Force Sensor Event Detection for Low-Power Always-On Input
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing force sensing systems in mobile devices face challenges in balancing low power consumption with responsive performance while maintaining acceptable sensitivity and size, particularly in detecting user interactions with human-machine interfaces.
Innovation Solution
A force sensing system comprising an input channel, activity detection stage, and event detection stage, which includes a sensor conditioning stage for normalizing and filtering inputs from force sensors, and a thresholding module for determining user inputs, allowing for power-gated operation to minimize power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If force sensing systems operate always-on to maintain high responsiveness, then detection speed is improved, but power consumption increases
Solution Approach 1:
The force sensing system is segmented into multiple processing stages: an input channel that continuously monitors force sensor signals, an activity detection stage that identifies potential user interactions, and an event detection stage that confirms actual events. This segmentation allows the system to process signals continuously at a basic level while only activating more power-intensive processing when activity is detected, thus maintaining detection speed while reducing overall power consumption.
Solution Approach 2:
The system dynamically adjusts its operational state based on detected activity levels. The activity detection stage continuously monitors input signals and dynamically transitions the event detection stage between active and inactive states. This dynamic operation enables the system to maintain high responsiveness when needed while consuming minimal power during idle periods, effectively resolving the contradiction between always-on operation and power consumption.
2Measurement precision
If force sensing systems use complex processing to maintain high sensitivity, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The signal processing function is segmented into distinct stages: an input channel for signal acquisition, an activity detection stage for preliminary analysis, and an event detection stage for final determination. Each stage performs a specific function with appropriate complexity level, allowing the system to achieve high sensitivity through multi-stage processing without requiring all components to be simultaneously complex, thus managing overall device complexity while maintaining measurement precision.
3Volume of moving object
If force sensing systems reduce size for mobile devices, then device portability is improved, but sensor sensitivity may deteriorate
Solution Approach 1:
The system addresses the size-sensitivity tradeoff by transitioning from a single-stage processing architecture to a multi-stage processing architecture. This dimensional change in system organization allows sensitivity enhancement through sequential processing stages rather than requiring larger individual sensor components, enabling high sensitivity to be achieved within the constrained size of mobile devices.
Data Source
AI summary
A force sensing system for determining if a user input has occurred, the system comprising: an input channel, to receive an input from at least one force sensor; an activity detection stage, to monitor an activity level of the input from the at least one force sensor and, responsive to an activity level which may be indicative of a user input being reached, to generate an indication that an activity has occurred at the force sensor; and an event detection stage to receive said indication, and to determine if a user input has occurred based on the received input from the at least one force sensor.