Heat Engine Acoustic Emission Mapping for Vehicle Noise Control
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Solution Overview
Problem
Transport vehicles with heat engines produce significant noise pollution, which affects human health and the environment, and existing regulations are insufficient to mitigate this issue, while current systems fail to account for driving behavior as a factor in acoustic emissions.
Innovation Solution
A transport vehicle equipped with an acoustic emission map and control system that adjusts the air-fuel mixture and engine revolutions in real time based on pre-measured data, using an on-board memory unit and sensors to minimize noise emissions, and provides feedback to the driver through a human-machine interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If government agencies impose approval requirements for acoustic emissions, then noise pollution control is improved, but the requirements are still too mild and limits are not sufficient to reduce noise pollution to levels that are less harmful to health and the environment
Solution Approach 1:
The system changes the operational parameters of the heat engine (air-fuel mixture ratio, engine revolutions) in real-time to minimize acoustic emissions. The control unit continuously adjusts these parameters based on driving conditions and pre-stored optimization data, enabling the vehicle to operate below current regulatory limits and potentially informing future stricter standards.
Solution Approach 2:
The system performs preliminary actions by pre-measuring and storing optimal operating conditions for minimizing noise emissions in the acoustic emission map before actual vehicle operation. This pre-characterization allows the control unit to quickly retrieve and apply optimal settings without real-time complex calculations, enabling immediate noise reduction when the vehicle is operated.
2Object-affected harmful factors
If acoustic emissions are reduced through regulatory measures, then noise pollution is decreased, but driving behavior remains a strong affecting factor with no valid instrument to impose or suggest modifications
Solution Approach 1:
The system introduces feedback by providing the driver with information about the acoustic emissions generated by their driving behavior through the human-machine interface. The control unit communicates with the driver to suggest modifications to driving behavior that would reduce noise emissions, creating a closed-loop system where driving actions are informed by their acoustic consequences.
Solution Approach 2:
The control unit acts as an intermediary between the driver's operating commands and the resulting acoustic emissions. It translates driver intent into optimized engine operation that minimizes noise while maintaining performance, and communicates the acoustic impact back to the driver, mediating the relationship between driving behavior and noise pollution.
3Object-affected harmful factors
If real-time adjustments of air-fuel mixture and engine revolutions are implemented, then noise emissions are minimized, but system complexity increases with control units, sensors, and memory units
Solution Approach 1:
The system reduces real-time complexity by performing the complex measurement and optimization work in advance. The acoustic emission map with optimal operating conditions is pre-calculated and stored in memory during the characterization phase, allowing the control unit to simply retrieve and apply pre-determined optimal settings during vehicle operation rather than performing complex real-time optimization.
4Extent of automation
If acoustic emission maps are created through pre-measurement and storage, then real-time noise optimization is enabled, but measurement and characterization processes become more complex and time-consuming
Solution Approach 1:
The system segments the noise optimization process into two distinct phases: an offline characterization phase where the acoustic emission map is created through systematic measurement of different operating conditions, and an online operation phase where the control unit simply retrieves and applies pre-stored optimal settings. This segmentation moves the complex measurement work to a separate development stage.
Data Source
AI summary
A transport vehicle (1) comprising: —a heat engine (8) operable at a number of revolutions varying between a minimum number and a maximum number; —an adjusting device (52) configured to adjust an infeed flow of air-fuel mixture to the heat engine (8); —at least one on-board memory unit (61) in which an acoustic emission map (70) of the transport vehicle (1) is stored, wherein for each data pair comprising a first data item correlated to an operating condition of the adjusting device (52) and a second data item correlated to the number of engine revolutions, the acoustic emission map (70) associates, as a function of the first data item and as a function of the second data item, a third data item correlated to an acoustic emission measurement by at least one acoustic sensor (S1) external to the transport vehicle (1) and arranged at a separation distance from the transport vehicle (1).