Onboard Control Device for Rapid Drive Source Abnormality Detection

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Solution Overview

Problem

Existing vehicle drive source control systems face challenges in quickly determining abnormal propulsive force due to variations in sensor performance and engine conditions, leading to potential safety risks from delayed abnormality detection.

Innovation Solution

An onboard control device that includes units for detecting accelerator opening degree, calculating command values, controlling propulsive force, estimating engine torque, and detecting abnormalities based on the rate of change in tolerance and estimation generation torques, with multiple thresholds and diagnosis delays set according to engine speed and vehicle speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large margin is set in the threshold for determining abnormality, then false positives are reduced, but abnormality detection time increases and safety response is delayed

Engineering Contradiction:
Improveabnormality determination accuracyVSAvoidabnormality detection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the abnormality detection process into multiple time intervals (first time interval and second time interval) with different thresholds. A first threshold is applied in the initial time interval for rapid detection, while a second threshold (with larger margin) is applied in subsequent intervals for confirmation, thereby reducing detection time while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the threshold based on the time interval and engine operating conditions. The threshold is not fixed but changes over time and with engine speed, allowing for faster initial detection when the engine is operating normally and more conservative thresholds when variations are expected, thus resolving the contradiction between speed and accuracy.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If sensor performance varies and engine conditions change, then measurement accuracy deteriorates, but maintaining a fixed threshold leads to either false alarms or delayed detection

Engineering Contradiction:
Improvetorque measurement accuracyVSAvoidthreshold adaptability to operating conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the threshold parameter based on engine speed and time interval. Instead of using a fixed threshold, the system adjusts the threshold value according to operating conditions (engine speed) and temporal context (time interval), allowing the system to adapt to varying sensor performance and engine conditions while maintaining reliable abnormality detection.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3103989B1Onboard control device
Publication Date: 2020.11.18 HITACHI AUTOMOTIVE SYST LTD
  • EP3103989B1 patent drawingFigure 1
  • EP3103989B1 patent drawingFigure 2
  • EP3103989B1 patent drawingFigure 3

AI summary

To quickly determine whether or not the propulsive force of a vehicle drive source is abnormal. The onboard control device pertaining to the present invention has a drive manipulated variable detection unit (101) for detecting or estimating a drive manipulated variable manipulated by a driver in order to impart a propulsive force to a vehicle, a command value calculation unit (109) for calculating a command value for a drive source of the vehicle on the basis of the drive manipulated variable, a propulsive force control unit (115) for controlling the propulsive force of the drive source on the basis of the command value, operating state detection units (102, 103) for detecting or estimating the operating states of the drive source, a drive manipulation rate of change calculation unit (110) for calculating the rate of change in drive manipulation, an operating state rate of change calculation unit (111) for calculating the rate of change in the operating state, and an abnormality detection unit (112) for detecting abnormalities in at least the drive source on the basis of the rate of change in drive manipulation and the rate of change in the operating state.