Aircraft Undercarriage Steering Reset Method
Solution Overview
Problem
The angular position origin and electrical origin of an aircraft's steerable undercarriage can drift over time due to wear or maladjustment, causing the aircraft to deviate from a straight line unless continuously corrected by the pilot.
Innovation Solution
A method that resets the electrical signal of the angular position sensor to a determined value when the undercarriage is fully extended in flight, using an angular indexing device to ensure accurate steering control, thereby maintaining alignment with the neutral position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the aircraft runs on the ground to set the electrical origin matching the angular position origin, then the origins are initially aligned, but drift occurs over time due to wear and maladjustment causing misalignment
Solution Approach 1:
The patent applies preliminary action by resetting the electrical origin to match the mechanical indexing position at predetermined moments (takeoff and landing) before drift can significantly affect operation. This proactive resetting ensures origin alignment is restored at critical transition points in the flight cycle, preventing cumulative drift from causing steering inaccuracies during actual ground operations.
Solution Approach 2:
The patent implements periodic action by automatically resetting the electrical origin signal at regular intervals corresponding to flight phases (takeoff and landing). This periodic resetting mechanism, triggered by flight phase detection, continuously recalibrates the sensor signal against the mechanical indexing position, eliminating drift accumulation and maintaining accurate steering control throughout repeated flight cycles.
2Ease of operation
If continuous pilot correction is required to maintain straight line flight, then steering control is maintained, but pilot workload increases and continuous manual intervention is needed
Solution Approach 1:
The patent applies self-service by implementing an automatic origin resetting system that actively maintains the alignment between electrical and mechanical reference positions without requiring continuous pilot intervention. The system autonomously detects flight phases and resets the sensor signal accordingly, allowing the steering system to self-correct drift issues and eliminating the need for continuous manual steering adjustments to maintain straight line flight.
3Manufacturing precision
If the undercarriage is compressed on the ground for origin setting, then mechanical indexing can be established, but the procedure requires ground running to impart correct angular position
Solution Approach 1:
The patent applies preliminary action by performing the origin resetting operation during flight phases (takeoff and landing) when the undercarriage is naturally in the extended position. This eliminates the need for separate ground-based calibration procedures requiring compressed undercarriage and straight-line running, as the mechanical indexing position is automatically captured and used for electrical origin resetting during normal flight operations.
Data Source
AI summary
The invention provides a steering resetting method for an aircraft undercarriage that includes a leg in which a steerable bottom portion is mounted to slide against a suspension force generated by a shock absorber, the undercarriage being provided with a controllable steering member for causing the steerable bottom portion to swivel in response to an angular position setpoint, the undercarriage also including at least one angular position sensor adapted to generate an electrical signal representative of the angular position of the steerable bottom portion and suitable for use in controlling the steering member; the method comprises the step, performed when the steerable bottom portion is in an indexed angular position while the aircraft is in flight and the undercarriage is fully extended, of setting the electrical signal from the sensor to a determined reset value.