Non-contact putting system and method for self-localization photo control point device in steep mountain

Abstract

The invention provides a non-contact releasing system and method for a self-positioning image control point device in a steep mountain, and relates to the technical field of large reservoir construction protection and geological disaster monitoring. The device comprises a multi-rotor unmanned aerial vehicle flying platform, a cable take-up and pay-off device, a magnetic attraction device, a self-positioning image control point device, a ground control module, an aerial photography sensor and other modules. According to the application method, the self-positioning image control point device is hung on a flight platform of the multi-rotor unmanned aerial vehicle, the self-positioning image control point device is put at an operation position through the cable take-up and pay-off device, and after operation is completed, the self-positioning device is recycled through the magnetic attraction device, and repeated use is achieved. According to the invention, three-dimensional reconstruction in a steep mountain and non-contact throwing and laying of ground surface deformation monitoring image control points can be realized, automation of image control point measurement is realized, measurable precision, measurement efficiency and safety of a periodic three-dimensional model are improved, and safety risks possibly faced by traditional manual laying and measurement in a steep mountain environment are effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical fields of large reservoir construction protection and geological disaster monitoring. Specifically, it relates to a non-contact delivery system and method for an independently positioned image control point device in a steep mountain body. Background Art

[0002] Constructing a digital twin water conservancy "sky-ground-hydraulic engineering" integrated all-element all-weather dynamic monitoring system is an important exploration in the field of water resource management and monitoring technology. Since most reservoir construction areas have steep mountain bodies, when carrying out high-precision three-dimensional reconstruction and periodic monitoring, it depends on object space image control points, and there are related technical solutions that cannot implement the layout of photogrammetric ground targets manually on-site and the manual measurement of their coordinates.

[0003] Therefore, if the image control points can be laid out in a non-contact and highly flexible manner, and based on this, the accuracy of the results obtained by the UAV for close-range photogrammetry can be improved, the three-dimensional reconstruction of the surrounding environment of large reservoirs can be achieved at close range, non-contact, and with high precision; at the same time, the independently positioned image control point device can freely transfer its position relying on the UAV according to the needs of different periods; the data obtained by the independently positioned image control point device and the UAV can also play an important role in the processes including the construction, monitoring, protection, and repair of reservoirs, and have great application potential.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present invention, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a non-contact delivery system for an independently positioned image control point device in a steep mountain body and a non-contact delivery method for an independently positioned image control point device in a steep mountain body, aiming to achieve a high degree of automation in the measurement and three-dimensional modeling processes of large steep mountain bodies, improve the measurability, efficiency, and safety during measurement, avoid the safety risks or the problem of inability to implement layout control in traditional image control point measurement in a steep mountain body environment where personnel need to reach the site for layout and manual coordinate measurement, and at the same time save labor, material resources, and time costs.

[0006] Other features and advantages of the present invention will become apparent through the following detailed description, or will be partially learned through the practice of the present invention.

[0007] According to the first aspect of the embodiments of the present invention, a non-contact delivery system for an independently positioned image control point device in a steep mountain body is provided, including: A multi-rotor UAV flight platform, configured to receive control instructions and perform flight movement according to the control instructions; The cable retracting and deploying device is fixedly connected to the multi-rotor UAV flight platform; The autonomous positioning image control point device is grabbed or released by the multi-rotor UAV flight platform through the cable retracting and deploying device; The ground control module is communicatively connected to the multi-rotor UAV flight platform and is used to send control instructions to the multi-rotor UAV flight platform to control the multi-rotor UAV flight platform to complete the deployment and recovery of the autonomous positioning image control point device; Among them, the cable retracting and deploying device completes the deployment or recovery of the autonomous positioning image control point device through magnetic attraction and in combination with the retracting and deploying of the cable.

[0008] In some exemplary embodiments of the present invention, based on the foregoing solution, the cable retracting and deploying device includes a bracket, a retracting and deploying motor, a cable winch, a cable, and a magnetic attraction device; the bracket has one end fixedly connected to the multi-rotor UAV flight platform; the retracting and deploying motor is fixed at the end of the bracket far from the multi-rotor UAV flight platform and is electrically connected to the cable winch. The retracting and deploying motor includes a power supply module, a wireless communication module, and a retracting and deploying controller; the cable winch is fixedly connected to the retracting and deploying motor, and a cable is wound around the cable winch. One end of the cable is fixed to the retracting and deploying motor and is electrically connected to the retracting and deploying motor, and the other end is equipped with a magnetic attraction device; the magnetic attraction device is connected to the end of the cable and is electrically connected to the retracting and deploying motor through the cable.

[0009] In some exemplary embodiments of the present invention, based on the foregoing solution, the autonomous positioning image control point device is adsorbed by the magnetic attraction device and moves with the multi-rotor UAV flight platform; the autonomous positioning image control point device includes a solar panel, an RTK positioning module, a power supply system, a photovoltaic controller, and a 4G module; the solar panel is connected to the autonomous positioning image control point device; the RTK positioning module is connected to the autonomous positioning image control point device; the power supply system is connected to the autonomous positioning image control point device, and a storage battery is provided in the power supply system; the photovoltaic controller is fixedly connected to the autonomous positioning image control point device and is electrically connected to the solar panel; the 4G module is connected to the autonomous positioning image control point device; among them, the RTK positioning module, the photovoltaic controller, and the 4G module are electrically connected to the power supply system; the RTK positioning module, the 4G module, and the multi-rotor UAV flight platform are all communicatively connected to the ground control module.

[0010] In some exemplary embodiments of the present invention, based on the foregoing solution, the multi-rotor UAV flight platform includes an aerial photography sensor, an aircraft communication radio, an autopilot module, and a distance sensor; the aerial photography sensor can be mounted on the multi-rotor UAV flight platform; the aircraft communication radio is connected to the multi-rotor UAV flight platform; the autopilot module is connected to the multi-rotor UAV flight platform and is used to provide GNSS and RTK functions. The autopilot module is electrically connected to the aircraft communication radio and is connected to the aerial photography sensor; the distance sensor can be connected to the multi-rotor UAV flight platform.

[0011] In some exemplary embodiments of the present invention, based on the foregoing solution, the multi-rotor UAV flight platform is a quad-rotor flight platform, and the number of cable winding and unwinding devices is four; the four cable winding and unwinding devices are respectively connected to the four corners of the multi-rotor UAV flight platform to ensure the balance of the connection.

[0012] In some exemplary embodiments of the present invention, based on the foregoing solution, the cable winding and unwinding motor is electrically connected to the ground control module and is electrically connected to the cable winch; the cable winding and unwinding motor receives the control instructions of the ground control module to control the clockwise or counterclockwise rotation of the cable winch to realize the winding and unwinding of the cable.

[0013] In some exemplary embodiments of the present invention, based on the foregoing solution, at least a pair of semi-circular iron rods are arranged inside the magnetic attraction device, and a plurality of turns of wire coils are evenly wound on the semi-circular iron rods. The wire coils generate magnetic force after being energized; the cable winding and unwinding motor receives the power supply or power-off from the ground control module to the magnetic attraction device, so that after the magnetic attraction device generates magnetic force or loses magnetic force, it adsorbs or drops the self-positioning image control point device with an iron shell.

[0014] In some exemplary embodiments of the present invention, based on the foregoing solution, the RTK positioning module is used to receive RTK base station information to complete the high-precision positioning of the image control point without measurement, obtain accurate position information and store it, so that the multi-rotor UAV flight platform can identify the position of the image control point, complete the non-measurement recovery of the self-positioning image control point device, and at the same time provide accurate observation data for the three-dimensional reconstruction of the multi-rotor UAV flight platform image.

[0015] In some exemplary embodiments of the present invention, based on the foregoing solution, the photovoltaic controller is respectively connected to the solar panel and the power supply system. The photovoltaic controller is used to control the output voltage of the solar panel to protect the battery in the power supply system from overcharging; the photovoltaic controller is also used to prevent the reverse flow of the battery power when the solar panel does not generate electricity; the photovoltaic controller is also used to control the battery to supply power to the outside when the solar panel charges the battery, and the power used by the load preferentially calls the energy storage in the solar battery, and the remaining power is stored in the battery. When it is detected that the power of the solar battery is insufficient, power is simultaneously dispatched from the battery to the load.

[0016] In some exemplary embodiments of the present invention, based on the foregoing solution, the 4G module is electrically connected to the ground control module and transmits information; the 4G module is configured to directly connect to the 4G communication network when detecting that the communication network is in a normal state, and transmit data to the base station through the 4G communication network, and then transmit it to the ground control module through the Internet; the 4G module is configured to transmit information through the radio station around the survey area when detecting that the communication network is in an abnormal state; the 4G module is further configured to encrypt and authenticate data.

[0017] In some exemplary embodiments of the present invention, based on the foregoing solution, the ground control module consists of a real-time video transmission screen and a control handle, and is communicatively connected to the aircraft communication radio through a wireless signal.

[0018] In some exemplary embodiments of the present invention, based on the foregoing solution, the aerial photography sensor includes at least one of a single-lens optical camera, a multi-lens optical camera, and an airborne lidar.

[0019] According to the second aspect of the embodiments of the present invention, a non-contact dropping method for an autonomous positioning image control point device in a steep mountain is provided, including: Step 1: For the first flight, use a multi-rotor UAV flight platform to carry an aerial photography sensor to obtain images or airborne lidar point cloud data, establish a real three-dimensional model of the measurement object or color point cloud data, and design obstacle avoidance and dropping order on the image control point position and dropping flight route based on the slope of the object real three-dimensional model; Step 2: For the second flight, use a multi-rotor UAV flight platform to mount a cable retracting and releasing device and an autonomous positioning image control point device, fly to above the preset dropping point based on RTK precise navigation, the multi-rotor UAV flight platform automatically descends to 5 meters above the set elevation, and continue to descend to 0.3 meters above the set dropping point based on the distance sensor and real-time video transmission, and the ground video transmission remote control controls the cable retracting and releasing device to drop the autonomous positioning image control point device to the ground; Step 3: The cable retracting and releasing device is continuously powered on during flight, so that the magnetic adsorption device at the end of the cable keeps adsorbing the autonomous positioning image control point device. After flying to the designated position, according to the instructions of the ground control module, the cable retracting and releasing device slowly releases the cable until the autonomous positioning image control point device touches the ground, and after confirming that the autonomous positioning image control point device is stable, the cable adsorption is released and the cable is retracted; Step 4: Determine the evaluation result of the dropping effect. The dropping effect evaluation method includes real-time video transmission visual rough determination, or fine determination of the stability of random items of the first batch of observation data; Step 5: Repeat Step 2, Step 3, and Step 4, return to reload the autonomous positioning image control point device and drop it again until all image control point positions are dropped and evaluated; Step 6: After confirming that the measurement task is completed, reset the route to realize the route design of completing the recovery task in sequence by recovering the autonomous positioning image control point devices one by one; Step 7: The third flight, with the help of the multi-rotor UAV flight platform to mount the cable retracting device, based on RTK precision navigation to fly to the preset release point, the multi-rotor UAV flight platform automatically lowered to 5 meters above the set altitude, based on the distance sensor and real-time image transmission video, continue to lower to 0.3 meters above the set release point, ready to use the ground image transmission remote control to control the cable retracting device to recover the autonomous positioning image control point device; Step 8: After flying to the designated location, according to the instructions of the ground remote control, the cable retracting device slowly rotates the cable winch, and the cable is extended until the magnetic device at the end contacts the autonomous positioning image control point device. After confirming stable contact, the magnetic device is powered on to generate magnetic force to adsorb the iron shell of the autonomous positioning image control point device. After confirming that the adsorption is successful, the cable retracting device slowly retracts the cable to make the autonomous positioning image control point device leave the ground, and then the multi-rotor UAV flight platform returns with the autonomous positioning image control point device; Step 9: Repeat steps 7 and 8, return to land and unload the recovered autonomous positioning image control point device, and take off again to recover the next autonomous positioning image control point device until all autonomous positioning image control point devices are recovered.

[0020] In some exemplary embodiments of the present invention, based on the above scheme, step one includes: Step 101: The ground GNSS base station sets up known points and records static data before the airborne RTK of the multi-rotor UAV flight platform is turned on. The epoch sampling frequency of the ground base station is not less than 1 Hz, and when the payload is an airborne laser radar, it is not less than 5 Hz; Step 102: Design a three-dimensional route by referring to the required measurement object range and the public DEM data, and obtain aerial photography data with qualified heading overlap, lateral overlap and ground resolution; Step 103: The multi-rotor UAV flight platform autonomously flies the flight route designed in step 102 under the control of the autopilot, and the multi-rotor UAV flight platform carries out automatic aerial photography with an aerial photography sensor during the flight, and the level flight speed of the multi-rotor UAV flight platform is less than or equal to 20 m / s; Step 104: After the flight is completed, the aircraft lands and the acquired real-time dynamic differential RTK data and aerial photography images are sorted out according to the electronic coupling relationship. The coordinate values ​​of the elements of the external orientation line of the exposure point in the local coordinate system are calculated in combination with the local transformation relationship of the survey area, and the aerial photography is completed. Step 105: Perform aerial triangulation calculation based on the precise camera parameters and the exterior orientation line element file of the exposure points. In the aerial triangulation, set the accurate observation weights of the exterior orientation line elements of the exposure points. The adjustment model prohibits adjusting and correcting the camera parameters to ensure that the three interior orientation elements do not participate in the adjustment calculation. According to the beam method constraint conditions, adjust the final values of the exterior orientation line elements of the exposure points to complete the aerial triangulation calculation without ground control points. Step 106: Use publicly available industry real scene three-dimensional modeling software to quickly output the real scene three-dimensional model in OSGB format or the colored point cloud three-dimensional model of the steep mountain site. Step 107: Conduct geological remote sensing interpretation and slope calculation in the real scene three-dimensional model to determine the approximate positions where ground control points need to be laid out subsequently. On this basis, select points with a slope less than 30 degrees, and the terrain within a 2-square-meter area around is flat and open to the sky without obstruction, ensuring that the requirements of subsequent measurement plans can be met. Finally, output the coordinate table of the final placement points of the self-positioning ground control point device.

[0021] In some exemplary embodiments of the present invention, based on the foregoing solution, step two includes: Step 201: According to the coordinate table of the final placement points output in step 107, use the flight control software of the video transmission remote controller to automatically lay out the safe placement flight path. Step 202: Perform centimeter-level navigation flight based on the RTK differential module of the self-positioning ground control point device, fly at high altitude to above the placement point; the aircraft autonomously reduces the flight altitude to 5 meters above the ground elevation of the placement point, and continues to reduce the altitude to 0.3 meters above the set placement point based on the distance sensor and real-time video transmission. Step 203: The ground video transmission remote controller controls the cable retracting and releasing device to place the self-positioning ground control point device on the ground.

[0022] In some exemplary embodiments of the present invention, based on the foregoing solution, step three includes: Step 301: Control the motor of the cable retracting and releasing device to rotate the cable winch, so that the cable lowers the self-positioning ground control point device to the ground. Step 302: After the self-positioning ground control point device stably contacts the ground, control the motor to stop powering the magnetic adsorption device at the end of the cable, and release the adsorption of the magnetic adsorption device on the self-positioning ground control point device. Step 303: After determining the position of the recoverable ground control point, control the motor of the cable retracting and releasing device to rotate the cable winch, so that the cable is recovered and wound on the cable winch.

[0023] In some exemplary embodiments of the present invention, based on the foregoing solution, step four includes: After each autonomous positioning image control point device is put into place, control the multi-rotor UAV flight platform to hover for 1 minute, and check whether the autonomous positioning image control point device is stable based on the real-time video transmission signal on the screen of the video transmission remote controller; at the same time, conduct a random item stability analysis based on the first batch of monitoring data transmitted back by the autonomous positioning image control point device for fine determination.

[0024] In some exemplary embodiments of the present invention, based on the foregoing solution, step seven includes: Step 701: According to the recovery sequence determined in step six, recover the autonomous positioning image control point device in accordance with the placement route; Step 702: Perform centimeter-level navigation flight based on the on-board RTK differential module, fly at high altitude above the recovery point; the aircraft autonomously reduces the flight altitude to 5 meters above the ground elevation of the recovery point, and continues to reduce the altitude to 0.3 meters above the set recovery point based on the distance sensor and the real-time video transmission; Step 703: The ground video transmission remote controller controls the multi-rotor UAV flight platform to carry the cable retracting and deploying device to recover the autonomous positioning image control point device.

[0025] In some exemplary embodiments of the present invention, based on the foregoing solution, step eight includes: Step 801: Control the motor of the cable retracting and deploying device to rotate the cable winch, so that the cable is lowered and the magnetic adsorption device at the end contacts the iron shell of the autonomous positioning image control point device; Step 802: After the magnetic adsorption device at the end of the cable stably contacts the autonomous positioning image control point device, control the motor to start continuously powering the magnetic adsorption device at the end of the cable to complete the adsorption of the magnetic adsorption device to the autonomous positioning image control point device; Step 803: Control the motor of the cable retracting and deploying device to rotate the cable winch to retract the cable and lift the autonomous positioning image control point device.

[0026] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: The present invention enables the remote device placement to have a safe and stable placement environment through the real scene three-dimensional model, and at the same time combines the RTK real-time navigation technology, real-time video transmission technology and distance sensor to achieve precise flight and fixed-point precise placement. The detachable load retracting and deploying motor is used to realize the remote autonomous placement and fixation of the image control point device, ensuring the reliability of the spatial position data of the image control point; the entire placement and recovery method non-contactedly and stably places the recoverable autonomous positioning image control point device at the planned location to assist photogrammetry, avoiding the safety risks or the situation where no layout can be carried out when personnel arrive at the scene in a steep mountain environment, and at the same time saving manpower, material resources and time costs.

[0027] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Description of the Drawings

[0028] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of a multi-rotor UAV flight platform in an exemplary embodiment of the present invention.

[0030] Figure 2 It is a schematic structural diagram of a retractable device and an aerial photography sensor carried in an exemplary embodiment of the present invention.

[0031] Figure 3 It is a schematic structural diagram of an autonomous positioning image control point device in an exemplary embodiment of the present invention.

[0032] Figure 4 It is a schematic structural diagram of a ground control module in an exemplary embodiment of the present invention.

[0033] Figure 5 It is a schematic flow diagram of a non-contact dropping method of an autonomous positioning image control point device in a steep mountain in an exemplary embodiment of the present invention.

[0034] In the figure: 1 - multi-rotor UAV flight platform; 2 - retractable cable device; 3 - bracket; 4 - retractable motor; 5 - cable winch; 6 - cable; 7 - magnetic attraction device; 8 - autonomous positioning image control point device; 9 - solar panel; 10 - RTK positioning module; 11 - power supply system; 12 - photovoltaic controller; 13 - 4G module; 14 - ground control module; 15 - aerial photography sensor; 16 - aircraft communication radio; 17 - autopilot module; 18 - distance sensor.

[0035] In the accompanying drawings, the same or corresponding reference numerals represent the same or corresponding parts. Detailed Embodiments

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1: Refer to Figure 1 、 Figure 2 and Figure 3As shown in the figure, the embodiment of the present invention first provides a non-contact delivery system for an autonomous positioning image control point device in a steep mountain. The system includes: A multi-rotor UAV flight platform 1, which is used to receive control instructions and perform flight movements according to the control instructions; A cable retracting and releasing device 2, which is fixedly connected to the multi-rotor UAV flight platform 1; An autonomous positioning image control point device 8, which is grabbed or released by the multi-rotor UAV flight platform 1 through the cable retracting and releasing device 2; A ground control module 14, which is communicatively connected to the multi-rotor UAV flight platform 1 and is used to send control instructions to the multi-rotor UAV flight platform 1 to control the multi-rotor UAV flight platform 1 to complete the delivery and recovery of the autonomous positioning image control point device 8; wherein, the cable retracting and releasing device 2 completes the delivery or recovery of the autonomous positioning image control point device 8 through magnetic attraction and the combination of cable retracting and releasing.

[0038] The cable retracting and releasing device 2 includes a bracket 3, a cable retracting and releasing motor 4, a cable winch 5, a cable 6 and a magnetic attraction device 7; One end of the bracket 3 is fixedly connected to the multi-rotor UAV flight platform 1; The cable retracting and releasing motor 4 is fixed at one end of the bracket 3 away from the multi-rotor UAV flight platform 1 and is electrically connected to the cable winch 5. The cable retracting and releasing motor 4 includes a power supply module, a wireless communication module and a cable retracting and releasing controller; The cable winch 5 is fixedly connected to the cable retracting and releasing motor 4. The cable 6 is wound around the cable winch 5. One end of the cable 6 is fixed to the cable retracting and releasing motor 4 and is electrically connected to the cable retracting and releasing motor 4, and the other end is installed with the magnetic attraction device 7; The magnetic attraction device 7 is connected to the end of the cable 6 and is electrically connected to the cable retracting and releasing motor 4 through the cable 6.

[0039] The autonomous positioning image control point device is adsorbed by the magnetic attraction device 7 and moves with the multi-rotor UAV flight platform 1. The autonomous positioning image control point device 8 includes a solar panel 9, an RTK positioning module 10, a power supply system 11, a photovoltaic controller 12 and a 4G module 13; The solar panel 9 is connected to the autonomous positioning image control point device 8; The RTK positioning module 10 is connected to the autonomous positioning image control point device 8; The power supply system 11 is connected to the autonomous positioning image control point device 8, and a storage battery is arranged in the power supply system 11; The photovoltaic controller 12 is fixedly connected to the autonomous positioning image control point device 8 and is electrically connected to the solar panel 9; The 4G module 13 is connected to the autonomous positioning image control point device 8; wherein, the RTK positioning module 10, the photovoltaic controller 12 and the 4G module 13 are electrically connected to the power supply system 11; The RTK positioning module 10, the 4G module 13 and the multi-rotor UAV flight platform 1 are all communicatively connected to the ground control module 14.

[0040] The multi-rotor UAV flight platform 1 includes an aerial photography sensor 15, an aircraft communication radio 16, an autopilot module 17, and a distance sensor 18; the aerial photography sensor 15 can be mounted on the multi-rotor UAV flight platform 1; the aircraft communication radio 16 is connected to the multi-rotor UAV flight platform 1; the autopilot module 17 is connected to the multi-rotor UAV flight platform 1 and is used to provide GNSS and RTK functions. The autopilot module 17 is electrically connected to the aircraft communication radio 16 and is connected to the aerial photography sensor 15; the distance sensor 18 can be connected to the multi-rotor UAV flight platform 1.

[0041] In an optional embodiment, the multi-rotor UAV flight platform 1 is a quad-rotor flight platform, and the number of cable retraction and deployment devices 2 is four; the four cable retraction and deployment devices 2 are respectively connected to the four corners of the multi-rotor UAV flight platform 1 to ensure the balance of the connection.

[0042] In an optional embodiment, the cable retraction and deployment motor 4 is electrically connected to the ground control module 14 and is electrically connected to the cable winch 5; the cable retraction and deployment motor 4 receives the control instructions of the ground control module 14 to control the clockwise or counterclockwise rotation of the cable winch 5 to realize the retraction and deployment of the cable.

[0043] In an optional embodiment, at least a pair of semi-circular iron rods are arranged inside the magnetic attraction device 7, and a number of turns of wire coils are evenly wound on the semi-circular iron rods. The wire coils generate magnetic force after being energized; the cable retraction and deployment motor 4 receives the control of the ground control module 14 to supply power or cut off power to the magnetic attraction device 7, so that after the magnetic attraction device 7 generates magnetic force or loses magnetic force, it adsorbs or drops the self-positioning image control point device 8 with an iron shell.

[0044] In an optional embodiment, the RTK positioning module 10 is used to receive RTK base station information to complete the high-precision positioning of the image control point without measurement, obtain accurate position information and store it, so that the multi-rotor UAV flight platform 1 can identify the position of the image control point, complete the non-measurement recovery of the self-positioning image control point device 8, and at the same time provide accurate observation data for the three-dimensional reconstruction of the multi-rotor UAV flight platform image.

[0045] In an optional embodiment, the photovoltaic controller 12 is respectively connected to the solar panel 9 and the power supply system 11. The photovoltaic controller 12 is used to control the output voltage of the solar panel 9 to protect the battery in the power supply system 11 from overcharging; the photovoltaic controller 12 is also used to prevent the reverse flow of the battery power when the solar panel 9 does not generate electricity; the photovoltaic controller 12 is also used to control the battery to supply power externally when the solar panel 9 charges the battery. The power used by the load preferentially calls the energy storage in the solar battery, and the remaining power is stored in the battery. When it is detected that the power of the solar battery is insufficient, power is simultaneously dispatched from the battery to the load.

[0046] In an alternative embodiment, the 4G module 13 is electrically connected to the ground control module 14 and transmits information; the 4G module 13 is configured to directly connect to the 4G communication network when detecting that the communication network is in a normal state, and transmit data to the base station through the 4G communication network, and then transmit it to the ground control module 14 through the Internet; the 4G module 13 is configured to transmit information through the radio station around the survey area when detecting that the communication network is in an abnormal state; the 4G module 13 is further configured to encrypt and authenticate data.

[0047] In an alternative embodiment, the ground control module 14 is composed of a real-time video transmission screen and a control handle, and is communicatively connected to the aircraft communication radio 16 through a wireless signal.

[0048] In an alternative embodiment, the aerial photography sensor 15 includes at least one of a single-lens optical camera, a multi-lens optical camera, and an airborne lidar.

[0049] In actual use, the multi-rotor UAV flight platform can be a multi-rotor UAV flight platform such as a quadcopter, hexacopter, octocopter, etc., and this embodiment is not limited thereto. In this embodiment, a quadcopter UAV flight platform is selected. Before flight, the ground control module needs to be set up on the ground, and the preset route data is remotely transmitted to the aircraft communication radio 16 by means of wireless Bluetooth technology, and finally transmitted to the autopilot module 17, and the autopilot module 17 is responsible for controlling the flight of the entire multi-rotor UAV flight platform 1.

[0050] The multi-rotor UAV flight platform is equipped with a real-time video transmission camera to obtain real-time images and transmit them to the real-time video transmission remote control screen of the ground control module 14 through the aircraft communication radio 16 in real time; the distance sensor 18 is used for accurate distance measurement before remotely deploying the autonomous positioning image control point device 8; the aircraft communication radio 16 is used for receiving external instructions and interactive transmission of flight data.

[0051] In specific applications, in the first flight, the multi-rotor UAV flight platform 1 is used to carry the aerial photography sensor 15 to obtain the image data of large steep mountains, establish a real-life three-dimensional model of the large steep mountains, and accurately arrange the design points and avoid obstacles on the flight route and design the delivery sequence based on the real-life model; the second flight begins to carry out point-by-point delivery of the autonomous positioning image control point device 8; the multi-rotor UAV flight platform 1 is equipped with the cable retracting device 2 and the autonomous positioning image control point device 8, and flies to the sky above the preset delivery point based on RTK precision navigation. The aircraft automatically descends to 5 meters above the set altitude, and based on the distance sensor 18 and real-time image transmission video, continue to descend to 0.3 meters above the set delivery point, the ground control module 14 remotely controls the cable retracting device to accurately deliver the autonomous positioning image control point device 8 to the ground; the cable retracting device is continuously powered on during the flight, so that the magnetic suction device at the end of the cable keeps adsorbing the autonomous positioning image control point device; after flying to the designated position, according to the instructions of the ground control module, the cable retracting device slowly lengthens the cable until the autonomous positioning image control point device touches the ground; after confirming that the autonomous positioning image control point device 8 is stable, the cable adsorption is released and the cable is retracted; the delivery effect evaluation methods are: ① Real-time visual judgment; ② First The stability of random items of batch observation data is precisely determined; at this time, a complete delivery process is completed, and the base station is returned to load a new autonomous positioning image control point device 8, and the delivery is continued until all delivery is completed; after all image control points are used up, a new round of flight is started to recover the autonomous positioning image control point device 8 point by point; the multi-rotor UAV flight platform 1 is equipped with a cable retracting device 2, and flies to the sky above the preset recovery point based on RTK precision navigation. The aircraft automatically descends to 5 meters above the set altitude, and continues to descend to 0.3 meters above the set delivery point based on the distance sensor 18 and real-time image transmission video. The ground control module 14 remotely controls the aircraft to fly to the preset recovery point, and then the aircraft is automatically lowered to 5 meters above the set altitude. Based on the distance sensor 18 and the real-time image transmission video, the aircraft is automatically lowered to 0.3 meters above the set delivery point. The cable retractable device is controlled to accurately recover the autonomous positioning image control point device 8; after flying to the specified position, according to the instructions of the ground remote control, the cable retractable device slowly rotates the cable winch, and lengthens the cable until the end of the magnetic device contacts the autonomous positioning image control point device; after confirming stable contact, the magnetic device is energized to generate magnetic force to absorb the iron shell of the autonomous positioning image control point device; after successful absorption, the cable retractable device slowly shortens the cable to make the autonomous positioning image control point device leave the ground, and then carries the device back; at this time, a complete recovery process is completed, and the autonomous positioning image control point device is removed from the ground control station, and the recovery is continued until all recovery is completed.

[0052] The autopilot module in this embodiment adopts the existing unmanned aerial vehicle automatic driving equipment, which is used for automatic flight control, aerial photography operation pulse signal sending and control; in actual use, it provides the aircraft with autonomous flight according to a preset three-dimensional route.

[0053] The aircraft communication radio in this embodiment uses the signal transmission module of the reference station and rover station in the existing GNSS-RTK technology, which is used for the real-time positioning information communication between the aerial photography sensor and the ground reference station, and at the same time for integrating and transmitting the real-time video transmission and distance detection signals back, realizing the stable and efficient transmission of the data transmission, video transmission signals and positioning coordinate signals between the flight platform and the ground control system in real time.

[0054] There are two payloads on the multi-rotor UAV flight platform 1 in the present invention. ① The aerial photography sensor 15 is used to obtain a fine real-scene three-dimensional model without ground control points and is only used in the first flight. ② The cable retracting and releasing device 2 carries or retrieves an autonomous positioning ground control point device for each subsequent flight, corresponding to the layout point of each autonomous positioning ground control point device, realizing the remote and precise dropping of the autonomous positioning ground control point device by the UAV. The present invention avoids the high risk of personnel entering the site of large and steep mountains for manual layout operations, and realizes the stable placement, retrieval and re-layout of the autonomous positioning ground control point device, realizing the safe, efficient and reliable real-time continuous monitoring of large and steep mountains or landslides.

[0055] Embodiment 2: Refer to Figure 2 As shown, the difference from Embodiment 1 is that there are four cable retracting and releasing devices 2 connected to the multi-rotor UAV flight platform 1; the four cable retracting and releasing devices 2 are respectively connected to the four corners of the multi-rotor UAV flight platform 1 to ensure the balance of the connection. The retracting and releasing motor 4 is electrically connected to the ground control module 14, and the retracting and releasing motor 4 is electrically connected to the cable winch 5; the retracting and releasing motor 4 receives the control instruction of the ground control module 14 and controls the clockwise or counterclockwise rotation of the cable winch 5 to realize the retraction and release of the cable.

[0056] The magnetic attraction device 7 is connected to the cable 6 and is electrically connected to the retracting and releasing motor 4 through the cable 6. A pair of semi-circular iron rods are arranged inside the magnetic attraction device 7, and several turns of wire coils are evenly wound on the iron rods, which can generate magnetic force after being electrified; the retracting and releasing motor 4 receives the control instruction of the ground control module 14, supplies power or cuts off the power to the magnetic attraction device 7, so that the magnetic attraction device 7 generates or loses magnetic force to adsorb or release the autonomous positioning ground control point device 8 with an iron shell.

[0057] Embodiment 3: Refer to Figure 3 As shown, the difference from Embodiment 1 is that the RTK positioning module 10 receives the RTK base station information to complete the high-precision positioning of the ground control points without measurement, obtains and stores accurate position information, enables the multi-rotor UAV flight platform 1 to identify the ground control points for retrieving the ground control point device without measurement, and at the same time provides accurate observation data for the three-dimensional reconstruction of the UAV flight platform images.

[0058] The photovoltaic controller 12 is connected to the solar panel 9 and the power supply system 11 respectively, and the power supply system 11 is equipped with a battery; the photovoltaic controller 12 controls the output voltage of the solar panel 9, which can protect the battery in the power supply system 11 from being overcharged. At the same time, when the solar panel 9 is not generating electricity at night, it can also prevent the battery from backflowing. It is completely feasible for the battery to supply power to the outside while the solar energy is charging the battery. In this case, the power used by the load will first use the power of the solar cell directly, and the remaining power will be charged to the battery; on the contrary, if the power of the solar cell is insufficient, it will also draw power from the battery.

[0059] The 4G module 13 is connected to the ground control module 14 via electrical signals and transmits information. When there is a network, the 4G module 13 can connect to the 4G network, transmit data to the base station via radio waves, and then transmit it to the ground control module 14 via the Internet. When there is no network, information is transmitted via radio stations around the survey area. The 4G module 13 will also encrypt and authenticate the data to ensure data security.

[0060] Embodiment 4: refer to Figure 4 As shown, an embodiment of the present invention also provides a non-contact delivery method of an autonomous positioning image control point device in a steep mountain, comprising the following steps: Step 1: For the first flight, use the multi-rotor UAV flight platform to carry aerial photography sensors to obtain images or airborne laser radar point cloud data, build a real-life 3D model of the object or color point cloud data, and perform image control point positions and obstacle avoidance and delivery sequence design on the delivery flight route based on the slope of the real-life 3D model of the object; Step 2: For the second flight, the multi-rotor UAV flight platform is equipped with a cable retracting device and an autonomous positioning image control point device. Based on RTK precision navigation, the multi-rotor UAV flight platform automatically descends to 5 meters above the set altitude. Based on the distance sensor and real-time image transmission video, it continues to descend to 0.3 meters above the set delivery point. The ground image transmission remote control controls the cable retracting device to drop the autonomous positioning image control point device to the ground. Step 3: The cable retracting device is continuously powered on during the flight, so that the magnetic device at the end of the cable keeps adsorbing the autonomous positioning image control point device. After flying to the designated position, according to the instructions of the ground control module, the cable retracting device slowly extends the cable until the autonomous positioning image control point device touches the ground. After confirming that the autonomous positioning image control point device is stable, the cable adsorption is released and the cable is retracted; Step 4: Determine the evaluation results of the delivery effect. The delivery effect evaluation methods include rough judgment of real-time image transmission visually, or detailed judgment of the stability of random items of the first batch of observation data; Step 5: Repeat steps 2, 3 and 4, return to reload the autonomous positioning image control point device and deploy it again until all image control points are deployed and evaluated; Step 6: After confirming that the measurement task is completed, reset the route to realize the route design of completing the recovery task in sequence by recovering the autonomous positioning image control point devices one by one; Step 7: The third flight, with the help of the multi-rotor UAV flight platform to mount the cable retracting device, based on RTK precision navigation to fly to the preset release point, the multi-rotor UAV flight platform automatically lowered to 5 meters above the set altitude, based on the distance sensor and real-time image transmission video, continue to lower to 0.3 meters above the set release point, ready to use the ground image transmission remote control to control the cable retracting device to recover the autonomous positioning image control point device; Step 8: After flying to the designated location, according to the instructions of the ground remote control, the cable retracting device slowly rotates the cable winch, and the cable is extended until the magnetic device at the end contacts the autonomous positioning image control point device. After confirming stable contact, the magnetic device is powered on to generate magnetic force to adsorb the iron shell of the autonomous positioning image control point device. After confirming that the adsorption is successful, the cable retracting device slowly retracts the cable to make the autonomous positioning image control point device leave the ground, and then the multi-rotor UAV flight platform returns with the autonomous positioning image control point device; Step 9: Repeat steps 7 and 8, return to land and unload the recovered autonomous positioning image control point device, and take off again to recover the next autonomous positioning image control point device until all autonomous positioning image control point devices are recovered.

[0061] In actual use, the present invention determines the reasonable layout of image control points and delivery routes through the real-life three-dimensional model, and the main factors to be considered are: obstacle avoidance on the route, image control point location, and image control point distribution density. With the help of RTK real-time navigation technology, real-time image transmission technology, and distance sensors, accurate flight and fixed-point precision delivery are achieved. The cable retracting device realizes the stable placement and recovery of the autonomous positioning image control point device to ensure the stability of the image control point. The autonomous positioning image control point device is equipped with RTK modules, 4G modules, solar panels, etc., which can autonomously locate and use solar energy for power supply. The entire device and the invention method improve the accuracy of surveying and mapping, and can provide more accurate reference data around the clock. At the same time, it has the characteristics of environmental protection and low cost. Compared with traditional spraying image control points, it can also realize the transfer of positions as needed at different times.

[0062] Embodiment five: The difference between this embodiment and the fourth embodiment is that step one also includes the following sub-steps: Step 101: Set up known points at the ground GNSS reference station and record static data earlier than the airborne RTK of the multi-rotor UAV flight platform is powered on. The epoch sampling frequency of the ground base station is not less than 1 Hz, and not less than 5 Hz when the payload is an airborne lidar; Step 102: Refer to the range of the measurement object to be measured and the publicly available DEM data to conduct three-dimensional flight line design, and obtain aerial photography data with qualified heading overlap, side overlap, and ground resolution; Step 103: The flight route designed in Step 102 is used to control the multi-rotor UAV flight platform to fly autonomously by the autopilot, and an aerial camera sensor is carried during flight for automatic aerial photography. The horizontal flight speed of the multi-rotor UAV flight platform is less than or equal to 20 m / s; Step 104: After landing after the flight, obtain the real-time kinematic differential RTK data and aerial images, sort them according to the electronic coupling relationship, and calculate the coordinate values of the exterior orientation line elements of the exposure points in the local coordinate system in combination with the local conversion relationship of the survey area. The aerial photography ends; Step 105: Conduct aerial triangulation calculation according to the precise camera parameters and the exterior orientation line element file of the exposure points. Set the accurate observation weights of the exterior orientation line elements of the exposure points in the aerial triangulation. The adjustment model prohibits adjusting and correcting the camera parameters to ensure that the three interior orientation elements do not participate in the adjustment calculation. According to the beam method constraint conditions, adjust the final values of the exterior orientation line elements of the exposure points to complete the aerial triangulation calculation without ground control points; Step 106: Use publicly available real-scene three-dimensional modeling software in the industry to quickly output a real-scene three-dimensional model in OSGB format or a color point cloud three-dimensional model of the steep mountain area; Step 107: Conduct geological remote sensing interpretation and slope calculation in the real-scene three-dimensional model to determine the approximate positions of the ground control points that need to be laid out subsequently. On this basis, select points with a slope less than 30 degrees, and the terrain is flat within 2 square meters around and open to the sky without obstruction, ensuring that the requirements of the subsequent measurement plan can be met. Finally, output the coordinate table of the final placement points of the self-positioning ground control point device.

[0063] In actual use, adopting the technical solution in this embodiment can achieve high-precision real-scene three-dimensional modeling without control, select the layout positions of the ground control points more accurately, and facilitate outputting the coordinates of the ground control points that can be stably and remotely placed.

[0064] Embodiment Six: The difference between this embodiment and Embodiment Four is that Step Two further includes the following sub-steps: Step 201: According to the coordinate table of the final placement points output in Step 107, use the flight control software of the video transmission remote controller to automatically lay out the safe placement flight route; Step 202: Perform centimeter-level navigation flight based on the RTK differential module of the autonomous positioning image control point device, fly at high altitude to above the dropping point; the aircraft autonomously reduces the flight altitude to 5 meters above the ground elevation of the dropping point, and based on the distance sensor and real-time video transmission, continues to reduce the altitude to 0.3 meters above the set dropping point; Step 203: The ground video transmission remote controller controls the cable retracting and deploying device to place the autonomous positioning image control point device on the ground.

[0065] In actual use, adopting this technical solution can achieve centimeter-level precise flight and autonomous altitude reduction, and accurately deploy the device in combination with real-time video transmission and real-time distance data.

[0066] Embodiment Seven: The difference between this embodiment and Embodiment Four is that Step Three further includes the following sub-steps: Step 301: Control the motor of the cable retracting and deploying device to operate and rotate the cable winch, so that the cable lowers the autonomous positioning image control point device to the ground; Step 302: After the autonomous positioning image control point device stably contacts the ground, control the motor to stop powering the magnetic adsorption device at the end of the cable, and release the adsorption of the magnetic adsorption device on the autonomous positioning image control point device; Step 303: After determining the position of the recoverable image control point, control the motor of the cable retracting and deploying device to operate and rotate the cable winch, so that the cable is recovered and wound on the cable winch.

[0067] In actual use, adopting the technical solution in this embodiment can ensure the stable placement of the autonomous positioning image control point device, greatly reduce the random data error caused by equipment instability, and improve the reliability of the data.

[0068] Embodiment Eight: The difference between this embodiment and Embodiment Four is that Step Seven further includes the following sub-steps: Step 701: According to the recovery sequence determined in Step Six, recover the autonomous positioning image control point device along the dropping route; Step 702: Perform centimeter-level navigation flight based on the on-board RTK differential module, fly at high altitude to above the recovery point; the aircraft autonomously reduces the flight altitude to 5 meters above the ground elevation of the recovery point, and based on the distance sensor and real-time video transmission, continues to reduce the altitude to 0.3 meters above the set recovery point; Step 703: The ground video transmission remote controller controls the multi-rotor UAV flight platform equipped with a cable retracting and deploying device to recover the autonomous positioning image control point device.

[0069] In actual use, adopting the technical solution in this embodiment can achieve accurate positioning and flight according to the collected data, and accurately recover the autonomous positioning image control point device in combination with real-time video transmission and real-time distance data.

[0070] Example Nine: The difference between this embodiment and Embodiment Four is that Step Eight further includes the following sub-steps: Step 801: Control the motor of the cable winding and unwinding device to operate and rotate the cable winch, so that the cable is lowered and the magnetic adsorption device at the end contacts the iron shell of the autonomous positioning image control point device; Step 802: After the magnetic adsorption device at the end of the cable stably contacts the autonomous positioning image control point device, control the motor to start continuously powering the magnetic adsorption device at the end of the cable to complete the adsorption of the magnetic adsorption device to the autonomous positioning image control point device; Step 803: Control the motor of the cable winding and unwinding device to operate and rotate the cable winch to pull up the autonomous positioning image control point device by winding the cable.

[0071] In actual use, adopting the technical solution of the present invention can ensure the reliable recovery of the autonomous positioning image control point device, improve the recovery efficiency, and effectively reduce the time required for the recovery device.

[0072] Example Ten: The difference between this embodiment and Embodiment Four is that the step of fine evaluation of the delivery effect in Step Four further includes that the stability method of the random item of the first batch of observation data is to determine the trajectory equation according to the continuous observation data by using the publicly available Kalman filtering algorithm, calculate a series of random items, evaluate the accuracy according to the observation data, analyze the significance of the change amount included in the random items, and then determine its own stability.

[0073] In actual use, adopting the technical solution in this embodiment, after the remote visual rough evaluation result in the real-time video transmission picture is stable, after the device is static for 10 minutes, the first batch of observation data can be remotely received for calculation and analysis of the stability of the data random items. For example, when using the method of the present invention in an emergency monitoring project, if the static time of the device exceeds 2 hours, it can be forcibly determined as stable and can be used for emergency monitoring.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0075] Without conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. The specific combination situations are not elaborated one by one here.

[0076] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0077] As described above, these are only the preferred embodiments of the present invention. The present invention will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A non-contact delivery system for autonomously positioning image control point devices in steep mountains, characterized in that: include: The multi-rotor UAV flight platform is used to receive control instructions and perform flight movements according to the control instructions; A cable retracting device, fixedly connected to the multi-rotor UAV flight platform; Autonomous positioning image control point device, which is captured or released by the multi-rotor UAV flight platform through the cable retracting device; The ground control module is connected to the multi-rotor UAV flight platform for communication, and is used to send control instructions to the multi-rotor UAV flight platform to control the multi-rotor UAV flight platform to complete the delivery and recovery of the autonomous positioning image control point device; The cable retracting device completes the deployment or recovery of the autonomous positioning image control point device by means of magnetic attraction and the retraction of the cable.

2. The contactless delivery system according to claim 1, characterized in that: The cable retracting and releasing device includes a bracket, a retracting and releasing motor, a cable winch, a cable and a magnetic suction device; A bracket, one end of which is fixedly connected to the multi-rotor UAV flight platform; The retractable and discharging motor is fixed on the bracket at one end away from the multi-rotor UAV flight platform and is electrically connected to the cable winch. The retractable and discharging motor includes a power module, a wireless communication module and a retractable and discharging controller; The cable winch is fixedly connected to the receiving and discharging motor. A cable is wound around the cable winch. One end of the cable is fixed to the receiving and discharging motor and electrically connected to the receiving and discharging motor. A magnetic attraction device is installed at the other end. The magnetic device is connected to the end of the cable and is electrically connected to the transmitting and receiving motor through the cable.

3. The contactless delivery system according to claim 1, characterized in that: The autonomous positioning image control point device is adsorbed by a magnetic device and moves with the multi-rotor UAV flight platform; The autonomous positioning image control point device includes solar panels, RTK positioning modules, power supply systems, photovoltaic controllers and 4G modules; Solar panels, connected to the autonomous positioning image control point device; RTK positioning module, connected to the autonomous positioning image control point device; A power supply system is connected to the autonomous positioning image control point device, and a storage battery is provided in the power supply system; A photovoltaic controller is fixedly connected to the autonomous positioning image control point device and is electrically connected to the solar panel; 4G module, connected to the autonomous positioning image control point device; Among them, the RTK positioning module, photovoltaic controller and 4G module are electrically connected to the power supply system; the RTK positioning module, 4G module and multi-rotor UAV flight platform are all communicatively connected to the ground control module.

4. The contactless delivery system according to claim 1, characterized in that: The multi-rotor UAV flight platform includes an aerial photography sensor, an aircraft communication radio, an autopilot module, and a distance sensor; Aerial photography sensors can be mounted on multi-rotor UAV flight platforms; An aircraft communication radio, which is connected to the multi-rotor UAV flight platform; The autopilot module is connected to the multi-rotor UAV flight platform to provide GNSS and RTK functions. The autopilot module is connected to the aircraft communication radio station electrical signal, and the autopilot module is connected to the aerial photography sensor; Distance sensor, which can be connected to the multi-rotor UAV flight platform.

5. The contactless delivery system according to claim 1 or 2, characterized in that: The multi-rotor UAV flight platform is a quad-rotor flight platform, and the number of the retractable cable devices is four; the four retractable cable devices are respectively connected to the four corners of the multi-rotor UAV flight platform to ensure the balance of the connection.

6. The contactless delivery system according to claim 2, characterized in that: The retractable motor is connected to the ground control module by electrical signals, and the retractable motor is electrically connected to the cable winch; the retractable motor receives the control command of the ground control module to control the cable winch to rotate clockwise or counterclockwise to realize the retraction and release of the cable.

7. The contactless delivery system according to claim 2, characterized in that: At least one pair of semicircular iron rods are arranged inside the magnetic attraction device, and a plurality of turns of conductive wires are evenly wound on the semicircular iron rods, and the conductive wires generate magnetic force after being energized; The transceiver receives control from the ground control module to supply power to or cut off power to the magnetic device, so that the magnetic device generates magnetic force or loses magnetic force, and then absorbs or puts down the autonomous positioning image control point device with an iron shell.

8. The contactless delivery system according to claim 3, characterized in that: The RTK positioning module is used to receive RTK base station information to complete high-precision positioning of image control points without measurement, obtain accurate position information and store it, so that the multi-rotor UAV flight platform can identify the position of image control points and complete the measurement-free recovery of the autonomous positioning image control point device. At the same time, it provides accurate observation data for the three-dimensional reconstruction of the multi-rotor UAV flight platform image.

9. The contactless delivery system according to claim 3, characterized in that: The photovoltaic controller is connected to the solar panel and the power supply system respectively. The photovoltaic controller is used to control the output voltage of the solar panel to protect the battery in the power supply system from being overcharged; The photovoltaic controller is also used to prevent the backflow of electricity from the battery when the solar panel is not generating electricity; The photovoltaic controller is also used to control the battery to supply power to the outside when the solar panel is charging the battery. The power used by the load is preferentially called upon the energy stored in the solar cell, and the remaining power is stored in the battery. When it is detected that the solar cell is running low on power, power is dispatched from the battery to the load at the same time.

10. The contactless delivery system according to claim 3, characterized in that: The 4G module is connected to the ground control module by electrical signals and transmits information; The 4G module is used to directly connect to the 4G communication network when it detects that the communication network is in a normal state, and transmit the data to the base station through the 4G communication network, and then transmit it to the ground control module through the Internet; The 4G module is used to transmit information through radio stations around the measurement area when it detects that the communication network is in an abnormal state; The 4G module is also used to encrypt and authenticate data.

11. The contactless delivery system according to claim 1, characterized in that: The ground control module consists of a real-time image transmission screen and a control handle, and is connected to the aircraft's communication radio via wireless signals.

12. The contactless delivery system according to claim 4, characterized in that: The aerial photography sensor includes at least one of a single-lens optical camera, a multi-lens optical camera and an airborne laser radar.

13. A non-contact delivery method for autonomously positioning an image control point device in a steep mountain, applied to the non-contact delivery system according to any one of claims 1 to 12, characterized in that: include: Step 1: For the first flight, use the multi-rotor UAV flight platform to carry aerial photography sensors to obtain images or airborne laser radar point cloud data, build a real-life 3D model of the object or color point cloud data, and perform image control point positions and obstacle avoidance and delivery sequence design on the delivery flight route based on the slope of the real-life 3D model of the object; Step 2: For the second flight, the multi-rotor UAV flight platform is equipped with a cable retracting device and an autonomous positioning image control point device. Based on RTK precision navigation, the multi-rotor UAV flight platform automatically descends to 5 meters above the set altitude. Based on the distance sensor and real-time image transmission video, it continues to descend to 0.3 meters above the set delivery point. The ground image transmission remote control controls the cable retracting device to drop the autonomous positioning image control point device to the ground. Step 3: The cable retracting device is continuously powered on during the flight, so that the magnetic device at the end of the cable keeps adsorbing the autonomous positioning image control point device. After flying to the designated position, according to the instructions of the ground control module, the cable retracting device slowly extends the cable until the autonomous positioning image control point device touches the ground. After confirming that the autonomous positioning image control point device is stable, the cable adsorption is released and the cable is retracted; Step 4: Determine the evaluation results of the delivery effect. The delivery effect evaluation methods include rough judgment of real-time image transmission visually, or detailed judgment of the stability of random items of the first batch of observation data; Step 5: Repeat steps 2, 3 and 4, return to reload the autonomous positioning image control point device and deploy it again until all image control points are deployed and evaluated; Step 6: After confirming that the measurement task is completed, reset the route to realize the route design of completing the recovery task in sequence by recovering the autonomous positioning image control point devices one by one; Step 7: The third flight, with the help of the multi-rotor UAV flight platform to mount the cable retracting device, based on RTK precision navigation to fly to the preset release point, the multi-rotor UAV flight platform automatically lowered to 5 meters above the set altitude, based on the distance sensor and real-time image transmission video, continue to lower to 0.3 meters above the set release point, ready to use the ground image transmission remote control to control the cable retracting device to recover the autonomous positioning image control point device; Step 8: After flying to the designated location, according to the instructions of the ground remote control, the cable retracting device slowly rotates the cable winch, and the cable is extended until the magnetic device at the end contacts the autonomous positioning image control point device. After confirming stable contact, the magnetic device is powered on to generate magnetic force to adsorb the iron shell of the autonomous positioning image control point device. After confirming that the adsorption is successful, the cable retracting device slowly retracts the cable to make the autonomous positioning image control point device leave the ground, and then the multi-rotor UAV flight platform returns with the autonomous positioning image control point device; Step 9: Repeat steps 7 and 8, return to land and unload the recovered autonomous positioning image control point device, and take off again to recover the next autonomous positioning image control point device until all autonomous positioning image control point devices are recovered.

14. The non-contact delivery method according to claim 13, characterized in that: Step one includes: Step 101: The ground GNSS base station sets up known points and records static data before the airborne RTK of the multi-rotor UAV flight platform is turned on. The epoch sampling frequency of the ground base station is not less than 1 Hz, and when the payload is an airborne laser radar, it is not less than 5 Hz; Step 102: Design a three-dimensional route by referring to the required measurement object range and the public DEM data, and obtain aerial photography data with qualified heading overlap, lateral overlap and ground resolution; Step 103: The multi-rotor UAV flight platform autonomously flies the flight route designed in step 102 under the control of the autopilot, and the multi-rotor UAV flight platform carries out automatic aerial photography with an aerial photography sensor during the flight, and the level flight speed of the multi-rotor UAV flight platform is less than or equal to 20 m / s; Step 104: After the flight is completed, the aircraft lands and the acquired real-time dynamic differential RTK data and aerial photography images are sorted out according to the electronic coupling relationship. The coordinate values ​​of the elements of the external orientation line of the exposure point in the local coordinate system are calculated in combination with the local transformation relationship of the survey area, and the aerial photography is completed. Step 105: Perform aerial triangulation calculation according to the precise camera parameters and the exposure point exterior orientation line element file. The aerial triangulation sets the accurate observation weights of the exposure point exterior orientation line elements. The adjustment model prohibits the adjustment correction of camera parameters to ensure that the three interior orientation elements do not participate in the adjustment calculation. According to the bundle method constraints, the final values ​​of the exposure point exterior orientation line elements are adjusted to complete the aerial triangulation calculation without image control points. Step 106: using industry-disclosed real-scene 3D modeling software to quickly output a real-scene 3D model of a steep mountain in an OSGB format or a color point cloud 3D model; Step 107: Perform geological remote sensing interpretation and slope calculation in the real-life 3D model to determine the approximate locations where image control points need to be deployed later. On this basis, select points with a slope of less than 30 degrees, a flat terrain of 2 square meters around, and open and unobstructed access to the sky to ensure that they can meet the requirements of the subsequent measurement plan. Finally, output the coordinate table of the final deployment points of the autonomous positioning image control point device.

15. The non-contact delivery method according to claim 14, characterized in that: Step 2 includes: Step 201: According to the final delivery point coordinate table outputted in step 107, the flight control software of the image transmission remote controller is used to automatically arrange a safe delivery route; Step 202: Perform centimeter-level navigation flight based on the RTK differential module of the autonomous positioning image control point device, and fly at high altitude to the air above the drop point; the aircraft autonomously lowers the altitude to 5 meters above the ground elevation of the device from the drop point, and continues to lower the altitude to 0.3 meters above the set drop point based on the distance sensor and real-time image transmission video; Step 203: The ground image transmission remote controller controls the cable retracting device to place the autonomous positioning image control point device on the ground.

16. The non-contact delivery method according to claim 13, characterized in that: Step three includes: Step 301: Control the motor of the cable retracting device to rotate the cable winch, so that the cable is lowered to the ground by the autonomous positioning image control point device; Step 302: After the autonomous positioning image control point device stably contacts the ground, the motor is controlled to stop supplying power to the magnetic device at the end of the cable, so as to release the magnetic device from adsorbing the autonomous positioning image control point device; Step 303: After the position of the recyclable image control point is determined, the motor of the cable retracting and releasing device is controlled to rotate the cable winch, so that the cable is retracted and wound on the cable winch.

17. The non-contact delivery method according to claim 13, characterized in that: Step 4 includes: After each autonomous positioning image control point device is deployed, the multi-rotor UAV flight platform is controlled to hover for 1 minute to check whether the autonomous positioning image control point device is stable based on the real-time image transmission signal on the image transmission remote control screen; at the same time, based on the first batch of monitoring data sent back by the autonomous positioning image control point device, a random item stability analysis is performed to make a detailed judgment.

18. The non-contact delivery method according to claim 13, characterized in that: Step seven includes: Step 701: Recover the autonomous positioning image control point device according to the recovery order determined in step 6 and according to the delivery route; Step 702: Perform centimeter-level navigation flight based on the onboard RTK differential module, and fly high to the recovery point; the aircraft autonomously lowers its altitude to 5 meters above the ground elevation of the recovery point, and continues to lower its altitude to 0.3 meters above the set recovery point based on the distance sensor and real-time image transmission video; Step 703: The ground image transmission remote controller controls the multi-rotor UAV flight platform equipped with a cable retracting device to retract the autonomous positioning image control point device.

19. The non-contact delivery method according to claim 13, characterized in that: Step eight includes: Step 801: Control the motor of the cable retracting device to rotate the cable winch, so that the cable is lowered and the end magnetic device contacts the iron shell of the autonomous positioning image control point device; Step 802: After the magnetic device at the end of the cable stably contacts the autonomous positioning image control point device, the control motor starts to continuously supply power to the magnetic device at the end of the cable, so that the magnetic device adsorbs the autonomous positioning image control point device; Step 803: Control the motor of the cable retracting device to rotate the cable winch, so that the cable is retracted and pulled up to form an autonomous positioning image control point device.

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