Time Division Multiplexing for Active Noise Cancellation Data Bus

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Solution Overview

Problem

Active noise cancellation (ANC) systems in vehicles require extensive electrical wiring due to the need for multiple data channels, which increases complexity and cost, and existing solutions do not efficiently manage noise cancellation with limited channels.

Innovation Solution

Implementing a time division multiplexing (TDM) scheme that allows multiple signals from accelerometers, microphones, and audio systems to be transmitted on a single data channel, using a first controller to generate a multiplexed stream and a second controller to separate the information for ANC functionality, reducing the need for additional channels while maintaining high performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple data channels are used to transmit signals from accelerometers, microphones, and audio systems, then the ANC system performance is maintained, but the electrical wiring complexity and cost increase

Engineering Contradiction:
ImproveANC system performanceVSAvoidelectrical wiring complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple data channels into a single data bus by implementing time-division multiplexing. The first controller aggregates data from accelerometers, microphones, and audio systems onto one communication bus, eliminating the need for separate electrical wiring for each channel while maintaining all necessary data transmission capabilities for ANC functionality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single data bus is designed to handle multiple functions simultaneously - transmitting data from various sensors (accelerometers, microphones), audio system information, and control signals all through one universal communication channel. This multi-functional approach replaces multiple dedicated wiring channels with a single versatile data bus

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If a single data channel is used to transmit multiplexed data, then the electrical wiring is reduced, but the data transmission bandwidth requirement increases

Engineering Contradiction:
Improveelectrical wiringVSAvoiddata transmission bandwidth
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The system employs time-division multiplexing where data from different sources is transmitted in periodic time slots over the single data bus. Each sensor and system communicates at specific intervals, allowing the bus to handle high total bandwidth requirements through time-based segmentation rather than requiring simultaneous high-speed transmission

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The data transmission system is designed to be dynamic, adjusting the timing and priority of data transmission based on current ANC requirements. The multiplexing scheme can dynamically allocate bandwidth to different data sources depending on which sensors or systems currently need the most attention for effective noise cancellation

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4170649B1Active noise cancellation system and method with time division multiplexing
Publication Date: 2024.11.27 HARMAN INT IND INC
  • EP4170649B1 patent drawingFigure 1~2
  • EP4170649B1 patent drawingFigure 3
  • EP4170649B1 patent drawingFigure 4

AI summary

In at least one embodiment, an active noise cancellation system. The system includes a first controller, a data bus, and a second controller. The first controller receives first information from a plurality of noise sensing devices and second information from an audio system. The first controller employs a time division multiplexing scheme to generate a multiplexed stream of data including the first information and the second information. The data bus transmits the multiplexed stream of data on a single data channel. The second controller receives the multiplexed stream of data on the single data channel and separates the first information from the second information on the multiplexed stream of data to perform ANC functionality.