A variable speed penetration rotor UAV system based on a controllable speed increasing device

Abstract

The present invention discloses a variable-speed anti-penetration rotor UAV system based on a controllable speed-increasing device. The UAV system comprises: a UAV platform and a controllable speed-increasing device. The UAV platform uses a multi-rotor UAV as a basic flight platform, capable of vertical take-off and landing, hovering, center-of-mass motion in four directions (forward, backward, left, and right), and attitude motion in three directions (pitch, yaw, and roll). The controllable speed-increasing device is mounted on the bottom of the UAV platform and comprises: a servo platform and a thrust generator. The servo platform is used to drive the thrust generator to rotate and control the direction in which the thrust generator generates thrust. The thrust generator generates thrust far greater than the rotor pull in a short period of time, which is used to increase the speed of the UAV system in a short period of time. The present invention can solve the problem of UAVs being difficult to use in battlefield environments with multiple obstacles and strong confrontation.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicle systems, and in particular relates to a variable-speed penetration rotor unmanned aerial vehicle system based on a controllable speed increasing device. Background Art

[0002] Rotary-wing drones (UAVs) rely on electric motors / internal combustion engines (mostly electric motors) to generate power for their rotors. They can achieve multi-directional movement, including vertical takeoff and landing, hovering, and forward and backward movements. They have the advantages of low landing and takeoff requirements and flexible trajectory changes. Compared to fixed-wing drones, rotary-wing drones are more suitable for flight in obstacle-ridden environments such as urban areas, and hovering is a maneuver that fixed-wing drones cannot achieve.

[0003] However, rotary-wing UAVs also have performance limitations, primarily low flight speed. Because the power generated by their rotors must overcome their own gravity, the power available for other maneuvers is limited. Most rotary-wing UAVs cruise at speeds below 20 m / s, while some highly maneuverable rotary-wing UAVs fly at speeds between 30 and 40 m / s. This performance limitation restricts most rotary-wing UAV applications to non-confrontational civilian applications such as aerial photography, line inspections, and agricultural plant protection, as well as low-confrontation military applications such as communications relay. In high-intensity confrontation environments involving firepower and electromagnetic warfare, rotary-wing UAVs' slow speed makes them vulnerable to enemy fire, resulting in limited penetration capabilities and low battlefield survivability.

[0004] With the development of cities around the world, the proportion of urban fighting in modern military conflicts is increasing. Urban fighting is characterized by numerous obstacles, complex environments, and overlapping areas of control between friendly and enemy forces. In such environments, fixed-wing drones, due to their limited steering flexibility, are difficult to operate in these obstacles. Traditional rotary-wing drones, due to their slow flight speed, are also difficult to use in such confrontational environments.

[0005] In summary, in order to address the problem that traditional drones are difficult to use in battlefield environments with multiple obstacles and strong confrontation, it is necessary to develop a drone system that is both flexible and maneuverable and has strong penetration and risk avoidance capabilities. Summary of the Invention

[0006] In view of this, the present invention provides a variable-speed penetration rotor UAV system based on a controllable speed increasing device, which can solve the problem that UAVs are difficult to use in a battlefield environment with multiple obstacles and strong confrontation.

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

[0008] A variable-speed anti-slip rotor UAV system based on a controllable speed-increasing device, the UAV system comprising: a UAV platform and a controllable speed-increasing device;

[0009] The UAV platform uses a multi-rotor UAV as a basic flight platform, which can perform vertical take-off and landing, hovering, center of mass movement in four directions of front, back, left and right, and attitude movement in three directions of pitch, yaw and roll;

[0010] The controllable speed-increasing device is installed at the bottom of the UAV platform, and the controllable speed-increasing device includes: a servo platform and a thrust generator; the servo platform is used to drive the thrust generator to rotate and control the direction of the thrust generated by the thrust generator; the thrust generator generates a thrust far greater than the rotor pull in a short period of time, which is used to increase the speed of the UAV system in a short period of time.

[0011] Furthermore, the UAV platform includes: a frame, an electrical compartment, a rotor, a motor and a landing gear;

[0012] The frame is a flat plate structure, with more than four arms extending outward and evenly distributed along the circumferential direction; a landing gear is connected below each arm, and a rotor is connected above each arm via a motor;

[0013] The electrical compartment is fixed on the flat plate structure of the frame; the electrical compartment has a built-in power supply, a flight control computer, an inertial measurement unit and a signal transceiver antenna. The power supply is used to provide power support for the UAV system. The inertial measurement unit is used to measure the acceleration and attitude angular velocity of the UAV system during flight and send them to the flight control computer. The flight control computer is used to calculate the speed, position and attitude angle of the UAV system during flight based on the acceleration and attitude angular velocity.

[0014] Furthermore, the UAV system also includes a fairing assembly and a deformable stabilizer assembly. The fairing assembly is installed at the front end of the UAV platform to reduce the aerodynamic resistance of the UAV system during high-speed movement; the deformable stabilizer assembly is installed at the rear end of the UAV platform to increase the flight stability of the UAV system.

[0015] Furthermore, the fairing assembly includes a body fairing and two rotor fairings;

[0016] The fuselage fairing is installed at the front end of the UAV platform, and the windward surface of the fuselage fairing is a wedge-shaped surface;

[0017] Each rotor fairing is fan-shaped and installed at the front end of the UAV platform; the two rotor fairings are located on both sides of the fuselage fairing, forming a semi-closed circular structure, which surrounds the outside of the two rotors at the front end of the UAV platform; the outer wall of the rotor fairing is processed into a slope.

[0018] Furthermore, the deformable stabilizer assembly includes: a stabilizer bracket, a push rod motor, a connecting rod mechanism and a flexible stabilizer;

[0019] The main structure of the stabilizer bracket is a round rod with a plate-like structure at one end and a fixed hinge at the other end. The fixed hinge is provided with two or more fixed hinge rings. A sliding hinge is sleeved on the round rod and can perform linear reciprocating motion along the axis of the round rod. The sliding hinge is provided with two or more sliding hinge rings. The fixed hinge and the sliding hinge are connected by a connecting rod mechanism.

[0020] Each linkage mechanism consists of two links, namely Link I and Link II. Link I has a hinge ring at each end. One end is connected to the sliding hinge ring in a hinged manner, and the other end is connected to one end of Link II in a hinged manner. The other end of Link II is connected to the fixed hinge ring of the stabilizer bracket in a hinged manner.

[0021] A flexible stabilizer is installed on the triangular surface formed by the connecting rods I and II of each linkage mechanism and the round rod of the stabilizer bracket; the flexible stabilizer is connected to the connecting rod I and the round rod of the stabilizer bracket;

[0022] The plate-like structure of the stabilizer bracket is connected to the rear end face of the UAV platform; the push rod motor is installed on the plate-like structure; the push rod end of the push rod motor is fixedly connected to the sliding hinge on the round rod of the stabilizer bracket, and is used to drive the sliding hinge to perform linear reciprocating motion along the axial direction of the round rod.

[0023] Furthermore, the flexible stabilizer is made of fiber woven materials or polymer materials.

[0024] Furthermore, the servo platform of the controllable speed increasing device adopts a two-degree-of-freedom servo platform; the two-degree-of-freedom servo platform is used to drive the thrust generator to rotate in vertical and horizontal directions.

[0025] Furthermore, the thrust generator of the controllable speed increasing device adopts a solid engine, a cold air jet device or a solid-liquid mixed fuel engine.

[0026] Furthermore, the control method of the drone system is:

[0027] This control method is based on the dynamic model of multi-mode control force input of "multi-rotor power + thrust". This model is:

[0028]

[0029] In formula (1), is the acceleration of the UAV system; are the attitude angular accelerations of the UAV system in the three directions of roll, yaw and pitch; are the attitude angular accelerations of the UAV system in the roll, yaw and pitch directions respectively; m is the weight of the UAV system; J x 、J y 、J z are the moments of inertia of the UAV system about the three principal axes of inertia; l is the wheelbase of the UAV system; g is the acceleration of gravity; U γ is the control force of the roll channel, U ψ is the control force of the yaw channel, is the control force of the pitch channel; is the interference force, is the interference torque;

[0030] In formula (1), is the projection of the thrust of the controllable speed increasing device in the acceleration direction, specifically:

[0031]

[0032] In formula (2), P is the thrust of the thrust generator, ε z is the elevation angle of the two-degree-of-freedom servo gimbal, ε y is the azimuth angle of the two-degree-of-freedom servo gimbal;

[0033] In formula (1), is the projection of the rotor thrust in the three acceleration directions, specifically:

[0034]

[0035] In formula (3), U r is the control force perpendicular to the rotor plane generated by the rotor, γ is the roll angle, ψ is the yaw angle, is the pitch angle;

[0036] In formula (1), is the projection of the aerodynamic force in the direction of acceleration, is the projection of the aerodynamic torque in the direction of angular acceleration, specifically:

[0037]

[0038] In formula (4), ρ is the atmospheric density, S is the frontal area, L is the length of the UAV system, is the aerodynamic coefficient of the UAV system, is the aerodynamic torque coefficient of the UAV system, is the flight speed of the UAV system;

[0039] The control method is as follows: when the controllable speed-increasing device is not working, the position control and attitude control of the UAV system are both achieved by the pull of the rotor; when the controllable speed-increasing device is working, the position control of the UAV system is achieved by the controllable speed-increasing device, and the attitude control is achieved by the pull of the rotor;

[0040] (1) When the controllable speed increasing device is not working, the expected control force is calculated as follows:

[0041] According to the desired acceleration and the thrust of the controllable speed increasing device is 0, the projection values ​​of the desired rotor thrust in the three acceleration directions are:

[0042]

[0043] Combining equations (3) and (5), we can arbitrarily select the desired yaw angle ψ D , the desired pitch angle can be obtained Roll angle γ D and the control force U perpendicular to the rotor plane generated by the rotor 7 r for:

[0044]

[0045] After calculating the desired attitude angle, the corresponding attitude angular acceleration can be obtained according to control algorithms such as PID and sliding mode control. The desired roll, yaw, and pitch control forces can be calculated based on the desired attitude angular acceleration:

[0046]

[0047] (2) When the controllable speed increasing device is working, the expected control force is calculated as follows:

[0048] The control force U generated by the rotor 7 is perpendicular to the rotor plane. r Need to overcome its own gravity, specifically:

[0049] U r =gm (8)

[0050] According to equations (1) and (8), the projection of the thrust of the controllable speed increasing device in the acceleration direction can be obtained as:

[0051]

[0052] Combining equations (9) and (2), we can obtain the thrust P of the thrust generator and the elevation angle ε of the two-degree-of-freedom servo gimbal: z and azimuth ε y for:

[0053]

[0054] The desired pitch angle and roll angle are 0, and the calculation method of the desired roll, yaw, and pitch control forces is the same as that of equation (7).

[0055] Beneficial effects:

[0056] (1) The present invention provides a variable-speed penetration rotor UAV system based on a controllable speed-increasing device, which uses a multi-axis rotor UAV as a basic flight platform and a speed-increasing device with controllable thrust magnitude and direction as a power source for speed increase. That is, a multi-axis rotor and jet thrust composite power mode is adopted, which has the characteristics of vertical take-off and landing, hovering and flexible maneuverability of the multi-rotor UAV; at the same time, the jet thrust can provide a large power input in a short time, which can enable the UAV system to move quickly and realize the functions of rapid penetration and emergency avoidance;

[0057] (2) The UAV system of the present invention further includes a fairing assembly and a deformable stabilizer assembly. The fairing assembly and the deformable stabilizer assembly constitute a drag reduction and stabilization mechanism, which can reduce the aerodynamic drag experienced by the UAV during high-speed movement and ensure that the UAV does not roll due to lateral aerodynamic forces, thereby enabling the multi-rotor UAV to have better aerodynamic characteristics during high-speed movement.

[0058] (3) The fairing assembly of the present invention includes a fuselage fairing and a rotor fairing. The windward surface of the fuselage fairing is a wedge-shaped surface, and the outer wall surface of the rotor fairing is processed into an inclined surface, both of which can ensure that the UAV system is subject to less aerodynamic resistance when moving at high speed. The rotor fairing can protect the rotor from damage due to lateral aerodynamic force and ensure that the pulling force generated when the rotor rotates is not affected by lateral aerodynamic force.

[0059] (4) The deformable stabilizer assembly of the present invention includes a deformable flexible stabilizer. When the unmanned aerial vehicle system does not need to perform high-speed maneuvers, the flexible stabilizer of the deformable stabilizer assembly is in a folded state; when the unmanned aerial vehicle system needs to perform high-speed maneuvers, the flexible stabilizer is in an open state to form a stabilizer, which can maintain the flight stability of the unmanned aerial vehicle system.

[0060] (5) The thrust generator of the controllable speed increasing device of the present invention adopts a solid engine. The solid propellant of the solid engine will produce a large amount of gas when burning. The reaction force of the gas ejected along the nozzle is the thrust generated by the thrust generator; the thrust generator can generate a thrust far greater than the rotor pull in a short time, thereby achieving the speed increase of the UAV system in a short time.

[0061] (6) The present invention adopts a UAV motion control algorithm based on a multi-mode control force model of "multi-rotor power + thrust" in the control method of the variable-speed penetration rotor UAV, so that the UAV can achieve the desired motion state under the combined effect of the pulling force of the multi-axis rotor and the thrust of the controllable speed-increasing device, thereby realizing the motion control of the variable-speed penetration rotor UAV during high-speed flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 An exploded view of the present invention;

[0063] Figure 2 (a) is a top view of the present invention, (b) is a side view of the present invention, and (c) is a schematic diagram of the oblique structure of the present invention;

[0064] Figure 3 It is a structural diagram of the deformable stabilizer assembly of the present invention;

[0065] Figure 4 Schematic diagram of the deformable stabilizer assembly of the present invention before and after deformation;

[0066] Figure 5 It is a workflow diagram of the present invention;

[0067] Among them, 1-UAV platform, 2-controllable speed increasing device, 4-fairing assembly, 3-deformable stabilizer assembly, 5-frame, 6-electrical compartment, 7-rotor, 8-motor, 9-landing gear, 10-two-degree-of-freedom servo gimbal, 11-thrust generator, 12-rotor fairing, 13-fuselage fairing, 14-stabilizer bracket, 15-push rod motor, 16-sliding hinge, 17-connecting rod I, 18-connecting rod II, 19-flexible stabilizer. DETAILED DESCRIPTION

[0068] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0069] Example 1:

[0070] This embodiment provides a variable speed anti-speed rotor UAV system based on a controllable speed increasing device; see the attached Figure 1-2 ,The UAV system includes: a UAV platform 1, a drag reduction and stabilization mechanism and a controllable speed increasing device 2;

[0071] The UAV platform 1 uses a multi-rotor UAV as a basic flight platform, which can perform vertical take-off and landing, hovering, center of mass movement in four directions of front, back, left and right, and attitude movement in three directions of pitch, yaw and roll. Specifically:

[0072] The UAV platform 1 includes: a frame 5, an electrical compartment 6, a rotor 7, a motor 8 and a landing gear 9;

[0073] The frame 5 is a flat plate structure with four or more arms extending outward and evenly distributed along the circumference. The arms are used to mount the rotor 7, the motor 8, and the landing gear 9. In this embodiment, the total number of arms is four, i.e., four arms extend from the flat plate structure to the four corners.

[0074] Each arm is connected to a landing gear 9 at the bottom, and a rotor 7 is connected to the top of each arm via a motor 8; the output shaft of the motor 8 is coaxially connected to the rotating shaft of the rotor 7 for controlling the rotation of the rotor 7;

[0075] The electrical compartment 6 is fixed to the flat plate structure of the frame 5 and is located below the flat plate structure. The electrical compartment 6 contains electrical components such as a power supply, a flight control computer, an inertial measurement unit, and a signal transceiver antenna. The electrical compartment 6 is used to provide the basic structure, partial power source, and electrical hardware for the UAV system. Among them, the power supply is used to provide electrical support for the UAV system, and the inertial measurement unit is used to measure the acceleration and attitude angular velocity of the UAV system during flight and send them to the flight control computer. The flight control computer is used to calculate the speed, position, and attitude angle of the UAV system during flight based on the acceleration and attitude angular velocity.

[0076] The drag reduction and stabilization mechanism includes: a fairing assembly 4 and a deformable stabilizer assembly 3; the fairing assembly 4 is installed at the front end of the UAV platform 1 to reduce the aerodynamic drag of the UAV system during high-speed movement; the deformable stabilizer assembly 3 is installed at the rear end of the UAV platform 1 to increase the flight stability of the UAV system.

[0077] The fairing assembly 4 includes a body fairing 13 and two rotor fairings 12; the body fairing 13 is installed at the front end of the UAV platform 1, specifically, it can be installed on the front end of the flat plate structure of the frame 5 or the front end of the electrical compartment 6; one end face of the body fairing 13 is a plane with a threaded hole on it for connecting with the front end face of the electrical compartment 6 by screws, and the other end is a wedge-shaped surface, which is the windward surface and is used to reduce the aerodynamic resistance of the UAV system when it moves at high speed; each rotor fairing 12 is a fan ring, and the lower end of the rotor fairing 12 has an arm, and one end of the arm is The threaded hole is used to connect to the arm of the frame 5 by screws; the two rotor fairings 12 are respectively located on both sides of the body fairing 13, and the two rotor fairings 12 form a semi-closed circular structure, and the semi-closed circular structure surrounds the outside of the two rotors 7 at the front end of the UAV platform 1, which is used to protect the rotor 7 from the influence of aerodynamic force when the UAV system moves at high speed, and the inner wall surface of the rotor fairing 12 is the same shape as the fan ring, and the outer wall surface of the rotor fairing 12 is processed into a bevel, which is used to ensure that the UAV system is subject to less aerodynamic resistance when moving at high speed.

[0078] See attached Figure 3-4 , the deformable stabilizer assembly 3 includes: a stabilizer bracket 14, a push rod motor 15, a connecting rod mechanism and a flexible stabilizer 19;

[0079] The main structure of the stabilizer bracket 14 is a round rod with a plate-like structure at one end and a fixed hinge at the other end. The fixed hinge is provided with two or more evenly distributed fixed hinge rings. A sliding hinge is sleeved on the round rod and can perform linear reciprocating motion along the axis of the round rod. The sliding hinge is provided with two or more evenly distributed sliding hinge rings. The fixed hinge and the sliding hinge are connected by a connecting rod mechanism. In this embodiment, the number of fixed hinge rings, sliding hinge rings and connecting rod mechanisms is equal, namely four. The two ends of each connecting rod mechanism are respectively hinged to a fixed hinge ring and a sliding hinge ring.

[0080] Each linkage mechanism includes two links, namely link I 17 and link II 18; link I 17 has a hinge ring at each end, one end of which is connected to the sliding hinge ring in a hinged manner, and the other end of which is connected to one end of link II 18 in a hinged manner, and the other end of link II 18 is connected to the fixed hinge ring of the stabilizer bracket 14 in a hinged manner;

[0081] A flexible stabilizer 19 is mounted on the triangular surface formed by the connecting rods I 17 and II 18 of each linkage mechanism and the round rod of the stabilizer bracket 14. The flexible stabilizer 19 is bonded to the connecting rods I 17 and the round rod of the stabilizer bracket 14 and is made of a flexible material such as a woven fiber material or a polymer material. In this embodiment, there are four flexible stabilizers 19 in total.

[0082] The plate-like structure of the stabilizer bracket 14 is machined with screw holes for connecting to the rear end face of the UAV platform 1 via screws; specifically, it can be connected to the rear end of the electrical compartment 6; the plate-like structure is also machined with a rectangular groove for mounting a push rod motor 15; the push rod motor 15 is used to achieve linear motion of its output end, i.e., the push rod, and the end of the push rod is fixedly connected to the sliding hinge on the round rod of the stabilizer bracket 14, and is used to drive the sliding hinge to perform linear reciprocating motion along the axial direction of the round rod;

[0083] The working principle of the deformable stabilizer assembly 3 is as follows: when the UAV system does not need to perform high-speed maneuvers, the push rod of the push rod motor 15 is retracted, driving the sliding hinge to move in the direction away from the fixed hinge of the stabilizer bracket 14, the angle between the connecting rod I 17 and the connecting rod II 18 and the round rod of the stabilizer bracket 14 becomes smaller, and the flexible stabilizer 19 is in a folded state; when the unmanned system needs to perform high-speed maneuvers, in order to maintain the flight stability of the UAV system, the push rod of the push rod motor 15 is pushed outward, driving the sliding hinge to move in the direction close to the fixed hinge of the stabilizer bracket 14, the angle between the connecting rod I 17 and the connecting rod II 18 and the round rod of the stabilizer bracket 14 increases, and the flexible stabilizer 19 is in an open state, forming a stabilizer.

[0084] The controllable speed increasing device 2 is installed at the bottom of the UAV platform 1, specifically at the bottom of the electrical cabin 6; the controllable speed increasing device 2 includes: a two-degree-of-freedom servo platform 10 and a thrust generator 11; the two-degree-of-freedom servo platform 10 is installed at the bottom of the UAV platform 1 by screws, and is used to drive the thrust generator 11 to rotate vertically and horizontally, and control the direction of the thrust generated by the thrust generator 11; the thrust generator 11 adopts a solid engine, and the solid propellant of the solid engine will produce a large amount of gas when burning. The reaction force of the gas ejected along the nozzle is the thrust generated by the thrust generator 11; the thrust generator 11 can generate a thrust far greater than the pulling force of the rotor 7 in a short time, thereby achieving the speed increase of the UAV system in a short time; in addition to the solid engine, the thrust generator 11 can also adopt a cold air jet device and a solid-liquid mixed fuel engine.

[0085] Example 2:

[0086] This embodiment, based on the first embodiment, provides a control method for a variable-speed anti-surge rotor UAV. This control method measures and resolves motion information based on the inertial measurement unit and flight control computer carried by the UAV system. Specifically, the inertial measurement unit measures the acceleration and attitude angular velocity of the UAV system during flight and sends them to the flight control computer. The flight control computer calculates the speed, position, and attitude angle of the UAV system during flight based on the acceleration and attitude angular velocity. The flight control computer then controls the power output of each rotor 7 and the thrust direction and magnitude of the controllable speed-increasing device 2. The control method is specifically as follows:

[0087] This control method is based on the dynamic model of multi-mode control force input of "multi-rotor power + thrust". This model is:

[0088]

[0089] In formula (1), is the acceleration of the UAV system; are the attitude angular accelerations of the UAV system in the three directions of roll, yaw and pitch; are the attitude angular accelerations of the UAV system in the roll, yaw and pitch directions respectively; m is the weight of the UAV system; J x 、J y 、J z are the moments of inertia of the UAV system about the three principal axes of inertia; l is the wheelbase of the UAV system; g is the acceleration of gravity; U γ is the control force of the roll channel, U ψ is the control force of the yaw channel, is the control force of the pitch channel; is the interference force, is the interference torque.

[0090] In formula (1), is the projection of the thrust of the controllable speed increasing device 2 in the acceleration direction, specifically:

[0091]

[0092] In formula (2), P is the thrust of the thrust generator 11, ε z is the elevation angle of the two-degree-of-freedom servo platform 10, ε y is the azimuth angle of rotation of the two-degree-of-freedom servo platform 10;

[0093] In formula (1), is the projection of the thrust of the rotor 7 in the three acceleration directions, specifically:

[0094]

[0095] In formula (3), U r is the control force perpendicular to the rotor plane generated by the rotor 7, γ is the roll angle, ψ is the yaw angle, is the pitch angle;

[0096] In formula (1), The projection of aerodynamic force (during the flight of the UAV system, due to its relative speed to the air, the air will have a strong effect on the UAV system, which is the aerodynamic force) in the direction of acceleration. is the projection of the aerodynamic torque in the direction of angular acceleration, specifically:

[0097]

[0098] In formula (4), ρ is the atmospheric density, S is the frontal area, L is the length of the UAV system, is the aerodynamic coefficient of the UAV system, is the aerodynamic torque coefficient of the UAV system, is the flight speed of the UAV system.

[0099] For the UAV system, the control method designed in this embodiment is as follows: when the controllable speed-increasing device 2 is not working, the position control and attitude control of the UAV system are both achieved by the pulling force of the rotor 7; when the controllable speed-increasing device 2 is working, the position control of the UAV system is achieved by the controllable speed-increasing device 2, and the attitude control is achieved by the pulling force of the rotor 7;

[0100] (1) When the controllable speed increasing device 2 is not working, the expected control force is calculated as follows:

[0101] According to the desired acceleration and the thrust of the controllable speed increasing device is 0, the projection values ​​of the desired rotor thrust in the three acceleration directions are:

[0102]

[0103] Combining equations (3) and (5), we can arbitrarily select the desired yaw angle ψ D , the desired pitch angle can be obtained Roll angle γ D and the control force U perpendicular to the rotor plane generated by the rotor 7 r for:

[0104]

[0105] After calculating the desired attitude angle, the corresponding attitude angular acceleration can be obtained according to control algorithms such as PID and sliding mode control. The desired roll, yaw, and pitch control forces can be calculated based on the desired attitude angular acceleration:

[0106]

[0107] (2) When the controllable speed increasing device 2 is working, the expected control force is calculated as follows:

[0108] The control force U generated by the rotor 7 is perpendicular to the rotor plane. r Need to overcome its own gravity, specifically:

[0109] U r =gm(8)

[0110] According to equations (1) and (8), the projection of the thrust of the controllable speed increasing device 2 in the acceleration direction can be obtained as follows:

[0111]

[0112] Combining equations (9) and (2), we can obtain the thrust P of the thrust generator 11 and the elevation angle ε of the two-degree-of-freedom servo platform 10: z and azimuth ε y for:

[0113]

[0114] The desired pitch angle and roll angle are 0, and the calculation method of the desired roll, yaw, and pitch control forces is the same as that of equation (7).

[0115] Example 3:

[0116] This embodiment provides a workflow of a drone system based on Embodiment 1 and Embodiment 2. Figure 5 The specific process is as follows:

[0117] Step 1: The UAV system takes off and cruises by relying on the pulling force of the rotor 7. At this time, the UAV system is moving at a low speed. The push rod of the push rod motor 15 is in the retracted state. The angle between the connecting rod I 17 and the connecting rod II 18 and the round rod of the stabilizer bracket 14 is small, and the flexible stabilizer 19 is in the folded state.

[0118] Step 2: When the UAV system detects an enemy fire threat or is under fire attack, it enters a variable speed penetration state. The push rod of the push rod motor 15 pushes outward, driving the sliding hinge 16 to move toward the fixed hinge of the stabilizer bracket 14. The angle between the connecting rod I 17 and the connecting rod II 18 and the round rod of the stabilizer bracket 14 increases, and the deformable flexible stabilizer 19 at the tail is opened; the flexible stabilizer 19 is in an open state, forming a stabilizer.

[0119] Step 3: The UAV system adjusts the pitch and roll angles of the aircraft to 0° through the rotor 7; at the same time, the two-degree-of-freedom servo gimbal 10 in the controllable speed-increasing device 2 adjusts the thrust direction of the thrust generator 11 to the desired movement direction;

[0120] Step 4: The thrust generator 11 works to increase the speed of the UAV system in a short period of time;

[0121] Step 5: After the UAV system completes the evasion of the threat, the thrust generator 11 is turned off, and the deformable flexible stabilizer 19 is retracted, and the position and attitude control is continued through the rotor 7.

[0122] Example 4:

[0123] Based on Examples 1-3, this embodiment can simplify and adjust the structural scheme of Example 1 according to actual usage: for example, when the penetration speed is not high or the atmospheric force is small due to altitude reasons, the body fairing 13 and the rotor fairing 12 can be removed; when the control capability of the selected UAV system is strong, the deformable stabilizer assembly 4 at the tail can be removed and used; if only horizontal penetration is required during penetration, the two-degree-of-freedom servo platform of the controllable speed-increasing device can also be replaced with a fixed platform.

[0124] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A variable speed anti-slip rotor UAV system based on a controllable speed increasing device, characterized in that: The UAV system includes: a UAV platform and a controllable speed increasing device; The UAV platform uses a multi-rotor UAV as a basic flight platform, which can perform vertical take-off and landing, hovering, center of mass movement in four directions of front, back, left and right, and attitude movement in three directions of pitch, yaw and roll; The controllable speed-increasing device is installed at the bottom of the UAV platform and includes a servo platform and a thrust generator. The servo platform is used to drive the thrust generator to rotate and control the direction of the thrust generated by the thrust generator. The thrust generator generates a thrust much greater than the rotor pull in a short period of time, which is used to increase the speed of the UAV system in a short period of time. The control method of the drone system is: This control method is based on the dynamic model of "multi-rotor power + thrust" multi-mode control force input. This model is: In formula (1), is the acceleration of the UAV system; are the attitude angular accelerations of the UAV system in the three directions of roll, yaw and pitch; are the attitude angular velocities of the UAV system in the roll, yaw and pitch directions respectively; m is the weight of the UAV system; J x 、J y 、J z are the moments of inertia of the UAV system about the three principal axes of inertia; l is the wheelbase of the UAV system; g is the acceleration of gravity; U γ is the control force of the roll channel, U ψ is the control force of the yaw channel, U θ is the control force of the pitch channel; is the interference force, is the interference torque; In formula (1), is the projection of the thrust of the controllable speed increasing device in the acceleration direction, specifically: In formula (2), P is the thrust of the thrust generator, ε z is the elevation angle of the two-degree-of-freedom servo gimbal, ε y is the azimuth angle of the two-degree-of-freedom servo gimbal; In formula (1), is the projection of the rotor thrust in the three acceleration directions, specifically: In formula (3), U r is the control force perpendicular to the rotor plane generated by the rotor, γ is the roll angle, ψ is the yaw angle, is the pitch angle; In formula (1), is the projection of the aerodynamic force in the direction of acceleration, is the projection of the aerodynamic torque in the direction of angular acceleration, specifically: In formula (4), ρ is the atmospheric density, S is the frontal area, L is the length of the UAV system, is the aerodynamic coefficient of the UAV system, is the aerodynamic torque coefficient of the UAV system, is the flight speed of the UAV system; The control method is as follows: when the controllable speed-increasing device is not working, the position control and attitude control of the UAV system are both achieved by the pull of the rotor; when the controllable speed-increasing device is working, the position control of the UAV system is achieved by the controllable speed-increasing device, and the attitude control is achieved by the pull of the rotor; (1) When the controllable speed increasing device is not working, the expected control force is calculated as follows: According to the desired acceleration and the thrust of the controllable speed increasing device is 0, the projection values ​​of the desired rotor thrust in the three acceleration directions are: Combining equations (3) and (5), we can arbitrarily select the desired yaw angle ψ D , the desired pitch angle can be obtained Roll angle γ D The control force U generated by the rotor 7 and perpendicular to the rotor plane r for: After calculating the desired attitude angle, the corresponding attitude angular acceleration can be obtained according to control algorithms such as PID and sliding mode control. The desired roll, yaw, and pitch control forces can be calculated based on the desired attitude angular acceleration: (2) When the controllable speed increasing device is working, the expected control force is calculated as follows: The control force U generated by the rotor 7 is perpendicular to the rotor plane. r Need to overcome its own gravity, specifically: U r =gm(8) According to equations (1) and (8), the projection of the thrust of the controllable speed increasing device in the acceleration direction can be obtained as: Combining equations (9) and (2), we can obtain the thrust P of the thrust generator and the elevation angle ε of the two-degree-of-freedom servo gimbal: z and azimuth ε y for: The desired pitch angle and roll angle are 0, and the calculation method of the desired roll, yaw, and pitch control forces is the same as that of equation (7).

2. A variable speed anti-surge rotor UAV system based on a controllable speed increasing device according to claim 1, characterized in that: The UAV platform includes: a frame, an electrical compartment, a rotor, a motor and a landing gear; The frame is a flat plate structure, with more than four arms extending outward and evenly distributed along the circumferential direction; a landing gear is connected below each arm, and a rotor is connected above each arm via a motor; The electrical compartment is fixed on the flat plate structure of the frame; the electrical compartment has a built-in power supply, a flight control computer, an inertial measurement unit and a signal transceiver antenna. The power supply is used to provide power support for the UAV system. The inertial measurement unit is used to measure the acceleration and attitude angular velocity of the UAV system during flight and send them to the flight control computer. The flight control computer is used to calculate the speed, position and attitude angle of the UAV system during flight based on the acceleration and attitude angular velocity.

3. The variable speed anti-slip rotor UAV system based on a controllable speed increasing device according to claim 1, characterized in that: The UAV system also includes a fairing assembly and a deformable stabilizer assembly. The fairing assembly is installed at the front end of the UAV platform to reduce the aerodynamic resistance of the UAV system during high-speed movement; the deformable stabilizer assembly is installed at the rear end of the UAV platform to increase the flight stability of the UAV system.

4. The variable speed anti-surge rotor UAV system based on a controllable speed increasing device according to claim 3, characterized in that: The fairing assembly includes a body fairing and two rotor fairings; The fuselage fairing is installed at the front end of the UAV platform, and the windward surface of the fuselage fairing is a wedge-shaped surface; Each rotor fairing is fan-shaped and installed at the front end of the UAV platform; the two rotor fairings are located on both sides of the fuselage fairing, forming a semi-closed circular structure, which surrounds the outside of the two rotors at the front end of the UAV platform; the outer wall of the rotor fairing is processed into a slope.

5. The variable speed anti-penetration rotor UAV system based on a controllable speed increasing device according to claim 3, characterized in that: The deformable stabilizer assembly includes: a stabilizer bracket, a push rod motor, a connecting rod mechanism and a flexible stabilizer; The main structure of the stabilizer bracket is a round rod with a plate-like structure at one end and a fixed hinge at the other end. The fixed hinge is provided with two or more fixed hinge rings. A sliding hinge is sleeved on the round rod and can perform linear reciprocating motion along the axis of the round rod. The sliding hinge is provided with two or more sliding hinge rings. The fixed hinge and the sliding hinge are connected by a connecting rod mechanism. Each linkage mechanism consists of two links, namely Link I and Link II. Link I has a hinge ring at each end. One end is connected to the sliding hinge ring in a hinged manner, and the other end is connected to one end of Link II in a hinged manner. The other end of Link II is connected to the fixed hinge ring of the stabilizer bracket in a hinged manner. A flexible stabilizer is installed on the triangular surface formed by the connecting rods I and II of each linkage mechanism and the round rod of the stabilizer bracket; the flexible stabilizer is connected to the connecting rod I and the round rod of the stabilizer bracket; The plate-like structure of the stabilizer bracket is connected to the rear end face of the UAV platform; the push rod motor is installed on the plate-like structure; the push rod end of the push rod motor is fixedly connected to the sliding hinge on the round rod of the stabilizer bracket, and is used to drive the sliding hinge to perform linear reciprocating motion along the axial direction of the round rod.

6. The variable speed anti-penetration rotor UAV system based on a controllable speed increasing device according to claim 5, characterized in that: The flexible stabilizer is made of fiber braided material or polymer material.

7. A variable speed anti-penetration rotor UAV system based on a controllable speed increasing device according to any one of claims 1 to 6, characterized in that: The servo platform of the controllable speed increasing device adopts a two-degree-of-freedom servo platform; the two-degree-of-freedom servo platform is used to drive the thrust generator to rotate in vertical and horizontal directions.

8. A variable speed anti-penetration rotor UAV system based on a controllable speed increasing device according to any one of claims 1 to 6, characterized in that: The thrust generator of the controllable speed increasing device adopts a solid engine, a cold air jet device or a solid-liquid mixed fuel engine.

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