A control method for hybrid lift distribution and deadweight return of a power airship

Abstract

The application discloses a control method for hybrid lift distribution and empty return of a power airship, and comprises the following steps: S1, taking the rope tension of the airship and the motor current of the propeller as the criterion, the current state of the airship is identified in real time; if the airship is in the hanging state, S2 is executed, and if the airship is in the empty state, S5 is executed; S2, taking the helium static buoyancy of the airship platform as the baseline lift for balancing the self weight of the airship platform, and taking the power lift generated by the propeller as the adjustable working lift; S3, calculating the working lift demand of the airship platform; S4, distributing the working lift demand to multiple power units; S5, the airship is automatically switched from the loaded transportation mode to the empty return mode, the empty working lift demand is recalculated, and the output of each power unit is smoothly reconstructed; and S6, in the empty return mode, the return is completed in the low-power state; the scheme improves the safety, stability and energy utilization efficiency of the power airship in the whole process of the mountain area hoisting and return.

Description

Technical Field

[0001] This invention relates to the field of heavy-load airship transportation technology, specifically to a control method for hybrid lift distribution and empty return of a powered airship. Background Technology

[0002] Power line construction in mountainous areas is typically conducted in complex terrains such as high mountains, valleys, and hills. Road conditions at construction sites are poor, temporary road construction is costly, and the transportation of materials such as tower materials, steel bars, and construction tools is difficult. Traditional methods rely heavily on manpower, animal power, cableways, temporary access roads, or small machinery, resulting in low efficiency, long cycles, and significant construction safety risks. In recent years, heavy-duty drones have begun to be used for transporting materials in mountainous power construction projects. However, limitations in rotor lift efficiency, battery energy density, and endurance restrict their application to scenarios involving large-mass components, long-distance transport, and continuous operation, making it difficult to meet the engineering requirements of heavy loads, long flight times, low costs, and high safety in mountainous power construction.

[0003] Airships, due to their static buoyancy support, long loiter time, and relatively low requirements for takeoff and landing sites, are considered a new type of aerial platform suitable for transporting goods in complex terrain. Unlike drones, which rely entirely on rotors for lift, airships can utilize gases lighter than air, such as helium, to provide basic lift, thereby reducing the continuous weight burden on the power system. Several airship or aerostat platform solutions have been proposed in the prior art. For example, patent CN214397181U relates to a drone logistics transport airship, patent CN203612191U relates to an intelligent transport airship powered by solar energy, patent CN112078775A relates to a drone logistics system centered on a carrier airship, patent CN109050866B relates to an airship, and patent CN102730179A relates to a composite lift deformable airship. Furthermore, prior art also discloses designs for hybrid lift-body buoyancy airships, where lift is provided by both static buoyancy and aerodynamic forces, suitable for heavy-load transport in complex terrain. Some proposals have suggested a hybrid hard and soft airship and its control method, which uses a controllable connecting valve to adjust the gas in the inner and outer gasbags to achieve lift regulation. Other proposals involve an airship buoyancy control system that calculates the buoyancy adjustment amount using load information.

[0004] However, existing airships or aerobatic platforms still have the following shortcomings when performing heavy-load hoisting operations for power construction in mountainous areas: First, there is a lack of a dynamic lift allocation method based on a static buoyancy baseline. Traditional airships mostly rely on static buoyancy or fixed-power lift, focusing primarily on improving platform load capacity or achieving basic flight control. They lack a control method that clearly separates and dynamically allocates the "static buoyancy baseline" and "adjustable lift." While existing hybrid airship designs involve the combined effects of static buoyancy and aerodynamic lift, they fail to establish a separate control architecture for real-time load changes during sling load operations, where static buoyancy bears the fixed self-weight and powered lift bears the variable load. This makes it difficult to achieve smooth lift adjustment when the load changes rapidly.

[0005] Second, there is a lack of mechanisms for rapid identification of the hoisting status and switching of operating conditions. Existing solutions often neglect the control requirements of the airship after the load is unloaded, and lack a mechanism for rapid detection of the load status and automatic matching of operating conditions based on multi-source sensor information. When the power lift output is not reduced in time during the unloading or empty return phase, it can cause the airship to rise rapidly, experience sudden attitude changes, or exhibit additional oscillations. Existing airship hoisting control usually relies on preset task phases or manual confirmation, resulting in a delayed response and difficulty in adapting to the rapid changes in load during the "loading-transportation-unloading-return" process.

[0006] Third, there is a lack of methods for reconstructing working lift after unloading. Existing airships or composite lift transport platforms typically focus on maintaining lift and flight stability during cargo transport during hoisting operations, with insufficient consideration given to sudden load changes at the moment of cargo unloading. They lack control methods to automatically remove the load weight, recalculate the empty lift requirement, and smoothly reduce the propeller's working lift after unloading confirmation, making it difficult to ensure continuous and stable flight after unloading.

[0007] Fourth, there is a lack of low-power control strategies for empty return. Existing powered airship transportation solutions often fail to dynamically adjust lift output according to load status during loading, unloading, and return, instead using the lift output from the loaded transportation phase. This results in the power system operating at unnecessary high power for extended periods, leading to high redundant energy consumption and severely limiting the airship's endurance and operational efficiency.

[0008] In summary, existing technologies have not yet provided a complete and effective solution for load abrupt changes, working lift reconfiguration, and empty return control of power construction airships in mountainous areas during hoisting operations. Summary of the Invention

[0009] To address the aforementioned shortcomings of the prior art, this invention provides a control method for the hybrid lift distribution and empty return of a powered airship, thereby solving the technical problems mentioned in the background section.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A control method for hybrid lift distribution and empty return of a powered airship is provided, which includes the following steps: S1: Based on the tension of the ropes hoisting the airship and the motor current of the propeller, identify the current state of the airship in real time; if it is in a loaded state, execute step S2; if it is in an unloaded state, execute step S5. S2: Using the static buoyancy of helium on the airship platform as the baseline lift to balance the self-weight of the airship platform, and using the power lift generated by the propeller as the adjustable working lift, a control architecture is established that separates the baseline lift from the working lift. S3: Calculate the current total lift requirement of the airship platform and obtain the working lift requirement after deducting the baseline lift; S4: Distribute the working lift demand to multiple power units. The output of each power unit includes a basic distribution component, an attitude correction component, and a disturbance compensation component. S5: The airship automatically switches from loaded transport mode to empty return mode, removes the load weight from the total lift requirement, recalculates the empty working lift requirement, and smoothly reconstructs the output of each power unit. S6: In the no-load return mode, the return altitude and return speed are set according to the terrain altitude of the return route and the remaining battery power, and the return is completed in a low-power state.

[0011] Furthermore, the formula for calculating the static buoyancy baseline in step S2 is: F 静 = K s × M 艇体 × g Among them, M 艇体 Let g be the mass of the airship platform, g be the acceleration due to gravity, and K be the mass of the airship platform. s This is the static buoyancy coefficient; The formula for calculating the total lift requirement in step S3 is as follows: F 总 = (M 艇体 + M 载荷 ) × g + F 垂向 + F 安全 Among them, M 载荷 For the load mass of the airship platform, F 垂向 To add vertical lift, F 安全 For lift safety margin; The formula for calculating the working lift requirement is: F 工 = F 总 - F 静 .

[0012] Furthermore, the formula for calculating the working lift output of the i-th power unit in step S4 is as follows: F i = αi × F 工 + ΔF i姿态 + ΔF i扰动 Where, ΔF i姿态 For attitude correction; ΔF i扰动 This represents the compensation amount for external disturbances; i = 1, 2, ..., n, where n is the number of power units; α i The basic allocation coefficient for the i-th power unit is α. When the load position, hoisting rope length, or airship attitude changes, α is dynamically updated based on the estimated load center of gravity value and through preset lookup tables, control allocation matrices, or online normalization calculations. i .

[0013] Furthermore, the attitude correction ΔFi is determined based on the airship's current attitude error, and its calculation formula is as follows: ΔF i姿态 = kφ i × eφ + kθ i × eθ + kψ i × eψ + kd i × de / dt Where eφ, eθ, and eψ are the roll, pitch, and yaw errors, respectively, de / dt is the rate of change of attitude error, and kφ i 、kθ i 、kψ i kd i The control gain is related to the installation position and control direction of the i-th power unit; Disturbance compensation amount ΔF i扰动 The formula for its calculation is determined based on external wind disturbance, height deviation, and changes in vertical acceleration. ΔF i扰动 = kw i × Vw + kh i × eh + ka i × az Where Vw is the equivalent wind disturbance, eh is the deviation between the current altitude and the target altitude, az is the change in vertical acceleration, and kw is the equivalent of the wind disturbance. i ,kh i ka i This represents the disturbance compensation gain corresponding to the i-th power unit.

[0014] Furthermore, the load state identification in step S1 specifically includes: S11: Collect the tension of the hoisting rope and the motor current of the propeller, and perform low-pass filtering or moving average processing on the rope tension and motor current. S12: If the rope tension is not less than the preset load threshold and the motor current is not less than the preset current threshold, it is determined to be in a loaded state; if the rope tension remains below the preset load threshold within a preset time period and the motor current shows a downward trend, it is determined to be in an unloaded state.

[0015] Furthermore, the smooth reconstruction of the output of each power unit in step S5 includes: The working lift output of each power unit satisfies the following rate of change constraint: |F i (t) - F i (t-Δt)| / Δt ≤ R max ; Rmax ≤ min(Rmotor, ΔFi / τ) Among them, F i (t) represents the working lift output of the i-th power unit in the current control cycle, F. i (t-Δt) represents the working lift output of the previous control cycle, Δt represents the control cycle, and R... max Rmotor represents the maximum permissible rate of change of lift, and ΔF represents the maximum permissible rate of change of thrust of the power unit. i Let τ be the difference in working lift required by the i-th power unit before and after unloading, and let τ be the smooth transition time of the power unit after unloading.

[0016] Furthermore, in step S6, the return altitude H r The expression is: H r = max(H y H z + ΔH) Among them, H y To preset the return flight path altitude, H z ΔH represents the maximum height of terrain or obstacles on the return path, and ΔH represents the safe obstacle clearance margin. Return speed V r The system determines the return speed based on the remaining battery charge (SOC): when the SOC is higher than the high charge threshold, the airship returns at the nominal return speed; when the SOC is lower than the high charge threshold but higher than the medium charge threshold, the airship switches to the economic return speed; when the SOC is lower than the medium charge threshold, the flight control computer prioritizes the nearest safe docking area or emergency landing area.

[0017] Furthermore, this solution also includes fault tolerance and redundancy strategies: It adopts a multi-motor redundancy architecture, so that when a single motor or sensor fails, it can maintain flight by boosting other motors or using backup sensors; Cross-validation using dual data sources is employed. When the tension sensor fails, changes in motor current and acceleration are used to assist in assessing the load status. The system employs a primary and backup redundant communication link and is equipped with command confirmation receipts, timeout retransmission, and communication interruption protection strategies. When the communication interruption exceeds the preset time, the flight control computer executes hovering, return to home, or nearby safe landing strategies according to the preset loss of connection protection strategy. When abnormal or instantaneous increase in rope tension is detected during the unloaded return process, and the rope tension exceeds the preset abnormal tension threshold, the system determines that the spreader has been mis-attached, the rope has collided with an obstacle, or the unloading has been misjudged. The system immediately restores the lifting force for loaded operation and suspends the unloaded return, entering hovering or emergency response mode.

[0018] Furthermore, it also includes a control system for performing the control method as described in any one of claims 1 to 8, comprising: The airship platform is filled with helium to provide static buoyancy. The power propulsion module, consisting of a battery pack, motor, ESC, and propeller, is used to generate controllable working lift and thrust. The lifting system, including a hook, rope retraction mechanism, and tension sensor, is used to suspend transport loads and sense changes in rope tension. The sensor system, including a load weight sensor, a tension sensor, an inertial measurement unit, an accelerometer, a barometric altimeter, and an anemometer, is used to provide sensing data to the flight control unit. The flight control system integrates an inertial navigation IMU, GNSS, barometer, wind speed and direction sensors, and a flight control computer.

[0019] The beneficial effects of this invention are as follows: 1. This invention separates the lift requirements corresponding to the airship's own weight from the lift requirements corresponding to the load. It utilizes helium static buoyancy to balance the platform's own weight and uses the propeller's working lift to bear variable loads and provide dynamic compensation. This method differs from the traditional approach of adjusting buoyancy through water tanks or hot gas. It does not require additional counterweights or changes in gas pressure. The working lift can be adjusted in real time and continuously according to load changes, with fast response speed and high adjustment accuracy. Compared with traditional hybrid airship solutions, this solution establishes a clear "static buoyancy baseline + adjustable working lift" separate control architecture, enabling the airship to maintain the optimal lift matching state under different load conditions, significantly improving the flexibility of lift adjustment and energy utilization efficiency.

[0020] 2. This solution uses rope tension and motor current to determine the loading and unloading status, and automatically triggers the switching of lift distribution strategy based on the identification results. Unlike traditional airship or UAV hoisting control that relies on preset task stages or manual confirmation, this invention can automatically and quickly complete the working condition switching according to the real-time load status, which significantly reduces the problems of response lag and mismatch between lift output and actual load, and improves the safety and stability of the airship under sudden load changes.

[0021] 3. After the suspended load is unloaded, this solution automatically removes the load weight and recalculates the empty lift requirement. At the same time, it sets a maximum rate of change limit on the working lift output of the power unit and uses a ramp transition or segmented reduction method to smoothly reduce the power output. This mechanism effectively avoids the problems of undesirable ascent, attitude change or oscillation caused by the power parameters of the loaded phase continuing into the empty return phase, and ensures the continuous stability of the flight state after unloading.

[0022] 4. During the empty return phase, this scheme sets the flight altitude according to the terrain altitude of the return route and dynamically adjusts the return speed according to the remaining battery power SOC to complete the return with lower lift output. Compared with the existing scheme that relies on full-load parameters for return, this method switches the control mode in a timely manner, which greatly reduces the power consumption during the return phase and can significantly extend the airship's endurance and operating radius.

[0023] 5. This solution adopts a multi-motor redundancy architecture, dual sensor cross-verification, primary and backup redundant communication links, and a disconnection protection strategy. Even if a single motor or sensor fails, flight can still be maintained by boosting other motors or using backup sensors. When a tension sensor failure, signal inconsistency, or communication interruption is detected, the system can automatically switch to the backup solution or execute a preset safety strategy, which significantly improves the reliability and safety of the system.

[0024] 6. This solution can be adapted to the control system on the existing powered airship platform without large-scale modification of the airship platform itself, and the engineering implementation cost is relatively controllable. Compared with the existing hybrid power aerial platform, this invention is aimed at the complete operation scenario of "mountain hoisting - transportation - unloading - return", and the technical solution is more focused and complete, with strong engineering applicability and promotion value. Attached Figure Description

[0025] 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 described 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. The above and other objects, features, and advantages of the present invention will become clearer through the accompanying drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual dimensions; the focus is on illustrating the main points of the invention.

[0026] Figure 1 Flowchart of the control method for hybrid lift distribution and empty return of powered airships Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] 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.

[0029] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0030] like Figure 1 As shown, the control method for the hybrid lift distribution and empty return of the powered airship in this scheme includes: S1: Based on the tension of the ropes hoisting the airship and the motor current of the propeller, identify the current state of the airship in real time; if it is in a loaded state, execute step S2; if it is in an unloaded state, execute step S5. S2: Using the static buoyancy of helium on the airship platform as the baseline lift to balance the self-weight of the airship platform, and using the power lift generated by the propeller as the adjustable working lift, a control architecture is established that separates the baseline lift from the working lift. S3: Calculate the current total lift requirement of the airship platform and obtain the working lift requirement after deducting the baseline lift; S4: Distribute the working lift demand to multiple power units. The output of each power unit includes a basic distribution component, an attitude correction component, and a disturbance compensation component. S5: The airship automatically switches from loaded transport mode to empty return mode, removes the load weight from the total lift requirement, recalculates the empty working lift requirement, and smoothly reconstructs the output of each power unit. S6: In the no-load return mode, the return altitude and return speed are set according to the terrain altitude of the return route and the remaining battery power, and the return is completed in a low-power state.

[0031] Specifically, the control system for the hybrid lift distribution and empty return of the powered airship in this scheme includes the airship platform, the power propulsion module, the sling system, the sensor system, and the flight control unit.

[0032] The airship platform is filled with helium to create static buoyancy, and the hull is constructed of advanced composite materials. The upper part houses a helium chamber providing static buoyancy, while the lower part connects to the propeller, hoisting system, and other functional components. The propulsion module consists of a battery pack, motors, an electronic speed controller (ESC), and a matching propeller, employing a multi-rotor layout to generate controllable lift and thrust. The ESC module controls the output of each motor. The hoisting system includes a hook, a rope retraction and deployment mechanism, and tension sensors. The rope can be actively retracted and deployed via a winch to hoist and transport loads, adjust the hoisting height, and detect changes in rope tension. The sensor system includes a load weight sensor, tension sensor, inertial measurement unit (IMU), accelerometer, barometric altimeter, and anemometer, providing sensory data to the flight control unit. The flight control system integrates an inertial navigation IMU, GNSS, barometer, anemometer, and flight control computer to achieve functions such as flight attitude control, navigation control, and lift distribution.

[0033] The system inputs of this solution include the airship platform's self-weight, static buoyancy baseline, real-time load weight, sling tension, sling length, flight altitude, vertical speed, airship attitude angle, motor current, remaining battery power, weather conditions (air pressure, temperature, wind speed and direction, etc.), and route information. The system outputs include the working lift commands, speed commands, attitude correction commands, load status flags, no-load return mode switching commands, return altitude commands, and return speed commands for each motor-propeller power unit.

[0034] The control methods of this scheme, when implemented in practice: This solution continuously acquires information such as payload mass, flight altitude, attitude, and wind speed to calculate the required total lift. It then allocates this lift to a fixed static buoyancy force and an adjustable powered lift force. Power output is dynamically adjusted during takeoff, transport, and return to achieve a coordinated distribution of the airship's helium static buoyancy force and the working lift force of the electric motors and propellers. This ensures stable flight of the airship under different loads and flight conditions. Specifically, this includes: 1. Calculation of total lift requirement The total lift requirement is calculated based on the airship platform's own weight, real-time load weight, and safety margin, while also considering the additional vertical load caused by wind disturbance. Sensors acquire parameters such as flight altitude, load mass, hoisting rope length (i.e., hoisting height), attitude angle, and wind speed to calculate the total lift required for each operating condition.

[0035]

[0036] In the formula, For total lift requirements, For the quality of the airship platform, For the load mass of the airship platform, To add vertical lift, For lift safety margin.

[0037] 2. Static buoyancy baseline setting The airship utilizes helium gas to provide static buoyancy, which serves as baseline lift to balance the platform's weight. In the calculations, the helium's static buoyancy is... The value is set close to the platform's own weight to reduce the burden on the power system.

[0038] Static buoyancy baseline setting Fstatic: Static buoyancy is provided by helium gas inside the airship, serving as baseline lift to balance the airship platform's weight. In the calculations, the helium static buoyancy Fstatic is set to a value matching the airship platform's weight, ensuring that static buoyancy bears the majority of the platform's weight, while the propulsion module provides the adjustable working lift required for payload weight, attitude adjustment, wind disturbance compensation, and safety margins. Therefore, the static buoyancy baseline satisfies: F 静 = K s M 艇体 g Among them, M 艇体 Let g be the mass of the airship platform, g be the acceleration due to gravity, and K be the mass of the airship platform. s K is the static buoyancy coefficient. s The value can be determined based on the airship platform mass, helium chamber volume, mission altitude, and safety control margin, with an optimal range of 0.90-0.98.

[0039] 3. Calculation of working lift requirements Subtracting the static buoyancy baseline from the total lift requirement yields the power lift generated by the motor-propeller power unit, which serves as the adjustable working lift, allowing the fixed self-weight and variable load to be borne by different lift sources.

[0040]

[0041] In the formula, To meet the needs of work improvement, This is the baseline for the static buoyancy of the airship.

[0042] 4. Lift Distribution Based on the number of power units, installation location, load center of gravity offset, hoisting rope length, and attitude control requirements, the working lift demand is allocated to each power unit. Let be the working lift output of the i-th power unit.

[0043] 5. Overlay attitude correction The flight control system adjusts the output of each power unit based on sensor data under current operating conditions, fine-tuning the thrust of each propeller to offset attitude deviations and wind disturbances, thus generating additional attitude correction components to maintain flight stability. For example, when the hull experiences roll or pitch errors, the attitude is corrected by differentially increasing or decreasing the thrust of the left and right or forward and backward propellers.

[0044] F i = α i × F 工 + ΔF i姿态 + ΔF i扰动 In the formula, α i Let i be the basic allocation coefficient for the i-th power unit. This is the attitude disturbance correction amount. This is the disturbance compensation correction; the basic allocation coefficient of each dynamic unit satisfies: Σα i = 1, α i ≥ 0; i = 1, 2, ..., n, where n is the number of power units.

[0045] α of this scheme i α is determined based on the position of the i-th power unit relative to the airship platform's center of mass, the maximum available thrust of the power unit, the offset of the load's center of mass relative to the airship platform's center of mass, the length of the sling rope, and the current attitude control requirements. i The dynamic adjustment method is as follows: When the load position, the length of the hoisting rope, or the attitude of the airship changes, the flight control computer updates the estimated value of the load center of gravity in real time based on the tension sensor, IMU, accelerometer, winch encoder and load position detection signal, and dynamically updates αi through preset lookup table, control allocation matrix or online normalization calculation method, so that the output of each power unit meets the total lift requirement and torque balance requirement.

[0046] The attitude correction amount is determined based on the airship's current attitude error. The flight control computer calculates the attitude correction amount based on the roll angle error, pitch angle error, yaw angle error, and their rate of change. The expression for this is: ΔF i姿态 = kφ i × eφ + kθ i × eθ + kψ i × eψ + kd i × de / dt Where eφ, eθ, and eψ are the roll, pitch, and yaw errors, respectively, de / dt is the rate of change of attitude error, and kφ i 、kθ i 、kψ i kd i The control gain is related to the installation position and control direction of the i-th power unit; The disturbance compensation amount is determined based on external wind disturbance, altitude deviation, and vertical acceleration changes. The flight control computer calculates the disturbance compensation amount based on the outputs from the wind speed and direction sensors, barometric altimeter, and accelerometer. Its expression is: ΔF i扰动 = kw i × Vw + kh i × eh + ka i × az Where Vw is the equivalent wind disturbance, eh is the deviation between the current altitude and the target altitude, az is the change in vertical acceleration, and kw is the equivalent of the wind disturbance. i ,kh i ka i This represents the disturbance compensation gain corresponding to the i-th power unit.

[0047] This scheme employs a load status determination algorithm based on multi-source signal fusion. It uses the hoisting rope tension signal as the primary criterion, and motor current changes, airship vertical acceleration changes, winch rope length changes, and load position detection signals as auxiliary criteria. This allows for real-time analysis of the airship's current loading, transport, unloading, or empty status, providing strategic support for lift distribution and return-to-base control. The specific load status identification method includes: S11: Collect the tension of the hoisting rope and the motor current of the propeller, and perform low-pass filtering or moving average processing on the rope tension and motor current. S12: If the rope tension is not less than the preset load threshold and the motor current is not less than the preset current threshold, it is determined to be in a loaded state; if the rope tension remains below the preset load threshold within a preset time period and the motor current shows a downward trend, it is determined to be in an unloaded state.

[0048] The empty return control method of this scheme includes: when the load status identification module determines that the suspended load has been unloaded, the airship system automatically switches from loaded transport mode to empty return mode, recalculates the total lift requirement of the airship in the empty state, and reduces power consumption during the empty phase. Simultaneously, based on mountainous terrain, return route, obstacle height, and real-time wind field information, a safe return altitude and heading control strategy are set to ensure that the airship maintains a sufficient obstacle-clearing altitude and stable flight in the empty state. Specifically, this includes: 1. Recalculation of Empty Lift Requirement: After unloading, the control system removes the weight of the suspended load from the total lift requirement and recalculates the total lift requirement under empty conditions only based on the airship platform weight, return route, safety margin, and environmental disturbances. The empty lift requirement no longer uses the power parameters from the loaded transport phase but is matched with the airship's empty weight and return conditions for subsequent lift reconfiguration and low-power return control.

[0049] 2. Working lift output reconfiguration: The lift output is reduced from the stable lift during loading to the lift output during unloaded return. A maximum lift reduction rate threshold is set to prevent the airship from rising unintended due to redundant working lift after unloading, or from altitude changes and attitude swaying due to excessively rapid reduction in working lift. At the same time, a transition filter can be inserted into the speed command during descent to ensure a smooth lift transition.

[0050] 3. Return Route and Altitude Planning: Based on terrain data and wind field forecasts, a return route is planned and a safe altitude is set to avoid obstacles such as mountains and power lines. The return altitude is usually higher than the highest ground obstacle by a certain safety margin. The propeller speed is adjusted according to the remaining battery power, and an appropriate flight speed is set to balance time and energy consumption.

[0051] 4. Low-power return control: In the no-load return mode, the control system uses the preset return route, target return altitude, target return speed, and target attitude angle as control references. It collects data such as the airship's three-axis attitude (pitch, yaw, roll), vertical speed, and current position in real time, calculates the three types of deviations in attitude, speed, and trajectory, and generates the speed correction and thrust correction for each propeller. This allows the airship to complete the return in a low-power state while meeting the requirements of safe altitude, attitude stability, and trajectory tracking.

[0052] The control method of this scheme also includes fault tolerance and redundancy strategies: a multi-motor redundant architecture is adopted, and when a single motor or sensor fails, flight is maintained by boosting other motors or using backup sensors; dual data source cross-validation is adopted, and when the tension sensor fails, the load status is assessed by relying on changes in motor current and acceleration; a primary and backup redundant communication link is adopted, and command confirmation receipt, timeout retransmission, and communication interruption protection strategies are set; when the communication interruption exceeds the preset time, the flight control computer executes hovering, return to home, or nearby safe landing strategies according to the preset loss of connection protection strategy; when abnormal or instantaneous increase in rope tension is detected during the empty return process, and the rope tension is greater than the preset abnormal tension threshold, it is determined that the spreader is misattached, the rope is snagging on an obstacle, or the unloading is misjudged, and the system immediately restores the working lift with load and suspends the empty return, entering hovering or emergency response mode.

[0053] The specific working process of this plan will be explained in detail below: Taking a mountain power tower transport airship equipped with 8 sets of motor-propeller power units as an example, the working lift distribution, load status identification, unloading determination and empty return control process of the present invention will be explained.

[0054] The airship system includes a helium-buoyed hull, eight motor-propeller power units, a battery pack, electronic speed controllers (ESCs), a hoisting winch, hoisting ropes, tension sensors, accelerometers, a motor current detection module, an inertial measurement unit, a barometric altimeter, an anemometer, and a flight control computer. The eight power units are denoted as follows: to The static buoyancy of the helium gas inside the airship serves as the baseline for static buoyancy. It is mainly used to balance the weight of the airship platform. Load weight And altitude maintenance and attitude correction during flight and wind disturbance compensation Powered by 8 sets of motor-propeller power units.

[0055] During the airship's takeoff without load and its journey to the material collection point, the flight control computer will display the load status flags. Set to an unloaded state, and adjust according to the weight of the airship platform. Static buoyancy baseline The airship's lift requirements for no-load operation are calculated based on the current flight altitude, transport route, wind speed and direction, and remaining battery power. At this time, the eight power units primarily provide the lift required for altitude maintenance, attitude correction, and wind resistance, enabling the airship to fly to the tower material stacking location at low power.

[0056] Upon reaching the material pick-up point, the hoisting winch lowers the hoisting ropes, and the hook connects to the tower material. The flight control computer collects the tension of the hoisting ropes in real time. Motor current I, airship vertical acceleration and the length of the hoisting rope, and the rope tension. The motor current I is filtered to obtain the filtered rope tension. The control system is preset with a rope tension no-load threshold. Mounting threshold Unloading threshold Mounting confirmation time and uninstallation confirmation time .

[0057] when From below the no-load threshold Continues to rise above the mounting threshold And the duration is longer than the mount confirmation time. Simultaneously, the motor current I or the airship's vertical acceleration When a change occurs that corresponds to an increase in load (e.g., I and...) (Simultaneously increase), the flight control computer determines that the tower material has been loaded, and changes the load status flag from no-load status. Switch to loaded mode and enter loaded working lift Allocation mode.

[0058] During the loaded takeoff and transport phases, the flight control computer calculates the total lift requirement based on the airship platform's own weight, payload weight, flight altitude, transport route, wind disturbance conditions, and safety margin. Subsequently, the static buoyancy baseline was subtracted. The required lifting capacity is obtained from the 8 power units. The flight control computer, based on to The system generates lifting commands, motor speed commands, or ESC control commands for each power unit based on the installation location, load center of gravity offset, hull attitude deviation, hoisting rope length, and wind disturbance.

[0059] During loaded transport, the flight control computer periodically updates the load status data: filtered rope tension. The system monitors factors such as hoisting rope length, flight altitude, attitude angle, battery charge, and wind speed and direction. When the airship needs to pass over obstacles such as mountains, trees, or power lines, the system adjusts the airship's flight altitude based on the target obstacle clearance height, or controls the winch to shorten the hoisting rope length to maintain a safe height above the ground for the tower materials. When a slingshot is detected... When fluctuations exceed the preset range, or when the airship's roll angle or pitch angle exceeds the preset attitude threshold, the flight control computer adjusts the output of the eight power units to suppress the swaying of the load and maintain the stability of the airship.

[0060] Upon arrival at the installation area, the flight control computer controls the hoisting winch to slowly lower the tower material to the target installation position or ground support location. The system continuously monitors the process during unloading. Motor current I, vertical acceleration And the winch's operating status. When From above the mount threshold Drop below the unload threshold And the duration is longer than the uninstallation confirmation time. Simultaneously, when the motor current or working lift command shows a decreasing trend, the flight control computer determines that the tower material has been unloaded and changes the load status flag from loaded to unloaded. Switch to no-load state .

[0061] After unloading is confirmed, the flight control computer automatically switches from loaded transport mode to empty return mode. The system removes the tower weight from the total lift requirement and adjusts the parameters based on the static buoyancy baseline. Vertical height requirements, safety margins, and environmental disturbances are all considered in the recalculation of no-load operating lift requirements. Subsequently, the flight control computer... to The motor speed command or thrust command is reconfigured to smoothly transition the power output from the loaded transport state to the unloaded return state.

[0062] To prevent the airship from unleashing unintended ascent due to redundant lift during unloading, or from sudden altitude changes caused by excessively rapid decreases in motor speed / thrust commands, the flight control computer sets a maximum rate of change limit for the lift output of each power unit. The system reduces power output by using a ramp transition or a phased reduction method; when the airship's altitude is detected to be below the safe altitude, the system briefly increases the altitude to maintain the required working lift.

[0063] The lift output of each power unit satisfies the following rate of change constraint: |F i (t) - F i (t-Δt)| / Δt ≤ R max ; Rmax ≤ min(Rmotor, ΔFi / τ) Among them, F i (t) represents the working lift output of the i-th power unit in the current control cycle, F. i (t-Δt) represents the working lift output of the previous control cycle, Δt represents the control cycle, and R... max Rmotor represents the maximum permissible rate of change of lift, and ΔF represents the maximum permissible rate of change of thrust of the power unit. i τ is the difference in working lift required by the i-th power unit before and after unloading, and τ is the smooth transition time of the power after unloading, preferably 2-8s.

[0064] During the empty return phase, the flight control computer sets the return altitude based on the return route, mountain terrain altitude, the location of power line obstacles, real-time wind speed and direction, and remaining battery power. Return speed And attitude angle limitations; at this time, the 8 power units no longer bear the weight of the tower, but only provide the working lift required for altitude maintenance, heading adjustment, attitude correction and wind resistance, so that the airship can return to the take-off and landing point or target docking area in a low power state while meeting the requirements of safe obstacle crossing and stable flight.

[0065] The return altitude of this plan is H. r The expression is: H r = max(H y H z + ΔH) Among them, H y To preset the return flight path altitude, H z ΔH represents the maximum height of terrain or obstacles on the return path, and ΔH is the safety margin for overcoming obstacles. ΔH is preferably 5-30 m.

[0066] The return speed Vr of this scheme is determined based on the remaining battery charge (SOC), return distance, real-time wind speed and direction, and expected safety margin: when the SOC is higher than the high charge threshold, the airship returns at the nominal return speed; when the SOC is lower than the high charge threshold but higher than the medium charge threshold, the airship switches to the economical return speed; when the SOC is lower than the medium charge threshold, the flight control computer prioritizes the nearest safe docking area or emergency landing area and sends a low battery alarm to the ground control station.

[0067] If detected during the empty return process If there is an abnormal or sudden increase in tension, and the change in tension does not conform to the tension range corresponding to the weight of the unloaded spreader, the flight control computer will determine that the spreader may be mis-attached, the rope may be caught on an obstacle, or the unloading may be misjudged. The system will immediately resume the loaded working ascent and suspend the unloaded return, and enter the hovering and emergency response mode, sending abnormal alarm information to the ground control station.

[0068] In this scheme, the airship and the ground control station interact via wireless communication links, including 4G / 5G cellular communication links, dedicated wireless data transmission links, BeiDou short message links, or combinations thereof. Downlink: The airship periodically uploads its position, altitude, speed, attitude angle, remaining battery power, hoisting rope tension, hoisting status indicators, return status, and abnormal alarm information to the ground control station. Uplink: The ground control station issues commands to the airship for return routes, hovering, landing, winch deployment / retraction, load status verification, threshold adjustment, and emergency response. The communication module employs redundant primary and backup communication links and is equipped with command confirmation receipts, timeout retransmission, and communication interruption protection strategies. When communication interruption exceeds a preset time, the flight control computer executes hovering, return, or nearby safe landing strategies according to the preset loss-of-connection protection strategy.

[0069] Although the specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent; various modifications and variations that can be made by a person skilled in the art without inventive effort within the scope described in the claims are still within the scope of protection of this patent.

Claims

1. A control method for hybrid lift distribution and empty-load return of a powered airship, characterized in that, Includes the following steps: S1: Based on the tension of the ropes hoisted by the airship and the motor current of the propeller, the current status of the airship is identified in real time; If the device is in a mounted state, proceed to step S2; if it is in an unloaded state, proceed to step S5. S2: Using the static buoyancy of helium on the airship platform as the baseline lift to balance the self-weight of the airship platform, and using the power lift generated by the propeller as the adjustable working lift, a control architecture is established that separates the baseline lift from the working lift. S3: Calculate the current total lift requirement of the airship platform and obtain the working lift requirement after deducting the baseline lift; S4: Distribute the working lift demand to multiple power units. The output of each power unit includes a basic distribution component, an attitude correction component, and a disturbance compensation component. S5: The airship automatically switches from loaded transport mode to empty return mode, removes the load weight from the total lift requirement, recalculates the empty working lift requirement, and smoothly reconstructs the output of each power unit. S6: In the no-load return mode, the return altitude and return speed are set according to the terrain altitude of the return route and the remaining battery power, and the return is completed in a low-power state.

2. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, The formula for calculating the static buoyancy baseline in step S2 is: F 静 = K s × M 艇体 × g Among them, M 艇体 Let g be the mass of the airship platform, g be the acceleration due to gravity, and K be the mass of the airship platform. s This is the static buoyancy coefficient; The formula for calculating the total lift requirement in step S3 is as follows: F 总 = (M 艇体 + M 载荷 ) × g + F 垂向 + F 安全 Among them, M 载荷 For the load mass of the airship platform, F 垂向 To add vertical lift, F 安全 For lift safety margin; The formula for calculating the required working lift is as follows: F 工 = F 总 - F 静 。 3. The control method for hybrid lift distribution and empty return of a powered airship according to claim 2, characterized in that, The formula for calculating the working lift output of the i-th power unit in step S4 is: F i = α i × F 工 + ΔF i姿态 + ΔF i扰动 Where, ΔF i姿态 For attitude correction; ΔF i扰动 This represents the compensation amount for external disturbances; i = 1, 2, ..., n, where n is the number of power units; α i The basic allocation coefficient for the i-th power unit is α. When the load position, hoisting rope length, or airship attitude changes, α is dynamically updated based on the estimated load center of gravity value and through preset lookup tables, control allocation matrices, or online normalization calculations. i .

4. The control method for hybrid lift distribution and empty return of a powered airship according to claim 3, characterized in that, The attitude correction amount ΔFi is determined based on the airship's current attitude error, and its calculation formula is as follows: ΔF i姿态 = kφ i × eφ + kθ i × eθ + kψ i × eψ + kd i × de / dt Where eφ, eθ, and eψ are the roll, pitch, and yaw errors, respectively, de / dt is the rate of change of attitude error, and kφ i 、kθ i 、kψ i kd i The control gain is related to the installation position and control direction of the i-th power unit; The disturbance compensation amount ΔF i扰动 The formula for its calculation is determined based on external wind disturbance, height deviation, and changes in vertical acceleration. ΔF i扰动 = kw i × Vw + kh i × eh + ka i × az Where Vw is the equivalent wind disturbance, eh is the deviation between the current altitude and the target altitude, az is the change in vertical acceleration, and kw is the equivalent of the wind disturbance. i ,kh i ka i This represents the disturbance compensation gain corresponding to the i-th power unit.

5. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, The load state identification in step S1 specifically includes: S11: Collect the tension of the hoisting rope and the motor current of the propeller, and perform low-pass filtering or moving average processing on the rope tension and motor current. S12: If the rope tension is not less than the preset load threshold and the motor current is not less than the preset current threshold, it is determined to be in a loaded state; if the rope tension remains below the preset load threshold within a preset time period and the motor current shows a downward trend, it is determined to be in an unloaded state.

6. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, Step S5 involves smoothly reconstructing the output of each power unit, including: The working lift output of each power unit satisfies the following rate of change constraint: |F i (t) - F i (t-Δt)| / Δt ≤ R max ; Rmax ≤ min(Rmotor, ΔFi / τ) Among them, F i (t) represents the working lift output of the i-th power unit in the current control cycle, F. i (t-Δt) represents the working lift output of the previous control cycle, Δt represents the control cycle, and R... max Rmotor represents the maximum permissible rate of change of lift, and ΔF represents the maximum permissible rate of change of thrust of the power unit. i Let τ be the difference in working lift required by the i-th power unit before and after unloading, and let τ be the smooth transition time of the power unit after unloading.

7. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, Return altitude H in step S6 r The expression is: H r = max(H y , H z + ΔH) Among them, H y To preset the return flight path altitude, H z ΔH represents the maximum height of terrain or obstacles on the return path, and ΔH represents the safe obstacle clearance margin. The return speed V r The system determines the return speed based on the remaining battery charge (SOC): when the SOC is higher than the high charge threshold, the airship returns at the nominal return speed; when the SOC is lower than the high charge threshold but higher than the medium charge threshold, the airship switches to the economic return speed; when the SOC is lower than the medium charge threshold, the flight control computer prioritizes the nearest safe docking area or emergency landing area.

8. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, It also includes fault tolerance and redundancy strategies: It adopts a multi-motor redundancy architecture, so that when a single motor or sensor fails, it can maintain flight by boosting other motors or using backup sensors; Cross-validation using dual data sources is employed. When the tension sensor fails, changes in motor current and acceleration are used to assist in assessing the load status. A primary and backup redundant communication link is adopted, and command confirmation receipt, timeout retransmission and communication interruption protection strategies are set. When communication is interrupted for more than a preset time, the flight control computer will execute hovering, return to home or safe landing at the nearest safe location according to the preset loss of communication protection strategy. When abnormal or instantaneous increase in rope tension is detected during the unloaded return process, and the rope tension exceeds the preset abnormal tension threshold, the system determines that the spreader has been mis-attached, the rope has collided with an obstacle, or the unloading has been misjudged. The system immediately restores the lifting force for loaded operation and suspends the unloaded return, entering hovering or emergency response mode.

9. The control method for hybrid lift distribution and empty return of a powered airship according to claim 1, characterized in that, It also includes a control system that performs the control method as described in any one of claims 1 to 8, comprising: The airship platform is filled with helium to provide static buoyancy. The power propulsion module, consisting of a battery pack, motor, ESC, and propeller, is used to generate controllable working lift and thrust. The lifting system, including a hook, rope retraction mechanism, and tension sensor, is used to suspend transport loads and sense changes in rope tension. The sensor system, including a load weight sensor, a tension sensor, an inertial measurement unit, an accelerometer, a barometric altimeter, and an anemometer, is used to provide sensing data to the flight control unit. The flight control system integrates an inertial navigation IMU, GNSS, barometer, wind speed and direction sensors, and a flight control computer.

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