Motion compensated robotic arm apparatus for drone launch and recovery and method of use

Abstract

The application provides a motion compensation mechanical arm device for unmanned aerial vehicle launching and recovery and a use method thereof, which comprises a multi-section mechanical arm and a six-degree-of-freedom motion compensation mechanism, the bottom end of the multi-section mechanical arm is fixed on a rotary table, the top end is connected with the six-degree-of-freedom motion compensation mechanism, the rotary table realizes 360-degree rotation adjustment, the six-degree-of-freedom motion compensation mechanism is connected with a launching and recovery track, a flight attitude measurement system and a combined navigation system are arranged on the launching and recovery track, the multi-section mechanical arm performs vertical and lateral displacement compensation on the launching and recovery track, and the six-degree-of-freedom motion compensation mechanism reversely compensates the pitching, yawing and rolling angles of a ship, the application has the ship pose motion compensation capability, and further has the track and mechanical arm folding and storage capability, so that the demand for the overall resources of the ship is reduced.

Description

Technical Field

[0001] This application relates to the technical field of aviation support equipment, and more specifically, to a motion compensation robotic arm device for UAV launch and recovery and its usage method. Background Technology

[0002] Unmanned aerial vehicles (UAVs) are playing an increasingly important and diverse role in modern maritime law enforcement and rights protection activities. Fixed-wing UAVs, with their advantages of low risk, large payload capacity, long flight time, and high reliability, have already played a crucial role in aerial reconnaissance, surveillance, photography, and evidence collection in maritime law enforcement and rights protection activities worldwide. However, deploying and recovering fixed-wing UAVs in the field or on ships is extremely difficult. For deployment, technologies such as rocket-assisted launch and launch pad deployment have been developed; for recovery, technologies such as parachute recovery, net-based recovery, and skyhook recovery have been developed.

[0003] Chinese patent (CN107600445B) discloses a short-range, common-rail launch and recovery device for fixed-wing unmanned aerial vehicles (UAVs), applicable to short-range catapult launch and arrested recovery operations on ships. The main process is as follows: Under the guidance of a guidance system, the UAV travels along the track. An arresting hook rises from its back. As the UAV moves, the arresting hook engages the arresting cable first. After engagement, due to inertia, the UAV nose tilts upwards. A hook mounted on the nose passes through the mesh of the arresting net and opens its auxiliary hook. As the nose falls back under gravity, it catches the arresting net, thus achieving two-point fixation and safe recovery of the UAV. However, because the launch and recovery device's robotic arm is fixed to the ship platform, the ship's movement is transmitted to the robotic arm, causing it to sway. Although the robotic arm has some motion compensation capability, it cannot ensure that the track remains relatively stationary relative to the Earth's coordinates for a certain period, failing to address the impact of ship movement on the UAV launch and recovery operation.

[0004] Solving the technical challenges of how ship movement affects UAV launch and recovery is of great technical significance for realizing short-range co-orbit launch and recovery technology for fixed-wing UAVs. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a motion compensation robotic arm device and method for launching and recovering unmanned aerial vehicles (UAVs) in response to the above-mentioned problems. The device can be used to overcome or compensate for part of the ship's motion on the suspended track for launching and recovering UAVs within a certain period of time, thereby creating favorable conditions for UAV launch and recovery operations.

[0006] The embodiments of this application are implemented as follows:

[0007] This application provides a motion compensation robotic arm device for UAV launch and recovery, characterized in that it includes a multi-segment robotic arm and a six-degree-of-freedom motion compensation mechanism. The bottom end of the multi-segment robotic arm is fixed to a turntable, and the top end is connected to the six-degree-of-freedom motion compensation mechanism. The turntable can be rotated 360°. The six-degree-of-freedom motion compensation mechanism is configured and connected to a launch and recovery track. An attitude measurement system and a combined navigation system are installed on the launch and recovery track. The multi-segment robotic arm performs displacement compensation on the launch and recovery track, and the six-degree-of-freedom motion compensation mechanism reverses the ship's pitch, yaw, and roll angles.

[0008] In some alternative implementations, the multi-segment robotic arm includes a main arm, a middle arm, and a forearm that are sequentially hinged together, with a main arm drive mechanism, a middle arm drive mechanism, and a forearm drive mechanism sequentially provided at each hinge point.

[0009] In some optional implementations, the six-degree-of-freedom motion compensation mechanism includes a pitch compensation rotary actuator, a yaw compensation rotary actuator, and a roll compensation drive mechanism. The pitch compensation rotary actuator is fixed to the top of the robotic arm. The yaw compensation rotary actuator is connected to the pitch compensation rotary actuator via a pitch support. The roll compensation drive mechanism is connected to the yaw compensation rotary actuator via a yaw support. The yaw support is equipped with a rotary guide mechanism connected to the launch and recovery track.

[0010] In some alternative implementations, the pitch compensation slewing actuation mechanism and the yaw compensation slewing actuation mechanism are respectively slewing drive devices, the roll compensation drive mechanism is a roll drive hydraulic cylinder, the pitch support is a plate with a 90° bend, the pitch compensation slewing actuation mechanism is vertically mounted at one end of the pitch support, the yaw compensation slewing actuation mechanism is horizontally mounted at the other end of the pitch support, the pitch drive hydraulic cylinder is fixed on the yaw support, and the telescopic rod is connected to the launch and recovery track.

[0011] In some alternative implementations, the bow rocker bracket is a cylindrical frame structure with an open bottom, a bracket at the top connected to the roll drive hydraulic cylinder, and slewing mounting positions at both ends, with the slewing guide mechanism installed at the slewing mounting positions.

[0012] In some alternative implementations, the rotary guide mechanism is a bottom-opening annular structure configured with the bow rocker bracket, with multiple guide wheel mounting grooves on its outer circumference, the guide wheels being embedded in the guide wheel mounting grooves, and the guide wheels contacting the inner wall of the rotary mounting position.

[0013] In some alternative implementations, the launch and recovery track includes two track sections and a track beam transition section connecting the two track sections, and the slewing guide mechanism is connected to the track beam transition section.

[0014] In some optional implementations, the boom drive mechanism is a boom drive hydraulic cylinder, the middle boom drive mechanism is a middle boom drive hydraulic cylinder, and the forearm drive mechanism includes a transition arm, a forearm drive hydraulic cylinder, and a folding and storage hydraulic cylinder. The transition arm is located at the connection between the middle boom and the forearm and is hinged to the middle boom and forearm via a pin. The forearm drive hydraulic cylinder is fixed to the middle boom and connected to the transition arm via a telescopic rod. The folding and storage hydraulic cylinder is fixed to the transition arm and connected to the forearm via a telescopic rod.

[0015] In some optional implementations, the vertical displacement compensation is 0-1.5m, the lateral displacement compensation is 0-2m, and the reverse compensation is ≥2° for the ship's pitch angle, ≥2° for the bow angle, and ≥5° for the roll angle.

[0016] The method of using a motion-compensating robotic arm device for UAV launch and recovery is characterized by comprising the following steps:

[0017] S1) A high-precision attitude measurement system installed on the launch and recovery track is used to collect the heading angle, roll angle, pitch angle and corresponding angular acceleration data of the launch and recovery track, which serves as the basis for launch and recovery track angle compensation; the heave, sway and pitch position data of the leading point of the launch and recovery track are collected by the integrated navigation system, which serves as the basis for track position compensation.

[0018] S2) Based on the absolute position information and angle data measured by the attitude measurement system and the integrated navigation system, a motion coordinate system is established, and the coordinate transformation matrix is ​​derived. The motion of each hydraulic cylinder is decomposed into the action of each hydraulic cylinder. The angle and displacement changes caused by the ship's motion are compensated in reverse by driving the cooperative motion of the hydraulic cylinder. The hydraulic cylinder displacement sensor is used to measure the extension of the hydraulic cylinder, thereby realizing closed-loop control.

[0019] The beneficial effects of this application are as follows: The motion compensation robotic arm device and its usage method for UAV launch and recovery provided by this application can compensate for the motion of the ship within a certain range, thereby creating favorable conditions for UAV launch and recovery operations, improving the recovery success rate, reducing recovery safety risks, and reducing the performance requirements of the guidance system and UAV flight control system; the multi-segment robotic arm can realize the folding and storage of the launch and recovery device, which can significantly save the overall resources of the ship. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of the six-degree-of-freedom motion compensation mechanism according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of the pitch support according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the bow rocker bracket according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the rotary guide mechanism according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the transition section of the track beam in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0033] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0035] This invention proposes a motion-compensating robotic arm device for UAV launch and recovery, addressing the impact of ship swaying motion on UAV launch and recovery. It allows the suspended track used for launching and recovering UAVs to overcome or compensate for some of the ship's motion within a certain timeframe, creating favorable conditions for UAV launch and recovery operations. Figure 1As shown, it mainly includes a multi-segment robotic arm and a six-degree-of-freedom motion compensation mechanism 1. The bottom end of the multi-segment robotic arm is fixed on a turntable 2, and the top end is connected to the six-degree-of-freedom motion compensation mechanism. The turntable can achieve 360° rotation adjustment. The six-degree-of-freedom motion compensation mechanism is configured and connected to the launch and recovery track 3. An attitude measurement system and a combined navigation system are installed on the launch and recovery track. The multi-segment robotic arm performs displacement compensation on the launch and recovery track, and the six-degree-of-freedom motion compensation mechanism performs reverse compensation for the ship's pitch, yaw, and roll angles.

[0036] The multi-segment robotic arm includes a main arm 4, a middle arm 5, and a forearm 6 connected in sequence by hinges. Corresponding to each hinge point, a main arm drive mechanism, a middle arm drive mechanism, and a forearm drive mechanism are sequentially provided. The main arm drive mechanism is a main arm drive hydraulic cylinder 7, the middle arm drive mechanism is a middle arm drive hydraulic cylinder 8, and the forearm drive mechanism includes a transition arm 9, a forearm drive hydraulic cylinder 10, and a folding and storage hydraulic cylinder 11. The transition arm is located at the connection between the middle arm and the forearm, and is hinged to both the middle arm and the forearm via a pin. The forearm drive hydraulic cylinder is fixed to the middle arm, and its telescopic rod is connected to the transition arm. The folding and storage hydraulic cylinder is fixed to the transition arm, and its telescopic rod is connected to the forearm.

[0037] The turntable allows the entire robotic arm to rotate 360°. The main arm is driven to rotate by a hydraulic cylinder fixed to the turntable, enabling lifting and lowering. The main arm, pushed by the hydraulic cylinder, allows for a wide range of posture adjustment. The middle arm, also driven by a hydraulic cylinder fixed to the main arm, is lifted and lowered, assisting in a relatively large range of posture adjustment. The transition arm is used to take over the lifting and straightening operations of the forearm and middle arm. It also serves as the fulcrum for the extension rod of the forearm drive hydraulic cylinder and the fulcrum for the folding and retracting hydraulic cylinder. The forearm drive hydraulic cylinder, fixed to the forearm, works in conjunction with the folding and retracting hydraulic cylinder to achieve smaller-range lifting and lowering of the track, thus enabling posture adjustment.

[0038] Since the ship is always in a directional navigation state, the sway motion can be ignored. Therefore, the ship's displacement motion is mainly heave and sway. The compensation for heave and sway motion is mainly completed by the joint action of the boom drive hydraulic cylinder driving the boom, the middle boom drive hydraulic cylinder driving the middle boom, the forearm drive hydraulic cylinder driving the forearm, and the folding and storage hydraulic cylinder driving the launch and recovery track.

[0039] like Figure 2 As shown, the six-degree-of-freedom motion compensation mechanism includes a pitch compensation rotary actuator 11, a yaw compensation rotary actuator 12, and a roll compensation drive mechanism 13. The pitch compensation rotary actuator is fixed to the top of the robotic arm. The yaw compensation rotary actuator is connected to the pitch compensation rotary actuator via a pitch support 14. The roll compensation drive mechanism is connected to the yaw compensation rotary actuator via a pitch support 15. The pitch support is equipped with a rotary guide mechanism 16 that is connected to the launch and recovery track.

[0040] In some alternative implementations, the pitch-compensating rotary actuator and the yaw-compensating rotary actuator are respectively rotary drive devices, the roll-compensating drive mechanism is a roll-drive hydraulic cylinder, and the pitch support is a plate with a 90° bend (see...). Figure 3 The pitch compensation rotary actuator is vertically mounted at one end of the pitch support, the yaw compensation rotary actuator is horizontally mounted at the other end of the pitch support, the roll drive hydraulic cylinder is fixed on the yaw support, and the telescopic rod is connected to the launch and recovery track.

[0041] like Figure 4 As shown, the bow rocker bracket is a cylindrical frame structure with an open bottom. The top is equipped with a bracket 17 connected to the rocker drive hydraulic cylinder. Rotary mounting positions 18 are provided on both sides, and the rotary guide mechanism is installed in the rotary mounting position.

[0042] like Figure 5 As shown, the slewing guide mechanism is a bottom-opening annular structure configured with the bow rocker support. Multiple guide wheel mounting slots are provided on its outer circumference. Guide wheels 19 are embedded in these slots, and the guide wheels contact the inner wall of the slewing mounting position. The launch and recovery track includes two track sections and a track beam transition section 20 connecting the two track sections (see...). Figure 6 The rotary guide mechanism is connected to the transition section of the track beam.

[0043] The pitch compensation slewing actuator uses the end face of the forearm as the mounting surface. It achieves slewing operation through its own slewing hydraulic motor, thereby achieving reverse compensation of the ship's pitch angle within a certain range. The bow compensation slewing actuator is fixed to the pitch compensation slewing actuator via a pitch support. It also achieves slewing operation through a slewing hydraulic motor, thereby achieving reverse compensation of the ship's bow angle within a certain range.

[0044] The roll compensation drive hydraulic cylinder (cylinder end) uses the bracket extending from the bow support as its mounting base. Its rod end is fixedly connected to the support on the transition section of the track beam to fix the track and prevent it from moving along its length. The transition section of the track beam is fixed to the slewing guide mechanism by bolts. The extension and retraction of the roll compensation drive hydraulic cylinder drives the track to achieve roll compensation. The slewing guide mechanism achieves slewing motion on the bow support through its own guide wheels.

[0045] The triggering mechanism for ship motion compensation is as follows: the heading angle, roll angle, pitch angle and corresponding angular acceleration data of the launch and recovery trajectory are collected by the attitude measurement system, which serves as the basis for launch and recovery trajectory angle compensation; the heave, sway and pitch position data of the robotic arm endpoint are collected by the integrated navigation system, which serves as the basis for launch and recovery trajectory position compensation.

[0046] Based on the absolute position and angle data measured by the attitude and bearing measurement system and the integrated navigation system, a motion coordinate system is established, and the coordinate transformation matrix is ​​derived and then decomposed into the action of each hydraulic cylinder. The coordinated motion of the driving hydraulic cylinders compensates for the angle and displacement changes caused by the ship's motion, and hydraulic cylinder displacement sensors are used to measure the extension of the hydraulic cylinders, thereby achieving closed-loop control.

[0047] Based on this invention, the following ship motion compensation capabilities can be achieved:

[0048] Vertical displacement compensation is 0–1.5 m, lateral displacement compensation is 0–2 m, and reverse compensation is ≥2° for pitch angle, ≥2° for bow angle, and ≥5° for roll angle.

[0049] All hydraulic cylinders and hydraulic motors are powered by the same hydraulic power module, which also powers the launch and recovery operations of the UAV.

Claims

1. A motion-compensating robotic arm device for UAV launch and recovery, characterized in that, The system includes a multi-segment robotic arm and a six-degree-of-freedom (DOF) motion compensation mechanism. The bottom end of the multi-segment robotic arm is fixed to a turntable, and the top end is connected to the six-DOF motion compensation mechanism. The turntable allows for 360° rotational adjustment. The six-DOF motion compensation mechanism is configured and connected to a launch and recovery track. An attitude measurement system and a combined navigation system are installed on the launch and recovery track. The multi-segment robotic arm compensates for vertical and lateral displacements on the launch and recovery track, while the six-DOF motion compensation mechanism compensates for the ship's pitch, yaw, and roll angles. The multi-segment robotic arm includes a main arm and a middle arm that are sequentially hinged together. The arm and forearm are equipped with a main arm drive mechanism, a middle arm drive mechanism, and a forearm drive mechanism in sequence at each hinge point; the six-degree-of-freedom motion compensation mechanism includes a pitch compensation rotary actuator, a yaw compensation rotary actuator, and a roll compensation drive mechanism. The pitch compensation rotary actuator is fixed to the top of the robotic arm. The yaw compensation rotary actuator is connected to the pitch compensation rotary actuator via a pitch bracket. The roll compensation drive mechanism is connected to the yaw compensation rotary actuator via a yaw bracket. The yaw bracket is equipped with a rotary guide mechanism connected to the launch and recovery track. The pitch compensation rotary actuator and the yaw compensation rotary actuator are rotary drive devices, the roll compensation drive mechanism is a roll drive hydraulic cylinder, the pitch support is a plate with a 90° bend, the pitch compensation rotary actuator is vertically mounted at one end of the pitch support, the yaw compensation rotary actuator is horizontally mounted at the other end of the pitch support, the pitch drive hydraulic cylinder is fixed on the yaw support, and the telescopic rod is connected to the launch and recovery track; The launch and recovery track includes two track sections and a track beam transition section connecting the two track sections, and the rotary guide mechanism is connected to the track beam transition section; The method of using the above-mentioned motion compensation robotic arm device for UAV launch and recovery includes the following steps: S1) A high-precision attitude measurement system installed on the launch and recovery track is used to collect the heading angle, roll angle, pitch angle and corresponding angular acceleration data of the launch and recovery track, which serves as the basis for launch and recovery track angle compensation; the integrated navigation system collects the heave, sway and pitch position data of the robotic arm endpoint, which serves as the basis for track position compensation. S2) Based on the absolute position information and angle data measured by the attitude measurement system and the integrated navigation system, a motion coordinate system is established, and the coordinate transformation matrix is ​​derived. The motion of each hydraulic cylinder is decomposed into the action of each hydraulic cylinder. The angle and displacement changes caused by the ship's motion are compensated in reverse by driving the cooperative motion of the hydraulic cylinder. The hydraulic cylinder displacement sensor is used to measure the extension of the hydraulic cylinder, thereby realizing closed-loop control.

2. The motion compensation robotic arm device for UAV launch and recovery according to claim 1, characterized in that, The bow rocker support is a cylindrical frame structure with an open bottom. The top is equipped with a support that is connected to the roll drive hydraulic cylinder. Rotation mounting positions are provided on both sides, and the rotation guide mechanism is installed at the rotation mounting positions.

3. The motion compensation robotic arm device for UAV launch and recovery according to claim 2, characterized in that, The slewing guide mechanism is a bottom-opening ring structure configured with the bow rocker bracket. Multiple guide wheel mounting grooves are provided on the outer circumference surface. The guide wheels are embedded in the guide wheel mounting grooves and contact the inner wall of the slewing mounting position.

4. The motion compensation robotic arm device for UAV launch and recovery according to claim 3, characterized in that, The boom drive mechanism is a boom drive hydraulic cylinder, the middle boom drive mechanism is a middle boom drive hydraulic cylinder, and the forearm drive mechanism includes a transition swing arm, a forearm drive hydraulic cylinder, and a folding and storage hydraulic cylinder. The transition swing arm is located at the connection between the middle boom and the forearm and is hinged to the middle boom and the forearm via a pin. The forearm drive hydraulic cylinder is fixed on the middle boom and its telescopic rod is connected to the transition swing arm. The folding and storage hydraulic cylinder is fixed on the transition swing arm and its telescopic rod is connected to the forearm.

5. The motion compensation robotic arm device for UAV launch and recovery according to claim 1, 2, 3, or 4, characterized in that, Vertical displacement compensation is 0–1.5 m, lateral displacement compensation is 0–2 m, and reverse compensation is ≥2° for pitch angle, ≥2° for bow angle, and ≥5° for roll angle.

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