Controlled Blocked Force Exciter for NVH Analysis
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Solution Overview
Problem
Current noise vibration and harshness (NVH) analysis techniques, such as classic Transfer Path Analysis (TPA), are labor-intensive and time-consuming, especially when characterizing structure-borne noise in complex assemblies, limiting their effectiveness in daily engineering applications.
Innovation Solution
The introduction of a controlled blocked force exciter system that enables in-situ multiple-input-multiple-output (MIMO) system identification and diagnosis, allowing for rapid characterization of blocked forces and system response functions, thereby reducing the time required for NVH analysis in complex structures like passenger vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classic TPA is used to characterize structure-borne noise, then the analysis can be performed with conventional measurement methods, but the process becomes labor-intensive and time-consuming due to the inverse approach requiring source removal for SRF measurements
Solution Approach 1:
The patent inverts the classic TPA approach by using blocked force measurements taken in-situ (with source installed) to directly calculate transfer paths, eliminating the need for source removal and subsequent refitting. This inversion of the measurement sequence maintains analytical accuracy while dramatically reducing measurement time and complexity
2Productivity
If in-situ blocked force method is used to eliminate decoupling stage, then the approach becomes faster and blocked forces become transferable between assemblies, but system identification and diagnosis steps become time-consuming
Solution Approach 1:
The patent replaces manual, labor-intensive system identification procedures with automated computational methods that use the measured blocked forces to directly calculate transfer paths and identify noise sources. This substitution of automated algorithms for manual analysis maintains the speed benefits of in-situ measurements while eliminating the time-consuming system identification step
3Measurement precision
If classic TPA requires source removal for SRF measurements, then measurements can be obtained, but decoupling of source and receiver induces errors in the TPA model
Solution Approach 1:
The patent performs blocked force measurements in-situ before any source removal or decoupling occurs, capturing the true operational conditions of the assembled system. This preliminary measurement approach preserves the integrity of the TPA model by avoiding the errors introduced by source-receiver decoupling, while still enabling accurate noise source identification
Data Source
AI summary
Methods and systems for in-situ determination of system response functions. One example method includes coupling a controlled blocked force exciter to a calibration receiver structure. The method also includes operating the controlled blocked force exciter under controlled operation conditions to induce vibration in the calibration receiver structure and measuring response data for the calibration receiver structure. The method further includes determining blocked forces based on the response data for the calibration receiver structure. The method also includes coupling the controlled blocked force exciter to a target receiver structure. The method further includes operating the controlled blocked force exciter under the controlled operation conditions to induce vibration in the target receiver structure and measuring response data for the target receiver structure. The method also includes determining system response functions by relating the response data for the target receiver structure to the blocked forces.