Engine Order Cancellation System Stability via Dynamic Parameter Adjustment
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Solution Overview
Problem
Current engine order cancellation systems face challenges in stability and robustness due to external disturbances, necessitating improved methods for effectively suppressing acoustic interference signals from motor vehicle drive units.
Innovation Solution
A method that operates an engine order cancellation system by detecting audio signals, generating compensation signals with specific spectral modifications, and adjusting operating parameters such as the forgetting factor and step size to enhance stability and robustness, using acoustic sensors and output devices like loudspeakers to minimize perceptible noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional EOC systems operate with standard parameters, then acoustic interference signals are compensated, but the system becomes susceptible to external disturbances and noise
Solution Approach 1:
The patent applies dynamics by making the operating parameters (forgetting factor λ and adaptation step size μ) adjustable and adaptable rather than fixed. The system can dynamically adjust these parameters in response to changing acoustic conditions and external disturbances, allowing it to maintain stability and robustness while effectively compensating for acoustic interference signals.
Solution Approach 2:
The patent explicitly changes the parameters λ (forgetting factor) and μ (adaptation step size) as key control variables. By modifying these parameters, the system can optimize its performance under different conditions, enhancing its ability to resist external disturbances while maintaining effective compensation of acoustic interference.
2Reliability
If the EOC system adjusts operating parameters to improve stability, then robustness against disturbances increases, but the complexity of system operation increases
Solution Approach 1:
The system performs self-adjustment of its operating parameters based on the detected acoustic environment. The control unit automatically modifies λ and μ without requiring external intervention or complex manual configuration, thereby improving robustness while avoiding the complexity of external control systems.
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously monitors the acoustic interference signals and adjusts its parameters accordingly. This closed-loop approach enables the system to adapt to changing conditions automatically, enhancing robustness while keeping the control logic integrated within the existing EOC architecture.
3Object-generated harmful factors
If the system uses standard compensation signals, then acoustic interference is suppressed, but external noise can mask the compensation effectiveness
Solution Approach 1:
The system performs preliminary detection and analysis of the acoustic environment before generating compensation signals. By pre-characterizing the acoustic interference patterns and adjusting parameters accordingly, the system ensures that compensation signals are optimized from the outset, making them more effective and less susceptible to masking by external noise.
Solution Approach 2:
The system dynamically adjusts the characteristics of compensation signals based on real-time detection of acoustic conditions. This dynamic adaptation allows the compensation signals to maintain their effectiveness even in the presence of varying external noise levels, preventing noise masking while suppressing acoustic interference.
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 results in a more stable and robust operation of the engine order cancellation system, effectively reducing the impact of external disturbances and ensuring acoustic interference signals are imperceptible to vehicle occupants.
Implementation Method 1
detection of corresponding acoustic interference signals by means of a suitable acoustic sensor device or associated acoustic sensor elements
Implementation Method 2
The compensation signals, particularly due to a phase opposite to that of the respective acoustic interference signals, cause a, if necessary complete, suppression of the acoustic interference signals
Data Source
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AI summary
A method for operating an engine order cancellation system (1), comprising the following steps: - capturing all the audio signals (13) which are to be output into a passenger compartment of a motor vehicle (5) by means of an audio output device (12), - generating a sum signal (15) which describes all the captured audio signals (13), - extracting the spectral components (23) of the sum signal (15), which is pre-filtered if necessary, the frequencies of said components (23) corresponding to the frequencies of the acoustic interference signals (3) which are to be compensated or are compensated by the EOC System (1), - modifying the respective extracted spectral components (23) in order to generate modified spectral components (23'), - converting the modified spectral components (23') into an operating parameter of the EOC system (1), - comparing the operating parameter of the EOC system (1) with a comparison operating parameter, - selecting the operating parameter having the most influence on the performance of the EOC system (1) and/or the stability of the EOC system (1), on the basis of the comparison, - operating the EOC system (1) by applying the selected operating parameter.