EV-15 — Vehicle Control Architecture

ASSUMPTION — This lesson introduces the control architecture at the system level. For CAN detail see BMS Academy → BMS-15.

1. Control Units

Unit	Role
VCU	Overall energy/torque coordination
BMS	Battery management
Inverter	Motor control
Brake ECU	Brake/regeneration coordination (ABS/ESC)
Thermal	Cooling/heating
OBC / DC/DC	Charging and 12V
Gateway	Bridge between networks

2. The VCU’s Role

The VCU sends the driver torque request to the inverter, receives battery limits from the BMS, and manages power. Regeneration, thermal, and charging coordination flow through the VCU.

3. Network Technologies

• CAN — low cost, real-time control (ISO 11898).
• CAN FD — higher data rate (up to 64 bytes).
• Automotive Ethernet — high bandwidth (ADAS, OTA).
• LIN — low-cost auxiliary tasks (sensors/actuators).

FACT — Powertrain/control uses CAN/CAN FD; ADAS/infotainment moves to Ethernet for bandwidth.

4. FAQ

What is the relationship between the VCU and the BMS?

FACT — The BMS reports battery limits (SOC/SOH/SOP) to the VCU, which manages torque and power within those limits.

Why is a gateway needed?

FACT — It bridges different networks (CAN, Ethernet) safely, managing speed/protocol differences.

5. Summary

• The VCU performs energy/torque coordination.
• The BMS, inverter, brake, and thermal take distributed roles.
• CAN/CAN FD for control, Ethernet for high bandwidth, LIN for auxiliary tasks.

6. Sources and Verification Note

Network standards are ISO/SAE-referenced.

• ISO 11898, SAE J1715.

Next Lesson

• EV-16 — Software / Control Units: domain, zonal, and central architecture.