Hybrid Vehicle Controller Shift Range Diagnosis Logic
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Solution Overview
Problem
In hybrid vehicles, erroneous recording of diagnosis information occurs when the state of charge (SOC) of the power storage device becomes low due to non-performance of engine electric power generation, leading to false detection of abnormalities in the engine and generator.
Innovation Solution
A controller that differentiates between two shift ranges, performing charging control and recording diagnosis information only when the vehicle is in the first range and not in the second range, thereby preventing erroneous recording of abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller records diagnosis information when SOC becomes low to detect engine or generator abnormalities, then abnormality detection capability is improved, but erroneous recording occurs when the vehicle is in shift ranges where engine electric power generation is not performed
Solution Approach 1:
The controller applies different recording rules to different shift ranges. In first shift ranges where engine electric power generation is performed, diagnosis information is recorded when SOC becomes low. In second shift ranges where engine electric power generation is not performed, diagnosis information is not recorded. This local differentiation eliminates erroneous recording while maintaining accurate abnormality detection capability where applicable.
Solution Approach 2:
The controller dynamically adjusts the diagnosis information recording behavior based on the current shift range. The recording function is activated or deactivated according to whether the engine is currently performing electric power generation, making the system adaptive to operational conditions and preventing false positives.
2Reliability
If the controller performs charging control to maintain SOC above threshold values, then power storage device health is improved, but engine electric power generation may not be performed in certain shift ranges causing SOC to decrease
Solution Approach 1:
The charging control is applied selectively to specific shift ranges where engine electric power generation is performed. The controller recognizes that in second shift ranges, the engine is not performing power generation regardless of charging control commands, so it avoids attempting charging control in those ranges, preventing futile operations while maintaining effective charging when conditions permit.
Data Source
AI summary
A controller for a hybrid vehicle performs charging control when a shift range of the hybrid vehicle is a first range, and does not perform the charging control when the shift range of the hybrid vehicle is a second range, the charging control being control of charging a power storage device with electric power generated by a generator driven by an engine. The controller records diagnosis information when an SOC of the power storage device is equal to or lower than a first threshold value and the shift range of the hybrid vehicle is the first range, and does not record the diagnosis information when the SOC of the power storage device is equal to or lower than the first threshold value and the shift range of the hybrid vehicle is the second range.