Adjusting tire pressure for dual tires

Abstract

Method for assisting in the adjustment of the inflation pressure of a tire (44, 45) of a dual tire (43) of a means of transport (40), comprising the steps: - Determining (10) a position (RP) of the tire (44, 45) within the dual tires (43) by a position determination module (22) using a localization stored in a tire pressure sensor (50) or in a control unit (48) for the tire pressure sensor (50); and - Determining (11) a target pressure (P i_t , P o_t ) for the tire (44, 45) by a pressure determination module (23), wherein the target pressure (P i_t ) for an inner tire (44) of the dual tires (43) is lower than the target pressure (P) o_t ) for an outer tire (45) of the dual tires (43) and in the case of a cold condition of the tires (44, 45) a difference between the target pressures (P i_t , P o_t) is designed to compensate for expected deviations in pressure increases when the tires are warm (44, 45).

Description

[0001] The present invention relates to a method, a computer program with instructions and a device for supporting an adjustment of the inflation pressure of a tire of a dual tire setup.

[0002] Tire pressure monitoring systems (TPMS) regularly monitor tire pressure. Measurements are taken independently for each tire, and the data is analyzed separately. If the pressure of a tire deviates significantly from the recommended pressure, the system alerts the responsible person, usually the driver. This prevents the tire from being used outside its recommended operating range, promoting more economical driving with reduced fuel consumption. Furthermore, it helps prevent potential damage and excessive tire wear.

[0003] Against this background, DE 10 2007 053 260 A1 describes a tire inflation device and a method for regulating tire pressure, wherein tires can be connected to a central pressure source via pneumatically controlled wheel valves, rotor connections, and control valves according to the inlet principle, where the supply line also serves as the control line. A control valve determines the pressure level in a common supply line, distinguishing and switching only between the states "no pressure" and "pressure present." The positions of the wheel valves involved do not depend on the applied pressure level itself; instead, the wheel valves are designed to react to changes in the pressure level.

[0004] DE 10 2009 011 236 A1 describes a tire pressure control system with a central pressure source, wherein tires are connected to supply lines via throttles and wheel valves, in the course of which rotor connections are arranged. The stationary part of the control system determines the pressure level in the supply lines by switching between significantly low and significantly high pressures, so that high-pressure intervals alternate with low-pressure intervals. Each wheel valve comprises a combination of different valves.

[0005] To adjust tire pressure, for example in response to a warning from a tire pressure monitoring system, inflation assistants exist that guide the user in inflating the tire to the correct pressure using visual or audible signals. For cold tires, the target pressure is the recommended cold pressure (RCP), while for warm tires, a temperature-compensated target pressure is used.

[0006] Against this background, DE 10 2006 008 085 A1 describes a device for monitoring the fill level of multiple tires of a vehicle. The device comprises a situation detection unit configured to recognize a situation in which an adjustment of the fill level of at least one of the vehicle's tires is to be expected. The device also includes a fill level adjustment assistant configured to automatically assist a vehicle user during the adjustment of the fill level of the at least one tire when the situation is detected.

[0007] US 2002 / 0130771 A1 describes a system for remotely sensing temperature and pressure in moving or stationary vehicle tires. The tire pressure and temperature data, along with a unique ID number, are transmitted from a sensor in the tire to a computer display in the driver's cab. A portable display device in the cab receives the data and assigns a unique wheel position to each sensor. The display device compensates for the local air pressure and the actual tire temperature in the pressure data and displays the compensated data to the driver. The display device can be removed from the cab for local use.

[0008] DE 34 41 512 A1 describes a special type of motor vehicle wheel with twin tires, in which the wheel comprises one tire with a winter tread and another tire with a summer tread, mounted on a common rim. Each tire is equipped with a tire pressure control device to achieve selectable pressure reduction or increase. This device is linked to a tire pressure monitoring device via a common control unit. Actuating switches that influence the control unit serve to synchronize the tire pressure settings for summer and winter operation.

[0009] Dual tires, also known as twin tires, are primarily used on commercial vehicles, but sometimes also on other types of vehicles. Reasons for using dual tires include better distribution of the axle load on the road surface and increased mobility and traction in difficult terrain. Furthermore, dual tires allow for higher axle loads. However, it has been observed that vehicles with dual tires exhibit specific wear patterns when the tires are inflated using a state-of-the-art inflation system.

[0010] It is an object of the present invention to provide improved solutions for supporting the adjustment of tire inflation pressure in dual tires.

[0011] This problem is solved by a method having the features of claim 1, by a computer program with instructions having the features of claim 6, and by a device having the features of claim 7. Preferred embodiments of the invention are the subject of the dependent claims.

[0012] According to a first aspect of the invention, a method for supporting an adjustment of the inflation pressure of a tire of a dual tire arrangement of a means of transport comprises the steps: - Determining the position of the tire within the dual tires by a positioning module using a localization stored in a tire pressure sensor or in a control unit for the tire pressure sensor; and - Determining a target pressure for the tire by a pressure determination module, wherein the target pressure for an inner tire of the dual tires is lower than the target pressure for an outer tire of the dual tires and in the case of a cold state of the tires a difference between the target pressures is designed to compensate for expected deviating pressure increases in a warm state of the tires.

[0013] According to another aspect of the invention, a computer program comprises instructions which, when executed by a computer, cause the computer to perform the following steps to support an adjustment of the inflation pressure of a tire of a dual-tire vehicle: - Determining the position of the tire within the dual tires using a localization stored in a tire pressure sensor or in a tire pressure sensor control unit; and - Determining a target pressure for the tire, wherein the target pressure for an inner tire of the dual tires is lower than the target pressure for an outer tire of the dual tires, and in the case of a cold state of the tires, a difference between the target pressures is designed to compensate for expected deviations in pressure increases when the tires are warm.

[0014] The term "computer" is to be understood broadly. In particular, it also includes control units, mobile devices such as smartphones and tablets, as well as other processor-based data processing devices.

[0015] The computer program can, for example, be made available for electronic retrieval or be stored on a computer-readable storage medium.

[0016] According to another aspect of the invention, a device for supporting an adjustment of the inflation pressure of a tire of a dual tire system of a means of transport comprises: - a positioning module for determining the position of the tire within the dual tires using a localization stored in a tire pressure sensor or in a control unit for the tire pressure sensor; and - a pressure determination module for determining a target pressure for the tire, wherein the target pressure for an inner tire of the dual tires is lower than the target pressure for an outer tire of the dual tires and in the case of a cold state of the tires a difference between the target pressures is designed to compensate for expected deviating pressure increases in a warm state of the tires.

[0017] The solution according to the invention is based on the understanding that the inflation pressures of the tires in a dual-tire setup develop differently during driving. This phenomenon results in irregular tire wear while driving. To counteract this problem, the solution according to the invention takes into account the different contact patches of the inner and outer tires by using an inflation assistant to specify different target pressures depending on the tire's position within the dual-tire setup. These counteract the heating during driving, so that at least an approximately equal tire pressure is achieved in the tires of the dual-tire setup when the tires are warm.

[0018] According to the invention, the target pressure for the inner tire of a dual-tire setup is lower than the target pressure for the outer tire. The pressure increase of the inner tire is higher than that of the outer tire during driving because the inner tire heats up more. This can be compensated for by the inflation assistant setting a lower target pressure for the inner tire than for the outer tire.

[0019] In the case of cold tires, a difference between the target pressures is designed to compensate for differing pressure increases when the tires warm up. The pressure difference expected during driving due to heating can be predicted, at least approximately. Instead of the same inflation pressure for both tires, targeted, different inflation pressures for the dual tires are specified by an inflation assistant, anticipating the pressure difference as accurately as possible when the tires are warm.

[0020] To determine the tire's position within the dual tire setup, a location stored in a tire pressure sensor or a control unit for the tire pressure sensor is used. Currently, tire pressure sensors in trucks are often programmed using a handheld device. The handheld device transmits an LF radio signal (LF: Low Frequency), for example, at a frequency of 125 kHz, which is received by the tire pressure sensor. The sensor then sends a response in the form of an RF radio signal (RF: Radio Frequency), for example, at a frequency of 315 MHz or 434 MHz. The range of the radio signal can be precisely controlled via the LF signal strength, allowing for targeted communication with the tire pressure sensors. As an alternative to programming using a handheld device, there are approaches that determine the positions of the tire pressure sensors, i.e.,The corresponding tire positions are automatically determined by a system in the vehicle based on the received signal strength at the vehicle's RF receivers. In both cases, the positions determined in this way can be stored in the tire pressure sensors or the associated control unit. This makes them available later for use by an inflation assistant.

[0021] According to one aspect of the invention, in the case of warm tires, the target pressures are temperature-compensated using temperature data from the tire pressure sensor. With warm tires, the inflation assistant not only compensates for the pressure increase due to the different heating during driving, but also temperature-compensates the target pressure.

[0022] According to one aspect of the invention, the localization is transmitted to an inflation assistant. For example, the tire position can be transmitted from the tire pressure sensor or the control unit to an inflation assistant, implemented as an application on a smartphone, via a BLE interface (BLE: Bluetooth Low Energy). In this way, the tire position can be made available very easily.

[0023] According to one aspect of the invention, a measured tire pressure is compared to the target pressure. Based on this comparison, an inflation device can then be activated, or information can be provided to the user. This information can, for example, consist of a prompt to increase or decrease the inflation pressure. For this purpose, acoustic or visual signals can be used. Alternatively, a corresponding display can be generated, for example, on the screen of a smartphone running the inflation assistant application. Another possibility is to use an inflation device controlled by the inflation assistant to adjust the inflation pressure to the correct value. In this way, no user intervention is required to adjust the inflation pressure.

[0024] Preferably, a device or method according to the invention is used in a means of transport, in particular in a commercial vehicle, e.g., in a truck or a bus. The solution according to the invention can also be used to assist in adjusting the tire pressure, at least for one axle with dual tires of a trailer.

[0025] Further features of the present invention will become apparent from the following description and the attached claims in conjunction with the figures. Fig. Figure 1 schematically shows a method for supporting the adjustment of the inflation pressure of a tire of a dual-tire vehicle; Fig. Figure 2 shows a first embodiment of a device for supporting the adjustment of the inflation pressure of a tire of a dual tire system of a means of transport; Fig. Figure 3 shows a second embodiment of a device for supporting the adjustment of the inflation pressure of a tire of a dual-tire vehicle; Fig. Figure 4 schematically shows a means of transport with one axle with double tires; Fig. Figure 5 schematically shows a tire for a motor vehicle in which a tire pressure sensor is installed; Fig. Figure 6 schematically shows the structure of a tire pressure sensor; Fig. Figure 7 shows a characteristic profile of the tire pressures of a dual-tire setup during driving; and Fig. Figure 8 shows the progression of the tire pressures of a dual tire setup during driving, taking into account an expected pressure difference between the tires.

[0026] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. The same reference numerals are used in the figures for identical or equivalently acting elements and are not necessarily described again for each figure. It is understood that the invention is not limited to the embodiments shown and that the described features can also be combined or modified without departing from the scope of protection of the invention as defined in the appended claims.

[0027] Fig. Figure 1 schematically shows a method for supporting the adjustment of the inflation pressure of a tire in a dual-tire setup of a vehicle. In a first step, the position of the tire within the dual-tire setup is determined (10). This can be done, for example, by using a location stored in a tire pressure sensor or in a control unit for the tire pressure sensor. A target pressure for the tire is also determined (11). The target pressure depends at least on the position of the tire within the dual-tire setup. In particular, the target pressure for an inner tire of the dual-tire setup is lower than the target pressure for an outer tire. When the tires are cold, a difference between the target pressures is designed to compensate for pressure increases when the tires are warm. When the tires are warm, the target pressures are preferably temperature-compensated.Subsequently, a comparison is made between the measured tire pressure and the target pressure. Based on this comparison, an inflation device can then be activated, or information can be provided to a user.

[0028] Fig. Figure 2 shows a simplified schematic representation of a first embodiment of a device 20 for supporting the adjustment of the inflation pressure of a tire of a dual-tire vehicle. The device 20 has an input 21, via which, for example, pressure data P can be received. i_a , P o_aand temperature data for a tire as well as data on a tire position can be received. The tire position data can, for example, be a location stored in a tire pressure sensor or in a control unit for the tire pressure sensor. From this data, a position determination module 22 determines a position RP of the tire within the dual tires. A pressure determination module 23 is configured to determine a target pressure P. i_t , P o_t to determine the target pressure P for the tire. i_t , P o_t This depends at least on the position RP of the tire within the dual tire setup. In particular, the target pressure P i_t for an inner tire of the dual tires lower than the target pressure P o_t for an outer tire of a dual tire setup. In the case of cold tires, a difference between the target pressures P i_t , P o_tDesigned to compensate for pressure increases when the tires are warm. In the event of warm tires, the target pressures P i_t , P o_t Preferably temperature compensated. A comparison of a measured filling pressure P can be made using a comparison module 24. i_a , P o_a of the tire with target pressure P i_t , P o_t Based on the comparison, a control module 25 can then control a filling device or provide information to a user. Control commands from the control module 25 can be output via an output 28 of the device 20.

[0029] The position determination module 22, the pressure determination module 23, the comparison module 24, and the control module 25 can be controlled by a control module 26. Settings of the position determination module 22, the pressure determination module 23, the comparison module 24, the control module 25, or the control module 26 can be changed via a user interface 29. The data generated in the device 20 can be stored in a memory 27 if required, for example, for later evaluation or for use by the components of the device 20. The input 21 and the output 28 can be combined into a bidirectional interface. The position determination module 22, the pressure determination module 23, the comparison module 24, the control module 25, and the control module 26 can be implemented as dedicated hardware, for example, as integrated circuits.Of course, they can also be partially or fully combined or implemented as software that runs on a suitable processor, for example a GPU or a CPU.

[0030] Fig. Figure 3 shows a simplified schematic representation of a second embodiment of a device 30 for supporting the adjustment of the inflation pressure of a tire of a dual-tire vehicle. The device 30 comprises a processor 32 and a memory 31. For example, the device 30 is a computer, a control unit, or a mobile device, e.g., a smartphone or a tablet. Instructions are stored in the memory 31 which, when executed by the processor 32, cause the device 30 to perform the steps according to one of the described methods. The instructions stored in the memory 31 thus embody a program executable by the processor 32, which implements the method according to the invention. The device 30 has an input 33 for receiving information, in particular pressure and temperature data for a tire, as well as data on a tire's position.Data generated by processor 32 is provided via output 34. It can also be stored in memory 31. Measurement data or calculation results can also be stored in memory 31. Input 33 and output 34 can be combined to form a bidirectional interface.

[0031] The processor 32 can comprise one or more processor units, such as microprocessors, digital signal processors, or combinations thereof.

[0032] The memory elements 27, 31 of the described embodiments can have both volatile and non-volatile memory areas and can include a wide variety of storage devices and storage media, for example hard disks, optical storage media or semiconductor memory.

[0033] Details of an embodiment of the invention will be presented below with reference to Fig. 4 to Fig. 8 will be described.

[0034] Fig. Figure 4 schematically shows a means of transport 40, which in this case is a truck. The means of transport 40 has one axle with single tires 41, each with a single tire 42, and two axles with dual tires 43, each with an inner tire 44 and an outer tire 45. The means of transport 40 also has a tire pressure monitoring system 46. Tire pressure sensors 50 are arranged in the tires 42, 44, 45 of the means of transport 40 and are used by the tire pressure monitoring system 46. For communication with the tire pressure sensors 50, the means of transport 40 has one or more receivers 47, which are connected to a central control unit 48 (CCU). Communication between the components in the means of transport 40 takes place, for example, via a network 49.The respective positions of the tire pressure sensors 50 can be automatically detected by evaluating the radio signal strength of the signals transmitted by the tire pressure sensors 50 to the receivers 47, e.g., the RSSI values ​​(RSSI: Received Signal Strength Indication). The signal strength of the radio signals at a receiver 47 depends on the distance between the transmitter and receiver 47 and therefore allows conclusions to be drawn about the tire position. The determined tire positions can be stored, for example, in the tire pressure sensors 50 or in the central control unit 48.

[0035] Fig. Figure 5 schematically shows a tire 42, 44, 45 for a means of transport in which a tire pressure sensor 50 is arranged. This can be attached to the inner liner 51 of the tire, for example by means of an adhesively attached container. Alternatively, the tire pressure sensor 50 can also be arranged on a valve 52 of the tire. This is indicated by the dashed box at the valve 52.

[0036] Fig. Figure 6 schematically shows the structure of a tire pressure sensor 50. The tire pressure sensor 50 has a pressure sensor 60 for measuring the tire pressure and an accelerometer 61 for detecting tire movement. The measured values ​​of the accelerometer 61 are typically used to activate different operating modes of the tire pressure sensor 50, e.g., a "Park" mode or a "Drive" mode. A power manager 62 regulates the power supply to the various components of the tire pressure sensor 50. Firmware, applications, and calibration data of the tire pressure sensor 50 are stored in a memory 63. This can, for example, be a ROM memory (ROM: Read-Only Memory). The device comprises a read-only memory and a flash memory. An RF transmitter 64 is provided for transmitting data; this transmitter can operate, for example, at a frequency of 315 MHz or 434 MHz. An LF receiver 65 is provided for receiving data; this receiver can operate, for example, at a frequency of 125 kHz. The measured values ​​from the pressure sensor 60 and the accelerometer 61 are converted into digital data by an A / D converter 56. The tire pressure sensor 50 is controlled by a microcontroller 67.

[0037] Fig. Figure 7 characteristically shows the development of the tire inflation pressure p over time t for a dual tire setup during driving, specifically for the outer tire P. o and the inner tire P iThe curves begin with the start of the journey. It can be seen that the pressure increase of the inner tire is higher than that of the outer tire because the inner tire heats up more. To prevent this phenomenon during driving and thus prevent or significantly reduce the resulting irregular tire wear, the expected temperature-related pressure difference during driving can be predicted. Instead of the same inflation pressure for both tires, targeted, different inflation pressures for the dual tires are specified using an inflation assistant, which directly counteracts the heating problem. Using these targeted, different inflation pressures, the tire inflation pressure profile can be calculated as shown in... Fig. 8 shown will be changed.

Claims

[1] Method for assisting an adjustment of the inflation pressure of a tire (44, 45) of a dual tire (43) of a means of transport (40), comprising the steps: - Determining (10) a position (RP) of the tire (44, 45) within the dual tires (43) by a position determination module (22) using a localization stored in a tire pressure sensor (50) or in a control unit (48) for the tire pressure sensor (50); and - Determining (11) a target pressure (P i_t , P o_t ) for the tire (44, 45) by a pressure determination module (23), wherein the target pressure (P i_t ) for an inner tire (44) of the dual tires (43) is lower than the target pressure (P) o_t ) for an outer tire (45) of the dual tires (43) and in the case of a cold condition of the tires (44, 45) a difference between the target pressures (P i_t , P o_t) is designed to compensate for expected deviations in pressure increases when the tires are warm (44, 45). [2] Method according to claim 1, wherein in the case of a warm state of the tires (44, 45) the target pressures (P i_t , P o_t ) are temperature compensated using temperature data from the tire pressure sensor (50). [3] Method according to claim 1 or 2, wherein the localization is transmitted to a filling assistant implemented as an application on a smartphone. [4] Method according to one of the preceding claims, wherein a comparison (12) of a measured filling pressure (P i_a , P o_a ) of the tire (44, 45) with the target pressure (P i_t , P o_t ). [5] Method according to claim 4, wherein a filling device is controlled (13) or information is provided to a user (14) based on the comparison (12). [6] Computer program with instructions which, when executed by a computer, cause the computer to perform the steps of a method according to any one of claims 1 to 5 for supporting an adjustment of the inflation pressure of a tire (44, 45) of a dual tire (43) of a means of transport (40). [7] Device (20) for assisting in the adjustment of the inflation pressure of a tire (44, 45) of a dual tire (43) of a means of transport (40), comprising: - a position determination module (22) for determining (10) a position (RP) of the tire (44, 45) within the dual tires (43) using a localization stored in a tire pressure sensor (50) or in a control unit (48) for the tire pressure sensor (50); and - a pressure determination module (23) for determining (11) a target pressure (P i_t , P o_t ) for the tire (44, 45), where the target pressure (P i_t) for an inner tire (44) of the dual tires (43) is lower than the target pressure (P) o_t ) for an outer tire (45) of the dual tires (43) and in the case of a cold condition of the tires (44, 45) a difference between the target pressures (P i_t , P o_t ) is designed to compensate for expected deviations in pressure increases when the tires are warm (44, 45).

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