Automatic identification of tire mounting position on a vehicle

Abstract

A computer implementation method for automatic detection of the mounting position of a tire on a vehicle having two or more tires, comprising: - transmitting one or more signals at each of a plurality of predetermined angular positions and a current measurement of the estimated load of the vehicle during at least one rotation of the tire by a tire mounting sensor mounted on the tire; - receiving the transmitted one or more signals and the estimated load measurement by a receiving unit; - processing the received one or more signals and the received estimated load measurement by a processing unit, - measuring the relative signal intensity indicator (RSSI) value of each of the one or more signals transmitted at each of the plurality of predetermined angular positions; - associating the derived angular RSSI values ​​with each of the plurality of predetermined angular positions based on the measured RSSI values; - grouping the derived angular RSSI values ​​into a group of angular RSSI values ​​that form an RSSI code associated with the tire; A computer implementation method comprising: processing by: - ​​associating the RSSI code associated with a tire with an estimated load measurement received by the tire to form a pair of RSSI code-and-load value associated with the tire; - retrieving a set of reference RSSI code-and-reference load value pairs, wherein each reference RSSI code in the set of reference pairs is associated with a known tire mounting position on the vehicle, and each reference load value in the set of reference pairs is associated with a known load measurement associated with a known mounting position; and - evaluating the difference between a tire-and-load value pair with respect to each pair in the set of reference RSSI code-and-reference load value pairs; and - determining the tire mounting position on the vehicle based on the evaluated difference between the RSSI code-and-load value pair and each pair in the set of reference RSSI code-and-reference load value pairs.

Description

[Technical Field]

[0001] The present invention relates to a system, method, and computer program for automatically identifying the mounting position of a tire on a vehicle, which is equipped with a tire-mounted sensor (TMS). [Background technology]

[0002] Sensors mounted on tires are generally called tire-mounted sensors (TMS). TMSs are used to monitor several parameters of the corresponding tire (pressure, temperature, load, speed, etc.) and / or to extract some information about the interaction between the tire and the surrounding environment (road surface and / or vehicle, etc.). TMSs also maintain a unique identification number (UID), which uniquely identifies the corresponding sensor and the tire on which it is mounted.

[0003] This association makes it possible to build a history of tire-related measurements, which not only allows for the detection of the tire's current state but also enables predictions about the tire's future state, such as wear rate and pressure loss rate, through appropriate analysis. Therefore, it is possible to identify a specific TMS unit at any time. The TMS unit itself can also store data indicating the tire's mounting position on the vehicle, in relation to data indicating its installation on the vehicle. This mounting position information is fundamental for properly utilizing, cross-checking, and integrating all tire and vehicle data provided by the TMS unit. An obvious example is given by the precise pressure of the tire, which is based on the position where the tire is mounted (e.g., front or rear). Another example is a scenario where the load is unevenly distributed across the vehicle suspension, and therefore the tires are not equally affected by the applied load. In this case as well, knowing the precise current mounting position of the tire on the vehicle allows for real-time correction of the more affected tire parameters, and at the same time, makes it possible to make more accurate predictions about the tire's wear rate.

[0004] However, during the lifespan of a vehicle, the tires mounted on it may be repositioned or the tires themselves may be replaced entirely, thereby determining the change in the tire mounting position on the vehicle. The TMS unit may also be detached from the tire and replaced with another one, for example, due to a physical rupture or battery depletion. In this case, manually verifying the tire mounting position on the vehicle at any given time is particularly cumbersome and time-consuming. Methods that enable such verification to be performed automatically thanks to the TMS unit mounted on the vehicle tire are known in the prior art, but they have several drawbacks. For example, (a) the on-board antenna that receives the TMS information signal must be positioned according to a fixed configuration because it is sensitive to noise to the extent that the signal may be lost and / or not accurately decoded; (b) the TMS signal must be collected while the vehicle is stopped or moving at a very limited speed, as increasing speed also increases the possibility of noise and errors in the collected signal; and (c) a high degree of synchronization and bidirectional communication is required between the antenna and the TMS unit, which has a significant impact on the resource usage of the TMS unit (especially battery consumption). [Overview of the Initiative]

[0005] The present invention aims to solve the above-mentioned drawbacks.

[0006] According to a first aspect of the present invention, a computer implementation method for automatic detection of the mounting position of tires on a vehicle having two or more tires is provided, the method being: - A tire mounting sensor attached to the tire transmits one or more signals at each of a plurality of predetermined angular positions and the current measured value of the estimated load of the vehicle during at least one rotation of the tire. - The receiving unit receives one or more transmitted signals and estimated load measurements, - The processing unit processes one or more received signals and the received estimated load measurements. - Measuring the relative signal strength indicator (RSSI) value of each of one or more signals transmitted at each of a plurality of predetermined angular positions; - Based on the measured RSSI values, associating the derived angular RSSI values with each of the plurality of predetermined angular positions; - Grouping the derived angular RSSI values into a group of angular RSSI values that form an RSSI code associated with the tire; - Associating the RSSI code associated with the tire with an estimated load measurement value received by the tire to form a pair of the RSSI code associated with the tire and a load value; - Retrieving a set of pairs of a reference RSSI code and a reference load value, wherein each reference RSSI code in the set of reference pairs is associated with a known tire mounting position on the vehicle, and each reference load value in the set of reference pairs is associated with a known load measurement value associated with the known mounting position, and - For each pair in the set of pairs of the reference RSSI code and the reference load value, evaluating the difference between the pair of the RSSI code associated with the tire and the load value; and processing by doing so; - Determining the mounting position of the tire on the vehicle based on the evaluated differences between the pair of the RSSI code and the load value and each pair in the set of pairs of the reference RSSI code and the reference load value. A computer-implemented method is included.

[0007] For the purposes of the present disclosure, the terms "wheel" and "tire" are used interchangeably and will continue to be used as such hereinafter.

[0008] Similarly, for the purposes of the present disclosure, the terms "code", "pattern", and "vector" are used interchangeably and will continue to be used as such hereinafter.

[0009] According to a second aspect of the present invention, a system for automatically detecting the mounting position of a tire on a vehicle equipped with two or more tires is provided, and the system is - A memory configured to store a set of pairs of reference RSSI codes and reference load values, wherein each reference RSSI code in the set of reference pairs is associated with a known tire mounting position on the vehicle, and each reference load value in the set of reference pairs is associated with a known load measurement value associated with the known mounting position, the memory; - A tire-mounted sensor configured to transmit, during at least one rotation of the tire, one or more signals at each of a plurality of predetermined angular positions and a current measurement of the estimated load of the vehicle; - A receiving unit configured to receive one or more transmitted signals and a measurement of the estimated load; - The one or more received signals and the received load measurement; - Measuring, for each of the one or more signals transmitted at each of a plurality of predetermined angular positions, a relative signal strength indicator (RSSI) value; - Based on the measured RSSI values, associating a derived angular RSSI value with each of a plurality of predetermined angular positions; - Grouping the derived angular RSSI values into a group of angular RSSI values that form an RSSI code associated with the tire; - Associating the RSSI code associated with the tire with the estimated load measurement received by the tire to form a pair of the RSSI code associated with the tire and a load value; - Retrieving a set of pairs of reference RSSI codes and reference load values; - A processing unit configured to process by evaluating, for each pair in the set of pairs of reference RSSI codes and reference load values, the difference between the pair of the RSSI code associated with the tire and the load value; - A determination unit configured to determine the mounting position of the tire on the vehicle based on the evaluated differences between the pair of the RSSI code and the load value and each pair in the set of pairs of the reference RSSI code and the reference load value, a system comprising.

[0010] For the purposes of this disclosure, the terms “signal” and “message” are, and will continue to be, used interchangeably.

[0011] According to a third aspect of the present invention, a computer program is provided, and when the program is executed by a computer, the computer is made to execute the method of the first aspect.

[0012] In this embodiment, the derived angle RSSI value is associated with each of a plurality of predetermined angle positions based on the measured RSSI value. Selecting the measured RSSI value of one or more signals transmitted at a predetermined angular position as the derived angular RSSI value associated with that predetermined angular position, or This includes averaging the measured RSSI values ​​of one or more signals transmitted at a predetermined angular position, and selecting the resulting average value as the derived angular RSSI value associated with the predetermined angular position.

[0013] In this embodiment, one or more transmitted signals encode a unique identifier of the corresponding tire-mounted sensor that transmits the signal.

[0014] In this embodiment, one or more transmitted signals encode a unique identification number corresponding to an RFID tag embedded in the corresponding tire, enabling the unambiguous identification of that tire.

[0015] In this embodiment, one or more transmission signals encode angular positions from a plurality of predetermined angular positions from which the signals are transmitted.

[0016] In the embodiments, the method according to the first aspect of the present invention further includes a pre-learning step for each tire mounted on the vehicle at a known mounting position, the pre-learning step being: - The step of forming an RSSI code associated with a tire based on the group of angle RSSI values ​​described in any one of the preceding claims, - The steps of associating the acquired RSSI code with the received current measurement of the estimated load of the vehicle to form a pair of reference RSSI code and reference load, - A method comprising the steps of storing the reference pair as a reference RSSI code and reference load pair, associated with a corresponding known mounting position of a tire on a vehicle.

[0017] In the embodiment, a plurality of predetermined angular positions are selected from the upper half of the tire arc.

[0018] In this embodiment, one or more transmission signals are wireless packets, and the receiving unit comprises a wireless receiver. [Brief explanation of the drawing]

[0019] Please refer to the attached drawings below. [Figure 1] This is a schematic diagram of a system for automatically identifying the mounting position of tires on a vehicle, according to one aspect of the present invention. [Figure 2] Figure 1 shows an example of communication methods between entities in the system. [Figure 3] An example of an RSSI vector related to the tires of a vehicle according to the present invention is shown. [Figure 4] Details of an exemplary RSSI vector according to the present invention are shown. [Figure 5] A schematic flowchart of a method for automatically identifying the mounting position of tires on a vehicle, according to one aspect of the present invention, is shown. [Figure 6] A schematic flowchart of a method for automatically identifying the mounting position of tires on a vehicle, according to another aspect of the present invention, is shown. [Figure 7] An example of a metric used to evaluate the distance between RSSI vectors according to the present invention is shown. [Figure 8] The results of implementing a system according to one aspect of the present invention on an exemplary truck having an eight-wheel trailer are shown. [Figure 9]The results of implementing a system according to one aspect of the present invention on an exemplary truck having an eight-wheel trailer are shown. [Figure 10] The results of implementing a system according to one aspect of the present invention on an exemplary truck having an eight-wheel trailer are shown. [Modes for carrying out the invention]

[0020] Figures 1 and 2 show a system for automatically identifying the mounting position of tires on a vehicle, according to one embodiment of the present invention.

[0021] This system comprises multiple tire mounting sensor (TMS) units, each unit mounted on a tire and therefore associated with its respective wheel.

[0022] The vehicle 1 shown in Figure 1 is a truck, merely as an example. The vehicle 1 is equipped with multiple tires 2, and each tire 2 has a TMS unit 3 attached to it. Each TMS unit 3 includes a microcontroller 4 with memory and a processor 5. Each TMS unit 3 is associated with a unique ID identification number that enables unambiguous identification from other TMS units.

[0023] Each TMS unit 3 also includes a transmitting module configured to communicate with a receiving unit 7 installed in the vehicle 1. In an exemplary embodiment, the receiving unit is a radio receiver (e.g., an antenna) configured to measure the received signal strength index (RSSI) of each signal (e.g., radio packet) received from the TMS unit, and the transmitting module of the TMS unit 3 is configured to transmit radio packets to the radio receiver.

[0024] In another exemplary embodiment, the transmit modulation may specifically be 433 MHz FSK.

[0025] Those skilled in the art will readily recognize that the present invention is not limited to any specific communication technology between any TMS unit and a receiving unit. Any known communication method and protocol for establishing a one-way or two-way communication channel is suitable for implementing signal transmission and reception between the TMS unit and the in-vehicle receiving unit according to the present invention.

[0026] In one embodiment, the TMS unit 3 may be configured to communicate with a remote device, such as a computer 8, a smartphone 9, or a remote server (not shown), via a network communication device (not shown) mounted on the vehicle. The network communication device may be a dongle plugged into a vehicle port (e.g., OBD port, FMS port, etc.), or it may be a permanently installed transceiver box. The remote server may comprise an online database / cloud / platform. In one exemplary embodiment, the TMS unit may communicate with the network communication device via a Bluetooth® connection, but it will be understood that any suitable form of short-range wireless communication or wired connection may be used. The network communication device may be networked, but may communicate with the remote device via a wireless network connection (e.g., a cellular network). The remote device may be further connected to an output device via a wireless network or another wired connection.

[0027] Each tire to which a corresponding TMS unit is attached may be equipped with an additional radio transmitter, such as an RFID sensor 6, configured to uniquely identify the tire. In this configuration, there are two identification codes associated with the tire: a unique identification number (UID) associated with the TMS unit 3 and a unique identification number (SGTIN-96) associated with the radio transmitter, such as the RFID sensor 6. The TMS unit 3 may be configured to be further coupled to a specific radio device; for example, if the RFID sensor 6 is mounted on or inside the tire, the TMS unit 3 may flash the RFID sensor 6 once to store the unique identification number carried by the RFID sensor in its own memory.

[0028] The transmitting module of each TMS unit 3 is configured to transmit a signal at a predetermined angular position relative to the collision point of the TMS unit 3 on the ground while the corresponding wheel is rotating on the road surface (which may be an actual road or the rolling surface of the test machine). This is also shown in Figure 4 and will be explained in more detail below.

[0029] The system in Figure 1 also comprises a processing unit and a decision unit (not shown). The functions of these units will become clear when considered in the following description of the automatic localization method, with further reference to Figures 5 and 6.

[0030] As the tire rotates, the TMS unit 3, which is attached to the tire by the sensor unit holding member, also rotates, positioning itself at different angles A1 to A5 relative to the ground. In reality, the position where the TMS unit 3 collides with the ground is considered to be position A0, which is 0 degrees.

[0031] The rotational motion of the TMS unit 3 generates centrifugal acceleration in the Z-axis direction, which can be measured by an accelerometer and converted into a digital sample by an analog-to-digital converter system. The digital sample can then be used to estimate several sensor / tire system parameters, including angular velocity during wheel rotation and ground collision events.

[0032] The TMS unit 3 uses a well-known algorithm, such as that described in European Patent Application No. 21193660, to determine the ground collision and rotation time T. rev It can recognize this. With each rotation of the tire, the sensor can evaluate its angular velocity Ω and estimate its angular position α in order to transmit a signal at a known angle.

[0033]

number

[0034] This invention relates to a fixed wheel angular position A i Message S transmitted by TMS unit 3 located at i This is based on the observation that the RSSI of each different angular position A remains essentially stable over time (only slight fluctuations are observed). i Then, several messages S from the same TMS unit 3 i The transmission and subsequent reception (for example, five messages S1-S5 transmitted over a wheel rotation) result in an RSSI pattern (or vector) 10 associated with the corresponding tire 2, which can be used to distinguish the tire and its mounting position on the vehicle 1 from other tires on the vehicle.

[0035] The time at which transmission must begin in order to send a message at a fixed, predetermined angular position can be calculated according to any algorithm known in the art. In an example where the message to be transmitted is an RF signal and the receiving unit performs an RSSI measurement of the received packet, which is the average value over the entire packet, the start of transmission is the angle α required to send the message according to the following formula. i It must be expected to center it to:

[0036]

number

[0037] To enable recognition of the tire positions on the vehicle 1 for each tire 2, several messages S i are transmitted by each TMS unit 3 at different angular positions A i during each rotation of the tire 2 to create a pattern 10 of RSSI values associated with each pair of TMS unit tires. Each RSSI pattern 10 can be considered as a vector in an n-dimensional space and is composed of n RSSI values corresponding to n transmission angles. In one embodiment, the transmission angle of each transmitted message is encoded within that message. In yet another embodiment, a sequence of messages from a fixed angle may be known a priori. This is possible because each message comprises a header section and a payload, and the header section comprises a PID field that identifies the type of the transmitted message.

[0038] The number and values of the transmission angles can be arbitrarily predetermined as long as there is sufficient inter-packet time between one transmission and the next to avoid interference. In addition to a particular selection of the transmission angles, since the angular position of the TMS unit during wheel rotation is clearly related to the wheel speed, it is also possible to maintain the desired value of the minimum inter-packet time constant by limiting the wheel speed without changing the selection of the predetermined transmission angles.

[0039] In one particularly advantageous embodiment, the transmissions during wheel rotation maintain their predetermined positions when the TMS unit 3 is in the upper half of the wheel arc, and this solution provides a higher RSSI value and minimizes interference due to proximity and collision between the TMS unit 3 and the ground. In one exemplary implementation of the embodiment shown in Figure 4, n is equal to 5, and thus five predetermined transmission angles A1 to A5 are determined at equal intervals of 45°, starting at 90° from a ground collision position A0 at 0°.

[0040] Each received message S i Regarding this, the corresponding RSSI value can be used as is, directly measured, or the RSSI value derived as described above (e.g., the mean, median, or arithmetic mean calculated over time or over the number of packets received, with respect to the same angle) can be used for evaluation. In the latter case, it is useful to obtain a reduction in unavoidable noise superimposed on the ideal RSSI value received under ideal conditions. This noise is due to several factors, including scattering of transmitted signals reflected by the ground, which changes over time due to unevenness of the ground or differences in road surface material, scattering of packet signals reflected by parts of the vehicle body, which changes over time due to vibrations and other geometric changes, such as changes in path length induced by vibrations from the vehicle's suspension.

[0041] Exemplary applicable averaging processes may be the calculation of the arithmetic mean, the median, or any other process known in the art that is suitable for filtering outliers due to the aforementioned RSSI noise.

[0042] Figures 3 and 4 show an example of a visual representation of an RSSI pattern 10 associated with n predetermined transmission angles A1, where n=5, and therefore n transmission angles A1 to A5 are shown.

[0043] Figure 3 shows, in particular, 12 wheels T including tractor wheels and trailer wheels. iThis shows a track having (i is 1 through 12). Tire T1 is in the left front (FL) position, tire T2 is in the right front (FR) position, tires T3 and T4 are left drive wheels in the outer (DLO) and inner (DLI) positions respectively, tires T5 and T6 are right drive wheels in the outer (DRO) and inner (DRI) positions respectively, tires T7, T8 and T9 are left tractor wheels in positions TL1, TL2 and TL3 respectively, and tire T 10 , T 11 , and T 12 These are the right tractor wheels located at positions TR1, TR2, and TR3, respectively.

[0044] Figures 3 and 4, when combined, show each tire T i The TMS unit 3 associated with (i is 1 to 12) transmits five signals S1 to S5 from five predetermined transmission angles A1 to A5, thereby each pattern V i Each tire T i 12 RSSI patterns V associated with i An exemplary embodiment is shown that brings about this outcome.

[0045] Multiple on-board radio receivers 7 (e.g., antennas) may be used as the receiving unit. In the specific case where vehicle 1 is a truck, radio receivers may be installed in association with the truck's tractor wheels, and additional radio receivers may be installed in association with the truck's trailer wheels. In yet another truck configuration where multiple trailers are mounted on a vehicle tractor, radio receivers may be positioned in association with each trailer. In these scenarios, each radio receiver receives transmitted signals from a TMS unit exclusively associated with the tires of the corresponding tractor / trailer section.

[0046] Those skilled in the art will readily see that such references to trucks are merely examples, and that the present invention is not particularly limited to any type of vehicle, but can be used to detect the mounting position of tires on passenger cars, as well as vehicles such as trucks, semi-trucks, and buses.

[0047] Figure 5 shows a schematic flowchart of a method for automatically identifying the mounting position of a tire 2 on a vehicle 1 according to one embodiment of the present invention.

[0048] The automatic positioning method includes a start step S0. This method involves n predetermined transmission angles A i This is based on the assumption that a reference RSSI vector (i.e., code or pattern) associated with a set of reference vectors is available for each given known wheel position on the vehicle 1. Each vector in the set of reference vectors has the same structure as the RSSI pattern 10 and contains n RSSI values ​​associated with n predetermined transmission angles, corresponding to a specific wheel at a known mounting position. The set of reference RSSI codes may simply be pre-stored in memory.

[0049] Those skilled in the art will readily understand that the specific location or association of memory storing the set of reference RSSI codes is not essential to the present invention, and that the set may be stored in memory associated with the TMS unit, memory associated with the receiving unit, any other memory associated with the processing and / or decision unit, or even any other memory associated with the remote server.

[0050] In one embodiment, a set of reference vectors is calculated in the learning phase of an optional method step S1, and during the learning phase, each TMS unit 3 on each tire 2 of the vehicle 1 transmits n predetermined transmission angles A over multiple wheel rotations. i Then, message S is sent to receiving unit 7. i The following is transmitted. Thus, a set of reference vectors is calculated for all wheels of the vehicle, and the reference vector associated with a given wheel at a given position is formed by the average, median, or arithmetic mean RSSI value derived for each transmission angle. Thus, at the end of learning stage S1, an association is established between each wheel at a specific mounting position on the vehicle and the corresponding RSSI reference code.

[0051] While not mandatory, the aforementioned pre-learning phase helps minimize potential positional errors. This is particularly useful in scenarios where the vehicle is a long vehicle with many wheels (e.g., a truck) and its tire configuration may change over time (e.g., changes in the configuration of the tractor section, trailer section, and the amount of twin tires). Even if it has been experimentally observed that the baseline RSSI code tends to remain stable for several days when no changes in tire configuration occur, in such scenarios, it may be further considered to repeat the learning phase regularly, for example, daily, to ensure that the baseline RSSI code reflects the updated tire configuration.

[0052] During execution, during transmission step S2, the TMS unit 3 of each wheel 2 transmits at the same predetermined transmission angle A as the reference RSSI code was calculated during the rotation of the wheel. i In the set, Message S i These messages are sent to the receiving unit 7. These messages are received by the receiving unit 7 (step S3).

[0053] The transmission step S2 is not limited to a specific position of the receiving unit 7 mounted on the vehicle 1. Some degree of asymmetry in the mounting position of the receiving unit 7 with respect to the center of the vehicle 1 can make the RSSI pattern 10 of the wheel more "characteristic" and thus allow for easier identification of the difference from the reference vector, but this is merely an optional requirement. This method can determine the mounting position of a particular wheel 2 with high accuracy, regardless of the position of the receiving unit 7 on the vehicle 1, as also shown in Figures 8 to 10 described below.

[0054] In step S4, the TMS unit 3 transmits n predetermined transmission angles A i n messages S sent to the receiving unit 7 i For a sequence of messages containing S, the processing unit performs multiple processing substeps. iThe RSSI value is measured (S4a), and the measured RSSI value and the predetermined transmission angle A of each signal Si from which it was transmitted are used. i Based on the association with the given angle, a single angle RSSI value associated with each predetermined angular position is derived (S4b), and the predetermined transmission angle A i Each predetermined transmission angle A forms an RSSI pattern 10 associated with all of them. i The derived angle RSSI values ​​are grouped and stored in memory (S4c), and then each of the calculated RSSI patterns 10 is compared with each code in the set of reference RSSI codes (S4d), the comparison including an evaluation of the difference between the RSSI pattern 10 under analysis and each RSSI code in the set of reference RSSI codes.

[0055] In step S5, the decision unit, based on the result of the evaluated difference, selects the sequence of messages S transmitted by the corresponding TMS unit 3. i Determine the mounting position of tire 2 associated with it. The process ends in step S6.

[0056] Step S4 described above involves n messages S over a single wheel rotation. i Not limited to the collection of messages, the RSSI pattern 10 associated with tire 2 can be calculated based on a single transmission sequence of n messages (i.e., a transmission sequence over only one wheel rotation), or it can be calculated based on two or more sequences of n messages (i.e., transmission sequences over multiple wheel rotations). In the latter case, it should be noted that in the RSSI pattern 10, the RSSI value corresponding to the i-th transmission angle may be the average, median, or arithmetic mean calculated over several transmissions received in relation to that angle, in order to improve the reliability of position detection.

[0057] In step S4d, an exemplary metric used to evaluate the difference between the RSSI pattern under analysis and each reference RSSI code is a simple distance metric, such as the Euclidean distance. The Euclidean distance approach is very robust to noise, yet simple and easy to implement and requires very few computing resources. However, it will be readily apparent to those skilled in the art that the evaluation step is not limited to any particular metric used, and that different types of metrics are applicable to perform the evaluation.

[0058] In the exemplary embodiment shown in Figure 7, combined with the tire configuration in Figure 3, the evaluation is based on Euclidean distance, and the determination of the wheel mounting position is based on the minimum Euclidean distance from each RSSI reference code within the set of reference RSSI codes. Figure 7 shows tire T 12 A simplified example is shown in which the RSSI vector 13 calculated in relation to is compared with the reference RSSI code 11 associated with tire mounting position TR2 and the reference RSSI code 12 associated with mounting position TR3. It is visually apparent that the RSSI vector 13 has the lowest Euclidean distance from the reference RSSI code 12. Therefore, it is determined that the wheel associated with the RSSI pattern 13 is at mounting position TR3. Figure 7 shows a simplified comparison, but as is evident from this disclosure, the evaluation is performed for each reference RSSI code associated with each known tire mounting position.

[0059] With respect to the processing unit and decision unit, it should be noted that several architectural possibilities are foreseen, without limiting the applicability and scope of the method according to the present invention. In one exemplary embodiment, the processing unit and the decision unit are separate hardware devices, each further comprising at least a processor and memory. In yet another embodiment, the processing unit and the decision unit may be implemented as a software layer by the same hardware device capable of implementing both the processing step and the decision step. In yet another embodiment, the processing unit and the decision unit may be implemented as a software layer within the receiving unit 7 itself, so that the onboard receiving unit 7 can perform all the functions of the method according to the present invention. In yet another embodiment, the processing may be distributed such that the processing step S4 and the decision step S5 may be implemented as a software layer on a remote device (i.e., a remote cloud computing system, etc., not installed in the vehicle).

[0060] Those skilled in the art will readily understand that the data processing required by the method of the present invention (including the final determination of the wheel mounting position S5) may be performed exclusively by a device installed in the vehicle, exclusively on a remote server, or shared between the remote server and the in-vehicle device.

[0061] Furthermore, the reliability of the automatic positioning method according to the present invention can be further enhanced by applying a machine learning algorithm in addition to, or instead of, the current evaluation step to determine the actual mounting position of a given wheel during analysis.

[0062] If vehicle 1 is used specifically for carrying cargo (e.g., a van, truck, etc.), an increase in load on the vehicle's suspension may affect the relative position of the receiving unit 7, and consequently, the RSSI pattern 10 of the relevant wheels may also be affected. This drawback can be overcome by modifying the method to further utilize load estimates measured by the TMS unit 3 during operation and transmitted to the receiving unit 7.

[0063] Figure 6 shows a schematic flowchart of a method for automatically identifying the mounting position of a tire 2 on a vehicle 1, according to another embodiment of the present invention.

[0064] The method shown in Figure 6 is a slightly modified version of the method described above with reference to Figure 5. This method addresses the known shortcomings of the same state-of-the-art technology described above in relation to Figure 5. However, in scenarios where vehicle load is a relevant parameter, it has been observed that this method improves the accuracy of automatic tire mounting position identification.

[0065] In this modified version of the method described above, each given reference RSSI code can be further associated with a given and / or expected load value associated with a specific wheel mounting position, thereby creating reference code-load pairs that can be pre-stored in association with a given wheel at a given position. These reference code / load pairs may be established as outputs of a pre-learning stage, if an optional pre-learning stage is anticipated.

[0066] Therefore, when a reference code-load pair is used, each RSSI reference code in the set of RSSI reference codes is further associated with a load or load range relative to the wheel position, in which case the processing and determination steps are further based on comparing and identifying the difference between the pair formed by the actual RSSI pattern under analysis and the load value transmitted by the corresponding TMS unit and each of the pairs formed by each reference RSSI code and reference load value (or range).

[0067] This method has a starting step S7. This method involves n predetermined transmission angles A i This is based on the assumption that a reference RSSI vector (i.e., code or pattern) associated with a set is available for each given known wheel position on vehicle 1. Each vector in the set of reference vectors has the same structure as the RSSI pattern 10 and contains n RSSI values ​​associated with n predetermined transmission angles, corresponding to a specific wheel at a known mounting position. Furthermore, predetermined and / or expected load values ​​or ranges for each known mounting position are also associated with each reference RSSI vector in the set. The reference RSSI code-load pairs may simply be pre-stored in memory in association with each known mounting position.

[0068] Step S8 is optional and corresponds to the learning stage described in relation to Step S1. However, during the learning stage S8, measured values ​​of the vehicle's estimated load are also transmitted and collected by the TMS unit 3 to associate with the corresponding reference RSSI code so as to form and store reference RSSI code-load pairs.

[0069] During execution, during transmission step S9, the TMS unit 3 of each wheel 2 transmits at the same predetermined transmission angle A as the reference RSSI code was calculated during the rotation of the wheel. i In the set, Message S i The TMS unit 3 transmits the current estimated load measurement of vehicle 1 to the receiving unit 7. These messages are received by the receiving unit 7 (step S10).

[0070] In step S11, n predetermined transmission angles A i n messages S sent i With respect to a sequence of messages including the current measurement of the estimated load of the vehicle from the TMS unit 3 to the receiving unit 7, the processing unit performs several processing substeps. It measures the RSSI value of each received message Si (S11a), and the measured RSSI value and each signal S iThe predetermined transmission angle A to which it was transmitted. i Based on the association with the given angle, a single angle RSSI value associated with each predetermined angular position is derived (S11b), and the predetermined transmission angle A i Each predetermined transmission angle A forms an RSSI pattern 10 associated with all of them. i The angle RSSI values ​​derived for are grouped and stored in memory (S11c), the RSSI patterns 10 thus obtained are associated with estimated load measurements received by the corresponding TMS unit to form RSSI pattern-load value pairs (S11d), a set of reference RSSI code-load pairs is retrieved (S11e), and each of the calculated RSSI pattern-load pairs is then compared with each pair in the set of reference RSSI code-load pairs (S11f), the comparison including an evaluation of the difference between each pair formed by the actual RSSI pattern in analysis and the load values ​​transmitted by the corresponding TMS unit and each pair formed by each reference RSSI code and reference load value (or range).

[0071] In step S12, the decision unit, based on the evaluated difference result, receives the message S transmitted by the corresponding TMS unit 3. i The mounting position of tire 2 is determined in the sequence and associated with the estimated load measurements. The method ends in step S13.

[0072] It should be noted that thanks to the method and system described above, it is possible to recognize changes in the position of the tires (for example, in the case of swapping the positions of the tires). It should also be noted that, using the method and system according to the present invention, it is also possible to recognize the position of a newly mounted tire 2 or a newly mounted TMS unit 3, as in the case of tire replacement or tire mounting sensor replacement. In these cases, as described in relation to Figure 1, the different TMS units 3 can be distinguished thanks to the fact that different TMS units 3 carry different unique identification numbers embedded in their transmitted messages, and the messages transmitted by the TMS units 3 may further include a specific identification number of the RFID sensor 6 of the tire 2 to which they are mounted.

[0073] The advantages of the present invention will become even clearer by referring to the examples shown in Figures 8 to 10.

[0074] Figure 8 shows the configuration of a truck with an 8-wheel trailer, where the trailer wheels W1 to W8 are positioned at their respective mounting locations P1 to P8.

[0075] Figure 9 shows a matrix representing the Euclidean distance values ​​of RSSI patterns 10 calculated for each wheel W1 to W8 after performing the method for automatically identifying the mounting position of the vehicle wheels according to the present invention. i Regarding the signal S transmitted by the corresponding TMS unit 3 i The data is collected, the corresponding RSSI vector 10 is derived, and the Euclidean distance of that vector from each code in the set of reference RSSI codes associated with positions P1-P8 is calculated and shown in the matrix accordingly. The matrix in Figure 9 shows, in particular, the case when none of the wheels W1-W8 have been replaced or their positions have been changed, with respect to when the set of reference RSSI codes has been calculated and pre-stored.

[0076] Note that, referring to the matrix, all the lowest values ​​lie on the diagonal of the matrix, which is consistent with the fact that the wheel positions have not changed.

[0077] Figure 10 also shows a matrix representing the Euclidean distance values ​​of RSSI patterns 10 calculated for each wheel W1 to W8 after performing the method for automatically identifying the mounting position of the vehicle wheels according to the present invention. i Regarding the signal S transmitted by the corresponding TMS unit 3 i The data is collected, the corresponding RSSI vector 10 is derived, and the Euclidean distance of the vector from each code in the set of reference RSSI codes associated with positions P1 to P8 is calculated and shown accordingly in the matrix. The matrix in Figure 10 shows, in particular, the case where wheel W1 at position P1 is swapped with wheel W8 at position P8, with respect to when the set of reference RSSI codes has been calculated and pre-stored, and so on. Wheels W2 to W7 remain unchanged at positions P2 to P7, respectively, but W8 is at position P1 and W1 is at position P8. The method according to the present invention makes it easy to identify the swapping of positions in such that the smallest calculated Euclidean distance of the RSSI vector 10 of wheel W1 is no longer related to the reference RSSI code of position P1, but to the reference RSSI code of position P8, and so on for wheel W8 and position P1.

[0078] The present invention has been described above with reference to preferred embodiments. It is intended that other embodiments may exist that refer to the same inventive concept and fall within the scope of the appended claims.

Claims

1. A computer implementation method for automatically detecting the mounting position of tires on a vehicle equipped with two or more tires, - The tire mounting sensor attached to the tire transmits one or more signals at each of a plurality of predetermined angular positions and the current measured value of the estimated load of the vehicle during at least one rotation of the tire. - The receiving unit receives one or more transmitted signals and the estimated load measurement values, - The processing unit processes the one or more received signals and the received estimated load measurement values. - Measure the relative signal strength indicator (RSSI) value of each of the one or more signals transmitted at each of the plurality of predetermined angular positions. - Associating the derived angle RSSI value with each of the plurality of predetermined angle positions based on the measured RSSI value, - Grouping the derived angle RSSI values ​​into a group of angle RSSI values ​​that form an RSSI code associated with the tire, - To associate the RSSI code associated with the tire with the estimated load measurement value received by the tire, thereby forming a pair of the RSSI code associated with the tire and the load value. - Retrieving a set of pairs of reference RSSI codes and reference load values, wherein each reference RSSI code in the set of reference pairs is associated with a known tire mounting position on the vehicle, and each reference load value in the set of reference pairs is associated with a known load measurement value associated with the known mounting position, and - With respect to each pair in the set of the reference RSSI code and the reference load value, evaluate the difference between the pair of the RSSI code and the load value associated with the tire. To process by, - Determining the mounting position of the tire on the vehicle based on the evaluated difference between the pair of RSSI code and load value and each pair in the set of the pair of reference RSSI code and reference load value, Computer implementation methods, including those mentioned above.

2. Associating the derived angle RSSI value with each of the plurality of predetermined angle positions based on the measured RSSI value is: - Selecting the measured RSSI value of one or more signals transmitted at the predetermined angular position as the derived angular RSSI value associated with the predetermined angular position, or - Average the measured RSSI values ​​of one or more signals transmitted at the predetermined angular position, and select the resulting average value as the derived angular RSSI value associated with the predetermined angular position. The method according to claim 1, including the method described in claim 1.

3. The one or more transmitted signals encode a unique identifier of the corresponding tire mounting sensor that transmits the signal, and / or The method according to claim 1 or 2, wherein the one or more transmitted signals encode a unique identification number corresponding to an RFID tag embedded in the corresponding tire, enabling unambiguous identification of the tire.

4. The process further includes a preliminary learning step for each tire mounted on the vehicle at a known mounting position, wherein the preliminary learning step is: - The step of forming an RSSI code associated with the tire based on the group of angle RSSI values ​​described in any one of claims 1 to 3, - The steps of associating the acquired RSSI code with the received current measurement of the estimated load of the vehicle to form a pair of reference RSSI code and reference load, - The steps of storing the reference pair as a pair of the reference RSSI code and the reference load, in association with the corresponding known mounting position of the tire on the vehicle, The method according to any one of claims 1 to 3, including

5. The method according to any one of claims 1 to 4, wherein the plurality of predetermined angular positions are selected from the upper half of the tire arc.

6. The method according to any one of claims 1 to 5, wherein the one or more transmitted signals encode the angular positions from the plurality of predetermined angular positions to which the signals are transmitted.

7. The method according to any one of claims 1 to 6, wherein the one or more transmitted signals are wireless packets, and the receiving unit comprises a wireless receiver.

8. A system for automatically detecting the mounting position of tires on a vehicle equipped with two or more tires, - A memory configured to store a set of pairs of reference RSSI codes and reference load values, wherein each reference RSSI code in the set of reference pairs is associated with a known tire mounting position on the vehicle, and each reference load value in the set of reference pairs is associated with a known load measurement value associated with the known mounting position. - A tire mounting sensor attached to the tire and configured to transmit one or more signals at each of a plurality of predetermined angular positions and the current measurement of the estimated load of the vehicle during at least one rotation of the tire, - A receiving unit configured to receive one or more transmitted signals and the estimated load measurements, - The one or more signals received and the received load measurement values ​​are used to obtain the following: - Measure the relative signal strength indicator (RSSI) value of each of the one or more signals transmitted at each of the plurality of predetermined angular positions. - Associating the derived angle RSSI value with each of the plurality of predetermined angle positions based on the measured RSSI value, - Grouping the derived angle RSSI values ​​into a group of angle RSSI values ​​that form an RSSI code associated with the tire, - To associate the RSSI code associated with the tire with the estimated load measurement value received by the tire, thereby forming a pair of the RSSI code associated with the tire and the load value. - Extracting the set of pairs of the aforementioned reference RSSI code and the aforementioned reference load value, - With respect to each pair in the set of the reference RSSI code and the reference load value, evaluate the difference between the pair of the RSSI code and the load value associated with the tire. A processing unit configured to process by, - A determination unit configured to determine the mounting position of the tire on the vehicle based on the evaluated difference between the pair of RSSI code and load value and each pair in the set of the pair of reference RSSI code and reference load value, A system that includes this.

9. Associating the derived angle RSSI value with each of the plurality of predetermined angle positions based on the measured RSSI value is: - Selecting the measured RSSI value of one or more signals transmitted at the predetermined angular position as the derived angular RSSI value associated with the predetermined angular position, or The measured RSSI values ​​of one or more signals transmitted at the predetermined angular position are averaged, and the resulting average value is selected as the derived angular RSSI value associated with the predetermined angular position. The system according to claim 8, including the following:

10. The one or more transmitted signals encode a unique identifier of the corresponding tire mounting sensor that transmits the signal, and / or The system according to claim 8 or 9, wherein the one or more transmitted signals encode a unique identification number corresponding to an RFID tag embedded in the corresponding tire, enabling unambiguous identification of the tire.

11. The process further includes a preliminary learning step for each tire mounted on the vehicle at a known mounting position, wherein the preliminary learning step is: - The step of forming an RSSI code associated with the tire based on the group of angle RSSI values ​​described in any one of claims 8 to 10, - The steps of associating the acquired RSSI code with the received current measurement of the estimated load of the vehicle to form a pair of reference RSSI code and reference load, - The steps of storing the reference pair as a pair of the reference RSSI code and the reference load, in association with the corresponding known mounting position of the tire on the vehicle, A system according to any one of claims 8 to 10, including the system described in any one of claims 8 to 10.

12. The system according to any one of claims 8 to 11, wherein the one or more transmitted signals encode the angular position from the plurality of predetermined angular positions to which the signals are transmitted.

13. The system according to any one of claims 8 to 12, wherein the plurality of predetermined angular positions are selected from the upper half of the tire arc.

14. A computer program, which, when executed by a computer, includes an instruction causing the computer to perform the method described in any one of claims 1 to 7.

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