CAN Bus Adapter Device for Mixed Protocol Integration

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Solution Overview

Problem

Existing CAN bus systems face compatibility issues between CAN and CAN FD subscriber stations, leading to errors and the need for replacing all CAN controllers when integrating CAN FD components, which is costly and disruptive to ongoing communication.

Innovation Solution

A subscriber station with an adapter device that evaluates and modifies messages between CAN and CAN FD protocols, allowing seamless operation of both types of components without errors, using a transceiver with additional logic to interpret and convert messages, thereby acting as a bridge between different network protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If CAN FD subscriber stations are introduced into a CAN bus system to increase data rate, then the data transmission speed is improved, but compatibility errors occur between CAN and CAN FD subscriber stations

Engineering Contradiction:
Improvedata transmission speedVSAvoidcommunication reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces an adapter device as an intermediary component between CAN and CAN FD subscriber stations. This adapter translates and adapts the communication protocols, allowing CAN FD high-speed messages to be transmitted through a CAN bus network without causing errors. The adapter acts as a bridge that mediates between the two different protocol standards, enabling seamless integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the subscriber station into distinct functional components: a CAN controller, a transceiver, and an adapter device. This segmentation allows each component to handle specific tasks - the CAN controller manages protocol logic, the transceiver handles physical layer signaling, and the adapter manages protocol translation. This modular approach enables flexible configuration and maintains compatibility with existing CAN networks.

Inventive Principle:
Principle #1Segmentation

2Speed

If all CAN controllers are replaced to enable CAN FD operation, then the system supports higher data rates, but the cost and complexity of the system increases

Engineering Contradiction:
Improvedata transmission speedVSAvoidsystem complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The adapter device provides multi-functionality by supporting both CAN and CAN FD protocols simultaneously. It can translate CAN FD messages to CAN format and vice versa, allowing the same hardware infrastructure to support multiple protocol standards. This universality eliminates the need for separate CAN and CAN FD networks, reducing overall system complexity.

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

Solution Approach 2:

The patent uses software-based CAN controllers that can be configured to emulate different protocol behaviors. Instead of requiring dedicated hardware for each protocol variant, the system uses configurable software copies of the controller logic that can adapt to different protocol requirements through configuration rather than physical replacement.

Inventive Principle:
Principle #26Copying

3Ease of manufacture

If existing CAN subscriber stations are used in a mixed CAN/CAN FD network, then cost is reduced, but errors occur due to inability to interpret high-rate middle data segment

Engineering Contradiction:
Improvecost effectivenessVSAvoidcommunication reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The adapter device serves as a mediator that protects existing CAN subscriber stations from protocol incompatibility issues. It translates CAN FD messages into a format that legacy CAN stations can understand, preventing error frames from being generated. This allows cost-effective use of existing hardware while maintaining communication reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements error detection and correction mechanisms in advance. The adapter device preemptively translates and adapts messages before they reach the CAN subscriber stations, preventing errors from occurring in the first place. This prior cushioning approach avoids the need for expensive error recovery procedures.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3055977B1Subscriber station in a bus system and method for operating a subscriber station
Publication Date: 2021.04.07 ROBERT BOSCH GMBH
  • EP3055977B1 patent drawingFigure 1~2
  • EP3055977B1 patent drawingFigure 3
  • EP3055977B1 patent drawingFigure 4~5

AI summary

An adaptation device (12) for a bus system (1; 2) and a method for operating a CAN subscriber station (10; 30) and a CAN FD subscriber station (20) in a bus system (1) are shown. The adaptation device (12) comprises a reception path evaluation unit (121) for evaluating received messages (45, 46, 47) in relation to whether or not the received message (45, 46, 47) is a message (46) based on the CAN FD specification, and a reception path output unit (122) for outputting a dummy frame to a communication control device (11) of a CAN subscriber station (10; 30) for the bus system (1) if the result of an evaluation by the reception path evaluation unit (121) is that the received message (45, 46, 47) is a message (46) based on the CAN FD specification. Alternatively or additionally, the adaptation device (12) may have: a transmission path evaluation unit (123) for evaluating whether or not an error frame is sent in the transmission path of a communication control device (11) of a CAN subscriber station (10; 30) for the bus system (1), and a transmission path output unit (124) for blocking an error frame if the transmission path evaluation unit (123) has identified an error frame in the transmission path.