Active Brake Noise Damping via Interfering Sound
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing noise damping technologies in motor vehicles are limited in their efficiency across narrow frequency intervals, failing to effectively mitigate the noise generated by braking systems, which affects passenger acoustic comfort.
Innovation Solution
An automotive active noise damping system that utilizes vibration sensors, such as piezoelectric accelerometers, to sense braking vibrations and an electronic control unit to compute and diffuse an interfering sound that disruptively cancels the noise, integrating with the vehicle's audio system through an on-board network, eliminating the need for expensive sound sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If active noise control is used to damp braking noise, then acoustic comfort is improved, but the system complexity increases due to requiring vibration sensors, electronic control units, and integration with audio systems
Solution Approach 1:
The patent uses vibration sensors as intermediaries to detect braking vibrations, which are then processed by an electronic control unit to generate noise cancellation signals. The audio system serves as another intermediary to deliver the cancellation signals to the passenger compartment, effectively mediating between the braking noise source and the passenger ear without direct contact.
Solution Approach 2:
The patent replaces traditional mechanical soundproofing materials with an active electronic control system that uses vibration sensors, electronic processing, and audio speakers to dynamically cancel braking noise, substituting passive mechanical damping with active electronic control for broader frequency effectiveness.
2Ease of manufacture
If passive soundproofing materials are used to damp noise, then implementation is simpler, but frequency coverage is limited and less effective for braking noise
Solution Approach 1:
The patent employs a dynamic active noise control system that continuously adapts to varying braking conditions and frequency content, unlike static passive soundproofing materials. The electronic control unit processes real-time vibration data and adjusts cancellation signals dynamically to match the changing acoustic environment during braking operations.
Solution Approach 2:
The system changes operational parameters by adjusting the frequency and amplitude of noise cancellation signals based on detected vibration characteristics. The electronic control unit modifies these parameters in real-time to effectively target the specific frequency spectrum of braking noise, which varies with braking intensity and vehicle conditions.
3Measurement precision
If vibration sensors are used to detect braking vibrations, then noise cancellation effectiveness is improved, but the cost increases due to sensor and electronic component requirements
Solution Approach 1:
The system uses the vehicle's existing vibration sensors (such as those already installed for other braking monitoring functions) to detect braking vibrations, allowing the noise cancellation system to leverage existing components rather than requiring entirely new sensors, thereby reducing additional cost while maintaining detection accuracy.
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 system efficiently reduces and potentially cancels braking noise in the passenger compartment by leveraging the sensed vibrations, enhancing acoustic comfort without requiring costly sound sensors, and optimizing noise reduction across a broader frequency range.
Implementation Method 1
vibration sensors, such as piezoelectric accelerometers, to sense braking vibrations
Implementation Method 2
an audio system operable to diffuse sounds in the passenger compartment
Data Source
Figure 1
Figure 2
AI summary
An automotive active brake noise damping system (ABND) to actively damp braking noise perceivable in the passenger compartment of a motor vehicle (MV) comprising a braking system (BS) comprising a plurality of braking assemblies (BA) associated with wheels (W) of the motor vehicle (MV). The automotive active brake noise damping system (ABND) comprises a sensory system (SENS) to sense quantities that allow braking noise perceived in the passenger compartment of the motor vehicle (MV) and generated by the braking assemblies (BA) during braking to be estimated, an audio system (AS) to diffuse sounds in the passenger compartment of the motor vehicle (MV), and an electronic control unit (ECU) connected to the sensory system (SENS) and the audio system (AS), and programmed to control the audio system (AS) based on the quantities sensed by the sensor system (SENS) to actively damp the braking noise perceived in the passenger compartment of the motor vehicle (MV). The sensory system (SENS) comprises vibration sensors (VS), conveniently in the form of piezoelectric accelerators, which are applied to the braking assemblies (BA) to sense the amplitude of the vibrations generated by the braking assemblies (BA) during braking, and the electronic control unit (ECU) is programmed to store a mathematical model, which correlates vibrations generated by the braking assemblies (BA) during braking with corresponding braking noise perceived in the passenger compartment of the motor vehicle (MV) and produced by the braking assemblies (BA) during braking, estimate the braking noise perceived in the passenger compartment of the motor vehicle (MV) and generated by the braking assemblies (BA) of the braking system (BS) during braking as a function of the vibrations generated by the braking assemblies (BA) during braking and sensed by the vibration sensors (VS) applied to the braking assemblies (BA) and of the stored mathematical model, compute an interfering sound to be diffused in the passenger compartment of the motor vehicle (MV) to damp the braking noise perceived in the passenger compartment of the motor vehicle (MV) and generated by the braking assemblies (BA) during braking, and control the audio system (AS) to cause it to diffuse the computed interfering sound.