Method for estimating change in load distribution on stationary trailer

Abstract

The invention relates to a method for estimating a change in the load borne by the inflation system of a trailer, resulting from the loading of the loading space of a stationary trailer, comprising the following steps:-loading the trailer; recording the internal pressure P in the fluid chamber of the inflation system equipped with the pressure sensor and the temperature sensor; recording the internal temperature T in the fluid chamber of the inflation system equipped with the pressure sensor and the temperature sensor; -based on the recorded internal pressure P and the recorded internal temperature T, evaluating a change in volume [Delta] V of the inflation system equipped with the pressure sensor and the temperature sensor using a model of a fluid undergoing an adiabatic transition, the fluid exhibiting a desired gas behavior; -estimating the variation [delta] Z of the load experienced by the inflation system equipped with the pressure sensor and the temperature sensor using a second function, the parameters of which comprise the intermediate variation [delta] V of the evaluated volume and the flattening stiffness KSG per unit volume of the inflation system.

Description

Technical Field

[0001] This invention relates to the field of determining applied quasi-static loads in real time, and particularly to the changes in loads caused by loading the loading space of a trailer (especially when the trailer is stationary and not connected to a tractor). Background Technology

[0002] Obtaining the quasi-static load applied to a stationary trailer allows for the determination of whether the trailer or each trailer axle is in a safe condition even before the trailer is started, thereby improving reliability and meeting road traffic safety requirements. Specifically, determining the load applied to the inflation system, such as the tire-wheel assembly, typically requires a balance scale and is difficult to determine outside of very specific loading locations (e.g., a quarry where trailers are loaded). To assess the load on the trailer and its individual axles outside these specific locations, the load on the individual tire-wheel assemblies can be assessed by measuring the tire indentation on the ground. While this can be done using a system that quantifies static pressure by inserting a measuring system between the inflation system and the ground, this is not a simple task, and the accuracy of the measurement depends on the correct positioning of the measuring system. An alternative approach is to determine the size of the contact patch under driving conditions by measuring the tire deformation as the wheels rotate. The load applied to the tire can be deduced by using a mathematical model that correlates tire type, inflation pressure, and the external dimensions of the ground indentation. Unfortunately, this measurement is performed under driving conditions. Therefore, the trailer may no longer be within its safe operating range when measurements are taken. Furthermore, achieving accuracy in these measurements becomes challenging under very heavy loads, where tire deformation, which determines load changes, tends to stabilize in the circumferential direction, and the changes in tire deformation measurements typically fall within this circumferential direction.

[0003] The following object and method of the present invention aims to solve the problem of measuring changes in load borne by a trailer in the absence of an external measuring system, i.e., it can be used at any time without requiring a specific measuring device. Furthermore, the assessment is performed while the trailer is stationary, so that it can be declared whether the trailer has been safely loaded before it begins to move. Summary of the Invention

[0004] This invention relates to a method for estimating the change in load on the inflation system of a trailer caused by loading the loading space of a stationary trailer, the method comprising the following steps: In the preparation stage, that is, before the trailer is loaded: • At least one pressure sensor is provided for at least one inflation system that serves as an interface between the ground and the trailer, such as a tire wheel assembly or a pneumatic cylinder, and is associated with a ground contact assembly of the trailer, such as a landing gear leg or an axle. The at least one sensor is capable of measuring the internal pressure of a fluid cavity of the inflation system defined by at least one deformable surface of the inflation system. Preferably, at least one pressure sensor is provided for at least one inflation system in each group of inflation systems associated with the same ground contact assembly of the trailer. Very preferably, at least one pressure sensor is provided for each inflation system of each ground contact assembly of the trailer. • Equip at least one inflation system with at least one temperature sensor, the at least one sensor being capable of measuring the internal temperature of the fluid cavity of the inflation system; • Determine the initial load Z1 applied to at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor; • Determine the initial inflation pressure P1 of the fluid chamber of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor. • Determine the initial internal temperature T1 of the fluid chamber of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor. • The initial volume V1 of the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor is evaluated using a first function, the parameters of which include the volume V0 of the fluid cavity of the inflation system when it is unloaded and inflated to an initial pressure P1, and the flattening stiffness K of the inflation system per unit volume. SG ; • The number of fluid moles n1 in the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor is evaluated using a model that takes into account inflation pressure P1, initial volume V1 and temperature T1. During the main phase, i.e., when loading the trailer: • Load the trailer's loading space; • Record the internal temperature T of the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor; • Record the internal pressure P of the fluid chamber of at least one inflation system equipped with a pressure sensor and a temperature sensor; • The intermediate volume change ΔV of at least one aeration system is evaluated by utilizing the recorded internal pressure P and recorded internal temperature T, based on a model of a fluid undergoing an adiabatic transition, wherein the fluid behaves as an ideal gas. • The load variation ΔZ experienced by at least one inflation system equipped with a pressure sensor and a temperature sensor is estimated using at least one second function, the parameters of which include the intermediate volume variation ΔV of the assessed volume and the flattening stiffness K per unit volume of the inflation system.SG .

[0005] According to a preferred embodiment, in the preparatory stage, the method includes the step of determining the evolution of the internal pressure P of the fluid cavity based on the internal temperature T during the adiabatic transition of the fluid in the fluid cavity of the inflated and loaded inflation system. In the main stage, the method includes the step of extracting the change in internal temperature T' caused solely by the adiabatic transition of the fluid from the recorded results of the internal temperature T. The method includes the step of determining the internal pressure P' of the fluid cavity based on the internal temperature T' and the evolution determined in the preparatory stage. The step of evaluating the volume change ΔV includes a first stage and at least one second stage. In the first stage, the evaluation is performed using the determined internal pressure P' and the extracted internal temperature T'. In the second stage, the evaluation is performed using a portion of the internal temperature T recorded outside the time range corresponding to the change in the extracted internal temperature T' and a portion of the internal pressure P recorded outside the time range.

[0006] Advantageously, the extraction of the change in internal temperature T' begins when the recorded internal temperature T first changes its rate of change, and ends when the recorded internal temperature T changes its rate of change for the second time, or after a duration T0 corresponding to the end of the adiabatic transition of the fluid. The start of the duration T0 corresponds to the first change in the rate of change of the recorded internal temperature T.

[0007] According to another preferred embodiment, in the preparatory stage, the method includes the step of determining the evolution of the internal temperature T of the fluid cavity based on the internal pressure P during the adiabatic transition of the fluid in the fluid cavity of the inflated and loaded inflated system. In the main stage, the method includes the step of extracting the change of the internal pressure P” solely due to the adiabatic transition of the fluid from the recorded results of the internal pressure P. The method includes the step of determining the internal temperature T” of the fluid cavity of the inflated system based on the internal pressure P” and the evolution determined in the preparatory stage. The step of evaluating the volume change ΔV includes a first stage and at least one second stage. In the first stage, the evaluation is performed using the extracted internal pressure P” and the determined internal temperature T”. In the second stage, the evaluation is performed using a portion of the internal pressure P recorded outside the time range corresponding to the change of the extracted internal pressure P” and a portion of the internal temperature T recorded outside the time range.

[0008] Advantageously, the extraction of the change in internal pressure P'' begins when the recorded internal pressure P first changes its rate of change, and ends when the recorded internal pressure P changes its rate of change for the second time, or after a duration T0 corresponding to the end of the adiabatic transition of the fluid. The start of duration T0 corresponds to the first change in the rate of change of the recorded internal pressure P.

[0009] The method for determining variations in applied load comprises two consecutive phases. The first phase involves identifying the inherent parameters of the inflation system prior to loading the trailer. This constitutes establishing a trailer measurement system and identifying initial parameters of the inflation system by mounting a measuring system to the trailer's ground contact components (e.g., the trailer's axles and landing gear legs), such as the volume of the fluid chamber, the amount of fluid contained within the enclosed volume defined by the fluid chamber, the initial load applied to the inflation system by the trailer, the internal temperature of the fluid chambers in each inflation system, and the inflation pressure of the fluid chambers. Intuitively, when estimating the amount of fluid trapped in the fluid chambers, it is assumed that the properties of the fluid are known.

[0010] The second phase represents the assessment of the load changes applied to the electronically equipped inflator system of the trailer due to loading the trailer's loading space in a single step or using multiple consecutive steps. Electronic devices, including pressure and temperature sensors, manage and record the measurement parameters of the regulating fluid. Therefore, when loading the trailer, the inflation pressure and internal temperature of the fluid cavity of the electronically equipped inflator system are recorded. In the transient phase, the temporal evolution of physical quantities related to the fluid cavity is relatively large. The step of loading the trailer triggers a first transition corresponding to the work generated by this additional load, which can be analogous to an adiabatic (i.e., rapid) transition and is dominant compared to the second transition. Then, after the rapid transition, there is a slower transition corresponding to the fluid cavity establishing thermal equilibrium with the external environment through the outer surface of the inflator system. This equilibrium is necessary after the change in the internal temperature of the fluid cavity related to the work generated by the additional load. This thermal equilibrium is established slowly due to the thermal inertia of the components of the inflator system. Furthermore, the thermal equilibrium generally has a smaller impact on the volume change of the fluid cavity compared to the work-related transition. Therefore, different sampling frequencies can be used for the two physical quantities, temperature and pressure. However, the same sampling frequency can also be used for both sensors.

[0011] Alternatively, if the evolution of the internal temperature is not suitable for observing the first transition of the fluid, for example due to the low sampling frequency of the temperature, the change in the internal temperature of the fluid in the fluid cavity can be determined using the change in the inflation pressure of the fluid cavity. For this purpose, the change in internal temperature is determined using an evolution law previously established in the preparatory stage. Under operating conditions (especially under load Z1, near inflation pressure P1 and temperature T1), this evolution law correlates the change in the internal temperature T of the inflation system with the change in the internal pressure P during the adiabatic transition of the fluid. This evolution law can be a default law or derived from experimental characterization or numerical simulation of a relevant inflation system.

[0012] Therefore, this evolution law converts the measured value of the internal pressure of the fluid in the fluid cavity into the determined value of the internal temperature of the fluid generated solely by the adiabatic transition.

[0013] The first intermediate change in volume can then be assessed using a model of the fluid undergoing an adiabatic transition. Here, "adiabatic" means that the transition the fluid undergoes due to the loading of the trailer occurs without heat exchange between the fluid cavity and the outside of the inflation system; this assumes the transition is rapid. Therefore, the first change in the volume of the fluid cavity caused by loading or unloading the trailer can be estimated by utilizing only the measured change in inflation pressure and the change in internal temperature determined by relating the change in the relevant internal temperature T of the tire-wheel assembly to the change in internal pressure P using measurements of internal pressure changes. For air or nitrogen, it is perfectly reasonable to assume that the gaseous fluid within the cavity of the trailer's inflation system, equipped with pressure and temperature sensors, is an ideal gas.

[0014] Next, a second intermediate change in volume is assessed using the second fluid transition. This second transition relates to the thermal equilibrium between the fluid and the external environment through the components of the inflation system (primarily deformable surfaces). Therefore, during the transient process associated with the loading of the trailer, but after the first fluid transition—that is, when the inflation pressure changes its temporal evolution for the second time—the second change in volume experienced by the inflation system during this second transition is assessed using recorded changes in internal temperature and pressure within the fluid cavity. Considering this second change in volume ensures greater accuracy in assessing the volume change of the fluid cavity, thereby improving the measurement accuracy of load changes in the inflation system equipped with pressure and temperature sensors. However, the first intermediate change in volume is sufficient to estimate the first overload applied to the inflation system on the order of magnitude. Next, a second step of loading or unloading the trailer's loading space may be performed. This second step can be decomposed into two consecutive fluid transitions, just as with the previous loading step. Continuous measurements during each step of loading or unloading the trailer allow for accurate estimation of volume changes in the fluid cavity of the inflation system, which is equipped with pressure and temperature sensors. This is because measurements of the internal pressure and temperature of the fluid are taken at the starting point before each new loading step, allowing the determination of the fluid cavity's internal volume. Therefore, knowing the initial point and recording fluid parameters during further loading steps, the change in internal volume during the second loading step can be determined without difficulty, up to the next loading step, or until the fluid in the fluid cavity reaches thermomechanical equilibrium.

[0015] Alternatively, if the evolution of internal pressure is not suitable for observing the first transition of the fluid, for example due to the low sampling frequency of internal pressure, the change in internal pressure of the fluid in the fluid cavity can be determined using the change in internal temperature of the fluid cavity. For this purpose, the change in internal pressure is determined using an evolution law previously established in the preparatory stage. Under operating conditions (especially under load Z1, near the inflation pressure P1 and temperature T1), this evolution law correlates the relevant changes in the internal temperature T of the inflation system with the changes in the internal pressure P. This evolution law can be a default law or derived from experimental characterization or numerical simulation of the relevant inflation system.

[0016] Therefore, this evolution law converts the measured value of the internal temperature of the fluid in the fluid cavity into the determined value of the internal temperature of the fluid generated solely by the adiabatic transition.

[0017] Similar to the methods described above, a model of a fluid undergoing an adiabatic transition can be used to assess the first intermediate change in volume. Therefore, by utilizing only the measured change in internal temperature and the change in internal pressure determined based on the change in internal temperature within the fluid cavity according to evolutionary laws, the first change in the volume of the fluid cavity caused by the work associated with loading or unloading the trailer, where the fluid has undergone an adiabatic transition, can be estimated.

[0018] Preferably, a second fluid transition is used to assess a second intermediate change in volume. This second transition relates to the thermal equilibrium between the fluid and the external environment through the components of the inflation system (primarily deformable surfaces). Therefore, during the transient process associated with loading the trailer, but after the first fluid transition—that is, when the internal temperature changes its temporal evolution for the second time—the second change in volume experienced by the inflation system during this second transition is assessed using recorded changes in the internal temperature within the fluid cavity. Taking into account this second change in volume ensures greater accuracy in assessing changes in the fluid cavity's volume, thereby improving the accuracy of measuring load changes in the inflation system equipped with pressure and temperature sensors. However, the first intermediate change in volume is sufficient to estimate the first overload applied to the inflation system on a first order of magnitude.

[0019] Of course, considering the change in the external temperature of the tire-wheel assembly due to the thermal equilibrium of the tire-wheel assembly also allows for improvement in the measurement of the second change in volume caused by loading the trailer at the inflation system equipped with pressure and temperature sensors. However, in a simpler approach, since the inflation system is preferably in a thermomechanically stable state, the initial internal temperature T1 of the fluid in the fluid chamber of the inflation system can be used as the external temperature.

[0020] These two transitions can occur in individual time increments or sequentially over a period of time. The assessment of these intermediate volumetric changes requires measurements established from the transient phase of trailer loading to the mechanical and potential thermal equilibrium of the trailer's inflation system. Once these forms of equilibrium are established, the temperature and pressure changes in the fluid chamber tend to be infinitesimally small, thus reaching a further thermomechanical steady state. Generally, when trailer loading is completed through a series of operations, there is no time to establish thermomechanical equilibrium; therefore, the thermomechanical state of the fluid needs to be used as a starting point before further work related to the loading operation, monitoring its continuous evolution throughout the trailer loading process. Due to this continuous assessment of the state, the volumetric changes of the inflation system, equipped with pressure and temperature sensors, are accurate.

[0021] Therefore, if the changes in internal pressure and internal temperature are satisfactory for identifying all phenomena, then the intermediate changes in volume related to the loading steps of loading the trailer can be evaluated directly by solving differential equations using the measured changes in internal pressure and internal temperature, which take into account the fact that the fluid is an ideal gas, the fluid undergoes an adiabatic transition, and the fluid is in thermal equilibrium with the external environment through the components of the inflation system.

[0022] Finally, it should be noted that the first transition of the fluid related to the work of the additional load, as well as its start and end, can be determined by calculating the first and / or second derivatives of the fluid parameter changes to detect the changes in the rate of evolution of these parameters.

[0023] Once the intermediate volume changes of the inflation systems equipped with pressure and temperature sensors have been assessed, it is necessary to evaluate the relevant changes in static load caused by loading the trailer for each inflation system equipped with pressure and temperature sensors. For this purpose, the intermediate volume changes of each inflation system need to be converted into equivalent load changes. This requires considering the characteristics of the inflation systems (especially the deformable surfaces of the inflation systems), referred to as the flattening stiffness K per unit volume. SG This quantity provides the correlation between the change in load on the inflatable system and the resulting change in the volume of the fluid cavity caused by the change in load, where the inflatable system is flattened on a ground perpendicular to the applied load. This characteristic can be a default value, obtained through experimental characteristics of the inflatable system, or derived through numerical simulations of the same inflatable system. The inflatable system needs to be operating under conditions close to those observed in the preparatory phase (i.e., near the internal temperature T1 and inflatable pressure P1). Typically, this flattening stiffness of the inflatable system is a quantity locally defined near the initial operating point of the inflatable system in a reference frame related to the internal pressure P, internal temperature T, and volume V of the fluid cavity.

[0024] Preferably, prior to the main steps, at least one inflation system equipped with pressure and temperature sensors is in a thermomechanically stable state.

[0025] Preferably, the transient phenomena recorded by the sensors in the electronic device are caused solely by disturbances to the trailer balance resulting from loading the trailer before recording begins. Therefore, other disturbances do not affect the sensor response, which improves the accuracy of load changes assessed using this method. However, the method remains fully relevant if the disturbance to the trailer balance occurs on a different timescale than the disturbance related to loading the trailer, or if such disturbances are expressed in a small magnitude in the sensor response of the electronic device. Once various successive loading operations have been performed, it is necessary to wait for the inflation system, equipped with pressure and temperature sensors, to become thermomechanically stable in order to achieve the highest possible accuracy in assessing load changes, thereby achieving the highest possible accuracy in assessing the load borne by the inflation system.

[0026] Advantageously, the temperature sensor and the pressure sensor are attached to at least one deformable surface of the inflation system equipped with the pressure sensor and the temperature sensor.

[0027] Advantageously, sensors measuring low-amplitude transient phenomena are placed close to where these transients occur, preventing them from being overwhelmed by measurement noise. Therefore, for example, when a centralized tire pressure monitoring system for an inflation system is present, it is advantageous to have the sensor located within the inflation system rather than within the centralized system. Following the same logic, if the sensor is located inside the fluid cavity on a deformable surface of the inflation system, the measurement will be more accurate than if the sensor is mounted on a less deformable surface of the inflation system, because the latter's measurement point is farther from the location where the physical phenomenon occurs, acting on the deformable surface due to the transient nature of the physical phenomenon.

[0028] Advantageously, at least one pressure sensor operates with a resolution of less than 1 millibar.

[0029] Advantageously, at least one temperature sensor operates with a resolution of less than one-hundredth of a degree.

[0030] Therefore, smaller volume changes can be evaluated, and thus smaller load changes can be evaluated.

[0031] Preferably, the sensor's acquisition frequency is between 0.1 Hz and 10 Hz.

[0032] To capture the fluid's rapid first transition, setting the sampling frequency to a higher value is advantageous. It is entirely possible to use the same sampling frequency for both sensors, but this is not mandatory due to alternative methods for estimating the fluid's adiabatic transformation.

[0033] According to a particular implementation, the determination of the initial volume V0 takes into account the geometry of the inflation system when it is unloaded and inflated to a reference pressure P0, preferably, the pressure P0 is the initial pressure P1.

[0034] Advantageously, the geometry of the inflation system is determined by means of an identifier of the inflation system equipped with pressure and temperature sensors, preferably obtained by radio frequency interrogation of electronic devices located on the inflation system.

[0035] In order to initialize the measurement system, in particular to determine the initial volume V1 of the fluid cavity, it is necessary to determine the volume V0 of the fluid cavity corresponding to the volume defined by the empty inflation system, that is, the pressure of the inflation system is the reference inflation pressure P0, preferably the initial pressure P1.

[0036] To determine the volume V0, the geometry of the inflation system at a reference inflation pressure P0 needs to be known. In practice, it is assumed that the geometry of the indeformable parts of the inflation system is unaffected by the inflation pressure. These geometries can be obtained from an inflation system database. Knowing the inflation system's identification information allows for precise determination of the correct geometry from this database. The inflation system's identification information can be obtained by optically reading regulatory markings attached to the outer surface of the inflation system. Identification information can also be transmitted via radio frequency interrogation of electronic devices present on the inflation system, such as Radio Frequency Identification (RFID) tags, tire-mounted sensors (TMS) mounted on the tire's inner liner (in the case of tires), or, for example, tire pressure monitoring systems (TPMS) mounted on the rim of the tire-wheel assembly.

[0037] Preferably, the change in load Z on at least one inflation system equipped with a pressure sensor and a temperature sensor is estimated using the following formula: [Formula 1] , where K P SG It is the aerodynamic flattening stiffness per unit volume of the inflation system.

[0038] This is a simple and basic model that combines the load applied to the inflation system with the fluid cavity of the inflation system in a first volume state V. i (e.g., unloaded) and second volume state V i+1The volume change, the inflation pressure P of the fluid cavity, and the aerodynamic stiffness of the inflation system corresponding to the overall horizontal position of the inflation system on the contact plane (in other words, regardless of pressure P, volume V, and temperature T) are related. This model assumes that the structural stiffness of the inflation system is negligible compared to its aerodynamic stiffness, an assumption that is realistic for trailer tires. However, in the previous formula, the structural stiffness of the inflation system could be fully considered by adding the product of the structural stiffness and the aerodynamic stiffness multiplied by the inflation pressure. If one state of the inflation system corresponds to zero load applied to the inflation system, then the change in load directly corresponds to the load borne by the inflation system in another volume state.

[0039] According to an advantageous implementation, the volume change ΔV of at least one inflation system equipped with a pressure sensor and a temperature sensor is estimated by solving the following differential equation: [Formula 2] , [Formula 3] , Where P is the internal pressure of the fluid cavity, V is the internal volume of the fluid cavity, and T is the internal temperature of the fluid cavity.

[0040] This differential equation reveals the correlation between parameters of the fluid within the inflation system cavity. These parameters are primarily determined by the adiabatic transformation of the fluid and secondarily by the fact that the fluid is an ideal gas. Thermal equilibrium with the external environment is considered by directly measuring the internal temperature of the fluid cavity and, possibly, the temperature of the external environment surrounding the tire and wheel assembly.

[0041] The present invention also relates to a method for estimating the change in load borne by a trailer due to loading the loading space of a stationary, unconnected trailer, the method comprising estimating the change in load borne by the trailer's inflation system due to loading the loading space of a stationary trailer, wherein, in a preparatory stage, at least one pressure sensor and at least one temperature sensor are provided for at least one inflation system of each ground contact assembly of the trailer, preferably, at least one pressure sensor and at least one temperature sensor are provided for each inflation system of each ground contact assembly of the trailer, the method comprising the step of estimating the change in load borne by the inflation system of the trailer's ground contact assembly without pressure and temperature sensors based on the estimated change in load borne by the inflation system equipped with pressure and temperature sensors, the method comprising, in a main stage, the step of determining the change in load borne by the trailer as the sum of the changes in load borne by each inflation system of each ground contact assembly of the trailer.

[0042] Here, the goal is no longer to estimate the load variation at a single inflation system associated with the trailer's ground contact assembly, but rather to determine the overall load variation borne by the trailer. For this purpose, each ground contact assembly of the trailer needs to be equipped with an inflation system fitted with pressure and temperature sensors. This allows for the estimation of the location of additional loads applied longitudinally and laterally within the trailer's loading space, based on the trailer's dimensions. Next, the additional loads applied to the individual ground contact assemblies of the trailer without measuring sensors are estimated based on the distribution of these estimated additional loads. Of course, this distribution is not essential if each inflation system of each ground contact assembly of the trailer is equipped with a measuring sensor. Then, preferably, the method is made more robust by providing control points that allow for checking the measurements relative to theory. The load variation applied to each inflation system of each ground contact assembly of the trailer can then be estimated. The final step is to sum the load variations borne by all these inflation systems to estimate the overall load variation borne by the trailer. By summing the changes in load applied to the trailer during each loading step, the total load borne by the trailer can be estimated, especially if the initial load on the trailer is determined before the first loading step (if this is relevant to the operation of the trailer). For example, the trailer load is not necessarily information relevant to estimating the weight of the load being transported by the trailer. However, the trailer load does help in estimating the total load borne by each axle of the trailer.

[0043] The present invention also relates to a method for estimating the load borne by an inflation system of a trailer, the method comprising a method for measuring the change in load borne by the inflation system of the trailer resulting from loading the loading space of a stationary trailer, the method being characterized in that the method comprises the step of estimating the load Z borne by at least one inflation system equipped with a pressure sensor and a temperature sensor by using the change ΔZ of the load borne by at least one inflation system equipped with a pressure sensor and a temperature sensor and the determination result of the initial load Z1 of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor.

[0044] The initial load Z1 borne by the inflation system or the inflation system of the trailer's ground contact assembly, or all inflation systems connected to the trailer's ground contact assembly, before loading the trailer's loading space, can be evaluated by adding the load change ΔZ assessed at the same inflation system. Thus, evaluating the total load borne by the trailer is equivalent to simply summing the static loads established on all ground contact assemblies of the trailer. Therefore, even before the trailer is connected to the tractor and begins to move, the load states between the trailer's ground contact assemblies or the inflation systems of the same ground contact assembly can be compared. In this way, the correct distribution of the total load or load change on the individual ground contact assemblies of the trailer or the entire trailer caused by loading the trailer can be verified.

[0045] The present invention also relates to a method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, and / or a system for estimating the change in load on a trailer caused by loading the loading space of a stationary, unattached trailer, and / or a system for estimating the load on the inflator system of a trailer, the system comprising: • Trailer, with at least one inflation system mounted on at least one ground contact component of the trailer, the at least one inflation system being equipped with electronic devices; • The electronic device includes at least one pressure sensor, at least one temperature sensor, at least one electronic chip, at least one storage space capable of recording signals from the sensors, and at least one first radio frequency communication device capable of transmitting. • At least one computing device; and • At least one display device, which includes at least one second radio frequency communication device capable of receiving signals.

[0046] As described in the method, the sensor should be located within the inflation system, which may rotate relative to the trailer, similar to the case of the tire and wheel assembly. Therefore, the electronics that regulate the signals from the sensor should be equipped with a communication device, such as a radio frequency (RF) communication device, to easily transmit data outside the inflation system, at least to the location of the display device. Specifically, an alternative is to integrate a computing device that calculates changes in the volume of the inflation system's internal cavity into the inflation system. This computing device can be integrated into the electronics or communicate with the electronics via a wired connection. Thus, the RF communication device of the electronics facilitates the transmission of the calculation results outside the inflation system. The RF communication from the electronics of the inflation system may be sent to the trailer, the vehicle, or somewhere outside these two components, and used by devices separate from these components, such as mobile phones, tablets, or computers. These three elements can represent a display device. However, the display device can also be a graphical interface for the trailer or vehicle, such as a graphical interface on the dashboard.

[0047] Therefore, the proposed structural form can be adapted to a variety of possible technical configurations, while also having the functionality to implement the method.

[0048] Preferably, the system includes an analysis device capable of analyzing the results output by at least one computing device.

[0049] The result of the calculation device is a change in volume or a change in load on the various inflation systems equipped with electronic devices. If these quantities are to be compared or sorted for display on a display device, one or more tasks may need to be performed before sending a message to the display device. This optional component of the system capable of servicing the trailer operator needs to be located between the calculation device and the display device. Structurally, it can be associated with one and / or the other via a wired connection, or it can be physically separated from these components via a radio frequency communication device.

[0050] According to a first specific embodiment, the at least one computing device includes at least one third radio frequency communication device capable of transmitting / receiving.

[0051] When the computing device is physically separated from the electronic and display devices, it needs to be able to communicate with the other two components. This is the case, for example, when the computing device is on a trailer: it collects data about the physical parameters of the fluid from the electronic device via radio frequency communication. On the other hand, if the display device is on a mobile phone, the calculation results are sent to the display device via the same radio frequency communication.

[0052] According to a second specific embodiment, the at least one analysis device includes at least one fourth radio frequency communication device capable of transmitting / receiving.

[0053] When the analysis device is physically separated from the computing and display devices, it needs to be able to communicate with the other two components. This is the case, for example, when the analysis device is located on a server far from the trailer: it collects information from the computing device, such as changes in loads applied to the various inflation systems of the trailer, via radio frequency communication with the computing device located on the trailer. On the other hand, if the display device is on a mobile phone or any other electronic device with a screen, the analysis device sends the comparison-generated messages to the display device via radio frequency communication.

[0054] According to a third specific embodiment, the system includes at least one reading device capable of reading data contained in at least one storage space of the electronic device, the at least one reading device including at least a fifth radio frequency communication device capable of receiving.

[0055] When the communication range of an electronic device is insufficient to provide communication for a computing or display device, a reading device should be used to collect data from the electronic device. This reading device performs the function of capturing measurement data. It then transmits this data via radio frequency communication to the display device or any other component in the system that requires data, for the remainder of the method. The reading device acts as an information relay, thereby optimizing communication coverage relative to the electronic device present in the inflation system. Specifically, to reduce the mass of the electronic device in the inflation system, the energy source required for data transmission should be limited; data transmission is an energy-consuming function of the electronic device.

[0056] Preferably, a portion of the communication performed by the communication device between the device and an element included in the group comprising an electronic device, at least one computing device, at least one display device, at least one analysis device, and at least one reading device is performed using UHF radio waves, and preferably using Bluetooth Low Energy (BLE).

[0057] The Ultra High Frequency (UHF) band enables high-volume data transmission at favorable bit rates, particularly at higher frequencies within the UHF band, such as the BLE band. UHF bands are commonly used in transportation applications, meaning that the system's communication equipment can share resources with existing communication equipment in vehicles, trailers, or roadside infrastructure.

[0058] Advantageously, the at least one display device is included in the group comprising a telephone, a computer, and a human-machine interface located on a trailer and / or vehicle, preferably on a vehicle dashboard.

[0059] The display device is used to warn operators working on the trailer, whether the operator is the driver of the semi-trailer truck unit sitting in the cab or someone else responsible for the proper loading of the trailer.

[0060] According to an advantageous embodiment, a portion of the at least one reading device is located on the trailer.

[0061] According to another advantageous embodiment, a portion of the at least one computing device and / or a portion of the at least one analysis device is located on the trailer, preferably on the inflation system.

[0062] The trailer acts as a natural information relay because the inflation system is connected to it. Therefore, while it is ideal for the system's structural components to be located on the trailer, alternatives are possible. However, the trailer provides a degree of data confidentiality, unlike communication with, for example, a server, unless a secure communication protocol is established. Of course, to minimize the system's impact on the trailer's environment (which is complex today), positioning the functionality on the inflation system limits interference with other structural components of the trailer and / or vehicle. Attached Figure Description

[0063] The invention will be better understood by reading the following description, which is given by way of non-limiting example only and with reference to the accompanying drawings, in which the same reference numerals always denote the same parts, wherein: Figure 1 The invention illustrates a method for estimating the load variation borne by the inflation system of a trailer and / or a system for estimating the load borne by the inflation system of a stationary trailer, according to a first embodiment of the invention. Figure 2 Another configuration of the system according to a second embodiment of the present invention is shown; Figure 3 A block diagram is shown of a method according to the invention for estimating the change in load and / or the load borne by the inflation system of a trailer during loading. Figure 4 The time evolution of the internal pressure of the fluid cavity output by the pressure sensor is shown; Figure 5 The time evolution of the internal temperature of the fluid cavity is shown; Figure 6 An estimate of the volume change of a fluid cavity relative to time according to the present invention is shown; Figure 7 The diagram shows an estimate of the change in load on the trailer's tire and wheel assembly relative to time, in relation to the loading of the trailer's cargo space. Detailed Implementation

[0064] Figure 1An example of system 2000 is shown, which implements a method for estimating the load variation borne by the inflation system of a trailer connected to a ground contact assembly and / or a method for estimating the load borne by the inflation system of a trailer connected to a ground contact assembly. System 2000 includes a trailer 2001, which includes three axles of a tire wheel assembly 2006 distributed on the trailer 2001. The trailer 2001 includes a pair of landing gear legs 2008 located at the front of the trailer, and one landing gear leg on each side of the trailer along the trailer 2001. The pair of landing gear legs 2008 and the three axles represent the ground contact assembly of the trailer. The trailer 2001 includes a point M located at the front of the trailer for connecting a towing vehicle's towing seat. Trailer 2001 has a center of gravity G. The weight P of the trailer and its cargo space is applied to this center of gravity G. This weight P corresponds to the force generated by the total mass of the trailer and its initial cargo, taking into account Earth's gravity. This weight P is balanced by the reaction forces applied to the trailer's tire-wheel assembly 2006 (these reaction forces are referred to as Z1 to Z3 depending on the axle to which the tire-wheel assembly 2006 is connected) and the reaction force applied to the landing gear legs 2008 (this reaction force is referred to as Z4). The reaction force can be seen here at the inflation system 2006 of the landing gear legs 2008, which is located at the interface between the landing gear legs 2008 and the trailer structure. It is entirely conceivable that the inflation system of the landing gear legs is located at the interface between the ground and the landing gear legs, or inserted along the length of the landing gear legs. The presence of an additional load on the trailer (corresponding to the loading space of the trailer 2001) will result in additional reaction forces ΔZ1 to ΔZ3 and ΔZ4, respectively, applied to the tire wheel assemblies 2006 of the respective axles. When a steady state is reached, the additional reaction forces ΔZ1 to ΔZ3 and ΔZ4 will stabilize to balance the additional load.

[0065] The purpose of the method is to determine the reaction forces on the individual inflation systems of a trailer that become stable when a steady state is reached, thereby deducing the load changes caused by loading (e.g., including unloading) the trailer.

[0066] Preferably, each inflation system 2006 of the trailer 2001 is equipped with an electronic device 2007. This electronic device 2007 is located within the fluid chamber of the inflation system 2006. In this case, the electronic device 2007 is located on the inner wall of the inflation system 2006, aligned with a deformable surface. The electronic device can be mounted on a rigid surface of the inflation system while remaining within the fluid chamber of the inflation system 2006. For example, for pneumatic tire wheel assemblies, the electronic device can be integrated into the rim valve, similar to some tire pressure monitoring systems (TPMS).

[0067] The electronic device 2007 includes pressure and temperature sensors associated with a microcontroller, as well as at least a radio frequency (RF) device capable of transmission. Therefore, the RF device includes a radio wave generator and a radio communication antenna for transmitting the generated radio waves. The RF device may also optionally include a radio wave receiver for receiving instructions from the outside, such as initiating a measurement. The electronic device 2007 also includes storage space for storing the sensor measurement data before transmitting it in the form of radio waves. The electronic device can transmit raw measurement data or data filtered by the microcontroller. The electronic device 2007 transmits both pressure and temperature data to the outside of the tire wheel assembly 2006. Here, the electronic device 2007 transmits radio waves in the Ultra High Frequency (UHF) band, and more specifically, in the Bluetooth Low Energy (BLE) band.

[0068] In this configuration, the exterior of the tire and wheel assembly 2006 includes at least a trailer 2001. The trailer 2001 first includes a radio data reader 2005 operating in the UHF range, with its antenna 2105 located near the inflation system 2006 to collect measurement data generated by the electronics 2007. The data is then transmitted here via a wired connection to a computing device 2002 located within the trailer 2001. Radio frequency transmission may also be performed using a specific communication device. The computing device 2002 includes storage space and a processor for performing the following tasks: identifying the quantities of the inflation system corresponding to an initial state; solving differential equations to determine the volume changes of the fluid cavities of the various inflation systems equipped with the electronics 2007; and finally, after pre-collecting the quantities of the inflation system required for this final task, calculating the load changes associated with the volume changes.

[0069] The results (especially the final data) are sent to the analysis device 2004. Here, this data is transmitted via wired connection, but radio frequency communication can also be established. The analysis device 2004 compares the results from the computing device 2002 and sorts the results for presentation to the display device. Of course, the analysis device 2004 can be integrated into the computing device 2002.

[0070] Finally, various output data from the analysis device 2004 are transmitted to the display device 2003 via the fourth communication device 2104 (specifically, by the radio communication antenna of the trailer 2001) and the second communication device 2102 present on the display device 2003.

[0071] These communication devices 2104 and 2102 transmit their data to a tablet or smartphone 2003 via a communication network to inform the trailer about the load distribution during loading.

[0072] If the trailer load distribution is not satisfactory, the loading needs to be modified (either by reducing the mass of the load or by changing the position of the load within the trailer) to better distribute the load across the ground contact components (e.g., the axles of trailer 2001) when the trailer is loaded. Measurement signals from the electronic device 2007 can be continuously recorded while the trailer load is being modified to estimate the new load borne by the various inflation systems 2006 of trailer 2001, which are equipped with the electronic device 2007.

[0073] Figure 2 Another configuration of system 2000 is shown. System 2000 includes a trailer 2001, which includes three axles of a tire-wheel assembly 2006 distributed on the trailer 2001. These axles correspond here to the ground contact assembly of the trailer and are numbered 1 to 3 along the forward direction of travel of the trailer 2001. The trailer 2001 includes a point M located at the front of the trailer for connecting a towing vehicle's towing seat. Furthermore, since the trailer 2001 is stationary, its front rests against a pair of landing gear legs 2008, one on each side of the trailer along the main direction of travel. Each landing gear leg 2008 includes an inflation system 2006. Here, the inflation system 2006, similar to a pneumatic suspension, is located between the top of the landing gear leg 2008 and the structure of the trailer 2001. This inflation system can be directly mounted between the ground and the bottom of the landing gear leg, or it can be inserted between the aforementioned two ends of the landing gear leg. If the trailer is connected to the tractor, the landing gear outriggers 2008 and / or the inflation system 2006 can pivot about a pivot mounted on the trailer structure and pointing laterally relative to the main direction of the trailer 2001.

[0074] Preferably, each inflation system 2006 of each ground contact component (e.g., axle or landing gear legs) of the trailer 2001 is equipped with an electronic device 2007. This electronic device 2007 is located within the fluid cavity of the inflation system 2006. In this case, the electronic device 2007 is located on the inner wall of the deformable surface of the inflation system. The electronic device can be mounted on the rigid surface of the inflation system while remaining within the fluid cavity of the inflation system 2006. For example, when the tire-wheel assembly, which is part of the inflation system, is located on the axle, the electronic device can be integrated into the rim valve, similar to some tire pressure monitoring systems (TPMS).

[0075] The electronic device 2007 includes a pressure sensor and a temperature sensor associated with a microcontroller, as well as at least a radio frequency (RF) device capable of transmission. Therefore, the RF device includes a radio wave generator and a radio communication antenna for transmitting the generated radio waves. The RF device may also optionally include a radio wave receiver for receiving instructions from the outside, such as initiating a measurement. The electronic device 2007 also includes storage space for storing the sensor's measurement data before transmitting it in the form of radio waves. The electronic device can transmit raw measurement data or data filtered by the microcontroller. The electronic device 2007 transmits both pressure and temperature data to the outside of the inflation system 2006. Here, the electronic device 2007 transmits radio waves in the Ultra High Frequency (UHF) band, and more specifically, in the Bluetooth Low Energy (BLE) band.

[0076] In this configuration, the exterior of the tire and wheel assembly 2006 includes at least a trailer 2001. The trailer 2001 first includes a radio data reader 2005 operating in the UHF range, with its antenna 2105 located near the inflation systems 2006 of the various ground contact components of the trailer 2001 to collect measurement data generated by the electronic device 2007. The data, after processing, is then transmitted via wired connection to a computing device 2002 and the transmitting antenna of a communication device 2104 located within the trailer 2001. Radio frequency transmission may also be performed using a specific communication device. The computing device 2002 includes storage space and a processor for performing specific tasks: for example, allocating quantities of the inflation system corresponding to an initial state, solving differential equations to determine changes in the volume of the fluid chambers of the various inflation systems 2006 equipped with the electronic device 2007. However, in this case, part of the task of the computing device 2002 is located in the cloud. For example, after the amount of the inflation system 2006 required for the final task and the first result of the computing device 2002 located on the trailer 2001 have been collected in advance and the first result has been sorted in advance by the analysis device 2004, the change of load related to the change of volume is calculated.

[0077] Here, data is transmitted via wired connection to a first computing device 2002 located within the trailer 2001. However, data can also be transmitted to a computing device 2002 located outside the trailer 2001.

[0078] The first computing device 2002 includes communication devices capable of transmitting / receiving. These communication devices... Figure 2 In configurations other than those described above, radio waves transmitted by the transmitting communication device 2105 can be received and converted into digital data usable by the first computing device 2002. The first computing device 2002 includes storage space and a processor for performing tasks such as identifying the quantities of the inflation system corresponding to an initial state, solving differential equations, and thus determining the volume changes of the fluid cavities of the various inflation systems equipped with the electronic device 2007. These first results, which may be sorted or supplemented by the first analysis device 2004 on the trailer, are transmitted to the second computing device 2002 in the cloud. For this purpose, after the quantities of the inflation system required for this final task have been pre-collected, the second computing device 2002 equipped with the transmitting communication device 2102 calculates, for example, the changes in load related to the volume changes.

[0079] These second results are sent to the second analysis device 2004. Here, this data is transmitted using radio frequency communication. The second analysis device 2004 sorts and compares the second results from the second computing device 2002.

[0080] Finally, various output data from the second analysis device 2004 are transmitted to the display device 2003 via the transmitting fourth communication device 2104 and the second communication device 2102 present on the display device 2003. Here, the display device may consist of a digital tablet computer 2003 that may be located remotely from the trailer 2001, and may also include a human-machine interface in the trailer 2001 containing a display screen. These display devices may also be screens on the dashboard of the tractor unit, with radio frequency transmission of the data to be displayed.

[0081] The display device 2003 is intended to alert the operator of the trailer 2001 to the load status of the trailer 2001, especially the load distribution among the various ground contact components of the trailer 2001.

[0082] Of course, these two implementations of the system for implementing a method for estimating changes in load and / or load borne by the inflation system of a trailer are merely illustrative examples of the system and are not limited to these two configurations. The first extreme configuration is: integrating all calculation and analysis devices into an electronic device mounted on the inflation system, which transmits the results to a display device remotely from the trailer. The other extreme configuration is: transmitting the measurement data recorded on the electronic device via radio waves, and performing other steps of the method on a device remotely from the trailer, without involving the trailer or tractor unit.

[0083] Figure 3 A block diagram is shown of a method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, and / or a method for estimating the load on the inflator system of a trailer caused by loading the loading space of a stationary trailer. The method includes multiple stages.

[0084] The first stage is the preparatory stage, which includes at least actions 1 to 6, depicted by solid lines, where the connecting systems follow each other. This preparatory stage, focusing on the unconnected trailer, obviously involves equipping the trailer (including its initial load) with pressure and temperature sensors (ideally) installed at the inflation system (e.g., the tire-wheel assembly), which can measure physical parameters, such as inflation pressure and internal temperature, of the fluid cavity defined by the deformable surface of the inflation system via dedicated electronics. Steps 1 and 2 involve determining physical quantities related to the fluid cavity of the inflation system equipped with measuring devices, such as inflation pressure P1 and internal temperature T1. Preferably, these determinations can be made with default values ​​or by capturing specific measurements. Step 3 involves determining the load Z1 borne by the inflation system equipped with measuring devices on the unconnected trailer. This determination can be made with default values, assuming the total load of the trailer is distributed among the various ground contact components of the trailer. The total initial load of the trailer is, for example, data from the trailer manufacturer and corresponds, for example, to the initial mass of the trailer specified in the trailer manufacturer's technical specifications. Of course, the initial load of the trailer, for example, provided through a previous assessment (preferably the last one), can also be incorporated. Step 4 corresponds to obtaining specific quantities of the inflation system equipped with measuring devices. One of these quantities is the volume V0, which corresponds to the volume occupied by the fluid cavity of the inflation system when it is inflated to pressure P1 (strictly speaking, at internal temperature T1), but without any applied load (i.e., the tire and wheel assembly is not even on the ground). The second quantity is the flattening stiffness K per unit volume of the inflation system. SGThis may depend on the inflation pressure P1, internal temperature T1, and the load Z1. Finally, the third set of quantities are quantities related to the laws governing the ideal gas behavior of the gas contained in the fluid cavity of the inflation system. Furthermore, the penultimate step of the preparatory stage (labeled 5) is the step of determining the volume V1 occupied by the fluid cavity of the inflation system equipped with a measuring device under load Z1, inflation pressure P1, and temperature T1. Finally, the last step of the preparatory stage (labeled 6) is to assess the amount of gas contained in the fluid cavity of the inflation system equipped with a measuring device by determining the number of gas moles n1 present in volume V1. Here, although the assumptions related to the ideal gas state do apply, it is still necessary to identify the nature of the gas composition, i.e., whether the gas is a single type of gas or a mixture of gases. Optionally, in this preparatory stage, even if not shown, it is crucial to determine the evolution law relating the change in internal pressure P of the fluid in the fluid cavity of the relevant inflation system to the change in internal temperature T during the adiabatic transition near the operating point of the inflation system (i.e., pressure P1, temperature T1, and load Z1). Alternatively, it can be envisioned that, when the trailer is not connected, the load is distributed on the various ground contact components of the trailer, preferably on the various inflation systems of the trailer.

[0085] The method then proceeds to the main steps, which begin with the first step of loading or unloading the loading space of a stationary, unattached trailer. The time-varying inflation pressure P(t) of each instrumented inflation system of the trailer must be recorded; in the case of a light-duty vehicle trailer, this variation is approximately 1 millibar. These records are then stored in a storage space so that the raw data can first be filtered using a low-pass filter to eliminate high-frequency phenomena; this corresponds to step 11. Simultaneously, the time-varying internal temperature T(t) of the fluid chambers of each instrumented inflation system of the trailer is recorded; in the case of a light-duty vehicle trailer, this variation is approximately 1 / 100th of a degree. These records are then stored in a storage space so that the raw data can first be filtered using a low-pass filter to eliminate high-frequency phenomena; this corresponds to step 12.

[0086] Optionally, if sampling of the internal temperature T(t) is insufficient, for example, to capture the adiabatic transition of the fluid associated with the work related to the trailer loading step, the time change of the internal temperature T'(t) of the fluid cavity is determined by utilizing the evolution law determined in the preparatory step, using the time change of the internal pressure P'(t) derived from the recorded results of P(t), which also corresponds to step 12. In this option, the recorded change of the internal pressure P'(t) is used to assess the adiabatic transition of the fluid in the fluid cavity corresponding to the work related to the trailer loading step. Next, the internal temperature T(t) and internal pressure P(t) beyond the adiabatic transition determined by the length of P'(t) are recorded to establish a thermal equilibrium between the fluid cavity and the external environment, which is necessary for the adiabatic transition of the fluid associated with trailer loading.

[0087] If the measurement of internal pressure P(t) (rather than the measurement of internal temperature T(t)) cannot satisfactorily identify the first transition of the fluid, the same method is used. In this case, the recorded internal temperature T(t) is used to determine the endpoints of the adiabatic transition of the fluid, and the recorded results T''(t) contained between these endpoints are extracted. Then, the internal pressure P''(t) between the same two endpoints is determined by utilizing the evolutionary pattern obtained earlier in the preparatory stage that links the internal pressure and internal temperature of the fluid during the adiabatic transition. The connection system between optional steps and steps indispensable to this method is indicated by gray lines instead of black. However, the connection system belonging to the main stage is shown as dashed lines, while the connection system of the preparatory stage is shown as solid lines.

[0088] One of the key steps in the main phase is determining the volume change ΔV of the fluid cavity in each instrumented inflation system via step 13. This step corresponds to solving the differential equation by substituting appropriate changes in the internal pressure and internal temperature of the same instrumented inflation system into the differential equation. Solving the differential equation in continuous time increments then identifies the temporal change in the fluid cavity volume at each time increment. At a minimum, the solution to the differential equation considers the adiabatic transition of the fluid associated with trailer loading. Preferably, the solution to the differential equation considers partial thermal equilibrium between the fluid in the fluid cavity and the external environment (ideally, until a steady state is reached). However, in most cases, a steady state is not reached, and further loading steps occur, resulting in further adiabatic transitions of the fluid, inevitably accompanied by further thermal equilibrium cycles. This continues until a steady state in the thermal equilibrium phase occurs, or until the last trailer loading event.

[0089] By utilizing the changes in internal pressure and internal temperature, these can be substituted into a differential equation that takes into account the above assumptions. Solving this differential equation with time increments yields an estimate of the relevant time change ΔV(t) of the fluid cavity volume, which corresponds to step 13.

[0090] Another important step in the main phase is to evaluate the change in applied load ΔZ, which is only related to the previously evaluated change in volume ΔV; this corresponds to step 14. For this, the flattening stiffness K per unit volume of the inflatable system needs to be considered again. SG This stiffness can include both aerodynamic and structural components. Only the aerodynamic component K is considered. P SG This may be sufficient to provide a reliable estimate of the load variation ΔZ.

[0091] Based on the change in load ΔZ, an initial load Z1 needs to be added to obtain the load borne by the instrumented inflation system in step 15. From this value at the inflation system scale, the load borne by each ground contact component of the trailer can be easily deduced for each instrumented inflation system, thus deducing the total load borne by the trailer.

[0092] Figure 4 The time evolution of pressure from a pressure sensor located on the tire wheel assembly of the trailer is shown. The curve consisting of point 10 is the raw measurement from the pressure sensor, while curve 11 corresponds to the time evolution of the filtered pressure, eliminating high-frequency noise. Then, in... Figure 3 The second curve is used in the block diagram. Here, the measurement time range only considers the first step of loading the trailer's loading space, which is sufficient to explain the method.

[0093] This time-based recording of the internal pressure of the fluid cavity in the tire wheel assembly begins in the preparatory phase before loading the trailer's loading space. The moment marking the first step of loading the trailer corresponds to the abscissa value of point 100, which marks the start of the main phase. It can be seen that from point 100, the internal pressure of the fluid cavity drops rapidly until point 101, at which point the pressure drop slows significantly, and the pressure even rises to a small extent. Point 101 marks the transition between the fluid work associated with trailer loading and the heat exchange with the outside; the former corresponds to the first transition of the fluid, which can be analogous to an adiabatic transition, and the latter corresponds to the second transition of the fluid. Considering that the time origin is the abscissa value of point 100, the abscissa value of point 101 corresponds to the duration T0. Therefore, the preparatory phase 50 ends at the abscissa value of point 100. The preparatory phase 50 precedes the main phase associated with the main steps of loading, which is divided into two consecutive phases. The first phase 51 can be analogous to the adiabatic transition of the fluid, corresponding to the work done by the fluid after loading the trailer. The second phase 52 corresponds to the heat exchange between the fluid and the outside. During this second stage 52, the second step of loading or unloading the trailer can begin, and in terms of internal pressure, the starting point is the internal pressure P on curve 11 associated with this starting point.

[0094] Figure 5 The temporal evolution of the internal temperature of the fluid cavity corresponding to the first step of loading the trailer is shown. Here, this temporal evolution is transmitted by a temperature sensor of an electronic device located on the trailer's tire-wheel assembly, as shown in curve 12. In the absence of a high-quality temperature sensor for measurement (especially for the adiabatic transition phase), an alternative is the estimation of the internal temperature, as shown in curve 12'. This estimation is based, on the one hand, on the recorded internal pressure and the evolution law relating the internal temperature to the internal pressure during the adiabatic transition of the fluid, and on the other hand, on the temperature outside the tire-wheel assembly, which serves as the basis for heat exchange between the fluid in the fluid cavity and the environment outside the tire-wheel assembly via a heat exchange coefficient. This heat exchange coefficient takes into account the thermal characteristics of the tire-wheel assembly. In this alternative, curve 70 shows the estimated evolution of the temperature outside the tire-wheel assembly.

[0095] These evolutions 12 and 12' of the internal temperature of the fluid cavity in the tire wheel assembly begin in the preparatory stage prior to the first step of loading the trailer. The moment when the first step of loading the trailer begins corresponds to the abscissa value of point 100, which marks the beginning of the main stage. It can be seen that from point 100, the internal temperature of the fluid cavity rapidly decreases until point 101, at which point the temperature decrease stops, and then the temperature increases to some extent. Point 101 marks the transition between the fluid work associated with trailer loading and the heat exchange with the outside; the former corresponds to the first transition of the fluid, which can be analogous to an adiabatic transition, and the latter corresponds to the second transition of the fluid. Considering that the time origin is the abscissa value of point 100, the abscissa value of point 101 corresponds to the duration T0. Therefore, the preparatory stage 50 ends at the abscissa value of point 100. The preparatory stage 50 precedes the main stage of the first step of loading the trailer, which is divided into two consecutive stages. The first stage 51 can be analogous to an adiabatic transition of the fluid, corresponding to the work done by the fluid after loading the trailer. The second stage 52 corresponds to the heat exchange between the fluid and the outside. During this second stage 52, the second step of loading or unloading the trailer can begin, with the starting point for internal temperature being the measured internal temperature T on curve 12 associated with this starting point. Specifically, according to the method, curve 12' replaces curve 12 only in the first stage 51.

[0096] Here, even in the first stage 51 of the main phase, a difference can be seen between the recorded internal temperature curve 12 and the estimated curve 12', which illustrates the inertia unique to temperature sensors. On the other hand, the assumption that the evolution of the fluid's internal pressure and internal temperature during the adiabatic transition may be overestimated. However, the trends between these curves 12 and 12' are very similar. Finally, in this case, the temperature outside the tire-wheel assembly is determined by extrapolating the internal temperature of the fluid cavity in the preparatory phase, rather than measuring the external temperature of the tire-wheel assembly, which is also a potential source of error. This estimation corresponds to... Figure 5 Line 70 in the figure. The heat exchange coefficient of the tire-wheel assembly can initially be approximated solely by the characteristics of the tire casing, for example, by estimating the exchange surface area between the tire and the external environment, representing the outer surface area of ​​the tire casing, and the heat exchange coefficient λ, which depends on the thermal properties of the tire material and the distribution of different types of heat exchange (such as radiation, conduction, and convection) within the tire casing. This coefficient λ can be estimated by the evolution of the internal temperature of the fluid cavity during the preparatory stage (e.g., before the main stage).

[0097] Figure 6The time evolution of the determined internal volume of the fluid cavity is shown. Here, this time evolution, represented by the curve, is the output of the volume change calculated using the proposed differential equation, which also takes into account the thermal equilibrium with the external environment during the first step of loading the trailer, prior to any other steps of loading or unloading the trailer.

[0098] The evolution of the internal volume of the fluid cavity in the tire-wheel assembly 13 begins in the preparatory stage before loading the trailer. The moment when the first step of loading the trailer begins corresponds to the abscissa value of point 100, which marks the beginning of the main stage. It can be seen that from point 100, the internal volume of the fluid cavity increases rapidly until point 101, at which point the increase in internal volume slows significantly, and then the volume tends to stabilize to some extent. Point 101 marks the transition between the fluid work and heat exchange with the outside associated with the first step of loading the trailer; the former can be analogous to an adiabatic transition, and the latter corresponds to the second transition of the fluid. Considering that the time origin is the abscissa value of point 100, the abscissa value of point 101 corresponds to the duration T0. Therefore, the preparatory stage 50 ends at the abscissa value of point 100. The preparatory stage 50 precedes the main stage, which is divided into two consecutive stages according to the loading or unloading steps. The first stage 51 can be analogous to an adiabatic transition of the fluid, corresponding to the work done by the fluid after loading the trailer. The second stage 52 corresponds to the heat exchange between the fluid and the outside. During the second stage 52, the second step of loading or unloading the trailer can begin, with the starting point in terms of the volume of the fluid cavity being the volume of the fluid cavity estimated on curve 13 in relation to that starting point.

[0099] It is noted that by the end of stage 51, a good estimate of the volume change of the tire-wheel assembly has been obtained, clearly indicating that the work generated by the change in load on the tire-wheel assembly occurs primarily during stage 51. The observed changes or oscillations correspond to fluctuations in the transient phase corresponding to the establishment of thermal equilibrium. Therefore, the method described herein allows for continuous measurement of the temporal variation of the load applied to the tire-wheel assembly in the time domain.

[0100] Figure 7 The temporal evolution of the load applied to the electronically equipped tire-wheel assembly is shown. The observed time range corresponds to the first step of loading the trailer. Here, this temporal evolution, represented by curve 14, is the output of calculating the volume change using the proposed differential equation and multiplying it by the flattened stiffness of the tire-wheel assembly. The stiffness used here is the locally identified stiffness at the initial pressure on the tire-wheel assembly, the initial load applied to the tire-wheel assembly, and corresponding to the initial temperature. The overall stiffness defined by the proposed formula can be used from the outset, which already gives a good order of magnitude.

[0101] This evolution 14 of the load change borne by the tire and wheel assembly begins in the preparatory stage before loading the trailer. The moment when the first step of loading the trailer begins corresponds to the abscissa value of point 100, which marks the beginning of the main stage. It can be seen that from point 100, the load decreases rapidly until point 101, at which point the load reduction essentially stops, and thereafter tends to stabilize to some extent. Point 101 marks the transition between the fluid work associated with trailer loading and the heat exchange with the outside, the former corresponding to the first transition of the fluid, which can be analogous to an adiabatic transition, and the latter corresponding to the second transition of the fluid. Considering that the time origin is the abscissa value of point 100, the abscissa value of point 101 corresponds to the duration T0. Therefore, the preparatory stage 50 ends at the abscissa value of point 100. The preparatory stage 50 precedes the main stage, which is divided into two consecutive stages according to the loading steps. The first stage 51 can be analogous to the adiabatic transition of the fluid, corresponding to the work done by the fluid after loading the trailer. The second stage 52 corresponds to the heat exchange between the fluid and the outside, until the second step of loading or unloading the trailer begins, or until the thermodynamic equilibrium of the fluid reaches a steady state.

[0102] It is noted that by the end of stage 51, a good estimate of the change in load applied to the tire-wheel assembly has been obtained, clearly indicating that the work generated by the load change occurs primarily during stage 51. The observed changes or oscillations correspond to fluctuations in the transient phase corresponding to the establishment of thermal equilibrium. Therefore, the method described herein can continuously measure the temporal variation of the load applied to the tire-wheel assembly in the time domain. Curve 80 corresponds to the overload measurement of the tire-wheel assembly applied to the trailer by the ground weighbridge during the first step of loading the trailer. In summary, the proposed method captures the variation in applied load very well.

Claims

1. A method for estimating the change in load on the inflation system of a trailer caused by loading the loading space of a stationary trailer, the method comprising the steps of: In the preparatory stage • At least one pressure sensor is provided for at least one inflation system, which serves as an interface between the ground and the trailer, such as a tire wheel assembly or a pneumatic cylinder, and is associated with a ground contact assembly of the trailer, such as a landing gear leg or an axle. The at least one sensor is capable of measuring the internal pressure of a fluid cavity of the inflation system defined by at least one deformable surface of the inflation system. Preferably, at least one pressure sensor is provided for each inflation system of each ground contact assembly of the trailer. • Equip at least one inflation system with at least one temperature sensor, the at least one temperature sensor being capable of measuring the internal temperature of the fluid cavity of the inflation system; • Determine the initial load Z1 applied to at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor; • Determine the initial inflation pressure P1 of the fluid chamber of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor. • Determine the initial internal temperature T1 of the fluid chamber of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor. • The initial volume V1 of the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor is evaluated using a first function, the parameters of which include the volume V0 of the fluid cavity of the inflation system when it is unloaded and inflated to an initial pressure P1, and the flattening stiffness K per unit volume of the inflation system. SG ; • The number of fluid moles n1 in the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor is evaluated using a model that takes into account inflation pressure P1, initial volume V1 and temperature T1. During the main phase: • Load the trailer's loading space; • Record the internal temperature T of the fluid cavity of at least one inflation system equipped with a pressure sensor and a temperature sensor; • Record the internal pressure P of the fluid chamber of at least one inflation system equipped with a pressure sensor and a temperature sensor; • The intermediate volume change ΔV of at least one aeration system is evaluated by utilizing the recorded internal pressure P and recorded internal temperature T, based on a model of a fluid undergoing an adiabatic transition, wherein the fluid behaves as an ideal gas. • The load variation ΔZ experienced by at least one inflation system equipped with a pressure sensor and a temperature sensor is estimated using at least one second function, wherein the parameters of the at least one second function include the intermediate volume variation ΔV of the assessed volume and the flattening stiffness K of the inflation system per unit volume. SG .

2. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, as described in claim 1, wherein, In the preparatory phase, the method includes determining the evolution of the internal pressure P of the fluid cavity based on the internal temperature T during the adiabatic transition of the fluid in the fluid cavity of the inflated and loaded inflation system. In the main phase, the method includes extracting the change in internal temperature T' caused solely by the adiabatic transition of the fluid from the recorded results of the internal temperature T. The method includes determining the internal pressure P' of the fluid cavity based on the internal temperature T' and the evolution determined in the preparatory phase. The step of evaluating the volume change ΔV includes a first phase and at least one second phase. In the first phase, the evaluation is performed using the determined internal pressure P' and the extracted internal temperature T'. In the second phase, the evaluation is performed using a portion of the internal temperature T recorded outside the time range corresponding to the change in the extracted internal temperature T' and a portion of the internal pressure P recorded outside the time range.

3. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, as described in claim 2, wherein, The extraction of the change in internal temperature T' begins when the recorded internal temperature T changes its rate of change for the first time, and ends when the recorded internal temperature T changes its rate of change for the second time, or after a duration T0 corresponding to the end of the adiabatic transition of the fluid. The start of duration T0 corresponds to the first change in the rate of change of the recorded internal temperature T.

4. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, as described in claim 1, wherein, In the preparatory stage, the method includes the step of determining the evolution of the internal temperature T of the fluid cavity based on the internal pressure P during the adiabatic transition of the fluid in the fluid cavity of the inflated and loaded inflated system. In the main stage, the method includes the step of extracting the change of the internal pressure P” solely due to the adiabatic transition of the fluid from the recorded results of the internal pressure P. The method includes the step of determining the internal temperature T” of the fluid cavity of the inflated system based on the internal pressure P” and the evolution determined in the preparatory stage. The step of evaluating the volume change ΔV includes a first stage and at least one second stage. In the first stage, the evaluation is performed using the extracted internal pressure P” and the determined internal temperature T”. In the second stage, the evaluation is performed using a portion of the internal pressure P recorded outside the time range corresponding to the change of the extracted internal pressure P” and a portion of the internal temperature T recorded outside the time range.

5. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, as described in claim 4, wherein... The extraction of the change in internal pressure P” begins when the recorded internal pressure P changes its rate of change for the first time, and ends when the recorded internal pressure P changes its rate of change for the second time, or after a duration T0 corresponding to the end of the adiabatic transition of the fluid. The start of duration T0 corresponds to the first change in the rate of change of the recorded internal pressure P.

6. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, according to any one of claims 1 to 5, wherein, Temperature and pressure sensors are attached to at least one deformable surface of an inflation system equipped with pressure and temperature sensors.

7. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, according to any one of claims 1 to 6, wherein, At least one pressure sensor operates with a resolution of less than 1 millibar.

8. The method for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, according to any one of claims 1 to 7, wherein, The following formula is used to estimate the change in load Z on at least one inflation system equipped with pressure and temperature sensors: [Formula 1] Among them, K P SG It is the aerodynamic flattening stiffness per unit volume of the inflation system.

9. A method for estimating the change in load borne by a trailer as a result of loading the loading space of a stationary, unattached trailer, the method comprising, according to any one of claims 1 to 8, a method for estimating the change in load borne by the trailer's inflation system as a result of loading the loading space of a stationary trailer, wherein, In the preparatory stage, at least one pressure sensor and at least one temperature sensor are provided for at least one inflation system of each ground contact assembly of the trailer. Preferably, at least one pressure sensor and at least one temperature sensor are provided for each inflation system of each ground contact assembly of the trailer. The method includes the step of estimating the load change borne by the inflation system of the trailer's ground contact assembly that is not equipped with pressure and temperature sensors based on the estimated load change borne by the inflation system equipped with pressure and temperature sensors. The method also includes, in the main stage, the step of determining the load change borne by the trailer as the sum of the load changes borne by each inflation system of each ground contact assembly of the trailer.

10. A method for estimating the load borne by an inflation system of a trailer, the method comprising a method for measuring the change in load borne by the inflation system of the trailer resulting from loading the loading space of a stationary trailer according to any one of claims 1 to 8, characterized in that the method comprises estimating the load Z borne by at least one inflation system equipped with a pressure sensor and a temperature sensor by using a change ΔZ in the load borne by at least one inflation system equipped with a pressure sensor and a temperature sensor and a determination result of the initial load Z1 of at least one inflation system of the trailer equipped with a pressure sensor and a temperature sensor.

11. A system (2000) for implementing the method for estimating the change in load on the inflation system of a trailer caused by loading the loading space of a stationary trailer according to any one of claims 1 to 8 and / or implementing the method for estimating the change in load on a trailer caused by loading the loading space of a stationary unconnected trailer according to claim 9 and / or implementing the method for estimating the load on the inflation system of a trailer according to claim 10, the system comprising: • Trailer (2001), with at least one inflation system (2006) mounted on at least one ground contact component of the trailer, the at least one inflation system being equipped with electronic devices (2007). • The electronic device (2007) includes at least one pressure sensor, at least one temperature sensor, at least one electronic chip, at least one storage space capable of recording signals from the sensors, and at least one first radio frequency communication device (2101) capable of transmitting. • At least one computing device (2002); and • At least one display device (2003) includes at least one second radio frequency communication device (2102) capable of receiving signals.

12. The system (2000) according to claim 11 for implementing a method for estimating the change in load borne by the inflator system of a trailer due to loading the loading space of a stationary trailer and / or for implementing a method for estimating the change in load borne by a trailer due to loading the loading space of a stationary, unconnected trailer and / or for implementing a method for estimating the load borne by the inflator system of a trailer, wherein, The system (2000) includes an analysis device (2004) capable of analyzing the results output by the at least one computing device (2002).

13. A system (2000) implementing a method for estimating the change in load borne by the inflation system of a trailer resulting from loading the loading space of a stationary trailer, and / or implementing a method for estimating the change in load borne by a trailer resulting from loading the loading space of a stationary unattached trailer, and / or implementing a method for estimating the load borne by the inflation system of a trailer, as claimed in any one of claims 11 and 12, wherein, The at least one computing device (2002) includes at least one third radio frequency communication device (2103) capable of transmitting / receiving.

14. The system (2000) according to claim 12 for implementing a method for estimating the change in load borne by the inflator system of a trailer due to loading the loading space of a stationary trailer and / or for implementing a method for estimating the change in load borne by a trailer due to loading the loading space of a stationary unconnected trailer and / or for implementing a method for estimating the load borne by the inflator system of a trailer, wherein, The at least one analysis device (2004) includes at least one fourth radio frequency communication device (2104) capable of transmitting / receiving.

15. A system (2000) implementing any one of claims 11 to 14 for estimating the change in load borne by the inflator system of a trailer due to loading the loading space of a stationary trailer and / or implementing a system for estimating the change in load borne by a trailer due to loading the loading space of a stationary unattached trailer and / or implementing a system for estimating the load borne by the inflator system of a trailer, wherein, The system (2000) includes at least one reading device (2005) capable of reading data contained in at least one storage space of the electronic device (2007), and includes at least one fifth radio frequency communication device (2105) capable of receiving data.

16. A system (2000) implementing any one of claims 11 to 15 for estimating the change in load borne by the inflation system of a trailer resulting from loading the loading space of a stationary trailer, and / or implementing a system for estimating the change in load borne by a trailer resulting from loading the loading space of a stationary, unattached trailer, and / or implementing a system for estimating the load borne by the inflation system of a trailer, wherein, Communication performed by the communication devices (2101, 2102, 2103, 2104, 2105) between a portion of the communication and the elements included in the group comprising the electronic device (2007), the at least one computing device (2002), the at least one display device (2003), the at least one analysis device (2004), and the at least one reading device (2005) is performed using UHF radio waves, preferably using BLE waves.

17. A system (2000) implementing any one of claims 11 to 16 for estimating the change in load borne by the inflator system of a trailer due to loading the loading space of a stationary trailer and / or implementing a system for estimating the change in load borne by a trailer due to loading the loading space of a stationary unattached trailer and / or implementing a system for estimating the load borne by the inflator system of a trailer, wherein, The at least one display device (2003) is included in the group comprising a telephone, a computer, and a human-machine interface located on a trailer (2001) and / or vehicle, preferably on a vehicle dashboard.

18. A system (2000) comprising, according to claim 15 or any one of claims 16 and 17 in conjunction with claim 15, for estimating the change in load on the inflator system of a trailer resulting from loading the loading space of a stationary trailer and / or for estimating the change in load on a trailer resulting from loading the loading space of a stationary, unattached trailer and / or for estimating the load on the inflator system of a trailer, wherein, A portion of the at least one reading device (2005) is located on the trailer (2001).

19. A system (2000) implementing any one of claims 11 to 18 for estimating the change in load on the inflator system of a trailer caused by loading the loading space of a stationary trailer, and / or implementing a system for estimating the change in load on a trailer caused by loading the loading space of a stationary, unattached trailer, and / or implementing a system for estimating the load on the inflator system of a trailer, wherein, A portion of the at least one computing device (2002) and / or a portion of the at least one analysis device (2004) is located on the trailer (2001), preferably on the inflation system (2006).

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