Rudder Angle Sensor Backlash Correction
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Solution Overview
Problem
Conventional rudder angle sensors face challenges in achieving high accuracy due to rotational discrepancies caused by backlash between gears, which complicates the detection of steering shaft rotation angles and results in larger sensor sizes, making it difficult to maintain both high accuracy and compactness.
Innovation Solution
A rudder angle sensor design that includes a main drive gear interlocked with a steering shaft, a driven gear, a measuring mechanism to detect the rotation angle, and a calculation means that uses a correction value stored in a storage device to compensate for rotational delays caused by backlash, allowing for precise angle detection without additional mechanical mechanisms to prevent backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a third gear is added to reduce backlash between gears, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces the mechanical backlash reduction mechanism (third gear) with a computational correction approach. The calculation means computes a correction value based on the detected rotation direction and applies it to compensate for backlash effects, thereby eliminating the need for additional mechanical gears while maintaining measurement precision.
Solution Approach 2:
The patent changes the approach from mechanical parameter adjustment (adding gears) to computational parameter adjustment (applying correction values). The correction value is calculated based on rotation direction and applied to the detected rotation angle, transforming the problem from a mechanical design challenge to a computational correction task.
2Measurement precision
If doubling structure or helical gear is used to reduce backlash, then measurement precision is improved, but device complexity and size increase
Solution Approach 1:
The patent substitutes complex mechanical backlash reduction structures (doubling structure, helical gear) with a computational correction system. The calculation means detects rotation direction and applies correction values to compensate for backlash, eliminating the need for these complex mechanical arrangements while achieving the same measurement precision.
3Measurement precision
If mechanical mechanisms to prevent backlash are added, then measurement precision is improved, but device size increases
Solution Approach 1:
The patent replaces mechanical backlash prevention mechanisms with a computational correction approach. By using the calculation means to compute and apply correction values based on rotation direction, the system achieves high measurement precision without adding physical components that would increase sensor size.
4Measurement precision
If correction value calculation is added, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The calculation means uses the information already detected by the detection means (rotation direction) to calculate the correction value. The system serves itself by utilizing its own detection output to correct its measurement error, eliminating the need for external correction mechanisms or additional sensors.
Data Source
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AI summary
To provide a rudder angle sensor with high accuracy, it is constituted such that a storage means capable of storing a correction value to correct a rotational delay of a driven gear relative to a main drive gear caused by a backlash at a time of reverse of a steering shaft is provided, a calculation means corrects a measured result of a measuring mechanism based on the correction value stored in the storage means, and thereby, a rotation angle of the steering shaft can be calculated. The measured result of the driven gear obtained by the measuring mechanism is corrected based on the correction value, and therefore, the backlash existing between the main drive gear and the driven gear can be matched completely or approximately. Namely, the high accuracy of the rudder angle sensor is realized.