Hybrid Powertrain Control System for Shifting Stability
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Solution Overview
Problem
Existing powertrain systems with electro-mechanical transmissions face challenges in efficiently managing transmission operating range states and engine states to optimize fuel economy, torque output, and battery state-of-charge, particularly under varying operating conditions and torque demands, leading to frequent and undesirable shifting events.
Innovation Solution
A control system that determines current and potential transmission operating range states and engine states, weights preferability factors, and selectively commands changes based on operator torque requests, using a biasing cost function to stabilize shifting and minimize power loss, thereby optimizing the balance between fuel economy, torque output, and battery state-of-charge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the transmission operating range state and engine state are frequently changed to optimize fuel economy and torque output, then the system adaptability improves, but the shifting stability deteriorates leading to frequent undesirable shifting events
Solution Approach 1:
The control system dynamically adjusts transmission operating range state and engine state based on real-time operating conditions. The method evaluates multiple potential states and selectively commands changes based on operator torque requests and preferability factors, enabling the system to adapt dynamically while maintaining stability through controlled transition criteria.
2Power
If the transmission operating range state is changed frequently to meet varying torque demands, then the torque output responsiveness improves, but the power loss increases due to frequent shifting events
Solution Approach 1:
The control system determines potential transmission operating range states and engine states in advance by evaluating preferability factors associated with different states. By pre-assessing which state changes would be beneficial based on current operating conditions and operator torque requests, the system can execute transitions more efficiently with reduced power loss.
3Ease of operation
If the transmission operating range state changes are stabilized to reduce frequent shifting, then the drivability improves, but the torque output optimization deteriorates under varying operating conditions
Solution Approach 1:
The control system continuously monitors current transmission operating range state and engine state, along with operator torque requests, to determine preferability factors for potential state changes. This feedback mechanism ensures that shifting stabilization does not compromise torque output optimization, as the system adjusts states based on real-time conditions and operator demands.
Data Source
AI summary
A powertrain system includes an engine mechanically coupled to an electro-mechanical transmission selectively operative in one of a plurality of transmission operating range states and one of a plurality of engine states. A method for controlling the powertrain system includes determining a current transmission operating range state and engine state, determining at least one potential transmission operating range state and engine state, providing an operator torque request, determining preferability factors associated with the current transmission operating range state and engine state, and potential transmission operating range states and engine states, preferentially weighting the preferability factors for the current transmission operating range state and engine state, and selectively commanding changing the current transmission operating range state and engine state based upon the preferability factors and the operator torque request.