Hybrid Drivetrain Torque Compensation Using Virtual Clutch Torque
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Solution Overview
Problem
In hybrid powertrains, permanent torque errors from the heat engine during driving phases like mountain driving can lead to premature discharge of the electric traction motor's battery, causing inconvenience.
Innovation Solution
A method that compares the target torque with the actual torque sum from the electric motor and heat engine, applying an additional torque and adding a virtual compensatory term to the clutch torque to compensate for heat engine torque differences, thereby limiting electric motor intervention and preventing battery discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor compensates for permanent torque errors from the heat engine, then the target torque is maintained, but the battery discharges prematurely
Solution Approach 1:
The system performs preliminary identification of permanent torque errors during a first driving phase before they cause battery depletion. By detecting the error magnitude in advance and adapting the compensation strategy proactively, the system prevents premature battery discharge while maintaining torque accuracy when needed.
Solution Approach 2:
The compensation strategy dynamically adapts based on detected torque errors. The system switches between different compensation modes (full compensation, partial compensation, or no compensation) depending on the magnitude of the permanent error and battery state, optimizing the balance between torque accuracy and energy conservation.
2Ease of operation
If the electric motor continuously compensates for torque differences, then the driver's acceleration desire is met, but the battery is emptied during mountain driving phases
Solution Approach 1:
The system continuously monitors the actual torque from the heat engine, compares it with the setpoint torque, and uses this feedback to detect permanent errors. Based on this feedback and battery state information, the control strategy is automatically adjusted to prevent battery depletion while maintaining acceptable driving performance.
Solution Approach 2:
The system changes the compensation parameter (electric motor torque contribution) based on detected permanent errors and battery state. When a permanent error is identified, the system adjusts the setpoint torque or compensation level to reduce electric motor intervention, thereby extending battery operating duration during challenging driving phases.
Data Source
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AI summary
The invention relates to a method for compensating for torque production errors of a combustion engine (11), comprising - a step of comparison between a target torque corresponding to a wish by a driver to accelerate and an actual torque equal to the sum of a torque applied by the electric traction motor (12) and a torque transmitted by the clutch (16) corresponding to the torque produced by the combustion engine (11), and - a step of applying an over-torque by the electric traction motor (12) if the actual torque is different from the target torque on account of a difference between the torque produced by the combustion engine (11) and a setpoint torque of the combustion engine (11), in order to reach the target torque, - said method additionally comprising a step of adding a virtual compensatory term into the torque transmitted by the clutch (16).