A real-time sensing system and method for normal force / pitch moment of aircraft

Abstract

This invention discloses a real-time sensing system and method for the normal force / pitch moment of an aircraft. The real-time sensing system includes a wing pressure measurement module, a power supply module, an aerodynamic intelligent sensing module, and a wireless signal transmission module. The real-time sensing method includes steps such as obtaining the pressure at specific sparse points along the wingspan in the leeward region of the aircraft, solving for the aircraft's normal force and pitch moment, estimating the aircraft's acceleration and comparing it with experimental data, determining whether the aircraft is at risk of stall or pitch oscillation, and sending the calculation and hazard prediction results to the flight control center. The real-time sensing system and method disclosed in this invention have the capabilities of autonomous measurement, self-calculation, and autonomous early warning. It can predict the aircraft's motion trend in a timely manner when the aircraft is subjected to sudden gusts of wind, issuing warning signals to the pilot (flashing lights and warning sounds) or providing aerodynamic status and control feedback information to the flight control center.

Description

Technical Field

[0001] This invention belongs to the field of artificial intelligence aircraft design technology, specifically a real-time sensing system and method for normal force / pitch moment of an aircraft. Background Technology

[0002] At high angles of attack, the complex flow around an aircraft can lead to uncontrolled motions, severely impacting its maneuverability and flight safety. To accurately control attitude during high-maneuverability, high angle-of-attack flight and anticipate dangerous flight conditions, precise aerodynamic models at high angles of attack are required. However, existing airborne equipment based on inertial components cannot directly provide unsteady aerodynamic parameters, often resulting in errors and time delays in the measurement and control system response, leading to serious consequences.

[0003] With the increasing demand for high-performance, stealthy unmanned aerial vehicles (UAVs), the traditional sensing devices and flight control systems on manned aircraft can no longer meet the requirements. Although computers can process data faster and react in less time than the human brain, UAV flight control systems rely more heavily on high-precision, high-reliability sensing devices and control algorithms. Extensive numerical simulations, modeling, and wind tunnel testing are needed to build a database and validate the sensing system and control algorithms, thereby providing a technical basis for UAVs to perceive flow fields, attitudes, and predict motion under extreme flight conditions.

[0004] Currently, there are few intelligent sensing methods for aerodynamic forces / torques during aircraft flight, and research in this area is still in its early stages. For example, Chinese invention patent application CN111156995A discloses an intelligent aircraft and flight method based on flight state perception. However, this method only determines the aircraft's roll torque and its motion trend, without addressing intelligent sensing systems and methods for aerodynamic forces / torques in other directions. There are still aspects that need improvement and unresolved issues. Therefore, improving intelligent aerodynamic sensing systems and methods for aircraft is beneficial for ensuring the safety of aircraft flying at high angles of attack. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a real-time sensing system and method for normal force / pitch moment of aircraft, which can improve the intelligent sensing and hazard warning capabilities of aircraft aerodynamic force / moment.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A real-time sensing system for normal force / pitch moment of an aircraft includes a wing pressure measurement module, a power supply module, an aerodynamic intelligent sensing module, and a wireless signal transmission module;

[0008] The wing pressure measurement module is used to collect pressure signals at specific sparse points along the wingspan in the leeward region of the aircraft and convert them into digital signals in real time, which are then transmitted to the aerodynamic intelligent sensing module for processing.

[0009] The power supply module includes a lithium battery for power supply and power wiring;

[0010] The aerodynamic intelligent sensing module includes a computing center and an output terminal. The computing center processes and calculates the digital signals received from the wing pressure measurement module in real time, compares them with the extreme state results in the database, and calculates the aircraft's normal force / pitch moment in real time through the output terminal. Based on the wireless signal transmission module, it provides safety warning signals to the pilot or provides real-time normal force / pitch moment information to the UAV flight control system.

[0011] Furthermore, the aircraft is a fixed-wing aircraft.

[0012] Furthermore, the aircraft's wings can be configured in a conventional, canard, or delta wing layout.

[0013] Furthermore, the wing pressure measurement module can be used alone or in combination.

[0014] Furthermore, the wing pressure measurement module is installed inside the aircraft by mechanical fixation or adhesive bonding.

[0015] Furthermore, the wing pressure measurement module uses a surface aperture pressure sensor or an optical pressure sensor to measure the pressure signal at a specific sparse point location.

[0016] The real-time sensing method for normal force / pitch moment of an aircraft based on the above system includes the following steps:

[0017] Step 1) Obtain pressure information at specific sparse points in the leeward region of the aircraft based on the wing pressure measurement module, and measure the current airspeed, flight status and flow around the aircraft.

[0018] Step 2) The digital signal converted by the wing pressure measurement module is transmitted to the aerodynamic intelligent sensing module to solve for the normal force and pitching moment of the aircraft. The acceleration of the aircraft motion is estimated based on the force state and compared with the database and danger threshold obtained from the wind tunnel test to determine whether the aircraft has stall and pitch oscillation danger under high angle of attack flight conditions.

[0019] Step 3) The aerodynamic calculation results and hazard prediction results of the aerodynamic intelligent sensing module are sent to the flight control center through the wireless signal transmission module to ensure flight safety.

[0020] Furthermore, in step 2), the digital signal is combined with the local reference area s of the specific sparse pressure measurement point on the surface corresponding to each pressure sensor and the distance b from the specific sparse point to the torque reference point to calculate the normal force F of the aircraft. N And pitching moment M;

[0021] The specific representation of the aircraft's normal force / pitch moment state is as follows:

[0022]

[0023]

[0024] Where, p i s represents the surface pressure at a specific sparse point location along the wingspan in the leeward region of an aircraft. i denoted by , where b represents the local reference area of ​​the corresponding sparse pressure measurement point, and b represents the distance from the sparse point location to the torque reference point.

[0025] Furthermore, in step 2), estimating the acceleration of the aircraft includes estimating the normal acceleration and pitch acceleration of the aircraft. Specifically, this is achieved by integrating the surface pressure at a specific sparse point along the wingspan in the leeward region of the aircraft to obtain the normal force F. N The real-time solution process for the pitch moment M, the normal acceleration of the aircraft, and the pitch angular acceleration is expressed as follows:

[0026]

[0027]

[0028] in, Let a be the normal acceleration of the aircraft. M For pitch acceleration, K M Here, m and J are the calibration coefficients, and m and J are the mass of the aircraft and the pitch inertia about the moment reference point, respectively.

[0029] Furthermore, in step 3), the aerodynamic calculation results and hazard prediction results of the aerodynamic intelligent sensing module are sent to the flight control center through the wireless signal transmission module. This includes providing timely warning signals to the pilot through the wireless signal transmission module, or generating feedback information and transmitting it to the UAV control center to adjust the aircraft's angle of attack and airspeed.

[0030] The present invention discloses a real-time sensing system and method for normal force / pitch moment of aircraft, which has the ability to autonomously measure, calculate and warn, and predict the flight trend of the aircraft in a timely manner when the aircraft is subjected to sudden gusts of wind, and issue warning signals (flashing light and warning sound) to the pilot or provide aerodynamic status and control feedback information to the flight control center. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the aircraft and the pressure measurement location of a specific sparse point in the leeward region in one embodiment of the present invention;

[0032] Figure 2 This is a flowchart of a real-time sensing system for normal force / pitch moment of an aircraft according to the present invention;

[0033] Figure 3 This is an experimental result diagram comparing the normal force obtained by surface pressure integration sensing with the force measured by a balance in one embodiment of the present invention.

[0034] Figure 4 This is an experimental result diagram comparing the pitching moment obtained by surface pressure integration sensing with the force measured by a balance in one embodiment of the present invention. Detailed Implementation

[0035] The following detailed description, in conjunction with the accompanying drawings, provides a method for real-time sensing of fluid thrust vector nozzle jet vector characteristics based on wall pressure information, as proposed in this invention. In this description, it should be understood that terms such as "left side," "right side," "upper part," "lower part," and "bottom," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for ease of description and simplification, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Sidewalls, inclined Coanda walls, etc., do not represent limitations on this invention. The specific dimensions and wall arrangement schemes used in this example are merely illustrative of the technical solution and do not limit the scope of protection of this invention.

[0036] like Figure 1 and Figure 2 As shown, this invention discloses a real-time sensing system and method for aircraft normal force / pitch moment based on surface pressure information, including a wing pressure measurement module, a power supply module, an aerodynamic intelligent sensing module, and a wireless signal transmission module.

[0037] The wing pressure measurement module has independent data acquisition, piezoelectric conversion, and transmission functions, and can be used alone or in combination. It can be installed inside the aircraft via mechanical fixing or adhesive bonding. The aircraft in this embodiment is generally a fixed-wing aircraft, including conventional, canard, and delta wing configurations.

[0038] The measurement module includes a certain number of surface-hole pressure sensors or optical pressure sensors and an embedded processor. Based on these sensors, pressure signals at specific sparse point locations are measured. The embedded processor converts the pressure signals into digital signals. In this embodiment, surface-hole pressure sensors are preferred to measure pressure signals under different angles of attack.

[0039] like Figure 1 As shown, the pressure sensors included in the wing pressure measurement module are distributed and installed at specific sparse points 1 along the wingspan in the leeward region of the aircraft. After piezoelectric conversion, the signals are transmitted to the aerodynamic intelligent sensing module for processing. The aerodynamic intelligent sensing module combines other atmospheric parameters to process and calculate the received digital signals in real time, compares them with the extreme state results in the database, and calculates the aircraft's normal force / pitch moment in real time through the output terminal. Based on the wireless signal transmission module, it provides a safety warning signal to the pilot or provides real-time normal force / pitch moment data to the UAV flight control system.

[0040] This invention also discloses a real-time sensing method for the normal force / pitch moment of an aircraft based on surface pressure information, the steps of which are as follows:

[0041] Step 1) Obtain the pressure p at a specific sparse point location along the wingspan in the leeward region of the aircraft using the wing pressure module. i And convert it into a digital signal;

[0042] Step 2) Transmit the digital signal to the aerodynamic intelligent sensing module, and combine it with the local reference area p of the sparse pressure measurement points corresponding to each pressure sensor already input into the system. i Calculate the normal force F acting on the aircraft respectively. N And the pitching moment M, the formula is:

[0043]

[0044]

[0045] Where, p i The surface pressure at a specific sparse point location along the wingspan in the leeward region of the aircraft is measured by the aforementioned wing pressure module; s i 'b' represents the local reference area of ​​the corresponding sparse pressure measurement point, determined during ground installation; 'b' represents the distance from the sparse point location to the torque reference point, determined during ground installation.

[0046] Step 3) The aerodynamic calculation results and hazard prediction results of the aerodynamic intelligent sensing module are sent to the flight control center through the wireless signal transmission module to ensure flight safety.

[0047] Using formulas (1) and (2), the normal force and pitch moment of the aircraft based on surface pressure measurement can be obtained by integration. Then, the real-time normal acceleration and pitch acceleration can be solved using the following formulas:

[0048] Based on the calculated normal force and pitch moment of the aircraft, the real-time normal acceleration is then calculated. and pitch acceleration a M The formula is:

[0049]

[0050]

[0051] in, Let a be the normal acceleration of the aircraft. M It is the pitch acceleration; K M The calibration coefficients are obtained through wind tunnel testing; m and J are the mass of the aircraft and the pitch inertia about the moment reference point, respectively, obtained through wind tunnel testing.

[0052] The real-time calculated normal acceleration of the aircraft and pitch acceleration a M With the pre-stored safety normal motion acceleration in the aerodynamic intelligent sensing module and safe pitch acceleration a M，sfae Comparison. Among them, the safe normal acceleration. and safe pitch acceleration a M，sfae The data is obtained through wind tunnel testing and calibration, pre-entered into the aerodynamic intelligent sensing module, and adjusted in a timely manner according to the actual condition of the aircraft.

[0053] If the normal acceleration of the aircraft and pitch acceleration a M One or two of them are greater than the safe normal acceleration. and safe pitch acceleration a M，sfae ,Right now or a M >a M，sfae The aerodynamic intelligent sensing module sends a warning signal through a wireless signal transmission module. In manned aircraft mode, the warning signal produces a red flashing light on the cockpit instrument panel and emits a warning sound, prompting the pilot to control the angle of attack and airspeed. In unmanned aircraft mode, the warning signal is used to generate a control signal, and the airspeed and attitude angle of the aircraft are continuously adjusted based on the aerodynamic sensing results.

[0054] like Figure 3 and 4The figure shown is an experimental result diagram comparing the normal force coefficient and pitching moment coefficient obtained by surface pressure measurement with the normal force coefficient and pitching moment coefficient obtained by balance force measurement. This is used to calibrate the feasibility of the aerodynamic force and moment sensing method of this system on the ground.

[0055] The normal force coefficient of the aircraft, obtained by solving the surface pressure information using the above formula (1), is: Figure 3 The curve marked with a semi-solid diamond. Simultaneously, in the ground wind tunnel calibration test, the actual normal force coefficient of the aircraft model was measured using a lever balance, i.e., the curve marked with a semi-solid square. It can be seen that the trends of the two are consistent, their amplitudes are similar, and their correlation coefficient is as high as 0.99.

[0056] The pitching moment coefficient of the aircraft, obtained by solving the surface pressure information using the above formula (2), is: Figure 4 The curve marked with a solid diamond. Simultaneously, in the ground wind tunnel calibration test, the actual pitch moment coefficient of the aircraft model was also measured using a lever balance, i.e., the curve marked with a solid square. It can be seen that the trends of the two are consistent, their amplitudes are similar, and their correlation coefficient is as high as 0.96.

[0057] Aerodynamic sensing results based on surface pressure information Correlation coefficient Sensing normal force and force measurement results from balance 0.99 Sensing pitch moment and balance force measurement results 0.96

[0058] Therefore, the normal force and pitch moment of an aircraft based on surface pressure measurements can be used to solve for the normal motion acceleration and pitch moment acceleration, which can be used for safety early warning.

[0059] Based on the description of preferred embodiments of the present invention, it should be clear that the present invention as defined by the appended claims is not limited to the specific details set forth in the above description, and many obvious modifications to the present invention without departing from its spirit or scope may also achieve the purpose of the present invention.

Claims

1. A method for real-time sensing of normal force / pitch moment of an aircraft, characterized in that, Includes the following steps: Step 1) Obtain pressure information at specific sparse points in the leeward region of the aircraft based on the wing pressure measurement module, and measure the current airspeed, flight status and flow around the aircraft. Step 2) The digital signal converted by the wing pressure measurement module is transmitted to the aerodynamic intelligent sensing module to solve for the normal force and pitching moment of the aircraft. The acceleration of the aircraft motion is estimated based on the force state and compared with the database and danger threshold obtained from the wind tunnel test to determine whether the aircraft has stall and pitch oscillation danger under high angle of attack flight conditions. Step 3) The aerodynamic calculation results and hazard prediction results of the aerodynamic intelligent sensing module are sent to the flight control center through the wireless signal transmission module to ensure flight safety; In step 2), the digital signal is combined with the local reference area s of the specific sparse pressure measurement point on the surface corresponding to each pressure sensor and the distance b from the specific sparse point to the torque reference point to calculate the normal force F of the aircraft. N And pitching moment M; The specific representation of the aircraft's normal force / pitch moment state is as follows: Where, p i s represents the surface pressure at a specific sparse point location along the wingspan in the leeward region of an aircraft. i denoted by , where b represents the local reference area of ​​the corresponding sparse pressure measurement point, and b represents the distance from the sparse point location to the torque reference point. Step 2) involves estimating the acceleration of the aircraft's motion, including estimating the normal acceleration and pitch acceleration. Specifically, this is achieved by integrating the surface pressure at a specific sparse point along the wingspan in the leeward region of the aircraft to obtain the normal force F. N The real-time solution process for the pitch moment M, the normal acceleration of the aircraft, and the pitch angular acceleration is expressed as follows: in, Let a be the normal acceleration of the aircraft. M For pitch acceleration, K M Here, m and J are the calibration coefficients, and m and J are the mass of the aircraft and the pitch inertia about the moment reference point, respectively.

2. The real-time sensing method for normal force / pitch moment of an aircraft according to claim 1, characterized in that, In step 3), the aerodynamic calculation results and hazard prediction results of the aerodynamic intelligent sensing module are sent to the flight control center through the wireless signal transmission module. This includes providing the pilot with timely warning signals or generating feedback information through the wireless signal transmission module, and transmitting it to the UAV control center to adjust the aircraft's angle of attack and airspeed.

3. A system for the real-time sensing method of normal force / pitch moment as described in claim 1 or 2, characterized in that, It includes a wing pressure measurement module, a power supply module, an aerodynamic intelligent sensing module, and a wireless signal transmission module; The wing pressure measurement module is used to collect pressure signals at specific sparse points along the wingspan in the leeward region of the aircraft and convert them into digital signals in real time, which are then transmitted to the aerodynamic intelligent sensing module for processing. The power supply module includes a lithium battery for power supply and power wiring; The aerodynamic intelligent sensing module includes a computing center and an output terminal. The computing center processes and calculates the digital signals received from the wing pressure measurement module in real time, compares them with the extreme state results in the database, and calculates the aircraft's normal force / pitch moment in real time through the output terminal. Based on the wireless signal transmission module, it provides safety warning signals to the pilot or provides real-time normal force / pitch moment information to the UAV flight control system.

4. The system for real-time sensing of normal force / pitch moment according to claim 3, characterized in that, The aircraft is a fixed-wing aircraft.

5. The system for real-time sensing of normal force / pitch moment according to claim 4, characterized in that, The aircraft's wings can be configured in a conventional, canard, or delta wing layout.

6. The system for real-time sensing of normal force / pitch moment according to claim 3, characterized in that, The wing pressure measurement module can be used alone or in combination.

7. The system for real-time sensing of normal force / pitch moment according to claim 3, characterized in that, The wing pressure measurement module is installed inside the aircraft by mechanical fixation or adhesive bonding.

8. The system for real-time sensing of normal force / pitch moment according to claim 3, characterized in that, The wing pressure measurement module uses a surface-hole pressure sensor or an optical pressure sensor to measure the pressure signal at a specific sparse point location.

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