Vehicle Control Apparatus Downshift Frequency Limiting

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Solution Overview

Problem

Electric and hybrid vehicles without stepped transmissions experience abrupt driving force increases and jolts due to improper downshifting in manual transmission mode, as existing technologies do not adequately limit the frequency of downshift instruction signals.

Innovation Solution

A vehicle control apparatus that outputs a downshift instruction signal and limits the number of driving force increases through downshifting within a predefined time, allowing for controlled increments of driving force based on vehicle speed, thereby suppressing excessive force increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the driver can select the shift range in manual transmission mode, then the driving force can be changed according to driver preference, but improper operations may cause excessive downshifting and abrupt driving force increases

Engineering Contradiction:

Improvedriver's ability to select shift rangeVSAvoidrisk of improper operation causing excessive downshifting

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The control device performs preliminary assessment before executing a downshift by checking whether the number of downshifts within the current time period has reached a predetermined threshold. This preliminary check prevents improper operations from causing excessive downshifting while still allowing manual shift selection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors the number of downshifts within a specific time period and provides feedback to the control unit. When the threshold is reached, the control unit prohibits further downshifts, creating a feedback loop that prevents excessive downshifting while maintaining manual transmission functionality.

Inventive Principle:

Principle #23Feedback

2Speed

If downshift instruction signals are output multiple times within a short time, then the driving force increases abruptly providing responsive acceleration, but the vehicle experiences significant jolts and discomfort

Engineering Contradiction:

Improverate of driving force increaseVSAvoidvehicle jolts and driver discomfort

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The control device divides time into discrete periods and counts downshifts within each period. By setting a threshold for the number of downshifts per time period, the system creates a periodic control mechanism that allows responsive acceleration while preventing excessive downshifting that causes jolts.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The control device changes the parameter of downshift acceptance by dynamically adjusting whether downshift instructions are accepted or prohibited based on the current count within the time period. This parameter change enables the system to provide responsive acceleration when needed while blocking excessive downshifts that would cause discomfort.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9273777B2Vehicle control apparatus

Publication Date: 2016.03.01 TOYOTA JIDOSHA KK

AI summary

In a manual transmission mode, a downshift instruction signal is outputted by a position sensor, and a shift range is lowered by one gear, as a result of an operation of a shift lever by the driver. The driving force of the vehicle is increased through downshifting. The number of times of downshifting within a predefined time is limited to a predefined number of times.