Method for monitoring wheel fastening elements of a motor vehicle and use

Abstract

The invention relates to a method for monitoring wheel fastening elements on a plurality of wheels of a motor vehicle and to the use of an evaluation device of a motor vehicle, wherein wheel fastening elements comprise wheel bolts and central nuts. It comprises an evaluation device for evaluating sensor data and wheel speed sensors are provided. During a load change, a speed difference between all wheel hubs and the respective associated wheel is monitored and the speeds are compared. In the event of a significant deviation at one of the wheels, the evaluation device detects a loosening wheel fastening element. Furthermore, the evaluation device uses a yaw rate sensor to monitor a yaw rate during cornering and detects a loosening wheel fastening element if lateral acceleration only builds up with a delay or if a building yaw rate changes suddenly.

Description

[0001] The invention relates to a method for monitoring wheel fastening elements of a motor vehicle and the use of a motor vehicle or an evaluation device of a motor vehicle for monitoring wheel fastening elements or detecting the loosening of wheel fastening elements of a motor vehicle.

[0002] Methods for monitoring the fastening of wheel bolts or a central nut of a vehicle are known from the prior art. DE 10 2013 211 697 A1 discloses a method in which wheel speed sensors are evaluated to detect a loose wheel. WO 98 / 40 230 A1 discloses analyzing wheel noises to detect a loose wheel bolt.

[0003] DE 10 2020 200 828 A1 discloses a method for providing artificial intuition for a vehicle, in which the vehicle's surroundings are detected using environmental sensors, thereby generating environmental data. Dynamic sensors detect the vehicle's dynamics, and dynamic data is generated. Furthermore, interior sensors detect the vehicle's interior, and interior data is generated. The environmental data, the dynamic data, and the interior data are evaluated and fused. Based on the fused environmental data, dynamic data, and interior data, a current situation of the vehicle is assessed using a trained artificial neural network, and a vehicle response is initiated by a control device based on the result of the assessment.Using the dynamic sensors and the optical data from the surrounding sensors and the acoustic data, loose wheel mountings on the vehicle can also be detected. Although this document mentions many sensors that are also intended to detect a film of moisture or a wall of fog on a road, there are no specific instructions on how this goal is to be achieved.

[0004] DE10 2015 000 998 A1 discloses a method for monitoring wheel fastening elements on a plurality of wheels of a motor vehicle. A loose wheel is detected based on a comparison of the wheel speeds of different wheels.

[0005] It is therefore the object of the present invention to provide a method for monitoring wheel fastening elements of a motor vehicle and a use of an evaluation device of a motor vehicle, whereby a reliable detection of loosening wheel fastening elements is repeatedly enabled.

[0006] This object is achieved by a method having the features of claim 1 and by the features of use claim 9. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the present invention will become apparent from the general description and the description of the exemplary embodiment.

[0007] A method according to the invention for monitoring wheel fastening elements on a plurality of wheels of a motor vehicle is carried out using an evaluation device for evaluating sensor data. The wheel fastening elements comprise at least wheel bolts and at least central nuts of the respective wheels. Wheel speed sensors are provided in order to monitor a speed difference between a wheel hub and an associated wheel on the plurality of wheels during a load change. This means that, in particular, at least one wheel speed sensor is assigned to each wheel. During a load change, the evaluation device and the speed sensors record and compare the speeds of the plurality of wheels, and a speed difference between all wheels of the plurality of wheels is recorded. In the event of a significant deviation on one of the wheels, the evaluation device detects a loosening wheel fastening element.According to the invention, the evaluation device monitors a yaw rate at least during cornering with a yaw rate sensor and detects a loosening wheel fastening element when lateral acceleration is only built up with a delay and / or a building yaw rate suddenly changes.

[0008] The method according to the invention has many advantages. A significant advantage is that, in addition to the known method for determining the wheel speed difference, a yaw rate sensor is also used to monitor the yaw rate during cornering. This allows for more reliable and high-quality results in far more cases.

[0009] The phrase "suddenly" changing a building yaw rate is understood in the context of this application to mean a discontinuous change in the yaw rate. In particular, a steering setting is also taken into account here. A lateral acceleration or yaw rate can be determined from the position of a steering angle of the wheels or the position of a steering wheel and the driving speed of the motor vehicle. If a change occurs in two or more consecutively measured values ​​of lateral acceleration that is greater than the measurement noise and creates a discontinuity in the curve, it is detected that a wheel fastening element has become loose. In autonomous vehicles, for example, a steering wheel may no longer be present, so that the steering angle of the wheels or the position of a controlled steering device can be evaluated.

[0010] A "significant deviation" is defined as a deviation that exceeds a predetermined threshold. The threshold may depend on the driving speed and other driving parameters such as the steering setting.

[0011] In preferred developments, an acoustic sensor is included in or assigned to at least one wheel housing of the plurality of wheels. The evaluation device then preferably detects the noises in the wheel housing. This allows monitoring of the noises in the wheel housing. In particular, the evaluation device detects a loosening wheel fastening element if the evaluation device detects or recognizes a clattering noise of a loosening wheel fastening element from the acoustic data of the acoustic sensor.

[0012] In particular, the evaluation device also detects a loosening wheel fastening element if the evaluation device detects a change in the position of the wheel on the wheel hub from the acoustic data of the acoustic sensor.

[0013] A load change can also be understood, in particular, as the starting of a motor vehicle. A load change can also be the deceleration or acceleration of the motor vehicle. A load change can also occur due to a change in the lateral acceleration. A loose or loose wheel fastening element can preferably be detected when changing from, for example, positive lateral acceleration to negative lateral acceleration.

[0014] Preferably, at least one surroundings camera is included. The evaluation device detects a loose wheel fastening element from the surroundings data. For example, the surroundings camera can detect a loose or flying central nut or wheel nut.

[0015] In advantageous embodiments, the driver is prompted by means of the evaluation device to brake and / or stop the motor vehicle if a loosening wheel fastening element is detected or if such an event is suspected or feared / considered predominantly likely.

[0016] Particularly in self-driving vehicles, the evaluation system automatically stops the vehicle if such a fault is detected. However, the evaluation system can also stop a vehicle driven by a driver if a loose wheel fastening element is detected and the driver fails to respond to a warning and / or a specific danger is imminent.

[0017] The invention is also directed to the use of an evaluation device of a motor vehicle and to the use of a motor vehicle with an evaluation device, wherein the motor vehicle comprises a plurality of wheels. The wheels are fastened by means of wheel fastening elements. The wheel fastening elements comprise, in particular, at least wheel bolts and at least one central nut or wheel nuts. The fastening state of the wheel fastening elements is monitored. An evaluation device is used to evaluate sensor data. Wheel speed sensors of the motor vehicle are used to monitor a speed difference between a wheel hub and an associated wheel in the plurality of wheels during a load change. During a load change, the evaluation device detects a speed of all wheels and a speed difference of all wheels of the plurality of wheels, and the speeds of the plurality of wheels are compared with one another.If a deviation occurs at one of the wheels, the evaluation unit detects a loosening wheel fastening element. The evaluation unit and a yaw rate sensor of the vehicle are used to monitor the yaw rate during cornering and to detect a loosening wheel fastening element if lateral acceleration builds up only after a delay and / or if a building yaw rate suddenly changes.

[0018] The use according to the invention also has many advantages.

[0019] Overall, the invention has the advantage that, for example, during regular, seasonal wheel changes on a vehicle, the risk of central nuts, wheel nuts, or wheel bolts coming loose (unnoticed) while driving is reduced or completely avoided. This allows the associated hazards to be avoided by warning the driver and, if necessary, by automatically braking the vehicle. By detecting a loose wheel bolt or central nut, the driver can be prompted to stop immediately. This function can also be used in self-driving or automated vehicles. This can prevent hazards to the driver, passengers, and pedestrians, as well as damage to the vehicle.

[0020] An advantage is that loose wheel fasteners can be detected by sensors (usually located) in the vehicle. In particular, wheel speed sensors, a yaw rate sensor, acoustic sensors in the wheel housing, surround-view cameras, as well as sensors such as the steering setting and driving speed are used.

[0021] The sensors installed in the vehicle regularly collect data while driving, which can be evaluated in a central computer or a special evaluation device within the vehicle. If one of the sensors detects a defect, the driver can be immediately informed or the (currently) self-driving or autonomous vehicle can be stopped. Preferably, the sensors are used interchangeably for plausibility checks.

[0022] It is possible that the installed sensors are used to detect a wheel that is coming loose.

[0023] The wheel speed sensors specifically evaluate whether play occurs between a wheel hub and a wheel during a load change or when starting off. Data from the other wheels can be used as a reference. This allows the specific defective wheel to be identified. Once a predefined threshold is reached, the driver can be warned and instructed to stop, or the vehicle can be stopped entirely.

[0024] The yaw rate sensor can detect, in particular, when a vehicle with a loose wheel only builds up lateral acceleration with a delay while cornering, and / or when a building yaw rate changes suddenly or discontinuously. This can happen, for example, when the loose wheel is pushed against the corresponding stop. This causes a discontinuous or suddenly changing lateral acceleration or yaw rate. This makes it possible to identify the corresponding wheel and warn the driver. This is particularly possible with the outside wheels of the curve.

[0025] An acoustic sensor in the wheel housing or an acoustic sensor associated with the wheel housing can, for example, detect the clacking of a loose wheel fastener. This method can also detect changes in the wheel's contact with the wheel hub. This can then warn the driver and prompt them to stop. An autonomous vehicle can be stopped immediately. This process also allows the affected wheel to be directly identified.

[0026] Surround cameras can capture images while driving, allowing the driver to detect whether a wheel bolt has come loose and is about to fall off or fly off the wheel. If this is detected, the driver can be warned and prompted to stop.

[0027] Further advantages and features of the present invention will become apparent from the embodiment which will be explained below with reference to the attached figure: The figures show: Fig. 1 a schematic representation of a motor vehicle and various sensors used.

[0028] In Fig. 1 shows a highly schematic representation of a motor vehicle and various sensors 10 (11, 12, 13, 14) integrated into the motor vehicle 1.

[0029] The motor vehicle has wheels 2. Here, an acoustic sensor 13 is assigned to each wheel housing 5. The motor vehicle 1 has at least one yaw rate sensor 12, which is preferably located in the center of the motor vehicle. It is also possible to use multiple yaw rate sensors 12, whose sensor data are added together to provide a representative yaw rate sensor.

[0030] The motor vehicle 1 can be controlled by a driver 9. However, it is also possible for the motor vehicle 1 to temporarily drive itself or to be designed as a self-driving motor vehicle 1 and to take over control not only for a few seconds, but also for longer.

[0031] The motor vehicle 1 has an evaluation device 4, which can be provided by a (central) computing device or is contained as a separate evaluation device 4 in the motor vehicle 1.

[0032] The evaluation device 4 receives the sensor data from the sensors 10 installed in the motor vehicle 1. In particular, wheel speed sensors 11 are assigned to some, and in particular all, wheels 2 in the motor vehicle 1. In addition to the yaw rate sensor 12, acoustic sensors 13 are also assigned to the respective wheel housings 5 ​​for each wheel 2. Furthermore, one or more surrounding cameras 14 can be included, with the area to the side of the wheel housings preferably also being detectable by surrounding cameras 14.

[0033] For partially or fully self-driving motor vehicles 1, a separate control computer 8 may be provided. A screen or display device 6 serves to output information and provide instructions to the driver 9. Preferably, an acoustic warning signal output may also be included.

[0034] During operation, a method for monitoring wheel fastening elements is performed while the motor vehicle is driving. Monitoring takes place on all wheels of the motor vehicle. Wheel speed sensors 11 monitor a speed difference between a wheel hub and a corresponding wheel 2 during a load change. The speed difference between all wheels is determined and compared.

[0035] In the event of a significant deviation on one of the wheels, the evaluation device 4 detects a loosening wheel fastening element 3. Detection also occurs, in particular, when the evaluation device monitors a yaw rate during cornering with the yaw rate sensor and detects a loosening wheel fastening element. This can occur, in particular, when lateral acceleration builds up with a delay and / or a building yaw rate suddenly changes.

[0036] In a specific embodiment, the method monitors whether a wheel fastening element 3, such as a wheel bolt or a central nut, is loosening. The wheel speed sensors compare the speed difference between the wheel hub and the wheel during load changes and when starting off. If a deviation occurs at one of the wheels, a loosening wheel bolt or a loosening central nut is detected. The yaw rate sensor is also used during monitoring, so that a loosening wheel fastening element is also detected in the event of delayed lateral acceleration or a continuously changing yaw rate.

[0037] Safety can be further enhanced by monitoring noises using acoustic sensors in the wheel housing. If a rattling noise is detected, it can be determined that a wheel bolt or other wheel fastening element is coming loose. A surround-view camera can also detect loose or flying wheel bolts and thus conclude that there is a defect.

Claims

[1] Method for monitoring wheel fastening elements on a plurality of wheels (2) of a motor vehicle (1), wherein wheel fastening elements (3) comprise wheel bolts and central nuts, wherein an evaluation device (4) for evaluating sensor data is included, wherein wheel speed sensors (11) are provided to monitor a speed difference between a wheel hub and an associated wheel (2) in the plurality of wheels (2) during a load change, and wherein, during a load change, the speeds of the plurality of wheels (2) are detected and compared with the evaluation device (4) and the wheel speed sensors (11), and a speed difference of all wheels (2) of the plurality of wheels (2) is detected, wherein in the event of a significant deviation on one of the wheels (2), the evaluation device (4) detects a loosening wheel fastening element (3), characterized by , that the evaluation device (4) monitors a yaw rate when cornering with a yaw rate sensor (11) and detects a loosening wheel fastening element (3) when a lateral acceleration is only built up with a delay or a building yaw rate suddenly changes. [2] Method according to claim 1, wherein an acoustic sensor (13) is included in at least one wheel housing (5) and the evaluation device (4) detects noises in the wheel housing (5). [3] Method according to claim 2, wherein the evaluation device detects a loosening wheel fastening element (3) when the evaluation device (4) detects a clattering of a loosening wheel fastening element (3) from the acoustic data of the acoustic sensor (13). [4] Method according to claim 2 or 3, wherein the evaluation device (4) detects a loosening wheel fastening element (3) when the evaluation device (4) detects a change in the contact of the wheel (2) with the wheel hub from the acoustic data of the acoustic sensor (13). [5] Method according to one of the preceding claims, wherein a load change is a starting of the motor vehicle (1). [6] Method according to one of the preceding claims, wherein at least one surroundings camera (14) is included and the evaluation device (4) detects a loosening wheel fastening element (3) from the surroundings data. [7] Method according to one of the preceding claims, wherein the driver is requested by means of the evaluation device (4) to stop the motor vehicle (1). [8] Method according to one of the preceding claims, wherein the evaluation device stops the motor vehicle (1) driven by a driver and / or self-driving. [9] Use of an evaluation device (4) of a motor vehicle (1) having a plurality of wheels (2), wherein the wheels (2) are fastened with wheel fastening elements (3) and comprise wheel bolts and central nuts, in order to monitor the wheel fastening elements (3), wherein the evaluation device (4) is used to evaluate sensor data, wherein wheel speed sensors (11) of the motor vehicle (1) are used to monitor a speed difference between a wheel hub and an associated wheel (2) in the plurality of wheels (2) during a load change, and wherein, during a load change, the evaluation device (4) detects a rotational speed of all wheels (2) and a rotational speed difference of all wheels (2) of the plurality of wheels (2) and compares the rotational speeds of the plurality of wheels (2) with one another, and wherein, in the event of a deviation on one of the wheels (2), the evaluation device (4) detects a loosening wheel fastening element (3), characterized by , that the evaluation device (4) and a yaw rate sensor (12) of the motor vehicle (1) are used to monitor a yaw rate when cornering and to detect a loosening wheel fastening element (3) when a lateral acceleration is only built up with a delay or a building yaw rate suddenly changes.

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