System and method for controlling stability of a vehicle equipped with a semi-active suspension

Abstract

A system (100) for controlling the stability of a vehicle (1) equipped with a semi-active shock absorber (4) comprises an actuator (5), a plurality of sensors (6C, 6D), a low-level control unit (8L), a high-level control unit (8H), and a control unit adapted to execute an algorithm (A) to calculate a damping level (C ref ) of the intermediate control unit (8M).

Description

Technical Field

[0001] The present invention relates to a system and method for controlling the stability of a vehicle, and in particular to a system and method for controlling the stability of a vehicle equipped with a semi-active suspension. Background Art

[0002] The suspension system has a great influence on the vehicle's driving performance and safety, as well as the driver's comfort on uneven roads.

[0003] Modern stability control systems involve two main types of suspension: electro-pneumatic suspension and semi-active suspension.

[0004] The difference between these two types of suspension is that electro-pneumatic suspension is active and is able to exert force, while semi-active suspension is passive and the resistance to contraction and extension of the suspension is adjustable.

[0005] However, semi-active suspensions have the advantage of having a higher control frequency and being less cumbersome in terms of weight and space, and consuming less energy since they are passive.

[0006] The control methods known to date implement skyhook type algorithms designed to limit as much as possible the dynamics of the damped mass (ie the vehicle body) compared to the substantially undamped mass in contact with the ground (ie the wheels).

[0007] 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.

[0008] Most suspension control methods developed are based on mathematical models of vehicle angles to locally attenuate shocks caused by road irregularities.

[0009] However, these systems fail to control the overall dynamics of the vehicle that affect vehicle stability and driving pleasure, such as side-to-side roll and pitch dynamics as determined by steering, braking and acceleration commands given by the driver.

[0010] To control these dynamics, the prior art teaches the use of a hierarchical system, where low-level controllers are used to handle the individual vehicle dynamics, and high-level controllers are used to determine which low-level controller has priority based on predetermined logic.

[0011] As a result, suspension control is managed in a suboptimal manner, as one control system takes precedence over the others, whose commands are therefore ignored.

[0012] Thus, when a higher priority is assigned to the left and right roll and pitch control systems, commands from the systems that control the damping of road bumps are ignored, and vice versa.

[0013] Therefore, these priority-based control systems cannot ensure comprehensive and synchronized control of vehicle dynamics, which can have a negative impact on the vehicle's driving comfort and road holding ability.

[0014] Therefore, the need to provide an overall system is particularly strongly felt in the field of vehicle stability control: a system that is able to deal with both road irregularities and overall vehicle dynamics. Summary of the invention

[0015] In this context, the main object of the present invention is to overcome the above-mentioned disadvantages.

[0016] Specifically, the object of the present disclosure is to propose a control system for the stability of a vehicle equipped with semi-active shock absorbers, which allows to simultaneously deal with oscillations caused by road surface irregularities and vehicle side-to-side rolling and pitching dynamics caused by driver manipulation.

[0017] According to one aspect of the present disclosure, a control system for stability of a vehicle equipped with a semi-active shock absorber includes:

[0018] - a plurality of actuators configured to continuously adjust the damping level of the semi-active shock absorbers;

[0019] - a first set of sensors configured to detect at least one dynamic parameter of the vehicle;

[0020] - a second set of sensors configured to capture input from a vehicle driver;

[0021] - an advanced control unit configured to calculate nominal damping parameters from the quantities detected by the two sets of sensors through a model;

[0022] - at least one intermediate control unit configured to calculate, by means of a parameterized algorithm, the damping level to be applied by the high-level control unit to each shock absorber as a function of the quantities detected by the first set of sensors;

[0023] - At least one low-level control unit configured to send drive signals to the actuators of the shock absorbers.

[0024] According to another aspect, the present disclosure relates to a method of controlling the stability of a vehicle, comprising the steps of capturing dynamic parameters of the vehicle, capturing input entered by a driver, executing an algorithm to calculate an optimal damping level to be applied to each shock absorber equipped on the vehicle, and finally implementing the calculated damping level. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features and advantages of the invention are more apparent in the non-limiting description of a preferred but not exclusive embodiment of a control system for the stability of a vehicle, as shown in the accompanying drawings, in which:

[0026] - Figure 1 A schematic side view of a vehicle equipped with the stability control system of the present patent specification is shown;

[0027] - Figure 2 Schematically shows Figure 1 details of the stability control system;

[0028] - Figure 3 The matching between the vehicle's dynamic parameters and the damping level is shown by a grayscale diagram. DETAILED DESCRIPTION

[0029] With specific reference to the drawings, reference numeral 100 denotes a control system for stability of a vehicle 1 .

[0030] As shown in the figure, a vehicle 1 has a vehicle body 2 and a plurality of wheels 3 which are points at which the vehicle contacts the ground.

[0031] The vehicle 1 preferably has four wheels 3 .

[0032] The vehicle 1 also has an axis of longitudinal extension x, an axis of transverse extension y and an axis of vertical extension z.

[0033] 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 shock absorber 4 is preferably technically identical for each wheel, for the sake of simplicity only one shock absorber 4 will be mentioned below.

[0034] The shock absorber 4 is interposed between the respective wheel 3 and the vehicle body 2 and is configured to damp oscillations of the vehicle body 2 along a vertical extension axis z of the vehicle 1 .

[0035] Preferably, the shock absorber 4 has a minimum damping level C min and the maximum damping level C max Continuously adjustable damping level between C ref .

[0036] In other words, the possible damping level C ref The quantity is not limited and predetermined, but can be purchased by C min and C max Set as needed within the limited range.

[0037] Advantageously, the damping level C is 1.000 mm / s compared to conventional ceiling systems which have a limited number of adjustment levels. refThe fact of being continuously adjustable allows the system 100 to have practically unlimited possibilities for setting the damping level, with clear advantages in terms of stability and driving pleasure of the vehicle 1 .

[0038] In a preferred but non-limiting embodiment, the semi-active damper 4 is a magnetorheological damper: that is to say, a damper in which the resistance to oscillations is adjusted by applying a magnetic field to modify the fluid dynamic properties of the liquid contained in the damper 4 itself.

[0039] In another embodiment, the semi-active vibration damper 4 is an electrorheological or electrohydrodynamic vibration damper.

[0040] The stability system 100 of the vehicle 1 is responsible for controlling and driving the shock absorbers 4 of the vehicle 1 in order to limit the oscillations of the vehicle body 2 along the vertical extension axis z, thereby ensuring optimal comfort for the driver of the vehicle 1 .

[0041] like Figure 2 As shown, the system 100 includes a device configured to continuously adjust the damping level C of the shock absorber 4. ref at least one actuator 5.

[0042] 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 .

[0043] The actuator 5 converts the control signal into a mechanical, electrical or magnetic stimulus for continuously varying the physical properties of the semi-active shock absorber 4 , thus regulating its response to oscillations of the corresponding wheel 3 and / or vehicle body 2 along the vertical extension axis z.

[0044] The system 100 comprises at least a first sensor 6D configured to measure at least one dynamic parameter of the vehicle 1 and to transmit at least a first signal S1 containing an item of information regarding the dynamic parameter.

[0045] Preferably, at least the first sensor 6D comprises at least one of the following:

[0046] an accelerometer 10 configured to measure the acceleration of the body 2 close to one wheel 3 along a direction parallel to the vertical extension axis z;

[0047] - a potentiometer 11 configured to measure the compression of the shock absorber 4 along its axis of extension;

[0048] - A GPS sensor configured to capture the position of the vehicle 1 .

[0049] As also shown, the system 100 comprises at least a second sensor 6C configured to capture an input entered by a driver of the vehicle 1 and to transmit at least a second signal S2 containing an item of information regarding the input.

[0050] Preferably, at least the second sensor 6C comprises at least one of the following sensors:

[0051] a steering angle sensor 12 configured to measure a steering angle δ determined by a steering wheel 13;

[0052] an accelerometer sensor 14 configured to measure the motions applied by commands from an accelerator 15 ;

[0053] A brake sensor 16 configured to measure the action exerted by a command from a brake 17 .

[0054] In other words, the second sensor 6C monitors the driver's behavior, whose actions are reflected (after a response interval) in the translational and oscillatory movements of the vehicle 1 , which are then monitored by the first sensor 6D.

[0055] Advantageously, the use of two different types of sensors, one for monitoring the movement of the vehicle 1 and the other for monitoring the actions of the driver, allows the future dynamics of the vehicle 1 to be predicted by the model, in particular the longitudinal and lateral accelerations to which the vehicle 1 will be subjected.

[0056] The ability to predict the future dynamics of the vehicle 1 also ensures that the system 100 can preventively adjust the state of the shock absorbers 4 to guarantee driving comfort for the driver while ensuring good road grip.

[0057] As also shown, the system 100 includes a high-level control unit 8H in communication with the first sensor 6D and the second sensor 6C.

[0058] The high-level control unit 8H is configured to calculate the nominal damping parameter C according to the first signal S1 and the second signal S2. nom .

[0059] Nominal damping parameter C nom φ denotes the level of damping that the shock absorber 4 must exert in order to prevent the vehicle body 2 or the corresponding wheel 3 from vibrating along the vertical axis of extension z of the vehicle 1 .

[0060] Advantageously, reliance on the second signal S2 received from the second sensor 6C allows the high-level control unit 8H to calculate the nominal damping level C also based on the driver's actions. nom , so that the response of the system 100 to the dynamics of the vehicle 1 can be predicted and therefore improved.

[0061] 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.

[0062] The intermediate control unit 8M is configured to receive the nominal damping parameter C from the high-level control unit 8H.nom and calculates the damping level C by an algorithm or calculation routine A from the first signal S1 received from the first sensor 6D ref .

[0063] In other words, the intermediate control unit 8M communicates with the high-level control unit 8H which is responsible for calculating the damping level C to be applied at the level of the shock absorber 4. ref Parameterization of algorithm A.

[0064] Therefore, the term "parameterization of the algorithm" is used to refer to the calculation of parameters that, when applied as input to the algorithm, affect the results of the algorithm in essentially the same way as the independent input variables (in our case, the signal S1).

[0065] The term algorithm is used to denote any computational routine that allows, by a finite number of steps executed according to a finite set of rules, to obtain values ​​for output variables from input variables and / or input parameters.

[0066] In one embodiment, the system 100 comprises an intermediate control unit 8M for each shock absorber 4 with which the vehicle 1 is equipped, so that each intermediate control unit 8M is responsible for calculating the damping level C of a single shock absorber 4 ref .

[0067] Preferably, the high-level control unit 8H sends the nominal damping level C constituting an input variable in the algorithm A to the intermediate control unit 8M. nom .

[0068] Therefore, the algorithm A is based on the first signal S1 received from the first sensor 6D and the nominal damping parameter C received from the high-level control unit 8H. nom To calculate the damping level C ref .

[0069] Specifically, each intermediate control unit 8M executes a respective algorithm A to calculate the optimal damping level C of the shock absorber 4 associated with it independently of the other intermediate control units 8M. ref .

[0070] Advantageously, the presence of an intermediate control unit 8M for each shock absorber 4 of the vehicle 1 allows each shock absorber 4 to execute a respective algorithm A differently and distinctly from the other shock absorbers 4 .

[0071] Nominal damping level C calculated by the high-level control unit 8H nom Sent to all intermediate control units 8M.

[0072] In one embodiment, the same nominal damping level C nomis sent to the intermediate control unit 8M and thus constitutes an input variable common to all algorithms A, each of which independently executes the algorithm A to calculate the optimal damping level C of the shock absorber 4 respectively associated therewith. ref .

[0073] In another embodiment, a different and specific nominal damping level C nom are sent to each intermediate control unit 8M and constitute the input variables of a corresponding algorithm A, which is therefore executed independently of the other algorithms of the other intermediate control units 8M to calculate the optimal damping level C of the shock absorber 4 associated therewith. ref .

[0074] The system 100 includes a low-level control unit 8L that communicates with the mid-level control unit 8M and the actuator 5 and is configured to send a drive signal to the actuator 5 .

[0075] More precisely, the low-level control unit 8L is configured to receive from the mid-level control unit 8M a signal containing the desired damping level C ref and generates a corresponding drive signal for the actuator 5.

[0076] 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 thus being responsible for driving a single actuator 5 .

[0077] In a preferred embodiment, the system 100 includes a computerized computing unit 7 in communication with the first sensor 6D, the second sensor 6C, the high-level control unit 8H, and the mid-level control unit 8M.

[0078] 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.

[0079] The unit 7 is also configured to send at least one derived signal to the high-level control unit 8H and the intermediate control unit 8M.

[0080] In other words, the unit 7 receives as input the raw data captured by the first sensor 6D and from the second sensor 6C and processes them by filtering or integration to derive the data used to calculate the damping level C to be applied to each shock absorber 4 present in the vehicle 1. ref .

[0081] 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 comprising items of information from the accelerometer 10 and the potentiometer 11 included in the system 100 to obtain the vertical speed z of the vehicle body close to the wheel 3. c and the shock absorber compression speed zd .

[0082] In other words, from the acceleration captured by the accelerometer 10 and the movement captured by the potentiometer 11, the computerized calculation unit 7 derives, by integration and differentiation (and filtering, if necessary), respectively, the vertical velocity z of the vehicle body close to the wheel 3. c and the compression speed z of the shock absorber d .

[0083] The following describes Figure 2 The preferred embodiment shown, in which the damping level C of the shock absorber 4 ref The corresponding intermediate control unit 8M uses an algorithm A according to the vertical speed z of the vehicle body. c and the compression speed z of the shock absorber d to calculate.

[0084] According to the convention adopted in this preferred embodiment, when the vehicle body 2 moves downward along the vertical extension axis z, c is defined as positive, and when the reference damper 4 is compressed z d is defined as positive.

[0085] In this embodiment, the algorithm A executed by the corresponding intermediate control unit 8M is defined as follows:

[0086]

[0087] Among them C min and C max are respectively the damping level C applicable to the shock absorber 4 ref The minimum and maximum values ​​of C ref The kinetic limit is [C min ,C max ] range, and K sky is a parameter representing the gain of algorithm A.

[0088] In other words, when K sky z c z d +C nom Falling in [C min ,C max ], the function sat maintains the value C ref unchanged, but when K sky z c z d +C nom Greater than C max When C ref =C max , and when K sky z cz d +C nom Greater than C min When C ref =C min .

[0089] Preferably, the gain K sky It can be selected by the driver of the vehicle 1 from a limited number of values ​​corresponding to different vehicle posture configurations.

[0090] In addition to the advanced control unit 8H, Figure 2 The preferred embodiment of the system 100 shown also comprises four mid-level control units 8M, four low-level control units 8L and four actuators 5 (one for each wheel 3 of the vehicle 1).

[0091] In the present embodiment, the high-level control unit 8H and the four intermediate control units 8M calculate the nominal damping level C for each wheel 3 independently. nom,i and damping level C ref,i (where i is an integral number from 1 to 4).

[0092] Advantageously, in this embodiment, the nominal damping C nom,i and damping C ref,i The independence between the different values ​​of allows an optimal adjustment of the attitude of the vehicle 1 .

[0093] Advantageously, the use of algorithm A allows a more uniform adjustment of the damping level C compared to a conventional skyhook algorithm having two stages. ref , for increased comfort.

[0094] In fact, the traditional skyhook algorithm is based on the vertical velocity z of the vehicle body. c and the compression speed z of the shock absorber d The damping level C is calculated as follows ref :

[0095]

[0096] This way of handling the operation of the shock absorbers can lead to undesirable jerkiness when the speeds involved are almost zero, because small changes caused by, for example, sensor noise can lead to many changes between the two states allowed by the damping level.

[0097] exist Figure 3 In the embodiment proposed and shown in FIG. nom = 0, the speed value z c and z d A small change in the damping value C refThis eliminates the bumps caused by state changes in the traditional implementation of the ceiling algorithm.

[0098] Advantageously, the use of this more uniform variant of the skyhook algorithm ensures that the damping level C of the shock absorber 4 ref A wider range of adjustments (which can better adapt to the bumps of vehicle 1), thereby improving the driving comfort of the driver.

[0099] Parameter C nom It is calculated by the high-level control unit 8H based on the first signal S1 and the second signal S2 (if necessary, processed by the computerized calculation unit 7) and transmitted to the intermediate control unit 8M.

[0100] As mentioned above, the nominal damping parameter C nom is when there is no oscillation (i.e., when z c =0 or z d =0) Shock absorber parameters to be applied to the shock absorber.

[0101] Again according to the preferred embodiment, the nominal damping parameter C nom Obtained by the advanced control unit 8H through the following relationship:

[0102] C nom =C0+C lat +C long ,

[0103] where C0 is the default nominal damping level applied when the vehicle 1 has no longitudinal or lateral acceleration, and where C lat and C long They are respectively a first addition factor and a second addition factor both calculated by the high-level control calculation unit 8H based on the first signal S1 and the second signal S2.

[0104] First additive factor C lat and the second additive factor C long The dynamics of the lateral acceleration and the longitudinal acceleration of the vehicle 1 are considered separately.

[0105] Preferably, the default nominal damping level C0 is selectable by the driver of the vehicle 1 from a limited number of values ​​corresponding to different attitude configurations of the vehicle 1 .

[0106] More specifically, in this preferred embodiment, the first addition factor C lat Calculated by the high-level control unit 8H as follows:

[0107] C lat =K lat A y,HP ,

[0108] Where K latis the adjustable gain factor, A y,HP It is as follows A y The quantity is preferably filtered through a high pass filter in the form of:

[0109]

[0110] Where v is the speed of vehicle 1, K us is the steering reference coefficient, and L is the model parameter describing the wheelbase length of vehicle 1.

[0111] Preferably, the movement speed v is derived by the computerized calculation unit 7 by processing at least a first signal S1 captured and transmitted by a GPS sensor equipped by the vehicle 1 .

[0112] Again according to the preferred embodiment, the second addition factor C is calculated by the high-level control unit 8H as follows long：

[0113] C long =K long A x,HP ,

[0114] Where K long is the adjustable gain factor, A x,HP The following quantity A x Preferably in the form of filtering through a high pass band filter:

[0115]

[0116] where ρ is the air density, S is the front surface of the vehicle 1, and C x is the aerodynamic friction coefficient of vehicle 1, m is the mass of vehicle 1, v is the moving speed of vehicle 1, k bk is the braking efficiency, P bk is the pressure on the brake controller 17 measured by the brake sensor 16, k pos is the first model parameter describing the efficiency of the propulsion unit, k neg is the second model parameter describing the efficiency of the propulsion unit, T eng,pos is a positive parameter describing the positive torque of the engine, T eng,neg is a negative 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 .

[0117] Preferably, accordingly, when T eng，pos When it is greater than 0, T eng,neg is equal to 0, and when T eng，neg When it is less than 0, T eng，pos is equal to 0. In other words, the last two addends in the previous equation cannot participate in A at the same time. x Calculation.

[0118] Advantageously, the first addition factor C lat and the second additive factor C long The presence of allows the stability control system 100 to take into account the side-to-side roll and pitch dynamics of the vehicle 1 separately.

[0119] More advantageously, the nominal damping level C nom (Thus, by adding the first factor C lat and the second additive factor C long The fact that algorithm A is parameterized (calculated additively) allows managing both ride comfort and road holding in the presence of roll and pitch dynamics.

[0120] In fact, the nominal damping level C calculated by the high-level control unit 8H nom The addition of allows the intermediate control unit 8M to execute the algorithm A with the vehicle posture previously optimized according to the second signal S2, ie according to the input entered by the driver.

[0121] According to the present 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 at least one semi-active shock absorber 4 for each wheel 3, the at least one semi-active shock absorber 4 being interposed between the corresponding wheel 3 and the body 2.

[0122] The method 200 comprises a first measuring step 201 for capturing dynamic parameters of the vehicle 1 .

[0123] The first measurement step 201 for capturing dynamic parameters of the vehicle 1 comprises at least one of the following sub-steps:

[0124] - measuring at least one acceleration of the vehicle body 2 close to the wheel 3 along a direction parallel to the vertical axis z of the vehicle 1 ;

[0125] - Measuring at least one compression of the shock absorber 4 along a direction approximately parallel to the vertical axis z.

[0126] Preferably, in an embodiment comprising at least the measurement of the acceleration of the vehicle body 2 and the 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 velocity z of the vehicle body close to the wheel 3 c and the compression speed z of the shock absorber d at least one sub-step.

[0127] After the first measuring step 201 , the method 200 comprises a second measuring step 202 for capturing an input entered by a driver of the vehicle 1 .

[0128] Preferably, the second measurement step 202 for capturing an input entered by the driver of the vehicle 1 comprises at least one of the following sub-steps:

[0129] - measuring the steering angle δ determined by the steering wheel 13;

[0130] - measuring the acceleration action applied by the command from the accelerator 15;

[0131] - Measuring the braking action applied by the command from the brake 16 .

[0132] Next, the method 200 comprises executing an algorithm A to calculate the damping level C of the shock absorber 4 based on the dynamic parameters captured in the first measurement step 201 and the input captured in the second measurement step 202. ref Step 203.

[0133] In a preferred embodiment comprising at least the sub-steps of measuring the acceleration of the vehicle body 2, measuring the compression of the shock absorber 4 and processing the dynamic parameters of the vehicle 1, executing step 203 comprises executing algorithm A, which is defined as

[0134]

[0135] Among them C min and C max The damping level C ref The minimum and maximum values ​​of C ref The kinetic limit is [C min , C max ] range, and K sky and C nom are two adjustable parameters, representing the gain of algorithm A and the velocity z in the absence of vertical vehicle body. c and the shock absorber compression speed z d Nominal damping level in the case of

[0136] Preferably, the nominal damping level C nom is calculated based on the dynamic parameters of the vehicle 1 captured during the first measurement step 201 and the inputs captured during the second measurement step 202 .

Claims

1. A system (100) for controlling the stability of a vehicle (1), the vehicle 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 at least one semi-active shock absorber (4) for each wheel (3), the at least one semi-active shock absorber being interposed between the respective wheel (3) and the body (2); the system (100) comprising: - at least one actuator (5) configured to continuously adjust the damping level C of the semi-active shock absorber (4) ref ; - at least a first sensor (6D) configured to measure at least one dynamic parameter of the vehicle (1) and to send at least a first signal (S1) containing an item of information about said dynamic parameter; - at least a second sensor (6C) configured to measure an input entered by a driver of said 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 said first sensor (6D) and said second sensor (6C) and configured to receive said first signal (S1) and said second signal (S2); - an intermediate control unit (8M) communicating with said high-level control unit (8H) and said first sensor (6D) to receive said first signal (S1); - a low-level control unit (8L) communicating with the actuator (5) and the mid-level control unit (8M) and configured to send a drive signal to the actuator (5); and characterized in that the high-level 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 control unit (8M) to calculate the damping level C according to the first signal (S1) ref ; Wherein, the damping level C of the shock absorber (4) ref is calculated by the intermediate control unit (8M) using the algorithm A, which is defined as: Among them C min and C max The applicable damping level C is ref The minimum and maximum values ​​of K sky and C nom are two adjustable parameters, representing the gain of the algorithm A and the velocity z in the absence of vertical vehicle body. c Or the shock absorber compression speed z d The nominal damping level for the case where When K sky z c z d +C nom Falling in [C min ,C max ], the function sat maintains the value C ref constant, When K sky z c z d +C nom Greater than C max When C ref =C max ; The system (100) further comprises a computerized computing unit (7); the computerized computing unit (7) is configured to: process the first signal (S1) and the second signal (S2); The first sensor (6D) comprises at least: - an accelerometer (10) configured to measure the acceleration of the vehicle body (2) close to the respective wheel (3) along a direction parallel to the vertical extension axis (z); and - a potentiometer (11) configured to measure the compression of the shock absorber (4) along a direction parallel to the vertical extension axis (z); The computerized calculation unit (7) is further configured to calculate the vertical speed z of the vehicle body close to the wheel (3) based on the first signal (S1) containing at least one information item from the accelerometer (10) and the potentiometer (11). c and the shock absorber compression speed z d .

2. The system (100) according to claim 1, wherein the computerized computing unit (7) communicates with the first sensor (6D), the second sensor (6C), the high-level control unit (8H) and the intermediate control unit (8M); and the computerized computing unit (7) is further configured to: send at least one quantity derived from the first signal (S1) and the second signal (S2) to the high-level control unit (8H) and the intermediate control unit (8M).

3. The system (100) of claim 1, wherein: The second sensor (6C) includes at least one of the following: - a steering angle sensor (12) configured to measure a steering angle δ determined by a steering wheel (13); - an accelerometer sensor (14) configured to measure a motion applied by a command from an accelerator (15); - A brake sensor (16) configured to measure the action applied by a command from a brake (17).

4. The system (100) of claim 1, wherein: The damping level C of the shock absorber (4) ref The intermediate control unit (8M) is based on the vertical speed z of the vehicle body. c and the shock absorber compression speed z d to calculate.

5. The system (100) according to claim 3, wherein: The nominal damping level C is calculated by the high-level control unit (8H) nom as follows: C nom =C0+C lat +C long , where C0 is the default nominal damping level and where C lat is a first addition factor calculated by the high-level control unit (8H) according to the first signal (S1), C long is a second addition factor calculated by the high-level control unit (8H) based on the second signal (S2).

6. The system (100) according to claim 5, wherein: The first additive factor C lat is calculated as follows: C lat =K lat A y,HP , Where K lat is the adjustable gain factor, A y,HP The following quantity A y Filter form: Where v is the speed of the vehicle (1), k us is the steering reference coefficient, and L is a parameter describing the wheelbase length of the vehicle (1).

7. The system (100) according to claim 5 or 6, wherein: The second addition factor C long is calculated as follows: C long =K long A x,HP , Where K lobg is the adjustable gain factor, A x,HP The following quantity A x Filter form: where 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 moving speed of the vehicle (1), k bk is the braking efficiency, P bk is the pressure on the brake (17) measured by the brake sensor (16), k pos is the first model parameter describing the efficiency of the propulsion unit, k neg is the second model parameter describing the efficiency of the propulsion unit, T eng,pos is the 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).

8. The system (100) of claim 1, wherein: The vibration damper (4) is a magnetorheological vibration damper.

9. A method (200) for controlling the stability of a vehicle (1), 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 at least one semi-active shock absorber (4) for each wheel (3), the at least one semi-active shock absorber being interposed between the respective wheel (3) and the body (2); the method (200) comprising the following steps: - a first measurement step (201) for capturing at least one dynamic parameter of the vehicle (1); - a second measuring step (202) for capturing at least one input entered by a driver of said vehicle (1); - executing algorithm A to calculate the damping level C of the shock absorber (4) based on the dynamic parameters and the input ref Step (203); - implementing the damping level C calculated by the algorithm A through an actuator (5) operatively connected to the shock absorber (4) ref Step (204); The execution step (203) includes executing the algorithm A, which is defined as: Among them C min and C max The applicable damping level C is ref The minimum and maximum values ​​of K sky and C nom are two adjustable parameters, representing the gain of the algorithm A and the velocity z in the absence of vertical vehicle body. c Or the shock absorber compression speed z d The nominal damping level for the case where When K sky z c z d +C nom Falling in [C min ,C max ], the function sat maintains the value C ref constant, When K sky z c z d +C nom Greater than C max When C ref =C max ; The first measuring step (201) for capturing at least one dynamic parameter of the vehicle (1) comprises the following sub-steps: - measuring at least one acceleration of the vehicle body (2) close to the wheel (3) in a direction parallel to the vertical extension axis (z) of the vehicle (1); - measuring at least one compression of the shock absorber (4) along a direction nearly parallel to the vertical extension axis (z); The first measuring step (201) comprises at least a sub-step of measuring at least one acceleration of the vehicle body (2) and a sub-step of measuring at least one compression of the shock absorber (4), wherein the first measuring step (201) comprises processing the dynamic parameters of the vehicle (1) to calculate a vertical velocity z of the vehicle body close to the wheel (3). c and the compression speed z of the shock absorber d sub-steps.

10. The method (200) according to claim 9, wherein: The second measuring step (202) for capturing an input entered by a 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 applied by the command from the accelerator (15); -Measurement of the braking action applied by the command from the brake (17).

11. The method (200) of claim 9, wherein: The parameter C is calculated based on the dynamic parameters of the vehicle (1) captured during the first measurement step (201) and the input captured during the second measurement step (202). nom .

Images