Autonomous navigation system and method for operation unmanned aerial vehicle battery changing vehicle

Abstract

The invention discloses an autonomous navigation system and method for an operation unmanned aerial vehicle battery changing vehicle, and belongs to the technical field of autonomous navigation of battery changing vehicles. According to the invention, the problems of high cost and low unmanned aerial vehicle battery replacement and operation efficiency of an existing remote operation unmanned aerial vehicle battery replacement method are solved. According to the method, only a single battery changing vehicle needs to be deployed in the operation area, and the early-stage investment and the later-stage maintenance cost are greatly reduced. According to the unmanned aerial vehicle working area scene map construction based on laser radar point cloud data and inertial positioning data, autonomous positioning and navigation and adaptive dynamic obstacle avoidance, manual intervention is not needed in the execution of an unmanned aerial vehicle battery replacement task, the labor cost is greatly reduced, and the working efficiency is improved. And the assembled sensing equipment enables the battery replacing vehicle to automatically execute unmanned aerial vehicle following and battery replacing tasks in the task execution process, the battery replacing efficiency of the unmanned aerial vehicle is improved, waiting does not need to be stopped in the battery replacing process of the unmanned aerial vehicle, and the operation efficiency of the unmanned aerial vehicle is improved. The method can be applied to autonomous navigation of the unmanned aerial vehicle battery changing vehicle.

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 a battery-swapping vehicle using an unmanned aerial vehicle. Background Art

[0002] Due to the excellent environmental adaptability of drones, 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 shortcoming of drone endurance has become an important factor restricting the efficiency of drone-assisted operations. Therefore, providing stable and reliable battery replacement services has become an important guarantee for improving the efficiency of drone long-distance operation tasks.

[0003] At present, common methods of battery replacement for drones include fixed battery replacement and mobile battery replacement. The fixed battery replacement method deploys a battery replacement station at a single point or multiple points in the drone operation area. For long-distance operating drones, the single-point deployment of a battery replacement station will cause the drone to travel back and forth between the battery replacement station and the operating location many times, which will have a great impact on the operating efficiency. The multi-point deployment of battery replacement stations will lead to high initial investment and subsequent maintenance costs. The currently commonly used mobile battery replacement method is that a dedicated person remotely controls the battery replacement vehicle to drive to the landing location of the drone to complete the battery replacement. This avoids the high cost problem brought by the fixed battery replacement method to a certain extent, but the manual driving and scheduling of the battery replacement vehicle will not only generate additional labor and learning costs, but also manual operation will have errors in the selection of the scheduling timing of the battery replacement vehicle, which will ultimately affect the drone battery replacement and drone operation efficiency. Therefore, the current common fixed battery replacement method and mobile battery replacement method are not suitable for long-distance operating drone battery replacement tasks. Summary of the invention

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

[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 UAV battery-swapping vehicle, the system includes an external device, a UAV battery-swapping unit, a computing unit, a battery-swapping vehicle chassis, and a sensing device, the external device includes a wireless communication unit and a remote control unit, and the sensing device includes a laser radar, a visual camera sensor, and an inertial measurement unit;

[0007] The computing unit is installed on the battery-swapping vehicle, and the computing unit 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 a remote control signal, a battery swap task signal and a battery swap end signal to a 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 driven to 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 replacement unit is used to receive the battery replacement signal sent by the computing unit, and the battery replacement vehicle starts to perform the UAV battery replacement 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 UAV from the ground, the logic processing module is used to encapsulate the status signal including the current height of the UAV from the ground and the battery level of the UAV, and the wireless transmission module is used to send the UAV status signal to the computing unit on the battery exchange vehicle.

[0016] According to another aspect of the present invention, an autonomous navigation method for operating a UAV battery replacement 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 drive to the starting point of the drone 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 the power inspection operation, 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-swapping 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, uses the omnidirectional antenna installed on the computing unit to wait for receiving 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 in the waiting state for battery replacement, execute step 4;

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

[0024] Step 4: According to the received current drone status signal, convert the drone's position in the battery swap vehicle coordinate system into the position coordinates in the world coordinate system of the scene map of the drone's operating area, 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 of the UAV operation area and the navigation point N 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 autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6;

[0026] Step 5: According to the received current UAV status signal, the position of the UAV in the battery swap vehicle coordinate system is converted into 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 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 execute step 3 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 needs to deploy a single battery-swapping vehicle in the drone operation area, which greatly reduces the initial investment and subsequent maintenance costs. Compared with the manually controlled battery-swapping vehicle, the present invention realizes the construction of the drone operation area scene map based on the laser radar point cloud data and inertial positioning data, autonomous positioning and navigation, and adaptive dynamic obstacle avoidance. In the execution of the drone battery-swapping task, not only does it not require human intervention, which greatly reduces the labor cost, but the installed sensing equipment allows the battery-swapping vehicle to automatically perform the drone following and battery-swapping tasks during the task execution, improving the drone battery-swapping efficiency, and the drone does not need to stop and wait while waiting for the battery to be swapped, and can continue to operate, solving the problem of low operating efficiency of the existing battery-swapping method.

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

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

[0034] The power inspection task execution route set 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 the overall flow chart of the method of the present invention;

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

[0038] Figure 4bIt 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 drone and the drone-to-telephone vehicle;

[0040] Figure 6 It 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 is described. The autonomous navigation system for operating a UAV battery-swapping vehicle described in this embodiment includes an external device, a UAV battery-swapping unit, a computing unit, a battery-swapping vehicle chassis, and a sensing device. The external device 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 a remote control signal, a battery swap task signal and a battery swap end signal to a 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 sense 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 attitude 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 drive to the starting point of the drone operation area; after the visual camera sensor senses that the battery swap vehicle has driven to 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 replacement unit is used to receive the battery replacement signal sent by the computing unit, and the battery replacement vehicle starts to perform the UAV battery replacement 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 UAV from the ground. The logic processing module is used to encapsulate status signals including the current height of the UAV from the ground and the power of the UAV (the power parameters of the UAV are obtained through the SDK provided by the UAV manufacturer). The wireless transmission module is used to send the UAV status signal to the computing unit on the battery-swapping vehicle.

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

[0053] Specific implementation method 2: Combination Figure 3 The present embodiment describes an autonomous navigation method for a battery-swapping vehicle used 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 drive to the starting point of the drone 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 the power inspection operation, 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 swap vehicle recognizes the QR code at the starting point, it means that the battery swap 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 in the waiting state for battery replacement, execute step 4;

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

[0061] Step 4: According to the received current drone status signal, convert the drone's position in the battery swap vehicle coordinate system into the position coordinates in the world coordinate system of the scene map of the drone's operating area, 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 of the UAV operation area and the navigation point N 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 autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6;

[0063] Step 5: According to the received current UAV status signal, the position of the UAV in the battery swap vehicle coordinate system is converted into 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 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 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 execute step 3 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 is different 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, wherein the request message req includes a source device code of the request to send and a destination device code of the request to send;

[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 and the signal strength indicator (RSSI) PL(d0) corresponding to the distance d0, and uses the distance d0 as the reference distance and the signal strength indicator corresponding to the reference distance as the reference RSSI value PL(d0).

[0071] The other steps and parameters are the same as those in the second specific implementation manner.

[0072] Specific implementation method 4: This implementation method is different from specific implementation methods 2 or 3 in that the drone status signal includes the current distance from the drone to the ground and the current power level of the drone.

[0073] The 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 is different from any one of the specific embodiments 2 to 4 in that, in step 4, the position of the drone in the battery-swapping vehicle coordinate system is converted into the position coordinates in the world coordinate system of the scene map of the drone operation area according to the received current drone 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 at that time);

[0077] Step 42: 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 The projection distance v i for:

[0078]

[0079] Step 43: Compare the RSSI values ​​of the drone status signal 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, and 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 denoted 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 44: Set the position coordinates 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 directions of the X-axis and Y-axis 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 laser radar 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 implementation method 6: This implementation method is different from any one of the specific implementation methods 2 to 5 in that the distance d between the drone and the battery-changing vehicle is i The calculation method is:

[0084]

[0085] Among them, PL(d i ) indicates receiving the drone status signal S i The signal strength indicator value between the UAV and the battery swap vehicle at d0, d0 represents the reference distance between the UAV and the battery swap vehicle, PL(d0) represents the reference signal strength indicator value when the distance between the UAV and the battery swap vehicle is the reference distance d0, and n represents the path loss index, which is generally taken 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. The smaller the signal strength indicator value, the weaker the 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 implementation method 7: This implementation method is different from the specific implementation methods 2 to 6 in that the specific process of step 44 is as follows:

[0091] Step 441: Use the Extended Kalman Filter (EKF) 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 car is exchanged;

[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, the adaptive Monte Carlo localization method (AMCL) is used 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, according to the current position and current posture information of the battery swap vehicle in the scene map of the UAV operation area, the rotation matrix R and the translation vector t between the battery swap vehicle coordinate system and the world coordinate system of the scene map of the UAV operation area 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 implementation eight: This implementation differs from any one of specific implementations 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 in the waiting state for battery replacement.

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

[0102] Specific implementation method 9: This implementation method is different from any one of specific implementation methods 2 to 8 in that the battery-swapping vehicle performs autonomous navigation according to the scene map of the drone operation area and travels to the navigation point N according to the autonomous navigation result. i ; The specific process is:

[0103] Step 1: The calculation unit performs global path planning on the loaded scene map of the UAV operation area according to 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 laser radar for real-time environmental 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-changing 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 implementation method ten: This implementation method is different from any one of specific implementation methods 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:

[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 Specific Embodiments 2 to 9.

[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 battery swap signal, the drone and the battery swap vehicle will fly in the direction of S5' at the same time, avoiding the problem of low operation efficiency caused by long-term hovering and 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 The drone will not hover and wait, causing unnecessary waiting delays, thereby improving the efficiency of drone battery replacement.

[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 a UAV status signal S1; the calculation unit calculates the coordinate position of the UAV in the operating 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 operating 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 operating 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 UAV power reaches the critical value for battery replacement, so the UAV 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 UAV landing point S5' with the shortest travel time for the battery replacement vehicle based on the UAV flight parameters and the battery replacement vehicle motion parameters. The battery replacement vehicle then autonomously navigates to this point and waits for the UAV to land to complete the battery replacement.

[0116] The above calculation examples of the present invention are only used to explain the calculation model and calculation process of the present invention in detail, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. An autonomous navigation system for operating drones to replace electric vehicles, characterized in that: The system includes external equipment, a UAV battery replacement unit, a computing unit, a battery replacement vehicle chassis and a sensing device, wherein the external equipment includes a wireless communication unit and a remote control unit, and the sensing device includes a laser radar, a visual camera sensor and an inertial measurement unit; The computing unit is installed on the battery-swapping vehicle, and the computing unit 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 a remote control signal, a battery swap task signal and a battery swap end signal to a 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 driven to 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 replacement unit is used to receive the battery replacement signal sent by the computing unit, and the battery replacement vehicle starts to perform the UAV battery replacement 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 UAV from the ground, the logic processing module is used to encapsulate the status signal including the current height of the UAV from the ground and the battery level of the UAV, and the wireless transmission module is used to send the UAV status signal to the computing unit on the battery exchange vehicle.

2. An autonomous navigation method for operating a drone to replace a battery car, 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 drive to the starting point of the drone 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 the power inspection operation, 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-swapping 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, uses the omnidirectional antenna installed on the computing unit to wait for receiving 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 in the waiting state for battery replacement, execute step 4; If the current drone status signal is waiting for battery replacement, execute step 5; Step 4: According to the received current drone status signal, convert the drone's position in the battery swap vehicle coordinate system into the position coordinates in the world coordinate system of the scene map of the drone's operating area, and set the converted position coordinates as the navigation point N of the battery swap vehicle. i ; The computing unit calculates the scene map of the UAV operation area and the navigation point N 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 autonomously navigates to the navigation point N according to the motion control signals. i , and execute step 6; Step 5: According to the received current UAV status signal, the position of the UAV in the battery swap vehicle coordinate system is converted into 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 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 execute step 3 until it receives the battery-swapping end signal, at which point the battery-swapping vehicle leaves the drone operation area.

3. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 2 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, wherein the request message req includes a source device code of the request to send and a destination device code of the request to send; 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 indication value corresponding to the distance d0. The distance d0 is used as the reference distance, and the signal strength indication value corresponding to the reference distance is used as the reference RSSI value PL(d0).

4. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 3 is 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.

5. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 4 is characterized in that: In the step 4, 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 42: 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 The projection distance v i for: Step 43: Compare the RSSI values ​​of the drone status signal 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, and 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 denoted 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 44: Set the position coordinates 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 ′).

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

7. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 6 is 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 laser radar 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 car is exchanged; Step 442: Based on the point cloud data, odometer data and the battery swap vehicle's own state data obtained by the inertial measurement unit, use the adaptive Monte Carlo positioning method to calculate the current position and current attitude information of the battery swap vehicle in the scene map of the drone operation area; Then, according to the current position and current posture information of the battery swap vehicle in the scene map of the UAV operation area, the rotation matrix R and the translation vector t between the battery swap vehicle coordinate system and the world coordinate system of the scene map of the UAV operation area are obtained; Then use the 4×4 homogeneous transformation matrix to realize the coordinate transformation: Among them, R is a 3×3 rotation matrix; t is a 3×1 translation vector.

8. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 7 is characterized in that: The determination of whether the drone is currently in a state of waiting for battery replacement is specifically as follows: 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 in the waiting state for battery replacement.

9. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 8, characterized in that: The battery-swapping vehicle performs autonomous navigation according to 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 scene map of the UAV operation area according to 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 laser radar for real-time environmental 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-changing vehicle will proceed to the navigation point N according to the path planned in step 1. i .

10. The autonomous navigation method for operating a UAV battery replacement vehicle according to claim 9, 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 according to the shortest encounter time t' and the initial navigation point; the specific process is: 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.

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