Windshield Damage Detection via Structure-Borne Sound Analysis
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Solution Overview
Problem
Existing methods for registering damage events on motor vehicle windshields fail to differentiate between types of damage, such as spalling and cracking, which are critical for timely repair and passenger safety.
Innovation Solution
A method that analyzes structure-borne sound signals using a sensor device and analysis unit, identifying signal jumps and amplitude decay to distinguish between minor and severe damage, with refinements including high-pass filtering, rectification, and energy-saving states to enhance accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a structure-borne sound signal is registered to detect damage events on glass surface, then damage detection capability is provided, but differentiation between damage types (spalling vs. cracking) is not achieved
Solution Approach 1:
The structure-borne sound signal is segmented into multiple components based on temporal characteristics. The first signal component (occurring before the first amplitude decay) contains information about impact events, while the second signal component (occurring after the first amplitude decay) contains information about damage type. This temporal segmentation enables differentiation between spalling and cracking by analyzing specific portions of the signal separately.
2Loss of time
If signal analysis is performed immediately after impact to detect damage, then response time is reduced, but the first signal component (shock wave) masks damage-specific information
Solution Approach 1:
The method performs preliminary identification of the first amplitude decay point in the signal. By identifying when the first amplitude has decayed, the system prepares to switch to analyzing the second signal component at the appropriate time. This preliminary action ensures that damage-specific information is captured without being masked by the initial shock wave, while maintaining efficient timing.
3Loss of information
If the entire structure-borne sound signal is analyzed continuously, then all signal components are captured, but processing complexity and energy consumption increase
Solution Approach 1:
The analysis unit operates periodically rather than continuously. It activates to analyze the first signal component when impact is detected, then enters a low-power state until the first amplitude has decayed. Upon decay detection, it activates again to analyze the second signal component for damage type differentiation, then returns to low-power state. This periodic operation reduces energy consumption while capturing all necessary information.
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
Enables precise differentiation between minor and severe damage on windshields, providing timely warnings for necessary repairs and improving passenger safety by accurately identifying damage severity.
Implementation Method 1
a piezoelectric film may particularly be used, generating electrical voltage signals in response to extensions and compressions
Data Source
AI summary
In a method for registering at least one damage event on a glass surface, particularly a windscreen of a motor vehicle, wherein at least one structure-borne sound signal is registered by a sensor device and the registered structure-borne sound signal is forwarded to at least one analysis unit, it is provided as essential to the invention that a first signal component of the registered structure-borne sound signal is analyzed, that further analysis is not begun until a first amplitude of the registered structure-borne sound signal has decayed, that the curve of the registered structure-borne sound signal is examined for the existence of signal jumps, and that conclusions may be drawn regarding at least one damage incident on the glass surface from the existend of at least one signal jump.