Head-Mounted Assistant Activation Using IMU Don-Doff Detection

Solution Overview

Problem

Existing assistant systems on head-mounted devices suffer from false activations due to touch inputs, leading to unnecessary power consumption and reduced battery life, without requiring additional memory footprint or power consumption.

Innovation Solution

Utilizing inertial measurement unit (IMU) signals for don/doff detection on head-mounted devices, employing finite state machines to determine transitions between donning, doffing, and normal states, thereby preventing false activations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If touch input is used for assistant activation, then ease of operation is improved, but false activations occur leading to increased power consumption

Engineering Contradiction:

Improveassistant activationVSAvoidpower consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent introduces an intermediary verification mechanism that cross-references touch input with IMU sensor data to determine whether activation is intentional. The IMU sensors detect head movements and device handling patterns that accompany genuine user intent, serving as a mediator to filter out false activations from accidental touches.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously monitoring IMU sensor data and comparing it with touch input patterns. This feedback loop allows the system to distinguish between intentional activation (where touch and head movement patterns align) and accidental activation (where patterns do not align), thereby preventing false positives and reducing unnecessary power consumption.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If touch input is used for assistant activation, then ease of operation is improved, but activation accuracy deteriorates due to false activations

Engineering Contradiction:

Improveassistant activationVSAvoidactivation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary verification mechanism that cross-references touch input with IMU sensor data to determine whether activation is intentional. The IMU sensors detect head movements and device handling patterns that accompany genuine user intent, serving as a mediator to filter out false activations from accidental touches.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously monitoring IMU sensor data and comparing it with touch input patterns. This feedback loop allows the system to distinguish between intentional activation (where touch and head movement patterns align) and accidental activation (where patterns do not align), thereby preventing false positives and reducing unnecessary power consumption.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If IMU signals are processed for don/doff detection, then activation accuracy is improved, but device complexity increases

Engineering Contradiction:

Improveactivation accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by using the IMU sensors for multiple purposes: both for don/doff detection (determining whether the device is being worn) and for activation verification (distinguishing intentional from accidental touches). This universal use of existing sensors avoids adding dedicated hardware while improving activation accuracy.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own existing IMU sensors to verify activation intent, making the system self-sufficient. Rather than requiring external verification hardware, the device leverages its built-in motion sensing capabilities to autonomously distinguish between genuine user intent and accidental activation.

Inventive Principle:

Principle #25Self-service

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

Improves user experience by ensuring accurate activation only when intended, and enhances battery life by reducing false activations on head-mounted devices.

Implementation Method 1

access one or more signals from one or more inertial measurement unit (IMU) sensors of the head-mounted device

Methodology Applied

Scientific EffectInertial measurement: Accelerometer

Data Source

PatentUS12561032B2Preventing false process execution responsive to received touch input

Publication Date: 2026.02.24 META PLATFORMS INC

AI summary

In one embodiment, a method includes receiving touch inputs from a user corresponding to an activation trigger for an assistant system executing on a head-mounted device at the head-mounted device, accessing signals from inertial measurement unit (IMU) sensors of the head-mounted device by the head-mounted device, determining that the user is either donning or doffing the head-mounted device by an on-device don/doff detection model and based only on the signals from the IMU sensors, and overriding the activation trigger to prevent an activation of the assistant system responsive to the received touch inputs.