Dish type fire extinguishing aircraft attitude control method based on visual positioning

Abstract

The invention relates to the technical field of aircraft control, and particularly discloses a disc-shaped fire extinguishing aircraft attitude control method based on visual localization, and the method comprises the steps: carrying out the analysis of the dense smoke distribution type in an edge precise region in the fire extinguishing process of the edge precise region of a forest fire through a fire extinguishing aircraft, and obtaining a fire extinguishing result; and when the dense smoke distribution type of the region is determined to be non-uniform distribution, carrying out high-temperature thermal distortion analysis on the edge precision sub-regions divided in the edge precision region, and screening out the high-concentration thermal distortion sub-regions and the low-concentration thermal distortion sub-regions, so that regions which have relatively large threats on visual positioning and flight safety of the aircraft can be accurately positioned, and the accuracy of the aircraft visual positioning and the flight safety can be improved. An aircraft operator or an intelligent control system can clearly know the danger distribution condition of a fire scene, and in the process that the aircraft enters the high-concentration thermal distortion subarea from the low-concentration thermal distortion subarea, data support can be provided for early warning of aircraft flight attitude adjustment.

Description

Technical Field

[0001] This invention relates to the field of aircraft control technology, specifically to an attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning. Background Technology

[0002] In forest fire fighting, firefighting drones have become an indispensable piece of equipment in modern firefighting due to their high flexibility and ability to quickly reach the fire scene. However, the on-site environment of high-rise building fire rescue or forest fires is complex and changeable, and many factors seriously affect the operational effectiveness and flight safety of firefighting drones. Among them, uneven distribution of dense smoke and high-temperature thermal distortion are particularly prominent, posing a great challenge to the visual positioning and attitude control of the drones.

[0003] During forest fires, the distribution of dense smoke is often extremely uneven, with significant differences in smoke concentration across different areas. This uneven distribution can severely interfere with the visual positioning system of aircraft. Furthermore, the high smoke concentration and the resulting high temperatures cause thermal distortion in the surrounding air, which can adversely affect the aircraft's visual positioning and flight attitude in multiple ways. From a visual positioning perspective, high-temperature thermal distortion alters the light propagation path, causing distortion and deformation in the images captured by visual sensors. In terms of flight attitude control, the complex and unstable airflow changes caused by high-temperature thermal distortion interfere with the aircraft's aerodynamic performance. The varying degrees of high-temperature thermal distortion in different areas result in significant differences in aerodynamic forces and moments experienced by the aircraft at different locations, making it difficult for the aircraft to maintain a stable flight attitude. This is especially true during transitions between sub-ranges of varying degrees of high-temperature thermal distortion, where attitude adjustment becomes significantly more difficult and prone to over-adjustment.

[0004] Therefore, the present invention provides an attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning. Summary of the Invention

[0005] The purpose of this invention is to provide a visual positioning-based attitude control method for a disc-shaped firefighting aircraft to solve the aforementioned background problems.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for attitude control of a disc-shaped firefighting aircraft based on vision positioning, comprising the following steps:

[0008] During the process of using firefighting aircraft to precisely target the edge of a forest fire, the distribution type of dense smoke within the precise edge area is analyzed to determine the regional dense smoke distribution type.

[0009] When the distribution type of dense smoke in the region is determined to be uneven, high-temperature thermal distortion analysis is performed on the edge precise sub-regions divided within the edge precise region to screen out high-concentration thermal distortion sub-regions and low-concentration thermal distortion sub-regions.

[0010] The positioning coordinates within the precise edge area of ​​the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region are extracted separately and transformed by simulation to obtain the target analysis sub-trajectory. The flight attitude monitoring cycle is set to analyze whether the attitude angle adjustment of the fire extinguishing aircraft is overcorrected and to evaluate the interference degree of attitude angle adjustment.

[0011] When evaluating the attitude angle altitude disturbance after the simulation conversion, analyze the mutual interference of attitude angle adjustment overshoot. If there is mutual interference of attitude angle adjustment overshoot, determine the dynamic correction amount of attitude angle and solve the problem of excessive flight attitude angle adjustment based on the dynamic correction amount of attitude angle.

[0012] As a further aspect of the present invention, the analysis process for the regional dense smoke distribution type is as follows:

[0013] The edge precision area is equally divided into several edge precision sub-regions. The smoke concentration in each edge precision sub-region is obtained as the sub-region smoke concentration. When the edge precision area is rectangular, the outer edge precision sub-regions corresponding to the four vertices and the center precision sub-region are extracted. The difference between the sub-region smoke concentration corresponding to each outer edge precision sub-region and the sub-region smoke concentration corresponding to the center precision sub-region is calculated and the absolute value is taken to obtain the sub-region smoke concentration difference.

[0014] The average value of the smoke density difference in all sub-regions is summed to obtain the regional smoke density distribution value. If the regional smoke density distribution value is greater than the regional smoke density distribution threshold, it is displayed as a smoke density uneven distribution signal.

[0015] As a further aspect of the present invention, the process of performing high-temperature thermal distortion analysis on the precisely defined sub-regions within the precisely defined edge region from a spatial dimension is as follows:

[0016] Each precise edge sub-region is divided into grids, and each grid intersection point within the grid-divided precise edge sub-region is used as a temperature monitoring spatial point. The temperature monitoring period of the sub-region is set, and the temperature monitoring period of the sub-region is equally divided into several temperature monitoring time points. The spatiotemporal temperature values ​​of all temperature monitoring spatial points at the same temperature monitoring time point are calculated by comparing them with the thermal distortion critical temperature value, and then the standard deviation is calculated to obtain the temperature standard deviation value at time.

[0017] The mean of the spatiotemporal temperature standard deviation is obtained by summing and averaging the temperature standard deviations at all times within the temperature monitoring period of the sub-region.

[0018] As a further aspect of the present invention, the process of performing high-temperature thermal distortion analysis on the edge-precise sub-regions divided within the edge-precise region based on the temperature gradient is as follows:

[0019] Within the sub-region temperature monitoring cycle, the unit spatiotemporal temperature value corresponding to each temperature monitoring time point is extracted and compared. The maximum and minimum unit spatiotemporal temperature values ​​are selected, and the difference is calculated. The ratio is then calculated with the thermal distortion critical temperature value, and finally with the area ratio of the edge precision sub-region corresponding to the edge precision sub-region. The result is the temperature gradient value of the sub-region at that time.

[0020] The average temperature gradient of a sub-region is calculated by summing the temperature gradient values ​​of the sub-region at all time points during the sub-region temperature monitoring cycle.

[0021] As a further aspect of the present invention, the screening process for the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region is as follows:

[0022] The mean of the spatiotemporal temperature standard deviation is summed with the mean of the sub-region temperature gradient to obtain the sub-region screening value. If the sub-region screening value is greater than the sub-region screening threshold, it is marked as a high-concentration thermal distortion sub-region.

[0023] If the sub-region screening value is less than or equal to the sub-region screening threshold, it is marked as a low-concentration thermal distortion sub-region.

[0024] As a further aspect of the present invention, the process of obtaining the target analysis sub-trajectory is as follows:

[0025] The edge precision region is simulated and transformed in two-dimensional coordinate system, and the high-concentration thermal distortion sub-region and low-concentration thermal distortion sub-region within the edge precision region are both located in coordinates to obtain the high thermal distortion coordinates and low thermal distortion coordinates.

[0026] Extract the flight trajectory of the firefighting aircraft within the edge precision zone, extract the local trajectories where high and low thermal distortion coordinates are adjacent, and extract the transition trajectory between high and low thermal distortion coordinates as the target analysis sub-trajectory.

[0027] As a further aspect of the present invention, the process of analyzing whether the attitude angle adjustment of the fire extinguishing aircraft is overcorrected is as follows:

[0028] The flight attitude monitoring cycle is divided into several flight attitude monitoring nodes. The flight attitude angle corresponding to the single axis attitude angle of each flight attitude monitoring node is obtained in real time. The difference between the single axis attitude angle and the theoretical adjustment angle is calculated, and the absolute value is taken to obtain the attitude adjustment deviation value.

[0029] During the flight attitude monitoring cycle, the flight attitude monitoring node whose attitude adjustment deviation value exceeds the attitude adjustment deviation threshold is regarded as the flight angle over-adjustment point.

[0030] The proportion of the number of over-adjustment points in flight attitude monitoring to the total number of flight attitude monitoring nodes within the flight attitude monitoring cycle is used as the ratio of over-adjustment points.

[0031] The attitude overshoot ratio is obtained by calculating the ratio of the attitude adjustment deviation value corresponding to each overshoot point in flight angle to the attitude adjustment deviation threshold.

[0032] The average attitude overshoot is calculated by summing the attitude overshoot ratios corresponding to all flight angle overshoot points.

[0033] As a further aspect of the present invention, the evaluation process for attitude angle adjustment interference is as follows:

[0034] The overcorrection analysis value is obtained by summing the ratio of the number of all angle overshoot points with the average value of the attitude overshoot.

[0035] If the overcorrection analysis value is greater than the overcorrection analysis threshold, it will be displayed as an adjustment high interference signal.

[0036] As a further aspect of the present invention, the analysis process for mutual interference of attitude angle adjustment overshoot is as follows:

[0037] Extract the attitude adjustment deviation values ​​corresponding to adjacent flight angle overshoot points within the flight attitude monitoring cycle, and calculate the ratio between the attitude adjustment deviation values ​​of the earlier flight angle overshoot points in the time dimension and the attitude adjustment deviation values ​​of the later flight angle overshoot points in the time dimension to obtain the overshoot inertial decay rate.

[0038] As a further aspect of the present invention, the process for determining the dynamic correction amount of the attitude angle is as follows:

[0039] If the overshoot inertial decay rate is greater than the preset overshoot inertial decay rate, it is an overshoot inertial interference signal. The attitude adjustment deviation value of the earlier overshoot point in the time dimension is multiplied by the overshoot inertial decay rate, and then summed with the attitude adjustment deviation value of the later overshoot point in the time dimension to obtain the dynamic correction amount of the attitude angle.

[0040] The beneficial effects of this invention are as follows:

[0041] 1. This invention utilizes firefighting aircraft to precisely target the edge of forest fires. During this process, the distribution type of dense smoke within the precise edge zone is analyzed. If the distribution of dense smoke is determined to be uneven, high-temperature thermal distortion analysis is performed on the sub-regions within the precise edge zone to identify high-density thermal distortion sub-regions and low-density thermal distortion sub-regions. This allows for precise location of areas that pose a significant threat to the aircraft's visual positioning and flight safety, enabling aircraft operators or intelligent control systems to clearly understand the dangerous distribution at the fire scene. Furthermore, when the aircraft moves from a low-density thermal distortion sub-region to a high-density thermal distortion sub-region, data support is provided for early warning of the aircraft's flight attitude adjustment.

[0042] 2. This invention determines the positioning coordinates within the precise edge region of the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region, performs simulation transformation to obtain the target analysis sub-trajectory, sets the flight attitude monitoring cycle, evaluates the attitude angle adjustment interference, evaluates the attitude angle height interference after the simulation transformation, analyzes the mutual interference of attitude angle adjustment overshoot, if there is mutual interference of attitude angle adjustment overshoot, determines the dynamic correction amount of attitude angle, judges the overshoot interference situation based on the overshoot inertial decay rate, and adjusts the interfered attitude, which can weaken the cumulative effect, suppress the fluctuation of flight attitude, adjust the accumulated error in a timely manner, reduce the further expansion of error, and thus improve the accuracy of attitude control. Attached Figure Description

[0043] The invention will now be further described with reference to the accompanying drawings.

[0044] Figure 1 This is a functional block diagram of the attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to the present invention.

[0045] Figure 2 This is a flowchart illustrating the attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning, as described in this invention. Detailed Implementation

[0046] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0047] Example 1

[0048] During the use of firefighting aircraft to extinguish forest fires, the high temperatures generated by the fire provide the energy for the formation of dense smoke, creating a low-visibility environment obscured by the smoke. This results in an uneven or uniform smoke screen, reducing the visual contrast of the firefighting aircraft and drastically decreasing the number of specific points. Furthermore, the high temperatures in this low-visibility environment cause thermal distortion, further interfering with visual positioning. This leads to oscillations in the hovering attitude of the firefighting aircraft, making it difficult to hover stably or accurately approach the fire source. This significantly increases the risk of the aircraft deviating from its target fire location. Therefore, if... Figure 1 - Figure 2 As shown in the embodiment of the present invention, a visual positioning-based attitude control method for a disc-shaped firefighting aircraft includes the following steps:

[0049] Step 1: During the firefighting operation using fire-fighting drones to precisely target the edge of a forest fire, the distribution type of dense smoke within that precise area is analyzed to determine the regional dense smoke distribution type.

[0050] In some embodiments, the edge precision region is equally divided into several edge precision sub-regions, wherein each edge precision sub-region has an equal area;

[0051] Obtain the smoke concentration within each precise edge sub-region as the sub-region smoke concentration;

[0052] Extract the edge precision sub-regions located at the center of the edge precision region and the edge precision sub-regions located at the edge of the edge precision region, respectively, as the central precision sub-region and the outer edge precision sub-region;

[0053] It should be noted that the extraction of the central and outer precise sub-regions can be performed using an AI region feature localization algorithm;

[0054] For example, if the precise edge area is a regular shape, such as a square or a rectangle;

[0055] When the edge precision region is rectangular, extract the outer edge precision sub-regions corresponding to the four vertex corners, as well as the center precision sub-region;

[0056] The difference between the smoke concentration of the sub-region corresponding to each precise sub-region on the outer edge and the smoke concentration of the sub-region corresponding to the precise sub-region in the center is calculated, and the absolute value is taken to obtain the smoke concentration difference of the sub-region.

[0057] The average value of the smoke density difference in all sub-regions is calculated to obtain the regional smoke density distribution value.

[0058] It is understandable that the regional smoke distribution value represents the quantitative representation of the uniformity of smoke distribution within the precise area at the edge of a forest fire. Specifically, the larger the regional smoke distribution value, the greater the difference in smoke concentration between the outer precise sub-areas and the central precise sub-area, and the higher the local smoke concentration within the precise area at the edge. Conversely, the smaller the regional smoke distribution value, the smaller the difference in smoke concentration between the outer precise sub-areas and the central precise sub-area, and the more uniform the smoke concentration among the precise sub-areas at the edge within the precise area.

[0059] If the regional smoke distribution value is greater than the regional smoke distribution threshold, it indicates that the greater the difference in smoke concentration between each outer precise sub-region and the central precise sub-region, the higher the local smoke concentration in the edge precise region, which shows a signal of uneven smoke distribution.

[0060] If the regional smoke distribution value is less than or equal to the regional smoke distribution threshold, it indicates that the smoke concentration difference between each outer edge precision sub-region and the central precision sub-region is small, and the smoke concentration between the edge precision sub-regions within the edge precision region is relatively uniform, showing a uniform smoke distribution signal.

[0061] It should be noted that the significance of determining the regional smoke distribution type lies in the following: From the perspective of aircraft flight attitude adjustment, when there is an uneven distribution of smoke, local areas with high smoke concentrations may experience complex environmental factors such as airflow changes. Firefighting aircraft need to adjust their flight attitude in a timely manner according to these changes. When approaching areas with high smoke concentrations, they may encounter updrafts, and the aircraft needs to adjust its pitch attitude to maintain stable flight. When uneven smoke distribution makes ground features indistinct, the aircraft may need to adjust its attitude, such as tilting, to change the observation angle and ensure the accuracy of visual positioning.

[0062] Step 2: When the distribution type of dense smoke in the region is determined to be uneven, high-temperature thermal distortion analysis is performed on the edge precise sub-regions divided within the edge precise region to screen out high-concentration thermal distortion sub-regions and low-concentration thermal distortion sub-regions.

[0063] In some embodiments, each edge precision sub-region is divided into a grid, and each grid intersection point inside the edge precision sub-region after grid division is used as a temperature monitoring spatial point.

[0064] It should be noted that the grid division of each precise edge sub-region can be performed using an AI grid subdivision algorithm;

[0065] Set a temperature monitoring cycle for the sub-area, and divide the temperature monitoring cycle for the sub-area into several temperature monitoring time points, with the interval between adjacent temperature monitoring time points being equal in length.

[0066] The temperature value of each temperature monitoring point in the sub-region temperature monitoring cycle is obtained as the unit spatiotemporal temperature value.

[0067] After calculating the ratio of the unit spatiotemporal temperature values ​​of all temperature monitoring spatial points at the same temperature monitoring time point to the critical temperature value of thermal distortion, the standard deviation is calculated to obtain the temperature standard deviation value at time point.

[0068] The average of the temperature standard deviations at all times within the sub-region temperature monitoring period is calculated to obtain the mean of the spatiotemporal temperature standard deviation.

[0069] It should be noted that the critical temperature value for thermal distortion refers to the temperature gradient threshold at which a difference in air density is sufficient to cause significant light refraction.

[0070] Within the sub-region temperature monitoring cycle, the unit spatiotemporal temperature value corresponding to each temperature monitoring time point is extracted and compared. The maximum and minimum unit spatiotemporal temperature values ​​are selected, and the difference is calculated. The ratio is then calculated with the thermal distortion critical temperature value, and finally with the area ratio of the edge precision sub-region corresponding to the edge precision sub-region. The result is the temperature gradient value of the sub-region at that time.

[0071] It should be noted that the area ratio of the edge precision sub-region to the edge precision region refers to the proportion of the area of ​​the edge precision region to the area of ​​the edge precision region. Since the area of ​​each edge precision sub-region within the edge precision region is equal, it is a fixed value.

[0072] The average temperature gradient of the sub-region is obtained by summing and averaging the temperature gradient values ​​of the sub-region at all temperature monitoring time points during the sub-region temperature monitoring cycle.

[0073] The mean of the spatiotemporal temperature standard deviation and the mean of the sub-region temperature gradient are summed to obtain the sub-region screening value;

[0074] Understandably, the sub-region screening value represents a key indicator for screening high-concentration thermal distortion sub-regions and low-concentration thermal distortion sub-regions, taking into account both the dispersion and the severity of temperature changes within the precise edge sub-region. On one hand, the mean standard deviation of temperature over time reflects the overall stability of temperature fluctuations in the sub-region over time and space. On the other hand, the mean temperature gradient of the sub-region reflects the temperature gradient at various times throughout the entire monitoring period, demonstrating the overall trend of temperature changes within the sub-region. Specifically, a larger sub-region screening value indicates a larger temperature difference at different spatial locations within the analyzed precise edge sub-region, and a greater degree of temperature fluctuation, leading to a higher probability of instantaneous changes in air density and exacerbating uneven light refraction. Conversely, a smaller sub-region screening value indicates a smaller temperature difference at different spatial locations within the analyzed precise edge sub-region, and a smaller degree of temperature fluctuation, resulting in a lower probability of instantaneous changes in air density and less exacerbating uneven light refraction.

[0075] If the sub-region screening value is greater than the sub-region screening threshold, it indicates that the temperature difference at different spatial locations within the analyzed edge precision sub-region is large and the temperature fluctuation is large, which increases the probability of instantaneous changes in air density and easily exacerbates the unevenness of light refraction height, and is marked as a high-concentration thermal distortion sub-region.

[0076] If the sub-region screening value is less than or equal to the sub-region screening threshold, it indicates that the temperature difference at different spatial locations within the analyzed edge precision sub-region is small, and the degree of temperature fluctuation is small, resulting in a low probability of instantaneous changes in air density and making it less likely to exacerbate uneven light refraction. This sub-region is marked as a low-concentration thermal distortion sub-region.

[0077] The specific solution in this embodiment is as follows: During the firefighting process of using a fire-fighting aircraft to extinguish fires in the precise edge zone of a forest fire, the distribution type of dense smoke in the precise edge zone is analyzed. When it is determined that the distribution type of dense smoke in the area is uneven, high-temperature thermal distortion analysis is performed on the precise edge sub-zones divided within the precise edge zone to screen out high-density thermal distortion sub-zones and low-density thermal distortion sub-zones. This can accurately locate areas that pose a greater threat to the aircraft's visual positioning and flight safety, allowing aircraft operators or intelligent control systems to clearly understand the dangerous distribution of the fire scene. Furthermore, when the aircraft moves from a low-density thermal distortion sub-zone to a high-density thermal distortion sub-zone, it can provide data support for early warning of the aircraft's flight attitude adjustment.

[0078] Example 2

[0079] like Figure 1 - Figure 2 As shown in the embodiment of the present invention, the attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning further includes the following steps:

[0080] Step 3: Extract the positioning coordinates within the precise edge area of ​​the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region respectively, and perform simulation conversion to obtain the target analysis sub-trajectory. Set the flight attitude monitoring cycle, analyze whether the attitude angle adjustment of the fire extinguishing aircraft is overcorrected, and evaluate the interference degree of attitude angle adjustment.

[0081] In some embodiments, the edge precision region is simulated and transformed in two-dimensional coordinate system, and the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region within the edge precision region are both located in coordinates to obtain the high thermal distortion coordinates and the low thermal distortion coordinates.

[0082] Extract the flight trajectory of the firefighting aircraft within the edge precision zone, extract the local trajectories where high and low thermal distortion coordinates are adjacent on the flight trajectory, and extract the transition trajectory between high and low thermal distortion coordinates as the target analysis sub-trajectory;

[0083] It should be noted that the flight attitude monitoring cycle refers to the set cycle for monitoring the flight attitude of the firefighting aircraft while it is flying on the target analysis sub-trajectory.

[0084] The flight attitude monitoring cycle is divided into several flight status monitoring nodes, wherein the time interval between adjacent flight status monitoring nodes is of equal length;

[0085] The flight attitude angle corresponding to the single-axis attitude angle of each flight state monitoring node is acquired in real time, and the difference between the single-axis attitude angle and the theoretical adjustment angle is calculated. The absolute value is then taken to obtain the attitude adjustment deviation value.

[0086] It should be noted that the single-axis attitude angles include the pitch axis attitude angle, the roll axis attitude angle, and the yaw axis attitude angle.

[0087] During the flight attitude monitoring cycle, the flight attitude monitoring node whose attitude adjustment deviation value exceeds the attitude adjustment deviation threshold is regarded as the flight angle over-adjustment point.

[0088] Flight state monitoring nodes whose attitude adjustment deviation values ​​do not exceed (including those equal to) the attitude adjustment deviation threshold are designated as constant flight state angle nodes.

[0089] The proportion of the number of over-adjustment points in flight attitude monitoring to the total number of flight attitude monitoring nodes within the flight attitude monitoring cycle is used as the ratio of over-adjustment points.

[0090] The attitude overshoot ratio is obtained by calculating the ratio of the attitude adjustment deviation value corresponding to each overshoot point in flight angle to the attitude adjustment deviation threshold.

[0091] The average attitude overshoot is calculated by summing the attitude overshoot ratios corresponding to all flight angle overshoot points.

[0092] The overcorrection analysis value is obtained by summing the ratio of the number of all angle overshoot points with the average value of the attitude overshoot.

[0093] Understandably, the overcorrection analysis value represents the following: it comprehensively considers the overshoot that occurs during the flight attitude adjustment process of the firefighting aircraft when passing through the target analysis sub-trajectory of high and low thermal distortion coordinate transition. On the one hand, the ratio of angle overshoot points reflects the proportion of the number of flight state monitoring nodes whose attitude adjustment deviation exceeds the attitude adjustment deviation threshold within the flight attitude monitoring cycle. On the other hand, the average attitude overshoot reflects the degree to which the attitude adjustment exceeds the normal range at each overshoot point within the entire flight attitude monitoring cycle. Specifically, if the overcorrection analysis value is larger, it indicates that the aircraft not only has a higher frequency of attitude adjustment overshoot on the target analysis sub-trajectory, but also a larger degree of overshoot, meaning that the severity of the overcorrection phenomenon in the aircraft's attitude angle adjustment is higher. If the overcorrection analysis value is smaller, it indicates that the aircraft not only has a lower frequency of attitude adjustment overshoot on the target analysis sub-trajectory, but also a smaller degree of overshoot, meaning that the severity of the overcorrection phenomenon in the aircraft's attitude angle adjustment is lower.

[0094] If the overcorrection analysis value is greater than the overcorrection analysis threshold, it indicates that the aircraft not only has a high attitude adjustment overshoot frequency on the target analysis sub-trajectory, but also a large degree of overshoot. That is, the severity of the overcorrection phenomenon in the aircraft's attitude angle adjustment is high, which is displayed as an adjustment altitude interference signal.

[0095] If the overcorrection analysis value is less than or equal to the overcorrection analysis threshold, it indicates that the aircraft not only has a low attitude adjustment overshoot frequency on the target analysis sub-trajectory, but also a small degree of overshoot. In other words, the severity of the overcorrection phenomenon in the aircraft's attitude angle adjustment is low, which is displayed as a low-degree interference signal.

[0096] Step 4: When evaluating the attitude angle altitude disturbance after the simulation conversion, analyze the mutual interference of attitude angle adjustment overshoot. If there is mutual interference of attitude angle adjustment overshoot, determine the dynamic correction amount of attitude angle and solve the problem of excessive flight attitude angle adjustment based on the dynamic correction amount of attitude angle.

[0097] In some embodiments, the attitude adjustment deviation values ​​corresponding to adjacent over-adjustment points of the flight attitude monitoring cycle are extracted, and the ratio of the attitude adjustment deviation value of the earlier over-adjustment point of the flight attitude in the time dimension to the attitude adjustment deviation value of the later over-adjustment point of the flight attitude in the time dimension is calculated to obtain the over-adjustment inertial decay rate.

[0098] If the overshoot inertia decay rate is less than or equal to the preset overshoot inertia decay rate, the overshoot inertia decays quickly, and the cumulative effect of the earlier overshoot on the later overshoot is relatively small. It is an overshoot inertia non-interference signal. Then, the attitude adjustment deviation value corresponding to the current flight angle overshoot adjustment point is used as the attitude angle dynamic correction amount.

[0099] If the overshoot inertial decay rate is greater than the preset overshoot inertial decay rate, the overshoot inertial decay is slow, and the cumulative effect of the earlier overshoot on the later overshoot is significant, which is an overshoot inertial interference signal. The attitude adjustment deviation value of the earlier flying angle overshoot point in the time dimension is calculated by multiplying it with the overshoot inertial decay rate, and then summed with the attitude adjustment deviation value of the later flying angle overshoot point to obtain the attitude angle dynamic correction amount.

[0100] It is important to note that the significance of determining the dynamic attitude angle correction is as follows: During the flight of a firefighting aircraft, attitude angle overshoot accumulates over time. When the aircraft passes through the target analysis sub-trajectory transitioning between high and low thermal distortion coordinates, if multiple overshoots occur and are not corrected in time, these overshoot deviations will continuously accumulate, causing the flight attitude to deviate more and more from the theoretical attitude. The dynamic attitude angle correction, by considering the attitude adjustment deviation values ​​of adjacent flight angle overshoot points and the overshoot inertial decay rate, can adjust the accumulated errors in a timely manner, reducing further expansion of errors and thus improving the accuracy of attitude control. Moreover, firefighting aircraft based on visual positioning need to determine their own position and attitude based on environmental information obtained from visual sensors. The dynamic attitude angle correction can ensure that the actual attitude of the aircraft matches the target attitude determined by visual positioning more accurately.

[0101] The specific scheme of this embodiment is as follows: Determine the positioning coordinates within the precise edge area of ​​the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region, and perform simulation transformation to obtain the target analysis sub-trajectory. Set the flight attitude monitoring cycle, evaluate the attitude angle adjustment interference degree, evaluate the attitude angle height interference after the simulation transformation, analyze the mutual interference of attitude angle adjustment overshoot, if there is mutual interference of attitude angle adjustment overshoot, determine the dynamic correction amount of attitude angle, judge the overshoot interference situation according to the overshoot inertial decay rate, and adjust the interfered attitude. This can weaken the cumulative effect, suppress the fluctuation of flight attitude, adjust the accumulated error in a timely manner, reduce the further expansion of error, and thus improve the accuracy of attitude control.

[0102] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for attitude control of a disc-shaped firefighting aircraft based on visual positioning, characterized in that: include: During the process of using firefighting aircraft to precisely target the edge of a forest fire, the distribution type of dense smoke within the precise edge area is analyzed to determine the regional dense smoke distribution type. When the distribution type of dense smoke in the region is determined to be uneven, high-temperature thermal distortion analysis is performed on the edge precise sub-regions divided within the edge precise region to screen out high-concentration thermal distortion sub-regions and low-concentration thermal distortion sub-regions. The positioning coordinates within the precise edge area of ​​the high-concentration thermal distortion sub-region and the low-concentration thermal distortion sub-region are extracted separately and transformed by simulation to obtain the target analysis sub-trajectory. The flight attitude monitoring cycle is set to analyze whether the attitude angle adjustment of the fire extinguishing aircraft is overcorrected and to evaluate the interference degree of attitude angle adjustment. When evaluating the attitude angle altitude disturbance after the simulation conversion, analyze the mutual interference of attitude angle adjustment overshoot. If there is mutual interference of attitude angle adjustment overshoot, determine the dynamic correction amount of attitude angle and solve the problem of excessive flight attitude angle adjustment based on the dynamic correction amount of attitude angle.

2. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The analysis process for the regional smoke distribution types is as follows: The edge precision area is equally divided into several edge precision sub-regions. The smoke concentration in each edge precision sub-region is obtained as the sub-region smoke concentration. When the edge precision area is rectangular, the outer edge precision sub-regions corresponding to the four vertices and the center precision sub-region are extracted. The difference between the sub-region smoke concentration corresponding to each outer edge precision sub-region and the sub-region smoke concentration corresponding to the center precision sub-region is calculated and the absolute value is taken to obtain the sub-region smoke concentration difference. The average value of the smoke density difference in all sub-regions is summed to obtain the regional smoke density distribution value. If the regional smoke density distribution value is greater than the regional smoke density distribution threshold, it is displayed as a smoke density uneven distribution signal.

3. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The process of performing high-temperature thermal distortion analysis on the precise sub-regions within the precise edge region in a spatial dimension is as follows: Each precise edge sub-region is divided into grids, and each grid intersection point within the grid-divided precise edge sub-region is used as a temperature monitoring spatial point. The temperature monitoring period of the sub-region is set, and the temperature monitoring period of the sub-region is equally divided into several temperature monitoring time points. The spatiotemporal temperature values ​​of all temperature monitoring spatial points at the same temperature monitoring time point are calculated by comparing them with the thermal distortion critical temperature value, and then the standard deviation is calculated to obtain the temperature standard deviation value at time. The mean of the spatiotemporal temperature standard deviation is obtained by summing and averaging the temperature standard deviations at all times within the temperature monitoring period of the sub-region.

4. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The process of performing high-temperature thermal distortion analysis on the edge-precise sub-regions within the edge-precise region based on the temperature gradient is as follows: Within the sub-region temperature monitoring cycle, the unit spatiotemporal temperature value corresponding to each temperature monitoring time point is extracted and compared. The maximum and minimum unit spatiotemporal temperature values ​​are selected, and the difference is calculated. The ratio is then calculated with the thermal distortion critical temperature value, and finally with the area ratio of the edge precision sub-region corresponding to the edge precision sub-region. The result is the temperature gradient value of the sub-region at that time. The average temperature gradient of a sub-region is calculated by summing the temperature gradient values ​​of the sub-region at all time points during the sub-region temperature monitoring cycle.

5. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The screening process for high-concentration thermal distortion sub-regions and low-concentration thermal distortion sub-regions is as follows: The mean of the spatiotemporal temperature standard deviation is summed with the mean of the sub-region temperature gradient to obtain the sub-region screening value. If the sub-region screening value is greater than the sub-region screening threshold, it is marked as a high-concentration thermal distortion sub-region. If the sub-region screening value is less than or equal to the sub-region screening threshold, it is marked as a low-concentration thermal distortion sub-region.

6. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The process of obtaining the target analysis sub-trajectory is as follows: The edge precision region is simulated and transformed in two-dimensional coordinate system, and the high-concentration thermal distortion sub-region and low-concentration thermal distortion sub-region within the edge precision region are both located in coordinates to obtain the high thermal distortion coordinates and low thermal distortion coordinates. Extract the flight trajectory of the firefighting aircraft within the edge precision zone, extract the local trajectories where high and low thermal distortion coordinates are adjacent, and extract the transition trajectory between high and low thermal distortion coordinates as the target analysis sub-trajectory.

7. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The process of analyzing whether the attitude and angle adjustments of the firefighting aircraft were overcorrected is as follows: The flight attitude monitoring cycle is divided into several flight attitude monitoring nodes. The flight attitude angle corresponding to the single axis attitude angle at each flight attitude monitoring node is obtained in real time. The difference between the single axis attitude angle and the theoretical adjustment angle is calculated, and the absolute value is taken to obtain the attitude adjustment deviation value. During the flight attitude monitoring cycle, the flight attitude monitoring node whose attitude adjustment deviation value exceeds the attitude adjustment deviation threshold is regarded as the flight angle over-adjustment point. The proportion of the number of over-adjustment points in flight attitude monitoring to the total number of flight attitude monitoring nodes within the flight attitude monitoring cycle is used as the ratio of over-adjustment points. The attitude overshoot ratio is obtained by calculating the ratio of the attitude adjustment deviation value corresponding to each overshoot point in flight angle to the attitude adjustment deviation threshold. The average attitude overshoot is calculated by summing the attitude overshoot ratios corresponding to all flight angle overshoot points.

8. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 7, characterized in that: The evaluation process for attitude angle adjustment disturbance is as follows: The overcorrection analysis value is obtained by summing the ratio of the number of all angle overshoot points with the average value of the attitude overshoot. If the overcorrection analysis value is greater than the overcorrection analysis threshold, it will be displayed as an adjustment high interference signal.

9. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 1, characterized in that: The analysis process of mutual interference of attitude angle adjustment overshoot is as follows: Extract the attitude adjustment deviation values ​​corresponding to adjacent flight angle overshoot points within the flight attitude monitoring cycle, and calculate the ratio between the attitude adjustment deviation values ​​of the earlier flight angle overshoot points in the time dimension and the attitude adjustment deviation values ​​of the later flight angle overshoot points in the time dimension to obtain the overshoot inertial decay rate.

10. The attitude control method for a disc-shaped fire extinguishing aircraft based on visual positioning according to claim 9, characterized in that: The process for determining the dynamic correction amount of attitude angle is as follows: If the overshoot inertial decay rate is greater than the preset overshoot inertial decay rate, it is an overshoot inertial interference signal. The attitude adjustment deviation value of the earlier overshoot point in the time dimension is multiplied by the overshoot inertial decay rate, and then summed with the attitude adjustment deviation value of the later overshoot point in the time dimension to obtain the dynamic correction amount of the attitude angle.

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