Model-Based Noise Immission Calculation Using Transfer Functions
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Solution Overview
Problem
Current methods for measuring noise emissions from self-propelled objects, such as motor vehicles, are complex, expensive, and require extensive efforts, especially for detecting drive-by noises, which necessitate either outdoor measurements or large test stands with multiple microphones.
Innovation Solution
A method using a model-based calculation with a location-dependent transfer function to predict noise emissions by simulating the movement on a test bench, where noise emissions are detected and calculated using a physical model, allowing for the simulation of drive-by noises without actual movement past a measuring device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If noise measurements are conducted outdoors along a test track to capture pass-by noise, then measurement accuracy is improved, but device complexity and measurement cost increase
Solution Approach 1:
The patent creates a virtual copy of the outdoor pass-by noise measurement scenario by using a location-dependent transfer function that mathematically simulates the acoustic propagation from the vehicle to remote receiving locations. Instead of physically moving microphones along a test track, the system copies the measurement outcome through calculation, achieving the same information gain with a single stationary measurement point.
Solution Approach 2:
The location-dependent transfer function acts as an intermediary that bridges the gap between the simple stationary test bench measurement and the complex outdoor pass-by noise scenario. This mathematical intermediary encapsulates the acoustic propagation effects, allowing the system to translate stationary measurement data into predictions for moving vehicle scenarios without requiring the physical complexity of outdoor measurements.
2Measurement precision
If extensive noise measurements are conducted during vehicle development, then noise emission determination accuracy is improved, but productivity and development time worsen
Solution Approach 1:
The patent performs preliminary action by pre-calculating and storing location-dependent transfer functions for various receiving locations along the movement path before actual noise measurements are needed. This allows the measurement system to be ready in advance, and when measurements are taken, the results can be quickly processed through the pre-prepared transfer functions to generate pass-by noise predictions, significantly reducing the time required for noise emission determination during vehicle development.
3Area of stationary object
If multiple microphones are used on a test bench to measure noise emissions, then measurement coverage is improved, but device complexity and cost increase
Solution Approach 1:
The patent transitions from a spatial dimension approach (using multiple microphones physically distributed in space to cover different areas) to a mathematical dimension approach (using a location-dependent transfer function that incorporates positional information as a variable). This allows the system to calculate noise levels at any location along the movement path using a single measurement point, effectively achieving unlimited spatial coverage without adding physical measurement devices.
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 simplifies and accelerates the determination of noise emissions, providing reliable forecasts under real conditions, reducing the need for complex external measurements and enabling more efficient vehicle development by allowing for virtual movement distance calculations and optimization of noise emissions.
Implementation Method 1
model-based calculation of the expected noise immission caused by the object moving self-propelled along a movement path at the at least one location in the hearing range of the movement path from the recorded noise immission at the at least one location on the test bench using a location-dependent transfer function
Data Source
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AI summary
A method for model-based calculation of the expected noise immission from a self-propelled object moving along a path of movement at at least one location in the audible range of the path of movement comprises the following steps: recording the noise immission from the object during operation on a test bench at at least one location on the test bench and model-based calculation of the expected noise immission from the self-propelled object moving along the path of movement at the at least one location in the audible range of the path of movement from the recorded noise immission at the at least one location on the test bench using a location-dependent transfer function.