Method and system for measuring water quantity of an aircraft

Abstract

The application discloses an aircraft water quantity measuring method and system, comprising the following steps: S01, obtaining the measurement data of a gyroscope and an accelerometer to calculate the three-axis acceleration of an aircraft, obtaining the attitude angle of the aircraft, and obtaining the water surface angle of a water tank according to the three-axis acceleration of the aircraft and the attitude angle of the aircraft; S02, obtaining the measurement data of a capacitive water level sensor to calculate the corresponding water surface height; and S03, obtaining the water quantity of the current water tank according to the corresponding relationship between the water surface angle, the water surface height and the water quantity in the water tank. The measurement data of the gyroscope and the accelerometer are directly used to obtain the three-axis acceleration of the aircraft, and the capacitive water quantity sensor is used to measure the water surface height, so that the synchronism of the measurement data of the water surface height and the three-axis acceleration is ensured, and the accurate measurement and real-time monitoring of the water quantity of the aircraft under complex flight states are improved.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology, and specifically relates to a method and system for measuring aircraft water volume. Background Technology

[0002] Measuring the water volume of aircraft has a significant impact on improving aircraft performance. For specialized firefighting aircraft, improving the accuracy of water volume measurement can increase the amount of firefighting water carried by the aircraft, thereby improving the efficiency of firefighting missions. For civil aircraft, it allows for more precise acquisition of the water tank capacity, enabling better monitoring of the real-time status of available water on board.

[0003] The most common aircraft water volume measurement system at home and abroad is to arrange multiple water level signalers in the water tank and measure the height of the water volume through the water level signalers. This point-based water volume measurement method is easily affected by the aircraft attitude, resulting in inaccurate measurement and failing to achieve real-time monitoring of the aircraft's water volume under complex flight conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for measuring aircraft water volume, which solves the problems of inaccurate measurement of aircraft water tank volume and difficulty in achieving real-time monitoring of aircraft water volume under complex flight conditions.

[0005] This invention is achieved through the following technical solution:

[0006] The method for measuring aircraft water content includes the following steps:

[0007] S01. Obtain the measurement data from the gyroscope and accelerometer to calculate the aircraft's three-axis acceleration, obtain the aircraft's attitude angle, and obtain the water surface angle of the water tank based on the aircraft's three-axis acceleration and attitude angle.

[0008] S02. Obtain the measurement data from the capacitive water level sensor and calculate the corresponding water level height;

[0009] S03. The current water volume in the tank is obtained based on the correspondence between the water surface angle, water surface height and water volume in the tank.

[0010] In some embodiments, the method further includes a step of verifying the data on the water surface angle in the water tank obtained in step S01, including:

[0011] S11. Obtain measurement data from multiple capacitive water level sensors located at different positions within the water tank, and calculate the water level height at the corresponding positions based on the measurement data;

[0012] S12. Based on the position data of each capacitive water level sensor in the water tank and the water level height at the corresponding position, calculate the water surface angle of the water tank, compare the water surface angle with the water surface angle obtained in step S01, and verify the water surface angle of the water tank obtained in step S01.

[0013] In some embodiments, the difference between the water surface angle of the water tank calculated in step S12 and the water surface angle obtained in step S01 is obtained, and the absolute value of the difference is compared with a set water surface angle threshold. When the absolute value of the difference is greater than the water surface angle threshold, a water surface angle fault alarm is triggered.

[0014] In some embodiments, the method further includes a step of verifying the accuracy of data acquired by multiple capacitive water level sensors, including:

[0015] S21. Based on the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank, calculate the relationship between the water surface height at the location of each capacitive water level sensor.

[0016] S22. Based on the measurement data obtained from each capacitive water level sensor, calculate the relationship between the measurement data;

[0017] S23. Compare the relationship between the water level heights at the locations of the various capacitive water level sensors obtained in step S21 with the relationship between the measurement data obtained in step S22 to verify the accuracy of the data acquired by the multiple capacitive water level sensors.

[0018] In some embodiments, based on the comparison results in step S23, a capacitive water level sensor with the largest deviation in measurement data is selected, and a fault alarm is triggered for that capacitive water level sensor.

[0019] In some embodiments, in step S03, a relationship curve between water surface angle, water surface height and water volume in the tank is established. The relationship curve is queried based on the current water surface angle and water surface height data, and the current water volume in the tank is obtained by linear interpolation.

[0020] On the other hand, the present invention also provides an aircraft water volume measurement system, comprising:

[0021] A three-axis acceleration measurement module, comprising a gyroscope and an accelerometer, is used to measure the three-axis acceleration of an aircraft.

[0022] An aircraft attitude angle measurement module, wherein the aircraft measurement module is used to measure the attitude angle of the aircraft;

[0023] A water level measurement module, comprising multiple capacitive water level sensors and a capacitance conversion unit disposed at different locations within a water tank, wherein the capacitance conversion unit is used to convert capacitance signals into frequency signals;

[0024] The control module is used to calculate the water surface angle of the water tank based on the acquired triaxial acceleration and the aircraft's attitude angle, and to calculate the corresponding water surface height based on the acquired frequency signal. It also calculates the current water volume in the water tank based on the correspondence between the water surface angle, water surface height, and water volume in the water tank.

[0025] In some embodiments, a water surface angle verification module is also included. The water surface angle verification module calculates the water surface height at corresponding positions by acquiring measurement data from multiple capacitive water level sensors, calculates the water surface angle of the water tank based on the position data of each capacitive water level sensor in the water tank and the water surface height data at the corresponding positions, and compares the calculated water surface angle with the water surface angle calculated based on the triaxial acceleration and the aircraft's attitude angle, and verifies the water surface angle of the water tank based on the comparison result.

[0026] In some embodiments, a water level sensor verification module is further included. The water level sensor verification module is used to calculate the relationship between the water level heights at the locations of the various capacitive water level sensors based on the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank, and to calculate the relationship between the measurement data based on the obtained measurement data of each capacitive water level sensor, and to compare the obtained relationship between the water level heights at the locations of the various capacitive water level sensors with the obtained relationship between the measurement data to verify the accuracy of the data obtained by the multiple capacitive water level sensors.

[0027] In some embodiments, a fault alarm module is also included, which is used to identify and alarm for faults in the triaxial acceleration measurement module, the aircraft attitude angle measurement module, and the water surface height measurement module.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] 1) The aircraft's three-axis acceleration is directly obtained by using measurement data from gyroscopes and accelerometers. At the same time, a capacitive water level sensor is used to measure the water level height, ensuring the synchronization of the water level height and three-axis acceleration measurement data. This improves the accuracy of water level measurement and real-time monitoring of the aircraft under complex flight conditions.

[0030] 2) By installing multiple capacitive water level sensors in the water tank, and combining the relationship between the placement of the capacitive water level sensors in the water tank, water level height measurement data, and water surface angle, the water surface angle obtained by the aircraft's three-axis acceleration and attitude angle, and the measurement data of the capacitive water level sensors are verified. This further ensures the accuracy of the measurement data, improves the accuracy and reliability of water volume measurement, and enables fault detection and alarm for the three-axis acceleration measurement module, aircraft attitude angle measurement module, and water surface height measurement module. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram illustrating the principle of aircraft water measurement in an embodiment of the present invention.

[0033] Figure 2 This is the frame of the aircraft water measurement system in an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the circuit principle of the aircraft water measurement system in an embodiment of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0036] To address the problems existing in the prior art, this invention uses measurement data from gyroscopes and accelerometers to directly obtain the aircraft's three-axis acceleration, while employing a capacitive water level sensor to measure the water level height, ensuring the synchronization of the water level height and three-axis acceleration measurement data. This enables accurate measurement and real-time monitoring of water volume for the aircraft under complex flight conditions.

[0037] In some embodiments, the aircraft water volume measurement method includes the following steps:

[0038] S01. Obtain the measurement data from the gyroscope and accelerometer to calculate the aircraft's three-axis acceleration, obtain the aircraft's attitude angle, and obtain the water surface angle of the water tank based on the aircraft's three-axis acceleration and attitude angle.

[0039] S02. Obtain the measurement data from the capacitive water level sensor and calculate the corresponding water level height;

[0040] S03. The current water volume in the tank is obtained based on the correspondence between the water surface angle, water surface height and water volume in the tank.

[0041] By acquiring measurement data from gyroscopes and accelerometers, the aircraft's three-axis acceleration n is obtained. x n y and n z The water surface angle of the water tank is calculated by combining the aircraft attitude angle data obtained from the aircraft's inertial navigation system; specifically, the aircraft attitude angle includes the aircraft roll angle α. n and pitch angle β n The water surface angle can be calculated using the following formula:

[0042]

[0043] Establish a relationship curve between water surface angle, water surface height and water volume in the tank. Based on the obtained current water surface angle and water surface height data, query the relationship curve and use linear interpolation to obtain the current water volume in the tank.

[0044] In some embodiments, the method further includes a step of verifying the data on the water surface angle in the water tank obtained in step S01, including:

[0045] S11. Obtain measurement data from multiple capacitive water level sensors located at different positions within the water tank, and calculate the water level height at the corresponding positions based on the measurement data;

[0046] S12. Based on the position data of each capacitive water level sensor in the water tank and the water level height at the corresponding position, calculate the water surface angle of the water tank, compare the water surface angle with the water surface angle obtained in step S01, and verify the water surface angle of the water tank obtained in step S01.

[0047] Verifying the current water surface angle using measurement data from a capacitive water level sensor can further ensure the accuracy of the acquired measurement data.

[0048] In some embodiments, the difference between the water surface angle of the tank calculated in step S12 and the water surface angle obtained in step S01 is obtained. The absolute value of this difference is compared with a set water surface angle threshold. When the absolute value of the difference is greater than the water surface angle threshold, a water surface angle fault alarm is triggered. By cross-validating the water surface angle data obtained under different methods, early warning of fault states of gyroscopes, accelerometers, aircraft inertial navigation systems, and capacitive water level sensors can be achieved, facilitating timely troubleshooting and further ensuring the accuracy of water volume detection.

[0049] In some embodiments, the method further includes a step of verifying the accuracy of data acquired by multiple capacitive water level sensors, including:

[0050] S21. Based on the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank, calculate the relationship between the water surface height at the location of each capacitive water level sensor.

[0051] S22. Based on the measurement data obtained from each capacitive water level sensor, calculate the relationship between the measurement data;

[0052] S23. Compare the relationship between the water level heights at the locations of the various capacitive water level sensors obtained in step S21 with the relationship between the measurement data obtained in step S22 to verify the accuracy of the data acquired by the multiple capacitive water level sensors.

[0053] Similarly, by comparing the relationship between the water level heights obtained from different data at different locations within the water tank, and through cross-validation between the two sets of data, the accuracy of the data acquired by the capacitive water level sensor is ensured, thus guaranteeing the precision of the water volume measurement in the water tank.

[0054] In some embodiments, based on the comparison results in step S23, the capacitive water level sensor with the largest deviation in measurement data is selected, and a fault alarm is triggered for that capacitive water level sensor. Through cross-validation between the two sets of data, when the data of the capacitive water level sensor at one of the two sets of data deviates significantly, it indicates that the capacitive water level sensor at that location is faulty. This facilitates timely isolation of the faulty capacitive water level sensor, thereby ensuring the accuracy of water volume measurement and enabling timely alarm for capacitive water level sensor faults.

[0055] On the other hand, the present invention also relates to an aircraft water volume measurement system, which enables accurate measurement of water volume using the above-mentioned measurement method.

[0056] In some embodiments, refer to Figure 1 , Figure 2 and Figure 3 The aircraft water measurement system includes:

[0057] The three-axis acceleration measurement module includes a gyroscope and an accelerometer, and is used to measure the three-axis acceleration of an aircraft.

[0058] Aircraft attitude angle measurement module; the aircraft measurement module is used to measure the attitude angles of an aircraft.

[0059] The water level measurement module includes multiple capacitive water level sensors and a capacitance conversion unit installed at different positions inside the water tank. The capacitance conversion unit is used to convert the capacitance signal into a frequency signal.

[0060] The control module is used to calculate the water surface angle of the water tank based on the acquired triaxial acceleration and the aircraft's attitude angle, and to calculate the corresponding water surface height based on the acquired frequency signal. It also calculates the current water volume in the water tank based on the correspondence between the water surface angle, water surface height, and water volume in the water tank.

[0061] In addition, there is a communication module, which is used to receive data such as aircraft attitude angles in real time and to realize data transmission between the control module and the onboard display system;

[0062] In addition, the power supply module converts the external 28V DC power supply into the working power of various devices and modules in the system, providing power for the normal operation of the system.

[0063] The control module consists of a TI TMS320F2812 CPU chip, a crystal oscillator circuit, a reset circuit, and a JTAG interface compatible with the IEEE 1149.1 international standard test protocol. The control module controls the digital-to-analog converter of the capacitance conversion unit to excite the capacitive water level sensor to obtain a digital capacitance signal and convert it into a digital water level height. At the same time, the control module receives the triaxial acceleration information output by the triaxial acceleration module and calculates the water surface angle by combining it with the attitude angle data received by the communication module. Finally, it queries the relationship curve representing the correspondence between water level height, water surface angle and water volume stored in the CPU, obtains the water volume information of the water tank through interpolation, and controls the communication module to send the water volume information to the onboard display system.

[0064] The CPU program of the control module is designed with power-on BIT, periodic BIT and maintenance BIT, which can improve the maintainability of the measurement system.

[0065] In some embodiments, the triaxial acceleration measurement module may be Murata’s SSCC 2230; the SSCC2230 combines a gyroscope and an accelerometer and communicates with the CPU via the SPI protocol to obtain the aircraft’s triaxial acceleration in real time in a direct manner, eliminating the synchronization problem of obtaining triaxial acceleration from other devices on the aircraft.

[0066] The capacitance conversion unit uses a multi-harmonic resonant circuit to measure the capacitive sensor. The multi-harmonic resonant circuit converts the water level signal detected by the capacitive water level sensor into a frequency signal, which is then acquired by the CPU to calculate the water level height in the water tank.

[0067] Meanwhile, the capacitor conversion unit is equipped with a BIT self-test channel. The excitation signal drives the BIT capacitor in a time-division manner. After balancing through the bridge arm, and then summing, filtering, and amplifying, the zero-critical value detector generates a rebalancing monitoring signal to realize BIT self-test and improve maintenance level.

[0068] The communication module uses 74LVC164245 and HS-3282 chips to meet the HB 6096 standard and realize ARINC 429 communication. The control module uses the CPU to control the communication module to receive the attitude angles of the aircraft's inertial navigation system in real time to calculate the water surface angle, and periodically outputs the water tank remaining water information to the onboard display system.

[0069] The power module includes an LC filter circuit, an energy storage circuit, and an EMI filter connected in series between the 28V DC power supply and the converter. The 28V DC power supply and the converter are connected in parallel to ground. The power filter conversion module in the power conversion module circuit converts the 28V DC power supply into the ±15V and +5V operating power required internally, and can meet the power characteristics, electromagnetic compatibility, and lightning protection requirements. The +5V power supply is then converted by a power conversion LDO to the 3.3V and 1.9V voltages required for chip operation.

[0070] In some embodiments, the aircraft water volume measurement system further includes a water surface angle verification module. The water surface angle verification module calculates the water surface height at corresponding positions by acquiring measurement data from multiple capacitive water level sensors, calculates the water surface angle of the water tank based on the position data of each capacitive water level sensor in the water tank and the water surface height data at the corresponding positions, and compares the calculated water surface angle with the water surface angle calculated based on the triaxial acceleration and the aircraft's attitude angle, and verifies the water surface angle of the water tank based on the comparison result.

[0071] In some embodiments, the aircraft water level measurement system further includes a water level sensor verification module. The water level sensor verification module is used to calculate the relationship between the water level heights at the locations of the various capacitive water level sensors based on the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank, and to calculate the relationship between the measurement data based on the obtained measurement data of each capacitive water level sensor. The module compares the obtained relationship between the water level heights at the locations of the various capacitive water level sensors with the obtained relationship between the measurement data to verify the accuracy of the data obtained by the multiple capacitive water level sensors.

[0072] The water surface angle verification module and the water level sensor verification module are connected to or integrated into the control module to achieve cross-verification of measurement data in the system and to enable self-checking and early warning of system faults.

[0073] In some embodiments, the aircraft water level measurement system further includes a fault alarm module. The fault alarm module is used to identify faults in the triaxial acceleration measurement module, the aircraft attitude angle measurement module, and the water level sensor verification module based on the water surface angle verification module and the water level sensor verification module, and to issue warnings based on the identification results.

[0074] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method of measuring the water quantity of an aircraft, characterized in that, The method comprises the following steps: S01, obtaining the measurement data of the gyroscope and the accelerometer to calculate the three-axis acceleration of the aircraft, obtaining the attitude angle of the aircraft, and obtaining the water surface angle of the water tank according to the three-axis acceleration of the aircraft and the attitude angle of the aircraft; The step of verifying the data of the water surface angle in the water tank obtained in step S01 comprises: S11, obtaining the measurement data of a plurality of capacitive water level sensors arranged at different positions in the water tank, and calculating the water surface height at the corresponding position according to the measurement data; S12, calculating the water surface angle of the water tank according to the position data of each capacitive water level sensor in the water tank and the water surface height at the corresponding position, and comparing the water surface angle with the water surface angle obtained in step S01 to verify the water surface angle of the water tank obtained in step S01; S02, obtaining the measurement data of the capacitive water level sensor to calculate the corresponding water surface height; S03, obtaining the water quantity of the current water tank according to the corresponding relationship between the water surface angle, the water surface height and the water quantity in the water tank.

2. The aircraft water quantity measurement method of claim 1, wherein, The difference between the water surface angle of the water tank calculated in step S12 and the water surface angle obtained in step S01 is obtained, and the absolute value of the difference is compared with the set water surface angle threshold value. When the absolute value of the difference is greater than the water surface angle threshold value, a water surface angle fault alarm is performed.

3. The method of claim 1, wherein, The step of verifying the accuracy of the data obtained by the plurality of capacitive water level sensors comprises: S21, calculating the relationship between the water surface heights at the positions of the capacitive water level sensors according to the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank; S22, calculating the relationship between the measurement data of each capacitive water level sensor according to the obtained measurement data of each capacitive water level sensor; S23, comparing the relationship between the water surface heights at the positions of the capacitive water level sensors obtained in step S21 with the relationship between the measurement data obtained in step S22 to verify the accuracy of the data obtained by the plurality of capacitive water level sensors.

4. The method of claim 3, wherein, According to the comparison result in step S23, the capacitive water level sensor with the largest measurement data deviation is selected, and a fault alarm is performed for the capacitive water level sensor.

5. The method of claim 1, wherein, In step S03, a relationship curve of the water surface angle, the water surface height and the water quantity of the water tank is established, the relationship curve is queried according to the current water surface angle and water surface height data, and the linear interpolation method is used to obtain the water quantity of the current water tank.

6. An aircraft water quantity measurement system characterized by, It comprises: a three-axis acceleration measurement module comprising a gyroscope and an accelerometer, used for measuring the three-axis acceleration of the aircraft; an aircraft attitude angle measurement module used for measuring the attitude angle of the aircraft; a water surface height measurement module comprising a plurality of capacitive water level sensors arranged at different positions in the water tank and a capacitive conversion unit, the capacitive conversion unit being used for converting the capacitive signal into a frequency signal; a control module used for calculating the water surface angle of the water tank according to the obtained three-axis acceleration and the attitude angle of the aircraft, calculating the corresponding water surface height according to the obtained frequency signal, and calculating the water quantity of the current water tank according to the corresponding relationship between the water surface angle, the water surface height and the water quantity in the water tank.

7. The aircraft water quantity measurement system of claim 6, wherein, The water surface angle verification module calculates the water surface height at the corresponding position by obtaining the measurement data of the plurality of capacitive water level sensors, calculates the water surface angle of the water tank according to the position data of each capacitive water level sensor in the water tank and the water surface height data at the corresponding position, compares the calculated water surface angle with the water surface angle calculated according to the three-axis acceleration and the attitude angle of the airplane, and verifies the water surface angle of the water tank according to the comparison result.

8. The aircraft water quantity measurement system of claim 6, wherein, The water level sensor verification module is used to calculate the relationship between the water surface heights at the positions of each capacitive water level sensor according to the position data of each capacitive water level sensor in the water tank and the obtained water surface angle of the water tank, calculate the relationship between the measurement data of each capacitive water level sensor according to the obtained measurement data of each capacitive water level sensor, compare the obtained relationship between the water surface heights at the positions of each capacitive water level sensor with the obtained relationship between the measurement data, and verify the accuracy of the data obtained by the plurality of capacitive water level sensors.

9. The aircraft water quantity measurement system of claim 7 or 8, wherein, The fault alarm module is used to identify and alarm the faults of the three-axis acceleration measurement module, the airplane attitude angle measurement module and the water surface height measurement module.

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