Hybrid Vehicle Clutch Failure Diagnosis and Control
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Solution Overview
Problem
Existing vehicle control systems fail to safely manage clutch failures, particularly in hybrid vehicles, as they do not effectively determine clutch failure based on temperature and load, leading to potential standing starts and safety risks.
Innovation Solution
A vehicle control method that primarily determines clutch failure by temperature and load, and secondarily by rotational engine and motor speeds, allowing for series driving mode engagement when the clutch is successfully opened, and speed limit driving or stop guidance when it is not, using a controller to diagnose clutch status and manage engine and motor operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If clutch failure is determined only by rotational speed, then the control system is simple, but the failure diagnosis is inaccurate leading to standing starts
Solution Approach 1:
The clutch failure diagnosis is segmented into multiple independent detection dimensions: primary determination based on temperature and load, and secondary determination based on rotational speed differences. This segmentation allows each detection method to focus on specific failure modes, improving overall diagnostic accuracy without requiring a single complex detection system.
Solution Approach 2:
The system monitors multiple parameters (temperature, load, rotational speed of engine and motor) to determine clutch failure, rather than relying on a single parameter. By changing from single-parameter to multi-parameter determination, the system achieves more accurate failure diagnosis while managing complexity through structured parameter evaluation.
2Reliability
If the clutch is not opened during failure, then the vehicle can continue operating, but standing start occurs causing safety risks
Solution Approach 1:
The controller proactively opens the clutch when failure is detected through temperature and load monitoring, before the failure progresses to cause standing start. This preliminary action prevents the harmful effect by addressing the root cause (clutch engagement) before the symptom (standing start) manifests.
Solution Approach 2:
The system continuously monitors temperature, load, and rotational speed parameters, providing real-time feedback on clutch condition. When feedback indicates failure (abnormal temperature, load, or speed differential), the controller responds by opening the clutch, creating a closed-loop safety mechanism that prevents standing start.
3Temperature
If speed limit driving is enforced during clutch failure, then overheating is prevented, but vehicle mobility is restricted
Solution Approach 1:
The speed limitation is not a fixed constraint but a dynamic control measure adjusted based on clutch failure severity and temperature conditions. The controller enforces speed limits during active failure to prevent overheating, but can modify or remove limitations when the clutch is successfully opened or temperature stabilizes, making the restriction adaptive rather than absolute.
Solution Approach 2:
The speed limit acts as a preventive measure applied before the clutch overheats completely. By restricting speed proactively during detected failure conditions, the system cushions against the potential harm of overheating, allowing continued operation under controlled conditions until the clutch can be fully opened or cooled.
Data Source
AI summary
A vehicle is provided that includes a motor connected to vehicle wheels and configured to generate electrical power. A first rotational speed detector detects rotational speed of the motor and an engine generates mechanical power. A second rotational speed detector detects rotational speed of the engine. A clutch is disposed between the engine and the motor to open and close the connection between the engine and the motor. A controller diagnoses a failure of the clutch and outputs an instruction to open the clutch and an instruction to turn off the engine when the clutch has a failure. The controller determines whether the clutch is successfully opened based on the detected rotational speed of the motor and the detected rotational speed of the engine, executes a series driving mode when that the clutch is successfully opened and speed limit driving when that the clutch has failed to be opened.