Airborne unmanned aerial vehicle system for excavating robot and collaborative operation method

Abstract

The invention discloses an airborne unmanned aerial vehicle system for an excavation robot and a collaborative operation method, and belongs to the technical field of collaborative operation of multiple unmanned systems, and the airborne unmanned aerial vehicle system comprises the excavation robot and an airborne platform arranged on the excavation robot; the airborne platform comprises a box body, a switch cabin door is arranged at the top of the box body, and a plurality of unmanned aerial vehicles, a lifting platform, a telescopic platform, a body positioning device, an image positioning module, a laser positioning module, an electromagnetic positioning module, a wireless charging transmitting module and an integrated circuit module are arranged in the box body; according to the method, information in a working area is displayed by a dense map formed by surveying and mapping and splicing of multiple unmanned aerial vehicles, multiple mining robots are guided to enter the working area for operation, and the working area and operation conditions of the mining robots are monitored in real time by multiple unmanned aerial vehicles; the working efficiency and the intelligent level of the multiple excavating robots and the multiple unmanned aerial vehicles in mines and construction sites are improved, and meanwhile the construction safety of the excavating robots is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of collaborative operation of multiple UAV systems, and in particular to an airborne UAV system for an excavating robot and a collaborative operation method. Background Art

[0002] In recent years, unmanned technology has been widely used in various fields. In mining and construction, the collaborative operation of excavation robots and drones as a new working mode has shown its great potential and advantages. Drones can efficiently map, monitor and inspect the working environment, while excavation robots can perform automated excavation, loading and transportation.

[0003] At present, most excavation robot systems use ground control stations for remote control or autonomous operation through preset paths, which has great limitations. For example, it is difficult to obtain real-time information about the surrounding environment, collision accidents are prone to occur, and manual path planning and task allocation are required. The operation efficiency needs to be improved. In complex terrain or dangerous environments, the operation capacity of excavation robots is limited. Most drone systems use ground base stations for remote control or autonomous flight, but they are limited by battery capacity, have short battery life, require frequent battery replacement or manual charging, are inefficient, and a single drone is difficult to complete complex tasks and needs to work in coordination with other equipment.

[0004] The construction engineering volume monitoring system based on 3D aerial photography of unmanned aerial vehicles disclosed in Chinese patent CN 109819241 A uses the 3D projection device of the unmanned aerial vehicle to detect and calculate the construction area after the construction is completed every day, and compares it with the previous day to obtain the volume of the project and the construction efficiency of the day. However, the device method adopted only focuses on the volume of the project and the construction efficiency, and cannot realize the coordinated operation control of the unmanned aerial vehicle and the excavation robot; and the generation of the 3D model takes time, and it is impossible to guide the operation of the excavation robot in real time; the excavator cannot perceive the surrounding environment when operating, and still needs manual control, and cannot realize autonomous operation. An excavator operation method, device and system disclosed in patent CN 116084481 A uses a high-definition pan-tilt module carried by the unmanned aerial vehicle to obtain the current image data of the area to be constructed, compares the current image with the target terrain data, obtains the deviation value between the two, and then determines the operating depth and position of the excavator, and guides the excavator to operate through display screens or wireless transmission, etc. However, the drone in this system method has a limited battery life and cannot be on standby in the air for a long time, which greatly reduces the construction efficiency of the excavator. Summary of the invention

[0005] The purpose of the present invention is to provide an airborne drone system and a collaborative operation method for an excavation robot. By mapping and stitching multiple drones together to form a dense map to display information in the working area, multiple excavation robots are guided to enter the site for operation. By means of the optimal scheduling and vertical landing method of collaborative charging of multiple drones, multiple drones can be used to monitor the working area and operation status of the excavation robots in real time, thereby improving the operating efficiency and intelligence level of multiple excavation robots and multiple drones in mines and construction sites, and at the same time increasing the construction safety of the excavation robots.

[0006] To achieve the above-mentioned purpose, the present invention provides an airborne drone system for an excavation robot, comprising an excavation robot and an airborne platform arranged on the excavation robot; the excavation robot is provided with an airborne laser radar unit, the airborne laser radar unit is used for the excavation robot to perceive the surrounding environment, the airborne platform comprises a box body, a switch hatch is provided on the top of the box body, and a plurality of drones, a lifting platform, a telescopic platform, a body positioning device, an image positioning module, a laser positioning module, an electromagnetic positioning module, a wireless charging transmitting module and an integrated circuit module are arranged inside the box body; the drone is provided with a camera unit, a laser radar unit, an IMU unit, a processor unit, a drone communication unit, a wireless charging receiving module and a positioning structure;

[0007] For the airborne platform, the switch hatch adopts a hatch design with top doors, and is equipped with symmetrical motors to drive opening and closing on both sides; the lifting platform and the telescopic platform are used to receive the UAV; the main body positioning device provides the absolute position information of the airborne platform; the image positioning module provides the UAV with pairing identification and lateral position locking during vertical landing; the laser positioning module is used to provide the UAV's height information during the vertical landing of the UAV to the airborne platform; the electromagnetic positioning module adsorbs the UAV's positioning structure based on the UAV's height information from the laser positioning module to fix the landing and docking position of the UAV; the wireless charging transmitting module is paired with the wireless charging receiving module to transmit electric energy;

[0008] For the UAV, a rotating structure is provided in the camera unit to obtain image information. The combination of the laser radar unit, the camera unit and the IMU unit is used by the UAV to map the working area and navigate the overall path. The positioning structure is configured as four square angle irons for adsorption of the electromagnetic positioning module.

[0009] Preferably, there are three image positioning modules, the first image positioning module is arranged in the switch hatch, the second image positioning module is arranged in the telescopic platform, and the third image positioning module is arranged in the lifting platform;

[0010] The electromagnetic positioning modules are set to two. The first electromagnetic positioning module is located on the telescopic platform, and the second electromagnetic positioning module is located on the lifting platform;

[0011] The laser positioning modules are set to two. The first laser positioning module is located at the switch hatch, and the second laser positioning module is located at the telescopic platform.

[0012] The lifting platform is used for the landing and charging of the UAV, and includes a lifting platform bracket and a lifting platform motor. The lifting platform uses a lead screw drive. The lifting platform motor drives the ball screw to rotate, and the connecting piece fixed by the lead screw nut converts the rotation of the ball screw into the vertical movement of the lifting platform bracket, driving the lifting mechanism to realize the lifting of the lifting platform;

[0013] The telescopic platform includes a telescopic platform bracket and a telescopic platform motor. The telescopic movement of the telescopic platform bracket is driven by the telescopic platform motor, so that the telescopic platform extends or retracts to one side.

[0014] Preferably, the integrated circuit module includes a voltage stabilization unit, a main control unit, a relay unit, a full-bridge drive unit, a wireless charging transmitting unit, a laser signal control unit, an excavator communication unit, and a power digital tube display unit;

[0015] The voltage stabilization units are set to three. The first voltage stabilization unit stabilizes the voltage to 3.3V and supplies power to the main control unit and the laser signal control unit. The second voltage stabilization unit stabilizes the voltage to 5V and supplies power to the relay unit. The third voltage stabilization unit stabilizes the voltage to 12V and supplies power to the wireless charging transmitting module, the full-bridge drive unit, and the relay unit;

[0016] The full-bridge drive unit includes a first full-bridge drive unit to control the power adjustment of the transmitting unit, a second full-bridge drive unit to control the motor of the lifting platform, a third full-bridge drive unit to control the motor of the telescopic platform, and a fourth full-bridge drive unit to control the switch hatch motor;

[0017] The main control unit controls the airborne UAV system;

[0018] The power digital tube display unit displays the charging power of the UAV.

[0019] A cooperative operation method for an airborne UAV system of an excavation robot includes the following steps:

[0020] Step 1: When several excavation robots are waiting outside the working area, the working area is segmented, and the unmanned aerial vehicle (UAV) in the airborne platform is released. The UAV flies to the designated operation area, and uses the multi-sensor fusion SLAM method to map the working area. After the mapping is completed, the obtained working area map is transmitted to the master control room through the excavation robot, and the sparse map of the working area is processed and transmitted back to the excavation robot, and then transmitted to the UAV by the excavation robot;

[0021] Step 2: The excavation robot uses the global path planning to approach the operation destination according to the transmitted sparse map of the working area;

[0022] Step 3: The UAV conducts target tracking on the excavation robot entering the operation area and hovers above the excavation robot for monitoring;

[0023] Step 4: During the monitoring process, when the UAV reaches the power threshold, the excavation robot that meets the requirements is determined by the optimal scheduling method for multi-UAV collaborative charging, and the UAV flies to the excavation robot that meets the requirements;

[0024] Step 5: The UAV vertically descends to the correct position, uses the electromagnetic module for adsorption and fixation, and after adsorption and fixation, starts the wireless charging transmitter module to wirelessly charge the UAV.

[0025] Preferably, in the above Step 1, the specific process is as follows:

[0026] The UAV uses the camera unit, lidar unit and IMU unit to obtain multi-sensor data, and uses the loosely coupled multi-sensor fusion SLAM method to map the working area. The excavation robot transmits the obtained working area map to the master control room. The master control room constructs a projection matrix for the working area map, establishes a Gaussian difference pyramid, finds the optimal feature points in the pyramid, establishes the descriptors of the feature points, projects the descriptors in the projection matrix, performs feature matching to overlay and splice the working area map to obtain a dense map, marks the stockpiling area and the excavation area, judges roadblocks, and uses the downsampling method to simplify the dense map to obtain the sparse map of the working area, and transmits the sparse map of the working area back to the excavation robot, and then transmits it to the UAV through the excavation robot.

[0027] Preferably, in the above Step 2, the method process of using the global path planning is as follows:

[0028] The excavation robot uses the sparse map of the working area as the prior point cloud map, sets the designated operation area as the target point, extracts and registers the obstacles in the map as polygons, establishes a visibility graph, and during the walking process of the excavation robot, uses the on-board lidar unit to sense the surrounding environment in real time, extracts the features of the surrounding obstacles, and updates the global visibility graph in a dynamically maintained manner to avoid obstacles dynamically and finally reach the destination;

[0029] Preferably, in step 3, the specific process is as follows:

[0030] After the excavation robot enters the operation area where the UAV has arrived, the first frame of the image captured by the camera is used to frame the excavation robot as prior information to determine the tracking target, calculate the relative position, establish a directed graph, find the path with the minimum cost in the directed graph for planning, and locally update the directed graph during the tracking process to adapt to the changes in the surrounding environment until it reaches above the excavation robot.

[0031] The UAV hovers above the excavation robot for monitoring. The multi-source sensor detection fusion algorithm is used with the camera unit and lidar unit to monitor the operation area of the excavation robot in the monitoring area in real time, providing real-time scene data support for the excavation robot scheduling, and monitoring whether there are abnormal actions of moving objects in the working area.

[0032] Preferably, in step 4, the optimal scheduling method for multi-UAV collaborative charging is as follows:

[0033] Step 41: After the UAV reaches the power threshold, it broadcasts its own position information and number information to all the excavation robots and UAVs that are working in the field.

[0034] Step 42: After the excavation robots in the field receive the signal, they send their current position information and charging vacancy information to the UAV. After the other working UAVs in the field receive the signal, they send their current position information and flight path status information to the UAV.

[0035] Step 43: After the UAV receives the information of the excavation robots, it establishes a set of the current positions and charging vacancy information status of all the excavation robots, and the current positions and flight path status information of all the UAVs, sets the action priority and time slice, and uses the dynamic time window method to select the optimal excavation robot as the target point.

[0036] Step 44: Using the sparse map of the working area as the sampling space, a rapid search tree is established, nodes are selected in the sampling space and connected to the remaining nodes to plan a conflict-free path, fly towards the excavation robot that meets the requirements, and send a landing preparation signal to the excavation robot.

[0037] Step 45: After the excavation robot receives the landing preparation signal, it opens the switch hatch and takes off another UAV parked in the on-board platform, flying to the area monitored by the UAV that has reached the power threshold for operation instead.

[0038] Preferably, in step 5, the process of the UAV performing vertical landing is as follows:

[0039] Step 51: After the drone reaches the mining robot that meets the requirements through the optimal scheduling method for multi-drone collaborative charging, it detects the first image positioning module through the camera unit, reaches directly above the airborne platform, and sends a target arrival signal to the mining robot below;

[0040] Step 52: After receiving the signal, the airborne platform opens the switch hatch and raises the lifting platform to an appropriate position;

[0041] Step 53: The drone starts to perform vertical landing, detects the third image positioning module through the camera unit, and uses the AprilTag information of the third image positioning module for secondary pairing. It fixes the lateral position through the closed-loop system and starts vertical landing;

[0042] The closed-loop system locks the lateral position by the following formula:

[0043]

[0044] In the above formula, v is the target speed that the drone propeller motor is expected to reach, v′ is the PWM value that needs to be output through the closed-loop system to control the motor, x1 is the center point position of the image positioning module equipped on the airborne platform captured by the camera module equipped on the drone, x0 is the viewing center point position of the camera module equipped on the drone, G(s)0, G(s)1 are open-loop transfer functions, G(s) b0 、G(s) f0 、G(s) b1 、G(s) f1 is the feedforward control transfer function, K0, T i0 、T d0 、K1、T i1 、T d1 are adjustment parameters;

[0045] Step 54: The drone lands at the first laser unit, and the airborne platform enables the second electromagnetic positioning module and the wireless charging transmitting module to enter the ready state;

[0046] Step 55: When the drone continues to land and passes through the second laser positioning module, after receiving the signal, it activates the second electromagnetic positioning module inside the airborne platform, adsorbs the four-corner iron sheets of the drone, fixes the drone to the correct charging position, and at the same time sends a signal to the drone to make the drone stop and wait for charging.

[0047] Therefore, the present invention adopts the above-mentioned airborne drone system and collaborative operation method for mining robots, and has the following advantages:

[0048] (1) In the present invention, the collaborative operation of the unmanned aerial vehicle (UAV) and the excavation robot can be realized. Multiple UAVs equipped with sensors such as cameras and lidar are responsible for high-altitude operations such as mine mapping. The map data is stitched together to form a dense map, marking the construction area and the stockpiling area, thereby improving the construction efficiency.

[0049] (2) In the present invention, through the optimal scheduling method for collaborative charging of multiple UAVs, the working time of multiple UAVs is infinitely extended. The UAVs seek the nearest excavation robot to dock and land for charging, and cooperate with the excavation robot for collaborative operation, providing a reliable endurance guarantee for collaborative mapping, real-time monitoring of the operation situation and abnormal information in the field.

[0050] (3) In the present invention, multiple UAVs hover and monitor at high altitude, identifying abnormal situations such as stockpiling conditions, entry of personnel into the working area, and using materials to determine whether the excavation area is incorrect. It can correct the operation position around the excavation robot in a timely manner, providing real-time scene data support for the scheduling of multiple excavation robots. At the same time, it can monitor whether there are abnormal actions of moving objects such as personnel in the working area, improving the construction safety guarantee.

[0051] (4) In the present invention, the UAV lands vertically on the onboard platform, and by using the method of locking the lateral position, the recovery charging and takeoff replacement operations of the UAV are realized, improving the stability and reliability of the collaborative operation system.

[0052] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0053] Figure 1 Schematic diagram of the position of the onboard platform of an onboard UAV system for an excavation robot provided by an embodiment of the present invention;

[0054] Figure 2 Device diagram of the onboard platform of an onboard UAV system for an excavation robot provided by an embodiment of the present invention;

[0055] Figure 3 UAV mounting device diagram in the onboard platform provided by the present invention;

[0056] Figure 4 Structural diagram of the integrated circuit module of an onboard UAV system for an excavation robot provided by the present invention;

[0057] Figure 5 Overall collaborative operation algorithm flowchart of an onboard UAV collaborative operation method for an excavation robot provided by the present invention;

[0058] Figure 6Algorithm flowchart of the optimal scheduling method for multi-UAV collaborative charging of an on-board UAV collaborative operation method for an excavation robot provided by an embodiment of the present invention;

[0059] Figure 7 Algorithm flowchart of the UAV vertical landing algorithm of an on-board UAV collaborative operation method for an excavation robot provided by an embodiment of the present invention;

[0060] Figure 8 Locking lateral position control block diagram of an on-board UAV collaborative operation method for an excavation robot provided by an embodiment of the present invention;

[0061] Reference numerals: 11, switch hatch; 12, switch hatch motor; 21, first image positioning module; 22, first lidar positioning module; 23, second lidar positioning module; 24, first electromagnetic positioning module; 25, second image positioning module; 26, second electromagnetic positioning module; 27, third image positioning module; 31, lifting platform motor; 32, lifting platform bracket; 4, wireless charging transmitting module; 5, processor unit; 6, wireless charging receiving module; 41, UAV; 42, on-board lidar; 71, camera unit; 72, IMU unit; 73, lidar unit; 8, electromagnetic positioning module; 91, telescopic platform motor; 92, telescopic platform bracket; 10, integrated circuit module. Detailed implementation manners

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. The specific model specifications need to be selected according to the actual specifications of the device, etc. The specific selection calculation method adopts the existing technology in the art, so it will not be described in detail here.

[0063] Embodiment

[0064] Such as Figures 1-8As shown, the present invention provides an airborne UAV system for an excavating robot, including an excavating robot and an airborne platform arranged on the excavating robot; an airborne laser radar 42 unit is arranged on the excavating robot, and the airborne laser radar 42 unit is used for the excavating robot to perceive the surrounding environment, and the airborne platform includes a box body, a switch hatch 11 is arranged on the top of the box body, and a plurality of UAVs 41, a lifting platform, a telescopic platform, a main body positioning device, an image positioning module, a laser positioning module, an electromagnetic positioning module 8, a wireless charging transmitting module 4 and an integrated circuit module 10 are arranged inside the box body; wherein the UAV 41 is provided with a camera unit 71, a laser radar unit 73, an IMU unit 72, a processor unit 5, a UAV communication unit, a wireless charging receiving module 6 and a positioning structure;

[0065] For the airborne platform, the switch door 11 adopts a door design with top doors, and symmetrical motor-driven doors are set on both sides to provide sufficient space for the UAV 41 to land and realize vertical take-off and landing; the lifting platform and the telescopic platform are used to receive the UAV 41 to realize the optimal scheduling of multi-UAV collaborative charging; the main body positioning device provides the absolute position information of the airborne platform, which is used for the information needs when the UAV 41 needs to land; the image positioning module provides the UAV 41 with pairing identification and lateral position locking during vertical landing; the laser positioning module is used to provide height information during the vertical landing of the UAV 41 to the airborne platform, and use the height information as a judgment on whether the electromagnetic positioning module 8 is enabled; after the electromagnetic positioning module 8 obtains the enabling information of the laser positioning module, it adsorbs the positioning structure of the UAV 41 to fix the landing and docking position of the UAV 41; the wireless charging transmitting module 4 is paired with the wireless charging receiving module 6 for power transmission;

[0066] For the drone 41, a rotating structure is provided in the camera unit 71 to facilitate the acquisition of image information in a larger range. The combination of the laser radar unit 73, the camera unit 71 and the IMU unit 72 is used by the drone 41 to map the working area and navigate the overall path. The drone 41 can be used for vertical landing positioning to capture image positioning units and hovering monitoring to identify abnormal situations such as material stacking, entry of personnel in the working area, and use of materials to determine whether the excavation area is wrong; the positioning structure is set to four angle irons for adsorption by the electromagnetic positioning module 8.

[0067] There are three image positioning modules, the first image positioning module 21 is set in the switch hatch 11, the second image positioning module 25 is set in the telescopic platform, and the third image positioning module 27 is set in the lifting platform; the first image positioning mark is used for the drone 41 to find the general landing position on the excavation robot, and the second image positioning module 25 and the third image positioning module 27 are used to lock the lateral landing position when the drone 41 lands vertically;

[0068] The electromagnetic positioning module 8 is set to two. The first electromagnetic positioning module 24 is located on the telescopic platform, and the second electromagnetic positioning module 26 is located on the lifting platform.

[0069] The laser positioning module is set to two. The first laser positioning module 22 is located at the switch hatch 11, and the second laser positioning module 23 is located on the telescopic platform. The first laser positioning module 22 is used to send an enabling signal to start the integrated circuit module 10, the second laser positioning module 23, the first electromagnetic positioning module 24, and the second electromagnetic positioning module 26 when the drone 41 lands at the switch hatch 11. The second laser positioning module 23 is used to enable the first electromagnetic positioning module 24 and the second electromagnetic positioning module 26.

[0070] The lifting platform is used for the landing and charging of the drone 41, including a lifting platform bracket 32 and a lifting platform motor 31. The lifting platform uses a lead screw drive. The lifting platform motor 31 drives the ball screw to rotate, and the connecting piece fixed by the lead screw nut converts the rotation of the ball screw into the vertical movement of the lifting platform bracket 32, driving the lifting mechanism to realize the lifting of the lifting platform.

[0071] The telescopic platform is used for the drone 41 to land and dock. The telescopic platform includes a telescopic platform bracket 92 and a telescopic platform motor 91. The telescopic movement of the telescopic platform bracket 92 is driven by the telescopic platform motor 91, so that the telescopic platform extends and retracts to one side.

[0072] The telescopic platform is set in the middle area as a partition, which can achieve partitioning in the airborne platform, and then drones are set separately. The lifting platform is set at the bottom of the airborne platform, and then the position of the bottom drone is adjusted.

[0073] The integrated circuit module 10 includes a voltage stabilizing unit, a main control unit, a relay unit, a full-bridge drive unit, a wireless charging transmitting unit, a laser signal control unit, an excavator communication unit, and a power digital tube display unit.

[0074] The voltage stabilizing unit is set to three. The first voltage stabilizing unit stabilizes the voltage to 3.3V and supplies power to the main control unit and the laser signal control unit. The second voltage stabilizing unit stabilizes the voltage to 5V and supplies power to the relay unit. The third voltage stabilizing unit stabilizes the voltage to 12V and supplies power to the wireless charging transmitting module 4, the full-bridge drive unit, and the relay unit.

[0075] The full-bridge drive unit includes a first full-bridge drive unit to control the power adjustment of the transmitting unit, a second full-bridge drive unit to control the motor of the lifting platform, a third full-bridge drive unit to control the motor of the telescopic platform, and a fourth full-bridge drive unit to control the switch hatch motor 12.

[0076] The main control unit receives the signals from the laser positioning module and the signals sent by the UAV 41, and outputs PWM signals to control the corresponding full-bridge drive unit to provide appropriate rotational speeds for the motors of the telescopic platform and the corresponding power for the charging and transmitting module. The optocoupler is used to control the adsorption relay unit, and then the relay unit is enabled to control the electromagnetic positioning module 8;

[0077] The excavator communication unit and the power digital tube display unit are connected to the main control unit. The main control unit transmits and interacts information with the industrial control computer on the excavation robot through the excavator communication unit, and the power digital tube display unit can display the charging power in real time;

[0078] A collaborative operation method for an on-board UAV system of an excavation robot includes the following steps:

[0079] Step 1: When multiple excavation robots are waiting outside the working area, the working area is divided, and the UAVs in the on-board platform are released. The UAVs fly to the designated operation area and use the multi-sensor fusion SLAM method to survey and map the working area. After the surveying and mapping is completed, the working area map data obtained by each UAV is transmitted back to the excavation robot through the UAV communication unit;

[0080] The process of surveying and mapping the working area using the multi-sensor fusion SLAM method is as follows:

[0081] The UAV uses the camera unit, lidar unit, and IMU unit to obtain multi-sensor data, and uses the loosely coupled multi-sensor fusion SLAM method to survey and map the area map data. After the excavation robot transmits the obtained initial working area map data to the master control room, the master control room constructs a projection matrix for the working area map, establishes a Gaussian difference pyramid, searches for the optimal feature points in the pyramid, establishes the descriptors of the feature points, projects the descriptors in the projection matrix, performs feature matching to overlay and splice the area maps to obtain the overall dense map, marks the stockpiling area and the excavation area, judges roadblocks, simplifies the dense map using the downsampling method to obtain a sparse map, transmits the sparse map back to the excavation robot, and then transmits it to the UAV through the excavation robot, which is used for the excavation robot and the UAV to perform full-field path planning, obstacle avoidance, and operation arrangement.

[0082] Step 2: The excavation robot performs global path planning on the transmitted sparse map of the working area and enters the operation destination. The global path planning and obstacle avoidance process is as follows:

[0083] The excavation robot uses the overall sparse map of the working area as the prior point cloud map, sets the specified operation area as the target point, extracts and registers the obstacles in the map as polygons, establishes a visibility graph, and during the walking process of the excavation robot, uses the on-board lidar unit to sense the surrounding environment in real time, extracts the features of surrounding obstacles in real time, updates the global visibility graph in a dynamically maintained manner, and avoids obstacles dynamically, and finally reaches the destination.

[0084] Step 3: The UAV conducts target tracking on the excavation robot entering the operation area, hovers above the excavation robot for monitoring. The target tracking process is as follows:

[0085] After the excavation robot enters the operation area where the UAV has arrived, use the first frame of the image captured by the camera to frame the excavation robot as prior information, determine the tracking target, calculate the relative position, establish a directed graph, find the path with the minimum cost in the directed graph for planning, and locally update the directed graph during the tracking process to respond to changes in the surrounding environment until it reaches above the excavation robot.

[0086] The hovering monitoring process is as follows: The UAV hovers and monitors in the corresponding area, uses the camera unit and lidar unit to adopt a multi-source sensor detection fusion algorithm to monitor the operation area of the excavation robot in the monitoring area in real time, identify the stockpiling situation, the entry of personnel in the working area, and use materials to judge whether the excavation area is incorrect, correct the operation position around the excavation robot in time, provide real-time scene data support for the excavation robot scheduling, and at the same time monitor whether there are abnormal actions of moving objects such as personnel in the working area;

[0087] Step 4: After the UAV reaches the power threshold, determine the excavation robot that meets the requirements through the optimal scheduling method for multi-UAV collaborative charging, and fly towards the excavation robot that meets the requirements; The optimal scheduling method for multi-UAV collaborative charging is as follows:

[0088] Step 41: After the UAV reaches the power threshold, send its own position information and number information to all the excavation robots and UAVs working in the field;

[0089] Step 42: After the excavation robots in the field receive the signal, send their current position information and whether there is a charging vacancy information to the UAV; After the other working UAVs in the field receive the signal, send their current position information and flight path status information to the UAV;

[0090] Step 43: After the UAV receives the information of all the working excavation robots, establish a set of the current positions of all the excavation robots and whether there is a charging vacancy information, the current positions of all the UAVs and flight path status information, set the action priority and time slice, and adopt the dynamic time window method to select the optimal excavation robot as the target point;

[0091] Step 44: Using the sparse map of the working area as the sampling space, establish a rapid search tree, select nodes in the sampling space and connect them with the remaining nodes to plan a conflict-free path, fly towards the mining robot that meets the requirements, and send a landing preparation signal to the mining robot;

[0092] Step 45: After receiving the landing preparation signal, the mining robot opens the switch hatch, takes off another UAV parked inside the airborne platform, flies to the area monitored by the UAV that has reached the power threshold for operation replacement, closes the switch hatch, and waits for the UAV that has reached the power threshold to land.

[0093] Step 5: The UAV vertically lands at the correct position and uses the electromagnetic module for adsorption and fixation. The process is as follows:

[0094] Step 51: After the UAV reaches the mining robot that meets the requirements through the optimal scheduling method for multi-UAV cooperative charging, it detects the first image positioning module through the camera unit, reaches directly above the airborne platform, and sends a signal of reaching the target to the mining robot below;

[0095] Step 52: After receiving the signal, the airborne platform opens the switch hatch and raises the lifting platform to a suitable position;

[0096] Step 53: The UAV starts to vertically land, detects the third image positioning module through the camera unit, and uses the AprilTag information of the third image positioning module for secondary pairing. The lateral position is fixed through the closed-loop system, and then the vertical landing begins;

[0097] The closed-loop system locks the lateral position through the following formula:

[0098]

[0099] In the above formula, v is the target speed that the desired UAV propeller motor reaches, v′ is the PWM value that needs to reach the control motor output through the closed-loop system, x1 is the center point position of the image positioning module equipped on the airborne platform captured by the camera module equipped on the UAV, x0 is the center point position of the viewing angle of the camera module equipped on the UAV, G(s)0, G(s)1 are the open-loop transfer functions, G(s) b0 、G(s) f0 、G(s) b1 、G(s) f1 are the feedforward control transfer functions, K0, T i0 、T d0 、K1、T i1 、T d1 are the adjustment parameters, and the implementation process is as Figure 8 shown;

[0100] Step 54: The drone lands at the first laser unit, and the on-board platform enables the second electromagnetic positioning module and the wireless charging transmitting module to enter the standby state;

[0101] Step 55: When the drone continues to land and passes by the second laser positioning module, after receiving the signal, the second electromagnetic positioning module inside the on-board platform is activated to adsorb the iron sheets at the four corners of the drone, fixing the drone at the correct charging position. Meanwhile, a signal is sent to the drone to make it stop and wait for charging.

[0102] Therefore, the present invention adopts an on-board drone system and a cooperative operation method for an excavation robot. By means of multi-drone mapping and stitching to form a dense map to display the information in the working area, it guides multiple excavation robots to enter the site for operation. Through the optimal scheduling and vertical landing method of multi-drone cooperative charging, it realizes real-time monitoring of the working area and operation conditions of multiple excavation robots by multiple drones, improves the operation efficiency and intelligent level of multiple excavation robots and multiple drones in mines and construction sites, and at the same time enhances the construction safety of the excavation robots.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements do not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An airborne drone system for an excavation robot, characterized in that: It comprises an excavation robot and an airborne platform arranged on the excavation robot; the excavation robot is provided with an airborne laser radar unit, the airborne laser radar unit is used for the excavation robot to perceive the surrounding environment, the airborne platform comprises a box body, a switch hatch is arranged on the top of the box body, and a plurality of drones, a lifting platform, a telescopic platform, a body positioning device, an image positioning module, a laser positioning module, an electromagnetic positioning module, a wireless charging transmitting module and an integrated circuit module are arranged inside the box body; the drone is provided with a camera unit, a laser radar unit, an IMU unit, a processor unit, a drone communication unit, a wireless charging receiving module and a positioning structure; For the airborne platform, the switch hatch adopts a hatch design with top doors, and is equipped with symmetrical motors to drive opening and closing on both sides; the lifting platform and the telescopic platform are used to receive the UAV; the main body positioning device provides the absolute position information of the airborne platform; the image positioning module provides the UAV with pairing identification and lateral position locking during vertical landing; the laser positioning module is used to provide the UAV's height information during the vertical landing of the UAV to the airborne platform; the electromagnetic positioning module adsorbs the UAV's positioning structure based on the UAV's height information from the laser positioning module to fix the landing and docking position of the UAV; the wireless charging transmitting module is paired with the wireless charging receiving module to transmit electric energy; For the UAV, a rotating structure is provided in the camera unit to obtain image information. The combination of the laser radar unit, the camera unit and the IMU unit is used by the UAV to map the working area and navigate the overall path. The positioning structure is configured as four square angle irons for adsorption of the electromagnetic positioning module.

2. The airborne drone system for an excavation robot according to claim 1, characterized in that: The image positioning modules are provided with three, the first image positioning module is provided in the switch hatch, the second image positioning module is provided in the telescopic platform, and the third image positioning module is provided in the lifting platform; The electromagnetic positioning modules are provided in two, the first electromagnetic positioning module is located on the telescopic platform, and the second electromagnetic positioning module is located on the lifting platform; The laser positioning modules are provided in two, the first laser positioning module is located at the switch hatch, and the second laser positioning module is located at the telescopic platform.

3. The airborne drone system for an excavation robot according to claim 2, characterized in that: The lifting platform is used for landing and charging of the drone, and includes a lifting platform bracket and a lifting platform motor. The lifting platform adopts a screw transmission, and the lifting platform motor drives the ball screw to rotate. The connecting piece fixed by the screw nut converts the rotation of the ball screw into the vertical movement of the lifting platform bracket, driving the lifting mechanism to realize the lifting of the lifting platform; The telescopic platform comprises a telescopic platform bracket and a telescopic platform motor. The telescopic platform bracket is driven to telescope by the telescopic platform motor, so that the telescopic platform is extended or retracted to one side.

4. The airborne drone system for an excavation robot according to claim 3, characterized in that: The integrated circuit module includes a voltage stabilizing unit, a main control unit, a relay unit, a full-bridge driving unit, a wireless charging transmitting unit, a laser signal control unit, an excavator communication unit, and a power digital tube display unit; The voltage stabilizing unit is set to three, the first voltage stabilizing unit is 3.3V stabilizing, which supplies power to the main control unit and the laser signal control unit, the second voltage stabilizing unit is 5V stabilizing, which supplies power to the relay unit, and the third voltage stabilizing unit is 12V stabilizing, which supplies power to the wireless charging transmitter module, the full-bridge drive unit and the relay unit; The full-bridge drive unit includes a first full-bridge drive unit for controlling the power adjustment of the transmitting unit, a second full-bridge drive unit for controlling the motor of the lifting platform, a third full-bridge drive unit for controlling the motor of the telescopic platform, and a fourth full-bridge drive unit for controlling the motor of the door opening and closing; The main control unit controls the onboard drone system; The power digital tube display unit displays the charging power of the drone.

5. A collaborative operation method of an airborne drone system for an excavating robot, comprising an airborne drone system for an excavating robot according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: When several excavation robots are waiting outside the working area, the working area is divided and the drones on the airborne platform are released. The drones fly to the designated working area and use the multi-sensor fusion SLAM method to map the working area. After the mapping is completed, the obtained working area map is transmitted to the main control room through the excavation robot, and the sparse map of the working area is processed and transmitted back to the excavation robot, and then transmitted to the drone by the excavation robot; Step 2: The excavation robot uses global path planning based on the sparse map of the work area transmitted back to the work destination; Step 3: The drone tracks the excavation robot that enters the working area and hovers over the excavation robot for monitoring; Step 4: During the monitoring process, when the UAV reaches the power threshold, the excavator robot that meets the requirements is determined through the multi-UAV collaborative charging optimal scheduling method, and the UAV flies to the excavator robot that meets the requirements; Step 5: The drone lands vertically to the correct position and is fixed by the electromagnetic module. After being fixed, the wireless charging transmitter module is started to charge the drone wirelessly.

6. The method for cooperative operation of an airborne drone system for an excavating robot according to claim 5, characterized in that: In step 1, the specific process is as follows: The UAV uses the camera unit, lidar unit and IMU unit to obtain multi-sensor data, and adopts the loosely coupled multi-sensor fusion SLAM method to map the working area. The excavation robot transmits the obtained working area map to the main control room. The main control room constructs a projection matrix for the working area map, establishes a Gaussian difference pyramid, finds the optimal feature point in the pyramid, establishes a descriptor of the feature point, uses the descriptor to project on the projection matrix, performs feature matching, overlays and splices the working area maps to obtain a dense map, marks the stockpiling area and the excavation area, determines the roadblocks, and uses the downsampling method to simplify the dense map to obtain a sparse map of the working area. The sparse map of the working area is transmitted back to the excavation robot, and then transmitted to the UAV through the excavation robot.

7. The method for cooperative operation of an airborne drone system for an excavating robot according to claim 6, characterized in that: In step 2, the global path planning method is as follows: The excavation robot uses the sparse map of the working area as the prior point cloud map, sets the designated working area as the target point, extracts and aligns the obstacles in the map with polygons, establishes a visible graph, and uses the airborne laser radar unit to perceive the surrounding environment in real time and extract the features of surrounding obstacles during the walking process of the excavation robot. The global visibility graph is updated in a dynamic maintenance manner, obstacles are avoided dynamically, and the destination is finally reached.

8. The method for cooperative operation of an airborne drone system for an excavating robot according to claim 7, characterized in that: In step 3, the specific process is as follows: After the excavator robot enters the working area where the drone has been, the first frame image captured by the camera is used to frame the excavator robot as prior information, determine the tracking target, calculate the relative position, establish a directed graph, find the path with the minimum cost in the directed graph for planning, and locally update the directed graph during the tracking process to respond to changes in the surrounding environment until it reaches the top of the excavator robot; The drone hovers above the excavator robot for monitoring, and uses the camera unit and lidar unit to adopt a multi-source sensor detection fusion algorithm to monitor the excavator robot's operating area in real time within the monitoring area, provide real-time scene data support for the excavator robot's scheduling, and monitor whether there are abnormal movements of moving objects in the working area.

9. The method for cooperative operation of an airborne drone system for an excavating robot according to claim 8, characterized in that: In step 4, the optimal scheduling method for multi-UAV collaborative charging is as follows: Step 41: After the UAV reaches the power threshold, it publishes its own location information and number information to all the excavation robots and UAVs working in the field; Step 42: After receiving the signal, the excavation robot in the field sends the current position information and charging space information to the drone. After receiving the signal, the other working drones in the field send the current position information and flight path status information to the drone. Step 43: After receiving the information of the excavation robot, the UAV sets the current position and charging space information status information of all excavation robots and the current position and flight path status information of all UAVs, sets the action priority and time slice, and uses the dynamic time window method to select the optimal excavation robot as the target point; Step 44: Use the sparse map of the working area as the sampling space, establish a fast search tree, select a node in the sampling space and connect it with the remaining nodes to plan a conflict-free path, fly to the excavation robot that meets the requirements, and send a landing preparation signal to the excavation robot; Step 45: After receiving the landing preparation signal, the excavation robot opens the hatch, takes off another drone parked on the airborne platform, and flies to the area previously monitored by the drone that has reached the power threshold to replace the operation.

10. The method for cooperative operation of an airborne drone system for an excavating robot according to claim 9, characterized in that: In step 5, the process of the drone performing vertical landing is as follows: Step 51: After the UAV reaches the excavation robot that meets the requirements through the multi-UAV cooperative charging optimal scheduling method, the UAV detects the first image positioning module through the camera unit, reaches directly above the airborne platform, and sends a target arrival signal to the excavation robot below; Step 52: After receiving the signal, the airborne platform opens the switch hatch and raises the lifting platform to a suitable position; Step 53: The UAV starts to land vertically, detects the third image positioning module through the camera unit, performs secondary pairing using the AprilTag information of the third image positioning module, fixes the lateral position through the closed-loop system, and starts to land vertically; The closed-loop system locks the lateral position using the following formula: In the above formula, v is the target speed that the propeller motor of the drone is expected to reach, v′ is the PWM value output by the closed-loop system to control the motor, x1 is the center point position of the image positioning module equipped on the airborne platform captured by the camera module equipped on the drone, x0 is the center point position of the viewing angle of the camera module equipped on the drone, G(s)0 and G(s)1 are open-loop transfer functions, and G(s) b0 、G(s) f0 、G(s) b1 、G(s) f1 is the feedforward control transfer function, K0, T i0 , T d0 , K1, T i1 , T d1 is the adjustment parameter; Step 54: The drone lands at the first laser unit, and the airborne platform enables the second electromagnetic positioning module and the wireless charging transmitting module to enter a ready state; Step 55: When the drone continues to land, it passes through the second laser positioning module. After receiving the signal, it stimulates the second electromagnetic positioning module inside the airborne platform to adsorb the four corner iron sheets of the drone, fix the drone to the correct charging position, and send a signal to the drone to stop the drone and wait for charging.

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