Mooring power supply unmanned aerial vehicle and unmanned aerial vehicle control method

Abstract

The invention relates to a mooring power supply unmanned aerial vehicle and an unmanned aerial vehicle control method.The mooring power supply unmanned aerial vehicle comprises an unmanned aerial vehicle body, a power trolley, a mooring cable and a take-up and pay-off unit used for taking up or releasing the mooring cable, and the power trolley comprises a high-voltage direct-current power source used for converting 380 V / 50 Hz three-phase alternating current into 1000 V direct current; the unmanned aerial vehicle body is electrically connected with the high-voltage direct-current power source through the mooring cable, the take-up and pay-off unit is arranged on the power trolley, and the power trolley, the take-up and pay-off unit and the unmanned aerial vehicle body are sequentially connected through the mooring cable. The take-up and pay-off unit can adjust the speed of taking up or releasing the mooring cable according to the tension of the mooring cable and the real-time distance between the unmanned aerial vehicle body and the power trolley, so that the mooring cable is in a tightened state. According to the mooring power supply unmanned aerial vehicle and the unmanned aerial vehicle control method, the problem that an existing mooring unmanned aerial vehicle is small in movement range is solved.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a tethered powered UAV and a UAV control method. Background Technology

[0002] For foreign objects at high altitudes, drones equipped with lasers are generally used for laser removal. Currently, most electric drones have limited battery capacity and short flight time. Therefore, they can be connected to a ground power source via cable to provide continuous power and extend the drone's flight time. However, existing tethered drones cannot carry excessively long cables due to their own weight, which limits their range of movement. Furthermore, if the cable gets tangled in obstacles on the ground, it will further reduce the drone's range of movement. Summary of the Invention

[0003] The main objective of this invention is to propose a tethered power supply drone and a drone control method, aiming to solve the problem of limited operating range in existing tethered drones.

[0004] To achieve the above objectives, the present invention proposes a tethered powered drone, comprising a drone body, a power supply trolley, a tether cable, and a cable retraction / release unit for retrieving or releasing the tether cable. The power supply trolley includes a high-voltage DC power supply for converting 380V / 50Hz three-phase AC power into 1000V DC power. The drone body is electrically connected to the high-voltage DC power supply via the tether cable. The cable retraction / release unit is mounted on the power supply trolley. The power supply trolley, the cable retraction / release unit, and the drone body are sequentially connected via the tether cable. The cable retraction / release unit can adjust the speed of retrieving or releasing the tether cable based on the tension of the tether cable and the real-time distance between the drone body and the power supply trolley, so that the tether cable is kept taut.

[0005] According to some embodiments of the present invention, a cable bracket is also included, which is disposed on the cable take-up and release unit and has a clamping groove for the tethered cable to pass through. The power trolley, the cable take-up and release unit, the cable bracket and the UAV body are connected in sequence through the tethered cable.

[0006] According to some embodiments of the present invention, the UAV body includes an emergency power supply, a drive assembly, and a power-off assembly for disconnecting the tether cable from the UAV body. The emergency power supply and the high-voltage DC power supply of the power supply trolley are both electrically connected to the drive assembly. The emergency power supply can supply power to the drive assembly after the high-voltage DC power supply stops supplying power.

[0007] Furthermore, the present invention also provides a drone control method based on any of the above-described tethered powered drones, the drone control method comprising the following steps:

[0008] After the drone takes off, the cable reeling unit is controlled to release the tether cable at a first preset speed.

[0009] The real-time controlled direction of the UAV body, the tension of the tether cable, and the real-time distance between the UAV body and the power supply trolley are obtained.

[0010] The take-up and take-up mode and speed of the tethered cable are determined based on the real-time controlled direction, the cable tension, and the real-time distance, and the take-up and take-up unit is controlled to take up and take down the tethered cable according to the take-up and take-up mode and speed.

[0011] The moving direction and speed of the power supply trolley are determined based on the real-time controlled direction and the real-time distance, and the movement of the power supply trolley is controlled based on the moving direction and speed.

[0012] When the UAV completes its operation and returns to base, the cable reeling unit is controlled to retrieve the tethered cable.

[0013] According to some embodiments of the present invention, determining the take-up and release mode and speed of the tethered cable based on the real-time controlled direction, the cable tension, and the real-time distance, and controlling the take-up and release unit to take up and release the tethered cable according to the take-up and release mode and speed, includes:

[0014] The deployment and retraction mode of the tethered cable is determined based on the real-time controlled direction and the real-time distance;

[0015] The retrieval speed of the tethered cable is determined based on the retrieval mode, the cable tension, and the real-time distance.

[0016] The take-up and take-up unit is controlled to take up and take down the mooring cable according to the take-up and take-up mode and the take-up and take-up speed.

[0017] According to some embodiments of the present invention, determining the deployment and retraction mode of the tethered cable based on the real-time controlled direction and the real-time distance includes:

[0018] When the real-time distance in the last two unit time periods gradually increases, and the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is greater than 90 degrees, it is determined that the tethered cable is in release mode.

[0019] When the real-time distance between the two most recent units of time gradually decreases, and the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is less than 90 degrees, it is determined that the tethered cable is in the recovery mode.

[0020] According to some embodiments of the present invention, determining the retraction speed of the tethered cable based on the retraction mode, the cable tension, and the real-time distance includes:

[0021] When the mooring cable is in release mode, the real-time distance is substituted into the first function to calculate the real-time release speed;

[0022] When the tethered cable is in the retrieval mode and the cable tension is less than the minimum preset tension, the real-time distance and the maximum cable length are substituted into the second function to calculate the real-time cable retrieval speed.

[0023] When the tethered cable is in retrieval mode and the cable tension is greater than the maximum preset tension, the real-time distance and the maximum cable length are substituted into the third function to calculate the real-time cable retrieval speed.

[0024] The first function is:

[0025]

[0026] The second function is:

[0027] v2 = K p ·(L max -D)+v0

[0028] The third function is:

[0029] v2 = K p ·(L max -D)-v0

[0030] v1 is the real-time line-laying speed, v2 is the real-time line-retrieval speed, D is the real-time distance, and L is the distance between the lines. max K is the maximum length of the cable. p K i and K d These are the real-time proportional, integral, and derivative parameters, respectively, and v0 is the gain speed.

[0031] According to some embodiments of the present invention, determining the retraction speed of the tethered cable based on the retraction mode, the cable tension, and the real-time distance further includes:

[0032] Obtain the real-time wind speed at the work site;

[0033] The increments of the proportional, integral, and derivative parameters are determined based on the real-time wind speed;

[0034] The real-time proportional parameter is calculated based on the preset proportional parameter and the increment of the proportional parameter;

[0035] The real-time integral parameters are calculated based on the preset integral parameters and the increment of the integral parameters.

[0036] The real-time differential parameters are calculated based on the preset differential parameters and the increments of the differential parameters;

[0037] The first function, the second function, and the third function are iteratively updated based on the real-time proportional parameter, the real-time integral parameter, and the real-time differential parameter, respectively.

[0038] According to some embodiments of the present invention, determining the moving direction and speed of the power supply trolley based on the real-time controlled direction and the real-time distance, and controlling the movement of the power supply trolley based on the moving direction and speed, includes:

[0039] When the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is greater than 90 degrees, and the real-time distance in the last two unit time periods gradually increases and the real-time distance is greater than the maximum preset distance, the real-time moving speed of the UAV body is obtained.

[0040] The movement direction of the power supply vehicle is determined based on the real-time controlled direction of the UAV body, so that the movement direction of the power supply vehicle is consistent with the controlled direction of the UAV body in the horizontal direction.

[0041] The moving speed of the power supply vehicle is determined based on the real-time moving speed and real-time controlled direction of the UAV body, so that the moving speed of the power supply vehicle is greater than the moving speed of the UAV body in the horizontal direction.

[0042] The power supply trolley is moved according to the moving direction and speed until the trend of the real-time distance change changes from decreasing to increasing within a preset time.

[0043] According to some embodiments of the present invention, it further includes:

[0044] When the real-time distance is greater than the minimum preset distance, and the cable tension is greater than the maximum warning tension or less than the minimum warning tension, an alarm signal is sent to the drone controller and the power-off unit is controlled to disconnect the tether cable from the drone body.

[0045] Control the emergency power supply on the drone body to supply power to the drive components so that the drone body has the power for returning to base;

[0046] When the cable tension exceeds the maximum warning tension, the take-up and release unit is controlled to retract the tethered cable at a second preset speed until the cable tension exceeds the tension threshold.

[0047] When the cable tension is less than the minimum warning tension, the take-up and release unit is controlled to retract the tethered cable at a third preset speed until the cable tension is greater than the tension threshold.

[0048] The second preset speed is less than the third preset speed.

[0049] The present invention has at least the following beneficial effects:

[0050] In this invention, the drone body is powered by a high-voltage DC power supply. This high-voltage power supply allows for the use of thinner tether cables, reducing the weight per unit length and enabling the drone body to carry longer tether cables, thus increasing its operational range. Furthermore, by mounting the cable retraction unit on a power supply trolley, the trolley can be controlled when the drone body flies to a greater distance. As long as the distance between the drone body and the power supply trolley does not exceed the length of the tether cable, the drone body can fly to any position, significantly increasing its operational range. The cable retraction unit adjusts the speed of cable retrieval or release based on the tension of the tether cable and the real-time distance between the drone body and the power supply trolley, ensuring the tether cable remains taut and reducing the probability of redundant cable between the power supply trolley and the drone body getting tangled in obstacles, thus limiting the operational range. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of a tethered power supply drone provided in an embodiment of the present invention;

[0053] Figure 2 for Figure 1 A simplified structural diagram of the UAV body when it is far from the power supply vehicle;

[0054] Figure 3 for Figure 1 A simplified structural diagram of the UAV body when it approaches the power supply vehicle;

[0055] Figure 4 This is a flowchart illustrating the first embodiment of the UAV control method of the present invention;

[0056] Figure 5 This is a flowchart illustrating the second embodiment of the UAV control method of the present invention;

[0057] Figure 6 This is a flowchart illustrating the third embodiment of the UAV control method of the present invention;

[0058] Figure 7 This is a flowchart illustrating the fourth embodiment of the UAV control method of the present invention;

[0059] Figure 8 This is a flowchart illustrating the fifth embodiment of the UAV control method of the present invention;

[0060] Figure 9 This is a flowchart illustrating the sixth embodiment of the UAV control method of the present invention;

[0061] Figure 10 This is a flowchart illustrating the seventh embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0062] Explanation of reference numerals in the attached figures:

[0063] 100-Tethered Powered Unmanned Aerial Vehicle; 1-Unmanned Aerial Vehicle Body; 2-Power Supply Trolley; 3-Tethered Cable; 4-Cable Retrieval Unit; 5-Cable Bracket. Detailed Implementation

[0064] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0065] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0066] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0067] This invention provides a tethered powered unmanned aerial vehicle (UAV) and a UAV control method. Figures 1 to 10 This invention provides a specific embodiment of a tethered power supply drone and a drone control method.

[0068] like Figure 1 As shown, this embodiment of the invention provides a tethered power supply drone 100, including a drone body 1, a power supply trolley 2, a tether cable 3, and a take-up / release unit 4 for retrieving or releasing the tether cable 3. The power supply trolley 2 includes a high-voltage DC power supply for converting 380V / 50Hz three-phase AC power into 1000V DC power. The drone body 1 is electrically connected to the high-voltage DC power supply via the tether cable 3. The take-up / release unit 4 is mounted on the power supply trolley 2. The power supply trolley 2, the take-up / release unit 4, and the drone body 1 are sequentially connected via the tether cable 3. The take-up / release unit 4 can adjust the speed of retrieving or releasing the tether cable 3 according to the tension of the tether cable 3 and the real-time distance between the drone body 1 and the power supply trolley 2, so that the tether cable 3 is kept taut.

[0069] In this invention, the drone body 1 is powered by a high-voltage DC power supply. This high-voltage power supply allows for the use of a thinner tether cable 3, reducing the weight of the tether cable 3 per unit length. This enables the drone body 1 to carry a longer tether cable 3, increasing its range of motion. Furthermore, by mounting the cable retraction unit 4 on the power supply trolley 2, the movement of the power supply trolley 2 can be controlled when the drone body 1 flies to a greater distance. As long as the distance between the drone body 1 and the power supply trolley 2 does not exceed the length of the tether cable 3, the drone body 1 can fly to any position, greatly enhancing its range of motion. The cable retraction unit 4 adjusts the speed of retrieving or releasing the tether cable 3 based on its tension and the real-time distance between the drone body 1 and the power supply trolley 2, ensuring the tether cable 3 remains taut and reducing the probability of redundant cable between the power supply trolley 2 and the drone body 1 becoming entangled in obstacles, thus reducing the range of motion.

[0070] It should be noted that the tension of the tethered cable 3 is detected by integrating a tension sensor in the cable take-up and release unit 4. At the same time, a UWB base station is set on the power supply trolley 2, and a UWB tag is set near the connection between the UAV body 1 and the tethered cable 3. The real-time distance between the UAV body 1 and the power supply trolley 2 is obtained by UWB positioning technology. The specific positioning principle is existing technology and will not be described in detail.

[0071] Preferably, the position of the tethered cable 3 can be indirectly adjusted by controlling the movement of the drone body 1 and the power supply trolley 2, so that the tethered cable 3 avoids obstacles and prevents it from getting tangled in obstacles, which would reduce the range of movement of the drone body 1.

[0072] In some embodiments, such as Figure 1 As shown, the tethered power supply drone 100 also includes a cable bracket 5, which is mounted on the cable reeling unit 4. The cable bracket 5 has a slot for the tethered cable 3 to pass through. The power supply trolley 2, the cable reeling unit 4, the cable bracket 5, and the drone body 1 are connected in sequence via the tethered cable 3. This configuration increases the release height of the tethered cable 3 by using the cable bracket 5, ensuring that the release height of the tethered cable 3 is higher than ground obstacles, thereby reducing the probability of the tethered cable 3 getting tangled in obstacles.

[0073] When the tethered cable 3 becomes entangled in an obstacle, if the drone body 1 continues to fly, the tension on the tethered cable 3 will continue to increase until the cable breaks. The drone body 1 will then fall due to a lack of power. Therefore, in some embodiments, such as... Figure 1 As shown, the drone body 1 includes an emergency power supply, a drive assembly, and a power-off assembly for disconnecting the tether cable from the drone body 1. Both the emergency power supply and the high-voltage DC power supply of the power trolley 2 are electrically connected to the drive assembly. The emergency power supply can supply power to the drive assembly after the high-voltage DC power supply stops supplying power. With this configuration, when the tether cable 3 breaks, causing the high-voltage DC power supply to stop supplying power, the emergency power supply can supply power to the drive assembly, ensuring that the drone body 1 has sufficient power for return. Simultaneously, if the tether cable 3 is entangled in an obstacle but has not yet broken, the power-off assembly can actively disconnect the tether cable from the drone body 1 to facilitate the subsequent return of the drone body 1.

[0074] Those skilled in the art will understand that the above-described structure does not constitute a limitation on the tethered power supply drone 100, and may include more or fewer components than described above, or combine certain components, or have different component arrangements.

[0075] like Figure 4 As shown, based on the tethered power supply UAV 100, this embodiment of the invention also provides a UAV control method, including the following steps:

[0076] Step S10: After the UAV body 1 takes off, control the cable reeling unit 4 to release the tether cable 3 at a first preset speed.

[0077] It should be noted that the first preset speed is 2m / s. Since most of the tether cable 3 is wound on the reel of the take-up and release unit 4 before the drone body 1 takes off, the first preset speed is relatively fast and can quickly release part of the tether cable 3 to avoid affecting the take-off of the drone body 1.

[0078] Step S20: Obtain the real-time controlled direction of the UAV body 1, the tension of the tether cable 3, and the real-time distance between the UAV body 1 and the power supply trolley 2.

[0079] It should be noted that the real-time controlled direction can be obtained by receiving the control signal from the UAV controller, the tension of the tether cable 3 can be detected by the tension sensor integrated in the cable take-up and release unit 4, and the real-time distance can be obtained by the cooperation of the UWB base station on the power supply trolley 2 and the UWB tag on the UAV body 1.

[0080] Step S30: Determine the winding and unwinding mode and speed of the tethered cable 3 according to the real-time controlled direction, the cable tension and the real-time distance, and control the winding and unwinding unit 4 to wind and unwind the tethered cable 3 according to the winding and unwinding mode and speed.

[0081] Step S40: Determine the moving direction and speed of the power supply trolley 2 based on the real-time controlled direction and the real-time distance, and control the movement of the power supply trolley 2 based on the moving direction and speed.

[0082] Step S50: When the UAV body 1 completes the operation and returns, control the cable reeling unit 4 to retrieve the tethered cable 3.

[0083] In this invention, the drone control method includes the following steps: after the drone body 1 takes off, the cable reeling unit 4 is controlled to release the tether cable 3 at a first preset speed; the real-time controlled direction of the drone body 1, the tension of the tether cable 3, and the real-time distance between the drone body 1 and the power supply trolley 2 are obtained; the reeling-in / reeling mode and speed of the tether cable 3 are determined according to the real-time controlled direction, the cable tension, and the real-time distance, and the cable reeling unit 4 is controlled to reel in and release the tether cable 3 according to the reeling-in / reeling mode and speed; the moving direction and speed of the power supply trolley 2 are determined according to the real-time controlled direction and the real-time distance, and the power supply trolley 2 is controlled to move according to the moving direction and speed; when the drone body 1 completes the operation and returns, the cable reeling unit 4 is controlled to retrieve the tether cable 3. This invention controls the movement of the power supply trolley 2 when the drone body 1 flies to a relatively far distance. As long as the distance between the drone body 1 and the power supply trolley 2 does not exceed the length of the tether cable 3, the drone body 1 can fly to any position, greatly improving the range of motion of the drone body 1. At the same time, the cable retraction unit 4 adjusts the speed of retrieving or releasing the tether cable 3 according to the tension of the tether cable 3 and the real-time distance between the drone body 1 and the power supply trolley 2, so that the tether cable 3 is always taut, reducing the probability that redundant cables between the power supply trolley 2 and the drone body 1 will get tangled in obstacles, thus reducing the range of motion.

[0084] refer to Figure 5 , Figure 5 This is a flowchart illustrating the second embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0085] Based on the first embodiment described above, the UAV control method of this embodiment includes the following in step S30:

[0086] Step S31: Determine the deployment and retraction mode of the tethered cable 3 based on the real-time controlled direction and the real-time distance.

[0087] Step S32: Determine the winding and unwinding speed of the tethered cable 3 based on the winding and unwinding mode, the cable tension, and the real-time distance.

[0088] It should be noted that the release and retraction modes are divided into release mode and retraction mode. In release mode, the tethered cable 3 is in a slack state for a long time, and the detected cable tension has a low impact on the release and retraction speed. In retraction mode, the tethered cable 3 is in a taut state for a long time, and the detected cable tension has a high impact on the release and retraction speed. Therefore, the determination of the release and retraction speed is related to the release and retraction mode.

[0089] Step S33: Control the take-up and take-up unit 4 to take up and take down the mooring cable 3 according to the take-up and take-up mode and take-up and take-up speed.

[0090] In this embodiment, the winding and unwinding mode of the tethered cable 3 is first determined according to the real-time controlled direction and the real-time distance. Then, the winding and unwinding speed of the tethered cable 3 is determined according to the winding and unwinding mode, the cable tension, and the real-time distance. Finally, the winding and unwinding unit 4 is controlled to wind and unwind the tethered cable 3 according to the winding and unwinding mode and the winding and unwinding speed.

[0091] refer to Figure 6 , Figure 6 This is a flowchart illustrating the third embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0092] Based on the second embodiment described above, the UAV control method of this embodiment includes the following in step S31:

[0093] Step S311: When the real-time distance in the last two unit time periods gradually increases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply trolley 2 is greater than 90 degrees, it is determined that the tethered cable 3 is in release mode.

[0094] It should be noted that the unit time can be set according to actual needs. For example, in this embodiment, the unit time can be set to 0.1s.

[0095] It should be noted that since the power supply vehicle 2 is equipped with a UWB base station and the UWB tag is equipped with a UWB tag, the distance and azimuth between the UWB base station and the UWB tag can be obtained through UWB positioning technology, thereby determining the direction of the line connecting the two points from the UWB tag to the UWB base station, which is equivalent to obtaining the direction of the line connecting the UWB tag to the power supply vehicle 2.

[0096] It should be noted that, as Figure 2 As shown, when the real-time distance in the last two unit time periods gradually increases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is greater than 90 degrees, it indicates that the movement trend of the UAV body 1 is moving away from the power supply vehicle 2, and the tethered cable 3 is determined to be in release mode.

[0097] Step S312: When the real-time distance in the last two unit time periods gradually decreases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is less than 90 degrees, it is determined that the tethered cable 3 is in the recovery mode.

[0098] It should be noted that, as Figure 3 As shown, when the real-time distance between the two most recent units of time gradually decreases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is less than 90 degrees, it indicates that the movement trend of the UAV body 1 is to move closer to the power supply vehicle 2, and the tethered cable 3 is determined to be in the recovery mode.

[0099] In this embodiment, when the real-time distance in the last two unit time intervals gradually increases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply trolley 2 is greater than 90 degrees, it indicates that the movement trend of the UAV body 1 is moving away from the power supply trolley 2, and the tethered cable 3 is determined to be in release mode. When the real-time distance in the last two unit time intervals gradually decreases, and the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply trolley 2 is less than 90 degrees, it indicates that the movement trend of the UAV body 1 is moving closer to the power supply trolley 2, and the tethered cable 3 is determined to be in retrieval mode.

[0100] refer to Figure 7 , Figure 7 This is a flowchart illustrating the fourth embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0101] Based on the second embodiment described above, the UAV control method of this embodiment includes the following in step S32:

[0102] Step S327: When the mooring cable 3 is in release mode, the real-time distance is substituted into the first function to calculate the real-time cable release speed.

[0103] Step S328: When the tethered cable 3 is in the retrieval mode and the cable tension is less than the minimum preset tension, the real-time distance and the maximum cable length are substituted into the second function to calculate the real-time cable retrieval speed.

[0104] Step S329: When the tethered cable 3 is in the retrieval mode and the cable tension is greater than the maximum preset tension, the real-time distance and the maximum cable length are substituted into the third function to calculate the real-time cable retrieval speed.

[0105] The first function is:

[0106]

[0107] The second function is:

[0108] v2 = K p ·(L max -D)+v0

[0109] The third function is:

[0110] v2 = K p ·(L max -D)-v0

[0111] v1 is the real-time line-laying speed, v2 is the real-time line-retrieval speed, D is the real-time distance, and L is the distance between the lines. max K is the maximum length of the cable. p K i and K d These are the real-time proportional, integral, and derivative parameters, respectively, and v0 is the gain speed.

[0112] It should be noted that when the mooring cable 3 is in the release mode, the mooring cable 3 is in a slack state for a long time. At this time, the detected cable tension has a low impact on the retraction and release speed. Therefore, it is not necessary to determine the cable tension in the release mode.

[0113] It should be noted that in the first function, the real-time cable release speed is dynamically adjusted according to the real-time distance using a PID algorithm. However, parameters such as Kp, Ki, and Kd need to be set according to actual needs. For example, increasing Kp can accelerate the response to distance changes, but if Kp is too large, it will cause excessive cable release when the UAV body 1 is far from the power supply trolley 2, resulting in too much redundant cable that is easily tangled in obstacles. Increasing Ki helps to eliminate the accumulation of historical errors, making the changes in the real-time cable release speed smoother. However, if Ki is too large, it will cause integral saturation, leading to oscillating changes in the cable release speed and increasing the mechanical wear of the cable take-up and release unit 4. Increasing Kd can predict environmental disturbances and sudden distance changes, thereby adjusting the cable release speed in advance. However, if Kd is too large, it will cause over-response to small distance changes, resulting in excessive cable release in a short period of time.

[0114] It should be noted that when the tethered cable 3 is in the retrieval mode, it is normally taut. If the cable tension is less than the minimum preset tension, it means that the tethered cable 3 is slack and the retrieval speed needs to be increased. Therefore, the gain speed v0 needs to be added to the second function. If the cable tension is greater than the maximum preset tension, it means that the tethered cable 3 is too taut and the retrieval speed needs to be reduced. Therefore, the gain speed v0 needs to be subtracted from the third function.

[0115] It should be noted that the minimum preset tension, the maximum preset tension, and the gain speed can all be set according to the actual situation. In this embodiment, the minimum preset tension is 50N, the maximum preset tension is 150N, and the gain speed is 0.5m / s.

[0116] In this embodiment, when the tethered cable 3 is in release mode, the real-time distance is substituted into a first function to calculate the real-time release speed; when the tethered cable 3 is in retraction mode and the cable tension is less than a minimum preset tension, the real-time distance and the maximum cable length are substituted into a second function to calculate the real-time retraction speed; when the tethered cable 3 is in retraction mode and the cable tension is greater than a maximum preset tension, the real-time distance and the maximum cable length are substituted into a third function to calculate the real-time retraction speed.

[0117] refer to Figure 8 , Figure 8 This is a flowchart illustrating the fifth embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0118] Based on the fourth embodiment described above, the UAV control method of this embodiment further includes, in step S32:

[0119] Step S321: Obtain the real-time wind speed at the work site.

[0120] It should be noted that since wind speed causes the tethered cable 3 to swing, directly affecting the stability of PID control, it is necessary to add wind speed as an auxiliary variable to optimize the proportional, integral and derivative parameters. The real-time wind speed can be obtained by detecting the wind speed sensor installed on the UAV body 1.

[0121] Step S322: Determine the increments of the proportional, integral, and derivative parameters based on the real-time wind speed.

[0122] It should be noted that the real-time wind speed is set to v. w The increment of the proportional parameter is set to ΔK. p The increment of the integral parameter is set to ΔK. i The increment of the differential parameter is set as ΔK. d .

[0123] ΔK p The calculation formula is:

[0124] ΔK p =-α·ln(1+|v w |)

[0125] ΔK i The calculation formula is:

[0126]

[0127] ΔK d The calculation formula is:

[0128] ΔK d =δ·|v w |

[0129] Where α is the proportional gain attenuation coefficient, with a value of 0.1; β is the integral gain suppression coefficient, with a value of 0.05; γ is the nonlinearity correction factor, with a value of 0.01; and δ is the differential gain enhancement coefficient, with a value of 0.15.

[0130] Step S323: Calculate the real-time proportional parameter based on the preset proportional parameter and the proportional parameter increment.

[0131] It should be noted that the preset ratio parameter is 0.5, and the real-time ratio parameter is the sum of the preset ratio parameter and the ratio parameter increment.

[0132] Step S324: Calculate the real-time integral parameters based on the preset integral parameters and the integral parameter increment.

[0133] It should be noted that the preset integration parameter is 0.2, and the real-time integration parameter is the sum of the preset integration parameter and the increment of the integration parameter.

[0134] Step S325: Calculate the real-time differential parameters based on the preset differential parameters and the differential parameter increments.

[0135] It should be noted that the preset differential parameter is 0.1, and the real-time differential parameter is the sum of the preset differential parameter and the increment of the differential parameter.

[0136] Step S326: Iteratively update the first function, the second function, and the third function according to the real-time proportional parameter, the real-time integral parameter, and the real-time differential parameter, respectively.

[0137] It should be noted that the functions obtained through iterative updates based on the current wind speed can be used as functions for the next unit of time.

[0138] It should be noted that there is no explicit execution order between steps S321 to S326 in the fifth embodiment and steps S327 to S329 in the fourth embodiment. The steps in the fifth embodiment are not executed first and then the steps in the fourth embodiment are executed.

[0139] In this embodiment, the real-time wind speed of the work site is first obtained. Then, the increments of the proportional, integral, and derivative parameters are determined according to the real-time wind speed. Next, the real-time proportional parameter is calculated according to the preset proportional parameter and the increment of the proportional parameter. The real-time integral parameter is calculated according to the preset integral parameter and the increment of the integral parameter. The real-time derivative parameter is calculated according to the preset derivative parameter and the increment of the derivative parameter. Finally, the first function, the second function, and the third function are iteratively updated according to the real-time proportional parameter, the real-time integral parameter, and the real-time derivative parameter, respectively.

[0140] refer to Figure 9 , Figure 9 This is a flowchart illustrating the sixth embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0141] Based on the first embodiment described above, the UAV control method of this embodiment includes the following in step S40:

[0142] Step S41: When the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is greater than 90 degrees, and the real-time distance in the last two unit time periods gradually increases and the real-time distance is greater than the maximum preset distance, the real-time moving speed of the UAV body 1 is obtained.

[0143] It should be noted that, as Figure 2 As shown, when the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is greater than 90 degrees, and the real-time distance in the last two unit time periods gradually increases, it indicates that the movement trend of the UAV body 1 is moving away from the power supply vehicle 2. The real-time distance being greater than the maximum preset distance indicates that most of the tethered cables 3 have been released. If the UAV body 1 continues to fly, it will be limited by the length of the cables.

[0144] Step S42: Determine the moving direction of the power supply vehicle 2 based on the real-time controlled direction of the UAV body 1, so that the moving direction of the power supply vehicle 2 is consistent with the controlled direction of the UAV body 1 in the horizontal direction.

[0145] It should be noted that the controlled direction of the UAV body 1 in the horizontal direction can be obtained from the real-time controlled direction of the UAV body 1, and the moving direction of the power supply trolley 2 is consistent with the controlled direction of the UAV body 1 in the horizontal direction.

[0146] Step S43: Determine the moving speed of the power supply vehicle 2 based on the real-time moving speed and real-time controlled direction of the UAV body 1, so that the moving speed of the power supply vehicle 2 is greater than the moving speed of the UAV body 1 in the horizontal direction.

[0147] It should be noted that the horizontal movement speed of the UAV body 1 can be obtained based on its real-time moving speed and real-time controlled direction. The movement speed of the power supply trolley 2 is generally set to 1.1 times the horizontal movement speed of the UAV body 1, but can also be set to other multiples depending on the actual situation.

[0148] Step S44: Control the power supply trolley 2 to move according to the moving direction and speed until the trend of the real-time distance change changes from decreasing to increasing within a preset time.

[0149] It should be noted that the preset time can be set to two or three units of time. When the trend of the real-time distance changes from decreasing to increasing within the preset time, it indicates that the distance between the power supply trolley 2 and the UAV body 1 in the current direction reaches its minimum within the preset time. At this time, the power supply trolley 2 is controlled to stop moving.

[0150] In this embodiment, when the angle between the real-time controlled direction and the line connecting the UAV body 1 to the power supply vehicle 2 is greater than 90 degrees, and the real-time distance in the last two unit time intervals gradually increases and the real-time distance is greater than the maximum preset distance, the real-time moving speed of the UAV body 1 is obtained. Then, the moving direction of the power supply vehicle 2 is determined according to the real-time controlled direction of the UAV body 1, so that the moving direction of the power supply vehicle 2 is consistent with the controlled direction of the UAV body 1 in the horizontal direction. The moving speed of the power supply vehicle 2 is determined according to the real-time moving speed of the UAV body 1 and the real-time controlled direction, so that the moving speed of the power supply vehicle 2 is greater than the moving speed of the UAV body 1 in the horizontal direction. Finally, the movement of the power supply vehicle 2 is controlled according to the moving direction and speed until the trend of the change in the real-time distance changes from decreasing to increasing within a preset time interval.

[0151] refer to Figure 10 , Figure 10 This is a flowchart illustrating the seventh embodiment of the unmanned aerial vehicle (UAV) control method of the present invention.

[0152] Based on the first embodiment described above, the UAV control method in this embodiment further includes:

[0153] Step S60: When the real-time distance is greater than the minimum preset distance, and the cable tension is greater than the maximum warning tension or less than the minimum warning tension, an alarm signal is sent to the UAV controller and the power-off unit is controlled to disconnect the tethered cable 3 from the UAV body 1.

[0154] It should be noted that the maximum warning tension is set to 180N and the minimum warning tension is set to 30N. When the real-time distance is greater than the minimum preset distance, it indicates that the UAV body 1 is in normal operation. However, if the cable tension is greater than the maximum warning tension or less than the minimum warning tension, it indicates that the tether cable 3 is about to break or has already broken. At this time, an alarm signal needs to be sent to the UAV controller, and the power-off unit should be controlled to disconnect the tether cable 3 from the UAV body 1 to ensure that the connection between the tether cable 3 and the UAV body 1 is broken, so as to avoid affecting the subsequent return of the UAV body 1.

[0155] Step S70: Control the emergency power supply on the UAV body 1 to supply power to the drive components so that the UAV body 1 has enough power for returning to base.

[0156] Step S80: When the cable tension is greater than the maximum warning tension, control the take-up and release unit 4 to retract the tethered cable 3 at a second preset speed until the cable tension is greater than the tension threshold.

[0157] It should be noted that the tension threshold is 200N. When the cable tension is greater than the maximum warning tension, it means that the tethered cable 3 may be tangled on an obstacle. The cable take-up and release unit 4 can be controlled to take back the tethered cable 3 at a slower speed to avoid the cable 3 breaking due to excessive speed. When the cable tension is greater than the tension threshold, it means that taking back the cable will cause it to break directly, so take-back is stopped.

[0158] Step S90: When the cable tension is less than the minimum warning tension, control the take-up and release unit 4 to retract the tethered cable 3 at a third preset speed until the cable tension is greater than the tension threshold.

[0159] It should be noted that when the cable tension is less than the minimum warning tension, it means that the tethered cable 3 may not be tangled in the obstacle. The cable reeling unit 4 can be controlled to reel in the tethered cable 3 at a relatively fast speed. When the cable tension is greater than the tension threshold, it means that the tethered cable 3 is tangled in the obstacle during the retrieval process. If the cable is retrieved again, it will cause the cable to break directly. Therefore, the retrieval is stopped.

[0160] In this embodiment, when the real-time distance is greater than the minimum preset distance, and the cable tension is greater than the maximum warning tension or less than the minimum warning tension, an alarm signal is sent to the UAV controller and the power-off unit is controlled to disconnect the tethered cable 3 from the UAV body 1. Then, the emergency power supply on the UAV body 1 is controlled to supply power to the drive components so that the UAV body 1 has enough power for return. When the cable tension is greater than the maximum warning tension, the cable reeling unit 4 is controlled to reel in the tethered cable 3 at a second preset speed until the cable tension is greater than the tension threshold. When the cable tension is less than the minimum warning tension, the cable reeling unit 4 is controlled to reel in the tethered cable 3 at a third preset speed until the cable tension is greater than the tension threshold.

[0161] It should be understood that although the steps in the flowcharts of this application's embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0162] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0163] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0164] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0165] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0166] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tethered, powered unmanned aerial vehicle (UAV), characterized in that, The device includes a drone body, a power supply trolley, a tether cable, and a cable retraction / release unit for retrieving or releasing the tether cable. The power supply trolley includes a high-voltage DC power supply for converting 380V / 50Hz three-phase AC power into 1000V DC power. The drone body is electrically connected to the high-voltage DC power supply via the tether cable. The cable retraction / release unit is mounted on the power supply trolley. The power supply trolley, the cable retraction / release unit, and the drone body are sequentially connected via the tether cable. The cable retraction / release unit can adjust the speed of retrieving or releasing the tether cable based on the tension of the tether cable and the real-time distance between the drone body and the power supply trolley, so that the tether cable is kept taut.

2. The tethered power supply UAV as described in claim 1, characterized in that, It also includes a cable bracket, which is disposed on the cable take-up and release unit. The cable bracket has a clamping groove for the tethered cable to pass through. The power trolley, the cable take-up and release unit, the cable bracket and the UAV body are connected in sequence through the tethered cable.

3. The tethered power supply UAV as described in claim 1, characterized in that, The UAV body includes an emergency power supply, a drive assembly, and a power-off assembly for disconnecting the tether cable from the UAV body. The emergency power supply and the high-voltage DC power supply of the power supply trolley are both electrically connected to the drive assembly. The emergency power supply can supply power to the drive assembly after the high-voltage DC power supply stops supplying power.

4. A method for controlling a drone, based on the tethered, powered drone as described in any one of claims 1 to 3, characterized in that, Includes the following steps: After the drone takes off, the cable reeling unit is controlled to release the tether cable at a first preset speed. The real-time controlled direction of the UAV body, the tension of the tether cable, and the real-time distance between the UAV body and the power supply trolley are obtained. The take-up and take-up mode and speed of the tethered cable are determined based on the real-time controlled direction, the cable tension, and the real-time distance, and the take-up and take-up unit is controlled to take up and take down the tethered cable according to the take-up and take-up mode and speed. The moving direction and speed of the power supply trolley are determined based on the real-time controlled direction and the real-time distance, and the movement of the power supply trolley is controlled based on the moving direction and speed. When the UAV completes its operation and returns to base, the cable reeling unit is controlled to retrieve the tethered cable.

5. The UAV control method as described in claim 4, characterized in that, The step of determining the take-up and release mode and speed of the tethered cable based on the real-time controlled direction, the cable tension, and the real-time distance, and controlling the take-up and release unit to take up and release the tethered cable according to the take-up and release mode and speed, includes: The deployment and retraction mode of the tethered cable is determined based on the real-time controlled direction and the real-time distance; The retrieval speed of the tethered cable is determined based on the retrieval mode, the cable tension, and the real-time distance. The take-up and take-up unit is controlled to take up and take down the mooring cable according to the take-up and take-up mode and the take-up and take-up speed.

6. The UAV control method as described in claim 5, characterized in that, The step of determining the deployment and retraction mode of the tethered cable based on the real-time controlled direction and the real-time distance includes: When the real-time distance in the last two unit time periods gradually increases, and the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is greater than 90 degrees, it is determined that the tethered cable is in release mode. When the real-time distance between the two most recent units of time gradually decreases, and the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is less than 90 degrees, it is determined that the tethered cable is in the recovery mode.

7. The UAV control method as described in claim 5, characterized in that, Determining the retraction speed of the tethered cable based on the retraction mode, the cable tension, and the real-time distance includes: When the mooring cable is in release mode, the real-time distance is substituted into the first function to calculate the real-time release speed; When the tethered cable is in the retrieval mode and the cable tension is less than the minimum preset tension, the real-time distance and the maximum cable length are substituted into the second function to calculate the real-time cable retrieval speed. When the tethered cable is in retrieval mode and the cable tension is greater than the maximum preset tension, the real-time distance and the maximum cable length are substituted into the third function to calculate the real-time cable retrieval speed. The first function is: The second function is: v2=K p ·(L max -D)+v0 The third function is: v2=K p ·(L max -D)-v0 v1 is the real-time line-laying speed, v2 is the real-time line-retrieval speed, D is the real-time distance, and L is the distance between the lines. max K is the maximum length of the cable. p K i and K d These are the real-time proportional, integral, and derivative parameters, respectively, and v0 is the gain speed.

8. The UAV control method as described in claim 7, characterized in that, The step of determining the retraction speed of the tethered cable based on the retraction mode, the cable tension, and the real-time distance further includes: Obtain the real-time wind speed at the work site; The increments of the proportional, integral, and derivative parameters are determined based on the real-time wind speed. The real-time proportional parameter is calculated based on the preset proportional parameter and the increment of the proportional parameter; The real-time integral parameters are calculated based on the preset integral parameters and the increment of the integral parameters. The real-time differential parameters are calculated based on the preset differential parameters and the increments of the differential parameters; The first function, the second function, and the third function are iteratively updated based on the real-time proportional parameter, the real-time integral parameter, and the real-time differential parameter, respectively.

9. The UAV control method as described in claim 4, characterized in that, The step of determining the moving direction and speed of the power supply trolley based on the real-time controlled direction and the real-time distance, and controlling the movement of the power supply trolley based on the moving direction and speed, includes: When the angle between the real-time controlled direction and the line connecting the UAV body to the power supply vehicle is greater than 90 degrees, and the real-time distance in the last two unit time periods gradually increases and the real-time distance is greater than the maximum preset distance, the real-time moving speed of the UAV body is obtained. The movement direction of the power supply vehicle is determined based on the real-time controlled direction of the UAV body, so that the movement direction of the power supply vehicle is consistent with the controlled direction of the UAV body in the horizontal direction. The moving speed of the power supply vehicle is determined based on the real-time moving speed and real-time controlled direction of the UAV body, so that the moving speed of the power supply vehicle is greater than the moving speed of the UAV body in the horizontal direction. The power supply trolley is moved according to the moving direction and speed until the trend of the real-time distance change changes from decreasing to increasing within a preset time.

10. The UAV control method as described in claim 4, characterized in that, Also includes: When the real-time distance is greater than the minimum preset distance, and the cable tension is greater than the maximum warning tension or less than the minimum warning tension, an alarm signal is sent to the drone controller and the power-off unit is controlled to disconnect the tether cable from the drone body. Control the emergency power supply on the drone body to supply power to the drive components so that the drone body has the power for returning to base; When the cable tension exceeds the maximum warning tension, the take-up and release unit is controlled to retract the tethered cable at a second preset speed until the cable tension exceeds the tension threshold. When the cable tension is less than the minimum warning tension, the take-up and release unit is controlled to retract the tethered cable at a third preset speed until the cable tension is greater than the tension threshold. The second preset speed is less than the third preset speed.

Images