Relative Inclination Sensing Using Dual Accelerometer Reference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional systems for determining the relative orientation of personal care appliances to a user require extensive sensing hardware and processing power, making them inefficient.
Innovation Solution
A system using accelerometers in both the appliance and a device worn by the user to compare inclinations relative to the earth, allowing for efficient determination of the appliance's inclination and position, with optional combination with other sensors like electromagnetic field sensors for precise location adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic field sensors and user head tracking devices are used to determine relative orientation, then measurement precision is improved, but device complexity and processing power requirements increase
Solution Approach 1:
The system divides the orientation determination task into two independent parts: (1) measuring the appliance's inclination relative to earth using an accelerometer in the appliance, and (2) measuring the user's body part inclination relative to earth using an accelerometer in the wearable device. By segmenting the measurement into separate independent components, the system avoids the need for complex electromagnetic field sensing while maintaining measurement capability.
Solution Approach 2:
The earth's gravitational field serves as an intermediary reference frame. Instead of directly measuring the relative orientation between appliance and user head using complex electromagnetic sensors, the system uses earth-gravity as a common reference to indirectly determine relative orientation through comparative measurement of both devices' inclinations relative to earth.
2Measurement precision
If electromagnetic field sensors are used to determine relative orientation, then measurement precision is improved, but processing power requirements increase
Solution Approach 1:
The calculation is segmented into simple independent steps: each accelerometer independently measures its own inclination relative to earth, then the processing unit performs a simple subtraction of these two inclination values. This segmented approach requires minimal processing power compared to complex electromagnetic field calculations.
Solution Approach 2:
The system replaces complex electromagnetic field sensing and processing with simple mechanical accelerometer-based inclination sensing. Accelerometers measure gravitational acceleration components, which are then used to calculate inclination angles through basic trigonometric relationships, requiring significantly less processing power.
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 processing power requirements while accurately determining the appliance's relative inclination and position to the user, enabling efficient functionality adjustments.
Implementation Method 1
a first orientation measuring unit arranged to measure an inclination of a first device relative to the earth
Implementation Method 2
a second orientation measuring unit arranged to measure an inclination of a second device relative to the earth
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present application relates to a system for determining an orientation of a first device relative to a user. The system comprises a first device including a first orientation measuring unit arranged to measure an orientation of the first device relative to the earth, a second device arranged to be worn by the user on a body part, the second device including a second orientation measuring unit arranged to measure an orientation of the second device relative to the earth. The system also comprises a processing unit arranged to calculate an orientation of the first device relative to the second device by comparing the measured orientation of the first device relative to the earth with the measured orientation of the second device relative to the earth.