Rotorcraft Control System for Variable-Pitch Propulsion
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Solution Overview
Problem
Existing rotorcraft control systems face challenges in efficiently managing power distribution between rotors and propellers, leading to increased weight, complexity, and cost, while struggling to maintain performance during both vertical flight and high-speed cruising.
Innovation Solution
A control system that regulates the rotor and propeller pitch and speed setpoints based on travel speed and thrust commands, using a combination of electronic circuits and software to optimize power distribution and reduce parasitic drag, allowing the rotor to provide lift during cruising while minimizing drag and maintaining efficient propulsion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the rotorcraft uses a conventional power transmission system with additional power units and antitorque rotors, then the vehicle can perform vertical flight and high-speed cruising, but the weight, complexity, and manufacturing cost increase significantly
Solution Approach 1:
The main rotor serves multiple functions: it provides lift during vertical flight when powered by the engine, and provides propulsion during high-speed cruising when operating in autorotation mode. This multi-functionality eliminates the need for separate power transmission systems and antitorque rotors for different flight modes, directly resolving the contradiction between adaptability and complexity
Solution Approach 2:
The rotor dynamically transitions between two operational modes: powered rotation for vertical flight and autorotation for high-speed cruising. The system adapts its configuration based on flight phase, allowing the same rotor mechanism to serve different purposes without requiring additional dedicated components for each mode
2Speed
If the rotorcraft is designed for high-speed cruising with propellers, then the cruising performance improves, but the system requires additional power transmission components increasing weight and cost
Solution Approach 1:
The main rotor serves dual purposes: providing lift during vertical flight when powered, and providing propulsion during high-speed cruising when in autorotation mode. This eliminates the need for separate propulsion systems and their associated power transmission components, achieving high cruising speed without additional weight
Solution Approach 2:
The invention extracts the propulsion function from a separate dedicated system and integrates it into the main rotor's autorotation capability. By removing the need for additional power transmission systems specifically for propulsion, the weight is reduced while maintaining high-speed cruising capability
3Device complexity
If the rotorcraft uses a simplified helicopter configuration, then the manufacturing cost and complexity are reduced, but the maximum horizontal speed is limited to about 300 km/h
Solution Approach 1:
The rotor dynamically transitions between powered rotation for vertical flight and autorotation for high-speed cruising. The system adapts its configuration based on flight phase, allowing the same rotor mechanism to serve different purposes without requiring additional dedicated components for each mode
Data Source
AI summary
A system (100) for controlling a rotorcraft (1) including a rotor (10), at least one variable-pitch propulsion propeller (6L, 6R), and a motor (5) for driving the rotor and the propeller(s), the system includes:a member (101, 101A, 102, 103, 104) for generating a propeller pitch setpoint (θp*+θd*, θp*−θd*) as a function at least of a thrust variation command (TCL);a member (105, 105A) for generating a setpoint (RPM*) for the drive speed (RPM) of the rotor and the propeller(s), as a function at least of the travel speed (VTAS) of the rotorcraft; anda member (106) for generating a setpoint (NG*) for the engine speed as a function at least of the thrust command (TCL), of the drive speed setpoint (RTM*), and of a rotor collective pitch command (θ0).