Straddled Vehicle Clutchless Shifting Detection System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing straddled vehicle systems for clutchless shifting face challenges in accurately detecting shift operations due to noise and performance issues with load sensors, leading to incorrect detection and increased costs for high-accuracy, noise-resistant sensors.

Innovation Solution

A system that uses a combination of load and angle detectors to determine if a shift operation has been intended by the rider, adjusting engine output only when both load and angular conditions are met, thereby reducing the need for costly high-accuracy sensors and preventing unintended gear changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a high-accuracy load sensor with excellent noise resistance is used to detect shift operations, then measurement precision is improved, but device cost increases

Engineering Contradiction:
Improveshift operation detection accuracyVSAvoiddevice cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent combines load detection and angle detection into a unified shift operation detection system. The shift determiner integrates both load detector signals and angle detector signals to make a combined determination, thereby improving detection accuracy without relying solely on an expensive high-precision load sensor

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The angle detector serves as an intermediary verification mechanism. Instead of relying exclusively on the load sensor, the system uses angle detection as a mediator to confirm whether a shift operation actually occurred, reducing false detections and allowing the use of lower-cost load sensors

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If only load detection is used to determine shift operations, then device complexity is reduced, but reliability of shift detection deteriorates due to noise and false detections

Engineering Contradiction:
Improvedetection system complexityVSAvoidshift operation detection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The shift determiner merges load detection results with angle detection results to make the final shift operation determination. This combined approach maintains relatively simple device structure while significantly improving detection reliability by cross-validating both detection signals

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system implements feedback verification where the angle detector provides confirmation feedback to validate load detector signals. When load detection indicates a shift operation but angle detection does not confirm corresponding cam rotation, the shift determiner can reject the false positive, thereby improving reliability

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3495255B1Straddled vehicle
Publication Date: 2020.03.18 YAMAHA MOTOR CO LTD
  • EP3495255B1 patent drawingFigure 1
  • EP3495255B1 patent drawingFigure 2
  • EP3495255B1 patent drawingFigure 3(a)~3(b)

AI summary

A load sensor SE5 detects the load applied by an operation of a shift pedal 210 performed by a rider. A shift cam sensor SE4 detects a rotation angle of a shift cam of a transmission 5. Determination is made whether a load condition is satisfied, the load condition being that a detection value of the load is larger than a load threshold value. Determination is made whether an angular condition is satisfied, the angular condition being that a detection value of a rotation angle is larger than an angular threshold value. When the load condition and the angular condition are satisfied, determination is made that a shift operation intended by the rider has been performed, and output adjustment for a change of a gear ratio is carried out. When at least one of the load condition and the angular condition is not satisfied, determination is made that the shift operation has not been performed.