MEMS wind speed and direction sensor and detection device

Abstract

The application relates to a MEMS wind speed and direction sensor and a detection device. The MEMS wind speed and direction sensor comprises a flexible substrate, a cavity is arranged in the interior of the flexible substrate, a through hole is arranged on the side surface of the flexible substrate, and the cavity is communicated with the through hole; a heating assembly is arranged on the surface of the flexible substrate and is connected with a power control circuit; a first heat-sensitive sensing assembly is arranged on the surface of the flexible substrate and surrounds the heating assembly; a second heat-sensitive sensing assembly is arranged on the surface of the flexible substrate and is located on the side of the first heat-sensitive sensing assembly away from the heating assembly, and the second heat-sensitive sensing assembly is connected with the first heat-sensitive sensing assembly to form a Wheatstone bridge circuit; wherein the surface of the flexible substrate for arranging the heating assembly is deformed along with the volume change of the gas in the cavity; thus, the application realizes the MEMS wind speed and direction sensor with adjustable sensitivity and range, and the sensor has simple structure, is easy to realize, has small volume and low cost.

Description

Technical Field

[0001] This application relates to the field of microelectromechanical systems (MEMS) technology, and in particular to a MEMS wind speed and direction sensor and detection device. Background Technology

[0002] With the development of science and technology and the progress of human society, the accurate measurement of wind speed and direction in meteorological measurements will have more practical significance.

[0003] Wind speed and direction sensors generally use mechanical, acoustic, and thermal principles to measure wind speed and direction. Mechanical wind speed and direction sensors have a simple measurement principle, but their mechanical parts are prone to wear. Ultrasonic wind speed and direction sensors have high sensitivity but are more expensive. In comparison, thermal wind speed and direction sensors are simple to measure, easy to manufacture, small in size, and relatively inexpensive. However, the sensitivity and measurement range of traditional thermal wind speed and direction sensors are not adjustable, which can limit their practical applications. Summary of the Invention

[0004] Therefore, it is necessary to provide a MEMS wind speed and direction sensor and detection device with adjustable sensitivity and range to address the above-mentioned technical problems.

[0005] Firstly, this application provides a MEMS wind speed and direction sensor. The MEMS wind speed and direction sensor includes:

[0006] A flexible substrate, wherein a cavity is provided inside the flexible substrate, and a through hole is provided on the side of the flexible substrate, and the cavity communicates with the through hole;

[0007] A heating component, located on the surface of the flexible substrate, is used to connect to a power control circuit.

[0008] A first thermal sensing component is located on the surface of the flexible substrate and is arranged around the heating component;

[0009] The second thermal sensing component is located on the surface of the flexible substrate and on the side of the first thermal sensing component away from the heating component. The second thermal sensing component is also connected to the first thermal sensing component to form a Wheatstone bridge circuit.

[0010] The flexible substrate is used to arrange the surface of the heating component to deform as the volume of gas in the cavity changes.

[0011] In one embodiment, the first thermal sensing component includes a first thermistor, a second thermistor, a third thermistor, and a fourth thermistor, and the second thermal sensing component includes a fifth thermistor, a sixth thermistor, a seventh thermistor, and an eighth thermistor.

[0012] The first thermistor, the third thermistor, the fifth thermistor, and the seventh thermistor are arranged along a first direction, and the second thermistor, the fourth thermistor, the sixth thermistor, and the eighth thermistor are arranged along a second direction, which is orthogonal to the first direction.

[0013] In one embodiment, the flexible substrate is used to set the surface of the heating component as a plane or an arc surface, and the cavity wall on the side of the cavity near the surface has a similar shape to the surface.

[0014] In one embodiment, the flexible substrate has a rectangular or arc-shaped cross-section along the thickness direction of the MEMS wind speed and direction sensor.

[0015] In one embodiment, a plurality of connecting blocks are located on the surface of the flexible substrate;

[0016] The heating component is led out to the power control circuit by at least two of the connecting blocks;

[0017] The two connecting blocks used to lead out the first thermistor are respectively connected to a connecting block used to lead out the third thermistor and a connecting block used to lead out the seventh thermistor;

[0018] The two connecting blocks used to lead out the fifth thermistor are respectively connected to another connecting block used to lead out the third thermistor and another connecting block used to lead out the seventh thermistor;

[0019] The two connecting blocks used to lead out the fourth thermistor are respectively connected to a connecting block used to lead out the second thermistor and a connecting block used to lead out the sixth thermistor;

[0020] The two connecting blocks used to lead out the eighth thermistor are respectively connected to another connecting block used to lead out the second thermistor and another connecting block used to lead out the sixth thermistor.

[0021] In one embodiment, the flexible substrate is made of polydimethylsiloxane.

[0022] In one embodiment, the materials of the first thermistor, the second thermistor, the third thermistor, the fourth thermistor, the fifth thermistor, the sixth thermistor, the seventh thermistor and / or the eighth thermistor include copper.

[0023] Secondly, this application also provides a detection device. The detection device includes: a power control circuit and a MEMS wind speed and direction sensor as described in the first aspect;

[0024] The power control circuit includes a control unit, a feedback circuit, an ambient temperature measuring resistor, a first resistor, a second resistor, a third resistor, a first power supply, and a second power supply.

[0025] The first end of the heating component is connected to the control unit, the second end of the heating component is connected to the first end of the first resistor, and the second end of the first resistor is connected to the second power supply.

[0026] The first end of the ambient temperature measuring resistor is connected to the first end of the heating component, the second end of the ambient temperature measuring resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the second power supply.

[0027] The first input terminal of the feedback circuit is connected to the first terminal of the first resistor, the second input terminal of the feedback circuit is connected to the first terminal of the third resistor, the third input terminal of the feedback circuit is connected to the first power supply, and the output terminal of the feedback circuit is connected to the first terminal of the heating component.

[0028] In one embodiment, the feedback circuit includes: an operational amplifier unit, a switching unit, and a fourth resistor;

[0029] The first input terminal of the operational amplifier unit serves as the first input terminal of the feedback circuit, the second input terminal of the operational amplifier unit serves as the second input terminal of the feedback circuit, the output terminal of the operational amplifier unit is connected to the first terminal of the switching unit through the fourth resistor, the second terminal of the switching unit serves as the third input terminal of the feedback circuit, and the third terminal of the switching unit serves as the output terminal of the feedback circuit.

[0030] In one embodiment, the detection device further includes: a first operational amplifier circuit and a second operational amplifier circuit;

[0031] The first end of the first thermistor is connected to the first power supply, and the second end of the first thermistor is connected to the first input terminal of the first operational amplifier circuit.

[0032] The first end of the third thermistor is connected to the first input terminal of the first operational amplifier circuit, and the second end of the third thermistor is connected to the second power supply.

[0033] The first end of the seventh thermistor is connected to the first power supply, and the second end of the seventh thermistor is connected to the second input terminal of the first operational amplifier circuit.

[0034] The first end of the fifth thermistor is connected to the second input terminal of the first operational amplifier circuit, and the second end of the fifth thermistor is connected to the second power supply.

[0035] The first end of the fourth thermistor is connected to the first power supply, and the second end of the fourth thermistor is connected to the first input terminal of the second operational amplifier circuit.

[0036] The first end of the second thermistor is connected to the first input terminal of the second operational amplifier circuit, and the second end of the second thermistor is connected to the second power supply.

[0037] The first end of the sixth thermistor is connected to the first power supply, and the second end of the sixth thermistor is connected to the second input terminal of the second operational amplifier circuit.

[0038] The first end of the eighth thermistor is connected to the second input terminal of the second operational amplifier circuit, and the second end of the eighth thermistor is connected to the second power supply.

[0039] The aforementioned MEMS wind speed and direction sensor and detection device uses a flexible substrate with an internal cavity. Through-holes are formed on the side of the flexible substrate, communicating with the cavity, allowing gas to be introduced into the cavity. Changes in the gas volume within the cavity cause deformation of the surfaces of the flexible substrate used to house the heating element, the first thermal sensing element, and the second thermal sensing element, resulting in a change in the contact area between the wind field and the sensor surface. Within a reasonable range, a larger gas volume within the cavity leads to greater deformation of the sensor surface, thus increasing the contact area between the wind field and the sensor surface. This makes it easier for the heating element, the first thermal sensing element, and the second thermal sensing element to sense temperature changes on the sensor surface. The sensor becomes more sensitive to the heat carried away by the wind, ensuring a smaller wind speed limit that the sensor can measure, thereby increasing its sensitivity. As the sensor's sensitivity is adjusted, its measurement range is also adjusted. This application thus realizes a MEMS wind speed and direction sensor with adjustable sensitivity and range, featuring a simple structure, ease of implementation, small size, and low cost. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a MEMS wind speed and direction sensor in one embodiment;

[0041] Figure 2 for Figure 1 A schematic diagram of the cross-section along the AA' direction;

[0042] Figure 3 This is a schematic diagram of the structure of a MEMS wind speed and direction sensor in one embodiment;

[0043] Figure 4 for Figure 3 A sectional view;

[0044] Figure 5 This is a structural block diagram of the detection device in one embodiment;

[0045] Figure 6 This is a circuit diagram of the power control circuit in one embodiment;

[0046] Figure 7 This is a structural block diagram of the detection device in one embodiment;

[0047] Figure 8 This is a circuit diagram of the first operational amplifier circuit in one embodiment;

[0048] Figure 9 This is a circuit diagram of the second operational amplifier circuit in one embodiment. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0050] like Figure 1 and Figure 2 As shown, this application provides a MEMS wind speed and direction sensor. In one embodiment, the MEMS wind speed and direction sensor 100 includes: a flexible substrate 1, a heating component 3, a first thermal sensing component 4, and a second thermal sensing component 5.

[0051] The flexible substrate 1 has an internal cavity 7 and a through-hole 2 on its side, which communicates with the cavity 7. The flexible substrate 1 can possess properties such as plastic deformation and insulation. In this embodiment, a sealed cavity 7 can be formed inside the flexible substrate 1, and a through-hole 2 can be formed on the side of the flexible substrate 1, connecting the through-hole 2 to the sealed cavity 7. Gas can enter the sealed cavity 7 through the through-hole 2, and the more gas is introduced into the cavity 7, the larger the gas volume inside the cavity 7. In another embodiment, a slit or opening can be formed on the side of the flexible substrate 1, communicating with the sealed cavity 7, allowing gas to enter the sealed cavity 7 through the slit or opening.

[0052] The heating component 3 is located on the surface of the flexible substrate 1, which supports the heating component 3. The heating component 3 can have both heating and temperature measurement functions. For example, before the airflow passes through the sensor, the sensor's temperature is a first temperature. After the airflow passes through the sensor, some of the sensor's heat is carried away by the airflow, and the sensor's temperature drops to a second temperature. At this point, the heating component 3 can heat the sensor, causing its temperature to rise from the second temperature back to the first temperature. In one embodiment, the heating component 3 is composed of at least one resistor. In this embodiment, the heating component 3 may include a heating resistor. For example, the resistance value of the heating resistor is positively correlated with the sensor's temperature; after the airflow passes through the sensor, the sensor's temperature decreases, and the corresponding resistance value of the heating resistor decreases.

[0053] The heating component 3 is connected to a power control circuit, which can be located outside the sensor. The power control circuit can control the output power of the heating component 3 to maintain a constant temperature difference between the sensor and the ambient temperature, thus representing the wind speed flowing through the sensor based on the output power of the heating component 3. For example, as the wind speed increases, the sensor loses more heat, and the power required by the heating component 3 to maintain a constant temperature difference between the sensor and the ambient temperature increases. The increase in power represents the wind speed flowing across the sensor surface.

[0054] A first thermal sensing component 4 is located on the surface of a flexible substrate 1 and is arranged around a heating component 3. The flexible substrate 1 can support the first thermal sensing component 4, and the heating component 3 can be located at the center of the surface of the flexible substrate 1. The first thermal sensing component 4 can sense its own temperature at its location on the surface of the flexible substrate 1. For example, as a wind field flows past the sensor, the sensor temperature changes, and the first thermal sensing component 4 can sense the temperature change at its location on the surface of the flexible substrate 1.

[0055] The second thermal sensing component 5 is located on the surface of the flexible substrate 1, and on the side of the first thermal sensing component 4 opposite to the heating component 3. The flexible substrate 1 can support the second thermal sensing component 5, which can sense its own temperature at its location on the surface of the flexible substrate 1. For example, as the wind flows past the sensor, the sensor temperature changes, and the second thermal sensing component 5 can sense this temperature change at its location on the surface of the flexible substrate 1.

[0056] The second thermal sensing component 5 is also connected to the first thermal sensing component 4 to form a Wheatstone bridge circuit. That is, based on the connection between the second thermal sensing component 5 and the first thermal sensing component 4, a Wheatstone bridge circuit can be formed on the surface of the flexible substrate 1. When a wind field flows through the sensor, the temperature field balance on the sensor surface is disrupted. The direction of the wind flowing through the sensor can be characterized by the Wheatstone bridge circuit. For example, multiple Wheatstone bridge circuits can be formed on the surface of the flexible substrate 1. When a wind field flows through the sensor, each Wheatstone bridge circuit represents the wind speed component on the sensor surface in the corresponding direction. Finally, the wind speed components in each direction are vector-synthesized to obtain the wind direction of the wind field flowing through the sensor surface.

[0057] Based on this, the aforementioned MEMS wind speed and direction sensor includes a flexible substrate 1, with a cavity 7 inside the flexible substrate 1. A through-hole 2 is formed on the side of the flexible substrate 1, communicating with the cavity 7. Due to the through-hole 2, the volume of gas inside the cavity 7 of the flexible substrate 1 can be changed, causing the surface of the flexible substrate 1 used to house the heating component 3 to deform with the change in gas volume within the cavity 7. This, in turn, changes the contact area between the sensor surface and the wind field. In other words, different gas volumes within the cavity 7 of the flexible substrate 1 correspond to different degrees of deformation of the sensor surface, and consequently, different sizes of contact areas between the sensor surface and the wind field. Within a reasonable range, the larger the gas volume inside cavity 7, the greater the deformation of the sensor surface, resulting in a larger contact area between the wind field and the sensor surface. This makes it easier for the heating component 3, the first thermal sensing component 4, and the second thermal sensing component 5 to detect temperature changes on the sensor surface. The sensor becomes more sensitive to the heat carried away by the wind field, thus ensuring a smaller wind speed limit that the sensor can measure, resulting in higher sensor sensitivity. Adjusting the sensor's sensitivity adjusts its range accordingly. In other words, different degrees of deformation of the sensor surface in this embodiment correspond to different sensitivities and ranges. This embodiment thus realizes a MEMS wind speed and direction sensor with adjustable sensitivity and range, and the sensor has a simple structure and small size.

[0058] Optionally, the flexible substrate 1 may be made of polydimethylsiloxane (PDMS) or other flexible materials. In this embodiment, PDMS is used to fabricate the flexible substrate 1, which is low-cost and easy to manufacture, thus making the sensor low-cost and easy to implement.

[0059] refer to Figure 1 and Figure 2 In one embodiment, the flexible substrate 1 is used to set the surface of the heating component 3 as a plane, and the cavity wall of the cavity 7 near the surface has a similar shape to the surface.

[0060] The flexible substrate 1 has a rectangular cross-sectional shape along the thickness direction z parallel to the MEMS wind speed and direction sensor 100. Therefore, when the gas volume changes within the cavity 7, the deformation of the cavity wall easily approaches an arc shape. The deformation of the cavity wall is similar to that of the surface, and the degree of deformation of the cavity wall is basically the same as that of the surface. The surface can undergo effective deformation, and the deformation is relatively uniform, allowing for a large degree of deformation. This enables the surface to have a large contact area with the wind field, making temperature changes on the sensor surface more easily sensed by the heating component 3, the first thermal sensing component 4, and the second thermal sensing component 5, thus making the sensor more sensitive to wind field detection.

[0061] Furthermore, such as Figure 3 and Figure 4 As shown, optionally, the surface of the flexible substrate 1 used for mounting the heating component 3 and the cavity wall of the cavity 7 near the surface are both arc-shaped. Specifically, the cross-sectional shape of the flexible substrate 1 along the thickness direction z parallel to the MEMS wind speed and direction sensor 100 is arc-shaped. Further, the surface of the flexible substrate 1 used for mounting the heating component 3 and the cavity wall of the cavity 7 near the surface can be hemispherical. Specifically, the cross-sectional shape of the flexible substrate 1 along the thickness direction z parallel to the MEMS wind speed and direction sensor 100 is semi-circular.

[0062] When the gas volume inside cavity 7 changes, the deformation of the cavity wall becomes more likely to approach a hemispherical shape. The deformation of the cavity wall is similar to the deformation of the surface, and the degree of deformation of the cavity wall is basically the same as that of the surface. The deformation of the surface becomes more uniform and can undergo a greater degree of deformation, so that the surface can have a larger contact area with the wind field. The temperature change of the sensor surface is more easily sensed by the heating component 3, the first thermal sensing component 4, and the second thermal sensing component 5, thereby making the sensor more sensitive to the detection of the wind field.

[0063] like Figure 1As shown, in one embodiment, the first thermistor component 4 includes a first thermistor R41, a second thermistor R42, a third thermistor R43 and a fourth thermistor R44, and the second thermistor component 5 includes a fifth thermistor R51, a sixth thermistor R52, a seventh thermistor R53 and an eighth thermistor R54.

[0064] The first thermistor R41, the third thermistor R43, the fifth thermistor R51, and the seventh thermistor R53 are arranged along the first direction x to form a first Wheatstone bridge circuit. The first Wheatstone bridge circuit can characterize the wind speed component along the first direction x on the sensor surface, which can be understood as the first Wheatstone bridge circuit being used to detect the thermal temperature difference on the sensor surface caused by the wind field in the east-west direction.

[0065] The second thermistor R42, the fourth thermistor R44, the sixth thermistor R52, and the eighth thermistor R54 are arranged along the second direction y to form a second Wheatstone bridge circuit. The second Wheatstone bridge circuit can characterize the wind speed component along the second direction x on the sensor surface. It can be understood that the second Wheatstone bridge circuit is used to detect the thermal temperature difference on the sensor surface caused by the wind field in the north-south direction.

[0066] The second direction y is orthogonal to the first direction x. After the wind field flows through the sensor, the wind speed component along the first direction x of the sensor surface, represented by the first Wheatstone bridge circuit, and the wind speed component along the second direction y of the sensor surface, represented by the second Wheatstone bridge circuit, are vector synthesized to obtain the wind direction of the wind field flowing through the sensor surface.

[0067] Optionally, the material of any one of the heating resistor R0, the first thermistor R41, the second thermistor R42, the third thermistor R43, the fourth thermistor R44, the fifth thermistor R51, the sixth thermistor R52, the seventh thermistor R53, and the eighth thermistor R54 may include copper or other metal materials. In this embodiment, both the first thermistor assembly 4 and the second thermistor assembly 5 include thermistors. Thermistors can sensitively and accurately sense the temperature at their location on the surface of the flexible substrate 1, ensuring that the sensor can achieve sensitive and accurate detection of the wind field. Furthermore, thermistors are low in cost and easy to manufacture, thus making the sensor low in cost and easy to implement.

[0068] like Figure 1 As shown, in one embodiment, the MEMS wind speed and direction sensor also includes a plurality of connecting blocks 6, which are located on the surface of the flexible substrate 1.

[0069] The heating component 3 is led out to the power control circuit by at least two connecting blocks 6. For example, the heating component 3 is located in the center of the flexible substrate 1 and is centrally symmetrically distributed, and is led out by four connecting blocks 6 in the orthogonal direction.

[0070] The two connecting blocks 6 used to lead out the first thermistor R41 are respectively connected to a connecting block 6 used to lead out the third thermistor R43 and a connecting block 6 used to lead out the seventh thermistor R53; the two connecting blocks 6 used to lead out the fifth thermistor R51 are respectively connected to another connecting block 6 used to lead out the third thermistor R43 and another connecting block 6 used to lead out the seventh thermistor R53.

[0071] The two connecting blocks 6 used to lead out the fourth thermistor R44 are respectively connected to one connecting block 6 used to lead out the second thermistor R42 and one connecting block 6 used to lead out the sixth thermistor R52; the two connecting blocks 6 used to lead out the eighth thermistor R54 are respectively connected to another connecting block 6 used to lead out the second thermistor R42 and another connecting block 6 used to lead out the sixth thermistor R52. In this embodiment, the connecting blocks 6 are set to lead out the heating component 3 and each thermistor to the corresponding circuit structure, so as to realize the sensor's measurement of wind speed and wind direction. The connecting block structure is simple, easy to manufacture, and low in cost. Moreover, it can be manufactured in the same process as the heating component 3 and each thermistor, making the sensor structure simple, the manufacturing process simple, and the cost low.

[0072] like Figure 5 As shown in the embodiments of this application, a detection device is also provided. In one embodiment, the detection device includes a power control circuit 200 and a MEMD wind speed and direction sensor 100 as described in any of the above embodiments.

[0073] Among them, such as Figure 6 As shown, the power control circuit 200 includes a control unit 210, a feedback circuit 220, an ambient temperature measuring resistor Rc, a first resistor R1, a second resistor R2, a third resistor R3, a first power supply VCC, and a second power supply.

[0074] The heating component 3 has a first end connected to the control unit 210, a second end connected to the first end of the first resistor R1, and a second power supply connected to the second power supply, which can be grounded. The heating component 3 may include a heating resistor R0, with the first end of the heating resistor R0 serving as the first end of the heating component 3 and the second end of the heating resistor R0 serving as the second end of the heating component 3.

[0075] The first end of the ambient temperature measuring resistor Rc is connected to the first end of the heating component 3, the second end of the ambient temperature measuring resistor Rc is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the second power supply.

[0076] The first input terminal of the feedback circuit 220 is connected to the first end of the first resistor R1, the second input terminal of the feedback circuit 220 is connected to the first end of the third resistor R3, the third input terminal of the feedback circuit 220 is connected to the first power supply VCC, and the output terminal of the feedback circuit 220 is connected to the first end of the heating component 3.

[0077] In this embodiment, the heating resistor R0, the ambient temperature measuring resistor Rc, the first resistor R1, the second resistor R2, and the third resistor R3 form a Wheatstone bridge structure. The heating resistor R0, located in the center of the sensor, and the ambient temperature measuring resistor Rc maintain a constant temperature difference. Adjusting the second resistor R2 controls the magnitude of the temperature difference. When wind flows through the sensor, the temperature of the heating resistor R0 decreases, and its resistance decreases. The feedback circuit 220 maintains a constant temperature difference between the sensor temperature and the ambient temperature. The feedback circuit 220 outputs a feedback voltage V to the control unit 210. CTD It can represent the real-time wind speed.

[0078] like Figure 6 As shown, in one embodiment, the feedback circuit 220 includes an operational amplifier unit 221, a switching unit 222, and a fourth resistor R4.

[0079] In this circuit, the first input terminal of the operational amplifier unit 221 serves as the first input terminal of the feedback circuit 220, the second input terminal of the operational amplifier unit 221 serves as the second input terminal of the feedback circuit 220, the output terminal of the operational amplifier unit 221 is connected to the first terminal of the switching unit 222 through the fourth resistor R4, the second terminal of the switching unit 222 serves as the third input terminal of the feedback circuit 220, and the third terminal of the switching unit 222 serves as the output terminal of the feedback circuit 220.

[0080] For example, operational amplifier unit 221 may include an operational amplifier, with its positive (+) input terminal serving as the first input terminal, its negative (-) input terminal serving as the second input terminal, and its output terminal serving as the output terminal. Switching unit 222 may include a transistor, with its base (b) serving as the first terminal, its collector (c) serving as the second terminal, and its emitter (e) serving as the third terminal; the second power supply is grounded.

[0081] In this embodiment, the heating resistor R0, the ambient temperature measuring resistor Rc, the first resistor R1, the second resistor R2, and the third resistor R3 form a Wheatstone bridge structure. The heating resistor R0, located in the center of the sensor, and the ambient temperature measuring resistor Rc maintain a constant temperature difference. When wind flows through the sensor, the temperature of the heating resistor R0 decreases, and its resistance decreases. The feedback circuit 220 maintains a constant temperature difference between the sensor temperature and the ambient temperature, and the operational amplifier unit 221 outputs a feedback voltage V to the control unit 210. CTD It can represent the real-time wind speed.

[0082] like Figure 7 As shown, in one embodiment, the detection device further includes a first operational amplifier circuit 300 and a second operational amplifier circuit 400.

[0083] Among them, such as Figure 8 As shown, the first terminal of the first thermistor R41 is connected to the first power supply VCC, and the second terminal of the first thermistor R41 is connected to the first input terminal of the first operational amplifier circuit 300; the first terminal of the third thermistor R43 is connected to the first input terminal of the first operational amplifier circuit 300, and the second terminal of the third thermistor R43 is connected to the second power supply; the first terminal of the seventh thermistor R53 is connected to the first power supply VCC, and the second terminal of the seventh thermistor R53 is connected to the second input terminal of the first operational amplifier circuit 300; the first terminal of the fifth thermistor R51 is connected to the second input terminal of the first operational amplifier circuit 300, and the second terminal of the fifth thermistor R51 is connected to the second power supply.

[0084] For example, the first operational amplifier circuit 300 may include an operational amplifier, with the positive input terminal (+IN) of the operational amplifier serving as the first input terminal of the first operational amplifier circuit 300, the negative input terminal (-IN) of the operational amplifier serving as the second input terminal of the first operational amplifier circuit 300, and the output terminal of the operational amplifier serving as the output terminal of the first operational amplifier circuit 300.

[0085] In the embodiments of this application, Figure 8 The diagram also exemplarily illustrates a first Wheatstone bridge circuit. When a wind field blows across the sensor along the first direction x, the temperature of the upstream thermistor among the first thermistor R41, third thermistor R43, fifth thermistor R51, and seventh thermistor R53 is lower than the temperature of the downstream thermistor. This disrupts the temperature field balance on the sensor surface, causing the first operational amplifier circuit 300 to output a first voltage V. X It can characterize the wind speed component in the first direction x.

[0086] like Figure 9As shown, the first terminal of the fourth thermistor R44 is connected to the first power supply VCC, and the second terminal of the fourth thermistor R44 is connected to the first input terminal of the second operational amplifier circuit 400; the first terminal of the second thermistor R42 is connected to the first input terminal of the second operational amplifier circuit 400, and the second terminal of the second thermistor R42 is connected to the second power supply; the first terminal of the sixth thermistor R52 is connected to the first power supply VCC, and the second terminal of the sixth thermistor R52 is connected to the second input terminal of the second operational amplifier circuit 400; the first terminal of the eighth thermistor R54 is connected to the second input terminal of the second operational amplifier circuit 400, and the second terminal of the eighth thermistor R54 is connected to the second power supply.

[0087] For example, the second operational amplifier circuit 400 may include an operational amplifier, with the positive input terminal (+IN) of the operational amplifier serving as the first input terminal of the second operational amplifier circuit 400, the negative input terminal (-IN) of the operational amplifier serving as the second input terminal of the second operational amplifier circuit 400, and the output terminal of the operational amplifier serving as the output terminal of the second operational amplifier circuit 400.

[0088] In the embodiments of this application, Figure 9 The second Wheatstone bridge circuit is also illustrated. When the wind blows across the sensor along the second direction y, the temperature of the upstream thermistor among the second thermistor R42, the fourth thermistor R44, the sixth thermistor R52, and the eighth thermistor R54 is lower than the temperature of the downstream thermistor. The temperature field balance on the sensor surface is broken, and the second voltage V output by the second operational amplifier circuit 400 is... Y It can characterize the wind speed component in the second direction y; the wind direction angle θ can be represented by the formula θ = arctan(V Y / V X )calculate.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A MEMS wind speed and direction sensor, characterized in that, include: A flexible substrate, wherein a cavity is provided inside the flexible substrate, and a through hole is provided on the side of the flexible substrate, and the cavity communicates with the through hole; A heating component, located on the surface of the flexible substrate, is used to connect to a power control circuit. A first thermal sensing component is located on the surface of the flexible substrate and is arranged around the heating component; The second thermal sensing component is located on the surface of the flexible substrate and on the side of the first thermal sensing component away from the heating component. The second thermal sensing component is also connected to the first thermal sensing component to form a Wheatstone bridge circuit. The flexible substrate is used to ensure that the surface of the heating component deforms as the volume of gas in the cavity changes. The first thermal sensing component includes a first thermistor, a second thermistor, a third thermistor, and a fourth thermistor; the second thermal sensing component includes a fifth thermistor, a sixth thermistor, a seventh thermistor, and an eighth thermistor. The first thermistor, the third thermistor, the fifth thermistor, and the seventh thermistor are arranged along a first direction, and the second thermistor, the fourth thermistor, the sixth thermistor, and the eighth thermistor are arranged along a second direction, which is orthogonal to the first direction. The flexible substrate is used to set the surface of the heating component as an arc surface, and the cavity wall on the side of the cavity near the surface has a similar shape to the surface; The flexible substrate has an arc-shaped cross-section along the thickness direction of the MEMS wind speed and direction sensor. The flexible substrate is made of polydimethylsiloxane.

2. The MEMS wind speed and direction sensor according to claim 1, characterized in that, Also includes: Multiple connecting blocks, the connecting blocks being located on the surface of the flexible substrate; The heating component is led out to the power control circuit by at least two of the connecting blocks; The two connecting blocks used to lead out the first thermistor are respectively connected to a connecting block used to lead out the third thermistor and a connecting block used to lead out the seventh thermistor; The two connecting blocks used to lead out the fifth thermistor are respectively connected to another connecting block used to lead out the third thermistor and another connecting block used to lead out the seventh thermistor; The two connecting blocks used to lead out the fourth thermistor are respectively connected to a connecting block used to lead out the second thermistor and a connecting block used to lead out the sixth thermistor; The two connecting blocks used to lead out the eighth thermistor are respectively connected to another connecting block used to lead out the second thermistor and another connecting block used to lead out the sixth thermistor.

3. The MEMS wind speed and direction sensor according to claim 1, characterized in that, The materials of the first thermistor, the second thermistor, the third thermistor, the fourth thermistor, the fifth thermistor, the sixth thermistor, the seventh thermistor and / or the eighth thermistor include copper.

4. A detection device, characterized in that, include: The power control circuit and the MEMS wind speed and direction sensor as described in any one of claims 1-3; The power control circuit includes a control unit, a feedback circuit, an ambient temperature measuring resistor, a first resistor, a second resistor, a third resistor, a first power supply, and a second power supply. The first end of the heating component is connected to the control unit, the second end of the heating component is connected to the first end of the first resistor, and the second end of the first resistor is connected to the second power supply. The first end of the ambient temperature measuring resistor is connected to the first end of the heating component, the second end of the ambient temperature measuring resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the second power supply. The first input terminal of the feedback circuit is connected to the first terminal of the first resistor, the second input terminal of the feedback circuit is connected to the first terminal of the third resistor, the third input terminal of the feedback circuit is connected to the first power supply, and the output terminal of the feedback circuit is connected to the first terminal of the heating component.

5. The detection device according to claim 4, characterized in that, The feedback circuit includes: an operational amplifier unit, a switching unit, and a fourth resistor; The first input terminal of the operational amplifier unit serves as the first input terminal of the feedback circuit, the second input terminal of the operational amplifier unit serves as the second input terminal of the feedback circuit, the output terminal of the operational amplifier unit is connected to the first terminal of the switching unit through the fourth resistor, the second terminal of the switching unit serves as the third input terminal of the feedback circuit, and the third terminal of the switching unit serves as the output terminal of the feedback circuit.

6. The detection device according to claim 4, characterized in that, Also includes: First op-amp circuit and second op-amp circuit; The first end of the first thermistor is connected to the first power supply, and the second end of the first thermistor is connected to the first input terminal of the first operational amplifier circuit. The first end of the third thermistor is connected to the first input terminal of the first operational amplifier circuit, and the second end of the third thermistor is connected to the second power supply. The first end of the seventh thermistor is connected to the first power supply, and the second end of the seventh thermistor is connected to the second input terminal of the first operational amplifier circuit. The first end of the fifth thermistor is connected to the second input terminal of the first operational amplifier circuit, and the second end of the fifth thermistor is connected to the second power supply. The first end of the fourth thermistor is connected to the first power supply, and the second end of the fourth thermistor is connected to the first input terminal of the second operational amplifier circuit. The first end of the second thermistor is connected to the first input terminal of the second operational amplifier circuit, and the second end of the second thermistor is connected to the second power supply. The first end of the sixth thermistor is connected to the first power supply, and the second end of the sixth thermistor is connected to the second input terminal of the second operational amplifier circuit. The first end of the eighth thermistor is connected to the second input terminal of the second operational amplifier circuit, and the second end of the eighth thermistor is connected to the second power supply.

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