Vehicle Torque Change Monitoring for Engine Abnormality Detection
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Solution Overview
Problem
Existing vehicle control devices struggle to accurately determine drive source abnormalities due to variations in sensor performance and drive source configurations, leading to delayed or incomplete danger avoidance capabilities.
Innovation Solution
A control device that calculates requested and estimated torque changes over time, using integrated differences to detect abnormalities and output appropriate determinations, thereby enabling timely and effective danger avoidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threshold value with a large margin is set for comparing estimated generation torque, then the control device becomes more reliable in avoiding false positives, but the abnormality determination becomes delayed or incomplete
Solution Approach 1:
The patent segments the abnormality determination process into two independent evaluation dimensions: (1) comparison of estimated generation torque with requested torque, and (2) comparison of torque change rates. This segmentation allows each dimension to use appropriate thresholds without compromising overall detection speed and accuracy
Solution Approach 2:
The patent introduces a new dimension of evaluation by comparing torque change rates (dTorque/dt) in addition to absolute torque values. This dimensional expansion enables the system to detect abnormalities based on the rate of change, providing an additional detection pathway that reduces reliance on single threshold margins
2Loss of time
If the threshold value is set with a small margin to enable faster abnormality determination, then the abnormality detection time is reduced, but the control device may produce false positives in normal states
Solution Approach 1:
The patent divides the determination logic into separate evaluation paths: one for absolute torque comparison and another for torque change rate comparison. This allows each path to use optimized thresholds appropriate to its detection purpose, reducing false positives while maintaining detection speed
Solution Approach 2:
The torque change rate comparison acts as an intermediary evaluation mechanism that filters out false positives from absolute torque comparisons. By requiring both conditions to be met or providing alternative detection pathways, the system reduces erroneous abnormality determinations
3Device complexity
If sensor performance variations and drive source configuration differences are not accounted for, then the device complexity is reduced, but the measurement precision of torque estimation deteriorates
Solution Approach 1:
The patent changes the parameter being monitored from absolute torque values to torque change rates (derivatives). This parameter transformation makes the measurement less sensitive to sensor performance variations and drive source configuration differences, improving precision without requiring complex calibration systems
Solution Approach 2:
The patent performs preliminary calculation of torque change rates before abnormality determination. This preliminary processing of the data prepares it for comparison in a form that is inherently more robust to variations in sensor and drive source characteristics
Data Source
AI summary
An in-vehicle control device includes: a requested torque calculation unit which calculates a requested torque on the basis of a driving state of a vehicle; a requested torque change amount calculation unit which calculates the amount of change in requested torque per unit time as a requested torque change amount; an estimated generation torque calculation unit which calculates estimated generation torque estimated as being generated by an engine; an estimated generation torque change amount calculation unit which calculates the amount of change in estimated generation torque per unit time as an estimated generation torque change amount; and an abnormality detection unit which detects an abnormality of the engine on the basis of the integrated value of a difference between the requested torque change amount and the estimated generation torque change amount, and outputs abnormality determination for the engine.