Wristband Back-EMF Sensing for Contact Force Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable devices face challenges in accurately collecting sensor data due to improper fitting, where a loose or tight wearable band can compromise data quality, making it difficult to detect and correct corrupt data.
Innovation Solution
Incorporating a wearable device with a wearable band, an actuator, and processors that measure back electromotive force (EMF) to determine contact force between the band and the user, allowing for the generation of quality metrics for sensor data and providing notifications or adjustments to ensure optimal fitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the wearable band is worn loosely or tightly, then the device is easier to wear, but the sensor data quality deteriorates
Solution Approach 1:
The system measures back EMF from the actuator to determine contact force between the band and user, then uses this information to assess sensor data quality and provide feedback about proper wearing tightness, enabling users to adjust the band for optimal data collection
Solution Approach 2:
The patent replaces direct mechanical measurement of contact force with electrical measurement of back EMF from the actuator, which indirectly indicates the contact force and band tightness, enabling non-intrusive sensing of wearing conditions
2Device complexity
If the wearable band tightness is not monitored, then the device structure remains simple, but the sensor data accuracy deteriorates
Solution Approach 1:
The actuator serves dual purposes: providing haptic feedback to the user and serving as a sensor through back EMF measurement to detect band tightness and contact force, eliminating the need for separate sensing components
Solution Approach 2:
The actuator monitors its own operating conditions by measuring its own back EMF, enabling self-diagnosis of wearing conditions without requiring external monitoring systems
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 solution enables the detection and correction of corrupt sensor data, ensuring accurate data collection by adjusting the band's tightness and compensating for suboptimal contact forces, thereby improving the reliability of sensor output.
Implementation Method 1
The processors can be configured to measure a back electromotive force ("EMF") of the actuator; determine, based on the measured back EMF, data that describes a contact force between the wearable band and the user
Data Source
AI summary
A wearable device can include a wearable band configured to contact a user of the wearable device, an actuator, a sensor, and one or more processors in communication with the actuator and the sensor. The processors can be configured to measure a back electromotive force (“EMF”) of the actuator; determine, based on the measured back EMF, data that describes a contact force between the wearable band and the user; and determine, based on the data that describes the contact force, a quality metric describing a data quality of sensor data collected by the sensor. In some embodiments, the processor(s) can determine, generate sensor output data based on the sensor data and based at least in part on the data describing the contact force between the wearable band and the user. For example, one or more machine-learned models maybe leveraged to generate sensor output data that is compensated for the wearable band being too tight or too loose.