Method for avoiding creaking noises during steering movements of a stationary and braked motor vehicle and a motor vehicle

Abstract

The invention relates to a method (100) for preventing creaking noises during steering movements of a stationary and braked motor vehicle (10). The invention further relates to a motor vehicle (10) having a front axle (20), a rear axle (30), and a braking system (40) for implementing such a method (100).

Description

[0001] The invention relates to a method for preventing creaking noises during steering movements of a stationary and braked motor vehicle. The invention further relates to a motor vehicle.

[0002] It is generally known that when a motor vehicle brake is applied, noises occur that are perceived as unpleasant and disturbing to the human ear.

[0003] The occurrence of such noises is based on the so-called stick-slip effect, which describes the jerky sliding of solid bodies moving against each other. This effect occurs particularly when static friction is greater than sliding friction. Damped-coupled surface components perform a rapid sequence of movements consisting of tension, separation, adhesion, and alignment. Depending on the tribological system, this excites vibrations that are radiated as noise from a surface capable of resonance.

[0004] Depending on the cause of the noise, different efforts are made to reduce such noise. Various methods are known from the state of the art to reduce the disturbing noise associated with the actuation of a braking system.

[0005] For example, US 2017 / 0057481 A1 discloses a method for reducing braking noise in a hydraulic vehicle braking system. The method determines whether a motor vehicle is operating in a condition in which braking noise may occur. This condition occurs when the driver suddenly brakes the motor vehicle from a higher speed to a lower speed. During the braking process of the motor vehicle, a pressure-generating device activates certain valves to control the pressure in the brake calipers, thereby reducing braking noise.

[0006] A disadvantage of the methods known from the prior art is that they are limited to reducing braking noise that has already occurred during a deceleration maneuver of a motor vehicle at increased speed, and not to preventing braking noise itself. Solutions for preventing noise, especially creaking noises, during steering movements of a stationary and braked motor vehicle are currently unknown.

[0007] Creaking noises during steering movements while a vehicle is stationary and braked are currently almost unavoidable, as a steering movement while stationary always also triggers a rotational movement of the wheels. If this rotational movement impacts a braked axle, creaking noises often occur due to stick-slip effects. Especially when the vehicle's auto-hold function is activated, such creaking noises while stationary are almost unavoidable and not necessarily understandable for the non-technical customer. Since the reaction torques of the wheels must also be supported, suspension movements are also introduced into the body, which are avoidable.

[0008] Based on this problem, the object of the invention is to create an improved and responsive method for preventing creaking noises in motor vehicles, avoiding the disadvantages of the prior art and advantageously developing the latter. In particular, a method is to be provided that enables the automatic prevention of creaking noises during steering movements of a stationary and braked motor vehicle, thereby improving driving comfort.

[0009] Furthermore, it is an object of the invention to provide a motor vehicle.

[0010] According to the invention, this object is achieved by a method according to patent claim 1. With regard to the motor vehicle, the object is achieved by the subject matter of patent claim 11. Further features, advantages, and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the motor vehicle according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0011] Specifically, the object is achieved according to a first aspect of the invention by a method for preventing creaking noises during steering movements of a stationary and braked motor vehicle. The motor vehicle has a front axle, a rear axle, and a braking system. The braking system has - a first front wheel brake for decelerating and blocking a first steerable front wheel of the motor vehicle, - a second front wheel brake for decelerating and blocking a second steerable front wheel of the motor vehicle, - a first rear wheel brake for decelerating and blocking a first rear wheel of the motor vehicle, - a second rear wheel brake for decelerating and blocking a second rear wheel of the motor vehicle, - a control unit for detecting a brake force distribution in the braking system of the motor vehicle, and - a control unit for regulating the brake force distribution in the braking system of the motor vehicle.

[0012] The procedure includes the following steps: - Detection of a stationary state of the motor vehicle, - Detection of a braked state of the motor vehicle, in particular a brake force distribution in the braking system of the motor vehicle, - Detection of a blockage of the first front wheel brake and the second front wheel brake, - when detecting the blocking of the first front wheel brake and the second front wheel brake, detecting at least one steering parameter that allows a conclusion to be drawn about a steering movement of the motor vehicle, and / or detecting at least one desired steering parameter that allows a conclusion to be drawn about an impending steering movement of the motor vehicle, - Evaluation of the recorded steering parameter and / or the recorded desired steering parameter to detect the steering movement or the impending steering movement of the motor vehicle, - upon detection of the steering movement or the impending steering movement of the motor vehicle, detection of a blockage of the first rear wheel brake and the second rear wheel brake, whereby - if a blockage of the first rear wheel brake and the second rear wheel brake is detected, the blockage of the first front wheel brake and the second front wheel brake is released and - if a non-blocking of the first rear wheel brake and the second rear wheel brake is detected, the first rear wheel brake and the second rear wheel brake are blocked and the blocking of the first front wheel brake and the second front wheel brake is released, in particular a distribution of the braking forces of the first front wheel brake and the second front wheel brake to the first rear wheel brake (43 L) and the second rear wheel brake is carried out.

[0013] The method according to the invention has the advantage that creaking noises in a motor vehicle can be prevented before they occur. As soon as a steering movement or an impending steering movement of a stationary and braked motor vehicle is detected, a signal is transmitted to a control unit of the motor vehicle's braking system in order to distribute the braking forces accordingly within the braking system, so that noise development can be prevented prematurely by distributing the braking forces. This means that, preferably, the method can distribute the braking force immediately after a slight steering movement is detected, i.e., before any creaking noises can even occur.

[0014] In other words, during a phase in which the driver intends or performs a steering movement, the braking forces acting in the braking system are automatically varied or distributed to prevent squealing. The distribution of the braking forces is to be carried out by a control unit that, for example, controls an electric motor or a valve. The automatic brake force distribution can be specifically defined. The automatic brake force distribution can be triggered by a trigger signal, such as a steering parameter or a desired steering parameter.

[0015] The noise only occurs in certain brake pressure ranges, i.e., not across the entire applicable brake pressure range. The brake pressure depends, among other things, on the brake force distribution in the brake system. The greatest noise development or the loudest creaking noises occur during steering movements when the front axle is locked or during steering movements while the steerable front wheels of the motor vehicle are locked. Therefore, when the at least one steering parameter or the at least one desired steering parameter is detected, a steering movement of the first steerable front wheel and the second steerable front wheel is preferably suppressed until the lock of the first front wheel brake and the second front wheel brake is released. After the lock of the first front wheel brake and the second front wheel brake has been released or after the braking forces have been distributed, the steering movement can be released again automatically.

[0016] The core idea of ​​the invention is to prevent creaking noises, especially when the motor vehicle is stationary and braked. The stationary and braked state of the motor vehicle occurs repeatedly, particularly in driving situations such as start-and-stop operation in traffic jams, turning at intersections, parking, reversing, or driving below walking speed, especially when controlled by adaptive cruise control.

[0017] The stationary state of the motor vehicle can be detected via the rotation of the front wheels and / or the rear wheels of the motor vehicle. The stationary state of the motor vehicle is preferably detected via the wheel speed, in particular via the wheel circumferential speed. The detection and evaluation are preferably carried out on a wheel-related basis, i.e. for each wheel individually. The stationary and braked state of the motor vehicle can also be detected via the speed measuring unit of the motor vehicle. The stationary and braked state of the motor vehicle can furthermore be detected via a signal from the auto-hold function of the motor vehicle. To detect reversing, for example, a sensor can be provided which senses the engagement of a reverse gear.

[0018] The braked state of the motor vehicle can preferably be detected via at least one wheel brake pressure force. In the braked state of the motor vehicle, the brake force distribution in the braking system of the motor vehicle is particularly detected. It is conceivable that the braked state of the motor vehicle is brought about by one, several, or all wheel brakes simultaneously, in pairs or diagonally.

[0019] To avoid, and especially prevent, creaking noises, it is extremely important to detect the locked state of the front axle or the locking of the steerable front wheels of the vehicle in a timely manner, especially before an impending steering movement, since a steering movement in a locked state already leads to creaking noises. The locked state of the front axle occurs when the first front wheel brake and the second front wheel brake of the braking system lock. This locked state occurs even at very low incremental brake pressures and is preferably detected via a wheel brake pressure force.

[0020] It has been shown that even incremental brake pressures, in particular incremental movements of the steerable front wheels of the motor vehicle, lead to noise generation when the vehicle is locked due to suspension movements in the body. Such noises have a fundamental frequency of less than 20 Hz, below the human hearing threshold, and are initially inaudible to the driver in the vehicle interior, but can be detected by sensors. It is therefore conceivable that the incremental values ​​in the locked state could also be recorded electroacously via one or more microphones, or vibration-acoustically via frequency-selective vibration sensors or pressure sensors with phase shift detection. For example, each wheel brake of the braking system could be assigned a vibration sensor in order to record incremental vibrations and the resulting noise.As soon as the vibrations exceed a threshold frequency of, for example, 1 Hz, the control unit activates an electric motor or a valve, depending on the braking system used. This allows even creaking noises that have already developed to be measured and eliminated through modulation, i.e., by pulsating and briefly increasing and / or decreasing the contact pressure of the brake pads on one or more wheel brakes. It is conceivable that pressure modulation could also be implemented for vibrations with a fundamental frequency greater than 20 Hz in order to reduce or eliminate the audible noise associated with the vibrations.

[0021] The method according to the invention is suitable for electrohydraulic, electromechanical, or hybrid braking systems. The method according to the invention is suitable for driver-assisted or autonomous vehicle guidance.

[0022] To prevent the vehicle from rolling, depending on the type of braking system used, it may be advantageous to distribute the braking forces in the braking system either axle-specifically or selectively wheel-specifically. For example, with an electromechanical braking system, it is possible to simply cancel the braking forces on the front wheel brakes during a steering movement or an imminent steering movement, preventing the vehicle from rolling via the braking force on the rear axle or rear wheel brakes. With a hydraulic braking system, for example, the inlet valves on the front axle can be closed and the outlet valves opened.

[0023] Preferably, the braking forces in the braking system are distributed axle-specifically or selectively wheel-specifically in such a way that the overall system brake pressure remains constant. This can be particularly advantageous when the vehicle requires increased braking force due to weather or road conditions. For example, when the vehicle is on an inclined surface such as a mountain slope or at the exit of an underground parking garage on black ice. The constant overall system brake pressure in the braking system prevents the vehicle from rolling backward or forward without having to activate the vehicle's Auto-Hold function.

[0024] Preferably, the braking forces in the braking system are distributed axle-wise or selectively wheel-wise in such a way that the overall system brake pressure is reduced. This can be particularly the case when a lower overall system brake pressure, in particular the braking force on the rear axle or the rear wheel brakes, is sufficient on its own to prevent the vehicle from rolling, for example, when turning at intersections. This can reduce wear on the wheel brakes.

[0025] Preferably, the at least one steering parameter is detected by measuring a steering force or a steering angle. The measurement can be performed, for example, via an interface of the motor vehicle's electronic power steering system. Typically, an electronic power steering system includes an electric motor equipped with a reduction gear that exerts an assisting torque on the vehicle's steering mechanism, namely the steering column or steering rack. The intensity of the torque applied to the steering mechanism and the steering wheel or steering angle can be detected via the electronic power steering system.

[0026] Preferably, the at least one desired steering parameter is detected by determining the location of the motor vehicle, in particular via the vehicle's GPS data in conjunction with previously stored historical data, and / or by activating a turn signal of the vehicle and / or by determining the viewing direction of a driver of the vehicle using a camera. The basic idea of ​​the invention is to preventively avoid creaking noises when the vehicle is stationary and braked. i.e., to prevent the noise from occurring in the first place. Modern motor vehicles have a variety of driver assistance systems to enable safe driver-assisted or autonomous vehicle control. For example, it is possible to predict an impending steering movement using a combination of several driver assistance systems. With the help of updated and data processing-supported traffic route network maps, which contain driver-specific route data and associated attribute data, such as location data for home and work parking spaces, route information for the commute, etc., recurring driving behavior or an impending steering movement can be predicted when the indicator is activated and / or by determining the driver's line of sight. This means that in the event of an impending steering movement when the vehicle is stationary and braked, the front axle can be unlocked or locked.a predetermined distribution of braking forces is carried out.

[0027] According to a second aspect of the invention, a motor vehicle with a front axle, a rear axle, and a braking system for implementing such a method is presented. Advantages described in detail for the method for preventing creaking noises during steering movements of a stationary and braked motor vehicle according to the first aspect of the invention equally apply to the motor vehicle according to the second aspect of the invention.

[0028] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0029] The invention is explained in more detail below with reference to the accompanying drawings.

[0030] The diagrams show: Fig. 1 shows a braking system of a motor vehicle according to an embodiment of the present invention; Fig. 2 shows a change in the brake distribution in the braking system of the motor vehicle upon detection of a steering movement in the stationary and braked state of the motor vehicle according to an embodiment of the present invention; and Fig. 3 is a block diagram illustrating the method steps for avoiding creaking noises during steering movements of a stationary and braked motor vehicle according to an embodiment of the present invention.

[0031] Fig. 1 shows a braking system 40 of a motor vehicle 10. The method 100 according to the invention is suitable for electrohydraulic, electromechanical, or hybrid braking systems. The function of such braking systems is generally known, so the braking system 40 will be described only to the extent necessary for understanding the present invention.

[0032] The braking system 40 has a first front wheel brake 42 L for decelerating and locking a first steerable front wheel 20 L of the motor vehicle 10, a second front wheel brake 42 R for decelerating and locking a second steerable front wheel 20 R of the motor vehicle 10, a first rear wheel brake 43 L for decelerating and locking a first rear wheel 30 L of the motor vehicle 10, a second rear wheel brake 43 R for decelerating and locking a second rear wheel 30 R of the motor vehicle 10 and brake lines 44.

[0033] The braking system 40 further comprises a control unit 50 and a control unit 60.

[0034] Each of the wheels 20L, 20R, 30L, and 30R of the motor vehicle 10 includes a disc brake system, i.e., each wheel has a brake caliper, a brake disc, and two brake pads. The brake discs are each attached to a hub. The brake caliper includes the brake pads, which interact with the brake disc to decelerate and lock the wheel. It is conceivable that the wheels 20L, 20R, 30L, and 30R each include a drum brake system.

[0035] Each of the wheels 20 L, 20 R, 30 L, and 30 R comprises a sensor unit, which can comprise a plurality of individual sensors. For example, each sensor unit can detect wheel speed, wheel circumferential speed, brake disc temperature, outside temperature, humidity, road wetness, and incremental vibration through a combination of multiple sensors. The sensor units can be coupled to a plurality of vehicle assistance systems and cameras to detect, for example, further parameters such as vehicle speed, vehicle acceleration, vehicle load, static and dynamic power distribution of the vehicle, uphill and downhill braking, and cornering braking with increased lateral acceleration. The sensor units can also be coupled to a plurality of driving stability systems, such as the anti-lock braking system (ABS), the traction control system (ASR), or the electronic stability program (ESP).The sensor units can be coupled to the electronic power steering of the motor vehicle 10 in order to detect a steering movement of the front wheels 20 L, 20 R, in particular an intensity of the torque exerted on the steering and the steering wheel or steering angle.

[0036] Fig. 2 shows a change in the brake distribution in the brake system 40 of the motor vehicle 10 upon detection of a steering movement when the motor vehicle 10 is stationary and braked.

[0037] The control unit 50 serves to detect a braking application received from the driver and, via the brake lines 44, to record a braking force distribution in the braking system 40 of the motor vehicle 10, in particular the braking force at each of the wheels 20 L, 20 R, 30 L, and 30 R. The control unit 60 serves to regulate the braking force distribution in the braking system 40 of the motor vehicle 10.

[0038] When the motor vehicle 10 is stationary and braked, the wheel circumferential speed and the associated wheel brake pressure or the associated wheel brake force are monitored for each of the wheels 20 L, 20 R, 30 L, and 30 R. The monitoring is carried out individually by means of the individual sensor units for each of the wheels 20 L, 20 R, 30 L, and 30 R. At the same time, a steering movement or an impending steering movement of the front wheels 20 L, 20 R is monitored. As soon as a steering movement or an impending steering movement is detected when the motor vehicle 10 is stationary and braked, a trigger signal is transmitted to the control unit 60 of the braking system 40 in order to distribute the braking forces accordingly in the braking system 40, so that noise development can be preventively avoided by distributing the braking forces.

[0039] The control unit 60 generates, in particular, commands for changing a standard brake force distribution between the front wheel brakes 42 L, 42 R of the front axle 20, on the one hand, and the rear wheel brakes 43 L, 43 R of the rear axle 30, on the other hand. The commands are oriented such that, on the one hand, the brake pressure at the noise-critical front wheel brakes 42 L, 42 R of the front axle 20 does not exceed a certain maximum brake pressure (pressure limitation), and, on the other hand, the brake pressure at the rear wheel brakes 43 L, 43 R of the rear axle 30, however, changes to such an extent that, depending on the driving situation, the sum of the brake pressures does not change or decreases in order to prevent the motor vehicle 10 from rolling. Consequently, the driver of the motor vehicle 10 does not notice the automatic intervention in the brake force distribution.

[0040] In other words, the standstill of motor vehicle 10 is monitored by a sensor unit for each wheel. When a driver presses the brake pedal or exerts pressure on the brake pedal while motor vehicle 10 is stationary, the system pressure in braking system 40 of motor vehicle 10 increases, which is detected by control unit 50. This detects the braked state of motor vehicle 10 or the locked state of the front wheel brakes 42 L, 42 R. In the event of a steering movement or an impending steering movement, a trigger signal is sent to control unit 60 to distribute the brake force accordingly to wheels 20 L, 20 R, 30 L, and 30 L of motor vehicle 10.Depending on the driving situation, such as during start-and-stop operation in traffic jams, turning at intersections, parking, reversing, or driving below walking speed, particularly when driving with adaptive cruise control, a specific brake force distribution, in particular an axle-based or wheel-based brake force distribution, may be advantageous. For example, if the motor vehicle 10 is on an inclined surface such as a mountain slope or at the exit of an underground parking garage in bad weather and poor road conditions, it may be advantageous if the brake force redistribution occurs in such a way that the sum of all brake forces at one or more of the wheel brakes 42 L, 42 R, 43 L, and 43 R does not change despite the changed brake force distribution, in order to prevent the motor vehicle 10 from rolling.If the motor vehicle 10 is, for example, on a straight plane, it may be advantageous if the braking force redistribution is carried out in such a way that the sum of all braking forces in the braking system 40 is reduced by canceling the braking force on the front wheel brakes 42 L, 42 R and preventing the motor vehicle 10 from rolling only via the rear wheel brakes 43 L, 43 R, in order to thus reduce the wear on the front wheel brakes 42 L, 42 R.

[0041] When the motor vehicle 10 is braked, the brake force distribution can be achieved, depending on the braking system 40 used, for example, via electrohydraulic valves, pressure regulators, or electric motors (brake actuators), which are controlled or regulated via the brake lines 44. In particular, the braking forces at the wheel brakes 42 L, 42 R, 43 L, and 43 R, in particular the contact forces of the brake pads on the brake discs, can be selectively increased or reduced via the brake lines 44.

[0042] The trigger signal can be a steering parameter such as a torque applied to the steering or a steering wheel angle or a steering angle of the front wheels 20 L, 20 R.

[0043] The monitoring of the steering movement of the front wheels 20 L, 20 R, in particular the monitoring of the intensity of the torque applied to the steering and the steering wheel or steering angle, is carried out via the electronic power steering system of the motor vehicle 10, which can be coupled to the sensor units. The steering wheel of the motor vehicle 10 can typically rotate approximately one and a half turns to the left and right from a neutral point. In other words, a rotation of the steering wheel of approximately three turns from a left end to a right end is possible. The electronic power steering system is equipped with a steering angle position sensor capable of detecting incremental steering angle changes within an angular range greater than or equal to three turns (3 × 360°). The monitoring of the steering movement can be additionally supported by the electronic lane correction or other vehicle assistance systems.

[0044] The electronic power steering may also comprise a detection system decoupled from the front wheels 20 L, 20 R or from the sensor units, by means of which a steering movement, in particular an intensity of the torque exerted on the steering and the steering wheel or steering angle, can be detected according to the steer-by-wire principle.

[0045] The trigger signal for the brake force distribution in the braking system 40 can also be a desired steering parameter, which allows a conclusion to be drawn about an impending steering movement of the motor vehicle 10. It is thus conceivable to use one or more characteristic maps to control a predetermined brake force distribution or a predetermined brake force distribution curve by means of the control unit 60 in the event of an impending steering movement or an impending occurrence of creaking noises. Boundary conditions of situations in which a steering movement or a creaking noise occurs can be stored in the characteristic maps. The brake force distribution can take place in a controlled manner, taking into account a change in at least one desired steering parameter resulting from the changed brake force distribution. Various desired steering parameters can be recorded and evaluated to detect an impending steering movement or an impending occurrence of creaking noises.It is essential that the desired steering parameter(s) taken into account, individually or in combination, allow a conclusion to be drawn about an impending steering movement or noise development.

[0046] In addition to the characteristic maps, data processing-supported traffic route network maps can be used to record a desired steering parameter that allows a conclusion to be drawn about an impending steering movement of the motor vehicle 10.

[0047] Data-based traffic network maps can be understood as maps of a traffic network navigable by vehicles that are automatically managed using data processing, such as digital maps typically used in autonomous vehicle guidance. Such maps contain recurring route or location data, which is defined as the data that defines and stores the route of the navigable sections of the road network. Time-related and recurring driver-specific vehicle guidance information can be derived from the maps, such as the location data of the home office and work parking space, the presence of downhill sections, inclines, curves, or intersections within a recurring route, such as the commute.

[0048] It is thus conceivable that, with the aid of such updated and data processing-supported traffic route network maps, which contain driver-specific route data and associated attribute data, a recurring driving behavior or a recurring steering and braking behavior can be predicted when the indicator is activated and / or by determining the driver's line of sight, so that in the event of an impending steering movement when the motor vehicle 10 is stationary and braked, a blockage of the front axle 20 can be released or a predetermined distribution of the braking forces can be carried out.

[0049] In other words, when the braked motor vehicle 10 is at a standstill, an impending steering movement can be predicted by activating the indicator and / or by determining the driver's line of sight and with the aid of updated and data-processing-supported traffic route network maps.

[0050] Fig.3 shows a block diagram illustrating the method steps for avoiding creaking noises during steering movements of a stationary and braked motor vehicle 10 by the method 100 according to the invention.

[0051] In the first step S1, a stationary state of the motor vehicle 10 is detected. In the second step S2, a braked state of the motor vehicle 10, in particular a brake force distribution in the braking system 40 of the motor vehicle 10, is detected. In the third step S3, a blockage of the first front wheel brake 42 L and the second front wheel brake 42 R of the braking system 40 is detected. Upon detection of the blockage of the first front wheel brake 42 L and the second front wheel brake 42 R, in the fourth step S4, at least one steering parameter that allows a conclusion to be drawn about a steering movement of the motor vehicle 10 and / or at least one desired steering parameter that allows a conclusion to be drawn about an impending steering movement of the motor vehicle 10 is detected. In the fifth step S5, the detected steering parameter and / or the detected desired steering parameter is evaluated to detect the steering movement or the impending steering movement of the motor vehicle 10.Upon detection of the steering movement or the impending steering movement of the motor vehicle 10, a blockage of the first rear wheel brake 43 L and the second rear wheel brake 43 R of the braking system 40 is detected in the sixth step S6. Upon detection of a blockage of the first rear wheel brake 43 L and the second rear wheel brake 43 R, the blockage of the first front wheel brake 42 L and the second front wheel brake 42 R is released in a seventh step S7.If it is determined that the first rear wheel brake 43 L and the second rear wheel brake 43 R are not locked, the first rear wheel brake 43 L and the second rear wheel brake 43 R are locked in a seventh step S7 and the lock of the first front wheel brake 42 L and the second front wheel brake 42 R is released in an eighth step S8, in particular a distribution of the braking forces of the first front wheel brake 42 L and the second front wheel brake 42 R to the first rear wheel brake 43 L and the second rear wheel brake 43 R is carried out. List of reference symbols 10 motor vehicle 20 front axle 20 L first steerable front wheel 20 R second steerable front wheel 30 rear axle 30 L first rear wheel 30 R second rear wheel 40 Brake system 42 L first front brake 42 R second front brake 43 L first rear brake 43 R second rear brake 44 brake lines 50 control unit 60 control unit 100 procedures QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2017 / 0057481 A1

[0005]

Claims

[1] Method (100) for avoiding creaking noises during steering movements of a stationary and braked motor vehicle (10), wherein the motor vehicle (10) has a front axle (20), a rear axle (30) and a braking system (40), the braking system (40) comprising: - a first front wheel brake (42 L) for decelerating and blocking a first steerable front wheel (20 L) of the motor vehicle (10), - a second front wheel brake (42 R) for decelerating and blocking a second steerable front wheel (20 R) of the motor vehicle (10), - a first rear wheel brake (43 L) for decelerating and blocking a first rear wheel (30 L) of the motor vehicle (10), - a second rear wheel brake (43 R) for decelerating and blocking a second rear wheel (30 R) of the motor vehicle (10), - a control unit (50) for detecting a brake force distribution in the brake system (40) of the motor vehicle (10), and - a control unit (60) for regulating the brake force distribution in the brake system (40) of the motor vehicle (10), wherein the method (100) comprises the steps: - detection (S1) of a stationary state of the motor vehicle (10), - detection (S2) of a braked state of the motor vehicle (10), in particular a brake force distribution in the brake system (40) of the motor vehicle (10), - Detection (S3) of a blockage of the first front wheel brake (42 L) and the second front wheel brake (42 R), - upon detection of the blocking of the first front wheel brake (42 L) and the second front wheel brake (42 R), detection (S4) of at least one steering parameter which allows a conclusion to be drawn about a steering movement of the motor vehicle (10), and / or detection of at least one desired steering parameter which allows a conclusion to be drawn about an impending steering movement of the motor vehicle (10), - evaluation (S5) of the detected steering parameter and / or the detected desired steering parameter to detect the steering movement or the impending steering movement of the motor vehicle (10), - upon detection of the steering movement or the impending steering movement of the motor vehicle (10), detection (S6) of a blocking of the first rear wheel brake (43 L) and the second rear wheel brake (43 R), wherein - upon detection of a blockage of the first rear wheel brake (43 L) and the second rear wheel brake (43 R), cancellation (S8) of the blockage of the first front wheel brake (42 L) and the second front wheel brake (42 R) and - if a non-blocking of the first rear wheel brake (43 L) and the second rear wheel brake (43 R) is detected, the first rear wheel brake (43 L) and the second rear wheel brake (43 R) are blocked (S7) and the blocking of the first front wheel brake (42 L) and the second front wheel brake (42 R) is canceled (S8), in particular a distribution of the braking forces of the first front wheel brake (42 L) and the second front wheel brake (42 R) to the first rear wheel brake (43 L) and the second rear wheel brake (43 R) is carried out. [2] Method (100) according to claim 1, characterized by that when the at least one steering parameter or the at least one desired steering parameter is detected, a steering movement of the first steerable front wheel (20 L) and the second steerable front wheel (20 R) is suppressed until the blocking of the first front wheel brake (42 L) and the second front wheel brake (42 R) is released. [3] Method (100) according to claim 1 or 2, characterized bythat the stationary state of the motor vehicle (10) is detected via the wheel speed, in particular via the wheel circumferential speed. [4] Method (100) according to one of the preceding claims, characterized by that the braked state of the motor vehicle (10) is detected via at least one wheel brake pressure force. [5] Method (100) according to one of the preceding claims, characterized by that the blocking of the first front wheel brake (42 L) and the second front wheel brake (42 R) is each detected via a wheel brake pressure force. [6] Method (100) according to one of the preceding claims, characterized by that the distribution of the braking forces in the braking system (40) is carried out axle-related or selectively wheel-related. [7] Method (100) according to claim 6, characterized by that the distribution of the braking forces in the braking system (40) is distributed in such a way that the overall system braking pressure does not change. [8] Method (100) according to claim 6, characterized by that the distribution of the braking forces in the braking system (40) is distributed in such a way that the overall system braking pressure is reduced. [9] Method (100) according to one of the preceding claims, characterized by that the at least one steering parameter is detected by measuring a steering force or a steering angle. [10] Method (100) according to one of the preceding claims, characterized by that the at least one desired steering parameter is recorded by determining the location of the motor vehicle (10), in particular via the GPS data of the motor vehicle (10) in conjunction with already stored data from the history, and / or by activating an indicator of the motor vehicle (10) and / or by determining the viewing direction of a driver of the motor vehicle (10) by a camera. [11] Motor vehicle (10) having a front axle (20), a rear axle (30) and a braking system (40) for carrying out a method (100) according to one of claims 1 to 10.

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