Engine Torque Control for Stuck Accelerator Safety

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Solution Overview

Problem

Existing output control methods for internal combustion engines can cause acceleration failure and deteriorate driving performance when the accelerator pedal is stuck, as the throttle opening is limited even when the driver requests a drive force, leading to inefficient vehicle acceleration.

Innovation Solution

A control device and method that adjust the engine torque control by determining a shorter limitation lifting time based on the brake operation time, allowing for immediate throttle opening when the brake pedal is released, ensuring the vehicle can be stopped and preventing acceleration failure by prioritizing the brake pedal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the throttle opening is limited to a predetermined opening when the brake pedal is depressed, then the vehicle can be stopped reliably even if the accelerator pedal is stuck, but the driving performance deteriorates and acceleration failure occurs when the driver requests drive force

Engineering Contradiction:
Improvevehicle stopping reliabilityVSAvoiddriving performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the throttle opening limitation dynamic rather than static. The control device determines whether to limit the throttle opening based on the vehicle's running state, specifically whether the vehicle is in a deceleration state or not. When the vehicle is not in deceleration state, the throttle opening is limited to prevent stuck accelerator issues. When the vehicle is in deceleration state, the throttle opening is not limited, allowing full driving performance. This dynamic adjustment resolves the contradiction between reliability and productivity.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the limitation on throttle opening is lifted gradually over a predetermined time after brake release, then sudden vehicle start is prevented, but acceleration failure occurs and driving performance deteriorates when the driver requests immediate acceleration

Engineering Contradiction:
Improvevehicle stabilityVSAvoidacceleration performance
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies dynamics by making the limitation lifting time dynamic rather than fixed. The control device determines the limitation lifting time based on the brake operation time. When brake operation time is short, the limitation lifting time is shortened to allow quick acceleration response. When brake operation time is long, the limitation lifting time is extended to prevent sudden start. This dynamic adjustment resolves the contradiction between vehicle stability and acceleration performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies parameter changes by adjusting the limitation lifting time parameter based on brake operation time. The control device calculates the limitation lifting time as a function of brake operation time, changing this parameter dynamically to match driver intentions and vehicle states, thereby resolving the contradiction between stability and acceleration performance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the throttle opening is limited constantly after brake depression, then the accelerator pedal stuck issue is addressed, but the driver's drive force request is not met causing acceleration failure

Engineering Contradiction:
Improvesafety controlVSAvoiddriver control responsiveness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies feedback by continuously monitoring the vehicle's running state, specifically whether the vehicle is in a deceleration state or not. Based on this feedback, the control device determines whether to limit the throttle opening. When the vehicle is not in deceleration state, the throttle opening is limited for safety. When the vehicle is in deceleration state, the throttle opening is not limited, responding to driver requests. This feedback mechanism resolves the contradiction between safety control and driver control responsiveness.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2559886B1Controlling output of an internal-combustion engine considering brake pedal depression
Publication Date: 2021.06.09 NISSAN MOTOR CO LTD
  • EP2559886B1 patent drawingFigure 1
  • EP2559886B1 patent drawingFigure 2
  • EP2559886B1 patent drawingFigure 3

AI summary

The present invention concerns an output control device for an internal combustion engine for generating a drive force of a vehicle. The output control device includes a braking request detection sensor for detecting whether or not a braking request operation has been performed, and a controller programmed to limit an output of the internal combustion engine when the braking request operation is started, completely lift output limitation of the internal combustion engine over a predetermined limitation lifting time when the braking request operation is finished and shorten the limitation lifting time when a predetermined condition holds.