Vertical launch vehicle launch window prediction control method, system and device and medium

Abstract

The invention discloses a vertical launch vehicle launch window prediction control method, system and device and a medium, and relates to the technical field of unmanned vehicles. The method comprises the steps that the six-degree-of-freedom motion state of the vehicle is sensed in real time through a multi-source sensor; the six-degree-of-freedom motion state comprises a three-dimensional position, a three-dimensional posture and corresponding linear velocity and angular velocity; forecasting the future short-time movement track of the vehicle based on the wave dynamics model; judging whether a dynamic launching window meeting the safe launching condition of the unmanned aerial vehicle exists or not according to the forecast result; based on the six-degree-of-freedom motion state, the attitude of the vehicle is controlled through cooperation of multiple execution mechanisms, so that the vehicle enters and is stabilized in the launching window; and triggering an unmanned aerial vehicle launching instruction after confirming that the attitude of the vehicle is stable. In a semi-floating state, the attitude of the unmanned aerial vehicle can be sensed, predicted and actively controlled, and the optimal opportunity is created and captured for vertical launching of the unmanned aerial vehicle in the cabin.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle technology, and in particular to a method, system, device and medium for predictive control of launch windows for vertical launch vehicles. Background Technology

[0002] Deploying and recovering unmanned aerial vehicles (UAVs) from waterborne platforms is a key technology for expanding their operational range. Existing technologies mainly fall into two categories: Large ship platforms: Utilizing deck area and relative stability, they are used for conventional takeoffs or the use of large catapult / recovery systems. However, they are bulky, expensive, and unsuitable for small, covert military or scientific research missions.

[0003] Simple floating devices: These are mostly passive floats or platforms, directly exposing the drone to the environment. Launch depends entirely on the operator observing sea conditions and choosing a "relatively calm" moment. This method has a low success rate and high risk, as the drone is highly susceptible to loss of control, capsizing, or collision with the platform the moment it takes off due to sudden rolling / pitching of the platform.

[0004] The technical challenges are particularly pronounced for launch schemes that house drones within a launch vehicle. Complex disturbances: The vehicle is subjected to the combined effects of waves, currents, and wind loads, resulting in complex motions with six degrees of freedom. The motion period and amplitude are far beyond those of land.

[0005] The window is demanding: because it needs to be launched from a launch tube or hatch on top of the launch vehicle, there are extremely strict limitations on the launch vehicle's attitude (especially roll and pitch) and vertical acceleration. Even a tiny deviation in attitude could cause the UAV to collide with the launch tube wall.

[0006] Sensing and control delay: From sensing the attitude, calculating the command, to driving the actuator to generate a stable torque, the delay of the entire system must be much smaller than the period of the wave disturbance; otherwise, the control will always be "half a beat slow" and will not be able to effectively suppress the swaying.

[0007] Currently, there is a lack of an intelligent solution that integrates high-precision motion prediction and real-time active stabilization specifically for semi-floating, embedded UAV launch scenarios. Summary of the Invention

[0008] The purpose of this invention is to provide a method, system, device and medium for predictive control of launch windows of vertical launch vehicles, which aims to solve or improve at least one of the above-mentioned technical problems.

[0009] To achieve the above objectives, the present invention provides the following solution: A method for predictive control of launch windows for vertical launch vehicles, comprising: The six degrees of freedom motion state of the carrier is sensed in real time by multiple source sensors; the six degrees of freedom motion state includes three-dimensional position, three-dimensional attitude and corresponding linear velocity and angular velocity; Predicting the short-term trajectory of the launch vehicle based on wave dynamics models; Determine whether a dynamic launch window exists that meets the conditions for safe launch of the UAV based on the forecast results; Based on the aforementioned six-degree-of-freedom motion state, the carrier's attitude is controlled collaboratively by multiple actuators, enabling the carrier to enter and stabilize within the launch window; The launch command for the drone is triggered after the carrier's attitude is confirmed to be stable.

[0010] Optionally, the multi-source sensor includes sensing elements and a computing unit; wherein, the sensing elements include an inertial measurement unit, a global navigation satellite system receiver, and an attitude reference system; the computing unit has a built-in fusion algorithm based on adaptive unscented Kalman filtering, used to estimate the six-degree-of-freedom motion state of the launch vehicle in real time based on each sensing element.

[0011] Optionally, the wave dynamics model is established by identifying the dominant wave direction and dominant frequency of the current sea state online, and is used to predict the trajectory of the launch vehicle in the next 10 to 30 seconds. The prediction results include roll angle, pitch angle and its angular velocity, and vertical acceleration.

[0012] Optionally, the criteria for determining the dynamic launch window include attitude angle limits, angular velocity limits, and vertical acceleration limits. A dynamic launch window is determined to exist when all three criteria are met simultaneously within a set time period. The attitude angle limit is that the roll and pitch angles do not exceed a set threshold. The angular velocity limit is that the roll and pitch angular velocities are close to zero. The vertical acceleration limit is that the vertical acceleration does not exceed a set threshold.

[0013] Optionally, the multi-actuator includes a ballast tank system and a fin / propeller system, which are coordinated by a multi-input multi-output model predictive controller to achieve an optimal balance between vehicle attitude stability and energy consumption.

[0014] The present invention also provides a launch window prediction and control system for a vertical launch vehicle, comprising: The sensing module is used to sense the six degrees of freedom motion state of the carrier in real time through multi-source sensors; the six degrees of freedom motion state includes three-dimensional position, three-dimensional attitude and corresponding linear velocity and angular velocity; The trajectory prediction module is used to predict the short-term trajectory of the launch vehicle based on a wave dynamics model. The judgment module is used to determine whether there is a dynamic launch window that meets the conditions for safe launch of the UAV based on the forecast results; The attitude control module is used to control the attitude of the launch vehicle through the coordinated control of multiple actuators based on the six degrees of freedom motion state, so that the launch vehicle enters and stabilizes within the launch window; The command output module is used to trigger the UAV launch command after confirming that the carrier's attitude is stable.

[0015] The present invention also provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the vertical launch vehicle launch window prediction control method described above.

[0016] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the vertical launch vehicle launch window prediction control method as described above.

[0017] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention discloses a method, system, device, and medium for predictive control of launch windows for vertical launch vehicles. The method includes real-time sensing of the six-degree-of-freedom motion state of the launch vehicle through multi-source sensors; the six-degree-of-freedom motion state includes three-dimensional position, three-dimensional attitude, and corresponding linear and angular velocities; predicting the short-term trajectory of the launch vehicle based on a wave dynamics model; determining whether a dynamic launch window meeting the safe launch conditions for unmanned aerial vehicles (UAVs) exists based on the prediction results; coordinating the attitude of the launch vehicle through multiple actuators based on the six-degree-of-freedom motion state to bring the launch vehicle into and stabilize it within the launch window; and triggering a UAV launch command after confirming the stability of the launch vehicle's attitude. This invention can create and capture the optimal opportunity for vertical launch of in-cabin UAVs by sensing, predicting, and actively controlling its own attitude in a semi-floating state. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0019] Figure 1 This is a schematic diagram of the vertical launch vehicle in this embodiment; Figure 2 This is a diagram showing the internal structure of the vertical launch vehicle in this embodiment; Figure 3 This is a schematic diagram of the vehicle control unit system in this embodiment; Figure 4 This is a flowchart of the vertical launch vehicle launch window prediction and control method in this embodiment.

[0020] Figure label: 1. Transport control unit; 2. Ballast water tank; 3. Loaded UAV; 4. Propulsion system. Detailed Implementation

[0021] 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.

[0022] The purpose of this invention is to provide a method, system, device and medium for predictive control of launch windows of vertical launch vehicles, which aims to solve or improve at least one of the above-mentioned technical problems.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] As a first aspect, such as Figures 1-4 As shown, this invention provides a launch window prediction and control method for vertical launch vehicles, constructing a four-in-one technical system of "global perception - motion prediction - window decision - platform stabilization and control". Its core lies in treating the launch vehicle itself as a controllable "active stabilization platform," rather than a passively subjected floating object. Among other things, Figure 2 This is a diagram of the internal structure of a vertical launch vehicle, showing the positional relationship between the launch control unit 1, the ballast water tank 2, the loaded UAV 3, and the propulsion system 4.

[0025] The specific steps of this method include: Step 100: Real-time sensing of the six degrees of freedom motion state of the carrier through multi-source sensors; the six degrees of freedom motion state includes three-dimensional position, three-dimensional attitude and corresponding linear velocity and angular velocity.

[0026] An inertial measurement unit (IMU), a Global Navigation Satellite System (GNSS) receiver, and an attitude reference system (AHRS) are configured on the launch vehicle. A fusion algorithm based on adaptive unscented Kalman filtering (AUKF) is employed to accurately estimate the launch vehicle's six-degree-of-freedom motion state in waves: three-dimensional position, three-dimensional attitude (roll), and three-dimensional attitude (pitch). (Pitch θ, yaw ψ) and their corresponding linear and angular velocities.

[0027] Step 200: Predict the short-term trajectory of the launch vehicle based on the wave dynamics model.

[0028] Disturbance modeling: The wave forces acting on the launch vehicle are considered as the primary disturbances. The dominant wave direction and frequency of the current sea state are identified online, and a simplified wave force transfer function model is established.

[0029] State Prediction: Using the current fused state as the initial value and combining it with a wave disturbance model, a high-precision prediction of the launch vehicle's trajectory over the next 10 to 30 seconds is made, especially the roll angle, which is crucial for launch safety. The pitch angle θ and vertical heave motion.

[0030] Step 300: Determine whether there is a dynamic launch window that meets the conditions for safe launch of the UAV based on the forecast results.

[0031] The launch window is defined not only based on the static attitude angle, but also by introducing a dynamic safety envelope based on the UAV's physical dimensions and launch dynamics model.

[0032] Core criteria: Attitude angle criterion: prediction And θ must be within the allowable range (e.g., ±5°) to ensure that the drone does not collide with the hatch when it leaves the rack.

[0033] Motion consistency criterion: predicted angular velocity 'and θ' must be close to zero to ensure that the launch vehicle is at the "knot point of motion" (i.e., the instant it recovers from swaying) at the moment of launch, rather than in the process of accelerating swaying.

[0034] Vertical acceleration criterion: The predicted vertical acceleration must be less than a threshold to avoid the drone being subjected to overload impact when it leaves the launch pad.

[0035] The system determines a "launchable window" only when the predicted trajectory simultaneously meets all of the above criteria within a complete future time window (e.g., 2-5 seconds).

[0036] Step 400: Based on the six-degree-of-freedom motion state, the attitude of the launch vehicle is controlled by multiple actuators in a coordinated manner, so that the launch vehicle enters and stabilizes within the launch window.

[0037] Controller design: A multi-input multi-output model predictive controller is used. The controlled variables of the controller are the roll, pitch, and vertical motion of the launch vehicle, and the control objective is to make it track an "ideal launch attitude" (i.e., all angles and angular velocities are zero).

[0038] Coordination among implementing agencies: Ballast tank system: Used to counteract low-frequency, large-amplitude roll / pitch by rapidly pumping ballast water between tanks to generate a restoring torque. It has a slower response but low power consumption and high torque.

[0039] Fin-rudder / propeller system: Used to counteract mid-to-high frequency disturbances, generating a fast-responding stabilizing torque by adjusting the rudder angle or propeller thrust.

[0040] Active suspension launcher (optional): Inside the launcher, the launcher itself has a fast-response active stabilization platform to counteract high-frequency residual vibrations that the launcher body cannot completely filter out.

[0041] Based on motion prediction results, the MPC controller continuously optimizes and allocates control commands to each actuator, guiding the launch vehicle to enter and "hover" within the predicted launch window in the most energy-efficient and fastest way.

[0042] Step 500: After confirming that the carrier attitude is stable, trigger the UAV launch command.

[0043] When the system confirms that the launcher's attitude has entered and stabilized within the "launchable window" and is predicted to remain so for the next few seconds, it automatically or after operator confirmation sends an ignition command to the UAV launch system (such as a catapult or cold launch device).

[0044] Based on the above technical solution, the following embodiments are provided.

[0045] Step 100: System initialization and sea state awareness. The launch vehicle is deployed to the water surface, and the system is powered on. The AUKF filter is initialized. The GNSS and IMU are activated, and initial alignment and state estimation begin. In the first few minutes, the system analyzes the launch vehicle's motion spectrum to estimate the dominant wave direction and characteristic period of the current sea state online, which is used to initialize the wave disturbance model.

[0046] Step 200: Real-time state estimation and motion prediction.

[0047] Data fusion: In each control cycle (e.g., 100ms), AUKF fuses GNSS position / velocity, IMU angular velocity / acceleration, and magnetometer / GPS heading data to output the optimal six-degree-of-freedom state estimate X(k).

[0048] Motion Forecasting: Substituting X(k) and the wave model into the forecasting algorithm, the motion trajectory of the launch vehicle X(k+1), ..., X(k+200) over the next 20 seconds is generated. Special attention is paid to roll. Pitch θ and its angular velocity ', θ', and vertical acceleration az.

[0049] Step 300: Online decision-making for the launch window.

[0050] Scan the predicted trajectory to find a continuous time interval [T_start, T_end] that simultaneously satisfies the following: | (t)|<3°&&|θ(t)|<3° (Attitude angle criterion) | θ'(t)|<0.5° / s &&|θ'(t)|<0.5° / s (Angular velocity criterion) |az(t) - g|<0.1g (Vertical overload criterion, where g is the acceleration due to gravity) If this window is found, the system enters the "launch ready" state and records the window's start time T_start.

[0051] Step 4: Multi-agency coordinated stability control The MPC controller starts working: Setpoint: Set the control target to =0, θ=0, '=0, θ'=0.

[0052] Optimization solution: In each control cycle, a finite time domain optimization problem is solved to calculate the sequence of pumping rate commands and rudder angle commands for the ballast tank in the next 10 seconds.

[0053] Command assignment: The first control command is sent to the actuators. The ballast system begins to adjust the water distribution, and the fins and rudders move simultaneously to guide the launch vehicle's attitude towards the ideal state at time T_start.

[0054] Step 5: Launch Execution The system monitors the consistency between the actual attitude and the predicted trajectory in real time. When the actual attitude stabilizes within the decision window and is sufficiently close to the T_start time, a "launch permission" command is issued. The UAV ignites and launches smoothly from inside the launch vehicle.

[0055] Step Six: Closed-Loop Operation If, during the control process, a sudden disturbance causes the prediction window to disappear or shift, the system immediately updates the forecast and recalculates the control commands, continuing to search for the next available window until the launch is successful.

[0056] In summary, this embodiment achieves a leap from a "waiting window" to a "creating window." By actively controlling the launch vehicle's attitude, it can proactively create and maintain the required launch conditions even in non-ideal sea conditions, greatly improving mission success rate and timeliness. Furthermore, by introducing a dynamic safety envelope and multi-criteria decision-making, it comprehensively considers multiple factors such as attitude, angular velocity, and acceleration, fundamentally avoiding launch collision and overload risks. This embodiment also integrates wave dynamics prediction and model predictive control, enabling the system to understand and predict environmental disturbances and make forward-looking optimal control decisions, possessing strong adaptive capabilities. Through MPC-based coordinated control of ballast tanks (high momentum, slow response) and fins / propellers (fast response, low momentum), it achieves an optimal balance between control effectiveness and energy consumption.

[0057] As a second aspect, the present invention also provides a vertical launch vehicle launch window prediction and control system, comprising: The sensing module is used to sense the six degrees of freedom motion state of the carrier in real time through multi-source sensors; the six degrees of freedom motion state includes three-dimensional position, three-dimensional attitude and corresponding linear velocity and angular velocity; The trajectory prediction module is used to predict the short-term trajectory of the launch vehicle based on a wave dynamics model. The judgment module is used to determine whether there is a dynamic launch window that meets the conditions for safe launch of the UAV based on the forecast results; The attitude control module is used to control the attitude of the launch vehicle through the coordinated control of multiple actuators based on the six degrees of freedom motion state, so that the launch vehicle enters and stabilizes within the launch window; The command output module is used to trigger the UAV launch command after confirming that the carrier's attitude is stable.

[0058] As a third aspect, the present invention also provides an electronic device, including a memory and a processor, the memory for storing a computer program, the processor for running the computer program to cause the electronic device to perform the vertical launch vehicle launch window prediction control method described above.

[0059] As a fourth aspect, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the vertical launch vehicle launch window prediction control method as described above.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0061] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for predictive control of launch windows for vertical launch vehicles, characterized in that, include: The six-degree-of-freedom motion state of the launch vehicle is sensed in real time through multiple source sensors; The six degrees of freedom motion states include three-dimensional position, three-dimensional attitude, and corresponding linear velocity and angular velocity; Predicting the short-term trajectory of the launch vehicle based on wave dynamics models; Determine whether a dynamic launch window exists that meets the conditions for safe launch of the UAV based on the forecast results; Based on the aforementioned six-degree-of-freedom motion state, the carrier's attitude is controlled collaboratively by multiple actuators, enabling the carrier to enter and stabilize within the launch window; The launch command for the drone is triggered after the carrier's attitude is confirmed to be stable.

2. The vertical launch vehicle launch window prediction and control method according to claim 1, characterized in that, The multi-source sensor includes sensing elements and a computing unit; wherein, the sensing elements include an inertial measurement unit, a global navigation satellite system receiver, and an attitude reference system; the computing unit has a built-in fusion algorithm based on adaptive unscented Kalman filtering, which is used to estimate the six-degree-of-freedom motion state of the launch vehicle in real time based on each sensing element.

3. The vertical launch vehicle launch window prediction and control method according to claim 1, characterized in that, The wave dynamics model is established by identifying the dominant wave direction and frequency of the current sea state online, and is used to predict the trajectory of the launch vehicle in the next 10 to 30 seconds. The prediction results include roll angle, pitch angle and its angular velocity, and vertical acceleration.

4. The vertical launch vehicle launch window prediction and control method according to claim 1, characterized in that, The criteria for determining the dynamic launch window include attitude angle limits, angular velocity limits, and vertical acceleration limits. A dynamic launch window is determined to exist when all three criteria are met simultaneously within a set time period. The attitude angle limit is that the roll and pitch angles do not exceed a set threshold. The angular velocity limit is that the roll and pitch angular velocities are close to zero. The vertical acceleration limit is that the vertical acceleration does not exceed a set threshold.

5. The vertical launch vehicle launch window prediction and control method according to claim 1, characterized in that, The multi-actuator system includes a ballast tank system and a fin / propeller system, which are coordinated by a multi-input multi-output model predictive controller to achieve an optimal balance between vehicle attitude stability and energy consumption.

6. A launch window prediction and control system for a vertical launch vehicle, characterized in that, include: The sensing module is used to sense the six degrees of freedom motion state of the carrier in real time through multi-source sensors; the six degrees of freedom motion state includes three-dimensional position, three-dimensional attitude and corresponding linear velocity and angular velocity; The trajectory prediction module is used to predict the short-term trajectory of the launch vehicle based on a wave dynamics model. The judgment module is used to determine whether there is a dynamic launch window that meets the conditions for safe launch of the UAV based on the forecast results; The attitude control module is used to control the attitude of the launch vehicle through the coordinated control of multiple actuators based on the six degrees of freedom motion state, so that the launch vehicle enters and stabilizes within the launch window; The command output module is used to trigger the UAV launch command after confirming that the carrier's attitude is stable.

7. An electronic device, characterized in that, The device includes a memory and a processor, the memory being used to store a computer program, and the processor running the computer program to cause the electronic device to perform the vertical launch vehicle launch window prediction control method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the vertical launch vehicle launch window prediction control method as described in any one of claims 1-5.

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