Hybrid Vehicle Engine Control Unit Emergency Travel

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Solution Overview

Problem

Hybrid vehicles cannot perform emergency travel using engine power when a communication abnormality occurs between the engine control unit and the hybrid control unit, as existing systems typically stop the engine to prevent excessive output, preventing the vehicle from exiting the roadway safely.

Innovation Solution

A control system that includes a first electronic control unit for the engine and a second electronic control unit for the rotary electric machine, allowing the engine to operate with fixed speed, output power, or output torque during communication abnormalities, enabling emergency travel by using engine power while maintaining control over drive power transmission to the wheels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engine control unit stops the engine when communication abnormality occurs, then excessive engine output is prevented, but the vehicle cannot perform emergency travel

Engineering Contradiction:
Improvesafety controlVSAvoidemergency travel capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The engine control unit dynamically switches between normal control mode (receiving commands from hybrid control unit) and abnormal control mode (independent fixed-value control) based on communication status. This dynamic adaptation allows the system to maintain safety while enabling emergency travel capability when communication fails.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system changes the engine operation parameters from variable (controlled by hybrid control unit) to fixed predetermined values when communication abnormality is detected. This parameter change enables the engine to continue operating in a controlled manner for emergency travel while preventing excessive output.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the engine operates independently during communication abnormality, then emergency travel is enabled, but control precision may be reduced

Engineering Contradiction:
Improveemergency travel capabilityVSAvoidcontrol precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system pre-establishes appropriate fixed control values for engine speed, output power, and output torque before communication failure occurs. These predetermined values are optimized to maintain sufficient control precision for emergency travel scenarios, eliminating the need for real-time calculations during abnormal conditions.

Inventive Principle:
Principle #10Preliminary action

3Duration of action of moving object

If the engine maintains fixed operation during communication abnormality, then continuous power supply is ensured, but flexibility in power adjustment is reduced

Engineering Contradiction:
Improvecontinuous operationVSAvoidpower adjustment flexibility
Core Design Contradiction:
Duration of action of moving objectVSAdaptability or versatility

Solution Approach 1:

The control system dynamically adapts its operation mode based on communication status. During normal operation, the engine responds flexibly to hybrid control unit commands. During communication abnormality, it transitions to fixed-value control that ensures continuous stable operation, balancing continuity with appropriate flexibility for emergency conditions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3141445B1Control system for hybrid vehicle
Publication Date: 2018.03.14 TOYOTA JIDOSHA KK
  • EP3141445B1 patent drawingFigure 1
  • EP3141445B1 patent drawingFigure 2~3
  • EP3141445B1 patent drawingFigure 4

AI summary

A control system includes a first electronic control unit (30) configured to control the engine (100) and a second electronic control unit (40) configured to control the rotary electric machine (200, 400). The second electronic control unit (40) is configured to output an engine command signal to the first electronic control unit (30) through communication with the first electronic control unit (30). The first electronic control unit (30) is configured to: control the engine in accordance with the engine command signal received from the second electronic control unit (40), when a communication abnormality with the second electronic control unit (40) does not occur; and execute fixing operation control in which the engine (100) is controlled such that at least one of speed, output power, and output torque of the engine (100) becomes a corresponding fixed value, when the communication abnormality with the second electronic control unit (40) occurs.