Engine Control Device Search Axis Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine control systems face accuracy issues in lean burn regions due to variations in air density with temperature and pressure, leading to inaccuracies in controlling engine operations based on requested torque, especially when the actual amount of intake air does not proportionally increase with torque.
Innovation Solution
An engine control device that detects actual intake air and requested torque, using a search axis value map to determine either the actual intake air or requested torque as the search axis in different regions, allowing for precise control target value acquisition by interpolating between grid points in the device control map.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If target torque is used as a search axis in lookup tables for lean burn control, then control simplicity is improved, but control accuracy deteriorates due to air density variations
Solution Approach 1:
The patent dynamically switches between two different search axis values (actual amount of intake air and target torque) based on the operating region. In the saturated operating region, it uses actual amount of intake air as the search axis, while in non-saturated regions, it uses target torque. This dynamic adaptation resolves the contradiction by selecting the appropriate parameter for each operating condition, maintaining both control simplicity and accuracy.
Solution Approach 2:
The patent changes the search axis parameter based on the operating region characteristics. By detecting whether the engine is in a saturated or non-saturated operating region, it switches between using actual intake air amount and target torque as the search axis. This parameter change strategy allows the system to maintain control accuracy across different operating conditions while preserving the simplicity of map-based control.
2Measurement precision
If actual amount of intake air is used as a search axis in lean burn control, then control accuracy is improved in non-saturated regions, but control becomes inappropriate in saturated regions where intake air amount does not change with torque
Solution Approach 1:
The system dynamically selects the search axis parameter based on the operating region. It detects whether the engine operates in a saturated or non-saturated region and switches between using actual intake air amount and target torque accordingly. This dynamic selection ensures the control system remains adaptable and accurate across all operating regions.
Solution Approach 2:
The patent changes the search axis parameter from actual intake air amount to target torque (or vice versa) depending on the operating region characteristics. This parameter change enables the control system to maintain both accuracy in non-saturated regions and applicability in saturated regions where intake air amount becomes saturated.
3Device complexity
If a single search axis is used for all operating regions, then device complexity is reduced, but control accuracy deteriorates in specific regions
Solution Approach 1:
The patent segments the operating region into saturated and non-saturated regions based on the relationship between intake air amount and target torque. By dividing the operating space, it can apply different search axis strategies to different segments, improving control accuracy in specific regions while maintaining relatively simple control logic through clear segmentation criteria.
Solution Approach 2:
The system dynamically adjusts the search axis selection based on the detected operating region. Rather than using a fixed single search axis, it adapts the search axis choice (actual intake air or target torque) according to the current operating conditions, improving accuracy without significantly increasing system complexity.
Data Source
AI summary
An engine control device includes an air amount detector, a requested torque acquisitor, a search axis value acquisitor, a storage, and a control target value acquisitor. The air amount detector detects an actual amount of intake air. The requested torque acquisitor acquires a requested torque. In a region of a lean burn region where the actual amount of intake air increases as the requested torque increases, the search axis value acquisitor acquires a value corresponding to the actual amount of intake air. In a region of the of the lean burn region where the actual amount of intake air does not increase as the requested torque increases, the search axis value acquisitor acquires a value corresponding to the requested torque. The control target value acquisitor acquires a control target value of an engine device by searching a device control map using an acquired search axis value.