VTOL Flight Control with Dynamic Zero-Acceleration Stick Reference
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Solution Overview
Problem
Fly-by-wire systems in VTOL aircraft and other non-conventional aircraft face challenges in providing intuitive transitions between vertical and forward flight modes, increasing pilot workload and complexity due to the need for simultaneous control of non-fixed wing and fixed wing operating behaviors.
Innovation Solution
A control system that dynamically adjusts a zero acceleration reference position for control sticks based on the current speed of the aircraft, using a flight control computer to generate continuous acceleration commands, allowing pilots to maintain a fixed position by releasing the control stick, thereby facilitating seamless transitions between vertical and forward flight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional mechanical flight control systems are replaced with fly-by-wire systems in VTOL aircraft, then control precision and system integration are improved, but pilot workload and control complexity increase
Solution Approach 1:
The control system dynamically adapts its characteristics based on flight mode. During vertical flight, the system provides positional control where the aircraft maintains a fixed position when the control stick is released. During forward flight, it transitions to conventional acceleration control. This dynamic adaptation reduces pilot workload while maintaining precision across different flight regimes.
Solution Approach 2:
The patent changes the control parameter from acceleration command (traditional) to position command (intuitive). By modifying what the control stick represents - from directly commanding acceleration to commanding desired position - the system achieves more intuitive control during VTOL operations while the fly-by-wire system handles the complexity of translation to actuator commands.
2Adaptability or versatility
If fly-by-wire systems support both non-fixed wing and fixed wing operating behaviors, then versatility is improved, but ease of operation deteriorates
Solution Approach 1:
The control system automatically transitions between vertical flight mode and forward flight mode based on aircraft state, eliminating the need for pilots to manually reconfigure controls. In vertical flight, the stick controls position; in forward flight, it controls acceleration. This dynamic mode transition maintains versatility while simplifying operation.
Solution Approach 2:
The flight control computer automatically determines the appropriate control law based on current flight conditions, selecting between positional control and acceleration control without pilot intervention. The system serves itself by autonomously adapting its control characteristics, reducing the cognitive burden on the pilot.
3Speed
If conventional acceleration control is used in VTOL aircraft, then control responsiveness is improved, but transition smoothness between flight modes deteriorates
Solution Approach 1:
The control system dynamically adjusts its characteristics based on flight phase. During vertical flight transitions, it provides positional control where the aircraft naturally decelerates as it approaches the commanded position, creating smooth transitions. During steady forward flight, it switches to acceleration control for responsive maneuvering. This dynamic switching maintains both responsiveness and transition smoothness.
Data Source
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AI summary
Fly-by-wire vehicle systems and related control systems are provided for controlling operation of a vehicle, such as an aircraft. An exemplary method of controlling a vehicle involves identifying an input position associated with actuation of a human-machine interface, identifying a current speed of the vehicle, determining a dynamic zero acceleration reference actuation position for the human-machine interface based at least in part on the current speed, determining an acceleration command for the vehicle based on a relationship between the input actuation position and the dynamic zero acceleration reference actuation position, and providing the acceleration command to a flight control law or other control system configurable to operate one or more actuators associated with the vehicle to influence the current speed of the vehicle in accordance with the acceleration command.