In-Vehicle ECU Power Relay Control for Selective Startup
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Solution Overview
Problem
Existing in-vehicle network systems struggle with managing the power supply and shutdown of lower control devices due to fixed relationships between intermediate ECUs and managed lower ECUs, making it difficult to finely manage power states and meet requirements for simultaneous startup of ECUs belonging to multiple clusters.
Innovation Solution
An in-vehicle network system with a power management unit and startup management unit in an upper control device that selectively manages relay circuits for lower control devices based on network management messages, allowing for partial networking and fine control of power states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the intermediate ECU supplies power to all lower ECUs when receiving a message, then the lower ECUs can be activated, but it becomes difficult to finely manage power states of individual lower ECUs
Solution Approach 1:
The patent segments the power management control by introducing individual relay circuits for each lower ECU. The upper ECU controls each relay circuit independently, allowing selective power supply to specific lower ECUs based on their operational requirements. This segmentation enables fine-grained power state management while maintaining system-wide coordination through the communication bus.
Solution Approach 2:
The patent implements dynamic power management where the power state of each lower ECU can be changed independently based on real-time operational needs. The upper ECU receives NM messages and dynamically controls relay circuits to transition lower ECUs between power-on and power-off states as required, making the power management system adaptable to varying operational conditions.
2Loss of energy
If the lower ECU is maintained in power-off state until message reception, then power consumption is reduced, but the startup response time may be delayed
Solution Approach 1:
The patent applies preliminary action by keeping lower ECUs in a ready state with power supply lines prepared but relay circuits initially off. When an NM message is received, the upper ECU can immediately activate the required lower ECU by simply closing its relay circuit, eliminating startup delays while maintaining power savings during idle periods. The communication interface remains active to receive wake-up messages.
3Device complexity
If fixed relationships are used between intermediate ECU and lower ECUs, then system structure is simplified, but it becomes difficult to meet requirements for simultaneous startup of ECUs in multiple clusters
Solution Approach 1:
The patent implements universality by enabling the upper ECU to manage power supply to multiple lower ECUs across different clusters through a unified control mechanism. The upper ECU can interpret NM messages and coordinate relay circuit activation to ensure simultaneous startup of lower ECUs belonging to multiple clusters, while maintaining a relatively simple overall system structure.
Data Source
AI summary
An in-vehicle network system includes control devices connected to a communication bus and capable of communicating with each other in a vehicle. The control devices include at least one upper control device and lower control devices. The upper control device includes: a power management unit that turns on and off relay circuits provided in a power supply line of each of the lower control devices; and a startup management unit that receives, on behalf of the lower control devices, a network management message that selectively instructs a startup of the lower control devices transmitted via the communication bus, and instructs the power management unit to turn on a relay circuit provided in the power supply line of the lower control device instructed to start by the network management message, to bring the lower control device instructed to start into a startup state.