Accelerator Pedal Depression Force Control for Wall Feeling Feedback

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Solution Overview

Problem

Existing accelerator pedal depression force control systems fail to provide a clear 'wall feeling' to the driver during transitions between different driving modes, leading to excessive pedal depression and inadequate feedback on sudden force increases.

Innovation Solution

An accelerator pedal depression force control apparatus that varies the depression force by adding a predetermined increase amount to the base force at a specific rate, increasing the force beyond the base when the accelerator opening degree exceeds a threshold, and gradually decreasing this increase as the opening degree decreases, ensuring the driver feels the force change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the increase amount of the depression force is suddenly returned (decreased) when the driving region returns from boundary to second region, then the system responds quickly to driving condition changes, but the accelerator pedal may be excessively depressed by reaction

Engineering Contradiction:
ImproveResponse speed of depression force changeVSAvoidAccelerator pedal operation stability
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the depression force characteristic changeable based on driving conditions. The ECU dynamically adjusts the depression force increase amount and its cancellation rate according to the driving region (stratified charge vs. homogeneous combustion), allowing the system to adapt between quick response and stable operation modes rather than using a fixed characteristic

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies beforehand cushioning by gradually returning the depression force increase amount at a predetermined rate rather than suddenly canceling it. This gradual return acts as a cushion that prevents excessive pedal depression reaction, absorbing the shock of the force change and maintaining operation stability

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of operation

If the increase amount of the depression force is gradually returned to prevent excessive depression, then the accelerator pedal operation becomes stable, but the increase amount becomes small when sudden increase is needed and the driver cannot feel the wall feeling

Engineering Contradiction:
ImproveAccelerator pedal operation stabilityVSAvoidDepression force increase amount
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent makes the depression force characteristic dynamic by detecting the driving region and adjusting the force increase behavior accordingly. In the boundary driving region transition, the system can apply a larger increase amount to maintain the wall feeling, while in other regions it uses gradual return for stability, optimizing both force magnitude and operation stability based on real-time conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by implementing different depression force control strategies for different driving regions. The boundary driving region receives special treatment with adjusted increase amounts and cancellation rates to provide both stability and perceptible wall feeling, while other regions use standard control characteristics

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2578433B1Accelerator pedal depression force control device
Publication Date: 2014.12.03 NISSAN MOTOR CO LTD
  • EP2578433B1 patent drawingFigure 1~2
  • EP2578433B1 patent drawingFigure 3~5
  • EP2578433B1 patent drawingFigure 6~8

AI summary

When the accelerator opening degree becomes equal to or smaller than an increase amount cancel threshold value (timing t2) while the depression force of an accelerator pedal 2 is increased than a base depression force by a predetermined increase amount of the depression force, the predetermined increase amount of the depression force is decreased at a predetermined rate, and moreover, when the accelerator opening degree becomes greater than a predetermined accelerator opening degree threshold value (timing t3) while the predetermined increase amount of the depression force is decreased, the depression force of the accelerator pedal 2 is increased with respect to the base depression force so that the increase amount of the depression force with respect to the base depression force becomes greater than the predetermined increase amount of the depression force.