Vehicle-mounted take-off and landing and following accompanying method and device for mooring unmanned aerial vehicle

Abstract

A target position point is sent to an unmanned aerial vehicle through ground equipment, the unmanned aerial vehicle takes the target point as a flight target, and the unmanned aerial vehicle flies to the target point, keeps relative positions with the target and always moves along with the ground target. Therefore, the mooring multi-rotor unmanned aerial vehicle can automatically follow the vehicle platform to synchronously fly. The unmanned aerial vehicle can automatically follow the vehicle to run, so that the maneuverability and task capability of the system are improved, and task deployment and team cooperation are more flexible.

Description

Technical Field

[0001] The invention relates to the technical field of tethered multi-rotor unmanned aerial vehicles, and in particular to a vehicle-mounted take-off and landing and follow-up flight method and device for a tethered unmanned aerial vehicle. Background Art

[0002] A tethered drone, also known as a tethered UAV, is a special form of multi-rotor drone. It uses ground power transmitted through a tethered cable as its power source, replacing traditional lithium batteries. Its most important feature is its ability to hover in the air for a long time.

[0003] Most of the tethered multi-rotor drones in the existing technology can only achieve fixed-point take-off, landing, hovering, self-stabilization, and fixed-altitude working modes. They do not have the ability to take off and land on a vehicle or follow and fly together, which limits the convenience and extensiveness of the system.

[0004] It can be seen that in current practical applications, the tethered multi-rotor system does not have the ability to maintain a stable relative position relationship with the moving vehicle, and does not have the ability to take off from the vehicle platform and land safely on the vehicle platform. This is mainly because there is no software and hardware platform support, and the lack of position data causes the flight control algorithm accuracy to fail to meet the use requirements. Summary of the invention

[0005] In view of the above problems, the present invention provides a method and device for taking off and landing a tethered UAV on a vehicle and for following and flying with it, which are used to overcome the above problems or at least partially solve the above problems.

[0006] The present invention provides the following scheme:

[0007] A method for taking off and landing a tethered UAV on a vehicle and accompanying flight, comprising:

[0008] The latitude and longitude of the current position of the UAV are obtained as the expected horizontal coordinates, and the expected vertical height value is determined as the expected take-off height parameter; the first posture information of the current UAV is obtained according to the posture solution, and the position and speed errors in the NED coordinate system are obtained according to the first posture information combined with the expected horizontal coordinates and the expected take-off height parameter, and the motor parameters are adjusted according to the first series PID control method, and the first posture control of the UAV is performed, so that the UAV takes off to the specified position height, thereby realizing the take-off function of the UAV;

[0009] Acquire the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, perform posture calculation according to the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, obtain the speed deviation in combination with the current speed of the UAV, adjust the motor parameters according to the first series PID control method, perform the second posture control on the UAV, and realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform;

[0010] After determining that a landing instruction has been received, the landing type contained in the landing instruction is judged, and the landing type includes direct landing and vehicle-mounted landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, and the third posture control is performed on the UAV to realize the autonomous landing function of the UAV.

[0011] Preferably: the first series PID control method includes:

[0012] The outer loop obtains the angle difference based on the expected posture and the current posture, acts on the proportional link of the outer loop, obtains the expected angular velocity and transmits it to the inner loop;

[0013] The inner loop obtains the angular velocity difference according to the desired angular velocity and the current angular velocity, and acts on the PID link of the inner loop. At the same time, the desired angular velocity is accumulated to the control amount output by the PID through the feedforward channel to obtain the final control amount to be transmitted to the mixer.

[0014] Preferably: the landing control strategy corresponding to the direct landing includes:

[0015] The positioning solution value in hover mode is used as the default value for target landing; when it is determined that direct landing is required, the current XY coordinates are locked and vertical landing is performed.

[0016] Preferably: the landing control strategy corresponding to the vehicle-mounted landing includes:

[0017] The drone is controlled to descend to the landing and return altitude of the following vehicle, the relative XY coordinate value of the drone relative to the vehicle platform is found, and the relative XY coordinate value found is locked to vertically land on the ground vehicle platform.

[0018] Preferably, the step of finding the relative XY coordinate value of the drone relative to the vehicle-mounted platform, locking the found relative XY coordinate value and vertically landing on the ground vehicle-mounted platform comprises:

[0019] According to the position and heading information given by the ground Beidou satellite navigation equipment and the airborne Beidou satellite navigation equipment, the relative position of the UAV and the ground vehicle platform in the NED coordinate system is calculated, and the expected relative position is calculated in combination with the landing point on the ground vehicle platform. The UAV is subjected to the third posture control according to the second series PID control method to achieve the landing of the UAV on the ground vehicle platform.

[0020] Preferably: the second series PID control method includes:

[0021] The outer loop position controller calculates the position deviation by combining the target position and the current position information of the UAV, multiplies it by the position proportional coefficient to obtain the target speed, and transmits the target speed to the inner loop speed PID controller;

[0022] The inner loop speed PID controller calculates the desired posture and the desired total pulling force by combining the target speed and the actual speed;

[0023] After the desired attitude and the desired total pulling force are transmitted to the attitude controller, the target motor drive signal is output through the mixer and the motor driver to adjust the attitude of the UAV and realize the control of movement from the current position to the target position.

[0024] Preferably: the received position coordinates of the ground vehicle-mounted platform are fed back via a target absolute position message.

[0025] A tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up flight device, used to perform the above-mentioned tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up flight method, the device comprising:

[0026] The take-off function realization unit is used to obtain the latitude and longitude of the current position point of the UAV as the expected horizontal coordinate, determine the expected vertical height value as the expected take-off height parameter; obtain the first position information of the current UAV according to the posture solution, obtain the position and speed error in the NED coordinate system according to the first posture information combined with the expected horizontal coordinate and the expected take-off height parameter, adjust the motor parameters according to the first series PID control method, perform the first posture control on the UAV, make the UAV take off to the specified position height, and realize the take-off function of the UAV;

[0027] The accompanying flight function realization unit is used to obtain the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, and perform posture calculation according to the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, combine the current speed of the UAV, obtain the speed deviation, adjust the motor parameters according to the first series PID control method, and perform the second posture control on the UAV to realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform;

[0028] The autonomous landing function implementation unit is used to determine the landing type contained in the landing instruction after receiving the landing instruction, and the landing type includes direct landing and vehicle-mounted landing; adjust the motor parameters according to the landing control strategy corresponding to the determined landing type, perform third posture control on the UAV, and realize the autonomous landing function of the UAV.

[0029] A tethered UAV vehicle-mounted take-off and landing and follow-up flight device, the device comprising a processor and a memory:

[0030] The memory is used to store program code and transmit the program code to the processor;

[0031] The processor is used to execute the above-mentioned tethered UAV vehicle-mounted take-off and landing and follow-up flight method according to the instructions in the program code.

[0032] A computer-readable storage medium is used to store program codes, and the program codes are used to execute the above-mentioned tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up flight method.

[0033] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0034] The embodiment of the present application provides a method and device for taking off and landing a tethered drone on a vehicle and following the drone. The ground equipment sends a target position point to the drone, and the drone takes the target point as the flight target and flies to this point. The drone and the target maintain relative positions and always follow the ground target. The tethered multi-rotor drone can automatically follow the vehicle platform to fly synchronously. Since the drone can automatically follow the vehicle, the system's mobility and mission capabilities are improved, making task deployment and team collaboration more flexible.

[0035] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 This is a flow chart of a method for taking off and landing a tethered UAV on a vehicle and following its flight provided by an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of a UAV following flight provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of an internal data interface of an aircraft platform provided by an embodiment of the present invention;

[0040] Figure 4 is a position control block diagram provided by an embodiment of the present invention;

[0041] Figure 5 is a posture control block diagram provided by an embodiment of the present invention;

[0042] Figure 6 is a takeoff control flow chart provided by an embodiment of the present invention;

[0043] Figure 7 is a vehicle landing control flow chart provided by an embodiment of the present invention;

[0044] Figure 8 This is a follow-up flight control flow chart provided by an embodiment of the present invention;

[0045] Fig. 9 It is a schematic diagram of a vehicle-mounted take-off and landing and follow-up flight device for a tethered UAV provided by an embodiment of the present invention;

[0046] Fig.10 It is a schematic diagram of a tethered UAV vehicle-mounted take-off and landing and follow-up flight equipment provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0048] See also Figure 1 , a method for taking off and landing a tethered UAV on a vehicle and accompanying flight provided by an embodiment of the present invention, such as Figure 1As shown, the method may include:

[0049] The latitude and longitude of the current position of the UAV are obtained as the expected horizontal coordinates, and the expected vertical height value is determined as the expected take-off height parameter; the first posture information of the current UAV is obtained according to the posture solution, and the position and speed errors in the NED coordinate system are obtained according to the first posture information combined with the expected horizontal coordinates and the expected take-off height parameter, and the motor parameters are adjusted according to the first series PID control method, and the first posture control of the UAV is performed, so that the UAV takes off to the specified position height, thereby realizing the take-off function of the UAV;

[0050] Acquire the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, perform posture calculation according to the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, obtain the speed deviation in combination with the current speed of the UAV, adjust the motor parameters according to the first series PID control method, perform the second posture control on the UAV, and realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform;

[0051] After determining that a landing instruction has been received, the landing type contained in the landing instruction is judged, and the landing type includes direct landing and vehicle-mounted landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, and the third posture control is performed on the UAV to realize the autonomous landing function of the UAV.

[0052] The embodiment of the present application provides a method for tethered UAV vehicle-mounted take-off and landing and follow-up flight. The target follow-up flight is to send the target position point to the UAV through ground equipment. The UAV takes this target point as the flight target and flies to this point. The UAV and the target maintain relative positions and always follow the movement of the ground target. At this time, the relative height, heading and horizontal position can also be adjusted by joystick or ground control instructions. The target position point usually adopts the position of the ground vehicle-mounted platform. By obtaining the position of the ground vehicle-mounted platform and the attitude information of the UAV itself, the UAV can realize the flight function of following the ground vehicle-mounted platform through the series PID control method.

[0053] Furthermore, the embodiment of the present application may provide that the first series PID control method includes:

[0054] The outer loop obtains the angle difference based on the expected posture and the current posture, acts on the proportional link of the outer loop, obtains the expected angular velocity and passes it to the inner loop; the inner loop obtains the angular velocity difference based on the expected angular velocity and the current angular velocity, acts on the PID link of the inner loop, and at the same time, the expected angular velocity is accumulated to the control amount output by the PID through the feedforward channel to obtain the final control amount to be passed to the mixer.

[0055] The autonomous landing provided by the embodiment of the present application can be divided into two modes: direct landing and vehicle-mounted landing. In specific implementation, the drone can determine the landing mode according to the instructions sent by the user, and then perform the landing operation according to the landing control strategies corresponding to different landing modes. In specific implementation, the landing control strategies corresponding to the direct landing provided by the embodiment of the present application include:

[0056] The positioning solution value in hover mode is used as the default value for target landing; when it is determined that direct landing is required, the current XY coordinates are locked for vertical landing. If the vehicle-mounted platform moves, the UAV follows it (the UAV is in the companion flight following mode at this time). If it lands directly at this time, the UAV will lock the current XY coordinates for vertical landing.

[0057] Furthermore, the landing control strategy corresponding to the vehicle-mounted landing includes:

[0058] The drone is controlled to descend to the landing and return altitude of the following vehicle, the relative XY coordinate value of the drone relative to the vehicle platform is found, and the relative XY coordinate value found is locked to vertically land on the ground vehicle platform.

[0059] In a specific implementation, the embodiment of the present application may provide that the relative XY coordinate value of the drone relative to the vehicle-mounted platform is found, and the relative XY coordinate value found is locked and vertically landed on the ground vehicle-mounted platform includes:

[0060] According to the position and heading information given by the ground Beidou satellite navigation equipment and the airborne Beidou satellite navigation equipment, the relative position of the UAV and the ground vehicle platform in the NED coordinate system is calculated, and the expected relative position is calculated in combination with the landing point on the ground vehicle platform. The UAV is subjected to the third posture control according to the second series PID control method to achieve the landing of the UAV on the ground vehicle platform.

[0061] The second series PID control method comprises:

[0062] The outer loop position controller calculates the position deviation by combining the target position and the current position information of the UAV, multiplies it by the position proportional coefficient to obtain the target speed, and transmits the target speed to the inner loop speed PID controller;

[0063] The inner loop speed PID controller calculates the desired posture and the desired total pulling force by combining the target speed and the actual speed;

[0064] After the desired attitude and the desired total pulling force are transmitted to the attitude controller, the target motor drive signal is output through the mixer and the motor driver to adjust the attitude of the UAV and realize the control of movement from the current position to the target position.

[0065] In order to ensure the accuracy of the acquired ground vehicle platform position information, the present embodiment can also provide the position coordinates of the ground vehicle platform received through the target absolute position message feedback. Follow-up flight and vehicle landing use ground station command data packets. Follow-up flight and vehicle landing require the ground to send the vehicle platform absolute position coordinates to the flight control. The flight control feeds back the received platform position coordinates through the target absolute position message.

[0066] The method provided in the embodiments of the present application is described in detail below.

[0067] In order to realize the vehicle-mounted take-off and landing and follow-up flight functions, the tethered cable retraction device needs to have dual antenna direction finding, and the ground unit needs to complete positioning and direction finding.

[0068] The vehicle-mounted takeoff function is consistent with the traditional takeoff function. First, the longitude and latitude of the current position of the drone are obtained as the expected horizontal coordinates, and the expected vertical height is set as the takeoff height parameter. The drone obtains the current first posture information based on the posture solution, and combines the expected position to obtain the position and speed errors in the NED coordinate system. The motor speed is further adjusted according to the series PID control method to realize the posture control of the drone and make it take off to the specified position height.

[0069] It is understandable that the drone takes off from the current position and enters the hovering mode after taking off to the specified height. For example, when the drone takes off from a vehicle-mounted platform, the current position information of the drone can be obtained in combination with the positioning information of the vehicle-mounted platform, and the latitude and longitude of the current position information are used as the expected horizontal coordinates. If it is a one-key takeoff, the drone will take off vertically to the specified position and enter the hovering mode. At this time, the XY coordinates of the hovering mode are consistent with the XY coordinates at takeoff.

[0070] However, if it is a manual takeoff, after manually controlling the flight to a certain stage, the mode is manually switched to hovering, and the drone enters the hovering mode. The coordinates at this time may deviate from the coordinates at the time of takeoff. The method provided in the embodiment of the present application is mainly described for the autonomous takeoff mode of one-key takeoff. The method for adjusting the coordinates during manual takeoff can refer to the coordinate adjustment method for manual takeoff of drones in the prior art.

[0071] Follow-and-fly function: The UAV obtains the position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation device, and performs posture calculation based on the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the position and heading information of the UAV, and then calculates the relative position of the UAV and the ground vehicle platform in the NED coordinates. According to the accompanying flight position instruction issued by the ground station, the flight control estimates the expected speed, combines the current speed of the UAV to obtain the speed deviation, and further implements the position control of the UAV according to the series PID control method to achieve accompanying flight with the vehicle. The following flight of the UAV to the ground target is shown in the figure below. Figure 2 shown.

[0072] Autonomous landing is divided into two modes: direct landing and vehicle-mounted landing. During the mission execution process, when the drone takes off to perform the mission, the positioning solution value in hover mode will be used as the default value for the target landing. When the landing button is clicked or emergency landing is performed, the drone will lock the current XY coordinates and then land vertically; when the vehicle-mounted landing is clicked, the drone will descend to the landing return altitude of the following vehicle, and then automatically find the XY coordinate value of the drone relative to the vehicle platform, lock the XY coordinates found, and then land vertically.

[0073] Vehicle-mounted landing control strategy: The UAV control software calculates the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinate system based on the position and heading information given by the ground Beidou satellite navigation device (on the vehicle-mounted platform) and the airborne Beidou satellite navigation device (on the UAV), and calculates the expected relative position based on the landing point on the ground vehicle-mounted platform. The UAV position control is further realized based on the series PID control method to achieve landing on the vehicle platform.

[0074] Software implementation methods include:

[0075] The internal data interface of the system is the interface for the data information required by the aircraft platform to realize the take-off and landing and follow-up flight functions of the motor vehicle. Figure 3 shown.

[0076] Compared with ordinary multi-rotor systems, the main functional requirements and required parameters of software configuration items for the realization of motor vehicle-mounted take-off and landing and follow-up flight functions are shown in Tables 1 and 2.

[0077] Table 1 List of software functional requirements

[0078]

[0079] Table 2 List of parameters related to maneuvering following and accompanying flight functions

[0080]

[0081]

[0082] Base station mode and output message configuration.

[0083] The ground unit deploys ground BeiDou satellite navigation equipment, and the airborne unit deploys airborne BeiDou satellite navigation equipment. By configuring the ground unit and airborne unit as dynamic base station mode, the positioning and direction finding output of the ground unit is increased to provide the flight control with the position and direction information of the ground vehicle platform. The positioning and direction finding data output of the airborne unit increases the relative position and relative heading, and is sent to the flight control through the serial port, realizing the vehicle-mounted take-off and landing and accompanying flight functions of the system. The configuration of the ground unit software and the airborne unit software is shown in Table 3.

[0084] Table 3 Software Configuration List

[0085]

[0086]

[0087] The mobile base station is different from the RTK base station (fixed base station). The RTK base station is a fixed station with precisely known coordinates. The mobile base station is in motion and sends the received satellite information directly or after processing to the mobile station receiver (to be determined) in real time. While receiving the satellite observation values, the mobile station receiver also receives the information of the mobile base station to perform relative positioning and determine the position of the mobile station relative to the mobile base station. The instructions for configuring the mobile base station (vehicle-mounted terminal) are shown in Table 4, and the instructions for configuring the mobile station (aircraft-mounted terminal) are shown in Table 5.

[0088] Table 4 Mobile base station mode (vehicle-mounted terminal) configuration instruction table

[0089]

[0090] Table 5 Rover mode (airborne) configuration command table

[0091]

[0092]

[0093] Communication protocol.

[0094] In order to realize the motor vehicle take-off and landing and follow-up flight functions, the system communication protocol is described as follows.

[0095] A. UAV ground station software command interface protocol.

[0096] Follow-up flight and vehicle-mounted landing use ground station command data packets. Follow-up flight and vehicle-mounted landing require the ground to send the vehicle-mounted platform absolute position coordinates to the flight control. The flight control feeds back the received platform position coordinates through the target absolute position message.

[0097] The state changes during the following and vehicle landing process will be fed back through the integer variable value "NAV_STATE"; the horizontal distance to the target will be fed back through the floating point variable value "PRLND_DIST". The ground station command message format is shown in Table 6, and the commands and parameter settings related to maneuvering following and vehicle take-off and landing are shown in Table 7.

[0098] Table 6 Ground station command message format

[0099]

[0100]

[0101] Table 7 Maneuvering following and vehicle-mounted take-off and landing related instructions and parameter settings

[0102]

[0103]

[0104] B. Shaft control software interface protocol.

[0105] The shaft control board sends the absolute position coordinates of the vehicle platform to the flight control. The message format is shown in Table 8.

[0106] Table 8 Absolute position message

[0107]

[0108] C. Flight control software interface protocol.

[0109] The flight control feeds back the current status data of the accompanying flight and vehicle take-off and landing. The integer variable values ​​are shown in Table 9, the variable bit definitions are shown in Table 10, the floating point variable values ​​are shown in Table 11, and the variable descriptions are shown in Table 12.

[0110] Table 9 Integer variable value table

[0111]

[0112] Table 10 Variable bit definition table

[0113]

[0114] Table 11 Floating point variable value table

[0115]

[0116]

[0117] Table 12 Variable Description Table

[0118] Variable Name illustrate PRLND_DIST Horizontal distance from the target point

[0119] d. Airborne Beidou satellite navigation equipment interface protocol.

[0120] Compared with common applications, mobile following and vehicle-mounted takeoff and landing need to add ALIGNBSLNENU multi-rover baseline information (relative to the baseline ENU component of the base station) for vehicle-mounted landing control. The ALIGNBSLNENU data format is shown in Table 13.

[0121] Table 13 ALIGNBSLNENU data format

[0122]

[0123] Software control strategy. The overall idea of ​​position control is the second cascade PID control algorithm. The position control model consists of a proportional P position controller in the outer loop and a PID speed controller in the inner loop. The controlled variable is the speed output of the drone. Figure 4 As shown. The outer loop position P controller calculates the position deviation by combining the target position and the current position information of the drone, multiplies it by the position proportional coefficient to get the target speed, and passes it to the inner loop speed PID controller. The speed PID controller calculates the expected attitude and expected total force by combining the target speed and the actual speed. After passing the expected data to the attitude controller, the mixer and the motor drive output the appropriate motor drive signal to adjust the attitude of the drone and realize the control of movement from the current position to the target position.

[0124] The multi-rotor attitude control adopts a composite control strategy of the first cascade PID plus feedforward. It is divided into two loops, the outer loop has only one proportional link, and the inner loop adopts the control method of PID plus feedforward. The outer loop obtains the angle difference between the desired attitude (expressed by quaternion) and the current attitude (expressed by quaternion), acts on the proportional link of the outer loop, obtains the desired angular velocity, and passes it to the inner loop; the inner loop obtains the angular velocity difference between the desired angular velocity and the current angular velocity, acts on the PID link of the inner loop, and at the same time, the desired angular velocity is accumulated to the control quantity output by the PID through the feedforward channel to obtain the final control quantity to be passed to the mixer (which can be understood as torque). Attitude control such as Figure 5 shown.

[0125] Software control process. A. Takeoff control process, such as Figure 6 shown.

[0126] The takeoff control logic of the system is as follows:

[0127] 1. The system receives the take-off command, and the flight control software determines whether the take-off conditions are met based on the current drone status. If so, it goes to step 2;

[0128] 2. Determine whether to exit the one-button takeoff control. If the condition is not met, proceed to step 3. Otherwise, proceed to step 6.

[0129] 3. Calculate the expected speed based on the take-off height command and the current posture data of the drone;

[0130] 4. Determine whether the motor has been unlocked. If not, execute the motor unlocking command. Otherwise, go to step 5.

[0131] 5. Connect PID control in series to control the drone to take off and determine whether it has reached the command height. If it has not reached the command height, it will enter 2, otherwise it will enter the hovering mode.

[0132] 6. Takeoff is complete.

[0133] B. Vehicle landing process, such as Figure 7 The control logic of vehicle landing is as follows:

[0134] 1. Receive the vehicle landing command and determine whether the current altitude meets the return altitude. If not, ascend to the return altitude. Otherwise, proceed to step 2.

[0135] 2. Start the return control, adjust the heading, and descend to the precise landing hovering height;

[0136] 3. Waiting for landing;

[0137] 4. Determine whether the current horizontal position error meets the accuracy requirements within a certain period of time (precision landing waiting time). If it does not meet the conditions, go to step 3;

[0138] 5. Land quickly and constantly check whether the horizontal position error meets the conditions. If not, increase the altitude to the precise landing hovering altitude and then enter 3;

[0139] 6. Determine whether the current altitude meets the propeller lock altitude. If it does, stop the propellers and lock them. Otherwise, proceed to step 5.

[0140] C. Follow the accompanying flight process, such as Figure 8 The control logic of the follow-up flight is as follows:

[0141] 1. Receive the accompanying flight command, obtain the position, speed and other information of the vehicle-mounted satellite navigation device to determine whether the accompanying flight conditions are met, and exit the accompanying flight if not met;

[0142] 2. Calculate the expected position and speed according to the accompanying flight altitude set by the accompanying flight instruction;

[0143] 3. Obtain the current posture data of the drone and calculate the control deviation;

[0144] 4. Execute series PID control to realize the drone companion flight function.

[0145] In summary, the vehicle-mounted take-off and landing and follow-up flight method of the tethered UAV provided in this application sends the target position point to the UAV through the ground equipment. The UAV takes this target point as the flight target and flies to this point. The UAV and the target maintain relative positions and always follow the ground target. The tethered multi-rotor UAV can automatically follow the vehicle platform to fly synchronously, and can also be installed on the vehicle. Since the UAV can automatically follow the vehicle, the mobility and mission capability of the system are improved, making task deployment and team collaboration more flexible.

[0146] See also Fig. 9 The embodiment of the present application can also provide a tethered UAV vehicle-mounted take-off and landing and follow-up flight device, such as Fig. 9 As shown, the device for executing the above-mentioned tethered UAV vehicle-mounted take-off and landing and follow-up flight method may include:

[0147] The take-off function realization unit 901 is used to obtain the latitude and longitude of the current position point of the UAV as the expected horizontal coordinate, determine the expected vertical height value as the expected take-off height parameter; obtain the first posture information of the current UAV according to the posture solution, obtain the position and speed error in the NED coordinate system according to the first posture information combined with the expected horizontal coordinate and the expected take-off height parameter, adjust the motor parameters according to the first series PID control method, perform the first posture control on the UAV, make the UAV take off to the specified position height, and realize the take-off function of the UAV;

[0148] The accompanying flight function realization unit 902 is used to obtain the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, and perform posture calculation according to the positioning and direction finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, combine the current speed of the UAV, obtain the speed deviation, adjust the motor parameters according to the first series PID control method, and perform the second posture control on the UAV to realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform;

[0149] The autonomous landing function implementation unit 903 is used to determine the landing type contained in the landing instruction after receiving the landing instruction, and the landing type includes direct landing and vehicle-mounted landing; adjust the motor parameters according to the landing control strategy corresponding to the determined landing type, and control the third posture of the UAV to realize the autonomous landing function of the UAV.

[0150] The embodiment of the present application may also provide a tethered UAV vehicle-mounted take-off and landing and follow-up flight device, the device comprising a processor and a memory:

[0151] The memory is used to store program code and transmit the program code to the processor;

[0152] The processor is used to execute the steps of the above-mentioned tethered drone vehicle-mounted take-off and landing and follow-up flight method according to the instructions in the program code.

[0153] like Fig.10 As shown, a tethered UAV vehicle-mounted take-off and landing and follow-up flight device provided in an embodiment of the present application may include: a processor 10, a memory 11, a communication interface 12 and a communication bus 13. The processor 10, the memory 11, and the communication interface 12 all communicate with each other through the communication bus 13.

[0154] In the embodiment of the present application, the processor 10 may be a central processing unit (CPU), an application specific integrated circuit, a digital signal processor, a field programmable gate array or other programmable logic devices.

[0155] The processor 10 can call the program stored in the memory 11. Specifically, the processor 10 can execute the operations in the embodiment of the tethered drone vehicle-mounted take-off and landing and follow-up flight method.

[0156] The memory 11 is used to store one or more programs, which may include program codes, and the program codes include computer operation instructions. In the embodiment of the present application, the memory 11 at least stores programs for implementing the following functions:

[0157] The positioning solution value in the hovering mode is used as the take-off origin, and the longitude and latitude of the take-off origin are used as the expected horizontal coordinates, and the expected vertical height value is determined as the expected take-off height parameter; the first posture information is obtained according to the posture solution, and the position and speed errors in the NED coordinate system are obtained according to the first posture information combined with the expected horizontal coordinates and the expected take-off height parameter, and the motor parameters are adjusted according to the first series PID control method, and the first posture control is performed on the UAV, so that the UAV takes off to the specified position height, thereby realizing the take-off function of the UAV;

[0158] Obtain the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, and perform posture calculation according to the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, combine the current speed of the UAV, obtain the speed deviation, adjust the motor parameters according to the first series PID control method, perform the second posture control on the UAV, and realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform;

[0159] After determining that a landing instruction has been received, the landing type contained in the landing instruction is judged, and the landing type includes direct landing and vehicle-mounted landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, and the third posture control is performed on the UAV to realize the autonomous landing function of the UAV.

[0160] In one possible implementation, the memory 11 may include a program storage area and a data storage area, wherein the program storage area can store an operating system and application programs required for at least one function (such as a file creation function, a data reading and writing function), etc.; the data storage area can store data created during use, such as initialization data, etc.

[0161] In addition, the memory 11 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device or other volatile solid-state storage device.

[0162] The communication interface 12 may be an interface of a communication module, and is used to connect to other devices or systems.

[0163] Of course, it should be noted that Fig.10 The structure shown does not constitute a limitation on the vehicle-mounted take-off and landing and follow-up flight equipment of the tethered drone in the embodiment of the present application. In actual applications, the vehicle-mounted take-off and landing and follow-up flight equipment of the tethered drone may include Fig.10 More or fewer components than shown, or combinations of certain components.

[0164] An embodiment of the present application may also provide a computer-readable storage medium, which is used to store program codes, and the program codes are used to execute the steps of the above-mentioned tethered drone vehicle-mounted take-off and landing and follow-up flight method.

[0165] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0166] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0167] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0168] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for taking off and landing a tethered UAV on a vehicle and accompanying it, characterized in that: include: The latitude and longitude of the current position of the UAV are obtained as the expected horizontal coordinates, and the expected vertical height value is determined as the expected take-off height parameter; the first posture information of the current UAV is obtained according to the posture solution, and the position and speed errors in the NED coordinate system are obtained according to the first posture information combined with the expected horizontal coordinates and the expected take-off height parameter, and the motor parameters are adjusted according to the first series PID control method, and the first posture control of the UAV is performed, so that the UAV takes off to the specified position height, thereby realizing the take-off function of the UAV; Obtaining the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, and performing posture calculation according to the positioning and direction finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and using the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; After receiving the accompanying flight position instruction, the expected speed is estimated, the speed deviation is obtained in combination with the current speed of the UAV, the motor parameters are adjusted according to the first series PID control method, and the second posture control is performed on the UAV to realize the accompanying flight function of the UAV relative to the ground vehicle platform; After determining that a landing instruction has been received, the landing type contained in the landing instruction is judged, and the landing type includes direct landing and vehicle-mounted landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, and the third posture control is performed on the UAV to realize the autonomous landing function of the UAV.

2. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 1, characterized in that: The first series PID control method comprises: The outer loop obtains the angle difference based on the expected posture and the current posture, acts on the proportional link of the outer loop, obtains the expected angular velocity and transmits it to the inner loop; The inner loop obtains the angular velocity difference according to the expected angular velocity and the current angular velocity, and acts on the PID link of the inner loop. At the same time, the expected angular velocity is accumulated to the control amount output by the PID through the feedforward channel to obtain the final control amount to be transmitted to the mixer.

3. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 1, characterized in that: The landing control strategy corresponding to the direct landing includes: The positioning solution value in hover mode is used as the default value for target landing; when it is determined that direct landing is required, the current XY coordinates are locked for vertical landing.

4. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 1, characterized in that: The landing control strategy corresponding to the vehicle-mounted landing includes: The drone is controlled to descend to the landing and return altitude of the following vehicle, the relative XY coordinate value of the drone relative to the vehicle platform is found, and the relative XY coordinate value found is locked to vertically land on the ground vehicle platform.

5. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 4, characterized in that: The step of finding the relative XY coordinate value of the drone relative to the vehicle-mounted platform, locking the found relative XY coordinate value and vertically landing on the ground vehicle-mounted platform comprises: According to the position and heading information given by the ground Beidou satellite navigation equipment and the airborne Beidou satellite navigation equipment, the relative position of the UAV and the ground vehicle platform in the NED coordinate system is calculated, and the expected relative position is calculated in combination with the landing point on the ground vehicle platform. The UAV is subjected to the third posture control according to the second series PID control method to achieve the landing of the UAV on the ground vehicle platform.

6. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 5, characterized in that: The second series PID control method comprises: The outer loop position controller calculates the position deviation by combining the target position and the current position information of the UAV, multiplies it by the position proportional coefficient to obtain the target speed, and transmits the target speed to the inner loop speed PID controller; The inner loop speed PID controller calculates the desired posture and the desired total pulling force by combining the target speed and the actual speed; After the desired attitude and the desired total pulling force are transmitted to the attitude controller, the target motor drive signal is output through the mixer and the motor driver to adjust the attitude of the UAV and realize the control of movement from the current position to the target position.

7. The method for taking off and landing a tethered UAV on a vehicle and accompanying it according to claim 5, characterized in that: The received position coordinates of the ground vehicle-mounted platform are fed back via a target absolute position message.

8. A vehicle-mounted take-off and landing and accompanying flight device for a tethered UAV, characterized in that: The device is used to perform the vehicle-mounted take-off and landing and follow-up flight method of a tethered UAV according to any one of claims 1 to 7, and comprises: The take-off function realization unit is used to obtain the latitude and longitude of the current position point of the UAV as the expected horizontal coordinate, determine the expected vertical height value as the expected take-off height parameter; obtain the first position information of the current UAV according to the posture solution, obtain the position and speed error in the NED coordinate system according to the first posture information combined with the expected horizontal coordinate and the expected take-off height parameter, adjust the motor parameters according to the first series PID control method, perform the first posture control on the UAV, make the UAV take off to the specified position height, and realize the take-off function of the UAV; The accompanying flight function realization unit is used to obtain the position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, and perform posture calculation according to the positioning and direction-finding message information output by the airborne Beidou satellite navigation device to obtain the second posture information of the UAV, and use the second posture information to calculate the relative position of the UAV and the ground vehicle-mounted platform in the NED coordinates; determine that after receiving the accompanying flight position instruction, estimate the expected speed, combine the current speed of the UAV, obtain the speed deviation, adjust the motor parameters according to the first series PID control method, and perform the second posture control on the UAV to realize the accompanying flight function of the UAV relative to the ground vehicle-mounted platform; The autonomous landing function implementation unit is used to determine the landing type contained in the landing instruction after receiving the landing instruction, and the landing type includes direct landing and vehicle-mounted landing; adjust the motor parameters according to the landing control strategy corresponding to the determined landing type, perform third posture control on the UAV, and realize the autonomous landing function of the UAV.

9. A vehicle-mounted take-off and landing and accompanying flight device for a tethered UAV, characterized in that: The device comprises a processor and a memory: The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the tethered UAV vehicle-mounted take-off and landing and follow-up flight method described in any one of claims 1-7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the tethered UAV vehicle-mounted take-off and landing and follow-up flight method described in any one of claims 1-7.

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