CN209727992U - A Calibration System for Miniature Multi-angle Wind Velocity Sensor - Google Patents

Abstract

The utility model is a miniature multi-angle wind speed sensor calibration system, which comprises a small calibration wind tunnel, a two-degree-of-freedom fixture and a wind speed control module. There are driving blades and guide vane blades driven by DC motors inside, honeycombs and damping nets are arranged in the stabilizing section, the contracting section adopts a quintic contraction curve, and several wind pressure sensors are inlaid on the inner surface of the air outlet end of the contracting section , the two-degree-of-freedom fixture is located on the air outlet side of the contraction section of the small calibration wind tunnel. The two-degree-of-freedom fixture is used to clamp the anemometer test sample and can drive the anemometer test sample to rotate in the vertical plane. The wind speed control module includes a single-chip microcomputer system , the wind pressure sensor controls the speed of the DC motor through the PID of the single-chip microcomputer system. The system can conveniently and accurately calibrate the wind speed sensor samples.

Description

A Calibration System for Miniature Multi-angle Wind Velocity Sensor

technical field

The utility model relates to the technical field of sensor calibration, in particular to a miniature multi-angle wind speed sensor calibration system.

Background technique

The anemometer needs to be calibrated before use, especially the hot-wire anemometer. The measurement of wind speed is an important part of the field of engineering technology measurement. At present, the measurement methods widely used in air velocity mainly include hot-line testing technology, ultrasonic testing technology, and differential pressure testing technology. Wait. The accurate calibration of the sensor before the wind speed test is the fundamental requirement to ensure the measurement accuracy, especially the hot wire test technology has high requirements for the calibration of the sensor, which must be calibrated before each use, which puts forward very high requirements for the calibration equipment. Large-scale wind tunnels can provide stable wind speed, but all devices in the test area must be emptied before use, which is inconvenient to use, and the cost of large-scale calibration tests is high.

Contents of the invention

The technical problem to be solved by the utility model is to provide a miniature multi-angle wind speed sensor calibration system, which can conveniently calibrate the wind speed sensor.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

A miniature multi-angle wind speed sensor calibration system is characterized in that it consists of a small calibration wind tunnel, a two-degree-of-freedom fixture and a wind speed control module. The small calibration wind tunnel is a cylindrical structure, including sequentially connected power sections, Stabilizing section and shrinking section, the driving blades and guide vane blades driven by DC motors are arranged in the power section, the honeycomb and damping net are arranged in the stabilizing section, and the shrinking section adopts quintic contraction Curve, the inner surface of the air outlet end of the contraction section is inlaid with several wind pressure sensors, and several wind pressure sensors are evenly distributed annularly along the air outlet end of the contraction section;

The two-degree-of-freedom fixture is located on the air outlet side of the contraction section of the small calibration wind tunnel. The two-degree-of-freedom fixture is used to clamp the anemometer test sample and can drive the anemometer test sample to rotate in the vertical plane. During the rotation process, ensure that the test end of the anemometer test sample is located on the extension line of the axis of the small calibration wind tunnel;

The wind speed control module includes a single-chip microcomputer system, the wind pressure sensor is connected to the input terminal of the single-chip computer system for signal control, and the output terminal of the single-chip computer system is connected to the controller signal control of the DC motor.

The DC motor is fixedly installed in the center of the guide vane hub, the hub is fixed on the inner wall of the power section through the guide vane blades, the driving blade is connected with the output shaft of the DC motor, and the driving blade and the guide vane The number of blades is a prime number to each other.

The driving blade adopts NACA blade shape, the hub ratio is 0.48, the number of driving blades is 7, the number of guide vane blades is 9, the rated speed of the DC motor is 7000rpm, the voltage is 24V, the torque is 0.1NM, and the power is 100W. The control voltage 2 is 0~5V.

The honeycomb is spliced by a plurality of regular hexagonal barrel structures to form a honeycomb structure. The opposite side length of each regular hexagonal barrel structure is 20mm, the thickness is 0.2mm, and the length is 60mm. The damping net is made of metal Made of silk.

The length of the stable section is 150mm.

The contraction section adopts a quintic contraction curve, and the contraction ratio is 7.72:1.

The length of the shrinkage section is 200mm.

The inner surface of the air outlet end of the shrinking section is inlaid with four wind pressure sensors, and the wind pressure sensors are connected to the single-chip system through the ii2 communication protocol signal, and the single-chip system uses PID to control the speed of the DC motor.

The two-degree-of-freedom fixture includes a base, the upper surface of the base is fixed with a steering gear through a bracket, the output shaft of the steering gear is connected to the swing arm, and the output shaft of the steering gear is used to drive The swing arm rotates in the plane where the swing arm is located, and the swing arm is provided with a fixed fixture, and the fixed fixture is used to clamp the anemometer test sample.

The beneficial effects that this kind of miniature multi-angle wind speed sensor calibration system can produce are as follows: First, by setting guide vane blades on the air outlet side of the driving blades, the airflow stability is ensured by the guide vane blades, and vortices are avoided in the pipeline. Second, honeycombs and damping nets are used to reduce turbulence and eliminate radial wind speed. Third, the wind pressure sensor performs AD conversion and transmits the data to the single-chip microcomputer in real time. The control program uses PID to control the motor speed to meet the standard wind speed within 0~55m/s. The wind pressure sensor forms a closed-loop control with the single-chip microcomputer and the DC motor. , to ensure the constant and accurate wind speed. Fourth, the anemometer test sample can make its yaw angle and pitch angle rotate 360° under the drive of the swing arm. The test end of the anemometer is on the central axis of the wind tunnel, so that the anemometer can test the stable wind output Angle of wind speed and wind direction. Fifth, compared with the traditional calibration wind tunnel, the small calibration wind tunnel in this structure does not repeatedly set the stable section at the tail. The reason is that the stable section at the tail is too long, which will affect the overall size. The anemometer that needs to be calibrated is controlled at the air outlet In the center, when the degree of turbulence control is good, there is no need to increase the stable section at the tail. Furthermore, if the stable section at the tail is set too long, the friction of the boundary layer will increase, which will affect the wind speed.

Description of drawings

FIG. 1 is a structural schematic diagram of a calibration system for a miniature multi-angle wind speed sensor of the present invention.

Fig. 2 is a structural schematic diagram of a miniature calibration wind tunnel of a miniature multi-angle wind speed sensor calibration system of the present invention.

Fig. 3 is a structural schematic diagram of a two-degree-of-freedom fixture of a miniature multi-angle wind speed sensor calibration system of the present invention.

Notes on drawings in the manual: 1. Small calibration wind tunnel; 2. Two-degree-of-freedom fixture; 3. Power section; 4. Stabilization section; 5. Contraction section; 6. DC motor; 9. Honeycomb device; 10. Damping net; 11. Wind pressure sensor; 12. Base; 13. Steering gear; 14. Swing arm; 15. Fixing fixture; 16. Anemometer test sample.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific preferred embodiments.

As shown in Figure 1, a miniature multi-angle wind speed sensor calibration system is characterized in that it includes a small calibration wind tunnel 1, a two-degree-of-freedom fixture 2 and a wind speed control module, and the small calibration wind tunnel 1 is a cylindrical structure , including a power section 3, a stabilizing section 4 and a constricting section 5 connected in sequence, the driving blade 7 and the guide vane blade 8 driven by a DC motor 6 are arranged in the power section 3, and the stabilizing section 4 is provided with There are honeycombs 9 and damping nets 10. The contraction section 5 adopts a quintic contraction curve. The inner surface of the air outlet end of the contraction section 5 is inlaid with several wind pressure sensors 11, and several wind pressure sensors 11 are embedded along the The end of the air outlet of the constriction section 5 is evenly distributed in a circular shape;

The two-degree-of-freedom fixture 2 is located on the air outlet side of the contraction section 5 of the small-scale calibration wind tunnel 1. The two-degree-of-freedom fixture 2 is used to clamp the anemometer test sample 16 and can drive the anemometer test sample 16 in the vertical direction. Rotate in a straight plane, and ensure that the test end of the anemometer test sample 16 is located on the extension line of the axis of the small calibration wind tunnel 1 during the rotation process;

The wind speed control module includes a single-chip microcomputer system, the wind pressure sensor 11 is connected to the input end of the single-chip microcomputer system, and the output end of the single-chip microcomputer system is connected to the controller of the DC motor 6 for signal control.

In this embodiment, the DC motor 6 is fixedly installed in the center of the guide vane hub, the hub is fixed on the inner wall of the power section 3 through the guide vane blades 8, and the drive blade 7 is connected to the output shaft of the DC motor 6 through transmission. The numbers of the driving blades 7 and guide vane blades 8 described above are prime numbers to each other.

In this embodiment, the driving blade 7 adopts NACA blade shape, the hub ratio is 0.48, the number of driving blades 7 is 7, the number of guide vane blades 8 is 9, the rated speed of the DC motor 6 is 7000rpm, the voltage is 24V, and the torque is 0.1 NM, the power is 100W, and the control voltage 2 is 0~5V.

In this embodiment, the honeycomb 9 is spliced by a plurality of regular hexagonal barrel structures to form a honeycomb structure. The opposite side length of each regular hexagonal barrel structure is 20 mm, the thickness is 0.2 mm, and the length is 60 mm. The damping The net 10 is woven from metal wires.

Further, the arrangement of the honeycomb 9 and the damping net 10 is used to reduce turbulence and eliminate radial wind speed. The setting of the damping net 10 can further break the vortex at the rear side of the honeycomb.

In this embodiment, the length of the stabilizing section 4 is 150mm.

In this embodiment, the contraction section 5 adopts a quintic contraction curve, and the contraction ratio is 7.72:1.

Furthermore, the constriction section can uniformly accelerate the airflow, so that it can reach the flow velocity required by the experiment, and at the same time can further improve the flow quality of the airflow and reduce the degree of turbulence.

In this embodiment, the length of the contraction section 5 is 200mm.

In this embodiment, four wind pressure sensors 11 are inlaid on the inner surface of the air outlet end of the contraction section 5, and the wind pressure sensors 11 are connected to the single-chip microcomputer system through the ii2 communication protocol signal, and the single-chip microcomputer system adopts PID to control the speed of the DC motor 6 .

Further, the wind pressure sensor 11 adopts Bosch bmp180 sensor, and the single-chip system adopts stm32 single-chip microcomputer main control. Since the wind pressure sensor 11 is embedded in the inner wall, it will not have any influence on the air from the air outlet. The four wind pressure sensors 11 perform AD conversion and transmit the data to the single-chip microcomputer system in real time. The control program uses PID to control the motor speed to meet the standard wind speed within 0~55m/s. A closed-loop control is formed between the wind pressure sensor, the single-chip microcomputer and the DC motor, which ensures the constant and accurate wind speed.

In this embodiment, the two-degree-of-freedom fixture 2 includes a base 12, the upper surface of the base 12 is fixed with a steering gear 13 through a bracket, and the output shaft of the steering gear 13 is connected to the swing arm 14 in transmission. The output shaft of the steering gear 13 is used to drive the swing arm 14 to rotate in the plane where the swing arm 14 is located. The swing arm 14 is provided with a fixing fixture 15, and the fixing fixture 15 is used to clamp the anemometer test sample 16.

Further, the two-degree-of-freedom fixture 2 can make the yaw angle and the pitch angle of the anemometer test sample 16 rotate 360° arbitrarily, because the test end of the anemometer test sample 16 is on the central axis of the small-scale calibration wind tunnel 1, so no matter How to rotate, the front end of the anemometer test sample 16 remains on the central axis of the small calibration wind tunnel 1 all the time, so that the anemometer test sample 16 can test the wind speed and direction of any angle of stable wind. Finally, the anemometer test sample 16 can be accurately calibrated.

When calibrating the measurement range and accuracy of the anemometer test sample 16, set some wind speed test points: 10m/s, 15m/s, 20m/s, 25m/s, 30m/s, 35m/s, 40m/s, 45m/s s, 50m/s, 55m/s, start the small calibration wind tunnel 1, set the wind pressure at the air outlet according to the above 10 test points, use the wind pressure sensor PID to control the speed of the DC motor 6, and collect the anemometer test sample 16 to measure the wind speed and For the actual wind speed in the wind tunnel, calculate the average value of the actual wind speed of the anemometer test sample 16 and the wind tunnel wind speed at each wind speed test point, and determine whether the anemometer test sample 16 meets the standard requirements through error analysis.

The above are only preferred implementations of the utility model, and the scope of protection of the utility model is not limited to the above-mentioned embodiments, and all technical solutions under the thinking of the utility model all belong to the scope of protection of the utility model. It should be pointed out that for those of ordinary skill in the art, some improvements and modifications without departing from the principle of the utility model should be regarded as the protection scope of the utility model.

Claims (9)

1. a kind of miniature multi-angle air velocity transducer calibration system, it is characterised in that: freely including small-sized calibration wind-tunnel (1), two Spending fixture (2) and blast velocity control module composition, the small-sized calibration wind-tunnel (1) is tubular structure, including sequentially connected Power section (3), stable section (4) and contraction section (5), the interior drive for being provided with direct current generator (6) driving of the power section (3) Movable vane piece (7) and guide vane blade (8), the stable section (4) is interior to be provided with honeycomb (9) and damping screen (10), the receipts Contracting section (5) uses five power shrinkage curves, and the air outlet terminal interior surface of the contraction section (5) is inlaid with several wind pressure biography Sensor (11), several wind pressure sensors (11) are uniformly distributed along the air outlet end annular of contraction section (5)；

The two-freedom fixture (2) is located at the air outlet side of small-sized calibration wind-tunnel (1) contraction section (5), and described two certainly By degree fixture (2) for clamping anemobiagraph test sample (16) and being able to drive anemobiagraph test sample (16) in perpendicular Rotation guarantees that the test lead of anemobiagraph test sample (16) is located at the extension of small-sized calibration wind-tunnel (1) axis during rotation On line；

The blast velocity control module includes SCM system, and the wind pressure sensor (11) and SCM system input terminal are believed Number connection, the controller signals of the SCM system output end and direct current generator (6), which control, to be connected.

2. a kind of miniature multi-angle air velocity transducer calibration system according to claim 1, it is characterised in that: described is straight Galvanic electricity machine (6) is fixedly mounted on guide vane hub centre, and the wheel hub is fixed on power section (3) inner wall by guide vane blade (8) On, the output shaft of the driving blade (7) and direct current generator (6) is sequentially connected, the driving blade (7) and guide vane blade (8) blade quantity prime number each other.

3. a kind of miniature multi-angle air velocity transducer calibration system according to claim 2, it is characterised in that: the drive Movable vane piece (7) uses NACA blade profile, and wheel hub ratio is 0.48, and driving blade (7) number is 7, and guide vane blade (8) number is 9, described Direct current generator (6) rated speed 7000rpm, voltage 24V, torque 0.1NM, power 100W, control voltage 2 be 0 ~ 5V。

4. a kind of miniature multi-angle air velocity transducer calibration system according to claim 1, it is characterised in that: the bee Nest device (9) is spliced to form honeycomb by multiple regular hexagon barrel-like structures, each regular hexagon barrel-like structure to edge lengths For 20mm, with a thickness of 0.2mm, length 60mm, the damping screen (10) is worked out by wire.

5. a kind of miniature multi-angle air velocity transducer calibration system according to claim 4, it is characterised in that: described is steady Determine section (4) length 150mm.

6. a kind of miniature multi-angle air velocity transducer calibration system according to claim 1, it is characterised in that: the receipts Contracting section (5) uses five power shrinkage curves, shrinkage ratio 7.72:1.

7. a kind of miniature multi-angle air velocity transducer calibration system according to claim 6, it is characterised in that: the receipts Contracting section (5) length 200mm.

8. a kind of miniature multi-angle air velocity transducer calibration system according to claim 1, it is characterised in that: the receipts The air outlet terminal interior surface of contracting section (5) is inlayed there are four wind pressure sensor (11), wind pressure sensor (11) and SCM system It is connected by ii2 communication protocol signals, the SCM system uses the revolving speed of PID control direct current generator (6).

9. a kind of miniature multi-angle air velocity transducer calibration system according to claim 1, it is characterised in that: described two Freedom degree fixture (2) includes pedestal (12), and the upper surface of the pedestal (12), which is fixed by the bracket, is equipped with steering engine (13), institute The output shaft for the steering engine (13) stated and swing arm (14) are sequentially connected, and the output shaft of the steering engine (13) is for driving swing arm (14) Stationary fixture (15), the stationary fixture are provided on rotation in surface where swing arm (14), the swing arm (14) (15) for clamping anemobiagraph test sample (16).