Wind speed detection method and circuit

Abstract

The invention relates to the technical field of environmental parameter detection, in particular to a wind speed detection method and circuit, comprising: firstly obtaining A, B, RTn-cold air set and RTn-hot air set by RTn, and obtaining C, RTp-cold air set and RTp-hot air set by RTp; then generating D by real-time detection by RTp, until D>A, judging whether it is cold air or hot air at this time according to B, C, D and E; when it is hot air, outputting the hot air speed after comprehensive judgment according to RTn-hot air set and RTp-hot air set respectively by E and D; when it is cold air, outputting the cold air speed according to RTp-cold air set accordingly by D; thereby realizing multiple wind speed-related judgments on the environment space according to the characteristics of two components, and then performing wind speed detection on more application scenarios, and the circuit cost is lower and the application is easier to expand.

Description

Technical Field

[0001] The invention relates to the technical field of environmental parameter detection, and in particular to a wind speed detection method and circuit. Background Art

[0002] At present, obtaining wind speed information through wind speed detection is of great significance to all walks of life. For example, in industrial applications, various pipelines are set up at the production site, and the wind speed in the pipeline needs to be detected to know the internal wind speed conditions as early as possible, so as to ensure that the wind speed distribution of each pipeline is uniform by adjusting the wind speed, thereby ensuring the stability of the aerodynamic conditions in the boiler.

[0003] A commonly used wind speed detection method is to use the characteristics of the thermistor itself, set the thermistor at the wind speed detection point to sense whether there is wind around the detection point, and convert the wind speed according to the change in the resistance value of the thermistor.

[0004] However, the above wind speed detection method is only effective for cold wind detection, and cannot be used for hot wind detection, let alone distinguishing between cold and hot air; therefore, the wind speed detection environment is limited, and cannot be applied to wind speed detection in an environment where cold and hot air alternate. Summary of the invention

[0005] In view of the above-mentioned defects, the purpose of the present invention is to propose a wind speed detection method and circuit, which can realize multiple wind speed-related judgments on the environmental space according to the characteristics of two components, so that wind speed detection can be performed on more application scenarios, and the circuit cost is lower and it is easier to expand applications.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A wind speed detection method comprises the following steps:

[0008] S1: obtain the calibration value A, the initial temperature value B, the RTn-cold wind speed data set and the RTn-hot wind speed data set from the negative temperature coefficient element RTn; obtain the initial temperature value C, the RTp-cold wind speed data set and the RTp-hot wind speed data set from the positive temperature coefficient element RTp;

[0009] S2: The positive temperature coefficient element RTp detects the change of ambient temperature in real time to generate a detection value D; when D>A, execute step S3; otherwise, execute step S2 in a loop;

[0010] S3: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate the detection value E and the detection value D; according to the initial temperature value B, the initial temperature value C, the detection value D and the detection value E, it is judged whether it is cold air or hot air at this time; when the judgment result is hot air, step S4 is executed; when the judgment result is cold air, step S5 is executed;

[0011] S4: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively, and the detection value E and the detection value D are respectively outputted after comprehensive judgment based on the RTn-hot air speed data set and the RTp-hot air speed data set;

[0012] S5: The positive temperature coefficient element RTp detects the change of the ambient temperature in real time to generate a detection value D and outputs the cold wind speed according to the RTp-cold wind speed data set.

[0013] Furthermore, in step S1, the relationship between RTn and the cold wind speed data set is: U= N;

[0014] The relationship between RTn and hot air speed data set is: U = N;

[0015] The relationship between RTp and cold wind speed data set is: U = N;

[0016] The relationship between RTp and hot wind speed data set is: U = N;

[0017] Wherein: U is the detection value of the negative temperature coefficient element RTn or the positive temperature coefficient element RTp, N is the cold air speed or the hot air speed, a is the cold air duct coefficient, b is the hot air duct coefficient, 0<a<1, 0<b<1.

[0018] Furthermore, the step S3 includes the following sub-steps:

[0019] S31: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D;

[0020] S32: When |DC| < preset threshold F and |EB| < preset threshold F, it is hot air, and step S4 is executed; otherwise, sub-step S33 is executed;

[0021] S33: When |DC|>preset threshold G and |EB|>preset threshold G, it is cold wind, and step S5 is executed; otherwise, sub-step S31 is executed.

[0022] Furthermore, in the sub-step S32 and the sub-step S33: the preset threshold F is less than the preset threshold G.

[0023] Furthermore, the step S1 includes the following sub-steps:

[0024] S11: experimentally obtain experimental detection values ​​of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp corresponding to the change of the cold wind and hot wind speed respectively, and collect the experimental detection values ​​and the wind speed into RTn-cold wind speed data set, RTn-hot wind speed data set, RTp-cold wind speed data set and RTp-hot wind speed data set respectively in one-to-one correspondence;

[0025] S12: After the system is powered on, the negative temperature coefficient element RTn detects and records the initial temperature value B, and the positive temperature coefficient element RTp detects and records the initial temperature value C;

[0026] S13: After the wind speed detection starts, the negative temperature coefficient element RTn detects the calibration value A of the initial ambient temperature and records it.

[0027] Furthermore, the step S4 includes the following sub-steps:

[0028] S41: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively;

[0029] S42: The detection value E and the detection value D are respectively used to obtain the hot air speed N1 and the hot air speed N2 according to the RTn-hot air speed data set and the RTp-hot air speed data set; when N1=N2, execute sub-step S43; otherwise, execute sub-step S41;

[0030] S43: Output hot air speed N1 or N2.

[0031] Furthermore, the step S5 may also be: the negative temperature coefficient element RTn detects the change of the ambient temperature in real time to generate a detection value E and outputs the cold wind speed accordingly according to the RTn-cold wind speed data set.

[0032] Furthermore, the sub-step S12 also includes: after the system is powered on, it is necessary to wait for the timing to reach a preset preheating time.

[0033] A wind speed detection circuit, applying the above-mentioned wind speed detection method, comprises a microcontroller, a capacitor EC1, a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a negative temperature coefficient element RTn and a positive temperature coefficient element RTp; the positive electrode of the capacitor EC1, the power supply end of the microcontroller, one end of the resistor R1 and one end of the resistor R2 are all connected to a DC power supply, the negative electrode of the capacitor EC1, the GND end of the microcontroller, one end of the capacitor C1, one end of the capacitor C2, one end of the negative temperature coefficient element RTn and one end of the positive temperature coefficient element RTp are all grounded, the other end of the capacitor C1, the other end of the resistor R1 and the other end of the negative temperature coefficient element RTn are all electrically connected to the first input end of the microcontroller, and the other end of the capacitor C2, the other end of the resistor R2 and the other end of the positive temperature coefficient element RTp are all electrically connected to the second input end of the microcontroller.

[0034] Furthermore, the negative temperature coefficient element RTn is an NTC thermistor, and the positive temperature coefficient element RTp is a PTC thermistor.

[0035] The technical solution provided by the present invention may include the following beneficial effects: the method obtains basic judgment data according to the characteristics of two elements, a negative temperature coefficient element RTn and a positive temperature coefficient element RTp; then, according to the sensitivity of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp to temperature changes (i.e., the sensitivity to wind speed changes), the low-sensitivity RTn is used to detect and obtain a detection value representing the presence or absence of wind (i.e., the calibration value A), and the high-sensitivity RTp detects the temperature change in real time to generate a detection value D and a calibration value A for cyclic comparison to determine whether there is wind in the environment at this time; then, a set of corresponding relationships between the two elements and the cold and hot wind speeds is used, and the hot wind speed with a higher identification difficulty is comprehensively judged by the two elements, and the cold wind speed is identified by the positive temperature coefficient element RTp with a higher sensitivity; finally, the presence or absence of wind, cold and hot wind judgment, and cold and hot wind speed judgment of the environment space are realized, so that wind speed detection is performed on more application scenarios, and the circuit implementation cost is lower, which is more convenient for expanding the application of the judgment results. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a wind speed detection method according to one embodiment of the present invention.

[0037] Figure 2 Yes Figure 1 Step S1 of a wind speed detection method is shown.

[0038] Figure 3 Yes Figure 1 Step S3 of a wind speed detection method is shown.

[0039] Figure 4Yes Figure 1 Step S4 of a wind speed detection method is shown.

[0040] Figure 5 Yes Figure 1 A graph of the RTn-cold wind speed data set is shown.

[0041] Figure 6 Yes Figure 1 A graph of the RTn-hot wind speed data set is shown.

[0042] Figure 7 Yes Figure 1 A graph of the RTp-cold wind speed data set is shown.

[0043] Figure 8 Yes Figure 1 A graph of the RTp-hot wind speed data set is shown.

[0044] Fig. 9 The present invention is a circuit diagram of a wind speed detection circuit according to one embodiment of the present invention.

[0045] Among them: microcontroller 1, capacitor EC1, capacitor C1, capacitor C2, resistor R1, resistor R2, negative temperature coefficient element RTn and positive temperature coefficient element RTp. DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0047] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0049] Combine the following Figures 1 to 9 , describing a wind speed detection method and circuit according to an embodiment of the present invention.

[0050] Example 1

[0051] A wind speed detection method comprises the following steps:

[0052] S1: obtain the calibration value A, the initial temperature value B, the RTn-cold wind speed data set and the RTn-hot wind speed data set from the negative temperature coefficient element RTn; obtain the initial temperature value C, the RTp-cold wind speed data set and the RTp-hot wind speed data set from the positive temperature coefficient element RTp;

[0053] S2: The positive temperature coefficient element RTp detects the change of ambient temperature in real time to generate a detection value D; when D>A, execute step S3; otherwise, execute step S2 in a loop;

[0054] S3: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate the detection value E and the detection value D; according to the initial temperature value B, the initial temperature value C, the detection value D and the detection value E, it is judged whether it is cold air or hot air at this time; when the judgment result is hot air, step S4 is executed; when the judgment result is cold air, step S5 is executed;

[0055] S4: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively, and the detection value E and the detection value D are respectively outputted after comprehensive judgment based on the RTn-hot air speed data set and the RTp-hot air speed data set;

[0056] S5: The positive temperature coefficient element RTp detects the change of the ambient temperature in real time to generate a detection value D and outputs the cold wind speed according to the RTp-cold wind speed data set.

[0057] The present invention proposes a wind speed detection method and a preferred embodiment of a circuit, such as Figure 1As shown, first, the negative temperature coefficient element RTn obtains the detection value representing its initial temperature as the initial temperature value B, obtains a one-to-one correspondence set representing the temperature change of its detection value caused by the cold wind speed as the RTn-cold wind speed data set, and obtains a one-to-one correspondence set representing the temperature change of its detection value caused by the hot wind speed as the RTn-hot wind speed data set; the positive temperature coefficient element RTp obtains the detection value representing its initial temperature as the initial temperature value C, obtains a one-to-one correspondence set representing the temperature change of its detection value caused by the cold wind speed as the RTp-cold wind speed data set, and obtains a one-to-one correspondence set representing the temperature change of its detection value caused by the cold wind speed as the RTp-hot wind speed data set; thereby obtaining subsequent judgment data. Furthermore, compared with the positive temperature coefficient element RTp (such as a PTC thermistor) and the negative temperature coefficient element RTn (such as an NTC thermistor), RTp is more sensitive to temperature changes than RTn. When the wind speed causes the ambient temperature to change, the detection value of RTp changes more. Therefore, the detection value representing the presence or absence of wind (i.e., the calibration value A) is obtained by detecting RTn, which is relatively insensitive to wind speed. In step S2, RTp, which is relatively sensitive to wind speed, detects the temperature change in real time to generate a detection value D and a calibration value A for cyclic comparison to determine whether there is wind in the environment at this time.

[0058] When it is confirmed that there is wind, the detection values ​​E and D are obtained in real time and combined with the previously prepared data to comprehensively judge whether the wind at this time is cold wind or hot wind; if it is hot air, since hot air has a certain amount of heat, two elements RTn and RTp with different temperature sensitivities are needed to comprehensively judge the hot air speed at this time and output it based on the set of relationships between themselves and the wind speed; if it is cold wind, since cold wind can intuitively lower the ambient temperature, it is preferred to detect the detection value D of RTp which is more sensitive to temperature and directly correspond to the RTp-cold wind speed data set to output the cold wind speed accordingly.

[0059] In summary, the method determines whether there is wind, hot and cold wind, and hot and cold wind speed in the environment space according to the application of the characteristics of the two elements, the negative temperature coefficient element RTn and the positive temperature coefficient element RTp, so that wind speed detection can be performed for more application scenarios.

[0060] Further, in step S1: the relationship between RTn and the cold wind speed data set is: U= N;

[0061] The relationship between RTn and hot air speed data set is: U = N;

[0062] The relationship between RTp and cold wind speed data set is: U = N;

[0063] The relationship between RTp and hot wind speed data set is: U = N;

[0064] Wherein: U is the detection value of the negative temperature coefficient element RTn or the positive temperature coefficient element RTp, N is the cold air speed or the hot air speed, a is the cold air duct coefficient, b is the hot air duct coefficient, 0<a<1, 0<b<1.

[0065] In this embodiment, the relationship between the negative temperature coefficient element RTn and the positive temperature coefficient element RTp and the wind speed can be fitted into a curve representing the one-to-one correspondence through previous experimental summary, such as Figures 5 to 8 As shown. Through the curve analysis, it can be known that the four relationship sets can be summarized into four relationship equations, so that the wind speed can be derived from the detection value of the component or the detection value can be derived from the wind speed by using the relationship equations, so that the data of the four sets in step S1 can be directly generated into sets by the relationship equations.

[0066] It should be noted that the cold air duct coefficient a and the hot air duct coefficient b (i.e., drag coefficient) are measured according to application scenarios (i.e., calibrated according to wind speed environment tests) or summarized from actual usage experience.

[0067] Furthermore, step S3 includes the following sub-steps:

[0068] S31: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D;

[0069] S32: When |DC| < preset threshold F and |EB| < preset threshold F, it is hot air, and step S4 is executed; otherwise, sub-step S33 is executed;

[0070] S33: When |DC|>preset threshold G and |EB|>preset threshold G, it is cold wind, and step S5 is executed; otherwise, sub-step S31 is executed.

[0071] In this embodiment, Figure 3 As shown, because hot air has its own heat and has little influence on the temperature drop, the detection value changes affecting RTn and RTp are small. Therefore, when it is confirmed that there is wind in step S2, the detection value with a small change is hot air. Therefore, a preset threshold F is set to see whether the change value is greater than the preset threshold F to determine whether it is hot air; because cold air has a greater influence on the temperature drop, the detection value changes affecting RTn and RTp are large. Therefore, when it is confirmed that there is wind in step S2, the detection value with a large change is cold wind. Therefore, a preset threshold G is set to see whether the change value is greater than the preset threshold G to determine whether it is cold air; finally, according to the logic of first judging the small change value and then judging the large change value, a loop judgment is performed until the hot and cold air judgment result is obtained.

[0072] Further, in sub-step S32 and sub-step S33: the preset threshold F<preset threshold G.

[0073] In this embodiment, when it is confirmed that the hot air detection change value is smaller than the cold air detection change value, and the loop judgment logic of first small and then large in step S3, in order to avoid overlapping judgment intervals, it is preferred that F<G.

[0074] Furthermore, step S1 includes the following sub-steps:

[0075] S11: experimentally obtain experimental detection values ​​of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp corresponding to the change of the cold wind and hot wind speed respectively, and collect the experimental detection values ​​and the wind speed into RTn-cold wind speed data set, RTn-hot wind speed data set, RTp-cold wind speed data set and RTp-hot wind speed data set respectively in one-to-one correspondence;

[0076] S12: After the system is powered on, the negative temperature coefficient element RTn detects and records the initial temperature value B, and the positive temperature coefficient element RTp detects and records the initial temperature value C;

[0077] S13: After the wind speed detection starts, the negative temperature coefficient element RTn detects the calibration value A of the initial ambient temperature and records it.

[0078] In this embodiment, Figure 2 As shown, in addition to being generated by the relational expression, the data of the four sets can also be obtained by experimental testing in advance and entered for subsequent table lookup when the relational expression is not summarized. Because the initial temperature value B is the detection value for knowing the degree of change of the detection value of the negative temperature coefficient element RTn, and is used for judging the hot and cold winds in step S3, it is necessary to ensure that the initial temperature value B is measured in the initial state. Therefore, the negative temperature coefficient element RTn detects the initial temperature value B and records it when the system is powered on (close to the windless state); similarly, the positive temperature coefficient element RTp also detects the initial temperature value C and records it when the system is powered on. Because the starting temperature of the wind speed detection cannot be in the windless state, the detection value representing the starting temperature (starting wind speed) at the start of the RTn detection with lower temperature sensitivity is directly used as the calibration value A. If the detection value is greater than A, it can be considered that there is wind.

[0079] Further, step S4 includes the following sub-steps:

[0080] S41: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively;

[0081] S42: The detection value E and the detection value D are respectively used to obtain the hot air speed N1 and the hot air speed N2 according to the RTn-hot air speed data set and the RTp-hot air speed data set; when N1=N2, execute sub-step S43; otherwise, execute sub-step S41;

[0082] S43: Output hot air speed N1 or N2.

[0083] In this embodiment, Figure 4 As shown, because the hot air speed requires two sets for comprehensive judgment, the hot air speed output by the two sets may be inconsistent. To ensure that the hot air speed output result is accurate, continuous cyclic detection is performed until the output results of the two sets are the same and then output.

[0084] Furthermore, step S5 may also be: the negative temperature coefficient element RTn detects the change of the ambient temperature in real time to generate a detection value E and outputs the cold wind speed accordingly according to the RTn-cold wind speed data set.

[0085] In this embodiment, in application scenarios where the sensitivity of wind speed detection is not required to be high, the cold wind speed determination in step S5 can also be performed using a negative temperature coefficient element RTn with a lower sensitivity.

[0086] Furthermore, sub-step S12 also includes: after the system is powered on, it is necessary to wait for the timing to reach a preset preheating time.

[0087] In this embodiment, when the positive temperature coefficient element RTp uses a PTC thermistor, the PTC thermistor needs to be preheated for a certain period of time (about 30 seconds) before working. Therefore, before the positive temperature coefficient element RTp detects and records the initial temperature value C, it is necessary to power on and wait for the timing to reach the preset preheating time before starting detection and recording to ensure that the data is accurate and valid.

[0088] Example 2

[0089] A wind speed detection circuit, applying the above-mentioned wind speed detection method, comprises a microcontroller 1, a capacitor EC1, a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a negative temperature coefficient element RTn and a positive temperature coefficient element RTp; the positive electrode of the capacitor EC1, the power supply end of the microcontroller 1, one end of the resistor R1 and one end of the resistor R2 are all connected to a DC power supply, the negative electrode of the capacitor EC1, the GND end of the microcontroller 1, one end of the capacitor C1, one end of the capacitor C2, one end of the negative temperature coefficient element RTn and one end of the positive temperature coefficient element RTp are all grounded, the other end of the capacitor C1, the other end of the resistor R1 and the other end of the negative temperature coefficient element RTn are all electrically connected to the first input end of the microcontroller 1, and the other end of the capacitor C2, the other end of the resistor R2 and the other end of the positive temperature coefficient element RTp are all electrically connected to the second input end of the microcontroller 1.

[0090] In this embodiment, a preferred embodiment of a wind speed detection circuit is also proposed to apply the above method, such as Fig. 9 As shown, after circuit analysis, it is obtained that: the detection value U of the negative temperature coefficient element RTn = UDC*RTn / (RTn+R1); the detection value U of the positive temperature coefficient element RTp = UDC*RTp / (RTp+R2); wherein: UDC is the DC power supply voltage, RTn is the resistance value of the negative temperature coefficient element RTn that is negatively correlated with temperature changes, RTp is the resistance value of the positive temperature coefficient element RTp that is positively correlated with temperature changes, R1 is the resistance value of the R1 resistor, and R2 is the resistance value of the R2 resistor; thus, the microcontroller 1 (such as MCU) can obtain the detection values ​​of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp in real time, and the microcontroller 1 is connected to the expansion circuit, the host computer or the display screen to output the final wind speed result, so as to adapt to more application scenarios and meet the requirements of the above-mentioned wind speed detection method, and more importantly, the circuit cost is lower.

[0091] Further, the negative temperature coefficient element RTn is an NTC thermistor, and the positive temperature coefficient element RTp is a PTC thermistor.

[0092] In this embodiment, the negative temperature coefficient element RTn is preferably an NTC thermistor, and the positive temperature coefficient element RTp is preferably a PTC thermistor, which meets the definition and requirements of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp in the above method.

[0093] A wind speed detection method and other circuit configurations and operations according to an embodiment of the present invention are well known to those skilled in the art and will not be described in detail herein.

[0094] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0095] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wind speed detection method, characterized in that: The following steps are involved: S1: obtain the calibration value A, the initial temperature value B, the RTn-cold wind speed data set and the RTn-hot wind speed data set from the negative temperature coefficient element RTn; obtain the initial temperature value C, the RTp-cold wind speed data set and the RTp-hot wind speed data set from the positive temperature coefficient element RTp; S2: The positive temperature coefficient element RTp detects the change of ambient temperature in real time to generate a detection value D; when D>A, execute step S3; otherwise, execute step S2 in a loop; S3: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate the detection value E and the detection value D; according to the initial temperature value B, the initial temperature value C, the detection value D and the detection value E, it is judged whether it is cold air or hot air at this time; when the judgment result is hot air, step S4 is executed; when the judgment result is cold air, step S5 is executed; S4: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively, and the detection value E and the detection value D are respectively outputted after comprehensive judgment based on the RTn-hot air speed data set and the RTp-hot air speed data set; S5: The positive temperature coefficient element RTp detects the change of ambient temperature in real time to generate a detection value D and outputs the cold wind speed according to the RTp-cold wind speed data set; In step S1: the relationship between RTn and the cold wind speed data set is: U= N; The relationship between RTn and hot air speed data set is: U = N; The relationship between RTp and cold wind speed data set is: U = N; The relationship between RTp and hot wind speed data set is: U = N; Wherein: U is the detection value of the negative temperature coefficient element RTn or the positive temperature coefficient element RTp, N is the cold air speed or the hot air speed, a is the cold air duct coefficient, b is the hot air duct coefficient, 0<a<1, 0<b<1.

2. A wind speed detection method according to claim 1, characterized in that: The step S3 comprises the following sub-steps: S31: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp respectively detect the change of the ambient temperature in real time to generate a detection value E and a detection value D; S32: When |DC| < preset threshold F and |EB| < preset threshold F, it is hot air, and step S4 is executed; otherwise, sub-step S33 is executed; S33: When |DC|>preset threshold G and |EB|>preset threshold G, it is cold wind, and step S5 is executed; otherwise, sub-step S31 is executed.

3. A wind speed detection method according to claim 2, characterized in that: In the sub-step S32 and the sub-step S33: the preset threshold F<the preset threshold G.

4. A wind speed detection method according to claim 1, characterized in that: The step S1 comprises the following sub-steps: S11: experimentally obtain experimental detection values ​​of the negative temperature coefficient element RTn and the positive temperature coefficient element RTp corresponding to the change of the cold wind and hot wind speed respectively, and collect the experimental detection values ​​and the wind speed into RTn-cold wind speed data set, RTn-hot wind speed data set, RTp-cold wind speed data set and RTp-hot wind speed data set respectively in one-to-one correspondence; S12: After the system is powered on, the negative temperature coefficient element RTn detects and records the initial temperature value B, and the positive temperature coefficient element RTp detects and records the initial temperature value C; S13: After the wind speed detection starts, the negative temperature coefficient element RTn detects the calibration value A of the initial ambient temperature and records it.

5. A wind speed detection method according to claim 1, characterized in that: The step S4 comprises the following sub-steps: S41: The negative temperature coefficient element RTn and the positive temperature coefficient element RTp detect the change of the ambient temperature in real time to generate a detection value E and a detection value D respectively; S42: The detection value E and the detection value D are respectively used to obtain the hot air speed N1 and the hot air speed N2 according to the RTn-hot air speed data set and the RTp-hot air speed data set; when N1=N2, execute sub-step S43; otherwise, execute sub-step S41; S43: Output hot air speed N1 or N2.

6. A wind speed detection method according to claim 1, characterized in that: The step S5 further includes: using the negative temperature coefficient element RTn to detect the change of the ambient temperature in real time to generate a detection value E and output the cold wind speed accordingly according to the RTn-cold wind speed data set.

7. A wind speed detection method according to claim 4, characterized in that: The sub-step S12 also includes: after the system is powered on, it is necessary to wait for the timing to reach a preset preheating time.

8. A wind speed detection circuit, characterized in that: A wind speed detection method according to any one of claims 1 to 7 is applied, comprising a microcontroller, a capacitor EC1, a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a negative temperature coefficient element RTn and a positive temperature coefficient element RTp; the positive electrode of the capacitor EC1, the power supply end of the microcontroller, one end of the resistor R1 and one end of the resistor R2 are all connected to a DC power supply, the negative electrode of the capacitor EC1, the GND end of the microcontroller, one end of the capacitor C1, one end of the capacitor C2, one end of the negative temperature coefficient element RTn and one end of the positive temperature coefficient element RTp are all grounded, the other end of the capacitor C1, the other end of the resistor R1 and the other end of the negative temperature coefficient element RTn are all electrically connected to the first input end of the microcontroller, and the other end of the capacitor C2, the other end of the resistor R2 and the other end of the positive temperature coefficient element RTp are all electrically connected to the second input end of the microcontroller.

9. A wind speed detection circuit according to claim 8, characterized in that: The negative temperature coefficient element RTn is an NTC thermistor, and the positive temperature coefficient element RTp is a PTC thermistor.

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