LIN Bus Slave Module Multi-Speed Adaptation

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Solution Overview

Problem

The LIN protocol's fixed communication speed limits its compatibility with vehicle equipment operating at different speeds, as there is no established method for data transmission from slave to master, restricting the coexistence of modules with varying communication speeds on the same bus.

Innovation Solution

A data transmission system where the master module transmits data at multiple speeds, and each slave module determines the transmission speed by analyzing the break signal duration and synchronization frequency, allowing it to recognize and respond to messages intended for it, thereby enabling operation of modules at different speeds on the same LIN bus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the LIN bus uses a fixed communication speed according to the standard, then the protocol compatibility and stability are maintained, but the ability to support multiple transmission speeds and coexist with different vehicle equipment is limited

Engineering Contradiction:
Improvecompatibility with equipment at different speedsVSAvoidcomplexity of speed adaptation mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The slave module dynamically adapts its reception speed to match the master module's transmission speed by detecting the break signal duration and synchronization frequency. This dynamic speed adjustment enables the system to support multiple transmission speeds (2400, 9600, 19200 bauds) while maintaining protocol compatibility, resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the reception speed parameter of the slave module based on detected transmission parameters. By measuring the break signal duration and synchronization frequency, the slave module identifies the master's transmission speed and adjusts its reception clock accordingly, enabling multi-speed operation without requiring complex hardware modifications.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the master module transmits data at variable speeds, then the communication flexibility and compatibility with different equipment are improved, but the difficulty of determining transmission speed and ensuring accurate reception increases

Engineering Contradiction:
Improvevariable transmission speed capabilityVSAvoiddifficulty of determining transmission speed
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The master module transmits preliminary identification information (break signal duration and synchronization frequency) before the actual data transmission. The slave module uses this preliminary information to determine the transmission speed and configure its reception parameters in advance, making speed detection straightforward and accurate without requiring complex real-time analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The slave module provides feedback by monitoring the break signal and synchronization frequency to automatically determine the transmission speed. This feedback mechanism enables the slave to adapt its reception parameters based on the master's transmission characteristics, simplifying the speed detection process while maintaining variable speed capability.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If slave modules operate at fixed baud rates, then the simplicity of operation and manufacturing is maintained, but the ability to recognize and process data from masters transmitting at different speeds is lost

Engineering Contradiction:
Improveease of slave module operationVSAvoiddata recognition accuracy at varying speeds
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The slave module automatically determines the transmission speed by itself through detecting the break signal duration and synchronization frequency, and automatically adjusts its reception parameters accordingly. This self-service capability maintains operational simplicity while ensuring reliable data recognition across different transmission speeds, eliminating the need for manual configuration or complex external control.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP1760952B1Method for controlling the transmission speed on a LIN bus
Publication Date: 2012.01.18 VALEO SYST THERMIQUES SAS
  • EP1760952B1 patent drawingFigure 1~2
  • EP1760952B1 patent drawingFigure 3

AI summary

The system has slave modules each comprising a determining unit for determining a baud rate of data during emission of the data, where the data is emitted on a serial communication bus by a master module at different baud rates. Each slave module has a recognizing unit that recognizes the data if the baud rate of the data is equal to the baud rate associated to the corresponding slave module and discards the data if the baud rate of the data is different. Independent claims are also included for the following: (1) a method for transmitting data between a master module and slave modules (2) a computer program comprising instructions for executing steps of a data transmitting method.