An outdoor cold environment-based unmanned helicopter snow blindness test method

Abstract

The present application provides a kind of unmanned helicopter snow blindness test method based on outdoor cold environment, belong to the field of helicopter flight test.The purpose is to solve the existing domestic in the field of helicopter snow field flight and snow blindness technology related research blank problem.The present application includes the following steps:S1 select the test environment and test site that meet the test conditions;S2 determine the flight operating condition of test safety;S3 test flight drill;S4 after determining the flight trajectory of unmanned helicopter in test site, install the equipment used for test;S5 unmanned helicopter flight pre-check;S6 measure the physical properties of snow in test site;S7 according to the determined flight operating condition, carry out test;S8 test end;S9 after end parameter measurement;S10 after test measurement equipment arrangement;S11 analysis recorded data.Through the present application, the influence characteristics of helicopter in snow field flight and snow blindness phenomenon can be studied in depth, and the domestic in the field of helicopter snow field flight and snow blindness technology related research blank is filled.

Description

Technical Field

[0001] This invention relates to flight testing technology, and more particularly to a snow blindness test method for unmanned helicopters based on outdoor cold environments, belonging to the field of helicopter flight testing. Background Technology

[0002] With the continuous development of the aviation industry, helicopters, thanks to their unique flight performance, are widely used in many special scenarios, including polar regions and other snow-covered areas. When helicopters take off, land, hover, or fly close to the ground in polar or other snow-covered environments, the rotor and ground interference create a complex, unsteady flow field. Under the influence of this complex flow field, the downwash generated by the rotor rapidly picks up snow particles from near the rotor, causing snow blindness. Once snow blindness occurs, the most direct consequence is a significant reduction in visibility outside the cockpit, severely obstructing the pilot's vision and preventing them from accurately judging their position on the ground, greatly affecting flight safety and accuracy.

[0003] At the same time, helicopter engine intake system components also face the problem of snow accumulation in snowy environments. When the snow accumulates to a certain extent, it will inevitably have a negative impact on the engine's intake function, thereby disrupting the engine's normal operation and posing a serious threat to helicopter flight safety.

[0004] Given the significant impact of helicopter flight in snowy areas and snow blindness on flight safety, in-depth research into the characteristics of these effects is of paramount importance. Summary of the Invention

[0005] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] In view of this, in order to address the current research gap in the field of helicopter snow flight and snow blindness technology in China, this invention provides a snow blindness test method for unmanned helicopters based on outdoor cold environments.

[0007] The technical solution of this invention is a snow blindness test method for unmanned helicopters based on outdoor cold environments, specifically including the following steps:

[0008] S1. Select a test environment and test site that meet the test conditions;

[0009] S2. Determine safe flight conditions for the test based on the performance of the unmanned helicopter and the limitations of the test environment and test site;

[0010] S3. The unmanned helicopter operator must conduct test flights on a snow-free ground according to the determined flight conditions; and determine whether the existing snow on the test site meets the test requirements to be blown up by the rotor downwash airflow to form a snow blind scenario. If the snow condition meets the test requirements, proceed directly to step S4; if the existing natural snow does not meet the test requirements, measures must be taken to make the ground snow cover meet the test requirements.

[0011] S4. After determining the flight path of the unmanned helicopter at the test site, install the equipment used for the test;

[0012] S5. Conduct pre-flight checks for unmanned helicopters;

[0013] S6. Measure the physical properties of snow accumulation at the test site;

[0014] S7. Conduct tests based on the determined flight conditions;

[0015] S8. After a single vehicle test is completed, ensure that the unmanned helicopter stops power output and check the status of the unmanned helicopter;

[0016] S9. Measure the snow parameters at the test site again and record the impact of the unmanned helicopter flight on the snow changes;

[0017] S10. Confirm if there are any remaining tests for the day; if there are remaining tests for the day, proceed to S5; if all tests are completed for the day, collect all measuring equipment used in the tests and store them indoors, and perform anti-corrosion treatment on the unmanned helicopter;

[0018] S11. Analyze the recorded data to assess the impact of meteorological environment, ground snow accumulation parameters, unmanned helicopter takeoff weight, and flight conditions on the severity of snow blindness.

[0019] Furthermore, the flight conditions described in S2 include the unmanned helicopter's takeoff weight, flight trajectory, flight altitude, horizontal speed, vertical speed, and flight and hovering time.

[0020] Furthermore, if the existing natural snow cover at the test site described in S3 cannot meet the requirements for the snow blindness test, the following measures must be taken:

[0021] Physical methods to loosen the snow layer: using mechanical equipment to directly act on the snow layer to loosen it through physical means; or, artificial snowmaking: using a snowmaking machine to make snow, and then using a snowplow or snow removal equipment to evenly distribute the snow generated by the snowmaking machine on the test site, thereby creating the loose snow conditions required for the test.

[0022] Furthermore, the equipment used in the test described in S4 includes a gimbal camera, a mobile weather station, an anemometer, and a camera; the gimbal camera is mounted on the front of the unmanned helicopter; and the mobile weather station is located in a safe position at the test site.

[0023] When conducting vertical take-off and landing and hovering tests of unmanned helicopters, the anemometer should be placed within a radius of twice the rotor radius, with the ground projection of the main rotor hub of the unmanned helicopter as the reference circle. The camera should be mounted on the ground at the test site so that the horizontal distance of the camera's imaging field of view is not less than six times the rotor radius.

[0024] When conducting forward flight tests, the ground projection of the center of the main rotor hub of the unmanned helicopter on the flight path of the unmanned helicopter is used as the ground reference trajectory line. Anemometers are set up at positions within twice the rotor radius on both sides of the ground reference trajectory line. The position of the ground camera at the test site is determined according to the ground reference trajectory line, and the horizontal distance of the camera's imaging field of view is not less than six times the rotor radius.

[0025] Furthermore, the method for measuring the physical properties of snow accumulation at the test site described in S6 specifically includes:

[0026] Snow temperature measurement method: Insert a probe-type temperature sensor into the snow-covered area to obtain snow temperature data at different depths;

[0027] Snow depth and density measurement method: Use a transparent snow density sampling measuring device to insert vertically downward into the snow area to be measured until it touches the ground. At this time, the measuring device has completed snow sampling. Seal the bottom of the measuring device with a cover plate, remove the snow, and read the snow depth through the scale line on the transparent measuring device. At the same time, measure the weight of the snow in the container to obtain the overall density of the snow.

[0028] Method for measuring snow particle shape and size: The shape and size of snow particles in the snow-covered area to be tested are measured using a calibrated electron microscope. The specific steps are as follows: Place the electron microscope outdoors to keep the snow particles in their original shape, turn on the power of the equipment, turn on the CCD camera and display screen, use a snow sample collection plate to sample the snow particles to be tested and place it in the observation area of ​​the electron microscope, adjust the brightness of the LED source, adjust the lens position to make the snow crystal image on the display screen clear, collect and measure multiple sets of image information, and analyze the snow particle shape and size data.

[0029] Furthermore, the unmanned helicopter needs to be equipped with a ground station and flight data acquisition, transmission and recording functions to achieve real-time monitoring of flight status.

[0030] Furthermore, the unmanned helicopter, through its flight data recording system, must be able to transmit the main rotor speed, collective pitch, and the unmanned helicopter's position, altitude, heading, horizontal speed, and vertical speed, with the unmanned helicopter's position information provided by a GPS positioning system.

[0031] The present invention has the following advantages over the prior art:

[0032] 1. This invention can conduct in-depth research on the impact characteristics of helicopters flying in snowy areas and snow blindness, filling the gap in domestic research on helicopters flying in snowy areas and snow blindness technology;

[0033] 2. By conducting actual flight tests in snow-covered areas, this invention can simulate the real snow blind phenomenon of helicopters, allowing researchers to intuitively observe the actual situation when snow blind occurs. This is more in line with the problems faced in actual flight and provides a reliable and realistic basis for in-depth research on the snow blind phenomenon. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0035] Figure 1 This is a flowchart of a snow blindness test method for unmanned helicopters in cold outdoor environments;

[0036] Figure 2 A schematic diagram of an unmanned helicopter equipped with a gimbal camera.

[0037] Figure 3 An aerial view of the layout of unmanned helicopters and measuring equipment at the test site.

[0038] In the picture: 1-unmanned helicopter, 2-gimbal camera, 3-mobile weather station, 4-anemometer, 5-camera. Detailed Implementation

[0039] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0040] Example 1, Reference Figure 1-3 This embodiment describes a snow blindness test method for unmanned helicopters in cold outdoor environments, specifically including the following steps:

[0041] S1. Select a test environment and test site that meet the test conditions:

[0042] The test environment was chosen to be a cold outdoor natural environment, and the test site was chosen to be a flat area far away from people, avoiding large undulations or obstacles; according to the size and flight characteristics of the unmanned helicopter 1, the test site needs to have sufficient space.

[0043] S2. Based on the performance of the unmanned helicopter 1 and the limitations of the test environment and test site, determine the safe flight conditions for the test:

[0044] S3. The unmanned helicopter operator must conduct test flights on snow-free ground according to the determined flight conditions; and determine whether the existing snow on the test site meets the test requirements to be blown up by the rotor downwash airflow to form a snow blind scenario. If the snow condition meets the test requirements, proceed directly to step S4; if the existing natural snow does not meet the test requirements, measures must be taken to make the ground snow cover meet the test requirements.

[0045] S4. After determining the flight trajectory of the unmanned helicopter 1 at the test site, install the equipment used for the test;

[0046] S5. Conduct pre-flight checks for unmanned helicopter 1:

[0047] Before conducting the test flight, ground maintenance personnel must perform a pre-flight check on the unmanned helicopter 1 to check whether the mechanical and electronic components of the unmanned helicopter 1 are normal, including the battery status, power system, and sensors; ensure that the communication connection between the unmanned helicopter 1 and the ground station is normal, and ensure that the control and data transmission are error-free;

[0048] S6. Measure the physical properties of snow accumulation at the test site;

[0049] S7. Conduct tests based on the determined flight conditions:

[0050] During vertical takeoff and vertical landing tests, the unmanned helicopter 1 should maintain a smooth and slow ascent and descent process; during hovering tests at different altitudes, it should maintain a fixed position and attitude as much as possible; during forward flight tests, the unmanned helicopter 1 should fly horizontally close to the ground along a set trajectory.

[0051] While conducting vertical takeoff and landing, hovering and forward flight tests, data were collected and recorded from unmanned helicopter 1, gimbal camera 2, mobile weather station 3, rotor downwash anemometer 4, and ground camera 5.

[0052] S8. After a single vehicle test is completed, ensure that the unmanned helicopter 1 stops power output, check the status of the unmanned helicopter 1, and promptly remove the snow on the aircraft to prevent snow particles from freezing on important components.

[0053] S9. Measure the snow parameters at the test site again and record the impact of the flight of the unmanned helicopter 1 on the snow changes;

[0054] S10. Confirm if there are any remaining tests for the day; if there are any remaining tests for the day, proceed to S5; if all tests are completed for the day, collect all measuring equipment used in the tests and store them indoors, and perform anti-corrosion treatment on the unmanned helicopter 1 to prevent surface rust or corrosion caused by wet snow and frost.

[0055] S11. Analyze the recorded data to assess the impact of meteorological environment, ground snow accumulation parameters, takeoff weight of unmanned helicopter 1, and flight conditions on the severity of snow blindness.

[0056] Furthermore, the flight conditions described in S2 include the takeoff weight, flight trajectory, flight altitude, horizontal speed, vertical speed, flight and hovering time of the unmanned helicopter 1.

[0057] Furthermore, if the existing natural snow cover at the test site described in S3 cannot meet the requirements for the snow blindness test, the following measures must be taken:

[0058] Physical methods to loosen the snow layer: using mechanical equipment to directly act on the snow layer to loosen it through physical means; or, artificial snowmaking: using a snowmaking machine to make snow, and then using a snowplow or snow removal equipment to evenly distribute the snow generated by the snowmaking machine on the test site, thereby creating the loose snow conditions required for the test.

[0059] Furthermore, the equipment used in the test described in S4 includes a gimbal camera 2, a mobile weather station 3, an anemometer 4, and a camera 5; the gimbal camera 2 is installed on the front of the fuselage of the unmanned helicopter 1; and the mobile weather station 3 is located in a safe position at the test site.

[0060] When conducting vertical take-off and landing and hovering tests of unmanned helicopter 1, the anemometer 4 is arranged within a range of twice the rotor radius, with the ground projection of the main rotor hub center of unmanned helicopter 1 as the reference circle center. The camera 5 is mounted on the ground of the test site so that the horizontal distance of the imaging field of view of the camera 5 is not less than six times the rotor radius.

[0061] When conducting the forward flight test, the ground projection of the center of the main rotor hub of the unmanned helicopter 1 on the flight path of the unmanned helicopter 1 is used as the ground reference trajectory line. Anemometers 4 are set up at positions within twice the rotor radius on both sides of the ground reference trajectory line. The position of the ground camera 5 at the test site is determined according to the ground reference trajectory line. The horizontal distance of the imaging field of view of the camera 5 is not less than six times the rotor radius.

[0062] Furthermore, the method for measuring the physical properties of snow accumulation at the test site described in S6 specifically includes:

[0063] Snow temperature measurement method: Insert a probe-type temperature sensor into the snow-covered area to obtain snow temperature data at different depths;

[0064] Snow depth and density measurement method: Use a transparent snow density sampling measuring device to insert vertically downward into the snow area to be measured until it touches the ground. At this time, the measuring device has completed snow sampling. Seal the bottom of the measuring device with a cover plate, remove the snow, and read the snow depth through the scale line on the transparent measuring device. At the same time, measure the weight of the snow in the container to obtain the overall density of the snow.

[0065] Method for measuring snow particle shape and size: The shape and size of snow particles in the snow-covered area to be tested are measured using a calibrated electron microscope. The specific steps are as follows: Place the electron microscope outdoors to keep the snow particles in their original shape, turn on the power of the equipment, turn on the CCD camera and display screen, use a snow sample collection plate to sample the snow particles to be tested and place it in the observation area of ​​the electron microscope, adjust the brightness of the LED source, adjust the lens position to make the snow crystal image on the display screen clear, collect and measure multiple sets of image information, and analyze the snow particle shape and size data.

[0066] Furthermore, the unmanned helicopter 1 needs to be equipped with a ground station and flight data acquisition, transmission and recording functions to achieve real-time monitoring of flight status.

[0067] Furthermore, the unmanned helicopter 1, through the flight data recording system, needs to be able to transmit the main rotor speed, collective pitch, and the position, altitude, heading, horizontal speed, and vertical speed of the unmanned helicopter 1, wherein the position information of the unmanned helicopter 1 is provided by the GPS positioning system.

[0068] This invention allows for in-depth research into the impact characteristics of helicopters flying in snowy areas and snow blindness, filling a gap in domestic research on helicopters flying in snowy areas and snow blindness.

[0069] This invention allows for the simulation of real-world snow blindness in helicopters by conducting actual flight tests in snow-covered areas. This enables researchers to directly observe the actual situation when snow blindness occurs, more closely mirroring the problems encountered in real-world flight and providing a reliable and realistic basis for in-depth research on the snow blindness phenomenon.

[0070] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A snow blindness test method for unmanned helicopters in outdoor cold environments, characterized in that, Specifically, the following steps are included: S1. Select a test environment and test site that meet the test conditions; S2. Determine the safe flight conditions for the test based on the performance of the unmanned helicopter (1) and the limitations of the test environment and test site; S3. Unmanned helicopter (1) The operator needs to conduct test flight exercises on a snow-free ground according to the determined flight conditions; and determine whether the existing snow on the test site meets the test requirements that can be blown up by the rotor downwash airflow to form a snow blind scenario. If the snow condition meets the test requirements, proceed directly to step S4. The existing natural snow cover does not meet the test requirements, and measures need to be taken to bring the ground snow cover to a state that meets the test requirements; S4. After determining the flight path of the unmanned helicopter (1) at the test site, install the equipment used for the test; S5. Conduct pre-flight checks on the unmanned helicopter (1); S6. Measure the physical properties of the snow accumulation at the test site; S7. Conduct tests based on the determined flight conditions; S8. After a single vehicle test is completed, ensure that the unmanned helicopter (1) stops power output and check the status of the unmanned helicopter (1); S9. Measure the snow parameters at the test site again and record the impact of the unmanned helicopter (1) flight on the snow changes. S10. Confirm whether there are any remaining tests for the day; if there are any remaining tests for the day, proceed to S5; if all tests are completed for the day, collect all the measuring equipment used in the tests and store them indoors, and perform anti-corrosion treatment on the unmanned helicopter (1); S11. Analyze the recorded data and assess the impact of meteorological environment, ground snow accumulation parameters, unmanned helicopter (1) takeoff weight and flight conditions on the severity of snow blindness.

2. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 1, characterized in that, The flight conditions described in S2 include the takeoff weight, flight trajectory, flight altitude, horizontal speed, vertical speed, flight and hovering time of the unmanned helicopter (1).

3. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 1, characterized in that, When the existing natural snow cover at the test site described in S3 cannot meet the requirements of the snow blindness test, the following measures must be taken: Physical methods to loosen the snow layer: using mechanical equipment to directly act on the snow layer to loosen it through physical means; or, artificial snowmaking: using a snowmaking machine to make snow, and then using a snowplow or snow removal equipment to evenly distribute the snow generated by the snowmaking machine on the test site, thereby creating the loose snow conditions required for the test.

4. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 1, characterized in that, The equipment used in the test described in S4 includes a gimbal camera (2), a mobile weather station (3), an anemometer (4), and a camera (5); the gimbal camera (2) is installed on the front of the fuselage of the unmanned helicopter (1); the mobile weather station (3) is located in a safe position at the test site; When conducting vertical take-off and landing and hovering tests of unmanned helicopter (1), the anemometer (4) is arranged within a range of twice the rotor radius, with the ground projection of the main rotor hub of the unmanned helicopter (1) as the reference center. The camera (5) is mounted on the ground of the test site so that the horizontal distance of the imaging field of view of the camera (5) is not less than six times the rotor radius. When conducting the pre-flight test, the ground projection of the center of the main rotor hub of the unmanned helicopter (1) on the flight path of the unmanned helicopter (1) is used as the ground reference trajectory line. Anemometers (4) are set up at positions within twice the rotor radius on both sides of the ground reference trajectory line. The position of the ground camera (5) at the test site is determined according to the ground reference trajectory line. The horizontal distance of the imaging field of view of the camera (5) is not less than six times the rotor radius.

5. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 1, characterized in that, The method for measuring the physical properties of snow accumulation at the test site described in S6 specifically includes: Snow temperature measurement method: Insert a probe-type temperature sensor into the snow-covered area to obtain snow temperature data at different depths; Snow depth and density measurement method: Use a transparent snow density sampling measuring device to insert vertically downward into the snow area to be measured until it touches the ground. At this time, the measuring device has completed snow sampling. Seal the bottom of the measuring device with a cover plate, remove the snow, and read the snow depth through the scale line on the transparent measuring device. At the same time, measure the weight of the snow in the container to obtain the overall density of the snow. Method for measuring snow particle shape and size: The shape and size of snow particles in the snow-covered area to be tested are measured using a calibrated electron microscope. The specific steps are as follows: Place the electron microscope outdoors to keep the snow particles in their original shape, turn on the power of the equipment, turn on the CCD camera and display screen, use a snow sample collection plate to sample the snow particles to be tested and place it in the observation area of ​​the electron microscope, adjust the brightness of the LED source, adjust the lens position to make the snow crystal image on the display screen clear, collect and measure multiple sets of image information, and analyze the snow particle shape and size data.

6. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 1, characterized in that, The unmanned helicopter (1) needs to be equipped with a ground station and flight data acquisition, transmission and recording functions to realize real-time monitoring of flight status.

7. The snow blindness test method for unmanned helicopters based on outdoor cold environments according to claim 6, characterized in that, The unmanned helicopter (1) is required to transmit the main rotor speed, collective pitch, and the position, altitude, heading, horizontal speed and vertical speed of the unmanned helicopter (1) through the flight data recording system. The position information of the unmanned helicopter (1) is provided by the GPS positioning system.

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