Braking method for a motor vehicle

Abstract

The motor vehicle has a main hydraulic braking circuit and an auxiliary electromechanical braking circuit, each configured to clamp a brake component onto a braking element. The procedure comprises the following steps: - detection of vehicle parking, - when the motor vehicle is detected as parked, clamping a brake component onto a braking element by means of the auxiliary electromechanical braking circuit, until a predetermined initial clamping force is obtained, - determination of the slope (S) of the motor vehicle, - determination of the temperature (T) of the braking element and / or the brake component.The braking process further comprises the following steps when the determined slope is greater than a predetermined value (S1) and / or when the determined temperature is greater than a predetermined value (T1): - selection, from the main hydraulic braking circuit and the auxiliary electromechanical braking circuit, based on the determined value of the slope (S) and the determined value of the temperature (T), of the tightening circuit configured to tighten the braking component onto the braking element, - selection of a number n of tightenings to be performed, n being a strictly positive integer predetermined and variable / configurable based on the determined value of the slope (S) and the determined value of the temperature. Figure for the abbreviation: Figure 1,

Description

Title of the invention: Braking method for a motor vehicle

[0001] The invention relates to the field of motor vehicle braking.

[0002] A braking system for a motor vehicle comprising, for example, a main hydraulic braking circuit and an electromechanical auxiliary braking circuit is already known in the state of the art.

[0003] The main hydraulic braking circuit is, for example, controlled by an electronic control device, also called an electric brake booster, which amplifies the hydraulic braking pressure, making it easier to apply pressure during manual braking by pressing a brake pedal, or during automatic braking control from an electronic control unit (ECU). The hydraulic braking circuit controls hydraulic actuators of braking components, such as hydraulic pistons.

[0004] The electromechanical auxiliary braking circuit provides an electric parking brake function, or preferably an automatic parking brake function. This electromechanical auxiliary braking circuit controls electric actuators of the braking components. In the event of a failure of the main hydraulic braking circuit, the electromechanical auxiliary braking circuit provides emergency dynamic braking—also known as rolling brake.

[0005] Hydraulically and / or electrically actuated braking components are configured to brake the wheels of the motor vehicle. For this purpose, each braking component includes, for example, a brake caliper with friction means, such as brake pads, which it drives towards braking elements, each attached to a wheel of the vehicle, such as brake discs. For example, the electric parking brake function of the electromechanical auxiliary braking circuit is activated, or deactivated, by pressing an activation button.

[0006] Furthermore, the electronic control device is, for example, configured to control the main hydraulic braking circuit, not only to ensure the main hydraulic braking function of the motor vehicle, but also to ensure certain dynamic braking functions, such as the anti-lock braking function – also known by the acronym ABS for “Anti-lock Braking System”. kiersystem in German - or electronic stability control for electronic trajectory control - also known by the acronym ESP for "Electronic Stability Program" in English or ESC for "Electronic Stability Control" in English.

[0007] In order to bring the motor vehicle to a stop, the braking system applies an initial clamping force to the braking elements. However, due to the design of the braking system and the braking elements, their temperature affects the clamping force. For example, the coefficient of friction between the brake pads and the brake discs decreases during a cooling phase, which reduces the clamping force applied. Thus, the clamping force may become insufficient to hold the motor vehicle stationary, and there is then a risk that the vehicle may start moving accidentally, for example, while parked on a slope.

[0008] Thus, in order to ensure that the motor vehicle remains stationary, it is necessary in certain cases to at least tighten the braking components to maintain the parking brake function. For example, when the estimated or measured temperature of the braking elements is below a predetermined threshold, such as 50°C: - when the vehicle is parked on a flat or slight incline, for example less than 15%, no tightening is carried out, - when the motor vehicle is parked on a medium slope, for example between 15 and 21%, three successive tightenings are carried out by the auxiliary electromechanical braking circuit, for example 3s, 30s and 300s after the motor vehicle has stopped, - when the motor vehicle is parked on a steep slope, for example greater than 21%, three successive tightenings are carried out by the main hydraulic braking circuit, for example 3s, 30s and 300s after the motor vehicle has stopped.

[0009] The following table presents an example of the three cases stated above as a function of the slope and temperature of the braking elements. In this table: - Category 1 corresponds to cases where no tightening is carried out. - Category 2 corresponds to cases where three successive tightenings are carried out by the electromechanical auxiliary braking circuit, for example 3s, 30s and 300s after the motor vehicle has stopped, and - Category 3 corresponds to cases where three successive tightenings are carried out by the main hydraulic braking circuit, for example 3s, 30s and 300s after the motor vehicle has stopped.

[0010] [Tables] Temperature (°C) Slope (%) 0-50 50-100 100-150 150-200 200-250 250-300 >300 0-4 1 1 1 1 1 1 3 4-6 1 1 1 1 1 2 3 6-8 1 1 1 1 2 2 3 8-10 1 1 1 2 2 2 3 10-12 1 1 2 2 2 2 3 12-13 1 2 2 2 2 2 3 13-15 1 2 2 3 3 3 3 15-21 2 2 2 3 3 3 3 >21 3 3 3 3 3 3 3

[0011] Even though these three cases allow the motor vehicle to remain stationary, such a tightening strategy is not optimal, since the braking components and elements are in some cases overstressed relative to the actual tightening requirement. Thus, in some cases, a single tightening might suffice to keep the vehicle stationary, instead of three successive tightenings. There is therefore a need to optimize the tightening strategy in order to increase the service life of the braking components and elements, and to reduce energy consumption while still allowing the motor vehicle to remain stationary.

[0012] The invention aims to provide a braking method for motor vehicles that allows the motor vehicle to be kept stationary while providing an optimized tightening strategy.

[0013] To this end, the invention relates to a method for braking a motor vehicle comprising a main hydraulic braking circuit and an auxiliary electromechanical braking circuit, each configured to clamp a braking component onto a braking element, the method being configured to keep the vehicle stationary and comprising the following steps:

[0014] - vehicle parking detection,

[0015] - when the parking of the motor vehicle is detected, tightening of a component of braking on a braking element by means of the electromechanical auxiliary braking circuit, until a predetermined initial clamping force is obtained,

[0016] - determination of the slope of the motor vehicle,

[0017] - determination of the temperature of the braking element and / or the component braking,

[0018] the braking method further comprising the following steps when the determined slope is greater than a predetermined value (SI) and / or when the determined temperature is greater than a predetermined value (Tl):

[0019] - selection between the main hydraulic braking circuit and the auxiliary circuit electromechanical braking, depending on the determined value of the slope and the determined value of the temperature, of the tightening circuit configured to tighten the braking component onto the braking element,

[0020] - selection of a number n of tightenings to be performed, n being an integer strictly positive, predetermined and variable depending on the determined value of the slope and the determined value of the temperature,

[0021] - for each tightening to be performed, selection of a following tightening instant obtaining the predetermined initial tightening force, each tightening instant being predetermined and variable depending on the determined value of the slope and the determined value of the temperature,

[0022] - perform n tightenings of the braking component on the braking element by the selected tightening circuit, each tightening being carried out at a predetermined tightening time until a predetermined tightening force is obtained.

[0023] Thus, the number of tightening operations to be performed varies according to the determined value of the slope and / or the determined value of the temperature, which allows for optimization of the tightening process. This avoids overstressing the braking components and elements while ensuring the vehicle remains immobilized, particularly when the vehicle is parked on a level or slight incline. In other words, it is proposed to perform a number of tightening operations adapted to the slope and / or temperature, sufficient to immobilize the vehicle but no more than necessary.

[0024] The steps for determining the vehicle's slope and temperature make it possible to determine whether a tightening is required, and if so, to select a tightening category required to prevent the vehicle from accidentally moving. Preferably, a tightening category defines the circuit performing the tightening (from among the main hydraulic braking circuit and the electromechanical auxiliary braking circuit), and a number of tightenings to be carried out, each associated with a given time after the parking function is activated.

[0025] In the proposed invention, the number of tightening operations to be performed is advantageously variable depending on the category chosen, as it depends on the determined value of the slope and the determined value of the temperature. Thus, advantageously:

[0026] - on a zero or slight slope, no or only one tightening is carried out,

[0027] - on a medium slope, two or three successive tightenings are carried out, and

[0028] - on a steep slope, three or four successive tightenings are carried out.

[0029]

[0030] The braking method may further include one or more of the following optional features, taken alone or in combination.

[0031] - The brake component is a brake caliper.

[0032] - The brake element is configured to be fixed to a wheel of the vehicle so that the wheel can be tightened after the parking function is activated. The braking element is specifically a brake disc.

[0033] - The vehicle parking detection step is performed by detecting The activation is triggered by pressing an activation button, preferably one for the electric parking brake function of the electromechanical auxiliary braking circuit. Such activation is generally detectable after driver intervention, for example, by manually pressing the button. It is understood that, ideally, the electromechanical auxiliary braking circuit is responsible for parking the vehicle by applying a predetermined initial clamping force.

[0034] - The step of determining the slope of the motor vehicle is carried out by the measurement of the slope of the motor vehicle by an inclination sensor.

[0035] - The value of the determined slope is an absolute value.

[0036] - The predetermined value (SI) of the slope triggering at least one tightening is a value between 0% and 15%. This predetermined value (SI) is preferably between 12% and 18%, for example close to 15%, for a given temperature close to 0°C.

[0037] - The step of determining the temperature of the braking element and / or of The braking system temperature is determined by estimation based on a braking command applied by the driver of the motor vehicle to the main hydraulic braking circuit. More precisely, the temperature is estimated from the hydraulic pressure applied by the driver, by converting the applied kinetic energy into heat energy. Alternatively, or in combination with other methods, the temperature determination of the braking element and / or the braking system is performed by a temperature sensor located near the wheels. Such sensors are generally used in vehicles modified for motor racing.

[0038] - The predetermined value (Tl) of the temperature triggering at least one tightening is a value between 0°C and 350°C. For a given slope close to 0%, this predetermined value (Tl) is preferably between 250°C and 350°C, for example close to 300°C.

[0039] - The method includes the following step: when the determined slope of the slope is lower than the predetermined value (SI) and when the determined temperature of the temperature is below the predetermined value (Tl), maintenance unchanged of the clamping of the braking component on the braking element.

[0040] It is understood that in this step no tightening is carried out by the braking component. Advantageously, this step of the braking process ensures that no unnecessary tightening is carried out when the vehicle is on a zero or very slight incline and that the vehicle can be held stationary solely by the clamping circuit, preferably the electromechanical auxiliary braking circuit when parked.

[0041] - The number n of tightenings to be carried out is between 1 and 20, preferably se selected from 1, 2, 3, 4, 5. In other words, the braking process allows for between 1 and 20 tightening operations, advantageously between 1 and 5, depending on the determined temperature and slope. For example, on a medium slope between 15% and 21%, preferably a single tightening operation is performed at a temperature close to 0°C, or three successive tightening operations are performed at a temperature between 150°C and 300°C. As another example, on a steeper slope greater than 21%, preferably two successive tightening operations are performed at a temperature close to 0°C, or four successive tightening operations are performed at a temperature greater than 200°C.

[0042] - Each predetermined instant is selected within an interval of 1s (seconds) to 3600 seconds, following the achievement of the predetermined initial tightening force, preferably within a range of 2 to 600 seconds, and even more preferably from 2 to 400 seconds. It is understood here that after parking detection, for example by pressing an activation button, tightening begins when the driver is present in the vehicle, and depending on the required level of tightening, this tightening continues, for example, even after the driver has left the vehicle. It is understood that the driver's presence in the vehicle is not necessary to ensure that the vehicle remains safely stationary, particularly on a slope.

[0043] - When the determined slope is greater than 21%: the tightening circuit The selected circuit is the main hydraulic braking system, with the number n equal to 2 when the specified temperature is below 200 °C and n equal to 4 when the specified temperature is above 200 °C. It is understood that such a setting is suitable for a vehicle parked on a steep incline. In general, under the effect of high temperatures, a greater number of retightenings is required, particularly because the coefficient of friction between the braking elements and the braking components decreases during the cooling phase, which tends to reduce the clamping force exerted by the main circuit.

[0044] - When the determined slope is between 15% and 21%: * The selected tightening circuit is the electromechanical auxiliary circuit of braking when the determined temperature is below 300 °C, the number n being equal to 1 when the determined temperature is below 150 °C and the number n being equal to 3 when the temperature is between 150 °C and 300 °C, and * The selected tightening circuit is the main hydraulic braking circuit when the determined temperature is above 300 °C, the number n being equal to 4. It is understood that such a parameterization is suitable for a vehicle which is placed on a medium slope.

[0045] - When the determined temperature is greater than 300 °C: the tightening circuit The selected circuit is the main hydraulic braking circuit, with the number n being equal to 3 when the determined slope is between 0% and 8%, and the number n being equal to 4 when the determined slope is greater than 8%. It is understood here that under high temperature conditions, the number of retightenings required is generally also high, even if the vehicle is positioned on a slope with a very slight incline, for example between 0% and 8%.

[0046] - When the determined temperature is between 150 °C and 200 °C:

[0047] * the selected tightening circuit is the electromechanical auxiliary circuit of braking when the slope is between 8% and 21%, the number n being equal to 3, and * the selected tightening circuit is the main hydraulic braking circuit when the determined slope is greater than 21%, the number n being equal to 2.

[0048] - When the determined temperature is between 100 °C and 150 °C:

[0049] * the selected tightening circuit is the electromechanical auxiliary circuit of braking when the slope is between 10% and 21%, the number n being equal to 1, and * the selected tightening circuit is the main hydraulic braking circuit when the determined slope is greater than 21%, the number n being equal to 2.

[0050] - When the selected tightening circuit is the auxiliary electrical circuit braking mechanics:

[0051] * when the number n is equal to 1, the predetermined time is 50s,

[0052] * when the number n is equal to 3, the predetermined times are 3s, 30s and 300s; And when the selected tightening circuit is the main hydraulic braking circuit: * When the number n is equal to 2, the predetermined times are 10s and 600s or 5s and 120s.

[0053] * when the number n is equal to 4, the predetermined times are 2s, 25s, 80s and 400s.

[0054] It is understood that the predetermined time for performing the tightenings is advantageously variable depending on the tightening circuit selected. The main hydraulic braking circuit and the electromechanical auxiliary circuit exhibit forces of different tightening methods. Therefore, when one or the other is selected by the braking process to perform a tightening, the selection is generally also based on the force that can be applied by each circuit before the optimal number of tightenings required and at what time they should be performed can be assessed. Brief description of the figures

[0055] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings, in which:

[0056] [Fig.1] is a diagram illustrating a braking method for a motor vehicle according to the invention. Detailed description

[0057] Figure [1] illustrates the braking procedure 100 of a motor vehicle including steps to determine if tightening is necessary to keep the vehicle stationary.

[0058] Such a method 100 is suitable for motor vehicles comprising a braking device acting at a wheel of the vehicle. The braking device generally comprises a braking component and a braking element. Preferably, the braking element is a brake disc fixed to an axle of the vehicle, and the braking component is a brake caliper which includes friction means, preferably brake pads intended to clamp the brake disc during braking.

[0059] The braking system is advantageously actuated by a braking circuit which is itself controlled by a control unit or ECU. Generally, the vehicle comprises a main hydraulic braking circuit and an electromechanical auxiliary braking circuit.

[0060] The main hydraulic braking circuit is controlled by an electronic control device, also called an electric brake booster, which allows the braking device to be activated when a manual command is requested by a driver, for example by pressing a brake pedal, or when an automatic braking command is issued from the electronic control unit (ECU).The electronic control unit is also configured to control the main hydraulic braking circuit in certain dynamic braking functions, such as the anti-lock braking system (ABS) or electronic stability control for electronic trajectory control (ESP) or electronic stability control.

[0061] The electromechanical auxiliary braking circuit generally provides an electric parking brake function (or, in English, "Electric Parking Brake"), or even an automatic parking brake function (in English, "Automatic Parking Brake"). Such an auxiliary circuit controls electric actuators of braking components. In the event of a failure of the main hydraulic braking circuit, the electromechanical auxiliary braking circuit provides emergency dynamic braking—also called rolling brake.

[0062] According to the embodiment illustrated in [Fig. 1], the braking process 100 comprises the following steps:

[0063] - a step 10 of vehicle parking activation. Such an activation is activated by pressing an activation button, the activation button is preferably an activation button for the electric parking brake function of the electromechanical auxiliary braking circuit.

[0064] - A step 20 of detecting a vehicle parking instruction. By For example, a parking instruction corresponds to a signal sent to the vehicle's control unit or ECU, such as a signal bearing the number 1 meaning that a parking instruction has been requested by the driver.

[0065] - A test step 30 on the applied clamping force, preferably corresponding The braking mechanism is tightened onto the brake element by means of the electromechanical auxiliary braking circuit. During step 30, the braking mechanism is pressed against the brake element until a predetermined initial clamping force is reached to maintain vehicle stability. If this clamping force is not reached, the procedure includes a step 40 which returns the system to the control unit, which then commands the braking mechanism to tighten onto the brake element again to ensure the vehicle's safety while parked. If the predetermined initial clamping force is reached, the process proceeds to step 50.

[0066] Step 50 is a step for determining the slope S of the motor vehicle and the temperature T of the braking element and / or braking component. This step involves determining the value of the slope S on which the vehicle is positioned, preferably using an inclination sensor present on the vehicle. Step 50 also involves determining the temperature T of the braking component and / or braking element by estimating it from the hydraulic pressure applied by the driver.This step 50 also allows these determined values ​​S, T to be compared to predetermined threshold values ​​of slope and temperature, in particular to a predetermined value of slope SI and a predetermined value of temperature TL. In this example, the predetermined value of slope SI is an absolute value which is between 12% and 18%, more precisely close to 15%; and the predetermined value of temperature Tl is between 250°C and 350°C, by . An example close to 300°C. These predetermined SI and Tl values ​​correspond here to conditions where tightening is not required by the vehicle.

[0067] When the determined value of the slope S is greater than the predetermined value of the slope S1 and / or when the determined value of the temperature T is greater than the predetermined value T1, the process 100 continues with a tightening step 60 in which an optimal braking circuit is selected from the main hydraulic braking circuit and the electromechanical auxiliary braking circuit based on the determined value of the slope S and the determined value of the temperature T. Then, a number n of optimal tightenings is selected, followed by a time tn to perform each tightening. More specifically, step 60 consists of choosing a tightening category from several parameterized categories to prevent the vehicle from accidentally starting to move.The tightening category defines which circuit performs the tightening, whether it be the main hydraulic braking circuit or the auxiliary electromechanical braking circuit, and the number of tightenings to be carried out, each associated with a given time after the parking function is activated. In this example, five tightening categories are considered, described below.

[0068] The braking method 100 further provides for a termination step 70 without re-tightening when the determined slope S is less than the predetermined value S1 and when the determined temperature T is less than the predetermined value TL. This step 70 allows the clamping force of the braking component on the braking element to remain unchanged. The vehicle conditions do not require re-tightening, and the electromagnetic auxiliary circuit alone is generally capable of holding the motor vehicle stationary.

[0069] The number n of tightenings to be carried out according to the tightening categories is selected from 1 and 20, preferably from 1, 2, 3, 4, 5.

[0070] For each n tightening operation to be performed, a tightening instant tn is selected according to the initial tightening force. Each tightening instant tn is predetermined and varies according to the determined value of the slope S and the determined value of the temperature T. Thus, a number n of tightening operations are performed by a selected tightening circuit, each n tightening being carried out at a predetermined tightening instant tn until a predetermined tightening force is obtained.

[0071] Each predetermined instant tn is selected in an interval of 1s to 3600s, preferably from 2s to 600s, even more preferably from 2s to 400s, depending on obtaining the predetermined initial clamping force.

[0072] When the vehicle is positioned on a steep incline, the electromechanical auxiliary braking circuit is generally selected to perform the tightening. In high-temperature conditions, the tightening is generally performed by the main hydraulic braking circuit. The tightening is performed by one or the other of the braking circuits under conditions of average temperatures and / or average inclines.

[0073] The following table presents the categories stated above as a function of the determined slope S and the determined temperature T of the braking elements.

[0074] [Tables2] Temperature (°C) Slope (%) 0-50 50-100 100-150 150-200 200-250 250-300 >300 0-4 1 1 1 1 1 1 4 4-6 1 1 1 1 1 4 4 6-8 1 1 1 1 4 4 4 8-10 1 1 1 4 4 4 5 10-12 1 1 2 4 4 4 5 12-13 1 2 2 4 4 4 5 13-15 1 2 2 4 4 4 5 15-21 2 2 2 4 4 4 5 >21 3 3 3 3 5 5 5

[0075] In this table: - Category 1 corresponds to cases where no tightening is carried out. - Category 2 corresponds to cases where tightening is carried out by the electromechanical auxiliary braking circuit, for example 50 seconds after the motor vehicle has stopped. - Category 3 corresponds to cases where two successive tightenings are carried out by the main hydraulic braking circuit, for example 50s and 120s after the motor vehicle has stopped, - Category 4 corresponds to cases where three successive tightenings are carried out by the electromechanical auxiliary braking circuit, for example 3s, 30s and 300s after the motor vehicle has stopped, and - Category 5 corresponds to cases where four successive tightenings are carried out by the main hydraulic braking circuit, for example 2s, 25s, 80s and 400s after the motor vehicle has stopped.

[0076] Thus, when the determined slope S is greater than 21%, the selected tightening circuit is preferably the main hydraulic braking circuit. Under these conditions of steep slope S, the number n is equal to 2 when the determined temperature T is less than 200 °C and the number n is equal to 4 when the determined temperature T is greater than 200 °C.

[0077] When the determined slope S is between 15% and 21%, that is to say in Under average gradient conditions, the selected tightening circuit is the electromechanical auxiliary braking circuit when the specified temperature T is below 300 °C. The value n is 1 when the specified temperature T is below 150 °C and 3 when the specified temperature T is between 150 °C and 300 °C. Under these same gradient conditions S, i.e., under average gradient conditions between 15% and 21%, the selected tightening circuit is the main hydraulic braking circuit when the specified temperature T is above 300 °C, and the value n is 4.

[0078] When the determined temperature T is greater than 300 °C, the selected tightening circuit is the main hydraulic braking circuit. The number n is equal to 3 when the determined slope S is between 0% and 8%, and the number n is equal to 4 when the determined slope S is greater than 8%.

[0079] When the specified temperature T is between 150 °C and 200 °C, the selected tightening circuit is the electromechanical auxiliary braking circuit when the slope S is between 8% and 21%. Under these conditions of generally average temperature T and average slope S, the number n is preferably equal to 3 or 4. Under the same average temperature conditions, the selected tightening circuit is the main hydraulic braking circuit when the specified slope S is greater than 21%. Under conditions of average temperature T and steep slope S, the number n is preferably equal to 2 or 3.

[0080] When the determined temperature T is between 100 °C and 150 °C: - the selected tightening circuit is the electromechanical auxiliary braking circuit when the slope S is between 10% and 21%, the number n being equal to 1, and - the selected tightening circuit is the main hydraulic braking circuit when the determined slope S is greater than 21%, the number n being equal to 2.

[0081] When the selected tightening circuit is the electromechanical auxiliary braking circuit: - when the number n is equal to 1, the predetermined time tn is 50s,

[0082] - when the number n is equal to 3, the predetermined times tn are 3s, 30s and 300s. Furthermore, when the selected tightening circuit is the main hydraulic braking circuit:

[0083] - when the number n is equal to 2, the predetermined times tn are 10s and 600s or of 5s and 120s,

[0084] - when the number n is equal to 4, the predetermined times are 2s, 25s, 80s and 400s.

[0085] The invention is not limited to the embodiments shown, and other embodiments will be obvious to a person skilled in the art. In particular, it is possible to A greater number of tightening cycles may be required to ensure vehicle stability on steep inclines, for example, above 21%, and / or at high temperatures, for example, above 300°C. It may be stipulated that on steep inclines, for example, above 21%, without temperature concerns, the selected tightening circuit is the electromechanical auxiliary braking circuit. Similarly, it may be stipulated that for high temperatures, for example, above 300°C, without incline concerns, the selected tightening circuit is the electromechanical auxiliary braking circuit. List of references

[0086] 100: Braking method, 10: Vehicle parking activation step, 20: step of detecting a vehicle parking instruction,

[0087] 30: step of carrying out the parking,

[0088] 40: Return step to the control unit,

[0089] 50: step of evaluating the slope of the vehicle and the temperature of the element braking and / or the braking component.

[0090] 60: tightening step

[0091] 70: End step without tightening

Claims

1. Demands Braking method (100) of a motor vehicle comprising a main hydraulic braking circuit and an auxiliary electromechanical braking circuit, each configured to clamp a braking device onto a braking element, the braking method being configured to keep the vehicle stationary and comprising the following steps: - Vehicle parking detection, - when the parking of the motor vehicle is detected, a braking component is tightened onto a braking element by means of the electromechanical auxiliary braking circuit, until a predetermined initial tightening force is obtained, - determination of the slope (S) of the motor vehicle, - determination of the temperature (T) of the braking element and / or the braking component, the braking process further comprising the following steps when the determined slope is greater than a predetermined value (SI) and / or when the determined temperature is greater than a predetermined value (Tl): - selection, from the main hydraulic braking circuit and the auxiliary electromechanical braking circuit, according to the determined value of the slope (S) and the determined value of the temperature (T), of the tightening circuit configured to perform a tightening of the braking component on the braking element, - selection of a number n of tightenings to be performed, n being a strictly positive integer predetermined and variable according to the determined value of the slope (S) and the determined value of the temperature, - for each n tightening to be performed, selection of a tightening instant (tn) following the attainment of the predetermined initial tightening force, each tightening instant (tn) being predetermined and variable according to the determined value of the slope (S) and the determined value of the temperature (T), - perform n; tightenings of the braking device on the braking element by the selected tightening circuit, each n tightening being carried out at a predetermined tightening instant (tn) until a predetermined tightening force is obtained.

2. Braking method (100) according to the preceding claim, which includes the following step: - when the determined slope (S) is less than the predetermined value (SI) and when the determined temperature (T) is less than a predetermined value (Tl), maintaining unchanged the clamping of the braking member on the braking element.

3. Braking method (100) according to any one of the preceding claims, wherein the number n is from 1 to 20, preferably selected from 1, 2, 3, 4, 5.

4. Braking method (100) according to any one of the preceding claims, wherein each predetermined instant (tn) is selected in an interval from 1s to 3600s following the attainment of the predetermined initial clamping force, preferably in an interval from 2s to 600s, more preferably from 2s to 400s.

5. Braking method (100) according to any one of the preceding claims, wherein, when the determined slope (S) is greater than 21%: - the selected tightening circuit is the main hydraulic braking circuit, the number n being equal to 2 when the determined temperature (T) is less than 200 °C and the number n being equal to 4 when the determined temperature (T) is greater than 200 °C.

6. Braking method (100) according to any one of the preceding claims, wherein, when the determined slope (S) is between 15% and 21%: - the selected tightening circuit is the electromechanical auxiliary braking circuit when the determined temperature (T) is less than 300 °C, the number n being equal to 1 when the determined temperature (T) is less than 150 °C and the number n being equal to 3 when the determined temperature (T) is between 150 °C and 300 °C, and - the selected tightening circuit is the main hydraulic braking circuit when the determined temperature (T) is greater than 300 °C, the number n being equal to 4.

7. A braking method (100) according to any one of the preceding claims, wherein, when the specified temperature (T) is greater than 300 °C: - the selected tightening circuit is the main hydraulic braking circuit, the number n being equal to 3 when the specified slope (S) is between 0% and 8% and the number n being equal to 4 when the determined slope (S) is greater than 8%.

8. Braking method (100) according to any one of the preceding claims, wherein, when the determined temperature (T) is between 150 °C and 200 °C: - the selected tightening circuit is the electromechanical auxiliary braking circuit when the slope (S) is between 8% and 21%, the number n being equal to 3, and - the selected tightening circuit is the main hydraulic braking circuit when the determined slope (S) is greater than 21%, the number n being equal to 2.

9. Braking method (100) according to any one of the preceding claims, wherein, when the determined temperature (T) is between 100 °C and 150 °C: - the selected tightening circuit is the electromechanical auxiliary braking circuit when the slope (S) is between 10% and 21%, the number n being equal to 1, and - the selected tightening circuit is the main hydraulic braking circuit when the determined slope (S) is greater than 21%, the number n being equal to 2.

10. Braking method (100) according to any one of the preceding claims, wherein: when the selected tightening circuit is the electromechanical auxiliary braking circuit: - when the number n is equal to 1, the predetermined time (tn) is 50s, - when the number n is equal to 3, the predetermined times (tn) are 3s, 30s and 300s; and when the selected tightening circuit is the main hydraulic braking circuit: - when the number n is equal to 2, the predetermined times (tn) are 10s and 600s or 5s and 120s, - when the number n is equal to 4, the predetermined times are 2s, 25s, 80s and 400s.

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