Steering Position Sensor with Multi-Gear Sub-Shafts
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Solution Overview
Problem
Current steering apparatuses lack a reliable and stable method to detect the position and movement of a rack bar in a vehicle, particularly in steer-by-wire systems where a mechanical connection is omitted, necessitating additional sensors for accurate linear motion detection.
Innovation Solution
A position sensor with a substrate featuring multiple shafts, gears, and sensing coils, where different gear ratios and rotational speeds allow the processor to identify impedance or reluctance changes to determine the rotation angles of sub-rotors, which are then used to calculate the rotation angle of the initial shaft connected to the rack bar assembly, enabling precise position and movement detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mechanical connection between the steering wheel and rack bar is removed in a steer-by-wire system, then the steering apparatus achieves greater design flexibility and electronic control capability, but an additional sensor is required to detect the linear motion of the rack bar, increasing device complexity
Solution Approach 1:
The patent combines multiple functions into a single integrated sensor unit. The sensor simultaneously detects both the rotational angle of the shaft and the linear position of the rack bar by integrating a rotary encoder and a linear displacement sensing mechanism into one device, thereby reducing the total number of sensors required in the steer-by-wire system.
Solution Approach 2:
The sensor is designed to perform multiple detection functions: it measures both angular displacement (rotation angle of the shaft) and linear displacement (position of the rack bar) using a unified sensing mechanism. This multi-functional approach eliminates the need for separate sensors and reduces system complexity.
2Measurement precision
If an additional sensor is added to detect rack bar linear motion, then position detection capability is improved, but the reliability and stability of position detection may be compromised due to increased system complexity and potential failure points
Solution Approach 1:
The sensor incorporates a feedback mechanism where the detected rotational and linear position data are continuously monitored and used to adjust the steering control. This closed-loop feedback ensures accurate and reliable position detection while allowing for error correction and system stabilization.
Solution Approach 2:
The patent replaces complex mechanical linkages with electronic sensing and signal processing. By using electromagnetic or optical sensing mechanisms instead of purely mechanical detection systems, the sensor achieves high measurement precision while reducing mechanical wear and failure points, thereby improving reliability.
3Measurement precision
If multiple gears with different gear ratios are used in the sensor mechanism, then the accuracy of rotation angle detection is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The sensor utilizes multiple gears with specifically designed different gear ratios to amplify or scale the rotational movement for more precise angle detection. By carefully selecting and varying the gear ratio parameters, the system achieves high detection accuracy while managing manufacturing tolerances through parameter optimization rather than requiring extremely tight manufacturing precision on all components.
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 solution enhances the reliability, stability, and robustness of position and movement detection for the rack bar, improving the accuracy and control of the steering apparatus by providing a robust method for identifying the rotation angles and linear displacement of the rack bar assembly.
Implementation Method 1
a rotor provided on the first side of the substrate and configured to rotate about the sub-shaft; and a sensing coil provided on the first surface of the substrate
Data Source
AI summary
A position sensor includes a substrate having a first surface and a second surface opposite to the first surface; an initial shaft passing through the first and the second surfaces of the substrate in a direction perpendicular to the substrate; an initial gear mounted to the initial shaft and positioned above the first surface of the substrate; a first sub-shaft positioned above the first surface of the substrate, and disposed perpendicular to the substrate and parallel to the initial shaft; a first sub-gear mounted to the first sub-shaft and positioned above the first surface of the substrate and rotatably engaged with the initial gear; a first sub-rotor mounted to the first sub-shaft and positioned above the first surface of the substrate; a first sensing coil disposed on the first surface of the substrate; a second sub-shaft positioned above the first surface of the substrate, and disposed perpendicular to the substrate and parallel to the initial shaft and the first sub-shaft; a second sub-gear mounted to the second sub-shaft and positioned above the first surface of the substrate and rotatably engaged with the initial gear; a second sub-rotor mounted to the second sub-shaft and positioned above the first surface of the substrate; and a second sensing coil disposed on the first surface of the substrate.