Electric Machine Torque Control During Engine Diagnostic Testing
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Solution Overview
Problem
In hybrid electric vehicles, diagnostic testing often requires the internal combustion engine to run for extended periods, even when electric traction is sufficient, leading to unnecessary fuel consumption and emissions.
Innovation Solution
A control system that manages the torque output of electric machines to allow vehicle drive torque demands to be met while the internal combustion engine operates within specific torque thresholds during diagnostic testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the internal combustion engine is kept running for diagnostic testing, then diagnostic testing can be performed, but fuel consumption increases and emissions are generated
Solution Approach 1:
The control system dynamically adjusts the torque output parameter of the internal combustion engine to maintain it within a predetermined threshold range during diagnostic testing. This parameter change allows the engine to run at optimized levels that satisfy diagnostic requirements while minimizing fuel consumption and emissions.
2Reliability
If the internal combustion engine is kept running for diagnostic testing, then diagnostic testing can be performed, but emissions are generated
Solution Approach 1:
The control system adjusts the engine torque parameter to remain within a predetermined threshold, which minimizes emissions while still allowing diagnostic testing to complete successfully.
3Power
If the internal combustion engine is operated to meet vehicle drive torque demand, then vehicle propulsion is provided, but the engine cannot be switched off during electric-only operation
Solution Approach 1:
The control system dynamically adjusts the torque output of the internal combustion engine based on real-time vehicle drive torque demands and diagnostic testing requirements. This dynamic control allows the engine to operate only when necessary and at optimized torque levels, enabling seamless transitions between engine-on and engine-off states while meeting power demands.
Solution Approach 2:
The internal combustion engine serves multiple functions: providing vehicle propulsion when needed and serving as a test subject for diagnostic testing. The control system manages the engine's dual role by adjusting torque output to satisfy both vehicle power demands and diagnostic requirements, allowing the same component to fulfill different functions at different times.
Data Source
AI summary
Aspects of the present invention relate to a method (400) and to a control system (208) for controlling at least one electric machine (212, 216) of a vehicle (10) to support diagnostic testing of a vehicle system (30) comprising an internal combustion engine (202), wherein the method (400) comprises: controlling a torque output (420) of the at least one electric machine (212,216) to allow a vehicle drive torque demand (410) to be met while the internal combustion engine (202) is operated within at least one torque threshold (432) for the diagnostic testing or operated at a torque setpoint (438) for the diagnostic testing.