CN203385750U - Ultrasonic wave anemorumbometer - Google Patents

Abstract

The utility model relates to an ultrasonic wave anemorumbometer comprising ultrasonic wave sensors, a sending drive circuit, a liquid crystal display, a signal detection circuit, a channel control circuit, a power supply module and a FPGA main chip. The channel control circuit comprises a sending channel control circuit and a reception channel control circuit. There are three pairs of and totaling six ultrasonic wave sensors. The control terminal of each ultrasonic wave sensor is connected with the control terminal of the FPGA main chip through the sending channel control circuit and the sending drive circuit. The signal output terminal of each ultrasonic wave sensor is connected with the signal acquisition terminal of the FPGA main chip through the reception channel control circuit and the signal detection circuit. The power supply module provides power to the FPGA main chip. The sending drive circuit, the signal detection circuit and the liquid crystal display are connected with the FPGA main chip. The ultrasonic wave anemorumbometer improves the sensitivity on wind speed and wind direction measurement.

Description

A kind of ultrasonic aerovane

Technical field:

The utility model relates to the wind speed and direction field of measuring technique, is specifically related to a kind of ultrasonic aerovane based on FPGA.

Background technology:

Along with scientific and technical development, wind speed and direction is measured and is being brought into play in a lot of fields more and more important effect, as environmental monitoring, navigation aviation monitoring, bridge tunnel monitoring, agricultural disaster monitoring, wind-power electricity generation etc.Under this background, rapidly, measurement means and method become increasingly abundant the development of wind vector surveying instrument.Commonly used have a vane anemoscope, and its cost is low, practical and convenient; But the mechanical hook-up volume is larger, rotator inertia can cause hesitation, and response speed is slow, the occasion that applicable accuracy requirement is lower; And there are rotatable parts in it, easily produce wearing and tearing; At the gentle breeze lower than starting wind speed, can't measure.The pitot tube anemoscope, pitot tube low price simple in structure, easily manufactured, but it belongs to single-point, permanent contact type measurement; In crosswind when speed, need to be measured the density of fluid, and the density variation with temperature of fluid and changing, low wind speed section sensitivity is low.The hot line hot film anemometer, the principle of work of hot line hot film anemometer is when wind speed changes, the temperature of tinsel or metallic film changes thereupon, thereby changes its resistance value, utilizes Wheatstone bridge can obtain and the dull relevant output signal of custom; It is little that it has a volume, wind field is disturbed little, without carrying out stabilizing compensation, reliable and stable; But it belongs to contact type measurement, probe can be given birth to certain disturbance to measured stream Channel Group movable property.

Laser Doppler Velocimeter, because it adopts non-contact measurement, stream field is noiseless; Spatial resolution is high, can meet the requirement of point measurement; But the composition of its measuring system is comparatively complicated, the experiment flow field needs printing opacity, and expensive cost is high.The ultrasonic wind speed and direction measuring method, because it belongs to non-contact measurement, so do not disturb wind field, lose without pressure, there is no mechanical rotation, do not have mechanical wear, there is no machinery inertial, so highly sensitive, output characteristics is linear, is easy to realize the calculating of Digital output and air speed value.

Summary of the invention:

While measuring in order to solve traditional anemoclinograph, the low problem of sensitivity, designed a kind of air speed measuring apparatus based on the ultrasound wave time difference method.It,, by means of the high speed signal handling property of the fpga chip of alter company high integration and higher clock frequency, can improve sampling precision to received signal.This measuring instrument has made up the low shortcoming of sensitivity of traditional mechanical type anemoclinograph widely.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of ultrasonic aerovane, comprise ultrasonic sensor, the emission driving circuit, liquid crystal display, signal deteching circuit, channel control circuit and power module, it is characterized in that: also comprise the FPGA master chip, described channel control circuit comprises transmission channel control circuit and receiving cable control circuit, described ultrasonic sensor comprises three pairs six, the control end of each ultrasonic sensor is through the transmission channel control circuit, the emission driving circuit connects the control end of FPGA master chip, the signal output part of each ultrasonic sensor is through the receiving cable control circuit, signal deteching circuit connects the signals collecting end of FPGA master chip, power module is the power supply of FPGA master chip, and emission driving circuit, signal deteching circuit, liquid crystal display are connected with the FPGA master chip.

Wherein, the FPGA master chip adopts the EP4CE15F17C8N chip; Described emission driving circuit adopts bipolar voltage to drive; Comparator circuit three parts that the two stage amplifer circuit that described signal deteching circuit consists of OP37, the second order bandwidth-limited circuit that TL082 forms and LM393 form form.

The FPGA master chip is also through standard RS232 serial ports and host computer communication connection.Liquid crystal display adopts 12864 liquid crystal display.The ultrasonic sensor model is FUS200A.

Three pairs of ultrasonic sensors are placed along three axles of rectangular coordinate system in space respectively, and two ultrasonic sensors placing in opposite directions along same coordinate axis are a pair of, and the wind speed that the party is made progress is measured.Place along coordinate axis is symmetrical for every pair, be placed on coordinate axis, place in opposite directions for two every pair, on the coordinate axis straight line, with the coordinate axis angle be 0.

The utlity model has following beneficial effect:

The utility model design adopts three pairs of ultrasonic sensors respectively wind speed on three directions to be measured, subsequently through the synthetic wind speed and direction value that obtains this moment.

Due to the measurement of the utility model wind speed and the speed of ultrasonic propagation, it doesn't matter, so do not need temperature compensation, improved the accuracy of measuring when simplifying the structure.The CYCLONE4 that the design master chip adopts ALTER company is for FPGA, and it has high clock frequency and sweep frequency, therefore can obtain more high-precision wind speed and direction and measure.

The accompanying drawing explanation:

Fig. 1 is the wind arrow spirogram under rectangular coordinate system.

Fig. 2 is general frame figure.

Fig. 3 is bipolar voltage driving circuit frame diagram.

Fig. 4 is ultrasonic transmit circuit.

Fig. 5 is signal deteching circuit.

Embodiment:

Below in conjunction with accompanying drawing, technical scheme of the present invention is elaborated:

Whole system is by three pairs of ultrasonic sensors of placing along three coordinate axis of rectangular coordinate system in space, the FPGA master chip, the emission driving circuit, liquid crystal display, signal deteching circuit, channel control circuit and power module form, every pair of sensor records the air speed value that the party makes progress, produced the square-wave signal of standard 200khz by FPGA, start-timing simultaneously, through the emission driving circuit, output meets the signal that ultrasonic sensor drives, then through the transmission channel control circuit, select, drive corresponding ultrasonic sensor, send excusing from death ripple signal by ultrasonic sensor, via the receiving cable control circuit, make it in accepting state simultaneously, after signal deteching circuit receives signal, signal is amplified, filtering, rectification, obtain envelope signal, this envelope signal again through threshold value relatively, finally by this signal input FPGA port, by master chip, this port is carried out to high-velocity scanning, when this port being detected and high level occurs, stop timing, take out this time and storage, be ultrasound wave and be sent to the corresponding other end time used from an end, postpone 10s, select to control by channel control circuit, measure the rightabout time, can calculate the wind speed component of this direction.Can measure respectively the wind speed component of other both directions successively.Finally, by chip, the data of collecting are processed, can be obtained the wind speed and direction value.Every mistake refreshes primary air velocity wind direction value in 5 minutes, and shows in liquid crystal display, passes to host computer by the RS232 serial ports simultaneously.

In Fig. 1, can find out, three pairs of ultrasonic sensors are placed along three coordinate axis of rectangular coordinate system in space, and from three-dimensional situation, consider: establishing wind speed degree v is vx at the component of 3 change in coordinate axis direction of rectangular coordinate system, vy, vz.

First ask wind speed in the x-direction.If l is two distances between ultrasonic sensor, c is hyperacoustic velocity of sound, t ₁, t ₂be respectively the time that forward and orientation measurement obtain,

$\left\{\begin{array}{c}c-v_x=\frac{l}{t_1}\\ c+v_x=\frac{l}{t_2}\end{array}\right.---\left(1\right)$

Can obtain wind speed in the x-direction by formula (1): $v_x=\frac{l}{2}(\frac{l}{t_1}-\frac{l}{t_2})=\frac{l(t_2-t_1)}{2t_1{t}_2}=\frac{\mathrm{l\Δt}}{2t_1{t}_2}.$ (2)

In like manner can calculate vy, vz, under rectangular coordinate system, as shown in Figure 1, resultant wind velocity is meaned by following formula

$\stackrel{\→}{v}=\stackrel{\→}{v_x}+\stackrel{\→}{v_y}+\stackrel{\→}{v_z}---\left(3\right)$

$v=\sqrt{{v_x}^2+{v_y}^2+{v_z}^2}---\left(4\right)$

${\mathrm{\θ}}_1={\tan }^{-1}\left(\frac{v_x}{v_y}\right)---\left(5\right)$

${\mathrm{\θ}}_2={\tan }^{-1}\left(\frac{v_y}{v_z}\right)---\left(6\right)$

${\mathrm{\θ}}_3={\tan }^{-1}\left(\frac{v_x}{v_z}\right)---\left(7\right)$

θ ₁, θ ₂, θ ₃it is respectively the angle of wind direction and three coordinate axis.According to this principle, just can draw the size of wind speed and the direction value of wind speed.

In Fig. 2, global design adopts take FPGA as master chip, and the chip model is EP4CE15F17C8N; Serial ports adopts standard RS232 serial ports and host computer to communicate; Liquid crystal display adopts 12864 liquid crystal to carry out the air speed value demonstration; Power acquisition is powered to whole system with 5v and 12v direct supply; Button adopts independent button pattern, realizes switch, the system of system power supply are restarted etc. to function; The emission driving circuit adopts the bipolar drive principle as shown in Figure 3, and the emission driving circuit is amplified the bipolar drive output signal, then drives ultrasonic sensor to send ultrasonic signal.

The model of ultrasonic sensor is FUS200A.

In Fig. 3, because driving, bipolar voltage doubles than unipolarity voltage driving-energy conversion ratio, so the driving of the utility model employing bipolar voltage, can reduce like this and drive and sensor energy consumption; And then more effectively reduce the energy consumption of entire system.

In Fig. 4, the square-wave pulse signal that the emission driving circuit receives is sent into the class B push-pull amplifying circuit, drive the CMOS pipe by its output signal, then its pulse signal is added to high-frequency pulse transformer carries out power amplification, make amplitude be increased to 60 volts, finally the pulse square wave signal of amplification is added on ultrasonic transducer and produces the ultrasound wave that frequency is 200kHz and it is launched.

In Fig. 5, the two stage amplifer circuit that signal deteching circuit consists of OP37, comparator circuit three parts that the second order bandwidth-limited circuit that TL082 forms and LM393 form form.Because the native system frequency is higher, echoed signal very a little less than, be the millivolt level, therefore be designed to the two-stage amplifying circuit, the first order is amplified 100 times, the second level is amplified 50 times, amplifies altogether 5000 times of left and right.Consider that in addition native system will adapt to the working environment of various complexity, therefore designed the high precision bandwidth-limited circuit formed by TL082, amplify the further filtering of laggard row for echoed signal, filtered signal is input to the comparer inverting input that LM393 forms, with reference voltage, compare, and it is compared to output voltage and carry out amplitude limit, its voltage is connected to d type flip flop, comparer goes out square-wave signal by the AC signal shaping after amplifying, it is connected to FPGA, start the receiver module counting, while reaching the train of impulses setting value, close timing counter and stop counting.

Claims (6)

1. a ultrasonic aerovane, comprise ultrasonic sensor, the emission driving circuit, liquid crystal display, signal deteching circuit, channel control circuit and power module, it is characterized in that: also comprise the FPGA master chip, described channel control circuit comprises transmission channel control circuit and receiving cable control circuit, described ultrasonic sensor comprises three pairs six, the control end of each ultrasonic sensor is through the transmission channel control circuit, the emission driving circuit connects the control end of FPGA master chip, the signal output part of each ultrasonic sensor is through the receiving cable control circuit, signal deteching circuit connects the signals collecting end of FPGA master chip, power module is the power supply of FPGA master chip, and emission driving circuit, signal deteching circuit, liquid crystal display are connected with the FPGA master chip.

2. ultrasonic aerovane according to claim 1, is characterized in that: FPGA master chip employing EP4CE15F17C8N chip; Described emission driving circuit adopts bipolar voltage to drive; Comparator circuit three parts that the two stage amplifer circuit that described signal deteching circuit consists of OP37, the second order bandwidth-limited circuit that TL082 forms and LM393 form form.

3. ultrasonic aerovane according to claim 1 is characterized in that: the FPGA master chip is also through standard RS232 serial ports and host computer communication connection.

4. ultrasonic aerovane according to claim 1, it is characterized in that: liquid crystal display adopts 12864 liquid crystal display.

5. ultrasonic aerovane according to claim 1, the ultrasonic sensor model is FUS200A.

6. ultrasonic aerovane according to claim 1 is characterized in that: three pairs of ultrasonic sensors are placed along three coordinate axis of rectangular coordinate system in space respectively, and two ultrasonic sensors placing in opposite directions along same coordinate axis are a pair of.

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