阅读说明：本技术 一种基于无人机的半航空电磁接收系统搭载结构 (Semi-aviation electromagnetic receiving system carrying structure based on unmanned aerial vehicle ) 是由 张栋 张一鸣 张晨浩 于 2021-09-24 设计创作，主要内容包括：本发明涉及一种基于无人机的半航空电磁接收系统搭载结构,用于解决由于半航空电磁探测系统在作业时产生的运动噪声,导致探测信号不准确的问题。具体包括凯夫拉细绳、阻尼系统底板、水平阻尼弹簧、牛眼轴承端盖、万向轮、牛眼轴承底盘、牛眼轴承主球、竖直阻尼弹簧、滚动钢珠、牛眼轴承底座,其中,牛眼轴承端盖、牛眼轴承底座和牛眼轴承底盘从上至下固定连接形成结构体,牛眼轴承主球置于牛眼轴承底座中,通过滚动钢珠与牛眼轴承底座润滑接触,结构体通过水平阻尼弹簧固定于阻尼系统底板上,凯夫拉细绳一部分用于连接无人机和阻尼系统底板,另一部分通过内置于牛眼轴承主球的竖直阻尼弹簧与电磁接收系统相连,隔绝了噪声影响。(The invention relates to a semi-aerial electromagnetic receiving system carrying structure based on an unmanned aerial vehicle, which is used for solving the problem of inaccurate detection signals caused by motion noise generated by a semi-aerial electromagnetic detection system during operation. The damping system comprises a Kevlar string, a damping system bottom plate, a horizontal damping spring, a bull's eye bearing end cover, a universal wheel, a bull's eye bearing chassis, a bull's eye bearing main ball, a vertical damping spring, a rolling steel ball and a bull's eye bearing base, wherein the bull's eye bearing end cover, the bull's eye bearing base and the bull's eye bearing chassis form a structural body from top to bottom through fixed connection, the bull's eye bearing main ball is arranged in the bull's eye bearing base, through the rolling steel ball and the lubrication contact of the bull's eye bearing base, the structural body is fixed on the damping system bottom plate through the horizontal damping spring, one part of the Kevlar string is used for connecting an unmanned aerial vehicle and the damping system bottom plate, the other part is connected with an electromagnetic receiving system through the vertical damping spring arranged in the bull's eye bearing main ball, and the influence of noise is isolated.)

1. The utility model provides a semi-aviation electromagnetic receiving system embarkation structure based on unmanned aerial vehicle which characterized in that includes: 10 parts of a Kevlar thin rope (1), a damping system bottom plate (2), a horizontal damping spring (3), a bull's eye bearing end cover (4), a universal wheel (5), a bull's eye bearing chassis (6), a bull's eye bearing main ball (7), a vertical damping spring (8), a rolling steel ball (9) and a bull's eye bearing base (10); the Kevlar thin rope (1) comprises four unmanned aerial vehicle connecting ropes (1-1), a vertical damping spring connecting rope (1-2) and four carrying electromagnetic method receiving system ropes (1-3), wherein the unmanned aerial vehicle connecting ropes (1-1) are used for connecting a damping system bottom plate (2) and an unmanned aerial vehicle, the carrying electromagnetic method receiving system ropes (1-3) are used for connecting the vertical damping spring connecting ropes (1-2) and an electromagnetic method signal receiving system, and the carrying electromagnetic method receiving system ropes (1-3) converge and carry the electromagnetic receiving system in a four-rope one-point mode; a damping system limiting hole (2-1), four unmanned aerial vehicle connecting rope fixing holes (2-2) and six horizontal spring mounting holes (2-3) are formed in the damping system bottom plate (2); the horizontal damping spring (3) comprises a spring (3-1), a damper (3-2) and two spring pull rings (3-3); the bull eye bearing end cover (4) is provided with four bull eye bearing base combination holes (4-1); the bull's eye bearing chassis (6) is provided with a bull's eye bearing base placing hole (6-1), four bull's eye bearing mounting holes (6-2), six horizontal damping spring mounting holes (6-3) and four universal wheel fixing holes (6-4); the main ball (7) of the bull's eye bearing is provided with a vertical damping spring mounting groove (7-1); the vertical damping spring (8) sequentially comprises a spring (8-1), a damper (8-2) and a spring pull ring (8-3) from top to bottom; the bull-eye bearing base (10) is in an inverted straw hat shape and is axially communicated, a downward groove is used for placing a bull-eye bearing main ball (7), a rolling steel ball placing groove (10-1) is circumferentially arranged at the bottom of the groove, a plurality of rolling steel balls (9) are placed in the rolling steel ball placing groove (10-1), and the bull-eye bearing main ball (7) is placed in the downward groove through the rolling steel balls (9) and moves; the downward groove of the bull's eye bearing base (10) penetrates through a bull's eye bearing base placing hole (6-1), so that the bull's eye bearing base (10) is placed on a bull's eye bearing base plate (6), a bull's eye bearing end cover (4) is placed on the bull's eye bearing base plate (10) provided with a bull's eye bearing main ball (7), fastening screws sequentially penetrate through a bull's eye bearing base combining hole (4-1), a bull's eye bearing end cover combining hole (10-2) and a bull's eye bearing mounting hole (6-2) to fixedly connect the bull's eye bearing end cover (4), the bull's eye bearing base plate (10) and the bull's eye bearing base plate (6) to form a structural body, wherein a vertical damping spring mounting groove (7-1) is arranged at the longitudinal diameter of the bull's eye bearing main ball (7), the vertical damping spring mounting groove (7-1) is divided into an upper section and a lower section, and the diameter of the upper section is larger than the diameter, the vertical damping spring (8) is arranged in the vertical damping spring mounting groove (7-1), and the vertical damping spring connecting rope (1-2) sequentially penetrates through the eyelet bearing base (10) and the vertical damping spring mounting groove (7-1) and is tied to the spring pull ring (8-3); the universal wheel (5) penetrates through a universal wheel fixing hole (6-4) and is fixed with the bull's eye bearing chassis (6) through a nut, the structural body is arranged on the damping system bottom plate (2) through the universal wheel (5), a downward groove of the bull's eye bearing base (10) penetrates through a damping system limiting hole (2-1) and limits movement of the structural body, and the structural body is connected with the damping system bottom plate (2) through six horizontal damping springs (3) which are uniformly arranged.

2. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the connection relation among the damping system bottom plate (2), the horizontal damping springs (3) and the bull's eye bearing chassis (6) is that two spring pull rings (3-3) of each horizontal damping spring (3) are respectively installed in the horizontal spring installation holes (2-3) and the horizontal damping spring installation holes (6-3) through fastening screws.

3. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the ball at the bottom of the universal wheel (5) is arranged on the damping system bottom plate (2) and can perform universal motion.

4. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: and a pull ring spring pull ring (8-3) of the vertical damping spring (8) is downwards placed in the vertical damping spring mounting groove (7-1).

5. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the bull eye bearing main ball (7) is in lubrication contact with the bull eye bearing base (10) through the rolling steel ball (9), and the bull eye bearing main ball (7) can rotate in the bull eye bearing base (10).

6. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the bull's eye bearing main ball (7), the bull's eye bearing end cover (4) and the bull's eye bearing base (10) are made of PC materials, and the lubricating ball is made of 304 stainless steel balls.

7. The semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the length r of the Kevlar string (1)₂The determination method of (2) is as follows: measuring the noise amplitude v of a receiving system at a noise reference point in a ground test₀The distance between the unmanned aerial vehicle and the receiving system is any known set value r₁Noise amplitude v of time-receiving system at noise reference point_n1The length r of the Kevlar rope of the unmanned aerial vehicle carrying the electromagnetic receiving system can be calculated₂The concrete formula is as follows:

8. the semi-aerial electromagnetic receiving system carrying structure based on the unmanned aerial vehicle as claimed in claim 1, wherein: the damping oil of the damping spring is dimethyl silicone oil.

Technical Field

The invention relates to a semi-aerial electromagnetic surveying technology, in particular to a semi-aerial electromagnetic receiving system carrying structure based on an unmanned aerial vehicle.

Background

Mineral products are used as non-renewable resources, and scientific and technical progress, social and economic development of any country and region must be supported by mineral resources. With the rapid development of national economy, China has entered the middle stage of industrialization development in which the usage of per capita mineral resources is rapidly increased. The method has good condition and great potential for mineral formation in China, three mineral formation areas in the world are distributed in China, and a plurality of large-scale mineral formation actions are superposed on the continents. However, in China, more than 20 tens of thousands of ore deposits (points) are found at present, and a considerable part of the deposits are not yet proved for technical reasons; the mining depth of the existing ore deposit is generally less than 500 meters, and the home bottom of the deep ore is not clear; the traditional ground prospecting method has low working efficiency in regions which are difficult to reach in the trails such as the west desert, the gobi and the like and vegetation and water system coverage areas in the south. These factors lead to serious shortage of guarantee capability of mineral resources in China, especially bulk mineral resources, and the problem of resource safety is always a core problem affecting national sustainable development.

The geophysical electromagnetic method is an important technical means for developing underground mineral resource detection, and is used for acquiring an electromagnetic transmission function of a ground system by observing electromagnetic response generated by the ground under the excitation of a natural or artificial field source and extracting electrical parameter distribution information of the ground on the basis of the electromagnetic transmission function. The electromagnetic methods mainly used at present may be classified into a terrestrial electromagnetic method and an aeroelectromagnetic method according to a working mode. The land electromagnetic method has the advantages that the transmitting power is high, the signal-to-noise ratio of the acquired data is high, the processing of the later data is facilitated, and the cost is high when the terrain is complex; the advantage of the aeroelectromagnetic method lies in surveying fast, but because the transmit power restriction, survey depth is lighter, surveys the data in addition and receives the gesture influence of aircraft great, and later stage result credibility is relatively poor. In recent years, with the continuous maturity of unmanned aerial vehicle technology, it has become a development trend to use an unmanned aerial vehicle platform to carry electromagnetic exploration equipment. The Semi-aeroelectromagnetic Method (SAEM) arranges a transmitting system (comprising a transmitter and a transmitting antenna) on the ground, only uses a flight platform to carry a receiving system (comprising a sensor and a collector) to carry out aeronautical observation, and is widely applied to the fields of resource exploration such as mineral resources, underground water, terrestrial heat and the like, geological mapping, environmental monitoring and the like. The method combines the advantages of large transmitting power of terrestrial electromagnetism and wide-range flexible receiving of airborne electromagnetism, is a new efficient exploration mode proposed in recent years, and is low in cost and wide in application. The method overcomes the defects that the ground electromagnetic method is greatly influenced by the environment and has low working efficiency, solves the problems of small detection depth and low signal-to-noise ratio of the aviation electromagnetic method, and is suitable for mineral resource detection in complex environments such as swamps, mountains, deserts and the like.

The semi-aviation electromagnetic detection system is simple to operate and has large development potential, but the current receiving mode is rough, and only the unmanned aerial vehicle is simply utilized to directly carry on the receiving system. For an electromagnetic reception system for airborne mobile measurements: the unmanned aerial vehicle can introduce electromagnetic noise; the attitude change of the unmanned aerial vehicle can introduce motion noise; the coil moves in the air to cut geomagnetic induction lines, and low-frequency movement noise consistent with movement frequency is introduced into the coil; the attitude change in the moving process of the coil causes the equivalent area of the coil on the measured magnetic field component to change and introduces other magnetic field components, thereby causing the noise with the same source and frequency as the measured signal. Motion noise is undoubtedly a key problem limiting the detection capability of the receiving system, and therefore, the mounting design (including mounting system structure, material selection and the like) of the electromagnetic receiving system is a key ring for improving the performance of the semi-aviation electromagnetic detection system.

Disclosure of Invention

The electromagnetic detection system aims at the problem that the existing carrying structure of the foreign semi-aviation electromagnetic detection system generally adopts a single-layer four-rope carrying mode, and introduces movement noise to an electromagnetic receiving system, so that detection signals are inaccurate. The specific technical scheme is as follows:

a semi-aviation electromagnetic receiving system carrying structure based on an unmanned aerial vehicle comprises 10 parts, namely Kevlar thin ropes, a damping system bottom plate, a horizontal damping spring, a bull's eye bearing end cover, a universal wheel, a bull's eye bearing chassis, a bull's eye bearing main ball, a vertical damping spring, rolling steel balls and a bull's eye bearing base; the Kevlar thin rope comprises an unmanned aerial vehicle connecting rope, a vertical damping spring connecting rope and an electromagnetic method carrying receiving system rope, wherein the unmanned aerial vehicle connecting rope is used for connecting a damping system bottom plate and the unmanned aerial vehicle, and the electromagnetic method carrying receiving system rope is used for connecting the vertical damping spring connecting rope and an electromagnetic method signal receiving system; the damping system bottom plate is provided with a damping system limiting hole, four unmanned aerial vehicle connecting rope fixing holes and six horizontal spring mounting holes; the horizontal damping spring comprises a spring, a damper and two spring pull rings; the end cover of the bull eye bearing is provided with four bull eye bearing base combination holes; the bull's eye bearing chassis is provided with a bull's eye bearing base placing hole, four bull's eye bearing mounting holes, six horizontal damping spring mounting holes and four universal wheel fixing holes; the main ball of the bull's eye bearing is provided with a vertical damping spring mounting groove; the vertical damping spring sequentially comprises a spring, a damper and a spring pull ring from top to bottom; the bullseye bearing base is in an inverted straw hat shape and is axially communicated, the downward groove is used for placing a bullseye bearing main ball, the bottom of the groove is circumferentially provided with a rolling steel ball placing groove, a plurality of rolling steel balls are placed in the rolling steel ball placing groove, and the bullseye bearing main ball is placed in the downward groove through the rolling steel balls and moves; the downward groove of the bull's eye bearing base penetrates through the bull's eye bearing base placing hole, so that the bull's eye bearing base is placed on the bull's eye bearing chassis, the bull's eye bearing end cover is placed on the bull's eye bearing base provided with the bull's eye bearing main ball, a fastening screw sequentially penetrates through the bull's eye bearing base combining hole, the bull's eye bearing end cover combining hole and the bull's eye bearing mounting hole to fixedly connect the bull's eye bearing end cover, the bull's eye bearing base and the bull's eye bearing chassis to form a structural body, wherein a vertical damping spring mounting groove is formed in the longitudinal diameter of the bull's eye bearing main ball, the vertical damping spring mounting groove is divided into an upper section and a lower section, the diameter of the upper section is larger than that of the lower section, the vertical damping spring is placed in the vertical damping spring mounting groove, and a vertical damping spring connecting rope sequentially penetrates through the bull's eye bearing base and the vertical damping spring mounting groove to be tied on a spring pull ring; the universal wheel passes through the universal wheel fixed orifices and is fixed with the bull's eye bearing chassis through the nut, and the structure is arranged in on the damping system bottom plate through the universal wheel, and the spacing hole of damping system is passed through to the decurrent recess of bull's eye bearing base to with this restriction this structure's removal, through six horizontal damping spring interconnect of evenly arranging between this structure and the damping system bottom plate.

The connection relationship of the damping system bottom plate, the horizontal damping springs and the bull eye bearing chassis is that two spring pull rings of each horizontal damping spring are respectively installed at the horizontal spring installation holes and the horizontal damping spring installation holes by fastening screws.

And balls at the bottom of the universal wheel are placed on a bottom plate of the damping system to perform universal motion.

The pull ring spring pull ring of the vertical damping spring is placed downwards in the vertical damping spring mounting groove.

The bull eye bearing main ball is in lubrication contact with the bull eye bearing base through the rolling steel ball, and can rotate in the bull eye bearing base

Compared with the prior art abroad, the invention has the innovation points that:

firstly, the invention adopts a double-layer carrying structure, an unmanned aerial vehicle directly carries a damping structure, and an electromagnetic receiving system is directly carried by an intermediate damping structure. The middle damping structure not only effectively isolates the influence of the attitude change of the unmanned aerial vehicle in the flying process on the electromagnetic receiving system, but also weakens the swing amplitude of the receiving system generated by air resistance.

And secondly, a self-made damping spring is adopted as a damping structure, a proper spring is selected to be matched with a damper, and the damper selects dimethyl silicon oil as damping oil. The bottom plate of the damping system is perforated and fixed with lifting ring screws in the horizontal direction, and the damping structure is connected with the bottom oxygen plate through the damping springs, so that the influence of air resistance on the receiving coil is weakened. Compare in foreign direct four-wire carry formula structure and can produce violent shock because air resistance, this structure very big has weakened the attitude change of receiving system self, has avoided introducing other magnetic field components. The damping spring in the vertical direction absorbs the energy generated by the up-and-down motion of the unmanned aerial vehicle and the high-frequency vibration of the unmanned aerial vehicle, and the influence on an electromagnetic receiving system is avoided.

And thirdly, a bearing structure is adopted in double-layer connection, a bull-eye bearing is manufactured, a PC material is used as a main ball, an end cover and a base material, and a 304 stainless steel ball is selected as a lubricating ball to prevent the eddy effect. The bull's eye bearing main ball is at the free rotation of injecing the angular range, has effectively guaranteed that unmanned aerial vehicle takes place in the twinkling of an eye violent attitude change and can not influence main ball lug connection's below receiving system when driving the damping structure.

And the length and distribution of the three-section Kevlar rope are reasonably selected, the first section adopts four parallel ropes to carry a damping system bottom plate, the second section adopts a rope to be connected up and down, the third section adopts four ropes to converge at one point to carry an electromagnetic receiving system, and the possibility that the electromagnetic receiving system is inclined and rolled due to the fact that the carrying ropes are wound during aerial exploration operation is effectively avoided.

Advantageous effects

The invention provides a carrying structure which has a double-layer carrying mode and a spring damping vibration attenuation system and is suitable for semi-aviation electromagnetic detection of an unmanned aerial vehicle. Under the condition that other system performance indexes are not changed, the double-layer carrying structure effectively isolates the influence of the attitude change of the unmanned aerial vehicle in the flying process on the electromagnetic receiving system, and the damping structure and the bearing structure weaken the influence of the attitude change of the unmanned aerial vehicle in all directions and high-frequency vibration on the receiving system. Compared with a semi-aviation carrying structure in foreign countries, the structure effectively reduces the motion noise generated in the aerial exploration operation and improves the performance of the semi-aviation electromagnetic detection system.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention used in conjunction with an unmanned aerial vehicle and an electromagnetic signal receiving system;

FIG. 2, a diagram of a damping system floor;

FIG. 3, horizontal damping spring diagram;

FIG. 4 is a view of a bull's eye bearing end cap;

FIG. 5, a universal wheel view;

FIG. 6, a bull's eye bearing chassis view;

FIG. 7 is a view of a bull's eye bearing master sphere;

FIG. 8, vertical damping spring diagram;

FIG. 9, rolling ball diagram;

FIG. 10, a view of a bull's eye bearing mount;

FIG. 11 is a view of a bullseye bearing structure;

FIG. 12 is a view showing the internal structure of a bull's eye bearing;

wherein, 1, Kevlar string, 1-1, unmanned aerial vehicle connecting rope, 1-2, vertical damping spring connecting rope, 1-3, electromagnetic method carrying receiving system rope, 2, damping system bottom plate, 2-1, damping system limiting hole, 2-2, unmanned aerial vehicle connecting rope fixing hole, 2-3, six horizontal spring mounting holes, 3, horizontal damping spring, 3-1, spring, 3-2, damper, 3-3, two spring pull rings, 4, bull eye bearing end cover, 4-1, bull eye bearing base combining hole, 5, universal wheel, 6, bull eye bearing chassis, 6-1, bull eye bearing base placing hole, 6-2, bull eye bearing mounting hole, 6-3, horizontal damping spring mounting hole, 6-4, universal wheel fixing hole, 7, bull eye bearing main ball, 7-1 parts of vertical damping spring mounting grooves, 8 parts of vertical damping springs, 8-1 parts of springs, 8-2 parts of dampers, 8-3 parts of spring pull rings, 9 parts of rolling steel balls, 10 parts of bull's eye bearing bases, 10-1 parts of rolling steel ball placing grooves, 10-2 bull's eye bearing end cover combining holes, 11 parts of electromagnetic method signal receiving systems, 11-1 parts of carrying rope grooves.

Detailed description of the preferred embodiments

In a specific embodiment of the mounting structure, the length of the kevlar rope on which the electromagnetic receiving system is mounted is determined in three parts. And secondly, determining the material and damping coefficient of the damping oil of the self-made damping spring. Thirdly, the mounting of the whole mounting structure. The specific relevant description is as follows:

firstly, determining the length of a Kevlar rope carrying an electromagnetic receiving system

Six rotor unmanned aerial vehicle are chooseed for use to the flight platform of half aviation electromagnetic detection system's receiver part, and unmanned aerial vehicle has 6 rotors, and the correspondence contains 6 brushless DC motor, and every motor is at the during operation, and the drive rotor rotates the stator and can produce rotating magnetic field, and rotating magnetic field's intensity and frequency receive the influence of motor speed, and this rotating magnetic field belongs to external magnetic field noise to receiving system.

Because the electromagnetic receiving system is the magnetic field sensitive element, the electromagnetic noise generated by the unmanned aerial vehicle can not be directly shielded, and the electromagnetic noise of the unmanned aerial vehicle can only be isolated by reasonably designing the distance between the unmanned aerial vehicle and the electromagnetic receiving system. Relative to the receiver system, the motor is equivalent to a magnetic dipole, and the spatial distribution of the generated magnetic field is expressed by the following formula:

in formula (1): h is magnetic field intensity, and m is the quality of electromagnetic method receiving system, and k is the rope elastic modulus that suspends in midair, and r is the distance between unmanned aerial vehicle and the receiving system, and i is motor operating current.

It can be seen that the magnetic field generated by the direct current motor of the unmanned aerial vehicle attenuates with the distance to the power of 5, so that the noise amplitude coupled to the receiving system in the flight experiment also attenuates with the distance to the power of 5. By taking the extreme point of the amplitude envelope of the platform noise low frequency band as a noise reference point and taking the noise intensity when the system works on the ground as the reference noise intensity (0 gain point), the magnetic field noise coupled into the receiving system can be calculated:

in the formula (2), v_nFor receiving the noise amplitude, v, of the system at the noise reference point in flight experiments₀The noise amplitude of the system at the noise reference point is received in the ground test.

Thus, when the noise L coupled into the receiving system is 0, the length of the line is obtained, and v is obtained_n＝v₀. The distance between an unmanned aerial vehicle and a receiving system is set to be r at will₁At the moment, the noise amplitude of the receiving system at the noise reference point in the flight experiment is v_n1(ii) a Assuming that the distance between the unmanned aerial vehicle and the receiving system is r₂At the moment, the noise amplitude of the receiving system at the noise reference point in the flight experiment is v_n2. The relationship between the two is:

the length of the line is determined when the noise L coupled into the receiving system is 0, and v is the same_n2＝v₀。

Then:

as can be seen from equation (4), the noise amplitude v of the receiving system at the noise reference point in the ground test is measured₀The distance between the unmanned aerial vehicle and the receiving system is r₁Noise amplitude v of time-receiving system at noise reference point_n1That is, the distance r between the unmanned aerial vehicle and the receiving system can be calculated₂，r₂That is, the length of the kevlar rope carrying the electromagnetic receiving system.

Secondly, determining the damping coefficient of damping oil of the self-made damping spring

The damping oil is generally liquid, and the damping grease is solid or semisolid. Under the same level, the damping grease has larger damping than the damping oil, and the damping spring utilized by the invention only needs to select the damping oil. The damping oil is generally silicone oil which is generally divided into two types of methyl silicone oil and modified silicone oil. The most commonly used silicone oil is methyl silicone oil, also called common silicone oil, the organic groups of which are all methyl groups, and the silicone oil is called dimethyl silicone oil, called methyl silicone oil for short because the structure contains two methyl groups. And finally selecting the dimethyl silicone oil as the damping oil of the self-made damping spring.

In order to generate better damping and shock absorption effects, the damping coefficient of the damping oil can be further calculated. The carrying structure of the unmanned aerial vehicle on the receiving system can be approximately seen as simple pendulum motion, and a kinetic equation of the whole system is established:

in formula (5): m is the sum of the mass of the structure of the invention and the mass of the electromagnetic method receiving system, L is the length of the swinging rope, beta is the damping coefficient, theta is the amplitude of the swinging, and g is the gravity acceleration.

Solving the kinematic equation of equation (5) yields:

in formula (6): theta₀And theta (t) is the offset angle of the receiving system which changes along with time when the receiving system does periodic swing motion.

The period T of θ (T) is then:

from equation (7), the wobble recovery period T is a function of β, and the damping coefficient value β when T is the minimum value is calculated by equation (7). Beta is the damping coefficient value beta of the damping system of the present invention₁Value of damping coefficient beta of air₀And (4) summing.

In the system without damping, the damping coefficient is completely the air damping coefficient, and can be obtained by the formula (7):

in the formula (8), T₀The recovery period of the oscillation of the electromagnetic receiving system when the damping system is not added is shown.

Therefore, the return period T of the oscillation of the electromagnetic receiving system is measured when the damping system is not added only under the condition that the damping spring is untied but other conditions are not changed₀Then the air damping coefficient value beta can be calculated₀. Then, according to the formula (7), calculating the damping coefficient value beta when the return period T of the swing of the electromagnetic receiving system is the minimum value, and then calculating the damping coefficient value beta of the damping system₁Comprises the following steps:

β₁＝β-β₀ (9)

mounting of three-in-one carrying structure

Semi-aviation electromagnetic receiving system carrying structure based on unmanned aerial vehicle, double-deck structure, syllogic hawser carry on. Four parallel kaivy stay cords carry on damping system bottom plate, connect unmanned aerial vehicle and damping system, and damping system structure comprises damping system bottom plate, 6 horizontal damping springs, bull's eye bearing end cover, 4 universal wheels, bull's eye bearing chassis, bull's eye bearing owner ball, vertical damping spring, several rolling steel ball, 9 parts of bull's eye bearing base. A single short rope is led out from a pull ring of a vertical damping spring in a main ball of the self-made bull eye bearing to connect a buckle, one end of four thin ropes below is connected with a single rope led out from the upper part in a buckle mode, and the other end of the four thin ropes below is respectively tied in a rope groove reserved on a framework of an electromagnetic signal receiving system.

The specific connection mode is as follows: firstly, a damping system structure is installed, and the first step is as follows: a pull ring spring pull ring of the vertical damping spring is downwards placed in a vertical damping spring mounting groove of a bull eye bearing main ball, and a thin rope is led out of the pull ring; a certain amount of rolling steel balls are placed in rolling steel ball placing grooves of the bull-eye bearing base, the rolling steel balls are paved, then bull-eye bearing main balls provided with damping springs are placed in the bull-eye bearing base, the bull-eye bearing main balls are in lubrication contact with the bull-eye bearing base through the rolling steel balls, and the bull-eye bearing main balls can freely rotate in the bull-eye bearing base. The second step is that: the end cover of the bull's eye bearing and the bull's eye bearing base are combined together and are installed at the four mounting holes of the bull's eye bearing by fastening screws. The third step: the universal wheels penetrate through the four universal wheel fixing holes and are fixed with the bull's eye bearing chassis through the nuts, then the bull's eye bearing chassis is placed on the damping system bottom plate, and the bottom balls of the universal wheels are in contact with the damping system bottom plate, so that universal movement can be carried out on the bottom balls of the universal wheels. The fourth step: and fastening screws are respectively arranged at six horizontal spring mounting holes on a damping system bottom plate and six horizontal damping spring mounting holes on a bull eye bearing chassis, the six horizontal damping springs are mounted on fastening screw rods at various positions one by one, and finally the six horizontal damping springs are fixed by nuts. And after the manufacture and the installation are finished, assembling each part. The fifth step: four strings are tied at four corners of the landing frame of the unmanned aerial vehicle respectively, the other ends of the strings are tied on the buckles, the lifting ring screws are fixed on the fixing holes of the connecting ropes of the unmanned aerial vehicle of the damping system bottom plate, and the buckles are connected with the lifting ring screws. And a sixth step: thin ropes are tied in four rope grooves reserved on a framework of the electromagnetic signal receiving system, and a buckle is led out from the other end of the electromagnetic signal receiving system and is connected with the thin ropes led out from a vertical damping spring pull ring. And the whole double-layer semi-aviation electromagnetic receiving system carrying structure is mounted.