Redundant Input Surface Detection for Unintentional Actuation Prevention
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Solution Overview
Problem
Existing input devices, particularly those in safety-critical applications like vehicle cruise control systems, face challenges in ensuring functional safety due to the risk of unintentional actuation, especially when multiple input surfaces are closely arranged and small, necessitating improved detection methods to differentiate between intentional and unintentional touches.
Innovation Solution
The input device employs multiple detection devices, including touch and actuation detection systems, with capacitive and force-sensing technologies, to independently detect touches and actuations, using redundant detection mechanisms to ensure accurate triggering and prevent incorrect operations. This includes capacitive touch sensors and piezoelectric force sensors, with an evaluation unit requiring consensus from multiple detection devices for functional assignment, and haptic feedback for confirmation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple detection devices are provided for redundant detection, then functional safety and reliability are improved, but device complexity increases
Solution Approach 1:
The patent combines multiple detection devices (first and second detection devices) into a single input device structure, where both devices share the same input surface and evaluation unit. This merging approach enables redundant detection for improved functional safety while avoiding the complexity of completely separate detection systems, as the devices are integrated within a unified structural framework.
2Reliability
If multiple detection devices are provided for redundant detection, then operational safety is improved, but space requirements increase
Solution Approach 1:
The patent implements a nested arrangement where the first and second detection devices are positioned adjacent to each other within the same input device housing, sharing common structural elements and the evaluation unit. This nesting strategy allows redundant detection functionality to be achieved without proportionally increasing the overall device volume, as both detection devices are efficiently packed within a compact integrated structure.
3Volume of stationary object
If input surfaces are arranged closely together to save space, then device compactness is improved, but the risk of unintentional activation increases
Solution Approach 1:
The patent employs feedback through redundant detection, where both the first and second detection devices independently monitor the input surface. The evaluation unit processes signals from both devices to verify intentional activation, providing a feedback mechanism that distinguishes between accidental touches and deliberate user input, thereby preventing unintentional activation even when input surfaces are closely arranged.
Solution Approach 2:
The patent implements preliminary verification through redundant detection before assigning switching or control functions. The evaluation unit requires confirmation from multiple detection devices before triggering an action, performing a preliminary check that ensures the activation is intentional. This preliminary action prevents unintentional activation before it can cause harmful effects.
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 enhances operational safety by reliably distinguishing between intentional and unintentional inputs, preventing accidental activations and ensuring correct operation, while being implemented in a structurally simple and space-saving manner.
Implementation Method 1
The touch detection device includes, for example, an optical or capacitive touch sensor. A capacitive touch sensor defines at least one measuring capacitance, the influence of which is detected when the input surface is touched by the touch sensor.
Implementation Method 2
The actuation detection device comprises at least one capacitive, resistive, and/or optical force sensor. At least one piezoelectric force sensor is provided as a force sensor for the actuation detection device.
Data Source
Figure 1
Figure 2a~2b
Figure 2c
AI summary
The invention relates to an input device (1), comprising at least one input surface (2), a plurality of detection apparatuses (T1, T2, F1, F2), which are designed to detect either touching of the input surface (2) or activation of the input surface (2) independently of each other, an evaluating unit (A), which is designed to assign a switching function or control function to the input device (1) in the event of activation or touching only in the case of detection by at least two of the detection apparatuses (T1, T2, F1, F2), characterized in that at least one detection apparatus (F1, F2) is designed to detect activation.