A control method and system for a vertical take-off and landing drone

Abstract

The application provides a control method and system of a vertical take-off and landing unmanned aerial vehicle. The control method comprises the following steps: using a vertical / horizontal flight state conversion module to convert the vertical flight state of the vertical take-off and landing unmanned aerial vehicle into the horizontal flight state, or convert the horizontal flight state of the vertical take-off and landing unmanned aerial vehicle into the vertical flight state; using a wind direction detection module to adjust the nose of the vertical take-off and landing unmanned aerial vehicle to an angle perpendicular to the wind direction in the hovering flight / position control mode, and improve the stability of the vertical take-off and landing unmanned aerial vehicle. In the above technical solution, the effective control of the vertical take-off and landing unmanned aerial vehicle is realized, and the complexity and maintenance cost of the vertical take-off and landing unmanned aerial vehicle control system are reduced.

Description

Technical Field

[0001] This application relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a control method and system for a vertical take-off and landing (VTOL) UAV. Background Technology

[0002] Vertical takeoff and landing (VTOL) drones have some technical drawbacks. These drawbacks mainly stem from their unique design and functional requirements, and include:

[0003] 1. Limited battery life and cruising speed.

[0004] Shorter flight time: Vertical takeoff and landing (VTOL) requires a significant amount of energy, which limits the range of drones. Due to issues with battery energy storage and rapid depletion, VTOL fixed-wing drones have relatively short flight times compared to traditional fixed-wing drones.

[0005] Lower cruising speed: In order to maintain the ability to take off and land vertically and hover, the design of drones needs to take into account both the vertical take-off and landing system and the flight system, which may result in their flight speed and maneuverability not being comparable to single-function aircraft.

[0006] 2. Low load capacity

[0007] Limited payload capacity: Because vertical takeoff and landing (VTOL) fixed-wing UAVs need to carry additional VTOL systems and control components, this increases the overall weight of the UAV, thus limiting its payload capacity. This limitation can be particularly pronounced in missions requiring the carrying of heavy equipment or supplies.

[0008] 3. Poor wind resistance

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

[0010] 4. Design complexity and maintenance costs

[0011] Design complexity: Vertical takeoff and landing (VTOL) fixed-wing UAVs need to simultaneously meet the requirements of vertical takeoff and landing and fixed-wing flight, which increases design complexity. UAVs require more control surfaces, motors, sensors, and other components to achieve these functions, potentially leading to more complex design solutions and increased production costs.

[0012] High maintenance costs: Due to their complex design and numerous components, the maintenance costs of vertical takeoff and landing fixed-wing UAVs are relatively high. This includes the costs of regular inspections, repairs, and component replacements.

[0013] Therefore, there is an urgent need to invent a control method and system for vertical take-off and landing unmanned aerial vehicles (UAVs) to solve the above problems. Summary of the Invention

[0014] This application provides a control method and system for a vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) to achieve effective control of the VTOL UAV and reduce the complexity and maintenance cost of the VTOL UAV control system.

[0015] Firstly, a control method for a vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) is provided, comprising the following steps:

[0016] The vertical / horizontal flight state conversion module is used to convert vertical take-off and landing UAVs from vertical flight state to horizontal flight state, or to convert vertical take-off and landing UAVs from horizontal flight state to vertical flight state.

[0017] By using a wind direction detection module, the nose of the VTOL UAV is adjusted to an angle perpendicular to the wind direction in hovering flight / position control mode, thereby improving the stability of the VTOL UAV.

[0018] In the above technical solution, a vertical / horizontal flight state conversion module is used to convert the vertical take-off and landing (VTOL) UAV from vertical flight state to horizontal flight state, or vice versa; a wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering / position control mode, thereby improving the stability of the VTOL UAV; effective control of the VTOL UAV is achieved, reducing the complexity and maintenance cost of the VTOL UAV control system.

[0019] In one specific implementation scheme, 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, as well as to identify and avoid obstacles.

[0021] In a specific feasible implementation, the steps for transitioning a vertical takeoff and landing (VTOL) UAV from vertical flight to horizontal flight are as follows:

[0022] First, the vertical takeoff and landing UAV is decelerated;

[0023] Then, the ailerons of the VTOL UAV rise, giving the VTOL UAV a nose-down moment, and under the action of the nose-down moment, the VTOL UAV begins to tilt and accelerate.

[0024] The transition from vertical to horizontal flight is completed when the pitch angle of the VTOL UAV meets the requirements for horizontal flight and the airspeed of the VTOL UAV meets the minimum airspeed for horizontal flight.

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

[0026] Wind direction is estimated by tracking the direction of the thrust vector.

[0027] In a specific feasible implementation, the steps for estimating wind direction are as follows:

[0028] The current attitude of the vertical takeoff and landing UAV is calculated using an inertial measurement sensor and an onboard state estimation module.

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

[0030] Calculate the thrust direction at the angle to achieve the set attitude, and estimate the opposite direction of the thrust direction as the wind direction;

[0031] Using the wind direction detection module, the heading of the vertical take-off and landing UAV is controlled by a yaw rate that turns towards the estimated wind direction.

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

[0033] In one specific implementation scheme, the steps of using a precise positioning and obstacle avoidance module to predict and locate the position of the vertical take-off and landing UAV, and to identify and avoid obstacles, are as follows:

[0034] The position of the vertical take-off and landing UAV is predicted and located using a real-time dynamic measurement module.

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

[0036] The obstacle avoidance module is used to replan the navigation path and avoid obstacles.

[0037] Secondly, a control system for a vertical take-off and landing unmanned aerial vehicle (UAV) is provided, including:

[0038] The vertical / horizontal flight state conversion module is used to convert vertical flight state to horizontal flight state for vertical take-off and landing UAVs, or to convert horizontal flight state to vertical flight state for vertical take-off and landing UAVs.

[0039] The wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering flight / position control mode, thereby improving the stability of the VTOL UAV.

[0040] In the above technical solution, a vertical / horizontal flight state conversion module is used to convert the vertical take-off and landing (VTOL) UAV from vertical flight state to horizontal flight state, or vice versa; a wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering / position control mode, thereby improving the stability of the VTOL UAV; effective control of the VTOL UAV is achieved, reducing the complexity and maintenance cost of the VTOL UAV control system.

[0041] In one specific implementation scheme, 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 one specific implementation scheme, the precise positioning and obstacle avoidance module includes:

[0044] A real-time dynamic measurement module is used to predict and locate the position of the vertical take-off and landing UAV.

[0045] A ranging sensor is used to sense the relative distance between the vertical takeoff and landing UAV and the external environment, and to identify obstacles;

[0046] The obstacle avoidance module is used to replan the navigation path and avoid obstacles. Attached Figure Description

[0047] Figure 1 A flowchart illustrating the control method for a vertical take-off and landing unmanned aerial vehicle provided in an embodiment of this application;

[0048] Figure 2 This is a structural block diagram of the control method for a vertical take-off and landing unmanned aerial vehicle provided in an embodiment of this application. Detailed Implementation

[0049] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0050] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0051] Furthermore, the technical features involved in the different embodiments of this 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 for a vertical takeoff and landing (VTOL) UAV provided in this application embodiment, its application scenario is first described. The control method for a VTOL UAV provided in this application embodiment is used to achieve effective control of the VTOL UAV, reducing the complexity and maintenance cost of the VTOL UAV control system. VTOL UAVs have some technical drawbacks. These drawbacks mainly stem from their unique design and functional requirements, including: 1. Limited endurance and cruising speed; Short endurance: Vertical takeoff and landing consume a large amount of energy, which limits the UAV's range. Due to battery energy storage and rapid consumption issues, the endurance of VTOL fixed-wing UAVs is relatively short, incomparable to traditional fixed-wing UAVs. Low cruising speed: To maintain vertical takeoff and landing and hovering capabilities, the UAV design needs to consider both the vertical takeoff and landing system and the flight system, which may result in its flight speed and maneuverability being incomparable to single-function aircraft. 2. Small payload capacity; Limited effective payload capacity: Since VTOL fixed-wing UAVs need to carry additional vertical takeoff and landing systems and control components, this increases the overall weight of the UAV, thereby limiting its effective payload capacity. This limitation may be particularly pronounced in missions requiring the carrying of heavy equipment or supplies. 3. Poor wind resistance; Insufficient wind resistance: VTOL fixed-wing UAVs 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 UAV. 4. Design complexity and maintenance costs; Design complexity: VTOL fixed-wing UAVs need to simultaneously meet the requirements of vertical takeoff and landing and fixed-wing flight, which increases design complexity. UAVs require more control surfaces, motors, sensors, and other components to achieve these functions, which may lead to more complex design schemes and increased production costs. High maintenance costs: Due to the design complexity and numerous components, the maintenance costs of VTOL fixed-wing UAVs are also relatively high. This includes the costs of regular inspections, repairs, and component replacements. To address this, this application provides a control method and system for a VTOL UAV to achieve effective control of the VTOL UAV and reduce the complexity and maintenance costs of the VTOL UAV control system. The following detailed description, in conjunction with specific accompanying drawings, illustrates the embodiments.

[0053] refer to Figure 1 and Figure 2 , Figure 1 A flowchart illustrating the control method for a vertical take-off and landing unmanned aerial vehicle provided in an embodiment of this application; Figure 2 This is a structural block diagram of the control method for a vertical take-off and landing unmanned aerial vehicle provided in an embodiment of this application.

[0054] exist Figure 1 This application provides a control method for a vertical take-off and landing unmanned aerial vehicle (UAV), comprising the following steps:

[0055] The vertical / horizontal flight state conversion module is used to convert vertical take-off and landing UAVs from vertical flight state to horizontal flight state, or to convert vertical take-off and landing UAVs from horizontal flight state to vertical flight state.

[0056] By using a wind direction detection module, the nose of the VTOL UAV is adjusted to an angle perpendicular to the wind direction in hovering flight / position control mode, thereby improving the stability of the VTOL UAV.

[0057] In the above technical solution, a vertical / horizontal flight state conversion module is used to convert the vertical take-off and landing (VTOL) UAV from vertical flight state to horizontal flight state, or vice versa; a wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering / position control mode, thereby improving the stability of the VTOL UAV; effective control of the VTOL UAV is achieved, reducing the complexity and maintenance cost of the VTOL UAV control system.

[0058] In one specific implementation scheme, 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, as well as to identify and avoid obstacles.

[0060] In a specific feasible implementation, the steps for transitioning a vertical takeoff and landing (VTOL) UAV from vertical flight to horizontal flight are as follows:

[0061] First, the vertical takeoff and landing UAV is decelerated;

[0062] Then, the ailerons of the VTOL UAV rise, giving the VTOL UAV a nose-down moment, and under the action of the nose-down moment, the VTOL UAV begins to tilt and accelerate.

[0063] The transition from vertical to horizontal flight is completed when the pitch angle of the VTOL UAV meets the requirements for horizontal flight and the airspeed of the VTOL UAV meets the minimum airspeed for horizontal flight.

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

[0065] Wind direction is estimated by tracking the direction of the thrust vector.

[0066] In a specific feasible implementation, the steps for estimating wind direction are as follows:

[0067] The current attitude of the vertical takeoff and landing UAV is calculated using an inertial measurement sensor and an onboard state estimation module.

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

[0069] Calculate the thrust direction at the angle to achieve the set attitude, and estimate the opposite direction of the thrust direction as the wind direction;

[0070] Using the wind direction detection module, the heading of the vertical take-off and landing UAV is controlled by a yaw rate that turns towards the estimated wind direction.

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

[0072] It should be noted that the wind direction detection module automatically turns the drone's nose to an angle perpendicular to the wind direction during hovering / position control mode. This improves stability and reduces the likelihood of crosswinds hitting the wings and causing the drone to roll or drift. During hovering, the drone needs to overcome wind resistance to maintain its position. By tracking the direction of the thrust vector, the wind direction can be estimated. Using an inertial measurement unit (IMU), the onboard state estimation module calculates the drone's current attitude (pitch / roll / yaw angle). By comparing the attitude angles set by the drone controller with the current attitude angles (both in magnitude and direction), the thrust direction required to reach the set angle is calculated, and the opposite direction of this thrust direction is approximated as the wind direction. The wind direction detection module is used to control the yaw rate that turns the drone's heading to the estimated wind direction.

[0073] In one specific implementation scheme, the steps of using a precise positioning and obstacle avoidance module to predict and locate the position of the vertical take-off and landing UAV, and to identify and avoid obstacles, are as follows:

[0074] The position of the vertical take-off and landing UAV is predicted and located using a real-time dynamic measurement module.

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

[0076] The obstacle avoidance module is used to replan the navigation path and avoid obstacles.

[0077] Specifically, by adding an RTK (Real-Time Kinematics) module to the UAV system, precise positioning is achieved during network takeoff and landing. RTK positioning technology is a real-time dynamic positioning technology based on carrier phase observations, which can provide the UAV's three-dimensional coordinates in a specified coordinate system with centimeter-level accuracy in real time. The UAV navigation system integrates these observation values ​​and converts them into the onboard navigation system to achieve accurate prediction and positioning.

[0078] Tail-mounted drones, flying in multi-rotor mode, require vertical takeoff and landing in complex environments at ultra-low altitudes (50m to ground level), necessitating the addition of obstacle avoidance modules to enhance safety. Specifically, this is achieved by adding ranging sensors, allowing the drone to perceive its relative distance to the external environment and identify obstacles. The drone's control system then replans its navigation path to avoid these obstacles.

[0079] exist Figure 2 In addition, this application embodiment also provides a control system for a vertical take-off and landing unmanned aerial vehicle (UAV), including:

[0080] The vertical / horizontal flight state conversion module is used to convert vertical flight state to horizontal flight state for vertical take-off and landing UAVs, or to convert horizontal flight state to vertical flight state for vertical take-off and landing UAVs.

[0081] The wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering flight / position control mode, thereby improving the stability of the VTOL UAV.

[0082] In the above technical solution, a vertical / horizontal flight state conversion module is used to convert the vertical take-off and landing (VTOL) UAV from vertical flight state to horizontal flight state, or vice versa; a wind direction detection module is used to adjust the nose of the VTOL UAV to an angle perpendicular to the wind direction in hovering / position control mode, thereby improving the stability of the VTOL UAV; effective control of the VTOL UAV is achieved, reducing the complexity and maintenance cost of the VTOL UAV control system.

[0083] In one specific implementation scheme, 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 one specific implementation scheme, the precise positioning and obstacle avoidance module includes:

[0086] A real-time dynamic measurement module is used to predict and locate the position of the vertical take-off and landing UAV.

[0087] A ranging sensor is used to sense the relative distance between the vertical takeoff and landing UAV and the external environment, and to identify obstacles;

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

[0089] Those skilled in the art will know that this application can be implemented as a system, method, or computer program product.

[0090] Therefore, this disclosure can be implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, this application can also be implemented as a computer program product in one or more computer-readable media, which contains computer-readable program code.

[0091] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0092] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application. Based on this, various substitutions and improvements can be made to this application, all of which fall within the protection scope of this application.

Claims

1. A control method of a vertical take-off and landing drone, characterized by, The method comprises the following steps: The vertical / horizontal flight state conversion module is used to convert the vertical flight state of the vertical take-off and landing UAV into the horizontal flight state, or convert the horizontal flight state of the vertical take-off and landing UAV into the 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; The method further comprises the following steps: The precise positioning and obstacle avoidance module is used to predict and position the vertical take-off and landing UAV, and determine and avoid obstacles; The step of converting the vertical flight state of the vertical take-off and landing UAV into the horizontal flight state comprises the following steps: First, 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 low head torque, and starts to tilt and accelerate under the action of the low head torque, 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, the conversion from the vertical state into the horizontal flight state is completed; The step of adjusting 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 comprises the following steps: The direction of the thrust vector is tracked to estimate the wind direction; The step of estimating the wind direction comprises the following steps: The current attitude of the vertical take-off and landing UAV is calculated by the on-board state estimation module using the inertial measurement sensor, The difference between the angle of the set attitude of the UAV controller and the angle of the current attitude is determined; The thrust direction reaching the angle of the set attitude is calculated, and the opposite direction of the thrust direction is estimated as the wind direction; The heading of the vertical take-off and landing UAV is controlled to turn to the yaw rate of the estimated wind direction by the wind direction detection module.

2. The control method of the vertical take-off and landing drone according to claim 1, wherein The current attitude of the vertical take-off and landing UAV includes the pitch angle, roll angle and yaw angle.

3. The control method of a vertical take-off and landing drone according to claim 2, wherein, The step of predicting and positioning the vertical take-off and landing UAV and determining and avoiding obstacles by the precise positioning and obstacle avoidance module comprises the following steps: The position of the vertical take-off and landing UAV is predicted and positioned by the real-time dynamic measurement module; The relative distance between the vertical take-off and landing UAV and the external environment is sensed by the distance measurement sensor to determine the obstacles; The navigation path is re-planned by the obstacle avoidance module to avoid the obstacles.

4. A control system for a vertical take-off and landing drone, characterized in that, The control method of the vertical take-off and landing UAV and the control system of the vertical take-off and landing UAV for realizing the method comprise the following steps: The vertical / horizontal flight state conversion module is used to convert the vertical flight state of the vertical take-off and landing UAV into the horizontal flight state, or convert the horizontal flight state of the vertical take-off and landing UAV into the vertical flight state; The wind direction detection module is used for adjusting the nose of the VTOL UAV to an angle perpendicular to the wind direction in the hovering flight / position control mode, and improving the stability of the VTOL UAV. Further comprising: The precise positioning and obstacle avoidance module is used for predicting and positioning the position of the VTOL UAV, and judging and avoiding obstacles. The precise positioning and obstacle avoidance module comprises: The real-time dynamic measurement module is used for predicting and positioning the position of the VTOL UAV. The distance measuring sensor is used for sensing the relative distance between the VTOL UAV and the external environment, and judging obstacles. The obstacle avoidance module is used for re-planning the navigation path and avoiding obstacles.

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