CAN Traffic Isolation for Mixed CAN FD and Legacy Nodes
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Solution Overview
Problem
Existing solutions fail to enable seamless coexistence of CAN FD and traditional CAN nodes within the same automotive network during runtime, requiring hardware and software upgrades or being limited to island solutions.
Innovation Solution
A CAN transceiver with a traffic control system that detects CAN FD traffic and disconnects the TXD and RXD interfaces when CAN FD mode is detected, allowing the CAN protocol controller to avoid error states and generate dummy frames, enabling concurrent operation with traditional CAN nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If passive partial networking transceivers are used to hide CAN FD traffic from old CAN engines, then implementation is easy and early availability is achieved, but CAN FD communication cannot be used concurrently with old nodes during normal operation
Solution Approach 1:
The patent introduces a gateway device as an intermediary between CAN FD nodes and legacy CAN nodes. The gateway translates CAN FD traffic into legacy CAN-compatible traffic, allowing both node types to coexist and communicate concurrently on the same network without requiring hardware upgrades to all nodes.
2Adaptability or versatility
If an active stand-alone CAN FD controller is used with an interface to a CAN FD bridge, then CAN FD can be run throughout the automobile, but hardware and software upgrades are required in each ECU
Solution Approach 1:
The patent segments the network into three distinct parts: legacy CAN nodes, CAN FD nodes, and a gateway device. This segmentation allows each segment to operate with its appropriate protocol without requiring upgrades to all ECUs, thereby achieving network-wide CAN FD capability while minimizing hardware and software changes.
3Reliability
If microcontrollers are upgraded with a new CAN FD block and old CAN engines are modified to be silent, then the impact on integrated CAN IP is small, but all microcontrollers must undergo hardware and software upgrade and network-wide CAN FD cannot be implemented
Solution Approach 1:
The gateway acts as a mediator that allows legacy CAN engines to remain silent and unchanged while still enabling network-wide CAN FD operation. The gateway handles all CAN FD traffic translation, so legacy nodes don't need to be upgraded or modified, yet CAN FD functionality is achieved across the entire network.
4Stability of the object's composition
If an alternative standard with inverse level scheme is used, then backward compatibility is achieved and old CAN nodes do not recognize fast traffic, but all nodes supporting CAN FDC need new CAN protocol engines plus a second CAN transceiver
Solution Approach 1:
Instead of requiring all nodes to implement the complex inverse level scheme with dual transceivers, the patent uses a gateway as an intermediary that handles the protocol translation. This maintains backward compatibility with legacy nodes while avoiding the need for expensive dual transceiver hardware in every ECU.
Data Source
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AI summary
Embodiments of a device and method are disclosed. In an embodiment, a CAN device (300) is disclosed. The CAN device (300) includes a TXD input interface (342), a TXD output interface (320), an RXD input interface (320), an RXD output interface (340), and a traffic control system (350) connected between the TXD input and output interfaces and between the RXD input and output interfaces. The traffic control system (350) is configured to detect (352) the presence of CAN Flexible Data-rate (FD) traffic on the RXD input interface (320) and if the traffic control system detects the presence of CAN FD traffic on the RXD input interface (320), disconnect (356) the RXD input interface from the RXD output interface and disconnect (358) the TXD input interface from the TXD output interface.