A system for controlling a brake device capable of performing parking brake and immobilization brake functions.

Abstract

The present invention relates to a control system (14) for controlling a brake device (16) capable of performing a parking brake function, characterized in that the control system (14) is configured to send a parking brake command to the brake device (16) which is essentially to apply a first predetermined force that enables the vehicle (10) to be kept stationary regardless of the vehicle's current state, and the control system (14) is configured to send a parking brake command to the brake device (16) which is essentially to apply a second clamping force that is smaller than the first magnitude but large enough to keep the vehicle (10) stationary.

Description

Technical Field

[0001] The present invention relates to a system for controlling at least one automotive brake device that enables the implementation of additional operations to keep a vehicle in a stationary state.

Background Art

[0002] An automobile has a brake device of the disc brake or drum brake type on each of its wheels, and the brake device includes a piston intended to move a brake pad and apply the brake pad against a disc or drum.

[0003] The piston is driven to move by an electromechanical system that is itself controlled by a brake control system (parking brake controller).

[0004] When an automobile stops, according to a known operating mode, the control system implements the parking brake function. The parking brake function essentially consists of controlling the electromechanical system in order to apply, via the piston, a braking force that is large enough to keep the vehicle in a stationary state regardless of the state of the vehicle.

[0005] This braking force is generally defined to enable the vehicle to remain stationary when the vehicle stops on an inclined ground with a large downward slope.

[0006] This braking mode is particularly suitable for parking a vehicle without a driver, in which case, in case of a brake failure, no one can intervene.

[0007] However, when the vehicle stops, for example, when stopping at a traffic signal, the implementation of the parking brake function results in applying an unnecessarily large braking force.

[0008] In addition, due to the large braking force, the implementation of the parking brake function involves significant mechanical stress on the components of the brake device, as well as a correspondingly large application time. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The objective of this invention is to propose a control system that can implement an additional immobile braking function. [Means for solving the problem]

[0010] The present invention relates to a system for controlling at least one brake device for an automobile capable of performing a parking brake function, wherein the brake device comprises, in particular, a piston capable of generating a force for clamping a disc or a disc brake caliper, and an electrical means for driving the piston to generate the clamping force, The control system is configured to send a parking brake command to at least one brake device, which essentially involves applying a first predetermined clamping force via a piston that can keep the vehicle stationary regardless of the vehicle's current state. The control system is configured to send a stationary brake command to at least one brake device, which essentially involves applying a clamping force via a piston having a second size that is smaller than a first size but large enough to keep the vehicle stationary.

[0011] Preferably, the control system is - The presence of the vehicle driver is detected. - The slope of the ground on which the vehicle is placed must be less than a predetermined value. - The vehicle comes to a stop. The system is configured to send a non-moving brake command to the at least one brake device when at least one of the operating conditions is met.

[0012] Preferably, the control system is configured to send a non-moving brake command to the at least one brake device when an operating condition is met in which the force of the pressure applied to the vehicle's brake pedal is greater than a predetermined threshold.

[0013] Preferably, the presence of a driver is - Detection of the brake, accelerator, and / or clutch pedal being pressed. - Detection of seat belt fastening, - Detection of load on the driver's seat when the car engine is running. It is detected by [this method].

[0014] Preferably, the control system is configured to send a parking brake command to the at least one brake device when at least one of the operating conditions is not met.

[0015] Preferably, the control system is configured to send either a parking brake command or a lock brake command, or the other, to the at least one brake device after the trigger condition is met.

[0016] Preferably, the trigger condition consists of pressing the vehicle's parking brake button or the vehicle's driver pressing the brake pedal with a force greater than a predetermined threshold.

[0017] The present invention also relates to an automobile comprising several wheels, several brake devices, and a control system according to the present invention, wherein each of the several brake devices is associated with a wheel, and the control system is capable of controlling at least one brake device for performing a parking brake function and a stationary brake function.

[0018] Preferably, the vehicle has four wheels, and the braking devices associated with two or four wheels of the vehicle can be controlled by a control system for implementing the parking brake function and the immobilization brake function.

[0019] The present invention also relates to a method of operating a control system according to the present invention for implementing a parking brake function or an immobilization brake function, the method comprising: - an initial step in which neither the parking brake function nor the immobilization brake function is implemented; - a step of verifying a condition for triggering or not triggering the implementation of the parking brake function or the immobilization brake function; - at least one step of verifying at least one operating condition when the trigger condition is verified; - a step of implementing the parking brake function or the immobilization brake function according to whether the at least one operating condition is satisfied or not satisfied. and including.

[0020] Preferably, when the trigger condition is satisfied, the at least one step of verifying at least one operating condition is performed.

[0021] Preferably, when at least one of the at least one operating conditions is not satisfied, the parking brake function is implemented.

[0022] Preferably, when all of the operating conditions are satisfied, the immobilization brake function is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] [Figure 1] It is a schematic view of an automobile provided with a system for controlling a braking device associated with each wheel of the vehicle. [Figure 2]This diagram shows the relationship between the current supplied to the brake device and the braking force applied by this brake device during the period the parking brake function is active. [Figure 3] This diagram, similar to that in Figure 2, shows the relationship between the current supplied to the brake device and the braking force applied by this brake device during the period in which the immobile brake function is in operation. [Figure 4] This is a flowchart illustrating the operation method of the control system 14. [Modes for carrying out the invention]

[0024] Figure 1 shows a vehicle 10, which is an automobile. It should be understood that the present invention is not limited to control systems for automobiles, and that the present invention can also relate to other vehicles, such as motorcycles.

[0025] Here, the vehicle 10 comprises four wheels 12, a plurality of brake devices 16, each of which is associated with one of the wheels 12, and a system 14 for controlling the brake devices 16.

[0026] Each brake device 16 consists of a disc brake or drum brake type brake and includes a piston that is driven by the motion of an electromechanical actuator under the control of the control system 14 to generate braking force.

[0027] For example, at least some or four of the brake devices 16, such as the brake devices 16 associated with the two rear wheels 12, can perform a parking brake function.

[0028] The following description refers to the braking force applied by the piston of a single brake device. This embodiment is applicable when only one of the brake devices 16 of the vehicle 10 is capable of performing the parking brake function.

[0029] This example can be extrapolated to the braking force applied by several brake devices 16. In this case, the value of the braking force described must be divided by the number of brake devices 16 performing the function in question in order to obtain the value of the braking force that each brake device 16 must apply.

[0030] The essence of this parking brake function is to generate a braking force via the piston of the brake device 16, and the magnitude of this braking force is large enough to keep the vehicle stationary regardless of the state of the vehicle, in other words, especially when the vehicle's engine is not running, when the driver is not in the driver's seat, when the parking brake command is issued, or when a significant downward slope is measured on the ground on which the vehicle is placed.

[0031] In this way, the control system 14 is configured to send a command to the brake device 16 to perform the parking brake function in order to apply the braking force specified above, according to the operating conditions.

[0032] The control system 14 is also configured to send a command to the brake device 16 to perform an additional immobile braking function, which essentially involves applying a clamping force via a piston having a second magnitude that is smaller than a first magnitude but large enough to keep the vehicle stationary under certain operating conditions of the vehicle.

[0033] Trigger conditions The trigger conditions are defined as the conditions that must be met for the control system 14 to be activated in order to perform either the parking brake function or the immobile brake function, or the other.

[0034] When one of these trigger conditions is met, the control system 14 performs an operation condition verification, and depending on whether the operation condition is met or not, the control system 14 performs either the parking brake function or the immobile brake function.

[0035] As an example of a non-limiting scenario, the trigger condition may consist of the vehicle's parking brake button being pressed, or the driver pressing the brake pedal with a force greater than a predetermined threshold.

[0036] Operating conditions The immobile braking function is preferably implemented when the vehicle is in a certain state where it does not require the application of all the braking force associated with the parking brake function.

[0037] Therefore, the control system is configured to detect certain operating conditions of the vehicle, and when those conditions are met, it sends a command to perform the immobile brake function rather than a command to perform the parking brake function.

[0038] Because the braking force applied by the piston is smaller when the immobile brake function is activated, this braking force may not be sufficient to keep the vehicle 10 stationary at all times.

[0039] Therefore, the operating conditions of vehicle 10 under which the immobile brake function is implemented are such that a certain level of safety for vehicle 10 can be guaranteed.

[0040] The first operating condition is the presence of a driver for vehicle 10.

[0041] In practice, if the application of the immobile braking function fails or becomes insufficient to keep the vehicle 10 stationary when a driver is present, the driver can intervene quickly.

[0042] Non-limited examples of means by which the presence of a driver can be verified include inspecting the seat belt buckle associated with the driver's seat, the fact that the engine of vehicle 10 is running, whether the brake pedal or accelerator pedal of vehicle 10 is pressed, or detecting a load on the driver's seat.

[0043] Another operating condition is that vehicle 10 is stopped. This condition is verified by the speedometer of vehicle 10.

[0044] In an unrestricted manner, vehicle 10 is considered to have stopped if the speed measured by the speedometer is less than or equal to a value predetermined and calibrated by the vehicle manufacturer. For example, the predetermined speed value is 3 km / h.

[0045] Another operating condition is that the engine of vehicle 10 is running.

[0046] This operating condition makes it possible to distinguish whether vehicle 10 can be parked and therefore immobile for a long period of time, or whether vehicle 10 can be parked for a short time and therefore may be moved again soon.

[0047] Another operating condition is that the driver is pressing the vehicle's brake pedal. This condition is preferably met when the force value is greater than a predetermined threshold.

[0048] Another operating condition is the slope of the ground on which the vehicle is placed. Preferably, the immobile braking function can be performed when the slope of the ground is less than a value predetermined and calibrated by the vehicle manufacturer. For example, the predetermined value of the slope is 10%.

[0049] For example, in the context of adaptive cruise control (ACC) type autonomous driving functions, braking can be triggered based on data provided by a single sensor, such as an optical sensor, proximity sensor, or radar.

[0050] Numerical examples As an unspecified example, in a brake device 16 consisting of a disc brake, the implementation of the parking brake function is essentially done by applying a disc clamping force of 14,500 N via a piston for a vehicle weighing approximately 2,500 kg. Furthermore, the time required for the actuator to reach this clamping force is approximately 0.99 seconds, and the time required for the actuator to release this clamping force is approximately 1.04 seconds, which consumes a total of 57.01 joules of energy.

[0051] As an unspecified example, in a brake device 16 consisting of a disc brake, the implementation of the immobile braking function is essentially done by applying a disc clamping force of 9500 N via a piston for a vehicle weighing approximately 2500 kg. Furthermore, the time required for the actuator to reach this clamping force is approximately 0.82 seconds, and the time required for the actuator to release this clamping force is approximately 0.87 seconds, which consumes a total of 33.05 joules of energy.

[0052] Comparison of Figures Figures 2 and 3 show curves representing the change in clamping force applied by the piston as a function of the current emitted when the control system 14 performs either the parking brake function (Figure 2) or the immobile brake function (Figure 3).

[0053] In Figures 2 and 3, the first curve 20 shows the change in current, and the second curve 22 shows the change in braking force applied by the piston of the brake device 16.

[0054] In Figure 1, the first curve 20 includes a peak 24 corresponding to the discharge by the control system 14 to the extent that it performs the parking brake function. Immediately after this peak 24, the current drops sharply and reaches a lower value.

[0055] The first curve 20 includes a straight section 26 corresponding to a phase where the current value remains nearly constant and is equal to a lower value.

[0056] The first curve 20 includes an increasing section 28 corresponding to the power supply to the brake device 16 for gradually increasing the braking force applied by the piston. The end of the increasing section corresponds to the time it takes to reach the required braking force.

[0057] Following this increasing section is an ending section 30 where the current value becomes zero, which is the end of the power supply to the brake device 16 for maintaining the braking force by the piston.

[0058] The second curve 22 corresponds to the braking force applied by the brake device 16. The second curve 22 includes a first flat section 32 where the braking force is zero. This first flat section 32 is related to the peak 24 and straight section 26 of the first curve 20 and corresponds to the time period during which the brake device 16 performs its function of compensating for the play between the various elements of the brake device 16. Therefore, the value of the current supplying power to the brake device 16 is non-zero, but not large enough for the brake device to generate a braking force.

[0059] The second curve 22 includes a second increasing section 34 corresponding to a gradual increase in braking force. This second increasing section 34 corresponds to the increasing section 28 of the first curve 20, and therefore corresponds to the period during which the brake device 16 is sufficiently powered to generate braking force by the piston.

[0060] The second curve 22 includes a final section 36 corresponding to the force required to maintain braking when the braking device is no longer powered.

[0061] Figure 2 shows the first upper line 38 corresponding to the value of the clamping force applied by the brake device 16 at the end of the parking brake function, and this value is defined above.

[0062] Figure 3 shows a second upper line 41 corresponding to the value of the clamping force applied by the brake device 16 at the end of the execution of the immobile braking function, and this value is defined above.

[0063] Finally, Figures 2 and 3 each show a second line 40 corresponding to the minimum clamping force that must be applied by the brake device 16 to maintain the vehicle after the immobile braking function has been performed, the value of which is defined above.

[0064] As can be seen in Figure 2, the magnitude of the clamping force is greater during the period when the parking brake function is in operation than during the period when the immobile brake function is in operation.

[0065] Therefore, as can be seen in Figure 2, the difference 42 between the magnitude of the clamping force during the period the parking brake function is in operation (line 38) and the value of the force that enables the vehicle to be maintained indicates the excess force applied by the brake device 16 during the period the parking brake function is in operation, while the operating conditions of the vehicle 10 correspond to those of the immobile brake function.

[0066] Similarly, Figure 3 shows the difference between the magnitude of the clamping force (line 41) during the period in which the immobile brake function is in operation and the value of the force that allows the vehicle to be held in place.

[0067] Comparing the two figures, it is clear that the excess force applied by the brake device 16 during the period when the immobile brake function is in operation is significantly smaller than the excess force applied by the brake device 16 during the period when the parking brake function is in operation.

[0068] Furthermore, comparing the two figures, it is clear that the endpoint of the increasing section 28 of the first curve 20 occurs earlier when the immobile brake function is applied compared to when the parking brake function is applied.

[0069] How it works Figure 4 is a flowchart illustrating how the control system 14 operates to determine whether to perform the parking brake function or the immobilization brake function.

[0070] In the first initial step 44, the brake device 16 is released. In other words, no braking force is applied by the brake device 16.

[0071] In the second step, step 46, the trigger conditions are checked.

[0072] If the trigger condition is not met, the control system 14 returns to the first step 44, as seen by branch 48.

[0073] If the trigger condition is met, the control system 14 considers whether the vehicle must be kept stationary for a long period of time, as can be seen by branch 50.

[0074] In the third step 52, the control system 14 verifies whether the first operating condition is met.

[0075] If the first operating condition is not met, this third step 52 is followed by step 56, which performs the parking brake function, as can be seen in branch 54.

[0076] If the first operating condition is met, another step 62 is performed to verify the second operating condition, as seen by branch 58.

[0077] If the second operating condition is not met, step 56 is performed, which involves performing the parking brake function, similar to step 52, which verifies whether the first operating condition is met, as seen by branch 64.

[0078] If the second operating condition is met, step 68 is performed to implement the immobile brake function, as seen in branch 66.

[0079] A flowchart can be understood as containing a different number of steps that verify a series of operating conditions. The number of these steps that verify the operating conditions corresponds to the number of operating conditions that must be met.

[0080] In this method, it is understood that step 56, which performs the parking brake function, is performed if at least one operating condition is not met. Conversely, if all of the target operating conditions are met, the immobile brake function is performed.

[0081] advantage Because the force applied by the piston during the period of non-operational braking is smaller than that during the period of parking brake operation, the stress on the components of the brake device is reduced, thereby improving the lifespan of the brake device.

[0082] This immobile braking function is more advantageous when the vehicle is in motion and temporarily stops, for example, during a stop at a traffic light.

[0083] It is also understood that this immobile braking function can be implemented faster while consuming less energy.

[0084] Because the braking force applied by the brake device 16 is smaller, disengagement is also faster. In other words, the immobile brake function can deactivate faster than the parking brake function, which adds responsiveness to the vehicle when it comes to a stop in traffic. [Explanation of symbols]

[0085] 10 vehicles 12 wheels 14 Control Systems 16 Brake devices 20 The first curve 22 The second curve 24 Peak 26. Straight section 28 Increased interval 30 End section 32. The first flat section 34. Second Increased Section 36 Final section 38. First upper siding 40. Second line 41. Second upper siding 42 Difference in values 44 steps 46 steps 48 branches 50 branches 52 steps 54 Branches 56 steps 58 Branches 62 steps 64 branches 66 Branches 68 steps

Claims

1. A system (14) for controlling at least one brake device (16) for an automobile (10) capable of performing a parking brake function, wherein the brake device (16) comprises, in particular, a piston capable of generating a force for clamping a disc or a disc brake caliper, and an electrical means for driving the piston to generate the clamping force, The control system (14) is configured to send a parking brake command to the at least one brake device (16) which essentially involves applying a first predetermined clamping force via the piston that can keep the vehicle (10) stationary regardless of the state of the vehicle (10), The system (14) is configured to send a stationary brake command to the at least one brake device (16) which essentially involves applying a clamping force via the piston having a second size that is smaller than the first predetermined size but large enough to keep the automobile (10) stationary.

2. The presence of the driver of the aforementioned automobile (10) is detected. The slope of the ground on which the aforementioned automobile (10) is placed is less than a predetermined value. The aforementioned automobile (10) is stopped. The control system (14) according to claim 1, characterized in that it is configured to send the immobile brake command to the at least one brake device (16) when all of the operating conditions are met.

3. The control system (14) according to claim 2, characterized in that it is configured to send the immobile brake command to the at least one brake device (16) when the operating condition is also met that the force of the pressure applied to the brake pedal of the automobile (10) is greater than a predetermined threshold.

4. The aforementioned presence of the driver, Detection of the brake, accelerator, and / or clutch pedal being pressed. Seat belt fastening detection, Detection of load on the driver's seat when the engine of the aforementioned automobile (10) is operating. The control system (14) according to claim 2, characterized in that it is detected by

5. The control system (14) according to any one of claims 2 to 4, characterized in that it is configured to send the parking brake command to the at least one brake device (16) when at least one of the above operating conditions is not met.

6. A control system (14) according to any one of claims 1 to 5, characterized in that it is configured to send one or the other of the parking brake command or the immobile brake command to the at least one brake device (16) after a trigger condition is met.

7. The control system (14) according to claim 6, characterized in that the trigger condition is the pressing of the parking brake button of the automobile (10), or the driver of the automobile (10) pressing the brake pedal with a force greater than a predetermined threshold.

8. An automobile (10) comprising several wheels (12), several brake devices, and a control system (14) according to any one of claims 1 to 7, wherein each brake device (16) of the several brake devices is associated with a wheel (12), and the control system (14) is capable of controlling at least one brake device (16) for performing a parking brake function and a stationary brake function.

9. The automobile (10) according to claim 8, characterized in that the automobile (10) comprises four wheels (12), and the brake devices associated with two or four wheels (12) of the automobile (10) can be controlled by the control system (14) for performing a parking brake function and a stationary brake function.

10. A method for operating the control system (14) according to any one of claims 1 to 7 for implementing the parking brake function or the immobile brake function, An initial step in which neither the parking brake function nor the immobile brake function is performed, A step of verifying the conditions for triggering or not triggering the parking brake function or the immobile brake function, At least one step of verifying at least one operating condition when the trigger condition is met, The steps include performing the parking brake function or the immobile brake function depending on whether or not the at least one of the aforementioned operating conditions is met, The method of operation, including the method of operation.

11. The method according to claim 10, characterized in that the parking brake function is performed if at least one of the above at least one operating conditions is not met.

12. The method according to claim 10 or 11, characterized in that the immobile brake function is performed when all of the above operating conditions are met.

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