A self-maintaining, self-diagnosing and self-clearing air speed tube control system

Abstract

The application discloses a kind of self-maintenance, self-diagnosis, self-draining air speed pipe control system, including air speed pipe body, built-in micro pressure sensor's pressure / airspeed converter, high-pressure gas control unit, temperature control unit and main control unit.Main control unit is configured as: before / after flight automatically drive high-pressure gas control unit to pulse air flow flush total pressure pipe line;When detecting pressure anomaly in cruise, automatically cut off sensor connection and execute high-pressure air flow dredging;If it is judged that icing, then start temperature control unit and thaw after dredging again.The system also supports multiple air speed pipe redundancy configuration and weighted fusion based on confidence.The application realizes the air speed pipe of exempting from manual maintenance, air self-diagnosis and self-draining, significantly improves the operation safety and reliability of unmanned aerial vehicle under adverse weather conditions.

Description

Technical Field

[0001] This invention belongs to the field of flight control technology, and in particular relates to a self-maintaining, self-diagnostic, and self-unblocking pitot tube control system. Background Technology

[0002] Pitot tubes are typically installed on the outer surface of an aircraft in areas with stable airflow and minimal impact from its own structure, such as the front of the nose, wingtip, or leading edge of the vertical tail. As a crucial sensor on the aircraft, the pitot tube accurately collects air pressure data in real time from the total pressure port in front of it and the static pressure port on the side (the static pressure port can also be separated from the pitot tube and arranged in other areas of stable airflow on the fuselage). The pressure is then transmitted through pipelines to a high-precision micro-pressure sensor, which calculates and corrects the airspeed information using a pressure-airspeed transducer. The flight control system then calculates flight control parameters based on the real-time airspeed information to ensure stable and safe flight of the aircraft.

[0003] When performing special missions such as meteorological monitoring, weather modification, and polar scientific expeditions, UAVs may pass through cumulonimbus clouds, supercooled water droplets, and high-altitude low-temperature areas. Once they encounter such risky weather conditions, the pitot tube's main pressure orifice is often the first to be affected. With the accumulation of moisture and water droplets, the front end of the main pressure orifice can sometimes be completely blocked by the water droplet diaphragm. Experiments have shown that although water, as a fluid, can transmit pressure, the adhesion between the water droplet diaphragm and the tube wall, as well as the surface tension of the water droplets, can lead to distortion in pressure transmission. Under more extreme conditions such as low temperatures and sudden cooling, the main pressure orifice may freeze and become blocked, preventing pressure transmission and posing a significant threat to flight safety.

[0004] After a passenger aircraft, whether a civil aviation or general aviation aircraft, lands, ground crew will install an airspeed tube cover to protect the airspeed tube and prevent foreign objects such as dust and small insects from accidentally entering. However, the risk of forgetting to install the airspeed tube cover due to human negligence cannot be completely avoided, and similar flight accidents have indeed occurred in aviation history.

[0005] Currently, drones with different configurations and functions are emerging in an endless stream. However, drones in the civilian field are usually not equipped with dedicated ground support personnel. The daily maintenance of important sensors such as pitot tubes is often not guaranteed in a timely manner. When pitot tube malfunctions occur, it is often necessary for drone manufacturers' technicians to provide on-site support or even send the entire drone back to the factory for maintenance. This has invisibly increased the cost of using drones and raised the technical threshold. Summary of the Invention

[0006] In view of this, the present invention aims to overcome the shortcomings of the prior art by proposing a self-maintaining, self-diagnostic, and self-unblocking pitot tube control system. By adding a bypass and introducing a controllable high-pressure air path in the pipeline between the pitot tube body and the high-precision micro-pressure sensor built into the rear pressure / pitot converter, and by installing a physical de-icing device in the pitot tube body, the pitot tube is equipped with functions such as pre-flight / post-flight automatic maintenance, in-flight blockage detection, and automatic cleaning / unblocking.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A self-maintaining, self-diagnostic, and self-unblocking pitot tube control system includes:

[0009] The pitot tube body is equipped with a total pressure port and a static pressure port;

[0010] Pressure / airspeed converter with built-in micro-pressure sensor;

[0011] The total pressure line and static pressure line connect the airspeed tube body to the pressure / airspeed converter.

[0012] The high-pressure air circuit unit includes a miniature air pump, an electrically controlled shut-off valve, and a high-pressure air circuit pressure sensor;

[0013] The main control unit is used to receive total pressure / static pressure data of the pitot tube, determine whether blockage or icing has occurred, and generate control commands.

[0014] The high-pressure gas control unit is electrically connected to the main control unit, receives the control command, and drives the micro gas pump and the electrically controlled shut-off valve to perform the unblocking action.

[0015] The temperature control unit, including a heater and a thermocouple, is located inside the airspeed tube and is electrically connected to the main control unit. It receives the control commands and drives the heater to perform the ice-melting action.

[0016] The main control unit is configured as follows:

[0017] Execute automatic maintenance procedures before or after flight: control the high-pressure gas control unit to disconnect the total pressure line from the pressure / airspeed converter, and control the micro air pump to output high-pressure airflow to the total pressure line in an intermittent pulse manner;

[0018] When an abnormal jump in total pressure data is detected during cruise, an automatic unblocking procedure is executed: the high-pressure gas control unit is controlled to disconnect the total pressure pipeline from the pressure / air speed converter, and the micro air pump is controlled to output high-pressure airflow for unblocking.

[0019] When it is determined that there is an ice blockage, the temperature control unit is controlled to heat and melt the ice, and the high-pressure gas control unit is controlled again to perform high-pressure airflow to clear the blockage.

[0020] After the blockage is cleared, restore the connection between the main pressure line and the micro-pressure sensor.

[0021] Furthermore, the electrically controlled shut-off valve is a normally open valve, which is turned on at low level and turned off at high level. The control system controls the connection and disconnection of the total pressure pipeline and the pressure / air speed converter by switching between high and low levels.

[0022] Furthermore, the micro air pump in the automatic maintenance program operates in a cyclical mode with intermittent start and stop times of 500ms, for a total of 5 cycles; the micro air pump in the automatic unblocking program operates for 100ms per cycle.

[0023] Furthermore, in the automatic unblocking procedure, the control system further compares the pressure value reported by the pressure sensor in the high-pressure gas circuit with the total pressure data from the micro-pressure sensor before the fault:

[0024] If 75%P t0 ≤P t1 ≤125%P t0 P t1 Total pressure data collected after the unblocking procedure; P t0 Based on the total pressure data recorded before the fault, the dredging was deemed successful.

[0025] If P t1 ≥5P t0 If the blockage is due to ice, the temperature control unit should be activated to heat the blockage before proceeding with unblocking.

[0026] Furthermore, the high-pressure gas control unit is connected to the main control unit via an electrical interface, and is used to receive start / stop commands and on / off commands sent by the main control unit, and to report the gas pressure value detected by the high-pressure gas circuit pressure sensor to the main control unit.

[0027] The high-pressure gas control unit is connected to the total pressure pipeline via a gas bypass, the output end of the micro gas pump is connected to the total pressure pipeline via a bypass, and the electrically controlled shut-off valve is connected in series in the total pressure pipeline and is located between the bypass access point and the micro pressure sensor.

[0028] The inlet of the high-pressure gas circuit pressure sensor is connected to the main pressure pipeline and is used to monitor the gas pressure in the pipeline in real time during unblocking.

[0029] Furthermore, the control system includes at least two independently operating pitot tube units, respectively installed on the nose and wing; the main control unit performs the following redundancy management and fault switching procedures:

[0030] Real-time monitoring of the data validity of each pitot tube; if the first pitot tube unit in use does not meet 75% P after completing the automatic unblocking procedure or heating and de-icing procedure. t0 ≤Pt1 ≤125%P t0 P t1 Total pressure data collected after the unblocking procedure; P t0 If the total pressure data was recorded before the fault, the main control unit will automatically switch the airspeed information source to the second airspeed tube unit.

[0031] After switching, periodically attempt to clear the faulty first pitot tube unit and monitor its data validity. Once its validity is restored, decide whether to switch back or keep it on standby.

[0032] Furthermore, the main control unit adopts a weighted fusion architecture, where the fused airspeed V{fusion} is derived by weighting the data from two sources:

[0033] ;

[0034] Wherein, k{nose} is the weighting coefficient of the nose pitot tube, k{wing} is the weighting coefficient of the wing pitot tube, V{nose} is the calculated airspeed of the nose pitot tube, V{wing} is the calculated airspeed of the wing pitot tube, and k{nose}+k{wing}=1. The weighting coefficients are dynamically adjusted according to the operating conditions and confidence level.

[0035] Furthermore, the confidence level is obtained by multiplying multiple factors:

[0036] ;

[0037] C{hardware} represents the hardware self-test status, C{range} represents the confidence level of the data range, and C{rate} represents the confidence level of the rate of change.

[0038] The weighting coefficient k{nose} = C{nose} / {C{nose} + C{wing}}; where k{nose} represents the weighting coefficient of the nose pitot tube, C{nose} represents the confidence level of the nose pitot tube, and C{wing} represents the confidence level of the wing pitot tube.

[0039] The weighting coefficients are then subjected to a first-order low-pass filter to limit the rate of change to within ±0.1 per second.

[0040] Furthermore, the main control unit includes a flight control system.

[0041] Compared with existing technologies, the self-maintenance, self-diagnosis, and self-unblocking pitot tube control system described in this invention has the following advantages:

[0042] (1) No manual maintenance required, which improves system reliability while reducing equipment operating costs;

[0043] (2) It has an airborne self-diagnosis anomaly function, and can handle blockages during cruise without having to make an emergency landing. It has high operational efficiency and high survival rate under sudden severe weather conditions.

[0044] (3) The system only starts short-term high-power de-icing after judging that ice blockage has occurred. The cumulative equivalent working time of the micro air pump during automatic maintenance and automatic unblocking is only in the hundreds of milliseconds, and the overall power consumption of the system is very low.

[0045] (4) It has multiple redundancies, strong survivability, and can ensure the accuracy of data acquisition under different working conditions. Attached Figure Description

[0046] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0047] Figure 1 This is a schematic diagram of the airspeed control system structure provided in Embodiment 1 of the present invention;

[0048] Figure 2 This is a structural diagram of the airspeed tube provided in Embodiment 1 of the present invention;

[0049] Figure 3 This is a schematic diagram of the system control logic provided in Embodiment 1 of the present invention. Detailed Implementation

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0054] Example 1:

[0055] like Figure 1 As shown, this embodiment provides a self-maintaining, self-diagnostic, and self-unblocking pitot tube control system, including a pitot tube body with a total pressure port and a static pressure port; a pressure / pitot converter with a built-in micro-pressure sensor; total pressure lines and static pressure lines connecting the pitot tube body and the pressure / pitot converter; a high-pressure gas circuit unit including a miniature air pump, an electrically controlled shut-off valve, and a high-pressure gas circuit pressure sensor; a main control unit for receiving pitot tube total pressure / static pressure data, determining whether blockage or icing has occurred, and generating control commands; a high-pressure gas control unit electrically connected to the main control unit, receiving the control commands, and driving the miniature air pump and the electrically controlled shut-off valve to perform unblocking actions; and a temperature control unit including a heater and a thermocouple, disposed within the pitot tube body, electrically connected to the main control unit, receiving the control commands, and driving the heater to perform de-icing actions. The main control unit can be an MCU, flight controller, ground station, etc. In this embodiment, the main control unit is a flight controller.

[0056] like Figure 2 As shown, the airspeed tube body is provided with a nose cone 2, a total pressure port 3, a static pressure port 6, a heater 4, a thermocouple 1, an airspeed tube outer tube 5, an airspeed tube seat 7, a heating power supply harness 8, a thermocouple harness 9, a static pressure tube 10, and a total pressure tube 11. The heater and the thermocouple are respectively connected to the temperature control unit through the heating power supply harness 8 and the thermocouple harness 9.

[0057] The control logic of this invention is as follows: Figure 3 As shown, it includes:

[0058] Pre-flight automated maintenance process:

[0059] The system first executes a pre-flight automatic pitot tube maintenance procedure. During this procedure, the high-pressure gas control unit (CACU) sends a high-level control signal to the electrically controlled shut-off valve (the shut-off valve is normally open; a low level signal activates the connection, and a high level signal cuts it off), disconnecting the front section of the pitot tube's total pressure line from the pressure / airspeed transducer to protect the micro-pressure sensor. Then, the CACU sends a start signal to the micro-pump, which operates in a 500ms intermittent cycle, generating pulsed high-pressure airflow to flush the total pressure line five times, thus removing any foreign objects that may have accidentally entered. After the automatic maintenance procedure is complete, the CACU sends a low-level control signal to the electrically controlled shut-off valve, opening the valve and connecting the front section of the total pressure pitot tube to the pressure / airspeed transducer. The pitot tube then enters normal operating mode, accurately acquiring real-time air pressure data from the total pressure port and the side static pressure port. This pressure is then transmitted to the high-precision pressure sensor via the total pressure / static pressure line. The pressure is then processed and corrected by the pressure / airspeed transducer to obtain the airspeed information.

[0060] Automatic dredging process during patrol:

[0061] During aircraft cruise, if the micro-pressure sensor detects an abnormal jump in total pressure—that is, a non-physical abrupt change in the total pressure measurement value within an extremely short sampling interval (e.g., 1-2 control cycles, approximately 20ms-50ms) where the amplitude of the total pressure measurement far exceeds the normal aerodynamic fluctuation range, specifically manifested as a pulse spike, a step-like climb, or a sudden drop—the main control unit determines that there is a foreign object blocking the pitot tube's total pressure port (usually water droplets accumulating at the total pressure port, causing pressure transmission distortion due to the surface tension of the water droplet diaphragm and the adhesion between the water droplet and the tube wall). The system then executes a cruise airspeed test. The automatic pipe clearing procedure begins. At this time, the high-pressure gas control unit (CACU) sends a high-level control signal to the electrically controlled shut-off valve (the shut-off valve is normally open; low level connects, high level disconnects), disconnecting the front section of the airspeed pipe's total pressure line from the pressure / airspeed converter to protect the micro-pressure sensor. Then, the CACU sends a start signal to the micro air pump. The pump operates for 100ms, generating high-pressure airflow to flush the total pressure line. Simultaneously, the pressure sensor in the high-pressure gas line reports the pipe pressure and compares it with the total pressure data from the micro-pressure sensor before the fault. If 75% P... t0 ≤P t1 ≤125%P t0 P t1 Total pressure data collected after the unblocking procedure; P t0 If the total pressure data recorded before the fault is used, it is determined that the blockage has been cleared, the automatic unblocking program is completed, the CACU sends a low-level control signal to the electrically controlled shut-off valve, the shut-off valve opens, the front section of the total pressure airspeed pipeline is connected to the pressure / airspeed converter, and the airspeed pipeline returns to normal operating mode. If the pressure sensor reports a pressure inside the pipe that is much higher than the total pressure data from the micro-pressure sensor before the fault, i.e., P... t1 ≥5P t0If the main pressure port is found to be icing, the temperature control unit will briefly heat the main pressure port to melt the ice. Then, the CACU will send a start signal to the micro air pump. The air pump will work for 100ms to generate high-pressure airflow to flush the main pressure pipeline. The pressure sensor in the maintenance system will report the pressure inside the pipe and compare it with the main pressure data of the micro pressure sensor before the fault. This process will continue until the data is close, at which point the blockage is cleared and the automatic unblocking program is completed. The CACU will then send a low-level control signal to the electronically controlled shut-off valve, which will open the valve and connect the front section of the main pressure airspeed pipeline to the pressure / airspeed converter. The airspeed pipeline will then return to normal working mode.

[0062] Post-flight automated maintenance process:

[0063] After the aircraft lands, the system automatically executes the same automatic maintenance procedures as before the flight to ensure that foreign objects in the airspeed inlet are promptly removed before the aircraft is stored / entered into the hangar.

[0064] In this embodiment, the unblocking control logic is illustrated using a single pitot tube as an example. In practical applications, to avoid single-device failures and ensure measurement accuracy under different operating conditions, this system also supports redundant configuration of multiple pitot tubes. The data fusion and redundancy management methods will be detailed in Embodiment 2.

[0065] Example 2:

[0066] To avoid special cases such as single-device failure and to consider the impact of aerodynamic characteristics of different areas of the aircraft under different operating conditions on airspeed data, a dual-pitot / multi-pitot configuration can be selected during actual installation, meaning at least one pitot tube is installed on the nose and one on each wing. For compound-wing UAVs, the strong downwash and wingtip vortices of the rotor system providing lift during vertical takeoff and landing (VTOL) and transition from VTOL to level flight have a significant impact on the wing pitot tube data. In this case, the data fed back to the flight control system from the nose pitot tube has the primary weight. When the aircraft is circling, because the pitot tubes on the wings are far from the fuselage, a certain turning radius speed difference will occur. In this case, the data fed back to the flight control system from the nose pitot tube has the primary weight. When the data fed back from any one pitot tube is abnormal and cannot be recovered, the data fed back to the flight control system from the other pitot tube has the primary weight.

[0067] In a preferred embodiment, the present invention employs a redundant configuration of dual / multiple pitot tubes, meaning that at least one set of pitot tubes is installed on both the nose and the wing, forming a spatial redundancy layout. Based on this, the flight control system introduces a redundancy management and data fusion calculation mechanism based on data quality assessment, specifically implemented as follows:

[0068] 1. Abnormal data judgment logic

[0069] 1) Physical layer and link layer detection: Monitor the current of the air tube heater, the communication status of the pressure sensor and CRC check, and directly mark it as "isolated" when there is a hardware abnormality;

[0070] 2) Data validity check: Perform range check (whether the airspeed is within the maximum design speed range) and rate of change check (whether the change between adjacent cycles exceeds the physical limit). If it exceeds the threshold, the confidence level is reduced.

[0071] 3) Cross-logic verification: If the difference between the airspeed of the computer head and the airspeed of the wing exceeds a preset threshold (e.g., 5 m / s) and lasts for more than 1 second, the data is considered inconsistent; at the same time, GPS ground speed and attitude information are introduced. Under windless level flight conditions, if the trends of airspeed and ground speed are contrary or the airspeed fluctuates violently while the ground speed is stable, the confidence of the corresponding data source is reduced.

[0072] 2. Redundancy switching and data fusion strategy

[0073] The system does not employ a simple "hard switch," but rather a weighted fusion architecture. The final fused airspeed V{fusion} used in the flight control calculation is derived by weighting the data from the two sources:

[0074]

[0075] Where k{nose} is the weighting coefficient of the nose pitot tube, k{wing} is the weighting coefficient of the wing pitot tube, V{nose} is the calculated airspeed of the nose pitot tube, V{wing} is the calculated airspeed of the wing pitot tube, and k{nose}+k{wing}=1. The weighting coefficients are dynamically adjusted according to the operating conditions and confidence level.

[0076] Vertical takeoff and landing and transition phase: The wing pitot tube is severely affected by the rotor downwash, so k{nose}=0.95 and k{wing}=0.05 are set, with the nose pitot tube being the primary factor;

[0077] Cruise and circling phases: During steady-state cruise, k{nose}=0.6 and k{wing}=0.4 are set; during steep circling, a linear velocity compensation algorithm is introduced. If the difference between the two data streams is still large after compensation, k{nose} is increased to above 0.8.

[0078] Fault switching: When a certain pitot tube is determined to be "isolated", its weight is reduced to zero, and it is 100% taken over by the healthy one.

[0079] 3. Dynamic weight calculation and confidence model

[0080] To avoid control variable oscillations caused by sudden weight changes, the system introduces a confidence level C (ranging from 0 to 1) to smoothly adjust the weights.

[0081] k{nose}=C{nose} / {C{nose}+C{wing}}, where k{nose} represents the weighting coefficient of the nose pitot tube, C{nose} represents the confidence level of the nose pitot tube, and C{wing} represents the confidence level of the wing pitot tube;

[0082] The confidence level is obtained by multiplying multiple factors:

[0083]

[0084] Where C{hardware} represents the hardware self-test status (1 for normal, 0 for abnormal), and C{range} and C{rate} reflect whether the data is within a reasonable range and whether the rate of change is reasonable, respectively.

[0085] Specifically, C{range} represents the confidence level of the data range, which is used to determine whether the airspeed measurement value is within the physically reliable range. The closer it is to the center of the normal flight envelope, the higher the confidence level.

[0086] The method for determining the value is as follows (taking the nose airspeed V{nose} as an example):

[0087] Define the normal flight airspeed range as: [V{min},V{max}], 25m / s~35m / s.

[0088] Define the absolute physical limit range as: [V{abs_min},V{abs_max}], 20m / s~40m / s.

[0089] C{range} uses a piecewise linear function:

[0090] When V ≤ V{abs_min}, C{range} = 0;

[0091] When V{abs_min}<V<V{min}

[0092] C{range}=(VV{abs_min}) / (V{min}-V{abs_min});

[0093] When V{min}≤V≤V{max}, C{range}=1;

[0094] When V{max}<V<V{abs_max}

[0095] C{range}=(V{abs_max}-V) / (V{abs_max}-V{max});

[0096] When V{abs_max} < V, C{range} = 0

[0097] For example:

[0098] V=13m / s→C{range}=0

[0099] V=22m / s→C{range}=(22-20) / (25-20)=0.4

[0100] V=30m / s→C{range}=1

[0101] V=38m / s→C{range}=(40-38) / (40-35)=0.4

[0102] V=41m / s→C{range}=0

[0103] C{rate} represents the confidence level of the rate of change, which is used to check whether the rate of change of air velocity in adjacent cycles (such as 20ms) exceeds the physical limit, and to suppress sudden changes caused by blockages, water accumulation, etc.

[0104] The method for obtaining the value is as follows:

[0105] Formula for calculating rate of change:

[0106] Vr = V(t) / △tV(t-△t) / △t, where V(t) is the airspeed sample value at the current moment, △t is the interval time, and V(t-△t) is the airspeed sample value at the previous moment;

[0107] Define the upper limit of the reasonable rate of change as Vrreasonable = 10 m / s 2

[0108] Define the upper limit of the maximum physical rate of change as Vrmax = 25 m / s 2

[0109] C{rate} uses a piecewise linear function:

[0110] When Vr ≤ Vrreasonable, C{rate} = 1;

[0111] When Vrreasonable<Vr<Vrmax, C{rate}=1-(Vr-Vrreasonable) / (Vrmax-Vrreasonable);

[0112] When Vrmax ≤ Vr, C{rate} = 0;

[0113] For example:

[0114] Vr=5m / s 2 →C{rate}=1

[0115] Vr=19m / s2 →C{rate}=1-(19-10) / (25-10)=0.4

[0116] Vr=28m / s 2 →C{rate}=0.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-maintaining, self-diagnostic, and self-unblocking pitot tube control system, characterized in that: include: The pitot tube body is equipped with a total pressure port and a static pressure port; Pressure / airspeed converter with built-in micro-pressure sensor; The total pressure line and static pressure line connect the airspeed tube body to the pressure / airspeed converter. The high-pressure air circuit unit includes a miniature air pump, an electrically controlled shut-off valve, and a high-pressure air circuit pressure sensor; The main control unit is used to receive total pressure / static pressure data of the pitot tube, determine whether blockage or icing has occurred, and generate control commands. The high-pressure gas control unit is electrically connected to the main control unit, receives the control command, and drives the micro gas pump and the electrically controlled shut-off valve to perform the unblocking action. The temperature control unit, including a heater and a thermocouple, is located inside the airspeed tube and is electrically connected to the main control unit. It receives the control commands and drives the heater to perform the ice-melting action. The main control unit is configured as follows: Execute automatic maintenance procedures before or after flight: control the high-pressure gas control unit to disconnect the total pressure line from the pressure / airspeed converter, and control the micro gas pump to output high-pressure airflow to the total pressure line in an intermittent pulse manner; When an abnormal jump in total pressure data is detected during cruise, an automatic unblocking procedure is executed: the high-pressure gas control unit is controlled to disconnect the total pressure pipeline from the pressure / air speed converter, and the micro air pump is controlled to output high-pressure airflow for unblocking. When it is determined that there is an ice blockage, the temperature control unit is controlled to heat and melt the ice, and the high-pressure gas control unit is controlled again to perform high-pressure airflow to clear the blockage. After the blockage is cleared, restore the connection between the main pressure line and the micro-pressure sensor; The control system includes at least two independently operating pitot tube units, respectively installed on the nose and wing; the main control unit performs the following redundancy management and fault switching procedures: Real-time monitoring of the data validity of each pitot tube; if the first pitot tube unit in use does not meet 75% P after completing the automatic unblocking procedure or heating and de-icing procedure. t0 ≤P t1 ≤125%P t0 P t1 Total pressure data collected after the unblocking procedure; P t0 If the total pressure data was recorded before the fault, the main control unit will automatically switch the airspeed information source to the second airspeed tube unit. After switching, periodically attempt to clear the faulty first pitot tube unit and monitor its data validity. Once its validity is restored, decide whether to switch back or keep it on standby. The main control unit adopts a weighted fusion architecture, and the fused airspeed V{fusion} is obtained by weighting two data streams: ； Wherein, k{nose} is the weighting coefficient of the nose pitot tube, k{wing} is the weighting coefficient of the wing pitot tube, V{nose} is the calculated airspeed of the nose pitot tube, V{wing} is the calculated airspeed of the wing pitot tube, and k{nose}+k{wing}=1. The weighting coefficients are dynamically adjusted according to the operating conditions and confidence level.

2. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: The electrically controlled shut-off valve is a normally open valve, which is turned on when the level is low and turned off when the level is high. The control system controls the on / off of the total pressure pipeline and the pressure / air speed converter by switching between high and low levels.

3. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: The micro air pump in the automatic maintenance program operates in a cycle mode with intermittent start and stop of 500ms each, for a total of 5 cycles; the micro air pump in the automatic unblocking program operates for 100ms per cycle.

4. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: In the automatic unblocking procedure, the control system further compares the pressure value reported by the pressure sensor in the high-pressure gas circuit with the total pressure data from the micro-pressure sensor before the fault: If 75%P t0 ≤P t1 ≤125%P t0 P t1 Total pressure data collected after the unblocking procedure; P t0 Based on the total pressure data recorded before the fault, the dredging was deemed successful. If P t1 ≥5P t0 If the blockage is due to ice, the temperature control unit should be activated to heat the blockage before proceeding with unblocking.

5. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: The high-pressure gas control unit is connected to the main control unit via an electrical interface, and is used to receive start / stop commands and on / off commands sent by the main control unit, and to report the gas pressure value detected by the high-pressure gas circuit pressure sensor to the main control unit. The high-pressure gas control unit is connected to the total pressure pipeline via a gas bypass, the output end of the micro gas pump is connected to the total pressure pipeline via a bypass, and the electrically controlled shut-off valve is connected in series in the total pressure pipeline and is located between the bypass access point and the micro pressure sensor. The inlet of the high-pressure gas circuit pressure sensor is connected to the main pressure pipeline and is used to monitor the gas pressure in the pipeline in real time during unblocking.

6. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: The confidence level is obtained by multiplying multiple factors: ； C{hardware} represents the hardware self-test status, C{range} represents the confidence level of the data range, and C{rate} represents the confidence level of the rate of change. The weighting coefficient k{nose} = C{nose} / {C{nose} + C{wing}}; where k{nose} represents the weighting coefficient of the nose pitot tube, C{nose} represents the confidence level of the nose pitot tube, and C{wing} represents the confidence level of the wing pitot tube. The weighting coefficients are then subjected to a first-order low-pass filter to limit the rate of change to within ±0.1 per second.

7. The self-maintenance, self-diagnosis, and self-unblocking pitot tube control system according to claim 1, characterized in that: The main control unit includes a flight control system.

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