Variable Feel Force Control via Autopilot Actuator Torque
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Solution Overview
Problem
Providing variable feel forces for aircraft controls in fully-powered flight control systems is complex and costly, with existing solutions involving mechanical or electronic means that require significant complexity and resources.
Innovation Solution
A method and system using force sensors and a conventional autopilot backdrive actuator to adjust feel forces by determining net force values and commanding actuator torque, allowing for continuously variable feel forces without increasing complexity or cost, by repurposing existing hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mechanical means (pneumatic and/or hydraulic means) are used to alter spring geometry for variable feel forces, then variable feel forces are achieved, but device complexity increases substantially
Solution Approach 1:
The patent replaces complex mechanical means (pneumatic and/or hydraulic systems) with an electronic control system. The flight control computer receives pilot input force signals and commands actuators to provide variable feel forces, eliminating the need for complex mechanical spring geometry alteration mechanisms while achieving the same functional result.
Solution Approach 2:
The patent changes the physical parameters of the feel force system by using actuators to dynamically adjust the feel force characteristics. Instead of altering spring geometry mechanically, the system changes the output force parameters of the actuators under computer control to provide variable feel forces across different flight conditions.
2Adaptability or versatility
If electronic means (controlling motors to emulate spring behavior) are used for variable feel forces, then variable feel forces are achieved, but device complexity increases substantially
Solution Approach 1:
The patent makes the flight control computer and actuator system perform multiple functions: they control flight control surfaces and simultaneously provide variable feel forces to the pilot. This eliminates the need for separate dedicated feel force mechanisms, reducing overall device complexity while maintaining the variable feel force capability.
Solution Approach 2:
The flight control system serves itself by using its existing computational and actuation resources to generate variable feel forces. The flight control computer uses the same sensors and actuators already present for flight control to also provide feel force feedback, eliminating the need for additional dedicated systems.
3Device complexity
If conventional hardware is repurposed for variable feel forces, then complexity and cost are reduced, but the ability to provide continuously variable feel forces may be limited
Solution Approach 1:
The patent makes the feel force system dynamic by using flight control actuators that can continuously adjust their output force based on real-time flight conditions and pilot input. The flight control computer dynamically commands the actuators to provide appropriate feel forces, enabling continuous variability rather than fixed mechanical characteristics.
Solution Approach 2:
The patent implements feedback control where the flight control computer receives signals about pilot input force and flight state, then commands actuators to provide appropriate feel force feedback. This closed-loop control enables continuously variable feel forces that adapt to changing flight conditions while using existing hardware resources.
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
Enables reduced complexity and cost in providing variable feel forces for aircraft controls, maintaining operational effectiveness while minimizing weight and complexity, by leveraging existing hardware and control logic.
Implementation Method 1
sensing, by each of at least one sensor associated with at least one aircraft control, a force sensor value
Implementation Method 2
determining, by at least one processor, an actuator torque command based on the adjusted force value. Further, the method comprises commanding, by at least one processor, an autopilot actuator with the actuator torque command to apply force to said at least one aircraft control
Data Source
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AI summary
A method for providing continuously variable feel forces for an aircraft comprises sensing, by each of at least one sensor (230a, 230b, 230c, 230d, 235a, 235b) associated with at least one aircraft control (130a, 130b, 140a, 140b, 140c, 140d), a force sensor value. The method further comprises determining a net force value by using the force sensor value for each of at least one sensor. Also, the method comprises comparing the net force value to a desired breakout force. In addition, the method comprises determining whether the net force value exceeds the desired breakout force. Additionally, the method comprises determining an adjusted force value by using the desired breakout force and the net force value, when the net force value exceeds the desired breakout force. Also, the method comprises determining an actuator torque command based on the adjusted force value. Further, the method comprises commanding an autopilot actuator with the actuator torque command to apply torque.