Dual-Scan Tactile Sensor Array for Force Feedback
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Solution Overview
Problem
Dynamic mechanical systems, such as robots, face challenges in accurately localizing and measuring multiple points of tactile force feedback due to the limitations of existing capacitive touch sensing technologies and other sensors, which often result in high rates of false positives and incorrect force measurements.
Innovation Solution
A dual-scanning technique is employed on a grid-based tactile sensing array, where a low-sensitivity scan is used to detect active areas and reduce false positives, followed by a high-sensitivity scan to accurately measure force at detected contact points, thereby improving the accuracy of contact detection and force measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high sensitivity mode is used throughout the sensor array, then force measurement precision is improved, but false positive rate increases
Solution Approach 1:
The sensor array operation is segmented into two distinct phases: a low-sensitivity scanning phase for contact detection and a high-sensitivity measurement phase for force quantification. This segmentation allows each phase to be optimized for its specific purpose, resolving the contradiction between detection reliability and measurement precision.
Solution Approach 2:
The sensor array dynamically switches between low-sensitivity and high-sensitivity modes based on operational requirements. The system transitions from a stable low-sensitivity state during scanning to a high-sensitivity state only at detected contact points, adapting the measurement parameters to the current operational context.
2Reliability
If low sensitivity mode is used throughout the sensor array, then false positive rate is reduced, but force measurement precision deteriorates
Solution Approach 1:
The measurement process is divided into two segments: initial contact detection using low-sensitivity scanning, followed by precise force measurement using high-sensitivity readings at identified contact points. This ensures both reliability in contact detection and precision in force measurement.
Solution Approach 2:
The system performs preliminary low-sensitivity scanning to identify contact points before conducting high-sensitivity force measurements. This preliminary action filters out false positives early in the process, ensuring that subsequent high-sensitivity measurements are performed only where contacts are reliably detected.
3Measurement precision
If point-in-place sensors or strain gauge sensors are used, then tactile force feedback measurement is improved, but ability to localize and measure multiple points deteriorates
Solution Approach 1:
The capacitive sensor array is designed to perform multiple functions: contact localization, contact detection, and force measurement. By utilizing the capacitive properties of the sensor array in different operational modes, the system achieves the functionality of multiple specialized sensors while maintaining a single sensor architecture.
Solution Approach 2:
The system changes the operational parameters of the capacitive sensor array to achieve different measurement objectives. By adjusting sensitivity levels and reading modes, the same sensor array can accurately perform localization and force measurement tasks that would otherwise require different sensor types.
Data Source
AI summary
Provided is a process that includes: obtaining low-sensitivity values mapped to respective locations within an area of a sensor array; determining differences between respective ones of the low-sensitivity values and respective ones of prior values for the locations, one example being tare values for the locations; obtaining a set of detection locations within the area of the sensor array based on differences exceeding a threshold; obtaining, after switching at least a portion of the sensor array to a high sensitivity mode, high sensitivity values mapped to respective locations within the area of the sensor array, each of the locations mapped to a respective second prior value, one example being a tare value in the high sensitivity mode; determining, for each location within the set of detected locations, a value based on the respective high sensitivity value and the respective second prior value; and outputting, the values and the locations.