Field of the invention

The invention relates to tire pressure monitoring sensors (herein called wheel units) for vehicles and specifically to universal tire pressure monitoring sensors which are configurable to a variety of vehicles.

Description of the related art

A tire-pressure monitoring system (TPMS) is an electronic system for monitoring the air pressure inside a pneumatic tire on various types of vehicles. A TPMS reports in near real-time tire-pressure information to the vehicle's control system and to the driver. The TPMS mentioned herein are direct TPMS, which use sensors mounted inside a tire (herein called wheel units) for measuring the pressure of gasses within the tire.

The wheel unit communicates with the vehicle's control module with the use of wireless signals, which are typically radio frequency (RF) signals. These signals contain the wheel unit pressure information and possibly other data like temperature, wheel unit identification number or wheel location information. Moreover, an external programming unit may be used to communicate with the wheel units, typically with the use of low frequency (LF) radio signals or physical contacts. The inbound communication may be used by a wheel unit installer to activate the wheel unit in order to receive diagnostic information, to change the wheel unit identification number or to modify the wheel unit to operate according to a particular TPM system specification. The wheel units may be installed by vehicle manufacturers as OEM (Original Equipment Manufacturers) products or they may be installed in installation facilities for replacement or refurbishment purposes as an after-market (AM) solution. The wheel units may operate differently in different TPM systems, depending on a vehicle manufacturer, model, year of production, make and TPMS manufacturer. The differences between TPM systems influence implementation of the wheel unit, for example: transitioning between different operation modes, triggering conditions for an internal program flow, learning algorithms, timing, wireless signal characteristics, communication protocol, data packet content, etc.

In order for a single wheel unit to cover most of the after-market (AM) TPM systems, these systems must be supported by the respective AM-TPMS wheel unit implementation(s). In order to accomplish this goal, one may either implement a multitude of wheel unit types, each implementing a single TPM system, or a universal wheel unit, which may be either used on all relevant existing vehicles directly, or which may be programmed/configured by an installer to support one or more TPM systems. Using a multitude of single-system wheel unit types is not desirable, as it requires the wheel unit installers to stock a multitude of wheel units. This results in a high initial investment for the installer and the supply chain and makes the wheel unit selection time consuming. A universal wheel unit seems to be a much more economical solution.

US 7,518,495 B2 discloses a method, systems and tools for programming wheel units with a software program supporting a single TPM system. Suitable program software for the wheel unit is selected from a database. This is very flexible as new program implementations may be added later to the database. As the full software has to be loaded to the wheel unit, the programming times are comparatively long, as a low speed communication interface is used. This interface is normally used for transmitting wheel unit specific data and triggers by the wheel unit installers. Furthermore, the intense communication would reduce the capac- ity of the battery built into the wheel unit. Alternatively, a wired interface may be used. Such a wired interface requires additional hardware like drivers and electrical contacts, which make the wheel unit susceptible to ESD damage and corrosion at the electrical contact points. The handling of a wired interface is more complex as a cable has to be connected to the wheel unit prior to programming and disconnected after programming.

US 8692661 B2 discloses a universal wheel unit. A plurality of selectable programs is stored in the wheel unit during production and for adapting the wheel unit to a specific vehicle, the required program is selected by the wheel unit installer. This allows for a very fast programming, as the correct program has to be only selected. The drawback of this solution is that a large number of programs have to be stored in the wheel unit which further requires a large overhead of memory, increasing the wheel units costs. Alternatively, the memory-limited microcontroller of the wheel unit may only be pre-configured for a selection of vehicle models or protocols, which would require keeping a large number of wheel units on stock to provide AM coverage. A further disadvantage is that, due to pre-stored programs, no adaption to future requirements is possible. Instead, new wheel units have to be developed.

US 2015/0202932 Al discloses a wheel unit storing a basic version of a program in its memory. For configuration, selected vehicle type program parameters are stored in memory. This allows for a comparatively fast programming, as only the parameters have to be transmitted to the wheel unit. An adaption to future requirements is only possible within the reach of the parameters. Basic new functions cannot be added.

EP 2821260 Al discloses a method for setting a wheel unit by deleting unnecessary encoding procedures. As initially a large number of encoding procedures has to be stored in memory, a comparatively large memory is required or the memory limitation of commercial micro-controllers forces a number of wheel units to be stocked which further increases the costs of the wheel unit. Finally, adaption to new TPM systems is not always possible, unless they fit into an existing TPM system. Otherwise a new wheel unit has to be released.

Whenever a new TPM system appears on a market or an existing system is modified or if improvement possibilities or errors are uncovered within existing wheel unit software, the software must be updated. Some of the above-mentioned prior art relies on an external programming unit used by the AM installer to perform field updates on a wheel unit by the means of wired or wireless communication. In US 2015/0202932 Al the range of field updates is limited by the underlying software system. This may require re-sending the wheel units by the installer back to the producer for updates. US In some cases such updates may not be possible due to hardware and software limitations, forcing the wheel units to be withdrawn. US 8692661 B2 and EP 2821260 Al do not permit any level of software updates, thus wheel unit replacement is always required. This is disadvantageous and onerous not only for the installers but also for the entire supply chain as well as the wheel unit producers themselves. It may also require introduction of new version number of the wheel unit for each software update, thus affecting all parties involved in the wheel unit after market with extra costs, greater handling complexity, time slips, human errors and return rates.

The disclosure of US 7,518,495 B2 enables full software field updates, but the loading times may be long, which makes them more prone to communication errors, forcing the installer to repeat the process. This is reportedly a major problem for the installers, as it induces extra costs and delays. Moreover, the intense data transfers may consume extended amount of battery power, thus limiting the wheel unit lifetime.

Summary of the invention The problem to be solved by the invention is to provide a universal TPMS wheel unit, which requires little maintenance, allows simple handling and provides large flexibility. More specifically, configuring the wheel unit to operate within a specific TPM system should be fast and error-free to simplify and accelerate the wheel unit installation, thus saving installation costs. The amount of data transferred to the wheel unit during the configuration should be low in order to minimize the impact on the battery lifetime. Moreover, the wheel unit must provide a means to perform full field updates of its software, which range is not limited by the wheel unit existing software, to enable introducing new TPM systems support, modifying the behavior of the existing TPM system implemented within the wheel units, as well as error fixing, optimization and possibly other modifications and/or configurations. Thus, the wheel units must not require withdrawal from the installation facilities for future updates. Consequently, the wheel units version number does not need to be updated on each software update, thus simplifying the handling, reducing supply-chain management costs and being less prone to human errors. The wheel unit should be configurable to a large number of vehicles using different TPM systems.

Solutions to the problem are described in the independent claims. The dependent claims relate to further improvements of the invention.

In a preferred embodiment, a TPMS wheel unit comprises at least one environmental sensing component like a pressure, acceleration or temperature sensor indicating at least one parameter indicative of at least one condition of or within the tire, a processing unit for executing a program, which may be a microcontroller, a non-volatile memory for storing at least one first program, at least one second program and at least one configuration code, and a wheel unit communication module which may comprise a wireless transmitter, a wireless or wired receiver or a wireless or wired transceiver for forwarding information to/from a vehicle and/or a programming unit. The information may comprise details about the at least one parameter indicative of at least one condition of or within the tire, for example pressure, temperature, rotation direction, the wheel unit's battery state, or some other information regarding the wheel unit state. The wheel unit preferably has a housing which may be mounted to a tire or a rim such that it is held within a tire mounted to the rim.

The first program may be an implementation of an application loader, for example a boot loader. The first program may comprise a first upload manager using the wheel unit communication module to receive and/or install at least one second program to the non-volatile memory using a first communication protocol. The installation may comprise at least one of loading the program to the memory, linking the program with other software already residing in the memory, like a system manager, and unpacking the program. The first communication protocol may be a system of rules that allows communication between the first upload manager and a programming unit. The rules may define for example the radio signal frequency and/or amplitude, synchronization method, content of data packets, types of the packets, sequence of exchanging the packets, timing information, etc. The first program may provide access to its functionality like code or data to other software residing within the wheel unit, like the second program.

The wheel units may operate differently in different TPM systems, depending on a vehicle manufacturer, model, year of production, make and TPMS manufacturer. The differences between TPM systems influence implementation of the wheel unit, for example: transitioning between different operation modes, triggering conditions for an internal program flow, learning algorithms, timing, wireless signal characteristics, communication protocol, data packet content, etc. The second program may configure the wheel unit to operate according to at least one TPM system based on at least one configuration code. The second program may either re-use the first upload manager and/or the first communication pro- tocol to receive and/or install the configuration code or it may comprise the configuration code within itself. The installation may comprise at least one of the steps of loading the program to the memory, linking the program with other software already residing in the memory, like the first program, and unpacking the program. The second program may also comprise a second upload manager using the wheel unit communication module to receive and/or install the configuration code with the use of a second communication protocol. The second communication protocol may be a system of rules that allows communication between the second upload manager and a programming unit. The rules may define for example the radio signal frequency and/or amplitude, synchronization method, content of data packets, types of the packets, sequence of exchanging the packets, timing information, etc. The second program may provide access to its functionality to other software residing within the wheel unit, like the first program.

The configuration code may comprise at least one of a third program, a data structure, replacement code or instructions and it may be used by the second program to configure at least one of the first program or preferably itself to operate according to at least one TPM system. The second program may perform the configuration immediately after receiving the configuration code or it may store the configuration code in the non-volatile memory and use them as instructions during the wheel unit operation.

The content of the configuration code may be used by the second program to configure the wheel unit to operate according to at least one TPM system using one or more methods, depending on a type of the second program. The second program may use a specific method of configuring the wheel unit. For example, the configuration code may comprise instructions according to which the second program deletes parts of the first program or the second program. The configuration code may also comprise replacement code and instructions instructing the second program which parts of the first program or the second program to replace with the replacement code. The configuration code may also comprise a data structure containing the information of which one or more TPM systems to support; at least one of the first program or preferably the second program may contain an implementation of more than one TPM system and it may use the data structure to decide according to which one or more of the implemented TPM systems to operate. The configuration code may also comprise a data structure with one or more TPM system parameters that characterize the TPM system, like transitioning between different operation modes, triggering conditions for an internal program flow, learning algorithms, timing, wireless signal characteristics, communication protocol, data packet content; the data structure is used by at least the first program or preferably the second program to configure the wheel unit to the specified TPM systems. The configuration code may also comprise a third program describing a behavior of at least one TPM system and the first program or the second program may contain a runtime interpreter interpreting the third program to make the wheel unit operate according to the specified TPM systems.

In another embodiment the wheel unit may comprise a system manager for general system management tasks, like power management, task scheduling or hardware management for the wheel unit resources like environmental sensing components, non-volatile memory, communication module, processing unit, etc. The system manager may also comprise utility functions, like timers, mathematical operators, memory manipulation, string manipulation, etc. The system manager may provide an access to the functionality it implements to at least one of the first program or the second program.

In a preferred embodiment at least one of the first program or the second program may comprise the system manager. In a preferred embodiment at least one of the first program or the second program may modify or configure the behavior or the functionality of the system manager.

In a further embodiment, a wheel unit configuration system may comprise at least a wheel unit as disclosed above and a programming unit, the programming unit further comprising a database containing information about vehicles and at least one of the first program, second program and the configuration code, a wired or wireless programming unit communication module to communicate with the wheel unit, and a microcontroller or a microprocessor. The wheel unit may be operated by an installer who prepares the wheel unit for use in a specific vehicle.

In a preferred embodiment the programming unit may be used for uploading at least one configuration code to the wheel unit in order to configure the wheel unit to operate according to one or more TPM system.

In a preferred embodiment the programming unit may be used for performing a full field software update that may comprise uploading at least one of the first program, the second program and/or a system manager to the wheel unit in order to at least add support for a new TPM system to the wheel unit, to modify the behavior of the wheel unit for one of the TPM systems supported by the wheel unit and to perform software error fixing and/or optimizations. The full field software updates eliminate the need to withdraw a sensor from the market for modifications, improvements or functionality extensions. This, in turn, simplifies handling the wheel units, it reduces supply-chain management costs and it makes the wheel unit management less prone to human errors.

In a preferred embodiment the programming unit may comprise an output device providing the installer with information messages and options selection, like a screen or a printer, and an input device letting the installer communicate his choices to the programming unit, like a keyboard, a touch screen, a barcode scanner or a camera. The programming unit input/output devices may allow the installer selecting one or more target TPM system, according to which the wheel unit should operate, for example by manually entering the vehicle identification number (VIN), by reading the VIN using a barcode scanner or a camera or by manually selecting the vehicle producer, make, model, production date, etc. The programming unit input/output devices may also enable inserting version numbers of the first and second programs and the configuration code, or inserting other information indicating such version numbers, like wheel unit serial number, which can be used by the programming unit to find the required version numbers in its memory. The programming unit may also acquire the version numbers directly from the wheel unit, using the wheel unit communication module. The programming unit may comprise an algorithm using the target TPM system selection and the version numbers to automatically detect if in order to configure the wheel unit to operate according to the target TPM system the wheel unit requires any of the full field software update, uploading the configuration code or no additional action.

In a preferred embodiment, the full field software update may require transferring much larger amount of data to the wheel unit than uploading the configuration code. Accordingly, the full field software update may be considerably more time-consuming than uploading the configuration code. Reportedly, uploading the configuration code may take as little as 3 seconds, compared to 30 seconds required by the full field software update.

In a preferred embodiment, the full field software update may, by its nature, be necessary only very seldom when configuring the wheel unit to a specific TPM system and uploading the configuration code very often. Since uploading the configuration code may be considerably less time-consuming than full field software update, the process of configuring the wheel unit to a specific TPM system may be relatively fast in vast majority of cases. Transferring small amount of data decreases probability of communication errors, thus improving reliability of the configuration process and minimizing its impact on the wheel unit battery lifetime. Fast and reliable configuration process accelerates the wheel unit installation, thus saving installation costs.

In a preferred embodiment the programming unit may comprise a battery as an energy source. In vast majority of cases configuring the wheel unit may require uploading only the configuration code, which may require transferring relatively small amount of data. Lower data transfers require less energy, thus prolonging the operational time of the programming unit after recharging or replacing the battery. That in turn simplifies handling the programming unit, resulting in time and cost savings.

In a preferred embodiment, the full field software updates are categorized to various levels of importance. Depending on the importance level, the programming unit may only warn the user that an update is required or silently choose to perform the full field software update without notifying the user, for example if a selected TPM system is currently not supported by the wheel unit, or it may let the user select if an update should be performed, for example if an update us unessential, like in case of battery lifetime optimizations. The policy used for the notifications may be partly or fully modifiable within the programming unit or it may be pre-determined by the programming unit producers.

In another embodiment, the choice of the of the second program type used in specific wheel units may be made depending on the current market situation, specific customer demands, specific vehicle demands, programming unit requirements, legal requirements and other reasons. Different types of the second programs have different properties which may prove advantageous in a given situation. Wheel units using various second programs may or may not be assigned with a different version number.

In another embodiment, the full field software update may either comprise the configuration code for configuring the wheel unit to one or more TPM systems, or the first program, second program or system manager, being a part of the full field software update, may be pre-configured to operate according to one or more TPM systems. The pre-configuration may be performed by the programming unit according to the configuration code, or it may be performed by an external tool and the pre-configured first program, second program and/or system manager stored in the database of the programming unit.

In a preferred embodiment at least one first program and/or second program and/or at configuration code may be installed in the wheel unit as default, during production. These are further mentioned as default first program, default second program and default configuration code. This way the installer may not only avoid the potentially lengthy process of loading and installing the second program, but they may even skip the step of configuring the wheel unit to a specific target TPM system, if the default configuration code supports the target TPM system. Thus, the wheel unit installation time can be significantly shortened. Preferably, the most popular TPM system should be used for the default configuration code.

In a preferred embodiment at least one default first program and/or the default second program and/or the default configuration code may be transferred to the wheel unit's non-volatile memory during production using a wheel unit direct access module. The direct access module provides direct access to the wheel unit control unit and the non-volatile memory, enabling reading and writing to the non-volatile memory without the need to use the communication module. The direct access module requires physical access to the connectors of a chip storing control unit or the non-volatile memory. That may imply that the access to the direct access module is not available after the wheel unit housing is sealed. The direct access module may provide faster data transfer rate than the wheel unit communication module, thus it may be advantageous to use it to accelerate the wheel unit production process.

In another embodiment at least the first program, the default second program and the default configuration code may be transferred to the wheel unit during production using both, the direct access module and the wheel unit communication module, simultaneously or in sequence. Using multiple methods of data transfer may be advantageous if the production is performed in many facilities or by many manufacturers. Preferably, a dedicated production programming unit is provided for installing the default programs during production, the unit using the direct access module or the wheel unit communication module for communication with the wheel unit.

In a preferred embodiment, the non-volatile memory and the processing unit reside on the same chip, although they may also be located on separate chips.

In a further embodiment, the first program may be implemented as a boot loader.

In another embodiment auxiliary data may be exchanged between the programming unit and the wheel unit. The auxiliary data may contain wheel unit identification number, firmware updates, data reception confirmation, protocol handshakes, version numbers of software residing on the sensor, checksums or code used for invoking wheel unit producer proprietary functionality.

In another embodiment the first and the second communication protocols may be identical. In another embodiment multiple second programs may be stored within the wheel unit memory to enable multiple methods of configuring the wheel unit to a specific TPM system.

In another embodiment multiple configuration codes may be stored within the wheel unit memory, adapting the wheel unit to operate according to a multitude of TPM systems simultaneously.

In another embodiment the second program may configure the wheel unit to operate with a multitude of TPM systems simultaneously based on a single configuration code.

In another embodiment the first program may be modified, configured or replaced with the use of the second program to enable error fixing, improvements or other maintenance task within the first program.

Description of Drawings

In the following the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment with reference to the drawings.

Figure 1 shows a basic structure and usage of a wheel unit configuration system.

Figure 2 shows details of a wheel unit configuration system.

Figure 3 shows the logic structure of a wheel unit.

Figure 4 shows the logic structure of a programming unit.

Figure 5 shows the details of the data transmitted between the wheel unit and the programming unit.

Figure 6 shows the wheel unit configuration system from the chronological and deployment perspective.

In figure 1 a basic structure and usage of a wheel unit configuration system is shown. A programming unit 100 may have an output device 110, preferably a display or a printer, and an input device 170, preferably a touch screen, a keyboard or a barcode scanner. The output device may provide an installer 830 a plurality of options, for example for selecting a target vehicle, within which the wheel unit must operate. The installer may communicate his options selection with the input device. The programming unit will configure the wheel unit, for example via a wireless communication interface 120, to make the wheel unit operate according a specific TPM system used by the vehicle selected by the installer. In figure 2, more details of a wheel unit configuration system are shown. The programming unit 100 preferably has a microcontroller or microprocessor 130 which is further connected to a memory 140 or storage. The memory may be organized as a database and may contain information about vehicles and wheel units. It may be any kind of RAM/ROM, a disk drive or a network connected storage. It is further preferred, if the information about vehicles comprise at least one of vehicle manufacturers, vehicle models, manufacturing years, vehicle identification number and specific TPMS requirements. The information about wheel units may comprise specific first programs, second programs and configuration codes. Furthermore, there may be cross links between specific vehicle manufacturers, models, years or individual vehicles and specific first programs, second programs and configuration codes. There may also be information about wheel unit hardware and software like manufacturer, model number, manufacturing year, software version numbers and specific hardware capabilities like processing power and memory space. The programming unit 100 may contain an update algorithm 180 to link the information about the vehicles and wheel units and other information stored within its memory to select the appropriate content of communication data 500 to be transferred to the wheel unit 200, for example via wireless communication 120. The communication data content may be further received and used by the wheel unit to configure itself for operation with a specific TPM system.

For communication with and software upload to a wheel unit, a programming unit communication module 160 may be provided. This communication module preferably is a wireless communication module, but may also be a wired communication module. Although a unique directional communication module is sufficient to upload data to the wheel unit, it is preferred to have a bidirectional communication module for transmitting data to a wheel unit and receiving information from a wheel unit. The received data may be information about the wheel unit like manufacturer, type, manufacturing year, software version or seri- al number. Also a checksum or confirmation of uploaded data may be received. It is further preferred, if the programming unit has an output device 110 and input device 170, which may be controlled by the microcontroller or microprocessor 130. It is further preferred that the microcontroller/microprocessor has access to a network interface 150 which may provide a connection to an external computer, an external network, external data storage or to the Internet. This may be used for updating the database 420, downloading and/or updating information about vehicles, wheel units, the first programs, second programs and configuration codes or any software required for handling and/or compiling such information.

A wheel unit 200 preferably comprises a processing unit 230 for controlling the wheel unit together with a non-volatile memory 240. The memory preferably may be a flash, EEPROM, ROM memory or a battery powered RAM. An environmental pressure sensor 280 may be provided for monitoring the gas pressure within the tire and providing such pressure information to the processing unit. There may be also at least one auxiliary sensor 290 for measuring the wheel unit environmental conditions, like acceleration, shock or temperature. For communication with the programming unit 100, at least one wheel unit communication module 260 may be provided comprising at least a wireless transmitter 261 and a wireless or wired receiver 262. This wheel unit communication module enables a first program 510 or a second program 520 at least to receive the communication data 500 from the programming unit 100 and store it into the memory 240. Preferably, the communication data are the first program, the second program or a configuration code 530. For powering the wheel unit 200, a battery 270 may be provided.

It is preferred that the same wheel unit communication module enables communication with a vehicle. Although the communication requirements for uploading the software from the programming unit 100 and during normal operation and tire pressure monitoring are significantly different, they may be handled by the same wheel unit communication module. The minimum requirement for data upload is the receiver 262 in the wheel unit communication module 260 to receive the first program 510, the second program 520, the configuration code 530 and the system manager 310, whereas the minimum requirement for tire pressure monitoring is the transmitter 261 for transmitting status information to a vehicle. There may be a low power transceiver for these both communication paths. There also may be a high speed high power transmitter. Of course any further combination like a full high-speed transceiver for software upload and a full low-power, low-speed transceiver for pressure monitoring may be provided.

Figure 3 shows the logic structure of a wheel unit. There may be a system manager 310 for general system management tasks, like power management, task scheduling or hardware management for the wheel unit resources like environmental sensing components, non-volatile memory, communication module, processing unit, etc. The system manager may also comprise utility functions, like timers, mathematical operators, memory manipulation, string manipulation, etc. The system manager may provide an access to the functionality it implements to at least one of a first program or a second program. The wheel unit may also comprise a first program 510 using the first upload manager 511 to receive the second program 520 and to store it within the non-volatile memory 240. The second program may be configured to operate within a specific TPM system based on a configuration code 530, received and installed with the use of the second upload manager 521.

Figure 4 shows the logic structure of the programming unit. It has an upload manager 410 for uploading data to a wheel unit. Furthermore, a database 420 may be provided for storing information about vehicles and/or wheel units and/or for storing related first programs, second programs, configuration codes and system managers. A user interface manager 430 may be provided to com- municate with an installer 830. There may further be a network manager 440 and a TPMS receiver manager 450 and an update algorithm 180.

Figure 5 shows the data transferred between the programming unit 100 and the wheel unit 200. The data 500 may comprise at least one of the first program 510, the second program 520, the configuration code 530, system manager 310 or auxiliary data 550. The auxiliary data 550 may contain a wheel unit identification number, firmware updates, data reception confirmation, protocol handshakes, version numbers of software residing on the sensor, checksums or code used for invoking wheel unit producer proprietary functionality What exactly is transmitted within the communication data 500 depends on a wheel unit memory 240 content, an update algorithm 180, current point in wheel unit lifetime and possibly other factors.

Figure 6 shows the wheel unit configuration system from a chronological and deployment perspective.

Figure 6a shows a first scenario, where a wheel unit 200 does not require a full field software update comprising updating a first program 510, a second program 520, a configuration code 530 or a system manager 310 residing in the nonvolatile memory 240. Within the production facility 800 a first program, a system manager, a default second program and a default configuration code is loaded (710) to the wheel unit's non-volatile memory 240 with the use of a production programming unit 600. The production programming unit is preferably able to handle multiple wheel units at a time and it may use either a wheel unit communication module 260 or its direct access module 220 to write to the non-volatile memory. In another embodiment only a first program may be uploaded to the processing unit using its direct access module 220 and the second program is uploaded with the use of the wheel unit communication module 260. Any other combination is also possible. Next, the wheel unit is shipped to the installation facility 820 via its supply chain 810. At the destination the programming unit 100 is used to specify to which target TPM system the wheel unit should be configured to. The programming unit communicates with the TPMS wheel unit and it uses the information received from the wheel unit, like version numbers of the software stored within the wheel unit, as well as its internal data base 420 to determine that the wheel unit does not require full field software update. The programming unit determines also, that the wheel unit requires installing a new configuration code. Accordingly, only the configuration code is transferred to the wheel unit (720), thus making it compatible with the required TPM system. The entire communication process is relatively fast, reportedly it lasts around 3s.

Figure 6b shows a second scenario, where the wheel unit requires the full field software update. Similarly to the process shown in figure 6a, the wheel unit is initialized in the production facility 800 and then it is shipped to the installation facility 820 via the supply chain 810. Similarly, the installer selects the target TPM system on the programming unit 100 and the tool determines whether the full field software update is necessary. According to the tool database the version of the second program residing in the wheel unit memory does not support the target TPM system. A newer version of the second program is uploaded to the wheel unit within the full field software update 710, the newer version supporting the target TPM system. After the upload is completed, the programming unit automatically uploads to the wheel unit the required configuration code (720) in order to make the newly uploaded second program configure the wheel unit to operate according to the target TPM system. The entire communication process is significantly longer than the process presented in Figure 6a, reportedly it lasts around 30s. The process presented in Figure 6a is much more common than the process presented in figure 6b, since updating the second program is only required when full field software updates are necessary. List of reference numerals

100 programming unit

110 output device

111 program options display

120 wireless communication

130 microcontroller/microprocessor

140 memory

150 network interface

160 programming unit communication module

170 input device

180 update algorithm

200 wheel unit

220 direct access module

230 processing unit

240 non-volatile memory

260 wheel unit communication module

261 wireless transmitter

262 wireless or wired receiver

270 battery

280 environmental pressure sensor

290 auxiliary sensor

310 system manager

410 upload manager

420 database

430 user interface manager

440 network manager

450 receiver manager

500 communication data

510 first program first upload manager

second program

second upload manager configuration code

auxiliary data

production programming unit full field software update uploading the configuration code production facility

supply chain

installation facility

installer

Wheel unit configuration system