Method for estimating the vehicle-distributed load resulting from the passengers in the vehicle

Abstract

Disclosed is a method for estimating the variation in the load of a mounted assembly on a vehicle, the variation being the result of a passenger boarding the vehicle, the method comprising the following steps: having the passenger board the vehicle; recording the internal pressure P in the fluidic cavity of an equipped mounted assembly; ascertaining the internal temperature T in the fluidic cavity of the equipped mounted assembly using a specified law of change; evaluating a variation in the volume ΔV of the equipped mounted assembly by means of the recorded internal pressure P and the ascertained internal temperature T using a model of a fluid in adiabatic transformation, the fluid having a perfect gas behavior; and estimating a variation in the load ΔZ carried by the n equipped mounted assembly using a second function comprising, as a parameter, the evaluated intermediate variation in volume ΔV and the flattening stiffness of the tire of the mounted assembly per unit volume KP.

Description

DESCRIPTION TITLE: METHOD FOR ESTIMATING THE LOAD DISTRIBUTED ON A VEHICLE DUE TO VEHICLE PASSENGERS Field of invention

[0001] The present invention relates to the field of real-time determination of the load variation generated by the boarding of passengers in the vehicle, in particular when the vehicle is stationary, making it possible to identify the number of passengers on board and their location in the passenger compartment of the vehicle. Technological background

[0002] Obtaining the variation in static load applied to a stationary vehicle makes it possible to determine the presence of people on board the vehicle. Indeed, determining the variation in load applied to inflatable systems such as mounted assemblies generally requires a balancing scale; it is not easy to determine this load outside of very specific loading locations. In order to evaluate the variation in load carried by the vehicle outside of these specific locations, it is possible to evaluate the load carried by each mounted assembly of the vehicle through an indication of the tire's footprint on the ground. If a measurement through a static pressure quantification system is possible by inserting the measuring system between the mounted assembly and the ground, its implementation is not simple and the accuracy of the measurement is subject to the correct positioning of the measuring system.Another alternative is to evaluate the dimension of the contact patch in rolling conditions through a measurement of the tire deformation at the wheel revolution in order to determine the dimension of the contact patch. Through a mathematical model, linking the type of tire, the inflation pressure and the external dimension of the footprint on the ground, we then go back to the variation of load applied to the tire casing. Unfortunately, this measurement is in rolling conditions. In addition, the precision of these measurements is delicate for very heavy loads where the deformation of the tire which determines the load variations tends to stabilize according to the circumferential direction on which the evolution of the measurement of the deformation of the tire casing generally relates. Therefore, we do not. can determine the number of passengers or their location in the vehicle before driving. In conclusion, it is not possible to check that each passenger's seat belts are properly fastened or to adapt the belt restraint force to the type of passenger seated, i.e. an adult or a child for example.

[0003] The following objects and methods of the invention aim to solve the problem of measuring the variation in load carried by the vehicle when passengers board the vehicle in the absence of a measuring system external to the vehicle, i.e. one that can be used at any time without specific measuring means. In addition, this evaluation is carried out while the vehicle is stationary, making it possible to determine the number of passengers and their location in the vehicle before any movement thereof. Description of the invention

[0004] The invention relates to a method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle comprising the following steps: • In the preliminary phase, that is to say before the boarding of at least one passenger in the vehicle, • Equip each mounted assembly of the vehicle with at least one pressure sensor, said sensor being capable of measuring the internal pressure of the fluid cavity of the mounted assembly delimited by a pneumatic casing and a wheel; • Determine the initial load ZI applied to at least one mounted assembly equipped with the vehicle; • Determine the initial inflation pressure PI of at least one assembly fitted to the vehicle; • Determine the initial internal temperature Tl of at least one mounted assembly equipped with the vehicle; • Evaluate the initial volume VI of each assembled assembly equipped at T using a first function comprising as parameter the volume V0 of the fluid cavity of the assembled assembly unloaded and inflated to the initial pressure PI and the flattening rigidity of the tire of the assembled assembly per unit of volume Kp • Evaluate the number of moles of fluid n in the fluid cavity of each assembled assembly equipped from a model taking into account the inflation pressure PI, the initial volume VI, the temperature Tl; • Determine a law of evolution of the internal temperature T of the fluidic cavity from the internal pressure P during an adiabatic transformation for at least one assembled assembly, inflated and subjected to the load Zl, equipped with at least one pressure sensor; • In the main phase, • Position at least one passenger in the vehicle; • Record the internal pressure P in the fluid cavity of each equipped assembly at an acquisition frequency Fl; • Determine the internal temperature T of the fluid cavity of each equipped assembly using the evolution law determined in the preliminary phase; • Evaluate an intermediate AV volume variation of each equipped assembly using the recorded internal pressure P and the internal temperature T determined using a fluid model in adiabatic transformation, the fluid having perfect gas behavior; and • Estimate a load variation AZ carried by each mounted assembly equipped using a second function including as parameter the intermediate volume variation AV evaluated, the flattening rigidity of the tire per unit of volume Kp.

[0005] According to a preferred embodiment, in the preliminary phase, each mounted assembly equipped with the vehicle comprising a temperature sensor capable of measuring the temperature of the fluid cavity, the method comprises, in the main phase, a step for recording the internal temperature T in the fluid cavity of each mounted assembly equipped at an acquisition frequency F2 and the method comprises a second step of evaluating the intermediate volume variation AV2 of each mounted assembly equipped taking into account the internal temperature T recorded using a fluid model having ideal gas behavior, subject to thermal equilibrium with the environment external to the fluid cavity.

[0006] The method for determining the applied load variation comprises two successive phases. The first phase consists of identifying the intrinsic parameters of the mounted assembly before the passenger boards the vehicle. This constitutes an installation of the vehicle measurement system through the implementation of the measurement systems at the mounted assemblies of the vehicle and the identification of the initial parameters of the mounted assemblies such as the volume of the fluid cavity, the quantity of fluid contained in the closed volume defined by the fluid cavity, the load initially applied to the mounted assembly by the vehicle, the internal temperature of the fluid cavity and the inflation pressure of the fluid cavity of each mounted assembly. Intuitively, the nature of the fluid is assumed to be known to estimate the quantity of fluid trapped in the fluid cavity.It is also necessary to have a law of evolution of the variation of internal temperature T associated with the variation of inflation pressure P of the assembled assembly when it is in use condition, in particular with the load ZI carried around the inflation pressure PI and the temperature TL This law of evolution can be fixed or result from an experimental characterization or a numerical simulation of the assembled assembly considered.

[0007] The second phase represents the step of evaluating the load variation applied to each mounted assembly equipped with an electronic device due to the passenger boarding the vehicle. The electronic device including the pressure sensor manages and conditions T pressure measurement recordings. Thus, recordings of the inflation pressure of the fluid cavity of each mounted assembly equipped with an electronic device are made at the time of the passengers boarding the vehicle. The temporal evolutions, in the transient phase, of the physical quantities of the fluid cavity are important. The boarding of the passengers causes a first transformation corresponding to the work generated by this additional load which is similar to an adiabatic transformation, i.e. rapid, which is moreover preponderant in front of the second transformation.After the rapid transformation, a slower transformation follows, which corresponds to the thermal equilibrium of the cavity. fluidic with the external environment through the tire casing and the wheel. This equilibrium is necessary following the modification of the internal temperature of the fluid cavity associated with the work generated by the boarding of passengers. This thermal equilibrium is slower to be implemented due to the thermal inertia of the tire and the wheel. In addition, the thermal equilibrium is of smaller magnitude on the variation of volume of the fluidic cavity than the transformation linked to the work. Therefore, it is possible to use sampling frequencies of the physical quantities, temperature and pressure, which are different. However, it is just as easy to use the same sampling frequency for both sensors. Preferably, the electronic device is fixed on the internal wall of the tire. The tire is in fact the most deformable element during the adiabatic transformation.If the method uses a temperature sensor, the temperature sensor being further away from the wheel, the relative temperature variations compared to the absolute temperature measured are greater because the thermal inertia of the casing is lower and the wheel, particularly the metal wheel, has by nature a greater inertia than the tire. This therefore improves the accuracy of temperature measurement and therefore the quality of the load variation method.

[0008] Using the variation of the inflation pressure of the fluid cavity, it is possible to determine the variation of the internal temperature of the fluid of the fluid cavity which is determined, for this purpose, by the evolution law previously determined in the preliminary phase. It therefore converts the measurement of the internal pressure of the fluid of the fluid cavity and an evaluation of the internal temperature of the fluid generated by the adiabatic transformation alone.

[0009] Then, it is possible to evaluate a first intermediate volume variation using a fluid model undergoing an adiabatic transformation. Here, the term adiabatic means that the transformation that the fluid undergoes due to the boarding of passengers in the vehicle is carried out without external heat exchange between the fluid cavity and the exterior of the mounted assembly, which assumes that it is rapid. Therefore, using only the variation of the measured inflation pressure and the internal temperature variation determined by the evolution law from the pressure variation of the fluid cavity, it is possible to estimate the first volume variation of the cavity fluidic generated by the boarding of the vehicle passengers, the fluid having undergone an adiabatic transformation. We will make the entirely suitable assumption for air or nitrogen that the fluid, in the gaseous state, of the cavity of the equipped mounted assembly is a perfect gas.

[0010] Preferably, a second intermediate volume variation is evaluated using a second fluid transformation. This second transformation is associated with the thermal equilibrium of the fluid with the exterior through the components of the mounted assembly, mainly the pneumatic envelope. The second volume variation undergone by the mounted assembly following this second transformation is then evaluated using the internal temperature variation recorded in the fluid cavity during the transient phase linked to passenger boarding but subsequent to the first fluid transformation, i.e. when the inflation pressure has reached the steady state. Taking this second volume variation into account guarantees better precision in the evaluation of the volume variation of the fluid cavity, which improves the precision of the measurement of the load variation at the level of each equipped mounted assembly.However, the first intermediate volume variation is sufficient to estimate, to a first order of magnitude, the overload applied to the assembled assembly.

[0011] Of course, taking into account the variation in the external temperature of the mounted assembly resulting from the thermal equilibrium of the mounted assembly also makes it possible to refine the measurement of the second variation in volume, generated by the boarding of passengers in the vehicle, at the level of each equipped mounted assembly. However, in a simple approach, the mounted assembly being preferably in a thermomechanically stable state, it is possible to take as the external temperature the initial internal temperature Tl of the fluid of the fluidic cavity of the mounted assembly.

[0012] These two transformations can take place at each time increment or one after the other over a period of time measurements. These evaluations of the intermediate volume variation must be made with measurements during the transient period of loading of the vehicle until the establishment of the mechanical and possibly thermal equilibrium of the mounted assemblies of the vehicle. Once these equilibria are established, the variations temperature and pressure of the fluidic cavity are infinitesimal, they are then in a new thermomechanically stable state.

[0013] Once the intermediate volume variation has been evaluated for each equipped mounted assembly, the associated static load variation resulting from passenger boarding must be evaluated for each equipped mounted assembly of the vehicle. To do this, the intermediate volume variation of each equipped mounted assembly must be transformed into an equivalent load variation. To this end, a characteristic of the mounted assembly, in particular that of the tire, which is called flattening rigidity per unit volume Kp, must be taken into account. This quantity makes it possible to relate the load carried by the mounted assembly to the volume variation of the fluid cavity generated by the load carried, the mounted assembly being crushed on a ground perpendicular to the applied load.This characteristic can of course be a fixed quantity or obtained by an experimental characterization of the assembled assembly or deduced from a numerical simulation campaign of the same assembled assembly. The assembled assembly must be in conditions of use close to those observed in the preliminary phase, that is to say around the internal temperature Tl and around the inflation pressure PI. Generally, this flattening rigidity of the assembled assembly is a quantity defined locally around the initial point of use of the assembled assembly in the reference frame associated with the internal pressure P, the internal temperature T and the volume of the fluid cavity V.

[0014] Preferably, before the main step, the at least one equipped mounted assembly is in a thermomechanically stabilized state.

[0015] It is preferable that the transient phenomena recorded at the level of the sensors of the electronic device are only due to the disturbance of the vehicle balance generated by the boarding of passengers. Thus, the other disturbances do not influence the response of the sensors, which improves the accuracy of the load variation evaluated by the method. However, if the disturbance of the vehicle balance occurs on a different time scale than the disturbance associated with the boarding of passengers or if this disturbance results in lower amplitudes of the responses of the sensors of the electronic device, the method remains entirely relevant.

[0016] Advantageously, the pressure sensor and / or the temperature sensor are placed in a sub-space of the closed fluid cavity delimited by the pneumatic casing and the wheel.

[0017] It is advantageous for sensors measuring low amplitude transient phenomena to be placed close to the occurrence of these transient phenomena so that the responses are not drowned in measurement noise. Thus, in the presence, for example, of a centralized inflation pressure system for mounted assemblies, it is advantageous for the sensors to be located at the mounted assembly and not at the centralized system. In the same logic, if the sensors are placed on the surface of the tire on the inside of the tire, the measurement will be more accurate than if the sensors are mounted on the wheel rim due to the distance of the measurement from the occurrence of the physical phenomenon which acts on the deformation of the tire casing due to the transient nature of the physical phenomenon.Finally, preferably, the sensors, mainly due to the temperature sensor, are positioned far away from the wheel which has a higher thermal inertia than the tire.

[0018] Advantageously, the pressure sensor operates with a resolution of less than a millibar.

[0019] Thus, it is possible to evaluate low volume variation and therefore low load variation.

[0020] Preferably, the acquisition frequency Fl is between 0.1 Hz and 10 Hz.

[0021] Optionally, the acquisition frequency F2 is lower than the acquisition frequency Fl.

[0022] It is useful for the acquisition frequency Fl to be high to capture the first transformation of the fluid which is fast. The frequency F2 being linked to the recording of the second sensor does not need such a high frequency since the second transformation of the fluid is slower by nature. However, it is quite possible to use the same acquisition frequency for both sensors by taking the frequency Fl as a reference.

[0023] According to a particular embodiment, the determination of the initial volume V0 takes into account the geometry of a wheel rim and the geometry of an unloaded tire, mounted on a rim and inflated to a reference pressure PO, preferably the reference pressure PO is the initial pressure PI.

[0024] Advantageously, the geometry of the tire and / or the geometry of the rim is determined using an identifier of the tire and / or the wheel of the fitted assembly, preferably obtaining the identifier of said tire and / or said wheel is carried out by radiofrequency interrogation of an electronic device located on the fitted assembly.

[0025] To initiate the measurement system and in particular the determination of the initial volume VI of the fluid cavity, it is necessary to determine the volume V0 of the fluid cavity which corresponds to the volume delimited by the unloaded mounted assembly, i.e. the tire is mounted on the rim with a reference inflation pressure PO which is preferably the initial pressure PI.

[0026] To determine this volume V0, the axisymmetric geometry of the unloaded tire for a reference inflation pressure PO must be known. It is realistic to assume that the rim geometry is not influenced by the inflation pressure of the mounted assembly. These geometries can be accessed via a tire database. Knowing the identity of the tire and / or the wheel rim allows the correct geometries to be isolated in this database. The identity of the tire can be obtained through an optical reading of the regulatory markings affixed to the sidewall of the tire.The identity can also be transmitted by radio frequency interrogation of an electronic device present on the mounted assembly such as an RFID tag (acronym in English for Radio Frequency Identification), a TMS (acronym in English for "Tyre Mounted Sensor") mounted on the internal rubber of the tire or "inner liner" or a TPMS (acronym in English for "Tyre Pressure Monitoring System") mounted on the wheel rim for example.

[0027] Preferably, the load Z of each equipped mounted assembly is estimated by a first relation according to the following formula [MATH1] Z = Kp P * P * A(V) = Kp P * P * (PI - PO) , where Kpp is the flat-flat pneumatic stiffness of the assembled tire per unit volume.

[0028] This is a simple and elementary model that links the load applied to the tire to the variation in the volume of the fluid cavity of the mounted assembly between a first state, for example unloaded, of volume VO and a second state of volume VI, the inflation pressure P of the fluid cavity and the pneumatic stiffness of the mounted assembly corresponding to the flattening of the mounted assembly on a plane. Through this model, we make the assumption that the structural stiffness of the mounted assembly is negligible compared to that of the pneumatic nature, which is a realistic assumption for a tire casing for a private vehicle. However, it is quite possible to take into account the structural stiffness of the tire in the previous formula by adding it to the product of the pneumatic stiffness by the inflation pressure.

[0029] According to an advantageous embodiment, the variation in AV volume of each equipped mounted assembly is estimated by solving a differential equation according to the following form: [MATH 2] , and With [MATH 3] ,where P is the internal pressure, V is the internal volume and T is the internal temperature of the fluid cavity.

[0030] This differential equation translates the link between the parameters of the fluid in the cavity of the mounted assembly which are controlled on the one hand by an adiabatic transformation of the fluid and on the other hand by the fact that the fluid is a perfect gas.

[0031] The invention also relates to a method for estimating the number and location of passengers in a vehicle comprising the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle in which, having determined a track value V and a wheelbase value E of the vehicle, as well as an average support point of a passenger on each seat of the vehicle, the method comprises the following steps; • Determination of the total load P generated by at least one passenger by the summation of the load variations AZ carried by each assembly fitted to the vehicle; • Determination of a center of gravity G of the total load P generated by at least one passenger and obtaining the coordinates of the center of gravity G in a reference frame R associated with the vehicle; • Determination of an average number of passengers N as being the ratio between the total load Z generated by the at least one passenger and a reference number REF, preferably the reference number REF represents the average weight of an adult; • Identification of location combinations on each seat of the vehicle and type of passenger respecting the average number of passengers N; • Determination of the coordinates of a center of gravity J of all passengers for each identified combination of passengers in the reference frame R; and • Identification of the best possible identified combination minimizing the distance between the center of gravity G and the center of gravity J.

[0032] Advantageously, the passenger type is included in the group comprising an adult male, an adult female, a teenager and a child.

[0033] The method of estimating the number of passengers in a vehicle and their location within the vehicle is based on estimating the load variation of all loaded mounted assemblies in the vehicle. The estimated load variation is generated by passengers boarding the vehicle at predestined locations in the vehicle such as a seat or a multi-seater bench.

[0034] The summation of the estimated load variations makes it possible to calculate the total load of passengers on board the vehicle. This corresponds to the first step. In addition, knowing the track V and the wheelbase E of the vehicle, it is easy to determine the center of gravity G of this total load of passengers which corresponds to the barycenter of the wheel centers of the vehicle's equipped mounted assemblies, each wheel center is weighted by the load variation observed on the corresponding equipped mounted assembly.

[0035] Then, we divide this total load P by a reference number REF which is similar to the mass of a certain type of passenger to obtain a number. Preferably, this is an adult passenger regardless of sex. The number resulting from this division gives a number close to an integer or an odd multiple of 0.5. The odd multiple of 0.5 then corresponds to the mass of a child whose mass is half that of an adult.

[0036] Depending on the number obtained, it is possible to identify various combinations of the number of passengers of different types. Since the number of passengers in the passenger car type vehicle is low, the possible combinations are few. For example, a number of 2.4 is similar to 2.5. This value of 2.5 corresponds to several possible combinations of the number of passengers of various types among the adult and child group. Thus, it may be one adult and 3 children, or two adults and one child for a child with an average mass corresponding to half that of an adult. This combination of possible number of passengers must be multiplied by the various possibilities of locating said passengers in the vehicle on the various seats and benches of the vehicle. This gives us all the possible combinations of passengers and their location in the vehicle.

[0037] Then for each potential combination i identified, we evaluate a center of gravity Ji which corresponds to the barycenter of the average support points of a passenger on each seat of the vehicle, each point is weighted by the mass of the passenger present on the associated seat. We express, as far as possible, the location of each center of gravity Ji of each combination i in the same vehicle frame as that in which the center of gravity G of the load variations is expressed.

[0038] Finally, we identify the best potential combination i, the one that would minimize the distance between the center of gravity G linked to the variation of load carried by the mounted assemblies and the center of gravity Ji of the combination i linked to a number of passengers and their location in the vehicle. The choice of taking the centers of gravity as a measure makes it possible to concentrate the identification on few parameters, thus facilitating the identification in terms of resource cost and time. In addition, in case of problems with a measurement of load variation by the mounted assembly, this will be reflected in the difference between the centers of gravity G and the potential points Ji.

[0039] The invention also relates to a system for implementing the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers in a vehicle comprising: • a vehicle capable of accommodating at least one passenger on a seat, each mounted unit of which is equipped with an electronic device; • the electronic device comprising at least one pressure sensor, at least one electronic chip, at least one memory space capable of recording the signals from the sensor, and at least one first means of radiofrequency communication at least in transmission, preferably, the electronic device is fixed on the internal wall of the tire, very preferably at the level of the crown of the tire; • at least one means of calculation; and • at least one display means comprising at least one second radiofrequency communication means at least in reception.

[0040] As mentioned by the method, the pressure sensor should be located on the mounted assembly which is driven by a rotational movement relative to the vehicle. In order to move away from the elements of the mounted assembly having the highest thermal inertia, the electronic device is fixed to the inner wall of the tire at the level of the crown of the tire, in particular if the device includes a temperature sensor. Therefore, the electronic device conditioning at least the signals from the pressure sensor should be provided with a means of communication, for example radio frequency, in transmission to simply transmit the data beyond the mounted assembly where at least the display means will be located. Indeed, an alternative consists of integrating the calculation means, that which performs the calculation of the variation in volume of the internal cavity of the mounted assembly at the level of the mounted assembly.This can be integrated into the electronic device or be in wired communication with the device. electronic. So, the radio frequency communication means of the electronic device is useful for transmitting the results of calculations beyond the mounted assembly. The radio frequency communication from the electronic device of the mounted assembly can be to the vehicle or outside the vehicle to a device separate from the vehicle such as a mobile phone, a tablet, a computer. These three elements can then represent the display means. However, the display means can also be a graphical interface of the vehicle at the dashboard level for example.

[0041] Therefore, the proposed structural form allows it to adapt to several possible technical configurations while being functional for implementing the said process.

[0042] Preferably, the system comprises an analysis means capable of analyzing a result output from at least one calculation means.

[0043] The result of the calculation means is on the one hand the variation in load carried by each mounted assembly equipped with the electronic device but also certain intermediate objects of the process to identify the best combination allowing to identify the number of passengers and their location in the vehicle. The analysis element allows to make a decision and in particular to identify the best potential combination i. This optional element of the system allowing to provide a service for the user of the vehicle must be positioned between the calculation means and the display means. Structurally, it can be associated with one and / or the other by a wired connection or be physically dissociated from these elements by means of radiofrequency communication means.

[0044] According to a first particular embodiment, the at least one calculation means comprises at least one third radiofrequency transmission / reception communication means.

[0045] In the case where the calculation means is physically separated from the electronic device on the one hand and from the display means on the other hand, it is appropriate that it can communicate with the other two elements. This is the case, for example, when the calculation means is on the vehicle; it retrieves the pressure data from the electronic device through radio frequency communication with the latter. On the other hand, if the means display is on a mobile phone, it transmits the calculation results to the display means by this radio frequency communication.

[0046] According to a second particular embodiment, the at least one analysis means comprises at least a fourth radiofrequency transmission / reception communication means.

[0047] In the case where the analysis means is physically separated from the calculation means and from the display means, it should be able to communicate with the other two elements. This is the case, for example, when the analysis means is on a server remote from the vehicle; it retrieves the variations in loads applied to the various mounted assemblies of the vehicle from the calculation means present on the vehicle through radio frequency communication with the latter. On the other hand, if the display means is on a mobile phone, or any other electronic device equipped with a screen, it transmits the messages resulting from the comparison between the center of gravity G and the centers of gravity Ji by transmitting the number of passengers and their location to the display means via radio frequency communication.

[0048] According to a third particular embodiment, the system comprises at least one reading means capable of at least reading data contained in the at least one memory space of the electronic device, comprising at least a fifth radiofrequency transmission / reception communication means.

[0049] In the case where the electronic device has a communication range that is not sufficient to ensure communication to the display means, it is appropriate to use a reading means to retrieve the data from the electronic device. This reading means ensures the function of capturing the measurement data. It then transfers them to the display means or any other element of the system requiring the data by radiofrequency communication for the rest of the process. This is a role of relaying the information by optimizing the communication coverage in relation to the electronic device present in the mounted assembly. Indeed, in order to reduce the mass of the electronic device at the tire level, it is appropriate to limit the energy source necessary for the transmission of data which is the energy-consuming function of the electronic device.

[0050] Preferably, part of the communication carried out by the communication means from and to the elements included in the group comprising the electronic device, the at least one calculation means, the at least one display means, the at least one analysis means and the at least one reading means is carried out by UHF radiofrequency waves, preferably in BLE (acronym in English for “Bluetooth Low Emission”).

[0051] The UHF band (acronym for Ultra High Frequencies) allows for significant data transmission with an interesting throughput, this is even more true in the high frequencies of the UHF band such as the BLE band (acronym in English for "Bluethooth Low Emission"). It is classically used in transport applications, which allows the system's communication means to be shared with those already present on the vehicle or in road infrastructures.

[0052] Advantageously, the at least one display means is included in the group comprising a telephone, a computer, a human-machine interface located on the vehicle, preferably located on the vehicle's instrument cluster.

[0053] The display means is used to warn the individual who is conducting operations on the vehicle of the safety of his convoy, whether he is the driver behind his driving position or another person responsible for the conformity of the convoy.

[0054] According to an advantageous embodiment, a part of the at least one reading means is located on the vehicle.

[0055] According to another advantageous embodiment, a part of the at least one calculation means and / or a part of the at least one analysis means is located on the vehicle, preferably located on the mounted assembly.

[0056] The vehicle is a natural information relay instrument since the assembled assembly is connected to it and the output of the process is intended for the vehicle or its user. Therefore, that the structural devices of the system are located on the vehicle is entirely desirable although the alternative is also possible. However, the vehicle allows to ensure a certain confidentiality of the data unlike communications to servers for example, unless secure communication protocols are implemented. Of course, in order to minimize the impact of this system in In today's complex and busy vehicle environment, locating functions at the assembled level limits interference with other structural components of the vehicle. Brief description of the drawings

[0057] The invention will be better understood on reading the following description, given solely as a non-limiting example and made with reference to the appended figures in which the same reference numbers designate identical parts throughout and in which: • Fig. 1 presents a system for implementing the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of passengers on board the vehicle according to the first embodiment of the invention; • Fig. 2 shows another system configuration according to the second embodiment of the invention; • Fig. 3 presents a block diagram of the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of passengers on board the vehicle and / or the method for estimating the number of passengers and their location in the vehicle according to the invention; • Fig. 4 shows a temporal evolution of the internal pressure of the fluid cavity at the outlet of the pressure sensor; • Fig. 5 shows a temporal evolution of the internal temperature of the fluid cavity; • Fig. 6 presents a temporal estimate of the variation in volume of the fluidic cavity according to the invention; • Fig. 7 presents a time estimate of the load variation of a mounted assembly of the vehicle associated with the boarding of passengers in the vehicle. Detailed description of the embodiments

[0058] Fig. 1 illustrates an example of a system 2000 enabling the implementation of the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of passengers on board the vehicle. This system 2000 comprises a vehicle 2001 comprising four mounted assemblies 2006 distributed over the two axles of the vehicle, the front axle and the rear axle following the direction of the vehicle 2001 in forward motion. The vehicle here comprises three passengers, only two of whom are shown in the figure. At the front are two adults while a child is seated at the rear on the seat located just behind the driver's seat. Thus, the three passengers exert a force P resulting from their individual mass at the passenger's support point on the seat of the vehicle 2001. This force P is exerted at the center of gravity G.The presence of an external force P on point G of the vehicle, which corresponds to the center of gravity of the masses of the passengers of the vehicle 2001, causes the appearance of an additional reaction force AZi and AZ2 on the mounted assemblies 2006 of each respective axle which stabilize when the permanent regime is reached to balance the force P.

[0059] The objective of the method is to determine the reaction forces on each mounted assembly of the vehicle which are stabilized when the steady state is reached.

[0060] Each 2006 mounted assembly of the 2001 vehicle is equipped with a 2007 electronic device. This 2007 electronic device is located in the fluid cavity of the 2006 mounted assembly. Here, the 2007 electronic device is placed on the inner wall of the tire in line with the tread of the tire casing which ensures contact between the ground and the tire casing. It would have been possible to install the electronic device at the wheel rim of the mounted assembly, while remaining in the fluid cavity of the 2006 mounted assembly. For example, the electronic device could have been integrated into the rim valve like certain TPMS systems (acronym in English for Tire Pressure Monitoring System).

[0061] This 2007 electronic device comprises a pressure sensor associated with a microcontroller and a radiofrequency device at least in transmission. The radiofrequency device therefore comprises a radio wave generator and a radiocommunication antenna for transmitting the generated radio waves. The radiofrequency device may also, optionally, comprise a wave receiver. radio waves to receive instructions from the outside in order, for example, to start a measurement. This electronic device 2007 also includes a memory space to store the measurement data from the pressure sensor before transmitting them in the form of radio waves. The electronic device can transmit the raw measurement data or the data filtered by the microcontroller. Of course, it is common for the pressure sensor to be accompanied by a temperature sensor. At this time, the electronic device 2007 transmits both types of data, pressure and temperature, to the outside of the mounted assembly 2006. Here, the electronic device 2007 transmits radio waves in the UHF frequency band (acronym in English for Ultra High Frequency) and particularly in the BLE band (acronym in English for Bluetooth Low Emission)

[0062] Here, the exterior comprises at least the vehicle 2001. This vehicle 2001 firstly comprises a radio data reader 2005, operating in the UHF range, the antennas of which are located near the mounted assemblies 2006 in order to recover the measurement data generated by the electronic device 2007. The data are then transferred, here by wire, to the calculation means 2002 located in the vehicle 2001. A radio frequency transmission using specific means of communication would also have been possible.This calculation means 2002 comprises memory space and a processor to carry out its tasks: identify the quantities of the mounted assembly corresponding to the initial state, solve the differential equation which leads to the determination of the variation in volume of the fluidic cavity of each mounted assembly equipped with an electronic device 2007, and calculate the variation in load associated with the variation in volume having previously recovered the quantities of the tires necessary for this task.Then the tasks associated with the process of estimating the best potential combination of passengers and their location involve summing the variations in load carried by each mounted assembly 2006 of the vehicle 2001 and positioning the barycenter G of the wheel centers of the mounted assemblies 2006 each weighted by the variation in individual load carried, estimating the overall number of passengers by dividing the total load carried by a reference number REF, identifying all potential combinations of passengers and their location in the vehicle, evaluating for each potential combination, the barycenter Ji of the support positions of the passengers in their seats weighted by the mass of each passenger. Finally, the last step consists of. identify the best potential combination, the one that minimizes the distance between points G and Ji.

[0063] The results, and especially the last data, are sent to an analysis means 2004. Here, the transmission of this data is done by wire, but radio frequency communication could have been set up. Of course, the analysis means 2004 can be integrated into the calculation means 2002.

[0064] Finally, the various output data from this analysis means 2004 are transmitted to display means 2003 via a fourth communication means 2104 which is embodied, among other things, by the radiocommunication antenna of the vehicle 2001 and a second communication means 2102 present on the display means 2003.

[0065] These means of communication 2104 and 2102 transfer their data via a communication network to a tablet or smartphone 2003 in order to warn of the conformity or non-conformity of the vehicle's loading in relation to the threshold values ​​admissible by the vehicle 2001 according to the legislation in force.

[0066] The result obtained can size certain safety elements of the vehicle or allow an additional check to ensure the correct configuration of the passengers on board the vehicle before setting the said vehicle in motion, for example.

[0067] Fig. 2 shows another configuration of the system 2000. This system 2000 includes a vehicle 2001 comprising four mounted assemblies 2006 distributed on the two axles of the vehicle, the front axle and the rear axle following the direction of the vehicle 2001 in forward motion. The vehicle includes a single passenger in the vehicle who will drive the vehicle 2001.

[0068] Each mounted assembly 2006 of the vehicle 2001 is equipped with an electronic device 2007. This electronic device 2007 is located in the fluid cavity of the mounted assembly 2006. Here, the electronic device 2007 is placed on the inner wall of the tire in line with the tread of the tire casing which ensures contact between the ground and the tire casing. It would have been possible to install the electronic device at the wheel rim of the mounted assembly, while remaining in the fluid cavity of the mounted assembly 2006. For example, the electronic device would have could be integrated into the rim valve like some TPMS systems (acronym in English for Tyre Pressure Monitoring System).

[0069] This electronic device 2007 comprises a pressure sensor associated with a microcontroller and a radiofrequency device at least in transmission. The radiofrequency device therefore comprises a radio wave generator and a radiocommunication antenna for transmitting the generated radio waves. The radiofrequency device can also, optionally, comprise a radio wave receiver for receiving instructions from the outside in order, for example, to launch a measurement. This electronic device 2007 also comprises a memory space for storing the measurement data from the pressure sensor before transmitting them in the form of radio waves. The electronic device can transmit the raw measurement data or the data filtered by the microcontroller. Of course, it is conventional for the pressure sensor to be accompanied by a temperature sensor.At this time, the electronic device 2007 transmits the two types of data, pressure and temperature, to the outside of the mounted assembly 2006. Here, the electronic device 2007 transmits radio waves in the UHF frequency band (acronym in English for Ultra High Frequency) and particularly in the BLE band (acronym in English for Bluetooth Low Emission).

[0070] Here, the exterior comprises at least the vehicle 2001. This vehicle 2001 firstly comprises a radio data reader 2005, operating in the UHF range, whose reception antennas 2105 are located near the mounted assemblies 2006 in order to recover the measurement data generated by the electronic device 2007. The data are then transferred, here by wire, to the transmission antenna of the communication means 2105 associated with the data reader 2005 located in the vehicle 2001. A radio frequency transmission using specific communication means would also have been possible between the transmission communication means 2105 and the data reader 2005.

[0071] The data is then transmitted to physical means remote from the vehicle 2001.

[0072] The first means is a calculation means 2002 comprising transmission / reception communication means 2102. These communication means 2102 receive the radio waves emitted by the transmission communication means 2105 to transform them into digital data usable by the calculation means 2002. The calculation means 2002 comprises memory space and a processor to carry out its tasks: identify the quantities of the assembled assembly corresponding to the initial state, solve the differential equation which leads to the determination of the variation in volume of the fluidic cavity of each assembled assembly equipped with an electronic device 2007, and finally calculate the variation in load associated with the variation in volume having previously recovered the quantities of the tires necessary for this final task.

[0073] The results and in particular the last data are sent to a second means which corresponds to an analysis means 2004. Here, the transmission of these data is done by means of a radio frequency communication. The analysis means 2004 carries out operations from the results of the calculation means 2002 which they recover by radio frequency transmission from the calculation means 2002 using reception communication means 2104 and the characteristics of the vehicle such as the track V and the wheelbase E between the mounted assemblies 2006 of the vehicle. These values ​​are possibly transmitted by querying a remote database containing data on the vehicle 2001. Of course, according to another embodiment, the analysis means 2004 can be integrated into the calculation means 2002.

[0074] Finally, the various output data from this analysis means 2004 are transmitted to display means 2003 via a fourth communication means 2104 in transmission and a second communication means 2102 present on the display means 2003. Here, the display means are twofold. Firstly, a digital tablet 2003 possibly remote from the vehicle 2001 and a man-machine interface 2003 within the vehicle 2001 comprising a display screen on the dashboard of the vehicle 2001.

[0075] The display means 2003 are intended to warn the driver or any control device of the vehicle 2001 of the number of passengers on board and their location in the vehicle 2001.

[0076] Of course, these two embodiments of the system for implementing the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of passengers within the vehicle are only examples. illustrative examples of the system which are not limited to these two configurations. A first extreme configuration consists of integrating all the calculation and analysis means within the electronic device on board the mounted assembly which transmits the results to a display means remote from the vehicle. The other extreme configuration consists of transferring by radio waves the measurement data recorded at the level of the electronic device and carrying out the other steps of the process on means remote from the vehicle, without ever going through the vehicle.

[0077] Fig. 3 shows a block diagram of the process for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of passengers within the stationary vehicle. This process comprises several phases.

[0078] The first is a preliminary phase which includes at least actions 1 to 6 which follow one another through a continuous line link system. This preliminary phase which focuses on the vehicle before boarding a passenger obviously includes the equipment of the vehicle, ideally at the level of the mounted assemblies, by the installation of a pressure sensor capable of measuring the pressure of the fluid cavity delimited by the internal surface of the tire and the wheel rim by means of a dedicated electronic device. The first steps, noted 1 and 2, consist of determining the physical quantities of the fluid cavity of the mounted assemblies equipped with the measuring device such as the inflation pressure PI and the internal temperature TL. Preferably, these determinations can be made as a lump sum or through a specific measurement.Step 3 consists of determining the load carried ZI by the mounted assembly equipped with the vehicle's measuring device. This determination can be made on a flat-rate basis by making assumptions about the distribution of the total load of the vehicle between the various axles of the vehicle. The total load of the vehicle being a given, for example from the manufacturer, corresponds for example to the unladen mass of the vehicle as specified by the technical instructions of the vehicle manufacturer. Of course, it is also possible to integrate a full tank of fuel, luggage in the trunk of the vehicle. Step 4 corresponds to obtaining specific quantities of the mounted assembly equipped with a measuring device. One of these quantities is the volume V0 corresponds to the volume occupied by the fluid cavity of the mounted assembly when the mounted assembly is inflated to the pressure PI, strictly speaking, under the internal temperature Tl, but in the absence of any. load carried, i.e. not resting on the ground. The second quantity is the flattening rigidity of the pneumatic envelope of the mounted assembly per unit of volume Kp, possibly dependent on the inflation pressure PI, the internal temperature Tl and the load carried Zl. Finally, a third set of quantities are those associated with the ideal gas behavior laws for the nature of the gas contained in the fluid cavity of the mounted assembly. And the penultimate step of the preliminary phase, referenced 5, is a step of determining the occupied volume VI by the fluid cavity of the instrumented mounted assembly subjected to the load Zl and under the inflation pressure PI and the temperature Tl. Finally, the last step, noted 6, of the preliminary phase is the evaluation of the quantity of gas contained in the fluid cavity of the instrumented mounted assembly by determining the number of moles of gas n present within the volume VI.Here, the assumptions associated with the ideal gas condition apply well, it is still necessary to identify the nature of the gas composition, i.e. a monatomic gas or a gas mixture. In addition, it is important in this preliminary phase, although not shown, to determine the evolution law linking the variation of internal pressure P to the variation of internal temperature T for the fluid of the fluidic cavity of the mounted assembly considered during an adiabatic transformation around the operating point of the mounted assembly, i.e. the pressure PI, the temperature Tl and the load Zl.

[0079] Then we move on to the main step, the beginning of which corresponds to the boarding of passengers in the vehicle. Necessarily, we record the temporal variation of the inflation pressure P(t) of each instrumented assembly of the vehicle, which are of the order of millibar for passenger vehicles. These recordings are then stored in a memory space to first filter the raw data using a low-pass filter to eliminate high-frequency phenomena, which corresponds to step referenced 11. Then we determine the temporal variation of internal temperature T(t) of the fluid cavity using the temporal variation of internal pressure P(t) by using the evolution law determined in the preliminary step, which corresponds to step 12.Optionally, the temporal variation of the internal temperature T(t) of each instrumented assembly of the vehicle is recorded, if it is equipped with a temperature sensor, which also corresponds to step 12. In this option, the recorded internal temperature variation T(t) is used to evaluate the isobaric or monobaric transformation of the fluid in the fluid cavity corresponding to the establishment of equilibrium. thermal between the fluidic cavity and the external environment which is made necessary by the adiabatic transformation of the fluid associated with the boarding of passengers. The connection system between optional steps and the essential steps in the process are illustrated with gray colored lines instead of being black. However, the connection systems of the main phase are illustrated by dotted lines, while those of the preliminary phase are solid lines. Finally, as we will see later, the secondary phase has a connection system in the form of dashed lines.

[0080] One of the important steps of the main phase is the determination of the volume variation AV of the fluid cavity of each instrumented mounted assembly through step 13. This corresponds to taking into account at least the adiabatic transformation of the fluid of the fluid cavity due to the boarding of passengers in the vehicle which modifies the thermomechanical equilibrium of all the mounted assemblies of the vehicle and consequently of the fluid trapped in each fluid cavity of the mounted assemblies. In addition, the fluid is assumed to follow the behavior of an ideal gas. From the internal pressure variation P(t) of each instrumented mounted assembly, it is possible to determine the internal temperature variation T(t) through the devolution law identified in the preliminary phase for an adiabatic transformation of the fluid.

[0081] Using the variation of the internal pressure and the internal temperature, it is possible to feed a differential equation taking into account the previous hypotheses. The resolution by time increment of the differential equation makes it possible to obtain an estimate of the associated time variation of the volume of the fluidic cavity AV(t). Optionally, the method can be completed by a measurement of the internal temperature T of the fluidic cavity in order to evaluate a second variation of volume of the fluidic cavity associated with the isobaric or monobaric transformation of the fluid due to the heat exchange which takes place between the fluidic cavity of the mounted assembly and the external environment through the components of the mounted assembly; that is to say the pneumatic casing and the wheel.This second transformation is generally subsequent to the adiabatic transformation since it is the temperature variation generated by the adiabatic transformation which is at the origin of the thermal imbalance between the fluidic cavity and the external environment.

[0082] Another important step in the main phase is the evaluation of the load variation AZ associated with the single volume variation previously evaluated AV which corresponds to step 14. For this, it is necessary to take into account again the flattening rigidity of the assembled assembly Kp per unit of volume. This rigidity can include a pneumatic component and a structural component. Taking into account a single pneumatic component Kpp can be sufficient for a reliable estimation of the load variation AZ.

[0083] For the method of estimating the number of passengers and their location in the vehicle, it is necessary to add up the variations in load carried AZ of each mounted assembly to obtain the weight P of the passengers and the barycenter G of the wheel centers of the mounted assemblies, each weighted by the variation in load of the mounted assembly in step 21. To do this, it is necessary to determine the track V and the wheelbase E of the vehicle, which corresponds to step 20. Thus, the wheel centers can be positioned relative to each other in a reference frame linked to the vehicle. From the weight P of all the passengers, a quantity N is calculated by dividing the weight P by a reference number REF in step 22. This number REF is similar to the mass of a type of passenger such as an adult for example.

[0084] Then, from the identified number N, the potential number of passengers is determined according to the various passenger types. What differs from one passenger type to another is the mass of the passenger. It is thus easy to create at least one adult passenger and one child passenger. The mass of the child passenger then accounts for half the mass of the adult passenger. Thus, in this specific case, the proximity of the number N to an integer or a multiple of 0.5 makes it possible to identify various combinations of passenger types. These possible combinations of passenger type must then be multiplied by their possible location in the vehicle to identify all the potential combinations i of passenger type and their location from the number N of step 22. The identification of these combinations i corresponds to step 23 of the block diagram in Figure 3.

[0085] From each potential combination i, it is possible to determine the barycenter of the support points of the passengers of each combination i by weighting the support points by the reference mass associated with the type of passenger present on each support point, which corresponds to step 25. For this it is preferable to determine the location of the support points of each passenger in a vehicle reference frame, preferably using the vehicle reference frame used to locate the barycenter G of the wheel centers of the mounted assemblies. This determination of the location of the passenger support points corresponds to step 24.

[0086] Finally, the identification of the exact number of passengers, the type of passenger and their location is carried out during step 26 by searching for the combination i of step 23 which minimizes the distance between the barycenter Ji associated with the combination i and the barycenter G associated with the variation of load carried by the mounted assemblies. The solution minimizing the distance with the point G is considered as the most probable combination i making it possible to identify the total number of passengers embarked in the vehicle, the type of passenger and its location on predefined positions represented by the seats of the vehicle.

[0087] Fig. 4 shows the time evolution of the pressure of the pressure sensor of the electronic device placed on a mounted assembly of the vehicle. The curve consisting of points 10 is the raw measurement of the pressure sensor while curve 11 corresponds to the time evolution of the filtered pressure, which is cleaned of high-frequency noise. It is this second curve which will then be used in the block diagram of figure 3.

[0088] This time recording of the internal pressure of the fluid cavity of the assembled assembly begins in the preliminary phase before the passenger boarding the vehicle. The moment of passenger boarding corresponds to the abscissa of point 100 which marks the beginning of the main phase. From this point 100, a rapid drop in the internal pressure of the fluid cavity is observed until point 101 where the drop in pressure stops and even increases to a lesser extent. This point 101 marks the transition between the work of the fluid associated with the passenger boarding which corresponds to a first transformation of the fluid which is similar to an adiabatic transformation and the heat exchange towards the outside which corresponds to a second transformation of the fluid. The abscissa of this point 101 corresponds to the duration T0 taking as the origin of the times the abscissa of point 100. Thus, the preliminary phase 50 ends at the abscissa of point 100.It preceded the main phase which is separated into two successive phases. first phase 51 is similar to an adiabatic transformation of the fluid corresponding to the work of the fluid following the boarding of the passenger(s). The second phase 52 corresponds to a thermal exchange of the fluid with the exterior.

[0089] Fig. 5 shows the time evolution of the internal temperature of the fluid cavity. Here, this time evolution is either delivered by a temperature sensor of the electronic device arranged on a mounted assembly of the vehicle as illustrated by curve 12. An alternative, in the absence of measurement by a temperature sensor, is an estimation of the internal temperature, illustrated by curve 12' from, on the one hand, the recorded internal pressure and an evolution law linking the internal temperature to the internal pressure during an adiabatic transformation of the fluid and, on the other hand, the temperature outside the mounted assembly serving as a basis for the heat exchange of the fluid of the fluidic cavity with the environment outside the mounted assembly through a heat exchange coefficient. This heat exchange coefficient takes into account the thermal characteristics of the mounted assembly.In this alternative, curve 70 illustrates the evolution of the external temperature of the assembled assembly.

[0090] These changes in the internal temperature 12 and 12' of the fluid cavity of the assembled assembly begin in the preliminary phase before the passenger(s) board the vehicle. The moment of boarding corresponds to the abscissa of point 100 which marks the beginning of the main phase. From this point 100, a rapid drop in the internal temperature of the fluid cavity is observed until point 101 where the drop in temperature stops and then increases to a certain extent. This point 101 marks the transition between the work of the fluid associated with the boarding of the passenger(s) which corresponds to a first transformation of the fluid which is similar to an adiabatic transformation and the heat exchange towards the outside which corresponds to a second transformation of the fluid. The abscissa of this point 101 corresponds to the duration T0 taking as the origin of the times the abscissa of point 100. Thus, the preliminary phase 50 ends at the abscissa of point 100.It precedes the main phase which is separated into two successive phases. The first phase 51 is similar to an adiabatic transformation of the fluid corresponding to the work of the fluid following the boarding of the passengers. The second phase 52 corresponds to a thermal exchange of the fluid with the exterior.

[0091] Here, we observe a difference between the recorded curve 12 and the estimated curve 12' of the internal temperature which illustrates on the one hand the inertia specific to the temperature sensor. On the other hand, the hypothesis that the evolution law linking the internal pressure to the internal temperature of the fluid during an adiabatic transformation is also perhaps overestimated. However, the trend between these curves 12 and 12' is quite similar. Finally, here we do not measure the temperature outside the assembled assembly, we determine it by extrapolation of the internal temperature of the fluid cavity in the preliminary phase, which is also a source of potential errors. This estimate corresponds to the linear line 70 in Figure 5.The heat exchange coefficient of the assembled assembly can be approximated by the sole characteristics of the tire casing initially through, for example, an estimation of the exchange surface of the tire with the external environment, which represents the external surface of the tire casing and a heat exchange coefficient X which depends on the thermal characteristics of the material properties of the tire with a distribution of the different types of heat exchange of the tire casing such as radiation, conduction and convection. This coefficient X can be estimated using the evolution of the internal temperature of the fluidic cavity in the preliminary phase, just before the main phase for example.

[0092] Fig. 6 shows the time evolution of the internal volume of the fluid cavity. Here, this time evolution, represented by the curve, is the output of the calculation of the volume variation by the proposed differential equation, also taking into account the thermal equilibrium with the external environment.

[0093] This evolution of the internal volume of the fluid cavity of the assembled assembly begins in the preliminary phase before the passenger(s) board the vehicle. The moment of boarding corresponds to the abscissa of point 100 which marks the beginning of the main phase. From this point 100, we then observe a rapid increase in the internal volume of the fluid cavity up to point 101 where the rise stops and then decreases to a certain extent. This point 101 marks the transition between the work of the fluid associated with boarding, which corresponds to a first transformation of the fluid similar to an adiabatic transformation, and the heat exchange towards the outside, which corresponds to a second transformation of the fluid. The abscissa of this point 101 corresponds to the duration T0 taking as the origin of the times the abscissa of the point 100. Thus, the preliminary phase 50 ends at the abscissa of the point 100. It precedes the main phase which is separated into two successive phases. The first phase 51 is similar to an adiabatic transformation of the fluid corresponding to the work of the fluid following the embarkation. The second phase 52 corresponds to a thermal exchange of the fluid with the exterior.

[0094] It is noted that at the end of phase 51, a good estimate of the volume variation of the mounted assembly is obtained, which clearly shows that the work generated by the load variation subjected to the mounted assembly occurs mainly during phase 51. The variations or oscillations observed correspond to the fluctuations of the transient phase corresponding to thermal equilibrium. Therefore, the method described here produces a continuous measurement of the internal volume of the mounted assembly in the time domain.

[0095] Fig. 7 shows the time evolution of the load variation applied to a mounted assembly equipped with the electronic device. Here, this time evolution, represented by curve 14, is the output of the calculation of the volume variation by the proposed differential equation taking into account the thermal equilibrium with the external environment which is multiplied by the flattening rigidity of the mounted assembly. Here, the rigidity taken is that which is locally identified at the level of the initial pressure of the mounted assembly, of the initial load applied to the mounted assembly and corresponding to the initial temperature. We could have taken into account the global rigidity defined by the proposed formula which would already have given a good order of magnitude.

[0096] This evolution of the applied load 14 from the fluid cavity to the mounted assembly begins in the preliminary phase before the passengers board the vehicle. The moment of boarding corresponds to the abscissa of point 100 which marks the beginning of the main phase. From this point 100, we observe a rapid decrease in the load up to point 101 where the load stabilizes and then increases to a certain extent. This point 101 marks the transition between the work of the fluid associated with the boarding of the passengers which corresponds to a first transformation of the fluid which is similar to an adiabatic transformation and the heat exchange towards the outside which corresponds to a second transformation of the fluid. The abscissa of this point 101 corresponds to the duration T0 taking as the origin of the times the abscissa of point 100. Thus, the phase preliminary phase 50 ends at the abscissa of point 100. It precedes the main phase which is separated into two successive phases. The first phase 51 is similar to an adiabatic transformation of the fluid corresponding to the work of the fluid following embarkation. The second phase 52 corresponds to a thermal exchange of the fluid with the exterior.

[0097] It is noted that at the end of phase 51, a good estimate of the load variation applied to the mounted assembly is obtained, which clearly shows that the work generated by the load variation occurs mainly during phase 51. The variations or oscillations observed correspond to the fluctuations of the transient phase corresponding to the thermal equilibrium. Therefore, the method described here produces a continuous measurement of the temporal load variation of the mounted assembly in the time domain. Curve 80 corresponds to the measurement on a ground scale of the overload applied to the mounted assembly of the trailer. In conclusion, the applied load variation is well captured by the proposed method.

Claims

CLAIMS 1. Method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle comprising the following steps: In the preliminary phase, - Equip each mounted assembly of the vehicle with at least one pressure sensor, said sensor being capable of measuring the internal pressure of the fluid cavity of the mounted assembly delimited by a pneumatic casing and a wheel; - Determine the initial load ZI applied to each assembly fitted to the vehicle; - Determine the initial inflation pressure PI of the fluid cavity of each assembly fitted to the vehicle; - Determine the initial internal temperature Tl of the fluid cavity of each assembly fitted to the vehicle; - Evaluate the initial volume VI of each equipped mounted assembly using a first function comprising as parameter the volume VO of the fluid cavity of the unloaded mounted assembly inflated to the initial pressure PI and the flattening rigidity of the tire of the mounted assembly per unit of volume Kp - Evaluate the number of moles of fluid n in the fluid cavity of each assembled assembly equipped from a model taking into account the inflation pressure PI, the initial volume VI, the temperature Tl; - Determine a law of evolution of the internal temperature T of the fluidic cavity from the internal pressure P during an adiabatic transformation for each assembly mounted, inflated and subjected to the load Z 1, equipped with at least one pressure sensor; In the main phase: - Position at least one passenger in the vehicle; - Record the internal pressure P in the fluid cavity of each equipped assembly at an acquisition frequency Fl; - Determine the internal temperature T of the fluid cavity of each equipped assembly using the evolution law determined in the preliminary phase; - Evaluate an intermediate volume variation AV of each equipped assembly using the recorded internal pressure P and the internal temperature T determined using a fluid model in adiabatic transformation, the fluid having a perfect gas behavior; and - Estimate a load variation AZ carried by each mounted assembly equipped using a second function including as parameter the intermediate AV volume variation evaluated and the flattening rigidity of the tire of the mounted assembly per unit of volume Kp.

2. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to claim 1 in which, in the preliminary phase, each mounted assembly equipped with the vehicle comprising a temperature sensor capable of measuring the temperature of the fluid cavity, the method comprises, in the main phase, a step for recording the internal temperature T in the fluid cavity of each mounted assembly equipped at an acquisition frequency F2 and the method comprises a second step of evaluating the variation in intermediate volume AV2 of each mounted assembly equipped taking into account the internal temperature T recorded using a fluid model having ideal gas behavior, subjected to thermal equilibrium with the environment outside the fluid cavity.

3. Method for estimating the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 2 in which, before the main step, each equipped mounted assembly is in a thermomechanically stabilized state.

4. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 3 in which the pressure sensor and / or the sensor temperature are placed in a subspace of the closed fluidic cavity delimited by the pneumatic envelope and the wheel.

5. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 4 in which the acquisition frequency Fl is between 0.1 Hz and 10 Hz.

6. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 2 to 5 in which the acquisition frequency F2 is lower than the acquisition frequency Fl.

7. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 6 in which the determination of the initial volume V0 takes into account the geometry of a wheel rim and the geometry of an unloaded tire, mounted on a rim and inflated to the reference pressure PO, preferably the reference pressure PO is the initial pressure PI.

8. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to claim 7 in which the geometry of the tire and / or the geometry of the rim is determined using an identifier of the tire and / or the wheel of the equipped mounted assembly, preferably obtaining the identifier of said tire and / or said wheel is carried out by a radiofrequency interrogation of an electronic device located on the mounted assembly.

9. Method for estimating the variation in the load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 8 in which the load Z of each equipped mounted assembly is estimated by a relationship according to the following formula: Z = K PP * P * A(F) = Kpp * P * (Fl - FO) [MATH1] Where Kpp is the flat tire stiffness of the assembled tire per unit volume.

10. Method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 9 in which the variation in volume AV of each equipped mounted assembly is estimated by solving the following differential equation: [MATH 2] , And With [MATH 3] where P is the internal pressure, V is the internal volume and T is the internal temperature of the fluid cavity.

11. Method for estimating the number and location of passengers in a vehicle comprising the method for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 10 in which, having determined a track value and a wheelbase value of the vehicle, as well as an average support point of a passenger on each seat of the vehicle, the method comprises the following steps; - Determination of the total load P generated by at least one passenger by the summation of the load variations AZ carried by each assembly fitted to the vehicle; - Determination of a center of gravity G of the total load P generated by the at least one passenger and obtaining the coordinates of the center of gravity G in a reference frame R associated with the vehicle; - Determination of an average number of passengers N as being the ratio between the total load Z generated by the at least one passenger and a reference number REF, preferably the reference number REF represents the average weight of an adult; Identification of the location combinations on each seat of the vehicle and type of passenger respecting the average number of passengers N; - Determination of the coordinates of a center of gravity J of all passengers for each identified combination of passengers in the reference frame R; and Identification of the best possible identified combination minimizing the distance between the center of gravity G and the center of gravity J.

12. Method for estimating the number and location of passengers in a vehicle according to claim 11, in which the type of passenger is included in the group comprising an adult male, an adult female, an adolescent and a child.

13. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle according to one of claims 1 to 10 and or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 11 to 12 comprising: - a vehicle (2001) capable of accommodating at least one passenger on a seat, each mounted assembly (2006) of which is equipped with an electronic device (2007); the electronic device (2007) comprising at least one pressure sensor, at least one electronic chip, at least one memory space capable of recording the signals from the sensor, and at least one first radiofrequency communication means (2101) at least in transmission; at least one calculation means (2002); and at least one display means (2003) comprising at least one second radiofrequency communication means (2102) at least in reception.

14. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to claim 13 in which the system (2000) comprises an analysis means (2004) capable of analyzing a result at the output of the at least one calculation means (2002).

15. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 13 to 14 in which the at least one calculation means (2002) comprises at least one third radiofrequency transmission / reception communication means (2103).

16. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to claim 15 in which the at least one analysis means (2004) comprises at least a fourth radiofrequency transmission / reception communication means (2104) 17. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 13 to 16 in which the system (2000) comprises at least one reading means (2005) capable of at least reading data contained in the at least one memory space of the electronic device (2007) comprising at least one fifth communication means (2105) at least in reception.

18. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 13 to 17 in which part of the communication carried out by the communication means (2101, 2102, 2103, 2104, 2105) from and to the elements included in the group comprising the electronic device (2007), the at least one calculation means (2002), the at least one display means (2003), the at least one analysis means (2004) and the at least one reading means (2005) is carried out by UHF radiofrequency waves, preferably in BLE.

19. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers in a vehicle according to one of claims 13 to 18 in which the at least one display means (2003) is included in the group comprising, a telephone, a computer, a human-machine interface located on the vehicle (2001), preferably located on the instrument cluster of the vehicle (2001).

20. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 13 to 19 in which a part of the at least one reading means (2005) is located on the vehicle (2001).

21. System (2000) for implementing the method (1000) for estimating the variation in load carried by a mounted assembly of a vehicle generated by the boarding of at least one passenger in the stationary vehicle and / or for implementing the method for estimating the number and location of passengers of a vehicle according to one of claims 13 to 20 in which a part of the at least one calculation means (2002) and / or a part of the at least one analysis means (2004) is located on the vehicle (2001), preferably located on the mounted assembly (2006).

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