Method for detecting an exchange of a wheel unit or a sensor device, tyre pressure control system, electronic control unit and vehicle

Abstract

The invention relates to a method (100) for detecting an exchange of a wheel unit (6) having a sensor device (7) or an exchange of the sensor device (7) of the wheel unit (6) of a vehicle (1) having a tyre pressure control system (4), wherein the sensor device (7) is designed to detect a tyre pressure parameter (R) and to transmit (120) sensor signals (S) to a receiving device (8) of the tyre pressure control system (4) and wherein a plurality of sensor signal criteria (SSK) of the transmitted sensor signal (S) are evaluated (130) in order to determine a combination (K) of sensor signal values (SSW) and based on the combination (K) of sensor signal values (SSW) an exchange of the wheel unit (6) or sensor device (7) is detected (E1-J). The invention furthermore relates to a tyre pressure control system (4) for a vehicle (1), an electronic control unit (5) for a tyre pressure control system (4) and a vehicle (1).

Description

[0001] Method for detecting a replacement of a wheel unit or a

[0002] Sensor device, tire pressure monitoring system, electronic control unit and vehicle

[0003] The invention relates to a method for detecting a replacement of a wheel unit having a sensor device or a replacement of the sensor device of the wheel unit of a vehicle having a tire pressure monitoring system. The invention further relates to a tire pressure monitoring system for a vehicle, an electronic control unit for a tire pressure monitoring system, and a vehicle, in particular a commercial vehicle.

[0004] Tire pressure monitoring systems monitor tire pressure parameters on vehicle wheels to prevent accident risks and increased fuel consumption. The tire pressure parameter can be measured directly as tire pressure using a tire pressure sensor, for example, or derived indirectly from other variables, such as a tire pressure-dependent change in the rolling circumference of the tires or frequency effects of the vibrations of rim-tire combinations, which can be detected, for example, by wheel speed sensors. The sensor-detected values, which directly or indirectly represent tire pressure, can be transmitted wirelessly, for example, to a tire pressure control unit in the vehicle. Manual and automatic assignment methods are known for assigning the transmitted values ​​to a specific wheel position. These methods can be used, for example, to link an identification code of a sensor unit to a wheel position.

[0005] A technical challenge for tire pressure monitoring systems arises when a wheel unit or a sensor device of a vehicle's wheel unit is replaced, if such a replacement is to be detected automatically. In particular, an unscheduled replacement of a wheel unit may result in a change in the type of sensor device on the wheel unit, so type-independent automatic replacement detection is desirable. At the same time, high detection reliability is desirable to prevent the system integrity of the tire pressure monitoring system from being compromised by false detections.

[0006] KR 10 0 783 958 B1 discloses a method in which temperature information from a tire pressure monitoring sensor is used to detect whether a spare wheel is being used as a replacement wheel.

[0007] KR 10 0 680 342 B1 describes a method in which acceleration information from a tire pressure monitoring sensor is used to detect whether a spare wheel is being used as a replacement wheel.

[0008] KR 10 2015 0 022 448 A relates to a method in which rotation angle information from a tire pressure monitoring sensor and a wheel speed sensor are used to detect whether a spare wheel is being used as a replacement wheel.

[0009] DE 10 2018 104 673 A1 is a method for assigning to wheels of a

[0010] Vehicle-mounted tire pressure monitoring units to the vehicle's wheel positions, in which signals from ABS sensors and level fluctuations of signals from the tire pressure monitoring units are evaluated.

[0011] DE 10 2020 106 754 A1 describes a method for automatically assigning tire pressure sensors to a wheel position by evaluating sensor data from the tire pressure sensors and wheel speed sensors at the wheel positions using measured signal strengths and recorded rotation angle positions of the wheels.

[0012] According to the features of independent claim 1, a method is proposed for detecting a replacement of a wheel unit having a sensor device or a replacement of the sensor device of the wheel unit of a vehicle having a tire pressure monitoring system, wherein the sensor device is configured to detect a tire pressure parameter and to transmit sensor signals to a receiving device of the tire pressure monitoring system, and wherein a plurality of sensor signal criteria of the transmitted sensor signal are evaluated in order to determine a combination of sensor signal values, and based on the combination of sensor signal values, a replacement of the wheel unit or the sensor device is detected.

[0013] In other words, a method for detecting a replacement of the wheel unit or the sensor device is provided. A joint evaluation of several sensor signal criteria enables a statistical decision basis, based on which a highly probable conclusion can be drawn that the component has been replaced. A replacement of the wheel unit or the sensor device can be reliably detected based on characteristic combinations of sensor signal values.

[0014] The proposed method can enable automated replacement detection without user intervention. This provides increased user convenience, while also ensuring immediate operational readiness of the tire pressure monitoring system with regard to the replaced wheel unit or sensor device, thus maintaining a high level of safety. Due to the joint evaluation of several factors, the method is highly error-prone, thus increasing the system integrity of the tire pressure monitoring system. This significantly reduces the risks of non-detection and false detection of a replacement of the wheel unit or sensor device, i.e., the unintentional reassignment of a sensor device to a wheel position.The proposed method is largely independent of the sensor type, vehicle type, or user intervention used, allowing for a high degree of autonomy. The sensor signal criteria used for evaluation can be flexibly defined and expanded or replaced at any time without major effort, enabling an adaptable evaluation process that can be further developed, for example, with future sensor types, vehicle types, and tire pressure monitoring methods available.

[0015] A wheel unit can be formed from a wheel of the vehicle and a sensor device arranged on the wheel. The sensor device can be configured to generate and transmit sensor signals. A sensor signal can represent a variable detected on the wheel by a sensor element of the sensor device, for example, a tire pressure or a wheel acceleration. A sensor signal can also be an operation-related sensor status signal, for example, a battery status of the sensor device. Sensor signals can be transmitted to a receiving device of the tire pressure monitoring system, in particular wirelessly. The receiving device of the tire pressure monitoring system can, for example, be assigned to an electronic control unit of the tire pressure monitoring system of the vehicle, in which the received sensor signals can be evaluated, for example, by means of a signal processing unit designed as a processor.The vehicle can in particular be a commercial vehicle, for example a towing vehicle, a trailer vehicle or a combination consisting of a towing vehicle and a trailer vehicle.

[0016] According to the proposed method, a plurality of sensor signal criteria of the transmitted sensor signal are evaluated. A plurality can be understood as a number of at least two, in particular at least three or at least four sensor signal criteria. Sensor signal criteria can, for example, include the sensor values ​​relating to a variable detected by a sensor element of the sensor device or an operation-related sensor state, or can be related to defined properties of the sensor signal, for example, a signal strength of the sensor signal. In this case, certain sensor values ​​or states or properties of the sensor signal can correlate with a replaced wheel unit or with a replaced sensor device and thus represent direct or indirect indicators of a completed replacement.During the evaluation, a combination of sensor signal values ​​is created based on the evaluated sensor signal criteria, which forms the basis for the decision for the intended replacement detection. In this case, each sensor signal value can represent a sensor signal criterion. According to one conceivable embodiment, a qualitative evaluation can be carried out, in which, for example, it is checked whether a sensor signal criterion is met or not met and, depending on the test result, an associated sensor signal value is determined. Such a sensor signal value can, for example, be a truth value. Alternatively or additionally, a quantitative evaluation can be carried out, in which, for example, a key figure or a probability value of the sensor signal criterion is determined and, depending on the result, an associated sensor signal value is determined.The sensor signal value can correspond to the quantitative value, for example, the key figure or the probability value. It is conceivable to combine qualitative and quantitative evaluations, for example, to determine one sensor signal criterion qualitatively and another sensor signal criterion quantitatively.

[0017] According to one embodiment, the plurality of sensor signal criteria may comprise one of the following sensor signal criteria:

[0018] - a battery warning signal;

[0019] - a pressure loss warning signal;

[0020] - a sensor loss signal;

[0021] - a fluctuation in the signal strength of the sensor signal;

[0022] - an acceleration signal;

[0023] - a direction of rotation signal and / or

[0024] - a driving status signal.

[0025] The aforementioned sensor signal criteria can be advantageously used to detect a replacement of a wheel unit or a sensor device, as they represent suitable indicators for such a replacement. The aforementioned sensor signal criteria can be recorded using sensor signals from the sensor device that are already provided to the tire pressure monitoring system, or they can be easily determined additionally. In this case, it is not necessary to provide additional sensors on the wheel unit or on the vehicle to detect a replacement of the wheel unit or the sensor device. The aforementioned sensor signal criteria represent clear, easily identifiable factors and can be easily evaluated.After transmission to the receiving device, the sensor signals can be stored, for example, in a memory unit of an electronic control unit of the tire pressure monitoring system, so that the electronic control unit can also use the aforementioned sensor signal criteria for evaluation at a later time after receipt of the sensor signal at the receiving device. Thus, at the time of a sensor signal criteria evaluation, it is possible to retrospectively check whether, for example, a battery warning signal or a pressure loss warning signal was transmitted. For example, a battery warning signal can represent information regarding a battery voltage of the sensor device falling below a predetermined level and be an indicator for replacing the sensor device.

[0026] A pressure loss warning signal can represent information regarding a tire pressure below a specified value for the wheel of the wheel unit and can be an indicator for replacing the wheel unit. Several types of pressure loss warning signals can be considered. For example, a distinction can be made between a minor and a significant pressure loss, each of which can represent different sensor signal criteria or form a common sensor signal criterion with different characteristic or probability values. A pressure loss warning signal indicating a significant pressure loss can correlate with a higher probability of replacing the wheel unit.

[0027] A sensor loss signal can be generated, for example, if no sensor signal has been received from the sensor device at the receiving device over a specified period of time, so that a sensor loss can be deduced, for example, from a corresponding timeout signal. A sensor loss signal can indicate a defective or removed sensor device and represent an indicator for replacing the sensor device or the wheel unit containing the sensor device. The sensor loss signal can be generated directly in an electronic control unit of the tire pressure monitoring system and stored in a memory unit of the tire pressure monitoring system.Compared to the other sensor signal criteria described, a sensor loss signal may be associated with a high probability of a replacement of the sensor device or the wheel unit, so that in some embodiments, this sensor signal criterion may be given greater importance, for example, a higher weighting, in a joint evaluation of sensor signal criteria.

[0028] A fluctuation in the signal strength of the sensor signal can correspond to a change in the signal strength of the sensor signal received at the receiving device over time. The signal strength of the sensor signal can be represented, for example, by an RSSI value, where an RSSI value (Received Signal Strength Indicator) is a measure of the received field strength of the wirelessly transmitted sensor signal. If a wheel unit with the sensor device moves relative to the vehicle equipped with the tire pressure monitoring system, the signal strength can fluctuate measurably due to a distance between the sensor device and the receiving device that changes with the rotation of the wheel, for example, even periodically at a constant speed.If, for example, a signal strength fluctuation in the sensor signal is detected to be abruptly reduced or no longer measurable, or to be within a specified tolerance range, this may indicate that the wheel unit or sensor device transmitting the sensor signal has been moved from its original wheel position and is, for example, located in a spare wheel holder or on the loading area of ​​the vehicle. Accordingly, a changed or insufficient signal strength fluctuation in the sensor signal may be an indicator that a wheel unit or a sensor device assigned to a wheel of the vehicle has been replaced.The sensor signal criterion described above can also be referred to as RSSI plausibility, since the evaluation of the sensor signal criterion involves an RSSI plausibility check to determine whether the signal strength of the received sensor signal lies within or outside a typical fluctuation range for wheel rotation.

[0029] An acceleration signal can, for example, be provided by a suitable acceleration sensor element of the sensor device and transmitted to the receiving device in addition to the variable detected by the sensor device for determining or monitoring the tire pressure. The acceleration signal can, in particular, represent a rotational acceleration of the sensor device at the associated wheel. If the acceleration signal falls below a predetermined acceleration value for an extended period of time and, in particular, the acceleration value is reduced compared to acceleration signals from other wheel units of the vehicle, it can be concluded that the wheel unit or sensor device transmitting the sensor signal has been moved from its original wheel position and is arranged, for example, in a spare wheel holder or on a loading area of ​​the vehicle.Accordingly, an acceleration signal value of the sensor signal that is too low or deviates from other acceleration values ​​can be an indicator that a wheel unit or a sensor device assigned to a wheel of the vehicle has been replaced. The sensor signal criterion described above can also be referred to as acceleration status plausibility, since the evaluation of the sensor signal criterion involves a plausibility check to determine whether an acceleration value of the received sensor signal lies within or outside a typical value range for wheel rotation. Alternatively or additionally, a check can be performed, for example, to determine whether the acceleration value matches the acceleration values ​​of other wheel units.

[0030] A rotation direction signal can be provided, for example, by a suitable rotation direction sensor element, such as a Hall sensor, of the sensor device and transmitted to the receiving device in addition to the variable detected by the sensor device for determining or monitoring the tire pressure. The rotation direction signal can, in particular, indicate a rotation direction of the sensor device on the associated wheel. If rotation direction information is missing for an extended period, it can be concluded that the wheel unit or the sensor device transmitting the sensor signal has been moved from its original wheel position and is located, for example, in a spare wheel holder or on a loading area of ​​the vehicle.Accordingly, a change in the direction of rotation information from an existing direction of rotation signal to a missing direction of rotation signal of the sensor signal can be an indicator of a replacement of a wheel unit or a sensor device assigned to a wheel of the vehicle.

[0031] A driving state signal can be a time-dependent criterion of the wheel unit, for example, a standstill or travel time information determined based on acceleration or speed, which, depending on the design, can be provided by the sensor device or determined by evaluating the sensor signals in a control unit of the tire pressure monitoring system. Using the driving state signal, for example, short or long standstill periods of the wheel unit can be detected and evaluated. The driving state signal can be used as a sensor signal criterion to detect a replacement of the sensor device or wheel unit, for example, when a standstill period of the wheel unit is reported to the receiving device, while other wheel units of the vehicle transmit a travel time for the affected period.Furthermore, the driving status signal can be used to trigger a check process to detect a replacement of the wheel unit or the sensor device. For example, a prolonged downtime of all wheel units can be an indicator of a possible replacement of a wheel unit, such as a wheel change. Conversely, if the vehicle is continuously driven for a longer period, it can be assumed that no check for replacement is currently necessary.

[0032] According to one embodiment, to determine the combination of sensor signal values, it can be checked whether the majority of sensor signal values ​​each fulfill a predefined condition. This allows for a simple evaluation of the combination of sensor signal values ​​with clear results. For example, a binary evaluation result can be determined for each sensor signal value, for example, a truth value with the possible outcomes "true" and "false," so that a simple comparison of the evaluation results with possible binary comparison combination series of the sensor signal criteria can be performed.With regard to the sensor signal criteria described above, a binary evaluation result can be used, for example, to check whether a battery warning signal is present, whether a pressure loss warning signal is present, whether a sensor loss signal is present, whether a signal strength of the received sensor signal is outside a typical fluctuation range for wheel rotation, whether an acceleration value of the received sensor signal is outside a typical value range for wheel rotation or whether an acceleration value of the received sensor signal does not match acceleration values ​​of other wheel units, whether a direction of rotation signal is present and / or whether a standstill time has been recorded.

[0033] According to one embodiment, the determined combination of sensor signal values ​​can be compared with stored comparison combinations of sensor signal values, with each comparison combination of sensor signal values ​​being assigned a result value. This enables a secure and reliable evaluation with a clear conclusion based on predetermined result values. According to one embodiment, binary result values ​​can be provided, for example, in the sense of "exchange completed" or "no exchange completed." This enables a comparatively simple embodiment of the method, which can, for example, be advantageously combined with binary sensor signal values.Alternatively, a more differentiated evaluation based on a plurality of possible outcome values ​​is conceivable, for example, with gradations such as "exchange very likely," "exchange likely," "exchange unlikely," or "exchange very unlikely." Furthermore, it is possible to provide outcome values ​​in the form of probability values, for example, "75 percent exchange probability." By providing greater differentiation using multiple possible outcome values, different follow-up actions can be offered or performed. For example, a reassignment can be performed based on a determined probability value depending on selected user settings, or an optional additional user input can be requested.

[0034] According to one embodiment, a replacement of the wheel unit or the sensor device can be detected if a predefined condition is met for two or more of the plurality of sensor signal criteria. This allows a conclusion to be drawn about a replacement using logical links between sensor signal values, for example, based on if-then rules, thus providing an easily implemented and flexible option for processing the evaluation results.

[0035] According to one embodiment, different priorities of the sensor signal criteria can be applied during the evaluation. For example, a positive result, which represents a completed replacement, can be output when a specific sensor signal criterion or several specific sensor signal criteria are met, independently of other sensor signal criteria. Alternatively or additionally, it is conceivable to weight sensor signal criteria differently, for example, by assigning larger or smaller key figures when evaluating a sensor signal criterion and summing the key figures to determine whether a replacement has been completed.Since some sensor signal criteria can be a stronger indicator of a possible replacement of the wheel unit or sensor device, the validity of the replacement detection can be increased if such sensor signal criteria are given greater consideration during the evaluation or can be incorporated more strongly into the test result. According to an advantageous refinement of the previously described embodiment, a replacement of the wheel unit or sensor device can be detected if a sensor loss signal is present. Accordingly, this sensor signal criterion can be prioritized over other sensor signal criteria. A sensor loss signal can be a reliable indicator of a replacement of the wheel unit or sensor device and can indicate such a replacement with a high degree of probability.Depending on the configuration of the sensor device or tire pressure monitoring system, the sensor loss indicated by the sensor loss signal may also reduce the number of evaluable sensor signal criteria, since the sensor signals cannot be further evaluated following the sensor loss. Therefore, it may be advisable not to evaluate any further sensor signal criteria when a sensor loss signal is received and to link the sensor loss signal to the result of a replacement of the wheel unit or sensor device.

[0036] According to one embodiment, in response to a detected replacement, a check can be performed to determine whether the detected replacement can be uniquely assigned to a wheel unit or a sensor device. Such a check can also be referred to below as a check for the unique assignability of the replacement. For example, a check can be performed to determine whether sensor signal criteria indicating a replacement are present only for a single sensor device, or a localization process can be initiated to identify the affected sensor device. This can prevent incorrect detection of a replacement and, for example, ensure that subsequent reassignment of a new sensor device can be carried out correctly.

[0037] According to one embodiment, a new sensor device can be reassigned in the tire pressure monitoring system in response to a detected replacement of the wheel unit or sensor device or in response to a unique assignability of the detected replacement. For example, after a positive replacement detection or after a recognized unique assignability of the replacement, an automated detection and query process can run to capture a sensor ID of a new sensor device, and a reassignment of the sensor ID to a wheel position stored for the previously replaced sensor device can take place. The reassignment can advantageously only be performed if a prior unique identification of the wheel unit and / or sensor device affected by the replacement has taken place.For example, a unique identification of the wheel unit and / or sensor device affected by the replacement can take place if an evaluation of the sensor signal criteria yields a positive replacement result for only one wheel unit or only one sensor device of the vehicle. This can reduce or eliminate the susceptibility to errors during reassignment. In particular, the reassignment of the new sensor device can be an automatic reaction of the tire pressure monitoring system to a detected replacement, requiring no user intervention. This achieves a higher degree of automation than, for example, with a tire pressure monitoring system that reports a completed replacement but subsequently requires manual reassignment of a sensor device.

[0038] According to one embodiment, the plurality of sensor signal criteria can be evaluated during a driving operation of the vehicle at a predetermined minimum speed. Such a minimum speed can, for example,

[0039] 20 km / h, 30 km / h, or 40 km / h. It is advantageous to check whether the specified minimum speed is maintained over a predefined period of time. Advantageously, a one-time recording and evaluation of the sensor signal criteria can be carried out during ferry operation and only repeated after a downtime of a specified minimum duration, for example, a minimum duration of 10, 15, or 20 minutes, since a certain minimum period of time can usually be required to replace the wheel unit or sensor device. An evaluation time during ferry operation of the vehicle at a specified minimum speed represents a favorable time for carrying out the test procedure in terms of energy and control technology.For example, at the start of a ferry operation of the vehicle, an energy- and query-intensive state may occur in the tire pressure monitoring system and / or other vehicle systems in order to check, for example, safety-relevant parameters of the vehicle systems. By carrying out the method during ferry operation at a predetermined minimum speed, such an initial state can be skipped and the vehicle's energy and signal processing resources can be initially conserved. A one-time evaluation of the majority of sensor signal criteria during ferry operation also increases the reliability of the testing process, as the sensor signal criteria are checked at a time at which they can logically be met. For example, an incorrect sensor loss signal due to a sensor signal from the sensor device initially being missing at the start of the journey can be avoided.Furthermore, for example, the susceptibility to errors in the process and the high utilization of a control unit of the tire pressure monitoring system can be reduced compared to continuous evaluation and testing of the sensor signal criteria.

[0040] The invention further relates to a tire pressure monitoring system for a vehicle, comprising a wheel unit having a sensor device for detecting a tire pressure parameter and transmitting sensor signals to a receiving device of the tire pressure monitoring system, and comprising an electronic control unit for implementing the above-described method. The proposed tire pressure monitoring system can also achieve the above-described advantages of automated replacement detection, increased user comfort, increased system integrity, a high degree of autonomy, and flexible adaptability. The receiving device of the tire pressure monitoring system can be connected to one or more sensor devices of wheel units of the vehicle via a suitable signal connection, for example, a wireless signal connection.The electronic control unit of the tire pressure monitoring system can be configured to evaluate the sensor signals with regard to the detected sensor variable and other sensor signal criteria. The electronic control unit can have a memory device for temporarily and / or permanently storing sensor signal values ​​and criteria. Processing information, such as machine-readable command sequences, tables, or evaluation rules, for implementing the method can also be stored in the memory unit. The electronic control unit can have a signal processing unit, such as a processor, for processing the sensor signals received at the receiving device. The invention further relates to an electronic control unit for a tire pressure monitoring system configured to implement the method described above.The control unit can be designed as a tire pressure control unit and, for example, be configured to transmit tire pressure information to a vehicle display. The electronic control unit can be configured to evaluate sensor signals from wheel units of a vehicle equipped with the tire pressure monitoring system with regard to the detected sensor variable and other sensor signal criteria. The electronic control unit can have a memory device for temporarily and / or permanently storing sensor signal values ​​and criteria. Processing information, for example machine-readable command sequences, tables, or evaluation rules, for implementing the method can also be stored in the memory unit. The electronic control unit can have a signal processing unit, for example a processor, for processing the sensor signals received at the receiving device.

[0041] The invention further relates to a vehicle, in particular a commercial vehicle, with a tire pressure monitoring system and / or an electronic control unit according to one of the aforementioned features. A commercial vehicle can be, for example, a towing vehicle, a trailer, or a combination consisting of a towing vehicle and a trailer. In principle, the invention can also be used on a passenger car. For a vehicle designed as a commercial vehicle, additional advantages may arise, or certain advantages may be more pronounced.For example, commercial vehicles, which may be designed to transport goods or large numbers of people, may have a higher number of axles and wheel units than passenger cars, so the probability of replacing a wheel unit or sensor device may be increased, and automated replacement detection may be associated with reduced maintenance effort for the driver. In addition, depending on the design, commercial vehicles may have a lifting axle, which, when raised, could lead to characteristic sensor signals such as a sharply reduced acceleration signal and thus trigger a replacement error detection. However, this can be avoided thanks to the proposed evaluation of a combination of sensor signal values.Thanks to the flexibility and adaptability in the selection and evaluation of suitable sensor signal criteria, an individually configurable and scalable tire pressure monitoring system with a high degree of autonomy can be provided on the vehicle and equipped accordingly with improved tire pressure monitoring.

[0042] The invention permits various embodiments and is explained in more detail below using exemplary embodiments with the accompanying drawings. They show schematically:

[0043] Fig. 1 is a schematic diagram of a vehicle with a tire pressure monitoring system in a side view;

[0044] Fig. 2 is a schematic flow diagram of a method for detecting a replacement of a wheel unit or sensor device of the vehicle;

[0045] Fig. 3 shows a schematic diagram of a control unit of the tire pressure monitoring system; and Fig. 4 shows a table example for evaluating sensor signal values ​​to obtain a result value.

[0046] Fig. 1 shows a simplified schematic diagram of a vehicle 1 designed as a commercial vehicle, which according to the illustrated embodiment is configured as a combination with a towing vehicle 2 and a trailer vehicle 3. The vehicle 1 has a tire pressure monitoring system 4 with an electronic control unit 5 designed as a tire pressure control unit and a receiving device 8 for receiving sensor signals S. The vehicle 1 further has a plurality of wheel units 6, each with a wheel 12 and a sensor device 7 arranged on the wheel 12. The sensor devices 7 are designed to detect a tire pressure parameter R of the wheel 12 on which they are arranged. The sensor devices 7 are connected to the receiving device 8 by means of signal connections 9, which can advantageously be wireless signal connections 9.Sensor signals S can be transmitted from the sensor devices 7 to the receiving device 8 of the electronic control unit 5 of the tire pressure monitoring system 4 via the signal connections 9. In Fig. 1, the vehicle 1 is shown in a ferry operation FB, in which it moves at a minimum speed Vmin on a roadway 13, so that an evaluation of sensor signal criteria of the sensor signals S can advantageously be carried out according to the method 100 described below.

[0047] Fig. 2 shows a schematic flow diagram of a method 100 for detecting a replacement of a wheel unit 6 having a sensor device 7 or a replacement of the sensor device 7 of the wheel unit 6 of a vehicle 1 having a tire pressure monitoring system 4, as shown for example in Fig. 1, wherein the sensor device 7 is set up to detect a tire pressure parameter R. According to the exemplary embodiment shown, the method 100 enters a loop-shaped sequence after a start 110. Sensor signals S are continuously transmitted 120 from the sensor devices 7 of the wheel units 6, for example at periodic time intervals, to a receiving device 8 of the tire pressure monitoring system 4. In response to a corresponding command from the control unit 5 of the tire pressure monitoring system 4, for example due to a fulfilled condition such as driving operation FB at a minimum speed Vmin, the following are shown in Fig.3 and 4, the sensor signal criteria SSKi to SSK? are shown and explained in more detail and evaluated 130 for a combination K of sensor signal values ​​SSW. Based on the combination K of sensor signal values ​​SSW, a decision E1 is made as to whether a replacement of the wheel unit 6 or the sensor device 7 has occurred E1-J or not E1-N. If it is decided that a replacement of the wheel unit 6 or the sensor device 7 has not occurred E1-N, the method is continued with the further transmission 120 of sensor signals S and, at the command of the control unit 5, with a renewed evaluation 130 of the sensor signal criteria SSKi to SSK?. If it is decided that a replacement of the wheel unit 6 or the sensor device 7 has occurred E1-J, a check is carried out according to the exemplary embodiment shown as to whether the detected replacement E1-J can be clearly assigned to a wheel unit 6 or a sensor device 7.If this is not the case, for example because an evaluation 130 of sensor signal criteria SSKi to SSK? shows that several wheel units 6 are candidates for a replacement, the method is continued according to path E2-N with the further transmission 120 of sensor signals S and, at the command of the control unit 5, with a renewed evaluation 130 of the sensor signal criteria SSKi to SSK?. However, if a decision is made E2-J that the detected replacement E1-J can be clearly assigned, a new sensor device 7 is reassigned 150 in the tire pressure monitoring system 4. The method is then continued with the further transmission 120 of sensor signals S and, at the command of the control unit 5, with a renewed evaluation 130 of the sensor signal criteria SSKi to SSK?.

[0048] Fig. 3 schematically shows a tire pressure monitoring system 4 with an electronic control unit 5, which has a signal processing unit 10, a receiving device 8, and a storage unit 11. At the receiving device 8, sensor signals S from the sensor device 7 relating to a tire pressure parameter R of the wheel unit 6 having the sensor device 7 can be received, for example wirelessly, and transferred to the signal processing unit 10. In the signal processing unit 10, sensor signal criteria SSKi to SSK? can be evaluated for a combination K of sensor signal values ​​SSW, indicated schematically in Fig. 4, in order to detect a replacement of the wheel unit 6 or the sensor device 7 based on the combination of sensor signal values ​​SSW.For example, the sensor signal criterion SSKi can represent a battery warning signal, the sensor signal criterion SSK2 a pressure loss warning signal, the sensor signal criterion SSK3 a sensor loss warning signal, the sensor signal criterion SSK4 a signal strength fluctuation of the sensor signal S, the sensor signal criterion SSKs an acceleration signal, the sensor signal criterion SSKe a rotation direction signal, and the sensor signal criterion SSK? a driving state signal. If necessary, the sensor signals S can be stored in the storage unit 11, so that an evaluation of the sensor signal criteria SSKi to SSK? can also take place at a later time after the sensor signals S have been received at the receiving device 8.

[0049] Fig. 4 shows an example table for evaluating sensor signal values ​​SSW to form a result value EW, wherein, according to the exemplary embodiment shown, the sensor signal criteria SSK2, SSK3, SSK4, or SSK5 are considered. Comparison combinations VK of sensor signal values ​​SSW, each with associated result values ​​EW, are stored in the table, so that a determined combination of sensor signal values ​​SSW can be compared with the comparison combinations VK, and an associated result value EW can be determined for a combination of sensor signal values ​​SSW. According to the exemplary embodiment shown, the sensor signal values ​​SSW are binary and represented by truth values ​​with the possible values ​​W for true and F for false, so that a qualitative evaluation can take place.The truth values ​​of the sensor signal values ​​SSW can, for example, indicate whether a predefined condition for the respective sensor signal criterion SSK2, SSK3, SSK4, or SSK5 is met (true) or not (false). The result values ​​EW, which are also represented as truth values, can, for example, indicate whether a decision is made to replace the wheel unit 6 or the sensor device 7 (true) or not (false). As can be seen from the result values ​​EW assigned to the sensor signal criterion SSK3 corresponding to a sensor loss warning signal, this sensor signal criterion SSK3 is given increased priority because the result value EW assumes a positive truth value (true), regardless of the other sensor signal values ​​SSW, if the condition of a sensor loss warning signal is met (true) as the sensor signal value SSW.If there is no sensor loss warning signal, the rule can be followed, for example, that two or more of the sensor signal values ​​SSW must assume a positive truth value (true) in order to obtain a positive result value EW (true), whereby, depending on individual logic, exceptions can be made for certain sensor signal criteria SSK, as is illustrated here by way of example with the sensor signal criteria SSK2 and SSK4.

[0050] With the presented method 100, the vehicle 1, the tire pressure monitoring system 4 and the electronic control unit 5, it is possible to realize an automatic replacement detection, which is accompanied by increased user comfort, increased system integrity, a high degree of autonomy and flexible adaptability.

[0051] Reference symbol (part of the description)

[0052] 1 vehicle

[0053] 2 towing vehicle

[0054] 3 trailer vehicle

[0055] 4 Tire pressure monitoring system

[0056] 5 Control unit

[0057] 6 wheel unit

[0058] 7 Sensor device

[0059] 8 Receiving device

[0060] 9 Signal connection

[0061] 10 Signal processing unit

[0062] 11 Storage device

[0063] 12 wheels

[0064] 13 Roadway

[0065] 100 procedures

[0066] 110 Start

[0067] 120 Transmission of sensor signals

[0068] 130 Evaluation of sensor signal criteria

[0069] 140 Comparison of sensor signal values ​​with comparison combinations

[0070] 150 Reassignment of a new sensor device

[0071] E1 Decision to exchange

[0072] E1-J Positive decision on exchange

[0073] E1-N Negative decision on exchange

[0074] E2 Check for assignability of the exchange

[0075] E2-J Positive decision on assignability

[0076] E2-N Negative decision on assignability

[0077] EW result value

[0078] F False

[0079] FB Ferry Operations

[0080] K Combination of sensor signal values

[0081] R Tire pressure parameters

[0082] S sensor signal

[0083] SSK sensor signal criterion SSKi battery warning signal

[0084] SSK2 pressure loss warning signal

[0085] SSK3 sensor loss signal

[0086] SSK4 Signal strength fluctuation of the sensor signal

[0087] SSK's acceleration signal

[0088] SSKe direction of rotation signal

[0089] SSK7 driving status signal

[0090] SSW sensor signal value

[0091] Vmin minimum speed

[0092] VK comparison combination

[0093] W True

Claims

Patent claims 1. Method (100) for detecting a replacement of a wheel unit (6) having a sensor device (7) or a replacement of the sensor device (7) of the wheel unit (6) of a vehicle (1) having a tire pressure monitoring system (4), wherein the sensor device (7) is configured to detect a tire pressure parameter (R) and to transmit (120) sensor signals (S) to a receiving device (8) of the tire pressure monitoring system (4), characterized in that a plurality of sensor signal criteria (SSK) of the transmitted sensor signal (S) are evaluated (130) in order to determine a combination (K) of sensor signal values ​​(SSW), and that a replacement of the wheel unit (6) or the sensor device (7) is detected (E1-J) based on the combination (K) of sensor signal values ​​(SSW).

2. Method (100) according to claim 1, characterized in that the plurality of sensor signal criteria (SSK) comprises one of the following sensor signal criteria (SSK): - a battery warning signal (SSKi); - a pressure loss warning signal (SSK2); - a sensor loss signal (SSK3); - a signal strength fluctuation of the sensor signal (SSK4); - an acceleration signal (SSKs); - a direction of rotation signal (SSKe) and / or - a driving status signal (SSK7).

3. Method (100) according to claim 1 or 2, characterized in that in order to determine the combination (K) of sensor signal values ​​(SSW), it is checked whether the plurality of sensor signal values ​​(SSW) each fulfills a predetermined condition (F, W).

4. Method (100) according to one of the preceding claims, characterized in that the determined combination (K) of sensor signal values ​​(SSW) is compared with stored comparison combinations (VK) of sensor signal values ​​(SSW) (140), whereby each comparison combination (VK) of sensor signal values ​​(SSW) is assigned a result value (EW).

5. Method (100) according to one of the preceding claims, characterized in that a replacement of the wheel unit (6) or the sensor device (7) is detected (E 1 -J) if a predetermined condition is met (F, W) for two or more of the plurality of sensor signal criteria (SSK).

6. Method (100) according to one of the preceding claims, characterized in that different priorities of the sensor signal criteria (SSK) are applied in the evaluation (130).

7. Method (100) according to claim 6, characterized in that a replacement of the wheel unit (6) or the sensor device (7) is detected (E1-J) when a sensor loss signal (SSK3) is present.

8. Method (100) according to one of the preceding claims, characterized in that in response to a detected exchange (E1-J) it is checked whether the detected exchange (E1-J) can be clearly assigned to a wheel unit (6) or a sensor device (7) (E2).

9. Method (100) according to one of the preceding claims, characterized in that in response to a detected replacement (E1-J) of the wheel unit (6) or of the sensor device (7) or in response to a unique assignability (E2-J) of the detected replacement (E1-J), a new assignment (150) of a new sensor device (7) in the tire pressure monitoring system (4) takes place.

10. Method (100) according to one of the preceding claims, characterized in that the plurality of sensor signal criteria (SSK) are determined during a driving operation (F) of the vehicle (1) at a predetermined minimum speed (v m in) is evaluated (130).

11. Tire pressure monitoring system (4) for a vehicle (1) with a wheel unit (6) comprising a sensor device (7) for detecting a tire pressure parameter (R) and Transmission of sensor signals (S) to a receiving device (8) of the tire pressure monitoring system (4), and with an electronic control unit (5) for carrying out the method (100) according to one of the preceding claims.

12. Electronic control unit (5) for a tire pressure monitoring system (4), configured to carry out the method (100) according to one of claims 1 to 10.

13. Vehicle (1), in particular a commercial vehicle, with a tire pressure monitoring system (4) according to claim 11 and / or an electronic control unit (5) according to claim 12.

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