Hybrid Vehicle Torque Control for Engine Diagnostic Testing
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Solution Overview
Problem
In hybrid electric vehicles, diagnostic testing requires the internal combustion engine to remain running for prolonged periods, even when sufficient electrical energy is stored, which is dissatisfying for vehicle owners and wastes fuel and emissions.
Innovation Solution
A control system that manages the torque output of electric machines to allow diagnostic testing without interruption, enabling the engine to be switched off sooner by operating within specific torque thresholds or setpoints, using electric machines to supplement or counteract engine torque as needed.
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 is wasted and emissions increase
Solution Approach 1:
The control system changes the operating parameters of the internal combustion engine by constraining it to specific torque thresholds (e.g., operating between 0-50 Nm) during diagnostic testing. This parameter change allows the engine to run in a low-torque state that consumes less fuel while still enabling diagnostic tests to be performed, thereby resolving the contradiction between completing diagnostics and reducing fuel consumption.
2Reliability
If the internal combustion engine is kept running for diagnostic testing, then diagnostic testing can be performed, but emissions increase
Solution Approach 1:
The control system changes the operating parameters of the internal combustion engine by constraining it to specific torque thresholds (e.g., operating between 0-50 Nm) during diagnostic testing. This parameter change allows the engine to run in a low-torque state that produces fewer emissions while still enabling diagnostic tests to be performed, thereby resolving the contradiction between completing diagnostics and reducing emissions.
3Reliability
If the internal combustion engine is kept running for diagnostic testing, then diagnostic testing can be performed, but vehicle owner satisfaction decreases
Solution Approach 1:
The control system changes the operating parameters of the internal combustion engine by constraining it to specific torque thresholds (e.g., operating between 0-50 Nm) during diagnostic testing. This parameter change allows the engine to run in a low-torque state that is less noticeable to the vehicle owner (reducing vibration and noise) while still enabling diagnostic tests to be performed, thereby resolving the contradiction between completing diagnostics and maintaining owner satisfaction.
Data Source
AI summary
Aspects of the present invention relate to a method (400) and to a control system (208) for controlling at least 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 toque threshold (432) for the diagnostic testing or operated at a torque setpoint (438) for the diagnostic testing.