Motion-Triggered Compass Heading Calculation for Power Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electronic compass modules in navigation devices frequently operate in active states due to constant polling for heading updates, leading to high power consumption and reduced battery life in portable devices.

Innovation Solution

Implementing a method where the electronic device transitions from an idle to an active operating state only when oriented in a specific orientation and rotated, using sensors to determine the orientation and rotation, and then activating the compass module to generate a heading, thereby minimizing continuous operation of the compass module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electronic compass module is frequently polled for heading updates, then the heading information is continuously available for navigation applications, but the power consumption increases and battery life decreases

Engineering Contradiction:

Improveheading availabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system transitions the electronic compass module between active and idle states based on periodic motion detection. The module operates actively only when motion is detected, and enters idle state when no motion is detected, converting continuous operation into periodic operation to reduce power consumption while maintaining heading availability when needed

Inventive Principle:

Principle #19Periodic action

2Productivity

If the electronic compass module operates continuously in active state, then accurate and responsive heading updates are provided, but battery life is reduced

Engineering Contradiction:

Improveheading update rateVSAvoidbattery life

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The compass module alternates between active operation during motion periods and idle state during stationary periods. Motion detection triggers active operation for heading updates, while absence of motion triggers transition to idle state, creating a periodic operation pattern that extends battery life while maintaining productivity when the device is in use

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses the device's own motion state to automatically control compass module operation. The motion detection mechanism triggers the state transition without external intervention, allowing the system to self-regulate power consumption based on actual usage conditions

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

This approach significantly reduces power consumption by limiting the active operation of the compass module to necessary instances, enhancing battery life in portable navigation devices.

Implementation Method 1

an electronic compass module detects variations in the Earth's magnetic field to determine its heading

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

an indication of rotation of the electronic device around an axis is received

Methodology Applied

Scientific EffectRotation detection: Accelerometer

Data Source

PatentUS8417975B2Motion triggered magnetic reading and compass heading calculations to reduce power consumption

Publication Date: 2013.04.09 TRIMBLE NAVIGATION LTD

AI summary

A method for reducing power consumption of an electronic device is disclosed. In one embodiment, an indication that an electronic device is oriented in a first orientation is received. An indication of rotation of the electronic device around an axis is received. A command is then generated to cause an electronic compass module disposed within the electronic device to transition from an idle operating state to an active operating state and to generate a compass heading.