Finger-Position HMI Supervising Element for Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing finger-position sensitive Human Machine Interfaces (HMIs) are not reliable for safety-related commands due to susceptibility to software bugs and electromagnetic fields, which can cause unintended activations.
Innovation Solution
A finger-position sensitive HMI system that includes a supervising element to verify the validity of user inputs by detecting touch coordinates and force signals, ensuring that a predefined pressure is applied and comparing observed button bitmap content indicators with source indicators to validate service requests, thereby reducing unwanted activations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a finger-position sensitive display with pressure sensor is used, then touch detection capability is improved, but reliability for safety-related commands deteriorates due to susceptibility to software bugs and electromagnetic fields
Solution Approach 1:
A supervising element is introduced as an intermediary between the touch display and the service request execution. This supervising element independently verifies touch inputs by comparing observed button bitmap content indicators with source indicators, and validates force signals, thereby mediating and filtering out false activations caused by software bugs or electromagnetic fields before they can trigger safety-related commands
Solution Approach 2:
The supervising element implements a feedback mechanism by continuously monitoring the display output, generating observed button bitmap content indicators, and comparing them with source indicators. This closed-loop feedback system detects and corrects discrepancies caused by electromagnetic interference or software malfunctions, ensuring only valid user inputs trigger service requests
2Reliability
If multiple validation checks are implemented in the supervising element, then reliability is improved, but device complexity increases
Solution Approach 1:
Multiple validation functions are merged into a single supervising element rather than distributing them across separate components. The supervising element combines bitmap content verification, force signal validation, and service request authorization in one integrated unit, reducing overall system complexity while maintaining comprehensive validation
Solution Approach 2:
The supervising element is designed as a multi-functional component that performs diverse validation tasks: generating observed button bitmap content indicators, comparing them with source indicators, validating force signals from the pressure sensor, and authorizing service requests. This universal approach consolidates multiple validation functions into one element, avoiding the complexity of separate dedicated components for each function
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
The system significantly enhances the reliability of safety-related commands by preventing unintended activations, even in the presence of electromagnetic interference or software malfunctions.
Implementation Method 1
The display is further arranged to detect a force signal caused by pressure being applied to the display
Data Source
AI summary
A finger position sensitive HMI for handling a user input of a user. The HMI includes an EDPU and includes a finger-position sensitive display. The display is arranged to display a generated button at the generated display location, to detect touch coordinates of a touched location on the display to provide the detected touch coordinates to the HMI OS, and to detect a force signal caused by pressure being applied to the display. The display is further arranged to provide the detected force signal to a supervising element. A check unit connected to the supervising element is arranged to observe a displayed button, and to generate an observed button bitmap content indicator of a pixel area related to the observed displayed button. The supervising element is arranged to release the provided service request related to the displayed button.