CAN Transceiver Emulating Error Management for FD Coexistence

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Solution Overview

Problem

Existing CAN bus systems face challenges in seamlessly transitioning to CAN FD mode while maintaining compatibility with older CAN nodes, as current techniques either require hardware and software upgrades or are limited to offline use.

Innovation Solution

A CAN transceiver device with a traffic control system that detects classic CAN traffic and emulates error management protocols, allowing it to disconnect from the bus when CAN FD traffic is detected, enabling coexistence with classic CAN protocol controllers without generating errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If CAN FD traffic is transmitted on the bus, then higher data rates are achieved, but classic CAN controllers generate bus errors and become error passive

Engineering Contradiction:
Improvedata rateVSAvoiderror state of classic CAN controllers
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces an intermediary device that sits between the CAN FD transceivers and the classic CAN controllers. This intermediary monitors the bus traffic, detects CAN FD frames, and injects artificial error flags to classic CAN controllers when CAN FD traffic is present. This prevents the classic controllers from entering error passive state due to actual bus errors, while still allowing CAN FD communication to proceed at high speeds.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If all ECUs are upgraded to CAN FD compatible hardware and software, then CAN FD communication is enabled, but system complexity and upgrade requirements increase

Engineering Contradiction:
ImproveCAN FD compatibilityVSAvoidhardware and software upgrade requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs an intermediary device that acts as a protocol translator and adapter. This intermediary handles the complexity of CAN FD protocol interpretation and error management, allowing classic CAN controllers to coexist with CAN FD transceivers without requiring upgrades to the classic controllers themselves. The intermediary absorbs the complexity of supporting both protocols simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The intermediary device is designed to be multi-functional, supporting both classic CAN and CAN FD protocols simultaneously. It can detect CAN FD frames, generate artificial error flags for classic controllers, and manage traffic from multiple transceivers with different protocol capabilities, thereby providing universal compatibility without requiring all ECUs to be upgraded.

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

3Ease of manufacture

If passive partial networking transceivers are used to hide CAN FD traffic, then implementation is simplified, but CAN FD communication cannot occur during runtime

Engineering Contradiction:
Improveimplementation simplicityVSAvoidruntime CAN FD communication capability
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent uses an intermediary device that actively manages protocol translation during runtime operations. Unlike passive transceivers that only work during FLASH-ing, this intermediary continuously monitors bus traffic and dynamically injects error flags when CAN FD frames are detected, enabling real-time coexistence of classic CAN and CAN FD communication without requiring system shutdown or reconfiguration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2985955B1Controller area network (CAN) device and method for emulating classic can error management
Publication Date: 2019.06.12 NXP BV
  • EP2985955B1 patent drawingFigure 1
  • EP2985955B1 patent drawingFigure 2
  • EP2985955B1 patent drawingFigure 3A

AI summary

Embodiments of a device and method are disclosed. In an embodiment, a CAN device is disclosed. The CAN device includes a transmit data (TXD) input interface, a TXD output interface, a receive data (RXD) input interface, an RXD output interface and a traffic control system connected between the TXD input and output interfaces and between the RXD input and output interfaces. The traffic control system is configured to detect the presence of classic CAN traffic on the RXD input interface and if the presence of classic CAN traffic is detected on the RXD input interface, emulate an error management protocol of a classic CAN controller in response to signals received on the TXD input interface.