Onboard Network Redundancy With Priority Traffic Switching

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Solution Overview

Problem

In on-board network systems, communication disturbances can cause jams in communications from integrated controllers or domain controllers to ECUs, leading to loss of main functions.

Innovation Solution

Each control device is connected via at least two communication paths, with traffic adjusted according to priority orders based on communication data types, ensuring continued functionality even if one path is disturbed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single communication path is used in the hierarchical network, then the device complexity is reduced, but the reliability deteriorates when communication disturbance occurs

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidnetwork configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The network is divided into multiple domains with separate domain controllers managing different functional areas. Each domain can operate independently, so communication disturbances in one domain do not affect others. This segmentation maintains reliability while keeping each domain's complexity manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a multi-dimensional communication architecture by adding alternative communication paths and hierarchical domain structures. When the primary communication path fails, data can transmit through alternative routes or via domain controller hierarchies, effectively adding spatial redundancy without proportionally increasing overall system complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple communication paths are provided for redundancy, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvenetwork reliabilityVSAvoidcommunication path complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple communication paths are organized into separate domains with dedicated domain controllers. This segmentation allows redundancy to be implemented in a structured manner where each domain manages its own communication paths independently, reducing the overall complexity of managing multiple paths across the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Domain controllers act as intermediaries that manage and coordinate communication between different domains and paths. These intermediaries abstract the complexity of multiple communication paths, providing a simplified interface for ECUs while maintaining reliable redundant communication paths underneath.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If traffic is adjusted according to priority order during communication disturbance, then the loss of main functions is reduced, but the control complexity increases

Engineering Contradiction:
Improvemain function availabilityVSAvoidtraffic control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Priority orders for different communication data types are predetermined and stored in the domain controllers and ECUs. When communication disturbance occurs, the system immediately applies these pre-established priority rules without requiring complex real-time decision-making, thus reducing control complexity while ensuring main functions are maintained.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The traffic adjustment mechanism dynamically switches between different communication paths and priority levels based on the detected disturbance. The system adapts its communication strategy in real-time by activating alternative paths and applying priority-based filtering, maintaining main function availability without requiring permanently complex control logic.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3940999B1Onboard network system
Publication Date: 2023.11.08 MAZDA MOTOR CORP
  • EP3940999B1 patent drawingFigure 1
  • EP3940999B1 patent drawingFigure 2
  • EP3940999B1 patent drawingFigure 3

AI summary

An on-board network system includes an arithmetic unit (100) and a plurality of control devices (61 to 64 and 81 to 83) connected to the arithmetic unit (100) via a communication network. The communication network is configured such that each of the control devices (61 to 64 and 81 to 83) are communicative with the arithmetic unit (100) and/or other one(s) of the control devices via at least two communication paths. In each of the communication paths, a priority order of communications is determined according to a type of communication data. If a communication disturbance is detected in one of the communication paths, the arithmetic unit (100) or one(s) of the control devices (61 to 64 and 81 to 83) adjusts the traffic of the communication data in accordance with the priority of the other one of the communication paths.