Electric Distributed Propulsion Rotor Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing anti-torque systems in helicopters face inefficiencies due to vortex interference between the main rotor and tail rotor, leading to reduced thrust efficiency and increased noise, as well as difficulties in maintaining precise control at low rotational speeds and avoiding motor speed dead bands.
Innovation Solution
An electric distributed propulsion system with multiple rotors controlled by speed, featuring an input control and logic to manage rotational speeds and directions of the rotors, allowing for precise thrust production while avoiding motor speed conditions and resonant frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If tail rotors are driven at high angular velocities to provide adequate aerodynamic responses, then thrust efficiency is improved, but vortex interference with main rotor increases leading to reduced efficiency and increased noise
Solution Approach 1:
The anti-torque system is divided into multiple independent rotors (typically four) distributed around the helicopter rather than a single集中的尾桨。Each rotor can be independently controlled, allowing the system to achieve the required counter-torque while reducing vortex interference through distributed positioning and differential speed control.
Solution Approach 2:
The system dynamically adjusts the rotational speeds of individual rotors based on flight conditions. The control system varies rotor speeds in real-time to optimize performance, allowing rotors to operate at different speeds to minimize vortex interference while maintaining adequate aerodynamic response.
2Measurement precision
If multiple rotors are used with individual motor speed control, then precise thrust production is achieved, but control complexity increases
Solution Approach 1:
The control system merges the control of multiple rotors into a unified control architecture that manages all rotors through a single set of pilot inputs. The flight control computer integrates the control signals and distributes appropriate speed commands to each motor, simplifying the interface while maintaining precise individual control.
Solution Approach 2:
The system employs feedback control where the flight control computer continuously monitors rotor speeds, thrust production, and flight conditions. Based on this feedback, the system automatically adjusts motor speeds to maintain precise thrust control, reducing the burden on the pilot and simplifying operation despite the multiple controlled elements.
3Use of energy by moving object
If rotors operate at low rotational speeds, then energy consumption is reduced, but motor speed dead band conditions occur reducing control precision
Solution Approach 1:
The system dynamically adjusts rotor speeds to operate just above the motor speed dead band when low thrust is required, rather than allowing operation within the dead band. The control system is programmed to recognize and avoid these problematic speed ranges, maintaining minimal but adequate rotational speeds that ensure precise control while consuming reasonable energy.
Solution Approach 2:
The control system changes the operational parameters of the motors by adjusting minimum speed thresholds and avoiding dead band regions. By modifying the speed at which rotors operate, the system maintains control precision without excessive energy consumption, adapting motor parameters to flight conditions while avoiding problematic operational zones.
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
This solution enhances thrust efficiency, reduces noise, and maintains precise control by operating rotors outside the motor speed dead band and resonant frequencies, ensuring stable and accurate heading control.
Implementation Method 1
two or more motors controlled by speed
Implementation Method 2
Tail rotors can be driven at high angular velocities to provide adequate aerodynamic responses
Data Source
AI summary
An exemplary electric distributed propulsion system includes two or more rotors that are individually controlled by the rotational speed of associated motors, an input control connected to the associated motors to provide rotational speed control to the two or more rotors to produce a desired net thrust, and a logic connected to the input control and the associated motors, the logic for controlling speed and direction of the two or more rotors to achieve the desired net thrust and to avoid a motor speed condition.