Powertrain Torque Control for Unintended Vehicle Motion

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Solution Overview

Problem

Existing vehicle control systems face issues with false positive torque security faults leading to unnecessary vehicle disablement due to unintended vehicle motion, which can be caused by a potential torque security fault exceeding a threshold level of vehicle acceleration, resulting in motion hazards.

Innovation Solution

A powertrain system that determines the magnitude of unintended vehicle motion by comparing actual and intended vehicle acceleration changes and limits propulsion torque when a fault is detected, but only if the motion deviation is below a predetermined threshold, thereby preventing unnecessary system shutdowns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If propulsion torque is removed to prevent unintended vehicle motion, then vehicle safety is improved, but false positive fault detection causes unnecessary vehicle disablement

Engineering Contradiction:

Improvevehicle safetyVSAvoidvehicle availability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system continuously monitors vehicle acceleration and compares actual acceleration against operator-intended acceleration to detect unintended vehicle motion. This feedback mechanism allows the system to distinguish between normal vehicle operation and actual unintended motion, reducing false positive fault detections while maintaining safety.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the parameter being monitored from simple torque security fault detection to magnitude of unintended vehicle motion based on acceleration differences. By measuring the magnitude of unintended motion and comparing it against thresholds, the system can differentiate between critical faults requiring disablement and non-critical conditions allowing continued operation.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If torque security fault detection is implemented, then unintended vehicle motion is prevented, but false positives lead to system shutdown

Engineering Contradiction:

Improveunintended vehicle motionVSAvoidfault detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The system replaces traditional mechanical torque monitoring with an acceleration-based detection method. By using acceleration sensors and comparing actual acceleration against intended acceleration, the system achieves more accurate fault detection that is less prone to false positives from mechanical noise or normal operation variations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system introduces magnitude of unintended vehicle motion as an intermediary parameter between torque security fault detection and system shutdown decisions. This intermediary allows for a graded response where non-critical faults can be monitored without triggering immediate shutdown, improving fault detection accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9126592B2Method and apparatus for monitoring unintended vehicle motion

Publication Date: 2015.09.08 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A powertrain system is configured to transfer propulsion torque to a driveline of a vehicle. A method for controlling the powertrain system includes determining a magnitude of unintended vehicle motion based upon a difference between a change in actual vehicle acceleration and a change in an operator-intended vehicle acceleration. Propulsion torque to the driveline is limited when a fault associated with unintended vehicle motion is detected and the magnitude of unintended vehicle motion is less than a predetermined first threshold.