Hot Wire Anemometer Control for Puff Detection and Ambient Tracking
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Solution Overview
Problem
Nicotine electronic vaping devices face challenges in efficiently controlling the hot wire anemometer (HWA) to maintain optimal vapor production and ambient temperature regulation during varying usage conditions.
Innovation Solution
The implementation of a method that utilizes two PID controllers to control the power applied to the HWA based on temperature setpoints and ambient temperature changes, ensuring precise power management and vapor production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single PID controller is used to control the HWA, then the control system is simple, but the temperature regulation precision and ambient temperature adaptation are insufficient
Solution Approach 1:
The control system is segmented into two independent PID controllers: a first PID controller for regulating the heated element temperature during puff detection, and a second PID controller for tracking and adjusting the ambient temperature. This segmentation allows each controller to specialize in one temperature parameter, achieving precise dual-temperature control without requiring a complex single-controller solution.
Solution Approach 2:
The dual PID controller system provides multi-functionality by simultaneously handling both heated element temperature control and ambient temperature tracking. The system can adapt to different operating conditions (puff detection mode and ambient tracking mode) using the same hardware architecture, making the control system universally applicable to various vaping scenarios.
2Productivity
If the HWA temperature is maintained at a high setpoint, then the vapor production is optimal, but the energy consumption increases
Solution Approach 1:
The system dynamically adjusts the HWA operating mode based on real-time conditions. During active puffs, the first PID controller maintains the heated element at a high temperature setpoint for optimal vapor production. During idle periods, the second PID controller tracks ambient temperature and adjusts the setpoint accordingly, reducing energy consumption when high vapor production is not required. This dynamic switching between operational states optimizes the balance between productivity and energy usage.
Solution Approach 2:
The system changes the temperature setpoint parameter based on operational state. The first PID controller uses a high temperature setpoint during puff detection for maximum vapor production efficiency. The second PID controller modifies the setpoint based on ambient temperature conditions during idle periods, allowing the system to adapt energy consumption levels to match actual usage requirements while maintaining vapor production capability when needed.
3Adaptability or versatility
If the ambient temperature changes are not tracked, then the control system is stable, but the vapor quality deteriorates under varying environmental conditions
Solution Approach 1:
The second PID controller implements feedback by continuously monitoring the drive signal setting value changes that indicate ambient temperature variations. When ambient temperature changes are detected through these drive signal variations, the controller automatically adjusts the temperature setpoint to compensate, ensuring consistent vapor quality across different environmental conditions while maintaining overall system stability through controlled adaptation.
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 effective puff detection, flow rate determination, and ambient temperature adjustment, resulting in improved vapor quality and device performance stability.
Implementation Method 1
a heater configured to generate a nicotine vapor by heating the nicotine pre-vapor formulation
Implementation Method 2
detecting, by a second PID controller, a change in an ambient temperature of the HWA
Data Source
AI summary
A method of controlling a hot wire anemometer (HWA) of a nicotine e-vaping device includes controlling, by a first PID controller, a level of power applied by the 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 nicotine e-vaping device; and while the puff detection signal indicates that a puff is not currently occurring with respect to the 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.