Leaning Vehicle Gear-Shift Controller Posture Stability

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Solution Overview

Problem

Existing gear-shift controllers in leaning vehicles often cause posture changes during turns due to gear shifts, leading to undesirable changes in the travel line, as the front wheel's load changes and steering angle shifts, affecting the vehicle's posture and travel trajectory.

Innovation Solution

A leaning vehicle equipped with a gear-type multi-stage automatic transmission and a gear-shift controller that predicts and mitigates posture changes by inhibiting gear stage changes, suppressing driving force changes, or adjusting suspension extension/contraction, based on vehicle state parameters like suspension extension/contraction amounts, rotation angles, and driving force, to minimize travel line changes during turns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If gear shifts are performed during turns in a lean state, then the multi-stage automatic transmission can automatically change gear stages to optimize driving force, but the front wheel load changes causing steering angle shifts and travel line deviations

Engineering Contradiction:
Improveautomatic gear shifting capabilityVSAvoidvehicle posture stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The gear-shift controller predicts the change of travel line before the gear shift is executed. Based on this prediction, the controller determines whether to suppress the gear shift or allow it to proceed. This preliminary prediction and decision-making prevents posture instability before it occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses sensors to detect vehicle state parameters (suspension extension/contraction amounts, rotation angles, driving force) and feeds this information back to the gear-shift controller. The controller continuously monitors these parameters and adjusts gear shift timing and suppression decisions based on real-time vehicle state, ensuring stability while maintaining automatic transmission functionality.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If the gear-shift controller suppresses gear stage changes during turns, then posture stability is improved, but the automatic transmission cannot optimize driving force through gear changes

Engineering Contradiction:
Improvevehicle posture stabilityVSAvoidautomatic gear shifting capability
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The gear-shift controller dynamically adjusts the suppression of gear shifts based on real-time vehicle state parameters. When the predicted travel line change is within acceptable ranges, gear shifts are permitted to maintain productivity. When the prediction exceeds thresholds, suppression is applied to maintain stability. This dynamic control optimizes the balance between stability and automatic transmission functionality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the transmission system by selectively suppressing gear stage changes based on predicted travel line changes. The controller modifies the gear shift behavior (permitting or suppressing) according to vehicle state parameters, thereby adapting the transmission performance to current driving conditions while maintaining overall system productivity.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the gear-shift controller suppresses extension and contraction of suspensions during turns, then posture stability is improved, but the suspension cannot adapt to road conditions

Engineering Contradiction:
Improvevehicle posture stabilityVSAvoidsuspension adaptability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The gear-shift controller predicts the change of travel line before suspension adjustment is executed. Based on this prediction, the controller determines whether to suppress suspension extension and contraction or allow normal operation. This preliminary prediction ensures posture stability while minimizing impact on suspension adaptability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors suspension extension/contraction amounts and other vehicle state parameters, feeding this information back to the gear-shift controller. The controller adjusts suspension suppression decisions based on real-time feedback, allowing the suspension to adapt to road conditions when stability is not compromised while maintaining posture stability when necessary.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3901021B1Leaning vehicle
Publication Date: 2023.05.03 YAMAHA MOTOR CO LTD
  • EP3901021B1 patent drawingFigure 1
  • EP3901021B1 patent drawingFigure 2
  • EP3901021B1 patent drawingFigure 3

AI summary

Provided is a leaning vehicle capable of reducing a posture change of the leaning vehicle by a gear-shift while the leaning vehicle turns in a lean state. A vehicle 1 as a leaning vehicle includes a front suspension 5, a rear suspension 6, an engine 11, a gear-type multi-stage automatic transmission 12 including a plurality of gear stages and a clutch, and a controller 7 that controls changing of the gear stages in the multi-stage automatic transmission 12. While the vehicle 1 that rotates about a rotation axis P extending in a left-right direction of the vehicle 1 by changing the gear stages in the multi-stage automatic transmission 12 turns in a lean state, the controller 7 performs at least one of suppression of a change of the driving force by changing the gear stages or suppression of extension and contraction of the front suspension 5 and the rear suspension 6, based on a vehicle state in which a change of a travel line of the leaning vehicle is predicted.