Unmanned aerial vehicle photogrammetry variable control point marker plate and control method thereof

Abstract

The application discloses a variable control point mark board for unmanned aerial vehicle photogrammetry and a control method thereof, and relates to the technical field of unmanned aerial vehicle photogrammetry. The mark board comprises a base plate which bears various functional areas of the mark board. The base plate is provided with a control point working area and a coding working area. The control point working area comprises a control point display area and a control point control area. The control point display area is used for displaying a control point image, and the control point control area is used for controlling the display content of the control point display area. In the application, the variable control point mark board has simple structure, low cost and low requirement for the working environment. The size and shape of the control point can be set according to different altitudes of the unmanned aerial vehicle, the determination precision of the control point is improved, different colors can be set to form a sharp contrast with the field environment, the control point is easy to be marked in the later stage, and the field operation is simple.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) photogrammetry technology, and in particular to a variable image control point marker board for UAV photogrammetry and its control method. Background Technology

[0002] With the development of UAV technology, UAV photogrammetry is being used more and more widely in various surveying fields. It boasts advantages such as mobility, efficiency, speed, and low operating costs, making it particularly suitable for acquiring high-precision image data in small areas and challenging surveying locations. In UAV photogrammetry, the role of image control points (ARPs) is crucial. They form the basis for subsequent data processing and accuracy analysis, correcting distortions in aerial imagery and ensuring consistency between the resulting data and the actual ground coordinate system. Therefore, the sharpness and accuracy of ARPs directly impact the achievement of the required measurement precision.

[0003] Users need to set up several image control points (ADCs) in the area to be measured. In related technologies, users generally complete the setup of ADCs by spraying pre-set marks on hardened ground. However, these technologies suffer from irregularities in the manually sprayed marks, inconsistent colors and sizes, uneven spraying, and the lack of coding for the ADCs, which makes them easy to mix up or misuse, leading to reduced measurement accuracy or errors. Summary of the Invention

[0004] To address the problems of irregular, inconsistent in color, size, and uneven spraying of manually painted control points, as well as the lack of coding, which makes control points easy to confuse or misidentify and leads to reduced measurement accuracy or errors, this invention adopts the following technical solution: A variable image control point marker board for UAV photogrammetry includes a base plate that carries the various functional areas of the entire marker board, and the base plate is provided with an image control point working area and an encoding working area. The image control point working area includes an image control point display area and an image control point control area. The image control point display area is used to display image control point images, and the image control point control area is used to control the display content of the image control point display area. The image control point display area is equipped with a number of image control point display LED beads. The encoding working area includes an encoding display area and an encoding control area. The encoding display area includes a left encoding display area and a right encoding display area. The left and right encoding display areas are used to display the encoding of the signboard. The encoding control area is used to control the encoding content of the left and right encoding display areas. Each of the left and right encoding display areas is equipped with a number of encoding display LED beads.

[0005] As described above, a variable control point marker board for UAV photogrammetry includes a control point control area comprising a control point size selection button, a control point color selection button, and a control point shape selection button. The control point size selection button controls the size of the control point image displayed in the control point display area, the control point color selection button controls the color of the control point image displayed in the control point display area, and the control point shape selection button controls the shape of the control point image displayed in the control point display area.

[0006] As described above, in a UAV photogrammetry variable image control point marker board, the encoding control area includes encoding adjustment buttons, which include a left encoding adjustment button and a right encoding adjustment button. The left encoding adjustment button is used to control the encoding content displayed in the left encoding display area, and the right encoding adjustment button is used to control the encoding content displayed in the right encoding display area. The encoding content displayed in the left encoding display area and the right encoding display area are combined to form a unique number for the image control point marker board.

[0007] As described above, a variable image control point marker board for UAV photogrammetry includes an image control point display LED bead and an encoding display LED bead, all encased in a synchronous display mechanism. The synchronous display mechanism includes a frame with several through slots, and a display mechanism is disposed within each slot. The display mechanism includes a transparent box containing several magnetic balls, each magnetic ball having two poles coated with different colors. An iron sheet is disposed at the bottom of the transparent box, and electromagnets are fixedly connected to both sides of the bottom of the iron sheet.

[0008] As described above, a variable image control point marker board for UAV photogrammetry includes a base plate with a built-in power module and a controller. The controller has built-in programs for controlling the on / off state of LED beads and the display state of a synchronous display mechanism. A circuit board is mounted on the top surface of the base plate, and the circuit board has a built-in driving circuit, which includes an LED driving circuit and a synchronous display mechanism driving circuit. The LED driving circuit receives control signals from the controller and controls the on / off state of the LED beads. The synchronous display mechanism driving circuit receives control signals from the controller and controls the display state of the synchronous display mechanism. A panel is covered on the top surface of the circuit board, and a power module button is mounted on the surface of the panel. The power module button is electrically connected to the power module, and the controller is electrically connected to the power module button.

[0009] As described above, a variable image control point marker board for UAV photogrammetry has a circular level mounted on the surface of the substrate. The circular level is used to indicate the horizontal state of the image control point marker board. Several retractable bottom screws are mounted on the bottom of the substrate. The retractable bottom screws have a screw extension and retraction function and are used to adjust the horizontal state of the image control point marker board.

[0010] As described above, a variable image control point marker board for UAV photogrammetry has a light-transmitting panel covering the top surface of the panel, one side of the light-transmitting panel being hinged to the panel, and a groove being formed at the bottom of the light-transmitting panel.

[0011] The control method for a variable image control point marker board in UAV photogrammetry, as described above, includes the following steps: Step 1: Turn on the power module; Step 2: Configure the control point display; Step 3: Adjust the encoding content; Step 4: Check the horizontal level; Step 5: Power off the power module and perform maintenance.

[0012] The control method for the variable image control point marker board and its control method for UAV photogrammetry, as described above, further includes the following steps in step two: Users can select easily identifiable control point shapes using the control point shape selection button, thereby improving the accuracy and efficiency of measurements. Users can select the appropriate image control point color for the current ambient light using the image control point color selection button to ensure that the drone can accurately capture the image control point; Users can adjust the size of the control points in the control point display area using the control point size selection button to adapt to different flight altitude requirements of the drone.

[0013] When the image control point size, color, and shape selection buttons are pressed, the controller synchronously transmits adjustment signals to the synchronous display mechanism. Upon receiving the adjustment signals, the synchronous display mechanism energizes the electromagnet, generating magnetism. Because the iron sheet is in contact with the electromagnet, it is magnetized by the electromagnet's magnetic field, temporarily exhibiting magnetism. Following the law of magnetic pole repulsion (like poles repel, unlike poles attract), the iron sheet attracts the end of the magnetic ball corresponding to its magnetic pole. Since the magnetic poles of the magnetic ball are painted, controlling the direction of the electromagnet's poles allows control over which colored side of the magnetic ball faces upwards, thus achieving a specific color display. By using several display mechanisms in combination, different colors can be displayed synchronously. Multiple synchronous display mechanisms working together can combine to form a pattern identical to the pattern displayed by the LED beads. The control method for the variable image control point marker board and its control method for UAV photogrammetry, as described above, further includes the following steps in step three: Users can use the coding adjustment buttons on the left to set the coding content in the coding display area on the left; Users can use the coding adjustment buttons on the right to set the coding content in the coding display area on the right, which together with the coding on the left constitutes the unique number of the signboard. When the left or right encoding adjustment button is pressed, the controller synchronously transmits an adjustment signal to the synchronous display mechanism. After receiving the adjustment signal from the controller, the synchronous display mechanism energizes the electromagnet and generates magnetism. Since the iron sheet is in contact with the electromagnet, it is magnetized by the electromagnet's magnetic field, thus temporarily exhibiting magnetism. The iron sheet follows the law of magnetic pole interaction, that is, like poles repel and unlike poles attract. Thus, the end of the magnetic ball corresponding to the magnetic pole is attracted by the iron sheet. Since the magnetic pole of the magnetic ball is painted with color, by controlling the direction of the electromagnet's magnetic pole, it is possible to control which colored side of the magnetic ball faces upward, thereby achieving a specific color display. By using several synchronous display mechanisms in combination, they can be combined to form the same encoded content as the LED light beads.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the variable control point marker board has a simple structure, is easy to manufacture, has low cost, and low requirements for the working environment. The size and shape of the control points can be set according to the different flight altitudes of the UAV, improving the accuracy of control point measurement. Different colors can be set to cope with different field environments, forming a sharp contrast with the field environment, making it easy to mark points later. Field operation is simple. Users only need to use a few buttons to easily set the display content and encoding content of the control points, which is not easy to confuse or make mistakes, improving measurement accuracy, reducing workload, increasing work efficiency, and can be reused, which can reduce the spraying of traditional control point paint, making it more environmentally friendly.

[0015] 2. In this invention, the design of the circular level and the retractable bottom screws allows the marker plate to be easily adjusted to a horizontal state, avoiding measurement errors caused by unevenness. These designs not only improve the stability and reliability of the marker plate but also ensure the accuracy and consistency of the measurement data.

[0016] 3. In this invention, the signboard uses high-quality LED beads and a robust and durable substrate material, ensuring its long-term stable operation. At the same time, the translucent panel design not only protects the internal electronic components but also makes the entire signboard more aesthetically pleasing.

[0017] 4. The control method of this invention clearly defines the control steps. Through an orderly arrangement of steps, the control method ensures the accuracy and reliability of the measurement. Including the leveling check as the fourth step further enhances the stability and reliability of the measurement. Checking the leveling status after completing the basic setup and adjustment of the signboard ensures that the signboard remains stable during the measurement process, avoiding measurement deviations caused by physical interference. This step demonstrates an emphasis on measurement details.

[0018] 5. In this invention, even without power interruption or when the LED beads are not working, the synchronous display mechanism can maintain the display of image control points and codes. Specifically, when the iron sheet is temporarily magnetized by the electromagnet, the magnetic balls and the iron sheet are attracted by opposite poles and repelled by like poles, thus achieving a consistent color on the surface of the magnetic balls facing upwards. Several magnetic balls can form the pattern of image control points. When the image control point marker board is de-energized, the LED beads turn off, and the information displayed by the LED beads disappears. However, because the magnetic balls themselves are magnetic, even if the iron sheet is not temporarily magnetized by the electromagnet, the magnetic balls will still be attracted to the iron sheet and will not easily rotate. Therefore, the pattern and color displayed by the synchronous display mechanism will continue to be maintained, ensuring the long-term retention of information and avoiding the loss of image control point function once the image control point marker board is de-energized, thereby improving the stability and reliability of measurement data.

[0019] In summary, this invention solves the problems of existing image control points having irregular, inconsistent colors, inconsistent sizes, uneven spraying, and no coding, which makes them easy to mix up or misidentify, leading to reduced measurement accuracy or errors. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a top view of a variable image control point marker board for UAV photogrammetry according to the present invention; Figure 2 This is a longitudinal sectional view of a variable image control point marker board for UAV photogrammetry according to the present invention; Figure 3 This is a front view of a variable image control point marker board for UAV photogrammetry according to the present invention; Figure 4 This is a rear view of a variable image control point marker board for UAV photogrammetry according to the present invention.

[0021] Figure 5 This is a cross-sectional view of an information retention mechanism for a variable image control point marker board for UAV photogrammetry according to the present invention. Figure 6This is a schematic diagram of the synchronous display mechanism of a variable image control point marker board for UAV photogrammetry according to the present invention; Figure 7 This is a cross-sectional view of the synchronous display mechanism of a variable image control point marker board for UAV photogrammetry according to the present invention. Figure 8 This is a schematic diagram of the internal structure of the synchronous display mechanism of a variable image control point marker board for UAV photogrammetry according to the present invention. Figure 9 This is a schematic diagram of the frame structure of a variable image control point marker board for UAV photogrammetry according to the present invention; Figure 10 for Figure 1 A magnified structural diagram of point A in the middle; Figure 11 for Figure 1 A magnified structural diagram of section B. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1 to 4 , Figures 6 to 11 As shown, the present invention provides a variable image control point marker board for UAV photogrammetry, including a base plate 1 that carries the various functional areas of the entire marker board. The base plate 1 is 50cm×50cm in size and 0.5cm thick. The base plate 1 is provided with an image control point working area 101 and an encoding working area 102.

[0024] Optionally, in some embodiments, the sign panel is made of carbon fiber, which is a high-strength, low-density material. Using carbon fiber as the material of the substrate 1 can significantly reduce the overall weight of the sign panel. Moreover, carbon fiber has excellent mechanical properties and can effectively resist physical damage that may be encountered during outdoor use, such as collisions and scratches, ensuring the stability and accuracy of the sign panel under long-term use.

[0025] The image control point working area 101 includes an image control point display area 2 and an image control point control area 16. The image control point display area 2 is located in the upper left corner of the substrate 1 and has a size of 40cm×40cm. The image control point display area 2 is used to display image control point images, and the image control point control area 16 is used to control the display content of the image control point display area 2.

[0026] The coding work area 102 includes a coding display area and a coding control area 17. The coding display area includes a left coding display area 7 and a right coding display area 8. The size of the left coding display area 7 and the right coding display area 8 is 10cm×10cm. The left coding display area 7 and the right coding display area 8 are used to display the coding of the signboard. The coding control area 17 is used to control the coding content of the left coding display area 7 and the right coding display area 8.

[0027] In the control point working area 101, the control point display area 2 is used to clearly display the image of the control point. Users can adjust the displayed content of the control points through the operation interface in the control point control area 16. Users can select different control point sizes to adapt to measurement needs of different distances and resolutions; select the color of the control points to make them more visible under specific ambient lighting conditions; and select the shape of the control points to improve their recognition in the image. These adjustments are transmitted in real time to the control point display area 2 through the control point control area 16, causing it to update the displayed content immediately.

[0028] In the coding work area 102, the left coding display area 7 and the right coding display area 8 are used to display the coding information of the signboards. This coding information is used for drone identification and positioning. Users can set these coding contents through the coding control area 17. The coding can be a combination of numbers, letters, or symbols to uniquely identify each signboard. Once the coding is set, it will be immediately displayed in the left coding display area 7 and the right coding display area 8 for drone capture and identification.

[0029] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the image control point display area 2 is equipped with a plurality of image control point display LED beads 3, which are arranged in a matrix according to the rules of horizontal and vertical directions. The left coding display area 7 and the right coding display area 8 are both equipped with a plurality of coding display LED beads 9, which are arranged in a matrix according to the rules of horizontal and vertical directions.

[0030] The image control point display LED bead 3 and the encoding display LED bead 9 are equipped with three LED chips, and the three LED chips can emit light of different colors respectively.

[0031] The image control point display area 2 and the encoding display area, including the left encoding display area 7 and the right encoding display area 8, are the core components of the UAV photogrammetry variable image control point marker board. Both areas utilize LED arrays for dynamic display. In image control point display area 2, several image control point display LEDs 3 arranged in a matrix can quickly change their on / off state, emission color, and flashing frequency according to control commands, thereby generating and displaying different image control point images. The high brightness and fast response characteristics of these LEDs ensure clear visibility of the image control points under complex environmental conditions. In the encoding display area, the encoding display LEDs 9 in the left encoding display area 7 and the right encoding display area 8 operate on the same principle. These LEDs are arranged in a matrix, and each LED can be independently controlled to maintain its on / off state. The user sets specific encoding content through the encoding control area 17, and the control system converts this encoding content into the on / off mode of the LEDs and sends it to the corresponding encoding display LEDs 9. These LEDs emit light according to the received mode, thereby displaying specific encoded information.

[0032] Optionally, in some embodiments, a liquid crystal display screen is installed in the control point display area 2 instead of a number of LED beads.

[0033] Optionally, in some embodiments, liquid crystal displays are installed in the left coding display area 7 and the right coding display area 8 instead of a number of LED beads.

[0034] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the control point control area 16 includes a control point size selection button 4, a control point color selection button 5, and a control point shape selection button 6. The control point size selection button 4 is used to control the size of the control point image displayed in the control point display area 2, the control point color selection button 5 is used to control the color of the control point image displayed in the control point display area 2, and the control point shape selection button 6 is used to control the shape of the control point image displayed in the control point display area 2.

[0035] Optionally, in some embodiments, there is one control point size selection button 4, one control point color selection button 5, and one control point shape selection button 6. Each function category (size, color, and shape) requires only one button, eliminating the need for users to switch between multiple similar buttons, reducing the possibility of misoperation, enabling users to quickly familiarize themselves with the operating logic, and improving work efficiency.

[0036] Optionally, in some embodiments, there are more than one control point size selection button 4, more than one control point color selection button 5, and more than one control point shape selection button 6.

[0037] There are one or more control point size selection buttons 4, each representing a different control point size. Users can select the appropriate control point size by pressing the corresponding button according to their actual measurement needs. When a button is pressed, the number and arrangement of the control point display LEDs 3 change according to the pressed button, thereby changing the size of the control points in the control point display area 2 in real time. This design allows users to easily adjust the size of the control points to adapt to different measurement scenarios and distances.

[0038] Image control point color selection buttons 5 are also provided, each representing a different color. Users can select the appropriate color according to ambient lighting conditions and visibility requirements. When a user presses a color selection button, the emission color of the image control point display LED 3 will be adjusted accordingly, so that the image control point is displayed in the color specified by the user. This flexibility ensures that the image control point is clearly visible under various lighting conditions, improving measurement accuracy.

[0039] There are also more than one control point shape selection button 6, each corresponding to a different shape. Users can select the appropriate shape to display the control point according to their actual needs. The control point display LED beads 3 display the user-selected shape by combining the on and off states. This design allows the control points to not only have clear location information, but also convey additional information or serve as special identifiers through their shapes.

[0040] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the encoding control area 17 includes encoding adjustment buttons, including a left encoding adjustment button 10 and a right encoding adjustment button 11. The left encoding adjustment button 10 is used to control the encoding content displayed in the left encoding display area 7, and the right encoding adjustment button 11 is used to control the encoding content displayed in the right encoding display area 8. The encoding content displayed in the left encoding display area 7 and the right encoding display area 8 are combined to form a unique number of the image control point marker.

[0041] Specifically, the left-side encoding adjustment button 10 is used to control the encoding content in the left-side encoding display area 7. Users can set or change the encoding in the left-side encoding display area by pressing different buttons or combinations of buttons. These encodings can be numbers, letters, or specific combinations of symbols, selected and adjusted according to actual needs. Similarly, the right-side encoding adjustment button 11 is used to control the encoding content in the right-side encoding display area 8. Its working principle is similar to that of the left-side encoding adjustment button 10, also involving user operation of the button to set or change the encoding content.

[0042] Once the coding content in the left coding display area 7 and the right coding display area 8 is set, the combination of the coding content in these two areas forms the unique number of the control point marker. This number is unique and used to identify and distinguish different markers. When a drone performs photogrammetry, it can identify and determine the unique number of the marker by capturing the coding content in these two coding display areas, thereby accurately associating measurement data with a specific marker.

[0043] The LED beads 3 for control point display and 9 for encoding display are encased in a synchronous display mechanism 21. The synchronous display mechanism 21 includes a frame 211 with several through slots 213. A display mechanism is housed within each through slot 213. The display mechanism includes a transparent box 212 containing several magnetic balls 216. The two poles of each magnetic ball 216 are coated with different colors. An iron sheet 215 is located at the bottom of the transparent box 212, and electromagnets 214 are fixedly connected to both sides of the bottom of the iron sheet 215. The through slots 213 on the frame 211 house the display mechanism; each display mechanism is equivalent to a display unit, and each through slot corresponds to a specific display area. The transparent box 212 of the display mechanism not only protects the internal structure but also allows external observation of the color changes of the internal magnetic balls 216, thus enabling the transmission of visual signals. Each magnetic ball 216 has two magnetic poles painted with different colors, which is key to the color display. By controlling the rotation or position of the magnetic ball 216, the specific colored side faces outward, thus achieving the color change display mechanism. The iron plate 215 at the bottom of the transparent box 212 works in conjunction with the electromagnet 214. By changing the magnetic poles of the electromagnet 214, the magnetization state of the iron plate 215 can be controlled, thereby indirectly moving the magnetic ball 216 and achieving the color change. Several synchronous display mechanisms 21 can be used together to form a pattern identical to the pattern displayed by the LED beads. The magnetic balls 216 of several synchronous display mechanisms 21 have one side with the same color. By using several display mechanisms in combination, different colors can be displayed by the synchronous display mechanism 21. The LED beads combined with the synchronous display mechanism 21 provide dual display, achieving both real-time and long-lasting display effects. Specifically, when the iron sheet 215 is temporarily magnetized by the electromagnet 214, the magnetic ball 216 and the iron sheet 215 attract each other and repel each other, thus ensuring that the color of the upward-facing side of the magnetic ball 216 is consistent. When the image control point marker board loses power, the LED beads turn off, and the information displayed by the LED beads disappears. However, since the magnetic ball 216 itself is magnetic, even if the iron sheet 215 is not temporarily magnetized by the electromagnet 214, the magnetic ball 216 will still be attracted to the iron sheet 215 and will not easily rotate. Therefore, the pattern and color displayed by the synchronous display mechanism 21 will continue to be maintained, ensuring the long-term retention of information and preventing the loss of the image control point function once the image control point marker board loses power.

[0044] The substrate 1 has a built-in power module and controller. The controller includes a processor and a memory. The processor receives input signals from the buttons and generates corresponding control signals. The memory stores programs and data to support the operation of the processor. The controller has built-in programs for controlling the on / off state of the LED beads and the display state of the synchronous display mechanism 21. A circuit board 19 is mounted on the top surface of the substrate 1. The circuit board 19 has a built-in driving circuit, which includes an LED driving circuit and a synchronous display mechanism 21 driving circuit. The LED driving circuit receives control signals from the controller and controls the on / off state of the LED beads. The synchronous display mechanism 21 driving circuit receives control signals from the controller and controls the display state of the synchronous display mechanism 21. A panel 20 is covered on the top surface of the circuit board 19. The color of the panel 20 is the same as the color of the side of the magnetic balls 216. A power module button 12 is mounted on the surface of the panel 20. The power module button 12 is electrically connected to the power module. The controller is electrically connected to the power module button 12. Image control point display LED beads 3 and encoding display LED beads 9 are electrically connected to the controller through an LED driving circuit. Synchronous display mechanism 21 is electrically connected to the controller through a synchronous display mechanism 21 driving circuit. Image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10 and right encoding adjustment button 11 are all electrically connected to the controller.

[0045] The power module button 12 controls the on / off state of the power module. When the user presses the power module button 12, the power module is activated, providing power to the entire control point signboard. Simultaneously, the power module button 12 establishes an electrical connection with the controller, transmitting the power module activation signal to the controller. Upon receiving the power module activation signal, the controller begins initialization and prepares to receive subsequent commands. The user can send commands to the controller by operating the control point size selection button 4, control point color selection button 5, control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11. The controller transmits the control signals to the LED driver circuit. Upon receiving the signals, the LED driver circuit controls the number, color, and arrangement of the control point display LEDs 3 and the encoding display LEDs 9, thereby achieving the display of different control points and codes. When the controller selects the control point size (4), control point color (5), and control point shape (6), it synchronously transmits adjustment signals to the synchronous display mechanism (21). After receiving the adjustment signals from the controller, the synchronous display mechanism (21) adjusts the upward-facing surface of the magnetic ball 216 of one of the display mechanisms of the LED beads that are lit, so that the shape and color of the control points displayed by the synchronous display mechanism (21) and the LED beads are consistent. When switching the control point pattern, size, and color (3), the synchronous display mechanism (21) of the LED beads that are not lit changes the magnetic pole of the iron plate 215 by controlling the current direction of the electromagnet 214, thereby controlling the side of the magnetic ball 216 that is the same color as the panel 20 to face upward, so that the color of the magnetic ball 216 blends with the color of the panel 20, further highlighting the information displayed by the LED beads and the synchronous display mechanism (21).

[0046] Optionally, in some embodiments, the control point display LED bead 3 and the encoding display LED bead 9 are covered with an information retention mechanism 18. The information retention mechanism 18 includes an annular frame 1801 and a transparent electrode sheet. The transparent electrode sheet is installed on the top of the annular frame 1801. A microcapsule polymer 1802 is disposed inside the annular frame 1801. The microcapsule polymer 1802 is composed of a plurality of microcapsules. Electrophoretic particles are disposed inside the microcapsules. The electrophoretic particles are divided into positively charged white electrophoretic particles and negatively charged black electrophoretic particles. Under normal conditions, the positively charged white electrophoretic particles are located above the negatively charged black electrophoretic particles or the negatively charged black electrophoretic particles are located above the positively charged white electrophoretic particles. The LED beads, combined with the information retention mechanism 18, provide a dual display, achieving both real-time and persistent display effects. Specifically, the image controller display LED beads 3 and the encoding display LED beads 9 serve as direct light sources, responsible for instantly displaying image controller images and encoded information, providing immediate and visible guidance for the drone. The information retention mechanism 18 plays the role of recording and persistent display, ensuring that important information is retained even when there is no power or the LEDs are not activated. The positions of the positively charged white electrophoretic particles and the negatively charged black electrophoretic particles can change according to the externally applied electric field, thus creating a visual black-and-white contrast to simulate text or patterns. Under normal conditions, the electrophoretic particles are arranged in layers, either with white particles above black particles displaying a bright background, or vice versa, forming a dark background. This layered arrangement can be stably maintained without the action of an external electric field, meaning that the display content can be maintained without consuming electrical energy, demonstrating bistable characteristics and ensuring long-term information retention.

[0047] Optionally, in some embodiments, the substrate 1 has a built-in power module and a controller. The controller includes a processor and a memory. The processor receives input signals from the buttons and generates corresponding control signals. The memory stores programs and data to support the processor's operation. The controller has built-in programs for controlling the on / off state of the LED beads and programs for controlling the display state of the information retention mechanism 18. A circuit board 19 is mounted on the top surface of the substrate 1. The circuit board 19 has a built-in driving circuit, including an LED driving circuit and an information retention mechanism driving circuit. The driving circuit is electrically connected to the transparent electrode sheet. The LED driving circuit receives control signals from the controller and controls the on / off state of the LED beads. The information retention mechanism driving circuit receives control signals from the controller and controls the display state of the information retention mechanism 18. A panel 20 is covered on the top surface of the circuit board 19. The color selection of panel 20 is the same as the color displayed by information retention mechanism 18 under normal conditions. That is, if the color displayed by information retention mechanism 18 under normal conditions is black, the color of panel 20 is black; if the color displayed by information retention mechanism 18 under normal conditions is white, the color of panel 20 is white. A power module button 12 is installed on the surface of panel 20. Power module button 12 is electrically connected to power module. Controller is electrically connected to power module button 12. Image control point display LED beads 3 and encoding display LED beads 9 are electrically connected to controller through LED driver circuit. Information retention mechanism 18 is electrically connected to controller through information retention mechanism driver circuit. Image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11 are all electrically connected to controller. Power module button 12 is used to control the on / off state of power module. When the user presses power module button 12, power module is activated, providing power to the entire image control point signboard. Simultaneously, the power module button 12 establishes an electrical connection with the controller, transmitting the power module activation signal to the controller. Upon receiving the power module activation signal, the controller begins initialization and prepares to receive subsequent commands. Users can send commands to the controller by operating the image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11. The controller transmits control signals to the LED driver circuit. Upon receiving the signals, the LED driver circuit controls the number, color, and arrangement of the image control point display LED beads 3 and the encoding display LED beads 9, thereby achieving the display of different image control points and codes. When the image control point shape selection button 6 is pressed, the controller synchronously transmits an adjustment signal to the information storage mechanism 18. Upon receiving the adjustment signal from the controller, the information storage mechanism 18 adjusts the distribution of the electrophoretic particles, causing white electrophoretic particles or negatively charged black electrophoretic particles to float, thus adjusting the image control point shape displayed by the synchronous display image control point LED beads 3.

[0048] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, a circular level 13 is mounted on the surface of the panel 20. The circular level 13 is used to indicate the horizontal state of the image control point marker plate. A plurality of bottom retractable foot screws 14 are mounted on the bottom of the base plate 1. The bottom retractable foot screws 14 have a spiral extension and retraction function and are used to adjust the horizontal state of the image control point marker plate.

[0049] By observing the position of the bubble in the circular level 13, if the bubble is not centered, the marker board is not level. In this case, the user needs to adjust the retractable leveling screws 14 at the bottom. By rotating these screws, the support height of the marker board at different positions can be changed. The user needs to repeatedly adjust each leveling screw until the bubble in the circular level 13 returns to the centered position, at which point the marker board is level. Maintaining the level of the image control point marker board is crucial for UAV photogrammetry. A level marker board ensures that the UAV obtains accurate data when capturing image control point images, avoiding measurement errors caused by marker board tilt.

[0050] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the top surface of the panel 20 is covered with a light-transmitting panel 15, which is a wear-resistant, high-transmittance acrylic sheet. One side of the light-transmitting panel 15 is hinged to the panel 20, and a groove is provided at the bottom of the light-transmitting panel 15.

[0051] The light-transmitting panel 15 not only protects the image control point display LED beads 3 and the code display LED beads 9 from direct environmental influences such as dust and rain, but also allows light to pass through, ensuring the light emitted by the LED beads is clearly visible. One side of the light-transmitting panel 15 is hinged to the panel 1, allowing it to open and close flexibly. When adjusting the image control points or code display, the user can easily open the light-transmitting panel 15 and directly operate the function buttons on the panel 20. After operation, the light-transmitting panel 15 is closed to protect the internal LED beads and function buttons. Recesses accommodate the LED beads and function buttons to prevent accidental activation of the light-transmitting panel 15.

[0052] In addition, the present invention also provides a control method for a variable image control point marker board for UAV photogrammetry, comprising the following steps: Step 1: Turn on the power module.

[0053] Based on the preliminary survey of the measurement area, the location of the image control points is determined. The variable image control point marker is placed at the location, and the user presses the power module button 12, and the power module built into the marker starts to supply power.

[0054] The controller receives the power module start signal, starts the entire control point signboard, and initializes each functional module.

[0055] After the power module is turned on, the controller enters the power module self-test mode, which checks the power of the power module until the power module is turned off. When the power of the power module is less than 10% of the total power, the controller controls the control point display LED bead 3 to flash, reminding the staff to charge or replace the power module.

[0056] Step 2: Set up the control point display.

[0057] Users can select an easily identifiable control point shape using the control point shape selection button 6, thereby improving the accuracy and efficiency of measurements.

[0058] Users can adjust the size of the control points in the control point display area 2 using the control point size selection button 4 to adapt to different flight altitude requirements of the drone.

[0059] Users can select the appropriate image control point color for the current ambient light using the image control point color selection button 5 to ensure that the drone can accurately capture the image control point.

[0060] When the image control point size selection button 4, image control point color selection button 5, and image control point shape selection button 6 are pressed, the controller synchronously transmits adjustment signals to the synchronous display mechanism 21. After the synchronous display mechanism 21 receives the adjustment signals from the controller, the electromagnet 214 is energized and generates magnetism. Since the iron sheet 215 is in contact with the electromagnet 214, the iron sheet 215 will be magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron sheet will follow the law of magnetic pole interaction, that is, like magnetic poles repel and unlike magnetic poles attract. Thus, one end of the magnetic pole corresponding to the magnetic ball 216 is attracted by the iron sheet 215. Since the magnetic pole of the magnetic ball 216 is painted with color, by controlling the direction of the magnetic pole of the electromagnet 214, it is possible to control which colored side of the magnetic ball is facing up, thereby achieving a specific color display. By using several display mechanisms in combination, different color displays of the synchronous display mechanism 21 can be achieved. Several synchronous display mechanisms 21 can be combined to form a pattern that is the same as the pattern displayed by the LED beads.

[0061] Step 3: Adjust the encoding content.

[0062] Users can use the left-side encoding adjustment button 10 to set the encoding content in the left-side encoding display area 7.

[0063] Users can use the right-side coding adjustment button 11 to set the coding content in the right-side coding display area 8, which together with the left-side coding constitutes the unique number of the signboard.

[0064] When the left-hand encoding adjustment button 10 or the right-hand encoding adjustment button 11 is pressed, the controller synchronously transmits an adjustment signal to the synchronous display mechanism 21. After the synchronous display mechanism 21 receives the adjustment signal from the controller, the electromagnet 214 is energized and generates magnetism. Since the iron sheet 215 is in contact with the electromagnet 214, the iron sheet 215 will be magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron sheet will follow the law of magnetic pole interaction, that is, like magnetic poles repel and unlike magnetic poles attract. Thus, one end of the magnetic pole corresponding to the magnetic ball 216 is attracted by the iron sheet 215. Since the magnetic pole of the magnetic ball 216 is painted with color, by controlling the direction of the magnetic pole of the electromagnet 214, it is possible to control which colored side of the magnetic ball is facing up, thereby achieving a specific color display. By using several synchronous display mechanisms 21 in combination, they can be combined to form the same encoded content as the LED light beads.

[0065] Step 4: Check the horizontal level.

[0066] Users observe the position of the bubble in the circular level 13 to determine whether the marker plate is horizontal.

[0067] If the signboard is not level, the user can make fine adjustments using the retractable foot screw 14 at the bottom. By rotating the foot screw, the tilt angle of the signboard can be adjusted until the bubble in the circular level is centered, indicating that the signboard has reached a level state.

[0068] Step 5: Power off the power module and perform maintenance.

[0069] After the measurement is completed, the user presses the power module button 12, and the power module built into the signboard is turned off.

[0070] Regularly clean and maintain the signboards to ensure long-term stable operation and extend their service life.

[0071] The implementation method of Example 1 is as follows: A variable image control point (ARPC) marker for UAV photogrammetry includes a base plate 1 that supports all functional areas of the marker plate. The base plate 1 is 50cm × 50cm in size and 0.5cm thick. The base plate 1 is provided with an ARPC working area 101 and an encoding working area 102. The marker plate is made of carbon fiber, which is a high-strength, low-density material. Using carbon fiber as the material of the base plate 1 can significantly reduce the overall weight of the marker plate. Moreover, carbon fiber has excellent mechanical properties and can effectively resist physical damage that may be encountered during outdoor use, such as collisions and scratches, ensuring the stability and accuracy of the marker plate during long-term use.

[0072] The image control point working area 101 includes an image control point display area 2 and an image control point control area 16. The image control point display area 2 is located in the upper left corner of the substrate 1 and has a size of 40cm×40cm. The image control point display area 2 is used to display image control point images, and the image control point control area 16 is used to control the display content of the image control point display area 2.

[0073] The coding work area 102 includes a coding display area and a coding control area 17. The coding display area includes a left coding display area 7 and a right coding display area 8. The size of the left coding display area 7 and the right coding display area 8 is 10cm×10cm. The left coding display area 7 and the right coding display area 8 are used to display the coding of the signboard. The coding control area 17 is used to control the coding content of the left coding display area 7 and the right coding display area 8.

[0074] In the control point working area 101, the control point display area 2 is used to clearly display the image of the control point. Users can adjust the displayed content of the control points through the operation interface in the control point control area 16. Users can select different control point sizes to adapt to measurement needs of different distances and resolutions; select the color of the control points to make them more visible under specific ambient lighting conditions; and select the shape of the control points to improve their recognition in the image. These adjustments are transmitted in real time to the control point display area 2 through the control point control area 16, causing it to update the displayed content immediately.

[0075] The encoding working area 102 includes an encoding display area and an encoding control area 17. The encoding display area includes a left encoding display area 7 and a right encoding display area 8, both 10cm × 10cm in size. The left and right encoding display areas 7 and 8 are used to display the encoding of the signboard. The encoding control area 17 is used to control the encoding content of the left and right encoding display areas 7 and 8. The image control point display area 2 is used to clearly display the image control points. Users can adjust the display content of the image control points through the operation interface in the image control point control area 16. Users can select different image control point sizes to adapt to measurement needs of different distances and resolutions; select the color of the image control points to make them more conspicuous under specific ambient lighting conditions; and select the shape of the image control points to improve their recognition in the image. These adjustments are transmitted in real time to the image control point display area 2 through the image control point control area 16, allowing it to immediately update the displayed content. The left-side coding display area 7 and the right-side coding display area 8 are used to display the coding information of the signboard. This coding information is used for the identification and positioning of drones. Users can set this coding content through the coding control area 17.

[0076] The image control point display area 2 is equipped with a number of image control point display LED beads 3, which are arranged in a matrix according to the horizontal and vertical rules. The left coding display area 7 and the right coding display area 8 are both equipped with a number of coding display LED beads 9, which are arranged in a matrix according to the horizontal and vertical rules.

[0077] The control point display LED bead 3 and the code display LED bead 9 each contain three LED chips, each capable of emitting a different color of light. The image control point display area 2 and the encoding display area, including the left encoding display area 7 and the right encoding display area 8, are the core components of the UAV photogrammetry variable image control point marker board. Both areas utilize LED arrays for dynamic display. In image control point display area 2, several image control point display LEDs 3 arranged in a matrix can quickly change their on / off state, emission color, and flashing frequency according to control commands, thereby generating and displaying different image control point images. The high brightness and fast response characteristics of these LEDs ensure clear visibility of the image control points under complex environmental conditions. In the encoding display area, the encoding display LEDs 9 in the left encoding display area 7 and the right encoding display area 8 operate on the same principle. These LEDs are arranged in a matrix, and each LED can be independently controlled to maintain its on / off state. The user sets specific encoding content through the encoding control area 17, and the control system converts this encoding content into the on / off mode of the LEDs and sends it to the corresponding encoding display LEDs 9. These LEDs emit light according to the received mode, thereby displaying specific encoded information.

[0078] The image control area 16 includes three image control point size selection buttons 4, three image control point color selection buttons 5, and three image control point shape selection buttons 6. The image control point size selection buttons 4 control the size of the image control point displayed in the image control point display area 2. The image control point color selection buttons 5 control the color of the image control point displayed in the image control point display area 2. The image control point shape selection buttons 6 control the shape of the image control point displayed in the image control point display area 2. Three image control point size selection buttons 4 are provided, each representing a different image control point size. Users can select the appropriate size image control point by pressing the corresponding button according to actual measurement needs. When a button is pressed, the number and arrangement of the image control point display LED beads 3 change according to the pressed button, thereby changing the size of the image control point in the image control point display area 2 in real time. This design allows users to easily adjust the size of the image control points to adapt to different measurement scenarios and distances. Three image control point color selection buttons 5 are also provided, representing white, red, and orange colors respectively. Users can select a suitable color based on ambient lighting conditions and visibility requirements. When a user presses a color selection button, the emission color of the control point display LED 3 adjusts accordingly, ensuring the control point is displayed in the user-specified color. This flexibility ensures the control point remains clearly visible under various lighting conditions, improving measurement accuracy. Three control point shape selection buttons 6 are also provided, each corresponding to a different shape. Users can select the appropriate shape to display the control point according to their needs. The control point display LED 3 illuminates or extinguishes in combination to present the user-selected shape. This design allows the control point to not only provide clear location information but also convey additional information or serve as a unique identifier through its shape.

[0079] The encoding control area 17 includes encoding adjustment buttons, specifically a left encoding adjustment button 10 and a right encoding adjustment button 11. The left encoding adjustment button 10 controls the encoding content displayed in the left encoding display area 7, and the right encoding adjustment button 11 controls the encoding content displayed in the right encoding display area 8. The combined encoding content of the left and right encoding display areas 7 and 8 forms the unique number of the control point marker. Both the left and right encoding adjustment buttons consist of two symmetrically positioned triangular buttons. The left encoding adjustment button 10 controls the encoding content in the left encoding display area 7, which can be numbers, letters, or a specific combination of symbols. Similarly, the right encoding adjustment button 11 controls the encoding content in the right encoding display area 8. Once the encoding content in both the left and right encoding display areas 7 and 8 is set, the combined encoding content of these two areas forms the unique number of the control point marker.

[0080] Specifically, the left-side encoding adjustment button 10 is used to control the encoding content in the left-side encoding display area 7. Users can set or change the encoding in the left-side encoding display area by pressing different buttons or combinations of buttons. These encodings can be numbers, letters, or specific combinations of symbols, selected and adjusted according to actual needs. Similarly, the right-side encoding adjustment button 11 is used to control the encoding content in the right-side encoding display area 8. Its working principle is similar to that of the left-side encoding adjustment button 10, also involving user operation of the button to set or change the encoding content.

[0081] Once the coding content in the left coding display area 7 and the right coding display area 8 is set, the combination of the coding content in these two areas forms the unique number of the control point marker. This number is unique and used to identify and distinguish different markers. When a drone performs photogrammetry, it can identify and determine the unique number of the marker by capturing the coding content in these two coding display areas, thereby accurately associating measurement data with a specific marker.

[0082] The LED beads 3 for control point display and 9 for encoding display are encased in a synchronous display mechanism 21. The synchronous display mechanism 21 includes a frame 211 with three through slots 213: a first through slot, a second through slot, and a third through slot. A display mechanism is housed within each through slot 213. The display mechanism includes a transparent box 212 containing several magnetic balls 216. The two poles of each magnetic ball 216 are coated with different colors: the north pole of the magnetic ball 216 in the first through slot is white, and the south pole is black; the north pole of the magnetic ball 216 in the second through slot is red, and the south pole is black; the north pole of the magnetic ball 216 in the third through slot is orange, and the south pole is black. An iron plate 215 is located at the bottom of the transparent box 212, and electromagnets 214 are fixedly connected to both sides of the bottom of the iron plate 215. The through slots 213 on the frame 211 are used to house the display mechanisms. Each display mechanism is equivalent to a display unit, and each through slot corresponds to a specific display area. The transparent box 212 of the display mechanism not only protects the internal structure but also allows external observation of the color changes of the internal magnetic balls 216, thus enabling the transmission of visual signals. Each magnetic ball 216 has two magnetic poles coated with different colors, which is key to the color display. By controlling the rotation or position of the magnetic balls 216, specific colored faces outward, thereby displaying color changes within the display mechanism. The iron plate 215 at the bottom of the transparent box 212 works in conjunction with an electromagnet 214. Changes in the magnetic poles of the electromagnet 214 control the magnetization state of the iron plate 215, indirectly moving the magnetic balls 216 and achieving color changes. Several synchronized display mechanisms 21 can be combined to form a pattern identical to that displayed by LED beads. The magnetic balls 216 of several synchronized display mechanisms 21 have one side that is the same color. By using several display mechanisms in combination, different colors can be displayed by the synchronous display mechanism 21. The LED beads combined with the synchronous display mechanism 21 provide dual display, achieving both real-time and long-lasting display effects. Specifically, when the iron sheet 215 is temporarily magnetized by the electromagnet 214, the magnetic ball 216 and the iron sheet 215 attract each other and repel each other, thus ensuring that the color of the upward-facing side of the magnetic ball 216 is consistent. When the image control point marker board loses power, the LED beads turn off, and the information displayed by the LED beads disappears. However, since the magnetic ball 216 itself is magnetic, even if the iron sheet 215 is not temporarily magnetized by the electromagnet 214, the magnetic ball 216 will still be attracted to the iron sheet 215 and will not easily rotate. Therefore, the pattern and color displayed by the synchronous display mechanism 21 will continue to be maintained, ensuring the long-term retention of information and preventing the loss of the image control point function once the image control point marker board loses power.

[0083] The substrate 1 has a built-in power module and controller. The controller includes a processor and a memory. The processor receives input signals from the button and generates corresponding control signals. The memory stores programs and data to support the operation of the processor. The controller has built-in programs for controlling the on / off state of the LED beads and the display state of the synchronous display mechanism 21. A circuit board 19 is mounted on the top surface of the substrate 1. The circuit board 19 has a built-in driving circuit, which includes an LED driving circuit and a synchronous display mechanism 21 driving circuit. The LED driving circuit receives control signals from the controller and controls the on / off state of the LED beads. The synchronous display mechanism 21 driving circuit receives control signals from the controller and controls the display state of the synchronous display mechanism 21. A panel 20 is covered on the top surface of the circuit board 19. The panel 20 is black. A power module button 12 is mounted on the surface of the panel 20. The power module button 12 is electrically connected to the power module. The controller is electrically connected to the power module button 12. Image control point display LED beads 3 and encoding display LED beads 9 are electrically connected to the controller through an LED driving circuit. Synchronous display mechanism 21 is electrically connected to the controller through a synchronous display mechanism 21 driving circuit. Image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10 and right encoding adjustment button 11 are all electrically connected to the controller.

[0084] The power module button 12 controls the on / off state of the power module. When the user presses the power module button 12, the power module is activated, providing power to the entire control point signboard. Simultaneously, the power module button 12 establishes an electrical connection with the controller, transmitting the power module activation signal to the controller. Upon receiving the power module activation signal, the controller begins initialization and prepares to receive subsequent commands. The user can send commands to the controller by operating the control point size selection button 4, control point color selection button 5, control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11. The controller transmits the control signals to the LED driver circuit. Upon receiving the signals, the LED driver circuit controls the number, color, and arrangement of the control point display LEDs 3 and the encoding display LEDs 9, thereby achieving the display of different control points and codes. When the controller selects the control point size (4), control point color (5), and control point shape (6), it synchronously transmits adjustment signals to the synchronous display mechanism (21). After receiving the adjustment signals from the controller, the synchronous display mechanism (21) adjusts the upward-facing surface of the magnetic ball 216 of one of the display mechanisms of the LED beads that are lit, so that the shape and color of the control points displayed by the synchronous display mechanism (21) and the LED beads are consistent. When switching the control point pattern, size, and color (3), the synchronous display mechanism (21) of the LED beads that are not lit changes the magnetic pole of the iron plate 215 by controlling the current direction of the electromagnet 214, thereby controlling the side of the magnetic ball 216 that is the same color as the panel 20 to face upward, so that the color of the magnetic ball 216 blends with the color of the panel 20, further highlighting the information displayed by the LED beads and the synchronous display mechanism (21).

[0085] A circular level 13 is mounted on the surface of panel 20. The circular level 13 indicates the horizontal state of the image control point marker board. Several retractable bottom screws 14 are mounted on the bottom of the base plate 1. These retractable bottom screws 14 have a screw extension / retraction function and are used to adjust the horizontal state of the image control point marker board. The position of the bubble in the circular level 13 is observed. If the bubble is not in the center, it indicates that the marker board is not horizontal. In this case, the user needs to adjust the retractable bottom screws 14. By rotating the screws, extending or retracting them, the support height of the marker board at different positions is changed. The user needs to repeatedly adjust each screw until the bubble in the circular level 13 returns to the center position, at which point the marker board is horizontal. Maintaining the horizontal state of the image control point marker board is crucial for UAV photogrammetry. A horizontal marker board ensures that the UAV obtains accurate data when capturing image control point images, avoiding measurement errors caused by marker board tilt.

[0086] A light-transmitting panel 15 covers the top surface of panel 20. The light-transmitting panel 15 is made of wear-resistant, high-transmittance acrylic sheet. One side of the light-transmitting panel 15 is hinged to panel 20, and a groove is provided at the bottom of the light-transmitting panel 15. The light-transmitting panel 15 not only protects the image control point display LED beads 3 and the code display LED beads 9 from direct environmental influences such as dust and rain, but also allows light to pass through, ensuring the light emitted by the LED beads is clearly displayed. The hinged design of one side of the light-transmitting panel 15 allows it to be opened and closed flexibly. When adjusting the image control points or code display, the user can easily open the light-transmitting panel 15 and directly operate the function buttons on panel 20. After operation, the light-transmitting panel 15 is closed to protect the internal LED beads and function buttons. The groove is used to accommodate the LED beads and function buttons to prevent accidental activation of the light-transmitting panel 15.

[0087] In addition, this embodiment also provides a control method for a variable image control point marker board in UAV photogrammetry, including the following steps: Step 1: Turn on the power module.

[0088] Based on the preliminary survey of the measurement area, the location of the image control points is determined. The variable image control point marker is placed at the location, and the user presses the power module button 12, and the power module built into the marker starts to supply power.

[0089] The controller receives the power module start signal, starts the entire control point signboard, and initializes each functional module.

[0090] After the power module is turned on, the controller enters the power module self-test mode, which checks the power of the power module until the power module is turned off. When the power of the power module is less than 10% of the total power, the controller controls the control point display LED bead 3 to flash, reminding the staff to charge or replace the power module.

[0091] Step 2: Set up the control point display.

[0092] Users can select an easily identifiable control point shape using the control point shape selection button 6, thereby improving the accuracy and efficiency of measurements.

[0093] Users can adjust the size of the control points in the control point display area 2 using the control point size selection button 4 to adapt to different flight altitude requirements of the drone.

[0094] Users can select the appropriate image control point color for the current ambient light using the image control point color selection button 5 to ensure that the drone can accurately capture the image control point.

[0095] When the image control point size selection button 4, image control point color selection button 5, and image control point shape selection button 6 are pressed, the controller synchronously transmits adjustment signals to the synchronous display mechanism 21. After the synchronous display mechanism 21 receives the adjustment signals from the controller, the electromagnet 214 is energized and generates magnetism. Since the iron sheet 215 is in contact with the electromagnet 214, the iron sheet 215 will be magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron sheet will follow the law of magnetic pole interaction, that is, like magnetic poles repel and unlike magnetic poles attract. Thus, one end of the magnetic pole corresponding to the magnetic ball 216 is attracted by the iron sheet 215. Since the magnetic pole of the magnetic ball 216 is painted with color, by controlling the direction of the magnetic pole of the electromagnet 214, it is possible to control which colored side of the magnetic ball is facing up, thereby achieving a specific color display. By using several display mechanisms in combination, different color displays of the synchronous display mechanism 21 can be achieved. Several synchronous display mechanisms 21 can be combined to form a pattern that is the same as the pattern displayed by the LED beads.

[0096] Step 3: Adjust the encoding content.

[0097] Users can use the left-side encoding adjustment button 10 to set the encoding content in the left-side encoding display area 7.

[0098] The user uses the right-side code adjustment button 11 to set the code content in the right-side code display area 8, which, together with the left-side code, constitutes the unique number of the signboard. When either the left-side code adjustment button 10 or the right-side code adjustment button 11 is pressed, the controller synchronously transmits an adjustment signal to the synchronous display mechanism 21. After the synchronous display mechanism 21 synchronously receives the adjustment signal from the controller, the electromagnet 214 is energized and generates magnetism. Since the iron sheet 215 is in contact with the electromagnet 214, the iron sheet 215 is magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron sheet follows the law of magnetic pole interaction, that is, like poles repel and unlike poles attract. Thus, one end of the magnetic ball 216 corresponding to the magnetic pole is attracted by the iron sheet 215. Since the magnetic pole of the magnetic ball 216 is painted with color, by controlling the direction of the magnetic pole of the electromagnet 214, it is possible to control which colored side of the magnetic ball faces upward, thereby achieving a specific color display. By using several synchronous display mechanisms 21 in combination, they can be combined to form the same code content as the LED light beads.

[0099] Step 4: Check the horizontal level.

[0100] Users observe the position of the bubble in the circular level 13 to determine whether the marker plate is horizontal.

[0101] If the signboard is not level, the user can make fine adjustments using the retractable foot screw 14 at the bottom. By rotating the foot screw, the tilt angle of the signboard can be adjusted until the bubble in the circular level is centered, indicating that the signboard has reached a level state.

[0102] Step 5: Power off the power module and perform maintenance.

[0103] After the measurement is completed, the user presses the power module button 12, and the power module built into the signboard is turned off.

[0104] Regularly clean and maintain the signboards to ensure long-term stable operation and extend their service life.

[0105] In summary, the present invention solves the problems of irregular manual spraying marks, inconsistent colors, inconsistent sizes, uneven spraying, and lack of coding for existing image control points, which can easily lead to confusion or errors, resulting in reduced measurement accuracy or errors. At the same time, even if the LED beads are unexpectedly powered off, the synchronous display mechanism 21 can continue to display the set information.

[0106] The implementation method of Example 2 is as follows: The difference between Embodiment 2 and Embodiment 1 lies in that the image control point display LED bead 3 and the encoding display LED bead 9 are encased in an information retention mechanism 18. The information retention mechanism 18 includes an annular frame 1801, within which a microcapsule polymer 1802 is disposed. The microcapsule polymer 1802 is composed of a plurality of microcapsules, each containing electrophoretic particles. These electrophoretic particles are divided into positively charged white electrophoretic particles and negatively charged black electrophoretic particles. Under normal conditions, the negatively charged black electrophoretic particles are located above the positively charged white electrophoretic particles. The LED beads combined with the information retention mechanism 18 provide dual display, achieving both real-time and persistent display effects. Specifically, the image control point display LED bead 3 and the encoding display LED bead 9 act as direct light sources, responsible for instantly displaying the image control point image and encoded information, providing immediate and visible guidance for the drone. The information retention mechanism 18 plays the role of recording and persistent display, ensuring that important information is still retained even when there is no power or the LEDs are not activated. The positions of positively charged white electrophoretic particles and negatively charged black electrophoretic particles can change according to the externally applied electric field, thus creating a visual black-and-white contrast to simulate text or patterns. Under normal conditions, the electrophoretic particles are arranged in layers, with black particles above white particles to display a dark background. This layered arrangement can be stably maintained without the action of an external electric field, that is, it can maintain the display content without consuming electrical energy, which reflects the bistable characteristic and ensures the long-term retention of information.

[0107] The substrate 1 houses a power module and a controller. The controller includes a processor and a memory. The processor receives input signals from the buttons and generates corresponding control signals. The memory stores programs and data to support the processor's operation. The controller contains programs for controlling the on / off state of the LED beads and for controlling the display status of the information storage mechanism 18. A circuit board 19 is mounted on the top surface of the substrate 1. The circuit board 19 contains a driving circuit, including an LED driving circuit and an information storage mechanism driving circuit. The LED driving circuit receives control signals from the controller and controls the on / off state of the LED beads. The information storage mechanism driving circuit receives control signals from the controller and controls the display status of the LED beads. The information retention mechanism 18 displays its status. A panel 20, black in color, covers the top of the circuit board 19. A power module button 12 is mounted on the surface of the panel 20, electrically connected to the power module. The controller is also electrically connected to the power module button 12. The image control point display LED beads 3 and the encoding display LED beads 9 are electrically connected to the controller via an LED driver circuit. The information retention mechanism 18 is electrically connected to the controller via an information retention mechanism driver circuit. The image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11 are all electrically connected to the controller. The power module button 12 controls the on / off state of the power module. The power module button 12 establishes an electrical connection with the controller, transmitting the power module activation signal to the controller. Upon receiving the power module activation signal, the controller begins initialization and prepares to receive subsequent instructions. Users can send commands to the controller by operating the image control point size selection button 4, image control point color selection button 5, image control point shape selection button 6, left encoding adjustment button 10, and right encoding adjustment button 11. The controller transmits control signals to the LED driver circuit. After receiving the signals, the LED driver circuit controls the number, color, and arrangement of the image control point display LED beads 3 and the encoding display LED beads 9 to achieve the display of different image control points and codes. When the image control point shape selection button 6 is pressed, the controller synchronously transmits an adjustment signal to the information storage mechanism 18. After receiving the adjustment signal from the controller, the information storage mechanism 18 adjusts the distribution of the electrophoretic particles, causing white electrophoretic particles or negatively charged black electrophoretic particles to float, so that the information storage mechanism 18 and the image control point display LED beads 3 display the image control point shape.

[0108] In addition, this embodiment also provides a control method for a variable image control point marker board in UAV photogrammetry, including the following steps: Step 1: Turn on the power module.

[0109] Based on the preliminary survey of the measurement area, the location of the image control points is determined. The variable image control point marker is placed at the location, and the user presses the power module button 12, and the power module built into the marker starts to supply power.

[0110] The controller receives the power module start signal, starts the entire control point signboard, and initializes each functional module.

[0111] After the power module is turned on, the controller enters the power module self-test mode, which checks the power of the power module until the power module is turned off. When the power of the power module is less than 10% of the total power, the controller controls the control point display LED bead 3 to flash, reminding the staff to charge or replace the power module.

[0112] Step 2: Set up the control point display.

[0113] Users can select an easily identifiable control point shape using the control point shape selection button 6, improving measurement accuracy and efficiency. When the control point shape selection button 6 is pressed, the controller synchronously transmits an adjustment signal to the information retention mechanism 18. After receiving the adjustment signal from the controller, the information retention mechanism 18 adjusts the distribution of the electrophoretic particles, causing the white electrophoretic particles to float. Compared with the black panel, this makes the control point shape displayed by the synchronous display LED beads 3 in the information retention mechanism 18 consistent with the control point shape displayed in the synchronous display LED beads 3. Even when the information retention mechanism 18 is without power, it can retain the setting information.

[0114] Users can adjust the size of the control points in the control point display area 2 using the control point size selection button 4 to adapt to different flight altitude requirements of the drone.

[0115] Users can select the appropriate image control point color for the current ambient light using the image control point color selection button 5 to ensure that the drone can accurately capture the image control point.

[0116] Step 3: Adjust the encoding content.

[0117] Users can use the left-side encoding adjustment button 10 to set the encoding content in the left-side encoding display area 7.

[0118] The user uses the right-side code adjustment button 11 to set the code content in the right-side code display area 8, which, together with the left-side code, constitutes the unique number of the signboard. The information retention mechanism 18, upon receiving the adjustment signal from the controller, adjusts the distribution of the electrophoretic particles, causing white electrophoretic particles or negatively charged black electrophoretic particles to float. This ensures that the image control point shape displayed by the information retention mechanism 18 and the synchronous display code LED beads 9 is consistent, allowing the information retention mechanism 18 to retain the setting information even when there is no power.

[0119] Step 4: Check the horizontal level.

[0120] Users observe the position of the bubble in the circular level 13 to determine whether the marker plate is horizontal.

[0121] If the signboard is not level, the user can make fine adjustments using the retractable foot screw 14 at the bottom. By rotating the foot screw, the tilt angle of the signboard can be adjusted until the bubble in the circular level is centered, indicating that the signboard has reached a level state.

[0122] Step 5: Power off the power module and perform maintenance.

[0123] After the measurement is completed, the user presses the power module button 12, and the power module built into the signboard is turned off.

[0124] Regularly clean and maintain the signboards to ensure long-term stable operation and extend their service life.

[0125] The implementation method of Example 3 is as follows: The difference between Embodiment 2 and Embodiment 1 lies in the number of buttons: one for control point size selection (4), one for control point color selection (5), and one for control point shape selection (6). This embodiment provides only one button for each of the control point's size, color, and shape. This design simplifies the user interface, allowing adjustment of each category via a single button, avoiding the hassle of frequently switching between numerous similar buttons. By reducing the number of buttons, this design lowers operational complexity, enabling users to learn and master the operating logic more quickly. A single button can be used in combination with other operations such as long presses, short presses, and continuous clicks to achieve more diverse function selections, thus simplifying the design without sacrificing functionality. User operation is more intuitive and accurate, thereby improving the efficiency of setting up control point markers on-site.

[0126] Comparison: Traditional image control points (ARPCs) are typically static landmarks pre-defined in the field environment. They lack variability and dynamic display capabilities. Traditional ARPCs are generally made of solid materials such as metal nails, reflective stickers, or spray-painted markings. They are fixed in size, usually cross-shaped or other easily identifiable geometric shapes in images, and are typically bright, contrasting colors to facilitate automatic or semi-automatic identification during aerial or drone photogrammetry.

[0127] Unlike the variable control point markers for UAV photogrammetry in the aforementioned patents, traditional control points lack electronic control and display capabilities, and cannot be adjusted in size, color, or shape via a user interface. Their encoded information is not dynamically displayed via LED arrays or LCD screens, but rather relies on fixed, physical codes or markings such as latitude and longitude coordinates or preset pattern codes, which cannot be altered after production.

[0128] Furthermore, traditional image control points (ARPCs) lack integrated power modules and controllers, circular levels for calibrating horizontal alignment, and retractable leveling screws for precise adjustment of the marker's horizontal position. In practical applications, ensuring the levelness and flatness of traditional ARPCs often relies on manual on-site adjustments and inspections, resulting in high maintenance costs, as damaged or worn ARPCs often require relocation.

[0129] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An unmanned aerial photogrammetry variable control point marker plate, characterized in that: The substrate (1) includes the various functional areas of the entire signboard, and the substrate (1) is provided with a control point working area (101) and an encoding working area (102). The image control point working area (101) includes an image control point display area (2) and an image control point control area (16). The image control point display area (2) is used to display image control point images, and the image control point control area (16) is used to control the display content of the image control point display area (2). The image control point display area (2) is equipped with a number of image control point display LED beads (3). The coding working area (102) includes a coding display area and a coding control area (17). The coding display area includes a left coding display area (7) and a right coding display area (8). The left coding display area (7) and the right coding display area (8) are used to display the coding of the signboard. The coding control area (17) is used to control the coding content of the left coding display area (7) and the right coding display area (8). The left coding display area (7) and the right coding display area (8) are each equipped with a number of coding display LED beads (9). The image control point display LED bead (3) and the coded display LED bead (9) are fitted with a synchronous display mechanism (21). The synchronous display mechanism (21) includes a frame (211). The frame (211) has several through slots (213). A display mechanism is provided in the through slots (213). The display mechanism includes a transparent box (212). Several magnetic balls (216) are provided in the transparent box (212). The two magnetic poles of the magnetic balls (216) are coated with different colors. An iron sheet (215) is provided at the bottom of the transparent box (212). Electromagnets (214) are fixedly connected to both sides of the bottom of the iron sheet (215). The substrate (1) has a built-in power module and a controller. The controller has a built-in program for controlling the on / off state of the LED beads and the display state of the synchronous display mechanism (21). The top surface of the substrate (1) is equipped with a circuit board (19). The circuit board (19) has a built-in driving circuit. The driving circuit includes an LED driving circuit and a synchronous display mechanism (21) driving circuit. The LED driving circuit is used to receive control signals from the controller and control the on / off state of the LED beads. The synchronous display mechanism (21) driving circuit is used to receive control signals from the controller and control the display state of the synchronous display mechanism (21). The top surface of the circuit board (19) is covered with a panel (20). The surface of the panel (20) is equipped with a power module button (12). The power module button (12) is electrically connected to the power module. The controller is electrically connected to the power module button (12).

2. The unmanned aerial photogrammetry variable ground control point marker board of claim 1, wherein: The image control area (16) includes an image control size selection button (4), an image control color selection button (5), and an image control shape selection button (6). The image control size selection button (4) is used to control the size of the image control image displayed in the image control display area (2). The image control color selection button (5) is used to control the color of the image control image displayed in the image control display area (2). The image control shape selection button (6) is used to control the shape of the image control image displayed in the image control display area (2).

3. The unmanned aerial photogrammetry variable ground control point marker board of claim 1, wherein: The encoding control area (17) includes encoding adjustment buttons, including a left encoding adjustment button (10) and a right encoding adjustment button (11). The left encoding adjustment button (10) is used to control the encoding content displayed in the left encoding display area (7), and the right encoding adjustment button (11) is used to control the encoding content displayed in the right encoding display area (8). The encoding content displayed in the left encoding display area (7) and the right encoding display area (8) are combined to form a unique number of the image control point marker.

4. The unmanned aerial photogrammetry variable ground control point marker board of claim 1, wherein: A circular level (13) is installed on the surface of the panel (20). The circular level (13) is used to indicate the horizontal state of the image control point marker plate. A plurality of bottom retractable foot screws (14) are installed on the bottom of the base plate (1). The bottom retractable foot screws (14) have a spiral extension function and are used to adjust the horizontal state of the image control point marker plate.

5. The unmanned aerial photogrammetry variable ground control point marker board of claim 1, wherein: The top surface of the panel (20) is covered with a light-transmitting panel (15), one side of the light-transmitting panel (15) is hinged to the panel (20), and a groove is provided at the bottom of the light-transmitting panel (15).

6. The control method of the unmanned aerial photogrammetry variable ground control point marker board according to any one of claims 1-5, characterized in that: Includes the following steps: Step 1: Turn on the power module; Step 2: Configure the control point display; Step 3: Adjust the encoding content; Step 4: Check the horizontal level; Step 5: Power off the power module and perform maintenance.

7. The control method of the unmanned aerial photogrammetry variable control point marker board according to claim 6, characterized in that: Step two also includes the following steps: Users can select an easily identifiable control point shape by using the control point shape selection button (6), thereby improving the accuracy and efficiency of measurement; Users can select the appropriate image control point color for the current ambient light by using the image control point color selection button (5), so that the drone can capture the image control point; Users can adjust the size of the control points in the control point display area (2) by using the control point size selection button (4) to adapt to different flight altitude requirements of the UAV; When the image control point size selection button (4), image control point color selection button (5), and image control point shape selection button (6) are pressed, the controller synchronously transmits adjustment signals to the synchronous display mechanism (21). After the synchronous display mechanism (21) receives the adjustment signals from the controller, the electromagnet (214) is energized and generates magnetism. Since the iron piece (215) is in contact with the electromagnet (214), the iron piece (215) will be magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron piece will follow the law of magnetic pole interaction, that is, like poles repel each other. Unlike magnetic poles attract each other, so one end of the magnetic ball (216) corresponding to the magnetic pole is attracted by the iron sheet (215). Since the magnetic poles of the magnetic ball (216) are painted with color, by controlling the direction of the magnetic poles of the electromagnet (214), it is possible to control which colored side of the magnetic ball faces upward, thereby achieving a specific color display. By using several display mechanisms in combination, different colors of the synchronous display mechanism (21) can be displayed. Several synchronous display mechanisms (21) can be combined to form a pattern that is the same as the pattern displayed by the LED beads.

8. The control method of the unmanned aerial photogrammetry variable control point marker board according to claim 6, characterized in that: Step three also includes the following steps: Users can use the left-side encoding adjustment button (10) to set the encoding content in the left-side encoding display area (7); Users can use the right-side coding adjustment button (11) to set the coding content in the right-side coding display area (8), which together with the left-side coding constitutes the unique number of the signboard; When the left-hand encoding adjustment button (10) or the right-hand encoding adjustment button (11) is pressed, the controller synchronously transmits the adjustment signal to the synchronous display mechanism (21). After the synchronous display mechanism (21) receives the adjustment signal from the controller, the electromagnet (214) is energized and generates magnetism. Since the iron sheet (215) is in contact with the electromagnet (214), the iron sheet (215) will be magnetized by the magnetic field of the electromagnet, thus temporarily exhibiting magnetism. The iron sheet will follow the law of magnetic pole interaction, that is, like magnetic poles repel each other and unlike magnetic poles attract each other. Thus, one end of the magnetic pole corresponding to the magnetic ball (216) is attracted by the iron sheet (215). Since the magnetic pole of the magnetic ball (216) is painted with color, by controlling the direction of the magnetic pole of the electromagnet (214), it is possible to control which color face of the magnetic ball is facing up, thereby realizing a specific color display. By using several synchronous display mechanisms (21) in combination, they can be combined to form the same encoding content as the LED light bead display.

Images