An unmanned aerial vehicle ground launching test system and method

Abstract

The present application relates to a kind of unmanned aerial vehicle ground delivery test system and method, test system includes aircraft model, attitude measurement sensor, electromagnet, counterweight, mounting disc, tower crane, elastic protection rope.Aircraft model is adsorbed on mounting disc by electromagnet, and the lifting of test model is completed by the lifting hook of tower crane;Remote autonomous delivery of aircraft model is realized by remote control to the energization, power-off situation of electromagnet using tower crane platform, and low-altitude delivery test of aircraft model is carried out;By replacing the counterweight of aircraft model tail, the position of model gravity center is adjusted to change longitudinal static stability margin, and by adjusting tail rudder surface deflection angle, longitudinal pitch trim is changed.Attitude measurement sensor data is read, and the influence of longitudinal static stability margin and longitudinal pitch trim on the diving and level flight dynamics characteristics of aircraft model after low-altitude delivery is obtained, to provide design basis for aircraft model diving and level control law.

Description

Technical Field

[0001] This invention belongs to the field of lightweight unmanned aerial vehicles (UAVs) and relates to a UAV ground deployment test system and method. Background Technology

[0002] With the development of aviation technology, the application range of light and small aircraft is becoming increasingly wide. Light and small aircraft have advantages such as small size and high maneuverability, but due to their limited fuel capacity, their endurance and effective combat radius are limited. Therefore, aircraft deployed to target areas and altitudes via drop platforms have emerged. For specific target missions, this type of aircraft generally uses parachutes for stable deployment. Compared to conventional aircraft, parachute-deployed aircraft undergo a unique "parachute descent-dive-level flight" phase during deployment. During this phase, the initial operating attitude of the aircraft has significant uncertainty, which in turn affects the design of the aircraft's control laws. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a ground-launch test system and method for unmanned aerial vehicles (UAVs). By adjusting the position of the center of gravity and the deflection angle of the tail fin, the dynamic characteristics of the aircraft's dive-to-level flight after low-altitude deployment are tested, providing a design basis for the aircraft's dive-to-level control law.

[0004] The solution of the present invention is: a ground deployment test system for unmanned aerial vehicles, including an aircraft model, an attitude measurement sensor, a hoisting mechanism, a crane, and an elastic protective rope, wherein the hoisting mechanism includes an electromagnet, a counterweight, and a mounting plate;

[0005] Attitude measurement sensors are located at the head of the aircraft model to measure and store its motion attitude data, including three-axis acceleration, three-axis angular velocity, and three-axis angle. Counterweights are installed at the tail of the aircraft model to adjust its attitude angles and center of gravity. Electromagnets attract the counterweights and mount them on a mounting plate, allowing the aircraft model to be released remotely. The mounting plate is suspended from a crane hook, which controls the raising and lowering of the aircraft model. An elastic safety rope is attached to the mounting plate at one end and to the tail of the aircraft model at the other to prevent it from touching the ground.

[0006] Furthermore, the electromagnet includes: a DC power supply, a magnetic attraction electromagnet, and a normally closed relay that can be remotely controlled to switch on and off; the normally closed relay is installed between the magnetic attraction electromagnet and the DC power supply.

[0007] Furthermore, the release of the aircraft model via remote-controlled electromagnet specifically involves: remotely de-energizing a normally closed relay on the ground, thereby de-energizing the electromagnet, causing the electromagnetic attraction between the counterweight and the electromagnet to disappear, thus enabling remote-controlled autonomous deployment of the aircraft model.

[0008] Furthermore, the aircraft model is a scaled-down model of the real aircraft, including an external dimension scaled down to a first preset ratio and a mass scaled down to a second preset ratio, ensuring that the wing loading of the aircraft model is the same as that of the real aircraft.

[0009] Furthermore, based on the system described in this invention, a method for conducting ground-based UAV deployment tests is provided, comprising the following steps:

[0010] Step 1: Perform ground operations:

[0011] Step 1.1: On the ground, adjust the rudder deflection angle and static stability margin parameters of the aircraft model. Adjust the initial attitude angle of the aircraft model by selecting counterweights so that the aircraft model reaches the preset attitude. Power on the attitude measurement sensor.

[0012] Step 1.2: Hoist the aircraft model onto the mounting plate using an electromagnet;

[0013] Step 1.3: Determine the length of the elastic protective rope according to the test conditions. Tie the first end of the elastic protective rope to the mounting plate and the last end to the tail of the aircraft model. Adjust the relative position of the aircraft model and the elastic protective rope to ensure that the elastic protective rope is on the side of the fuselage.

[0014] Step 1.4: Suspend the installation plate on the hook of the crane tower;

[0015] Step 2: Perform lifting and lowering operations: Keep the cantilever of the crane at its maximum height, and use the hook to lift the aircraft model to the predetermined height;

[0016] Step 3: Release Operation: After the aircraft model rises to the predetermined altitude, measure and record the wind speed and direction; remotely control the normally closed relay on the ground to de-energize the electromagnet, and the aircraft model begins to be released. During the descent, the aircraft model automatically changes from a dive to level flight; the elastic safety rope holds the aircraft model to prevent it from touching the ground or flying too far and causing damage to surrounding buildings; the attitude measurement sensor measures and stores the motion attitude data of the entire process from power-on to flight stop.

[0017] Step 4: Lower the aircraft model to the ground using a hook, export the motion attitude data from the attitude measurement sensor, and obtain the dynamic characteristics between the static stability margin and the aircraft attitude motion changes during the dive-to-level flight phase after the aircraft model is deployed, as well as the dynamic characteristics between the longitudinal pitch trim and the aircraft attitude motion changes.

[0018] Furthermore, the adjustment method for the rudder deflection angle of the aircraft model described in step 1.1 is as follows: the rudder deflection angle is adjusted by disassembling and reassembling the tail fin and replacing the transition wedge between the tail fin and the aircraft fuselage; the trailing edge of the tail fin...

[0019] Downward, the aircraft's pitch trim angle of attack decreases; upward, the tail fin's trailing edge increases the aircraft's pitch trim angle of attack.

[0020] Furthermore, the specific method for adjusting the static stability margin of the aircraft model in step 1.1 is as follows: different counterweights have different weights. By replacing the counterweights with heavier ones, the center of gravity of the aircraft is shifted backward, thereby reducing the static stability margin of the aircraft; by replacing the counterweights with lighter ones, the center of gravity of the aircraft is shifted forward, thereby increasing the static stability margin.

[0021] Static stability margin of large aircraft.

[0022] Furthermore, the method for adjusting the initial attitude angle of the aircraft model in step 1.1 is as follows: the counterweight has different oblique surfaces, and the initial attitude angle of the aircraft is adjusted by replacing the counterweight with different oblique surfaces and attracting it with the electromagnet.

[0023] 5. Furthermore, for each test, step 1.1 adjusts the rudder deflection angle, static stability margin, or initial attitude angle individually by controlling variables.

[0024] The advantages of this invention compared to the prior art are:

[0025] (1) The experimental model of this invention can achieve different static stability margins and rudder deflection angles by disassembling and assembling components.

[0026] The setup facilitates the adjustment of test conditions; and the deployment test only requires simple test fixtures and a scaled-down aircraft model, making the test method simple and the cost low.

[0027] (2) The present invention uses an electromagnet to connect the aircraft and the mounting plate. The power on and power off of the electromagnet is remotely controlled by a relay, so as to realize the remote autonomous deployment of the aircraft. The control method is simple and reliable.

[0028] (3) This invention adjusts the center of gravity by replacing the counterweight and adjusts the longitudinal pitching moment by adjusting the tail fin deflection angle. After the drop test, the sensor data is read and the trend of change is analyzed to achieve the goal of testing the dynamic characteristics of the aircraft's dive-to-level flight after low-altitude drop, and to provide a design basis for the aircraft's dive-to-level control law. Attached Figure Description

[0029] Figure 1 This is a connection diagram of the UAV ground deployment test system according to an embodiment of the present invention. Detailed Implementation

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] like Figure 1As shown, a ground deployment test system for unmanned aerial vehicles (UAVs) is characterized by comprising an aircraft model 1, an attitude measurement sensor 2, a hoisting mechanism, a crane 6, and an elastic protective rope 7. The hoisting mechanism includes an electromagnet 3, a counterweight 4, and a mounting plate 5.

[0032] Attitude measurement sensor 2 is located at the head of aircraft model 1 and is used to measure and store the motion attitude data of aircraft model 1, including three-axis acceleration, three-axis angular velocity, and three-axis angle. Counterweight 4 is installed at the tail of aircraft model 1 and is used to adjust the attitude angle and center of gravity position of aircraft model 1. Electromagnet 3 attracts counterweight 4 and is installed on mounting plate 5. The aircraft model 1 is released by remote control of electromagnet 3. Mounting plate 5 is suspended on hook of crane tower 6 and the crane tower 6 completes the lifting and lowering of aircraft model 1. The first end of elastic protective rope 7 is tied to mounting plate 5 and the second end is tied to the tail of aircraft model 1 to prevent aircraft model 1 from touching the ground.

[0033] In this embodiment, the aircraft model 1 has the ability to adjust attitude angle, rudder deflection angle, and static stability margin parameters. Specifically, the initial attitude angle of the aircraft model 1 is adjusted by replacing the counterweights 4 with different oblique sections and their attraction to the electromagnet 3. The rudder deflection angle is adjusted by removing and installing the tail fin and replacing the transition wedge between the tail fin and the aircraft fuselage; a downward-pointing tail fin reduces the pitch trim angle of attack, while an upward-pointing tail fin increases the pitch trim angle of attack. The static stability margin is adjusted by using different counterweights 4 with different weights; replacing them with heavier counterweights shifts the aircraft's center of gravity rearward, thus reducing the static stability margin; replacing them with lighter counterweights shifts the aircraft's center of gravity forward, thus increasing the static stability margin.

[0034] In this embodiment, the aircraft model 1 is a scaled-down model of the real aircraft, including a scaled-down external size and a scaled-down mass, to ensure that the wing loading of the aircraft model is the same as that of the real aircraft.

[0035] In this embodiment, electromagnet 3 includes: a 48V DC power supply, a 48V / 200kg suction electromagnet, and a 48V normally closed relay that can be remotely controlled to switch on and off. The normally closed relay is installed between the 48V / 200kg suction electromagnet and the 48V DC power supply. By remotely de-energizing the normally closed relay from the ground, the electromagnet 3 is de-energized, and the electromagnetic attraction between the counterweight 4 and the electromagnet 3 is lost, thus enabling remote-controlled autonomous deployment of the aircraft model 1.

[0036] Using the UAV ground deployment test system described in this invention, a UAV ground deployment test is conducted, including the following steps:

[0037] S1. Conduct ground operations:

[0038] S1.1 Adjust the state of aircraft model 1 on the ground to 0° tail rudder deflection angle; select the flat-section counterweight 4 to adjust the initial pitch attitude angle of aircraft model 1 to -90°; the mass of counterweight 4 is m1kg, and the longitudinal static stability margin of aircraft model 1 is 15%; energize attitude measurement sensor 2.

[0039] S1.2 The aircraft model 1 is hoisted onto the mounting plate 5 by electromagnet 3;

[0040] S1.3. Based on the deployment height, the length of the elastic protective rope 7 is determined to be 60m. The first end of the elastic protective rope 7 is tied to the mounting plate 5, and the tail end is tied to the tail of the aircraft model 1. Adjust the relative position of the aircraft model 1 and the elastic protective rope 7 to ensure that the elastic protective rope 7 is on the side of the fuselage.

[0041] S1.4 Suspend the mounting plate 5 on the hook of the crane 6.

[0042] S2. Perform lifting operation: Keep the cantilever of the crane 6 at its maximum height and lift the aircraft model 1 to a height of 100m using the hook.

[0043] S3. Perform the release operation: After the aircraft model 1 rises to a height of 100m, measure and record the wind speed and wind direction; remotely control the normally closed relay on the ground to de-energize the electromagnet 3, and the aircraft model 1 begins to be released. During the descent, the aircraft model 1 automatically changes from a dive to level flight; the elastic protective rope 7 holds the aircraft model 1 to prevent it from touching the ground or flying too far and causing damage to surrounding buildings; the attitude measurement sensor 2 measures and stores the motion attitude data of the entire process from power-on to the stop of flight.

[0044] S4. Lower the aircraft model 1 to the ground using the hook and export the motion attitude data of the attitude measurement sensor 2;

[0045] S5. Adjust test conditions: Select a larger mass m2kg and a flat-section counterweight 4, adjust the longitudinal static stability margin of aircraft model 1 to 10%, keep the tail rudder deflection angle of aircraft model 1 at 0°, and the initial pitch attitude angle at -90°, and repeat the above operations S1.2 to S4.

[0046] S6. Comparative Analysis: By analyzing the motion attitude data of aircraft model 1 during dive-to-level flight under different longitudinal static stability margin conditions, it can be determined that the smaller the longitudinal static stability margin, the greater the pitch angular velocity of aircraft model 1 during flight, the shorter the time required to change from dive to level flight, and the greater the vertical overload on the aircraft body during the leveling process.

[0047] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for ground-based deployment testing of unmanned aerial vehicles (UAVs), characterized in that, The method is based on a UAV ground deployment test system, which includes an aircraft model (1), an attitude measurement sensor (2), a hoisting mechanism, a crane (6), and an elastic protective rope (7). The hoisting mechanism includes an electromagnet (3), a counterweight (4), and a mounting plate (5). The attitude measurement sensor (2) is located at the head of the aircraft model (1) and is used to measure and store the motion attitude data of the aircraft model (1), including three-axis acceleration, three-axis angular velocity and three-axis angle; the counterweight (4) is installed at the tail of the aircraft model (1) and is used to adjust the attitude angle and center of gravity of the aircraft model (1); the electromagnet (3) attracts the counterweight (4) and is installed on the mounting plate (5), and the aircraft model (1) is released by remote control of the electromagnet (3); the mounting plate (5) is suspended on the hook of the crane (6) and the aircraft model (1) is raised and lowered by the hook of the crane (6); the elastic protective rope (7) is tied to the mounting plate (5) at the head and to the tail of the aircraft model (1) at the tail to prevent the aircraft model (1) from touching the ground; The method includes the following steps: Step 1: Perform ground operations: Step 1.1: On the ground, adjust the rudder deflection angle and static stability margin parameters of the aircraft model (1). Adjust the initial attitude angle of the aircraft model (1) by selecting the counterweight (4) so ​​that the aircraft model (1) reaches the preset attitude. Then, power on the attitude measurement sensor (2). Step 1.2: The aircraft model (1) is attached to the mounting plate (5) by electromagnet (3); Step 1.3: Determine the length of the elastic protective rope (7) according to the test conditions. Tie the first end of the elastic protective rope (7) to the mounting plate (5) and the tail end to the tail of the aircraft model (1). Adjust the relative position of the aircraft model (1) and the elastic protective rope (7) to ensure that the elastic protective rope (7) is on the side of the fuselage. Step 1.4: Suspend the installation plate (5) on the hook of the crane tower (6); Step 2, Perform lifting operation: Keep the cantilever of the crane (6) at its maximum height, and lift the aircraft model (1) to the predetermined height using the hook; Step 3, release operation: After the aircraft model (1) rises to the predetermined height, measure and record the wind speed and wind direction; remotely control the normally closed relay on the ground to de-energize the electromagnet (3), and the aircraft model (1) begins to be released. During the descent, the aircraft model (1) automatically changes from a dive to level flight; the elastic protective rope (7) holds the aircraft model (1) to prevent it from touching the ground or flying too far and causing damage to surrounding buildings; the attitude measurement sensor (2) measures and stores the motion attitude data of the entire process from power-on to flight stop. Step 4: Lower the aircraft model (1) to the ground using a hook, export the motion attitude data of the attitude measurement sensor (2), and obtain the dynamic characteristics between the static stability margin and the change in attitude motion of the aircraft model (1) during the dive-to-level flight phase after deployment, as well as the dynamic characteristics between the longitudinal pitch trim and the change in attitude motion of the aircraft.

2. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, The specific method for adjusting the rudder deflection angle of the aircraft model (1) described in step 1.1 is as follows: the tail wing rudder deflection angle is adjusted by disassembling and assembling the tail wing and replacing the transition wedge between the tail wing and the aircraft fuselage; when the trailing edge of the tail wing is downward, the pitch trim angle of attack of the aircraft decreases; when the trailing edge of the tail wing is upward, the pitch trim angle of attack of the aircraft increases.

3. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, Step 1.1 The method for adjusting the static stability margin of the aircraft model (1) is as follows: different counterweights (4) have different weights. By replacing the heavier counterweights (4), the center of gravity of the aircraft is moved backward, thereby reducing the static stability margin of the aircraft; by replacing the lighter counterweights (4), the center of gravity of the aircraft is moved forward, thereby increasing the static stability margin of the aircraft.

4. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, The method of adjusting the initial attitude angle of the aircraft model (1) in step 1.1 is as follows: the counterweight (4) has different oblique surfaces, and the initial attitude angle of the aircraft is adjusted by replacing the counterweight (4) with different oblique surfaces and attracting it to the electromagnet (3).

5. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, For each test, step 1.1 involves individually adjusting the rudder deflection angle, static stability margin, or initial attitude angle by controlling variables.

6. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, The electromagnet (3) includes: a DC power supply, a magnetic electromagnet, and a normally closed relay that can be remotely controlled to switch on and off; the normally closed relay is installed between the magnetic electromagnet and the DC power supply.

7. The method for ground deployment testing of unmanned aerial vehicles according to claim 6, characterized in that, The release of the aircraft model (1) by remote control electromagnet (3) is specifically achieved by: remotely controlling the normally closed relay to de-energize on the ground, thereby controlling the electromagnet (3) to de-energize, and the electromagnetic attraction between the counterweight (4) and the electromagnet (3) is lost, so as to realize the remote control autonomous release of the aircraft model (1).

8. The method for ground deployment testing of unmanned aerial vehicles according to claim 1, characterized in that, The aircraft model (1) is a scaled-down model of the real aircraft, including a first preset scaled-down ratio for external dimensions and a second preset scaled-down ratio for mass, to ensure that the wing loading of the aircraft model is the same as that of the real aircraft.

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