Steering Wheel Rim Contact Detection Across Sensor Dead Zones
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional steering wheel units cannot detect hand contact in dead zones where sensors are not present, leading to potential erroneous operation or failure in hands-on detection.
Innovation Solution
The steering wheel unit incorporates a mode switcher that toggles between self capacitance and mutual capacitance detection modes, using a capacitance measurer to determine hand contact based on electrostatic capacitance thresholds, allowing contact detection even in dead zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrostatic capacitance sensors are arranged only in specific areas of the steering wheel rim, then the device complexity is reduced and manufacturing is simplified, but hand contact detection coverage is incomplete due to dead zones
Solution Approach 1:
The patent combines self-capacitance sensors and mutual-capacitance sensors into a single steering wheel rim structure. The self-capacitance sensors are arranged in a first region while mutual-capacitance sensor pairs are arranged in a second region, creating overlapping detection coverage that eliminates dead zones and improves overall hand contact detection reliability without requiring separate sensor systems
Solution Approach 2:
The steering wheel rim structure is designed to serve multiple functions: it houses both self-capacitance sensors and mutual-capacitance sensors, providing comprehensive hand contact detection across different regions. The rim acts as both a structural component and a multi-functional sensing platform, reducing the need for additional dedicated components
2Measurement precision
If self capacitance detection mode is used, then the device complexity is low and implementation is simple, but detection precision is insufficient in dead zones where sensors are not present
Solution Approach 1:
The system dynamically switches between self-capacitance detection mode and mutual-capacitance detection mode based on the operational context. The control unit selects the appropriate detection mode to match the hand contact scenario, optimizing detection precision for different situations without requiring a permanently complex system architecture
Solution Approach 2:
The patent changes the detection parameter by switching between self-capacitance and mutual-capacitance measurement modes. This parameter change allows the system to adapt its detection characteristics to suit different hand contact scenarios, improving measurement precision while maintaining relatively simple implementation
3Adaptability or versatility
If multiple detection modes are implemented, then detection precision is improved for different contact scenarios, but device complexity increases due to mode switching mechanisms
Solution Approach 1:
The control unit automatically selects the appropriate detection mode based on the operational context without requiring external intervention or complex switching mechanisms. The system self-adjusts between self-capacitance and mutual-capacitance modes according to the detected conditions, providing adaptability while keeping the control logic relatively simple
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 enables accurate detection of hand contact on the steering wheel, including in dead zones without sensors, thereby enhancing the reliability of hands-on detection systems.
Implementation Method 1
a capacitance measurer configured to measure a respective first electrostatic capacitance at each of the plurality of electrodes
Implementation Method 2
a mode switcher configured to switch between a self capacitance detection mode and a mutual capacitance detection mode
Implementation Method 3
a mode switcher configured to switch between a self capacitance detection mode and a mutual capacitance detection mode
Data Source
AI summary
In a steering wheel unit, when any one of electrostatic capacitances measured by a capacitance measurer while a self capacitance detection mode is set by a mode switcher is equal to or larger than a first threshold value, it is determined that the operator's hand is in contact with a rim at a position that overlaps at least one of electrodes. When the electrostatic capacitance is equal to or larger than a second threshold value, which is smaller than a first threshold value, and smaller than the first threshold value, the mode is switched to the mutual capacitance detection mode. After the switching, when an electrostatic capacitance newly measured in the mutual capacitance detection mode is equal to or larger than a third threshold value, it is determined that the operator's hand is in contact with the rim at a position that overlaps a gap between the electrodes.