Capacitive Touch Sensing With Temperature Drift Compensation
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Solution Overview
Problem
Capacitive touch sensors in safety-interlock systems for machinery and equipment often experience unreliable detection of user or operator presence due to temperature drift, leading to unintended deactivation or activation of safety features, causing mistakes, injuries, frustration, or delays.
Innovation Solution
Implementing a temperature-compensated touch sensing method that adjusts sensor signals based on temperature measurements to determine a reliable touch state, ensuring accurate detection of user presence and preventing latching issues by applying an active temperature compensation algorithm from startup, modifying the sensor signal rather than the criteria for touch state determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature compensation is not applied to capacitive touch sensors, then the device complexity is low, but the reliability of user presence detection deteriorates due to temperature drift
Solution Approach 1:
The patent applies temperature compensation by adjusting the sensor signal based on temperature parameters. A temperature compensation value is calculated based on the temperature difference between current and reference conditions, and this value is used to adjust the capacitive touch sensor signal to compensate for temperature drift effects.
Solution Approach 2:
The patent introduces a temperature compensation algorithm as an intermediary between the temperature sensor and the touch sensor signal processing. This intermediary calculates compensation values based on temperature measurements and applies them to correct the touch sensor readings, effectively mediating the temperature drift issue.
2Measurement precision
If temperature compensation algorithm is applied from startup, then the measurement precision of touch state is improved, but the loss of time during startup increases
Solution Approach 1:
The patent performs temperature compensation calculations during the startup phase to establish accurate baseline values for touch state detection. By completing the temperature compensation algorithm execution during startup, the system ensures that precise temperature-compensated touch detection is available for subsequent operation, preventing future detection errors.
Solution Approach 2:
The patent implements continuous temperature monitoring and compensation throughout device operation. The temperature compensation is not a one-time event but an ongoing process that continuously adjusts touch sensor readings based on current temperature conditions, ensuring sustained detection accuracy.
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 enhances the reliability of user presence detection, preventing unintended use of machinery or equipment and reducing operator frustration by accurately distinguishing between touched and untouched states, thus ensuring safer and more efficient operation.
Implementation Method 1
receiving, by the processor and from a temperature sensor of the device, a temperature value corresponding to a first temperature measurement associated with the device and captured by the temperature sensor
Implementation Method 2
The first sensor may be a capacitive touch sensor and the first measured value may be a capacitive value
Data Source
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AI summary
Embodiments included herein are directed towards a method for determining a temperature-compensated touch state of a device, and related systems. The method may include receiving, by a processor of the device and from a first sensor of the device, a first measured value corresponding to a first sensor measurement captured by the first sensor. The method may further include receiving, by the processor and from a temperature sensor of the device, a temperature value corresponding to a first temperature measurement associated with the device and captured by the temperature sensor. The method may also include adjusting a signal corresponding to the first sensor measurement based upon, at least in part, the temperature value, to create a temperature-compensated touch signal. The method may additionally include determining, by the processor, the temperature-compensated touch state of the device based upon, at least in part, the temperature-compensated touch signal.