Wind speed and direction sensor based on dual MEMS thermal flow chips and wind speed and direction calculation method

Abstract

The present invention discloses a wind speed and direction sensor based on a dual MEMS thermal flow chip, which relates to the field of wind speed and direction detection, and includes: a signal sensing part for sensing wind speed and wind direction; a signal differential amplification part for differentially amplifying small electrical signal differences; a data processing part for calculating and processing wind speed and wind direction to form wind speed and wind direction data; a digital output part for outputting corresponding data to the user; a power control part for controlling the power supply of each part of the sensor; and a structural part for installing a wind speed and direction sensor based on a dual MEMS thermal flow chip. The above-mentioned sensor achieves beneficial effects: it realizes comprehensive electronic measurement, effectively reduces the inherent physical disadvantages of traditional wind speed mechanical structures, and ensures the accuracy and dynamic performance of wind speed. Through actual calibration and measurement, the wind direction can be accurately determined, the anti-interference ability is strong, the overall size is small, and it can be applied to a variety of environments such as outdoor and indoor.

Description

Technical Field

[0001] The present invention relates to the technical field of wind speed and direction detection, and particularly to an anemometer and wind direction sensor based on a dual MEMS thermal flow chip and a method for calculating wind speed and direction. Background Art

[0002] Traditional anemometers adopt a mechanical structure such as a propeller or a cup anemometer. The cup anemometer consists of three parabolic or hemispherical empty cups fixed on a frame at 120 degrees to each other, all facing the same side. The entire frame together with the cups is mounted on a freely rotatable shaft. Under the action of wind force, the cups rotate around the shaft, and its rotation speed is proportional to the wind speed. The rotation speed can be recorded by electric contacts, tachogenerators or photoelectric counters, etc. The propeller anemometer, etc., is an anemometer in which a set of three - or four - blade propellers rotate around a horizontal axis. The propeller is installed in the front of a wind vane so that its rotation plane is always facing the direction of the incoming wind, and its rotation speed is proportional to the wind speed. Due to the presence of rotating parts, there are wear and tear losses, and it is easily interfered by weather factors such as sand, dust, rain and snow, and the external dimensions are relatively large. Therefore, the design using a thermal flow chip has no rotating parts, the structure design is simple, stable and reliable, avoiding the disadvantages of machinery and ensuring accuracy and dynamic performance. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an embodiment of the present invention provides an anemometer and wind direction sensor based on a dual MEMS thermal flow chip, which uses two thermal flow chips to measure wind speed and direction, uses an instrumentation amplifier to amplify the small signal changes sensed by the thermal flow chips, and then the MCU detects and processes the amplified signals and outputs them to the terminal for reading through a serial port.

[0004] An anemometer and wind direction sensor based on a dual MEMS thermal flow chip according to an embodiment of the present invention is characterized in that the sensor includes: a signal sensing part, a signal differential amplification part, a data processing part, a digital output part, a power control part, and a structure part;

[0005] The signal sensing part, connected to the signal differential amplification part, includes a dual MEMS thermal flow chip and is used to sense the wind speed and direction in the measured environment; when gas flows to form wind, the MEMS thermal flow chip element will generate a small electrical signal difference and input it to the signal differential amplification part;

[0006] The signal differential amplification part, connected to the signal sensing part, is used to differentially amplify the small electrical signal difference generated by the signal sensing part and input it to the data processing part;

[0007] The data processing part, connected to the signal differential amplification part, receives the electrically amplified signal and performs wind speed and direction calculation processing, forms wind speed and direction data and inputs it to the digital output part;

[0008] The digital output part is connected to the data processing part to output corresponding data to the user or other devices or components that use data.

[0009] The power control part is connected to the signal sensing part, signal differential amplification part, data processing part, and digital output part to provide a power supply.

[0010] The structure part is used to install the signal sensing part, signal differential amplification part, data processing part, digital output part, and power control part.

[0011] Further, the third pin HTR1 of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with one end of the sixth resistor, one end of the second resistor, one end of the seventh capacitor, one end of the fifth capacitor, one end of the first resistor, and the fifth pin OUT of the power management chip; the sixth pin HTR1 of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel to the ground through the other end of the seventh capacitor; the first pin UP+ of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the fifteenth pin of the microcontroller chip and the third capacitor; the second and fourth pins of the first MEMS chip of the dual MEMS thermal flow chip are connected in parallel with one end of the fourth capacitor, the sixteenth pin of the microcontroller chip, the second pin of the second MEMS thermal chip of the dual MEMS thermal flow chip, and the fourth pin of the second MEMS thermal chip; the fifth pin of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the other end of the third capacitor and the fourteenth pin of the microcontroller chip; the sixth pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is grounded; the third pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected to one end of the second resistor; the first pin UP+ of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with one end of the ninth capacitor and the sixth pin of the microcontroller chip; the fifth pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the other end of the ninth capacitor and the fourth pin of the microcontroller chip.

[0012] Further, the signal differential amplification part includes a microcontroller chip, which differentially amplifies the tiny electrical signal differences generated by the signal sensing part.

[0013] Further, the data processing part includes a microcontroller chip. The nineteenth pin of the microcontroller chip is connected in parallel with one end of a first capacitor, one end of an eighth capacitor, the first pin of a power control chip, and one end of a third voltage stabilizing diode. The eighteenth pin of the microcontroller chip is connected to one end of a second capacitor. The twentieth pin of the microcontroller chip, the other end of the second capacitor, the seventeenth pin of the microcontroller chip, the other end of the first capacitor, and the other end of the eighth capacitor are connected to ground in parallel. The eighth pin of the microcontroller chip is connected to the ICPCK terminal of the second pin of a first interface socket. The seventh pin of the microcontroller chip is connected to the ICPDA terminal of the third pin of the first interface socket. The fifth pin of the microcontroller chip is connected to the LDO_EN terminal. The ninth pin of the microcontroller chip is connected to the UART_RX terminal of a second interface socket. The twelfth pin of the microcontroller chip is connected to one end of a third resistor, and the other end of the third resistor is connected to the eleventh pin of the microcontroller chip and the fourth pin of the second interface socket (UART_TX terminal).

[0014] Further, the digital output part includes a first interface socket and a second interface socket. The ninth pin of the microcontroller chip is connected to the UART_RX terminal of the second interface socket. The twelfth pin of the microcontroller chip is connected to one end of a third resistor, and the other end of the third resistor is connected to the eleventh pin of the microcontroller chip and the fourth pin of the second interface socket (UART_TX terminal). The first pin of the second interface socket is connected to the VIN terminal, and the second pin of the second interface socket is connected to ground. The first pin of the first interface socket is connected to the VIN terminal, and the fourth pin of the first interface socket is connected to ground. The eighth pin of the microcontroller chip is connected to the second pin (ICPCK) of the first interface socket, and the seventh pin of the microcontroller chip is connected to the third pin of the first interface socket. The fourth pin of the first interface socket is grounded.

[0015] Further, the power control part further includes a power control chip, which provides power control for the signal sensing part, the signal differential amplification part, the data processing part, and the digital output part. The third pin of the power control chip is connected to the LDO_EN terminal. The second pin of the power control chip is grounded. The fourth pin of the power control chip is connected in series with a first resistor and a sixth resistor and connected to the HTR1 terminal of the third pin of a first MEMS thermal chip. The first pin of the power control chip is connected to the nineteenth pin of the microcontroller chip. The fifth pin of the power control chip is connected in series with a second resistor and connected to the third pin of a second MEMS thermal chip. The fifth pin of the power control chip is connected to one end of a seventh capacitor, and the other end of the seventh capacitor is connected to the sixth pin of the first MEMS thermal chip in parallel and grounded. The fourth pin of the power control chip is connected in parallel with one end of a first resistor, one end of a ninth resistor, and one end of a fifth capacitor. The other end of the ninth resistor is grounded. The other end of the fifth capacitor, the other end of the first resistor, one end of the sixth resistor, one end of the seventh capacitor, and one end of the second resistor are connected in parallel.

[0016] Furthermore, the structural part includes an upper cover, a sensor circuit board, a column, and a lower cover; the upper cover and the lower cover are supported and connected by the column to form an air flow space; the sensor circuit board is installed inside the lower cover.

[0017] Furthermore, the upper cover and the lower cover are cylindrical, the edges of the upper cover and the lower cover are arc-shaped, and the middle part is flat.

[0018] Furthermore, the sensor is installed at the axial center position of the upper cover and the lower cover, and the two MEMS thermal flow chips on the sensor circuit board are arranged perpendicular to the upper cover. The wind direction is judged by different wind speed components on the XY axis.

[0019] Another aspect of the present invention proposes a method for calculating wind speed and wind direction based on a wind speed and wind direction sensor with dual MEMS thermal flow chips. The calculation method is executed by the wind speed and wind direction sensor with dual MEMS thermal flow chips. There is a linear relationship between the differential amplified voltage ADC value of the thermal flow chip and the wind speed. The calculation method includes:

[0020] Set multiple calibration points for the first MEMS thermal chip and the second MEMS thermal chip. The calibration points record the wind speed and the corresponding differential amplified voltage ADC value;

[0021] Collect the differential amplified voltage ADC value of the first MEMS thermal chip multiple times, and calculate the average value ADC_Avg1 of the differential amplified voltage ADC values collected multiple times;

[0022] Collect the differential amplified voltage ADC value of the second MEMS thermal chip multiple times, and calculate the average value ADC_Avg2 of the differential amplified voltage ADC values collected multiple times;

[0023] Compare the average value of the differential amplified voltage ADC value of the first MEMS thermal chip collected with the calibration point ADC_Cal1[n] of the first thermal flow chip in sequence. When ADC_Cal1[n] < ADC_Avg1 <= ADC_Cal1[n+1], the wind speed Speed1 measured by the first thermal flow chip = Speed_Cal1[n] + k1 * (ADC_Avg1 - Speed_Cal1[n]), where: k1 = (Speed_Cal1[n+1] - Speed_Cal1[n]) / (ADC_Cal1[n+1] - ADC_Cal1[n]);

[0024] Compare the average value of the differential amplified voltage ADC values of the collected second MEMS thermal chip with the calibration points of the second thermal flow chip in sequence. When ADC_Cal2[n] < ADC_Avg2 <= ADC_Cal2[n+1], the measured wind speed Speed2 of the second MEMS thermal chip = Speed_Cal2[n] + k2 * (ADC_Avg2 - Speed_Cal2[n]), where: k2 = (Speed_Cal2[n+1] - Speed_Cal2[n]) / (ADC_Cal2[n+1] - ADC_Cal2[n]);

[0025] Set the installation direction of the first MEMS thermal chip as the x-axis and the installation direction of the second MEMS thermal chip as the y-axis, and record the wind direction angle as Θ. The calculation method of the wind direction angle Θ is: tanΘ = Speed1 / Speed2, where Speed1 is the wind speed in the direction of the first MEMS thermal chip and Speed2 is the wind speed in the direction of the second MEMS thermal chip.

[0026] The technical solution provided by the embodiment of the present invention uses a pair of thermal sensors, designs a laminar flow structure, has no rotating parts, greatly reduces the size, can adapt to more scenarios, and at the same time ensures the stability of the air flow and the signal through the arc design of the upper cover and the lower cover, and is also convenient for disassembly and cleaning. The present invention utilizes the electronic design of wind speed measurement to solve the problems of poor accuracy and weak dynamic performance caused by mechanical structure wear and pollution. Brief Description of the Drawings

[0027] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0028] Figure 1 It is a schematic structural diagram of the signal sensing part of a wind speed and wind direction sensor based on a dual MEMS thermal flow chip according to an embodiment of the present invention;

[0029] Figure 2 It is a schematic circuit principle structural diagram of a wind speed and wind direction sensor based on a dual MEMS thermal flow chip according to an embodiment of the present invention;

[0030] Figure 3 It is a schematic structural diagram of a wind speed and wind direction sensor based on a dual MEMS thermal flow chip according to an embodiment of the present invention;

[0031] Reference numerals: Among them, the upper cover 1, the sensor circuit board 2, the column 3, the lower cover 4, and the air flow space 5 of the sensor. Detailed Embodiments

[0032] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0033] Referring to Figures 1 to 3 , the present invention discloses an anemometer and wind vane sensor based on a dual MEMS thermal flow chip, which includes five parts, namely a signal sensing part, a signal differential amplification part, a data processing part, a digital output part, and a structure part.

[0034] The signal sensing part includes a dual MEMS thermal flow chip. The MEMS thermal flow chip includes two thermopiles. Air convection causes both thermopiles to generate weak differences. The two-channel differential signals of the dual MEMS thermal flow chip are input into the differential instrumentation amplifier of the MCU for proportional amplification. After the MCU processes the amplified data through mathematical operations, it is then output to the outside through the UART serial port for the terminal to read. Different wind speeds and wind directions generate different differential signals for the MEMS thermal flow chip. The MCU amplifies and performs mathematical calculations to convert them into different wind speed and wind direction values.

[0035] The sensor structure part includes an upper cover 1, a circuit board 2, a column 3, a lower cover 4, and the air flow space 5 of the sensor. Air enters from the air flow space. The edges of the upper cover and the lower cover are designed with arc surfaces. The air flow passes through the surface of the sensor in the air flow space of the platform and the circuit sensor and then flows out.

[0036] Referring to Figure 1 , the signal sensing part of an anemometer and wind vane sensor based on a dual MEMS thermal flow chip in this embodiment is described as follows:

[0037] The signal sensing part uses an advanced MEMS thermal flow chip F1 (hereinafter simply referred to as the sensor chip) and MEMS thermal flow chip F2 as sensing devices. After providing a stable voltage to the heater of the thermal flow chip, that is, applying a fixed voltage to the HTR1 and HTR2 terminals of the MEMS thermal chip, the heater will heat the adiabatic base, and the thermocouple will generate a millivolt output, that is: a millivolt output will be generated between its thermocouples UP+ and UP-, DWN+ and DWN-.

[0038] When the air medium passing through the sensor chip is not flowing, i.e., in a windless state, the differential output voltage of the thermocouple is zero, that is: the difference between the voltages of thermocouple UP+ and UP- and the voltages of thermocouple DWN+ and DWN- is zero. If the air medium flowing through the surface of the sensor chip, according to the principle of wind generation, the upstream thermocouple will be cooled by the air medium. After the flowing medium passes through the heater, it brings heat to the downstream thermocouple, and the differential voltage signal output by the thermocouple (i.e., the voltage of the downstream thermocouple minus the voltage of the upstream thermocouple) will change with the flow rate of the medium.

[0039] Refer to Figure 3 , for this embodiment, the circuit connection of the signal sensing part is as follows:

[0040] The third pin HTR1 end of the first MEMS thermal chip F1 is connected in parallel with one end of the sixth resistor R6, one end of the second resistor R2, one end of the seventh capacitor C7, one end of the fifth capacitor C5, one end of the first resistor R1, and the fifth pin OUT end of the power management chip U2; the sixth pin HTR1 end of the first MEMS thermal chip F1 is connected in parallel to the ground through the other end of the seventh capacitor C7; the first pin UP+ end of the first MEMS thermal chip F1 is connected in parallel with the fifteenth pin of the microcontroller chip U1 and the third capacitor C3; the second and fourth pins of the first MEMS chip F1 are connected in parallel with one end of the fourth capacitor C4, the sixteenth pin of the microcontroller chip U1, the second pin of the second MEMS thermal chip F2, and the fourth pin of the second MEMS thermal chip F2; the fifth pin of the first MEMS thermal chip F1 is connected in parallel with the other end of the third capacitor C3 and the fourteenth pin of the microcontroller chip U1; the sixth pin of the second MEMS thermal chip F2 is grounded; the third pin of the second MEMS thermal chip F2 is connected to one end of the second resistor R2; the first pin UP+ end of the second MEMS thermal chip F2 is connected in parallel with one end of the ninth capacitor C9 and the sixth pin of the microcontroller chip U1; the fifth pin of the second MEMS thermal chip F2 is connected in parallel with the other end of the ninth capacitor C9 and the fourth pin of the microcontroller chip U1.

[0041] Refer to Figure 3 , for further explanation of the signal differential amplification part, the signal differential amplification part is completed by the microcontroller chip U1. The microcontroller chip U1 has a built-in signal amplifier. In this embodiment, the model of the microcontroller chip selected is: BH66F5242.

[0042] The signal change generated by the sensor enters the signal amplifier as a differential signal. Differential input can make the circuit only amplify the differential mode signal. The amplifier converts the weak differential signal into a single-ended voltage at the output end. The single-ended voltage is output to the 24bit ADC after programmable gain amplification inside the microcontroller chip.

[0043] Refer to Figure 3, the signal processing part will be further described. The signal processing part is still completed by the microcontroller chip U1.

[0044] The wind speed signal is amplified by the operational amplifier of the microcontroller chip U1 and then undergoes ADC conversion. The microcontroller chip (abbreviation: MCU) collects, transforms, filters and processes the signal. By calculating the magnitude of the differential signals on the two sensors, the wind speed and wind direction are calculated. The principle of the calculation method is as follows:

[0045] Since there is a linear relationship between the ADC value of the thermal flow chip and Speed (wind speed), the relationship between the ADC value of the MEMS thermal flow chip F1 and Speed can be expressed by the following formula:

[0046] Speed1 = k1*ADC1 + d1

[0047] Where, k1 is the slope and d1 is the intercept.

[0048] Similarly, the relationship between the ADC value of the MEMS thermal flow chip F2 and Speed can be expressed by the following formula:

[0049] Speed1 = k2*ADC1 + d2

[0050] Where, k2 is the slope and d2 is the intercept.

[0051] The differential amplified voltage ADC value of the MEMS thermal flow chip F1 collected by the microcontroller chip U1 is denoted as ADC_Raw1, and the differential amplified voltage ADC value of the MEMS thermal flow chip F2 collected is denoted as ADC_Raw2. After collecting and recording the values of ADC_Raw1 and ADC_Raw2 for MAX_CNT times, calculate the average value of ADC_Raw1 for MAX_CNT times and denote it as ADC_Avg1, calculate the average value of ADC_Raw2 for MAX_CNT times and denote it as ADC_Avg2.

[0052] The MEMS thermal flow chip F1 and the MEMS thermal flow chip F2 are respectively set with several calibration points. At each calibration point, a certain wind speed and the corresponding ADC value are respectively recorded. The values of the calibration points are recorded in the EEPROM of the MCU. Denote the nth calibration point of the MEMS thermal flow chip F1 as {ADC_Cal1[n], Speed_Cal1[n]}, and denote the nth calibration point of the MEMS thermal flow chip F2 as {ADC_Cal2[n], Speed_Cal2[n]}.

[0053] By comparing ADC_Avg1 with the ADC values of each calibration point in sequence, when the condition ADC_Cal1[n] < ADC_Avg1 <= ADC_Cal1[n+1] is satisfied, the current wind speed Speed1 corresponding to ADC_Avg1 can be calculated according to the linear relationship, and the calculation method is as follows:

[0054] Speed1 = Speed_Cal1[n] + k1 * (ADC_Avg1 - Speed_Cal1[n])

[0055] Where: k1 = (Speed_Cal1[n+1] - Speed_Cal1[n]) / (ADC_Cal1[n+1] - ADC_Cal1[n])

[0056] Similarly, by comparing ADC_Avg2 with the ADC values of each calibration point in sequence, when the condition ADC_Cal2[n] < ADC_Avg2 <= ADC_Cal2[n+1] is satisfied, the current wind speed Speed2 corresponding to ADC_Avg2 can be calculated according to the linear relationship, and the calculation method is as follows:

[0057] Speed2 = Speed_Cal2[n] + k2 * (ADC_Avg2 - Speed_Cal2[n])

[0058] Where: k2 = (Speed_Cal2[n+1] - Speed_Cal2[n]) / (ADC_Cal2[n+1] - ADC_Cal2[n])

[0059] Since the orientations of the MEMS thermal flow chip F1 and the MEMS thermal flow chip F2 are at a right angle, the direction of the MEMS thermal flow chip F1 is defined as the x-axis, the direction of the MEMS thermal flow chip F2 is defined as the y-axis, and the wind direction angle is denoted as Θ. Then, the relationship between the wind direction angle Θ and the wind speed Speed1 in the direction of the MEMS thermal flow chip F1 and the wind speed Speed2 in the direction of the MEMS thermal flow chip F2 is as follows:

[0060] tanΘ = Speed1 / Speed2.

[0061] The nineteenth pin of the microcontroller chip U1 is connected in parallel with one end of the first capacitor C1, one end of the eighth capacitor C8, the first pin of the power control chip U2, and one end of the third voltage stabilizing diode D3; the eighteenth pin of the microcontroller chip U1 is connected to one end of the second capacitor C2; the twentieth pin of the microcontroller chip U1 is connected in parallel to ground with the other end of the second capacitor C2, the seventeenth pin of the microcontroller chip U1, the other end of the first capacitor C1, and the other end of the eighth capacitor C8; the eighth pin of the microcontroller chip U1 is connected to the ICPCK terminal of the second pin of the first interface socket J1; the seventh pin of the microcontroller chip U1 is connected to the ICPDA terminal of the third pin of the first interface socket J1; the fifth pin of the microcontroller chip U1 is connected to the LDO_EN terminal; the ninth pin of the microcontroller chip U1 is connected to the UART_RX terminal of the second interface socket J2; the twelfth pin of the microcontroller chip U1 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the eleventh pin of the microcontroller chip U1 and the fourth pin UART_TX terminal of the second interface socket J2.

[0062] Referring to Figure 3 , the digital output part is further described. In this embodiment, the wind speed and wind direction are output to the external main control circuit through the serial port.

[0063] The ninth pin of the microcontroller chip U1 is connected to the UART_RX terminal of the second interface socket J2; the twelfth pin of the microcontroller chip U1 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the eleventh pin of the microcontroller chip U1 and the fourth pin UART_TX terminal of the second interface socket J2. The first pin of the second interface socket J2 is connected to the VIN terminal, and the second pin of the second interface socket J2 is connected to ground.

[0064] To make this technical solution have better interconnection, an e-link interface is provided for the digital output part. The specific implementation method is as follows:

[0065] The first pin of the first interface socket J1 is connected to the VIN terminal, and the fourth pin of the first interface socket J1 is connected to ground; the eighth pin of the microcontroller chip U1 is connected to the ICPCK of the second pin of the first interface socket J1, and the seventh pin of the microcontroller chip U1 is connected to the third pin of the first interface socket J1; the fourth pin of the first interface socket J1 is grounded.

[0066] In this embodiment, the power control section includes a power control chip U2. One end of the first pin of the power control chip U2 and one end of the third voltage stabilizing diode D3 are connected in parallel; the third pin of the power control chip U2 is connected to the LDO_EN terminal; the second pin of the power control chip U2 is grounded; the fourth pin of the power control chip U2 is connected in series with the first resistor R1 and the sixth resistor R6 and is connected to the HTR1 terminal of the third pin of the first MEMS thermal chip F1; the first pin of the power control chip U2 is connected to the nineteenth pin of the microcontroller chip U1; the fifth pin of the power control chip U2 is connected in series with the second resistor R2 and is connected to the third pin of the second MEMS thermal chip F2; the fifth pin of the power control chip U2 is connected to one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is connected in parallel with the sixth pin of the first MEMS thermal chip F1 and grounded; the fourth pin of the power control chip U2 is connected in parallel with one end of the first resistor R1, one end of the ninth resistor R9, and one end of the fifth capacitor C5, and the other end of the ninth resistor R9 is grounded; the other end of the fifth capacitor, the other end of the first resistor, one end of the sixth resistor, one end of the seventh capacitor, and one end of the second resistor are connected in parallel.

[0067] Referring to Figure 2 , to achieve the purpose of the present invention, this embodiment will describe the structural design part.

[0068] The sensor structure part includes an upper cover 1, a sensor circuit board 2, a column 3, a lower cover 4, and an air flow space 5 of the sensor. The column 3 is vertically arranged between the lower covers 4. For better detection effect and structural stability, there are three columns.

[0069] The overall design of the sensor structure is circular to ensure that the air flows coming from all directions are consistent. The edges of the upper cover and the lower cover are arc-shaped, and the middle part is flat to ensure the stability of the air flow.

[0070] During installation, the sensor circuit board 2 includes two parts that form the core components of the sensor. It is located at the axis position of the upper cover and the lower cover. The two MEMS thermal flow chips in the sensor circuit board 2 are arranged perpendicular to the upper cover 1, and the wind direction is judged by the different wind speed components on the XY axis.

[0071] With the above design, with the cooperation of several parts of the circuit, the comprehensive measurement is realized electronically, effectively reducing the inherent physical disadvantages of the traditional wind speed mechanical structure, ensuring the accuracy and dynamic performance of the wind speed. After actual calibration and measurement, the wind direction can be accurately judged, with strong anti-interference ability and small overall size, and it can be applied to various environments such as outdoor and indoor.

[0072] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art, various changes can be made without departing from the purpose of the present invention.

[0073] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0075] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wind speed and direction sensor based on dual MEMS thermal flow chips, characterized in that: The sensor includes: a signal sensing part, a signal differential amplification part, a data processing part, a digital output part, a power supply control part, and a structural part; The signal sensing part is connected to the signal differential amplifier part, and includes a dual MEMS thermal flow chip, which is used to sense the wind speed and wind direction in the measured environment; when the gas flows to form wind, the MEMS thermal flow chip element will generate a tiny electrical signal difference and input it to the signal differential amplifier part; The signal differential amplification part is connected to the signal sensing part and is used to differentially amplify the tiny electrical signal difference generated by the signal sensing part and input it to the data processing part; The data processing part is connected to the signal differential amplification part, receives the electrical signal of the signal differential amplification, performs wind speed and wind direction calculation processing, forms wind speed and wind direction data and inputs it into the digital output part; The digital output part is connected to the data processing part to output the corresponding data to the user or other devices or components that use the data; The power control part connects the signal sensing part, the signal differential amplification part, the data processing part, and the digital output part to provide power supply; The structural part is used to install the signal sensing part, the signal differential amplification part, the data processing part, the digital output part, and the power control part.

2. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The third pin HTR1 end of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with one end of the sixth resistor, one end of the second resistor, one end of the seventh capacitor, one end of the fifth capacitor, one end of the first resistor, and the fifth pin OUT end of the power management chip; the sixth pin HTR1 end of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the other end of the seventh capacitor to the ground; the first pin UP+ end of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the fifteenth pin of the microcontroller chip and the third capacitor; the second and fourth pins of the first MEMS chip of the dual MEMS thermal flow chip are connected to one end of the fourth capacitor, the sixteenth pin of the microcontroller chip, the second MEMS of the dual MEMS thermal flow chip The second pin of the S thermal chip and the fourth pin of the second MEMS thermal chip are connected in parallel; the fifth pin of the first MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the other end of the third capacitor and the fourteenth pin of the microcontroller chip; the sixth pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is grounded; the third pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected to one end of the second resistor; the UP+ end of the first pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with one end of the ninth capacitor and the sixth pin of the microcontroller chip; the fifth pin of the second MEMS thermal chip of the dual MEMS thermal flow chip is connected in parallel with the other end of the ninth capacitor and the fourth pin of the microcontroller chip.

3. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The signal differential amplification part includes a microcontroller chip, and the microcontroller chip differentially amplifies the tiny electrical signal difference generated by the signal sensing part.

4. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The data processing part includes a microcontroller chip, the nineteenth pin of the microcontroller chip is connected in parallel with one end of the first capacitor, one end of the eighth capacitor, the first pin of the power control chip, and one end of the third voltage-stabilizing diode; the eighteenth pin of the microcontroller chip is connected to one end of the second capacitor; the twentieth pin of the microcontroller chip is connected to the other end of the second capacitor, the seventeenth pin of the microcontroller chip, the other end of the first capacitor, and the other end of the eighth capacitor in parallel and grounded; the eighth pin of the microcontroller chip is connected to the second pin ICPCK end of the first interface socket; the seventh pin of the microcontroller chip is connected to the third pin ICPDA end of the first interface socket; the fifth pin of the microcontroller chip is connected to the LDO_EN end; the ninth pin of the microcontroller chip is connected to the UART_RX end of the second interface socket; the twelfth pin of the microcontroller chip is connected to one end of the third resistor, and the other end of the third resistor is connected to the eleventh pin of the microcontroller chip and the fourth pin UART_TX end of the second interface socket.

5. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The digital output part includes a first interface socket and a second interface socket, the ninth pin of the microcontroller chip is connected to the UART_RX end of the second interface socket; the twelfth pin of the microcontroller chip is connected to one end of the third resistor, the other end of the third resistor is connected to the eleventh pin of the microcontroller chip and the fourth pin of the second interface socket UART_TX end, the first pin of the second interface socket is connected to the VIN end, and the second pin of the second interface socket is connected to the ground; the first pin of the first interface socket is connected to the VIN end, and the fourth pin of the first interface socket is connected to the ground; the eighth pin of the microcontroller chip is connected to the second pin ICPCK of the first interface socket, the seventh pin of the microcontroller chip is connected to the third pin of the first interface socket; the fourth pin of the first interface socket is grounded.

6. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The power control part also includes a power control chip, which provides power control for the signal sensing part, the signal differential amplification part, the data processing part, and the digital output part; the third pin of the power control chip is connected to the LDO_EN end; the second pin of the power control chip is grounded; the fourth pin of the power control chip is connected in series with the first resistor and the sixth resistor and is connected to the third pin HTR1 end of the first MEMS thermal chip; the first pin of the power control chip is connected to the nineteenth pin of the microcontroller chip; the fifth pin of the power control chip is connected in series with the second resistor and is connected to the third pin of the second MEMS thermal chip; the fifth pin of the power control chip is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is connected in parallel with the sixth pin of the first MEMS thermal chip and is grounded; the fourth pin of the power control chip is connected in parallel with one end of the first resistor, one end of the ninth resistor, and one end of the fifth capacitor, and the other end of the ninth resistor is grounded; the other end of the fifth capacitor, the other end of the first resistor, one end of the sixth resistor, one end of the seventh capacitor, and one end of the second resistor are connected in parallel.

7. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 1 is characterized in that: The structural part comprises an upper cover, a sensor circuit board, a column and a lower cover; the upper cover and the lower cover are supported and connected by the column to form an airflow space; the sensor circuit board is installed in the lower cover.

8. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 7 is characterized in that: The upper cover and the lower cover are cylindrical, the edges of the upper cover and the lower cover are arc-shaped, and the middle part is flat.

9. The wind speed and direction sensor based on dual MEMS thermal flow chips according to claim 7 is characterized in that: The sensor is installed at the axial center of the upper cover and the lower cover. The two MEMS thermal flow chips on the sensor circuit board are arranged vertically with the upper cover. The wind direction is judged by different wind speed components on the XY axis.

10. A method for calculating wind speed and direction, characterized in that: The calculation method is performed by the wind speed and direction sensor based on the dual MEMS thermal flow chip according to any one of claims 1 to 6, and there is a linear relationship between the differential amplification voltage ADC value of the thermal flow chip and the wind speed. The calculation method includes: Setting a plurality of calibration points on the first MEMS thermal chip and the second MEMS thermal chip, wherein the calibration points record the wind speed and the corresponding differential amplifier voltage ADC value; Collect the differential amplified voltage ADC values ​​of the first MEMS thermal chip multiple times, and calculate the average value ADC_Avg1 of the differential amplified voltage ADC values ​​collected multiple times; Collect the differential amplified voltage ADC values ​​of the second MEMS thermal chip multiple times, and calculate the average value ADC_Avg2 of the differential amplified voltage ADC values ​​collected multiple times; The average value of the collected differential amplified voltage ADC value of the first MEMS thermal chip is compared with the calibration point ADC_Cal1[n] of the first thermal flow chip in turn. When ADC_Cal1[n] < ADC_Avg1 <= ADC_Cal1[n+1] is satisfied; the wind speed measured by the first thermal flow chip Speed1 = Speed_Cal1[n] + k1 (ADC_Avg1- Speed_Cal1[n]), where: k1 = (Speed_Cal1[n+1]-Speed_Cal1[n]) / (ADC_Cal1[n+1]- ADC_Cal1[n]); The average value of the collected differential amplified voltage ADC value of the second MEMS thermal chip is compared with the calibration point of the second thermal flow chip in turn. When ADC_Cal2[n] < ADC_Avg2 <= ADC_Cal2[n+1] is satisfied; the wind speed measured by the second MEMS thermal chip Speed2 = Speed_Cal2[n] + k2 (ADC_Avg2- Speed_Cal2[n]), where: k2 = (Speed_Cal2[n+1]-Speed_Cal2[n]) / (ADC_Cal2[n+1]- ADC_Cal2[n]); The installation direction of the first MEMS thermal chip is set as the x-axis, the installation direction of the second MEMS thermal chip is set as the y-axis, and the wind direction angle is recorded as θ. The calculation method of the wind direction angle θ is: tanθ = Speed1 / Speed2, where Speed1 is the wind speed in the direction of the first MEMS thermal chip, and Speed2 is the wind speed in the direction of the second MEMS thermal chip.

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