Steering Angle Sensing via Rotated Bit Value Difference
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Solution Overview
Problem
Existing steering angle sensing systems face challenges in accurately detecting absolute steering angles and are prone to errors due to signal conversion processes, which can be costly and reduce reliability.
Innovation Solution
A steering angle sensing apparatus and method that utilizes a shaft gear coupled to a steering shaft, with sub gears and magnets rotating at different rates, digitally processing the changes in magnetic fields to calculate the steering angle, eliminating the need for analog-to-digital conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If analog-to-digital conversion is used in steering angle sensing, then signal processing capability is improved, but error potential increases and reliability decreases
Solution Approach 1:
The patent extracts and eliminates the analog-to-digital conversion process from the steering angle sensing system. By using magnets that rotate with the steering shaft and directly generating digital signals through magnetic field detection, the system removes the conversion step that introduces errors, thereby improving reliability while maintaining digital processing capability
Solution Approach 2:
The patent replaces the traditional mechanical/electrical analog signal generation and conversion system with a magnetic field-based direct digital signaling system. Magnets rotate with the steering shaft and are detected by magnetic sensors that directly output digital signals, substituting the analog conversion mechanism with a magnetic detection mechanism that inherently provides digital output
2Measurement precision
If multiple magnets with different rotation cycles are used, then absolute steering angle detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the steering angle detection into multiple independent magnetic field detection channels, each using a magnet with a different rotation cycle. By dividing the detection task across multiple magnets rotating at different speeds, the system can accurately determine absolute steering angle through digital processing of the combined signals without requiring a single complex sensing mechanism
Solution Approach 2:
The patent changes the rotation cycle parameter of multiple magnets to create distinguishable signal patterns. Each magnet rotates at a different cycle relative to the steering shaft rotation, creating unique magnetic field variation patterns that can be digitally processed to accurately determine absolute steering angle position
3Productivity
If analog-to-digital converter is eliminated, then cost is reduced and processing speed is improved, but signal conversion capability is worsened
Solution Approach 1:
The patent extracts and removes the analog-to-digital converter component from the system architecture. By designing the sensing system to directly generate digital signals through magnetic field detection, the conversion function is eliminated entirely, reducing cost and improving processing speed while maintaining full digital signal capability through alternative means
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
This approach allows for accurate detection of absolute steering angles with reduced error potential, improved reliability, faster processing, and cost savings by eliminating the need for signal conversion, while enabling a smaller and more efficient sensing apparatus.
Implementation Method 1
a first angle detecting portion outputting a first rotated bit value corresponding to a change in a magnetic field of the rotating first magnet; a second angle detecting portion outputting a second rotated bit value corresponding to a change in a magnetic field of the rotating second magnet
Data Source
AI summary
A steering angle sensing apparatus and method are provided. The apparatus and method sense the steering angle of a steering shaft by using a rotated bit value difference corresponding to the rotated angles of magnets, which are respectively coupled on an axis of one of a plurality of sub gears, when the sub gears with respectively different gear ratios rotate with a shaft gear that rotates together with the steering shaft.