Fuel oil measuring system and method based on dual-channel time-sharing sampling control

Abstract

The invention relates to the technical field of aviation fuel measurement, in particular to a fuel measurement system and method based on dual-channel time-sharing sampling control. Comprising an A acquisition board card and a B acquisition board card which are the same in structure, and each single acquisition board card is composed of a double-channel time-sharing sampling control circuit, a CPU processing module, an oil quantity sensor acquisition channel change-over switch and an oil quantity sensor signal acquisition module. The double-channel time-sharing sampling control module is matched with a control signal of the CPU processing module to carry out cross time-sharing acquisition on two groups of external oil quantity sensors; the CPU processing module outputs a signal to control the work of the dual-channel time-sharing sampling control circuit, the oil quantity sensor acquisition channel change-over switch and the oil quantity sensor signal acquisition module, processes and calculates data of an oil quantity sensor, and converts the data into fuel mass; a plurality of paths of external oil quantity sensors are sequentially connected to the oil quantity sensor signal acquisition module through the oil quantity sensor acquisition channel change-over switch; the oil quantity sensor signal acquisition module converts capacitance signals of an oil quantity sensor into voltage signals and sends the voltage signals to the CPU processing module for data resolving.

Description

Technical Field

[0001] The invention relates to the technical field of aviation fuel measurement, and in particular to a fuel measurement system and method based on dual-channel time-sharing sampling control. Background Art

[0002] At present, in order to improve the reliability of fuel measurement computers, dual redundancy design is generally adopted. There are two common design methods. One is to set up two sets of main / slave acquisition boards in the fuel measurement computer, plus a set of arbitration boards. After power-on, the main board in the fuel measurement computer starts to collect, process, and calculate the signals of the fuel level sensor, and the slave board is in a waiting state. During the working process, if the main board fails, the arbitration board will issue a main / slave switching instruction. At this time, the main board stops all work, and the slave board starts to collect, process, and calculate the signals of the fuel level sensor. The advantage of this method is that the switching of the two acquisition boards is determined by the arbitration board, and there is no risk of risky competition. However, its disadvantage is that the working mode of the two boards belongs to cold backup, and only one board works at the same time. In addition, an arbitration board is set up additionally, which consumes more computer hardware resources when completing the same work. The other method is to set up only two sets of acquisition boards (main and auxiliary) in the fuel measurement computer. After power-on, the main and auxiliary boards in the fuel measurement computer start to collect, process, and calculate the signals of the fuel level sensor. However, the main and auxiliary boards can only complete the signal collection of half of the fuel level sensor respectively. Then, the collected fuel level sensor information is exchanged through communication between the boards to obtain complete fuel level sensor data and finally calculate the accurate fuel level value. The advantage of this method is that the architecture of the two acquisition boards is simple and they do not interfere with each other, but the disadvantage is that the two boards can only complete the collection of half of the fuel level sensor respectively. If a single board fails, half of the fuel level sensor information will be lost, and the accuracy of fuel measurement will be degraded. Summary of the invention

[0003] Aiming at the problem that two boards in the existing fuel measurement method can only complete the acquisition of half of the fuel quantity sensors, if a single board fails, half of the fuel quantity sensor information will be lost, and the accuracy of fuel measurement is degraded, the present invention proposes a fuel measurement system and method based on dual-channel time-sharing sampling control; the system comprises an A acquisition board and a B acquisition board of the same structure; a dual-channel time-sharing sampling control module uses MOS tubes and optical coupling devices, cooperates with the control signal of a CPU processing module, and performs cross-time-sharing acquisition of two groups of external fuel quantity sensors; the CPU processing module outputs a signal to control the dual-channel time-sharing sampling control circuit, a fuel quantity sensor acquisition channel switching switch, and a fuel quantity sensor signal acquisition module, and processes and calculates the data of the fuel quantity sensor and converts it into fuel quantity; the fuel quantity sensor acquisition channel switching switch connects the external multi-channel fuel quantity sensors to the fuel quantity sensor signal acquisition module in sequence; the fuel quantity sensor signal acquisition module converts the capacitance signal of the fuel quantity sensor into a voltage signal, and sends it to the CPU processing module for data solution, thereby realizing dual-redundancy fuel measurement.

[0004] The specific implementation contents of the present invention are as follows:

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

[0006] The A acquisition board and the B acquisition board are connected via the oil level sensor acquisition channel switching switch;

[0007] The oil level sensor collection channel switching switch is connected to the dual-channel time-sharing sampling control module and the CPU processing module;

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

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

[0010] The dual-channel time-sharing sampling control module is used to cross-time-sharingly collect the capacitance signal of the external oil level sensor according to the control signal obtained from the CPU module;

[0011] The oil level sensor acquisition channel switching switch is used to sequentially connect the external multiple oil level sensors to the oil level sensor signal acquisition module;

[0012] The oil level sensor signal acquisition module is used to convert the capacitance signal obtained from the oil level sensor acquisition channel switching switch into a voltage signal;

[0013] The CPU module is used to calculate the fuel quantity according to the voltage signal.

[0014] In order to better implement the present invention, further, the dual-channel time-sharing sampling control module includes: a sensor acquisition channel switching switch operation enabling control circuit, a dual-channel time-sharing sampling control circuit;

[0015] The dual-channel time-sharing sampling control circuit includes an optical coupling unit and a MOS tube unit;

[0016] The first input end of the optical coupling unit is connected to the power supply, the second input end is connected to the ground end through the MOS tube unit, the first output end of the optical coupling unit is connected to another group of acquisition boards, and the second output end of the optical coupling unit is connected to the ground end.

[0017] In order to better implement the present invention, further, the MOS tube unit includes a first MOS tube, a second MOS tube, a third MOS tube, and a fourth MOS tube;

[0018] The drain of the first MOS tube is connected to the second input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the first MOS tube is connected to the drain of the second MOS tube, and the gate of the first MOS tube inputs a reset signal;

[0019] The gate of the second MOS tube is connected to the CPU module, and the source of the second MOS tube is connected to the ground terminal;

[0020] The drain of the third MOS tube is connected to the first input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the third MOS tube is connected to the drain of the fourth MOS tube, and the gate of the third MOS tube inputs a reset signal;

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

[0022] In order to better implement the present invention, further, the oil level sensor signal acquisition module includes an excitation source circuit, a filter amplifier circuit, a voltage follower circuit, and an AD conversion circuit;

[0023] One end of the excitation source circuit is connected to the external oil level sensor through the sensor acquisition channel switching switch, and the other end is connected to the 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 filtering and amplifying circuit is used to convert the sinusoidal voltage signal into a DC voltage signal;

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

[0028] Based on the above-mentioned fuel measurement system based on dual-channel time-sharing sampling control, in order to better realize the present invention, further, a fuel measurement method based on dual-channel time-sharing sampling control is proposed, which is implemented based on the above-mentioned fuel measurement system based on dual-channel time-sharing sampling control; specifically, it includes:

[0029] Capacitance signals are obtained by cross-collecting the external A group of oil level sensors and the external B group of oil level sensors in a time-sharing manner according to the control signal;

[0030] According to the set sampling value upper limit and sampling value lower limit, the capacitance signal is converted into a voltage signal, and the oil level sensor signal sampling value is calculated;

[0031] The fuel quantity is calculated based on the fuel quantity sensor signal sampling value and the set stable limit value.

[0032] In order to better realize the present invention, further, when the A acquisition board collects the external A group oil level sensor, the sensor acquisition channel switching switch state corresponding to the A group oil level sensor is set to "on", and the sensor acquisition channel switching switch state of the B group oil level sensor is set to "off". At this time, the state of the sensor acquisition channel switching switch corresponding to the A group oil level sensor collected by the B acquisition board is forced to be "off" by the output stage of the optocoupler device of the A acquisition board, and the B acquisition board collects the B group oil level sensor in this time period; after the A acquisition board finishes collecting the A group oil level sensor, the sensor acquisition channel switching switch state of the B group oil level sensor is set to "on". If the B acquisition board does not collect the B group oil level sensor in this time period, the A acquisition board collects the B group oil level sensor. If the B acquisition board is collecting the B group oil level sensor in this time period, the state of the oil acquisition channel switching switch corresponding to the B group oil level sensor collected by the A acquisition board is forced to be "off" by the output stage of the optocoupler device of the B acquisition board.

[0033] In order to better implement the present invention, further, the capacitive signal is converted into a voltage signal according to setting the upper limit of the sampling value and the lower limit of the sampling value, and the sampling value of the fuel level sensor signal is calculated, which specifically includes:

[0034] According to the multiple iteration successive approximation algorithm, set the lower limit of the sampling value to X 下 , set the upper limit of the sampling value to X 上 , get the first assumed sample value after power-on and set it to The hypothetical sampling 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, the second hypothetical sampling value is set to If the theoretical current value is less than the actual current value, the second assumed sampling value is set to Then convert the assumed sampling value into a current signal and repeat the above work until the theoretical current value and the actual current value are less than the threshold value X preset by the algorithm. 阈 , then X i The final value is acquired as the fuel level sensor signal.

[0035] In order to better implement the present invention, further, the fuel quality is calculated according to the fuel quantity sensor signal sampling value and the set stable limit value, which specifically includes:

[0036] According to the chasing algorithm with dynamic adjustment of the limit, the current fuel sensor sampling value is assumed to be X1, the previous fuel sensor sampling value is X2, and the stable limit value is W. The value of W is determined according to the fuel consumption rate of the aircraft. Under the ground and cruising attitudes, the fuel volume changes according to the stable limit value W; under other flight attitudes, if X2>X1, the limit value is dynamically adjusted to W+ΔW, and the processed fuel sensor sampling value is X2-(W+ΔW); if X2≤X1, the limit value is dynamically adjusted to W-ΔW, and the processed fuel sensor sampling value is X2-(W-ΔW).

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

[0038] The present invention uses only two sets of acquisition boards without adding an arbitration board. The signal acquisition, processing, calculation and other tasks of the external complete fuel quantity sensor are realized through the dual-channel time-sharing sampling control circuit on the acquisition board. The method reasonably allocates hardware resources and perfectly realizes the dual-redundancy fuel measurement computer function. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0041] Figure 3 This is a schematic diagram of the dual-channel time-sharing sampling control flow provided by the present invention. DETAILED DESCRIPTION

[0042] 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.

[0043] 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 elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Embodiment 1:

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

[0046] The A acquisition board and the B acquisition board are connected via the oil level sensor acquisition channel switching switch;

[0047] The oil level sensor collection channel switching switch is connected to the dual-channel time-sharing sampling control module and the CPU processing module;

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

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

[0050] The dual-channel time-sharing sampling control module is used to cross-time-sharingly collect the capacitance signal of the external oil level sensor according to the control signal obtained from the CPU module;

[0051] The oil level sensor acquisition channel switching switch is used to sequentially connect the external multiple oil level sensors to the oil level sensor signal acquisition module;

[0052] The oil level sensor signal acquisition module is used to convert the capacitance signal obtained from the oil level sensor acquisition channel switching switch into a voltage signal;

[0053] The CPU module is used to calculate the fuel quantity according to the voltage signal.

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

[0055] The dual-channel time-sharing sampling control circuit includes an optical coupling unit and a MOS tube unit;

[0056] The first input end of the optical coupling unit is connected to the power supply, the second input end is connected to the ground end through the MOS tube unit, the first output end of the optical coupling unit is connected to another group of acquisition boards, and the second output end of the optical coupling unit is connected to the ground end.

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

[0058] The drain of the first MOS tube is connected to the second input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the first MOS tube is connected to the drain of the second MOS tube, and the gate of the first MOS tube inputs a reset signal;

[0059] The gate of the second MOS tube is connected to the CPU module, and the source of the second MOS tube is connected to the ground terminal;

[0060] The drain of the third MOS tube is connected to the first input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the third MOS tube is connected to the drain of the fourth MOS tube, and the gate of the third MOS tube inputs a reset signal;

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

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

[0063] One end of the excitation source circuit is connected to the external oil level sensor through the sensor acquisition channel switching switch, and the other end is connected to the 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 filtering and amplifying circuit is used to convert the sinusoidal voltage signal into a DC voltage signal;

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

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

[0069] The dual-channel time-sharing sampling control module uses MOS tubes and optocouplers to form a pure hardware circuit, and cooperates with the control signal of the CPU processing module to perform cross-time-sharing sampling of the external oil level sensors of group A and group B;

[0070] The CPU processing module outputs signals to control the operation of the dual-channel time-sharing sampling control circuit, the oil level sensor acquisition channel switching switch, and the oil level sensor signal acquisition module, and processes and calculates the data of the oil level sensor and converts it into fuel quality; the oil level sensor acquisition channel switching switch connects the external multi-channel oil level sensors to the oil level sensor signal acquisition module in sequence; the oil level sensor signal acquisition module converts the capacitance signal of the oil level sensor into a voltage signal and sends it to the CPU processing module for data solution.

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

[0072] The oil level sensor acquisition channel switching switches include 4 on a single acquisition board, 2 in a group, and the two groups are used to control the acquisition of the oil level sensors in groups A and B respectively. The oil level sensor acquisition channel switching switch is a multiple-choice type. The channel selection of the oil level sensor acquisition channel switching switch is controlled by the CPU processing module, and the operation enable of the oil level sensor acquisition channel switching switch is controlled by the dual-channel time-sharing sampling control circuit.

[0073] The dual-channel time-sharing sampling control circuit includes two parts: a sensor acquisition channel switching switch working enable control circuit of the A group oil level sensor and a sensor acquisition channel switching switch working enable control circuit of the B group oil level sensor. The dual-channel time-sharing sampling control circuit is composed of an optocoupler device, four MOS tubes and multiple current-limiting resistors. One end of the input stage of the optocoupler device on the A acquisition board is powered, and the other end is connected to the system ground after being connected in series with two MOS tubes. One end of the output stage of the optocoupler device is connected to the B acquisition board, and the other end is connected to the system ground. When the A acquisition board collects the external A group oil level sensor, the sensor acquisition channel switching switch state corresponding to the A group oil level sensor is set to "on", and the sensor acquisition of the B group oil level sensor is turned off. The channel switching switch state is set to "off". At this time, the state of the sensor acquisition channel switching switch corresponding to the oil level sensor of group A collected by the B acquisition board is forced to be "off" by the output stage of the optocoupler device of the A acquisition board, and the B acquisition board collects the oil level sensor of group B in this time period; after the A acquisition board finishes collecting the oil level sensor of group A, the state of the sensor acquisition channel switching switch of the oil level sensor of group B is set to "on". If the B acquisition board has not collected the oil level sensor of group B in this time period, the A acquisition board collects the oil level sensor of group B. If the B acquisition board is collecting the oil level sensor of group B in this time period, the state of the oil level sensor acquisition channel switching switch corresponding to the oil level sensor of group B collected by the A acquisition board is set to "off" by the output stage of the optocoupler device of the B acquisition board.

[0074] The gates of the two MOS tubes connected to the A acquisition board optocoupler device in the dual-channel time-sharing sampling control circuit 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 MOS tube is connected to one end of the input stage of the optocoupler device, the drain of the first MOS tube is used as the working enable signal of the oil quantity sensor acquisition channel switching switch corresponding to the A group oil quantity sensor, the source of the first MOS tube is connected to the drain of the second MOS tube, and the source of the second MOS tube is connected to the system ground; the dual-channel time-sharing sampling control circuit is not connected to the A acquisition board optocoupler device The gates of the two connected MOS tubes, the gate of the first MOS tube is connected to the reset signal of the fuel measurement computer, the gate of the second MOS tube is connected in parallel with one end of the output stage of the B acquisition board optocoupler device and the second control signal output by the CPU processing module through a current limiting resistor, the drain of the first MOS tube is connected to the power supply through a current limiting resistor, the drain of the first MOS tube is used as the working enable signal of the oil quantity sensor acquisition channel switching switch corresponding to the B group oil quantity sensor, the source of the first MOS tube is connected to the drain of the second MOS tube, and the source of the second MOS tube is connected to the system ground.

[0075] After the CPU processing module of the A acquisition board is initialized, the fuel measurement computer reset signal is high, and the first MOS tube connected to the A acquisition board optocoupler device and the first MOS tube not connected to the A acquisition board optocoupler device are turned on at the same time. The first control signal output by the CPU processing module turns on the second MOS tube on the same line with the A acquisition board optocoupler device, and the second control signal output by the CPU processing module turns off the second MOS tube not on the same line with the A acquisition board optocoupler device. At this time, the oil quantity sensor acquisition channel switching switch corresponding to the A group oil quantity sensor is enabled, and the oil quantity sensor acquisition channel switching switch corresponding to the B group oil quantity sensor is turned off. At the same time, the optocoupler device on the A acquisition board is turned on, and the oil quantity sensor acquisition channel switching switch corresponding to the A group oil quantity sensor on the B acquisition board is turned off and enabled, thereby disconnecting the possibility of the B acquisition board collecting the A group oil quantity sensor at the same time. After the CPU processing module of the B acquisition board is initialized, the reset signal of the fuel measurement computer is high level, and the first MOS tube connected to the optocoupler device of the B acquisition board and the first MOS tube not connected to the optocoupler device of the B acquisition board are turned on at the same time. The first control signal output by the CPU processing module turns on the second MOS tube on the same line with the optocoupler device of the B acquisition board, and the second control signal output by the CPU processing module turns off the second MOS tube not on the same line with the optocoupler device of the B acquisition board. At this time, the oil quantity sensor acquisition channel switching switch corresponding to the B group oil quantity sensor is enabled, and the oil quantity sensor acquisition channel switching switch corresponding to the A group oil quantity sensor is turned off. At the same time, the optocoupler device on the B acquisition board is turned on, and the oil quantity sensor acquisition channel switching switch corresponding to the B group oil quantity sensor on the A acquisition board is turned off and enabled, thereby disconnecting the possibility of the A acquisition board collecting the B group oil quantity sensor at the same time.

[0076] After the CPU processing module of the A acquisition board completes the acquisition of the A group of oil level sensors, the first control signal output by the CPU processing module turns off the second MOS tube on the same line with the A acquisition board optocoupler device, and the second control signal output by the CPU processing module turns on the second MOS tube that is not on the same line with the A acquisition board optocoupler device. If the B acquisition board is not acquiring the B group of oil level sensors at this time, the A acquisition board acquires the oil level sensor acquisition channel switch corresponding to the B group of oil level sensors, which is enabled; if the B acquisition board is acquiring the B group of oil level sensors at this time, the CPU processing module of the A acquisition board The processing module starts to wait for the signal when the B acquisition board finishes collecting the oil level sensors of group B. After it finishes, the A acquisition board collects the oil level sensor collection channel switching switch corresponding to the oil level sensors of group B, which is enabled; if the CPU processing module of the A acquisition board waits for the signal when the B acquisition board finishes collecting the oil level sensors of group B for more than a fixed time, the CPU processing module of the A acquisition board returns to the collection of the oil level sensors of group A; if the A acquisition board is in the middle of collecting the oil level sensors of group B, and the B acquisition board starts collecting the oil level sensors of group B, the CPU processing module of the A acquisition board returns to the collection of the oil level sensors of group A.

[0077] Embodiment 2:

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

[0079] The dual-channel time-sharing sampling control module uses MOS tubes and optocoupler devices to form a pure hardware circuit, and cooperates with the control signal of the CPU processing module to perform cross-time-sharing acquisition of the external oil level sensors of group A and group B; the CPU processing module outputs signals to control the dual-channel time-sharing sampling control circuit, the oil level sensor acquisition channel switching switch, and the oil level sensor signal acquisition module, and processes and calculates the data of the oil level sensor and converts it into fuel quality; the oil level sensor acquisition channel switching switch connects the external multi-channel oil level sensors to the oil level sensor signal acquisition module in sequence; the oil level sensor signal acquisition module converts the capacitance signal of the oil level sensor into a voltage signal and sends it to the CPU processing module for data solution.

[0080] In this embodiment, an oil level sensor signal acquisition algorithm is set in the CPU processing module. The oil level sensor signal acquisition algorithm is a successive approximation algorithm based on 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 , then the first assumed sampling value after the fuel measurement computer is powered on is set to The assumed sampling value is input into the 12-bit digital / analog conversion chip, converted into a theoretical 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, the second assumed sampling value is set to If the theoretical current value is less than the actual current value, the second assumed sampling value is set to

[0081] Then input the assumed sampling value into the 12-bit digital / analog conversion chip and repeat the above work until the theoretical current value and the actual current value are less than the threshold value X preset by the algorithm. 阀 , then X i The final value of the oil level sensor signal is collected to calculate the oil level.

[0082] In this embodiment, a fuel quantity calculation algorithm is set in the CPU processing module. The fuel quantity calculation algorithm is a chasing algorithm based on dynamic adjustment of the limit. Assume that the current fuel quantity sensor sampling value is X1, the previous fuel quantity sensor sampling value is X2, and the stable limit value is W. The value of W is determined according to the fuel consumption speed of the aircraft. Under the ground and cruising attitudes, the fuel quantity changes according to the stable limit value W; under other flight attitudes, if X2>X1, the limit value is dynamically adjusted to W+ΔW, and the processed fuel quantity sensor sampling value is X2-(W+ΔW); if X2≤X1, the limit value is dynamically adjusted to W-ΔW, and the processed fuel quantity sensor sampling value is X2-(W-ΔW).

[0083] In this embodiment, a dual-channel time-sharing sampling control algorithm is set in the CPU processing module, which is a logic algorithm based on the fusion processing of the control signal and the feedback signal of the dual-channel time-sharing sampling control circuit. After the CPU processing module of the A acquisition board is initialized, the reset signal of the fuel measurement computer is high, and the first MOS tube connected to the A acquisition board optocoupler device and the first MOS tube not connected to the A acquisition board optocoupler device are turned on at the same time. The first control signal output by the CPU processing module turns on the second MOS tube on the same line with the A acquisition board optocoupler device, and the second control signal output by the CPU processing module turns off the second MOS tube not on the same line with the A acquisition board optocoupler device. At this time, the oil quantity sensor acquisition channel switching switch corresponding to the A group oil quantity sensor is enabled, and the oil quantity sensor acquisition channel switching switch corresponding to the B group oil quantity sensor is turned off. At the same time, the optocoupler device on the A acquisition board is turned on, and the oil quantity sensor acquisition channel switching corresponding to the A group oil quantity sensor on the B acquisition board is controlled. The switch is turned off and enabled, and the possibility of the B acquisition board collecting the oil quantity sensor of group A at the same time is disconnected; similarly, after the CPU processing module of the B acquisition board is initialized, the fuel measurement computer reset signal is high, and the first MOS tube connected to the optocoupler device of the B acquisition board and the first MOS tube not connected to the optocoupler device of the B acquisition board are turned on at the same time, and the first control signal output by the CPU processing module turns on the second MOS tube on the same line with the optocoupler device of the B acquisition board, and the second control signal output by the CPU processing module turns off the second MOS tube not on the same line with the optocoupler device of the B acquisition board. At this time, the oil quantity sensor collection channel switching switch corresponding to the oil quantity sensor of group B is enabled, and the oil quantity sensor collection channel switching switch corresponding to the oil quantity sensor of group A is turned off. At the same time, the optocoupler device on the B acquisition board is turned on, and the oil quantity sensor collection channel switching switch corresponding to the oil quantity sensor of group B on the A acquisition board is turned off and enabled, disconnecting the possibility of the A acquisition board collecting the oil quantity sensor of group B at the same time.

[0084] Working principle: This embodiment uses only two sets of acquisition boards without adding additional arbitration boards. The signal acquisition, processing, and calculation of the external complete fuel level sensor are realized through the dual-channel time-sharing sampling control circuit on the acquisition board. This method reasonably 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 of the above-mentioned embodiment 1, and thus will not be described in detail.

[0086] 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 fuel measurement system based on dual-channel time-sharing sampling control, characterized in that: It 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-sharing sampling control module, a CPU processing module, an oil level sensor acquisition channel switching switch, and an oil level sensor signal acquisition module; The A acquisition board and the B acquisition board are connected via the oil level sensor acquisition channel switching switch; The oil level sensor collection channel switching switch is connected to the dual-channel time-sharing sampling control module and the CPU processing module; The input end of the dual-channel time-sharing sampling control module is connected to an external sensor and a power supply, and the output end is connected to another group of acquisition boards of the CPU processing module; The oil level sensor signal acquisition module is connected to the oil level sensor acquisition channel switching switch and the CPU processing module; The dual-channel time-sharing sampling control module is used to cross-time-sharingly collect the capacitance signal of the external oil level sensor according to the control signal obtained from the CPU module; The oil level sensor acquisition channel switching switch is used to sequentially connect the external multiple oil level sensors to the oil level sensor signal acquisition module; The oil level sensor signal acquisition module is used to convert the capacitance signal obtained from the oil level sensor acquisition channel switching switch into a voltage signal; The CPU module is used to calculate the fuel quantity according to the voltage signal.

2. A fuel measurement system based on dual-channel time-sharing sampling control according to claim 1, characterized in that: The dual-channel time-sharing sampling control module includes: a sensor acquisition channel switching switch operation enabling control circuit and a dual-channel time-sharing sampling control circuit; The dual-channel time-sharing sampling control circuit includes an optical coupling unit and a MOS tube unit; The first input end of the optical coupling unit is connected to the power supply, the second input end is connected to the ground end through the MOS tube unit, the first output end of the optical coupling unit is connected to another group of acquisition boards, and the second output end of the optical coupling unit is connected to the ground end.

3. A fuel measurement system based on dual-channel time-sharing sampling control according to claim 2, characterized in that: The MOS tube unit includes a first MOS tube, a second MOS tube, a third MOS tube, and a fourth MOS tube; The drain of the first MOS tube is connected to the second input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the first MOS tube is connected to the drain of the second MOS tube, and the gate of the first MOS tube inputs a reset signal; The gate of the second MOS tube is connected to the CPU module, and the source of the second MOS tube is connected to the ground terminal; The drain of the third MOS tube is connected to the first input end of the optical coupling unit and the work enable signal of the oil level sensor acquisition channel switching switch, the source of the third MOS tube is connected to the drain of the fourth MOS tube, and the gate of the third MOS tube inputs a reset signal; The gate of the fourth MOS tube is connected to the CPU module through a limiting resistor, and the source of the fourth MOS tube is connected to the ground terminal.

4. A fuel measurement system based on dual-channel time-sharing sampling control according to claim 1, characterized in that: The oil level sensor signal acquisition module includes an excitation source circuit, a filter amplifier circuit, a voltage follower circuit, and an AD conversion circuit; one end of the excitation source circuit is connected to the external oil level sensor through a sensor acquisition channel switching switch, and the other end is connected to the 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 filtering and amplifying circuit is used to convert the sinusoidal voltage signal into a DC voltage signal; The AD conversion circuit is used to convert a DC voltage signal into a digital voltage signal.

5. A fuel measurement method based on dual-channel time-sharing sampling control, implemented based on the fuel measurement system based on dual-channel time-sharing sampling control as claimed in claim 1; characterized in that: Specifically include: Capacitance signals are obtained by cross-collecting from external group A oil level sensors and external group B oil level sensors in a time-sharing manner according to the control signal; the capacitance signals are converted into voltage signals according to the set sampling value upper limit and sampling value lower limit, and the sampling value of the oil level sensor signal is calculated; The fuel quantity is calculated based on the fuel quantity sensor signal sampling value and the set stable limit value.

6. A fuel measurement method based on dual-channel time-sharing sampling control according to claim 5, characterized in that: When the A acquisition board collects the external A group oil level sensor, the sensor acquisition channel switching switch state corresponding to the A group oil level sensor is set to "on", and the sensor acquisition channel switching switch state of the B group oil level sensor is set to "off". At this time, the state of the sensor acquisition channel switching switch corresponding to the A group oil level sensor collected by the B acquisition board is forced to be "off" by the output stage of the optocoupler device of the A acquisition board, and the B acquisition board collects the B group oil level sensor in this time period; after the A acquisition board finishes collecting the A group oil level sensor, the sensor acquisition channel switching switch state of the B group oil level sensor is set to "on". If the B acquisition board does not collect the B group oil level sensor in this time period, the A acquisition board collects the B group oil level sensor. If the B acquisition board is collecting the B group oil level sensor in this time period, the state of the oil acquisition channel switching switch corresponding to the B group oil level sensor collected by the A acquisition board is forced to be "off" by the output stage of the optocoupler device of the B acquisition board.

7. A fuel measurement method based on dual-channel time-sharing sampling control according to claim 5, characterized in that: The method of converting the capacitance signal into a voltage signal and calculating the fuel level sensor signal sampling value according to setting the sampling value upper limit and the sampling value lower limit specifically includes: According to the multiple iteration successive approximation algorithm, set the lower limit of the sampling value to X 下 , set the upper limit of the sampling value to X 上 , get the first assumed sample value after power-on and set it to The hypothetical sampling 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, the second hypothetical sampling value is set to If the theoretical current value is less than the actual current value, the second assumed sampling value is set to Then convert the assumed sampling value into a current signal and repeat the above work until the theoretical current value and the actual current value are less than the threshold value X preset by the algorithm. 阀 , then X i The final value is acquired as the fuel level sensor signal.

8. A fuel measurement system based on dual-channel time-sharing sampling control according to claim 5, characterized in that: The method of calculating the fuel quantity according to the fuel quantity sensor signal sampling value and the set stable limit value specifically includes: According to the chasing algorithm with dynamic adjustment of the limit, the current fuel sensor sampling value is assumed to be X1, the previous fuel sensor sampling value is X2, and the stable limit value is W. The value of W is determined according to the fuel consumption rate of the aircraft. Under the ground and cruising attitudes, the fuel volume changes according to the stable limit value W; under other flight attitudes, if X2>X1, the limit value is dynamically adjusted to W+ΔW, and the processed fuel sensor sampling value is X2-(W+ΔW); if X2≤X1, the limit value is dynamically adjusted to W-ΔW, and the processed fuel sensor sampling value is X2-(W-ΔW).

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