A fuel measuring system and method based on double-channel time-sharing sampling control

Abstract

The present application relates to aviation fuel measurement technical field, specifically, it is a kind of fuel measurement system and method based on double channel time-sharing sampling control;Including the same structure A acquisition board card and B acquisition board card, the single acquisition board card is by double channel time-sharing sampling control circuit, CPU processing module, oil quantity sensor acquisition channel switch, oil quantity sensor signal acquisition module composition;Double channel time-sharing sampling control module cooperates the control signal of CPU processing module, and the two groups of oil quantity sensor outside are carried out cross time-sharing acquisition;CPU processing module output signal controls double channel time-sharing sampling control circuit, oil quantity sensor acquisition channel switch, oil quantity sensor signal acquisition module work, and the data of oil quantity sensor are handled and calculated, and are converted into fuel quality;Oil quantity sensor acquisition channel switch will be accessed in oil quantity sensor signal acquisition module in turn to the external multiple oil quantity sensors;Oil quantity sensor signal acquisition module converts the capacitance signal of oil quantity sensor into voltage signal, and sends into CPU processing module and carries out data solution.

Description

Technical Field

[0001] This invention relates to the field of aviation fuel measurement technology, and more specifically, to a fuel measurement system and method based on dual-channel time-division sampling control. Background Technology

[0002] Currently, to improve the reliability of fuel measurement computers, a dual-redundancy design is generally adopted. There are two common design methods. One method involves setting up two sets of acquisition boards (primary and secondary) within the fuel measurement computer, plus an arbitration board. After power-on, the main board begins acquiring, processing, and calculating signals from the fuel level sensor, while the secondary board remains in a standby state. During operation, if the main board malfunctions, the arbitration board issues a primary / secondary switching command. At this point, the main board stops all operations, and the secondary board begins acquiring, processing, and calculating signals from the fuel level sensor. The advantage of this method is that the switching between the two acquisition boards is determined by the arbitration board, eliminating the risk of risky competition. However, its disadvantage is that the two boards operate in a cold backup mode, with only one board working at a time. Furthermore, the additional arbitration board consumes more computer hardware resources to perform the same tasks. Another method involves a fuel measurement computer with only two sets of acquisition boards, a primary and a secondary one. Upon power-up, both boards begin acquiring, processing, and calculating signals from the fuel level sensors. However, each board can only acquire half of the fuel level sensor signal at a time. The acquired data is then exchanged between the boards to obtain complete fuel level sensor data, ultimately leading to an accurate fuel level value. The advantage of this method is its simple architecture and lack of interference between the two acquisition boards. However, its disadvantage is that each board can only acquire half of the fuel level sensor data; if one board fails, half of the fuel level sensor information will be lost, degrading the accuracy of the fuel measurement. Summary of the Invention

[0003] This invention addresses the problem in existing fuel measurement methods where each of the two boards can only complete the acquisition of half of the fuel quantity sensor data. If a single board fails, half of the fuel quantity sensor information is lost, leading to a degradation in fuel measurement accuracy. This invention proposes a fuel measurement system and method based on dual-channel time-sharing sampling control. The system includes two identical acquisition boards, A and B. The dual-channel time-sharing sampling control module uses MOSFETs and optocouplers, along with control signals from the CPU processing module, to perform cross-time-sharing acquisition of data from two external fuel quantity sensors. The CPU processing module outputs signals to control the operation of the dual-channel time-sharing sampling control circuit, the fuel quantity sensor acquisition channel switching switch, and the fuel quantity sensor signal acquisition module. It also processes and calculates the data from the fuel quantity sensors, converting it into fuel quantity. The fuel quantity sensor acquisition channel switching switch sequentially connects multiple external fuel quantity sensors to the fuel quantity sensor signal acquisition module. The fuel quantity sensor signal acquisition module converts the capacitance signal from the fuel quantity sensors into a voltage signal, which is then sent to the CPU processing module for data processing, achieving dual-redundancy fuel measurement.

[0004] The specific implementation details of this invention are as follows:

[0005] A fuel measurement system based on dual-channel time-division sampling control includes an A acquisition board and a B acquisition board; both the A acquisition board and the B acquisition board include a dual-channel time-division sampling control module, a CPU processing module, a fuel quantity sensor acquisition channel switching switch, and a fuel quantity sensor signal acquisition module.

[0006] The A acquisition board and the B acquisition board are connected via a fuel level sensor acquisition channel switching switch.

[0007] The oil quantity sensor acquisition channel switching switch is connected to the dual-channel time-division sampling control module and the CPU processing module;

[0008] The input end of the dual-channel time-division sampling control module is connected to an external sensor and power supply, and the output end is connected to another set of acquisition boards of the CPU processing module.

[0009] The oil quantity sensor signal acquisition module is connected to the oil quantity sensor acquisition channel switching switch and the CPU processing module;

[0010] The dual-channel time-division sampling control module is used to collect the capacitance signal of the external oil quantity sensor in a cross-time division according to the control signal obtained from the CPU module.

[0011] The oil quantity sensor acquisition channel switching switch is used to connect multiple external oil quantity sensors to the oil quantity sensor signal acquisition module in sequence.

[0012] The oil quantity sensor signal acquisition module is used to convert the capacitive signal obtained from the oil quantity sensor acquisition channel switching switch into a voltage signal.

[0013] The CPU module is used to calculate the amount of fuel based on the voltage signal.

[0014] To better realize the present invention, the dual-channel time-division sampling control module further includes: a sensor acquisition channel switching switch enable control circuit and a dual-channel time-division sampling control circuit;

[0015] The dual-channel time-division sampling control circuit includes an optocoupler unit and a MOS transistor unit;

[0016] The first input terminal of the optocoupler unit is connected to the power supply, the second input terminal is connected to the ground terminal through a MOS transistor unit, the first output terminal of the optocoupler unit is connected to another set of acquisition boards, and the second output terminal of the optocoupler unit is connected to the ground terminal.

[0017] To better realize the present invention, the MOS transistor unit further includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor;

[0018] The drain of the first MOS transistor is connected to the second input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the first MOS transistor is connected to the drain of the second MOS transistor. The gate of the first MOS transistor receives a reset signal.

[0019] The gate of the second MOSFET is connected to the CPU module, and the source of the second MOSFET is connected to ground.

[0020] The drain of the third MOS transistor is connected to the first input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the third MOS transistor is connected to the drain of the fourth MOS transistor. The gate of the third MOS transistor receives a reset signal.

[0021] The gate of the fourth MOS transistor is connected to the CPU module through a limiting resistor, and the source of the fourth MOS transistor is connected to ground.

[0022] To better realize the present invention, the oil quantity sensor signal acquisition module further includes an excitation source circuit, a filter amplification circuit, a voltage follower circuit, and an AD conversion circuit;

[0023] One end of the excitation source circuit is connected to an external fuel level sensor via a sensor acquisition channel switching switch, and the other end is connected to a filter amplifier circuit.

[0024] One end of the voltage follower circuit is connected to the filter amplifier circuit, and the other end is connected to the AD conversion circuit;

[0025] The excitation source circuit is used to generate a sinusoidal voltage signal;

[0026] The filter amplifier circuit is used to convert the sinusoidal voltage signal into a DC voltage signal;

[0027] The AD conversion circuit is used to convert DC voltage signals into digital voltage signals.

[0028] Based on the aforementioned fuel measurement system based on dual-channel time-sharing sampling control, to better realize this invention, a fuel measurement method based on dual-channel time-sharing sampling control is further proposed, implemented based on the aforementioned fuel measurement system based on dual-channel time-sharing sampling control; specifically including:

[0029] Capacitive signals are obtained by time-division cross-collection of external fuel quantity sensors A and B based on control signals.

[0030] Based on the set upper and lower limits of the sampling value, the capacitance signal is converted into a voltage signal, and the sampling value of the fuel level sensor signal is calculated.

[0031] The fuel quantity is calculated based on the sampled value of the fuel quantity sensor signal and the set stability limit value.

[0032] To better implement this invention, further, when the A acquisition board acquires data from the external A group of fuel level sensors, it sets the sensor acquisition channel switch corresponding to the A group of fuel level sensors to "on" and sets the sensor acquisition channel switch for the B group of fuel level sensors to "off". At this time, the state of the sensor acquisition channel switch corresponding to the B group of fuel level sensors is forcibly set to "off" by the output stage of the optocoupler of the A acquisition board, and the B acquisition board acquires data from the B group of fuel level sensors during this time period. After the A acquisition board finishes acquiring data from the A group of fuel level sensors, it sets the sensor acquisition channel switch for the B group of fuel level sensors to "on". If the B acquisition board does not acquire data from the B group of fuel level sensors during this time period, then the A acquisition board acquires data from the B group of fuel level sensors. If the B acquisition board is acquiring data from the B group of fuel level sensors during this time period, then the state of the fuel level sensor acquisition channel switch corresponding to the A acquisition board acquiring data from the B group of fuel level sensors is forcibly set to "off" by the output stage of the optocoupler of the B acquisition board.

[0033] To better implement this invention, the step of converting the capacitance signal into a voltage signal based on the set upper and lower limits of the sampling value, and calculating the sampled value of the fuel level sensor signal, specifically includes:

[0034] Based on the successive approximation algorithm with multiple iterations, the lower limit of the sampling value is set to X. 下 Set the upper limit of the sampling value to X. 上 The first hypothetical sample value obtained after power-on is set to The hypothetical sampled value is converted into a current signal and compared with the actual current signal fed back by the capacitance sensor. If the theoretical current value is greater than the actual current value, then the second hypothetical sampled value is set to... If the theoretical current value is less than the actual current value, then the second assumed sampled value is set to... Then, convert the assumed sampled values ​​into current signals and repeat the above process until the theoretical current value and the actual current value are both less than the algorithm's preset threshold X. 阈 , to X at this time i This is used as the final value of the signal acquired by the oil level sensor.

[0035] To better realize the present invention, the step of calculating the fuel mass based on the sampled value of the fuel quantity sensor signal and the set stability limit value specifically includes:

[0036] According to the dynamic adjustment chasing algorithm based on amplitude limit, let the current fuel level sensor sampling value be X1, the previous fuel level sensor sampling value be X2, and the stable amplitude limit value be W. The value of W is determined according to the aircraft's fuel consumption rate. Under ground and cruise attitude conditions, the fuel level changes according to the stable amplitude limit value W. Under other flight attitude conditions, if X2 > X1, the amplitude limit value is dynamically adjusted to W + ΔW, and the processed fuel level sensor sampling value is X2 - (W + ΔW). If X2 ≤ X1, the amplitude limit value is dynamically adjusted to W - ΔW, and the processed fuel level sensor sampling value is X2 - (W - ΔW).

[0037] The present invention has the following beneficial effects:

[0038] This invention achieves signal acquisition, processing, and calculation from an external complete fuel quantity sensor using only two sets of acquisition boards without adding an additional arbitration board. This method rationally allocates hardware resources and perfectly realizes the dual-redundancy fuel measurement computer function. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the dual-channel time-division sampling control circuit provided by the present invention.

[0040] Figure 2 This is a schematic diagram of the oil quantity sensor acquisition channel switching switch structure provided by the present invention.

[0041] Figure 3 This is a schematic diagram of the dual-channel time-division sampling control process provided by the present invention. Detailed Implementation

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments, and therefore should not be regarded as a limitation on the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" 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.

[0044] Example 1:

[0045] This embodiment proposes a fuel measurement system based on dual-channel time-division sampling control, such as... Figure 1 , Figure 2 As shown, it includes acquisition board A and acquisition board B; both acquisition board A and acquisition board B include a dual-channel time-division sampling control module, a CPU processing module, a fuel level sensor acquisition channel switching switch, and a fuel level sensor signal acquisition module.

[0046] The A acquisition board and the B acquisition board are connected via a fuel level sensor acquisition channel switching switch.

[0047] The oil quantity sensor acquisition channel switching switch is connected to the dual-channel time-division sampling control module and the CPU processing module;

[0048] The input end of the dual-channel time-division sampling control module is connected to an external sensor and power supply, and the output end is connected to another set of acquisition boards of the CPU processing module.

[0049] The oil quantity sensor signal acquisition module is connected to the oil quantity sensor acquisition channel switching switch and the CPU processing module;

[0050] The dual-channel time-division sampling control module is used to collect the capacitance signal of the external oil quantity sensor in a cross-time division according to the control signal obtained from the CPU module.

[0051] The oil quantity sensor acquisition channel switching switch is used to connect multiple external oil quantity sensors to the oil quantity sensor signal acquisition module in sequence.

[0052] The oil quantity sensor signal acquisition module is used to convert the capacitive signal obtained from the oil quantity sensor acquisition channel switching switch into a voltage signal.

[0053] The CPU module is used to calculate the amount of fuel based on the voltage signal.

[0054] The dual-channel time-division sampling control module includes: a sensor acquisition channel switching switch enable control circuit and a dual-channel time-division sampling control circuit;

[0055] The dual-channel time-division sampling control circuit includes an optocoupler unit and a MOS transistor unit;

[0056] The first input terminal of the optocoupler unit is connected to the power supply, the second input terminal is connected to the ground terminal through a MOS transistor unit, the first output terminal of the optocoupler unit is connected to another set of acquisition boards, and the second output terminal of the optocoupler unit is connected to the ground terminal.

[0057] The MOS transistor unit includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor;

[0058] The drain of the first MOS transistor is connected to the second input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the first MOS transistor is connected to the drain of the second MOS transistor. The gate of the first MOS transistor receives a reset signal.

[0059] The gate of the second MOSFET is connected to the CPU module, and the source of the second MOSFET is connected to ground.

[0060] The drain of the third MOS transistor is connected to the first input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the third MOS transistor is connected to the drain of the fourth MOS transistor. The gate of the third MOS transistor receives a reset signal.

[0061] The gate of the fourth MOS transistor is connected to the CPU module through a limiting resistor, and the source of the fourth MOS transistor is connected to ground.

[0062] Furthermore, the oil quantity sensor signal acquisition module includes an excitation source circuit, a filter amplification circuit, a voltage follower circuit, and an AD conversion circuit;

[0063] One end of the excitation source circuit is connected to an external fuel level sensor via a sensor acquisition channel switching switch, and the other end is connected to a filter amplifier circuit.

[0064] One end of the voltage follower circuit is connected to the filter amplifier circuit, and the other end is connected to the AD conversion circuit;

[0065] The excitation source circuit is used to generate a sinusoidal voltage signal;

[0066] The filter amplifier circuit is used to convert the sinusoidal voltage signal into a DC voltage signal;

[0067] The AD conversion circuit is used to convert DC voltage signals into digital voltage signals.

[0068] Working principle: such as Figure 1 As shown, the fuel measurement system based on dual-channel time-sharing sampling control proposed in this embodiment includes an A acquisition board and a B acquisition board. The hardware of the two acquisition boards is exactly the same. Each acquisition board consists of a dual-channel time-sharing sampling control circuit, a CPU processing module, a fuel quantity sensor acquisition channel switching switch, and a fuel quantity sensor signal acquisition module.

[0069] The dual-channel time-division sampling control module uses MOSFETs and optocouplers to form a pure hardware circuit, which, together with the control signals of the CPU processing module, performs cross-time sampling of the external A and B groups of fuel level sensors.

[0070] The CPU processing module outputs signals to control the operation of the dual-channel time-division sampling control circuit, the fuel quantity sensor acquisition channel switching switch, and the fuel quantity sensor signal acquisition module. It also processes and calculates the data from the fuel quantity sensor, converting it into fuel quality. The fuel quantity sensor acquisition channel switching switch sequentially connects multiple external fuel quantity sensors to the fuel quantity sensor signal acquisition module. The fuel quantity sensor signal acquisition module converts the capacitance signal from the fuel quantity sensor into a voltage signal, which is then sent to the CPU processing module for data processing.

[0071] The fuel level sensor signal acquisition module includes an excitation source circuit, a filter amplification circuit, a voltage follower circuit, and an A / D conversion circuit. The excitation source circuit generates a sinusoidal voltage signal, which, after passing through the fuel level sensor acquisition channel switching switch, excites one end of an external capacitive fuel level sensor. The sinusoidal current signal generated at the other end, after passing through the sensor acquisition channel switching switch, enters the filter amplification circuit and is processed into a stable DC voltage signal. The DC voltage signal then passes through the voltage follower circuit and enters the A / D conversion circuit, where it is converted into a digital signal corresponding to the voltage and then calculated by the CPU processing module.

[0072] The fuel level sensor acquisition channel switching switch has four units on a single acquisition board, with two units forming a group. The two groups are used to control the acquisition of fuel level sensors A and B, respectively. The fuel level sensor acquisition channel switching switch is a multi-select type. The channel selection of the fuel level sensor acquisition channel switching switch is controlled by the CPU processing module. The operation enable of the fuel level sensor acquisition channel switching switch is controlled by the dual-channel time-division sampling control circuit.

[0073] The dual-channel time-division sampling control circuit comprises two parts: a sensor acquisition channel switching enable control circuit for group A fuel quantity sensors and a sensor acquisition channel switching enable control circuit for group B fuel quantity sensors. The dual-channel time-division sampling control circuit consists of one optocoupler, four MOSFETs, and multiple current-limiting resistors. One end of the input stage of the optocoupler on the group A acquisition board is powered, and the other end is connected in series with two MOSFETs and then connected to system ground. One end of the output stage of the optocoupler is connected to the group B acquisition board, and the other end is connected to system ground. When the group A acquisition board acquires data from the external group A fuel quantity sensor, it sets the sensor acquisition channel switching switch corresponding to the group A fuel quantity sensor to "on," enabling the sensor acquisition of the group B fuel quantity sensor. When the channel switching switch is set to "OFF", the state of the sensor acquisition channel switching switch corresponding to the fuel level sensor in group A on acquisition board B is forcibly set to "OFF" by the output stage of the optocoupler on acquisition board A. Acquisition board B acquires fuel level sensor data during this time period. After acquisition board A finishes acquiring fuel level sensor data for group A, it sets the sensor acquisition channel switching switch for fuel level sensor B to "ON". If acquisition board B does not acquire fuel level sensor data for group B during this time period, acquisition board A acquires fuel level sensor data for group B. If acquisition board B is acquiring fuel level sensor data for group B during this time period, the state of the fuel level sensor acquisition channel switching switch corresponding to the fuel level sensor in group B on acquisition board A is set to "OFF" by the output stage of the optocoupler on acquisition board B.

[0074] In the dual-channel time-division sampling control circuit, the gates of the two MOSFETs connected to the optocoupler on the A acquisition board are respectively connected to the fuel measurement computer reset signal and the first control signal output by the CPU processing module. The drain of the first MOSFET is connected to one end of the input stage of the optocoupler. The drain of the first MOSFET serves as the enable signal for the fuel quantity sensor acquisition channel switching switch corresponding to the A group fuel quantity sensor. The source of the first MOSFET is connected to the drain of the second MOSFET, and the source of the second MOSFET is connected to system ground. The dual-channel time-division sampling control circuit does not connect to the optocoupler on the A acquisition board. The gates of the two connected MOSFETs are connected as follows: the gate of the first MOSFET is connected to the reset signal of the fuel measurement computer; the gate of the second MOSFET is connected in parallel with one end of the output stage of the optocoupler of the B acquisition board and the second control signal output by the CPU processing module through a current-limiting resistor; the drain of the first MOSFET is connected to the power supply through a current-limiting resistor; the drain of the first MOSFET serves as the working enable signal for the fuel quantity sensor acquisition channel switching switch corresponding to the B group fuel quantity sensor; the source of the first MOSFET is connected to the drain of the second MOSFET; and the source of the second MOSFET is connected to system ground.

[0075] After the CPU processing module of the A acquisition board is initialized, the fuel measurement computer reset signal is high. Simultaneously, the first MOSFET connected to the optocoupler of the A acquisition board and the first MOSFET not connected to the optocoupler of the A acquisition board are turned on. The first control signal output by the CPU processing module turns on the second MOSFET on the same line as the optocoupler of the A acquisition board, and the second control signal output by the CPU processing module turns off the second MOSFET not on the same line as the optocoupler of the A acquisition board. At this time, the fuel quantity sensor acquisition channel switching switch corresponding to group A fuel quantity sensor is enabled, and the fuel quantity sensor acquisition channel switching switch corresponding to group B fuel quantity sensor is turned off. Simultaneously, the optocoupler on the A acquisition board is turned on, enabling the control switch on the B acquisition board that controls the fuel quantity sensor acquisition channel switching switch corresponding to group A fuel quantity sensor to turn off, thus preventing the B acquisition board from simultaneously acquiring data from group A fuel quantity sensors. After the CPU processing module of the B acquisition board is initialized, the fuel measurement computer reset signal is high. Simultaneously, the first MOSFET connected to the optocoupler of the B acquisition board and the first MOSFET not connected to the optocoupler are turned on. The first control signal output by the CPU processing module turns on the second MOSFET on the same line as the optocoupler of the B acquisition board. The second control signal output by the CPU processing module turns off the second MOSFET not on the same line as the optocoupler of the B acquisition board. At this time, the fuel quantity sensor acquisition channel switching switch corresponding to the B group fuel quantity sensor is enabled, and the fuel quantity sensor acquisition channel switching switch corresponding to the A group fuel quantity sensor is turned off. Simultaneously, the optocoupler on the B acquisition board is turned on, enabling the control switch on the A acquisition board to turn off the fuel quantity sensor acquisition channel switching switch corresponding to the B group fuel quantity sensor, thus disconnecting the possibility of the A acquisition board acquiring the B group fuel quantity sensor's data simultaneously.

[0076] After the CPU processing module of acquisition board A completes the acquisition of fuel level sensors A, the first control signal output by the CPU processing module turns off the second MOSFET on the same line as the optocoupler of acquisition board A, and the second control signal output by the CPU processing module turns on the second MOSFET not on the same line as the optocoupler of acquisition board A. If acquisition board B is not acquiring fuel level sensors B at this time, the fuel level sensor acquisition channel switching switch corresponding to the fuel level sensors B on acquisition board A is enabled. If acquisition board B is acquiring fuel level sensors B at this time, the CPU processing module of acquisition board A... The processing module starts waiting for the signal from the B acquisition board when it finishes acquiring the fuel level sensor group B. After it finishes, the A acquisition board enables the fuel level sensor acquisition channel switching switch corresponding to the B group fuel level sensor. If the CPU processing module of the A acquisition board waits for the signal from the B acquisition board when it finishes acquiring the fuel level sensor group B for more than a fixed time, the CPU processing module of the A acquisition board returns to acquiring the fuel level sensor group A. If the B acquisition board starts acquiring the fuel level sensor group B while the A acquisition board is acquiring the fuel level sensor group B, the CPU processing module of the A acquisition board returns to acquiring the fuel level sensor group A.

[0077] Example 2:

[0078] This embodiment is based on the above embodiment 1, such as... Figure 3 As shown, a fuel measurement method based on dual-channel time-division sampling control is proposed.

[0079] The dual-channel time-division sampling control module uses MOSFETs and optocouplers to form a purely hardware circuit. In conjunction with the control signals from the CPU processing module, it performs cross-time sampling from two external fuel level sensors (Group A and Group B). The CPU processing module outputs signals to control the operation of the dual-channel time-division sampling control circuit, the fuel level sensor acquisition channel switching switch, and the fuel level sensor signal acquisition module. It also processes and calculates the data from the fuel level sensors, converting it into fuel quality. The fuel level sensor acquisition channel switching switch sequentially connects multiple external fuel level sensors to the fuel level sensor signal acquisition module. The fuel level sensor signal acquisition module converts the capacitance signal from the fuel level sensors into a voltage signal, which is then sent to the CPU processing module for data processing.

[0080] This embodiment incorporates a fuel level sensor signal acquisition algorithm within the CPU processing module. This algorithm is a successive approximation algorithm based on multiple iterations, with a lower limit for the sampling value set to X. 下 Set the upper limit of the sampling value to X. 上 The first assumed sample value after the fuel measurement computer is powered on is set to... The hypothetical sampled value is input into a 12-bit digital-to-analog converter chip, converted into a theoretical current signal, and then compared with the actual current signal fed back by the capacitance sensor. If the theoretical current value is greater than the actual current value, then the second hypothetical sampled value is set to... If the theoretical current value is less than the actual current value, then the second assumed sampled value is set to...

[0081] Then input the assumed sampled value into a 12-bit digital-to-analog converter chip and repeat the above process until the theoretical current value and the actual current value are less than the algorithm's preset threshold X. 阀 , to X at this time i The oil quantity is calculated using the final value of the oil quantity sensor signal.

[0082] This embodiment incorporates a fuel quantity calculation algorithm within the CPU processing module. This algorithm is a chasing algorithm based on dynamic adjustment of the limiting value. Let the current fuel quantity sensor sampling value be X1, the previous fuel quantity sensor sampling value be X2, and the stable limiting value be W. The value of W is determined based on the aircraft's fuel consumption rate. Under ground and cruise attitudes, the fuel quantity changes according to the stable limiting value W. Under other flight attitudes, if X2 > X1, the limiting value is dynamically adjusted to W + ΔW, resulting in a processed fuel quantity sensor sampling value of X2 - (W + ΔW). If X2 ≤ X1, the limiting value is dynamically adjusted to W - ΔW, resulting in a processed fuel quantity sensor sampling value of X2 - (W - ΔW).

[0083] This embodiment incorporates a dual-channel time-division sampling control algorithm in the CPU processing module. This algorithm is a logical processing method based on the fusion of control signals and feedback signals from a dual-channel time-division sampling control circuit. After the CPU processing module of the A acquisition board is initialized, the fuel measurement computer reset signal is high. Simultaneously, the first MOSFET connected to the optocoupler of the A acquisition board and the first MOSFET not connected to the optocoupler of the A acquisition board are turned on. The first control signal output by the CPU processing module turns on the second MOSFET on the same line as the optocoupler of the A acquisition board, and the second control signal output by the CPU processing module turns off the second MOSFET not on the same line as the optocoupler of the A acquisition board. At this time, the fuel quantity sensor acquisition channel switching switch corresponding to the A group fuel quantity sensor is enabled, and the fuel quantity sensor acquisition channel switching switch corresponding to the B group fuel quantity sensor is turned off. Simultaneously, the optocoupler on the A acquisition board is turned on, switching the fuel quantity sensor acquisition channel corresponding to the A group fuel quantity sensor on the B acquisition board. When the switch is turned off, the possibility of the B acquisition board simultaneously acquiring data from the A group of fuel level sensors is disconnected. Similarly, after the CPU processing module of the B acquisition board is initialized, the fuel measurement computer reset signal is high, simultaneously turning on the first MOSFET connected to the optocoupler of the B acquisition board and the first MOSFET not connected to the optocoupler of the B acquisition board. The first control signal output by the CPU processing module turns on the second MOSFET on the same line as the optocoupler of the B acquisition board, and the second control signal output by the CPU processing module turns off the second MOSFET not on the same line as the optocoupler of the B acquisition board. At this time, the fuel level sensor acquisition channel switching switch corresponding to the B group of fuel level sensors is enabled, and the fuel level sensor acquisition channel switching switch corresponding to the A group of fuel level sensors is turned off. At the same time, the optocoupler on the B acquisition board is turned on, turning off the fuel level sensor acquisition channel switching switch on the A acquisition board that controls the B group of fuel level sensors, thus disconnecting the possibility of the A acquisition board simultaneously acquiring data from the B group of fuel level sensors.

[0084] Working principle: This embodiment uses only two sets of acquisition boards without adding an additional arbitration board. It realizes the signal acquisition, processing, and calculation of the external complete fuel quantity sensor through the dual-channel time-division sampling control circuit on the acquisition board. This method rationally allocates hardware resources and perfectly realizes the dual-redundancy fuel measurement computer function. It has the advantages of reasonable hardware resource allocation and complete signal acquisition.

[0085] The other parts of this embodiment are the same as those in Embodiment 1 above, so they will not be described again.

[0086] 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 fuel measurement system based on dual-channel time-division sampling control, characterized in that, It includes acquisition board A and acquisition board B; both acquisition board A and acquisition board B include a dual-channel time-division sampling control module, a CPU processing module, a fuel level sensor acquisition channel switching switch, and a fuel level sensor signal acquisition module. The A acquisition board and the B acquisition board are connected via a fuel level sensor acquisition channel switching switch. The oil quantity sensor acquisition channel switching switch is connected to the dual-channel time-division sampling control module and the CPU processing module; The input end of the dual-channel time-division sampling control module is connected to an external sensor and power supply, and the output end is connected to another set of acquisition boards of the CPU processing module. The oil quantity sensor signal acquisition module is connected to the oil quantity sensor acquisition channel switching switch and the CPU processing module; The dual-channel time-division sampling control module is used to collect the capacitance signal of the external oil quantity sensor in a cross-time division according to the control signal obtained from the CPU module. The oil quantity sensor acquisition channel switching switch is used to connect multiple external oil quantity sensors to the oil quantity sensor signal acquisition module in sequence. The oil quantity sensor signal acquisition module is used to convert the capacitive signal obtained from the oil quantity sensor acquisition channel switching switch into a voltage signal. The CPU module is used to calculate the amount of fuel based on the voltage signal; The dual-channel time-division sampling control module includes: a sensor acquisition channel switching switch enable control circuit and a dual-channel time-division sampling control circuit; The dual-channel time-division sampling control circuit includes an optocoupler unit and a MOS transistor unit; The first input terminal of the optocoupler unit is connected to the power supply, the second input terminal is connected to the ground terminal through a MOS transistor unit, the first output terminal of the optocoupler unit is connected to another set of acquisition boards, and the second output terminal of the optocoupler unit is connected to the ground terminal.

2. The fuel measurement system based on dual-channel time-division sampling control according to claim 1, characterized in that, The MOS transistor unit includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor; The drain of the first MOS transistor is connected to the second input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the first MOS transistor is connected to the drain of the second MOS transistor. The gate of the first MOS transistor receives a reset signal. The gate of the second MOSFET is connected to the CPU module, and the source of the second MOSFET is connected to ground. The drain of the third MOS transistor is connected to the first input terminal of the optocoupler unit and the working enable signal of the oil quantity sensor acquisition channel switching switch. The source of the third MOS transistor is connected to the drain of the fourth MOS transistor. The gate of the third MOS transistor receives a reset signal. The gate of the fourth MOS transistor is connected to the CPU module through a limiting resistor, and the source of the fourth MOS transistor is connected to ground.

3. The fuel measurement system based on dual-channel time-division sampling control according to claim 1, characterized in that, The oil quantity sensor signal acquisition module includes an excitation source circuit, a filter amplification circuit, a voltage follower circuit, and an AD conversion circuit; One end of the excitation source circuit is connected to an external fuel level sensor via a sensor acquisition channel switching switch, and the other end is connected to a filter amplifier circuit. One end of the voltage follower circuit is connected to the filter amplifier circuit, and the other end is connected to the AD conversion circuit; The excitation source circuit is used to generate a sinusoidal voltage signal; The filter amplifier circuit is used to convert the sinusoidal voltage signal into a DC voltage signal; The AD conversion circuit is used to convert DC voltage signals into digital voltage signals.

4. A fuel measurement method based on dual-channel time-division sampling control, implemented based on the fuel measurement system based on dual-channel time-division sampling control as described in claim 1; characterized in that, Specifically, it includes: Capacitive signals are obtained by time-division cross-collection of external fuel quantity sensors A and B based on control signals. Based on the set upper and lower limits of the sampling value, the capacitance signal is converted into a voltage signal, and the sampling value of the fuel level sensor signal is calculated. The fuel quantity is calculated based on the sampled value of the fuel quantity sensor signal and the set stability limit value.

5. The fuel measurement method based on dual-channel time-division sampling control according to claim 4, characterized in that, When acquisition board A acquires data from external fuel level sensors (group A), it sets the sensor acquisition channel switch corresponding to group A fuel level sensors to "on" and sets the sensor acquisition channel switch for group B fuel level sensors to "off". At this time, the state of the sensor acquisition channel switch for group B fuel level sensors is forcibly set to "off" by the output stage of the optocoupler on acquisition board A. Acquisition board B acquires data from group B fuel level sensors during this time period. After acquisition board A finishes acquiring data from group A fuel level sensors, it sets the sensor acquisition channel switch for group B fuel level sensors to "on". If acquisition board B did not acquire data from group B fuel level sensors during this time period, acquisition board A acquires data from group B fuel level sensors. If acquisition board B is acquiring data from group B fuel level sensors during this time period, the state of the sensor acquisition channel switch for group B fuel level sensors is forcibly set to "off" by the output stage of the optocoupler on acquisition board B.

6. The fuel measurement method based on dual-channel time-division sampling control according to claim 4, characterized in that, The step of converting the capacitance signal into a voltage signal and calculating the sampled value of the fuel level sensor signal based on the set upper and lower limits of the sampling value specifically includes: Based on the successive approximation algorithm with multiple iterations, the lower limit of the sampled value is set as follows: Set the upper limit of the sampling value to The first hypothetical sample value obtained after power-on is set to The hypothetical sampled value is converted into a current signal and compared with the actual current signal fed back by the capacitive sensor. If the theoretical current value is greater than the actual current value, then the second hypothetical sampled value is set to... If the theoretical current value is less than the actual current value, then the second assumed sample value is set to... Then, the assumed sampled values ​​are converted into current signals, and the above process is repeated until the theoretical current value and the actual current value are less than the algorithm's preset threshold. , at this time This is used as the final value of the signal acquired by the oil level sensor.

7. The fuel measurement method based on dual-channel time-division sampling control according to claim 4, characterized in that, The calculation of fuel quantity based on the sampled value of the fuel quantity sensor signal and the set stability limit value specifically includes: Based on the chasing algorithm that dynamically adjusts the amplitude limit, let the current fuel level sensor sampling value be... The previous fuel level sensor sample value was The stable amplitude limit is , The value is determined based on the aircraft's fuel consumption rate. Under ground and cruise attitude conditions, the fuel quantity is determined according to the stability limit value. Make changes; in other flight attitudes, if The amplitude limit will then be dynamically adjusted to... The processed oil level sensor sample value is ;like The amplitude limit will then be dynamically adjusted to... The processed oil level sensor sample value is .

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