A floating wing tandem type full-airborne transient electromagnetic detection structure and control method

Abstract

The application discloses a kind of float wing series connection type full aviation transient electromagnetic detection structure, from top to bottom sequentially include suspension unmanned aerial vehicle, buoyancy capsule and lift unmanned aerial vehicle, suspension unmanned aerial vehicle is connected with buoyancy capsule by upper traction rotating mechanism, buoyancy capsule and lift unmanned aerial vehicle are connected by lower traction rotating mechanism;Geophysical main cabin accommodating transient electromagnetic detection system is opened in lift unmanned aerial vehicle, system includes transient electromagnetic transmitter, receiver, geophysical power supply, data logger and electromagnetic coil assembly, electromagnetic coil assembly is located at the outside of geophysical main cabin, and is connected at the bottom of lift unmanned aerial vehicle by shock-absorbing suspension assembly.It is realized that longitudinal series connection cooperation is realized by suspension unmanned aerial vehicle, buoyancy capsule and lift unmanned aerial vehicle, and endurance time is multiplied, wind compensation and high-altitude buoyancy compensation are also proposed, adapt to a variety of cruise conditions.

Description

Technical Field

[0001] This invention relates to the fields of airborne geophysical exploration and UAV control technology, specifically to a floating-wing tandem all-airborne transient electromagnetic detection structure and control method. Background Technology

[0002] Transient electromagnetic methods, as a classic and important geophysical exploration technique, have been widely used in mineral resource exploration, geological hazard investigation, and groundwater resource detection. Traditional airborne transient electromagnetic detection operations mostly rely on manned helicopters or fixed-wing aircraft as platforms. These operations are costly in the field, have stringent requirements for take-off and landing site terrain conditions, and have poor low-altitude following and terrain-following capabilities in complex mountainous areas, cliffs, and other harsh terrains.

[0003] In recent years, with the increasing maturity of multi-rotor UAV technology, using multi-rotor UAVs equipped with transient electromagnetic detection systems for airborne geophysical exploration has gradually become a research hotspot in the industry due to its advantages such as low cost, flexible deployment, high level of intelligence, and strong ability to follow ultra-low altitude terrain.

[0004] However, in practical applications, in order to obtain deeper exploration depths and higher signal-to-noise ratios, transient electromagnetic detection systems typically require high-power transmitters, high-capacity power supplies, and large-diameter transmitting coils, which significantly increases the overall weight and load requirements of the entire detection structure.

[0005] Multi-rotor drones rely entirely on the dynamic lift generated by the rotor rotation. When faced with the aforementioned heavy payload requirements, the motors of multi-rotor drones need to operate at high power and high energy consumption for extended periods. This leads to rapid battery depletion and a drastically reduced flight time, typically only lasting ten to twenty minutes. Frequent takeoffs and landings for battery replacements not only severely reduce the continuity and efficiency of geophysical exploration operations but also limit the detection coverage area of ​​a single flight, failing to meet the practical needs of large-scale, deep geological exploration.

[0006] Furthermore, since airborne transient electromagnetic detection typically requires low-altitude following or terrain-following flight, the flight platform is highly susceptible to external airflow disturbances in complex mountainous or windy environments, causing the detection coil to generate severe high-frequency vibrations and attitude swaying, which seriously affects the acquisition quality and signal-to-noise ratio of geophysical data. At the same time, in low-air-density environments such as high altitudes, the static buoyancy of conventional airbag platforms and the aerodynamic efficiency of multi-rotors will decrease significantly, further exacerbating the load on the power system and the risk of overheating and burnout.

[0007] Therefore, how to resolve the inherent contradiction between heavy load and long endurance in airborne transient electromagnetic detection, and significantly improve the operational stability and dynamic adaptability of the detection structure in windy conditions and harsh high-altitude environments, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] To address the above technical problems, this invention provides a floating wing tandem all-airborne transient electromagnetic detection structure and control method, which significantly improves the overall detection structure's wind resistance stability and high-altitude dynamic adaptability under harsh conditions while enabling heavy-load, long-endurance geophysical exploration operations.

[0009] The technical solution is as follows: The first aspect of the present invention provides a floating wing series-type all-airborne transient electromagnetic detection structure, the key point of which is: from top to bottom, it consists of a suspended UAV, a buoyancy bag and a lifting UAV, the suspended UAV and the buoyancy bag are connected by an upper traction and rotation mechanism, and the buoyancy bag and the lifting UAV are connected by a lower traction and rotation mechanism.

[0010] The lifting drone has a geophysical main unit compartment for accommodating the transient electromagnetic detection system. A shock-absorbing suspension assembly is installed at the bottom of the lifting drone, and the electromagnetic coil assembly of the transient electromagnetic detection system is suspended below the geophysical main unit compartment through the shock-absorbing suspension assembly.

[0011] Preferably, the top and bottom walls of the buoyancy bladder are respectively provided with a rigid force-bearing top cover and a rigid base;

[0012] The rigid load-bearing top cover includes an arc-shaped load-bearing cover and a first elastic protective pad disposed between the arc-shaped load-bearing cover and the top of the buoyancy bladder. A hook assembly is provided on the outer wall of the arc-shaped load-bearing cover, and the upper traction rotation mechanism is connected to the top of the buoyancy bladder through the hook assembly.

[0013] The rigid base includes an arc-shaped base and a second elastic protective pad disposed between the arc-shaped base and the bottom of the buoyancy bladder. A suspension cable bearing lug is disposed on the outer wall of the arc-shaped base, and the lower traction rotation mechanism is connected to the bottom of the buoyancy bladder through the suspension cable bearing lug.

[0014] Preferably, the upper traction rotation mechanism includes an upper rotating disk, the upper part of which is provided with a main traction rope connected to the bottom of the suspended UAV, and the lower part is provided with an upper inclined line connected to the top wall of the buoyancy bag.

[0015] The lower traction and rotation mechanism includes a lower rotating disk, the upper part of which is provided with a lower suspension cable connected to the bottom of the buoyancy bag, and the lower part of the lower rotating disk is connected to the lifting drone.

[0016] Preferably, a tension sensor is also provided on the main traction rope.

[0017] Preferably, the lower rotating disk includes a lower rotating plate and an upper rotating plate sleeved above the lower rotating plate, with a rotating bearing assembled between the two, and a rope lug for connecting the upper inclined line and / or the lower suspension cable integrally formed at the outer edge of the upper rotating plate.

[0018] The upper and lower rotating disks have the same structure.

[0019] Preferably, a C-shaped rigid rod is also provided between the lower rotating disk and the drone being lifted;

[0020] The C-shaped rigid rod includes a C-shaped main rod and reinforcing ribs set on the inner arc surface of the C-shaped main rod. The upper and lower ends of the C-shaped main rod are respectively provided with an upper joint that is hinged to the lower rotating disk and a lower joint that is fixed to the lifting drone.

[0021] Preferably, the shock-absorbing suspension assembly includes a fixed back plate fixed to the bottom of the drone and a suspension load frame disposed below the fixed back plate, with a damping shock-absorbing ball installed between the two, and a pull wire for suspending the electromagnetic coil assembly is also provided on the suspension load frame.

[0022] The second aspect of the present invention provides a control method based on the floating wing series all-airborne transient electromagnetic detection structure of the first aspect of the present invention, the key point of which is that: the suspended UAV has an upper flight control assembly and the lifting UAV has a lower flight control assembly.

[0023] The control method can achieve dual-machine coordinated control by suspending the UAV and lifting the UAV and buoyancy capsule;

[0024] The dual-machine collaborative control includes the following steps:

[0025] S1: Dual-engine autonomous coordinated takeoff and trim, the upper flight control assembly and the lower flight control assembly establish a communication link, the lifting UAV starts and rises to the preset geophysical exploration height in coordination with the buoyancy bag, the suspension UAV takes off synchronously and stays above the buoyancy bag, adjusts its own lift, so that the main traction rope and the buoyancy bag are in a critical trim state.

[0026] S2: Serial cruise geophysical exploration, the suspended UAV and the lifting UAV work together to output forward flight power, cruise along the preset geophysical exploration route, collect geophysical exploration data using electromagnetic coil components, and transmit it to the transient electromagnetic detection system;

[0027] S3: Wind drift monitoring and wind resistance compensation vector calculation. The two flight control assemblies monitor the state parameters of the UAV in real time during flight. When the ambient wind force increases and causes the UAV to produce a horizontal displacement or attitude tilt angle exceeding the preset threshold, wind resistance compensation is triggered.

[0028] The flight control assembly calculates the wind direction vector W of the ambient wind in real time based on the UAV's tilt angle change method and the thrust direction caused by the abnormal increase in motor power consumption. d Wind force vector W f Then, the wind-resistant compensation tension vector F of the suspended UAV was calculated. c The thrust is matched with the attitude of the drone being lifted;

[0029] S4: Series dynamic collaborative wind resistance adjustment, the suspended UAV receives commands from the flight control assembly, adjusts its flight attitude, and moves towards the wind vector W. d The drone tilts and flies in the opposite direction, while the lifting drone adjusts its own vector thrust to maintain horizontal and vertical stability in the wind.

[0030] S5: Linked landing and safe recovery. After the operation is completed, the lifting drone gradually reduces the motor speed to overcome the buoyancy of the buoyancy bag and gradually descend. During the descent, the suspension drone is always above the buoyancy bag, keeping the main traction rope and lower suspension cable in a taut state until the entire structure lands safely.

[0031] Preferably, the control method can also achieve single-unit degradation control by lifting the UAV and the buoyancy capsule;

[0032] The single-unit degradation control retains the lifting drone, which independently performs takeoff, cruise geophysical exploration, wind and sway control, and landing and recovery steps, and dynamically compensates for external environmental disturbances through its own structure in conjunction with the buoyancy of the buoyancy bag.

[0033] Preferably, the dual-machine coordinated control mode further includes high-altitude static buoyancy collaborative compensation, wherein the lifting drone and / or suspension drone are electrically connected to an altimeter or atmospheric pressure sensor to obtain real-time altitude data or air density data of the environment in which the overall structure is located;

[0034] The aforementioned high-altitude static buoyancy collaborative compensation refers to the flight control assembly acquiring the current altitude or air density in real time under high-altitude conditions with no wind or light wind, and calculating the static buoyancy loss ΔF of the buoyancy capsule caused by the decrease in air density. b According to the static buoyancy loss ΔF b Calculate the vertical dynamic lifting compensation force F of the suspended UAV. v cpmp And send it to the suspended drone;

[0035] After receiving the command, the suspended UAV increases the pulling force and uses the main traction rope to pull the buoyancy capsule upward to compensate for the static buoyancy loss ΔF. b Maintain the working state of the lifting drone described below.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: The present application achieves longitudinal series coordination through the upper layer suspending the drone, the middle layer buoyancy bladder and the lower layer lifting the drone. The static buoyancy provided by the buoyancy bladder overcomes the heavy load, while the drones jointly make up for the dynamic thrust gap, thereby doubling the endurance.

[0037] Meanwhile, in windy conditions, by tilting the suspended drone in the opposite direction of the windward side and using the leverage effect of the long rope to apply a counterbalance force at the center of the top cover, the tilting and drift of the buoyancy bag caused by the wind is countered, thus improving wind resistance. In the thin air at high altitudes, the suspended drone makes up for the load gap caused by the sudden reduction in the buoyancy bag, completely avoiding the risk of motor overheating and burning out of the bottom-mounted drone due to the dual pressure of "high load + high altitude".

[0038] This application has strong mission adaptability. Under favorable working conditions with sufficient buoyancy or weak wind, it can actively omit the overhead suspended drone and directly degenerate into a simplified "airbag + lifter" structure for independent operation. This not only reduces deployment costs but also provides extremely high hardware fault tolerance and mission flexibility for complex field environments. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the present invention;

[0040] Figure 2 This is a schematic diagram of the upper structure of the buoyancy capsule 200;

[0041] Figure 3 This is a schematic diagram of the lower structure of the buoyancy capsule 200;

[0042] Figure 4 This is a schematic diagram of the structure of the lower rotating disk 240;

[0043] Figure 5 A schematic diagram of the structure of a C-type rigid rod 250;

[0044] Figure 6 This is a schematic diagram of the results for the shock absorber suspension assembly 500. Detailed Implementation

[0045] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0046] Example 1

[0047] like Figure 1As shown, a floating-wing tandem all-aviation transient electromagnetic detection structure includes, from top to bottom, a suspended UAV 100, a buoyancy capsule 200, and a lifting UAV 300. The buoyancy capsule 200 is filled with a light gas with a density less than air, which can generate upward static buoyancy. The suspended UAV 100 and the buoyancy capsule 200 are connected by an upper traction and rotation mechanism, and the buoyancy capsule 200 and the lifting UAV 300 are connected by a lower traction and rotation mechanism.

[0048] A geophysical exploration main unit 400, housing a transient electromagnetic detection system, is located within the lifting drone 300. This transient electromagnetic system is an electromagnetic instrument used in earth science and mining engineering fields, which detects underground electrical structures by emitting step electromagnetic waves and receiving secondary field signals, such as the WuKongDTEM UAV-based airborne transient electromagnetic system. The transient electromagnetic system includes a transient electromagnetic transmitter, a receiver, a geophysical power supply, a data logger, and an electromagnetic coil assembly 600. A shock-absorbing suspension assembly 500 is installed at the bottom of the lifting drone 300, suspending the electromagnetic coil assembly 600 below the geophysical exploration main unit 400. The electromagnetic coil assembly 600 includes a transmitting coil for emitting transient electromagnetic excitation signals into the ground and a receiving coil for receiving underground echo signals. The working principle of transient electromagnetic method is to use a high-power ground transmitter (such as JDD-100 transmitter) to transmit step electromagnetic wave signals into the ground. After the transmission current is turned off, the spatial magnetic field generated by electromagnetic induction excites the earth and the underground electrical difference body. The electromagnetic induction secondary field signal generated by the underground electrical difference body is received and analyzed by the receiving coil mounted on the UAV, thereby achieving the exploration of underground target bodies.

[0049] The suspended UAV 100 provides longitudinal tension and dynamic wind-resistant thrust, the buoyancy capsule 200 provides upward buoyancy, and the lifting UAV 300 provides lift and flight power. The overall structure forms a three-layer all-aviation physical layout in a longitudinal series, and then a transient electromagnetic detection system is used for exploration.

[0050] like Figures 1 to 3 As shown, the top and bottom walls of the buoyancy bladder 200 are respectively provided with a rigid force-bearing top cover 210 and a rigid base 220. Both the rigid force-bearing top cover 210 and the rigid base 220 are arc-shaped shell structures that fit the buoyancy bladder 200, forming an upper and lower clamping and covering of the buoyancy bladder 200.

[0051] The rigid load-bearing top cover 210 includes an arc-shaped load-bearing cover 211 and a first elastic protective pad 214 disposed between the arc-shaped load-bearing cover 211 and the top of the buoyancy bladder 200. A plurality of hook assemblies 215 arranged symmetrically in a circle are provided on the outer wall of the arc-shaped load-bearing cover 211. The upper traction rotation mechanism is connected to the top of the buoyancy bladder 200 through the hook assemblies 215.

[0052] The upper traction rotation mechanism includes an upper rotating disk 212. The upper part of the upper rotating disk 212 is provided with a main traction rope 110 connected to the bottom of the suspended drone 100, and the lower part is provided with several upward-sloping lines 213 connected to the top wall of the buoyancy bag 200. The first end of each upward-sloping line 213 is fastened to a corresponding hook assembly 215, and the second end is radially hinged to the upper rotating disk 212. A tension sensor 120 is also configured on the main traction rope 110 to monitor the tension of the main traction rope 110 in real time.

[0053] The rigid base 220 includes an arc-shaped base 221 and a second elastic protective pad 223 disposed between the arc-shaped base 221 and the bottom of the buoyancy bladder 200. Multiple suspension cable bearing lugs 222 are disposed on the outer wall of the arc-shaped base 221. The suspension cable bearing lugs 222 are distributed on the same circumference with the center line of the arc-shaped base 221 as the center. The lower traction rotation mechanism is connected to the bottom of the buoyancy bladder 200 through the suspension cable bearing lugs 222.

[0054] The lower traction rotation mechanism includes a lower rotating disk 240. The upper part of the lower rotating disk 240 is provided with a lower suspension cable 230 connected to the bottom of the buoyancy bag 200. Each lower suspension cable 230 is hinged to the suspension cable force-bearing lug 222 of the rigid base 220 at the bottom of the buoyancy bag 200 by a hinge pin. The lower part of the lower rotating disk 240 is connected to the lifting drone 300.

[0055] The first elastic protective pad 214 inside the rigid force-bearing top cover 210 and the second elastic protective pad 223 inside the rigid base 220 can prevent external structures from directly rubbing against the buoyancy bladder 200, thus preventing damage to the bladder skin and affecting buoyancy. Furthermore, both the arc-shaped force-bearing cover 211 and the arc-shaped base 221 are hot-pressed from high-modulus carbon fiber reinforced composite material, with a wall thickness of 4.0mm-6.0mm, preferably 5.0mm.

[0056] The number of upper inclined wires 213 and hook assemblies 215 corresponds to each other, as does the number of lower suspension cables 230 and suspension cable force-bearing plates 222. All these numbers are denoted as N, where N is an integer greater than or equal to 3; in this embodiment, N=4. Both the upper inclined wires 213 and the lower suspension cables 230 are made of ultra-high molecular weight polyethylene braided rope, with a fiber tensile strength σ... uts Not less than 2.8 GPa, rope diameter d rThe diameter is 6mm-8mm. Mechanically, this flexible cable connection can be equivalent to a nonlinear tension spring, and its mechanical mechanism for releasing bending moment stress satisfies the following equation:

[0057] Let F be the axial tension on the main traction rope 110. z The angle between each stay cable 213 or lower suspension cable 230 and the vertical central axis of the structure is θ. When the floating wing is disturbed by airflow resistance and produces pitch or roll deviation, the resulting disturbance bending moment is M. x With M y At that time, the actual tension F borne by the i-th cable i It satisfies the following mechanical equations:

[0058]

[0059] in, and Let be the Cartesian coordinate of the i-th hook component on the horizontal projection plane of the arc-shaped base. The equivalent polar moment of inertia for the cable-stayed configuration is calculated using the following formula: .

[0060] The above mechanical equations show that the flexible cable structure can absorb the overturning moment M generated by disturbance. x and M y It is completely converted into pure axial tensile stress F inside the cable. i This prevents the transmission of destructive shear and bending moments to the arc-shaped base 221 or the arc-shaped force-bearing cover 211, thus avoiding fatigue fracture and failure of the rigid connection root under alternating stress, and significantly improving the mechanical life of the detection structure and the flight accuracy in high wind speed environments.

[0061] like Figure 4 As shown, the lower rotating disk 240 includes a lower rotating plate 242 and an upper rotating plate 241 sleeved above the lower rotating plate 242. A rotating bearing 243 is assembled between the two. The rotating bearing 243 is a double-row deep groove ball rotating bearing with a rated dynamic load C. r The torque is not less than 25kN, thus meeting the dynamic thrust bearing requirements under high buoyancy conditions. The outer edge of the upper rotating plate 241 is integrally formed with a rope lug for connecting the upper inclined line 213 and / or the lower suspension cable 230. The upper and lower rotating disks have the same structure. The rotating disk connects the buoyancy capsule 200 to the upper inclined line 213 and / or the lower suspension cable 230, completely decoupling the upper inclined line 213 and / or the lower suspension cable 230 from the buoyancy capsule 200 in the horizontal rotation direction, allowing free rotation and effectively preventing the fatal hazard of rope self-spinning, entanglement, and knotting during flight.

[0062] like Figure 5As shown, a C-shaped rigid rod 250 is also provided between the lower rotating disk 240 and the lifting drone 300. The C-shaped rigid rod 250 includes a C-shaped main rod 251 and reinforcing ribs 254 provided on the inner arc surface of the C-shaped main rod 251. The C-shaped main rod 251 is made of high-strength carbon fiber and is manufactured by pultrusion process. Its elastic modulus E is 130-150 GPa, its outer diameter d0 is 45 mm, and its inner diameter d i The C-shaped main rod 251 has a diameter of 39mm and a wall thickness of 3mm. The upper and lower ends of the C-shaped main rod 251 are respectively equipped with an upper connector 252 and a lower connector 253, both made of titanium alloy. The upper connector 252 is rigidly hinged to the lower rotating disk 240 via an anti-loosening positioning pin and a threaded locking structure. The lower connector 253 is fixedly connected to the load-bearing structure of the drone 300's fuselage frame via a transition rod, aligning with the drone 300's center of gravity. The reinforcing rib 254 enhances the reverse bending stiffness of the C-shaped rigid rod 250, enabling the C-shaped main rod 251 to withstand the maximum horizontal thrust F generated by the drone 300's maneuvering. push At that time, its central deflection y max For deflections less than 5mm, the deflection calculation formula satisfies the following equation:

[0063]

[0064] Where L is the arc unfolded length of the C-shaped main rod 251, and M(s) is the thrust bending moment function distributed along the arc length s. The moment of inertia of the C-shaped main rod 251 is given. This high-precision rigid constraint design ensures that the safe clearance between the blade edge and the buoyancy bag 200 of the lifting UAV 300 remains above 350mm in all maneuvering attitudes, preventing blade collision accidents.

[0065] like Figure 6 As shown, the shock-absorbing suspension assembly 500 includes a fixed back plate 501 fixed to the bottom of the lifting drone 300, and a suspension load frame 503 disposed below the fixed back plate 501. Multiple circumferentially distributed damping shock-absorbing balls 502 are installed between the two. The damping shock-absorbing balls 502 are made of high viscoelastic silicone material and are used to dampen and absorb the high-frequency micro-amplitude vibrations generated by the drone rotor rotation, preventing high-frequency mechanical vibrations from being transmitted to the geophysical sensor. A pull wire 510 for suspending the electromagnetic coil assembly 600 is also provided on the suspension load frame 503. The pull wire 510 is hooked onto a pull wire hook 504 on the lower surface of the suspension load frame 503, achieving flexible vibration isolation suspension of the electromagnetic coil assembly 600.

[0066] Both the suspended UAV 100 and the lifting UAV 300 are multi-rotor UAVs. The suspended UAV 100 is connected to the upper rotating disk 212 via the main traction rope 110, and then connected to the top of the buoyancy bag 200 via the upper inclined line 213. The bottom of the buoyancy bag 200 is connected to the lower rotating disk 240 via multiple lower suspension cables 230. The lower rotating disk 240 is connected to the fuselage of the lifting UAV 300 via a C-shaped rigid rod 250, and the lower rotating disk 240 can rotate freely relative to the C-shaped rigid rod 250, together forming a longitudinal series aero-powered architecture.

[0067] Among them, the main traction rope 110 and the lower suspension cable 230 serve as flexible connectors, which can generate angle-following deflection when the structure is tilted by wind disturbance, adaptively releasing bending and torsional stress, and avoiding fatigue damage to the connection point due to alternating loads. At the same time, the C-shaped rigid rod between the lifting drone 300 and the lower rotating disk 240 forms a rigid boundary with a fixed spatial distance, which constrains the relative displacement between the buoyancy bladder 200 and the lifting drone 300, completely preventing the buoyancy bladder 200 from colliding with the rotor blades of the drone below due to swinging, and greatly improving the mechanical structure reliability when the two drones work together.

[0068] The suspended UAV 100 contains an upper flight control assembly 130, and the lifting UAV 300 contains a lower flight control assembly 310. When the suspended UAV 100, the buoyancy capsule 200, and the lifting UAV 300 are in a critical tension state, the basic force balance equation of their overall structure in the vertical direction is:

[0069]

[0070] in, The total dynamic upward pull generated by the suspended UAV 100 The total dynamic upward thrust generated to support the 300 drone. The static buoyancy generated by the buoyancy capsule 200 The total gravity of the entire tandem structure is calculated using the following formula:

[0071]

[0072] In the formula, For the weight of the suspended drone 100 itself, The total mass of the buoyancy chamber 200 and the inflatable gas is... To support the weight of the drone itself, The total mass of the geophysical main unit is 400. Let g be the total mass of the electromagnetic coil assembly 600, and g be the acceleration due to gravity.

[0073] According to the aerodynamic momentum theory of multi-rotor UAVs, the shaft power P required for the rotor to generate thrust T satisfies the following nonlinear relationship:

[0074]

[0075] In the traditional approach, without a buoyancy capsule 200, the total thrust of the UAV must be exactly equal to its total weight, i.e. At this time, the shaft power consumption of the motor is This application introduces a tandem architecture, incorporating a buoyancy capsule 200 to share the static heavy load, and the two drones jointly bear the dynamic thrust. Lifting the UAV 300 and suspending the UAV 100 only requires supplementing the insufficient buoyancy. Since the power consumption P is positively correlated with the thrust T to the power of 3 / 2, when the thrust decreases linearly, the power consumption of the motor will decrease exponentially, thus extending the cruise geophysical exploration endurance by several times while keeping the total battery energy constant.

[0076] Example 2

[0077] Based on the above-mentioned longitudinal series aero-engine architecture, a control method for a floating wing series all-aero-transient electromagnetic detection structure is proposed. The control method can achieve dual-aircraft coordinated control by suspending the UAV 100 and lifting the UAV 300 and the buoyancy capsule 200.

[0078] The dual-machine collaborative control includes the following steps:

[0079] S1: Dual-aircraft autonomous coordinated takeoff and trim. The upper flight control assembly 130 and the lower flight control assembly 310 establish a high-frequency communication link through a local radio station. The lifting UAV 300 starts and, together with the buoyancy capsule 200, rises to a preset geophysical exploration height, such as 30m. The suspension UAV 100 takes off synchronously and remains above the buoyancy capsule 200, finely adjusting its own lift to keep the main traction control rope 110 in a critical trim state that is just taut but does not exert additional downward force on the buoyancy capsule 200.

[0080] S2: Serial cruise geophysical exploration, the suspended UAV 100 and the lifting UAV 300 work together to output forward flight power, cruise along the preset geophysical exploration route, collect geophysical exploration data using the electromagnetic coil assembly 600, and record the echo;

[0081] S3: Wind drift monitoring and wind resistance compensation vector calculation. The two flight control assemblies monitor the attitude tilt angle of the suspended UAV 100, the attitude tilt angle of the lifted UAV 300, the motor output power of the two UAVs, and the tension sensor data 120 of the main traction rope 110 in real time during flight. When a sudden strong lateral wind occurs, the wind-receiving area of ​​the buoyancy bag 200 increases, which may cause the UAV to produce a horizontal displacement or attitude tilt angle exceeding the preset threshold, triggering wind resistance compensation.

[0082] The flight control system calculates the wind direction vector W in real time based on the monitored direction of the UAV's tilt angle change and the direction of the thrust caused by the abnormal increase in motor power consumption. d Wind force vector W f Then, the wind-resistant compensation tension vector Fc of the suspended UAV 100 and the attitude balance thrust of the lifting UAV 300 were calculated.

[0083] S4: Serial dynamic coordinated wind resistance adjustment, the suspended UAV 100 receives commands from the flight control assembly, adjusts its flight attitude, and moves towards the wind vector W. d The drone is flying at an angle in the opposite direction. At this moment, the main traction rope 110 is pulled in instantly, and the data of the tension sensor 120 spikes. The horizontal tension component and the vertical tension component generated by the suspension drone 100 in the opposite direction are pulled back to the horizontal state by the rigid force-bearing top cover 210, thus offsetting the lateral wind force. At the same time, the lifting drone 300 adjusts its own vector thrust, so that the electromagnetic coil assembly 600 of the flexible suspension remains stable in the strong wind, and the geophysical data does not show waveform distortion.

[0084] S5: Linked landing and safe recovery. After the operation is completed, the lifting drone 300 gradually reduces the motor speed to overcome the buoyancy of the buoyancy bag 200 and gradually descend. During the descent, the suspension drone 100 is always above the buoyancy bag 200, keeping the main traction rope 110 and the lower suspension cable 230 in a taut state until the entire structure lands safely.

[0085] Example 3

[0086] Transient electromagnetic detection for geophysical exploration requires travel to high-altitude areas. However, in high-altitude conditions, such as operations at altitudes above 3000 meters, the air density ρ... alt The air density ρ0 at sea level is significantly lower, resulting in a decrease in the static buoyancy F generated by the buoyancy capsule 200. b As it decreases, a static buoyancy loss ΔF is generated. bTherefore, a high-altitude static buoyancy collaborative compensation is also proposed, in which an altimeter or atmospheric pressure sensor is electrically connected to the lifting UAV 300 and / or the suspension UAV 100 to obtain the altitude data or air density data of the environment in which the overall structure is located in real time;

[0087] Under high-altitude conditions with no wind or light wind, the flight control assembly acquires the current altitude or air density in real time and calculates the static buoyancy loss ΔF of the buoyancy capsule 200 caused by the decrease in air density. b If the static buoyancy loss ΔF b If the preset dynamic balancing threshold is exceeded, static buoyancy compensation is triggered.

[0088] Based on the static buoyancy loss ΔF b Calculate the vertical dynamic lifting compensation force F of the suspended UAV 100. v cpmp The control commands are sent to the suspended drone 100, which increases its output power in the vertical direction, generating a continuous upward vertical tension through the main traction rope 110. At this time, the force balance equation of the structure in the vertical direction is corrected to:

[0089]

[0090] In the formula, After receiving the high-altitude collaborative compensation command, the suspended UAV 100 increases the motor shaft power to output an additional dynamic lifting compensation force in the vertical direction, thus enabling... This transfers all or part of the buoyancy loss load caused by high altitude to the suspended drone 100 above, maintaining the working state of the lifting drone 300 below, so that it does not have to be forced to increase the motor output thrust due to the increase in altitude.

[0091] Example 4

[0092] In the event of a sudden communication link interruption between the suspended UAV 100 and the lifting UAV 300 due to external electromagnetic interference during cruise, or a sudden breakage of the main traction rope 110, the control heartbeats of the suspended UAV 100 and the lifting UAV 300 will stop, immediately triggering the safety recovery procedure. The suspended UAV 100 is equipped with an electric release device at its bottom, which instantly performs a hook-breaking action, discarding the main traction rope 110 and autonomously ascending for a safe return. The lifting UAV 300 then instantly takes over independent control of the entire aircraft, adjusting the power of its multi-rotor power assembly to a safe emergency landing setting. This overcomes the residual buoyancy transmitted by the buoyancy capsule 200 and the lower suspension cable 230, protecting the geophysical exploration main unit 400 fixed to its fuselage structure and the suspended electromagnetic coil assembly 600 as they smoothly land on the ground, achieving safe recovery.

[0093] Example 5

[0094] The control method can also achieve single-unit degradation control by lifting the UAV 300 and the buoyancy capsule 200;

[0095] In field operations with weak winds and ample static buoyancy and power, the longitudinally connected architecture directly omits the top-level suspended UAV 100 and main traction rope 110. The overall architecture is reduced to a single-unit dynamic geophysical exploration structure consisting of a buoyancy capsule 200, a lower suspension cable 230, a lower rotating disk 240, and a UAV 300. The vertical takeoff, flight path geophysical exploration, wind-resistant and anti-sway control, and landing and recovery steps of this single-unit dynamic geophysical exploration structure are all independently executed by the UAV 300 and its control assembly. The buoyancy capsule 200 dynamically compensates for external environmental disturbances, independently balancing minor environmental disturbances and completing geophysical data acquisition. This operational state simplifies the deployment and recovery process on the field surface, reduces overall energy consumption and operating costs, and demonstrates the mission flexibility and hardware fault tolerance of the longitudinally connected architecture under different field operation conditions.

[0096] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A floating-wing series-connected all-airborne transient electromagnetic detection structure, characterized in that: From top to bottom, it includes a suspended drone (100), a buoyancy bag (200), and a lifting drone (300). The suspended drone (100) and the buoyancy bag (200) are connected by an upper traction and rotation mechanism, and the buoyancy bag (200) and the lifting drone (300) are connected by a lower traction and rotation mechanism. The lifting drone (300) has a geophysical main unit compartment (400) for accommodating the transient electromagnetic detection system. A shock-absorbing suspension assembly (500) is provided at the bottom of the lifting drone (300). The electromagnetic coil assembly (600) of the transient electromagnetic detection system is suspended below the geophysical main unit compartment (400) by the shock-absorbing suspension assembly (500).

2. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 1, characterized in that: The top and bottom walls of the buoyancy bladder (200) are respectively provided with a rigid force-bearing top cover (210) and a rigid base (220). The rigid load-bearing top cover (210) includes an arc-shaped load-bearing cover (211) and a first elastic protective pad (214) disposed between the arc-shaped load-bearing cover (211) and the top of the buoyancy bladder (200). A hook assembly (215) is provided on the outer wall of the arc-shaped load-bearing cover (211). The upper traction rotation mechanism is connected to the top of the buoyancy bladder (200) through the hook assembly (215). The rigid base (220) includes an arc-shaped base (221) and a second elastic protective pad (223) disposed between the arc-shaped base (221) and the bottom of the buoyancy bladder (200). A suspension cable bearing lug (222) is provided on the outer wall of the arc-shaped base (221). The lower traction rotation mechanism is connected to the bottom of the buoyancy bladder (200) through the suspension cable bearing lug (222).

3. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 2, characterized in that: The upper traction rotation mechanism includes an upper rotating disk (212), the upper part of which is provided with a main traction rope (110) connected to the bottom of the suspended drone (100), and the lower part is provided with an upper inclined line (213) connected to the top wall of the buoyancy bladder (200). The lower traction rotation mechanism includes a lower rotating disk (240), the upper part of which is provided with a lower suspension cable (230) connected to the bottom of the buoyancy bag (200), and the lower part of the lower rotating disk (240) is connected to the lifting drone (300).

4. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 3, characterized in that: A tension sensor (120) is also installed on the main traction rope (110).

5. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 3, characterized in that: The lower rotating disk (240) includes a lower rotating plate (242) and an upper rotating plate (241) sleeved above the lower rotating plate (242), with a rotating bearing (243) assembled between them. The outer edge of the upper rotating plate (241) is integrally formed with a rope lug (244) for connecting the upper inclined line (213) and / or the lower suspension cable (230). The upper rotating disk (212) and the lower rotating disk (240) have the same structure.

6. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 5, characterized in that: A C-shaped rigid rod (250) is also provided between the lower rotating disk (240) and the lifting drone (300). The C-shaped rigid rod (250) includes a C-shaped main rod (251) and a reinforcing rib (254) provided on the inner arc surface of the C-shaped main rod (251). The upper end and lower end of the C-shaped main rod (251) are respectively provided with an upper connector (252) that is hinged to the lower rotating disk (240) and a lower connector (253) that is fixed to the lifting drone (300).

7. The floating-wing series-connected all-airborne transient electromagnetic detection structure according to claim 1, characterized in that: The shock-absorbing suspension assembly (500) includes a fixed back plate (501) fixed to the bottom of the lifting drone (300) and a suspension load frame (503) disposed below the fixed back plate (501), with a damping shock-absorbing ball (502) installed between the two, and a pull wire (510) for suspending the electromagnetic coil assembly (600) also disposed on the suspension load frame (503).

8. A control method for a tandem floating-wing all-airborne transient electromagnetic detection structure according to any one of claims 1-7, characterized in that: The suspended UAV (100) has an upper flight control assembly (130) inside, and the lifting UAV (300) has a lower flight control assembly (310) inside. The control method enables dual-machine coordinated control through a suspended UAV (100), a lifting UAV (300), and a buoyancy capsule (200); The dual-machine collaborative control includes the following steps: S1: Dual-engine autonomous coordinated takeoff and trim, the upper flight control assembly (130) and the lower flight control assembly (310) establish a communication link, the lifting UAV (300) starts and cooperates with the buoyancy capsule (200) to rise to the preset geophysical exploration height, the suspension UAV (100) takes off synchronously and stays above the buoyancy capsule (200), adjusts its own lift, so that the main traction rope (110) and the buoyancy capsule (200) are in a critical trim state; S2: Serial cruise geophysical exploration, the suspended UAV (100) and the lifting UAV (300) work together to output forward flight power, cruise along the preset geophysical exploration route, collect geophysical exploration data using the electromagnetic coil assembly (600), and record the echo; S3: Wind drift monitoring and wind resistance compensation vector calculation. The two flight control assemblies monitor the state parameters of the UAV in real time during flight. When the ambient wind force increases and causes the UAV to produce a horizontal displacement or attitude tilt angle exceeding the preset threshold, wind resistance compensation is triggered. The flight control assembly calculates the wind direction vector W of the ambient wind in real time based on the direction of the UAV's tilt angle change and the direction of the thrust caused by the abnormal increase in motor power consumption. d Wind force vector W f Then, the wind-resistant compensation tension vector F of the suspended UAV (100) was calculated. c And the attitude balance thrust for lifting the drone (300); S4: Series dynamic coordinated wind resistance adjustment, the suspended UAV (100) receives instructions from the flight control assembly, adjusts its flight attitude, and moves towards the wind vector W. d The drone tilts in the opposite direction while the lifting drone (300) adjusts its own vector thrust to maintain horizontal and vertical stability in the wind. S5: Linked landing and safe recovery. After the operation is completed, the lifting drone (300) gradually reduces the motor speed so that it overcomes the buoyancy of the buoyancy bag (200) and gradually descends. During the descent, the suspension drone (100) is always above the buoyancy bag (200) to keep the main traction rope (110) and the lower suspension cable (230) in a taut state until the whole structure lands safely.

9. The control method for a tandem floating-wing all-airborne transient electromagnetic detection structure according to claim 8, characterized in that: The control method can also achieve single-unit degradation control by lifting the UAV (300) and the buoyancy capsule (200); The single-unit degradation control retains the lifting drone (300), which independently performs the take-off, cruise geophysical exploration, wind and anti-sway control and landing and recovery steps, and uses its own structure in conjunction with the buoyancy capsule (200) to dynamically compensate for external environmental disturbances.

10. The control method for a tandem floating-wing all-airborne transient electromagnetic detection structure according to claim 8, characterized in that: The dual-machine coordinated control mode also includes high-altitude static buoyancy collaborative compensation. The lifting drone (300) and / or suspension drone (100) are electrically connected to an altimeter or atmospheric pressure sensor to obtain the altitude data or air density data of the environment in which the overall structure is located in real time. The aforementioned high-altitude static buoyancy compensation refers to the flight control assembly acquiring the current altitude or air density in real time under high-altitude conditions with no wind or light wind, and calculating the static buoyancy loss ΔF of the buoyancy capsule (200) caused by the decrease in air density. b According to the static buoyancy loss ΔF b Calculate the vertical dynamic lifting compensation force F of the suspended UAV (100). v cpmp And send it to the suspended drone (100). After receiving the command, the suspended UAV (100) increases the pulling force and pulls the buoyancy capsule (200) upward through the main traction rope (110) to compensate for the static buoyancy loss ΔF. b Maintain the working state of the lifting drone (300) below.

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