Take-off and landing system for ship-based composite wing unmanned aerial vehicle and control method

Abstract

A compensation platform of the take-off and landing system comprises a supporting frame, a bottom plate and a telescopic supporting shaft, the upper end of the telescopic supporting shaft is hinged to the supporting frame through an upper hinge joint, and the lower end of the telescopic supporting shaft is hinged to the bottom plate through a lower hinge joint; the clamping mechanism comprises a clamping frame, a first belt moving mechanism and a second belt moving mechanism, the clamping frame is fixedly arranged on the supporting frame, the first belt moving mechanism is arranged at one end of the clamping frame, the second belt moving mechanism is arranged at the other end of the clamping frame, the first belt moving mechanism is provided with a rotatable first clamping belt, and the second belt moving mechanism is provided with a rotatable second clamping belt. The first belt moving mechanism is provided with a rotatable first clamping belt, the first clamping belt is provided with a first clamping deflector rod, the second belt moving mechanism is provided with a rotatable second clamping belt, and the second clamping belt is provided with a second clamping deflector rod. According to the invention, the influence of regular reciprocating harmonic motion of the deck caused by sea waves on the take-off and landing of the unmanned aerial vehicle can be blocked, and the dependence on a complex flight control system and a high-precision sensor is reduced.

Description

Technical Field

[0001] The invention relates to the field of composite wing UAVs, in particular to a take-off and landing system and a control method for a shipborne composite wing UAV. Background Art

[0002] With the development of technology, composite wing UAVs are increasingly widely used in the shipborne field. Composite wing UAVs have both the efficient cruising capability of fixed-wing UAVs and the vertical take-off and landing capability of multi-rotor UAVs, which gives them significant advantages in the shipborne environment. However, composite wing UAVs also face many problems in shipborne take-off and landing, the most prominent of which is the shaking of the ship deck, which will bring great instability to the take-off and landing of the UAV.

[0003] There are two main ways to solve the above problems in the prior art: one is to improve the flight control system of the UAV, which uses sensors to sense the shaking of the deck in real time and adjust the flight attitude of the UAV accordingly; the other is to install a special take-off and landing platform on the ship, such as a platform with a shake reduction device, to reduce the impact of deck shaking on the take-off and landing of the UAV, thereby improving the stability of take-off and landing. However, in order to ensure the success rate and stability of the shipborne take-off and landing of the UAV, the above method has problems such as complex flight control system and high precision requirements for related detection components, and may not be able to fully and effectively cope with large-scale shaking of the deck under severe sea conditions. In addition, due to its structural characteristics, the endurance and power redundancy of the composite wing UAV in the multi-rotor state are very limited. Therefore, it is also very difficult to adjust the UAV only through the flight controller to achieve the purpose of rapid shipborne take-off and landing.

[0004] The patent with publication number CN111596687A discloses a landing guidance device for a vertical take-off and landing UAV mobile platform and its guidance method. The device includes a stable platform mounted on a ship deck, and a target is arranged on the upper platform of the stable platform. When the device is working, the UAV first autonomously follows the movement of the deck and gradually approaches the landing point until it reaches above the target. Then the UAV gradually lowers its height and approaches the landing point through dynamic-to-dynamic differential relative positioning technology until the deck reaches the vicinity of the visual capture point of the UAV. Then the UAV introduces visual navigation, and the deck is required to automatically adjust the inclination angle to offset the deck attitude movement during landing. This method requires the UAV to mount differential modules, inertial navigation modules, inertial navigation / GPS combined navigation systems and other modules. The entire flight control system is relatively complex, and its stable platform needs to be equipped with acquisition sensors to collect the attitude change data of the platform in real time to achieve control, which requires ensuring the detection accuracy of the acquisition sensors. In addition, the device only uses three support rods to achieve leveling, and the upper and lower ends of the support rods are hinged by conventional Hook hinges. The support structure and strength cannot meet the requirements of large swings of the deck in severe sea conditions.

[0005] The patent with publication number CN115675900A discloses a mobile shipborne vertical take-off and landing UAV automatic leveling platform and leveling method, which has four tilt sensors installed at the four corners of the support plane, and an electric control component is provided in the base to receive the plane tilt information transmitted by the tilt sensor and the hull vibration information detected by the gyroscope, and then calculate the telescopic length of the four hydraulic support legs to control the hydraulic cylinder to achieve shaking compensation. However, the device also needs to ensure the detection accuracy of detection elements such as tilt sensors, and once encountering severe sea conditions, the platform cannot meet the use requirements of large swings of the deck. Summary of the invention

[0006] The purpose of the present invention is to provide a take-off and landing system and control method for a ship-borne composite-wing UAV, which can block the influence of the regular reciprocating harmonic motion of the deck caused by the influence of waves on the take-off and landing of the UAV, and reduce the dependence on the complex flight control system and high-precision sensors of the UAV.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A take-off and landing system for a shipborne composite-wing UAV comprises a clamping mechanism and a compensation platform, wherein the compensation platform comprises a support frame, a base plate and a telescopic support shaft, the upper end of the telescopic support shaft is hinged to the support frame through an upper hinge joint, and the lower end is hinged to the base plate through a lower hinge joint, the clamping mechanism comprises a clamping frame, a first belt moving mechanism and a second belt moving mechanism, wherein the clamping frame is fixedly mounted on the support frame, the first belt moving mechanism is arranged at one end of the clamping frame, and the second belt moving mechanism is arranged at the other end of the clamping frame, the first belt moving mechanism is provided with a rotatable first clamping belt, and the first clamping belt is provided with a first clamping lever, the second belt moving mechanism is provided with a rotatable second clamping belt, and the second clamping belt is provided with a second clamping lever.

[0009] The telescopic support shaft includes a telescopic drive motor, a telescopic rod, an outer cylinder body and a support shaft base, wherein the lower end of the outer cylinder body and the telescopic drive motor are both arranged on the support shaft base, the telescopic rod is inserted into the outer cylinder body and driven to extend and retract by the telescopic drive motor, the upper end of the telescopic rod is hinged to the support frame through an upper hinge joint, and the lower side of the support shaft base is hinged to the base plate through a lower hinge joint.

[0010] The upper articulated joint and the lower articulated joint have the same structure, both comprising an upper connecting plate, a joint middle ring, a lower connecting plate, a first folded angle spring plate and a second folded angle spring plate, wherein a first connecting column is provided on the lower side of the upper connecting plate, a second connecting column is provided on the upper side of the lower connecting plate, a connecting folding ear is provided on the joint middle ring, and one side of the connecting folding ear is provided with a first folded ear connecting hole arranged obliquely upward, and the other side is provided with a second folded ear connecting hole arranged obliquely downward, adjacent first folded angle spring plates and second folded angle spring plates are staggered, and one end of the first folded angle spring plate is fixed at the first folded ear connecting hole on the corresponding connecting folding ear, and the other end is connected to the second connecting column corresponding to the lower side, one end of the second folded angle spring plate is fixed at the second folded ear connecting hole on the corresponding connecting folding ear, and the other end is connected to the first connecting column corresponding to the upper side, and the folding angle extension lines of each first folded angle spring plate and each second folded angle spring plate intersect at the joint rotation point.

[0011] According to the compensation control method for the take-off and landing system of a shipborne composite wing UAV, six telescopic support shafts are provided between the support frame and the bottom plate, and the control method comprises the following steps:

[0012] Step 1: Perform fast Fourier transform on the deck motion, specifically:

[0013]

[0014]

[0015] In the above formula (1), represents the predicted frequency of deck swing, represents the deck prediction phase angle, represents the predicted amplitude of deck swing, It indicates that the peak detector identifies the frequency corresponding to the i-th harmonic in the main N harmonic functions generated by the deck movement in the α dimension, where the α dimension includes the roll angle roll, the pitch angle pitch, the heading angle yaw, the X-direction displacement Δx, the Y-direction displacement Δy, and the Z-direction displacement Δz. T represents the time value within one cycle time. represents the amplitude corresponding to the i-th harmonic after Fourier transform at time T, Represents the first-order derivative value of the amplitude corresponding to the i-th harmonic after Fourier transform at time T;

[0016] Step 2: Superimpose the estimated harmonics of different frequencies to obtain the predicted T pre Deck expects motion signal after time

[0017]

[0018] In the above formula (2), the compensation value ρ α(t) is a constant at time t, which is calculated as:

[0019] Where T≤t≤T pre , represents the estimated value of the odd wave at time T;

[0020] Step 3: Construct the inverse kinematics solution formula of the upper support frame in the compensation platform:

[0021]

[0022] In the above formula (3), R x represents the expected roll of the support frame; R y represents the desired pitch of the support frame; R z represents the desired heading of the support frame, P x represents the x-direction displacement of the support frame; P y Indicates the Y-direction displacement of the support frame; P z Indicates the Z-direction displacement of the support frame; 0 represents the default height difference between the support frame and the base plate (202);

[0023] Step 4: Obtain the telescopic amount L of each telescopic support axis n :

[0024]

[0025] In the above formula (8), sqrt represents the square root operation, c represents the cosine operation, s represents the sin operation, and T nx and T ny are the X and Y components of the coordinate values ​​of the center points of each upper articulated joint in the support frame coordinate system, B nx , B ny , B nz They respectively represent the X, Y, and Z components of the coordinate values ​​of the center point of the lower hinge joint in the base plate coordinate system.

[0026] Step 5: The device control system controls the extension and retraction of each telescopic support shaft according to Ln obtained in step 4.

[0027] 5. The compensation control method for the take-off and landing system of a shipborne composite wing UAV according to claim 4 is characterized in that: in step 4, the transformation matrix T between the support frame coordinate system and the base plate coordinate system is first obtained according to the change of the support frame C :

[0028]

[0029] Then according to the transformation matrix T C The coordinate values ​​of the center points of the six upper articulated joints in the base plate coordinate system are obtained as follows:

[0030]

[0031] In the above formula (5), i=1...6, and the above formula (5) can be further written as:

[0032] T n =[T nx T ny 0 1], where T n is the coordinate value vector of the center point of each upper hinge joint in the base plate coordinate system;

[0033] The coordinate vector B of the center point of each lower articulated joint in the base plate coordinate system n Directly expressed as:

[0034] B n =[B nx B ny 0 1];

[0035] Then, in the base plate coordinate system, according to T n and B n The change in distance between the center point of the upper articulated joint and the center point of the corresponding lower articulated joint is calculated to obtain the telescopic amount Ln of the telescopic support shaft.

[0036] The first belt moving mechanism includes a first slide and a second slide, wherein a first lead screw driven to rotate by a first reduction motor is provided on one side of the a-end of the clamping frame, and the first slide is mounted on the first lead screw, and a second lead screw driven to rotate by a second reduction motor is provided on the other side of the a-end of the clamping frame, and the second slide is mounted on the second lead screw, first pulleys are provided on both the first slide and the second slide, a first clamping belt passes around each first pulley, and a first belt motor is provided on the first slide to connect with the corresponding first pulley.

[0037] The second belt moving mechanism includes a third slide and a fourth slide, wherein a third lead screw driven to rotate by a third reduction motor is provided on one side of the b end of the clamping frame, and the third slide is mounted on the third lead screw, and a fourth lead screw driven to rotate by a fourth reduction motor is provided on the other side of the b end of the clamping frame, and the fourth slide is mounted on the fourth lead screw, second pulleys are provided on the third slide and the fourth slide, the second clamping belt is passed around each second pulley, and a second belt motor is provided on the third slide to connect with the corresponding second pulley.

[0038] Each corner end of the support frame is provided with a mounting column, and the two side beam ends of the clamping frame are respectively fixed to the corresponding mounting columns through fixed connecting parts. The clamping frame is provided with a first slide rail on one side and a second slide rail on the other side. The first slider arranged at the lower side of the first slide seat and the third slider arranged at the lower side of the third slide seat cooperate with the first slide rail, and the second slider arranged at the lower side of the second slide seat and the fourth slider arranged at the lower side of the fourth slide seat cooperate with the second slide rail.

[0039] A method for controlling the take-off and landing system of a shipborne composite-wing UAV comprises the following steps:

[0040] Step 1: Determine the serial numbers of each motor in the clamping mechanism, wherein the first reduction motor and the second reduction motor have the same serial number, the third reduction motor and the fourth reduction motor have the same serial number, and the first belt motor and the second belt motor are respectively marked with a serial number, for a total of 4 serial numbers;

[0041] Step 2: Construct the relationship function between motor torque and error:

[0042]

[0043] In the above formula (9), i represents the motor number determined in step 1, i = 1, 2...4, M i represents the inertia characteristic of the i-th motor, D i represents the damping characteristic of the i-th motor, K i represents the stiffness characteristic of the i-th motor, e i represents the motion position error of the i-th motor, and are the first-order derivative and second-order derivative of ex according to time, is the expected torque of the i-th motor;

[0044] Step 3: The device control system obtains the desired torque according to step 2 Control the actions of each motor of the clamping mechanism, wherein the device control system first controls the first reduction motor and the second reduction motor as well as the third reduction motor and the fourth reduction motor to start so that the first clamping belt and the second clamping belt complete the clamping of the UAV tripod in the left and right directions, and then controls the first belt motor and the second belt motor to start so that the first clamping lever and the second clamping lever complete the clamping of the UAV tripod in the front and back directions.

[0045] In step 2, after the drone issues a landing command, the device control system sends the expected position x of each motor to the sub-control system of the clamping mechanism according to the pre-set settings, and calculates the expected position x and the current position x according to the pre-set settings. 0 Subtraction calculation error e i .

[0046] The advantages and positive effects of the present invention are:

[0047] 1. The present invention can meet the compensation requirements of large-amplitude and high-frequency shaking of the deck in complex sea conditions (sea conditions of level 4 and below), thereby blocking the influence of the regular reciprocating harmonic motion of the deck caused by the influence of waves on the take-off and landing of the UAV. The upper articulated joint and the lower articulated joint of the present invention do not adopt the conventional universal articulated structure, but adopt an articulated joint with a folded spring plate to realize the connection of the telescopic support shaft. This articulated joint can provide a large-angle rotation of 50° and a torsion of 20°, and has strong support stiffness. At the same time, the installation space it requires is shorter and smaller, so it is very suitable for use in a large swing platform. At the same time, because it has a certain torsion angle space, it can reduce the torque generated by the mechanical error of the telescopic support shaft, thereby improving the service life of the equipment.

[0048] 2. The compensation platform of the present invention is supported by six telescopic support shafts, and a deck motion prediction algorithm based on fast Fourier transform is designed. At the same time, PID control is combined to realize real-time rapid telescopic control of the six telescopic support shafts, thereby achieving the purpose of rapid, large-load, and multi-dimensional movement of the upper support frame of the compensation platform, thereby being able to quickly and stably compensate for deck motion, suppress vibration, and reduce dependence on complex flight control systems and high-precision sensors of the UAV.

[0049] 3. The double-belt clamping mechanism on the upper side of the compensation platform of the present invention can ensure the fixation and centering functions of the UAV before take-off and after landing, and can further ensure that the UAV is firmly fixed. The clamping force of the clamping mechanism is controllable, which ensures that the UAV is firmly clamped without causing damage to the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is an overall schematic diagram of the present invention,

[0051] Figure 2 for Figure 1 Schematic diagram of the structure of the middle support table.

[0052] Figure 3 for Figure 1 The structural diagram of the present invention after removing the supporting table,

[0053] Figure 4 for Figure 1 The structural diagram of the compensation platform.

[0054] Figure 5 for Figure 1 A magnified diagram of the upper hinge joint at center A.

[0055] Figure 6 for Figure 5Another structural diagram of the upper-middle articulated joint.

[0056] Figure 7 for Figure 6 Schematic diagram of the upper middle connection plate, the middle ring of the joint and the lower connection plate.

[0057] Figure 8 for Figure 1 The enlarged schematic diagram of point B in the figure is as follows:

[0058] Fig. 9 for Figure 1 Structural diagram of the clamping mechanism.

[0059] Fig.10 for Fig. 9 The enlarged schematic diagram of point C in the figure is as follows:

[0060] Fig.11 for Fig. 9 The structural diagram of the first slide seat in FIG.

[0061] Fig.12 for Fig. 9 The structural diagram of the second slide seat in the figure is as follows:

[0062] Fig.13 for Fig. 9 A schematic diagram of the structure of the first clamping lever and the second clamping lever,

[0063] Fig.14 for Fig. 9 Schematic diagram of the working status of the clamping mechanism.

[0064] Among them, 1 is a clamping mechanism, 101 is a first reduction motor, 102 is a first lead screw, 103 is a first slide, 1031 is a first slider, 104 is a first clamping belt, 105 is a first belt motor, 106 is a second slide, 1061 is a second slider, 107 is a second lead screw, 108 is a second reduction motor, 109 is a first pulley, 110 is a second slide rail, 111 is a third reduction motor, 112 is a third lead screw, 113 is a third slide, 114 is a second clamping belt, 115 is a second belt motor, 116 is a fourth slide, 117 is a fourth lead screw, 118 is a fourth reduction motor, 119 is a second pulley, 120 is a first slide rail, 121 is a second clamping lever, 1211 is a first clamping plate, 1212 is a second clamping plate, 1213 is a lever shaft, 1214 is a clamping plate screw, 122 is a clamping frame, 12 3 is a first clamping lever, 2 is a compensation platform, 201 is a support frame, 2011 is an upper hinge seat, 2012 is a mounting column, 2013 is a fixed connection member, 202 is a bottom plate, 2021 is a lower hinge seat, 203 is a telescopic support shaft, 2031 is a telescopic drive motor, 2032 is a telescopic rod, 2033 is a support shaft base, 2034 is an outer cylinder, 204 is a lower hinge joint, 205 is an upper hinge joint, 20 6 is the lower connecting plate, 2061 is the second connecting column, 207 is the joint middle ring, 2071 is the connecting folding ear, 2072 is the first folding ear connecting hole, 2073 is the second folding ear connecting hole, 208 is the upper connecting plate, 2081 is the first connecting column, 209 is the second folding angle spring plate, 210 is the first folding angle spring plate, 211 is the joint rotation point, 3 is the supporting table, 301 is the stand, 302 is the table plate, and 303 is the fixed seat. DETAILED DESCRIPTION

[0065] The present invention will be further described below in conjunction with the accompanying drawings.

[0066] like Figures 1 to 14 As shown, the system of the present invention includes a clamping mechanism 1 and a compensation platform 2, wherein the compensation platform 2 includes a support frame 201, a base plate 202 and a telescopic support shaft 203, the upper end of the telescopic support shaft 203 is hinged to the support frame 201 through an upper hinge joint 205, and the lower end is hinged to the base plate 202 through a lower hinge joint 204, the clamping mechanism 1 includes a clamping frame 122, a first belt moving mechanism and a second belt moving mechanism, wherein the clamping frame 122 is fixed on the support frame 201, the first belt moving mechanism is movably arranged at one end of the clamping frame 122, and the second belt moving mechanism is movably arranged at the other end of the clamping frame 122, as shown in FIG. Fig. 9As shown, the first belt moving mechanism is provided with a rotatable first clamping belt 104, and the first clamping belt 104 is provided with a first clamping lever 123, and the second belt moving mechanism is provided with a rotatable second clamping belt 114, and the second clamping belt 114 is provided with a second clamping lever 121.

[0067] like Figure 3 As shown, in this embodiment, the telescopic support shaft 203 includes a telescopic drive motor 2031, a telescopic rod 2032, an outer cylinder body 2034 and a support shaft base 2033, wherein the lower end of the outer cylinder body 2034 and the telescopic drive motor 2031 are both arranged on the support shaft base 2033, the telescopic rod 2032 is inserted into the outer cylinder body 2034 and driven to telescope by the telescopic drive motor 2031. In this embodiment, the lower part of the telescopic rod 2032 is a screw segment, and a transmission component is provided inside the support shaft base 2033, and one end of the transmission component is installed on the power shaft of the telescopic drive motor 2031, and the other end is provided with a nut sleeved on the screw segment. The transmission component can adopt gear transmission, belt transmission and other structures as needed. The above is a well-known technology in the field. For example, the lifting screw drive structure in patents such as CN215625098U and CN106241641B can be adopted.

[0068] like Figures 1 to 8 As shown, in this embodiment, the upper end of the telescopic rod 2032 of the telescopic support shaft 203 is hinged to the corresponding upper hinge seat 2011 provided on the lower side of the support frame 201 through the upper hinge joint 205, and the lower side of the support shaft base 2033 of the telescopic support shaft 203 is hinged to the corresponding lower hinge seat 2021 provided on the bottom plate 202 through the lower hinge joint 204. The upper hinge joint 205 and the lower hinge joint 204 of the present invention do not adopt a conventional universal hinge structure, because ordinary cross-axis universal joints require a relatively high installation space, which is particularly not conducive to the stability of the platform when the deck swings greatly, and the angle and bearing capacity need to be further improved.

[0069] like Figures 5 to 8 As shown, the upper articulated joint 205 and the lower articulated joint 204 of the present invention have the same structure, and both include an upper connecting plate 208, a joint middle ring 207, a lower connecting plate 206, a first angled spring plate 210 and a second angled spring plate 209, wherein Figure 7As shown, the lower side of the upper connecting plate 208 is evenly distributed with three first connecting columns 2081 along the circumferential direction, the upper side of the lower connecting plate 206 is evenly distributed with three second connecting columns 2061 along the circumferential direction, the joint middle ring 207 is evenly distributed with three connecting folding ears 2071 along the circumferential direction, and the folding ear inward concave angle of the connecting folding ear 2071 is 90°, one side of the connecting folding ear 2071 is provided with a first folding ear connecting hole 2072 arranged obliquely upward, and the other side is provided with a second folding ear connecting hole 2073 arranged obliquely downward, the first folding angle spring plate 210 and the second folding angle spring plate The angles of the first and second folded spring plates 209 are all 84°, and the adjacent first folded spring plates 210 and second folded spring plates 209 are arranged alternately, wherein one end of the first folded spring plate 210 is fixed by bolts to the first folded ear connection hole 2072 arranged obliquely upward on the corresponding connection folded ear 2071, and the other end is connected to the second connection column 2061 corresponding to the lower side by bolts, and one end of the second folded spring plate 209 is fixed by bolts to the second folded ear connection hole 2073 arranged obliquely downward on the corresponding connection folded ear 2071, and the other end is connected to the first connection column 2081 corresponding to the upper side by bolts. The first folded spring plate 210 and the second folded spring plate 209 are made of silicon manganese spring steel after stamping and tempering, which has a high elastic limit, and as Figure 6 As shown, the angle extension lines of each first angle spring plate 210 and the angle extension lines of each second angle spring plate 209 intersect at the same point, which is also the joint rotation point 211. This articulated joint can provide a large angle rotation of 50° and a torsion of 20°, and has strong support stiffness. At the same time, it requires a shorter and smaller installation space, which is very suitable for use in a large swing platform. Moreover, since it has a certain torsion angle space, it can reduce the torque generated by the mechanical error of the telescopic support shaft 203, thereby increasing the service life of the equipment.

[0070] like Figures 9 to 14 As shown, in this embodiment, the first belt moving mechanism includes a first slide 103 and a second slide 106, wherein one side of the a end of the clamping frame 122 is provided with a first screw 102 driven to rotate by the first reduction motor 101, and the first slide 103 is mounted on the first screw 102, and the other side of the a end of the clamping frame 122 is provided with a second screw 107 driven to rotate by the second reduction motor 108, and the second slide 106 is mounted on the second screw 107, and the first slide 103 and the second slide 106 are both provided with a first pulley 109, the first clamping belt 104 passes around each first pulley 109, and the first slide 103 is provided with a first belt motor 105 connected to the corresponding first pulley 109, and the first pulley 109 is an active pulley that drives the first clamping belt 104 to rotate.

[0071] like Figures 9 to 14As shown, in this embodiment, the second belt moving mechanism includes a third slide 113 and a fourth slide 116, wherein a third lead screw 112 driven to rotate by a third reduction motor 111 is provided on one side of the b end of the clamping frame 122, and the third slide 113 is mounted on the third lead screw 112, and a fourth lead screw 117 driven to rotate by a fourth reduction motor 118 is provided on the other side of the b end of the clamping frame 122, and the fourth slide 116 is mounted on the fourth lead screw 117, and a second pulley 119 is provided on both the third slide 113 and the fourth slide 116, and the second clamping belt 114 passes around each second pulley 119, and a second belt motor 115 is provided on the third slide 113 to connect with the corresponding second pulley 119, and the second pulley 119 is an active pulley to drive the second clamping belt 114 to rotate.

[0072] The clamping mechanism 1 is used to realize the fixing and centering functions of the drone before take-off and after landing, wherein Fig.14 As shown, the first clamping belt 104 and the second clamping belt 114 are respectively driven by the corresponding slides to move and approach to clamp the drone tripod to the left and right, and then the first clamping belt 104 and the second clamping belt 114 are respectively rotated to drive the first clamping lever 123 and the second clamping lever 121 to move forward and backward to clamp the drone tripod, so that the drone is completely fixed, wherein the first slide 103, the second slide 106, the third slide 113 and the fourth slide 116 are all provided with nuts respectively mounted on the corresponding screws to achieve movement, which is a well-known technology in the art.

[0073] like Fig. 9 As shown, in this embodiment, both sides of the clamping frame 122 are provided with slide rails. Figures 11-12 As shown, the first slide 103, the second slide 106, the third slide 113 and the fourth slide 116 are each provided with sliders on the lower sides thereof, which cooperate with the slide rails on the corresponding sides respectively; wherein the clamping frame 122 is provided with a first slide rail 120 on one side and a second slide rail 110 on the other side; the first slider 1031 on the lower side of the first slide 103 and the third slider on the lower side of the third slide 113 cooperate with the first slide rail 120; the second slider 1061 on the lower side of the second slide 106 and the fourth slider on the lower side of the fourth slide 116 cooperate with the second slide rail 110.

[0074] like Fig.10 As shown, in this embodiment, each corner end of the support frame 201 is provided with a mounting column 2012, and the two side beam ends of the clamping frame 122 in the left and right directions are respectively fixed to the corresponding mounting columns 2012 through fixed connectors 2013. In this embodiment, the fixed connector 2013 adopts a right-angle connecting seat.

[0075] like Fig.13As shown, in this embodiment, the first clamping lever 123 and the second clamping lever 121 have the same structure, and both include a first clamping plate 1211 and a second clamping plate 1212 respectively arranged on both sides of the corresponding clamping belt, the first clamping plate 1211 and the second clamping plate 1212 are fixedly connected by a clamping plate screw 1214, and a lever shaft 1213 is provided on the second clamping plate 1212 facing inward.

[0076] like Figures 1-2 As shown, a support table 3 is provided on the support frame 201 at a position corresponding to the clamping mechanism 1, and the support table 3 includes a stand 301, a table 302 and a fixing seat 303, wherein the stand 301 is fixed to the support frame 201 through the fixing seat 303, and the table 302 is fixed to the stand 301 through bolts. In this embodiment, the fixing seat 303 is a right-angle connection seat, and the table 302 is made of an aluminum-plastic plate, which is both light and thin and can bear the composite wing UAV.

[0077] The working principle of the present invention is:

[0078] The control of the present invention includes two parts, one is the control of the compensation platform 2, and the other is the control of the clamping mechanism 1. The various telescopic support shafts 203 of the compensation platform 2 do not adopt a conventional universal joint structure, but are as follows: Figures 5 to 8 As shown, the upper articulated joint 205 and the lower articulated joint 204 of the present invention both include an upper connecting plate 208, a joint middle ring 207, a lower connecting plate 206, a first angled spring plate 210, a second angled spring plate 209 and other structures, wherein the adjacent first angled spring plates 210 and second angled spring plates 209 are arranged alternately, and the angled extension lines of each first angled spring plate 210 and the angled extension lines of each second angled spring plate 209 intersect at the same point, which is also the joint rotation point 211. This articulated joint can provide a large angle rotation of 50° and a torsion of 20°, and has a strong support stiffness. At the same time, the installation space it requires is shorter and smaller, so it is very suitable for use in a large swing platform. In addition, since it has a certain torsion angle space, it can reduce the torque generated by the telescopic support shaft 203 due to mechanical errors, thereby increasing the service life of the equipment.

[0079] In addition, the present invention forms a compensation control method for the compensation platform 2 (six-degree-of-freedom platform) of the six telescopic support shafts 203 in combination with fast Fourier transform, which specifically includes the following steps:

[0080] Step 1: Perform fast Fourier transform on the deck motion, specifically:

[0081]

[0082]

[0083] In the above formula (1), represents the predicted frequency of deck swing, represents the deck prediction phase angle, represents the predicted amplitude of deck swing, It indicates that the peak detector identifies the frequency corresponding to the i-th harmonic in the main N harmonic functions generated by the deck movement in the α dimension, where the α dimension includes the roll angle roll, the pitch angle pitch, the heading angle yaw, the X-direction displacement Δx, the Y-direction displacement Δy, and the Z-direction displacement Δz. T represents the time value within one cycle time. represents the amplitude corresponding to the i-th harmonic after Fourier transform at time T, Represents the first-order derivative value of the amplitude corresponding to the i-th harmonic after Fourier transform at time T;

[0084] The peak detector is a well-known technology in the art and is a commercially available product.

[0085] Step 2: Superimpose the estimated harmonics of different frequencies to obtain the predicted T pre Deck expects motion signal after time

[0086]

[0087] (t=1,...,N,T≤t≤T pre ) (2);

[0088] In the above formula (2), the compensation value ρ α (t) is a constant at time t, which is calculated as:

[0089] Where T≤t≤T pre , represents the estimated value of the odd wave at time T;

[0090] Step 3: Construct the inverse kinematics solution formula of the upper support frame 201 in the compensation platform 2:

[0091]

[0092]

[0093] In the above formula (3), R x represents the expected roll of the support frame 201; R y represents the desired pitch of the support frame 201; R z represents the desired heading of the support frame 201, P x represents the x-direction displacement of the support frame 201; P y P represents the Y-direction displacement of the support frame 201; z represents the Z-direction displacement of the support frame 201;0 Indicates the default height difference between the support frame 201 and the base plate 202;

[0094] Step 4: Obtain the telescopic amount L of each telescopic support shaft 203 n , specifically:

[0095] First, according to the change of the support frame 201, the transformation matrix T between the support frame coordinate system and the base plate coordinate system is obtained: C :

[0096]

[0097] In the above formula (4), c represents the cosine operation and s represents the sin operation;

[0098] According to the transformation matrix T C The coordinate values ​​of the center points of the six upper articulated joints 205 in the base plate coordinate system are obtained as follows:

[0099]

[0100] In the above formula (5), i = 1...6;

[0101] The coordinate transformation calculation of the above formula (5) is a well-known technique in the art, and the above formula (5) can be

[0102] To further write:

[0103] T n =[T nx T ny 0 1] (6);

[0104] In the above formula (6), T n is the coordinate value vector of the center point of each upper articulated joint 205 in the base coordinate system, Tn x和 T ny are the X and Y components of the coordinate values ​​of the center points of each upper articulated joint 205 in the support frame coordinate system.

[0105] Each lower articulated joint 204 is directly connected to the base plate 202, so the coordinate value vector B of the center point of each lower articulated joint 204 in the base plate coordinate system is n It can be directly expressed as:

[0106] B n =[B nx B ny 0 1] (7);

[0107] In the above formula (7), B nx and B ny Respectively represent the X and Y components of the coordinate values ​​of the center point of the lower articulated joint 204 in the base plate coordinate system;

[0108] The present invention unifies the center points of each upper articulated joint 205 and each lower articulated joint 204 in the base plate coordinate system through the above process, and the base plate is fixedly connected to the deck and swings synchronously, so that the center point of the upper articulated joint 205 (i.e., T n ) and the corresponding lower hinge joint 204 center point (ie B n ) The distance change is used to obtain the telescopic amount Ln of the corresponding telescopic support shaft 203:

[0109] L n =sqrt(cR y C z T nx -cR y sR z T ny +P x -B nx ) 2 +((sR x sR y C z +cR x sR z )T nx +(-sR x sR y sR z +cR x C z )T ny +P y -B ny ) 2 ((-cR x sR y C z +sR x sR z )T nx +(cR x sR y sR z +sR x C z )T ny +P z -B nz ) 2 ) (8);

[0110] In the above formula (8), sqrt represents the square root operation, B nz It is the Z component of the coordinate value of the center point of the lower articulated joint 204 in the base plate coordinate system. Since the base plate 202 is fixedly connected to the deck and swings synchronously, this value can be regarded as the deck Δz in step one.

[0111] Step 5: The device control system controls the extension and retraction of each telescopic support shaft 203 according to the Ln obtained in step 4, so that the support frame 201 on the upper side of the compensation platform 2 always remains horizontal, thereby blocking the influence of the regular reciprocating harmonic motion of the deck caused by the influence of waves on the take-off and landing of the UAV, and reducing the dependence on the complex flight control system and high-precision sensors of the UAV.

[0112] like Fig.14 As shown, the clamping mechanism 1 of the present invention is used to realize the fixing and centering functions of the UAV before take-off and after landing, wherein during clamping, the first clamping belt 104 and the second clamping belt 114 are respectively driven by the corresponding slide seats to move and approach to clamp the UAV tripod, and then the first clamping belt 104 and the second clamping belt 114 are respectively rotated to drive the first clamping lever 123 and the second clamping lever 121 to clamp the UAV tripod forward and backward, so that the UAV is completely fixed. At the same time, the present invention ensures that the clamping force of the clamping mechanism 1 is controllable through flexible control, thereby ensuring that the UAV is firmly fixed and avoiding damage to the UAV or the clamping belt.

[0113] In addition, the clamping control method of the clamping mechanism 1 during the landing of the drone includes the following steps:

[0114] Step 1: Determine the serial number of each motor in the clamping mechanism 1, wherein the first reduction motor 101 and the second reduction motor 108 are used to synchronously drive the first clamping belt 104 to move, and their serial numbers are the same. Similarly, the third reduction motor 111 and the fourth reduction motor 118 are used to synchronously drive the second clamping belt 114 to move, and their serial numbers are also the same. The first belt motor 105 and the second belt motor 115 are respectively marked with a serial number, so that the motors in the clamping mechanism 1 are respectively represented by serial numbers 1 to 4. In this embodiment, the first reduction motor 101 and the second reduction motor 108 are serial numbers 1, the third reduction motor 111 and the fourth reduction motor 118 are serial numbers 2, the first belt motor 105 is serial number 3, and the second belt motor 115 is serial number 4.

[0115] Step 2: Construct the relationship function between motor torque and error, as follows:

[0116]

[0117] In the above formula (9), i represents the motor number determined in step 1, i = 1, 2...4, M i represents the inertia characteristic of the i-th motor, D i represents the damping characteristic of the i-th motor, K i represents the stiffness characteristics of the i-th motor. These three characteristics are the dynamic properties of the motor. They can be obtained after the motor is installed through motor tuning and mechanical simulation model testing, and finally determined through on-site fine-tuning. iRepresents the motion position error of different motors, that is, e=xx 0 , and e i The first and second derivatives with respect to time, is the expected torque of the i-th motor;

[0118] where e i The specific acquisition is as follows: after the UAV issues a landing command, the device control system sends the expected position x of each motor to the sub-control system of the clamping mechanism 1 according to the pre-set settings, and calculates the expected position x and the current position x according to the expected position x. 0 Calculation error e i , that is, e = xx 0 Finally, the expected torque is obtained according to the above formula (9):

[0119] Step three: The device control system obtains the desired torque according to step two, and first controls the first reduction motor 101 and the second reduction motor 108 (serial number 1) and the third reduction motor 111 and the fourth reduction motor 118 (serial number 2) to start so that the first clamping belt 104 and the second clamping belt 114 complete the clamping of the UAV tripod. As the UAV tripod is clamped and fixed, the first clamping belt 104 and the second clamping belt 114 will be blocked and stop moving. At this time, the device control system can adjust the torque of each reduction motor to gradually reduce according to the position feedback of each slide seat (obtained by rotating the screw and nut, which is a well-known technology in the art), etc., so as to ensure that the UAV is clamped without damaging the UAV or the clamping belt.

[0120] Then, the device control system obtains the desired torque according to step 2 to control the start of the first belt motor 105 (serial number 3) and the second belt motor 115 (serial number 4), so that the first clamping lever 123 and the second clamping lever 121 complete the clamping limit of the UAV tripod from the front and rear directions. At this time, the device control system can also adjust the torque of each belt motor to gradually reduce according to the lever position feedback (obtained by belt pulley rotation conversion, which is a well-known technology in the art), so as to ensure that the UAV is clamped without damaging the UAV or the clamping lever, which is a well-known technology in the art.

Claims

1. A take-off and landing system for a shipborne composite-wing UAV, characterized in that: The invention comprises a clamping mechanism (1) and a compensation platform (2), wherein the compensation platform (2) comprises a support frame (201), a base plate (202) and a telescopic support shaft (203), wherein the upper end of the telescopic support shaft (203) is hinged to the support frame (201) through an upper hinge joint (205), and the lower end is hinged to the base plate (202) through a lower hinge joint (204), and the clamping mechanism (1) comprises a clamping frame (122), a first belt moving mechanism and a second belt moving mechanism, wherein the clamping frame (122) is fixedly provided with On the support frame (201), a first belt moving mechanism is arranged at one end of the clamping frame (122), and a second belt moving mechanism is arranged at the other end of the clamping frame (122); the first belt moving mechanism is provided with a rotatable first clamping belt (104), and a first clamping lever (123) is provided on the first clamping belt (104); the second belt moving mechanism is provided with a rotatable second clamping belt (114), and a second clamping lever (121) is provided on the second clamping belt (114).

2. The take-off and landing system for a shipborne composite wing UAV according to claim 1, characterized in that: The telescopic support shaft (203) comprises a telescopic drive motor (2031), a telescopic rod (2032), an outer cylinder body (2034) and a support shaft base (2033), wherein the lower end of the outer cylinder body (2034) and the telescopic drive motor (2031) are both arranged on the support shaft base (2033), the telescopic rod (2032) is inserted into the outer cylinder body (2034) and driven to be telescopic by the telescopic drive motor (2031), the upper end of the telescopic rod (2032) is hinged to the support frame (201) via an upper hinge joint (205), and the lower side of the support shaft base (2033) is hinged to the bottom plate (202) via a lower hinge joint (204).

3. The take-off and landing system for a shipborne composite wing UAV according to claim 1 or 2, characterized in that: The upper articulated joint (205) and the lower articulated joint (204) have the same structure, and both include an upper connecting plate (208), a joint middle ring (207), a lower connecting plate (206), a first folded angle spring plate (210), and a second folded angle spring plate (209), wherein the lower side of the upper connecting plate (208) is provided with a first connecting column (2081), the upper side of the lower connecting plate (206) is provided with a second connecting column (2061), the joint middle ring (207) is provided with a connecting folding ear (2071), and one side of the connecting folding ear (2071) is provided with a first folding ear connecting hole (2072) arranged obliquely upward, and the other side is provided with a second folding ear connecting hole (2073) arranged obliquely downward. ), adjacent first folded angle spring plates (210) and second folded angle spring plates (209) are arranged alternately, and one end of the first folded angle spring plate (210) is fixed to the first folded ear connection hole (2072) on the corresponding connecting folded ear (2071), and the other end is connected to the second connecting column (2061) corresponding to the lower side, and one end of the second folded angle spring plate (209) is fixed to the second folded ear connection hole (2073) on the corresponding connecting folded ear (2071), and the other end is connected to the first connecting column (2081) corresponding to the upper side, and the folded angle extension lines of each first folded angle spring plate (210) and the folded angle extension lines of each second folded angle spring plate (209) intersect at the joint rotation point (211).

4. A compensation control method for a take-off and landing system of a shipborne composite-wing UAV according to claim 1, characterized in that: Six telescopic support shafts (203) are provided between the support frame (201) and the bottom plate (202), and the control method comprises the following steps: Step 1: Perform fast Fourier transform on the deck motion, specifically: In the above formula (1), represents the predicted frequency of deck swing, represents the deck prediction phase angle, represents the predicted amplitude of deck swing, It indicates that the peak detector identifies the frequency corresponding to the i-th harmonic in the main N harmonic functions generated by the deck movement in the α dimension, where the α dimension includes the roll angle roll, the pitch angle pitch, the heading angle yaw, the X-direction displacement Δx, the Y-direction displacement Δy, and the Z-direction displacement Δz. T represents the time value within one cycle time. represents the amplitude corresponding to the i-th harmonic after Fourier transform at time T, Represents the first-order derivative value of the amplitude corresponding to the i-th harmonic after Fourier transform at time T; Step 2: Superimpose the estimated harmonics of different frequencies to obtain the predicted T pre Deck expects motion signal after time (i=1,...,N,T≤t≤T pre ) (2); In the above formula (2), the compensation value ρ α (t) is a constant at time t, which is calculated as: Where T≤t≤T pre , represents the estimated value of the odd wave at time T; Step 3: Construct the inverse kinematics solution formula of the upper support frame (201) of the compensation platform (2): In the above formula (3), R x represents the expected roll of the support frame (201); R y represents the desired pitch of the support frame (201); R z represents the desired heading of the support frame (201), P x represents the x-direction displacement of the support frame (201); P y represents the Y-direction displacement of the support frame (201); P z represents the Z-direction displacement of the support frame (201); Z0 represents the default height difference between the support frame (201) and the base plate (202); Step 4: Obtain the telescopic amount L of each telescopic support shaft (203) n : In the above formula (8), sqrt represents the square root operation, c represents the cosine operation, s represents the sin operation, and T nx and T ny are the X and Y components of the coordinate values ​​of the center points of each upper articulated joint (205) in the support frame coordinate system, and B nx , B ny , B nz They respectively represent the X, Y and Z components of the coordinate values ​​of the center point of the lower articulated joint (204) in the base plate coordinate system. Step 5: The device control system controls the extension and retraction of each telescopic support shaft (203) according to Ln obtained in step 4.

5. The compensation control method for the take-off and landing system of a shipborne composite wing UAV according to claim 4 is characterized in that: In step 4, the transformation matrix T between the support frame coordinate system and the base plate coordinate system is first obtained according to the change of the support frame (201). C : Then according to the transformation matrix T C The coordinate values ​​of the center points of the six upper articulated joints (205) in the base plate coordinate system are obtained as follows: In the above formula (5), i=1...6, and the above formula (5) can be further written as: T n =[T nx T ny 0 1] where T n is the coordinate value vector of the center point of each upper articulated joint (205) in the base plate coordinate system; The coordinate value vector B of the center point of each lower articulated joint (204) in the base plate coordinate system n Directly expressed as: B n =[B nx B ny 0 1]; Then, in the base plate coordinate system, according to T n and B n The change in distance between the center point of the upper articulated joint (205) and the center point of the corresponding lower articulated joint (204) is calculated, thereby obtaining the telescopic amount Ln of the telescopic support shaft (203).

6. The take-off and landing system for a shipborne composite wing UAV according to claim 1, characterized in that: The first belt moving mechanism comprises a first slide (103) and a second slide (106), wherein a first lead screw (102) driven to rotate by a first reduction motor (101) is provided on one side of the a-end of the clamping frame (122), and the first slide (103) is mounted on the first lead screw (102); a second lead screw (107) driven to rotate by a second reduction motor (108) is provided on the other side of the a-end of the clamping frame (122), and the second slide (106) is mounted on the second lead screw (107); both the first slide (103) and the second slide (106) are provided with a first pulley (109); the first clamping belt (104) passes around each first pulley (109), and the first slide (103) is provided with a first belt motor (105) connected to the corresponding first pulley (109).

7. The take-off and landing system for a shipborne composite-wing UAV according to claim 6, characterized in that: The second belt moving mechanism comprises a third slide (113) and a fourth slide (116), wherein a third lead screw (112) driven to rotate by a third reduction motor (111) is provided on one side of the b end of the clamping frame (122), and the third slide (113) is mounted on the third lead screw (112); a fourth lead screw (117) driven to rotate by a fourth reduction motor (118) is provided on the other side of the b end of the clamping frame (122), and the fourth slide (116) is mounted on the fourth lead screw (117); the third slide (113) and the fourth slide (116) are both provided with a second pulley (119), the second clamping belt (114) passes around each second pulley (119), and the third slide (113) is provided with a second belt motor (115) connected to the corresponding second pulley (119).

8. The take-off and landing system for a shipborne composite-wing UAV according to claim 7, characterized in that: Each corner end of the support frame (201) is provided with a mounting column (2012), and the two side beam ends of the clamping frame (122) are respectively fixed to the corresponding mounting columns (2012) through fixed connecting pieces (2013); one side of the clamping frame (122) is provided with a first slide rail (120) and the other side is provided with a second slide rail (110); a first slider (1031) provided at the lower side of the first slide seat (103) and a third slider provided at the lower side of the third slide seat (113) cooperate with the first slide rail (120); a second slider (1061) provided at the lower side of the second slide seat (106) and a fourth slider provided at the lower side of the fourth slide seat (116) cooperate with the second slide rail (110).

9. A method for controlling the take-off and landing system of a shipborne composite-wing UAV according to claim 7, characterized in that: The steps include: Step 1: Determine the serial number of each motor in the clamping mechanism (1), wherein the first reduction motor (101) and the second reduction motor (108) have the same serial number, the third reduction motor (111) and the fourth reduction motor (118) have the same serial number, and the first belt motor (105) and the second belt motor (115) are each marked with a serial number, for a total of 4 serial numbers; Step 2: Construct the relationship function between motor torque and error: In the above formula (9), i represents the motor number determined in step 1, i = 1, 2...4, M i represents the inertia characteristic of the i-th motor, D i represents the damping characteristic of the i-th motor, K i represents the stiffness characteristic of the i-th motor, e i represents the motion position error of the i-th motor, and e i The first and second derivatives with respect to time, is the expected torque of the i-th motor; Step 3: The device control system obtains the desired torque according to step 2 The actions of the motors of the clamping mechanism (1) are controlled, wherein the device control system first controls the first reduction motor (101) and the second reduction motor (108) as well as the third reduction motor (111) and the fourth reduction motor (118) to start so that the first clamping belt (104) and the second clamping belt (114) complete the clamping of the drone tripod in the left and right directions, and then controls the first belt motor (105) and the second belt motor (115) to start so that the first clamping lever (123) and the second clamping lever (121) complete the clamping of the drone tripod in the front and back directions.

10. The method for controlling the take-off and landing system of a shipborne composite-wing UAV according to claim 9, characterized in that: In step 2, after the drone issues a landing command, the device control system sends the expected position x of each motor to the sub-control system of the clamping mechanism (1) according to the pre-set settings, and calculates the error e by subtracting the expected position x from the current position x0. i .

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