Braking device for a wheel of a vehicle

Abstract

A braking device for a wheel of a vehicle comprises brake pads for generating a braking force when the brake pads engage a brake disc, the brake disc being associated with the wheel of the vehicle; a brake actuator adapted to move the brake pads towards the brake disc and bring the brake pads into contact with the brake disc, thereby generating a requested braking force in response to a brake action request; and a control unit configured to determine whether a brake action request is present; determine whether the vehicle is stationary; and when the control unit determines that a brake action request is present and the control unit determines that the vehicle is stationary, instruct the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

Description

[Technical field]

[0001] The present invention relates to a braking device for the wheels of a vehicle, a vehicle equipped with such a braking device, a method for adjusting the braking force exerted by a braking device of a vehicle, and a computer program for adjusting the braking force exerted by a braking device of a vehicle. [Background technology]

[0002] A common type of braking device for vehicle wheels comprises a brake disc which rotates with the wheel and brake pads which are pressed against the brake disc during a braking action, the pressing of the brake pads against the brake disc causing friction between the brake pads and the brake disc, thereby slowing down the wheel with which the brake disc is associated.

[0003] After a braking action, the brake pads are pulled away from the brake disc. However, if the brake pads are not pulled away from the brake disc a sufficient distance, for example due to wear or the presence of contaminants such as dirt or rust, some contact remains between the brake pads and the brake disc during normal driving, i.e. when no braking action is requested by the driver or by the vehicle's automation system. This undesirable contact during normal driving is referred to in the art as "brake drag". Brake drag has a negative impact on the energy efficiency of the vehicle.

[0004] Many solutions have been proposed in the art to reduce, mitigate, or eliminate brake drag. For example, mechanical elements such as springs have been proposed to provide a return force to the brake pads when braking action is no longer required. However, such elements often exert a continuous force that must be overcome to bring the brake pads into engagement with the brake disc. This causes a greater force to have to be applied to bring about the braking action, which can also affect the "pedal feel" experienced by the driver when depressing the brake pedal to bring about the braking action. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a braking system and method for controlling braking force which reduces the risk of brake drag. [Means for solving the problem]

[0006] This object of the invention is a braking device for a wheel of a vehicle, the braking device comprising: - a brake pad arranged to interact with a brake disc to generate a braking force when the brake pad engages the brake disc, the brake disc being associated with a wheel of the vehicle; - a brake actuator adapted to move brake pads towards and into contact with a brake disc, thereby generating a required braking force in response to a brake action request; a control unit, - determining whether a braking action request exists; and - determining whether the vehicle is stationary; and - when the control unit determines that a brake action request exists and the control unit determines that the vehicle is stationary, instructing a brake actuator to reduce the braking force with which the brake pads engage the brake discs; A control unit configured to: This is realized by a brake device comprising:

[0007] The braking device according to the invention comprises brake pads arranged to interact with a brake disc and generate a braking force when the brake pads engage the brake disc, the brake disc being associated with a wheel of the vehicle and rotating together with said wheel, the brake disc being for example a dedicated brake disc having the main purpose of braking or the rotor of an in-wheel motor.

[0008] The braking device further includes a brake actuator adapted to move the brake pads towards and into contact with the brake disc, thereby generating a required braking force.

[0009] The requested braking force is generated in response to a brake action request, which can be triggered, for example, by a driver engaging the brake pedal or by an automated vehicle system (e.g., an automated vehicle safety system or an autonomous driving system) that triggers the brake action request, for example, to avoid a collision.

[0010] The braking device according to the present invention further comprises a control unit, - determining whether a braking action request exists; and - determining whether the vehicle is stationary; and - when the control unit determines that a brake action request exists and the control unit determines that the vehicle is stationary, instructing the brake actuator to reduce the braking force with which the brake pads engage the brake discs.

[0011] A vehicle is stationary if it is not moving in the direction of travel over the ground surface as a result of the rotation of the vehicle's wheels and / or the sliding of the vehicle's wheels on the ground surface.

[0012] Thus, when the vehicle is already stationary and a brake action request is still present, for example when the driver continues to depress the brake pedal while the vehicle is stationary in front of a red traffic light, the control system instructs the brake actuator to reduce the braking force with which the brake pads engage the brake discs. Thus, the braking force is reduced when full braking force is no longer required because the vehicle is already stationary.

[0013] By doing so, the braking force that must be overcome to move the brake pads off the brake disc when the braking action demand is removed is also reduced, making it easier to move the brake pads off the brake disc once the vehicle is again put into motion, thereby reducing the risk of brake drag occurring.

[0014] The braking system according to the invention is different from the situation where the driver removes his / her foot from the brake pedal after bringing the vehicle to a complete stop (e.g. in front of a red traffic light) because when the driver removes his / her foot from the brake pedal, the brake action request is no longer present.The braking system according to the invention is different from an anti-brake lock system (ABS) because an ABS reduces or removes the braking force while the vehicle is still moving.

[0015] Optionally, in a braking device according to the invention, the brake actuator is or comprises a piston, which is connected, either directly or indirectly, to the brake pads for moving the brake pads towards the brake disc and for pressing the brake pads against the brake disc with a braking force that creates friction between the brake pads and the brake disc, which friction slows down the wheel of the vehicle with which the brake disc is associated. Typically, the brake disc is connected to the wheel with which said brake disc is associated.

[0016] The piston of the brake actuator may be, for example, hydraulically, electrically or pneumatically operated.

[0017] In one embodiment, the brake actuator is mechanically connected or mechanically connectable to a brake pedal. Optionally, the brake pedal is part of a braking system.

[0018] In one embodiment, the brake actuator is activated by a control signal (e.g., an electrical or electronic control signal) that is triggered, for example, when the brake pedal is depressed by the driver or by an automated vehicle system (e.g., an autonomous driving system, etc.) or an automated vehicle safety system (e.g., a collision avoidance system, etc.).

[0019] In one embodiment, the brake actuator is adapted to move the brake pads towards the brake disc, pressing the brake pads against the brake disc, as well as to move the brake pads away from the brake disc when the brakes are released (i.e., when the brake action request is removed), for example, when the driver releases the brake pedal or when the automated vehicle system that triggered the brake action request no longer maintains the brake action request.

[0020] In one embodiment, the control unit is adapted to receive a brake action signal indicating that a brake action request is present. This brake action signal and / or the input for the brake action signal can be provided by, for example, a force sensor, a pressure sensor, a position sensor, a displacement sensor, and / or by an automated vehicle system. Optionally, the force sensor determines the force exerted on the brake pedal. Optionally, the pressure sensor determines the pressure exerted on the brake pedal. Optionally, the position sensor determines the position of the brake pedal. Optionally, the displacement sensor determines the displacement of the brake pedal. The force sensor, the pressure sensor, the position sensor, and / or the displacement sensor are sensors that are also used by at least one other system in the vehicle, for example. Alternatively, the speed sensor is a dedicated sensor forming part of the braking equipment.

[0021] Optionally, the control unit comprises a brake action signal input port, the brake action signal input port adapted to receive the brake action signal.

[0022] In one embodiment, the control unit is adapted to receive a vehicle speed signal indicative of the speed of the vehicle. The control unit is adapted to derive from the vehicle speed signal whether the vehicle is stationary or not. This vehicle speed signal and / or the input for the vehicle speed signal can be provided, for example, by a speed sensor determining the overall speed of the vehicle or by a rotation speed sensor determining the rotation speed and / or angular speed of the wheels of the vehicle. Alternatively or additionally, the vehicle speed signal and / or the input for the vehicle speed signal can be provided by an automated vehicle system. Optionally, the speed sensor is, for example, a sensor that is also used by at least one other system in the vehicle. Alternatively, the speed sensor is, for example, a dedicated sensor forming part of a braking device.

[0023] Optionally, the control unit comprises a vehicle speed signal input port adapted to receive a vehicle speed signal.

[0024] In one embodiment, the control unit includes a microprocessor, a brake action signal input port, a vehicle speed signal input port, and a brake force signal output port.

[0025] The brake action signal input port is adapted to receive a brake action signal, the brake action signal indicating the presence of a brake action request, and the vehicle speed signal input port is adapted to receive a vehicle speed signal, the vehicle speed signal indicating a speed of the vehicle.

[0026] The control unit microprocessor is adapted to process the brake action signal and the vehicle speed signal to determine whether a brake action request is present and whether the vehicle is stationary or moving.

[0027] When the control unit microprocessor determines that a brake action request is present and the vehicle is stationary (i.e., not moving on the ground surface in the direction of travel as a result of the rotation of the vehicle's wheels and / or the skid of the vehicle's wheels on the ground surface), the control unit generates a brake force signal. The brake force signal is sent to the brake actuator via a brake force signal output port of the control unit. The brake force signal instructs the brake actuator to reduce the braking force with which the brake pads engage the brake discs.

[0028] Optionally, the brake force signal output port is connected to a brake actuator via a wired or wireless connection.

[0029] Optionally, the brake actuator comprises a piston connected to the brake pads, an electric motor adapted to drive the brake pads via the piston, and a brake actuator controller adapted to control the electric motor of the brake actuator such that the electric motor imposes a desired movement and / or braking force on the brake pads. In this case, a brake force signal from the control unit is received by the brake actuator controller, via which the electric motor is instructed to reduce the braking force with which the brake pads engage the brake disc. Optionally, the control unit and the brake actuator controller are integrated into a single control system. Optionally, the control unit and the brake actuator controller are separate components.

[0030] Optionally, the brake actuator comprises a hydraulic piston connected to the brake pads, a hydraulic drive system adapted to drive the brake pads via the piston, and a brake actuator controller adapted to control the hydraulic drive system of the brake actuator such that the hydraulic drive system imposes a desired movement and / or braking force on the brake pads. In this case, a brake force signal from the control unit is received by the brake actuator controller, via which the hydraulic drive system is instructed to reduce the braking force with which the brake pads engage the brake disc. Optionally, the control unit and the brake actuator controller are integrated into a single control system. Optionally, the control unit and the brake actuator controller are separate components.

[0031] In one embodiment, the control unit is configured to instruct the brake actuator to remove the braking force.

[0032] In this embodiment, the brake actuators are instructed to reduce the brake force to zero when the control unit determines (i.e., establishes) that a brake action request is present and that the vehicle is stationary.

[0033] Optionally, the brake actuator is instructed to disengage the brake pads from the brake disc, for example by actively moving the brake pads away from the brake disc, for example by exerting a force on a piston to which the brake pads are connected, or, optionally, in the case where a biasing force is present urging the brake pads away from the brake disc and the braking force overcomes the biasing force when braking action is required, the braking force is eliminated or removed and the biasing force urges the brake pads away from the brake disc.

[0034] In one embodiment, the braking system further comprises a brake pedal and a brake pedal pressure sensor. The brake pedal is adapted to be used by a driver of the vehicle to generate a brake action request. The brake pedal pressure sensor is adapted to measure a pedal pressure exerted on the brake pedal by the driver, and the brake actuator is adapted to generate a requested brake force having a predetermined relationship to the measured pedal pressure. For example, the requested brake force is proportional to the measured pedal pressure.

[0035] Optionally, the brake pedal pressure sensor is adapted to generate a brake action signal and / or an input for a brake action signal indicating that a brake action request is present.

[0036] In one embodiment, the braking device according to the invention further comprises a speed sensor configured to measure the speed of the vehicle, and the control unit is further configured to determine whether the vehicle is stationary based on the measurement value of the speed sensor.

[0037] Optionally, the control unit is configured to determine that the vehicle is stationary if the result of the measurement of the speed sensor is equal to 0 m / s.Furthermore, the control unit is configured to determine that the vehicle is not stationary if the result of the measurement of the speed sensor is not equal to 0 m / s.

[0038] In one embodiment, the braking device according to the invention further comprises an electronic parking brake configured to bring brake pads into contact with the brake disc when the vehicle is stationary, thereby generating a braking force for keeping the vehicle stationary. In this embodiment, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

[0039] The brake pads which may be brought into contact with the brake disc may be brake pads of a braking device or dedicated parking brake pads.

[0040] Optionally, the electronic parking brake comprises a parking brake actuator, which is separate from the brake actuator of the braking device. The parking brake actuator is preferably an electric or electronic actuator, which comprises, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator cooperating with a brake pedal, the parking brake actuator does not need to be designed for the right "pedal feel" (i.e. the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator to be optimized to minimize the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake is disengaged, the brake pads can be retracted more tightly than if the braking device itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of an electronic parking brake allows the brake pads to be retracted such that the risk of brake dragging is minimized.

[0041] Optionally, the electronic parking brake comprises a parking brake controller adapted to receive a parking brake activation signal from a control unit of the braking equipment and activates the electronic parking brake configured to bring the brake pads into contact with the brake disc.

[0042] In one embodiment, the control unit of the braking system according to the invention is configured to monitor the speed of the vehicle after the control unit has instructed the brake actuator to reduce the braking force with which the brake pads engage the brake discs, and in this embodiment, the control unit is configured to instruct the brake actuator to restore the braking force to the requested braking force when the control unit determines that the vehicle is not stationary.

[0043] This embodiment adds a safety feature to the braking system according to the invention. When the braking force is reduced after the vehicle has come to a standstill (e.g. in front of a traffic light), it is possible that the vehicle may start moving again, for example because the vehicle is standing on a sloped surface. When monitoring of the vehicle's speed after the reduction in braking force indicates that the vehicle is no longer stationary (i.e. moving), the braking force is restored and the vehicle is thus brought to a standstill again.

[0044] Optionally, in this embodiment, the control unit of the braking device is further configured to detect whether a drive system for driving the vehicle (e.g., comprising a central electric motor, a plurality of electric in-wheel motors, and / or an internal combustion engine) is active. If the control unit detects that the drive system is not active, the control unit is configured to instruct the brake actuator to restore the brake force to the requested brake force, but if the control unit detects that the drive system is active, the control unit is configured not to instruct the brake actuator to restore the brake force. In this way, it is ensured that only unintentional movements of the vehicle are suppressed by the restoration of the brake force.

[0045] Optionally, in a variation of this embodiment, the braking device according to the invention further comprises an electronic parking brake configured to bring brake pads into contact with the brake disc when the vehicle is stationary, thereby generating a braking force for keeping the vehicle stationary. In this variation, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc and after it has been determined by the control unit that the vehicle is no longer stationary.

[0046] In this variant, the brake pads that can be brought into contact with the brake disc can be the brake pads of the braking device or dedicated parking brake pads.

[0047] Optionally, in this variant, the electronic parking brake comprises a parking brake actuator, which is separate from the brake actuator of the braking device. The parking brake actuator is preferably an electric or electronic actuator, which comprises, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator cooperating with a brake pedal, the parking brake actuator does not need to be designed for a correct "pedal feel" (i.e. the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator to be optimized to minimize the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake is disengaged, the brake pads can be retracted more strictly than if the braking device itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of an electronic parking brake allows the brake pads to be retracted such that the risk of brake dragging is minimized.

[0048] Optionally, in this variation, the electronic parking brake comprises a parking brake controller adapted to receive a parking brake activation signal from a control unit of the braking equipment and activates the electronic parking brake configured to bring the brake pads into contact with the brake disc.

[0049] In one embodiment, the control unit of the braking system according to the invention comprises: - determining whether the vehicle is located on a sloped surface; - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, when the control unit determines that the vehicle is located on a sloped surface, instructing the brake actuator to restore the braking force to a requested braking force.

[0050] This embodiment adds a safety feature to the braking system according to the invention: in case the vehicle is on a sloped surface, there is a risk that the vehicle may start to move unintentionally when the braking force is reduced.

[0051] Optionally, in this embodiment, the braking device further includes an inclination sensor configured to measure an inclination of the vehicle relative to a horizontal direction, and the control unit configured to determine whether the vehicle is located on a sloped surface based on a measurement of the inclination sensor. Optionally, the control unit is configured to determine that the vehicle is located on a sloped surface if the measurement of the inclination sensor is not substantially equal to 0°, and to determine that the vehicle is not located on a sloped surface if the measurement of the inclination sensor is substantially equal to 0°.

[0052] In a variant of this embodiment, the control unit of the braking device according to the invention comprises: - determining whether the vehicle is located on a sloped surface; - avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

[0053] Optionally, in a further variation of this embodiment, the braking device according to the invention further comprises an electronic parking brake configured to bring brake pads into contact with the brake disc when the vehicle is stationary, thereby generating a braking force for keeping the vehicle stationary. In this variation, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc and after it is determined by the control unit that the vehicle is located on a sloped surface.

[0054] In this variant, the brake pads that can be brought into contact with the brake disc can be the brake pads of the braking device or dedicated parking brake pads.

[0055] Optionally, in this variant, the electronic parking brake comprises a parking brake actuator, which is separate from the brake actuator of the braking device. The parking brake actuator is preferably an electric or electronic actuator, which comprises, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator cooperating with a brake pedal, the parking brake actuator does not need to be designed for a correct "pedal feel" (i.e. the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator to be optimized to minimize the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake is disengaged, the brake pads can be retracted more strictly than if the braking device itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of an electronic parking brake allows the brake pads to be retracted such that the risk of brake dragging is minimized.

[0056] Optionally, in this variation, the electronic parking brake comprises a parking brake controller adapted to receive a parking brake activation signal from a control unit of the braking equipment and activates the electronic parking brake configured to bring the brake pads into contact with the brake disc.

[0057] In one embodiment, the control unit of the braking system according to the invention comprises: - determining whether an object is approaching the vehicle; and - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, when the control unit determines (i.e. detects) that an object is approaching the vehicle, instructing the brake actuator to restore the braking force to a requested braking force.

[0058] This embodiment adds a safety feature to the braking device according to the invention: in case the vehicle is approached by an object capable of moving the vehicle from its stationary position, the control unit commands the brake actuator to restore the braking force to the requested braking force. In this way, undesired movement of the vehicle is prevented. The object is for example another vehicle moving towards the vehicle with the braking device.

[0059] Optionally, the control unit is configured to determine whether the vehicle is located within a predicted trajectory of an object determined to be an approaching vehicle, and is configured to instruct the brake actuator to restore the brake force to the requested brake force only when the control unit determines that the vehicle is located within or adjacent to the predicted trajectory.

[0060] In a variant of this embodiment, the control unit of the braking device according to the invention comprises: - determining whether an object is approaching the vehicle; and - avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

[0061] Optionally, in this embodiment, the braking equipment according to the invention further comprises a camera configured to capture a stream of pictures of the area around the vehicle. In addition, the control unit is - analyzing a stream of photos of an area around the vehicle to obtain a photo stream analysis result; - determining whether an object is approaching the vehicle based on the photo stream analysis result.

[0062] Optionally, the control unit is configured to determine a predicted trajectory of the object based on the photo stream analysis.

[0063] Optionally, as an alternative to or in addition to the camera, this embodiment of the braking apparatus according to the invention further comprises a radar and / or a lidar configured to detect a position and / or a speed and / or an acceleration of an object in an area around the vehicle. The control unit is further configured to determine whether an object is approaching the vehicle based on the position and / or the speed and / or the acceleration of the object in the area around the vehicle. Optionally, the control unit is configured to determine a predicted trajectory of the detected object based on input received by the control unit from the radar and / or the lidar.

[0064] Optionally, in a variation of this embodiment, the braking device according to the invention further comprises an electronic parking brake configured to bring brake pads into contact with the brake disc when the vehicle is stationary, thereby generating a braking force for keeping the vehicle stationary. In this variation, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc and after it is determined by the control unit that an object is approaching the vehicle.

[0065] In this variant, the brake pads that can be brought into contact with the brake disc can be the brake pads of the braking device or dedicated parking brake pads.

[0066] Optionally, in this variant, the electronic parking brake comprises a parking brake actuator, which is separate from the brake actuator of the braking device. The parking brake actuator is preferably an electric or electronic actuator, which comprises, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator cooperating with a brake pedal, the parking brake actuator does not need to be designed for a correct "pedal feel" (i.e. the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator to be optimized to minimize the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake is disengaged, the brake pads can be retracted more strictly than if the braking device itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of an electronic parking brake allows the brake pads to be retracted such that the risk of brake dragging is minimized.

[0067] Optionally, in this variation, the electronic parking brake comprises a parking brake controller adapted to receive a parking brake activation signal from a control unit of the braking equipment and activates the electronic parking brake configured to bring the brake pads into contact with the brake disc.

[0068] In one embodiment, the braking device according to the invention comprises: - a plurality of brake pads, each brake pad arranged to interact with an associated brake disc to generate a braking force when the brake pad engages the associated brake disc, each brake disc being associated with a single wheel of the vehicle; - a plurality of brake actuators, each brake actuator adapted to move a respective brake pad towards its associated brake disc and bring the respective brake disc into contact with the associated brake disc, thereby generating a required braking force in response to a brake action request; Equipped with When the control unit determines that a brake action request exists and the control unit determines that the vehicle is stationary, the control unit is configured to instruct the brake actuator to reduce a braking force with which at least two of the plurality of brake pads engage their respective brake discs.

[0069] In this embodiment, the benefits of the invention are extended to multiple wheels of the vehicle, and optionally to all wheels of the vehicle. In this way, the energy loss caused by brake drag can be further reduced or even eliminated.

[0070] This embodiment can be combined with any one or more of the embodiments described above and below.

[0071] Optionally, in this embodiment, the control unit is configured to instruct all but one of the brake actuators to reduce or eliminate their respective braking forces.

[0072] Optionally, in this embodiment, the control unit is configured to instruct the multiple brake actuators to reduce their respective braking forces equally.

[0073] The present invention further provides a vehicle, the vehicle comprising: - at least one wheel; a braking device according to the invention, Equipped with The braking system relates to a vehicle, which comprises as many brake pads and as many brake actuators as there are wheels on the vehicle.

[0074] Optionally, the braking equipment comprises a greater number of brake pads and / or a greater number of brake actuators than the number of wheels of the vehicle.

[0075] Optionally, the braking device is or comprises an embodiment of a braking device according to the invention as described above or below.

[0076] Optionally, the braking device is or comprises one of the embodiments of a braking device according to the invention as described above or below.

[0077] The present invention further relates to a method for adjusting the braking force exerted by a braking system of a vehicle, the method comprising the steps of: - obtaining a brake action status indicating whether a brake action request is present; - obtaining a stationary status indicating whether the vehicle is stationary; - when the brake action status indicates that a brake action request exists and the stationary status indicates that the vehicle is stationary, instructing a brake actuator of the brake equipment to reduce a brake force with which brake pads of the brake equipment engage brake discs of the vehicle; The present invention relates to a method comprising the steps of:

[0078] In one embodiment, the method according to the present invention comprises the steps of: - after instructing a brake actuator of the braking device to reduce the braking force with which brake pads of the braking device engage brake discs of the vehicle, when the brake action status indicates that a brake action request exists and the stationary state status indicates that the vehicle is not stationary, instructing the brake actuator to restore the brake force to the requested brake force.

[0079] In one embodiment, the method according to the present invention comprises the steps of: - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, if the vehicle is stationary, instructing the electronic parking brake to bring the brake pads into contact with the brake disc, thereby generating a braking force to keep the vehicle stationary.

[0080] In one embodiment, the method according to the present invention comprises the steps of: - obtaining a grade status indicating whether the vehicle is located on a graded surface; - after instructing a brake actuator of the braking device to reduce the braking force with which brake pads of the braking device engage brake discs of the vehicle, instructing the brake actuator to restore the brake force to the requested brake force when the brake action status indicates that a brake action request exists and the grade status indicates that the vehicle is located on a graded surface; Further includes:

[0081] In one embodiment, the method according to the present invention comprises the steps of: - obtaining an object approach status indicating whether an object is approaching the vehicle; - after instructing a brake actuator of the braking device to reduce the braking force with which brake pads of the braking device engage brake discs of the vehicle, instructing the braking device to engage the brake actuator with the requested braking force when the brake action status indicates that a brake action request exists and the object approach status indicates that an object is approaching the vehicle; Further includes:

[0082] Optionally, this embodiment of the method further includes determining whether the vehicle is located within a predicted trajectory of an object determined to be approaching the vehicle, and further includes instructing the brake actuator to restore the brake force to the requested brake force only when the control unit determines that the vehicle is located within or adjacent to the predicted trajectory.

[0083] The invention further relates to a computer program comprising instructions, which, when executed by a computer, causes the computer to carry out the method according to the invention.

[0084] The invention will be explained in more detail below with reference to the drawings, in which exemplary embodiments of the invention are shown in a non-limiting manner. [Brief description of the drawings]

[0085] [Figure 1] FIG. 1 shows a first embodiment of a braking device according to the invention with brake pads engaging a brake disc to generate a braking force; [Diagram 2] 2 shows the braking device in the embodiment of FIG. 1 with the brake pads engaging the brake disc with a reduced braking force; [Diagram 3]FIG. 2 shows a second embodiment of a braking device according to the invention, comprising an electronic parking brake. [Figure 4a] FIG. 3 shows a third embodiment of a braking device according to the invention, in which the braking device detects whether an object is approaching the vehicle. [Figure 4b] FIG. 4 shows a fourth embodiment of a braking device according to the invention, with the vehicle positioned on a sloped surface. [Figure 5a] FIG. 1 illustrates a schematic diagram of a first embodiment of a flow diagram of a method according to the invention. [Figure 5b] FIG. 5b illustrates a schematic flow diagram of the embodiment of FIG. 5a with additional steps of the method according to the invention. [Figure 5c] FIG. 5b diagrammatically illustrates a flow diagram of the embodiment of FIG. 5b with additional steps of the method according to the invention. [Figure 6] FIG. 2 illustrates a schematic diagram of a second embodiment of a flow diagram of a method according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0086] Figures 1 and 2 show a first embodiment of a braking device 1 according to the invention. The braking device 1 can be used for a wheel of a vehicle. In Figure 1, brake pads engage a brake disc and generate a braking force. Figure 2 shows the embodiment of Figure 1 again, but now the brake pads engaging the brake disc have a reduced braking force.

[0087] In the embodiment of Figures 1 and 2, the braking device 1 comprises a housing 2. The housing 2 is, for example, a brake caliper or part thereof.

[0088] The braking device 1 comprises a brake pad 3. In this embodiment, the brake pad 3 comprises a brake pad body 4, which is arranged on a brake pad holder 5. In FIG. 1, the brake pad 3 interacts with a brake disc 6 to generate a braking force when the brake pad 3 engages the brake disc 6. The brake disc 6 is associated with a wheel of the vehicle and rotates together with said wheel. The brake disc 6 can for example be a dedicated brake disc having the main purpose of braking or it can be the rotor of an in-wheel motor.

[0089] The braking device 1 further comprises a brake actuator 7 adapted to move the brake pads 3 towards the brake disc 6 and to bring the brake pads 3 into contact with the brake disc 6, thereby generating a required braking force. In Fig. 1, the arrow F indicates the direction of the braking force. The braking force generates friction between the brake pads 3 and the brake disc 6, which friction slows down a wheel of the vehicle with which the brake disc 6 is associated. Usually, the brake disc 6 is connected to the wheel, with which said brake disc 6 is associated.

[0090] The requested braking force is generated in response to a brake action request, which can be triggered, for example, by a driver engaging the brake pedal or by an automated vehicle system (e.g., an automated vehicle safety system or an autonomous driving system) that triggers the brake action request, for example, to avoid a collision.

[0091] In the embodiment shown in Figures 1 and 2, the brake actuator 7 includes a piston 7a which is indirectly connected to the brake pads 3 for moving the brake pads 3 towards the brake disc 6 and for pressing the brake pads 3 against the brake disc 6 with the required braking force.

[0092] In the embodiment of Figures 1 and 2, the brake actuator 7 is a hydraulic actuator. The hydraulic actuator includes a piston 7a and a hydraulic control unit 8. A seal 7b is provided to prevent leakage of hydraulic fluid. The hydraulic control unit 8 provides hydraulic pressure to the piston 7a when a brake action demand is present. When a brake action demand is present, the seal 7b deforms as shown in Figure 2. When the brake action demand is removed, the hydraulic pressure to the piston 7a is released. The seal 7b returns to the shape as shown in Figure 1, thereby withdrawing the piston 7a and disengaging the brake pads 3 from the brake disc 6.

[0093] Alternatively, the piston 7a of the brake actuator 7 is electrically operated. In that case, the brake actuator 7 comprises, for example, an electric or electronic motor in combination with a spindle for driving the piston 7a.

[0094] The brake actuator 7 is, for example, mechanically connected or mechanically connectable to a brake pedal (not shown in Figures 1 and 2). Alternatively, there is a brake-by-wire system, which transmits input to the brake pedal to the brake actuator 7. Optionally, the brake pedal is part of the braking device 1.

[0095] The brake actuator 7 is activated by a control signal 9a (e.g., an electrical or electronic control signal) sent by a control unit 9. The control signal 9a from the control unit 9 is triggered, for example, when the brake pedal is depressed by the driver or by an automated vehicle system (e.g., an autonomous driving system, etc.) or an automated vehicle safety system (e.g., a collision avoidance system, etc.).

[0096] The control unit 9 is - determining whether a braking action request exists; and - determining whether the vehicle is stationary; and - when the control unit 9 determines that a brake action request is present and when the control unit 9 determines that the vehicle is stationary, instructs the brake actuator 7 via a control signal 9a to reduce the braking force with which the brake pads 3 engage the brake disc 6.

[0097] A vehicle is stationary if it is not moving in the direction of travel over the ground surface as a result of the rotation of the vehicle's wheels and / or the sliding of the vehicle's wheels on the ground surface.

[0098] The brake actuator 7 is adapted to move the brake pads 3 towards the brake disc 6, pressing the brake pads against the brake disc, as well as to move the brake pads 3 away from the brake disc 6 when the brakes are released (i.e. when the brake action request is removed). The brake action request is removed, for example, when the driver releases the brake pedal or when the automated vehicle system that triggered the brake action request no longer maintains the brake action request.

[0099] The control unit 9 is adapted to receive a brake action signal 10 (see FIG. 1a) indicating that a brake action request is present. This brake action signal 10 is provided by a sensor 11. The sensor 11 can be, for example, a force sensor, a pressure sensor, a position sensor, a displacement sensor, and / or an automated vehicle system. Optionally, the force sensor determines the force exerted on the brake pedal. Optionally, the pressure sensor determines the pressure exerted on the brake pedal. Optionally, the position sensor determines the position of the brake pedal. Optionally, the displacement sensor determines the displacement of the brake pedal. The force sensor, the pressure sensor, the position sensor and / or the displacement sensor are, for example, sensors that are also used by at least one other system in the vehicle. Alternatively, the speed sensor is a dedicated sensor forming part of the braking equipment.

[0100] Optionally, the control unit 9 includes a brake action signal input port, which is adapted to receive a brake action signal 10 .

[0101] In the embodiment of Fig. 1 and Fig. 2, the control unit 9 is adapted to receive a vehicle speed signal 21 indicative of the speed of the vehicle. The control unit 9 is adapted to derive from the vehicle speed signal 21 whether the vehicle is stationary or not. This vehicle speed signal 21 and / or the input for the vehicle speed signal can be provided, for example, by a speed sensor 22 determining the overall speed of the vehicle or by a rotation speed sensor determining the rotation speed and / or angular speed of the wheels of the vehicle. Alternatively or additionally, the vehicle speed signal 21 and / or the input for the vehicle speed signal can be provided by an automated vehicle system. Optionally, the speed sensor is, for example, a sensor that is also used by at least one other system in the vehicle. Alternatively, the speed sensor is, for example, a dedicated sensor forming part of the brake device 1.

[0102] Optionally, the control unit 9 includes a vehicle speed signal input port adapted to receive a vehicle speed signal.

[0103] When the control unit 9 determines that the vehicle has already come to a standstill, while the brake action request is still present, for example when the driver continues to depress the brake pedal while the vehicle is stationary in front of a red traffic light, the control unit 9 instructs the brake actuator 7 to reduce the braking force with which the brake pads 3 engage the brake disc 6. Thus, the braking force is reduced when full braking force is no longer required because the vehicle is already stationary. The reduction in the braking force is indicated in FIG. 2 by the arrow F, which is oriented in the other direction compared to the situation visualized in FIG. 1.

[0104] By doing so, it also reduces the braking force that must be overcome to move the brake pads 3 away from the brake disc 6 when the braking action demand is removed. This makes it easier to move the brake pads 3 away from the brake disc 6 once the vehicle is put into motion again, thereby reducing the risk of brake drag occurring.

[0105] In the embodiment of Figures 1 and 2, the braking device 1 further comprises an inclination sensor 24, which is configured to measure the inclination of the vehicle relative to the horizontal. The control unit 9 is adapted to receive an inclination signal 23 from the inclination sensor 24 indicative of the inclination of the vehicle. Thereby, the control unit 9 is configured to determine, based on the measurement of the inclination sensor 24, whether the vehicle is located on a sloped surface. The control unit 9: - further configured to instruct the brake actuator 7 to restore the brake force to a requested brake force when the control unit 9 determines, after instructing the brake actuator 7 to reduce the braking force with which the brake pads 3 engage the brake disc 6, that the vehicle is located on a sloped surface.

[0106] This adds a safety feature to the braking device 1. In case the vehicle is on a sloped surface, there is a risk that the vehicle may start to move unintentionally when the braking force is reduced.

[0107] Optionally, the control unit 9 is configured to determine that the vehicle is located on a sloped surface if the measurement value of the tilt sensor 24 is not substantially equal to 0°, and is configured to determine that the vehicle is not located on a sloped surface if the measurement value of the tilt sensor 24 is substantially equal to 0°.

[0108] Alternatively, the control unit 9 of the braking device 1 may - determining whether the vehicle is located on a sloped surface; - avoiding commanding the brake actuator 7 to reduce the braking force with which the brake pads 3 engage the brake disc 6.

[0109] Figure 3 shows a second embodiment of a braking device 31 according to the invention. The braking device 31 can be used for a wheel of a vehicle. In figure 3, the brake pads engage with a brake disc and generate a braking force. Figure 3 shows that the brake pads engaging with the brake disc have a reduced braking force.

[0110] In the embodiment of Fig. 3, the braking device 31 comprises a housing 2. The housing 2 is, for example, a brake caliper or part thereof.

[0111] The braking device 31 comprises a brake pad 3. In this embodiment, the brake pad 3 comprises a brake pad body 4, which is arranged on a brake pad holder 5. In FIG. 3, the brake pad 3 interacts with a brake disc 6 to generate a braking force when the brake pad 3 engages the brake disc 6. The brake disc 6 is associated with a wheel of the vehicle and rotates together with the wheel. The brake disc 6 can be, for example, a dedicated brake disc having the main purpose of braking or the rotor of an in-wheel motor.

[0112] In the embodiment of Fig. 3, the braking device 1 further comprises a brake actuator 7 adapted to move the brake pads 3 towards and into contact with the brake disc 6, thereby generating a required braking force. The braking force generates friction between the brake pads 3 and the brake disc 6, which friction slows down a wheel of the vehicle with which the brake disc 6 is associated. Typically, the brake disc 6 is connected to and associated with a wheel.

[0113] In the embodiment of FIG. 3, the brake actuator 7 is a hydraulic actuator. The hydraulic actuator includes a piston 7a and a hydraulic control unit 8. A seal 7b is provided to prevent leakage of hydraulic fluid. The hydraulic control unit 8 provides hydraulic pressure to the piston 7a when a brake action demand is present. When a brake action demand is present, the seal 7b deforms as shown in FIG. 2. When the brake action demand is removed, the hydraulic pressure to the piston 7a is released. The seal 7b returns to the shape as shown in FIG. 1, thereby withdrawing the piston 7a and disengaging the brake pads 3 from the brake disc 6.

[0114] The brake actuator 7 is activated by a control signal 9a (e.g., an electrical or electronic control signal) sent by a control unit 9. The control signal 9a from the control unit 9 is triggered, for example, when the brake pedal is depressed by the driver or by an automated vehicle system (e.g., an autonomous driving system, etc.) or an automated vehicle safety system (e.g., a collision avoidance system, etc.).

[0115] The control unit 9 is - determining whether a braking action request exists; and - determining whether the vehicle is stationary; and - when the control unit 9 determines that a brake action request is present and when the control unit 9 determines that the vehicle is stationary, instructs the brake actuator 7 via a control signal 9a to reduce the braking force with which the brake pads 3 engage the brake disc 6.

[0116] A vehicle is stationary if it is not moving in the direction of travel over the ground surface as a result of the rotation of the vehicle's wheels and / or the sliding of the vehicle's wheels on the ground surface.

[0117] The brake actuator 7 is adapted to move the brake pads 3 towards the brake disc 6, pressing the brake pads 3 against the brake disc 6, as well as to move the brake pads 3 away from the brake disc 6 when the brake is released (i.e. when the brake action request is removed). The brake action request is removed, for example, when the driver releases the brake pedal or when the automated vehicle system that triggered the brake action request no longer maintains the brake action request.

[0118] The brake actuator 7 may alternatively be, for example, electrically or pneumatically actuated.

[0119] In the embodiment of Fig. 3, the braking device 31 further includes an electronic parking brake 32. The electronic parking brake 32 is configured to bring the brake pads 3 into contact with the brake disc 6 when the vehicle is stationary, thereby generating a braking force to keep the vehicle stationary. In this embodiment, the control unit 9 is further configured to instruct the electronic parking brake 32 to bring the brake pads 3 into contact with the brake disc 6 after instructing the brake actuator 7 to reduce the braking force with which the brake pads 3 engage the brake disc 6.

[0120] The brake pads 3 which may be brought into contact with the brake disc 6 may be brake pads 3 of a braking device 31 or may be dedicated parking brake pads.

[0121] The electronic parking brake 32 includes a parking brake actuator 32a, which in the embodiment of FIG. 3 is separate from the brake actuator 7 of the braking device 31. The parking brake actuator 32a is preferably an electric or electronic actuator, which includes, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator cooperating with the brake pedal, the parking brake actuator 32a does not need to be designed for the correct "pedal feel" (i.e. the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator 32a to be optimized to minimize or even eliminate the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake 32 is disengaged, the brake pads 3 can be retracted more tightly than if the braking device 31 itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of the electronic parking brake 32 allows the brake pads 3 to be retracted so that the risk of brake drag is minimised or even eliminated.

[0122] Further, the electronic parking brake 32 includes a parking brake controller 33 adapted to receive a parking brake activation signal 34 from the control unit 9 of the braking device 31, activating the electronic parking brake 32 and bringing the brake pads 3 into contact with the brake disc 6.

[0123] Fig. 4a shows a third embodiment of a braking device according to the invention, which detects whether an object is approaching the vehicle. In Fig. 4a, the vehicle 41 (which is stationary) is a passenger car, which comprises four wheels (in Fig. 4a only the left front wheel is visible) and a braking device, for example according to Fig. 1, Fig. 2 and / or Fig. 3. The braking device comprises the same number of brake pads and the same number of brake actuators as the number of wheels of the vehicle 41.

[0124] The control unit of the brake system - determining whether an object 42 is approaching the vehicle 41; - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake discs, instructing the brake actuator to restore the braking force to the requested braking force when the control unit determines (i.e. detects) that an object 42 is approaching the vehicle 41. The object 42 in Fig. 4a is another vehicle moving towards the vehicle 41 equipped with a braking device.

[0125] This adds a safety feature to the braking system: when the vehicle 41 is approached by an oncoming vehicle 42, it can cause the vehicle 41 to move from the position where it is stationary. The control unit of the braking system commands the brake actuators to restore the braking force to the requested braking force. In this way, undesired movement of the vehicle 41 is prevented.

[0126] Optionally, the control unit is configured to determine whether the vehicle 41 is located within a predicted trajectory of an approaching vehicle 42 determined to be an approaching vehicle, and is configured to instruct the brake actuator to restore the brake force to the requested brake force only when the control unit determines that the vehicle is located within or adjacent to the predicted trajectory.

[0127] Optionally, the braking equipment further comprises a camera, the camera being configured to capture a stream of pictures of the area around the vehicle. - further configured to analyze the stream of photos of the area around the vehicle to obtain a photo stream analysis result; - further configured to determine, based on the photo stream analysis result, whether an object is approaching the vehicle.

[0128] Optionally, the control unit is configured to determine a predicted trajectory of the object based on the photo stream analysis.

[0129] Optionally, as an alternative to or in addition to the camera, the braking device further includes a radar and / or a lidar, which is configured to detect a position and / or a speed and / or an acceleration of an object in an area around the vehicle. The control unit is further configured to determine whether an object is approaching the vehicle based on the position and / or a speed and / or an acceleration of the object in an area around the vehicle. Optionally, the control unit is configured to determine a predicted trajectory of the detected object based on input received by the control unit from the radar and / or the lidar.

[0130] Optionally, the braking device further includes an electronic parking brake configured to bring brake pads into contact with a brake disc when the vehicle is stationary, thereby generating a braking force to keep the vehicle stationary. In this variation, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc and after the control unit has determined that an object has approached the vehicle.

[0131] In a variant of this embodiment, the control unit of the braking device may alternatively - determining whether an object is approaching the vehicle; and - avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

[0132] Figure 4b shows a fourth embodiment of the braking device according to the invention, with the vehicle positioned on a sloped surface. In Figure 4b, the vehicle 41 (which is at rest on a sloped surface 43) is a passenger car, which comprises four wheels (only the left front wheel and the left rear wheel are visible in Figure 4b) and a braking device, for example according to Figures 1, 2 and / or 3. The braking device comprises the same number of brake pads and the same number of brake actuators as the number of wheels of the vehicle 41.

[0133] The control unit of the brake system - determining whether the vehicle 41 is located on a sloped surface 43; - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake discs, when the control unit determines that the vehicle 41 is located on a sloped surface 43, instructing the brake actuator to restore the braking force to the requested braking force.

[0134] This embodiment adds a safety feature to the braking system: because the vehicle 41 is on the sloped surface 43, there is a risk that the vehicle 41 may begin to move unintentionally when the braking force is reduced.

[0135] Optionally, in this embodiment the braking device further comprises an inclination sensor (see also FIG. 2 ), the inclination sensor configured to measure the inclination of the vehicle 41 relative to the horizontal, and the control unit configured to determine whether the vehicle is located on a sloped surface 43 based on the measurement value of the inclination sensor. Optionally, the control unit is configured to determine that the vehicle 41 is located on the sloped surface 43 if the measurement value of the inclination sensor is not substantially equal to 0°, and to determine that the vehicle is not located on a sloped surface if the measurement value of the inclination sensor is substantially equal to 0°.

[0136] In a variant of this embodiment, the control unit of the braking device comprises: - determining whether the vehicle is located on a sloped surface; - avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc.

[0137] Alternatively, in a further variation of this embodiment, the braking device further includes an electronic parking brake configured to bring brake pads into contact with a brake disc when the vehicle is stationary, thereby generating a braking force to keep the vehicle stationary. In this variation, the control unit is further configured to instruct the electronic parking brake to bring the brake pads into contact with the brake disc after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc and after the control unit determines that the vehicle is located on a sloped surface.

[0138] The brake pads which may be brought into contact with the brake disc may be brake pads of a braking device or dedicated parking brake pads.

[0139] Optionally, in the embodiment of FIG. 4b or in a variant thereof, the electronic parking brake includes a parking brake actuator, which is separate from the brake actuator of the braking device. The parking brake actuator is preferably an electric or electronic actuator, which includes, for example, an electric or electronic motor in combination with a spindle and / or a piston, or a linear actuator. In contrast to a brake actuator that cooperates with a brake pedal, the parking brake actuator does not need to be designed for the correct "pedal feel" (i.e., the feedback that the brake pedal gives to the driver). This allows the design of the parking brake actuator to be optimized to minimize or even eliminate the risk of brake dragging after disengagement of the parking brake. For example, when the electronic parking brake is disengaged, the brake pads can be retracted more tightly than if the braking device itself does it. Thus, in this embodiment, the risk of brake dragging is reduced, even if a braking force is present when the vehicle is stationary. The use of an electronic parking brake allows the brake pads to be retracted such that the risk of brake dragging is minimized or eliminated.

[0140] Optionally, in the embodiment of FIG. 4b or in a variation thereof, the electronic parking brake includes a parking brake controller adapted to receive a parking brake activation signal from a control unit of the braking equipment and activates the electronic parking brake configured to bring the brake pads into contact with the brake disc.

[0141] FIG. 5a shows a schematic diagram of a first embodiment of a flow diagram of a method according to the invention for adjusting the braking force exerted by the braking system of a vehicle.

[0142] The method according to the invention comprises a first step 51 of obtaining a braking action status indicating whether a braking action request is present.

[0143] The next step 52 in the method according to the invention is to obtain a stationary status indicating whether the vehicle is stationary.

[0144] In a further step 53 of the method according to the invention, when the brake action status indicates that a brake action request is present (step 51) and the stationary status indicates that the vehicle is stationary (step 52), the brake actuators of the brake equipment are instructed to reduce the braking force with which the brake pads of the brake equipment engage the brake discs of the vehicle.

[0145] When there is no brake action request (step 51) and / or the vehicle is not stationary (step 52), steps 51 and 52 of the flow diagram of FIG. 5a are executed again, creating a closed loop.

[0146] FIG. 5b illustrates diagrammatically a first embodiment of the flow diagram of the method according to the invention of FIG. 5a with an additional step for adjusting the braking force exerted by the vehicle's brake system.

[0147] The method according to the invention further includes the additional step 54 of instructing the brake actuator of the braking device to reduce the braking force with which the brake pads of the braking device engage the brake discs of the vehicle, followed by instructing the electronic parking brake to bring the brake pads into contact with the brake discs, thereby generating a braking force to keep the vehicle stationary.

[0148] FIG. 5c illustrates diagrammatically an embodiment of the flow diagram of the method according to the invention of FIG. 5b with an additional step for adjusting the braking force exerted by the vehicle's braking system.

[0149] The method according to the present invention further comprises the step 55 of obtaining a grade status indicating whether the vehicle is located on a graded surface.

[0150] The next step 56 in the method according to the present invention is to obtain an object approaching status, which indicates whether an object is approaching the vehicle.

[0151] In a further step 57 of the method according to the invention, after instructing the brake actuator of the braking device to reduce the braking force with which the brake pads of the braking device engage the brake discs of the vehicle, the brake actuator is instructed to restore the brake force to the requested brake force when the brake action status indicates that a brake action request is present and when the grade status indicates that the vehicle is located on a sloped surface and / or when the object approach status indicates that an object is approaching the vehicle.

[0152] As an alternative to this step 57, the method includes the step of avoiding instructing a brake actuator of the braking device to reduce the braking force with which the brake pads engage the brake discs when the brake action status indicates that a brake action request exists and when the grade status indicates that the vehicle is located on a sloped surface and / or when the object approach status indicates that an object is approaching the vehicle.

[0153] When it is determined that the vehicle is not located on a sloped surface (step 55) and that no objects are approaching the vehicle (step 56), steps 55 and 56 of the flow diagram of FIG. 5c are executed again to create a closed loop.

[0154] Optionally, this embodiment of the method further includes determining whether the vehicle is located within a predicted trajectory of an object determined to be approaching the vehicle, and instructing the brake actuator to restore the brake force to the requested brake force only when it is determined that the vehicle is located within or adjacent to the predicted trajectory.

[0155] FIG. 6 shows a schematic diagram of a second embodiment of a flow diagram of a method according to the invention for adjusting the braking force exerted by the braking system of a vehicle.

[0156] The second embodiment includes a first step 61 of obtaining a braking action status indicating whether a braking action request is present.

[0157] The next step 62 is to obtain a stationary status, which indicates whether the vehicle is stationary.

[0158] When there is no brake action request (step 61) and / or the vehicle is not stationary (step 62), steps 61 and 62 of the flow diagram of FIG. 6 are executed again, creating a closed loop.

[0159] The method further includes a step 63 of determining whether the vehicle is located on a sloped surface and / or a step 64 of determining whether an object is approaching the vehicle.

[0160] When it is determined that the vehicle is not located on a sloped surface (step 63) and that no object is approaching the vehicle (step 64), the brake actuator of the brake system is instructed to reduce the braking force with which the brake pads of the brake system engage the vehicle's brake discs (step 65).

[0161] When it is determined that the vehicle is located on a sloped surface (step 63) and / or an object is approaching the vehicle (step 64), the flow diagram of FIG. 6 is executed again from the beginning, creating a closed loop.

[0162] The embodiment of Figure 6 further includes the additional step 66 of instructing the brake actuator of the braking device to reduce the braking force with which the brake pads of the braking device engage the brake discs of the vehicle, followed by instructing the electronic parking brake to bring the brake pads into contact with the brake discs, thereby generating a braking force to keep the vehicle stationary. [Explanation of symbols]

[0163] 1 Brake device 2. Housing 3. Brake pads 4 Brake pad body 5 Brake pad holder 6 Brake discs 7 Brake Actuator 7a Piston 7b Seal 8 Hydraulic Control Unit 9. Control Unit 9a Control Signal 10 Brake action signal 11 Sensors 21 Vehicle speed signal 22 Speed ​​sensor 23 Tilt signal 24 Tilt Sensor 31 Brake device 32 Electronic Parking Brake 32a Parking brake actuator 33 Parking brake controller 34 Parking brake activation signal 41 Vehicles 42 Object 43 Beveled Surfaces F Arrow

Claims

1. 1. A braking device for a wheel of a vehicle, comprising: brake pads arranged to interact with a brake disc to generate a braking force when said brake pads engage said brake disc, said brake disc being associated with said wheel of said vehicle; a brake actuator adapted to move the brake pads towards the brake disc and bring them into contact with the brake disc, thereby generating a required braking force in response to a braking action request; a control unit, - determining whether a braking action request exists; - determining whether the vehicle is stationary; - when the control unit determines that a brake action request exists and the control unit determines that the vehicle is stationary, instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc; a control unit configured to: A braking device comprising:

2. The braking device of claim 1 , wherein the control unit is configured to instruct the brake actuator to remove the braking force.

3. The braking device further includes a brake pedal and a brake pedal pressure sensor. the brake pedal is adapted for use by a driver of the vehicle to generate a brake action request; the brake pedal pressure sensor is adapted to measure a pedal pressure exerted on the brake pedal by a driver; 3. A braking system according to claim 1 or 2, wherein the brake actuator is adapted to generate a demanded braking force having a predetermined relationship to the measured pedal pressure.

4. 3. The braking device according to claim 1, further comprising a speed sensor configured to measure a speed of the vehicle, and the control unit configured to determine whether the vehicle is stationary based on a measurement value of the speed sensor.

5. 5. The brake device according to claim 4, wherein the control unit is configured to determine that the vehicle is stationary if the result of the measurement of the speed sensor is equal to 0 m / s, and to determine that the vehicle is not stationary if the result of the measurement of the speed sensor is not equal to 0 m / s.

6. The braking device is an electronic parking brake, which is configured to bring brake pads into contact with the brake disc when the vehicle is stationary, thereby generating a braking force to keep the vehicle stationary; Furthermore, The control unit - instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, and then instructing the electronic parking brake to bring the brake pads into contact with the brake disc; 3. The brake device according to claim 1, further comprising:

7. 3. The brake system of claim 1, wherein the control unit is configured to monitor a speed of the vehicle after the control unit instructs the brake actuator to reduce the braking force with which the brake pads engage the brake discs, and to instruct the brake actuator to restore the braking force to the requested braking force when the control unit determines that the vehicle is not stationary.

8. The control unit - determining whether the vehicle is located on a sloped surface; - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, instructing the brake actuator to restore the braking force to the requested braking force when the control unit determines that the vehicle is on a sloped surface, or avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc when the control unit determines that the vehicle is located on a sloped surface; The braking device of claim 1 or 2, further configured to:

9. 9. The braking device of claim 8, further comprising an inclination sensor configured to measure an inclination of the vehicle relative to a horizontal direction, and the control unit configured to determine whether the vehicle is located on a sloped surface based on measurements of the inclination sensor.

10. 10. The braking apparatus of claim 9, wherein the control unit is configured to determine that the vehicle is located on a sloped surface if the measurement of the tilt sensor is not equal to 0°, and to determine that the vehicle is not located on a sloped surface if the measurement of the tilt sensor is equal to 0°.

11. The control unit determining whether an object is approaching said vehicle; - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, instructing the brake actuator to restore the braking force to the requested braking force when the control unit detects that an object is approaching the vehicle, or avoiding commanding the brake actuator to reduce the braking force with which the brake pads engage the brake disc when the control unit determines that an object is approaching the vehicle; The braking device of claim 1 or 2, further configured to:

12. The braking device further comprises a camera configured to capture a stream of photographs of an area around the vehicle, and the control unit - analyzing the stream of photos of the area around the vehicle to obtain a photo stream analysis result; - determining whether an object is approaching the vehicle based on the photo stream analysis results; The braking device of claim 11 , further configured to:

13. 12. The braking device of claim 11, further comprising a radar or lidar configured to detect a position, or a velocity, or an acceleration of an object in an area around the vehicle, and the control unit is further configured to determine whether an object is approaching the vehicle based on the position, or the velocity, or the acceleration of an object in the area around the vehicle.

14. The braking device is a plurality of brake pads, each brake pad arranged to interact with an associated brake disc to generate a braking force when said brake pad engages said associated brake disc, each brake disc being associated with a single wheel of said vehicle; a plurality of brake actuators, each brake actuator adapted to move a respective brake pad towards its associated brake disc and bring a respective said brake disc into contact with said associated brake disc, thereby generating a required braking force in response to a braking action request; Equipped with 3. The brake device of claim 1, wherein when the control unit determines that the brake action request exists and the control unit determines that the vehicle is stationary, the control unit is configured to instruct the brake actuator to reduce the braking force with which at least two brake pads of the plurality of brake pads engage their respective brake discs.

15. 15. The braking device of claim 14, wherein the control unit is configured to instruct all but one of the brake actuators to reduce or eliminate the respective braking force.

16. 15. The braking device of claim 14, wherein the control unit is configured to instruct the plurality of brake actuators to reduce the respective braking forces equally.

17. A vehicle, - at least one wheel; - a braking device according to claim 14; Equipped with A vehicle, wherein the braking device comprises the same number of brake pads and brake actuators as the number of wheels of the vehicle.

18. 1. A method for modulating the braking force exerted by a braking system of a vehicle, the method comprising: - obtaining a brake action status indicating whether a brake action request exists; - obtaining a stationary status indicating whether the vehicle is stationary; - when the brake action status indicates that a brake action request exists and the stationary status indicates that the vehicle is stationary, instructing a brake actuator of the brake device to reduce the braking force with which brake pads of the brake device engage brake discs of the vehicle; A method comprising:

19. - after instructing a brake actuator of the brake device to reduce the braking force with which the brake pads of the brake device engage the brake discs of the vehicle, instructing the brake actuator to restore the braking force to the requested braking force when the brake action status indicates that a brake action request exists and the stationary status indicates that the vehicle is not stationary; 20. The method of claim 18, further comprising:

20. - after instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc, if the vehicle is stationary, instructing an electronic parking brake to bring the brake pads into contact with the brake disc, thereby generating a braking force to keep the vehicle stationary; 20. The method of claim 18 or 19, further comprising:

21. - obtaining a gradient status indicating whether the vehicle is located on a gradient surface; - after instructing a brake actuator of the brake device to reduce the braking force with which the brake pads of the brake device engage the brake discs of the vehicle, instructing the brake actuator to restore the braking force to the requested braking force when the brake action status indicates that a brake action request exists and the grade status indicates that the vehicle is located on a graded surface, or avoiding instructing the brake actuator to reduce the braking force with which the brake pads engage the brake disc when the brake action status indicates that a brake action request exists and the grade status indicates that the vehicle is located on a sloped surface; 20. The method of claim 18 or 19, further comprising:

22. - obtaining an object approach status indicating whether an object is approaching said vehicle; - after instructing a brake actuator of the brake device to reduce the braking force with which the brake pads of the brake device engage the brake discs of the vehicle, instructing the brake device to engage the brake actuator with the requested braking force when the brake action status indicates that a brake action request exists and the object approach status indicates that an object is approaching the vehicle, or - avoiding instructing the brake actuator to reduce the braking force with which the brake pads engage the brake discs when the brake action status indicates that a brake action request exists and the object approach status indicates that an object is approaching the vehicle; 20. The method of claim 18 or 19, further comprising:

23. A computer program comprising instructions which, when said program is executed by a computer, cause said computer to carry out the method of claim 18 or 19.

Images