Hot Wire Anemometer Control for Puff Detection Across Ambient Changes
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Solution Overview
Problem
Existing non-nicotine electronic vaping devices lack efficient control mechanisms for managing power delivery to hot wire anemometers (HWAs) based on temperature variations, leading to suboptimal performance during puff detection and ambient temperature changes.
Innovation Solution
Implementing a dual PID control system within the non-nicotine e-vaping device, where a first PID controller manages power delivery to the HWA based on temperature setpoints, and a second PID controller adjusts the temperature setpoint in response to detected ambient temperature changes, while also generating a puff detection signal based on drive signal gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single PID controller is used to control power delivery to the HWA, then the control system is simple, but the device cannot adapt to ambient temperature changes and maintain optimal performance
Solution Approach 1:
The control system is segmented into two distinct PID controllers: a first PID controller that manages power delivery to the HWA based on temperature setpoints, and a second PID controller that adjusts the temperature setpoint in response to ambient temperature changes. This segmentation allows each controller to handle specific aspects of temperature control, improving adaptability while maintaining manageable complexity through functional decomposition.
Solution Approach 2:
The temperature setpoint acts as an intermediary parameter between the second PID controller (which detects ambient temperature changes) and the first PID controller (which controls power delivery). The second PID controller adjusts the setpoint based on ambient conditions, and the first PID controller uses this adjusted setpoint to control the HWA, creating a cascaded control structure that enables adaptive temperature control.
2Measurement precision
If the HWA operates at fixed temperature setpoint, then the control system is stable, but puff detection accuracy decreases during ambient temperature variations
Solution Approach 1:
The second PID controller continuously monitors ambient temperature changes and provides feedback by adjusting the temperature setpoint accordingly. This feedback mechanism ensures that the HWA operates at an optimal temperature adapted to current ambient conditions, thereby maintaining high puff detection accuracy across varying environmental temperatures.
Solution Approach 2:
The temperature setpoint transitions from a static fixed value to a dynamic parameter that automatically adjusts in response to ambient temperature changes. The second PID controller enables the setpoint to vary dynamically based on environmental conditions, allowing the HWA to maintain optimal operating temperature and detection accuracy across different ambient temperatures.
3Reliability
If power delivery to the HWA is not adjusted based on temperature, then the device structure is simple, but performance deteriorates during ambient temperature changes
Solution Approach 1:
The dual PID control system enables the device to self-adjust to ambient temperature changes without external intervention. The second PID controller automatically detects ambient temperature variations and modifies the temperature setpoint, while the first PID controller automatically adjusts power delivery to the HWA, allowing the system to maintain consistent performance across varying environmental conditions through autonomous temperature management.
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 precise control of power delivery to the HWA, improving puff detection accuracy and maintaining optimal performance across varying ambient temperatures, thus enhancing the overall vaping experience.
Implementation Method 1
hot wire anemometer (HWA) ... temperature of a heated element of the HWA
Implementation Method 2
controlling, by a first PID controller, a level of power applied by the non-nicotine e-vaping device to the HWA based on a temperature of a heated element of the HWA and a temperature setpoint
Data Source
AI summary
A method of controlling a hot wire anemometer (HWA) of a non-nicotine e-vaping device includes controlling, by a first PID controller, a level of power applied by the non-nicotine e-vaping device to the HWA based on a temperature of a heated element of the HWA and a temperature setpoint; generating a puff detection signal indicating whether or not a puff is currently occurring with respect to the non-nicotine e-vaping device; and while the puff detection signal indicates that a puff is not currently occurring with respect to the non-nicotine e-vaping device, detecting, by a second PID controller, a change in an ambient temperature of the HWA, and controlling, by the second PID controller, the temperature setpoint such that the temperature setpoint changes in response to the detected change in the ambient temperature of the HWA.