Powered Seat Actuator Obstruction Detection via Feedback Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aircraft seat actuation systems face challenges in detecting obstructions, particularly due to variations in passenger weight and nonlinear behavior of mechanical designs, which can lead to damage or injury from pinch events between moving seat components and immovable objects.
Innovation Solution
A method and system for controlling the motion of powered seat components using a controller that monitors feedback signals from actuators, determines a reference state during acceleration, sets a feedback-signal acceptance range, and terminates motion if the signal departs from this range during steady-state phases, effectively detecting obstructions without additional sensors and accounting for changes in load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If foil sensors are arranged on the seat to detect obstructions, then obstruction detection capability is improved, but device complexity and weight increase
Solution Approach 1:
The patent uses feedback from the actuator's current draw and position sensor to detect obstructions. The controller monitors the relationship between actuator current and position, comparing actual values against expected values to identify pinch events, eliminating the need for separate foil sensors.
Solution Approach 2:
The patent uses the actuator's existing current and position data as an intermediary to detect obstructions. Instead of directly sensing obstruction force with separate sensors, the system infers obstruction presence through the mediator of actuator electrical and positional parameters.
2Device complexity
If actuator current is used to detect obstructions, then device complexity is reduced, but measurement precision deteriorates due to passenger weight variations
Solution Approach 1:
The system uses feedback from both position sensors and current draw, but more importantly, it uses feedback from multiple measurement points (acceleration and steady-state phases) to dynamically adjust detection thresholds, improving precision while maintaining simple device architecture.
Solution Approach 2:
The patent dynamically adjusts obstruction detection thresholds based on the detected passenger load. By measuring actuator behavior during acceleration and steady-state phases, the system adapts its detection criteria to the current loading condition, maintaining high precision across varying weights.
3Device complexity
If simple current-based obstruction detection is used, then device complexity is reduced, but reliability deteriorates due to nonlinear mechanical behavior
Solution Approach 1:
The patent segments the actuator's motion range into multiple zones (retraction zones, extension zones, intermediate zones) and applies different detection criteria to each zone. This segmentation allows the simple current-based detection to account for nonlinear mechanical behavior at different positions, improving reliability without adding complexity.
Solution Approach 2:
The system dynamically adjusts detection parameters based on the actuator's operating phase (acceleration vs. steady-state) and position zone. By making the detection criteria dynamic rather than static, the simple current-based system achieves high reliability despite nonlinear mechanical characteristics.
Data Source
AI summary
A method of controlling motion of movable components of a powered seat includes, using the controller, monitoring a feedback signal of an actuator during motion of a component. During an acceleration phase of the motion of the component, a reference state of the time-varying motion command is detected and a reference value of the monitored feedback signal is determined as a reference value. A feedback-signal acceptance range is determined using the reference value of the monitored feedback signal. During a steady-state phase of the motion, the motion of the component is terminated if the monitored feedback signal departs the determined feedback-signal acceptance range. A control system for a powered seat of a vehicle is described. A powered seat assembly is described.