Method for controlling wheel slip in a braking system applying BbW technology of a vehicle and the system thereof

Abstract

A method (500) for controlling wheel slip in a braking system of a vehicle, wherein the method comprises: - A step (501) of receiving information representing a vehicle and information representing an estimation of the vehicle state by the input interface module of the slip control module; - A step (502) of outputting input wheel slip control information by the above input interface module; - A step (503) of determining wheel slip control parameters based on information representing the vehicle and information representing the state of the vehicle by the parameter self-loading module of the input interface module; - A step (505) of determining a plurality of activation signals for wheel slip control based on received input wheel slip control information and received wheel slip control parameters by a plurality of wheel slip control activation modules of the slip control module; and - To minimize the error between the defined slip setpoint and the estimated wheel slip, the method includes the step (506) of determining the setpoint value of a control variable to be applied to each vehicle corner based on the defined slip setpoint and the estimated wheel slip value by each closed-loop wheel slip control module of the plurality of closed-loop wheel slip control modules of the slip control module.

Description

Technology Field

[0001] The present invention relates to a braking system for a vehicle, and more particularly to a method for controlling wheel slip and a system in a braking system to which BbW technology is applied for a vehicle. Background Technology

[0002] Wheel slip control is critical in vehicles, and in this regard, it is added to the configuration of braking systems that must be able to ensure a high level of control optimization and flexibility.

[0003] Conventional braking systems feature operating circuits equipped with numerous valves where braking management is typically performed via discontinuous-cycle control algorithms (periodical de-application of braking requests). For example, there are architectures that do not allow for the separation between vehicle wheel slip control and the control of continuous force modulation by actuators employed to deliver braking to the wheels. Consequently, this effectively limits all kinds of optimization and flexibility in the overall method for controlling the braking system to achieve optimal performance in terms of wheel control, while simultaneously restricting tuning techniques to empirical methods.

[0004] The most recent innovative architecture proposes a braking system equipped with an electronic braking system utilizing BbW ("Brake-by-Wire") technology, where, for example, the braking action of the brake caliper at the wheel is achieved using one or more electromechanical or electro-hydraulic actuators.

[0005] However, based on the considerations regarding the conventional braking system described above, the vehicle wheel slip control method available in the conventional braking system is not suitable for application to a braking system provided with an electronic braking system utilizing BbW technology.

[0006] Therefore, nowadays, there is a perceived need to define specific and optimized modes for controlling vehicle wheel slip even for braking systems equipped with electronic braking systems utilizing BbW technology, and such control modes can be configured as state evaluation functions for one or more wheels and / or the vehicle itself. The problem to be solved

[0007] The objective of the present invention is to devise and make available a method for controlling wheel slip in a braking system of a vehicle that can prevent the disadvantages raised above in relation to the prior art by further optimizing the responsiveness and performance of wheel slip control as well as braking convenience and ensuring greater flexibility, thereby enabling such a control mode to be configured at least partially, in particular, as a function of the condition evaluation of one or more wheels and / or the vehicle itself. means of solving the problem

[0008] Such an objective is achieved by the method according to claim 1.

[0009] The present invention also relates to a system for controlling wheel slip in a vehicle braking system.

[0010] Additional advantageous implementation examples are the subject of the dependent terms. Brief explanation of the drawing

[0011] Further features and advantages of the method and system according to the present invention will become apparent from the following description of preferred embodiments given by exemplary and non-limiting examples with reference to the accompanying drawings: - FIG. 1 is a block diagram illustrating a vehicle and an electronic braking system to which brake-by-wire technology can be employed for a system to control wheel slip in a braking system of a vehicle object according to the present invention; - FIG. 2 is a block diagram showing a vehicle and an electronic braking system with the brake-by-wire technology of FIG. 1 applied, showing each internal component in detail; - FIGS. 3a, 3b, and 3c are block diagrams illustrating systems for controlling wheel slip of a vehicle according to various embodiments of the present invention; - FIGS. 4a to 4g are schematic diagrams illustrating each component of a system for controlling wheel slip in a braking system of a vehicle according to the present invention; - FIG. 5 is a block diagram illustrating a method for controlling wheel slip in a braking system of a vehicle according to one embodiment of the present invention; - Figure 6 is a block diagram showing an example of the operation of a system component for controlling wheel slip in a vehicle braking system. Specific details for implementing the invention

[0012] Now, referring to the drawings described above, reference numeral 100 represents an entire system (hereinafter also simply referred to as the system) for controlling wheel slip in a braking system of a vehicle according to the present invention.

[0013] It should be noted that identical or similar elements in the drawing are indicated by the same numeric or alphanumeric reference.

[0014] For the purposes of this description, the term "vehicle" as depicted only schematically in the drawings refers to any commercial type of vehicle or motorcycle having two, three, four, or more wheels.

[0015] In addition, "braking system" refers to the entirety of all components (mechanical and / or electric or electronic, brake fluid) that contribute to generating the vehicle's service braking or parking braking.

[0016] The system (100) is an electronic system with brake-by-wire technology applied.

[0017] The above system (100) is operably connected to the vehicle (1).

[0018] More specifically, the system (100) includes a slip control module (101).

[0019] Wheel slip refers to the behavior of a wheel caused by the relative difference between wheel speed and vehicle speed.

[0020] The above slip control module (101) is, for example, a hardware module or software logic module of a braking system or, more generally, a main hardware module of a vehicle (1).

[0021] The above system (100) further includes a plurality of actuator modules (102).

[0022] Each of the plurality of actuator modules (102) includes each actuator control module and each actuator configured to execute a braking command based on control received from each actuator control module.

[0023] Each actuator control module is, for example, a hardware module or software logic module of a braking system or generally a main hardware module of a vehicle (1).

[0024] Each actuator is of the electro-mechanical or electro-hydraulic type.

[0025] The above slip control module (101) is configured to receive information (MD) representing a vehicle (1) and to transmit one or more commands representing a braking request (BR) based on such information (MD) to the plurality of actuator modules (102).

[0026] For the purposes of this description, "information representing a vehicle (MD)" refers to detection and / or estimation information from detection devices (actual or virtual sensors) installed on the vehicle, i.e., at the corner (front or rear of the vehicle), but is not necessarily related only to the vehicle's braking system.

[0027] The plurality of actuator modules (102) are configured to apply one or more braking actions (BA) to the corners (110) of the vehicle (1) based on one or more commands representing a braking request (BR) received from the slip control module (101).

[0028] It is worth noting that "braking action" refers to the braking force / torque that can be applied by the actuator module of the corresponding wheel.

[0029] It is worth noting that the above-mentioned slip control module (101) is configured to provide a plurality of actuator modules (102) with a control mode (MC) and configuration parameters (CP), which will be described in more detail below, in addition to transmitting one or more braking request (BR) commands.

[0030] Referring to FIG. 2, the wheel slip control module (101) includes a plurality of wheel slip control submodules (103).

[0031] The wheel slip control submodules of such a plurality of wheel slip control submodules (103) are configured to control each corner of the vehicle (1).

[0032] More specifically, when the vehicle (1) has four wheels (two on the front axle and two on the rear axle), a plurality of wheel slip control submodules (103) are:

[0033] - First wheel slip control submodule (C-FL) at the front left corner;

[0034] - Second wheel slip control submodule (C-FR) at the front right corner;

[0035] - Third wheel slip control submodule (C-RL) at the rear left corner;

[0036] - Includes a fourth wheel slip control submodule (C-RR) for the rear right corner.

[0037] Referring again to FIG. 2, the plurality of actuator control modules (102) are distributed at the corners of the vehicle (1).

[0038] More specifically, when the vehicle (1) again has four wheels (two on the front axle and two on the rear axle), the plurality of actuator control modules (102) are:

[0039] - First actuator control module (A-FL) at the front left corner;

[0040] - Second actuator control module (A-FR) at the front right corner;

[0041] - Third actuator control module (A-RL) at the rear left corner;

[0042] - Includes a fourth actuator control module (A-RR) at the rear right corner.

[0043] One or more commands representing a braking request (BR) transmitted from a slip control module (101) to a plurality of actuator control modules (102) are:

[0044] - A first braking request (BR1) provided to the first actuator control module (A-FL) of the front left corner by the first wheel slip control submodule (C-FL) of the front left corner;

[0045] - A second braking request (BR2) provided to the second actuator control module (A-FR) of the front right corner by the second wheel slip control submodule (C-FR) of the front right corner;

[0046] - A third braking request (BR3) provided to the third actuator control module (A-RL) of the rear left corner by the third wheel slip control submodule (C-RL) of the rear left corner;

[0047] - Includes a fourth braking request (BR4) provided to the fourth actuator control module (A-RR) of the rear right corner by the fourth wheel slip control submodule (C-RR) of the rear right corner.

[0048] It is worth noting that each wheel slip module is configured to provide control modes MC-1, MC-2, MC-3, or MC-4 and configuration parameters CP-1, CP-2, CP3, or CP-4, which will be described in more detail below, to a plurality of actuator modules (102), in addition to transmitting each braking request BR1, BR2, BR3, or BR4.

[0049] One or more braking operations (BA) that the above plurality of actuator modules (102) can perform in the vehicle (1) are:

[0050] - A first braking action (BA1) provided to the front left wheel (W-FL) of the vehicle (1) by the first actuator control module (A-FL) of the front left corner;

[0051] - A second braking action (BA2) provided to the front right wheel (W-FR) of the vehicle (1) by the second actuator control module (A-FR) of the front right corner;

[0052] - A third braking action (BA3) provided to the rear left wheel (W-RL) of the vehicle (1) by the third actuator control module (A-RL) of the rear left corner;

[0053] - Includes a fourth braking action (BA4) provided to the rear right wheel (W-RR) of the vehicle (1) by the fourth actuator control module (A-RR) of the rear right corner.

[0054] It is worth noting that in FIG. 2, the vehicle (1) further includes a chassis (CS) in which a front axle including a front left wheel (W-FL) and a front right wheel (W-FR) and a rear axle including a rear left wheel (W-RL) and a rear right wheel (W-RR) are operably connected.

[0055] Additionally, as again schematically illustrated in FIG. 2, the vehicle (1) includes a braking request module (111) configured to transmit a braking request to the vehicle (1).

[0056] The braking request that the above braking request module (111) can transmit is one of the items of information (MD) representing a vehicle provided to the control module (100).

[0057] In the embodiment shown in FIG. 2, the braking request module (111) includes a brake pedal (BP) configured to allow the driver of the vehicle (1) to transmit a braking request to the vehicle (1).

[0058] In this embodiment, such a braking request refers to the position and / or pressure of the brake pedal.

[0059] According to another embodiment, the braking request module (111), which is replaced or combined with the former and is indicated by a dashed line in FIG. 2, includes one or more control logics (BC) configured to transmit braking requests, such as automatic vehicle driving assistance logic of the automatic emergency brake (AEB) type, automatic autonomous driving logic, etc.

[0060] According to various implementation examples schematically illustrated in FIGS. 3a, 3b and 3c, the system (100) can be configured in terms of software based on the distribution of one or more electronic control units within the vehicle (1).

[0061] One or more electronic control units have various operations, one of which is to perform a sleep control module (101).

[0062] It is worth noting that a single electronic control unit can be configured to perform up to N wheel slip control submodules.

[0063] In the case of a vehicle having a single electronic control unit configured to perform N corners and all N wheel slip control submodules, the system (100) is named centrally.

[0064] Instead, for a vehicle having N corners and N electronic control units, each is configured to perform a single wheel slip submodule, and the system (100) is named distributed.

[0065] This modularity of the system (100) according to these implementation examples allows for greater flexibility of the system (100) itself regarding various distribution configurations of one or more electronic control units within the vehicle (1).

[0066] According to an example of implementation, as shown in FIG. 3a, a plurality of wheel slip control submodules (103) distributed at a single corner (C-1, C-2, ..., CN) of the system (100), particularly of the vehicle (1), may be configured to control the number of corners of the vehicle in a controlled manner such that the number of corners of the vehicle is less than or equal to the total number of corners of the vehicle (1).

[0067] In this configuration, also known as a fully distributed system (BbW distributed - fully distributed), the distribution of the electronic control unit and the wheel slip control submodule is based on the corners of vehicle 1.

[0068] Such a configuration may, in one embodiment, provide for the presence of an electronic control unit for each corner and a wheel slip control submodule for each control unit associated with the associated corner.

[0069] For example, referring to FIG. 3a, the corner (C-1) may be the front left corner corresponding to the first wheel slip control submodule (C-FL).

[0070] According to an additional implementation example configured to provide greater flexibility, the electronic control unit may be configured to perform a number of corner wheel slip control submodules, whereas other electronic control units are not configured to perform any wheel slip control submodule.

[0071] According to an additional implementation example shown in FIG. 3b, a plurality of wheel slip control submodules (103) distributed on a single axle (A-1, A-2, ..., AN) of a system (100), particularly a vehicle (1), may be configured to control the number of axles in a coordinated manner to be less than or equal to the total number of axles of the vehicle (1).

[0072] In this configuration, also known as a partially distributed system (BbW distributed - partially distributed), the distribution of the electronic control unit and the wheel slip control submodule is based on the axles of vehicle 1.

[0073] In an example implementation, this configuration may provide for the presence of an electronic control unit for each axle and a wheel slip control submodule for each control unit associated with the corner associated with the axle.

[0074] For example, referring to FIG. 3b, a single axle (A-1) may be a front axle and may include a first wheel slip control submodule (C-FL) and a second wheel slip control submodule (C-FR).

[0075] According to an additional implementation example configured to provide greater flexibility, the electronic control unit may be configured to perform multiple wheel slip control submodules of the axle.

[0076] According to an additional implementation example shown in FIG. 3c, if the system (100), in particular the slip control module (101), is centralized, it can be configured to control the number of corners of the vehicle (1) in a coordinated manner, such that the number of corners of the vehicle (1) is less than or equal to the total number of corners of the vehicle (1).

[0077] This configuration, also known as a centralized system (BbW centralized), includes a single electronic control unit comprising a plurality of wheel slip control submodules (103) for a single corner (C-1, C-2, ..., CN) of the vehicle (1).

[0078] Now, with reference to FIGS. 4a through 4g, the slip control module (101) will be described in more detail.

[0079] From a software perspective, each wheel slip control submodule of the wheel slip control module (101) and the plurality of wheel slip control modules (103) according to the same is configured to execute a method for controlling wheel slip in a braking system of a vehicle as described below.

[0080] The above-mentioned sleep control module (101) includes an input interface module (40).

[0081] For example, the input interface module (40) is a hardware module or software logic module of a braking system or, more generally, a main hardware module of a vehicle (1).

[0082] The above input interface module (40) is configured to receive input information (MD) representing the vehicle (1) previously introduced with reference to FIGS. 1 and FIGS. 2 and information (MS) representing the estimation of the vehicle state.

[0083] Information (MD) representing the vehicle (1) is provided by components mounted on the vehicle (1), such as sensors and / or a CAN (Controller Area Network) network and / or one or more electronic control units in a single corner of the vehicle.

[0084] In this regard, as shown in FIG. 4a, information representing a vehicle (MD) includes one or more of the following information groups:

[0085] - A first information group (MD-1) detectable by a sensor mounted on the vehicle (1);

[0086] - A second information group (MD-2) detectable by the CAN network or other data communication channel of the vehicle (1);

[0087] - A third information group (MD-3) detectable by one or more electronic control units of a single vehicle corner.

[0088] It is worth noting that this third information group (MD-3) includes additional information detectable at vehicle corners other than the vehicle corner associated with the slip control module (101).

[0089] Instead, information (MS) indicating such vehicle state estimation is provided by a vehicle state estimation module (MSV; shown only in FIG. 6).

[0090] For example, the vehicle state estimation module (MSV) is a hardware module or software logic module of the braking system or generally the main hardware module of the vehicle (1).

[0091] In an example implementation, the module (MSV) may be located inside the system (100).

[0092] According to another implementation example, as an alternative to the prior implementation example, the module (MSV) may be located outside the system (100).

[0093] Returning to the input interface module (40), it is configured to output input wheel slip control information (SCD) to be provided as an input to an additional module of the slip control module (101) arranged downstream of the input interface module (40).

[0094] Input wheel slip control information (SCD) is essential information for the wheel slip control module (101) to control wheel slip, and is selected by the interface module (40) from among information (MD) representing the vehicle (1) and information (MS) representing the vehicle status.

[0095] More specifically, the input wheel slip control information (SCD) includes at least the following:

[0096] - Wheel speed (detectable by sensors mounted on the vehicle);

[0097] - Longitudinal acceleration of the vehicle (detectable by sensors mounted on the vehicle);

[0098] - Lateral acceleration of the vehicle (detectable by sensors mounted on the vehicle);

[0099] - Yaw rate (detectable by sensors mounted on the vehicle);

[0100] - Vehicle speed (provided by the vehicle status estimation module);

[0101] - Wheel slip (provided by the vehicle condition estimation module);

[0102] - Road grip (provided by the vehicle status estimation module);

[0103] - Wheel acceleration (provided by the vehicle state estimation module);

[0104] - Side slip angle (provided by the vehicle status estimation module);

[0105] - Side wheel slip (provided by the vehicle condition estimation module);

[0106] - Identification of vehicle maneuver type (provided by the vehicle status estimation module);

[0107] - Status information of other vehicle corners (SlipControlEnable, SCE, and SP-V setpoint values ​​of control variables to be applied to each vehicle corner, as described below).

[0108] Referring again to FIG. 4a, the input interface module (40) includes a parameter self-loading module (41).

[0109] For example, the above parameter self-loading module (41) is a software module or software logic module of a braking system or generally a main hardware module of a vehicle (1).

[0110] The above parameter self-loading module (41) is configured to determine a wheel slip control parameter (SCP) used by the control logic of the wheel slip control module (101) based on information (MD) representing the vehicle (1) and information (MS) representing the state of the vehicle (1).

[0111] The above wheel slip control parameter (SCP) is a parameter used in a formula / law for controlling an additional module of the wheel slip control module (101) arranged downstream of the input interface module (40) and described below with reference to FIGS. 4b to 4g.

[0112] Some examples of these parameters are the controller's gain and time constant, the slip setpoint table, and the trigger threshold of the aforementioned module.

[0113] An example of a decision regarding loading a parameter set as a function of the load grip is shown in the following section.

[0114] The wheel slip control parameter (SCP) can be divided into discontinuous subsets or determined as the output of an interpolation function based on information (MD) representing the vehicle (1) and information (MS) representing the state of the vehicle (1).

[0115] According to one embodiment, the wheel slip control parameter (SCP) may be divided into various subsets according to various load grips ("high grip," "medium grip," "low grip") and the estimated load grip received from the vehicle (1) state estimation module, and such parameters are configured such that the self-loading module (41) loads the corresponding subset of the wheel slip control parameter (SCP).

[0116] According to another embodiment, as an alternative to the preceding embodiment, the parameter self-loading module (41) is configured to determine the wheel slip control parameter (SCP) as a function of the estimated load grip received from the vehicle (1) state estimation module, for example:

[0117] Parameter SCP = Base Parameter SCP × Function(Base Grip / Estimated Grip), where:

[0118] - Basic Parameter SCP: Associated / corrected parameter for basic grip (e.g., specific gain of a wheel slip control module)

[0119] - Function = Interpolation logic for applying parameters to the estimated grip (e.g., using linear interpolation logic: parameter SCP = base parameter SCP × (base grip / estimated grip);

[0120] - Basic grip: High grip, dry asphalt, μ = 1.

[0121] Referring to FIG. 4b, the wheel slip control module (101) further includes a plurality of wheel slip control activation modules (42).

[0122] For example, each of the multiple wheel slip control activation modules (42) is a software module or software logic within a braking system or, more generally, a main hardware module of a vehicle (1).

[0123] The plurality of wheel slip control activation modules (42) include at least one wheel slip control activation module for each corner of the vehicle.

[0124] For example, referring to FIG. 4b, such a plurality of wheel slip control activation modules (42) are:

[0125] - First activation module (E-FL) for front left corner wheel slip control;

[0126] - Second activation module (E-FR) for front right corner wheel slip control;

[0127] - Third activation module (E-RL) for rear left corner wheel slip control;

[0128] - Includes a fourth activation module (E-RR) for rear right corner wheel slip control.

[0129] The plurality of wheel slip control activation modules (42) are configured to generate a plurality of activation signals (SCE) for wheel slip control based on received input wheel slip control information (SCD) and received wheel slip control parameters (SCP).

[0130] More specifically, each wheel slip control activation module of the plurality of wheel slip control activation modules (42) is configured to determine each activation signal of a plurality of activation signals (SCE) of wheel slip control based on received input wheel slip control information (SCD) and received wheel slip control parameters (SCP).

[0131] It is worth noting that the wheel slip control activation module (42) is configured to activate wheel slip control when it detects an imminent loss of wheel stability and / or vehicle stability.

[0132] For example, the wheel slip control activation module (42) is configured to detect an imminent loss of wheel stability by evaluating a wheel slip estimation evaluation (WheelSlip) and comparing such evaluation with a functional threshold of the vehicle state (SlipThreshold[f(vehicle speed, road grip, brake pedal speed, wheel acceleration)]) and to activate wheel slip control (True) for one or more corners of the vehicle:

[0133] If WheelSlip >= SlipThreshold[f(vehicle speed, road grip, brake pedal speed)], then SlipControlEnable(SCE) = True.

[0134] According to an additional implementation example schematically illustrated in FIG. 4c, in combination with the preceding implementation example, the slip control module (101) further includes a plurality of wheel slip setpoint specification modules (43).

[0135] For example, each of the plurality of wheel slip setpoint regulation modules (43) is a software module or software logic within a braking system or, more generally, a main hardware module of a vehicle (1).

[0136] The plurality of wheel slip setpoint regulation modules (43) include at least one wheel slip setpoint regulation module for each corner of the vehicle.

[0137] Referring to FIG. 4c, the plurality of wheel slip setpoint specification modules (43) are:

[0138] - First regulation module (D-FL) of the first wheel slip setting point for the front left corner;

[0139] - Second regulation module (D-FR) of the second wheel slip setting point for the front right corner;

[0140] - Third regulation module (D-RL) of the third wheel slip setting point for the rear left corner;

[0141] - Includes the fourth regulation module (D-RR) of the fourth wheel slip setting point for the rear right corner.

[0142] The plurality of wheel slip setpoint specification modules (43) are configured to generate a wheel slip setpoint (SP-S) based on the received input wheel slip control information (SCD) and the received wheel slip control parameter (SCP).

[0143] In one implementation example, the slip setpoint is a constant value named as a reference slip setpoint defined by the parameter self-loading module (41) of the input interface module (40).

[0144] According to another implementation example, in combination with the preceding implementation example, the slip setpoint is determined by each regulation module starting from each reference slip setpoint as a function of information (MS) representing the state of the vehicle.

[0145] The above plurality of wheel slip setpoint specification modules (43) are configured to modulate a reference wheel slip setpoint for each single corner of the vehicle based on the received input wheel slip control information (SCD) and the received wheel slip control parameter (SCP) to obtain an optimal wheel slip setpoint in real time to effectively maximize dynamic performance when braking the vehicle.

[0146] For example, the wheel slip setpoint can be modulated as a function of the vehicle's road grip and lateral acceleration, starting from the reference wheel slip setpoint:

[0147] Slipsetpoint = Slipsetpoint reference * f(load grip, lateral acceleration).

[0148] Referring to FIG. 4d, the slip control module (101) further includes a plurality of closed-loop wheel slip control modules (44).

[0149] For example, each of the plurality of closed-loop wheel slip control modules (44) is a software module or software logic within a braking system or, more generally, a main hardware module of a vehicle (1).

[0150] The plurality of wheel slip closed-loop control modules (44) include at least one closed-loop wheel slip control module for each corner of the vehicle.

[0151] Referring to FIG. 4d, the plurality of closed-loop wheel slip control modules (44) are:

[0152] - First closed-loop wheel slip control module (CL-1) for the front left corner;

[0153] - Second closed-loop wheel slip control module (CL-2) for the front right corner;

[0154] - Third closed-loop wheel slip control module (CL-3) for the rear left corner;

[0155] - Includes a fourth closed-loop wheel slip control module (CL-4) for the rear right corner.

[0156] Each closed-loop wheel slip control module, comprising software adjustment logic (e.g., PID-type control, where PID stands for Proportional-Integral-Derivative), is configured to determine the setpoint value (SP-V) of the control variable to be applied to each vehicle corner based on a defined slip setpoint (SP-S) and an estimated wheel slip value in each execution cycle of each software, thereby minimizing the error between the defined slip setpoint (SP-S) and the estimated wheel slip value.

[0157] Examples of control variables are force or position, electrical voltage or pressure, torque, or current that can be applied through each actuator of the vehicle corner.

[0158] In one embodiment, in combination with the preceding embodiment, each closed-loop wheel slip control module includes software logic for initializing or resetting control logic based on individual events (event-based logic for control activation and / or exceeding error thresholds and / or decreasing or increasing required force) to effectively make control changes faster in the face of abrupt changes in operating conditions.

[0159] According to another embodiment, as schematically illustrated in FIG. 4e, in combination with the preceding embodiment, the slip control module (101) further includes a plurality of reference target correction modules (45).

[0160] "Reference Target" refers to the setpoint value (SP-V) of the control variable to be applied to each vehicle corner, determined by the closed-loop wheel slip control module described above.

[0161] For example, each of the plurality of reference target correction modules (45) is a software module or software logic within a braking system or, more generally, a main hardware module of a vehicle (1).

[0162] The plurality of reference target correction modules (45) include at least one reference target correction module for each corner of the vehicle.

[0163] Referring to FIG. 4e, the plurality of target correction modules (45) are:

[0164] - First reference target correction module (CT-1) for the front left corner;

[0165] - Second reference target correction module (CT-2) for the front right corner;

[0166] - Third reference target correction module (CT-3) for the rear left corner;

[0167] - Includes a fourth reference target correction module (CT-4) for the rear right corner.

[0168] The plurality of reference target correction modules (45) are configured to correct (overwrite and / or reduce) the reference target value received as input by providing a corrected reference target value (TC) as output based on individual events (slip threshold exceeded and / or wheel acceleration threshold exceeded and / or open-loop control request of a single corner).

[0169] It is worth noting that the above-mentioned plurality of reference target correction modules (45) are configured to correct the reference target value by performing a non-linear change.

[0170] Such nonlinear changes in control variables can increase the responsiveness of the control to a given abrupt change in the controlled variable, for example, by reducing the force value when there is high wheel acceleration (WheelAcc):

[0171] If WheelAcc >= WheelAccThreshold [f(vehicle speed, road grip, …)], then ForceTarget = ForceTarget - Forcecompensation), where:

[0172] - WheelAcc = Wheel Acceleration (from input wheel slip control information (SCD);

[0173] - WheelAccThreshold = acceleration threshold at which correction is performed;

[0174] - ForceTargetOut = Force TC (corrected reference target value) output from a plurality of reference target correction modules (45);

[0175] - ForceTargetIn = Force SP_V (set point value) input to the multiple reference target correction modules (45);

[0176] - Force compensation = Force compensation value (included in the wheel slip control parameter (SCP)).

[0177] Additionally, referring now to FIG. 4f, in combination with the preceding module, the slip control module (101) further includes a plurality of adjustment modules (46) of a force FC defined for the corners of individual vehicle axles.

[0178] For example, each force adjustment module specified for the corners of the plurality of individual vehicle axles is a software module or software logic within the braking system or, more generally, the main hardware module of the vehicle (1).

[0179] The plurality of adjustment modules (46) include at least one force adjustment module defined for each corner of the vehicle axle of each corner of the vehicle.

[0180] Referring to FIG. 4f, a plurality of force adjustment modules (46) for the defined force for the corners of the individual vehicle axles are:

[0181] - A first adjustment module of force (FA-S) configured to provide a first slip control force (FC-1) for the front left corner of the vehicle and a second slip control force (FC-2) for the front right corner of the vehicle, specifically defined for the corner of the front axle; and

[0182] - Includes a second force adjustment module (RA-S) configured to provide a third slip control force (FC-3) for the rear left corner of the vehicle and a fourth slip control force (FC-4) for the rear right corner of the vehicle, specifically defined for the corner of the rear axle.

[0183] The plurality of adjustment modules (46) are configured to evaluate the vehicle's grip, vertical load, stability, and speed conditions to determine the saturation for the maximum and / or minimum force required for a single corner of each axle based on the reference target value TC (setpoint value) of the control variable provided by the preceding modules.

[0184] These restrictions allow for and optimize the adjustment of prescribed logic for each corner / side of the vehicle to ensure the overall stability of the vehicle.

[0185] For example, if different load grips exist on two sides of a vehicle, the higher grip side can be restricted based on load grip and vehicle speed using the following logic:

[0186] Force saturation on the high grip side = Required force on the low grip side + Force value defined by a mathematical function receiving vehicle information as input.

[0187] According to an additional implementation example schematically illustrated in FIG. 4g, the slip control module (101) further includes a plurality of interface configuration modules (47) of actuator control modules present in each actuator module of a plurality of actuator modules (102).

[0188] For example, each of the configuration interface modules (47) is a software module or software logic within a braking system or, more generally, a main hardware module of a vehicle (1).

[0189] The plurality of interface configuration modules (47) include at least one interface configuration module of an actuator control module for each corner of the vehicle.

[0190] For example, referring to FIG. 4g, the plurality of interface configuration modules (47) are:

[0191] - First configuration interface module (CNF-1) of the front left corner actuator control module;

[0192] - Second configuration interface module (CNF-2) of the front right corner actuator control module;

[0193] - Third configuration interface module (CNF-3) of the rear left corner actuator control module;

[0194] - Includes the fourth configuration interface module (CNF-4) of the rear right corner actuator control module.

[0195] Each of the above-mentioned interface configuration modules (47) is configured to define the control (logic) mode (MC) of the actuator control module of each vehicle corner.

[0196] Additionally, each of the plurality of interface configuration modules (47) is configured to define a set of configuration parameters (CP) provided to be loaded into the actuator control module of the relevant corner of the vehicle.

[0197] As exemplified in Fig. 4g:

[0198] - The first configuration interface module (CNF-1) is configured to define a first control mode (MC-1) of the front left corner actuator control module and a set of first configuration parameters (CP-1) provided to be loaded into the front left corner actuator control module;

[0199] - The second interface module (CNF-2) is configured to define a second control mode (MC-2) of the front right corner actuator control module and a set of second configuration parameters (CP-2) provided for loading into the front right corner actuator control module;

[0200] - The third interface module (CNF-3) is configured to define the third control mode (MC-3) of the rear left corner actuator control module and the set of third configuration parameters (CP-3) provided for loading into the rear left corner actuator control module;

[0201] - The fourth interface module (CNF-4) is configured to define the fourth control mode (MC-4) of the rear right corner actuator control module and the set of fourth configuration parameters (CP-4) provided for loading into the rear right corner actuator control module.

[0202] More specifically, each interface configuration module of the plurality of interface configuration modules (47) is configured to define the most suitable configuration for the actuator control module of each corner of the vehicle in terms of the set of configuration parameters (CP) to be provided for control (logic) mode (MC) and loading, based on the received wheel slip control information SCD (same as single corner information), based on wheel slip control parameters (SCP) such as individual wheel conditions (slip and / or high acceleration, tire / road grip conditions), based on information MS indicating the state of the vehicle (vehicle speed, maneuver type, road type, vehicle instability condition), and based on the set point value SP-V (see FIG. 4d) of the control variable (e.g., force) to be applied to each corner of the vehicle.

[0203] The above control (logic) mode (MC) represents different control modes that can be activated to control the actuator.

[0204] A specific control mode is distinguished from other control modes depending on the type of control module and / or control architecture (e.g., position control or actuator force control).

[0205] The configuration parameter set is used for the specific activated control mode (MC).

[0206] For example, when the high-grip slip control mode (MC) is enabled, the configuration interface module implements, for instance, a closed-loop force control mode to maximize the modulation speed as the control mode MC, and specific configuration parameters to control the expected high-grip force as a set of configuration parameters (CP).

[0207] With reference to the drawings and the block diagram of FIG. 5a, a method (500) for controlling wheel slip in a braking system of a vehicle according to the present invention will now be described.

[0208] It should be noted that the components and information mentioned below, along with the description of the method, have already been previously described in relation to the system (100) and will not be repeated for the sake of brevity.

[0209] The method (500) includes a starting step (ST).

[0210] The above method (500) includes the step (501) of receiving information (MD) representing a vehicle (1) and information (MS) representing an estimation of the vehicle state by the input interface module (40) of the slip control module (101).

[0211] The above method (500) further includes the step (502) of outputting input wheel slip control information (SCD) by the input interface module (40).

[0212] The above method (500) further includes the step (503) of determining a wheel slip control parameter (SCP) by the parameter self-loading module (41) of the input interface module (40) based on information (MD) representing the vehicle (1) and information (MS) representing the state of the vehicle (1).

[0213] According to one embodiment, the wheel slip control parameter (SCP) may be divided into various subsets as a function of the estimated load grip received from the vehicle (1) state estimation module, each associated with different load grips ("high grip," "medium grip," "low grip").

[0214] In this example of implementation, the determining step (503) includes the step (504) of loading a corresponding subset of wheel slip control parameters (SCP) by the parameter self-loading module (41) of the input interface module (40).

[0215] According to another embodiment, as an alternative to the preceding embodiment, the determining step (503) is performed by the parameter self-loading module (41) of the input interface module (40) to determine the wheel slip control parameter (SCP) as a function of the estimated load grip received from the vehicle (1) state estimation module (MSV).

[0216] Generally, returning to FIG. 5, the method (500) further includes the step (505) of determining a plurality of activation signals (SCE) of wheel slip control by a plurality of wheel slip control activation modules (42) of the slip control module (101) based on received input wheel slip control information (SCD) and received wheel slip control parameters (SCP).

[0217] The above method (500) further includes the step (506) of determining, by each closed-loop wheel slip control module of a plurality of closed-loop wheel slip control modules (44) of the slip control module (101), a set point value (SP-V) of a control variable to be applied to each vehicle corner based on the prescribed slip set point (SP-S) and the estimated wheel slip value, in order to minimize the error between the prescribed slip set point (SP-S) and the estimated wheel slip.

[0218] The above method (500) includes a termination step (ED).

[0219] According to an example of implementation (shown in FIG. 5 with a dotted line), in combination with any one of the preceding examples, the method (500) follows the determining step (506):

[0220] - A step (507) of defining the control (logic) mode (MC) of the actuator control module of the relevant corner of the vehicle (1) by each interface configuration module (47) of the actuator control module present in each actuator module of the plurality of actuator modules (102);

[0221] - Includes a step (508) of defining a set of configuration parameters (CP) provided to be loaded into an actuator control module of a relevant corner of a vehicle (1) by each interface configuration module (47) of an actuator control module present in each actuator module of a plurality of actuator modules (102).

[0222] In one embodiment, in combination with any one of the preceding embodiments (shown in FIG. 5 with a dotted line), the method (500) includes a step (509) of generating a slip setpoint (SP-S) based on input wheel slip control information (SCD) and received wheel slip control parameters (SCP) by a plurality of wheel slip setpoint specification modules (43) of the slip control module (101) between a determining step (505) and a determining step (506).

[0223] In an implementation example (indicated by a dotted line in FIG. 5), in combination with a preceding implementation example, the generating step (509) includes a step (510) of providing a constant slip setpoint value as a reference slip setpoint by the parameter self-loading module (41) of the input interface module (40).

[0224] In an additional implementation example (again indicated by a dotted line in FIG. 5), in combination with the preceding implementation example, the generating step (509) further includes a step (511) of determining a slip set point starting from each reference slip set point by each regulation module as a function of information (MS) representing the state of the vehicle (1).

[0225] According to an additional implementation example (indicated by a dashed line in FIG. 5), in combination with one of the above, between the determining step (506) and the defining step (507), based on individual events (wheel slip threshold exceeding and / or wheel acceleration threshold exceeding and / or open-loop control request of a single corner), each reference target value received from the input is corrected by a plurality of reference target correction modules (45) of each wheel slip control module (512), and then the corrected reference target value (TC) is output.

[0226] According to an additional implementation example (indicated by a dashed line in FIG. 5), in combination with the preceding implementation example, the method (500) further includes, between the correction step (512) and the regulation step (507), a step (513) of evaluating conditions of grip, vertical load, stability, and speed of the vehicle and regulating the saturation of maximum and / or minimum force that can be requested for a single corner of each axle based on the setpoint value of a control variable by a plurality of adjustment modules (46) of the force (FC) regulated for the corner of a single axle of the vehicle.

[0227] Referring to FIG. 6, an example of the operation of the sleep control module (101) will now be described.

[0228] The input interface module (40) is configured to receive input information MD representing the vehicle (1) previously introduced with reference to FIGS. 1 and FIGS. 2, and information (MS) representing the estimation of the vehicle state provided by the vehicle state estimation module (MSV).

[0229] The above input interface module (40) outputs input wheel slip control information (SCD) and determines wheel slip control parameters (SCP) based on information (MD) representing the vehicle (1) and information (MS) representing the state of the vehicle (1) through the parameter self-loading module (41).

[0230] The first slip control activation module (E-FL) generates a first wheel slip control activation signal (SCE) for the front left corner based on the received wheel slip control parameter (SCP) and input wheel slip control information (SCD).

[0231] The first wheel slip setpoint specification module (D-FL) of the front left corner generates a first wheel slip setpoint (SP-S) based on the received wheel slip control parameter (SCP) and the received input wheel slip control information (SCD).

[0232] The first closed-loop wheel slip control module (CL-1) for the front left corner, after receiving the first activation signal (SCE), determines the setpoint value (SP-V) of the control variable to be applied to each vehicle corner in each execution cycle of each software, based on the defined slip setpoint (SP-S) and the estimated wheel slip value, in order to minimize the error between the defined slip setpoint (SP-S) and the estimated wheel slip.

[0233] Upon receipt of the first activation signal (SCE), the first reference target correction module (CT-1) for the front left corner corrects (overwrites and / or reduces) the reference target value received as input by providing a corrected reference target value (TC) as an output based on individual events (exceeding the slip threshold and / or exceeding the wheel acceleration threshold and / or an open-loop control request for a single corner).

[0234] The first adjustment module (FA-S) of the defined force for the front axle corner provides the first slip control force (F1) of the front left corner of the vehicle.

[0235] The first configuration interface module (CNF-1) of the front left corner actuator control module defines a first configuration parameter set (CP-1) provided to load the first control mode (MC-1) of the front left corner actuator control module and the first braking action (BA1) applied to the front left wheel (W-FL) of the vehicle (1) to the first front left corner actuator control module (A-FL).

[0236] It is worth noting that the objective of the present invention has been fully achieved.

[0237] The method for controlling wheel slip in a braking system of a vehicle according to the present invention and each system are specialized in a brake-by-wire architecture having the possibility to configure a control mode of a single vehicle corner as a function of a wheel and / or vehicle state evaluation determined by a control and management algorithm.

[0238] The above method and each control system can manage wheel slip in a specific and optimized manner for a brake-by-wire system, and a control system for vehicle braking logics is defined in one or more control units, the logics are related to the control of corners / wheels and the control of actuators, and a BbW actuator is provided at each corner.

[0239] In addition, the method and each control system of the present invention select an optimal configuration and parameter set to prioritize and optimize control responsiveness and performance over braking comfort, and specify a control mode in which the wheel slip control module configures a single corner actuator control module according to the condition of the wheel and / or vehicle.

[0240] Furthermore, the method and each control system of the present invention have modularity / flexibility for changing the vehicle category due to the possibility of adjustment between the corners of the vehicle.

[0241] In addition, the method and each system of the present invention can continuously employ control logic based on the measurement and estimation of vehicle distribution signals thanks to a more comprehensive architectural configuration and information / estimation / evaluation of vehicle distribution.

[0242] In addition, the method and each control system of the present invention are:

[0243] - Continuous modulation of wheel slip control;

[0244] - The calibration of control logic is simpler because it is based on physical laws that enable the use of theoretical calibrations to support empirical / experimental techniques instead of typically empirical / experimental methodologies;

[0245] - Ensures the adoption of control mode / actuator control parameters as a function of the control logic of the wheel slip control module of each vehicle corner.

[0246] Those skilled in the art may make changes and adaptations to the implementation examples of the aforementioned methods and each system, or may replace elements with other functionally equivalent elements to satisfy incidental needs without exceeding the scope of protection of the associated claims. All features described above as belonging to one possible implementation example may be implemented independently of other described implementation examples.

Claims

Claim 1 A method (500) for controlling wheel slip in a braking system of a vehicle (1), comprising: - a step (501) of receiving information (MD) representing the vehicle (1) and information (MS) representing the estimation of the state of the vehicle (1) by means of an input interface module (40) of a slip control module (101); - a step (502) of outputting input wheel slip control information (SCD) by means of the input interface module (40); - a step (503) of determining wheel slip control parameters (SCP) based on the information (MD) representing the vehicle (1) and the information (MS) representing the state of the vehicle (1) by means of a parameter self-loading module (41) of the input interface module (40); - a step (505) of determining a plurality of activation signals (SCE) for wheel slip control based on the received input wheel slip control information (SCD) and the received wheel slip control parameters (SCP) by means of a plurality of wheel slip control activation modules (42) of the slip control module (101). and - to minimize the error between the defined slip setpoint (SP-S) and the estimated wheel slip, the method includes the step (506) of determining the setpoint value (SP-V) of the control variable to be applied to each vehicle corner based on the defined slip setpoint (SP-S) and the estimated wheel slip value by each closed-loop wheel slip control module of the plurality of closed-loop wheel slip control modules (44) of the slip control module (101); and after the determining step (506): - the step (507) of determining the control mode (MC) of the actuator control module of the relevant corner of the vehicle (1) by each interface configuration module of the plurality of interface configuration modules (47) of the actuator control module present in each actuator module of the plurality of actuator modules (102);A method (500) for controlling wheel slip in a braking system of a vehicle (1), comprising the step (508) of defining a set of configuration parameters (CP) provided to be loaded into an actuator control module of a relevant corner of the vehicle (1) by each interface configuration module (47) of an actuator control module present in each actuator module of a plurality of actuator modules (102). Claim 2 delete Claim 3 A method (500) for controlling wheel slip in a braking system of a vehicle (1), comprising, between the determining step (505) and the determining step (506), a step (509) of generating a slip setpoint (SP-S) based on received input wheel slip control information (SCD) and received wheel slip control parameters (SCP) by a plurality of wheel slip setpoint defining modules (43) of the slip control module (101). Claim 4 A method (500) for controlling wheel slip in a braking system of a vehicle (1), wherein the generating step (509) includes the step (510) of providing a constant slip setpoint value as a reference slip setpoint by the parameter self-loading module (41) of the input interface module (40). Claim 5 A method (500) for controlling wheel slip in a braking system of a vehicle (1), wherein the generating step (509) further comprises the step (511) of determining a slip set point from each reference slip set point as a function of information (MS) representing the state of the vehicle (1) by each regulation module. Claim 6 A method (500) for controlling wheel slip in a braking system of a vehicle (1), wherein, between the determining step (506) and the defining step (507), the method further comprises the step of correcting each reference target value received from an input based on an individual event by a plurality of reference target correction modules (45) of the slip control module (101) (512), and then outputting a corrected reference target value (TC). Claim 7 A method (500) for controlling wheel slip in a braking system of a vehicle (1), further comprising, between the correction step (512) and the regulation step (507), a step (513) of evaluating conditions of grip, vertical load, stability, and speed of the vehicle (1) and regulating at least one of the maximum force and minimum force that can be requested for a single corner of each axle based on the setpoint value of a control variable by a plurality of modules (46) for adjusting the force regulated for a corner of a single axle of the vehicle (1). Claim 8 A method (500) for controlling wheel slip in a braking system of a vehicle (1), wherein, in claim 1, the wheel slip control parameter (SCP) is divided into different subsets associated with different load grips according to the estimated load grip received from the vehicle (1) state estimation module (MSV), and the determining step (503) includes the step (504) of loading the corresponding wheel slip control parameter (SCP) subset by the parameter self-loading module (41) of the input interface module (40). Claim 9 A method (500) for controlling wheel slip in a braking system of a vehicle (1), wherein the determining step (503) is performed by the parameter self-loading module (41) of the input interface module (40) to determine a wheel slip control parameter (SCP) as a function of the estimated load grip received from the vehicle (1) state estimation module. Claim 10 A system (100) for controlling wheel slip in a braking system of a vehicle (1), comprising: a slip control module (101); and a plurality of actuator modules (102), wherein each actuator module of the plurality of actuator modules (102) comprises a respective actuator control module and a respective actuator configured to execute a braking command based on a control received from the respective actuator control module, wherein the slip control module (101) is configured to receive information (MD) representing the vehicle (1) and, based on such information (MD), transmit one or more commands representing a braking request (BR) to the plurality of actuator modules (102), and wherein the slip control module (101) is configured to perform a method for controlling wheel slip in a braking system of a vehicle (1) according to any one of claims 1, 3 to 9. Claim 11 A system (100) for controlling wheel slip in a braking system of a vehicle (1), wherein the slip control module (101) comprises a plurality of wheel slip control submodules (103) distributed in a single corner (C-1, C-2, ..., CN) of the vehicle (1), and the plurality of wheel slip control submodules (103) are configured to control the number of vehicle corners in a controlled manner such that the number of vehicle corners is less than or equal to the total number of corners of the vehicle (1). Claim 12 A system (100) for controlling wheel slip in a braking system of a vehicle (1), wherein the slip control module (101) comprises a plurality of wheel slip control submodules (103) distributed on a single axle (A-1, A-2, ..., AN) of a vehicle (1), and the plurality of wheel slip control submodules (103) are configured to control a number of axles that is less than or equal to the total number of axles of the vehicle (1) in an adjusted manner. Claim 13 A system (100) for controlling wheel slip in a braking system of a vehicle (1), wherein the slip control module (101) is centralized and the slip control module (101) is configured to control the number of corners of the vehicle (1) in a controlled manner, which is less than or equal to the total number of corners of the vehicle (1).

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