Control method and system of vertical takeoff and landing unmanned aerial vehicle

Abstract

The invention provides a control method and system for a vertical takeoff and landing unmanned aerial vehicle, and the method comprises the following steps: converting the vertical takeoff and landing unmanned aerial vehicle from a vertical flight state to a horizontal flight state through a vertical / horizontal flight state conversion module, or the vertical takeoff and landing unmanned aerial vehicle is converted from the horizontal flight state to the vertical flight state; a wind direction detection module is used for adjusting a nose of the vertical takeoff and landing unmanned aerial vehicle to an angle perpendicular to the wind direction in a hovering flight / position control mode, and the stability of the vertical takeoff and landing unmanned aerial vehicle is improved. According to the technical scheme, effective control over the vertical takeoff and landing unmanned aerial vehicle is achieved, and the complexity and maintenance cost of a control system of the vertical takeoff and landing unmanned aerial vehicle are reduced.

Description

Background Art

[0002] Vertical take-off and landing drones have some technical shortcomings. These shortcomings are mainly due to their unique design and functional requirements, mainly:

[0003] 1. Limited endurance and cruising speed

[0004] Short flight time: Vertical take-off and landing requires a lot of energy, which limits the range of the drone. Due to the problem of battery energy storage and rapid consumption, the flight time of vertical take-off and landing fixed-wing drones is relatively short and cannot be compared with traditional fixed-wing drones.

[0005] Low cruising speed: In order to maintain the ability to take off and land vertically and hover, the design of the drone needs to take into account both the vertical take-off and landing system and the flight system, which may result in its flight speed and maneuverability being unable to compare with single-function aircraft.

[0006] 2. Small load capacity

[0007] Limited payload capacity: Since VTOL fixed-wing drones need to carry additional VTOL systems and control components, this increases the overall weight of the drone, thereby limiting its payload capacity. This limitation may be particularly noticeable in missions that require carrying heavier equipment or supplies.

[0008] 3. Poor wind resistance

[0009] Insufficient wind resistance: VTOL fixed-wing drones may be relatively complex in design and structure, which may result in relatively poor wind resistance when facing severe weather conditions such as strong winds. This may affect the stability and safety of the drone.

[0010] 4. Design complexity and maintenance costs

[0011] Complex design: VTOL fixed-wing UAVs need to meet the requirements of both VTOL and fixed-wing flight, which increases the complexity of the design. UAVs require more control surfaces, motors, sensors and other components to achieve these functions, which may lead to complex design solutions and increased production costs.

[0012] High maintenance cost: Due to its complex design and numerous components, the maintenance cost of vertical take-off and landing fixed-wing drones is also relatively high. This includes the cost of regular inspections, repairs, and replacement of parts.

[0013] Therefore, there is an urgent need to invent a control method and system for a vertical take-off and landing UAV to solve the above problems. Summary of the invention

[0014] The present application provides a control method and system for a vertical take-off and landing UAV, which are used to achieve effective control of the vertical take-off and landing UAV and reduce the complexity and maintenance cost of the vertical take-off and landing UAV control system.

[0015] In a first aspect, a control method for a vertical take-off and landing drone is provided, comprising the following steps:

[0016] Using the vertical / horizontal flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state;

[0017] By utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV.

[0018] In the above technical scheme, by utilizing the vertical / level flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state; by utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV; effective control of the vertical take-off and landing UAV is achieved, and the complexity and maintenance cost of the vertical take-off and landing UAV control system are reduced.

[0019] In a specific embodiment, it also includes:

[0020] The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, and to identify and avoid obstacles.

[0021] In a specific implementation scheme, the steps of converting the vertical take-off and landing UAV from a vertical flight state to a horizontal flight state are specifically as follows:

[0022] Firstly, the vertical take-off and landing UAV is decelerated;

[0023] Then, the aileron of the vertical take-off and landing UAV is raised, so that the vertical take-off and landing UAV obtains a nose-down moment, and under the action of the nose-down moment, the vertical take-off and landing UAV begins to tilt and accelerate.

[0024] The conversion from the vertical state to the horizontal flight state is completed until the pitch angle of the vertical take-off and landing UAV meets the requirement of the horizontal flight state and the airspeed of the vertical take-off and landing UAV meets the minimum airspeed of the horizontal flight.

[0025] In a specific implementation scheme, the step of using a wind direction detection module to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode to improve the stability of the vertical take-off and landing UAV includes:

[0026] By tracking the direction of the thrust vector, an estimate of the wind direction is made.

[0027] In a specific implementation scheme, the step of estimating the wind direction is specifically as follows:

[0028] Using an inertial measurement sensor, the onboard state estimation module calculates the current attitude of the vertical take-off and landing UAV.

[0029] Determine the difference between the angle of the drone controller's set attitude and the angle of the current attitude;

[0030] calculating the thrust direction of the angle to achieve the set attitude, and estimating the opposite direction of the thrust direction as the wind direction;

[0031] The wind direction detection module is used to control the yaw rate of the vertical take-off and landing UAV to turn the heading to the estimated wind direction.

[0032] In a specific implementation scheme, the current posture of the vertical take-off and landing UAV includes a pitch angle, a roll angle, and a yaw angle.

[0033] In a specific implementation scheme, the steps of predicting and locating the position of the vertical take-off and landing UAV, and determining and avoiding obstacles by using the precise positioning and obstacle avoidance module are as follows:

[0034] Using a real-time dynamic measurement module to predict and locate the position of the vertical take-off and landing UAV;

[0035] Using a distance measuring sensor to sense the relative distance between the vertical take-off and landing UAV and the external environment, and to determine obstacles;

[0036] Use the obstacle avoidance module to replan the navigation path and avoid obstacles.

[0037] In the second aspect, a control system for a vertical take-off and landing UAV is provided, comprising:

[0038] A vertical / horizontal flight state conversion module is used to convert a vertical take-off and landing UAV from a vertical flight state to a horizontal flight state, or to convert a vertical take-off and landing UAV from a horizontal flight state to a vertical flight state;

[0039] The wind direction detection module is used to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode, so as to improve the stability of the vertical take-off and landing UAV.

[0040] In the above technical scheme, by utilizing the vertical / level flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state; by utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV; effective control of the vertical take-off and landing UAV is achieved, and the complexity and maintenance cost of the vertical take-off and landing UAV control system are reduced.

[0041] In a specific embodiment, it also includes:

[0042] The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, as well as to identify and avoid obstacles.

[0043] In a specific implementation scheme, the precise positioning and obstacle avoidance module includes:

[0044] A real-time dynamic measurement module, used for predicting and locating the position of the vertical take-off and landing UAV;

[0045] A distance measuring sensor is used to sense the relative distance between the vertical take-off and landing UAV and the external environment and determine obstacles;

[0046] The obstacle avoidance module is used to replan the navigation path and avoid obstacles. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A flowchart of a control method for a vertical take-off and landing UAV provided in an embodiment of the present application;

[0048] Figure 2 A structural block diagram of the control method of the vertical take-off and landing drone provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0050] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0051] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0052] To facilitate understanding of the control method and system of the vertical take-off and landing UAV provided in the embodiment of the present application, its application scenario is first explained. The control method of the vertical take-off and landing UAV provided in the embodiment of the present application is used to realize the effective control of the vertical take-off and landing UAV, reducing the complexity and maintenance cost of the vertical take-off and landing UAV control system. There are some technical disadvantages of vertical take-off and landing UAVs. These disadvantages are mainly due to their unique design and functional requirements, mainly including: 1. Limited endurance and cruising speed; short endurance: vertical take-off and landing requires a lot of energy, which limits the range of the UAV. Due to the energy storage and rapid consumption of the battery, the endurance of the vertical take-off and landing fixed-wing UAV is relatively short and cannot be compared with traditional fixed-wing UAVs. Low cruising speed: In order to maintain the ability of vertical take-off and landing and hovering, the design of the UAV needs to take into account the vertical take-off and landing system and the flight system, which may cause its flight speed and maneuverability to be incomparable with single-function aircraft. 2. Small load capacity; limited payload capacity: Since the vertical take-off and landing fixed-wing UAV needs to carry additional vertical take-off and landing systems and control components, this increases the overall weight of the UAV, thereby limiting its payload capacity. This limitation may be particularly evident in missions that require carrying heavier equipment or supplies. 3. Poor wind resistance; Insufficient wind resistance: Vertical take-off and landing fixed-wing drones may be relatively complex in design and structure, which may result in relatively poor wind resistance when facing severe weather conditions such as strong winds. This may affect the stability and safety of the drone. 4. Design complexity and maintenance cost; Design complexity: Vertical take-off and landing fixed-wing drones need to meet the needs of vertical take-off and landing and fixed-wing flight at the same time, which increases the complexity of the design. Drones require more control surfaces, motors, sensors and other components to achieve these functions, which may lead to the complication of the design scheme and the increase of production costs. High maintenance cost: Due to the complex design and numerous components, the maintenance cost of vertical take-off and landing fixed-wing drones is also relatively high. This includes regular inspections, repairs and replacement of parts. For this reason, the embodiment of the present application provides a control method and system for a vertical take-off and landing drone to achieve effective control of a vertical take-off and landing drone, reducing the complexity and maintenance cost of the vertical take-off and landing drone control system. The following is a detailed description of the embodiment in conjunction with specific drawings.

[0053] refer to Figure 1 and Figure 2 , Figure 1 A flowchart of a control method for a vertical take-off and landing UAV provided in an embodiment of the present application; Figure 2 A structural block diagram of the control method of the vertical take-off and landing drone provided in an embodiment of the present application.

[0054] exist Figure 1 In the embodiment of the present application, a control method for a vertical take-off and landing drone is provided, comprising the following steps:

[0055] Using the vertical / horizontal flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state;

[0056] By utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV.

[0057] In the above technical scheme, by utilizing the vertical / level flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state; by utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV; effective control of the vertical take-off and landing UAV is achieved, and the complexity and maintenance cost of the vertical take-off and landing UAV control system are reduced.

[0058] In a specific embodiment, it also includes:

[0059] The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, and to identify and avoid obstacles.

[0060] In a specific implementation scheme, the steps of converting the vertical take-off and landing UAV from a vertical flight state to a horizontal flight state are specifically as follows:

[0061] Firstly, the vertical take-off and landing UAV is decelerated;

[0062] Then, the aileron of the vertical take-off and landing UAV is raised, so that the vertical take-off and landing UAV obtains a nose-down moment, and under the action of the nose-down moment, the vertical take-off and landing UAV begins to tilt and accelerate.

[0063] The conversion from the vertical state to the horizontal flight state is completed until the pitch angle of the vertical take-off and landing UAV meets the requirement of the horizontal flight state and the airspeed of the vertical take-off and landing UAV meets the minimum airspeed of the horizontal flight.

[0064] In a specific implementation scheme, the step of using a wind direction detection module to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode to improve the stability of the vertical take-off and landing UAV includes:

[0065] By tracking the direction of the thrust vector, an estimate of the wind direction is made.

[0066] In a specific implementation scheme, the step of estimating the wind direction is specifically as follows:

[0067] Using an inertial measurement sensor, the onboard state estimation module calculates the current attitude of the vertical take-off and landing UAV.

[0068] Determine the difference between the angle of the drone controller's set attitude and the angle of the current attitude;

[0069] calculating the thrust direction of the angle to achieve the set attitude, and estimating the opposite direction of the thrust direction as the wind direction;

[0070] The wind direction detection module is used to control the yaw rate of the vertical take-off and landing UAV to turn the heading to the estimated wind direction.

[0071] In a specific implementation scheme, the current posture of the vertical take-off and landing UAV includes a pitch angle, a roll angle, and a yaw angle.

[0072] It should be noted that the function of the wind direction detection module is to automatically turn the nose of the drone to an angle perpendicular to the wind direction in the hovering flight / position control mode to improve stability and reduce the possibility of side wind blowing against the wings and causing the body to flip or drift. During hovering flight, the drone needs to overcome the resistance imposed by the wind to maintain its position. By tracking the direction of the thrust vector, the wind direction can be estimated. Using the inertial measurement sensor (IMU, Inertial Measurement Unit), the current attitude of the drone (pitch angle / roll angle / yaw angle) is calculated by the airborne state estimation module, and the difference (size and direction) between the attitude angle set by the drone controller and the current attitude angle is judged. The thrust direction that reaches the set angle is calculated, and the opposite direction of its thrust direction is approximately regarded as the wind direction. The wind direction detection module is used to control the yaw rate that turns the heading of the drone to the estimated wind direction.

[0073] In a specific implementation scheme, the steps of predicting and locating the position of the vertical take-off and landing UAV, and determining and avoiding obstacles by using the precise positioning and obstacle avoidance module are as follows:

[0074] Using a real-time dynamic measurement module to predict and locate the position of the vertical take-off and landing UAV;

[0075] Using a distance measuring sensor to sense the relative distance between the vertical take-off and landing UAV and the external environment, and to determine obstacles;

[0076] Use the obstacle avoidance module to replan the navigation path and avoid obstacles.

[0077] Specifically, by adding an RTK (real-time kinematic measurement) module to the drone system, accurate positioning can be achieved in the case of networked take-off and landing. RTK positioning technology is a real-time dynamic positioning technology based on carrier phase observations. It can provide the three-dimensional coordinates of the drone in a specified coordinate system in real time with centimeter-level accuracy. The drone navigation system integrates this observation value and converts it into the airborne navigation system to achieve accurate prediction and positioning of the position.

[0078] When a tail-mounted UAV flies in multi-rotor mode, it needs to take off and land vertically in a complex environment at an ultra-low altitude of 50m to the ground, so an obstacle avoidance module is required to increase safety. Specifically, by adding a ranging sensor, the UAV can sense the relative distance between the UAV and the external environment and make obstacle determinations. Then, the navigation path can be replanned through the UAV control system to avoid obstacles.

[0079] exist Figure 2 In the embodiment of the present application, a control system for a vertical take-off and landing UAV is provided, comprising:

[0080] A vertical / horizontal flight state conversion module is used to convert a vertical take-off and landing UAV from a vertical flight state to a horizontal flight state, or to convert a vertical take-off and landing UAV from a horizontal flight state to a vertical flight state;

[0081] The wind direction detection module is used to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode, so as to improve the stability of the vertical take-off and landing UAV.

[0082] In the above technical scheme, by utilizing the vertical / level flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state; by utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV; effective control of the vertical take-off and landing UAV is achieved, and the complexity and maintenance cost of the vertical take-off and landing UAV control system are reduced.

[0083] In a specific embodiment, it also includes:

[0084] The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, as well as to identify and avoid obstacles.

[0085] In a specific implementation scheme, the precise positioning and obstacle avoidance module includes:

[0086] A real-time dynamic measurement module, used for predicting and locating the position of the vertical take-off and landing UAV;

[0087] A distance measuring sensor is used to sense the relative distance between the vertical take-off and landing UAV and the external environment and determine obstacles;

[0088] The obstacle avoidance module is used to replan the navigation path and avoid obstacles.

[0089] Those skilled in the art will appreciate that the present application may be implemented as a system, method or computer program product.

[0090] Therefore, the present disclosure may be specifically implemented in the following forms, namely: it may be completely hardware, it may be completely software (including firmware, resident software, microcode, etc.), or it may be a combination of hardware and software, generally referred to herein as a "circuit", "module" or "system". In addition, in some embodiments, the present application may also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable medium may contain computer-readable program code.

[0091] Any combination of one or more computer-readable media can be used. Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: electrical connections with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this document, computer-readable storage media can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0092] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present application. On this basis, a variety of replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A control method for a vertical take-off and landing UAV, characterized in that: The following steps are involved: Using the vertical / horizontal flight state conversion module, the vertical take-off and landing UAV is converted from a vertical flight state to a horizontal flight state, or the vertical take-off and landing UAV is converted from a horizontal flight state to a vertical flight state; By utilizing the wind direction detection module, the nose of the vertical take-off and landing UAV is adjusted to an angle perpendicular to the wind direction in the hovering flight / position control mode, thereby improving the stability of the vertical take-off and landing UAV.

2. The control method of a vertical take-off and landing UAV according to claim 1, characterized in that: Also includes: The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, and to identify and avoid obstacles.

3. The control method of the vertical take-off and landing UAV according to claim 2, characterized in that: The steps for converting a vertical take-off and landing UAV from a vertical flight state to a horizontal flight state are as follows: Firstly, the vertical take-off and landing UAV is decelerated; Then, the aileron of the vertical take-off and landing UAV is raised, so that the vertical take-off and landing UAV obtains a nose-down moment, and under the action of the nose-down moment, the vertical take-off and landing UAV begins to tilt and accelerate. The conversion from the vertical state to the horizontal flight state is completed until the pitch angle of the vertical take-off and landing UAV meets the requirement of the horizontal flight state and the airspeed of the vertical take-off and landing UAV meets the minimum airspeed of the horizontal flight.

4. The control method of the vertical take-off and landing UAV according to claim 3, characterized in that: The step of using a wind direction detection module to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in a hovering flight / position control mode to improve the stability of the vertical take-off and landing UAV includes: By tracking the direction of the thrust vector, an estimate of the wind direction is made.

5. The control method of a vertical take-off and landing UAV according to claim 4, characterized in that: The steps to estimate wind direction are as follows: Using an inertial measurement sensor, the onboard state estimation module calculates the current attitude of the vertical take-off and landing UAV. Determine the difference between the angle of the drone controller's set attitude and the angle of the current attitude; calculating the thrust direction of the angle to achieve the set attitude, and estimating the opposite direction of the thrust direction as the wind direction; The wind direction detection module is used to control the yaw rate of the vertical take-off and landing UAV to turn the heading to the estimated wind direction.

6. The control method of the vertical take-off and landing UAV according to claim 5, characterized in that: The current posture of the vertical take-off and landing UAV includes a pitch angle, a roll angle, and a yaw angle.

7. The control method of a vertical take-off and landing UAV according to claim 6, characterized in that: The steps of using the precise positioning and obstacle avoidance module to predict and locate the position of the vertical take-off and landing UAV, and to determine and avoid obstacles are as follows: Using a real-time dynamic measurement module to predict and locate the position of the vertical take-off and landing UAV; Using a distance measuring sensor to sense the relative distance between the vertical take-off and landing UAV and the external environment, and to determine obstacles; Use the obstacle avoidance module to replan the navigation path and avoid obstacles.

8. A control system for a vertical take-off and landing UAV, characterized in that: include: A vertical / horizontal flight state conversion module is used to convert a vertical take-off and landing UAV from a vertical flight state to a horizontal flight state, or to convert a vertical take-off and landing UAV from a horizontal flight state to a vertical flight state; The wind direction detection module is used to adjust the nose of the vertical take-off and landing UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode, so as to improve the stability of the vertical take-off and landing UAV.

9. The control system of the vertical take-off and landing UAV according to claim 8, characterized in that: Also includes: The precise positioning and obstacle avoidance module is used to predict and locate the position of the vertical take-off and landing UAV, as well as to identify and avoid obstacles.

10. The control system of the vertical take-off and landing UAV according to claim 9, characterized in that: The precise positioning and obstacle avoidance module includes: A real-time dynamic measurement module, used for predicting and locating the position of the vertical take-off and landing UAV; A distance measuring sensor is used to sense the relative distance between the vertical take-off and landing UAV and the external environment and determine obstacles; The obstacle avoidance module is used to replan the navigation path and avoid obstacles.

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