Wrist Terminal Motion Recognition Threshold Adaptation

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Solution Overview

Problem

Existing motion recognition techniques for wristwatch-type input apparatuses often inaccurately recognize daily arm movements as operational inputs due to similar motion patterns, leading to erroneous recognition.

Innovation Solution

A wrist terminal equipped with an acceleration sensor dynamically adjusts threshold values for motion recognition based on detected acceleration data and user activity, distinguishing between operational and daily arm movements by employing a threshold value setting unit and count unit to refine the recognition process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If motion recognition is performed using acceleration sensor detection, then input operation recognition capability is enabled, but erroneous recognition of daily arm movements as operations occurs

Engineering Contradiction:
Improvemotion recognition capabilityVSAvoidrecognition accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies dynamics by making the threshold value adaptive rather than fixed. The threshold dynamically changes based on the user's current state (detected through acceleration patterns and time since last operation). When the user is detected to be in a stationary state for a prolonged period, the threshold increases to prevent false recognition of daily movements. When recent operations occurred, the threshold remains lower to ensure responsive recognition. This dynamic adjustment resolves the contradiction between maintaining recognition capability and preventing erroneous recognition.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of threshold value based on temporal context and detected motion patterns. By modifying the threshold parameter according to the time elapsed since the last operation and the current acceleration state, the system adapts its sensitivity. This parameter change allows the same motion recognition algorithm to function reliably in both active and inactive states, resolving the accuracy vs. versatility contradiction.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a fixed threshold value is used for motion recognition, then simple recognition processing is achieved, but accurate distinction between operational and daily movements is compromised

Engineering Contradiction:
Improverecognition processing simplicityVSAvoidmotion distinction accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-establishing multiple threshold values corresponding to different user states (active vs. inactive). Rather than calculating complex dynamic thresholds in real-time, the system pre-defines threshold levels and selects the appropriate one based on the time since the last operation and current acceleration state. This approach maintains processing simplicity while improving distinction accuracy between operational and daily movements.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the accuracy of recognizing user-operated motions while minimizing false positives from daily arm movements, ensuring reliable input recognition.

Implementation Method 1

a motion recognizing unit that recognizes a motion of a wrist and an arm when a predetermined time has elapsed from a time point at which it is detected, based on a detection result of the acceleration sensor, that the wrist terminal is in a stationary state

Methodology Applied
Scientific EffectAcceleration sensor detection: Accelerometer

Data Source

PatentEP2816450B1Information processing apparatus, and information processing method
Publication Date: 2019.07.24 CASIO COMPUTER CO LTD
  • EP2816450B1 patent drawingFigure 1
  • EP2816450B1 patent drawingFigure 2
  • EP2816450B1 patent drawingFigure 3

AI summary

There is provided an information processing apparatus including: a determining unit (71) that determines that an apparatus worn on a user is in a reference state when an angle of a display unit of the apparatus with respect to a predetermined direction is within a range of a threshold value; a recognizing unit (71) that recognizes a motion of the apparatus from the reference state when the determining unit determines that the apparatus is in the reference state; an input unit (72) that receives an input operation corresponding to the motion of the apparatus from the reference state recognized by the recognizing unit; a time measuring unit (74) that measures a time; a detecting unit (60) that detects a motion state of the apparatus; and a setting unit (73) that sets the threshold value according to the time and the motion state of the apparatus.