A digital pressure refueling pre-adjuster, aircraft fuel measurement system and method

Abstract

The present invention relates to the technical field of aircraft fuel measurement, and more specifically, to a digital pressure refueling pre-adjuster, an aircraft fuel measurement system and method. The digital pressure refueling pre-adjuster comprises a panel and a housing, and the panel is provided with a digital tube display screen, a fuel quantity preset adjustment knob, and a brightness adjustment button; a data processing module, a CPU module, and a power supply are provided inside the housing; the data processing module comprises an AD sampling circuit, a switch quantity acquisition circuit, an RS422A interface circuit, an RS232 interface circuit, and a digital tube interface circuit respectively connected to the CPU module. The digital pressure refueling pre-adjuster digitally displays the preset fuel quantity through a digital tube display screen to avoid gross errors caused by manual readings. At the same time, in the aircraft fuel measurement system, the digital pressure refueling pre-adjuster and the fuel quantity indicator and the measurement and control system are transmitted through digital signals, which ensures the pre-adjustment accuracy and improves the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft fuel measurement, and in particular to a digital pressure refueling pre-adjuster, an aircraft fuel measurement system and a method. Background Art

[0002] There are two ways to add fuel to an aircraft: gravity refueling and pressure refueling. Common pressure refueling systems are mainly composed of fuel level sensors, fuel level indicators, pressure refueling pre-adjusters, refueling control systems, refueling pipelines, etc. The pressure refueling pre-adjusters work together with the fuel level indicators to achieve automatic control of aircraft refueling and defueling. Using this type of pressure refueling system for refueling and defueling has the advantages of high automation, short refueling time, prevention of oil contamination, and safety of refueling personnel.

[0003] The existing pressure refueling pre-adjuster is a pointer dial type, which uses a coil potentiometer as the oil quantity adjustment signal. Its internal circuit and part of the circuit in the oil quantity indicator together form an analog AC unbalanced bridge to output an unbalanced signal. The unbalanced signal is transmitted in the form of an analog signal, and after being processed by the analog signal detection circuit and the amplifier circuit, a control signal is generated to control the pressure refueling system. The method of manually reading the pointer reading on the dial has uncontrollable reading errors, which will seriously affect the accuracy of the oil quantity pre-adjustment. Therefore, the existing pressure refueling pre-adjuster has the disadvantage that manual reading will lead to gross errors. Summary of the invention

[0004] In view of the problem that manual reading of pointer dial type pressure refueling pre-adjuster in the prior art may lead to gross errors, the present invention provides a digital pressure refueling pre-adjuster, an aircraft fuel measurement system and method.

[0005] The digital pressure refueling pre-adjuster provided by the present invention can display the preset oil quantity digitally through a digital tube display screen, thereby avoiding the situation where manual reading when using a pointer-type instrument causes a gross error. At the same time, it transmits digital signals with an external oil quantity indicator and a measurement and control system, thereby ensuring the pre-adjustment accuracy and increasing the service life.

[0006] Specifically, a digital pressure oiling pre-adjuster comprises a panel and a shell, wherein the panel is provided with a digital tube display screen, a preset oil quantity adjustment knob, and a brightness adjustment button; a data processing module, a CPU module, and a power supply for providing working voltage to the data processing module and the CPU module are arranged inside the shell; the data processing module comprises an AD sampling circuit, a switch quantity acquisition circuit, an RS422A interface circuit, an RS232 interface circuit, and a digital tube interface circuit respectively connected to the CPU module;

[0007] The power supply is respectively connected to the digital tube display screen and the CPU module to provide working voltage. At the same time, one power supply output generates an analog signal reflecting the preset oil volume after passing through the oil volume preset adjustment knob and sends it to the AD sampling circuit. The other power supply output generates a switch signal reflecting the screen brightness after passing through the brightness adjustment button and sends it to the switch volume acquisition circuit.

[0008] The CPU module is connected to the AD sampling circuit and is used to obtain the preset oil volume according to the signal output by the AD sampling circuit;

[0009] The CPU module is connected to the switch quantity acquisition circuit and is used to obtain the screen brightness according to the signal output by the switch quantity acquisition circuit;

[0010] The CPU module exchanges data with an external oil level indicator via an RS422A interface circuit, is used to interactively preset the oil level, is used to obtain the self-test result of the RS422A interface circuit, and is also used to send a fault code to the oil level indicator when a fault occurs during the self-test;

[0011] The CPU module exchanges data with an external measurement and control system through an RS232 interface circuit, and is used for zero and full calibration of the oil volume preset adjustment knob and online software upgrade of the CPU module;

[0012] The CPU module exchanges data with the digital tube display screen through the digital tube interface circuit, and is used to send the screen control instructions generated according to the preset oil volume and screen brightness to the digital tube display screen to control the display content and display brightness, and to obtain the power-on self-test result of the digital tube interface circuit;

[0013] The digital tube display screen digitally displays the value of the preset oil volume according to the screen control instruction.

[0014] Further, in order to better implement the present invention, the CPU module includes a digital processing circuit, a state monitoring circuit and a storage circuit for storing data;

[0015] The digital processing circuit communicates with the AD sampling circuit, the switch quantity acquisition circuit, the RS422A interface circuit, the RS232 interface circuit, the digital tube interface circuit, the state monitoring circuit, and the storage circuit respectively;

[0016] The CPU module performs a power-on self-test after power-on and a periodic self-test during operation. This self-test is recorded as the CPU self-test. During the CPU self-test, the digital processing circuit sends a dog feeding signal to the status monitoring circuit to detect whether the dog feeding is normal. When the dog feeding is abnormal, a reset signal is sent to the digital processing circuit to reset the CPU module.

[0017] Furthermore, in order to better implement the present invention, the digital processing circuit adopts a processor architecture based on the STM32 single-chip microcomputer and has a SWD debugging interface.

[0018] Furthermore, in order to better implement the present invention, the storage circuit uses an SPI serial interface bus to expand an SPI Flash memory for storing data.

[0019] Furthermore, in order to better implement the present invention, a voltage follower is provided in the AD sampling circuit to isolate the analog signal reflecting the preset oil quantity.

[0020] Furthermore, in order to better realize the present invention, the RS422A interface circuit performs a power-on self-test after being powered on and performs a periodic self-test during operation. This self-test is recorded as a preset potentiometer self-test. During the preset potentiometer self-test, the working state of the oil quantity preset adjustment knob is collected through the AD sampling circuit and the CPU module, and it is checked whether the working state of the oil quantity preset adjustment knob is normal. When the working state of the oil quantity preset adjustment knob is abnormal, an abnormal signal is sent to the oil quantity indicator through the RS422A interface circuit to provide fault feedback.

[0021] Furthermore, in order to better implement the present invention, the digital tube interface circuit performs a power-on self-test after power-on, and this self-test is recorded as a return-to-zero self-test; during the return-to-zero self-test, the CPU module drives each digit displayed on the digital tube display screen to zero through the digital tube interface circuit and then traverses each digit to check whether the working state of the digital tube display screen is normal, and performs fault feedback when the working state of the digital tube display screen is abnormal.

[0022] The aircraft fuel measurement system provided by the present invention comprises a fuel quantity sensor, a fuel quantity indicator, a pressure refueling pre-adjuster, a pressure refueling control system and a refueling pipeline; wherein the pressure refueling pre-adjuster adopts the above-mentioned digital pressure refueling pre-adjuster.

[0023] The digital pressure oiling pre-adjuster outputs a preset oil quantity to the oil quantity indicator;

[0024] The fuel level sensor collects the current fuel level of the aircraft fuel tank in real time and sends it to the fuel level indicator;

[0025] The oil quantity indicator sends a working signal to the pressure refueling control system according to the comparison result between the preset oil quantity and the current oil quantity;

[0026] The pressure refueling control system is connected to the aircraft fuel tank through a refueling pipeline, and starts the refueling mode, starts the oil discharge mode or stops working according to the working signal.

[0027] Furthermore, in order to better implement the present invention, the digital pressure refueling pre-adjuster performs a power-on self-check when it starts working, and performs a periodic self-check during the working process.

[0028] The method provided by the present invention is a method for adjusting the amount of aircraft fuel based on the above-mentioned aircraft fuel measurement system.

[0029] The present invention has the following beneficial effects.

[0030] (1) The digital pressure refueling pre-adjuster of the present invention uses a digital tube display screen to intuitively display the preset oil volume digitally, thereby avoiding the situation where manual readings when using pointer-type instruments lead to gross errors.

[0031] (2) The digital pressure refueling pre-adjuster described in the present invention has a preset oil quantity adjustment function, can change the value of the preset oil quantity, and is easy to operate and has high control accuracy.

[0032] (3) The digital pressure refueling pre-adjuster described in the present invention has a screen brightness adjustment function, which can change the display brightness of the digital tube by pressing the brightness adjustment button on the panel, thereby meeting the display requirements in different light environments.

[0033] (4) The digital pressure refueling pre-adjuster described in the present invention has a self-checking function and can respond in the event of a fault.

[0034] (5) The digital pressure refueling pre-adjuster of the present invention has a software online upgrade function. No disassembly is required for software maintenance and upgrade. Online upgrade can be performed through a reserved communication interface, thereby improving the maintainability of the digital pressure refueling pre-adjuster.

[0035] (6) In the aircraft fuel measurement system of the present invention, the digital pressure refueling pre-adjuster, the fuel quantity indicator, and the measurement and control system are transmitted via digital signals, thereby improving the measurement accuracy of the aircraft fuel measurement system and further increasing the service life of the entire system while ensuring the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The specific structure of the present invention is given by the following embodiments and the accompanying drawings, but the present application is not limited to the scope of the embodiments.

[0037] Figure 1 It is a schematic diagram of the panel of the digital pressure refueling pre-adjuster of the present invention.

[0038] Figure 2 The present invention is a block diagram of the working principle of the digital pressure refueling pre-adjuster.

[0039] Figure 3It is a schematic diagram of the connection relationship of each electronic control module in the digital pressure refueling pre-adjuster described in Example 1.

[0040] Figure 4 It is a structural block diagram of the CPU module described in Example 2.

[0041] Figure 5 It is a schematic diagram of the main process of the zero return self-check of the digital tube display screen in Example 4.

[0042] Figure 6 It is a schematic diagram of the main flow of the self-test of the preset potentiometer in Example 4.

[0043] Figure 7 This is a schematic diagram of the main functional modules of the pressure refueling presetter software in Example 3.

[0044] Figure 8 It is a schematic diagram of the framework of an aircraft fuel measurement system.

[0045] Explanation of numbers in the figure: 1. Digital tube display screen; 2. Oil volume preset adjustment knob; 3. Brightness adjustment button. DETAILED DESCRIPTION

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technical personnel in this field without making creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Embodiment 1:

[0049] This embodiment provides a digital pressure refueling pre-adjuster, including a panel and a housing. Figure 1 As shown, the panel is provided with a digital tube display screen 1, an oil volume preset adjustment knob 2, and a brightness adjustment button 3. Figure 2 As shown, a data processing module, a CPU module and a power supply are arranged inside the housing. Figure 3As shown, the data processing module includes an AD sampling circuit, a switch quantity acquisition circuit, an RS422A interface circuit, an RS232 interface circuit, and a digital tube interface circuit.

[0050] The power supply is respectively connected to the CPU module, the AD sampling circuit, the switch quantity acquisition circuit, the RS422A interface circuit, the RS232 interface circuit, and the digital tube interface circuit. One of the power supply outputs generates an analog signal reflecting the preset oil quantity after passing through the oil quantity preset adjustment knob 2 and sends it to the AD sampling circuit, and another power supply output generates a switch quantity signal reflecting the screen brightness after passing through the brightness adjustment button 3 and sends it to the switch quantity acquisition circuit.

[0051] The CPU module is respectively connected with the power supply, the AD sampling circuit, the switch quantity acquisition circuit, the RS422A interface circuit, the RS232 interface circuit, and the digital tube interface circuit.

[0052] The oil quantity preset adjustment knob 2 is a knob-type potentiometer that receives a voltage excitation signal, outputs a voltage return signal, and changes the voltage return signal by changing the resistance value. The voltage return signal here is an analog signal reflecting the preset oil quantity. The output of a power supply connected to the AD sampling circuit is first connected to the AD sampling circuit through the oil quantity preset adjustment knob 2. Turning the oil quantity preset adjustment knob 2 changes the analog signal input to the AD sampling circuit, thereby changing the signal output by the AD sampling circuit. The signal maps the preset oil quantity. The output of a power supply connected to the switch quantity acquisition circuit is first connected to the switch quantity acquisition circuit through the brightness adjustment button 3. Pressing the brightness adjustment button 3 changes the signal output by the switch quantity acquisition circuit. The signal maps the screen brightness. After the CPU module obtains the preset oil quantity by obtaining the signal output by the AD sampling circuit and obtains the screen brightness by obtaining the signal output by the switch quantity acquisition circuit, it generates the corresponding screen control instruction and sends it to the digital tube display screen 1 through the digital tube interface circuit. The digital tube display screen 1 digitally displays the value of the preset oil quantity according to the screen control instruction. Therefore, the digital tube display screen 1 can not only display the value of the preset oil volume, but also change the brightness of the screen display to better adapt to different light environments.

[0053] In another specific embodiment, a voltage follower is provided in the AD sampling circuit to isolate the analog signal reflecting the preset oil volume. The AD sampling circuit samples the analog signal output by the preset oil volume adjustment knob 2 and isolates it using a voltage follower, and the isolated output signal is output to the CPU module. The CPU module determines the working state of the preset oil volume adjustment knob 2 by reading the signal output by the AD sampling circuit and obtains the corresponding preset oil volume.

[0054] In another specific embodiment, the switch quantity acquisition circuit acquires the switch quantity signal output by the brightness adjustment button 3, and outputs the signal to the CPU module based on the cycle counting or signal value acquisition principle. The CPU module determines the working state of the brightness adjustment button 3 by reading the signal output by the switch quantity acquisition circuit, and acquires the corresponding screen brightness.

[0055] In another specific embodiment, the CPU module exchanges data with an external fuel quantity indicator through an RS422A interface circuit for interactive preset fuel quantity. The transmitting driver chip and receiving driver chip of the RS422A interface circuit are independent, capable of power-on self-test and periodic self-test, and capable of real-time transmission of the target value and self-test results of the aircraft fuel quantity adjustment. The target value of the aircraft fuel quantity adjustment is the preset fuel quantity.

[0056] It should be noted that, based on the digital pressure refueling pre-adjuster described in this embodiment, there are two ways to set the preset oil volume: one is mechanical setting, that is, manually rotating the oil volume preset adjustment knob 2 changes the sampling value obtained by the input end of the AD sampling circuit to change the preset oil volume obtained by the CPU module; the other is digital setting, that is, the staff directly inputs the preset oil volume through the host computer or the oil volume indicator capable of human-computer interaction. When the mechanical setting preset oil volume mode is adopted, the CPU module obtains the preset oil volume and sends it to the oil volume indicator through the RS422A interface circuit for interaction. When the digital setting preset oil volume mode is adopted, the host computer or the oil volume indicator capable of human-computer interaction obtains the preset oil volume and sends it to the CPU module through the RS422A interface circuit for interaction.

[0057] Furthermore, the RS422A interface circuit has a self-checking function, and when an abnormality occurs in the self-checking, fault feedback is performed, such as sending fault information to the oil level indicator so that a specific fault code is displayed on the oil level indicator.

[0058] In another specific embodiment, the CPU module exchanges data with an external measurement and control system through an RS232 interface circuit. When the external measurement and control system is a calibration and detection device, the CPU module is connected to the calibration and detection device through the RS232 interface circuit for zero and full calibration of the oil preset adjustment knob 2. When the external measurement and control system is software driven, the CPU module is connected to the software driver through the RS232 interface circuit for online software upgrade of the CPU module.

[0059] It should be noted that the digital pressure refueling pre-adjuster described in this embodiment usually does not perform zero-full calibration, software upgrades, etc. during normal operation. Usually, zero-full calibration is the preparatory work or daily maintenance work before the digital pressure refueling pre-adjuster works normally; similarly, software upgrades are the preparatory work or daily maintenance work before the digital pressure refueling pre-adjuster works normally. Therefore, zero-full calibration and software upgrades do not need to be performed in the same time period, so the external measurement and control system during zero-full calibration and the external measurement and control system during software upgrades can share the same RS232 interface circuit. Of course, in actual use, multiple RS232 interface circuits can also be set up to connect to different external measurement and control systems.

[0060] In another specific embodiment, the CPU module exchanges data with the digital tube display screen 1 through the digital tube interface circuit, and is used to send screen control instructions generated according to the preset oil volume and screen brightness to the digital tube display screen 1 to control the display content and display brightness.

[0061] Furthermore, the digital tube interface circuit has a self-checking function, and when an abnormality occurs in the self-checking, fault feedback is performed, such as: sending fault information to the oil level indicator and / or the digital tube display screen 1, so that a specific fault code is displayed on the oil level indicator and / or the digital tube display screen 1.

[0062] The traditional pressure refueling pre-adjuster is a pointer dial instrument. During the process of fuel pre-adjustment, the error between the pre-adjustment result and the required fuel quantity for flight is mainly composed of two parts: one is the gross error caused by manually reading the pointer reading on the dial; the other is the system error caused by the unbalanced signal output by the analog AC unbalanced bridge inside the pressure refueling pre-adjuster after being processed by the analog signal detection circuit and amplification circuit.

[0063] The digital pressure refueling pre-adjuster described in this embodiment is a digital instrument, which realizes continuous adjustment of the preset oil quantity value through the oil quantity preset adjustment knob 2, and performs intuitive digital display through the digital tube display screen 1, effectively avoiding the gross error caused by manual reading of the pointer instrument, and improving the adjustment accuracy. Furthermore, the digital pressure refueling pre-adjuster performs data exchange through digital signals through RS422A interface circuit, RS232 interface circuit, and digital tube interface circuit. Compared with analog signal transmission, digital signal transmission has the advantages of strong anti-interference ability, controllable transmission quality, good compatibility and flexibility, and high integration. Therefore, by setting the interface circuit, the adjustment accuracy and service life of the entire system can be improved.

[0064] Embodiment 2:

[0065] This embodiment is further explained based on the embodiment 1.

[0066] like Figure 4As shown, the CPU module includes a digital processing circuit, a state monitoring circuit and a storage circuit for storing data; the digital processing circuit communicates with the AD sampling circuit, the switch quantity acquisition circuit, the RS422A interface circuit, the RS232 interface circuit, the digital tube interface circuit, the state monitoring circuit and the storage circuit respectively. Among them, the digital processing circuit is used to process the signals output by the AD sampling circuit and the switch quantity acquisition circuit, and is also used to drive the digital tube in the digital tube display screen 1, the 422 communication chip in the RS422A interface circuit and the 232 communication chip in the RS232 interface circuit.

[0067] The digital processing circuit is connected to the oil level indicator via an RS422A interface circuit. The sending drive chip and the receiving drive chip of the RS422A interface circuit are independent.

[0068] The digital processing circuit is connected to the measurement and control systems such as the upgrade drive, calibration and detection equipment through the RS232 interface circuit.

[0069] In another specific embodiment, the digital processing circuit adopts a processor architecture based on an STM32 single-chip microcomputer and has a SWD debugging interface. At this time, the CPU module can use an emulator to perform online simulation and burn programs, or use an upgrade driver to download programs through an RS232 interface circuit to achieve online software upgrades.

[0070] In another specific embodiment, the digital processing circuit sends a dog-feeding signal to the status monitoring circuit. When the program runs away or the power supply is unstable, the status monitoring circuit cannot receive the dog-feeding signal. At this time, a reset signal will be sent to reset the CPU module to ensure that the product can work stably and reliably. This process is called CPU self-check.

[0071] In another specific implementation, the storage circuit uses a SPI serial interface bus and an external SPI Flash memory to store data.

[0072] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0073] Embodiment 3:

[0074] This embodiment is further described based on the embodiment 1 or the embodiment 2.

[0075] The CPU module has built-in management software for the pressure refueling pre-adjuster. The software includes system initialization, power-on BIT, power-on calibration value reading, zero return detection, periodic BIT, fault display, oil volume preset, calibration, day / night mode switching, RS-422A data packaging, RS-232 data packaging, communication reception, dog feeding, etc. A set of pressure refueling pre-adjuster software has been developed in conjunction with the digital pressure refueling pre-adjuster described in Example 1 and Example 2, and its functional modules are as follows: Figure 7 shown.

[0076] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0077] Embodiment 4:

[0078] In order to further improve the pre-adjustment accuracy, thereby extending the service life of the equipment while ensuring the accuracy, the digital pressure refueling pre-adjuster is optimized and designed based on any one of Examples 1 to 3.

[0079] The digital pressure refueling pre-adjuster described in this embodiment also has a self-detection function, and is divided into power-on self-detection and periodic self-detection according to the timing and frequency of self-detection. The power-on self-detection includes zero return self-detection, CPU self-detection, and pre-adjustment potentiometer self-detection; the periodic self-detection includes CPU self-detection and pre-adjustment potentiometer self-detection.

[0080] The zero return self-check means that after the digital tube interface circuit is powered on, the digital tube display of the digital tube display screen 1 returns to zero, and then each digit starts from 0 and increases by 1 until the maximum number that can be displayed is reached, and the display process is checked to see if it is normal. During the zero return self-check, the communication zero return valid signal, i.e. the zero return flag, is first set to valid until the CPU module receives the zero return flag feedback from the RS422A interface circuit.

[0081] like Figure 5 As shown, take the four-digit digital tube as an example to explain: when returning to zero detection, first make the communication return to zero valid signal valid and the return to zero mark 0, and judge whether the received communication return to zero mark is 0: if so, set the return to zero mark to 1, and judge whether the received communication return to zero mark is 1: if so, judge whether the communication return to zero valid signal is invalid; if so, set the communication return to zero mark to 0, and then judge whether the return to zero mark is 1. If so, the digital tube first displays "0000" and keeps it for about 3 seconds; then the four-digit digital tube starts to display from "0000", and the digital tube corresponding to each digit increases by 1 every 1s until "9999" is displayed. At this time, after the display is completed, the return to zero mark is set to 0. Check whether the display process is normal, and provide fault feedback if abnormal. Usually, the display of the digital tube is checked by manual observation.

[0082] The zero return self-test is only started when the power is turned on, and it is not started when the digital tube display screen 1 is working normally.

[0083] CPU self-check means: the digital processing circuit sends a dog feeding signal to the status monitoring circuit to check whether the dog feeding is normal. If the dog feeding is abnormal, a reset signal is sent to the digital processing circuit to reset the CPU module.

[0084] When the program runs out of control or the power supply is unstable, the status monitoring circuit cannot receive the dog feeding signal and will promptly send a reset signal to reset the CPU to ensure that the product can work stably and reliably.

[0085] When the power is turned on, the digital processing circuit starts to send the dog feeding signal and repeats it periodically, so the CPU self-test starts at power-on and starts periodically.

[0086] The self-test of the preset potentiometer refers to: Figure 6 As shown, the digital processing circuit obtains the preset oil volume and compares the preset oil volume with the zero-full range to check whether the preset oil volume is obtained normally and whether the preset oil volume is within the zero-full range. The preset potentiometer self-test starts at power-on and starts periodically.

[0087] When the preset potentiometer is self-checked, the working state of the oil preset adjustment knob 2 is collected through the AD sampling circuit and the CPU module, and the working state of the oil preset adjustment knob 2 is checked to see if it is normal. When the working state of the oil preset adjustment knob 2 is abnormal, an abnormal signal is sent to the oil indicator through the RS422A interface circuit for fault feedback. The predicted oil value corresponding to each working position of the oil preset adjustment knob 2 is stored in the storage module in advance for easy retrieval.

[0088] If each self-test is normal, the normal self-test information will be sent to the oil level indicator through the RS422A interface circuit; if one or more self-tests are abnormal, the detected fault information will be displayed on the panel in the form of a fixed code, and the fault information will be sent to the oil level indicator through the RS422A interface circuit. The two feedback methods of "displaying the fault information on the panel in the form of a fixed code" and "sending the fault information to the oil level indicator through the RS422A interface circuit" can be used either or both.

[0089] In another specific embodiment, when executing the preset potentiometer self-test, the CPU module first calls the data output by the AD sampling circuit to determine whether there is a fault in the sampling of the oil preset adjustment knob 2; if there is no fault in the sampling of the oil preset adjustment knob 2, it is further determined whether the currently set preset oil volume is within the zero-full value range; if the currently set preset oil volume is within the zero-full value range, the preset oil volume is output to the digital tube display screen 1 for display; if there is a fault in the sampling of the oil preset adjustment knob 2 or the previously set preset oil volume exceeds the zero-full value range, a fault feedback is given.

[0090] The other parts of this embodiment are the same as any one of Embodiments 1 to 3, and thus will not be described in detail.

[0091] Embodiment 5:

[0092] This embodiment provides an aircraft fuel measurement system, such as Figure 8 As shown, it includes an oil level sensor, an oil level indicator, a pressure refueling pre-adjuster, a pressure refueling control system and a refueling pipeline; the pressure refueling pre-adjuster adopts a digital pressure refueling pre-adjuster as described in any one of Examples 1 to 4.

[0093] The pressure oiling pre-adjuster outputs a preset oil quantity to the oil quantity indicator;

[0094] The fuel level sensor collects the current fuel level of the aircraft fuel tank in real time and sends it to the fuel level indicator;

[0095] The oil quantity indicator sends a working signal to the pressure refueling control system according to the comparison result between the preset oil quantity and the current oil quantity;

[0096] The pressure refueling control system is connected to the aircraft fuel tank through a refueling pipeline, and starts the refueling mode, starts the oil discharge mode or stops working according to the working signal.

[0097] The other parts of this embodiment are the same as any one of Embodiments 1 to 4, and thus will not be described in detail.

[0098] Embodiment 6:

[0099] This embodiment provides a method for adjusting the fuel quantity of an aircraft, and the aircraft fuel measurement system described in Embodiment 5 is used to adjust the fuel quantity of the aircraft. First, the digital pressure refueling pre-adjuster described in any one of Embodiments 1 to 4 is started, and the system initialization and power-on self-test are performed in sequence. After the power-on self-test passes, the oil quantity preset adjustment knob 2 is turned until the value of the preset oil quantity is displayed on the digital tube display screen 1; then, the oil quantity indicator compares the preset oil quantity sent by the digital pressure refueling pre-adjuster with the current oil quantity collected in real time by the oil quantity sensor, and sends a working signal to the pressure refueling control system according to the comparison result, and the pressure refueling control system adjusts the fuel quantity of the aircraft tank.

[0100] Specifically, if the value of the preset oil amount is greater than the value of the current oil amount, an open command is sent to the pressure refueling control system, and the aircraft fuel tank is refueled through the pressure refueling control system; if the value of the preset oil amount is less than the value of the current oil amount, a shutoff command is sent to the pressure refueling control system, and the aircraft fuel tank is drained through the pressure refueling control system; if the value of the preset oil amount is equal to the value of the current oil amount, the pressure refueling control system will temporarily not work.

[0101] The other parts of this embodiment are the same as any one of Embodiments 1 to 5, and thus will not be described in detail.

[0102] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A digital pressure refueling pre-adjuster, comprising a panel and a housing; characterized in that: The panel is provided with a digital tube display screen (1), an oil volume preset adjustment knob (2), and a brightness adjustment button (3); the housing is provided with a data processing module, a CPU module, and a power supply for providing working voltage to the data processing module and the CPU module; the data processing module comprises an AD sampling circuit, a switch quantity acquisition circuit, an RS422A interface circuit, an RS232 interface circuit, and a digital tube interface circuit respectively connected to the CPU module; The power supply is respectively connected to the digital tube display screen (1) and the CPU module to provide working voltage. At the same time, one power supply output passes through the oil volume preset adjustment knob (2) to generate an analog signal reflecting the preset oil volume and sends it to the AD sampling circuit. Another power supply output passes through the brightness adjustment button (3) to generate a switch signal reflecting the screen brightness and sends it to the switch volume acquisition circuit. The CPU module is connected to the AD sampling circuit and is used to obtain the preset oil volume according to the signal output by the AD sampling circuit; The CPU module is connected to the switch quantity acquisition circuit and is used to obtain the screen brightness according to the signal output by the switch quantity acquisition circuit; The CPU module exchanges data with an external oil level indicator via an RS422A interface circuit, is used to interactively preset the oil level, is used to obtain the self-test result of the RS422A interface circuit, and is also used to send a fault code to the oil level indicator when a fault occurs during the self-test; The CPU module exchanges data with an external measurement and control system via an RS232 interface circuit, and is used for zero and full calibration of the oil volume preset adjustment knob (2) and online software upgrade of the CPU module; The CPU module exchanges data with the digital tube display screen (1) via the digital tube interface circuit, and is used to send screen control instructions generated according to the preset oil volume and screen brightness to the digital tube display screen (1) to control the display content and display brightness, and is used to obtain the power-on self-test result of the digital tube interface circuit; The digital tube display screen (1) digitally displays the value of the preset oil volume according to the screen control instruction.

2. A digital pressure refueling pre-adjuster according to claim 1, characterized in that: The CPU module includes a digital processing circuit, a state monitoring circuit and a storage circuit for storing data; The digital processing circuit communicates with the AD sampling circuit, the switch quantity acquisition circuit, the RS422A interface circuit, the RS232 interface circuit, the digital tube interface circuit, the state monitoring circuit, and the storage circuit respectively; The CPU module performs a power-on self-test after power-on and a periodic self-test during operation. This self-test is recorded as the CPU self-test. During the CPU self-test, the digital processing circuit sends a dog feeding signal to the status monitoring circuit to detect whether the dog feeding is normal. When the dog feeding is abnormal, a reset signal is sent to the digital processing circuit to reset the CPU module.

3. A digital pressure refueling pre-adjuster according to claim 2, characterized in that: The digital processing circuit adopts a processor architecture based on the STM32 single-chip microcomputer and has a SWD debugging interface.

4. A digital pressure refueling pre-adjuster according to claim 2, characterized in that: The storage circuit uses the SPI serial interface bus to expand an SPI Flash memory for storing data.

5. A digital pressure refueling pre-adjuster according to claim 1, characterized in that: The AD sampling circuit is provided with a voltage follower for isolating the analog signal reflecting the preset oil quantity.

6. A digital pressure refueling pre-adjuster according to claim 1, characterized in that: The RS422A interface circuit performs a power-on self-test after being powered on and performs a periodic self-test during operation. This self-test is recorded as a preset potentiometer self-test. During the preset potentiometer self-test, the AD sampling circuit and the CPU module collect the working state of the oil quantity preset adjustment knob (2), and check whether the working state of the oil quantity preset adjustment knob (2) is normal. When the working state of the oil quantity preset adjustment knob (2) is abnormal, an abnormal signal is sent to the oil quantity indicator through the RS422A interface circuit to provide fault feedback.

7. A digital pressure refueling pre-adjuster according to claim 1, characterized in that: The digital tube interface circuit performs a power-on self-test after being powered on, and this self-test is recorded as a zero return self-test; during the zero return self-test, the CPU module drives each digit displayed on the digital tube display screen (1) to return to zero through the digital tube interface circuit, and then traverses each digit, thereby checking whether the working state of the digital tube display screen (1) is normal, and when the working state of the digital tube display screen (1) is abnormal, a fault feedback is performed.

8. An aircraft fuel measurement system, comprising a fuel quantity sensor, a fuel quantity indicator, a pressure refueling pre-adjuster, a pressure refueling control system and a refueling pipeline; characterized in that: The pressure refueling pre-adjuster adopts the digital pressure refueling pre-adjuster as described in any one of claims 1 to 7; The digital pressure oiling pre-adjuster outputs a preset oil quantity to the oil quantity indicator; The fuel level sensor collects the current fuel level of the aircraft fuel tank in real time and sends it to the fuel level indicator; The oil quantity indicator sends a working signal to the pressure refueling control system according to the comparison result between the preset oil quantity and the current oil quantity; The pressure refueling control system is connected to the aircraft fuel tank through a refueling pipeline, and starts the refueling mode, starts the oil discharge mode or stops working according to the working signal.

9. An aircraft fuel measurement system according to claim 8, characterized in that: The digital pressure refueling pre-adjuster performs a power-on self-check when it starts working, and performs a periodic self-check during the working process.

10. A method for adjusting the fuel quantity of an aircraft, using the aircraft fuel measurement system according to claim 8 to adjust the fuel quantity of the aircraft, characterized in that: First, the digital pressure refueling pre-adjuster is started, and the system initialization and power-on self-test are performed in sequence. After the power-on self-test is passed, the oil quantity preset adjustment knob (2) is turned until the value of the preset oil quantity is displayed on the digital tube display screen (1); then, the oil quantity indicator compares the preset oil quantity sent by the digital pressure refueling pre-adjuster with the current oil quantity collected in real time by the oil quantity sensor, and sends a working signal to the pressure refueling control system based on the comparison result, and the pressure refueling control system adjusts the fuel quantity in the aircraft tank.

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