A highly reliable airborne tire pressure monitoring method

Abstract

The present invention provides a highly reliable airborne tire pressure monitoring method, which includes dynamically adjusting the working state of sensor nodes to switch the sensor nodes among three states: active state, pre-sleep state, and sleep state; when the sensor nodes are in the active state or the pre-sleep state, adjusting the sampling frequency of the sensor nodes based on the sampling frequency dynamic adjustment algorithm, and collecting the tire temperature data and tire pressure data of the tires associated with the sensor nodes; the sensor nodes and the gateway nodes output the tire temperature data and tire pressure data by adopting an exponential retransmission control strategy according to the data requests received by them. The airborne tire pressure monitoring method designed by the present invention can achieve an expanded data collection range, adaptively adjust the data collection frequency and transmission frequency, and can realize the multi-channel collection and summary of data, meeting the applications in airborne scenarios and maintenance scenarios.

Description

Technical Field

[0001] The invention belongs to the technical field of airborne computer communication, relates to the design technology of an airborne tire pressure wireless monitoring system, and particularly relates to a highly reliable airborne tire pressure monitoring method. Background Art

[0002] The airborne tire pressure, that is, the pressure value of an aircraft tire, is one of the important indicators for measuring the health of an aircraft tire. Too high or too low tire pressure will cause a sharp reduction in the working performance of the aircraft tire, and even a tire blowout may occur. Preventing flight safety problems caused by abnormal tire pressure has become the top priority of routine aircraft maintenance work. Therefore, effective monitoring of tire pressure has become an indispensable requirement for pilots and ground crew. Currently, the current mainstream aircraft tire pressure monitoring methods are divided into two types: based on wired communication and based on wireless communication.

[0003] Among them, for the tire pressure monitoring method using the wired communication method, after the aircraft docks at the airport, the ground crew connects the tire pressure measuring instrument to the tire valve through a wired connection to complete the tire pressure measurement work. This method has the following disadvantages: (1) Tire pressure monitoring cannot be carried out in real time, and it can only be completed after the aircraft docks at the airport. The tire pressure information cannot be fed back in time, and there is a risk of missing the detection of abnormal tire pressure during flight or a sharp change in tire pressure after the measurement is completed, reducing the pilots' or ground crew's ability to predict and respond to potential risks in a timely manner; (2) Connecting the tire pressure measuring instrument to the tire valve itself has a risk of damaging the valve, which may cause air leakage caused by tire pressure measurement, endangering flight safety; (3) Wired connection relies on ground crew to poll for tire pressure information, with low manpower and man-hour efficiency, directly delaying the aircraft maintenance time and reducing the economy and flight effectiveness of the aircraft.

[0004] A method for monitoring tire pressure using wireless communication usually physically separates the sensor from the data receiving unit. By establishing a wireless communication system, real-time monitoring of tire pressure information is achieved. Compared with the wired method, the wireless method can obtain on-board data in real time without relying on manual measurement, improving the efficiency of daily maintenance of aircraft tires and reducing the occurrence of dangerous situations. The on-board wireless tire pressure monitoring system is of great significance for improving the pilot's real-time control ability of aircraft tires, ensuring landing performance and aircraft safety. However, existing related research, such as patents CN101774337A, US 2017 / 0087943A1, US 2005 / 026440.6A1, etc., focuses on the completeness of the construction of the tire pressure monitoring system, that is, the design of the main components of the system, while ignoring the reliability challenges brought by the complex physical environment conditions and complex wireless transmission conditions on board during the actual operation of the system. It has the following deficiencies: (1) The sampling frequency of the tire pressure sensor is a fixed value, which cannot fully reflect the dynamic changes of the tire pressure value, especially in scenarios such as landing and takeoff, reducing the reliability of the sensing and monitoring system; (2) The data transmission frequency of the tire pressure sensor is a fixed value, which cannot take into account the wireless communication channel states generated at different tire positions, resulting in differences in the wireless communication quality of sensor nodes at different positions. Especially in scenarios such as after the aircraft lands and stops and after the landing gear is retracted after takeoff, there is a risk that sensing information is difficult to obtain due to poor communication channels, reducing the reliability of system data acquisition; (3) The reporting channel for sensing information is single, which cannot simultaneously meet the needs of pilots and ground crew for obtaining on-board data, and it is impossible to quickly deploy an emergency plan according to the risk level prompted by the data. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems of missed detection risk, air leakage caused by damaging the valve, low monitoring efficiency, long maintenance time, poor system reliability, and inability to quickly deploy an emergency plan existing in the above two tire pressure monitoring methods of wired communication and wireless communication, and design a highly reliable on-board tire pressure monitoring method.

[0006] The technical solution for achieving the invention purpose is as follows: A highly reliable on-board tire pressure monitoring method includes the following steps:

[0007] Dynamically adjust the working state of the sensor node to enable the sensor node to switch between three states: active state, pre-sleep state, and sleep state;

[0008] When the sensor node is in the active state or the pre-sleep state, adjust the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm, and collect the tire temperature data and tire pressure data of the tire associated with the sensor node; when the sensor node is in the sleep state, the sensor node stops collecting the tire temperature data and tire pressure data of the tire associated with the sensor node;

[0009] The sensor nodes and the gateway node output the tire temperature data and the tire pressure data by adopting an exponential retransmission control strategy according to the data requests received by them.

[0010] In an embodiment of the present invention, a highly reliable airborne tire pressure monitoring method includes designing an airborne tire pressure monitoring system, and the airborne tire pressure monitoring system includes sensor nodes, a gateway node, a handheld data receiving node, and a ground fixed data receiving node;

[0011] Each tire of the aircraft is provided with the associated sensor node, and the sensor node collects and outputs the tire temperature data and the tire pressure data of the tire;

[0012] The gateway node is communicatively connected to the sensor nodes at its lower level and to the handheld data receiving node, and the gateway node is further communicatively connected to the ground fixed data receiving node through the airborne interface unit and the airborne wireless interface unit at its upper level;

[0013] The handheld data receiving node is communicatively connected to the ground fixed data receiving node and to the sensor nodes. The handheld data receiving node is used for sending a data request to any one of the gateway nodes or any one of the sensor nodes, and receiving the tire temperature data and the tire pressure data output by the gateway node or the sensor node, and is used for performing network access authentication, configuration update, and maintenance on the sensor nodes.

[0014] Further, the sensor node is located at the tire valve, and the sensor node is associated with the tire. The sensor node is internally provided with a wireless transceiver module, a working state module, a sampling frequency calculation unit, a first data sending frequency calculation unit, and a first storage module;

[0015] The gateway node is internally provided with a sensor node working state management and scheduling module, a second storage module, and a second data sending frequency calculation unit.

[0016] In an embodiment, a method for dynamically adjusting the working state of the sensor node to enable the sensor node to switch between three states of an active state, a pre-sleep state, and a sleep state includes:

[0017] S101. Determine the aircraft state based on an acceleration sensor;

[0018] S102. When the aircraft enters the takeoff state or the landing state, control the sensor node to switch from the sleep state to the active state;

[0019] S103. When the aircraft completes takeoff or landing, obtain the tire temperature and the ambient temperature of the aircraft, or obtain the tire pressure and the ambient pressure of the aircraft;

[0020] S104. Compare the tire temperature with the ambient temperature. When the tire temperature is not within the preset safe range relative to the ambient temperature, control the sensor node to switch from the active state to the pre-sleep state;

[0021] Or compare the tire pressure with the ambient pressure. When the tire pressure is not within the preset safe range relative to the ambient pressure, control the sensor node to switch from the active state to the pre-sleep state;

[0022] S105. When the tire temperature enters the preset safe range relative to the ambient temperature, control the sensor node to switch from the pre-sleep state to the sleep state;

[0023] Or compare the tire pressure with the ambient pressure. When the tire pressure is not within the preset safe range relative to the ambient pressure, control the sensor node to switch from the pre-sleep state to the sleep state.

[0024] Further, the switching of the sensor node among the active state, the pre-sleep state, and the sleep state is based on the acceleration sensor data obtained by the gateway node, as well as the tire temperature data or tire pressure data of the tire associated with the gateway node, to form and send an activation instruction, a pre-sleep instruction, or a sleep instruction to its next-level sensor node.

[0025] In one embodiment, the method for dynamically adjusting the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm is as follows:

[0026] Obtain the ambient temperature of the aircraft;

[0027] Compare the ambient temperature of the aircraft with the working range of the sensor node;

[0028] Dynamically adjust the sampling frequency of the sensor node according to the comparison result and the strategy of stepped response to the ambient temperature.

[0029] Further, the method for dynamically adjusting the sampling frequency of the sensor node according to the comparison result and the strategy of stepped response to the ambient temperature is as follows:

[0030] When the ambient temperature of the aircraft is within the [minimum operating temperature, optimal operating temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the minimum operating temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal operating temperature. At the same time, adjust the sampling frequency of the sensor node in combination with the strategy of stepped response to the ambient temperature;

[0031] When the ambient temperature of the aircraft is within the [optimal operating temperature, maximum operating temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the maximum operating temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal operating temperature. At the same time, the sampling frequency of the sensor node is adjusted in combination with the ambient temperature stepped response strategy.

[0032] In an improved embodiment of the above embodiment, the airborne tire pressure monitoring method further includes a handheld data receiving node communicating with the sensor node to perform network access authentication, parameter configuration, network disconnection operation, and configuration update on the sensor node.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. The sampling frequency of the sensor node (i.e., the tire pressure sensor and the tire temperature sensor) in the airborne tire pressure monitoring method can be adaptively adjusted according to the ambient environment of the aircraft and the operating temperature range of the sensor node, which can cover the tire usage environment under harsh conditions such as aircraft landing and takeoff, and improve the sensing reliability of the tire pressure monitoring system;

[0035] 2. The transmission frequencies of the tire temperature data and the tire pressure data in the airborne tire pressure monitoring method can be adaptively adjusted according to the wireless link state, which is compatible with the transmission requirements under complex link states and improves the data transmission reliability of the tire pressure monitoring system; and according to the exponential retransmission control strategy, the active retransmission ability of the sensor node can be enhanced to ensure the reliability of data transmission;

[0036] 3. The design of the airborne tire pressure monitoring system can collect and summarize sensing information through multiple channels, which can simultaneously meet the airborne scenario and the maintenance scenario, support the ground 5G network, and improve the reliability of data collection and system control of the tire pressure monitoring system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only for the present invention to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of the airborne tire pressure monitoring system in the specific implementation manner;

[0039] Figure 2 It is a connection diagram of each node of the airborne tire pressure monitoring system in the specific implementation manner;

[0040] Figure 3 It is a flowchart of the airborne tire pressure monitoring method in the specific implementation manner. Specific implementation manner

[0041] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description progresses. However, these embodiments are merely exemplary and do not constitute any limitation to the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and forms of the technical solutions of the present invention without departing from the spirit and scope of the present invention, and such modifications and substitutions all fall within the protection scope of the present invention.

[0042] In the description of this embodiment, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0043] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0044] Embodiment 1:

[0045] This specific implementation manner designs a highly reliable airborne tire pressure monitoring system. Refer to Figure 1 and Figure 2 As shown, the airborne tire pressure monitoring system includes sensor nodes, gateway nodes, handheld data receiving nodes, and ground fixed data receiving nodes.

[0046] Refer to Figure 1 As shown, sensor nodes (which can also be called sensor modules) are provided at the tire valve positions of each tire of the aircraft. Through the handheld data receiving node for network access authentication operation, the sensor nodes are associated with the tires. The sensor nodes are used to collect and output the tire temperature data and tire pressure data of the tires. For example, a plurality of tires are provided in the nose landing gear bay, the rear left landing gear bay, and the rear right landing gear bay of the aircraft, and each tire is provided with an associated sensor node.

[0047] Specifically, a wireless transceiver module, a working state module, a sampling frequency calculation unit, a first data transmission frequency calculation unit, and a first storage module are provided inside the sensor node. The wireless transceiver module is used to receive various control instructions and data request instructions sent by its upper-level gateway node or handheld data receiving node, and output the collected data; the working state module includes an active state module, a pre-sleep state module, and a sleep state module, and switches between the above three modules; the sampling frequency calculation unit is used to calculate the sampling frequency of the sensor node according to the sampling frequency dynamic adjustment algorithm; the first data transmission frequency calculation unit calculates the frequency of the sensor node sending data according to the exponential retransmission control strategy; the first storage module is used to store the tire temperature data and tire pressure data it collects.

[0048] See Figure 1 and Figure 2 As shown, a gateway node is provided at the position of the aircraft landing gear, and the gateway node is communicatively connected to its lower-level sensor nodes and handheld data receiving nodes, and the gateway node is also communicatively connected to the ground fixed data receiving node through its upper-level airborne interface unit and airborne wireless interface unit.

[0049] A sensor node working state management and scheduling module, a second storage module, and a second data transmission frequency calculation unit are provided inside the gateway node. Among them, the sensor node working state management and scheduling module sends an active state instruction, a pre-sleep state instruction, or a sleep state instruction to its lower-level sensor nodes according to the ambient temperature and tire temperature (or tire pressure), and dynamically adjusts the working state of its lower-level sensor nodes; the second storage module is used to store the tire temperature data and tire pressure data output by its lower-level sensor nodes; the second data transmission frequency calculation unit calculates the frequency of the gateway node sending data according to the exponential retransmission control strategy.

[0050] In this embodiment, see Figure 1 and Figure 2 As shown, there are multiple gateway nodes, which are respectively arranged in the front landing gear compartment, the rear left landing gear compartment, and the rear right landing gear compartment, and each gateway node is connected to its lower-level multiple sensor nodes through wireless communication to send control instructions to the sensor nodes and receive the data output by them; each gateway node is connected to its upper-level airborne interface unit and airborne wireless interface unit through a low-speed bus. The airborne wireless interface unit is an airborne device for wireless communication between the aircraft and the ground, and its data comes from the electromechanical system bus. The device is built-in with a 5G communication module and can transmit the data stored in the device to the ground fixed data receiving node through the 5G network.

[0051] See Figure 1 and Figure 2As shown, the handheld data receiving node (which can also be called a handheld data receiving device) is communicatively connected to a ground-fixed data receiving node and a sensor node. The handheld data receiving node is used to send a data request to any one of the gateway nodes or any one of the sensor nodes, and receive the tire temperature data and tire pressure data output by the gateway node or the sensor node, and is used to perform network access authentication, configuration update, and maintenance on the sensor node.

[0052] In this embodiment, the handheld data receiving node has a capacitive display screen. The ground crew can quickly call up the tire distribution map of the corresponding aircraft model through the navigation window. When replacing the sensor node, according to the unique factory QR code sprayed on the surface of the device, the ground crew can quickly determine the tire position where the new node for network access or the old node for network disconnection is located, and complete the one-to-one matching between the sensor node and the aircraft tire. When the handheld data receiving node receives a data request from the sensor node, due to the different positions of the ground crew, there is also a problem that the packet loss rate increases due to the change in the quality of the wireless communication link. Here, the aforementioned exponential retransmission control strategy is used to reduce the overall power consumption of the node.

[0053] And for the sake of portability, the built-in memory capacity of the handheld data receiving node is limited. The data collected by the device can be transmitted back to the ground-fixed data receiving node through the 5G network for final storage. The handheld data receiving node can receive instructions from the ground-fixed data receiving node to perform an additional inspection on a certain sensor node.

[0054] Among them, the ground-fixed data receiving node mainly consists of an antenna, a baseband chip, and a 5G communication module, which jointly realize data interaction with the airborne wireless interface unit or the handheld data receiving node.

[0055] Embodiment 2:

[0056] This specific embodiment designs a highly reliable airborne tire pressure monitoring method. The airborne tire pressure monitoring method uses the monitoring system in Embodiment 1 to monitor the tire pressure and tire temperature of the aircraft tire. See Figure 3 As shown, the airborne tire pressure monitoring method includes the following steps:

[0057] S1. Dynamically adjust the working state of the sensor node so that the sensor node switches between three states: the active state, the pre-sleep state, and the sleep state;

[0058] S2. When the sensor node is in the active state or the pre-sleep state, adjust the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm, and collect the tire temperature data and tire pressure data of the tire associated with the sensor node; when the sensor node is in the sleep state, the sensor node stops collecting the tire temperature data and tire pressure data of the tire associated with the sensor node;

[0059] S3, the sensor nodes and the gateway node output the tire temperature data and the tire pressure data according to the data requests they receive, using an exponential retransmission control strategy.

[0060] In one embodiment, since there is still a possibility of tire burst after the landing gear of the aircraft is retracted, and a tire burst will cause serious damage to the aircraft after it occurs. Therefore, from the perspective of safety guarantee, the present invention adjusts the existing sleep scheduling strategy, that is, after the aircraft completes takeoff and landing and the tires stop moving, the sensors are not immediately switched to the sleep scheduling state, but a pre-sleep state is introduced.

[0061] Specifically, a method for dynamically adjusting the working state of the sensor nodes to enable the sensor nodes to switch between three states: the active state, the pre-sleep state, and the sleep state, includes:

[0062] S101, determining the state of the aircraft based on the acceleration sensor;

[0063] S102, when the aircraft enters the takeoff state or the landing state, controlling the sensor nodes to switch from the sleep state to the active state;

[0064] S103, when the aircraft completes takeoff or landing, obtaining the tire temperature and the ambient temperature of the aircraft, or obtaining the tire pressure and the ambient pressure of the aircraft;

[0065] S104, comparing the tire temperature with the ambient temperature, and when the tire temperature is not within the preset safe range relative to the ambient temperature, controlling the sensor nodes to switch from the active state to the pre-sleep state;

[0066] Or comparing the tire pressure with the ambient pressure, and when the tire pressure is not within the preset safe range relative to the ambient pressure, controlling the sensor nodes to switch from the active state to the pre-sleep state;

[0067] S105, when the tire temperature enters the preset safe range relative to the ambient temperature, controlling the sensor nodes to switch from the pre-sleep state to the sleep state;

[0068] Or comparing the tire pressure with the ambient pressure, and when the tire pressure is not within the preset safe range relative to the ambient pressure, controlling the sensor nodes to switch from the pre-sleep state to the sleep state.

[0069] Further, the switching of the sensor nodes between the active state, the pre-sleep state, and the sleep state is an activation instruction, a pre-sleep instruction, or a sleep instruction formed by the gateway node according to the obtained acceleration sensor data and the tire temperature data or tire pressure data of the tire associated with the gateway node, and sent to its lower-level sensor nodes.

[0070] In one embodiment, setting the sampling frequency too high will cause excessive power consumption of the sensor and reduce the lifespan, while too low a frequency will reduce the sensing accuracy. Therefore, it is necessary to reasonably set the sampling frequency of the sensor. Specifically, the method for dynamically adjusting the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm is as follows:

[0071] Obtain the ambient temperature of the aircraft;

[0072] Compare the ambient temperature of the aircraft with the operating range of the sensor node;

[0073] Dynamically adjust the sampling frequency of the sensor node according to the comparison result and the ambient temperature step response strategy.

[0074] Furthermore, the method for dynamically adjusting the sampling frequency of the sensor node according to the comparison result and the ambient temperature step response strategy is as follows:

[0075] When the ambient temperature of the aircraft is within the [lowest operating temperature, optimal operating temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the lowest operating temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal operating temperature. At the same time, the sampling frequency of the sensor node is adjusted in combination with the ambient temperature step response strategy;

[0076] When the ambient temperature of the aircraft is within the [optimal operating temperature, highest operating temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the highest operating temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal operating temperature. At the same time, the sampling frequency of the sensor node is adjusted in combination with the ambient temperature step response strategy.

[0077] Generally, the sensing accuracy of the sensor is strongly correlated with the ambient temperature it is in, that is, the higher the temperature, the lower the accuracy. The present invention determines that the sampling frequency of the sensor should be positively correlated with the ambient temperature, that is, after exceeding the optimal operating temperature of the sensor, the higher the temperature, the higher the sampling frequency. When the temperature reaches the maximum value of the aircraft tire under normal use conditions, the sampling frequency reaches the highest set value. At the same time, when the ambient temperature is lower than the optimal operating temperature of the sensor, the sensing accuracy of the sensor will also be adversely affected. At this time, the sampling frequency should be negatively correlated with the ambient temperature, that is, the lower the temperature, the higher the sampling frequency. When the temperature reaches the minimum value of the aircraft tire under normal use conditions, the sampling frequency reaches the highest set value.

[0078] Specifically, the normal operating temperature range of the sensor node is [a, b], the lowest and highest temperatures in extreme cases are A and B respectively, the optimal operating temperature is C, and the corresponding sampling frequency of the sensor node is f s , and the range is [α, β]. Based on the physical property limitations of common sensors, its sampling frequency is usually a discrete value, that is, within the specified sampling frequency range, there are m selectable sampling frequencies. Here, a strategy of stepped response according to the ambient temperature is adopted, that is, according to the values of A, B, and C, the temperature value intervals [A, C] and [C, B] are respectively divided into m equal parts. Then any temperature value will correspond to a sampling frequency, where the temperature C corresponds to the lowest sampling frequency α, and the temperatures A and B correspond to the highest sampling frequency β.

[0079] In one embodiment, since the data acquisition frequency of the sensor node is not fixed, the frequency of its external data output also changes accordingly. Specifically, the calculation method of the external data output frequency of the sensor node is: the data sending time interval of the sensor node is T tx , and the sensor node sending time interval is usually much larger than the sensor node sampling time interval. Therefore, N sampling values V n (n ∈ [1, N]) of weighted average information are included in a single transmission of the sensor node. For the calculation of this weighted average, directly using the mean of N samplings cannot accurately and dynamically reflect the change of the tire state. To solve this problem, a weighted smoothing method is adopted here to first perform smoothing preprocessing on the N sampling values, and then use the means of the N smoothed values as the return value. That is where represents the q weighting coefficient, q ∈

[0080] [0.1, 0.9]. When q tends to 0.1, will be equalized, that is, the state of the N sampling values is reflected on average. When q tends to 0.9, the change of the sampling value will be more intense, that is, the original state of the N sampling values is reflected. It can be seen that the choice of q acts on the final state of the N sampling values. Then, the sensor node will in a single transmission time window adopt the mean method to report to the gateway node or the handheld data receiving node, and the finally sent sensing value s can be expressed as:

[0081]

[0082] The above operations are completed by relying on the small computing unit inside the sensor node. Based on the above analysis, the tire temperature will be strongly correlated with the value of q. The determination method of q here is the same as the method for determining the value of the sampling frequency described above. The temperature value intervals [A, C] and [C, B] are respectively divided into m equal parts. Then any temperature value will correspond to a q, where the temperature C corresponds to the highest weight value q = 0.9, and the temperatures A and B correspond to the lowest weight value q = 0.1. Finally, the pressure sensing value s is sent to the gateway node during the sending period, and can also be returned after being requested by the gateway node or the handheld data receiving node.

[0083] In one embodiment, for the gateway node, the aircraft tire and its sensor node belong to rotating components, and the communication quality between nodes changes with the change of the relative position. When there is physical occlusion between the gateway node and the sensor node or the antenna polarization adaptation is not conducive to wireless communication, the communication packet loss rate will increase significantly, reducing the communication stability and increasing the power consumption of the sensor node. Therefore, the present invention adopts an exponential retransmission control strategy to output the tire temperature data and tire pressure data to enhance the active retransmission ability of the sensor node.

[0084] Specifically, the method for the exponential retransmission control strategy to output the tire temperature data and tire pressure data is as follows: The gateway node will send a control instruction to the sensor nodes at its lower level, specifying the number of active retransmissions of the sensor nodes, assumed to be 2 γ times, where γ gradually increases from 0 to 5. When the gateway node first sends a data request to the sensor node, γ = 0. If the gateway node does not receive the data from the sensor node within the specified time interval τ, the value of γ is incremented by 1, and so on until γ = 5. According to practical experience derivation, this number of retransmissions basically covers common communication scenarios.

[0085] At the same time, the processing unit in the gateway node will calculate the data reception success rate. Within the set time interval (this value can be configured), if the data reception success rate reaches 99%, the number of retransmissions will be gradually decreased, that is, γ new = γ - 1.

[0086] In an improved embodiment of the above embodiment, the airborne tire pressure monitoring method further includes that the handheld data receiving node communicates with the sensor node to perform network access authentication, parameter configuration, network disconnection operation, and configuration update on the sensor node.

[0087] Specifically, the handheld data receiving node has a capacitive display screen. Ground crew can quickly call up the tire distribution map of the corresponding aircraft model through the navigation window. When replacing the sensor node, according to the unique factory QR code sprayed on the device surface, the ground crew can quickly determine the tire position where the new node to be networked or the old node to be de-networked is located, and complete the one-to-one matching between the sensor node and the aircraft tire. When the handheld data receiving node receives a data request from the sensor node, due to the different positions of the ground crew, there is also a problem that the packet loss rate increases due to the change in the quality of the wireless communication link. Here, the aforementioned exponential retransmission control strategy is used to reduce the overall power consumption of the node.

[0088] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0089] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An airborne tire pressure monitoring method with high reliability, characterized in that Including the following steps: Dynamically adjust the working state of the sensor node, enabling the sensor node to switch among three states: the active state, the pre-sleep state, and the sleep state, including: determining the aircraft state based on the acceleration sensor; when the aircraft enters the takeoff state or the landing state, controlling the sensor node to switch from the sleep state to the active state; when the aircraft completes takeoff or landing, obtaining the tire temperature and the ambient temperature of the aircraft, or obtaining the tire pressure and the ambient pressure of the aircraft; comparing the tire temperature with the ambient temperature, and when the tire temperature is not within the preset safe range relative to the ambient temperature, controlling the sensor node to switch from the active state to the pre-sleep state; or comparing the tire pressure with the ambient pressure, and when the tire pressure is not within the preset safe range relative to the ambient pressure, controlling the sensor node to switch from the active state to the pre-sleep state; when the tire temperature enters the preset safe range relative to the ambient temperature, controlling the sensor node to switch from the pre-sleep state to the sleep state; or comparing the tire pressure with the ambient pressure, and when the tire pressure is not within the preset safe range relative to the ambient pressure, controlling the sensor node to switch from the pre-sleep state to the sleep state; When the sensor node is in the active state or the pre-sleep state, adjust the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm, and collect the tire temperature data and tire pressure data of the tire associated with the sensor node. Adjusting the sampling frequency of the sensor node based on the sampling frequency dynamic adjustment algorithm includes: obtaining the ambient temperature of the aircraft; comparing the ambient temperature of the aircraft with the working range of the sensor node; when the ambient temperature of the aircraft is within the [lowest working temperature, optimal working temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the lowest working temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal working temperature, and adjust the sampling frequency of the sensor node in combination with the ambient temperature step response strategy; when the ambient temperature of the aircraft is within the [optimal working temperature, highest working temperature] range of the sensor node, the sampling frequency of the sensor node is negatively correlated with the ambient temperature of the aircraft; the maximum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the highest working temperature, and the minimum sampling frequency of the sensor node is the frequency corresponding to the sensor node at the optimal working temperature, and adjust the sampling frequency of the sensor node in combination with the ambient temperature step response strategy; The sensor node and the gateway node output the tire temperature data and tire pressure data according to the data request they receive, using the exponential retransmission control strategy.

2. The high-reliability airborne tire pressure monitoring method according to claim 1, wherein: The airborne tire pressure monitoring method includes designing an airborne tire pressure monitoring system, and the airborne tire pressure monitoring system includes a sensor node, a gateway node, a handheld data receiving node, and a ground fixed data receiving node; Each tire of the aircraft is provided with the associated sensor node, and the sensor node collects and outputs the tire temperature data and tire pressure data of the tire; The gateway node is communicatively connected to the sensor nodes at its lower level and the handheld data receiving node, and the gateway node is also communicatively connected to the ground fixed data receiving node through the airborne interface unit and the airborne wireless interface unit at its upper level; The handheld data receiving node is communicatively connected to the ground fixed data receiving node and the sensor nodes. The handheld data receiving node is used to send data requests to any one of the gateway nodes or any one of the sensor nodes, and receive the tire temperature data and tire pressure data output by the gateway node or the sensor node, and is used for network access authentication, configuration update and maintenance of the sensor nodes.

3. The high-reliability airborne tire pressure monitoring method according to claim 2, wherein: The sensor nodes are located at the tire valves, and the sensor nodes are associated with the tires. The sensor nodes are provided with a wireless transceiver module, a working state module, a sampling frequency calculation unit, a first data transmission frequency calculation unit, and a first storage module; The gateway node is provided with a sensor node working state management and scheduling module, a second storage module, and a second data transmission frequency calculation unit.

4. The high-reliability airborne tire pressure monitoring method according to claim 1, wherein: The switching of the sensor nodes among the active state, the pre-sleep state, and the sleep state is based on the acceleration sensor data obtained by the gateway node, as well as the tire temperature data or tire pressure data of the tire associated with the gateway node, to form and send an activation instruction, a pre-sleep instruction, or a sleep instruction to the sensor nodes at its lower level.

5. The high-reliability airborne tire pressure monitoring method according to any one of claims 1 to 4, characterized in that: The airborne tire pressure monitoring method further includes that the handheld data receiving node is communicatively connected to the sensor nodes to perform network access authentication, parameter configuration, network disconnection operation, and configuration update on the sensor nodes.

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