Vehicle ECU Communication With Relay-Aware Delay Timing
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Solution Overview
Problem
Conventional vehicle communication systems with relay stations have communication delay times that increase with the number of relay stations, making it difficult to achieve high responsivity.
Innovation Solution
A vehicle communication system with synchronous and asynchronous communication buses, where ECUs determine a transmission standby time based on the activation time of the closest relay ECU, and transmit control signals after this standby time has elapsed, using activation instructions repeatedly at predetermined intervals for asynchronous buses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the delay time is uniformly set in accordance with the number of interposed relay stations, then the communication system can operate with simple delay calculation, but the margin time included in the delay time increases as the number of relay stations increases, making it difficult to achieve high responsivity
Solution Approach 1:
The patent segments the delay time into two distinct components: propagation delay (calculated based on the number of relay stations) and margin time (fixed value). This segmentation allows the system to calculate only the necessary propagation delay while maintaining a constant, minimized margin time, thereby reducing overall communication delay without increasing complexity.
Solution Approach 2:
The patent changes the parameter calculation method from uniform delay time setting to differentiated calculation where propagation delay varies with the number of relay stations while margin time remains constant. This parameter change optimizes the balance between reliability (maintaining adequate margin) and responsivity (minimizing total delay).
2Reliability
If the margin time is increased to ensure reliable signal reception through relay stations, then communication reliability improves, but the total communication delay time increases, reducing system responsivity
Solution Approach 1:
The patent applies partial action by setting the margin time to the minimum necessary value rather than increasing it excessively. This allows the system to maintain adequate signal reception reliability while avoiding unnecessary delay accumulation, achieving optimal responsivity.
3Adaptability or versatility
If the number of relay stations is increased to extend communication range, then the system can cover more distant ECUs, but the communication delay time increases, reducing system responsivity
Solution Approach 1:
The patent implements dynamic delay time adjustment where the propagation delay component automatically adapts to the number of relay stations in the signal path. This allows the system to extend communication range by adding relay stations while maintaining optimized delay times through dynamic recalculation based on the actual network topology.
Data Source
AI summary
A vehicle communication system includes a plurality of ECUs connected by the communication network including a plurality of communication transmission lines. Each of the ECUs includes an identification unit that identifies a target ECU to be a communication partner, and a relay transmission line and a relay ECU through which communication with the target ECU is routed, a standby time determination unit that determines a transmission standby time based on information on the relay ECU, the transmission standby time being a time from transmission of an activation instruction to another one of the ECUs closest to the ECU along the relay transmission line to transmission of a control signal toward the target ECU, and a communication unit that transmits the control signal after an elapse of the transmission standby time after transmitting the activation instruction to the relay transmission line closest to the ECU.