An autonomous navigation system and method for operating drone battery replacement vehicles

Abstract

An autonomous navigation system and method for an operating drone battery-swapping vehicle, which belongs to the field of autonomous navigation technology for battery-swapping vehicles. The present invention solves the problems of high cost, low drone battery-swapping and operation efficiency in existing long-distance drone battery-swapping methods. The present invention only requires the deployment of a single battery-swapping vehicle in the operating area, which greatly reduces the initial investment and subsequent maintenance costs. Based on the construction of drone operating area scene maps based on lidar point cloud data and inertial positioning data, autonomous positioning and navigation, and adaptive dynamic obstacle avoidance, not only does it not require manual intervention in the execution of drone battery-swapping tasks, greatly reducing labor costs, but the installed sensing equipment allows the battery-swapping vehicle to automatically perform drone following and battery-swapping tasks during the execution of the task, thereby improving the drone battery-swapping efficiency, and there is no need to stop and wait while the drone is waiting for battery-swapping, thereby improving the efficiency of drone operations. The method of the present invention can be applied to the autonomous navigation of drone battery-swapping vehicles.

Description

Technical Field

[0001] The present invention belongs to the technical field of autonomous navigation of battery-swapping vehicles, and specifically relates to an autonomous navigation system and method for operating drone battery-swapping vehicles. Background Art

[0002] Due to their exceptional adaptability to environmental conditions, drone-assisted operations have become an indispensable tool for improving efficiency in many fields. However, in long-distance operations such as power inspections and road monitoring, the limited endurance of drones has become a significant factor limiting the effectiveness of these operations. Therefore, providing a stable and reliable battery swapping service is crucial for improving the efficiency of long-distance drone operations.

[0003] Currently, common methods for replacing batteries for drones include fixed and mobile battery replacement. Fixed battery replacement involves deploying battery replacement stations at a single or multiple locations within the drone's operating area. For drones operating over long distances, deploying a battery replacement station at a single location will cause the drone to make multiple round trips between the battery replacement station and the operating location, significantly impacting operational efficiency. Deploying battery replacement stations at multiple locations, on the other hand, results in high initial investment and subsequent maintenance costs. Currently, the commonly used mobile battery replacement method involves a dedicated person remotely controlling a battery replacement vehicle to drive to the drone's landing location to complete the battery replacement. This, to a certain extent, avoids the high costs associated with fixed battery replacement methods. However, manual battery replacement vehicle operation and scheduling not only incurs additional labor and learning costs, but also introduces errors in the timing of battery replacement vehicle scheduling, ultimately impacting drone battery replacement and operational efficiency. Therefore, both the currently common fixed and mobile battery replacement methods are unsuitable for battery replacement missions for drones operating over long distances. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of high cost and low efficiency of battery replacement and operation of existing long-distance operation drone battery replacement methods, and to propose an autonomous navigation system and method for operating drone battery replacement vehicles.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] According to one aspect of the present invention, an autonomous navigation system for operating a drone battery-swapping vehicle comprises an external device, a drone battery-swapping unit, a computing unit, a battery-swapping vehicle chassis, and a sensing device. The external device comprises a wireless communication unit and a remote control unit. The sensing device comprises a laser radar, a visual camera sensor, and an inertial measurement unit.

[0007] The computing unit is installed on the battery-swapping vehicle and is used to communicate with the UAV battery-swapping unit, the battery-swapping vehicle chassis, external devices, and sensing devices;

[0008] The remote control unit is used to send remote control signals, battery swap task signals and battery swap end signals to the computing unit on the battery swap vehicle;

[0009] After receiving the battery swap task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV. After the communication between the computing unit and the wireless communication unit is established, the battery swap vehicle enters the remote control mode;

[0010] In remote control mode, the laser radar is used to perceive environmental information, and the inertial measurement unit is used to obtain the battery swap vehicle's own status data and the battery swap vehicle's position; the remote control unit is used to send a remote control signal to the computing unit based on the environmental information, the battery swap vehicle's own status data and the battery swap vehicle's position, and the computing unit sends a motion control signal to the battery swap vehicle chassis based on the received remote control signal to control the battery swap vehicle to drive to the starting point of the drone operation area. After the visual camera sensor senses that the battery swap vehicle has reached the starting point, the battery swap vehicle switches to autonomous navigation mode;

[0011] In the autonomous navigation mode, the computing unit is used to perform autonomous navigation based on the drone status signal, environmental information, battery swap vehicle position and battery swap vehicle status data sent by the wireless communication unit, send motion control signals to the battery swap vehicle chassis according to the autonomous navigation results, and send battery swap signals to the drone battery swap unit mounted on the battery swap vehicle;

[0012] The UAV battery swap unit is used to receive the battery swap signal sent by the computing unit, and the battery swap vehicle starts to perform the UAV battery swap operation after driving to the target position of autonomous navigation;

[0013] After the computing unit receives the battery swap end signal, the battery swap vehicle leaves the drone operation area;

[0014] The wireless communication unit is installed on the drone, and includes a distance measurement module, a logic processing module and a wireless transmission module;

[0015] The distance measurement module is used to measure the current height of the drone from the ground, the logic processing module is used to encapsulate the status signal including the current height of the drone from the ground and the battery level of the drone, and the wireless transmission module is used to send the drone status signal to the computing unit on the battery-swapping vehicle.

[0016] According to another aspect of the present invention, an autonomous navigation method for operating a UAV battery-changing vehicle comprises the following steps:

[0017] Step 1: When the UAV receives a power inspection task, the operator uses the remote control unit to send a power exchange task signal to the computing unit on the battery exchange vehicle. After receiving the power exchange task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV to establish a connection between the computing unit and the wireless communication unit.

[0018] Step 2: The operator uses the remote control unit to remotely control the drone and the battery-swapping vehicle to the starting point of the drone's operation area. The drone starts to perform power inspection operations from the starting point of the operation area. During the process of the drone performing power inspection operations, the wireless communication unit on the drone sends a drone status signal to the computing unit at fixed intervals.

[0019] When the visual camera sensor on the battery swap vehicle recognizes the QR code at the starting point, the computing unit loads the scene map of the current drone operation area according to the recognized QR code, and at the starting point, the omnidirectional antenna installed on the computing unit waits to receive the drone status signal;

[0020] When receiving the drone status signal, start executing step three;

[0021] Step 3: Determine whether the received current drone status signal is a waiting for battery replacement status signal;

[0022] If the current drone status signal is not waiting for battery replacement, proceed to step 4;

[0023] If the current drone status signal is waiting for battery replacement, proceed to step 5;

[0024] Step 4: Convert the drone's position in the battery swap vehicle coordinate system to the world coordinate system of the scene map of the drone's operating area based on the current drone status signal received, and set the converted position coordinates as the navigation point N of the battery swap vehicle. i ;

[0025] The computing unit calculates the scene map and navigation point N of the UAV operation area. i Perform global path planning and send motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6;

[0026] Step 5: According to the current UAV status signal received, the UAV's position in the battery swap vehicle coordinate system is converted to the position coordinates in the world coordinate system of the scene map of the UAV operation area, and the converted position coordinates are set as the initial battery swap point R of the battery swap vehicle. i ;

[0027] Calculate the shortest encounter time t' between the UAV and the battery swap vehicle, and then calculate the revised battery swap point R based on the shortest encounter time t' and the initial battery swap point i ';

[0028] The computing unit performs global path planning based on the scene map of the UAV operation area and the corrected battery swap point, and sends motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the corrected navigation point R according to the motion control signals sent by the computing unit. i ', the UAV lands on the battery swap unit carried by the battery swap vehicle to swap batteries and executes step six;

[0029] Step 6: The battery-swapping vehicle waits to receive the next drone status signal at the navigation point it has reached. After receiving the drone status signal, it returns to step 3 and continues until it receives the battery-swapping end signal, at which point the battery-swapping vehicle leaves the drone operation area.

[0030] The beneficial effects of the present invention are:

[0031] The present invention only requires the deployment of a single battery-swapping vehicle within the drone operation area, greatly reducing the initial investment and subsequent maintenance costs. Compared with manually controlled battery-swapping vehicles, the present invention realizes the construction of a drone operation area scene map based on lidar point cloud data and inertial positioning data, autonomous positioning and navigation, and adaptive dynamic obstacle avoidance. In the execution of drone battery-swapping tasks, not only is there no need for human intervention, which greatly reduces labor costs, but the installed sensing equipment allows the battery-swapping vehicle to automatically perform drone following and battery-swapping tasks during the execution of the task, thereby improving the drone battery-swapping efficiency. In addition, the drone does not need to stop and wait while waiting for battery replacement, and can continue to operate, solving the problem of low operating efficiency of existing battery-swapping methods.

[0032] The present invention proposes an autonomous navigation method for a battery-swapping vehicle used for long-duration and long-distance UAV operations, which has lower labor and maintenance costs and higher battery-swapping efficiency when performing battery-swapping tasks, and provides a reliable solution for battery-swapping UAVs operating for long periods of time and long distances. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is an exemplary scene graph of the present invention;

[0034] The power inspection mission route planned by UAV D1 is from transmission line tower T1 to T5, and the initial positioning point is set at power tower T1;

[0035] Figure 2 It is the overall framework diagram of the system of the present invention;

[0036] Figure 3 It is an overall flow chart of the method of the present invention;

[0037] Figure 4a This is a schematic diagram of the process of applying the autonomous navigation method proposed by the present invention. Figure 1 ;

[0038] Figure 4bThis is a schematic diagram of the process of applying the autonomous navigation method proposed by the present invention. Figure 2 ;

[0039] Figure 5 It is a schematic diagram of the distance and position relationship between the UAV and the UAV-exchange vehicle;

[0040] Figure 6 This is a framework diagram of the wireless communication unit installed on the drone;

[0041] Figure 7 It is a flow chart of establishing communication between the UAV wireless communication unit and the UAV battery-swapping vehicle. DETAILED DESCRIPTION

[0042] Specific implementation method 1: Combination Figure 2 and Figure 6 This embodiment describes an autonomous navigation system for a battery-swapping vehicle operated by a drone. The system includes external equipment, a drone battery-swapping unit, a computing unit, a battery-swapping vehicle chassis, and a sensing device. The external equipment includes a wireless communication unit and a remote control unit. The sensing device includes a laser radar, a visual camera sensor, and an inertial measurement unit.

[0043] The computing unit is installed on the battery-swapping vehicle and is used to communicate with the UAV battery-swapping unit, the battery-swapping vehicle chassis, external devices, and sensing devices. The wireless communication unit communicates with the computing unit using LTE communication technology, and the remote control unit communicates with the computing unit using 2.4G wireless communication technology.

[0044] The remote control unit is used to send remote control signals, battery swap task signals and battery swap end signals to the computing unit on the battery swap vehicle;

[0045] After receiving the battery swap task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV. After the communication between the computing unit and the wireless communication unit is established, the battery swap vehicle enters the remote control mode;

[0046] In remote control mode, the laser radar is used to perceive environmental information, and the inertial measurement unit is used to obtain the battery swap vehicle's own status data (including current speed information, acceleration information, and posture information) and the battery swap vehicle's position; the remote control unit is used to send a remote control signal to the computing unit based on the environmental information, the battery swap vehicle's own status data, and the battery swap vehicle's position; the computing unit sends a motion control signal to the battery swap vehicle chassis based on the received remote control signal to control the battery swap vehicle to travel to the starting point of the drone operation area. After the visual camera sensor senses that the battery swap vehicle has reached the starting point, the battery swap vehicle switches to autonomous navigation mode;

[0047] In the autonomous navigation mode, the computing unit is used to perform autonomous navigation based on the drone status signal, environmental information, battery swap vehicle position and battery swap vehicle status data sent by the wireless communication unit, send motion control signals to the battery swap vehicle chassis according to the autonomous navigation results, and send battery swap signals to the drone battery swap unit mounted on the battery swap vehicle;

[0048] The UAV battery swap unit is used to receive the battery swap signal sent by the computing unit, and the battery swap vehicle starts to perform the UAV battery swap operation after driving to the target position of autonomous navigation;

[0049] After the computing unit receives the battery swap end signal, the battery swap vehicle leaves the drone operation area;

[0050] The wireless communication unit is installed on the drone, and includes a distance measurement module (using an ultrasonic sensor), a logic processing module (using an STM32F103 development board) and a wireless transmission module (using an LTE wireless communication module);

[0051] The distance measurement module is used to measure the current height of the drone from the ground. The logic processing module is used to encapsulate status signals including the current height of the drone from the ground and the drone's battery level (the drone's battery level parameters are obtained through the SDK provided by the drone manufacturer). The wireless transmission module is used to send drone status signals to the computing unit on the battery-swapping vehicle.

[0052] The present invention does not specifically limit the models of the drone battery replacement unit and the battery replacement vehicle chassis. Different models and styles of devices can be assembled according to different scenarios, and it can realize long-term and long-distance drone battery replacement and receive motion control signals.

[0053] Specific implementation method 2: Combination Figure 3 This embodiment describes a method for autonomous navigation of a battery-swapping vehicle for operating a drone, and the method specifically includes the following steps:

[0054] Step 1: When the UAV receives a power inspection task, the operator uses the remote control unit to send a power exchange task signal to the computing unit on the battery exchange vehicle. After receiving the power exchange task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV to establish a connection between the computing unit and the wireless communication unit.

[0055] Step 2: The operator uses the remote control unit to remotely control the drone and the battery-swapping vehicle to the starting point of the drone's operation area. The drone starts to perform power inspection operations from the starting point of the operation area. During the process of the drone performing power inspection operations, the wireless communication unit on the drone sends a drone status signal to the computing unit at fixed intervals.

[0056] When the visual camera sensor on the battery-swapping vehicle recognizes the QR code at the starting point, it indicates that the battery-swapping vehicle is currently driving to the starting point of the drone operation area. This QR code marks the scene map information corresponding to the current drone operation area. The computing unit loads the scene map of the current drone operation area according to the recognized QR code, and at the starting point, uses the omnidirectional antenna installed on the computing unit to wait for receiving the drone status signal;

[0057] When receiving the drone status signal, start executing step three;

[0058] Step 3: Determine whether the received current drone status signal is a waiting for battery replacement status signal;

[0059] If the current drone status signal is not waiting for battery replacement, proceed to step 4;

[0060] If the current drone status signal is waiting for battery replacement, proceed to step 5;

[0061] Step 4: Convert the drone's position in the battery swap vehicle coordinate system to the world coordinate system of the scene map of the drone's operating area based on the current drone status signal received, and set the converted position coordinates as the navigation point N of the battery swap vehicle. i ;

[0062] The computing unit calculates the scene map and navigation point N of the UAV operation area. i Perform global path planning and send motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6;

[0063] Step 5: According to the current UAV status signal received, the UAV's position in the battery swap vehicle coordinate system is converted to the position coordinates in the world coordinate system of the scene map of the UAV operation area, and the converted position coordinates are set as the initial battery swap point R of the battery swap vehicle. i ; The calculation method of the navigation point is the same as that in step 4;

[0064] Calculate the shortest encounter time t' between the UAV and the battery swap vehicle, and then calculate the revised battery swap point R based on the shortest encounter time t' and the initial battery swap point i ';

[0065] The computing unit performs global path planning based on the scene map of the UAV operation area and the corrected battery swap point, and sends motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the corrected navigation point R according to the motion control signals sent by the computing unit. i ', the UAV lands on the battery swap unit carried by the battery swap vehicle to swap batteries and executes step six;

[0066] Step 6: The battery-swapping vehicle waits to receive the next drone status signal at the navigation point it has reached. After receiving the drone status signal, it returns to step 3 and continues until it receives the battery-swapping end signal, at which point the battery-swapping vehicle leaves the drone operation area.

[0067] Specific implementation method three: Combination Figure 7 This embodiment differs from the second embodiment in that the connection between the computing unit and the wireless communication unit is established before each operation of the drone. The specific process is as follows:

[0068] The computing unit sends a communication establishment request message req to the wireless communication unit on the drone, where the request message req includes a source device code and a destination device code.

[0069] After receiving the request message req, the wireless communication unit on the drone confirms that the source device code is the bound computing unit device code and returns a communication establishment confirmation ack to the computing unit;

[0070] After receiving the ack, the computing unit establishes a communication connection between the computing unit and the wireless communication unit on the drone, and records the distance d0 between the computing unit and the wireless communication unit when the communication connection is established, as well as the signal strength indicator (RSSI) PL(d0) corresponding to the distance d0. The distance d0 is used as the reference distance, and the signal strength indicator corresponding to the reference distance is used as the reference RSSI value PL(d0).

[0071] Other steps and parameters are the same as those in the second embodiment.

[0072] Specific embodiment 4: This embodiment differs from specific embodiment 2 or 3 in that the drone status signal includes the current distance from the drone to the ground and the current battery level of the drone.

[0073] Other steps and parameters are the same as those in the second or third embodiment.

[0074] Specific implementation method five: Combination Figure 5 This embodiment differs from any one of the second to fourth embodiments in that, in step 4, the position of the UAV in the battery-swapping vehicle coordinate system is converted to the position coordinates in the world coordinate system of the scene map of the UAV operation area based on the received current UAV status signal, and the converted position coordinates are set as the navigation point of the battery-swapping vehicle; specifically:

[0075] Step 4.1. Record the received drone status signal as S i , the drone status signal Si The distance information in is recorded as h i , h i The wireless communication unit sends the drone status signal S i The distance from the drone to the ground;

[0076] The computing unit receives the drone status signal S i The RSSI value PL(d i ), calculate the distance d between the UAV and the battery-swapping vehicle i (Since the signal transmission process is close to real-time transmission, the drone status signal S is also sent here. i the distance between the UAV and the battery-swapping vehicle);

[0077] Step 4.2: Send the drone status signal S i The position of the UAV at this time is recorded as P i , the distance d between the drone and the battery-swapping vehicle i Projection distance v i for:

[0078]

[0079] Step 4.3: Compare the RSSI values ​​of the drone status signals received by the antennas in different directions on the calculation unit, and take the receiving direction of the antenna corresponding to the largest RSSI value as the drone status signal S i direction, the drone status signal S i The angle between the direction of and the positive direction of the x-axis of the coordinate system of the electric vehicle is recorded as θ i , according to the projection distance v i and θ i Calculate and send the drone status signal S i When the UAV's position coordinates in the battery-changing vehicle coordinate system are source =(x i ,y i ,z i );

[0080] Step 4. Set the position coordinate P source =(x i ,y i ,z i ) is converted into the position coordinate N in the world coordinate system of the scene map of the UAV operation area i =(x i ′,y i ′,z i ′).

[0081] The other steps and parameters are the same as those in the second to fourth embodiments.

[0082] The battery-swapping vehicle coordinate system takes the center of mass of the battery-swapping vehicle as the origin, the forward direction of the battery-swapping vehicle as the positive direction of the x-axis, the right turn direction of the battery-swapping vehicle as the positive direction of the y-axis, the upward direction as the positive direction of the z-axis, and the z-axis coordinate is always 0. The scene map of the drone operation area is a two-dimensional grid map, so the Z-axis coordinate value of the scene map of the drone operation area in the world coordinate system is also 0, and the X-axis and Y-axis directions are the same as the coordinate axis directions of the three-dimensional rectangular coordinate system. The drone operation area scene map is used for autonomous navigation of the battery-swapping vehicle and is constructed using the Simultaneous Localization And Mapping (SLAM) method. The map includes the drone operation boundary and range, known static obstacles in the operation area, and the drivable area of ​​the drone battery-swapping vehicle. The data of the drone operation area scene map is provided by the lidar and visual camera sensors in the perception device. These sensor data can accurately reflect the spatial position relationship of the drone operation area, and provide more accurate environmental perception data for the autonomous navigation method of the drone battery-swapping vehicle proposed in the present invention.

[0083] Specific embodiment 6: This embodiment differs from any one of specific embodiments 2 to 5 in that the distance d between the drone and the battery-swapping vehicle is i The calculation method is:

[0084]

[0085] Among them, PL(d i ) indicates that the drone status signal S is received i The signal strength indicator value between the UAV and the battery-swapping vehicle at d0 is d0, the reference distance between the UAV and the battery-swapping vehicle is PL(d0), and the reference signal strength indicator value when the distance between the UAV and the battery-swapping vehicle is the reference distance d0 is n. It is a path loss index, which is generally set between 2 and 4 according to environmental factors.

[0086] The distance d i The calculation formula is converted to:

[0087]

[0088] The other steps and parameters are the same as those in the second to fifth embodiments.

[0089] The signal strength indicator value indicates the strength of the received signal. A smaller signal strength indicator value indicates a weaker signal. It is usually expressed as a negative value (dBm). The signal strength indicator value is provided by the wireless communication unit and can be obtained by the calculation unit through analysis.

[0090] Specific embodiment seven: This embodiment differs from any one of specific embodiments two to six in that the specific process of step four is as follows:

[0091] Step 441: Use the Extended Kalman Filter (EKF) to fuse the point cloud data obtained by the lidar and the battery swap vehicle position data obtained by the inertial measurement unit to obtain the received drone status signal S i The odometer data of the electric vehicle is exchanged at this time;

[0092] Step 442: Based on the point cloud data, odometer data, and the battery-swapping vehicle's own state data obtained by the inertial measurement unit, use the Adaptive Monte Carlo Localization (AMCL) method to calculate the current position and current attitude information of the battery-swapping vehicle in the scene map of the UAV operation area;

[0093] Then, based on the current position and current posture information of the battery-swapping vehicle in the scene map of the drone operation area, the rotation matrix R and translation vector t between the battery-swapping vehicle coordinate system and the world coordinate system of the drone operation area scene map are obtained;

[0094] Then use the 4×4 homogeneous transformation matrix to realize the coordinate transformation:

[0095]

[0096] Among them, R is a 3×3 rotation matrix, which represents the rotation relationship between coordinate systems; t is a 3×1 translation vector, which represents the translation relationship between coordinate systems; [0 1] is used to maintain the homogeneous form of the matrix.

[0097] The other steps and parameters are the same as those in the second to sixth embodiments.

[0098] Specific embodiment eight: This embodiment differs from any one of specific embodiments two to seven in that the determination of whether the drone is currently in a state of waiting for battery replacement is specifically as follows:

[0099] If the drone status signal S i If the drone battery level is greater than 10%, the drone is not currently in the waiting state for battery replacement;

[0100] If the drone status signal S i If the drone battery level is less than or equal to 10%, the drone is currently waiting for battery replacement.

[0101] The other steps and parameters are the same as those in the second to seventh embodiments.

[0102] Specific embodiment nine: This embodiment differs from any one of specific embodiments two to eight in that the battery-swapping vehicle performs autonomous navigation based on the scene map of the drone operation area and travels to the navigation point N according to the autonomous navigation results. i ; The specific process is:

[0103] Step 1: The calculation unit performs global path planning on the loaded UAV operation area scene map based on the current position of the battery-swapping vehicle and the calculated navigation point position;

[0104] Step 2: The computing unit obtains the point cloud data of the lidar for real-time environment perception;

[0105] If a dynamic obstacle that is not in the loaded scene map is detected in the environment, the global path planning result in step 1 is corrected through local path planning (realizing real-time obstacle avoidance of dynamic obstacles), and the battery-swap vehicle follows the corrected path to the navigation point N. i ;

[0106] If there are no new dynamic obstacles in the loaded scene map, the battery-swap vehicle will proceed to the navigation point N according to the path planned in step 1. i .

[0107] The other steps and parameters are the same as those in any one of the second to eighth embodiments.

[0108] Specific embodiment ten: This embodiment differs from any one of specific embodiments two to nine in that the shortest encounter time t' between the drone and the battery-swapping vehicle is calculated, and the corrected navigation point is calculated based on the shortest encounter time t' and the initial navigation point; the specific process is as follows:

[0109]

[0110] Among them, V car is the speed of changing trams, V drone is the speed of the drone;

[0111] R i =(x i ′-V drone t'cosθ i ′,y i ′-V drone t'sinθ i ′)

[0112] Among them, θ i ′ is the drone status signal S i The angle between the direction of and the positive direction of the X-axis of the world coordinate system of the UAV operation area scene map is given by θ i It is obtained by transforming the rotation matrix and translation vector.

[0113] The other steps and parameters are the same as those in the second to ninth embodiments.

[0114] When the wireless communication unit sends the drone status signal, the drone will not hover and wait for the battery swap vehicle to arrive, but will remain in the operation execution state. After sending the waiting for battery swap signal, the drone and the battery swap vehicle will fly towards the S5' direction at the same time, avoiding the problem of low operation efficiency caused by long-term hovering waiting for the battery swap vehicle to arrive, and allowing the battery swap vehicle to meet the drone in the shortest time and enter the battery swap state in the shortest time, avoiding the drone in N i It can avoid unnecessary waiting delays and thus improve the battery replacement efficiency of drones.

[0115] An exemplary scene diagram of the present invention is as follows Figure 1 As shown, Figure 1 The process of applying the autonomous navigation method proposed by the present invention is as follows: Figure 4a As shown, during the inspection of the UAV from T1 to T2, the UAV wireless communication unit sends the UAV status signal S1; the calculation unit calculates the coordinate position of the UAV in the operation area scene map when the UAV status signal S1 is sent based on the UAV height information and signal strength indicator value (RSSI) included in the UAV status signal S1; then the battery-swapping vehicle takes the current position as the starting point, and the coordinate position of the UAV in the operation area scene map as the navigation point S1, and autonomously navigates to the navigation point S1; that is, the battery-swapping vehicle travels along the planned path to the navigation point S1, and automatically avoids obstacles O1 in the UAV operation scene; after arriving at the navigation point S1, it continues to wait for the reception of the next UAV status signal S2. After multiple cycles, the battery-swapping vehicle has reached the position corresponding to when the UAV wireless communication unit sent the UAV status signal S4 in the previous cycle, as shown in FIG. Figure 4b As shown, at this time the drone's power reaches the critical value for battery replacement, so the drone status signal S5 sent in this cycle will be determined by the calculation unit as a waiting signal for battery replacement. After calculating the position coordinates at S5, the calculation unit solves the drone landing point S5' with the shortest battery replacement vehicle travel time based on the drone's flight parameters and the battery replacement vehicle's motion parameters. The battery replacement vehicle then autonomously navigates to this point and waits for the drone to land to complete the battery replacement.

[0116] The above examples are merely illustrative of the calculation model and process of the present invention and are not intended to limit the embodiments of the present invention. Persons skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. This list of embodiments is not exhaustive; however, any obvious variations or modifications derived from the technical solution of the present invention remain within the scope of protection of the present invention.

Claims

1. An autonomous navigation method for operating a UAV to replace a battery vehicle, characterized in that: The method specifically comprises the following steps: Step 1: When the UAV receives a power inspection task, the operator uses the remote control unit to send a power exchange task signal to the computing unit on the battery exchange vehicle. After receiving the power exchange task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV to establish a connection between the computing unit and the wireless communication unit. Step 2: The operator uses the remote control unit to remotely control the drone and the battery-swapping vehicle to the starting point of the drone's operation area. The drone starts to perform power inspection operations from the starting point of the operation area. During the process of the drone performing power inspection operations, the wireless communication unit on the drone sends a drone status signal to the computing unit at fixed intervals. When the visual camera sensor on the battery swap vehicle recognizes the QR code at the starting point, the computing unit loads the scene map of the current drone operation area according to the recognized QR code, and at the starting point, the omnidirectional antenna installed on the computing unit waits to receive the drone status signal; When receiving the drone status signal, start executing step three; Step 3: Determine whether the received current drone status signal is a waiting for battery replacement status signal; If the current drone status signal is not waiting for battery replacement, proceed to step 4; If the current drone status signal is waiting for battery replacement, proceed to step 5; Step 4: Convert the drone's position in the battery swap vehicle coordinate system to the world coordinate system of the scene map of the drone's operating area based on the current drone status signal received, and set the converted position coordinates as the navigation point N of the battery swap vehicle. i ; The computing unit calculates the scene map and navigation point N of the UAV operation area. i Perform global path planning and send motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6; Step 5: According to the current UAV status signal received, the UAV's position in the battery swap vehicle coordinate system is converted to the position coordinates in the world coordinate system of the scene map of the UAV operation area, and the converted position coordinates are set as the initial battery swap point R of the battery swap vehicle. i ; Calculate the shortest encounter time t' between the UAV and the battery swap vehicle, and then calculate the revised battery swap point R based on the shortest encounter time t' and the initial battery swap point i '; The computing unit performs global path planning based on the scene map of the UAV operation area and the corrected battery swap point, and sends motion control signals to the battery swap vehicle chassis according to the planned path. The battery swap vehicle chassis then autonomously navigates to the corrected navigation point R according to the motion control signals sent by the computing unit. i ', the UAV lands on the battery swap unit carried by the battery swap vehicle to swap batteries and executes step six; Step 6: The battery-swapping vehicle waits to receive the next drone status signal at the navigation point it has reached. After receiving the drone status signal, it returns to step 3 and continues until it receives the battery-swapping end signal, at which point the battery-swapping vehicle leaves the drone operation area.

2. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 1 is characterized in that: The specific process of establishing the connection between the computing unit and the wireless communication unit is as follows: The computing unit sends a communication establishment request message req to the wireless communication unit on the drone, where the request message req includes a source device code and a destination device code. After receiving the request message req, the wireless communication unit on the drone confirms that the source device code is the bound computing unit device code and returns a communication establishment confirmation ack to the computing unit; After receiving the ack, the computing unit establishes a communication connection between the computing unit and the wireless communication unit on the drone, and records the distance d0 between the computing unit and the wireless communication unit when the communication connection is established and the signal strength indicator value corresponding to the distance d0. The distance d0 is used as the reference distance, and the signal strength indicator value corresponding to the reference distance is used as the reference RSSI value PL(d0).

3. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 2, characterized in that: The drone status signal includes the current distance from the drone to the ground and the current battery level of the drone.

4. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 3 is characterized in that: In the fourth step, the position of the UAV in the battery-swapping vehicle coordinate system is converted into the position coordinates in the world coordinate system of the scene map of the UAV operation area according to the received current UAV status signal, and the converted position coordinates are set as the navigation point of the battery-swapping vehicle; Specifically: Step 4.1: Record the received drone status signal as S i , the drone status signal S i The distance information in is recorded as h i , h i The wireless communication unit sends the drone status signal S i The distance from the drone to the ground; The computing unit receives the drone status signal S i The RSSI value PL(d i ), calculate the distance d between the UAV and the battery-swapping vehicle i ; Step 4.2: Send the drone status signal S i The position of the UAV at this time is recorded as P i , the distance d between the drone and the battery-swapping vehicle i Projection distance v i for: Step 4.3: Compare the RSSI values ​​of the drone status signals received by the antennas in different directions on the calculation unit, and take the receiving direction of the antenna corresponding to the largest RSSI value as the drone status signal S i direction, the drone status signal S i The angle between the direction of and the positive direction of the x-axis of the coordinate system of the electric vehicle is recorded as θ i , according to the projection distance v i and θ i Calculate and send the drone status signal S i When the UAV's position coordinates in the battery-changing vehicle coordinate system are source =(x i ,y i ,z i ); Step 4. Set the position coordinate P source =(x i ,y i ,z i ) is converted into the position coordinate N in the world coordinate system of the scene map of the UAV operation area i =(x i ′,y i ′,z i ′).

5. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 4 is characterized in that: The distance d between the drone and the battery-swapping vehicle i The calculation method is: Among them, PL(d i ) indicates that the drone status signal S is received i The signal strength indicator value between the UAV and the battery-swapping vehicle at d0 is d0, the reference distance between the UAV and the battery-swapping vehicle is PL(d0), and the reference signal strength indicator value when the distance between the UAV and the battery-swapping vehicle is the reference distance d0 is n. The distance d i The calculation formula is converted to:

6. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 5, characterized in that: The specific process of step 44 is as follows: Step 441: Use the extended Kalman filter method to fuse the point cloud data obtained by the lidar and the battery swap vehicle position data obtained by the inertial measurement unit to obtain the received drone status signal S i The odometer data of the electric vehicle is exchanged at this time; Step 442: Based on the point cloud data, odometer data, and the battery-swapping vehicle's own state data obtained by the inertial measurement unit, use the adaptive Monte Carlo positioning method to calculate the battery-swapping vehicle's current position and current attitude information in the scene map of the UAV operation area; Then, based on the current position and current posture information of the battery-swapping vehicle in the scene map of the drone operation area, the rotation matrix R and translation vector t between the battery-swapping vehicle coordinate system and the world coordinate system of the drone operation area scene map are obtained; Then use the 4×4 homogeneous transformation matrix to realize the coordinate transformation: Where R is a 3×3 rotation matrix and t is a 3×1 translation vector.

7. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 6, characterized in that: Determine whether the drone is currently in the waiting state for battery replacement, specifically: If the drone status signal S i If the drone battery level is greater than 10%, the drone is not currently in the waiting state for battery replacement; If the drone status signal S i If the drone battery level is less than or equal to 10%, the drone is currently waiting for battery replacement.

8. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 7, characterized in that: The battery-swapping vehicle performs autonomous navigation based on the scene map of the drone operation area and moves to the navigation point N according to the autonomous navigation results. i ; The specific process is: Step 1: The calculation unit performs global path planning on the loaded UAV operation area scene map based on the current position of the battery-swapping vehicle and the calculated navigation point position; Step 2: The computing unit obtains the point cloud data of the lidar for real-time environment perception; If a dynamic obstacle that is not in the loaded scene map is detected in the environment, the global path planning result in step 1 is corrected through local path planning, and the battery-swap vehicle follows the corrected path to the navigation point N. i ; If there are no new dynamic obstacles in the loaded scene map, the battery-swap vehicle will proceed to the navigation point N according to the path planned in step 1. i .

9. The autonomous navigation method for operating a UAV battery-changing vehicle according to claim 8, characterized in that: The shortest encounter time t' between the UAV and the battery-swapping vehicle is calculated, and the corrected navigation point is calculated based on the shortest encounter time t' and the initial navigation point. The specific process is as follows: Among them, V car is the speed of changing trams, V drone is the speed of the drone; R i =(x i ′-V drone t'cosθ i ′,y i ′-V drone t'sinθ i ′) Among them, θ i ′ is the drone status signal S i The angle between the direction and the positive direction of the X-axis of the world coordinate system of the UAV operation area scene map.

10. An autonomous navigation system for operating a UAV to replace a battery vehicle, characterized in that: The system is used to execute an autonomous navigation method for an operating drone battery-swapping vehicle as described in any one of claims 1 to 9, and the system includes an external device, a drone battery-swapping unit, a computing unit, a battery-swapping vehicle chassis, and a sensing device, wherein the external device includes a wireless communication unit and a remote control unit, and the sensing device includes a lidar, a visual camera sensor, and an inertial measurement unit; The computing unit is installed on the battery-swapping vehicle and is used to communicate with the UAV battery-swapping unit, the battery-swapping vehicle chassis, external devices, and sensing devices; The remote control unit is used to send remote control signals, battery swap task signals and battery swap end signals to the computing unit on the battery swap vehicle; After receiving the battery swap task signal, the computing unit initiates a communication establishment request to the wireless communication unit on the UAV. After the communication between the computing unit and the wireless communication unit is established, the battery swap vehicle enters the remote control mode; In remote control mode, the laser radar is used to perceive environmental information, and the inertial measurement unit is used to obtain the battery swap vehicle's own status data and the battery swap vehicle's position; the remote control unit is used to send a remote control signal to the computing unit based on the environmental information, the battery swap vehicle's own status data and the battery swap vehicle's position, and the computing unit sends a motion control signal to the battery swap vehicle chassis based on the received remote control signal to control the battery swap vehicle to drive to the starting point of the drone operation area. After the visual camera sensor senses that the battery swap vehicle has reached the starting point, the battery swap vehicle switches to autonomous navigation mode; In the autonomous navigation mode, the computing unit is used to perform autonomous navigation based on the drone status signal, environmental information, battery swap vehicle position and battery swap vehicle status data sent by the wireless communication unit, send motion control signals to the battery swap vehicle chassis according to the autonomous navigation results, and send battery swap signals to the drone battery swap unit mounted on the battery swap vehicle; The UAV battery swap unit is used to receive the battery swap signal sent by the computing unit, and the battery swap vehicle starts to perform the UAV battery swap operation after driving to the target position of autonomous navigation; After the computing unit receives the battery swap end signal, the battery swap vehicle leaves the drone operation area; The wireless communication unit is installed on the drone, and includes a distance measurement module, a logic processing module and a wireless transmission module; The distance measurement module is used to measure the current height of the drone from the ground, the logic processing module is used to encapsulate the status signal including the current height of the drone from the ground and the battery level of the drone, and the wireless transmission module is used to send the drone status signal to the computing unit on the battery-swapping vehicle.

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