Steering Wheel Electrode Convex Portions for Touch Sensitivity
Solution Overview
Problem
Existing steering wheels with sensor electrodes have low touch sensitivity due to the design of the concave groove portions, which affects the detection accuracy and ease of winding the detecting portion.
Innovation Solution
The steering wheel design includes convex portions on the electrode that project out in the width direction at the sides of the concave groove portions, increasing the surface area and guiding the detecting portion, thereby enhancing touch sensitivity and workability during winding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor electrode is affixed to the outer periphery of a rim metal core with concave groove portions, then the sensor can detect hand contact, but the touch sensitivity is reduced at the concave groove portions
Solution Approach 1:
The electrode is designed with convex portions at specific locations corresponding to the concave groove portions of the base. These convex portions have different geometric properties (protruding outward) compared to the surrounding electrode areas, creating local quality variations that compensate for the reduced touch sensitivity at the concave groove portions.
Solution Approach 2:
The electrode transitions from a flat two-dimensional structure to a three-dimensional structure with convex portions that protrude outward. This dimensional change allows the electrode to extend into the space above the concave groove portions, maintaining closer proximity to the user's hand and thereby preserving touch sensitivity in these previously problematic areas.
2Ease of manufacture
If the detecting portion is wound on the base portion with concave groove portions, then the sensor can be installed, but the winding workability is reduced due to the concave groove portions
Solution Approach 1:
The convex portions of the electrode act as intermediary guide elements during the winding process. These protruding features provide reference points and physical guides that help align and position the detecting portion as it is wound onto the base portion, making the installation process easier and more precise.
3Area of stationary object
If the electrode surface area at concave groove portions is reduced, then the electrode fits the base portion shape, but the touch sensitivity decreases
Solution Approach 1:
Rather than simply increasing the two-dimensional surface area of the electrode, the invention uses three-dimensional convex portions that protrude outward from the electrode plane. This vertical extension into the third dimension effectively increases the functional sensing area without altering the electrode's footprint on the base portion, thereby maintaining fit while improving touch sensitivity.
Data Source
AI summary
A steering wheel including: a detecting portion wound on a base portion that has a concave groove portion, the detecting portion being configured to detect contact of a person; an electrode that is sheet-shaped, the electrode structuring the detecting portion; and a convex portion formed at a side of the concave groove portion of the electrode, the convex portion projecting-out in a width direction of the electrode.