Multicopter type unmanned aerial vehicle with extended flight range

Abstract

FIELD: aviation technology.SUBSTANCE: invention relates in particular to the design of multicopter-type unmanned aerial vehicles. A multicopter unmanned aerial vehicle consists of a frame, a body, propeller groups, a flight controller and batteries. The body is designed as an aerodynamic profile - a supporting wing, rigidly connected to the frame and installed at a fixed angle, from 2° up to 60°, to the plane of rotation of the rotor blades. The body can be made of composite materials, plastic or metal and is an element that performs aerodynamic and load-bearing functions.EFFECT: increase in the range and duration of a multicopter flight, without complicating the power plant and electronics.1 cl, 2 dwg

Description

[0001] The invention relates to the field of aviation technology, in particular to the designs of unmanned aerial vehicles (UAV) of the multicopter type, and is aimed at increasing their energy efficiency, range and flight duration while maintaining or improving flight safety and controllability by using the body as a functional supporting aerodynamic profile.

[0002] The "Multicopters with Rotating Wings" (patent RU 2700084 C2, B64C 27 / 08, published October 3, 2028) is known. The patent describes a multicopter energy management system, including algorithms for optimizing load distribution between motors and battery modules.

[0003] Main differences and disadvantages: the invention operates only at the level of algorithms for distributing loads between engines and does not affect the design features of the supporting structure or the aerodynamic characteristics of the aircraft; it does not reduce aerodynamic drag or increase the efficiency of the rotors; the effect is limited to software control without physically improving flight conditions.

[0004] The "System for Increasing the Flight Duration and Range of a Multicopter" patent RU 2657666 C1 B64C 27 / 08, published June 14, 2018, and the "Multicopter Frame" patent RU 2657650 C1, B64C 27 / 08, B64C 29 / 00 are known. The inventions disclose multicopter frame designs including longitudinal spars and cross beams to which propeller-motor assemblies are attached. Scalability is provided for various tasks - from drones to passenger and cargo platforms.

[0005] Key differences and disadvantages: the frame design in these inventions includes longitudinal spars and cross beams, but does not take into account the aerodynamic interaction between the propellers and supporting elements; the multicopter frame lacks aerodynamic optimization; there is no protection against turbulent losses and airflow interference.

[0006] A multicopter with a fully rotating rudder, a hybrid propulsion system, and combined propeller-motor groups (PMGs) is known. The PMGs are equipped with an internal combustion engine (ICE) connected to a generator, and at least four PMGs are configured as FPV drones with electric motors located on the top of the multicopter arms. The at least four FPV drones are capable of separating from the multicopter. The FPV drones have at least four PMGs with electric motors, each with a propeller. The PMGs of the multicopter itself are located below the arms of the multicopter, the propellers of the electric motors of which are located in parallel planes. The thrust generated by the propeller of the PMG of the multicopter itself is at least equal to the thrust of the propellers of the electric motors of the FPV drone. The solution is aimed at increasing the lifting capacity and reliability (patent RU 2831361 C1, B64U 10 / 14, published 04.12.2024).

[0007] Main differences and disadvantages: the invention has a combined VMG and a fully adjustable rudder; design and maintenance are complex due to the presence of a hybrid power plant; overall, the applied solutions contribute to an increase in the weight and cost of the aircraft; the unsolvable problem of aerodynamic efficiency during long-term horizontal flight.

[0008] The “Small-sized vertical takeoff / landing aircraft with increased flight range” (patent RU 2681464 C1, B64C 27 / 00, B64C 29 / 00, published on March 6, 2019) describes a small-sized vertical takeoff / landing aircraft with increased range due to the frame layout and battery placement.

[0009] Main differences and disadvantages: this invention uses a standard arrangement of propeller-motor groups without aerodynamic fairings, there is no integration of the supporting structure with airflow control functions, further increase in range is limited by the energy capacity of the batteries and the efficiency of the propellers.

[0010] A known unmanned aerial vehicle (patent RU 2666493 C1, B64C 27 / 08, B64C 39 / 02, published 09 / 07 / 2018) proposes the use of rings with an aerodynamic profile around the rotors to increase thrust and stability.

[0011] Main differences and disadvantages: the rings are made as separate suspended elements, not integrated into the supporting frame, do not provide additional functionality (for example, heat dissipation, strengthening the structure), possible increase in weight without a proportional increase in efficiency.

[0012] A known patent (GB 2469431 B, B64C 29 / 00, B64C 39 / 02, B64C 39 / 10, published 06.08.2010) is closest in technical essence to the proposed invention, describes a flying wing aircraft with vertical takeoff and landing, equipped with two vector thrust units located front and rear relative to the center of mass. These units can rotate individually or synchronously for pitch, yaw and roll control. The design assumes the presence of aerodynamic surfaces (flaps, control surfaces, swept consoles), which makes the device hybrid in nature - combining the features of an airplane and a VTOL platform. The advantages of our proposed solution over GB 2469431 B: simplicity and reliability, the absence of rotary assemblies, chain drives and complex aerodynamic controls significantly increases reliability and reduces production and maintenance costs.Our proposed solution does not require redesigning the control systems - it operates on standard components (flight controller, electronic speed controller (ESC), brushless motors). The "body as a wing" concept is applicable to both micro-drones and mid-range platforms, whereas the one in patent GB 2469431 B is not scalable due to the complexity of the mechanisms. The low energy efficiency of the aircraft described in the patent (GB 2469431 B, B64C 29 / 00; B64C 39 / 02; B64C 39 / 10, published 04.07.2012) from active thrust vectoring requires constant correction and energy consumption. Our solution uses passive flow around the body, set before flight, which provides a gain in energy consumption without additional power consumption.

[0013] Technical result - increasing the range and duration of a multicopter flight without complicating the power plant and electronics.

[0014] The technical result is achieved in that in an unmanned aerial vehicle of the multicopter type with an increased flight range, containing a frame, a body, propeller-motor groups, a flight controller and batteries, that the body is made in the form of an aerodynamic profile - a supporting wing, rigidly connected to the frame and installed at a fixed angle, within the range from 2° to 60°, to the plane of rotation of the supporting rotors, the body can be made of composite materials, plastic or metal and is an element that performs aerodynamic and supporting functions.

[0015] A multicopter type unmanned aerial vehicle with an increased flight range creates additional lift, partially compensating for the weight of the apparatus, which reduces the total thrust of the propellers, which, as a result, reduces energy consumption, thereby increasing the flight time and / or range.

[0016] The invention is illustrated by figures where:

[0017] Fig. 1 - UAV flight diagram in horizontal movement mode: the position of the body-wing at the angle of attack, the direction of the air flow and the lift vector are shown.

[0018] Fig. 2 - General view of the multicopter: the body is designed as an aerodynamic profile, installed at an angle of +10° to the plane of rotation of the propellers; the propeller-motor groups and mounting rods are indicated.

[0019] The multicopter unmanned aerial vehicle comprises a body 1, constructed as a single aerodynamic profile ("body-wing"), oriented at a fixed angle, for example, +10° in the range from 2° to 60°, to the plane of rotation of the rotors 2. Mounted on the booms 3 are propeller-motor groups with brushless motors 4, controlled by a standard flight controller and electronic speed controllers (ESC). The body may be made of composite materials, plastic, or metal.

[0020] The invention is a classic multicopter body, made in the form of a supporting profile, installed at a fixed angle, selected depending on the tasks to be performed, in the range of angles from 2° to 60° to the plane of rotation of the rotors, the use of the body is permissible in the manufacture of UAVs of the multicopter type, both as an independent product, and when modifying multicopters due to minimal changes by adding it as a “supporting profile” of the frame without adding moving elements.

[0021] During level flight, the aircraft automatically assumes a pitched attitude (front lower than rear), giving the wing-body an angle of attack relative to the oncoming airflow. As a result, the body generates additional lift, partially offsetting the aircraft's weight. This reduces the total propeller thrust and energy consumption, directly increasing flight time and range.

[0022] In the event of failure of one of the engines, the presence of lift from the body provides the possibility of a glider descent, increasing safety.

[0023] The solution is applicable both to the production of new UAVs and to the modification of existing multicopters by replacing the standard frame with a wing body.

[0024] The long range multicopter unmanned aerial vehicle operates as follows:

[0025] Mode 1: Vertical takeoff and hovering

[0026] During takeoff and hover, the flight controller ensures uniform thrust distribution between all propeller and engine groups. The aircraft maintains a horizontal orientation relative to the ground. In this mode, the body / wing is parallel to the ground, and the angle of attack relative to the oncoming airflow is zero or close to zero. Lift is generated exclusively by the rotors. Energy consumption is maximized, as the entire aircraft mass is compensated by the rotor thrust.

[0027] Mode 2: Transition from hover to level flight

[0028] To initiate horizontal flight, the pilot or autopilot commands forward movement. The flight controller generates pitch by differentially changing the thrust of the propeller units: the thrust of the front engines decreases, while the thrust of the rear engines increases. This creates a torque that causes the entire aircraft to tilt forward.

[0029] When the horizontal speed reaches 3-5 m / s, the oncoming airflow begins to interact with the wing-body. As a result of aerodynamic influence, the wing-body assumes a position where the angle of attack approaches the wing-body pitch angle.

[0030] Mode 3: Steady-state level flight

[0031] In steady, level flight, the body-wing 1 occupies a position with an angle of attack α close to its pitch angle. This creates additional lift in accordance with the aerodynamic equation:

[0032]

[0033] where:

[0034] L корпус - lifting force of the body

[0035] ρ - air density (approximately 1.225 kg / m 3 at sea level),

[0036] v - horizontal flight speed,

[0037] S - body-wing area in plan,

[0038] C L (α) is the lift coefficient, which depends on the angle of attack α.

[0039] This lifting force is L корпус compensates for the weight of the mg apparatus, which reduces the required total thrust of the propellers:

[0040] T треб =mg-L корпус

[0041] The power consumption of the engines is proportional to the thrust to the power of 3 / 2 for an ideal propeller (P T 3 / 2 ), even a small reduction in the required thrust yields significant energy savings.

[0042] Mode 4: Maneuvering and changing trajectory

[0043] When performing turns or changing altitude, the flight controller adjusts the thrust distribution between the propeller groups in accordance with pilot or autopilot commands. The airframe continues to generate lift proportional to the square of the current speed. As speed decreases, lift decreases, and the aircraft automatically increases propeller thrust to maintain altitude.

[0044] Mode 5: Landing

[0045] For landing, the pilot or autopilot reduces horizontal speed. At horizontal speeds below 2-3 m / s, the aircraft's lift becomes negligible. The flight controller gradually increases thrust on all engines to compensate for the aircraft's full weight and performs a vertical landing.

[0046] Experimental results.

[0047] Tests of a 1 kg prototype at a horizontal flight speed of 8 m / s showed:

[0048] - Increase flight duration by 22%,

[0049] - Increased flight range by 32%.

[0050] The solution does not require modifications to the powertrain, control system, or flight controller software. It can be used both in the production of new UAVs and in modifying existing multicopters by replacing the standard supporting structure with a body-wing.

[0051] The invention enables a UAV body made of composite materials, plastic, or metal to generate additional lift, partially offsetting the weight of the aircraft. This reduces the overall thrust of the propellers and, consequently, reduces energy consumption. This increases both the duration and range of a flight without changing the weight, battery capacity, or powertrain design.

Claims

An unmanned aerial vehicle of the multicopter type with an increased flight range, comprising a frame, a body, propeller-motor groups, a flight controller and batteries, characterized in that the body is made in the form of an aerodynamic profile - a supporting wing, rigidly connected to the frame and installed at a fixed angle, within the range of 2° to 60°, to the plane of rotation of the supporting rotors, the body can be made of composite materials, plastic or metal and is an element that performs aerodynamic and supporting functions.

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