Fixed-Angle Rotor UAV Architecture for Stable VTOL Transitions
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Solution Overview
Problem
Existing UAVs face challenges in achieving stable transitions between vertical take-off and landing (VTOL) and level cruising flight modes, with issues of instability, structural complexity, high weight, and reduced energy efficiency due to multiple rotor systems and complex drivetrains.
Innovation Solution
A hybrid fixed and rotating wings UAV design with a pair of elongated arcuate drivetrain members, a fuselage, and a rear horizontal inverted airfoil, featuring rotors mounted at fixed deflection angles to create self-stabilizing aerodynamic systems, and an autonomous autopilot module for seamless mode transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple rotor systems and complex drivetrains are used to achieve VTOL and level cruising flight modes, then the UAV can perform both vertical takeoff/landing and horizontal flight, but the weight increases and energy efficiency decreases
Solution Approach 1:
The patent employs a tiltrotor mechanism where the rotor assembly can dynamically change its orientation from vertical to horizontal position. This dynamic reconfiguration allows a single rotor system to provide both vertical lift during VTOL operations and horizontal thrust during cruising flight, eliminating the need for separate rotor systems for each flight mode and thereby reducing overall aircraft weight
Solution Approach 2:
The rotor assembly is designed to perform multiple functions: it provides vertical lift during takeoff and landing, transitions to provide horizontal thrust during cruising flight, and can be adjusted to various intermediate angles during transition phases. This multi-functionality of a single rotor system replaces what would traditionally require multiple dedicated rotor systems, reducing weight and improving energy efficiency
2Adaptability or versatility
If rotors are rotated or tilted for variable flight modes, then the UAV can transition between VTOL and level cruising flight, but the structural complexity and drivetrain weight increase
Solution Approach 1:
The drivetrain is segmented into modular components including the rotor hub, tilt mechanism, and drive shafts. Each module performs a specific function and can be independently designed, maintained, and replaced. This modular segmentation reduces overall system complexity by breaking down the complex tiltrotor drivetrain into manageable, standardized subsystems
Solution Approach 2:
A mechanical intermediary mechanism (tilt mechanism) is introduced between the rotor assembly and the fuselage to enable smooth transition between vertical and horizontal rotor orientations. This intermediary component simplifies the overall drivetrain architecture by providing a dedicated, specialized mechanism for angle adjustment rather than attempting to achieve the same function through complex direct coupling of multiple drive systems
3Adaptability or versatility
If complex drivetrains with rotating or tilting rotors are used, then variable flight modes are achieved, but the stability during transition modes deteriorates
Solution Approach 1:
The patent incorporates flight control systems with sensors that continuously monitor the aircraft's attitude, rotor angle, and flight parameters during transition modes. This feedback information is used by the control system to make real-time adjustments to rotor thrust and tilt angle, stabilizing the aircraft during the dynamic transition between vertical and horizontal flight modes and preventing instability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides improved controllability and stability during hover and cruising flight, reducing weight and increasing energy efficiency while enabling seamless transitions and enhanced payload capacity.
Implementation Method 1
rotors mounted at fixed deflection angles to create self-stabilizing aerodynamic systems
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
An unmanned aerial vehicle (UAV) system configured for Vertical Take-Off and Landing (VTOL), comprising: an aircraft (10) having: a) a pair of elongated arcuate drivetrain members (100,100'), each having a basal end (101,101') and an apical end (102,102') and each defining a basal (1001), mid (1002), and apical (1003) inflection points, wherein each elongated arcuate drivetrain member (100,100') further comprises a first VTOL rotor (110,110') extending apically from the basal inflection point (1001) and a second VTOL rotor (120,120') extending basally from the elongated arcuate drivetrain member (100,100') between the mid inflection point (1002) and the apical inflection point (1003); b) a fuselage (200); c) a structural member (300) defining a longitudinal axis, having an upper surface (3003) and a basal surface (3004), with a pair of lateral ends extending laterally from the fuselage (200) and coupled to each of the elongated arcuate drivetrain members (100,100') at each lateral end; and d) a pair of fixed wings (400,400'), operably coupled to, and extending laterally from each elongated arcuate drivetrain members (100,100'), wherein the aircraft center of gravity (COG) during vertical takeoff and landing is disposed directly beneath an intersection of projected diagonals drawn through the rotational axes of the first VTOL rotor and the second VTOL rotor in each elongated arcuate drivetrain member.