Automotive ECU Communication via Dynamic CAN Interface Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing CAN bus communication protocol in automotive electronic control units is prone to failure, leading to operational issues when a single CAN line becomes defective, resulting in potential vehicle shutdowns, despite redundancy solutions being costly and only providing additional functionality during failures.
Innovation Solution
A method involving two communication interfaces with microcontrollers, a diagnostic system, and a message scheduler that includes a logic switch to select and schedule message transmission over one or the other interface based on priority, speed, and recurrence, ensuring continuous communication and increased transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single CAN line is used for communication between electronic control units, then the device complexity and cost are reduced, but the reliability deteriorates because communication fails completely when the CAN line is defective
Solution Approach 1:
The system dynamically switches between one CAN line and two parallel CAN lines based on the operational status of the CAN lines. When both CAN lines are functional, the system uses both in parallel for redundant communication. When one CAN line fails, the system automatically switches to use only the remaining functional CAN line, ensuring continuous communication without requiring permanent dual-line configuration
Solution Approach 2:
The system changes the operational parameters of the communication interface based on detected conditions. The microcontroller monitors the status of each CAN line and adjusts the number of active communication channels from one to two, and vice versa, based on diagnostic results. This parameter change allows the system to optimize between reliability and complexity based on actual operational needs
2Reliability
If two CAN lines are used in parallel for redundant communication, then the reliability is improved, but the device complexity and cost increase
Solution Approach 1:
Rather than permanently configuring two CAN lines, the system dynamically activates one or two CAN lines based on real-time diagnostic results. The microcontroller monitors CAN line status and switches between single-line and dual-line modes, providing redundancy only when needed while reducing complexity when redundancy is not required
Solution Approach 2:
The system includes self-diagnostic capabilities where the microcontroller automatically monitors the functionality of each CAN line and autonomously decides which communication interface to use. The diagnostic system detects defects and the microcontroller automatically switches communication paths without external intervention, making the system self-managing regarding communication reliability
3Reliability
If a redundant communication interface is implemented, then the reliability is improved during failure scenarios, but the productivity during normal operation is reduced due to no additional functionality
Solution Approach 1:
The second CAN line serves dual purposes: it provides redundancy during failure scenarios and simultaneously increases communication throughput during normal operation. By using both CAN lines in parallel when both are functional, the system achieves faster message transmission while maintaining the ability to switch to single-line mode if needed, making the redundant interface beneficial in both failure and normal conditions
Data Source
AI summary
A method of communication between at least two automotive electronic control units, including two communication interfaces between the units enabling messages to be sent via one or the other of the interfaces, the units each including a microcontroller linked to the interfaces managing sending and receiving of the messages according to a given priority level, transmission speed and recurrence, and including a diagnostic system for checking the functionality of the interfaces, a message scheduler, the method including: introducing a logic switch into each microcontroller, for selecting one or the other interface; checking that neither interface is defective; scheduling by the scheduler the sending of messages in succession via one or the other of the interfaces; selecting one or the other of the interfaces to send the messages scheduled by the message scheduler; and sending the scheduled messages in succession by one or the other of the interfaces.