Multi-mode Transmission Engine Speed Torque Optimization
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Solution Overview
Problem
Multi-mode powertrain systems face challenges in determining optimal engine speed and torque settings to efficiently manage torque transfer between internal combustion engines and electric machines while considering factors like fuel economy, emissions, and drivability.
Innovation Solution
A method is introduced to select between two search windows to iteratively determine a preferred engine speed and torque by generating candidate operating points within these windows, using a system torque optimization scheme and power cost model to identify the optimum operating point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single large search window is used to find optimal engine operating points, then the search covers all possible operating conditions, but the computational complexity and time required increase significantly
Solution Approach 1:
The patent divides the single large search window into multiple smaller search windows, each covering a specific operating condition range. This segmentation allows the control system to perform targeted searches in relevant regions rather than exhaustively searching the entire operating space, thereby reducing computational complexity while maintaining adequate coverage of important operating conditions.
Solution Approach 2:
The patent implements dynamic selection of search windows based on current operating conditions. The control system adapts which search window to use depending on factors such as vehicle speed, load, and driver behavior, making the search process more efficient by focusing computational resources on the most relevant operating regions rather than using a static, comprehensive search approach.
2Measurement precision
If iterative generation of candidate operating points is performed across the entire operating range, then all possible solutions are evaluated, but the processing time and computational resources increase
Solution Approach 1:
By segmenting the search space into multiple windows, the patent reduces the number of candidate operating points that need to be generated and evaluated in each iteration. This maintains optimization accuracy within each relevant region while significantly reducing the total processing time compared to evaluating the entire operating range.
Solution Approach 2:
The patent performs preliminary selection of appropriate search windows based on current operating conditions before generating candidate operating points. This preliminary action filters out irrelevant regions, so that iterative generation and evaluation are performed only on candidate points that are likely to be optimal, reducing processing time while maintaining accuracy.
3Productivity
If multiple search windows are maintained and selected dynamically, then the system can adapt to different operating conditions efficiently, but the control system complexity increases
Solution Approach 1:
The patent implements dynamic selection logic that automatically chooses the appropriate search window based on current operating conditions such as vehicle speed, load, and driver behavior. This dynamic approach improves operational efficiency by adapting to different scenarios without requiring manual intervention or complex configuration, while the selection logic itself remains relatively simple and rule-based.
Solution Approach 2:
The patent creates a universal search window selection framework that can handle multiple different operating conditions using a standardized set of search windows and selection criteria. This multi-functional approach allows the same control structure to efficiently manage various operating scenarios (acceleration, cruising, deceleration, different loads) without requiring separate control systems for each condition.
Data Source
AI summary
A method for determining a preferred engine speed and a preferred engine torque of a selected operating range state of an electro-mechanical multi-mode transmission configured to transfer torque among an engine, at least one electric machine and a drive includes selecting between of a first search window and a second search window. Each of the first and second search windows includes a two-dimensional search window definable by a first axis having minimum and maximum engine speed values and a second axis having minimum and maximum engine torque values. A plurality of candidate operating points within the selected one of the first and second search windows is iteratively generated. One of the plurality of candidate operating points within the selected one of the first and second search windows is iteratively determined as an optimum operating point.