Single Collective Stick Layout for Coaxial Rotor Workload Control
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Solution Overview
Problem
Rotary wing aircraft typically require dedicated collective and cyclic inputs for each pilot seat, which can be cumbersome and limit pilot workload management, especially in high-speed flight modes where traditional helicopters experience unstable rolling moments and lift imbalances due to retreating blade stalls.
Innovation Solution
A dual rotor, counter-rotating coaxial main rotor assembly with a translational thrust system and a fly-by-wire control system that allows for a single collective control input positioned between two seats, enabling independent control of the main rotor assembly and translational thrust system through a predefined schedule based on airspeed, reducing pilot workload and stabilizing aircraft attitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If dedicated collective and cyclic inputs are provided for each pilot seat, then each pilot has independent control capability, but the device complexity and pilot workload increase
Solution Approach 1:
The patent merges the collective control inputs for both pilot seats into a single collective stick positioned between the seats. This single collective stick controls both rotor assemblies simultaneously, eliminating the need for separate collective inputs for each pilot while maintaining full control capability for both seats through the shared control element.
Solution Approach 2:
The single collective stick serves multiple functions: it controls collective pitch for both rotor assemblies, provides independent cyclic control capability when combined with seat-specific cyclic inputs, and enables coordinated control for both pilots. This multi-functional design reduces overall system complexity while maintaining operational flexibility.
2Stability of the object's composition
If traditional helicopter configuration is used with retreating blade stalls, then simple control mechanism is maintained, but aircraft stability deteriorates in high-speed flight modes
Solution Approach 1:
The patent employs a dynamic control system where the single collective stick is coupled with individual cyclic controls for each seat through a fly-by-wire system. This allows the control system to dynamically adjust and coordinate responses between the two rotor assemblies, maintaining stability across varying flight conditions including high-speed modes where traditional helicopters experience retreating blade stalls.
Solution Approach 2:
The fly-by-wire control system incorporates feedback mechanisms that monitor aircraft state and automatically coordinate the response of both rotor assemblies. This feedback control enables the system to maintain stability in high-speed flight by compensating for asymmetric blade effects without requiring complex mechanical control linkages.
3Stability of the object's composition
If counter rotating coaxial rotor assembly is implemented, then lift balance and torque cancellation are improved, but device complexity increases
Solution Approach 1:
The patent uses counter-rotating coaxial rotor assemblies where the two rotors rotate in opposite directions. This asymmetric rotation configuration naturally cancels out torque effects and balances lift distribution, eliminating the need for complex tail rotors or other torque compensation mechanisms while improving overall aircraft stability.
Data Source
AI summary
An aircraft is provided including an airframe, an extending tail, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe. A cockpit in the airframe, the cockpit including two seats and a single collective control input positioned between the two seats.