SYSTEM AND METHOD FOR CONTROLLING THE STABILITY OF A VEHICLE EQUIPPED WITH A SEMI-ACTIVE SUSPENSION

Abstract

A system (100) for controlling the stability of a vehicle equipped with semi-active suspension comprises: an actuator (5), a plurality of sensors (6c, 6d), a low-level control unit (8l), a high-level control unit (8h) as well as a medium-level control unit (8m) adapted to execute an algorithm (a) to calculate a damping level (cref).

Description

1 / 15 SYSTEM AND METHOD FOR CONTROLLING THE STABILITY OF A VEHICLE EQUIPPED WITH A SEMI-ACTIVE SUSPENSION Technical field

[001] This invention relates to a system and a method for controlling the stability of a vehicle, specifically a system and a method for controlling the stability of a vehicle equipped with semi-active suspension. Foundation

[002] Suspension systems have a major impact on a vehicle's handling and safety, as well as on driver comfort on an uneven road surface.

[003] Modern stability control systems mainly involve two types of suspension: electronic air suspensions and semi-active suspensions.

[004] The difference between the two types of suspensions lies in the fact that electronic air suspensions are active and capable of applying forces, while semi-active suspensions are passive and the resistance of the suspensions to contraction and extension can be adjusted.

[005] Semi-active suspensions, however, have the advantage of having a higher control frequency and being less heavy in terms of weight and space and less energy intensive insofar as they are passive.

[006] The control methods known so far implement sÁy / wÁ type algorithms; which are designed to limit, as much as possible, the dynamics of the damped mass - that is, the vehicle body - compared to the substantially undamped mass that is in contact with the ground - which is composed of the wheels.

[007] Based on the vertical velocities of the body and wheels, measured by specific sensors, the skyhook algorithms calculate an ideal damping level that the shock absorbers should apply to ensure optimal ride quality.

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

[009] These systems, however, fail to control the overall dynamics of the vehicle which Petition 870240082912, dated 09 / 27 / 2024, page 20 / 40 2 / 15 affects vehicle stability and driving pleasure, such as, for example, roll and pitch dynamics determined by the driver's driving, braking and acceleration controls. Documents GB2260106, FR2701902 and JP2002219921 are known in the state of the art.

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

[0011] Suspension control is therefore managed in a sub-ideal manner, since one control system has priority over the others, whose commands are therefore ignored.

[0012] Thus, when a higher priority is assigned to the roll and pitch control system, the commands issued by the system that controls the damping of irregularities in the runway surface are ignored and vice versa.

[0013] These priority-based control systems, therefore, do not guarantee full and simultaneous control of vehicle dynamics, which negatively impacts driving comfort and vehicle holding capacity.

[0014] Consequently, a particularly felt need in the field of vehicle stability control is to provide total systems: that is, systems capable of simultaneously dealing with irregularities in the road surface and overall vehicle dynamics. Objective of the invention

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

[0016] Specifically, the objective of this description is to propose a system for controlling the stability of a vehicle equipped with semi-active shock absorbers and that, simultaneously, allows dealing with oscillations caused by irregularities in the road surface and the rolling and tilting dynamics of the vehicle due to driver maneuvers.

[0017] According to one aspect of this description, the system for controlling the Petition 870240082912, dated 09 / 27 / 2024, page 21 / 40 3 / 15 The stability of a vehicle equipped with semi-active shock absorbers comprises: - a plurality of actuators configured to continuously regulate the damping level of the semi-active dampers; - a first group of sensors configured to detect at least one dynamic parameter of the vehicle; - a second group of sensors configured to capture the driver's input, i.e., commands; - a high-level control unit configured to calculate a nominal damping parameter, using a model, based on the quantities detected by the two groups of sensors; - at least one mid-level control unit configured to calculate, based on the quantities detected by the first group of sensors, the damping level to be applied by the high-level control unit to each damper using a parameterized algorithm; - at least one low-level control unit, configured to send drive signals to the shock absorber actuators.

[0018] According to another aspect, this description refers to a method or control of vehicle stability, comprising the steps of capturing dynamic vehicle parameters, capturing input (commands) provided by the driver, executing an algorithm to calculate the ideal damping level to be applied to each shock absorber with which the vehicle is equipped and, finally, implementing the calculated damping levels. Brief description of the drawings

[0019] Other features and advantages of this invention are more evident in the non-limiting description of a preferred, but not exclusive, embodiment of a system for controlling the stability of a vehicle, as illustrated in the accompanying drawings, in which: Figure 1 shows a schematic side view of a vehicle equipped with the stability control system described in this patent application; Figure 2 schematically illustrates a detail of the control system of Petition 870240082912, dated 09 / 27 / 2024, page 22 / 40 4 / 15 stability of figure 1; and Figure 3 illustrates, through a grayscale map, the correspondence between the vehicle's dynamic parameters and the damping level. Detailed description of the preferred embodiments of the invention.

[0020] With specific reference to the drawings, the number 100 denotes a system for controlling the stability of a vehicle 1.

[0021] As illustrated, vehicle 1 has a vehicle body 2 and a plurality of wheels 3, which are the points where the vehicle touches the ground.

[0022] Preferably, vehicle 1 has four wheels 3.

[0023] Vehicle 1 also has a longitudinal axis of length x, a transverse axis of length y and a vertical axis of length z.

[0024] Vehicle 1 further comprises at least one semi-active shock absorber 4 for each wheel 3 with which vehicle 1 is fitted; for the sake of simplification, hereafter only one shock absorber 4 will be referred to, since the semi-active shock absorbers 4 are preferably all technically identical for each wheel.

[0025] The shock absorber 4 is interposed between the respective wheel 3 and the vehicle body 2 and is configured to dampen the oscillations of the vehicle body 2 along the vertical extension axis z of the vehicle 1.

[0026] Preferably, damper 4 has a damping level Gr that is continuously adjustable between a minimum damping level Cmin and a maximum damping level Cmax.

[0027] In other words, the number of possible damping levels Gr is not finite and predetermined, but configurable as needed within the range defined by Cm / ne Cmax.

[0028] Advantageously, compared to traditional skyhook systems with a finite number of adjustment levels, the fact that the Gr damping level can be continuously regulated allows the 100 system to have virtually infinite possibilities for setting the damping level, with obvious advantages in terms of vehicle stability and driving pleasure 1.

[0029] In a preferred, but not limiting, embodiment, the damper Petition 870240082912, dated 09 / 27 / 2024, page 23 / 40 5 / 15 semiactive 4 is a magnetorheological damper: that is, a type of damper in which the resistance to oscillations is regulated by the application of a magnetic field in order to modify the fluid dynamic properties of a liquid included in the damper itself 4.

[0030] In another embodiment, the semiactive damper 4 is an electrorheological or electrohydraulic damper.

[0031] A stability system 100 for vehicle 1 is responsible for controlling and actuating the shock absorber 4 of vehicle 1, in order to limit the oscillations of the body of vehicle 2 along the vertical extension axis z, thus ensuring optimal comfort for the driver of vehicle 1.

[0032] As illustrated in figure 2, system 100 comprises at least one actuator 5 configured to continuously regulate a damping level Gerdo damper 4.

[0033] Preferably, each shock absorber 4 with which vehicle 1 is supplied is associated with an actuator 5 responsible for actuating the respective shock absorber 4.

[0034] The actuator 5 transduces the control signal into a mechanical, electrical or magnetic stimulus to continuously modify the physical properties of the semi-active damper 4 which conditions its response to oscillations along the vertical extension axis z of the corresponding wheel 3 and / or the vehicle body 2.

[0035] System 100 comprises at least one first sensor 6D, configured to measure at least one dynamic parameter of vehicle 1 and send at least one first signal S1 containing an information item with reference to the dynamic parameter.

[0036] Preferably, the first 6D sensor comprises at least one of the following: - an accelerometer 10 configured to measure an acceleration of the vehicle body 2 in the vicinity of one of the wheels 3 along a direction parallel to the vertical axis of the z-axis; - a potentiometer 11 configured to measure the compression of the shock absorber 4 along its extension axis; - a GPS sensor, configured to capture the vehicle's position 1. Petition 870240082912, dated 09 / 27 / 2024, page 24 / 40 6 / 15

[0037] Also as illustrated, system 100 comprises at least one second sensor 6C configured to capture an input (command) provided by a driver of vehicle 1 and to send at least one second signal S2 containing an item of information regarding such input.

[0038] Preferably, the second sensor 6C comprises at least one of the following: - a steering angle sensor 12 configured to measure the steering angle δ determined by a steering wheel 13; - a throttle sensor 14 configured to measure an action applied by means of a throttle command 15; - a brake sensor 16 configured to measure an action applied by means of a brake command 17.

[0039] 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 movement of vehicle 1, which is then monitored by the first sensor 6D.

[0040] Advantageously, the use of two different types of sensors, one to monitor the movement of vehicle 1 and the other to monitor the driver's actions, allows predicting, through a model, the future dynamics of vehicle 1, specifically the longitudinal or lateral accelerations to which vehicle 1 is about to be subjected.

[0041] The ability to predict the future dynamics of the vehicle 1 also ensures that the system 100 can proactively adapt the state of the shock absorber 4 in order to guarantee the driver driving comfort and, at the same time, good grip on the road surface.

[0042] As also illustrated, system 100 comprises a high-level control unit 8H in communication with the first sensor 6D and with the second sensor 6C.

[0043] The high-level control unit 8H is configured to calculate a nominal damping parameter Gom as a function of the first signal S1 and the second signal S2.

[0044] The nominal damping parameter Cnom represents the level of Petition 870240082912, dated 09 / 27 / 2024, page 25 / 40 7 / 15 damping that shock absorber 4 must apply when the vehicle body 2 or the respective wheel 3 is not subject to oscillations along the vertical z-axis of the vehicle 1.

[0045] Advantageously, the dependence of the second signal S2 received from the second sensor 6C allows the high-level control unit 8H to calculate the nominal damping level Cnom also based on the driver's actions, making it possible to anticipate and thus improve the response of the system 100 to the vehicle dynamics 1.

[0046] System 100 also comprises a medium-level control unit 8M, in communication with the high-level control unit 8H and with the first sensor 6D.

[0047] The medium-level control unit 8M is configured to receive the nominal damping parameter Cnom from the high-level control unit 8H and calculate, by means of an algorithm or calculation routine A, a damping level Ger as a function of the first signal S1 received from the first sensor 6D.

[0048] In other words, the medium-level control unit 8M is in communication with the high-level control unit 8H, which parameterizes algorithm A responsible for calculating the damping level Cref to be applied to the damper level 4.

[0049] The term parameterization of an algorithm is therefore used to mean the calculation of a parameter which, when applied as input to an algorithm, substantially influences the result of the algorithm in the same way as an independent input variable (in our case, the signal S1).

[0050] The term algorithm is used to designate any calculation routine that, through a finite number of steps performed according to a finite set of rules, allows obtaining the value of an output variable as a function of the input variables and / or input parameters.

[0051] In one embodiment, the system 100 comprises a mid-level control unit 8M for each shock absorber 4 that the vehicle 1 is equipped with, such that each mid-level control unit 8M is responsible for calculating the damping level G?rde of a single shock absorber 4.

[0052] Preferably, the high-level control unit 8H sends to the unit of Petition 870240082912, dated 09 / 27 / 2024, page 26 / 40 8 / 15 medium level control 8M the nominal damping level Cnom, which constitutes an input variable in algorithm A.

[0053] Thus, algorithm A calculates the damping level G^ as a function of the first signal S1 received from the first sensor 6D and the nominal damping parameter Cnom received from the high-level control unit 8H.

[0054] Specifically, each 8M mid-level control unit executes the respective algorithm A to calculate, independently of the other 8M mid-level control units, the ideal damping level Cref for the damper 4 associated with it.

[0055] Advantageously, the presence of an 8M mid-level control unit for each of vehicle 1 shock absorbers allows each of the 4 shock absorbers to execute the respective algorithm A in a different and distinct way from the others.

[0056] The nominal damping level Cnom, calculated by the high-level control unit 8H, is sent to all medium-level control units 8M.

[0057] In one embodiment, the same nominal damping level Cnom is sent to the 8M mid-level control units and thus constitutes a common input variable to all algorithms A, which are then executed independently by each 8M mid-level control unit to calculate the ideal damping level Cap for the damper 4 to which each is associated.

[0058] In another embodiment, a distinct and specific nominal damping level Cnom is sent to each 8M mid-level control unit and constitutes an input variable of the respective algorithm A, which is therefore executed independently of the other algorithms of the other 8M mid-level control units to calculate the ideal damping level Cref for the damper 4 to which it is associated.

[0059] System 100 comprises a low-level control unit 8L, in communication with the medium-level control unit 8M and with the actuator 5 and configured to send an actuation signal to the actuator 5.

[0060] More precisely, the low-level control unit 8L is configured to receive from the medium-level control unit 8M an information item containing the level Petition 870240082912, dated 09 / 27 / 2024, page 27 / 40 9 / 15 of desired damping Crete to generate a corresponding drive signal for actuator 5.

[0061] Preferably, system 100 comprises a low-level control unit8L for each actuator 5 with which vehicle 1 is equipped, such that each low-level control unit8L is responsible for actuating a single actuator 5.

[0062] In a preferred embodiment, the system 100 comprises a computerized calculation unit 7 communicating with the first sensor 6D, the second sensor 6C, the high-level control unit 8H and the medium-level control unit 8M.

[0063] 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.

[0064] Unit 7 is also configured to send at least one derived signal to the high-level control unit 8H and the medium-level control unit 8M.

[0065] In other words, unit 7 receives as input the raw data captured by the first sensor 6D and second sensor 6C and processes it, through filtering or integration, to derive other quantities used to calculate the Creta damping level to be applied to each shock absorber 4 present in vehicle 1.

[0066] In an 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 information item from the accelerometer 10 and the potentiometer 11 included in the system 100, to obtain a vertical velocity of the vehicle body zc in the vicinity of the wheels 3 and a compression velocity of the shock absorber Zd.

[0067] In other words, from the accelerations captured by the accelerometer 10 and the movements captured by the potentiometer 11, the computerized calculation unit 7 derives the vertical velocity zc of the vehicle body in the vicinity of the wheel 3 and the compression velocity Zd ​​of the shock absorber by integration and differentiation (and filtering, if necessary), respectively.

[0068] Below is described a preferred embodiment, illustrated in figure 2, where the damping level G-erdo damper 4 is calculated by the respective mid-level control unit 8M using algorithm A as a function of the vertical velocity zcdo vehicle body and the compression velocity Zd ​​of the damper. Petition 870240082912, dated 09 / 27 / 2024, page 28 / 40 10 / 15

[0069] According to the convention adopted in this preferred embodiment, zcé is defined as positive when the vehicle body 2 moves downwards along the vertical extension axis ze Zdé is defined as positive when the reference damper 4 is compressed.

[0070] In this embodiment, algorithm A, executed by the respective mid-level control unit 8M, is defined as follows Cre, = + sat + (ΚΛ„ζ.ζΛ+ C^] , (1) [ref^L^min^maxj where Cm / 7?e Cmax are, respectively, a minimum and a maximum value for the damping level Cref applicable to damper 4, saí is a saturation function that restricts the dynamics of G? to the interval [Cmm, Cmax] and where Á^y is a parameter that represents a gain of algorithm A.

[0071] In other words, the sai function keeps the Cref value unchanged when KskyZcZd + Cnom falls within the interval [Cm / / ?, Cmax], but applies Cref= Cmax when KskyZcZd+ Cnom is greater than Cmax and Cref= Cmin when KskyZcZd + Cnom is greater than Cmin.

[0072] Preferably, the gain / G^ is selectable by the driver of vehicle 1 from a finite number of values, corresponding to different vehicle attitude configurations.

[0073] The preferred embodiment of the system 100 illustrated in figure 2 comprises, in addition to the high-level control unit 8H, 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).

[0074] In this embodiment, the high-level control unit 8H and the four medium-level control units 8M calculate, respectively, the nominal damping levels CnOm, i.e., the damping levels Cond (where i is an integer from 1 to 4) independently for each wheel 3.

[0075] Advantageously, in this embodiment, the independence between the different values ​​of nominal damping Cnorm and damping G?# allows for the ideal adjustment of the vehicle's attitude 1.

[0076] Advantageously, the use of algorithm A allows regulating the damping level. Petition 870240082912, dated 09 / 27 / 2024, page 29 / 40 11 / 15 Cef is applied more uniformly, for greater comfort, compared to traditional two-stage sA'y / zooA' algorithms.

[0077] In fact, traditional skyhook algorithms calculate the damping level G^r as a function of the vertical velocity zc of the vehicle body and the compression velocity Zd ​​of the damper as follows—ref — c '-•min r '-•max if zczd< 0, if zczd> 0. '

[0078] This way of handling the damper operation causes unwanted jolts when the speeds involved are almost zero, since small variations, for example, caused by sensor noise, result in numerous changes between the two states allowed by the damping level.

[0079] In the proposed embodiment illustrated in Figure 3, in the configuration where Cnom = 0, small variations in the velocity values ​​zce Zd cause only small variations in the damping value Cref, thus canceling the jolts caused by state changes in traditional implementations of skyhook algorithms.

[0080] Advantageously, the use of this more uniform variant of a skyhook algorithm ensures a greater range of adjustments to the damping level of the shock absorber 4 (which can better adapt to vehicle bumps 1), thus improving driving comfort for the driver.

[0081] The Cnom parameter is calculated by the high-level control unit 8H as a function of the first signal S1 and the second signal S2 (if necessary, processed by the computerized calculation unit 7) and transmitted to the medium-level control unit 8M.

[0082] As described above, the nominal damping parameter Cnom is a damping parameter to be applied to dampers when there are no oscillations (i.e., when zc = 0 or Zd = 0).

[0083] Again according to the preferred embodiment, the nominal damping parameter Cnomé is obtained by the high-level control unit 8H through the following relation Cnom = Co + Gat + Ch)ng, (2) Petition 870240082912, dated 09 / 27 / 2024, pages 30 / 40 12 / 15 where Co is a standard nominal damping level, applied when there are no longitudinal or lateral accelerations of vehicle 1, and C / at and Ciong are, respectively, a first additive factor and a second additive factor, both calculated by the high-level control unit 8H as a function of the first signal S1 and the second signal S2.

[0084] The first additive factor C / up to the second additive factor G <w levam em consideração a dinâmica da aceleração lateral e longitudinal do veículo 1, respectivamente.

[0085] de preferência, o nível de amortecimento nominal padrão co é selecionável pelo motorista 1 partir um número finito valores, correspondendo diferentes configurações atitude 1.

[0086] More specifically, in this preferred embodiment, the first additive factor G# is calculated by the high-level control unit 8H as follows Gat= KlatAyfHP, (3) In which / ^is an adjustable gain factor and A^is a filtered version, preferably by a high-pass filter, of the quantity =y= v2<5 Kusv2+ L ,(4) In which iz is the speed of movement of vehicle 1, Xí / 5 is a steering reference coefficient and is a model parameter that describes the length of the wheelbase of vehicle 1.

[0087] Preferably, the speed of movement iz is derived by the computerized calculation unit 7 by processing at least one first signal S1 captured and sent by the GPS sensor with which vehicle 1 is equipped.

[0088] Again, according to the preferred embodiment, the second additive factor Go / ^ is calculated by the high-level control unit 8H as follows Ciong = Kio5g AxfHP, (5) In which Á / 0 / # is an adjustable gain factor and A^pé is a version, preferably filtered by a high-pass filter, of the quantity _ pSCxv2Teng,posg)engTenginegü)eng= = 2 ++^bk^bk+Kpos+Knegv Petition 870240082912, dated 09 / 27 / 2024, pp. 31 / 40 13 / 15 where p is air density, α is the frontal surface area of ​​vehicle 1, G is the aerodynamic friction coefficient of vehicle 1, m is the mass of vehicle 1, v is the speed of movement of vehicle 1, α is a braking efficiency, β is a pressure in the braking control 17 measured by the brake sensor 16, A is a first parameter of the model that describes the efficiency of the propulsion unit, A is a second parameter of the model that describes the efficiency of the propulsion unit, β is a positive parameter that describes a positive torque of the engine, β is a negative parameter that describes a negative torque of the engine and γ is a parameter that describes a number of revolutions of the engine of vehicle 1.

[0089] Preferably, when 7^, és is greater than 0, then Teng, ég is equal to 0 and when 7^,negé is less than 0, then Teng, és is equal to 0, respectively. In other words, it is impossible for the last two addenda in the previous equation to contribute simultaneously to the calculation of Ax.

[0090] Advantageously, the presence of the first additive factor Gat and the second additive factor O? / ?? allows the stability control system 100 to take into account the roll and pitch dynamics of the vehicle 1, respectively.

[0091] Even more advantageously, the fact that the nominal damping level Cnom (thus calculated by adding the first additive factor Gat and the second additive factor Gong) parameterizes algorithm A allows driving comfort and road grip to be managed simultaneously in the presence of both roll and pitch dynamics.

[0092] In fact, the addition of the nominal damping level Cnom calculated by the high-level control unit 8H, allows the medium-level control unit 8M to execute algorithm A with a vehicle attitude previously optimized as a function of the second signal S2, which is, as a function of the inputs entered by the driver.

[0093] Also defined, according to the invention, is a method 200 for controlling the stability of a vehicle 1 having a longitudinal axis of length x, a transverse axis of length ye and a vertical axis of length ze comprising a body 2, a plurality of wheels 3 and, for each wheel 3, at least one semi-active damper 4 interposed between the respective wheel 3 and the body 2. Petition 870240082912, dated 09 / 27 / 2024, pp. 32 / 40 14 / 15

[0094] Method 200 comprises a first measurement step 201, to capture a dynamic parameter of the vehicle 1.

[0095] The first measurement step 201 to capture a dynamic parameter of vehicle 1 comprises at least one of the following substeps: - measure at least one acceleration of body 2 in the vicinity of wheels 3 along a direction parallel to the vertical z-axis of vehicle 1; - measure at least one compression of the shock absorbers 4 along a direction nearly parallel to the vertical z-axis.

[0096] 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 absorbers 4, the first measurement step 201 comprises at least one sub-step of processing the dynamic parameters of the vehicle 1 to calculate a vertical velocity zc of the vehicle body in the vicinity of the wheels 3 and a compression velocity Zd ​​of the shock absorbers.

[0097] After the first measurement step 201, the method 200 comprises a second measurement step 202 to capture an input entered by the driver of the vehicle 1.

[0098] Preferably, the second measurement step 202 for capturing an input entered by the driver of vehicle 1 comprises at least one of the following substeps: - measure the steering angle δ determined by a steering wheel 13; - to measure an acceleration action applied by means of a throttle command 15; - to measure a braking action applied by means of a brake command 16.

[0099] Next, method 200 comprises a step 203 of executing an algorithm A to calculate a damping level Ger for damper 4 as a function of the dynamic parameter captured in the first measurement step 201 and the input captured in the second measurement step 202.

[00100] In a preferred embodiment comprising at least the measurement of the acceleration of the vehicle body 2, the measurement of the compression of the shock absorbers 4 and the sub-step of processing the dynamic parameters of the vehicle 1, the execution step 203 comprises the execution of algorithm A defined as =ref = [ [Cfrat] kKskyzczd + Gtom) , (1) [ref^i^min^maxi Petition 870240082912, dated 09 / 27 / 2024, pp. 33 / 40 15 / 15 where Cm / ne Cmax are, respectively, a minimum and a maximum value for the damping level G# s to a saturation function that restricts the dynamics of Cref to the interval [G™, Cmax] and where KSkye Cnom are two adjustable parameters that represent, respectively, a gain of algorithm A and a nominal damping level in the absence of vertical body velocity z or damper compression velocity Zd

[00101] Preferably, the nominal damping level Cnom is calculated as a function of the vehicle dynamic parameters 1 captured during the first measurement stage 201 and the input captured during the second measurement stage 202. Petition 870240082912, dated 09 / 27 / 2024, pp. 34 / 40< / w>

Claims

1 / 6 Claims 1. System (100) for controlling the stability of a 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), a semi-active damper (4) interposed between the respective wheel (3) and the body (2); the control system (100) comprising: - an actuator (5) configured to continuously regulate a damping level (G? / ) of the semi-active damper (4); - a first sensor (6D), configured to measure a dynamic parameter of the vehicle (1) and to send a first signal (S1) containing an information item related to the dynamic parameter; - a second sensor (6C) configured to measure an input entered by a driver of the vehicle (1) and to send a second signal (S2) containing an information item related to the input;- a high-level control unit (8H) communicating 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) communicating with the high-level control unit (8H) and the first sensor (6D) to receive the first signal (S1); - a low-level control unit (8L) communicating with the actuator (5) and the medium-level control unit (8M) and configured to send a drive signal to the actuator (5);characterized by the high-level control unit (8H) being configured to parameterize, as a function of the first signal (S1) and the second signal (S2), an algorithm (A) executed by the medium-level unit (8M), to calculate the damping level (G? / ) as a function of the first signal (S1) and a computerized calculation unit (7) in communication with the first sensor (6D), the second sensor (6C), the high-level control unit (8H) and the medium-level control unit (8M); the computerized calculation unit (7) being configured to process the first signal (S1) and the second signal (S2) and send a quantity derived from the first signal (S1) and the second signal (S2) Petition 870240082912, dated 09 / 27 / 2024, page 35 / 40 2 / 6 to the high-level control unit (8H) and to the medium-level control unit (8M).; 2. System (100), according to claim 1, characterized in that the first sensor (6D) comprises at least one chosen from the following: - an accelerometer (10) configured to measure an acceleration of the body (2) in the vicinity of the respective wheel (3) along a direction parallel to a vertical extension axis (z); - a potentiometer (11) configured to measure a compression of the semi-active damper (4) along a direction parallel to the vertical extension axis (z); wherein the second sensor (6C) comprises at least one chosen from the following: - a steering angle sensor (12) configured to measure a steering angle (δ) determined by a steering wheel (13); - a throttle sensor (14) configured to measure an action applied by means of a throttle command (15); - a brake sensor (16) configured to measure an action applied by means of a braking command (17).

3. System (100), according to claim 1, characterized in that the first sensor (6D) comprises at least the potentiometer (10) and the accelerometer (11), the computerized calculation unit (7) being configured to calculate a vertical velocity of the body (zc) in the vicinity of the wheel (3) and a compression velocity of the shock absorber (Zd) as a function of the first signal (S1) containing at least one item of information from the accelerometer (10) and the potentiometer (11).

4. System (100), according to claim 3, characterized in that the damping level (G«) of the semi-active damper (4) is calculated by the medium level control unit (8M) based on the vertical velocity of the body (zc) and the compression velocity of the damper (zz).

5. System (100), according to claim 4, characterized in that the damping level (Ó7e / ) of the semi-active damper (4) is calculated by the medium level control unit (8M) using an algorithm (A) defined as: Petition 870240082912, dated 27 / 09 / 2024, page 36 / 40 3 / 6 =r ef = [ ^írat r íKskyzczd + Cnom) , (1) [ref^L^min^maxj where (Q / / ?) and (Cmax) are, respectively, a minimum and a maximum value for the applicable damping level (Oe> / ) and, wherein (Kty) and (Cnom) are two adjustable parameters that represent, respectively, a gain of algorithm (A) and a nominal damping level in the absence of vertical body velocity (zc) or damper compression velocity (zo).

6. System (100), according to claim 5, characterized in that the nominal damping level (Cnom) is calculated by the high-level control unit (8H) as follows: Cnom — Co + Cat + C / ong, (2) wherein (G?) is a standard nominal damping level and wherein (Gat) and (C / ong) are, respectively, a first additive factor and a second additive factor, both calculated by the high-level control unit (8H) as a function of the first signal (S1) and the second signal (S2).

7. System (100), according to claim 6, characterized in that the first additive factor (Cat) is calculated as follows: —t= KlatAy,HP, (3) wherein (K / at) is an adjustable gain factor and (Aυ,ηρ) is a filtered version of the quantity =y = ν2δ Kusv2 + L ,(4) wherein (u) is a vehicle movement speed (1), (Kus') is a steering reference coefficient and (A) is a parameter describing a length of the vehicle wheelbase (1).

8. System (100), according to claim 6, characterized in that the second additive factor (C / ong) is calculated as follows: —long — A / o / jg Ax,HP, (5) wherein (K / Ong) is an adjustable gain factor and (Ax,hp) is a filtered version of the quantity pSCxv2 =x = 2~ϊη + ^bk^bk + kpos Teng.posMeng + kneg Teng.neg ^eng ,(6) Petition 870240082912, of 27 / 09 / 2024, p.37 / 40 4 / 6 wherein (p) is an air density, (5) is the frontal surface area of ​​the vehicle (1), (G) is a coefficient of aerodynamic friction of the vehicle (1), (rrí) is a mass of the vehicle (1), (u) is a speed of movement of the vehicle (1), (kw) is a braking efficiency, (Pu) is a pressure in a braking control (17) measured by a brake sensor (16), (kpo) is a first parameter of the model that describes an efficiency of the propulsion unit, (kneg) is a second parameter of the model that describes the efficiency of the propulsion unit, (Teng,pos) is a parameter that describes a positive torque of a vehicle motor, (Teng,neg) is a parameter that describes a negative torque of the motor and (ω&κ) is a parameter that describes a number of revolutions of the motor.

9. System (100), according to claim 1, characterized in that the semiactive damper (4) is a magnetorheological damper.

10. Method (200), intended to control the stability of a vehicle (1), having a longitudinal axis of extension (x), a transverse axis of extension (y) and a vertical axis of extension (z) and comprising a body (2), a plurality of wheels (3) and, for each wheel (3), a semi-active damper (4) interposed between the respective wheel (3) and the body (2); the method (200) being implemented by a system as defined in any of the preceding claims, said method characterized by comprising: - a first measurement step (201), to capture a dynamic parameter of the vehicle (1); - a second measurement step (202), to capture an input entered by a driver of the vehicle (1); - a step (203) of executing an algorithm (A) to calculate a damping level (Ga) for the damper (4) as a function of the dynamic parameter and the input;- a step (204) of implementing the damping level (Ga), calculated by the algorithm (A), by an actuator (5) that is operationally connected to the semi-active damper (4); wherein the first measurement step (201) to capture at least one dynamic parameter of the vehicle (1) comprises at least one of the following substeps: Petition 870240082912, dated 09 / 27 / 2024, page 38 / 40 5 / 6 - measuring at least one acceleration of the body (2) in the vicinity of the wheels (3) along a direction parallel to the vertical axis (z) of the vehicle (1); - measuring at least one compression of the semi-active dampers (4) along a direction almost parallel to the vertical axis (z).; 11. Method (200), according to claim 10, characterized in that the 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 semi-active shock absorbers (4), the first measurement step (201) comprising a sub-step of processing the dynamic parameters of the vehicle (1) to calculate a vertical velocity (zc) of the body in the vicinity of the wheels (3) and a compression velocity (zd) of the semi-active shock absorbers (4).

12. Method (200), according to claim 10, characterized in that the second measurement step (202), for capturing the input entered by the vehicle driver (1), comprises at least one of the following substeps: - measuring a steering angle (δ) determined by a steering wheel (13); - measuring an acceleration action applied by means of a throttle command (15); - measuring a braking action applied by means of a brake command (16).

13. Method (200), according to claim 11, characterized in that the execution step (203) comprises the execution of algorithm (A) defined as: = = = =ref + +at + +Kskyzczd + Cnom) , (1) [reft LCm[n,CmaxJ wherein (Cmin) and (G?%) are, respectively, a minimum and a maximum value for the applicable damping level (G? / ) and wherein (Ks / q) and (Cnom) are two adjustable parameters that represent, respectively, a gain of algorithm (A) and a nominal damping level in the absence of vertical body velocity (zc) or damper compression velocity (zo).

14. Method (200), according to claim 13, characterized in that the parameter (Cnom) is calculated as a function of the vehicle dynamic parameter (1) captured during the first measurement step (201) and the input captured during the second measurement step (202). Petition 870240082912, dated 27 / 09 / 2024, page 39 / 40 6 / 6

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