously, the damping level C is comparable to a conventional ceiling system with a limited number of adjustment levels_refThe fact that it is continuously adjustable allows the system 100 to have virtually unlimited possibilities of setting the damping level, with obvious advantages in terms of stability and driving pleasure of the vehicle 1.

In a preferred but non-limiting embodiment, the semi-active damper 4 is a magnetorheological damper: that is, a shock absorber in which the resistance to oscillation is adjusted by applying a magnetic field to change the fluid dynamic characteristics of the liquid contained in the shock absorber 4 itself.

In another embodiment, the semi-active damper 4 is an electrorheological or electrohydrodynamic damper.

The stability system 100 of the vehicle 1 is responsible for controlling and driving the shock absorbers 4 of the vehicle 1 to limit the oscillations of the vehicle body 2 along the vertically extending axis z, so as to ensure an optimal comfort for the driver of the vehicle 1.

As shown in FIG. 2, the system 100 includes a damper configured to continuously adjust the damping level C of the shock absorber 4_refAt least one actuator 5.

Preferably, each shock absorber 4 with which the vehicle 1 is equipped is associated with an actuator 5 responsible for driving the respective shock absorber 4.

The actuator 5 converts the control signal into a mechanical, electrical or magnetic stimulus for continuously varying the physical characteristics of the semi-active shock absorber 4, thus adjusting its response to the oscillation of the corresponding wheel 3 and/or vehicle body 2 along the vertically extending axis z.

The system 100 comprises at least a first sensor 6D configured to measure at least one kinetic parameter of the vehicle 1 and to send at least a first signal S1 containing an item of information about the kinetic parameter.

Preferably, the at least first sensor 6D comprises at least one of:

an accelerometer 10 configured to measure the acceleration of the body 2 close to one wheel 3 along a direction parallel to the vertically extending axis z;

a potentiometer 11 configured to measure the compression of the shock absorber 4 along its extension axis;

a GPS sensor configured to capture the position of the vehicle 1.

As also shown, the system 100 comprises at least a second sensor 6C configured to capture an input entered by the driver of the vehicle 1 and to send at least a second signal S2 containing an item of information about the input.

Preferably, the at least second sensor 6C comprises at least one of the following sensors:

a steering angle sensor 12 configured to measure a steering angle δ determined by a steering wheel 13;

an accelerator sensor 14 configured to measure the action exerted by a command from an accelerator 15;

a brake sensor 16 configured to measure the action exerted by a command from the brake 17.

In other words, the second sensor 6C monitors the driver's behaviour, the driver's actions being reflected (after the response interval) on the translational and oscillatory movements of the vehicle 1, which are then monitored by the first sensor 6D.

Advantageously, the use of two different types of sensors (one for monitoring the movements of the vehicle 1 and the other for monitoring the movements of the driver) allows to predict, by means of a model, the future dynamics of the vehicle 1, in particular the longitudinal and lateral accelerations to which the vehicle 1 will be subjected.

The possibility of predicting the future dynamics of the vehicle 1 also ensures that the system 100 can preventively adjust the state of the shock absorber 4 to guarantee the driving comfort of the driver, while guaranteeing good grip.

Also as shown, the system 100 includes a high level control unit 8H in communication with the first sensor 6D and the second sensor 6C.

The advanced control unit 8H is configured to calculate a nominal damping parameter C from the first signal S1 and the second signal S2_nom。

Nominal damping parameter C_nomIndicating the level of damping that the shock absorbers 4 have to exert when not vibrating the vehicle body 2 or the respective wheel 3 along the vertically extending axis z of the vehicle 1.

Advantageously, relying on the second signal S2 received from the second sensor 6C allows the advanced control unit 8H to calculate the nominal damping level C also based on the driver' S actions_nomSo that the response of the system 100 to the dynamics of the vehicle 1 can be predicted and thus improved.

The system 100 also includes a mid-level control unit 8M in communication with the high-level control unit 8H and the first sensor 6D.

The intermediate control unit 8M is configured to receive the nominal damping parameter C from the high level control unit 8H_nomAnd calculates, by an algorithm or calculation routine a, a damping level C from the first signal S1 received from the first sensor 6D_ref。

In other words, the intermediate-level control unit 8M communicates with the high-level control unit 8H, the high-level control unit 8H being responsible for calculating the damping level C to be applied at the level of the shock absorber 4_refIs parameterized.

Thus, the term "parameterization of the algorithm" is used to denote a calculation parameter which, when applied as an input to the algorithm, affects the result of the algorithm in substantially the same way as the independent input variable (in our case, the signal S1).

The term algorithm is used to denote any calculation routine that allows to obtain the value of an output variable from an input variable and/or an input parameter by a limited number of steps performed according to a limited set of rules.

In one embodiment, system 100 comprises a medium-level control unit 8M for each shock absorber 4 with which vehicle 1 is equipped, each medium-level control unit 8M thus being responsible for calculating the damping level C of a single shock absorber 4_ref。

Preferably, the high level control unit 8H sends to the medium level control unit 8M the nominal damping level C constituting the input variable in algorithm a_nom。

Thus, algorithm a is based on the first signal S1 received from the first sensor 6D and the nominal damping parameter C received from the advanced control unit 8H_nomTo calculate the damping level C_ref。

Specifically, each intermediate-level control unit 8M executes a respective algorithm A to calculate an optimal damping level C for its associated shock absorber 4 independently of the other intermediate-level control units 8M_ref。

Advantageously, the presence of the intermediate-level control unit 8M of each shock absorber 4 of the vehicle 1 allows each shock absorber 4 to perform a respective algorithm a differently and distinctly from the other shock absorbers 4.

Nominal damping level C calculated by advanced control unit 8H_nomIs sent to all the intermediate level control units 8M.

In one embodiment, the same nominal damping level C_nomIs sent to the intermediate-level control units 8M and thus constitutes an input variable common to all the algorithms A, each intermediate-level control unit 8M then independently executing the algorithms A to calculate the optimum damping levels C of the shock absorbers 4 respectively associated therewith_ref。

In another embodiment, a different and specific nominal damping level C_nomIs sent to each intermediate-stage control unit 8M and constitutes an input variable of the corresponding algorithm A, which is therefore executed independently of the other algorithms of the other intermediate-stage control units 8M to calculate the optimal damping level C of the shock absorber 4 associated therewith_ref。

The system 100 includes a low-level control unit 8L, the low-level control unit 8L being in communication with the medium-level control unit 8M and the actuator 5 and configured to send a drive signal to the actuator 5.

More specifically, the low level control unit 8L is configured to receive a signal containing the required damping level C from the medium level control unit 8M_refAnd generates a corresponding drive signal for the actuator 5.

Preferably, the system 100 comprises a low level control unit 8L for each actuator 5 with which the vehicle 1 is equipped, each low level control unit 8L therefore being responsible for driving a single actuator 5.

In a preferred embodiment, the system 100 comprises a computerized calculation unit 7 in communication with the first sensor 6D, the second sensor 6C, the advanced control unit 8H and the intermediate control unit 8M.

The unit 7 is configured to process the first signal S1 from the first sensor 6D and the second signal S2 from the second sensor 6C.

Unit 7 is also configured to send at least one derived signal to advanced control unit 8H and intermediate control unit 8M.

In other words, unit 7 receives as input the raw data captured by first sensor 6D and from second sensor 6C and processes them by filtering or integration to derive a damping level C for calculating the damping to be applied to each shock absorber 4 present in vehicle 1_ref。

In the embodiment comprising at least one accelerometer 10 and at least one potentiometer 11, the computerized calculation unit 7 processes the first signal S1 containing the items of information from the accelerometer 10 and the potentiometer 11 comprised in the system 100 to obtain the vertical speed z of the vehicle body close to the wheel 3_cAnd shock absorber compression velocity z_d。

In other words, acceleration and electricity captured from the accelerometer 10The movement captured by the gauge 11, the computerized calculation unit 7 derives the vertical speed z of the body of the vehicle close to the wheel 3 by integration and differentiation (and filtering, if necessary) respectively_cAnd the compression velocity z of the damper_d。

Described below is the preferred embodiment shown in FIG. 2, wherein the damping level C of the shock absorber 4_refAccording to the vertical speed z of the vehicle body, by means of the algorithm A, the respective intermediate control unit 8M_cAnd the compression velocity z of the damper_dTo calculate.

According to the convention adopted in this preferred embodiment, z is the vertical extension axis z when the vehicle body 2 moves downwards_cIs defined as positive, and z is when the reference damper 4 is compressed_dIs defined as positive.

In the present embodiment, the algorithm a executed by the corresponding intermediate-stage control unit 8M is defined as follows:

wherein C is_minAnd C_maxRespectively, the damping level C for the shock absorber 4_refIs the minimum and maximum of, sat is C_refIs limited in [ C ]_min,C_max]A saturation function within a range, and wherein K_skyIs a parameter representing the gain of algorithm a.

In other words, when K_skyz_cz_d+C_nomFalls on [ C ]_min,C_max]When in range, the function sat holds the value C_refNot changed, but when K_skyz_cz_d+C_nomGreater than C_maxWhen, the function sat is applied to C_ref＝C_maxAnd when K is_skyz_cz_d+C_nomGreater than C_minWhen, the function sat is applied to C_ref＝C_min。

Preferably, the gain K_skyMay be selected by the driver of the vehicle 1 from a limited number of values corresponding to different vehicle attitude configurations.

In addition to the high level control unit 8H, the preferred embodiment of the system 100 shown in fig. 2 also comprises four medium level control units 8M, four low level control units 8L and four actuators 5 (one for each wheel 3 of the vehicle 1).

In the present embodiment, the high-level control unit 8H and the four intermediate-level control units 8M calculate the nominal damping level C for each wheel 3 independently and respectively_nom,iAnd damping level C_ref,i(where i is the overall number from 1 to 4).

Advantageously, in the present embodiment, the nominal damping C is_nom,iAnd damping C_ref,iThe independence between the different values of (a) allows an optimal adjustment of the attitude of the vehicle 1.

Advantageously, the use of algorithm a allows a more uniform adjustment of the damping level C compared to a traditional skyhook algorithm with two phases_refTo increase comfort.

In fact, the traditional skyhook algorithm depends on the vertical speed z of the vehicle body_cAnd the compression velocity z of the damper_dThe damping level C is calculated as follows_ref：

This way of dealing with the operation of the shock absorber can lead to undesirable jerks when the speeds involved are almost zero, since small variations, for example caused by sensor noise, can lead to many variations between the two states allowed by the damping level.

In the embodiment proposed and illustrated in fig. 3, at C_nomIn the configuration of 0, the velocity value z_cAnd z_dOnly causes a damping value C_refThereby eliminating the jerkiness caused by state changes in the implementation of the traditional skyhook algorithm.

Advantageously, the use of such a more uniform variant of the skyhook algorithm ensures the damping level C of the shock absorber 4_refIs more widely adjusted (it can better adapt to the jolt of the vehicle 1), thereby increasingThe driving comfort of the driver.

Parameter C_nomCalculated by the high-level control unit 8H from the first signal S1 and the second signal S2 (processed by the computerized calculation unit 7 if necessary) and transmitted to the medium-level control unit 8M.

As mentioned above, the nominal damping parameter C_nomIs in the absence of oscillation (i.e., when z is_c0 or z_d0) the damper parameter to be applied to the damper.

Again according to the preferred embodiment, the nominal damping parameter C_nomObtained by the advanced control unit 8H through the following relationship:

C_nom＝C₀+C_lat+C_long，

wherein C is₀Is a default nominal damping level applied when the vehicle 1 is not having longitudinal or lateral acceleration, and wherein C_latAnd C_longRespectively, a first addition factor and a second addition factor, both calculated by the advanced control calculating unit 8H from the first signal S1 and the second signal S2.

First addition factor C_latAnd a second addition factor C_longThe dynamics of the lateral acceleration and the longitudinal acceleration of the vehicle 1 are considered separately.

Preferably, the default nominal damping level C₀May be selected by the driver of the vehicle 1 from a limited number of values corresponding to different attitude configurations of the vehicle 1.

More specifically, in the present preferred embodiment, the first addition factor C_latCalculated by the high level control unit 8H as follows:

C_lat＝K_latA_y,HP，

wherein K_latIs an adjustable gain factor, A_y,HPIs as follows A_yThe amount is preferably in the form of a filtered by a high-pass band filter:

where v is the speed of movement of the vehicle 1, K_usIs a steering reference coefficient, and L is a model parameter describing the length of the wheel base of the vehicle 1.

Preferably, the movement speed v is derived by the computerized unit 7 by processing at least the first signal S1 captured and transmitted by a GPS sensor equipped with the vehicle 1.

Again according to the preferred embodiment, the second addition factor C is calculated by the advanced control unit 8H as follows_long：

C_long＝K_longA_x,HP，

Wherein K_longIs an adjustable gain factor, A_x,HPIs the following amount A_xPreferably in the form of filtering by a high-pass band filter:

where ρ is the air density, S is the front surface of the vehicle 1, C_xIs the aerodynamic friction coefficient of the vehicle 1, m is the mass of the vehicle 1, v is the speed of movement of the vehicle 1, k_bkIs the braking efficiency, P_bkIs the pressure, k, on the brake controller 17 measured by the brake sensor 16_posIs a first model parameter, k, describing the efficiency of the propulsion unit_negIs a second model parameter, T, describing the efficiency of the propulsion unit_eng,posIs a positive parameter describing the positive torque of the engine, T_eng,negIs a negative parameter describing the negative torque of the engine, and ω_engIs a parameter describing the number of revolutions of the engine of the vehicle 1.

Preferably, when T is equal to_eng，posWhen greater than 0, then T_eng,negIs equal to 0, and when T_eng，negWhen less than 0, then T_eng，posEqual to 0. In other words, the last two addends in the preceding equation cannot participate in A at the same time_xAnd (4) calculating.

Advantageously, the first addition factor C_latAnd a second addition factor C_longThe presence of (b) allows the stability control system 100 to take into account the roll and pitch dynamics of the vehicle 1, respectively.

More advantageouslyNominal damping level C_nom(thus by applying the first addition factor C_latAnd a second addition factor C_longAdditive calculation) allows managing driving comfort and grip simultaneously in the presence of both left and right roll and pitch dynamics.

In fact, the nominal damping level C calculated by the advanced control unit 8H_nomAllows the intermediate control unit 8M to execute algorithm a with the vehicle attitude previously optimized according to the second signal S2 (i.e. according to the input entered by the driver).

According to the invention, a method 200 for controlling the stability of a vehicle 1 is also defined, the vehicle 1 having a longitudinal extension axis x, a transverse extension axis y and a vertical extension axis z and comprising a body 2, a plurality of wheels 3 and, for each wheel 3, at least one semi-active shock absorber 4, the at least one semi-active shock absorber 4 being interposed between the respective wheel 3 and the body 2.

The method 200 comprises a first measurement step 201 for capturing a kinetic parameter of the vehicle 1.

The first measurement step 201 for capturing the kinetic parameters of the vehicle 1 comprises at least one of the following sub-steps:

measuring at least one acceleration of the body 2 close to the wheel 3 along a direction parallel to the vertical axis z of the vehicle 1;

at least one compression of the shock absorber 4 along a direction almost parallel to the vertical axis z is measured.

Preferably, in an embodiment comprising at least a measurement of the acceleration of the vehicle body 2 and a measurement of the compression of the shock absorber 4, the first measurement step 201 comprises processing the dynamic parameters of the vehicle 1 to calculate the vertical speed z of the vehicle body close to the wheel 3_cAnd the compression velocity z of the damper_dAt least one substep of (a).

After the first measuring step 201, the method 200 comprises a second measuring step 202 for capturing input entered by the driver of the vehicle 1.

Preferably, the second measuring step 202 for capturing the input entered by the driver of the vehicle 1 comprises at least one of the following sub-steps:

measuring the steering angle δ determined by the steering wheel 13;

measuring the acceleration action exerted by the instructions from the accelerator 15;

measuring the braking action applied by the command from the brake 16.

Next, method 200 includes executing algorithm A to calculate a damping level C for shock absorber 4 based on the kinetic parameters captured in first measurement step 201 and the inputs captured in second measurement step 202_refStep 203.

In a preferred embodiment comprising at least the sub-steps of measurement of the acceleration of the vehicle body 2, measurement of the compression of the shock absorber 4 and processing of the dynamic parameters of the vehicle 1, the execution of step 203 comprises the execution of an algorithm a, defined as algorithm a

Wherein C is_minAnd C_maxRespectively damping level C_refIs the minimum and maximum of, sat is C_refIs limited in [ C ]_min，C_max]A saturation function within a range, and wherein K_skyAnd C_nomAre two adjustable parameters, representing the gain of algorithm A and the speed z of the vehicle body in the absence of vertical_cAnd shock absorber compression velocity z_dNominal damping level in the case of (2).

Preferably, nominal damping level C_nomIs calculated from the kinetic parameters of the vehicle 1 captured during the first measurement step 201 and the inputs captured during the second measurement step 202.