Engine Control Torque Request Security Diagnostic

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Solution Overview

Problem

Internal combustion engines face challenges in maintaining torque output stability when wheel drag events occur, particularly on low-friction surfaces or during gear shifts, leading to uneven wheel speeds and potential wheel lockup, which can compromise vehicle stability and control.

Innovation Solution

An engine control system incorporating a torque module and a drag request evaluation module that adjusts torque output based on driven and undriven wheel speeds, disabling torque increases when the driven wheel speed exceeds the undriven wheel speed by a predetermined amount, and considering other conditions such as accelerator pedal actuation and vehicle deceleration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If torque output is increased based on wheel drag torque request to eliminate wheel drag, then vehicle stability and control are improved, but wheel lockup may occur when driven wheel speed already exceeds undriven wheel speed

Engineering Contradiction:

Improvevehicle stabilityVSAvoidwheel lockup

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors driven wheel speed and undriven wheel speed, using this feedback to determine whether to execute the drag torque request. When the driven wheel speed exceeds the undriven wheel speed by more than a predetermined amount, the system disables the torque increase, preventing wheel lockup while maintaining stability when appropriate.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts torque output based on real-time wheel speed conditions. The drag torque request execution is not static but adapts to changing driving conditions, enabling torque increase when it benefits stability and disabling it when it risks causing wheel lockup.

Inventive Principle:

Principle #15Dynamics

2Speed

If drag torque request is executed to accelerate driven wheels during low-friction surface operation, then wheel deceleration is reduced, but unnecessary torque increases may occur when not actually needed

Engineering Contradiction:

Improvedriven wheel speedVSAvoidunnecessary torque increase

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The system evaluates wheel speed conditions before executing the drag torque request. By checking whether the driven wheel speed already exceeds the undriven wheel speed by more than a predetermined amount before applying torque, the system prevents unnecessary energy consumption while ensuring torque is applied when actually needed to eliminate wheel drag.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the system monitors wheel speed differences to prevent wheel lockup, then vehicle control safety is improved, but system complexity increases due to additional evaluation requirements

Engineering Contradiction:

Improvevehicle control safetyVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The drag request evaluation module performs multiple functions: it monitors wheel speed differences, determines whether drag torque request execution would cause wheel lockup, and controls the torque module accordingly. This multi-functional approach improves safety without proportionally increasing system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9475388B2Drag torque request security diagnostic systems and methods

Publication Date: 2016.10.25 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An engine control system for a vehicle comprises a torque module and a drag request evaluation module. The torque module controls torque output of an engine based on a driver torque request and increases the torque output based on a wheel drag torque request generated based on a driven wheel speed. The drag request evaluation module disables the increase of the torque output when the driven wheel speed is greater than an undriven wheel speed by more than a predetermined speed.