Active Noise System for Hybrid Electric Vehicle Pedestrian Warning
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Solution Overview
Problem
Hybrid Electric Vehicles face the challenge of providing necessary noise to pedestrians and meeting legislative requirements without the added cost and complexity of external speaker systems, as existing noise modification systems rely on ICE noise which is not present when the vehicle is in electric-only mode.
Innovation Solution
An active noise system with a controller that generates noise replicative of an Internal Combustion Engine (ICE) noise when the ICE is inactive, using noise sensors and speakers integrated into the ICE exhaust system, allowing noise modification based on vehicle parameters like acceleration and pedal position, eliminating the need for additional noise-making systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external speaker systems are added to generate vehicular noise when travelling under electric power, then pedestrian warning capability is improved, but vehicle cost and complexity increase
Solution Approach 1:
The patent combines the pedestrian warning function with the existing active noise modification system by using the same speaker units fitted to the exhaust system. The controller generates artificial ICE-like noise through these speakers when the ICE is inactive, merging two functions (noise modification and pedestrian warning) into a single system rather than adding separate external speakers.
Solution Approach 2:
The active noise system's speaker units are made multi-functional: they serve both to modify exhaust noise when the ICE is active and to generate pedestrian warning noise when the ICE is inactive. This universal use of existing components eliminates the need for dedicated external speaker systems.
2Reliability
If external speaker systems are added to generate vehicular noise when travelling under electric power, then pedestrian warning capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the pedestrian warning function with the existing active noise modification system, utilizing the same speaker units and control infrastructure. This eliminates the need to manufacture and install separate external speaker systems, thereby reducing manufacturing costs while maintaining pedestrian warning capability.
Solution Approach 2:
The existing active noise system serves itself by taking on the additional function of generating pedestrian warning noise. The same controller that manages noise modification during ICE operation now also generates artificial ICE-like noise during electric-only operation, making the system self-sufficient and eliminating additional manufacturing expenses.
3Reliability
If active noise systems use noise waveforms derived from ICE exhaust noise, then noise cancellation or enhancement is achieved, but the system cannot generate appropriate noise when ICE is inactive
Solution Approach 1:
The patent implements dynamic operation of the active noise system based on ICE status. When the ICE is active, the system modifies exhaust noise using waveforms derived from actual exhaust noise. When the ICE is inactive, the system dynamically switches to generating artificial ICE-like noise waveforms. This dynamic adaptation allows the system to maintain effectiveness across different operational modes.
Solution Approach 2:
The controller changes the noise generation parameters based on operational mode. During ICE operation, it processes actual exhaust noise signals for cancellation or enhancement. During electric-only operation, it generates synthetic noise waveforms that replicate ICE characteristics, adjusting frequency content, amplitude, and temporal patterns to match expected ICE noise profiles for different driving conditions.
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 Hybrid Electric Vehicles to produce necessary noise without extra equipment, meeting safety and legislative requirements while reducing costs and complexity by using integrated noise generation within the ICE exhaust system.
Implementation Method 1
The electroacoustical transducer is configured to produce an acoustical signal in dependence on an electrical input signal
Implementation Method 2
the controller is adapted to receive a signal to obtain a reading of noise in the ICE exhaust system
Implementation Method 3
These noise waveforms are typically used to 'cancel out', minimise or suppress native exhaust notes
Data Source
Figure 1
AI summary
Aspects of the present invention relate to an active noise system, a controller for an active noise system, a method and a hybrid electric vehicle. The invention relates to use of an active noise system for providing noise when an ICE is not active.