Method for controlling the operating mode of a tire pressure monitoring device and tire pressure monitoring device

Abstract

The invention relates to a method for controlling the operating mode of a tire pressure monitoring device, wherein the tire pressure monitoring device is mounted on a vehicle wheel and comprises a pressure measuring device for determining the tire pressure, an acceleration sensor, and a transmission device for wirelessly transmitting tire pressure measurements to a receiving device, and can assume at least two operating modes, wherein in a first operating mode the tire pressure is repeatedly measured and transmitted at first time intervals, and in a second operating mode the tire pressure is repeatedly measured and transmitted at second time intervals that are shorter than the first time intervals, and wherein a switching condition is calculated.If, in the first operating mode, the accelerometer detects readings below a predefined reference value, and in the second operating mode, the accelerometer detects readings above the reference value, and a switching signal is generated from this, causing the tire pressure monitoring device to switch from the current operating mode to the other operating mode, a timer with a predefined runtime is provided, which is started when the switching condition is calculated and delays the generation of the switching signal until the runtime is reached. A corresponding tire pressure monitoring device is also specified.

Description

[0001] The invention relates to a method for controlling the operating mode of a tire pressure monitoring device, wherein the tire pressure monitoring device is mounted on a vehicle wheel and has a pressure measuring device for determining the tire pressure, an acceleration sensor and a transmission device for wirelessly transmitting tire pressure measurement values ​​to a receiving device and can assume at least two operating modes, wherein in a first operating mode the tire pressure is repeatedly measured and transmitted at first time intervals and in a second operating mode the tire pressure is repeatedly measured and transmitted at second time intervals which are shorter than the first time intervals and wherein a switching condition is calculated,if in the first operating mode the acceleration sensor detects measured values ​​below a specified reference value and in the second operating mode the acceleration sensor detects measured values ​​above the reference value and a switching signal is generated from this, which causes the tire pressure monitoring device to switch from the current operating mode to the other operating mode.

[0002] The invention further relates to a tire pressure monitoring device which is intended for mounting on a vehicle wheel and has a pressure measuring device for determining the tire pressure, an acceleration sensor and a transmission device for wirelessly transmitting tire pressure measurement values ​​to a receiving device and has at least two operating modes, wherein in a first operating mode the tire pressure can be repeatedly measured and transmitted at first time intervals and in a second operating mode the tire pressure can be repeatedly measured and transmitted at second time intervals which are shorter than the first time intervals and wherein the tire pressure monitoring device is designed to calculate a switching condition,if in the first operating mode the acceleration sensor detects measured values ​​below a predetermined reference value and in the second operating mode the acceleration sensor detects measured values ​​above the reference value and a switching signal can be generated from this, which causes the tire pressure monitoring device to switch from the current operating mode to the other operating mode.

[0003] Tire pressure monitoring devices of the type mentioned above are widely known and, as so-called TPMS sensors, are now standard equipment in motor vehicles, especially passenger cars. They feature a pressure measuring device for determining tire pressure and are located either in a suitable installation position, for example, on the inner surface of the pneumatic tire mounted on the vehicle wheel or near the valve.

[0004] The tire pressures measured by the pressure measuring device are transmitted at set intervals, usually wirelessly, to a receiver installed on the vehicle or to an external or stationary receiver. With a receiver installed on the vehicle, the transmitted tire pressures are further processed in the vehicle's electronics to, for example, display the tire pressure or issue warnings in the event of an incorrectly set inflation pressure or a sudden loss of pressure. The tire pressure monitoring device has an integrated power supply, provided by a battery, which is typically designed for a specific service life or lifetime of the vehicle wheel being monitored.

[0005] It is known to operate such tire pressure monitoring devices in different operating modes. This serves to ensure that the sensor information is available sufficiently frequently, but also to conserve battery power as much as possible.

[0006] From US 6,232,875 B1, for example, it is known to control the transmitting unit of the tire pressure monitoring device depending on a determined movement pattern and to set a different operating mode when the vehicle wheel is moving than when the vehicle wheel is stationary.

[0007] WO 2017 / 050513 A1 discloses a tire pressure monitoring device whose operating modes are changed based on the measured tire pressure.

[0008] The number of different operating modes in which a tire pressure monitoring device can operate is limited due to the limitations of the integrated circuits within the device. However, it is currently unavoidable that a particular operating mode, which is available and used to transmit sensor information, is used too frequently due to individual driving behavior or driving profile. This has a particularly detrimental impact on the battery life of the tire pressure monitoring device.

[0009] The object of the invention is to propose a method for controlling the operating mode of a tire pressure monitoring device and such a tire pressure monitoring device which overcomes the disadvantages of the prior art.

[0010] To achieve the stated object, the invention proposes the design of a method according to the features of patent claim 1.

[0011] Advantageous embodiments and further developments of the method according to the invention are the subject of the dependent claims.

[0012] A tire pressure monitoring device for solving the stated problem is the subject of patent claim 6.

[0013] To achieve the stated object, the invention provides that a timer with a predetermined running time is specified, which is started when the switching condition is calculated and the generation of the switching signal for changing the operating mode is delayed until the running time of the timer is reached.

[0014] In this way, with a minor modification that can easily be implemented even within the limited circuitry of a tire pressure monitoring device, a timer ties the change in the tire pressure monitoring device's operating mode to two different conditions: a change in movement must be detected, and the defined timer, which is started when the change in movement is detected, must have expired. This intentionally delays the change in the tire pressure monitoring device's operating mode.

[0015] Such a delay in the change of operating mode by the timer provided according to the invention ensures an effective extension of the battery life, particularly in situations in which a change of operating mode should only take place under special conditions. This is useful, for example, to distinguish between a brief stop of the motor vehicle, for example at a traffic light, and a longer stop of the motor vehicle. According to the invention, the timer excludes short stops, for example at traffic lights or bus stops, from changes in the operating mode of the tire pressure monitoring device. This is particularly effective in cases in which, when the motor vehicle is stationary, the tire pressure monitoring device is switched to an operating mode in which a significantly more frequent transmission of sensor data to the receiving device is to take place.

[0016] According to a proposal of the invention, after the switching signal has been generated and the operating mode has changed accordingly, the timer is reset to the value 0 so that when the movement profile changes again, the timer can be restarted with the intended running time and delays the change of the operating mode accordingly.

[0017] According to a further proposal of the invention, the continuation of the switching condition is regularly monitored during the running time of the timer, i.e. after it has been triggered, and if the switching condition is interrupted, the timer is reset. This has the consequence that only a brief movement of the vehicle with the tire pressure monitoring device in the operating mode corresponding to a standstill of the vehicle, for example maneuvering the vehicle and then coming to a standstill again or only a brief stop with the tire pressure monitoring device in the operating mode corresponding to a driving of the vehicle, for example at a pedestrian crossing, does not cause a change of the operating mode. Rather, if the switching condition is interrupted, the timer is immediately reset to the value 0 and started again with the entire running time when the next switching condition is reached.

[0018] The running time of the timer can be specified by the person skilled in the art within wide limits, whereby according to a proposal of the invention, running times between approximately 30 to 150 seconds, for example 32 or 64 seconds, are considered reasonable.

[0019] Likewise, the time interval for monitoring the switching condition can be specified by the person skilled in the art within wide limits, whereby according to a proposal of the invention, running times between approximately 5 and 40 seconds, for example 8 or 16 seconds, are considered reasonable.

[0020] Thus, according to the invention, it is possible to vary the time intervals between individual transmissions of measured tire pressures, as well as the frequency of tire pressure measurements, depending on the operating mode. Measurements are generally performed more frequently than transmissions in order to quickly identify potential problems while avoiding the high energy consumption associated with transmission. For example, a tire pressure measurement can always be performed every 16 seconds, regardless of the operating mode. The wireless transmission or sending of the measured tire pressure, however, can occur every 128 seconds in the first operating mode, for example, and every 32 seconds in the second operating mode, for example.

[0021] According to a further proposal of the invention, the tire pressure monitoring device can also comprise a temperature sensor to determine the current temperature of the vehicle wheel and to wirelessly transmit it to the receiving device in addition to the determined tire pressure.

[0022] The tire pressure monitoring device according to the invention, which is intended for mounting on a vehicle wheel and has a pressure measuring device for determining the tire pressure, an acceleration sensor and a transmission device for wirelessly transmitting tire pressure measurement values ​​to a receiving device and has at least two operating modes, wherein in a first operating mode the tire pressure can be repeatedly measured and transmitted at first time intervals and in a second operating mode the tire pressure can be repeatedly measured and transmitted at second time intervals which are shorter than the first time intervals and wherein the tire pressure monitoring device is designed to calculate a switching condition,If, in the first operating mode, the acceleration sensor determines measured values ​​below a predetermined reference value and, in the second operating mode, the acceleration sensor determines measured values ​​above the reference value and a switching signal can be generated from this, which causes the tire pressure monitoring device to switch from the current operating mode to the other operating mode, is characterized in that a timer with a predetermined running time is provided, which can be activated when the switching condition is calculated in order to delay the generation of the switching signal until the running time is reached.

[0023] With the tire pressure monitoring device according to the invention and using the method according to the invention, it is possible to operate the tire pressure monitoring device in at least two different operating modes, wherein the change of the operating modes is carried out depending on the situation or driving profile.

[0024] For example, the tire pressure monitoring device according to the invention is in a second operating mode when a motor vehicle is stationary with the wheels correspondingly stationary, and in a first operating mode when a motor vehicle is moving with the wheels correspondingly moving. In this second operating mode, the time intervals at which the tire pressure is determined and wirelessly transmitted to the receiving device are shorter than in the first operating mode.

[0025] The movement of the motor vehicle with the vehicle wheels moving accordingly is detected by an acceleration sensor present in the tire pressure monitoring device, in particular an integrated one, and the tire pressure monitoring device is switched to the first operating mode, in which the measured values ​​for the tire pressure and, if applicable, also the temperature of the vehicle wheel are transmitted wirelessly to the receiving device of the motor vehicle, for example every 2 minutes.

[0026] If the motor vehicle is stopped, the tire pressure monitoring device detects an acceleration value below a predefined reference value, which can be set, for example, at 3 g or any other suitable value. From this, the tire pressure monitoring device determines a switching condition when the reference value is undershot. However, the corresponding switching signal, which causes the tire pressure monitoring device to switch to the second operating mode associated with the vehicle's standstill, is not yet generated. Instead, a timer is first started in the tire pressure monitoring device with a defined running time, for example, 32 seconds or 64 seconds.

[0027] When the timer reaches its defined running time, the switching signal is generated based on the given switching condition, and the tire pressure monitoring device switches to the other, in this case the second, operating mode. In this mode, for the purpose of more reliable data transmission, the sensor information on tire pressure and / or temperature is transmitted to the receiving device at shorter time intervals, for example, every 16 or 32 seconds. This mode can also be used more effectively as a yard reader mode by an external reading device. If the switching condition is canceled within the timer's running time, for example, by the vehicle being set in motion again, the timer is stopped and reset to 0, and the process begins again.A change of the operating mode requires two conditions, namely the existence of the switching condition, in this case little or no acceleration, and also the reaching of the running time of the started timer.

[0028] The same can also be provided for switching the tire pressure monitoring device from the second operating mode to the first operating mode, whereby the switching condition occurs and is calculated when the acceleration sensor detects a measured value above the reference value and also initially starts the timer to delay the generation of the switching signal according to the timer's running time. Furthermore, it is also possible to switch between more than the two different operating modes explained above. 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 6,232,875 B1

[0006] WO 2017 / 050513 A1

[0007]

Claims

[1] Method for controlling the operating mode of a tire pressure monitoring device, wherein the tire pressure monitoring device is mounted on a vehicle wheel and has a pressure measuring device for determining the tire pressure, an acceleration sensor and a transmission device for wirelessly transmitting tire pressure measurement values ​​to a receiving device and can assume at least two operating modes, wherein in a first operating mode the tire pressure is repeatedly measured and transmitted at first time intervals and in a second operating mode the tire pressure is repeatedly measured and transmitted at second time intervals which are shorter than the first time intervals and wherein a switching condition is calculated,if in the first operating mode the acceleration sensor detects measured values ​​below a predetermined reference value and in the second operating mode the acceleration sensor detects measured values ​​above the reference value and a switching signal is generated from this, which causes the tyre pressure monitoring device to switch from the current operating mode to the other operating mode, , characterized by that a timer with a predetermined running time is provided, which is started when the switching condition is calculated and the generation of the switching signal is delayed until the running time is reached. [2] Method according to claim 1, characterized by that the timer is reset after the switching signal is generated. [3] Method according to one of claims 1 or 2, characterized by that the continuation of the switching condition is regularly monitored during runtime and that the timer is reset if the switching condition is interrupted. [4] Method according to one of claims 1 to 3, characterized by that the timer runs for 30 to 150 seconds. [5] Method according to one of claims 1 to 4, characterized by that the tire pressure monitoring device comprises a temperature sensor and the transmitting device also transmits temperature measured values ​​wirelessly to the receiving device. [6] A tyre pressure monitoring device intended for mounting on a vehicle wheel and comprising a pressure measuring device for determining the tyre pressure, an acceleration sensor and a transmission device for wirelessly transmitting tyre pressure measurement values ​​to a receiving device, and comprising at least two operating modes, wherein in a first operating mode the tyre pressure can be repeatedly measured and transmitted at first time intervals and in a second operating mode the tyre pressure can be repeatedly measured and transmitted at second time intervals which are shorter than the first time intervals, and wherein the tyre pressure monitoring device is designed to calculate a switching condition,if in the first operating mode the acceleration sensor detects measured values ​​below a predetermined reference value and in the second operating mode the acceleration sensor detects measured values ​​above the reference value and a switching signal can be generated from this, which causes the tyre pressure monitoring device to switch from the current operating mode to the other operating mode, , characterized by that a timer with a predetermined running time is provided, which can be activated when the switching condition is calculated in order to delay the generation of the switching signal until the running time is reached.