An unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning

Abstract

The present invention relates to the field of drone control technology, and in particular to an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning, including an information acquisition module, a simulation module, a data processing module, an autonomous obstacle avoidance module and a flight control module; the simulation module simulates the fire spread of the fire scene and the distribution of hot air flow around the fire scene according to fire parameters and weather parameters to determine the initial fire extinguishing path of the unmanned helicopter; the autonomous obstacle avoidance module determines whether to trigger the temperature correction condition according to the temperature fluctuation diagram of each position and the overall temperature fluctuation diagram, determines whether to trigger the autonomous obstacle avoidance condition according to the stable flight state, and determines the flight adjustment strategy of the unmanned helicopter's waiting flight route according to the triggering judgment results of the temperature correction condition and the autonomous obstacle avoidance condition. The present invention not only improves the efficiency and safety of fire extinguishing tasks, but also enhances its coping ability in complex environments through intelligence and autonomy.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle control, and in particular to an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning. Background Art

[0002] As a new type of fire-fighting tool, unmanned helicopters can quickly respond to fire accidents without being restricted by terrain by carrying fire-fighting equipment, such as dry powder, foam and other fire-fighting agents, and can accurately strike the source of the fire. In addition, unmanned helicopters can also conduct aerial reconnaissance to provide ground commanders with real-time fire conditions so that more scientific and reasonable fire-fighting plans can be formulated. However, in the process of unmanned helicopters performing fire-fighting tasks, the impact of the hot air flow generated by the fire source on the unmanned helicopter cannot be ignored: the hot air flow will affect the flight stability of the unmanned helicopter, which may cause the unmanned helicopter to lose control; the hot air flow will also have an adverse effect on the electronic equipment and mechanical structure of the unmanned helicopter, reducing the reliability and service life of the unmanned helicopter. Therefore, how to overcome the impact of the hot air flow generated by the fire source on the unmanned helicopter is a key issue that needs to be solved in the unmanned helicopter's fire-fighting mission.

[0003] Chinese patent publication number CN116149346A discloses a fire-fighting drone obstacle avoidance and control method and system based on binocular vision and Realsense, including: calibrating the binocular camera; setting multiple path points; obtaining the current latitude and longitude parameters of the drone, and setting the next path point as the target preset position; using the binocular camera to obtain the distance parameters of the obstacles in front of the drone, and obtaining the depth map; filtering the depth map, filtering the influence of far-point obstacles, setting the perception range, and filtering obstacles outside the perception range; multiplying the filtered depth map matrix with the roll coefficient matrix, throttle coefficient matrix, fuselage coefficient matrix and unit matrix to obtain the Hadamard product; deriving the roll angle coefficient, throttle coefficient and pitch angle coefficient as input into the drone control system, controlling the drone's posture and motion trajectory, thereby achieving obstacle avoidance; after obstacle avoidance is completed, flying back to the current target point. This invention solves the technical problems of poor obstacle avoidance effect, low real-time performance and low safety of drones. It can be seen that the invention has the following problems:

[0004] This invention does not take into account the problem that the unstable flight of the drone caused by thermal air currents when the drone is performing fire-fighting missions affects the timeliness of the drone's fire-fighting and rescue operations. Summary of the invention

[0005] To this end, the present invention provides an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning, so as to overcome the problem in the prior art that the unsteady flight of the unmanned aerial vehicle is caused by thermal airflow, thus affecting the timeliness of the unmanned aerial vehicle fire fighting and rescue.

[0006] To achieve the above object, the present invention provides an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning, comprising:

[0007] An information acquisition module is used to collect flight parameters of the unmanned helicopter during flight, obtain fire parameters and weather parameters of the fire scene, and determine the real-time temperature of each preset position of the unmanned helicopter during flight, wherein the flight parameters include flight altitude, flight attitude, flight speed and motor audio data, the fire parameters include the location of the fire point and the scope of the fire scene, and the weather parameters include the current wind speed and the current temperature;

[0008] a simulation module, which is connected to the information acquisition module, and is used to simulate the fire spread of the fire scene and the distribution of thermal airflow around the fire scene according to the fire condition parameters and the weather parameters, and determine the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the distribution of thermal airflow;

[0009] A data processing module connected to the information acquisition module, for determining the stable flight state of the unmanned helicopter according to the flight attitude and the motor audio data, and determining a position temperature fluctuation diagram and an overall temperature fluctuation diagram of each preset position according to the real-time temperature of each preset position;

[0010] The autonomous obstacle avoidance module is connected to the data processing module and the simulation module respectively, and is used to determine whether to trigger the temperature correction condition according to the temperature fluctuation diagram of each position and the overall temperature fluctuation diagram, determine whether to trigger the autonomous obstacle avoidance condition according to the stable flight state, and determine the flight adjustment strategy of the unmanned helicopter's waiting flight route according to the triggering judgment results of the temperature correction condition and the autonomous obstacle avoidance condition, including:

[0011] Adjust flight parameters, or control the simulation module to redefine the fire-fighting path of the unmanned helicopter;

[0012] The flight control module is connected to the simulation module and the autonomous obstacle avoidance module respectively, and is used to control the unmanned helicopter to continue flying and performing the fire-fighting mission according to the flight adjustment strategy.

[0013] Further, the information acquisition module includes a sensor unit, and the sensor unit includes a plurality of temperature sensors and audio sensors;

[0014] The temperature sensor is used to determine the real-time temperature of each preset position of the unmanned helicopter during flight;

[0015] The audio sensor is used to determine the motor audio data during the flight of the unmanned helicopter.

[0016] Furthermore, the simulation module includes CFD simulation software for simulating the fire spread and the thermal airflow distribution and path planning software for determining the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the thermal airflow distribution.

[0017] Further, the data processing module determines the flight stability state according to whether the change of the flight attitude satisfies the attitude fluctuation condition and whether the current motor audio data exceeds the audio data range, so that the autonomous obstacle avoidance module determines whether the autonomous obstacle avoidance condition is triggered;

[0018] The stable flight state includes an implicit flight jitter state and an explicit flight jitter state.

[0019] Furthermore, the attitude fluctuation condition includes that a change in any parameter in the flight attitude exceeds a preset ratio.

[0020] Furthermore, the audio data range is determined based on the average value and standard deviation of the historical audio data.

[0021] Furthermore, the data processing module determines the value of the overall temperature fluctuation diagram at the corresponding time according to the real-time temperature of each preset position at the same time.

[0022] Furthermore, the autonomous obstacle avoidance module determines whether to trigger the temperature correction condition based on the temperature fluctuation graph of a single position and the overall temperature fluctuation graph, including:

[0023] If the real-time temperature of a single preset position at the current time is greater than or equal to the preset temperature and the value of the overall temperature fluctuation graph at the current time is greater than or equal to the preset value, it is determined that the preset position triggers the temperature correction condition.

[0024] Furthermore, the autonomous obstacle avoidance module determines the flight adjustment strategy of the unmanned helicopter's flight route according to the triggering judgment result of the temperature correction condition and the autonomous obstacle avoidance condition, including:

[0025] If the temperature correction condition and the autonomous obstacle avoidance condition are triggered at the same time, it is determined that the unmanned helicopter increases its flight altitude and then hovers, and the simulation module is controlled to re-determine the fire extinguishing path of the unmanned helicopter.

[0026] Furthermore, the autonomous obstacle avoidance module determines the flight adjustment strategy of the unmanned helicopter's flight route according to the triggering judgment result of the temperature correction condition and the autonomous obstacle avoidance condition, including:

[0027] If only the temperature correction condition is triggered, it is determined that the unmanned helicopter adjusts its flight attitude to increase the ground height of the preset position that triggers the temperature correction condition;

[0028] If the number of preset positions triggering attitude correction is greater than or equal to a reference value, the flight altitude of the unmanned helicopter is increased.

[0029] Compared with the prior art, the beneficial effect of the present invention is that the unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning provided by the present invention not only improves the efficiency and safety of fire-fighting tasks, but also enhances its response capabilities in complex environments through intelligence and autonomy, thereby promoting the modernization of fire-fighting technology.

[0030] Furthermore, the simulation module combines CFD simulation software and path planning software to achieve accurate simulation of fire spread and thermal air flow distribution, thereby quickly determining the initial fire-fighting path of the unmanned helicopter.

[0031] Furthermore, the data processing module can effectively identify the stable flight state of the unmanned helicopter by analyzing the changes in flight attitude and motor audio data. This intelligent data processing combined with the autonomous obstacle avoidance mechanism improves the adaptability and flight safety of the unmanned helicopter in complex environments, and provides a guarantee for the successful execution of fire rescue missions.

[0032] Furthermore, the autonomous obstacle avoidance module can flexibly adjust the flight strategy of the unmanned helicopter by comprehensively considering the temperature correction conditions and the triggering status of the autonomous obstacle avoidance conditions, thereby effectively improving the execution efficiency of the fire-fighting mission and the flight safety of the UAV, and ensuring the UAV's stable operation capability in complex fire environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A connection diagram of an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to an embodiment of the present invention;

[0034] Figure 2 This is a working flow chart of an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to an embodiment of the present invention;

[0035] Figure 3 A flow chart for determining a flight adjustment strategy according to an embodiment of the present invention;

[0036] Figure 4 A two-dimensional relationship diagram of the actual fire range, the fire impact range and the flight safety range in an embodiment of the present invention;

[0037] In the figure: 1. Actual fire range; 2. Fire impact range; 3. Flight safety range. DETAILED DESCRIPTION

[0038] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0040] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0041] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] See also Figure 1 , Figure 2 and Figure 3 As shown, they are respectively a connection diagram of an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to an embodiment of the present invention, a work flow chart of an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to an embodiment of the present invention, and a flow chart of determining a flight adjustment strategy according to an embodiment of the present invention. An embodiment of the present invention provides an unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning, comprising:

[0043] An information acquisition module is used to collect flight parameters of the unmanned helicopter during flight (which can be obtained from the unmanned aerial vehicle), obtain fire parameters and weather parameters of the fire scene (weather parameters are obtained through the Internet, and fire parameters are obtained by receiving alarm information and reconnaissance by reconnaissance drones), and determine the real-time temperature of each preset position of the unmanned helicopter during flight. The flight parameters include flight altitude, flight attitude, flight speed and motor audio data, the fire parameters include the location of the fire point and the scope of the fire scene, and the weather parameters include the current wind speed and the current temperature;

[0044] a simulation module, which is connected to the information acquisition module, and is used to simulate the fire spread of the fire scene and the distribution of thermal airflow around the fire scene according to the fire condition parameters and the weather parameters, and determine the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the distribution of thermal airflow;

[0045] A data processing module connected to the information acquisition module, for determining the stable flight state of the unmanned helicopter according to the flight attitude and the motor audio data, and determining a position temperature fluctuation diagram and an overall temperature fluctuation diagram of each preset position according to the real-time temperature of each preset position;

[0046] The autonomous obstacle avoidance module is connected to the data processing module and the simulation module respectively, and is used to determine whether to trigger the temperature correction condition according to the temperature fluctuation diagram of each position and the overall temperature fluctuation diagram, determine whether to trigger the autonomous obstacle avoidance condition according to the stable flight state, and determine the flight adjustment strategy of the unmanned helicopter's waiting flight route according to the triggering judgment results of the temperature correction condition and the autonomous obstacle avoidance condition, including:

[0047] Adjust flight parameters, or control the simulation module to redefine the fire-fighting path of the unmanned helicopter;

[0048] The flight control module is respectively connected to the simulation module and the autonomous obstacle avoidance module, and is used to control the unmanned helicopter to continue flying and performing the fire-fighting mission according to the initial fire-fighting route or the flight adjustment strategy (it can be understood that if the temperature correction conditions and the autonomous obstacle avoidance conditions are not triggered, there is no need to formulate a flight adjustment strategy for the route to be flown, and the flight will continue according to the initial fire-fighting route).

[0049] It can be understood that the unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning provided by the present invention not only improves the efficiency and safety of fire-fighting tasks, but also enhances its response capabilities in complex environments through intelligence and autonomy, and promotes the modernization of fire-fighting technology.

[0050] Specifically, the information acquisition module includes a sensor unit, which includes a number of temperature sensors and audio sensors;

[0051] The temperature sensor is used to determine the real-time temperature of each preset position of the unmanned helicopter during flight;

[0052] The audio sensor is used to determine the motor audio data during the flight of the unmanned helicopter;

[0053] It is understandable that the number of preset positions is at least 5, including a central preset position and several edge preset positions, the central preset position is located at the geometric center of the bottom of the unmanned helicopter, and the edge preset positions are evenly distributed on the bottom edge of the unmanned helicopter.

[0054] Specifically, the simulation module includes CFD simulation software for simulating the fire spread and the thermal airflow distribution and path planning software for determining the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the thermal airflow distribution.

[0055] It can be understood that CFD simulation software is a simulation tool for computational fluid dynamics, which is widely used in engineering and scientific research to simulate and analyze fluid flow, heat transfer and other related physical phenomena. In implementation, CFD simulation software includes MATLAB such as Fluent.

[0056] In implementation, the path planning software is existing technology, including AUSE-V1R emergency firefighting drone tactical drill simulation system, UavSim, and drone firefighting path planning simulation based on particle swarm algorithm.

[0057] See also Figure 4 As shown, it is a two-dimensional relationship diagram of the actual fire range, fire impact range and flight safety range of the embodiment of the present invention. In implementation, the actual fire range can be determined according to the distribution of hot air flow, the fire impact range is determined according to the actual fire range to determine the flight safety range, and the path planning software determines the fire extinguishing path within the flight safety range; the fire impact range is 1.1 times the actual fire range to 1.5 times the actual fire range, and the flight safety range is the range outside the fire impact range.

[0058] In practice, the fire impact range is determined based on the size of the fire (the area of ​​the fire location): if the fire size is ≤10m 2 , then the fire impact range is 1.1 times the actual fire range; 10m 2 <If the fire size is ≤30m 2 , the fire impact range is positively correlated with the fire size (1.1 times the actual fire range ~ 1.5 times the actual fire range); if the fire size is > 30m 2 , the fire impact range is 1.5 times the actual fire range.

[0059] It is understandable that the simulation module achieves accurate simulation of fire spread and hot air flow distribution by combining CFD simulation software and path planning software, so as to quickly determine the initial fire-fighting path of the unmanned helicopter. CFD software (such as Fluent and MATLAB) effectively analyzes fluid flow and heat transfer, and provides a scientific basis for the calculation of the actual fire range and the fire impact range: the fire impact range is flexibly adjusted according to the size of the fire scene to ensure the accurate delineation of the flight safety range; this dynamic adaptability enhances the safety and effectiveness of fire-fighting operations, minimizes the risks of drones in the process of performing tasks, and improves the accuracy of fire-fighting path planning, so that unmanned helicopters can efficiently complete fire-fighting tasks in complex environments.

[0060] Specifically, the data processing module determines the flight stability state according to whether the change of the flight attitude satisfies the attitude fluctuation condition and whether the current motor audio data exceeds the audio data range, so that the autonomous obstacle avoidance module determines whether the autonomous obstacle avoidance condition is triggered;

[0061] The stable flight state includes an implicit flight jitter state and an explicit flight jitter state.

[0062] It can be understood that the data processing module determines that the flight stability state is an explicit flight jitter state based on the change in the flight attitude satisfying the attitude fluctuation condition and / or the current motor audio data exceeds the audio data range, and the autonomous obstacle avoidance module determines that the autonomous obstacle avoidance condition is triggered; the data processing module determines that the flight stability state is an invisible flight jitter state based on the change in the flight attitude not satisfying the attitude fluctuation condition and the current motor audio data does not exceed the audio data range, and the autonomous obstacle avoidance module determines that the autonomous obstacle avoidance condition is not triggered.

[0063] During implementation, when in the explicit flight jitter state, the unmanned helicopter is affected by the hot air flow in the fire scene, which causes the stability of the unmanned helicopter to deteriorate, and therefore automatically triggers the autonomous obstacle avoidance condition to prevent the hot air flow from affecting the sensors, engines and structural materials of the drone, thereby reducing the safety of the unmanned helicopter; when in the implicit flight jitter state, the unmanned helicopter is not affected by the hot air flow in the fire scene, nor does it affect the safety of the unmanned helicopter, so there is no need to trigger the autonomous obstacle avoidance condition.

[0064] It is understandable that the data processing module can effectively identify the stable flight state of the unmanned helicopter by analyzing the flight attitude changes and motor audio data. This intelligent data processing combined with the autonomous obstacle avoidance mechanism improves the adaptability and flight safety of the unmanned helicopter in complex environments, and provides a guarantee for the successful execution of fire rescue missions.

[0065] Specifically, the attitude fluctuation condition includes that the change of any parameter in the flight attitude exceeds a preset ratio.

[0066] It can be understood that the key parameters of flight attitude include: (1) pitch angle, which is the rotation angle of the drone body around the front-back axis (i.e., pitch axis). It is positive when it is forward and negative when it is backward, affecting the rise and fall of the drone; (2) roll angle, which is the rotation angle of the drone body around the left-right axis (i.e., roll axis). It is positive when it is to the left and negative when it is to the right, affecting the left and right tilt of the drone; (3) yaw angle, which is the rotation angle of the drone body around the vertical axis (i.e., yaw axis). According to the right-hand rule, it is positive when it is counterclockwise and negative when it is clockwise, affecting the left and right rotation of the drone; (4) attitude angular velocity, which is the angular velocity of the drone rotating around the three axes, corresponding to the pitch angular velocity (q), roll angular velocity (p) and yaw angular velocity (r) respectively; (5) attitude angular acceleration, which is the rate of change of the drone's angular velocity.

[0067] During implementation, if the values ​​of the above five key parameters exceed the preset ratio, it means that the flight attitude of the unmanned helicopter has undergone a sudden change due to external force, which may be caused by a sudden change in the fire intensity, thus triggering the attitude fluctuation condition (such as the fire suddenly becomes bigger, the influence range of the hot air flow becomes larger, making the lift of the unmanned helicopter smaller, and the attitude of the unmanned helicopter suddenly changes when the unmanned helicopter does not increase the thrust).

[0068] In implementation, the value of the preset ratio needs to balance sensitivity and fire extinguishing effect. The smaller the preset ratio is, the higher the obstacle avoidance sensitivity is, but the fire extinguishing effect is not as expected. Therefore, the preset ratio ∈ [5%, 15%] is preferably set to 10%.

[0069] In implementation, the change amount of a single parameter is the ratio of the difference between the current value of the parameter and the value of the parameter at the immediately preceding moment to the value of the parameter at the immediately preceding moment.

[0070] Specifically, the audio data range is determined based on the average value of the historical audio data and the standard deviation of the historical audio data.

[0071] It can be understood that the audio data range is the difference between the average value of the historical audio data and the standard deviation of the historical audio data and the sum of the average value of the historical audio data and the standard deviation of the historical audio data.

[0072] In practice, the calculation formulas for the mean value and the standard deviation are prior art, so they will not be described in detail.

[0073] It is understandable that, for the current time point, the audio data before the current time point are all historical audio data. Therefore, as the time point changes, the historical audio data also changes in real time, so the audio data range also changes in real time.

[0074] Specifically, the data processing module determines the value of the overall temperature fluctuation diagram at the corresponding time according to the real-time temperature of each preset position at the same time.

[0075] In implementation, the value of the overall temperature fluctuation graph at time A is the variance of the real-time temperature of each preset position at time A, so as to represent the degree of deviation of the real-time temperature of each preset position at time A.

[0076] Specifically, the autonomous obstacle avoidance module determines whether to trigger the temperature correction condition based on the temperature fluctuation graph of a single location and the overall temperature fluctuation graph, including:

[0077] If the real-time temperature of a single preset position at the current time is greater than or equal to the preset temperature and the value of the overall temperature fluctuation graph at the current time is greater than or equal to the preset value, then it is determined that the preset position triggers the temperature correction condition; it can be understood that if the real-time temperature of a single preset position is greater than the preset temperature and the value of the corresponding overall fluctuation graph also exceeds the preset value, it is determined that the temperature change of the single preset position is large and has an impact on the whole, so the temperature correction condition is triggered;

[0078] If the real-time temperature of a single preset position at the current time is greater than or equal to the preset temperature, but the value of the overall temperature fluctuation graph at the current time is less than the preset value, it is necessary to determine how many preset positions have the current real-time temperature greater than or equal to the preset temperature. If the number of preset positions whose current real-time temperature is greater than or equal to the preset temperature is greater than / equal to half of the number of all preset positions, it is determined that the preset position triggers the temperature correction condition (at this time, it may be because the number of preset positions that meet the real-time temperature greater than or equal to the preset temperature is greater, resulting in a more stable value of the overall temperature fluctuation graph, that is, less than the preset value). If the number of preset positions whose current real-time temperature is greater than or equal to the preset temperature is less than half of the number of all preset positions, it is determined that the preset position does not trigger the temperature correction condition (at this time, although the real-time temperature of a single preset position changes suddenly, it does not affect the flight of the unmanned helicopter, so no response is made for the time being);

[0079] If the real-time temperature of a single preset position at the current time is lower than the preset temperature, and the value of the overall temperature fluctuation graph at the current time is lower than the preset value, it is determined that the preset position does not trigger the temperature correction condition (the unmanned helicopter is in normal flight at this time).

[0080] In implementation, the preset temperature is determined based on the temperature tolerance of the bottom material of the unmanned helicopter, and is generally set to be about 50°C lower than the melting point of the bottom material. The heat resistance of the bottom material usually needs to be determined through experiments and tests to ensure that the material can work safely and effectively within the expected temperature range. Therefore, the preset temperature is mostly set to the highest temperature corresponding to the heat resistance; the preset value is generally 1 times the value of the overall temperature fluctuation chart at the previous moment to 1.2 times the value of the overall temperature fluctuation chart at the previous moment, usually 1.2 times the value of the overall temperature fluctuation chart at the previous moment, that is, the preset value changes in real time with time.

[0081] Specifically, the autonomous obstacle avoidance module determines the flight adjustment strategy of the unmanned helicopter's flight route based on the temperature correction conditions and the triggering judgment results of the autonomous obstacle avoidance conditions, including:

[0082] If the temperature correction condition and the autonomous obstacle avoidance condition are triggered at the same time (at this time the fire intensity changes greatly and the initial fire extinguishing route is no longer suitable for the drone to continue to perform the fire extinguishing task), it is determined that the unmanned helicopter increases its flight altitude and then hovers, and the simulation module is controlled to re-determine the safe flight range and fire extinguishing path of the unmanned helicopter.

[0083] In practice, when the unmanned helicopter is hovering after increasing its altitude, the height increase range is 10m to 50m. In order to prevent the unmanned helicopter from being damaged in the re-planned fire-fighting path, it is preferred to increase the altitude by 20m.

[0084] Specifically, the autonomous obstacle avoidance module determines the flight adjustment strategy of the unmanned helicopter's flight route based on the temperature correction conditions and the triggering judgment results of the autonomous obstacle avoidance conditions, including:

[0085] If only the temperature correction condition is triggered, it is determined that the unmanned helicopter adjusts its flight attitude to increase the height above the ground of the preset position that triggers the temperature correction condition, and returns it to the command center so that subsequent unmanned helicopters can adapt in advance; (it can be understood that at this time, in order to balance the fire-fighting efficiency and flight safety, the appropriate increased flight altitude is 10m~30m, and it is preferably increased to 10m to determine whether the temperature correction condition is still triggered. If it is triggered, continue to increase by 10m. If not, keep increasing by 10m on the basis of the original fire-fighting path to continue the fire-fighting task); among them, if the number of preset positions that trigger attitude correction is greater than or equal to the reference value, the flight altitude of the unmanned helicopter is increased, and the flight attitude of the unmanned helicopter is not changed (it can be understood that this indicates that the fire has changed but has not caused changes in the thermal air flow around it. Therefore, it is necessary to increase the flight altitude at this time to prevent the drone from being affected by high temperature).

[0086] It is understandable that the triggering of the temperature correction condition may lead to the triggering or non-triggering of the autonomous obstacle avoidance condition, and the triggering of the autonomous obstacle avoidance condition is necessarily accompanied by the triggering of the temperature correction condition.

[0087] It is understandable that the autonomous obstacle avoidance module can flexibly adjust the flight strategy of the unmanned helicopter by comprehensively considering the temperature correction conditions and the triggering status of the autonomous obstacle avoidance conditions, thereby effectively improving the execution efficiency of the fire-fighting mission and the flight safety of the UAV, and ensuring the UAV's stable operation capability in complex fire environments.

[0088] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning, characterized in that: include: An information acquisition module is used to collect flight parameters of the unmanned helicopter during flight, obtain fire parameters and weather parameters of the fire scene, and determine the real-time temperature of each preset position of the unmanned helicopter during flight, wherein the flight parameters include flight altitude, flight attitude, flight speed and motor audio data, the fire parameters include the location of the fire point and the scope of the fire scene, and the weather parameters include the current wind speed and the current temperature; Wherein, the preset position is located at the bottom of the unmanned helicopter; a simulation module, which is connected to the information acquisition module, and is used to simulate the fire spread of the fire scene and the distribution of thermal airflow around the fire scene according to the fire condition parameters and the weather parameters, and determine the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the distribution of thermal airflow; A data processing module connected to the information acquisition module, for determining the stable flight state of the unmanned helicopter according to the flight attitude and the motor audio data, and determining a position temperature fluctuation diagram and an overall temperature fluctuation diagram of each preset position according to the real-time temperature of each preset position; The autonomous obstacle avoidance module is connected to the data processing module and the simulation module respectively, and is used to determine whether to trigger the temperature correction condition according to the temperature fluctuation diagram of each position and the overall temperature fluctuation diagram, determine whether to trigger the autonomous obstacle avoidance condition according to the stable flight state, and determine the flight adjustment strategy of the unmanned helicopter's waiting flight route according to the triggering judgment results of the temperature correction condition and the autonomous obstacle avoidance condition, including: Adjust flight parameters, or control the simulation module to redefine the fire-fighting path of the unmanned helicopter; The autonomous obstacle avoidance module determines whether to trigger the temperature correction condition according to the temperature fluctuation graph of a single position and the overall temperature fluctuation graph, wherein: If the real-time temperature of a single preset position at the current time is greater than or equal to the preset temperature and the value of the overall temperature fluctuation graph at the current time is greater than or equal to the preset value, it is determined that the preset position triggers the temperature correction condition; The autonomous obstacle avoidance module determines the flight adjustment strategy of the unmanned helicopter's flight route according to the temperature correction condition and the trigger determination result of the autonomous obstacle avoidance condition, including: If the temperature correction condition and the autonomous obstacle avoidance condition are triggered at the same time, it is determined that the unmanned helicopter increases its flight altitude and then hovers, and the simulation module is controlled to re-determine the fire extinguishing path of the unmanned helicopter; If only the temperature correction condition is triggered, it is determined that the unmanned helicopter adjusts its flight attitude to increase the ground height of the preset positions that trigger the temperature correction condition, wherein if the number of preset positions that trigger the attitude correction is greater than or equal to the number reference value, the flight altitude of the unmanned helicopter is increased; The flight control module is connected to the simulation module and the autonomous obstacle avoidance module respectively, and is used to control the unmanned helicopter to continue flying and performing the fire-fighting mission according to the flight adjustment strategy.

2. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 1, characterized in that: The information acquisition module includes a sensor unit, and the sensor unit includes a plurality of temperature sensors and an audio sensor; The temperature sensor is used to determine the real-time temperature of each preset position of the unmanned helicopter during flight; The audio sensor is used to determine the motor audio data during the flight of the unmanned helicopter.

3. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 1, characterized in that: The simulation module includes CFD simulation software for simulating the fire spread and the hot air flow distribution, and path planning software for determining the initial fire extinguishing path of the unmanned helicopter according to the fire spread and the hot air flow distribution.

4. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 1, characterized in that: The data processing module determines the stable flight state according to whether the change of the flight attitude satisfies the attitude fluctuation condition and whether the current motor audio data exceeds the audio data range, so that the autonomous obstacle avoidance module determines whether the autonomous obstacle avoidance condition is triggered; The stable flight state includes an implicit flight jitter state and an explicit flight jitter state.

5. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 4, characterized in that: The attitude fluctuation condition includes that a change in any parameter in the flight attitude exceeds a preset ratio.

6. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 4, characterized in that: The audio data range is determined based on the average value and standard deviation of historical audio data.

7. The unmanned helicopter flight control system based on autonomous obstacle avoidance and path planning according to claim 1, characterized in that: The data processing module determines the value of the overall temperature fluctuation diagram at a corresponding time according to the real-time temperature of each preset position at the same time.

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