CN115339276A

CN115339276A - Bionic tilting four-rotor mechanism

Info

Publication number: CN115339276A
Application number: CN202211016778.2A
Authority: CN
Inventors: 宁扬; 张锋; 金波; 赵玉成; 王汉鹏; 张君宇
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2022-08-24
Filing date: 2022-08-24
Publication date: 2022-11-15

Abstract

The invention discloses a bionic tilting four-rotor mechanism which comprises 4 motors, a control cabin, a steering engine, a machine body and a support beam; the motor is arranged on the steering engine, and a propeller is arranged on the motor; the steering engines are arranged at two ends of the supporting beam and connected with the propeller; the machine body is fixed on the support beam, and the gravity center of the machine body is positioned in the centers of the four propellers; the fuselage comprises a ribbed slab and a skin arranged outside the ribbed slab, and the fuselage is similar to a ray (a round fan fish) in the sea, but is narrower; on the floor was located to the control cabin, the control cabin was equipped with control module, battery and the electricity that is used for controlling the flight of unmanned aerial vehicle and transfers in the control cabin. The invention combines the characteristics of the fixed wings and the multiple rotary wings, can hover and Vertically Take Off and Land (VTOL), and can generate lift force in the air through the fuselage body, thereby improving the endurance capacity; the flow channel is arranged on the machine body, so that the material is saved, the weight is reduced, the flow guide effect is realized on airflow and water flow, and the resistance is smaller.

Description

Bionic tilting four-rotor mechanism

Technical Field

The invention relates to a bionic tilting four-rotor mechanism which can be used for water-air amphibious.

Background

The multi-rotor unmanned aerial vehicle can hover, is flexible to operate and convenient to control, is widely applied to the engineering field, and plays an important role in occasions such as aerial photography, detection, search, investigation and the like. The fixed wing can not hover, so the fixed wing is caught in aspects such as detection and the like compared with a plurality of rotors, and the taking-off and landing required fields are larger. Because the fixed wing offsets gravity by the lift that the wing produced, and many rotors offset gravity by rotor thrust, consequently compare with the fixed wing unmanned aerial vehicle that provides lift through the wing, the many rotor unmanned aerial vehicle that provides lift by the rotor has the duration poor, flight inefficiency shortcoming. At present, a structure combining fixed wings and four rotors is also provided, for example, a Nezha series water-air amphibious aircraft manufactured by Shanghai university of traffic, but the Nezha series is only provided with wings and rotors on an unmanned aerial vehicle, and the two are simply combined, and the structure generates a large rolling moment on the force of ocean current on the wings due to large wingspan under water, so that the structure is easily interfered and influenced by the ocean current, the total weight of the Nezha III is more up to 18kg, and the difficulty in realizing gravity offset through the wings is large.

Patent CN 110466752B-a tilt rotor unmanned aerial vehicle's control method and tilt rotor unmanned aerial vehicle also is the unmanned aerial vehicle that verts that has combined fixed wing and four rotors, and this unmanned aerial vehicle also has the wing to expand greatly, easily receives the shortcoming of interference under water, and this four rotors cross installation has the fuselage to the problem of rotor air current interference in addition in X type installation.

The patent CN105730692B of Beijing aerospace university, a tilting quad-rotor long-endurance composite aircraft, realizes long-time endurance by installing fixed wings and rotary wings, has the same defects as Nezha and the like, and is easily influenced by ocean current in wingspan and is not suitable for underwater.

Shenyang automation research institute provides two kinds of fixed wing auxiliary flight four-rotor wing mechanisms, < CN 112278258A-a four-rotor wing unmanned aerial vehicle with foldable soft wing auxiliary flight mechanism, scheme one for short, and < CN 112278259A-a foldable wing auxiliary flight four-rotor wing unmanned aerial vehicle, scheme two for short.

The first scheme also has the problems of overlarge wingspan and large ocean current influence; scheme one is for avoiding soft wing and folding wing to cause the thrust of four rotors to blockking after launching, and the size that needs between the four rotors is great, and the soft wing can not produce lift for the horizontally in addition fuselage gesture, needs certain angle of attack just can produce lift, and the soft wing has great resistance when producing lift.

In 2021, jilin university patent CN 113753229A-foldable fixed wing four-rotor wing composite unmanned aerial vehicle and control method thereof provide a variable wing tilting four-rotor wing scheme, which needs at least 8 motors and 8 steering engines, and has large overall weight, small fixed wings and limited generated lift force.

Disclosure of Invention

The invention provides a novel bionic tilting quadrotor mechanism aiming at the problems that the cruising ability of the existing tilting quadrotor is insufficient and the appearance is not suitable for running underwater.

The bionic tilting quadrotor mechanism provided by the invention has the core idea that a fuselage and wings are integrated, the lift force is generated through the fuselage body to improve the endurance capacity, the fuselage body is in a ray-like shape and has the characteristics of good underwater resistance characteristic and less influence of ocean current, and the quadrotors adopt a tilting vector propulsion mode and are more flexible to control.

The invention adopts the following technical scheme:

a bionic tilting four-rotor mechanism comprises 4 motors, a control cabin, a steering engine, a machine body and a support beam; the support beam is used as a beam of the whole unmanned aerial vehicle and is used for bearing the whole unmanned aerial vehicle;

the motor is arranged on the steering engine, and a propeller is arranged on the motor; the steering engines are arranged at two ends of the supporting beam and connected with the propeller; the machine body is fixed on the support beam, and the center of gravity of the machine body is positioned in the centers of the four propellers; the shape of fuselage does: the top view of the machine body is similar to a ray, and the specific shape is that two first oblique lines are connected to the back surface of a small circular arc at the head of the machine body, the two first oblique lines extend backwards and are connected with two second oblique lines (the included angle between the second oblique lines and the central axis of the machine body is smaller than that between the first oblique lines and the central axis of the machine body), and finally the two second oblique lines are connected through a section of large circular arc positioned at the tail of the machine body; the front and left views of the fuselage take on the existing standard airfoil shape. The machine body in the shape has good hydrodynamic characteristics and stronger interference resistance; runners are symmetrically arranged on the left side and the right side of the upper part of the machine body; the machine body is provided with a water outlet (a small hole is formed in the lower part of the machine body and used for draining water);

a rib plate is arranged inside the machine body and used for maintaining the shape of the machine body; the outer part of the rib plate is covered with a skin which is made of a flexible low-density windproof material;

the control cabin is arranged on the rib plate and is waterproof and pressure-resistant; the control cabin is including the control module who is used for controlling unmanned aerial vehicle flight, battery and electricity are transferred.

The invention has the beneficial effects that:

1. by combining the flight modes of the fixed wings and the multiple rotors, hovering (facilitating execution of investigation and observation tasks) and vertical take-off and landing (VTOL) can be achieved, occupied space is reduced, partial gravity can be offset through the lift force generated by the fuselage body, and the cruising ability is improved;

2. the outer part of the machine body is coated by flexible materials, and the inner part of the machine body is supported by a framework by using low-density ribbed plates, so that the machine body is lighter compared with a method of using hard plastics to make the whole shell, and the design is favorable for reducing the whole weight;

3. the integrated design concept of the fuselage and the wings is adopted, the lift force is generated through the fuselage body to improve the endurance, and compared with the design of the fuselage and the wings, the size is more compact, so that the underwater ocean current influence is smaller;

4. the flow channel is arranged on the machine body and is used for guiding flow, so that the resistance can be effectively reduced, and the ocean current interference can be reduced under water;

5. the rotor can incline through the steering wheel and incline, and control mode and motion mode are more nimble.

Drawings

Fig. 1 is an overall structural view of the present invention.

Fig. 2 is a plan view of the body 4.

Fig. 3 is a front view of the body 4.

Fig. 4 is a left side view of the body 4.

Fig. 5 is a schematic view of a four-rotor level flight.

The underwater motor is arranged on the underwater vehicle, the control cabin is arranged on the underwater vehicle, the steering engine is arranged on the control cabin, the vehicle body is arranged on the control cabin, the rib plates are arranged on the control cabin, the supporting beams are arranged on the supporting beams, the flow channels are arranged on the supporting beams, and the propellers are arranged on the supporting beams.

Detailed Description

Fig. 1 shows a bionic tilting quad-rotor mechanism according to the invention. The 4 (underwater) motors are provided with a

propeller

8,2 control cabin, 3 steering engines, 4 machine bodies, 5 ribbed plates and 6 supporting beams.

The motor 1 is arranged on the steering engine 3.

The control cabin 2 is provided with a control module for controlling the unmanned aerial vehicle to fly, a battery for supplying power, an electric controller for executing power and the like, and if the control cabin is only used in the air but not used underwater, the control cabin can not be made into the shape of a figure or even not required; if the water-air amphibious function is realized, the control cabin is necessary (the shape of the control cabin can be set according to requirements), and the function is waterproof and pressure-resistant.

The steering engines are arranged at two ends of the support beam 6 and connected with the propeller; the function of tilting the wings is realized through the rotation of the steering engine 3, the thrust generated by the rotor wings to the fuselage can be upwards, and the direction can be towards any direction in 360 degrees through the rotation of the steering engine.

The fuselage 4 (with the center of gravity at the center of the four propellers) is fixed to a support beam 6. The top view of the body 4 is shown in fig. 2, and the shape of the body is designed to be similar to a ray (round fan fish) in the sea through a bionic idea. To reduce the overall size and at the same time to reduce the effect of the ocean currents on it, the fuselage is made narrower than the usual ray. Both the front and left views of the fuselage 4 are scaled to a standard airfoil shape, in this case a NACA4415 airfoil. A left side view of the fuselage 4 is shown in fig. 4. The front view of the machine body 4 is shown in fig. 3, two flow channels 7 are symmetrically arranged at the upper part of the machine body, the flow channels 7 are used for reducing the using amount of rib plate materials 1, reducing the whole weight 2 and reducing the fluid resistance by diversion 3, and air/water can flow through the flow channels particularly underwater. The lower part of the machine body 4 is provided with a small hole for draining water. The fuselage 'skin' is made of low-density flexible windproof material, and specifically, the density is lower than 1.5g/cm ³ The flexible material is easy to deform and is similar to wing-mounted flight materials such as high-performance nylon 66 filaments; the rib plate 5 is used as a framework of the fuselage, and the flexible material is used as skin, so that the lightweight fuselage design is realized.

The rib plates 5 (arranged in the fuselage) are made of low-density materials and high-strength materials (such as carbon fibers), and have the functions of supporting the outer skin and maintaining the shape of the fuselage 1 and bearing force 2 to prevent the fracture in the flight process. The control cabin 2 (arranged on the ribbed plate 5) is internally provided with a control module for controlling the flight of the unmanned aerial vehicle, a battery for supplying power, an electric speed regulator for executing power and the like, and if the unmanned aerial vehicle is only used in the air and not used underwater, the control cabin can be unnecessary; if the water-air amphibious function is realized, the control cabin is necessary, and the function is water resistance and pressure resistance.

The supporting beam 6 is the most important bearing part as the beam of the whole unmanned aerial vehicle structure, and can be made of high-strength low-density carbon fiber materials.

The bionic tilting four-rotor mechanism disclosed by the invention combines the characteristics of the fixed wing and the multiple rotors, can hover and Vertically Take Off and Land (VTOL), and can generate lift force in the air through the airframe body, so that the cruising ability is improved; different from a common fixed wing unmanned aerial vehicle, the unmanned aerial vehicle does not provide lift force through wings but provides lift force through a body of the unmanned aerial vehicle, and the whole size is compact, so that the unmanned aerial vehicle is less interfered by ocean currents underwater; the runner is arranged on the machine body, so that the material is saved, the weight is reduced, the flow guide effect is realized on airflow and water flow, and the resistance is smaller.

The invention can generate lift force when the machine body is horizontal, has smaller resistance, does not need a folding device, has simpler structure in this respect, and has smaller weight because the driving execution motor of the folding device is not needed.

The flight modes of the bionic tilting four-rotor mechanism comprise underwater operation, air flight and the conditions of air-to-water and water-to-air.

When the bionic tilting four-rotor mechanism flies in the air: the vertical take-off and landing is shown in figure 1, the propeller generates thrust to the fuselage upwards, the force generated by the propeller 8 is mainly used for overcoming gravity, the propeller moves like a common four-rotor wing, the horizontal speed is low, and the mode is used for finely adjusting the position of a four-rotor wing mechanism; the horizontal flight mode is faster in speed and has the effect of quickly reaching a target position, when the vertical take-off and landing mode is changed to the horizontal flight mode, the thrust direction (shown in figure 5) of the propeller 8 to the machine body 4 is gradually changed through the steering engine 3 until the thrust of the propeller 8 to the machine body 3 is changed to be forward, at the moment, more force generated by the propeller 8 is used for overcoming resistance, and compared with the vertical take-off and landing mode, the horizontal flight mode is faster in speed and higher in efficiency. The switching between the vertical take-off and landing mode and the horizontal flying mode is realized by adjusting the tilting angle of the propeller 8 through the steering engine 3.

When the bionic tilting quad-rotor mechanism sails underwater, the propeller 8 faces backwards relative to the airframe 4 (as shown in figure 5), the attitude of the airframe 4 is changed through the tilting propeller 8, the force generated by the propeller 8 is forward along the airframe 4 relative to the airframe 4 all the time, and the resistance of the airframe 4 can be kept minimum (the incident flow area is minimum).

The specific process of bionical four rotor mechanisms that vert from aerial to aquatic does, converts the VTOL mode into earlier, and 8 relative fuselages of screw 4 up (as figure 1) for the thrust balancing gravity that 8 propellers produced, after four rotor mechanisms go into water completely, steering wheel 3 moves, and the relative fuselages of adjustment propeller 8 are towards the back (as figure 5), begin underwater navigation.

The specific process of the bionic tilting four-rotor mechanism from water to air is as follows: the underwater water craft is in an underwater navigation mode at first, the propeller 8 moves backwards relative to the craft body 4 (as shown in figure 5) to be close to the water surface, the posture of the craft body 4 is vertical at the moment, then the posture of the craft body 4 is adjusted to be horizontal, the propeller 8 is adjusted to be upwards relative to the craft body 4 through the steering engine 3 (as shown in figure 1), then the underwater water craft takes off vertically to discharge water, and the water stops on the water surface slightly after the water discharge, so that the water is discharged fully.

As shown in fig. 1, the propeller 8 in the VTOL mode has upward thrust on the fuselage, and vertical take-off and landing have less field requirements than horizontal accelerated take-off.

As shown in fig. 5, the thrust of the propeller 8 on the fuselage 4 is forward in the fly-by mode, and the lift generated by the fuselage 4 counteracts (part of) the gravity.

Proven by Fluent simulation, the lift generated by adding and not adding the airframe to the flow channel 7 has little difference, but can effectively reduce the resistance.

Claims

1. A bionic tilting four-rotor mechanism is characterized by comprising 4 motors, a control cabin, a steering engine, a machine body and a support beam; the motor is arranged on the steering engine, and a propeller is arranged on the motor; the steering engines are arranged at two ends of the supporting beam and connected with the propeller; the machine body is fixed on the support beam, and the gravity center of the machine body is positioned in the centers of the four propellers; the machine body comprises a rib plate and a skin arranged outside the rib plate; the shape of fuselage does: a top view similar to a ray, but with a narrower fuselage; the front view and the left view of the fuselage are in a standard airfoil shape; on the floor was located to the control cabin, the control cabin was equipped with control module, battery and the electricity that is used for controlling unmanned aerial vehicle flight in the control cabin and transfers.

2. The biomimetic tilting quad-rotor mechanism according to claim 1, wherein two flow channels are symmetrically disposed on the upper portion of the fuselage; the lower part of the machine body is provided with a small hole for draining water.

3. A biomimetic tilt-quad rotor mechanism according to claim 1, wherein the rib plate material is carbon fiber.