Vehicle brake control method, device, system and vehicle

Abstract

The application provides a vehicle braking control method, device, system and vehicle, and relates to the technical field of vehicles.The method comprises the following steps: acquiring vehicle driving parameters, driving control parameters and the state of an electric energy storage unit; in the case that the electric energy storage unit is in a non-chargeable state, controlling a switching unit to switch a regenerative braking current for braking unit braking; the regenerative braking current is generated by a driving unit; determining a first braking force according to the vehicle driving parameters and the driving control parameters; and controlling the braking unit braking according to the first braking force.The application uses the regenerative braking current for braking unit braking in the case that the electric energy storage unit is in a non-chargeable state, and the regenerative braking does not stop, which can reduce the braking force of the braking unit and reduce the wear of the braking unit.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle braking control method, device, system, and vehicle. Background Technology

[0002] Hybrid vehicles can brake through regenerative braking and friction braking. During regenerative braking, the electric motor can act as a generator to convert the vehicle's kinetic energy into electrical energy, which is then used to charge the battery.

[0003] In related technologies, regenerative braking needs to be supplemented by friction braking. During braking, the friction braking unit may experience brake pad wear, vibration, or brake squealing, which reduces the driver's braking experience. Summary of the Invention

[0004] Embodiments of the present invention provide a vehicle braking control method, device, system, and vehicle. The vehicle braking control method can avoid abnormalities in the friction braking unit during braking, thereby improving the driver's braking experience.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] Firstly, a vehicle braking control method is provided, including:

[0007] Acquire vehicle driving parameters, driving control parameters, and the status of the energy storage unit;

[0008] When the energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking of the braking unit; the regenerative braking current is generated by the drive unit.

[0009] The first braking force is determined based on the vehicle driving parameters and the driving control parameters;

[0010] The braking unit is controlled to brake according to the first braking force.

[0011] Optionally, the step of determining the first braking force based on the vehicle driving parameters and the driving control parameters includes:

[0012] The first friction braking force is determined based on the driving control parameters;

[0013] The first current value of the regenerative braking current is determined based on the vehicle driving parameters.

[0014] The first regenerative braking force and the current friction braking force are determined based on the first current value of the regenerative braking current.

[0015] The first braking force is determined based on the first regenerative braking force, the current frictional braking force, and the first frictional braking force.

[0016] Optionally, after the step of obtaining the state of the energy storage unit, the method further includes:

[0017] When the energy storage unit is in a rechargeable state, the regenerative braking current is controlled to charge the energy storage unit.

[0018] The second braking force is determined based on the vehicle driving parameters and the driving braking parameters;

[0019] Braking is controlled by the second braking force control braking unit.

[0020] Optionally, the step of determining the second braking force based on the vehicle driving parameters and the driving braking parameters includes:

[0021] The second current value of the regenerative braking current is determined based on the vehicle driving parameters;

[0022] The second regenerative braking force is determined based on the second current value of the regenerative braking current;

[0023] The second friction braking force is determined based on the driving control parameters;

[0024] The second braking force is determined based on the second regenerative braking force and the second frictional braking force.

[0025] Optionally, the step of determining the first regenerative braking force based on the first current value of the regenerative braking current includes:

[0026] A first characteristic quantity is determined based on the first current value of the regenerative braking current;

[0027] Obtain a first parameter, which includes at least one of a first acceleration, the weight of the vehicle, and the road slope;

[0028] The correction coefficient is obtained based on the first parameter;

[0029] The first characteristic quantity is corrected according to the correction coefficient, and the first regenerative braking force is determined.

[0030] Optionally, the step of obtaining vehicle driving parameters and driving control parameters includes:

[0031] Obtain the vehicle driving parameters and driving control parameters determined by the vehicle system control unit;

[0032] The vehicle driving parameters include at least one of vehicle yaw angle, first acceleration, second acceleration, and wheel speed; the driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

[0033] Optionally, the step of obtaining the state of the energy storage unit includes:

[0034] The charging current, discharging current, voltage, and temperature values ​​of the energy storage unit are obtained.

[0035] The state of the energy storage unit is determined based on the charging current value, the discharging current value, the voltage value, and the temperature value.

[0036] Secondly, embodiments of this application provide a vehicle braking control device, including:

[0037] The vehicle parameter acquisition module is used to acquire vehicle driving parameters, driving control parameters, and the status of the energy storage unit;

[0038] A switching control module is used to control the switching unit to switch the regenerative braking current for the electric friction braking unit when the energy storage unit is in a non-rechargeable state; the regenerative braking current is generated by the drive unit.

[0039] The first braking force acquisition module is used to determine the first braking force based on the driving control parameters and the regenerative braking current.

[0040] A braking control module is used to control the braking unit to brake according to the first braking force.

[0041] Thirdly, embodiments of this application provide a vehicle braking control system, including: a regenerative braking unit, a drive control unit, an electric energy storage unit, a switching unit, and an electric friction braking unit;

[0042] The drive control unit is electrically connected to the drive unit, the braking unit, and the switching unit, respectively.

[0043] The drive control unit is used to acquire vehicle driving parameters, driving control parameters, and the status of the electric energy storage unit; when the electric energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking by the braking unit; the regenerative braking current is generated by the drive unit; a first braking force is determined according to the vehicle driving parameters and the driving control parameters; the braking unit is controlled to brake according to the first braking force.

[0044] Fourthly, embodiments of this application provide a vehicle including a vehicle braking control device, the vehicle braking control device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the vehicle braking control method as described in any of the first aspects.

[0045] This application provides a vehicle braking control method, device, system, and vehicle. The vehicle braking control method includes acquiring vehicle driving parameters, driving control parameters, and the state of an electric energy storage unit; when the electric energy storage unit is in a non-rechargeable state, controlling a switching unit to switch regenerative braking current for braking by the braking unit; the regenerative braking current is generated by a drive unit; determining a first braking force based on the vehicle driving parameters and the driving control parameters; and controlling the braking of the braking unit based on the first braking force.

[0046] This application embodiment controls the switching unit to switch the regenerative braking current to the braking unit when the electric energy storage unit is in a non-rechargeable state, thereby avoiding the inability to achieve regenerative braking due to the electric energy storage unit being in a non-rechargeable state, thereby reducing the vehicle's friction braking force and reducing the friction loss of the braking unit. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic flowchart of a vehicle braking control method provided in an embodiment of the present invention;

[0049] Figure 2 A schematic flowchart of another vehicle braking control method provided in an embodiment of the present invention;

[0050] Figure 3 A schematic diagram illustrating the change of a first braking force over time, provided as an embodiment of this application;

[0051] Figure 4A This is a schematic diagram illustrating the relationship between initial frictional braking force and brake pedal travel, provided in an embodiment of the present invention.

[0052] Figure 4B A schematic diagram illustrating the relationship between a second frictional braking force and braking time, provided in an embodiment of the present invention;

[0053] Figure 5A schematic diagram of the structure of a vehicle provided in an embodiment of the present invention;

[0054] Figure 6 A is a schematic diagram of an electric friction brake provided in an embodiment of the present invention;

[0055] Figure 6 B is an electric friction brake provided in an embodiment of the present invention. Figure 6 A schematic diagram of the cross section along the AA direction in section A;

[0056] Figure 7 This is a schematic diagram of the structure of a vehicle braking control device provided in an embodiment of the present invention;

[0057] Figure 8 This is a schematic diagram of the structure of a vehicle braking control system provided in an embodiment of the present invention;

[0058] Figure 9 This is a schematic diagram of another vehicle structure provided in an embodiment of the present invention. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0061] Additionally, it should be noted that when describing the elements and embodiments thereof in this application, the articles “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more elements; unless otherwise stated, “multiple” means two or more; the terms “comprising,” “including,” “containing,” and “having” are intended to be inclusive and indicate that additional elements may exist besides those listed; the terms “first,” “second,” “third,” etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or order of formation.

[0062] In this specification, "electrical connection" includes the situation where components are connected together by elements that have a certain electrical function. There are no particular limitations on what constitutes an "electrical function," as long as it allows for the transmission and reception of electrical signals between the connected components. Examples of "electrical functions" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0063] This application provides a vehicle braking control method, referring to... Figure 1 ,include:

[0064] Step S101: Obtain vehicle driving parameters, driving control parameters, and the status of the energy storage unit.

[0065] The vehicle braking control method provided in this application is applied to a vehicle braking control device. For example, the vehicle braking control device includes a drive control unit.

[0066] In this embodiment of the application, vehicle driving parameters are used to determine the driving state of the vehicle. For example, the vehicle driving parameters include at least one of wheel speed, first acceleration, second acceleration, and vehicle yaw angle.

[0067] Wherein, wheel speed is the rotational speed of the vehicle's wheels, first acceleration is the acceleration along the vehicle's direction of travel, second acceleration is the lateral acceleration perpendicular to the vehicle's direction of travel, and vehicle yaw angle is the rotation angle of the vehicle body when rotating around the vertical body axis.

[0068] In this embodiment, wheel speed is detected by wheel speed sensor, first acceleration is detected by front and rear G-accelerometer sensors, second acceleration is detected by lateral G-accelerometer sensor, and vehicle yaw angle is detected by yaw sensor.

[0069] In some embodiments, the wheel speed sensor, the first acceleration sensor, the second acceleration sensor, and the yaw sensor are electrically connected to the drive control unit, and the drive control unit directly acquires the vehicle driving parameters.

[0070] In other embodiments, the wheel speed sensor, the first acceleration sensor, the second acceleration sensor, and the yaw sensor are electrically connected to the vehicle system control unit, and the drive control unit obtains vehicle driving parameters through the vehicle system control unit.

[0071] In this embodiment of the application, driving control parameters are used to determine the driver's control state. For example, driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

[0072] Among them, the accelerator pedal travel is the distance the driver travels when pressing the accelerator pedal, which can be obtained through the accelerator pedal sensor; the brake pedal travel is the distance the driver travels when pressing the brake pedal, which can be obtained through the brake pedal sensor; and the vehicle steering angle is the vehicle steering angle desired by the driver when controlling the steering wheel, which can be obtained through the steering angle sensor.

[0073] In some embodiments, the accelerator pedal sensor, brake pedal sensor, and steering angle sensor are electrically connected to the drive control unit, and the drive control unit directly acquires the driving control parameters.

[0074] In other embodiments, the accelerator pedal sensor, brake pedal sensor, and steering angle sensor are electrically connected to the vehicle system control unit, and the drive control unit obtains driving control parameters through the vehicle system control unit.

[0075] In this application embodiment, the energy storage unit includes a vehicle battery. In some embodiments, the vehicle battery can be used to power the vehicle, for example, to power vehicle components, vehicle motors, or braking units.

[0076] The energy storage unit has two states: a rechargeable state and a non-rechargeable state. In the rechargeable state, the regenerative braking current can charge the energy storage unit; in the non-rechargeable state, the regenerative braking current cannot charge the energy storage unit.

[0077] For example, the capacity of the energy storage unit is limited. Therefore, when the energy storage unit is fully charged, the regenerative braking current cannot be used to charge the energy storage unit; or, if the energy storage unit is damaged, the regenerative braking current cannot charge the energy storage unit either.

[0078] For example, the state of an energy storage unit can be determined by its charging current, discharging current, and battery energy.

[0079] For example, if the charging current value is greater than a preset current threshold, the energy storage unit is determined to be in an unchargeable state; if the charging current value is less than the preset current threshold, the energy storage unit is determined to be in a rechargeable state; wherein, the preset current threshold is obtained based on experiments, and this application embodiment does not specifically limit it.

[0080] For example, if the charging current value is greater than the discharging current value of the energy storage unit and the energy of the energy storage unit is greater than a preset energy threshold, the energy storage unit is determined to be in a non-rechargeable state; if the charging current value is less than or equal to the discharging current value, or the energy of the energy storage unit is less than or equal to the preset energy threshold, the energy storage unit is determined to be in a rechargeable state; wherein, the charging current value and the discharging current value can be obtained by a current detector, and the preset energy threshold is obtained experimentally, and this application embodiment does not specifically limit it.

[0081] In step S102, when the energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking of the braking unit; the regenerative braking current is generated by the drive unit.

[0082] In this embodiment of the application, the vehicle includes a switching unit, a braking unit, and a drive unit:

[0083] The switching unit is used to switch the regenerative braking current for charging the electric energy storage unit or braking the electric friction braking unit under the control of the drive control unit.

[0084] For example, refer to Figure 5 The switching unit 5 includes an input terminal, a first output terminal, and a second output terminal;

[0085] In this embodiment, the first output terminal is connected to the electric energy storage unit, and the second output terminal is connected to the electric friction braking unit; in some embodiments, the input terminal is electrically connected to the regenerative braking unit; in other embodiments, the input terminal is electrically connected to the regenerative braking unit through a drive control unit.

[0086] When the energy storage unit is in a rechargeable state, the drive control unit controls the regenerative braking current to charge the energy storage unit through the first output terminal of the switching unit;

[0087] When the energy storage unit is in a non-rechargeable state, the drive control unit controls the regenerative braking current to be used for braking by the electric friction braking unit through the second output terminal of the switching unit.

[0088] The vehicle includes a braking unit, see reference. Figure 5 The braking unit includes an electric friction braking unit 101 and electric friction brakes (12fr, 12fl, 12rr, 12rl) at each tire. In some embodiments, the drive control unit controls each electric friction brake (12fr, 12fl, 12rr, 12rl) through the electric friction braking unit 101 to achieve electric friction braking.

[0089] The vehicle includes a drive unit, see reference Figure 5The drive unit includes an electric motor 2 and a regenerative braking unit 103. The regenerative braking unit 103 uses the electric braking of the electric motor 2 to generate a reverse force to slow down or stop the vehicle. During electric braking, the electric motor 2 is in the power generation state and generates regenerative braking current.

[0090] In this embodiment, vehicle braking includes regenerative braking and electro-friction braking. When regenerative braking meets preset conditions, vehicle braking exhibits a build-up characteristic. This build-up characteristic refers to the gradual increase in vehicle braking force due to the rising temperature and friction coefficient of the brake pads in the friction braking unit, while the driver's brake pedal travel remains constant.

[0091] In this embodiment, the regenerative braking force and regenerative braking current that generate the build-up characteristic can be determined based on vehicle driving parameters and driving control parameters. Specifically, these can be obtained through experiments, and this embodiment does not impose any specific limitations on them.

[0092] Step S103: Determine the first braking force based on the vehicle driving parameters and driving control parameters.

[0093] In the embodiments of this application, reference is made to Figure 3 The first braking force Ft generated by the braking unit includes regenerative braking force Rs*Gs and friction braking force Fs.

[0094] Among them, the regenerative braking force Rs*Gs increases with the braking time under the Build Up characteristic, and the vehicle's braking force increases with the braking time, resulting in a better braking experience for the driver.

[0095] The friction braking force Fs consists of two parts. The first part Fm is generated by the regenerative braking current. The larger the value of the regenerative braking current, the larger the value of the first part Fm.

[0096] The second part, Fs-Fm, is determined by the brake pedal travel. Specifically, the second part is directly controlled by the driver. The greater the travel of the driver's brake pedal, the greater the value of the second part, Fs-Fm.

[0097] In this embodiment of the application, the regenerative braking force generated by the build-up characteristic in the first braking force increases with the increase of braking time.

[0098] Step S104: Control the braking unit to brake based on the friction braking force.

[0099] In some embodiments, the braking unit includes four electric friction brakes, which are respectively mounted on the wheels and perform electric friction braking.

[0100] In some embodiments, refer to Figure 5 The drive control unit 102 controls each electric friction brake (12fr, 12fl, 12rr, 12rl) through the electric friction braking unit 101 to achieve electric friction braking.

[0101] This application provides a vehicle braking control method, including: acquiring vehicle driving parameters, driving control parameters, and the state of an electric energy storage unit; when the electric energy storage unit is in a non-rechargeable state, controlling a switching unit to switch regenerative braking current for braking by the braking unit; the regenerative braking current is generated by a drive unit; determining a first braking force based on the vehicle driving parameters and driving control parameters; and controlling the braking by the braking unit based on the first braking force. By controlling the switching unit to switch the regenerative braking current for braking by the braking unit when the electric energy storage unit is in a non-rechargeable state, regenerative braking is avoided from being impossible due to the electric energy storage unit being in a non-rechargeable state, thereby reducing the vehicle's frictional braking force and reducing the wear of the braking unit.

[0102] Optionally, the step of determining the first braking force based on vehicle driving parameters and driving control parameters includes:

[0103] The first frictional braking force is determined based on the driving control parameters; the first current value of the regenerative braking current is determined based on the vehicle driving parameters; the first regenerative braking force and the current frictional braking force are determined based on the first current value of the regenerative braking current; and the first braking force is determined based on the first regenerative braking force, the current frictional braking force, and the first frictional braking force.

[0104] In the embodiments of this application, reference is made to Figure 3 The first braking force Ft includes the first regenerative braking force Rs*Gs and the first frictional braking force Fs; the first frictional braking force Fs includes the current frictional braking force Fm generated by the regenerative braking current and the pedal frictional braking force Fs-Fm determined by the brake pedal travel.

[0105] In some embodiments, the pedal friction braking force can be determined based on the brake pedal travel; the greater the brake pedal travel, the greater the pedal friction braking force; the smaller the brake pedal travel, the smaller the pedal friction braking force.

[0106] This application does not specifically limit the correspondence between brake pedal travel and initial frictional braking force in its embodiments; for example, refer to... Figure 4A The braking force of the pedal friction is directly proportional to the travel of the brake pedal.

[0107] In this embodiment, a first current value that can generate a regenerative braking current with build-up characteristics can be determined based on driving control parameters, and then the current friction braking force and the first regenerative braking force are determined based on the first current value.

[0108] In some embodiments, a first characteristic quantity Rs can be determined based on a first current value, wherein the first characteristic quantity Rs is the regenerative braking force that increases with braking time due to the build-up characteristics.

[0109] In some embodiments, the first regenerative braking force Rs*Gs can be obtained by correcting the first characteristic quantity Rs based on the braking deceleration. For example, referring to Figure 4, the greater the braking deceleration, the faster the temperature of the brake pad of the electric friction braking unit rises, the greater the increase in the coefficient of friction, and the faster the first characteristic quantity Rs increases; the smaller the braking deceleration, the slower the temperature of the brake pad of the electric friction braking unit rises, the less the increase in the coefficient of friction, and the slower the first characteristic quantity Rs increases.

[0110] In some embodiments, the first regenerative braking force Rs*Gs is equal to the standard first characteristic quantity Rs multiplied by the correction coefficient Gs:

[0111] For example, the correction factor Gs can be equal to the absolute value of the ratio of braking deceleration to standard deceleration; when Gs is greater than 1, the first regenerative braking force increases faster with braking time; when Gs is less than 1, the first regenerative braking force increases slower with braking time. Here, standard deceleration is the frictional braking force that increases with braking time due to the build-up characteristics at standard deceleration.

[0112] In this embodiment, the frictional braking force generated by the regenerative braking current is the current frictional braking force fm. The larger the current value of the regenerative braking current, the larger the current frictional braking force; the smaller the current value of the regenerative braking current, the smaller the current frictional braking force.

[0113] In this embodiment of the application, the first braking force is:

[0114] f1=Fs-fm+Rs*Gs (1)

[0115] Wherein, f1 is the first braking force of the braking unit controlled by the drive control unit, fs is the first frictional braking force, fm is the current frictional braking force, Fs is the first frictional braking force, and Rs*Gs is the first regenerative braking force.

[0116] In this embodiment of the application, the step of determining the first braking force based on vehicle driving parameters and driving control parameters includes: determining the first frictional braking force based on the driving control parameters; determining the first current value of the regenerative braking current based on the vehicle driving parameters; determining the first regenerative braking force and the current frictional braking force based on the first current value of the regenerative braking current; and determining the first braking force based on the first regenerative braking force, the current frictional braking force, and the first frictional braking force.

[0117] In this way, by controlling the switching unit to switch the regenerative braking current to the braking unit when the electric energy storage unit is in a non-rechargeable state, regenerative braking can be avoided because the electric energy storage unit is in a non-rechargeable state, thereby reducing the vehicle's friction braking force and reducing the wear of the braking unit.

[0118] This application provides a vehicle braking control method, referring to... Figure 2 ,include:

[0119] Step S201: Obtain vehicle driving parameters, driving control parameters, and the status of the energy storage unit;

[0120] Step S201 is the same as step S101 and will not be repeated here.

[0121] Step S202: When the energy storage unit is in a rechargeable state, control the regenerative braking current to charge the energy storage unit.

[0122] In this embodiment, when the energy storage unit is in a rechargeable state, the drive control unit controls the switching unit to switch the regenerative braking current for charging the energy storage unit.

[0123] Step S203: Determine the second braking force based on the vehicle driving parameters and driving braking parameters.

[0124] In this embodiment, the second braking force is the braking force of the braking unit controlled by the drive control unit when the energy storage unit is in a rechargeable state.

[0125] When the energy storage unit is in a rechargeable state, the braking force of the electric friction braking unit does not have the current friction braking force fm generated by the regenerative braking current, and the second braking force is equal to the sum of the second friction braking force and the second regenerative braking force.

[0126] Optionally, step S203, determining the second braking force based on vehicle driving parameters and driving braking parameters, includes:

[0127] A second current value of the regenerative braking current is determined based on the vehicle driving parameters; a second regenerative braking force is determined based on the second current value of the regenerative braking current; a second frictional braking force is determined based on the driving control parameters; and a second braking force is determined based on the second regenerative braking force and the second frictional braking force.

[0128] In some embodiments, the second frictional braking force can be determined based on the brake pedal travel; the greater the brake pedal travel, the greater the second frictional braking force; the smaller the brake pedal travel, the smaller the second frictional braking force.

[0129] The embodiments of this application do not specifically limit the specific correspondence. For example, the second friction braking force is proportional to the brake pedal travel.

[0130] In this embodiment, a second current value that can generate a regenerative braking current with build-up characteristics can be determined based on driving control parameters, and then the current friction braking force and the first regenerative braking force are determined based on the second current value.

[0131] In some embodiments, the first current value and the second current value are equal, and the regenerative braking force does not change when switching the application of the regenerative braking current, resulting in a relatively stable braking effect.

[0132] In some embodiments, a first characteristic quantity Rs can be determined based on a second current value, wherein the first characteristic quantity Rs is the regenerative braking force that increases with braking time due to the build-up characteristics.

[0133] In some embodiments, the second regenerative braking force Rs*Gs can be obtained by correcting the first characteristic quantity Rs based on the braking deceleration. For example, the greater the braking deceleration, the faster the temperature of the brake pad of the electric friction braking unit rises, the greater the increase in the coefficient of friction, and the faster the first characteristic quantity Rs increases; the smaller the braking deceleration, the slower the temperature of the brake pad of the electric friction braking unit rises, the less the increase in the coefficient of friction, and the slower the first characteristic quantity Rs increases.

[0134] In this embodiment, the first feature quantity increases with the braking time; in some embodiments, the first feature quantity is proportional to the braking time.

[0135] In this embodiment, the second frictional braking force can be obtained by correcting the first characteristic quantity based on the braking deceleration. For example, see [reference]. Figure 4B The greater the braking deceleration, the faster the temperature of the brake pads in the braking unit rises, the greater the increase in the coefficient of friction, and the faster the first characteristic quantity increases; the smaller the braking deceleration, the slower the temperature of the brake pads in the braking unit rises, the less the coefficient of friction increases, and the slower the first characteristic quantity increases.

[0136] In some embodiments, the second regenerative braking force Rs*Gs is equal to the first characteristic quantity Rs multiplied by the correction coefficient Gs.

[0137] For example, the correction factor Gs can be equal to the absolute value of the ratio of braking deceleration to standard deceleration; when Gs is greater than 1, the second regenerative braking force increases faster with braking time; when Gs is less than 1, the second regenerative braking force increases slower with braking time.

[0138] In this embodiment of the application, the second braking force is equal to the sum of the second frictional braking force and the second crushing braking force:

[0139] F2= Fm+Rs*Gs (2)

[0140] In this embodiment, the second regenerative braking force generated by the build-up characteristic increases with the increase of braking time, resulting in a better braking effect.

[0141] Step S206: Control the electric friction braking unit to brake according to the second braking force.

[0142] In some embodiments, the second braking force is equal to the first braking force, and the total braking force of the vehicle remains unchanged regardless of the state of the electric energy storage unit, resulting in a better braking experience for the driver.

[0143] In some embodiments, the braking unit includes four electric friction brakes, which are respectively mounted on the wheels and perform electric friction braking.

[0144] Step S205: When the energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking of the braking unit; the regenerative braking current is generated by the drive unit.

[0145] Step S206: Determine the first braking force based on the vehicle driving parameters and driving control parameters;

[0146] Step S207: Control the braking unit to brake according to the first braking force.

[0147] Steps S205-S207 refer to steps S102-S104 and will not be repeated here.

[0148] In this embodiment of the application, regenerative braking current can be used to charge the energy storage unit when the energy storage unit is in a rechargeable state, thereby achieving regenerative braking.

[0149] Optionally, the step of determining the first regenerative braking force based on the first current value of the regenerative braking current includes: determining a first characteristic quantity based on the first current value of the regenerative braking current; obtaining a first parameter, the first parameter including at least one of a first acceleration, the weight of the vehicle, and the road surface slope; obtaining a correction coefficient based on the first parameter; and correcting the first characteristic quantity based on the correction coefficient to determine the first regenerative braking force.

[0150] In this embodiment, the first acceleration is the acceleration along the vehicle's direction of travel, and when the vehicle brakes, the first acceleration is the braking deceleration.

[0151] The embodiments of this application do not specifically limit the method of obtaining the first acceleration. For example, it can be obtained by detection through front and rear G-accelerometers.

[0152] This application does not specifically limit the method of obtaining the vehicle's weight. For example, it can be obtained through a weight sensor or from the vehicle's memory.

[0153] This application does not specifically limit the method of obtaining the road surface slope in its embodiments. For example, it can be obtained by detecting the slope using an inclination sensor.

[0154] In this embodiment of the application, the first feature quantity is obtained by detection under standard deceleration, standard weight, and standard slope;

[0155] The correction factor can be the absolute value of the ratio of the second acceleration to the standard deceleration, or the absolute value of the ratio of the vehicle's weight to the standard weight, or the difference between the road surface slope and the standard slope.

[0156] In some embodiments, there is one correction factor; in other embodiments, there are multiple correction factors, and this application does not specifically limit this.

[0157] In this embodiment, the first characteristic quantity is corrected according to the correction coefficient to determine the second friction braking force. For example, the correction coefficient can be multiplied by the first characteristic quantity to calculate and determine the second friction braking force; or, the second friction braking force can be calculated and determined according to other relationships. This embodiment does not limit this.

[0158] In this embodiment, the step of determining the first regenerative braking force based on the first current value of the regenerative braking current includes: determining a first characteristic quantity based on the first current value of the regenerative braking current; obtaining a first parameter, the first parameter including at least one of a first acceleration, the weight of the vehicle, and the road slope; obtaining a correction coefficient based on the first parameter; and correcting the first characteristic quantity based on the correction coefficient to determine the first regenerative braking force. This results in a more accurate first braking force determined by the first regenerative braking force, improving braking accuracy and thus enhancing the driver's braking experience.

[0159] Optionally, the steps for obtaining vehicle driving parameters and driving control parameters include:

[0160] Obtain vehicle driving parameters and driving control parameters determined by the vehicle system control unit;

[0161] Vehicle driving parameters include at least one of vehicle yaw angle, first acceleration, second acceleration, and wheel speed; driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

[0162] In this embodiment, vehicle driving parameters and driving control parameters are obtained through the vehicle system control unit, which then sends the vehicle driving parameters and driving control parameters to the drive control unit.

[0163] In this embodiment of the application, vehicle driving parameters are used to determine the driving state of the vehicle. For example, the vehicle driving parameters include at least one of wheel speed, first acceleration, second acceleration, and vehicle yaw angle.

[0164] Wherein, wheel speed is the rotational speed of the vehicle's wheels, first acceleration is the acceleration along the vehicle's direction of travel, second acceleration is the lateral acceleration perpendicular to the vehicle's direction of travel, and vehicle yaw angle is the rotation angle of the vehicle body when rotating around the vertical body axis.

[0165] In this embodiment, wheel speed is detected by wheel speed sensor, first acceleration is detected by front and rear G-accelerometer sensors, second acceleration is detected by lateral G-accelerometer sensor, and vehicle yaw angle is detected by yaw sensor.

[0166] In this embodiment of the application, driving control parameters are used to determine the driver's control state. For example, driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

[0167] Among them, the accelerator pedal travel is the distance the driver travels when pressing the accelerator pedal, which can be obtained through the accelerator pedal sensor; the brake pedal travel is the distance the driver travels when pressing the brake pedal, which can be obtained through the brake pedal sensor; and the vehicle steering angle is the vehicle steering angle desired by the driver when controlling the steering wheel, which can be obtained through the steering angle sensor.

[0168] In some embodiments, the vehicle system control unit includes an electric friction braking unit.

[0169] In this embodiment, vehicle driving parameters and driving control parameters are obtained through the vehicle system control unit, eliminating the need to obtain data from each sensor individually, thus improving the efficiency of obtaining vehicle driving parameters and driving control parameters.

[0170] Optionally, step S103, determining the state of the energy storage unit based on the regenerative braking current value, includes: acquiring the charging current value, discharging current value, voltage value, and temperature value of the energy storage unit; and determining the state of the energy storage unit based on the charging current value, discharging current value, voltage value, and temperature value.

[0171] In this embodiment, the charging current is the regenerative braking current.

[0172] For example, the electrical energy of an energy storage unit can be determined based on voltage and temperature values;

[0173] If the charging current is greater than the discharging current of the energy storage unit and the energy of the energy storage unit is greater than the preset energy threshold, the energy storage unit is determined to be in an unchargeable state; if the charging current is less than or equal to the discharging current, or the energy of the energy storage unit is less than or equal to the preset energy threshold, the energy storage unit is determined to be in a rechargeable state.

[0174] The charging current value, discharging current value, voltage value, and temperature value can be obtained through the battery status monitoring unit. The preset energy threshold is obtained through experiments, and this application embodiment does not specifically limit it.

[0175] In this embodiment, the charging current, discharging current, voltage, and temperature values ​​of the energy storage unit are acquired; based on these values, the state of the energy storage unit is determined. This allows for accurate determination of the energy storage unit's state, thereby enabling precise control of the switching unit's state, improving the accuracy of the braking control method, and ultimately enhancing the driver's braking experience.

[0176] Reference Figure 5 This application provides a schematic diagram of a vehicle structure, the vehicle comprising:

[0177] Electric friction brakes (12fr, 12fl, 12rr, 12rl) are used to achieve electric friction braking.

[0178] The drive control unit includes: power unit 1, electric motor 2, frequency converter 4, electric energy storage unit 3 used in regenerative braking control and drive control, wheel speed sensors (11fl, 11fr, 11rl, 11rr) for detecting wheel speed, yaw sensor 24 for detecting vehicle driving status, lateral G sensor 25, front and rear G sensors 26, brake pedal sensor 21 for detecting driver driving control status, accelerator pedal sensor 22, steering angle sensor 23, battery status monitoring unit 5 for monitoring battery charging status, drive control unit 102, electric friction braking unit 101, and regenerative braking unit 103.

[0179] Reference Figure 6 A and Figure 6B. This application provides a schematic diagram of an electric friction brake 12. The electric friction brake 12 includes a pair of friction pads 32 disposed on both sides of a brake disc 31, a caliper 33 designed to move freely along the axial direction of the central axis of the circular brake disc 31, and a caliper 33 that clamps the brake disc 31 from both sides by means of the pair of friction pads 32 disposed on the outer and inner sides. The pair of friction pads 32 on the outer and inner sides are respectively mounted on a housing 34 with a structure that slides in the direction of their respective axes 34a. The caliper 33 has a housing 34, which is fixed to a support mounting part of the vehicle. The housing 34 constitutes part of a mechanism for fixing an electric motor 39 that rotates a cylindrical rotor 35. The electric motor 39 includes a fixed housing 34, a coil 36 fixed to the inner periphery of the housing 34, a cylindrical rotor 35 rotatably supported by the coil 36, and a bearing (not shown) supporting the rotating components, and a magnet 38 fixed to the outer peripheral surface of the rotor 35 in a manner located inside the coil 38.

[0180] The electric motor 39 generates torque according to a command signal from the brake control unit. A cylindrical ball screw nut assembly 37, located inside the cylindrical rotor 35, is designed to rotate freely. The ball screw nut assembly 37 is supported by a housing 34 so that the shaft portion 37a at the right end of the figure can rotate freely. A housing 40 is fixed to the shaft portion 37a of the ball screw nut assembly 37, and three planetary gears 41 are mounted on the housing 40. Additionally, a sun gear 42 with external teeth is fixed to the right end of the ball screw nut assembly 37, and a gear ring 43 with internal teeth is fixed inside the housing 34, forming a planetary gear mechanism. When the electric motor 39 rotates the rotor 37, its power is transmitted to the balls via the aforementioned planetary gear mechanism. Inside the ball screw nut assembly 37, a rod-shaped ball screw spindle assembly 51 is provided via the ball screw structure 50.

[0181] A shim pressing part 52 is provided at the front end of the ball screw main shaft assembly 51. When the ball screw main shaft assembly 51 moves toward the brake disc, the shim pressing part 52 exerts a pressing action, causing the friction pads 32 on both sides to clamp into the brake disc 31 and perform a squeezing action;

[0182] When the electric motor 39 causes the ball screw nut assembly 37 to rotate forward, for example, the rotational power is transmitted through the aforementioned planetary gear mechanism, causing the ball screw spindle assembly 51 to rotate forward. In this way, the ball screw mechanism 50 moves the ball screw spindle assembly 51 towards the brake disc 31, and a pair of friction pads 32 press against the brake disc 31, contacting it and generating braking force. The pressing force is estimated based on the motor's rotation. Alternatively, a pressing force sensor can be added.

[0183] refer to Figure 7As shown, an embodiment of the present invention provides a vehicle braking control device, the device comprising:

[0184] The vehicle parameter acquisition module 601 is used to acquire vehicle driving parameters and driving control parameters;

[0185] The switching control module 602 is used to control the switching unit to switch the regenerative braking current for the electric friction braking unit when the energy storage unit is in a non-rechargeable state; the regenerative braking current is generated by the drive unit.

[0186] The first braking force acquisition module 603 is used to determine the first braking force based on the driving control parameters and the regenerative braking current.

[0187] The braking control module 604 is used to control the braking unit to brake according to the first braking force.

[0188] The vehicle braking control device provided in this application embodiment controls the switching unit to switch the regenerative braking current for braking of the braking unit when the electric energy storage unit is in a non-rechargeable state. This avoids the inability to achieve regenerative braking due to the electric energy storage unit being in a non-rechargeable state, thereby reducing the vehicle's friction braking force and reducing the wear of the braking unit.

[0189] Optionally, the first braking force acquisition module includes:

[0190] The first friction braking force determination submodule is used to determine the first friction braking force based on the driving control parameters.

[0191] The first current value determination submodule is used to determine the first current value of the regenerative braking current based on the vehicle driving parameters.

[0192] The first regenerative braking force and current friction braking force determination submodule is used to determine the first regenerative braking force and current friction braking force based on the first current value of the regenerative braking current.

[0193] The first braking force determination submodule is used to determine the first braking force based on the first regenerative braking force, the current frictional braking force, and the first frictional braking force.

[0194] Optionally, the device further includes:

[0195] A charging module is used to control the regenerative braking current to charge the energy storage unit when the energy storage unit is in a rechargeable state.

[0196] The second braking force acquisition module is used to determine the second braking force based on the vehicle driving parameters and the driving braking parameters.

[0197] A braking control module is used to control the braking unit to brake according to the second braking force.

[0198] Optionally, the second braking force acquisition module includes:

[0199] The second current value acquisition submodule is used to determine the second current value of the regenerative braking current based on the vehicle driving parameters.

[0200] The second regenerative braking force acquisition submodule is used to determine the second regenerative braking force based on the second current value of the regenerative braking current.

[0201] The second friction braking force acquisition submodule is used to determine the second friction braking force based on the driving control parameters.

[0202] The second braking force acquisition submodule is used to determine the second braking force based on the second regenerative braking force and the second frictional braking force.

[0203] Optionally, the first regenerative braking force determination submodule includes:

[0204] The first characteristic quantity determination submodule is used to determine the first characteristic quantity based on the first current value of the regenerative braking current.

[0205] The first parameter acquisition submodule is used to acquire a first parameter, which includes at least one of the first acceleration, vehicle weight, and road slope.

[0206] The correction coefficient acquisition submodule is used to acquire the correction coefficient based on the first parameter;

[0207] The first regenerative braking force acquisition submodule is used to correct the first characteristic quantity according to the correction coefficient and determine the first regenerative braking force.

[0208] Optionally, the vehicle parameter acquisition module is used to acquire the vehicle driving parameters and the driving control parameters determined by the vehicle system control unit;

[0209] The vehicle driving parameters include at least one of vehicle yaw angle, first acceleration, second acceleration, and wheel speed; the driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

[0210] Optionally, the energy storage unit state determination module includes:

[0211] The energy storage unit parameter acquisition submodule is used to acquire the charging current value, discharging current value, voltage value and temperature value of the energy storage unit;

[0212] The energy storage unit status determination submodule determines the status of the energy storage unit based on the charging current value, the discharging current value, the voltage value, and the temperature value.

[0213] Reference Figure 8 This application provides a vehicle braking control system, including: a drive unit 701, a drive control unit 702, an electric energy storage unit 703, a switching unit 704, and a braking unit 705;

[0214] The drive control unit 702 is electrically connected to the drive unit 701, the braking unit 705 and the switching unit 704 respectively;

[0215] The drive control unit 702 is used to acquire vehicle driving parameters, driving control parameters, and the status of the electric energy storage unit; when the electric energy storage unit 703 is in a non-rechargeable state, the control switching unit 704 switches the regenerative braking current to be used for braking by the braking unit 705; the regenerative braking current is generated by the drive unit 701; a first braking force is determined according to the driving control parameters and vehicle driving parameters; and the braking unit 705 is controlled to brake according to the first braking force.

[0216] The vehicle braking control system provided in this application embodiment controls the switching unit 704 to switch the regenerative braking current to the braking unit 705 when the electric energy storage unit 705 is in a non-rechargeable state. This avoids the inability to achieve regenerative braking because the electric energy storage unit 703 is in a non-rechargeable state, thereby reducing the vehicle's friction braking force and reducing the wear of the braking unit.

[0217] Reference Figure 9 This application provides a vehicle including the vehicle braking control device 801 described above. The vehicle braking control device 801 includes a processor 803, a memory 802, and a computer program stored in the memory 802 and executable on the processor 803. When the processor 803 executes the program, it implements any of the vehicle braking control methods described in this specification and has any of the above-mentioned beneficial effects.

[0218] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A vehicle braking control method, characterized in that, include: Acquire vehicle driving parameters, driving control parameters, and the status of the energy storage unit; When the energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking of the braking unit; the regenerative braking current is generated by the drive unit. The first braking force is determined based on the vehicle driving parameters and the driving control parameters; The braking unit is controlled to brake according to the first braking force; When the energy storage unit is in a rechargeable state, the regenerative braking current is controlled to charge the energy storage unit. The second braking force is determined based on the vehicle driving parameters and the driving control parameters; Braking is controlled by the second braking force control braking unit; The second braking force is equal to the first braking force; The switching unit is used, under the control of the drive control unit, to switch the regenerative braking current for charging the electric energy storage unit or braking the electric friction braking unit.

2. The braking control method according to claim 1, characterized in that, The step of determining the first braking force based on the vehicle driving parameters and the driving control parameters includes: The first friction braking force is determined based on the driving control parameters; The first current value of the regenerative braking current is determined based on the vehicle driving parameters. The first regenerative braking force and the current friction braking force are determined based on the first current value of the regenerative braking current. The first braking force is determined based on the first regenerative braking force, the current frictional braking force, and the first frictional braking force.

3. The braking control method according to claim 1, characterized in that, The step of determining the second braking force based on the vehicle driving parameters and the driving control parameters includes: The second current value of the regenerative braking current is determined based on the vehicle driving parameters; The second regenerative braking force is determined based on the second current value of the regenerative braking current; The second friction braking force is determined based on the driving control parameters; The second braking force is determined based on the second regenerative braking force and the second frictional braking force.

4. The braking control method according to claim 2, characterized in that, The step of determining the first regenerative braking force based on the first current value of the regenerative braking current includes: A first characteristic quantity is determined based on the first current value of the regenerative braking current; Obtain a first parameter, which includes at least one of a first acceleration, the weight of the vehicle, and the road slope; The correction coefficient is obtained based on the first parameter; The first characteristic quantity is corrected according to the correction coefficient, and the first regenerative braking force is determined.

5. The braking control method according to claim 1, characterized in that, The steps for obtaining vehicle driving parameters and driving control parameters include: Obtain the vehicle driving parameters and driving control parameters determined by the vehicle system control unit; The vehicle driving parameters include at least one of vehicle yaw angle, first acceleration, second acceleration, and wheel speed; the driving control parameters include at least one of accelerator pedal travel, brake pedal travel, and vehicle steering angle.

6. The braking control method according to claim 1, characterized in that, The step of obtaining the state of the energy storage unit includes: The charging current, discharging current, voltage, and temperature values ​​of the energy storage unit are obtained. The state of the energy storage unit is determined based on the charging current value, the discharging current value, the voltage value, and the temperature value.

7. A vehicle braking control device, characterized in that, include: The vehicle parameter acquisition module is used to acquire vehicle driving parameters, driving control parameters, and the status of the energy storage unit; A switching control module is used to control the switching unit to switch the regenerative braking current for the electric friction braking unit when the energy storage unit is in a non-rechargeable state; the regenerative braking current is generated by the drive unit. The first braking force acquisition module is used to determine the first braking force based on the driving control parameters and the regenerative braking current. A braking control module is used to control the braking unit to brake according to the first braking force. A charging module is used to control the regenerative braking current to charge the energy storage unit when the energy storage unit is in a rechargeable state. The second braking force acquisition module is used to determine the second braking force based on the vehicle driving parameters and the driving control parameters; A braking control module is used to control the braking unit to brake according to the second braking force. The second braking force is equal to the first braking force; The switching unit is used, under the control of the drive control unit, to switch the regenerative braking current for charging the electric energy storage unit or braking the electric friction braking unit.

8. A vehicle braking control system, characterized in that, include: Drive unit, drive control unit, electric energy storage unit, switching unit, and braking unit; The drive control unit is electrically connected to the drive unit, the braking unit, and the switching unit, respectively; the drive control unit is used to acquire vehicle driving parameters, driving control parameters, and the status of the electric energy storage unit. When the energy storage unit is in a non-rechargeable state, the control switching unit switches the regenerative braking current to be used for braking by the braking unit; the regenerative braking current is generated by the drive unit; the first braking force is determined according to the vehicle driving parameters and the driving control parameters. The braking unit is controlled to brake according to the first braking force; The system is used to execute the vehicle braking control method as described in any one of claims 1-6.

9. A vehicle, characterized in that, The system includes a vehicle braking control device, which comprises a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the vehicle braking control method as described in any one of claims 1-6.

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