A temperature control device and method for electrically heated non-burning cigarette smoking articles

Abstract

The present invention discloses a temperature control device for an electrically heated non-combustible cigarette smoking device, and the temperature control device includes the following units: a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, an air pressure detection unit, a button, and a display unit. The present invention also discloses a control method for the temperature control device for an electrically heated non-combustible cigarette smoking device. The present invention uses a high-precision temperature sensor to collect the real-time temperature of the heating unit, and the error in the whole process is smaller, which can meet the requirements of precise temperature control. At the same time, the present invention can adjust the output power of the smoking device according to the air pressure changes caused by different suction strengths, providing consumers with a better suction experience.

Description

Technical Field

[0001] The present invention relates to the field of electric heating non-burning cigarette smoking articles, and in particular to a temperature control device and a control method for electric heating non-burning cigarette smoking articles. Background Art

[0002] As global tobacco control efforts increase and consumers become more aware of the safety and environmental protection of smoking, more and more tobacco companies have joined in the research and development of new tobacco products, and heat-not-burn cigarette products have come into being. Their characteristic of only heating the cigarette instead of burning it greatly reduces the production of harmful components in the smoke while releasing smoke for consumers to inhale.

[0003] At present, most of the heat-not-burn cigarette products on the market are electric heat-not-burn cigarette products. Electric heat-not-burn cigarette smoking utensils heat special cigarettes to release smoke without burning the tobacco or producing a large amount of tar and harmful substances. During the heating process, the heating temperature must be kept within a certain range. If the heating temperature is too low, the cigarette will not be heated sufficiently and the appropriate amount of smoke cannot be baked for consumers to inhale; if the temperature is too high, the cigarette will be burnt, causing the tobacco to carbonize quickly, greatly shortening the smoking time, and failing to bring consumers a pleasant smoking experience.

[0004] At present, the strategy for controlling the heating temperature of smoking devices is to detect the change in the resistance of the heating element, calculate the temperature of the heating element according to the temperature-resistance relationship table of the heating element, and then compare it with the set target temperature. The output power of the heating unit is adjusted accordingly by the controller in order to achieve the purpose of controlling the temperature. However, the TCR curve (temperature coefficient of resistance, referred to as TCR, represents the relative change of resistance when the temperature changes by 1 degree Celsius, in units of ppm / ℃) of the heating element material is mostly nonlinear. The slope of the temperature resistance change curve of some heating element materials is small, resulting in a small change in resistance during the entire heating process, which is difficult to detect, and has great limitations on the heating element material. At the same time, there is a delay in this temperature control process, and the temperature cannot be adjusted in time. The temperature control accuracy is not high during the heating process, which affects the consumer's smoking experience. Summary of the invention

[0005] In view of the above problems, the present invention provides a temperature control device and control method for an electrically heated non-combustible cigarette smoking device. The smoking device temperature control device includes: a power supply unit, an MCU control unit (MCU for short), a power drive unit, a heating unit, a temperature detection unit, an air pressure detection unit, a button and a display unit, etc. The smoking device temperature control device adjusts the output power of the smoking device by collecting the real-time temperature of the heating unit and the air pressure change at the air inlet, so that the smoking device can work within a certain temperature range, and can adjust the output power of the smoking device according to the air pressure change caused by different suction strengths, providing consumers with a better suction experience. The smoking device has high temperature control accuracy and can heat different special cigarettes by setting the target temperature, which greatly expands the scope of application of the smoking device.

[0006] The technical solution of the present invention is as follows:

[0007] The first aspect of the present invention discloses a temperature control device for electrically heated non-combustion cigarettes, the temperature control device comprising the following units: a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, an air pressure detection unit, a button and a display unit;

[0008] Preferably, the MCU control unit is electrically connected to the power supply unit, the air pressure detection unit, and the temperature detection unit upstream, respectively, and is electrically connected to the power drive unit downstream; the MCU control unit is electrically connected to the button and display unit and provides mutual feedback; the power drive unit is electrically connected to the heating unit downstream, the heating unit is electrically connected to the temperature detection unit downstream, and the temperature detection unit is electrically connected to the MCU control unit downstream; the MCU control unit and the button and display unit are electrically connected downstream of the power supply unit.

[0009] The second aspect of the present invention discloses a control method of the temperature control device for the electrically heated non-burning cigarette smoking article, comprising the following steps:

[0010] Step S1: determining whether a cigarette is inserted, if yes, executing step S2; otherwise, switching the working mode of the temperature control device to the sleep mode;

[0011] Step S2: Complete the input of preset parameters through the buttons and display unit and store them in the MCU control unit. The preset parameters include the target temperature T ω , Target air pressure value P ω , target temperature threshold ε1 and target air pressure threshold ε2;

[0012] Step S3: Under the control of the MCU control unit, during the preheating time, the power drive unit heats with an initial constant power to make the heating unit reach the preheating temperature. At this time, the temperature detection unit collects the real-time temperature of the heating unit at a relatively low sampling frequency and feeds it back to the MCU control unit to avoid excessive consumption of hardware; after the heating unit is powered on, it heats the cigarette to release smoke, and an air pressure sensor is set at the air inlet to detect the air pressure change in the cigarette cavity, and the air pressure change is fed back to the MCU control unit. The MCU control unit adjusts the output power of the smoking device according to the fed-back real-time temperature of the heating unit and the air pressure change at the air inlet, thereby achieving temperature control; the power supply unit is composed of a charging module and a lithium battery. The power supply unit can manage the voltage and current during charging and discharging to meet the power supply requirements of each unit;

[0013] Step S4: After the preheating time is over, the temperature detection unit and the air pressure detection unit collect the real-time temperature value of the heating unit and the air pressure value at the air inlet at a relatively high sampling frequency and feed them back to the MCU control unit to ensure the sampling accuracy and compare them with the target temperature T ω And the target air pressure value P ω The deviation is obtained by subtracting, and the output power of the heating unit is controlled by feedback through the PID algorithm;

[0014] Step S5: If the real-time temperature of the heating unit is less than T ω -ε1, under the control of the MCU control unit, the power drive unit increases the output pulse width and the duty cycle becomes larger, thereby increasing the output power of the heating unit; if the real-time temperature of the heating unit is (T ω -ε1,T ω +ε1), the power drive unit maintains the current output pulse width, so that the temperature of the heating unit is stably maintained in the interval (T ω -ε1,T ω +ε1); if the real-time temperature of the heating unit is greater than T ω +ε1, under the control of the MCU control unit, the power driving unit reduces the output pulse width, thereby reducing the output power of the heating unit; synchronously, the air pressure detection unit collects the real-time air pressure value at the air inlet in real time. If the real-time air pressure at the air inlet is less than P ω -ε2, under the control of the MCU control unit, the power drive unit reduces the output pulse width, thereby reducing the output power of the heating unit to reduce the smoke concentration; if the real-time air pressure at the air inlet is (P ω -ε2,P ω+ε2), the power drive unit maintains the current output pulse width and bakes out smoke with appropriate concentration; if the real-time air pressure at the air inlet is greater than P ω +ε2, under the control of the MCU control unit, the power driving unit increases the output pulse width, thereby increasing the output power of the heating unit, and baking out smoke with a higher concentration;

[0015] Step S6: Check whether the MCU control unit receives a stop heating signal. If so, terminate the heating of the temperature control device; otherwise, execute step S4 to keep the temperature of the heating unit within a constant range.

[0016] Each unit of the temperature control device of the present invention has specific components and functions. The button and display unit has an LED display screen; the MCU microcontroller unit is used to control the entire system function, such as button input detection, charging control, output control, LED display, etc.; the MCU microcontroller unit adjusts the output power according to the real-time temperature feedback from the temperature detection unit and the air pressure change feedback from the air pressure detection unit to control the temperature of the heating unit.

[0017] The power driving unit is electrically connected to the MCU control unit and the heating unit respectively. The power driving unit receives the output signal of the MCU control unit and adjusts the output power by outputting pulse width modulation with different duty cycles to control the temperature of the heating unit.

[0018] The temperature detection unit is connected to the heating unit and the MCU control unit respectively, and uses a thermocouple sensor to detect the real-time temperature of the heating unit, and feeds back the real-time temperature of the heating unit to the MCU control unit. The MCU control unit adjusts the temperature of the heating unit according to the deviation between the preset target temperature and the real-time temperature.

[0019] The air pressure detection unit is electrically connected to the MCU control unit. An air pressure sensor is arranged at the air inlet of the smoking device to detect the air pressure change in the cigarette cavity, and the air pressure change value is fed back to the MCU control unit. The air pressure value of the air pressure detection unit is adjusted according to the deviation between the preset target air pressure value and the real-time air pressure value.

[0020] The button and display unit is electrically connected to the MCU control unit, and the target temperature and target air pressure value are set by the button input, and the target temperature and target air pressure value are stored in the MCU control unit. The button and display unit includes an LED screen for displaying parameters such as the power of the power unit, the target temperature setting value, the target air pressure setting value, the real-time temperature value, and the real-time air pressure value.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides a temperature control device and control method for an electrically heated non-combustible cigarette smoking device, which uses a PID algorithm to control the temperature of the smoking device heating unit and the real-time air pressure at the air inlet, and realizes the function of adjusting the output power by changing the pulse width length. Compared with other electronic smoking device temperature control system designs, the beneficial effects of the present invention are: there is no need to input a data table corresponding to the temperature and resistance in the storage unit of the controller in advance. This method indirectly reflects the temperature change through the change of the resistance value, which has a certain error and makes the entire working process more complicated. The present invention uses a high-precision temperature sensor to collect the real-time temperature of the heating unit, and the error in the whole process is smaller, which can meet the requirements of precise temperature control. At the same time, the present invention uses an air pressure sensor to collect the air pressure at the air inlet, and can adjust the output power of the smoking device according to the air pressure changes caused by different suction strengths, providing consumers with a better suction experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the functional modules of the temperature control device for the electrically heated non-burning cigarette smoking device of the present invention;

[0024] Figure 2 is a flow chart of the temperature control method of the present invention;

[0025] Figure 3 is a circuit schematic diagram of a temperature control system according to an embodiment of the present invention; DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. All other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] like Figure 1 As shown, a temperature control device for electrically heated non-combustion cigarette smoking articles comprises the following units: a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, an air pressure detection unit, a button and a display unit;

[0028] Preferably, the upstream of the MCU control unit is electrically connected to the power supply unit, the air pressure detection unit, and the temperature detection unit, respectively, and the downstream of the MCU control unit is electrically connected to the power drive unit; the MCU control unit is electrically connected to the button and display unit and feedback is given to each other; the downstream of the power drive unit is electrically connected to the heating unit, the downstream of the heating unit is electrically connected to the temperature detection unit, and the downstream of the temperature detection unit is electrically connected to the MCU control unit; the downstream of the power unit is electrically connected to the MCU control unit and the button and display unit. The button and display unit have an LED display screen, and the button is connected to the MCU control unit through an I / O interface, so as to realize the input and display of information; the real-time temperature of the heating unit is sent to the MCU control unit, and the heating unit heats the cigarette to release smoke after being powered on, and an air pressure sensor is set at the air inlet to detect the change of air pressure in the cigarette cavity, and the air pressure change value is fed back to the MCU control unit, and the MCU control unit adjusts the output power of the smoking device according to the feedback of the real-time temperature of the heating unit and the change of air pressure at the air inlet, so as to realize the control of temperature. And the output power of the smoking device can be adjusted according to the air pressure change caused by different suction strengths, providing consumers with a better suction experience. The power supply unit is composed of a charging module and a lithium battery. The power supply unit can manage the voltage and current during charging and discharging to meet the power supply requirements of each unit. The MCU microcontroller is used to control the entire system function, key input detection, charging control, output control, LED display, etc. The controller chip model selected by the MCU microcontroller of the present invention is STM32F103RBT6. The power drive unit is electrically connected to the MCU control unit and the heating unit respectively, and the power drive unit receives the output signal of the MCU control unit and adjusts the output power by outputting pulse width modulation with different duty cycles. To achieve control of the temperature of the heating unit.

[0029] The temperature detection unit is connected to the heating unit and the MCU control unit respectively, and uses a thermocouple sensor to detect the real-time temperature of the heating unit, and feeds back the real-time temperature of the heating unit to the MCU control unit. The MCU control unit adjusts the temperature of the heating unit according to the deviation between the preset target temperature and the real-time temperature.

[0030] The air pressure detection unit is electrically connected to the MCU control unit, and an air pressure sensor is arranged at the air inlet to detect the air pressure change in the cigarette cavity, and the air pressure change value is fed back to the MCU control unit, and the air pressure value of the air pressure detection unit is adjusted according to the deviation between the preset target air pressure value and the real-time air pressure value.

[0031] The button and display unit is electrically connected to the MCU control unit, and the target temperature and target air pressure value are set by the button input, and the target temperature and target air pressure value are stored in the MCU control unit. The button and display unit includes an LED screen for displaying parameters such as the power supply unit power, target temperature setting value, target air pressure setting value, real-time temperature value, and real-time air pressure value.

[0032] The specific steps of the control method of the temperature control device for electrically heated non-burning cigarette smoking articles of the present invention are as follows: Figure 2 As shown:

[0033] Step S1: determining whether a cigarette is inserted, if yes, executing step S2; otherwise, switching the working mode of the temperature control device to the sleep mode;

[0034] Step S2: Complete the input of preset parameters through the buttons and display unit and store them in the MCU control unit. The preset parameters include the target temperature T ω , Target air pressure value P ω , target temperature threshold ε1 and target air pressure threshold ε2;

[0035] Step S3: Under the control of the MCU control unit, during the preheating time, the power drive unit heats with an initial constant power to make the heating unit reach the preheating temperature. At this time, the temperature detection unit collects the real-time temperature of the heating unit at a relatively low sampling frequency and feeds it back to the MCU control unit; after the heating unit is powered on, it heats the cigarette to release smoke, and an air pressure sensor is set at the air inlet to detect the air pressure change in the cigarette cavity, and the air pressure change is fed back to the MCU control unit. The MCU control unit adjusts the output power of the smoking device according to the fed-back real-time temperature of the heating unit and the air pressure change at the air inlet, thereby achieving temperature control; the power supply unit is composed of a charging module and a lithium battery, and the power supply unit can manage the voltage and current during charging and discharging to meet the power supply requirements of each unit;

[0036] Step S4: After the preheating time is over, the temperature detection unit and the air pressure detection unit collect the real-time temperature value of the heating unit and the air pressure value at the air inlet at a relatively high sampling frequency and feed them back to the MCU control unit, and compare them with the target temperature T ω And the target air pressure value P ω The deviation is obtained by subtracting, and the output power of the heating unit is controlled by feedback through the PID algorithm;

[0037] [Note] PID is the abbreviation of Proportional, Integral, and Differential. As the name implies, the PID control algorithm is a control algorithm that integrates the three links of proportional, integral, and differential. It is the most mature and widely used control algorithm in continuous systems. This control algorithm appeared in the 1930s and 1940s and is suitable for occasions where the model of the controlled object is not clearly understood. Both actual operation experience and theoretical analysis have shown that when this control law is used to control many industrial processes, relatively satisfactory results can be obtained. The essence of PID control is to perform operations based on the input deviation value according to the functional relationship of proportional, integral, and differential, and the operation results are used to control the output.

[0038] Step S5: If the real-time temperature of the heating unit is less than T ω -ε1, under the control of the MCU control unit, the power drive unit increases the output pulse width and the duty cycle becomes larger, thereby increasing the output power of the heating unit; if the real-time temperature of the heating unit is (T ω -ε1,T ω +ε1), the power drive unit maintains the current output pulse width, so that the temperature of the heating unit is stably maintained in the interval (T ω -ε1,T ω +ε1); if the real-time temperature of the heating unit is greater than T ω +ε1, under the control of the MCU control unit, the power driving unit reduces the output pulse width, thereby reducing the output power of the heating unit; synchronously, the air pressure detection unit collects the real-time air pressure value at the air inlet in real time. If the real-time air pressure at the air inlet is less than P ω -ε2, under the control of the MCU control unit, the power drive unit reduces the output pulse width, thereby reducing the output power of the heating unit to reduce the smoke concentration; if the real-time air pressure at the air inlet is (P ω -ε2,P ω +ε2), the power drive unit maintains the current output pulse width and bakes out smoke with appropriate concentration; if the real-time air pressure at the air inlet is greater than P ω +ε2, under the control of the MCU control unit, the power driving unit increases the output pulse width, thereby increasing the output power of the heating unit, and baking out smoke with a higher concentration;

[0039] Step S6: Check whether the MCU control unit receives a stop heating signal. If so, terminate the heating of the temperature control device; otherwise, execute step S4 to keep the temperature of the heating unit within a constant range.

[0040] Example 1

[0041] like Figure 3 As shown, the temperature control device in this embodiment includes a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, and an air pressure detection unit. The temperature detection unit includes a thermocouple sensor, an A / D converter, and a signal amplification circuit. The smoking device can realize multiple working modes, which can be selected according to the user's preference. In the single temperature variable control mode, the sensor in the MCU control unit generates a low-level signal to put the air pressure detection unit in a suspended state. At this time, the variable controlled by the smoking device is only the temperature. The MCU control unit calculates the deviation between the feedback real-time temperature and the target temperature, generates a PWM signal (Pulse Width Modulation, which can modulate the bias of the gate of the MOS tube according to the change of the corresponding load to achieve the change of the MOS tube conduction time) and transmits it to the gate of the MOS tube (metal oxide semiconductor field effect tube, a power semiconductor device commonly used in power electronics) in the power drive unit, and controls the duty cycle of the output power of the heating unit by adjusting the on / off time of the MOS tube. Two control MOS tubes Q1 and Q2 are used, and the output power of the heating unit is controlled by adjusting the duty cycle of the conduction time of the MOS tubes.

[0042] Example 2

[0043] like Figure 3 As shown, the temperature control device in this embodiment includes a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, and an air pressure detection unit. The air pressure detection unit includes an air pressure sensor, an A / D converter, and a signal amplification circuit. The smoking device can realize multiple working modes, which can be selected according to the user's preference. In the single air pressure variable control mode, the MCU sensor generates a low-level signal to put the temperature detection unit in a suspended state. At this time, the variable controlled by the smoking device is only the air pressure. The MCU control unit calculates the deviation between the feedback real-time air pressure and the target air pressure, generates a PWM signal and transmits it to the gate of the MOS tube in the power drive unit, and controls the duty cycle of the output power of the heating unit by adjusting the on / off time of the MOS tube. Use two-way control MOS tube Q1 and MOS tube Q2, and control the output power of the heating unit by adjusting the duty cycle of the on time of the MOS tube.

[0044] Example 3

[0045] like Figure 3As shown, the temperature control device in this embodiment includes a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, and an air pressure detection unit. The air pressure detection unit includes an air pressure sensor, an A / D converter, and a signal amplification circuit. The temperature detection unit includes a thermocouple sensor, an A / D converter, and a signal amplification circuit. The smoking device can realize multiple working modes and can be selected according to the user's preferences. In the mixed dual variable control mode, the MCU sensor generates a high-level signal and transmits it to the temperature detection unit and the air pressure detection unit respectively, so that the temperature detection unit and the air pressure detection unit are both in working state. At this time, the smoking device makes a decision based on the temperature and air pressure dual variables. The MCU control unit calculates the feedback temperature and air pressure deviation respectively, generates a PWM signal and transmits it to the gate of the MOS tube in the power drive unit, and controls the duty cycle of the output power of the heating unit by adjusting the on / off time of the MOS tube. Use two-way control MOS tube Q1 and MOS tube Q2, and control the output power of the heating unit by adjusting the duty cycle of the on time of the MOS tube.

[0046] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for controlling a temperature control device for an electrically heated non-burning cigarette, characterized in that: The temperature control device comprises the following units: a power supply unit, an MCU control unit, a power drive unit, a heating unit, a temperature detection unit, an air pressure detection unit, a button and a display unit; the upstream of the MCU control unit is electrically connected to the power supply unit, the air pressure detection unit and the temperature detection unit respectively, and the downstream of the MCU control unit is electrically connected to the power drive unit; the MCU control unit is electrically connected to the button and the display unit and provides mutual feedback; the downstream of the power drive unit is electrically connected to the heating unit, the downstream of the heating unit is electrically connected to the temperature detection unit, and the downstream of the temperature detection unit is electrically connected to the MCU control unit; the downstream of the power supply unit is electrically connected to the MCU control unit and the button and the display unit respectively; The control method comprises the following steps: Step S1: determining whether a cigarette is inserted, if yes, executing step S2; otherwise, switching the working mode of the temperature control device to the sleep mode; Step S2: Complete the input of preset parameters through the buttons and display unit and store them in the MCU control unit. The preset parameters include the target temperature T ω , Target air pressure value P ω , target temperature threshold ε1 and target air pressure threshold ε2; Step S3: Under the control of the MCU control unit, during the preheating time, the power driving unit heats the heating unit at an initial constant power to make the heating unit reach the preheating temperature. At this time, the temperature detection unit collects the real-time temperature of the heating unit at a relatively low sampling frequency and feeds it back to the MCU control unit; Step S4: After the preheating time is over, the temperature detection unit and the air pressure detection unit collect the real-time temperature value of the heating unit and the air pressure value at the air inlet at a relatively high sampling frequency and feed them back to the MCU control unit, and compare them with the target temperature T ω And the target air pressure value P ω The deviation is obtained by subtracting, and the output power of the heating unit is controlled by feedback through the PID algorithm; Step S5: If the real-time temperature of the heating unit is less than T ω -ε1, under the control of the MCU control unit, the power driving unit increases the output pulse width and the duty cycle becomes larger, thereby increasing the output power of the heating unit; If the real-time temperature of the heating unit is (T ω -ε 1， T ω +ε1), the power drive unit maintains the current output pulse width, so that the temperature of the heating unit is stably maintained in the interval (T ω -ε 1， T ω +ε1); if the real-time temperature of the heating unit is greater than T ω +ε1, under the control of the MCU control unit, the power driving unit reduces the output pulse width, thereby reducing the output power of the heating unit; synchronously, the air pressure detection unit collects the real-time air pressure value at the air inlet in real time. If the real-time air pressure at the air inlet is less than P ω -ε2, under the control of the MCU control unit, the power drive unit reduces the output pulse width, thereby reducing the output power of the heating unit to reduce the smoke concentration; if the real-time air pressure at the air inlet is (P ω -ε2,P ω +ε2), the power drive unit maintains the current output pulse width and bakes out smoke with appropriate concentration; if the real-time air pressure at the air inlet is greater than P ω +ε2, under the control of the MCU control unit, the power driving unit increases the output pulse width, thereby increasing the output power of the heating unit, and baking out smoke with a higher concentration; Step S6: Check whether the MCU control unit receives a stop heating signal. If so, terminate the heating of the temperature control device; otherwise, execute step S4 to keep the temperature of the heating unit within a constant range.

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