A tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method and device

Abstract

The application discloses a tethered unmanned aerial vehicle vehicle-mounted taking-off and landing and following method and device, a target position point is sent to the unmanned aerial vehicle through a ground device, the unmanned aerial vehicle takes the target position point as a flight target and flies to the point, the unmanned aerial vehicle and the target keep a relative position and always follow the ground target to move, so that the tethered multi-rotor unmanned aerial vehicle can automatically follow the vehicle platform to synchronously fly. Since the unmanned aerial vehicle can automatically follow the vehicle to travel, the system mobility and task capacity are improved, and task deployment and team cooperation are more flexible.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tethered multi-rotor unmanned aerial vehicle, in particular to a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method and device. BACKGROUND

[0002] The tethered unmanned aerial vehicle is also called tethered unmanned aerial vehicle, which is a special form of multi-rotor unmanned aerial vehicle, uses the ground power transmission through the tether cable as the power source instead of the traditional lithium battery, and the most important feature is the long-time hovering capability.

[0003] The tethered multi-rotor unmanned aerial vehicle in the prior art can only realize the working modes of fixed-point take-off, landing, hovering, self-stabilization, and height stabilization, and does not have the vehicle-mounted take-off and landing and following flight capability, thereby limiting the use convenience and universality of the system.

[0004] It can be seen that in the current actual application, the tethered multi-rotor system does not have the capability of maintaining a stable relative position relationship with the running vehicle and does not have the capability of taking off from the vehicle platform and safely landing on the vehicle platform. The main reason is that there is no software and hardware platform support, and the lack of position data leads to the fact that the flight control algorithm accuracy cannot meet the use requirements. SUMMARY

[0005] In view of the above problems, the present application provides a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method and device for overcoming the above problems or at least partially solving the above problems.

[0006] The present application provides the following solutions:

[0007] A tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method, comprising:

[0008] Obtaining the longitude and latitude of the current position point of the unmanned aerial vehicle as the expected horizontal coordinate, determining the vertical take-off height expectation value as the expected take-off height parameter; obtaining the first pose information of the unmanned aerial vehicle according to the pose solution, obtaining the position and speed error in the NED coordinate system according to the first pose information combined with the expected horizontal coordinate and the expected take-off height parameter, adjusting the motor parameter according to the first series PID control method, and performing the first pose control on the unmanned aerial vehicle, so as to make the unmanned aerial vehicle take off to the specified position height, and realize the take-off function of the unmanned aerial vehicle;

[0009] The position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation device is acquired, and the second pose information of the unmanned aerial vehicle is obtained by solving the pose according to the positioning and direction finding message output by the airborne Beidou satellite navigation device. The relative position of the unmanned aerial vehicle and the ground vehicle platform in the NED coordinate is calculated by using the second pose information; after receiving the accompanying position instruction, the expected speed is estimated, the speed deviation is obtained in combination with the current speed of the unmanned aerial vehicle, the motor parameters are adjusted according to the first series PID control method, the second pose control is performed on the unmanned aerial vehicle, and the accompanying flight function of the unmanned aerial vehicle relative to the ground vehicle platform is realized.

[0010] After receiving the landing instruction, the landing type contained in the landing instruction is determined, the landing type includes direct landing and vehicle landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, the third pose control is performed on the unmanned aerial vehicle, and the autonomous landing function of the unmanned aerial vehicle is realized.

[0011] Preferably, the first series PID control method comprises:

[0012] The outer ring obtains the angle difference according to the expected attitude and the current attitude, acts on the proportional element of the outer ring, obtains the expected angular velocity and transmits it to the inner ring;

[0013] The inner ring obtains the angular velocity difference according to the expected angular velocity and the current angular velocity, acts on the PID element of the inner ring, and at the same time, the expected angular velocity is accumulated to the control amount of the PID output through the feedforward channel, to obtain the final control amount to be transmitted to the mixer controller.

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

[0015] The positioning solution value in the hovering mode is taken as the default value of the target landing; when it is determined that direct landing is needed, the current XY coordinate vertical landing is locked.

[0016] Preferably, the landing control strategy corresponding to the vehicle landing comprises:

[0017] The unmanned aerial vehicle is controlled to descend to the car-following landing return height, the relative XY coordinate value of the unmanned aerial vehicle relative to the vehicle platform is found, and the found relative XY coordinate value is locked for vertical landing to the ground vehicle platform.

[0018] Preferably, the finding of the relative XY coordinate value of the unmanned aerial vehicle relative to the vehicle platform and the vertical landing of the found relative XY coordinate value to the ground vehicle platform comprise:

[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 unmanned aerial vehicle and the ground vehicle platform in the NED coordinate system is calculated, the expected relative position is calculated combined with the landing point on the ground vehicle platform, the third pose control of the unmanned aerial vehicle is realized according to the second series PID control method, and the landing of the unmanned aerial vehicle on the ground vehicle platform is realized.

[0020] Preferably, the second series PID control method comprises:

[0021] The outer loop position controller calculates the position deviation combined with the target position and the current position information of the unmanned aerial vehicle, multiplies 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 expected attitude and the expected total tension combined with the target speed and the real speed;

[0023] After the expected attitude and the expected total tension are transmitted to the attitude controller, the target motor driving signal is output through the mixer and the motor driving to adjust the attitude of the unmanned aerial vehicle, so as to realize the control of moving from the current position to the target position.

[0024] Preferably, the position coordinates of the ground vehicle platform received are fed back through the target absolute position message.

[0025] A tethered unmanned aerial vehicle vehicle take-off and landing and following companion flying device is used to execute the tethered unmanned aerial vehicle vehicle take-off and landing and following companion flying method, and the device comprises:

[0026] The take-off function implementation unit is used to obtain the longitude and latitude of the current position point of the unmanned aerial vehicle as the expected horizontal coordinates, determine the vertical take-off height expected value as the expected take-off height parameter, obtain the first pose information of the current unmanned aerial vehicle according to the pose calculation, obtain the position and speed error in the NED coordinate system combined with the first pose information, the expected horizontal coordinates and the expected take-off height parameter, adjust the motor parameters according to the first series PID control method, and control the first pose of the unmanned aerial vehicle, so that the unmanned aerial vehicle takes off to the specified position height, and the take-off function of the unmanned aerial vehicle is realized.

[0027] The accompanying flight function implementation unit is configured to acquire position and heading information of a ground vehicle platform reported by a ground Beidou satellite navigation device, and to obtain second pose information of the UAV by solving the pose according to the positioning and direction finding message information output by the airborne Beidou satellite navigation device, and to calculate the relative position of the UAV and the ground vehicle platform in NED coordinates by using the second pose information; to estimate the expected speed after receiving the accompanying flight position instruction, to obtain the speed deviation in combination with the current speed of the UAV, to adjust the motor parameters according to the first series PID control method, to perform second pose control on the UAV, and to realize the accompanying flight function of the UAV relative to the ground vehicle platform;

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

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

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

[0031] The processor is configured to execute the above-mentioned tethered UAV vehicle take-off and landing and following accompanying flight method according to the instructions in the program code.

[0032] A computer readable storage medium for storing program code, the program code being used to execute the above-mentioned tethered UAV vehicle take-off and landing and following accompanying flight method.

[0033] According to the embodiments of the present application, the following technical effects are provided:

[0034] The tethered UAV vehicle take-off and landing and following accompanying flight method and device provided by the embodiments of the present application send a target position point to the UAV through a ground device, the UAV takes this target point as a flight target and flies to this point, the UAV and the target maintain a relative position and move along with the ground target. The tethered multi-rotor UAV can automatically follow the vehicle platform and fly synchronously. Since the UAV can automatically follow the vehicle, the mobility and task capability of the system are improved, and the task deployment and team cooperation are more flexible.

[0035] Of course, implementing any product of the present application does not necessarily require all the advantages described above to be achieved at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some of the embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

[0037] Figure 1 is a flow chart of a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up accompanying flight method provided by the embodiments of the present application;

[0038] Figure 2 is a follow-up accompanying flight schematic diagram of an unmanned aerial vehicle provided by the embodiments of the present application;

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

[0040] Figure 4 is a position control block diagram provided by the embodiments of the present application;

[0041] Figure 5 is an attitude control block diagram provided by the embodiments of the present application;

[0042] Figure 6 is a take-off control flow chart provided by the embodiments of the present application;

[0043] Figure 7 is a vehicle-mounted landing control flow chart provided by the embodiments of the present application;

[0044] Figure 8 is a follow-up accompanying flight control flow chart provided by the embodiments of the present application;

[0045] Figure 9 is a schematic diagram of a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up accompanying flight device provided by the embodiments of the present application;

[0046] Figure 10 is a schematic diagram of a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up accompanying flight device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0048] Reference Figure 1 is a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-up accompanying flight method provided by the embodiments of the present application, like Figure 1As shown, the method can include:

[0049] The latitude and longitude of the current position point of the unmanned aerial vehicle are acquired as expected horizontal coordinates, a vertical take-off height expectation value is determined as an expected take-off height parameter, first pose information of the unmanned aerial vehicle is obtained according to pose calculation, a position and a speed error in an NED coordinate system are obtained according to the first pose information in combination with the expected horizontal coordinates and the expected take-off height parameter, motor parameters are adjusted according to a first series PID control method, first pose control is performed on the unmanned aerial vehicle, the unmanned aerial vehicle is taken off to a specified position height, and a take-off function of the unmanned aerial vehicle is realized.

[0050] Position and heading information of a ground vehicle platform reported by a ground Beidou satellite navigation device is acquired, second pose information of the unmanned aerial vehicle is obtained by performing pose calculation according to positioning and direction finding report information output by an airborne Beidou satellite navigation device, a relative position of the unmanned aerial vehicle and the ground vehicle platform in an NED coordinate is calculated by using the second pose information, an expected speed is estimated after receiving a companion flying position instruction, a speed deviation is obtained in combination with a current speed of the unmanned aerial vehicle, the motor parameters are adjusted according to the first series PID control method, second pose control is performed on the unmanned aerial vehicle, and a companion flying function of the unmanned aerial vehicle relative to the ground vehicle platform is realized.

[0051] After receiving a landing instruction, a landing type contained in the landing instruction is determined, the landing type includes direct landing and vehicle landing, the motor parameters are adjusted according to a landing control strategy corresponding to the determined landing type, third pose control is performed on the unmanned aerial vehicle, and an autonomous landing function of the unmanned aerial vehicle is realized.

[0052] The tethered unmanned aerial vehicle vehicle take-off and landing and following companion flying method provided by the embodiment of the application is that target following companion flying is performed by sending a target position point to the unmanned aerial vehicle by a ground device, the unmanned aerial vehicle takes the target point as a flight target and flies to the point, the unmanned aerial vehicle and the target keep a relative position and always follow the ground target to move. At this time, the relative height, heading and horizontal position can also be adjusted by a joystick or a ground control instruction. The target position point usually adopts a position of a ground vehicle platform, the companion flying function of the unmanned aerial vehicle following the ground vehicle platform is realized by acquiring the position of the ground vehicle platform and attitude information of the unmanned aerial vehicle and by using a series PID control method.

[0053] Further, the first series PID control method can include the following steps.

[0054] The outer ring obtains an angle difference according to a desired attitude and a current attitude, acts on a proportional element of the outer ring, obtains a desired angular velocity, and is transmitted to the inner ring; the inner ring obtains an angular velocity difference according to the desired angular velocity and a current angular velocity, acts on a PID element of the inner ring, and the desired angular velocity is accumulated to a control amount of the PID output through a feedforward channel to obtain a final control amount to be transmitted to the hybrid controller.

[0055] The autonomous landing provided by the embodiments of the present application can be divided into two modes: direct landing and vehicle-mounted landing. In the specific implementation, the unmanned aerial vehicle can determine the landing mode according to the instruction sent by the user, and then perform the landing operation according to the landing control strategy corresponding to the different landing modes. In the specific implementation, the embodiments of the present application can provide the landing control strategy corresponding to the direct landing, which includes:

[0056] The positioning solution value in the hovering mode is taken as the default value of the target landing, and the current XY coordinate is locked for vertical landing after determining that direct landing is needed. If the vehicle-mounted platform moves, the unmanned aerial vehicle follows the companion flight (at this time, the unmanned aerial vehicle is in the companion flight following mode), and if direct landing is performed at this time, the unmanned aerial vehicle will lock the current XY coordinate for vertical landing.

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

[0058] The unmanned aerial vehicle is controlled to descend to a follow-the-car landing return height, the relative XY coordinate value of the unmanned aerial vehicle relative to the vehicle-mounted platform is found, and the found relative XY coordinate value is locked for vertical landing to the ground vehicle-mounted platform.

[0059] In the specific implementation, the embodiments of the present application can provide that the relative XY coordinate value of the unmanned aerial vehicle relative to the vehicle-mounted platform is found, and the found relative XY coordinate value is locked for vertical landing to the ground vehicle-mounted platform, which 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 unmanned aerial vehicle and the ground vehicle-mounted platform in the NED coordinate system is solved, the expected relative position is calculated in combination with the landing point on the ground vehicle-mounted platform, and the unmanned aerial vehicle is controlled in the third pose according to a second series PID control method, so as to realize the landing of the unmanned aerial vehicle on the ground vehicle-mounted platform.

[0061] The second series PID control method includes:

[0062] The outer ring position controller calculates a position deviation in combination with a target position and current position information of the unmanned aerial vehicle, multiplies the position deviation by a position proportional coefficient to obtain a target speed, and transmits the target speed to an inner ring speed PID controller.

[0063] The inner loop speed PID controller combines the target speed and the real speed to calculate the expected attitude and the expected total tension;

[0064] After the expected attitude and the expected total tension are transmitted to the attitude controller, a target motor driving signal is outputted through the hybrid controller and the motor driver to adjust the attitude of the unmanned aerial vehicle, so as to realize the control of moving from the current position to the target position.

[0065] In order to ensure the accuracy of the obtained position information of the ground vehicle platform, the embodiment of the present application can also provide the position coordinates of the ground vehicle platform received through the target absolute position message feedback. The ground station instruction data packet is used for following and accompanying flight and vehicle landing. The ground vehicle platform absolute position coordinates need to be sent to the flight control by the ground station. The platform position coordinates received by the flight control are fed back through the target absolute position message.

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

[0067] In order to realize the vehicle take-off and landing and following and accompanying flight functions, the tether cable winding and unwinding device needs to have double antenna direction finding, and the ground unit needs to complete positioning and direction finding.

[0068] The vehicle take-off function is consistent with the traditional take-off function. First, the latitude and longitude of the current position point of the unmanned aerial vehicle are obtained as expected horizontal coordinates, and the vertical take-off height expectation value is set as the take-off height parameter. The unmanned aerial vehicle obtains the first pose information according to the pose solution, obtains the position and speed error in the NED coordinate system in combination with the expected position, and further adjusts the motor speed according to the series PID control method, so as to realize the pose control of the unmanned aerial vehicle and make it take off to the specified position height.

[0069] It can be understood that the unmanned aerial vehicle takes off from the current position, and after taking off to the specified height, it enters the hovering mode. For example, when the unmanned aerial vehicle takes off on the vehicle platform, the current position information of the unmanned aerial vehicle can be obtained in combination with the positioning information of the vehicle platform, and the latitude and longitude of the current position information are taken as the expected horizontal coordinates. If it is one-key take-off, the unmanned aerial vehicle 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 the time of take-off.

[0070] However, if it is manual take-off, the mode is manually switched to hovering after flying to a certain stage, at which time the unmanned aerial vehicle enters the hovering mode. At this time, the coordinates may deviate from the coordinates at the time of take-off. The method provided by the embodiment of the present application is mainly described for the autonomous take-off mode of one-key take-off. The adjustment mode of the coordinates during manual take-off can refer to the coordinate adjustment mode of the manual take-off of the unmanned aerial vehicle in the prior art.

[0071] Follow-up flying function: the unmanned aerial vehicle obtains the position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation device, and obtains the position and heading information of the unmanned aerial vehicle according to the positioning and direction finding report information output by the airborne Beidou satellite navigation device, and then calculates the relative position of the unmanned aerial vehicle and the ground vehicle platform in the NED coordinate. According to the follow-up position instruction issued by the ground station, the flight control estimates the expected speed, combines the current speed of the unmanned aerial vehicle to obtain the speed deviation, and further realizes the position control of the unmanned aerial vehicle according to the series PID control method, and realizes the follow-up flying with the vehicle. The follow-up flying of the unmanned aerial vehicle to the ground target is as shown in Figure 2

[0072] Autonomous landing is divided into direct landing and vehicle-mounted landing. During the task execution process, when the unmanned aerial vehicle takes off to execute the task, the positioning solution value in the hovering mode is taken as the default value of the target landing. When the landing button is clicked or the emergency landing is clicked, the unmanned aerial vehicle will lock the current XY coordinate, and then land vertically; when the vehicle-mounted landing is clicked, the unmanned aerial vehicle will descend to the follow-up landing height, and then automatically find the XY coordinate value of the unmanned aerial vehicle relative to the vehicle-mounted platform, lock the found XY coordinate, and then land vertically.

[0073] Vehicle-mounted landing control strategy: the unmanned aerial vehicle control software calculates the relative position of the unmanned aerial vehicle and the ground vehicle platform in the NED coordinate system according to 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 unmanned aerial vehicle), calculates the expected relative position combined with the landing point on the ground vehicle-mounted platform, and further realizes the position control of the unmanned aerial vehicle according to the series PID control method, so as to realize the landing on the vehicle platform.

[0074] The software implementation method includes:

[0075] The internal data interface of the system is as shown in Figure 3

[0076] The main function requirements and required parameters of the software configuration items involved in the realization of the mobile vehicle-mounted take-off and landing and follow-up flying function compared with the ordinary multi-rotor system are shown in Table 1 and Table 2.

[0077] Table 1 Software function requirement list

[0078]

[0079] Table 2 List of parameters related to mobile follow-up and flying function

[0080]

[0081] ​​

[0082] Base station mode and output message configuration.

[0083] The ground unit is deployed with a ground Beidou satellite navigation device, and the airborne unit is deployed with an airborne Beidou satellite navigation device. By configuring the ground unit and the airborne unit as a mobile base station mode, the positioning and direction finding outputs of the ground unit are increased to provide the position and direction information of the ground vehicle platform to the flight control, and the positioning and direction finding data outputs of the airborne unit are increased to provide the relative position and relative heading, and are sent to the flight control through a serial port to realize the vehicle landing and accompanying flight functions of the system. The software configuration of the ground unit and the airborne unit is shown in Table 3.

[0084] Table 3 Software configuration list

[0085]

[0086]

[0087] The mobile base station is different from the RTK reference station (fixed base station), and the RTK reference station is a fixed station with known coordinates. The mobile reference station is in a motion state, and the received satellite information is directly or processed and sent to the mobile station receiver (to be determined) in real time. The mobile station receiver receives satellite observation values and also receives information from the mobile reference station, performs relative positioning, and determines the position of the mobile station relative to the mobile reference station. The instructions for configuring the mobile reference station (vehicle end) are shown in Table 4, and the instructions for configuring the mobile station (airborne end) are shown in Table 5.

[0088] Table 4 Mobile base station mode (vehicle end) configuration instruction table

[0089]

[0090] Table 5 Mobile station mode (airborne end) configuration instruction table

[0091]

[0092]

[0093] Communication protocol.

[0094] To realize the vehicle landing and accompanying flight functions, the system communication protocol is as follows.

[0095] A, unmanned aerial vehicle ground station software instruction interface protocol.

[0096] The ground station instruction data packet is used for accompanying flight and vehicle landing. The ground station needs to send the absolute position coordinates of the vehicle platform to the flight control. The flight control receives the platform position coordinates through the target absolute position message feedback.

[0097] The state change during the process of vehicle following and landing is fed back by the integer variable value "NAV_STATE", and the horizontal distance from the target is fed back by the floating-point variable value "PRLND_DIST". The format of the ground station instruction message is shown in Table 6, and the instructions and parameter settings related to the vehicle following and landing are shown in Table 7.

[0098] Table 6 Format of the ground station instruction message

[0099]

[0100]

[0101] Table 7 Instructions and parameter settings related to the vehicle following and landing

[0102]

[0103]

[0104] B. Interface protocol of the shaft control software

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

[0106] Table 8 Absolute position message

[0107]

[0108] C. Interface protocol of the flight control software

[0109] The flight control feeds back the state data of the current following flight and vehicle landing. The integer variable value is shown in Table 9, the variable bit definition is shown in Table 10, the floating-point variable value is shown in Table 11, and the variable description is 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 Description PRLND_DIST Horizontal distance from target point

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

[0120] 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 a second cascade PID control algorithm. The position control model is composed of a P position controller in the outer loop and a PID speed controller in the inner loop. The controlled quantity is the output of the speed of the UAV as shown in Figure 4 The outer loop P position controller calculates the position deviation by combining the target position and the current position information of the UAV, multiplies the position proportional coefficient to obtain the target speed, and transmits it to the inner loop speed PID controller. The speed PID controller calculates the expected attitude and expected total pull by combining the target speed and the real speed, and transmits the expected data to the attitude controller. After that, the appropriate motor driving signal is output through the mixing controller and the motor driver to adjust the attitude of the UAV, so as to realize the control of moving from the current position to the target position.

[0124] The multi-rotor attitude control adopts a compound control strategy of first cascade PID plus feedforward. There are two loops, the outer loop has only a proportional link, and the inner loop adopts a PID plus feedforward control mode. The outer loop is to obtain the angle difference from the expected attitude (using quaternion) and the current attitude (using quaternion), and act on the proportional link in the outer loop to obtain the expected angular velocity, which is transmitted to the inner loop. The inner loop is to obtain the angular velocity difference from the expected angular velocity and the current angular velocity, and act on the PID link in the inner loop, while the expected angular velocity is accumulated to the control quantity of the PID output through the feedforward channel, to obtain the final control quantity (which can be understood as torque) to be transmitted to the mixing controller. The attitude control is as shown in Figure 5 .

[0125] Software control flow. A, take-off control flow, as shown in Figure 6 .

[0126] The take-off control logic of the system is as follows:

[0127] 1. The system receives the take-off instruction, and the flight control software judges whether the take-off condition is met according to the current UAV state. If it is met, go to 2;

[0128] 2. Judge whether to exit the one-key take-off control. If the condition is not met, go to 3, otherwise go to 6;

[0129] 3、 According to the take-off height instruction and the current pose data of the UAV, the expected speed is calculated;

[0130] 4、Judge whether the motor has been unlocked, if not, execute the motor unlocking instruction, otherwise go to 5;

[0131] 5、Series PID control, control the UAV take-off, and judge whether the command height is reached, if not, go to 2, otherwise go to the hovering mode;

[0132] 6、Take-off is completed.

[0133] B、Vehicle landing process, as shown in Figure 7 The control logic of vehicle landing is as follows:

[0134] 1、Receive the vehicle landing instruction, judge whether the current height meets the return height, if not, rise to the return height, otherwise go to 2;

[0135] 2、Start return control, adjust the heading and lower the height to the precise landing hover height;

[0136] 3、Wait for landing;

[0137] 4、Judge whether the current horizontal position error meets the accuracy requirement within a certain time (precise landing waiting time), if not, go to 3;

[0138] 5、Quick landing, and constantly judge whether the horizontal position error meets the condition, if not, rise to the precise landing hover height and then go to 3;

[0139] 6、Judge whether the current height meets the lock propeller height, if so, stop the propeller and lock, otherwise go to 5.

[0140] C、Follow the companion flight process, as shown in Figure 8 The control logic of following the companion flight is as follows:

[0141] 1、Receive the companion flight instruction, get the position, speed and other information of the vehicle satellite navigation device, and judge whether the companion flight condition is met, if not, exit the companion flight;

[0142] 2、According to the companion flight height set by the companion flight instruction, calculate the expected position and speed;

[0143] 3、Get the current pose data of the UAV, calculate the control deviation;

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

[0145] In summary, the tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method provided in the application sends a target position point to the unmanned aerial vehicle through a ground device, the unmanned aerial vehicle takes the target position point as a flight target and flies to the point, the unmanned aerial vehicle and the target keep a relative position and move along with the ground target. The tethered multi-rotor unmanned aerial vehicle can automatically follow the vehicle platform to fly synchronously, and can also be installed on the vehicle. Since the unmanned aerial vehicle can automatically follow the vehicle to travel, the mobility and task capability of the system are improved, and the task deployment and team cooperation are more flexible.

[0146] Referring to Figure 9 The embodiments of the application can also provide a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight device, as shown in Figure 9 The device can include:

[0147] The take-off function implementation unit 901 is configured to obtain the longitude and latitude of the current position point of the unmanned aerial vehicle as a desired horizontal coordinate, determine a vertical take-off height expectation value as a desired take-off height parameter, obtain first pose information of the unmanned aerial vehicle according to pose calculation, obtain position and speed error in the NED coordinate system according to the first pose information combined with the desired horizontal coordinate and the desired take-off height parameter, adjust the motor parameter according to a first series PID control method, perform first pose control on the unmanned aerial vehicle, and make the unmanned aerial vehicle take off to a specified position height, thereby realizing the take-off function of the unmanned aerial vehicle.

[0148] The following flight function implementation unit 902 is configured to obtain position and heading information of the ground vehicle-mounted platform reported by the ground Beidou satellite navigation device, perform pose calculation on the basis of the positioning and direction finding report information output by the airborne Beidou satellite navigation device to obtain second pose information of the unmanned aerial vehicle, calculate the relative position of the unmanned aerial vehicle and the ground vehicle-mounted platform in the NED coordinate system by using the second pose information, estimate an expected speed after receiving a following flight position instruction, obtain a speed deviation in combination with the current speed of the unmanned aerial vehicle, adjust the motor parameter according to the first series PID control method, perform second pose control on the unmanned aerial vehicle, and realize the following flight function of the unmanned aerial vehicle relative to the ground vehicle-mounted platform.

[0149] The autonomous landing function implementation unit 903 is configured to determine the landing type contained in the landing instruction after receiving the landing instruction, the landing type including direct landing and vehicle-mounted landing, adjust the motor parameter according to the landing control strategy corresponding to the determined landing type, perform third pose control on the unmanned aerial vehicle, and realize the autonomous landing function of the unmanned aerial vehicle.

[0150] The embodiments of the application can also provide a tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight device, the device including a processor and a memory:

[0151] The memory is configured to store program code and transmit the program code to the processor.

[0152] The processor is configured to execute the steps of the tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method according to the instructions in the program code.

[0153] As shown in Figure 10 The tethered unmanned aerial vehicle vehicle-mounted take-off and landing and following flight equipment provided by the embodiment of the present application can 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 complete communication with each other through the communication bus 13.

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

[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 unmanned aerial vehicle vehicle-mounted take-off and landing and following flight method.

[0156] The memory 11 is configured to store one or more programs. The program can include program code, and the program code includes computer operation instructions. In the embodiment of the present application, the memory 11 at least stores a program for implementing the following functions:

[0157] The positioning solution value in the hovering mode is taken as a take-off origin, the longitude and latitude of the take-off origin are taken as expected horizontal coordinates, the vertical take-off height expected value is determined as an expected take-off height parameter, the first pose information is obtained according to the pose solution, the position and speed error in the NED coordinate system are obtained according to the first pose information, the expected horizontal coordinates and the expected take-off height parameter, the motor parameters are adjusted according to the first series PID control method, the first pose control is performed on the unmanned aerial vehicle, the unmanned aerial vehicle is taken off to a specified position height, and the take-off function of the unmanned aerial vehicle is realized.

[0158] The position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation device is acquired, and the second pose information of the unmanned aerial vehicle is obtained by solving the pose according to the positioning and direction finding message output by the airborne Beidou satellite navigation device; the relative position of the unmanned aerial vehicle and the ground vehicle platform in the NED coordinate is calculated by using the second pose information; after receiving the accompanying position instruction, the expected speed is estimated, the speed deviation is obtained by combining the current speed of the unmanned aerial vehicle, the motor parameters are adjusted according to the first series PID control method, the second pose control is performed on the unmanned aerial vehicle, and the accompanying function of the unmanned aerial vehicle relative to the ground vehicle platform is realized.

[0159] After receiving the landing instruction, the landing type contained in the landing instruction is determined, the landing type includes direct landing and vehicle landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type, the third pose control is performed on the unmanned aerial vehicle, and the autonomous landing function of the unmanned aerial vehicle is realized.

[0160] In a possible implementation manner, the memory 11 can include a program storage area and a data storage area, wherein the program storage area can store an operating system, and application programs required by at least one function (such as a file creation function, a data read-write function) and the like; the data storage area can store data created in the use process, such as initialization data and the like.

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

[0162] The communication interface 12 can be an interface of a communication module, used for connecting with other devices or systems.

[0163] Of course, it needs to be explained that, Figure 10 The structure shown does not constitute a limitation on the tethered unmanned aerial vehicle vehicle take-off and landing and following accompanying flight device in the embodiments of the present application, and in actual application, the tethered unmanned aerial vehicle vehicle take-off and landing and following accompanying flight device can include more or less components than Figure 10 the structure shown, or combine certain components.

[0164] The embodiments of the present application can also provide a computer readable storage medium for storing program codes, the program codes being used for executing the steps of the tethered unmanned aerial vehicle vehicle take-off and landing and following accompanying flight method.

[0165] It should be noted that, in the specification, relational terms such as first and second, and the like, can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0166] From the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary universal hardware platforms. Based on such an understanding, the technical solutions of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in various embodiments or some parts of the embodiments.

[0167] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments. In particular, for the system or system embodiments, since it is basically similar to the method embodiments, it is described more simply, and the relevant parts can be referred to the part of the method embodiments. The above-described system and system embodiments are merely illustrative, and the units described as separate components can be or can not be physically separated, and the components displayed as units can be or can not be physical units, i.e., they can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to the actual needs. Those skilled in the art can understand and implement it without creative labor.

[0168] The above only describes the preferred embodiments of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application is included in the protection scope of the present application.

Claims

1. A method for tethered unmanned aerial vehicles (UAVs) to take off and land on a vehicle and to follow and accompany other UAVs, characterized in that, include: The latitude and longitude of the current position of the UAV are obtained as the desired horizontal coordinates, and the desired vertical height is determined as the desired take-off height parameter. The first attitude information of the UAV is obtained according to the attitude calculation. The position and velocity error in the NED coordinate system are obtained according to the first attitude information, the desired horizontal coordinates and the desired take-off height parameter. The motor parameters are adjusted according to the first series PID control method to control the first attitude of the UAV, so that the UAV takes off to the specified position height, thereby realizing the take-off function of the UAV. The system obtains the position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation equipment, and performs pose calculation based on the positioning and direction finding message information output by the airborne Beidou satellite navigation equipment to obtain the second pose information of the UAV. The system then uses the second pose information to calculate the relative position of the UAV and the ground vehicle platform in NED coordinates. After confirming that the accompaniment position command has been received, the desired speed is estimated, and the speed deviation is obtained by combining it with the current speed of the UAV. The motor parameters are adjusted according to the first series PID control method, and the UAV is subjected to second pose control to realize the accompaniment function of the UAV relative to the ground vehicle platform. After receiving a landing command, the landing type included in the landing command is determined, including direct landing and vehicle-mounted landing; the motor parameters are adjusted according to the landing control strategy corresponding to the determined landing type to perform third pose control on the UAV and realize the autonomous landing function of the UAV.

2. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method according to claim 1, characterized in that, The first series PID control method includes: The outer ring obtains the angle difference based on the desired attitude and the current attitude, acts on the proportional element of the outer ring to obtain the desired angular velocity, and transmits it to the inner ring; The inner loop obtains the angular velocity difference based on the desired angular velocity and the current angular velocity, and applies it to the PID loop. 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 transmitted to the mixer.

3. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method according to claim 1, characterized in that, The landing control strategy corresponding to the direct landing includes: Use the positioning solution value in hover mode as the default value for target landing; when it is determined that a direct landing is required, lock the current XY coordinates for vertical landing.

4. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method 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 with the vehicle, and its relative XY coordinates with respect to the vehicle platform are located. Once the relative XY coordinates are located, the drone is vertically landed on the ground vehicle platform.

5. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method according to claim 4, characterized in that, Finding the relative XY coordinates of the drone with respect to the vehicle platform, and locking the found relative XY coordinates for vertical landing on the ground vehicle platform, includes: Based on the position and heading information provided by the ground-based 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. Combined with the landing point on the ground vehicle platform, the desired relative position is calculated. The UAV is then subjected to third attitude control according to the second series PID control method to realize the landing of the UAV on the ground vehicle platform.

6. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method according to claim 5, characterized in that, The second series PID control method includes: 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 scaling factor 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 attitude and desired total tension by combining the target speed and the actual speed. After the desired attitude and the desired total tension are transmitted to the attitude controller, the target motor drive signal is output through the mixer and motor drive to adjust the attitude of the UAV, thereby achieving control of movement from the current position to the target position.

7. The tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along method according to claim 5, characterized in that, The location coordinates of the ground vehicle platform are received via a target absolute position message.

8. A tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along flight device, characterized in that, The apparatus for performing the tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-up flight method according to any one of claims 1-7, the apparatus comprising: The takeoff function implementation unit is used to obtain the latitude and longitude of the current position of the UAV as the desired horizontal coordinates, determine the desired vertical height as the desired takeoff height parameter; obtain the first attitude information of the current UAV based on the attitude calculation, obtain the position and velocity error in the NED coordinate system based on the first attitude information combined with the desired horizontal coordinates and the desired takeoff height parameter, adjust the motor parameters according to the first series PID control method, perform first attitude control on the UAV, so that the UAV takes off to the specified position height, thereby realizing the takeoff function of the UAV. The accompanying flight function implementation unit is used to acquire the position and heading information of the ground vehicle platform reported by the ground Beidou satellite navigation equipment, and to perform pose calculation based on the positioning and direction finding message information output by the airborne Beidou satellite navigation equipment to obtain the second pose information of the UAV. The second pose information is used to calculate the relative position of the UAV and the ground vehicle platform in NED coordinates. After determining that the accompanying flight position command has been received, the desired speed is estimated. Combined with the current speed of the UAV, the speed deviation is obtained. The motor parameters are adjusted according to the first series PID control method to perform second pose control on the UAV, thereby realizing the accompanying flight function of the UAV relative to the ground vehicle platform. The autonomous landing function implementation unit is used to determine the landing type included in the received landing command after receiving the landing command. The landing type includes direct landing and vehicle-mounted landing. The unit adjusts the motor parameters according to the landing control strategy corresponding to the determined landing type to perform third pose control on the UAV and realize the autonomous landing function of the UAV.

9. A tethered unmanned aerial vehicle (UAV) vehicle-mounted take-off and landing and follow-along flight device, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-along method according to any one of 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 code for executing the tethered unmanned aerial vehicle vehicle-mounted take-off and landing and follow-along method according to any one of claims 1-7.

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