Unmanned aerial vehicle formation flight control system and method based on virtual host

Abstract

The invention discloses an unmanned aerial vehicle formation flight control system and method based on a virtual host, an unmanned aerial vehicle formation flight device comprises a virtual host unit, a communication unit and a plurality of slave units, and the virtual host unit simulates the flight state of the whole formation. The slave unit maintains the formation and responds to the flight state of the virtual host, the communication unit communicates between the host unit and the slave unit, and the unmanned aerial vehicle formation flight method comprises the steps of initialization, takeoff, position point matching, formation forming, virtual host flight, state judgment, slave following flight, landing and the like. Step consistency is maintained between the virtual host unit and the slave unit through the communication unit. The host in the unmanned aerial vehicle formation is simulated by a program and is not actually existing, and all actually existing unmanned aerial vehicles are equivalent to slaves, so that the negative effects of formation flight caused by errors and abnormities of the host are reduced, and the accuracy and the stability of the formation flight are improved.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft control. Background Art

[0002] Most existing drone formations use a master-slave model, primarily consisting of a master unit, a communication unit, and slave units. The master unit, acting as the leader of the formation, is directly controlled by the operator and determines the overall flight path and speed of the formation. The communication unit exchanges data between the master and slave units, while the slave units, acting as followers, control their own flight based on flight data from the master unit to maintain the formation's formation. The entire formation is centered around the master unit, and the flight of all slave units depends on it.

[0003] The existing technology has the following shortcomings:

[0004] 1. It relies on the accuracy of the host's flight data perception. If there is a large deviation in the host's position and speed information, the formation will be difficult to maintain.

[0005] 2. It depends on the flight performance and processor power of the host. If the host cannot complete its own flight mission well, the flight mission of the slave aircraft will also be affected.

[0006] 3. It depends on the stability of the host communication. If the host is interrupted or an error occurs in receiving data, all slaves will not be able to receive correct data. Summary of the Invention

[0007] To solve the above problems, the present application provides a UAV formation flight control system and method based on a virtual host.

[0008] According to a first aspect of the present application, the present application provides a UAV formation flight control system based on a virtual host, comprising:

[0009] The virtual host unit is used to simulate the flight state, path and speed of the entire formation of drones to form simulation information;

[0010] The communication unit is used to communicate between the virtual master unit and the plurality of slave units to transmit the simulation information;

[0011] The plurality of slave units are used to maintain the formation of the UAV formation and respond to the virtual host unit to perform respective flight missions according to the simulation information.

[0012] Furthermore, the virtual host unit is implemented by computer program simulation and includes a data module and a control module; wherein the data module is used to generate information on the virtual host's position, flight speed, and angular velocity, and to obtain surrounding geographic information and generate the simulation information for the slave based on this information; the control module is used to control the flight status of the virtual host.

[0013] Furthermore, the communication unit includes a master data transmission module and multiple slave data transmission modules, and the master and slave data transmission modules can communicate bidirectionally. The master data transmission module is used to support one-to-many broadcast communication, and each slave data transmission module is used to support directional communication to the master data transmission module.

[0014] Furthermore, each of the slave units includes a power supply module, a sensor module, a control module and a power module, wherein the power supply module is used to supply power to the corresponding slave, the sensor module is used to sense the position and speed of the corresponding slave and generate flight data, the control module is used to calculate the flight data and control the behavior logic of the corresponding slave, and the power module is used to provide the power required for the corresponding slave to perform flight.

[0015] According to a second aspect of the present application, the present application provides a virtual host-based drone formation control method, which is applied to the drone formation flight control system described in the first aspect of the present application. The drone formation flight control method includes:

[0016] System initialization steps include establishing communication relationships between each virtual master and slave, and checking the status of each slave;

[0017] The slave takeoff step includes controlling each slave to enable the motor and take off to a specified height;

[0018] The position point matching step includes matching the current position set of each slave aircraft with the planned position set of each slave aircraft in the next formation to generate the target waypoint of each slave aircraft;

[0019] The formation generation step includes each slave aircraft performing obstacle avoidance flight according to its corresponding target waypoint and the position of other slave aircraft to form a target formation;

[0020] The virtual host flight steps include updating its own flight status information and the flight status information of the formation, and sending the flight status information of the formation to each slave;

[0021] The flight end judgment step includes each slave machine judging whether the flight has ended based on the flight status information sent by the virtual host;

[0022] The formation change judgment step includes each slave determining whether a formation change is required based on the flight status information sent by the virtual host;

[0023] The slave aircraft follows the flight steps, including each slave aircraft calculating its own desired speed based on its own position and the master aircraft's position, speed, and yaw angle information, and performing speed control;

[0024] The slave aircraft landing step includes each slave aircraft landing in place and disabling its motor.

[0025] Furthermore, in the slave aircraft take-off step and the slave aircraft landing step, each slave aircraft can control the vertical speed of the slave aircraft through PID according to the distance from the target height, the current vertical speed and acceleration.

[0026] Furthermore, in the position point matching step, the current position set of each slave machine and the planned position set in the next formation are sorted according to the coordinates projected on the specific coordinate axis, and the two sorted ordered position sets are matched.

[0027] Furthermore, in the formation generation step, the target speed of each slave is expressed as

[0028]

[0029] where p i Indicates the current position of the slave numbered i, d j Indicates the relative distance to the slave numbered j, k t 、k s represents the proportional coefficient for converting distance to speed, v tm Indicates the maximum speed, direction and k towards the waypoint t (w i -p i ) is consistent, v sm Indicates the maximum speed, direction and distance away from other slaves consistent.

[0030] Furthermore, in the virtual host flight step, the virtual host's own flight status information includes information on flight speed, angular velocity, position, and yaw angle, and the formation's flight status information includes information on following flight, formation change, landing, and information on position, speed, yaw angle, and angular velocity.

[0031] Furthermore, in the slave following flight step, the target speed of each slave is expressed as

[0032]

[0033] where v m Indicates the flight speed of the virtual host, ω m Indicates the rotation angular velocity of the virtual host, Indicates the yaw angle of the virtual host, Represents the rotation matrix corresponding to the host yaw angle, d i Indicates the target relative position of the slave numbered i and the virtual host, k p represents the proportional coefficient for converting distance to speed, p i Indicates the actual position of the slave, p m Indicates the actual location of the virtual host.

[0034] The beneficial effects of this application are:

[0035] According to the above-mentioned implementation of the virtual host-based drone formation flight device and method, since the host in the drone formation is simulated by a program and does not actually exist, all actually existing drones are equivalent to slaves, thereby reducing the negative impact of host errors and anomalies on formation flight and improving the accuracy and stability of formation flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of a UAV formation flying device based on a virtual host is provided for this application;

[0037] Figure 2 This is a schematic diagram of a virtual host unit of a UAV formation flying device based on a virtual host in the present application;

[0038] Figure 3 Schematic diagram of a communication unit of a UAV formation flying device based on a virtual host in the present application;

[0039] Figure 4 This is a schematic diagram of a slave unit of a UAV formation flying device based on a virtual host in the present application;

[0040] Figure 5 A schematic diagram of a UAV formation flight method based on a virtual host is provided for this application;

[0041] Figure 6 This is a schematic diagram of a motion model of a formation generation step of a UAV formation flying method based on a virtual host in this application;

[0042] Figure 7 This application provides a motion model diagram of a UAV formation flying method based on a virtual host, in which a slave follows the flight steps. DETAILED DESCRIPTION

[0043] The present application will be further described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0044] This embodiment discloses a UAV formation flight control system based on a virtual host. Figure 1In a specific embodiment, it mainly includes a virtual host unit 11, a communication unit 12, and multiple slave units 13. Each unit is introduced below.

[0045] The virtual host unit 11 is used to simulate the flight of the host in the UAV formation, as well as the flight state, path and speed of the entire formation in the UAV formation and form simulation information. Figure 2 In a specific embodiment, the virtual host unit 11 can be a flight simulation system, including a control module 21 and a data module 22; wherein the data module 22 includes a flight data module 23, which is used to generate information on the position, flight speed, and angular velocity of the virtual host, and is updated at a fixed frequency, and the simulation information for the slave is generated based on this information, a geographic data module 24, which is used to obtain the surrounding geographic information, and a data display module 25, which is used to display the flight data of the virtual host and the geographic information of its flight area; the control module is used to control the flight status of the virtual host, and can receive control signals from a keyboard or remote control, and convert them into data for controlling the status, speed, and angular velocity of the virtual host's flight.

[0046] Understandably, Figure 1 and Figure 2 In the figure, the virtual host unit 11 is simulated by a computer program and includes a data module 22 and a control module 21; wherein the data module 22 is used to generate information on the position, flight speed, and angular velocity of the virtual host 11, and to obtain surrounding geographic information and generate simulation information for the slave based on this information; the control module 21 is used to control the flight status of the virtual host.

[0047] The communication unit 12 is used to communicate between the virtual master unit and the slave unit and transmit analog information. Figure 3 In a specific embodiment, the communication unit 12 includes a master data transmission module 31 and multiple slave data transmission modules 32. The MAC address is used to network the data transmission. The master data transmission module 42 stores the MAC addresses of all slave data transmission modules 43, and the slave data transmission module 43 stores the MAC address of the master data transmission module 42. The data source is identified by the MAC address, so that the master data transmission module 42 can broadcast information to all slave data transmission modules 43, and the slave data transmission module 43 can send information to the master data transmission module 42 in a targeted manner.

[0048] Understandably, Figure 1 and Figure 3 In the figure, the communication unit 12 includes a master data transmission module 31 and multiple slave data transmission modules 32, which can communicate bidirectionally. The master data transmission module 31 is used to support one-to-many broadcast communication, and each slave data transmission module 32 is used to support directional communication to the master data transmission module 31.

[0049] The multiple slave units 13 are used to perform their own flight missions, such as maintaining the formation of the drone formation, and respond to the virtual master unit 11 to perform their respective flight missions according to the simulation information. Figure 4 In one embodiment, the slave unit 13 includes a sensor module 41, a power module 42, a control module 43, and a power module 44. The sensor module 41 is used to sense the position and velocity of the corresponding slave and generate flight data. It includes a compass 45, a three-axis accelerometer 46, a GPS 47, an air pressure sensor 48, and a three-axis gyroscope 49, and is connected to the MCU 412 via a serial port. The power module is used to power the corresponding slave and includes a battery 411 and an ammeter 412. The control module is used to calculate flight data and control the behavior logic of the corresponding slave. It is powered by the power module 42, receives data from the sensor module 41, and outputs the required control signals to the power module 44. It includes an MCU 412 and a remote controller 413. The MCU 412 can also receive control commands from the remote controller 413 or the communication unit 12. The power module 44 is used to provide the power required for the corresponding slave to execute flight. It is powered by the power module 42 and receives control signals from the control module 43. It includes an electronic speed controller 414 and a motor 415. In other specific embodiments, a six-axis gyroscope may be used instead of the three-axis accelerometer 46 and the three-axis gyroscope 49 .

[0050] Understandably, Figure 1 and Figure 4 In the figure, each slave unit 13 includes a power module 42, a sensor module 41, a control module 43 and a power module 44, wherein the power module 42 is used to supply power to the corresponding slave, the sensor module 41 is used to sense the position and speed of the corresponding slave and generate flight data, the control module 43 is used to calculate the flight data and control the behavior logic of the corresponding slave, and the power module 44 is used to provide the power required for the corresponding slave to perform flight.

[0051] This embodiment discloses a UAV formation flight control method based on a virtual host, which is applied to the UAV formation flight control system described in this embodiment. Figure 5 In a specific embodiment, it includes a system initialization step S51, a slave takeoff step S52, a position point matching step S53, a formation generation step S54, a virtual host flight step S55, a flight end judgment step S56, a formation change judgment step S57, a slave follow flight step S58, and a slave landing step S59, which are described below.

[0052] S51, system initialization step, establishes a communication relationship between the virtual host and the slaves, obtains and ensures that each slave has a unique identification code, ensures that the actual communication rate is not less than the minimum required rate, and checks the status of each slave to ensure that all slaves can be positioned normally and the motors can be unlocked normally.

[0053] S52, slave takeoff step: the master sends a takeoff command to all slaves and waits. Each slave has no horizontal speed, only vertical speed. It detects its own altitude through the fusion data of the barometer and GPS, and performs EKF filtering on the altitude data to obtain the takeoff speed and acceleration. According to the distance to the target altitude, the current vertical speed and acceleration, the takeoff speed is controlled by the limited PID until it stabilizes at the desired altitude. After takeoff is completed, the master sends its own number and takeoff completion information to the virtual master. This step ends after the virtual master receives the message that all slaves have completed takeoff.

[0054] S53, position point matching step, each slave performs positioning and sends its own number i and position information p i Send it to the virtual host. When the virtual host receives the position information of all slaves, it converts the coordinates of all slaves in the NED coordinate system into the relative position d with the virtual host. i (x, y), rotate the xy coordinate axis so that the relative position on one of the coordinate axes is the most discrete. This coordinate axis is the principal component axis of the relative position, and sort the point set of the relative position according to the coordinates on the principal component axis. The specific method is as follows: Calculate all relative positions d i The center of mass For all d i The x and y coordinates of (x, y) are linearly regressed to obtain the regression line l1 and the centroid And the straight line l2 perpendicular to l1, l1 and l2 are the new coordinate axes to establish a coordinate system, and calculate d i (x, y) coordinate d in the new coordinate system i (x', y'). i Sort by x' coordinate in ascending order, and for d with the same x' coordinate i Sort by y' coordinate in ascending order to get the ordered point set D. The relative position d' of each slave and virtual host in the next formation i Perform similar processing to obtain the centroid Regression line l'1, perpendicular line l'2 through the centroid, coordinates d'i(x, y) in the coordinate system formed by l'1 and l'2, d'i(x", y"), and ordered point set D' sorted by x" and y" coordinates. Match the points in the sorted point sets D and D' in order, and match their corresponding points in the xy coordinate system to obtain the next target position w of each slave. i and sends the target position point to each slave machine.

[0055] S54, formation generation step, each slave performs positioning and sends its own number i and position information p iAfter receiving the position information of all slaves, the virtual host converts the coordinates of all slaves in the NED coordinate system into relative positions with the virtual host and sends them to each slave. After receiving the relative positions of all slaves and the virtual host sent by the virtual host, each slave calculates the distance D between itself and all other slaves = {d1, d2, ... d i-1 ,d i+1 ,……,d n}, then calculate the expected flight speed v i , the corresponding motion model is as follows Figure 6 As shown, the target speed of each slave is expressed as

[0056]

[0057] where p i Indicates the current position of the slave numbered i, d j Indicates the relative distance between the slave and the slave numbered j, k t 、k s represents the proportional coefficient for converting distance to speed, v tm Indicates the maximum speed, direction and k towards the waypoint t (w i -p i ) is consistent, v sm Indicates the maximum speed, direction and distance away from other slaves Each slave performs speed control to make itself run at the desired speed v i Fly, after a certain time interval Δt, repeat this step from the beginning. i -p i |<δ d and|v i |<δ v When the slaves arrive at the waypoint, the flight stops and a message of arrival at the waypoint is sent to the virtual host. The virtual host ends this step after receiving the message that all slaves have arrived at the waypoint.

[0058] S55, virtual host flight step, according to the operator's instructions to update the flight status of the formation (follow flight, formation change, flight end), and send the next flight status to each slave. If the flight status of the formation is follow flight, the virtual host receives the ppm signal of the remote controller and converts the ppm signal into the speed v of the virtual host. m , angular velocity ω m , with a fixed frequency f m Update own position p m , yaw angle So that p' m =p m +v m / f m , And change its own position p m , speed v m , yaw angle Angular velocity ω m Send to each slave; if the flight state of the formation is the formation change state and the flight end state, make the speed of the virtual host v m =0, angular velocity ω m =0.

[0059] S56, flight end judgment step, each slave determines whether the formation flight is ended based on the information sent by the virtual host. If the formation flight is not ended, enter S57 formation change judgment step. If the formation flight is ended, enter S58 landing step.

[0060] S57, formation change judgment step, each slave determines whether a formation change is required based on the information sent by the virtual host. If a formation change is required, the process proceeds to S53 position point matching step; if no formation change is required, the process proceeds to S58 slave follow flight step.

[0061] S58, the slaves follow the flight steps, each slave reads its own position information, and obtains the current accurate position data p through the EKF filtering method. i , and then calculate the expected flight speed v i , the corresponding motion model is as follows Figure 7 As shown, the target speed of each slave is expressed as

[0062]

[0063] where v m Indicates the flight speed of the virtual host, ω m Indicates the rotation angular velocity of the virtual host, Indicates the yaw angle of the virtual host, Represents the rotation matrix corresponding to the host yaw angle, d i Indicates the target relative position of the slave numbered i and the virtual host, k p represents the proportional coefficient for converting distance to speed, p i Indicates the actual position of the slave, p m Indicates the actual position of the virtual master. Each slave performs speed control to make itself move at the desired speed v i flight.

[0064] S59, slave landing step: each slave reduces its horizontal speed to zero, retaining only the vertical speed and starting to land. The altitude is detected by fusion data of the barometer and GPS, and the altitude data is EKF filtered to obtain the landing speed and acceleration. The landing speed is controlled by a limited PID algorithm based on the distance to the target altitude and the current vertical speed and acceleration. The motor stops when landing on the ground and a landing completion message is sent to the virtual host. This step ends after the virtual host receives the message that all slaves have completed landing.

[0065] The virtual host-based drone formation flight device and method proposed in this application, since the host in the drone formation is simulated by a program and does not actually exist, all actually existing drones are equivalent to slaves, thereby reducing the negative impact of host errors and anomalies on formation flight and improving the accuracy and stability of formation flight.

[0066] The above content is a further detailed description of the present application in conjunction with specific implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the inventive concept of the present application.

Claims

1. A UAV formation flight control system based on a virtual host, characterized in that: Includes a virtual master unit, a communication unit, and multiple slave units: The virtual host unit is used to simulate the flight state, path and speed of the entire formation of drones to form simulation information; The communication unit is used to communicate between the virtual master unit and the plurality of slave units to transmit the simulation information; The plurality of slave units are used to maintain the formation of the UAV formation and respond to the virtual host unit to perform respective flight missions according to the simulation information.

2. The UAV formation flight control system based on a virtual host according to claim 1, characterized in that: The virtual host unit is implemented by computer program simulation and includes a data module and a control module; wherein the data module is used to generate information on the virtual host's position, flight speed, and angular velocity, and to obtain surrounding geographic information and generate the simulation information for the slave based on this information; the control module is used to control the flight status of the virtual host.

3. The UAV formation flight control system based on virtual host according to claim 1, characterized in that: The communication unit includes a master data transmission module and multiple slave data transmission modules. The master data transmission module and the slave data transmission modules can communicate bidirectionally. The master data transmission module is used to support one-to-many broadcast communication, and each slave data transmission module is used to support directional communication to the master data transmission module.

4. The UAV formation flight control system based on a virtual host according to claim 1, characterized in that: Each of the slave units includes a power module, a sensor module, a control module and a power module, wherein the power module is used to supply power to the corresponding slave, the sensor module is used to sense the position and speed of the corresponding slave and generate flight data, the control module is used to calculate the flight data and control the behavior logic of the corresponding slave, and the power module is used to provide the power required for the corresponding slave to perform flight.

5. A UAV formation flight control method, characterized in that: The UAV formation flight control system according to any one of claims 1 to 4, wherein the UAV formation flight control method comprises: System initialization steps include establishing communication relationships between the virtual master and each slave, and checking the status of each slave; The slave takeoff step includes controlling each slave to enable the motor and take off to a specified height; The position point matching step includes matching the current position set of each slave aircraft with the planned position set of each slave aircraft in the next formation to generate the target waypoint of each slave aircraft; The formation generation step includes each slave aircraft performing obstacle avoidance flight according to its corresponding target waypoint and the position of other slave aircraft to form a target formation; The virtual host flight steps include updating its own flight status information and the flight status information of the formation, and sending the flight status information of the formation to each slave; The flight end judgment step includes each slave machine judging whether the flight has ended based on the flight status information sent by the virtual host; The formation change judgment step includes each slave determining whether a formation change is required based on the flight status information sent by the virtual host; The slave aircraft follows the flight steps, including each slave aircraft calculating its own desired speed based on its own position and the master aircraft's position, speed, and yaw angle information, and performing speed control; The slave aircraft landing step includes each slave aircraft landing in place and disabling its motor.

6. The formation flight control method according to claim 5, wherein: In the slave aircraft take-off step and the slave aircraft landing step, each slave aircraft can control the vertical speed of the slave aircraft through PID according to the distance from the target height, the current vertical speed and acceleration.

7. The UAV formation flight control method according to claim 5, wherein: In the position point matching step, the current position set of each slave machine and the planned position set in the next formation are sorted according to the coordinates projected on the specific coordinate axis, and the two sorted ordered position sets are matched.

8. The UAV formation flight control method according to claim 5, wherein: In the formation step, the target speed of each slave is expressed as Among them, p i Indicates the current position of the slave numbered i, d j Indicates the relative distance to the slave numbered j, k t 、k s represents the proportional coefficient for converting distance to speed, v t Indicates the maximum speed, direction and k towards the waypoint t (w i -p i ) consistent, v s Indicates the maximum speed, direction and distance away from other slaves consistent.

9. The UAV formation flight control method according to claim 5, wherein: In the virtual host flight step, the virtual host's own flight status information includes flight speed, angular velocity, position, and yaw angle information, and the formation's flight status information includes follow-up flight, formation change, landing information and position, speed, yaw angle, and angular velocity information.

10. The UAV formation flight control method according to claim 5, wherein: In the slave following flight step, the target speed of each slave is expressed as Among them, v m Indicates the flight speed of the virtual host, ω m Indicates the rotation angular velocity of the virtual host, Indicates the yaw angle of the virtual host, Represents the rotation matrix corresponding to the host yaw angle, d i Indicates the target relative position of the slave numbered i and the virtual host, k p represents the proportional coefficient for converting distance to speed, p i Indicates the actual position of the slave, p m Indicates the actual location of the virtual host.

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