CN205352653U - Accurate ranging system of supersound in low speed wind tunnel - Google Patents

Abstract

The utility model discloses an accurate ranging system of supersound in low speed wind tunnel, including setting up ultrasonic sensor no. 1 in the wind -tunnel, ultrasonic sensor no. 2, ultrasonic sensor no. 3, ultrasonic sensor no. 4, ultrasonic sensor no. 5 and controller, wherein ultrasonic sensor no. 1, ultrasonic sensor no. 2 fix on the wind -tunnel inner wall, and ultrasonic sensor no. 3 sets up in the wind -tunnel for removing the end, and ultrasonic sensor no. 4, ultrasonic sensor no. 5 set up on two testees separately, and the testee setting is in the wind -tunnel, location method adopts the gap method to obtain the real -time velocity of sound in the low -speed wind tunnel test section, utilizes two -way detection algorithm to obtain the spatial distance of two objects in the low -speed wind tunnel test section through the real -time velocity of sound. The utility model discloses an adopt gap method and diphase detection algorithm to realize the interior distance measurement of low speed wind tunnel, avoided the influence to the range finding result such as the interior air flow rate of test chamber, density, pressure, temperature and humidity.

Description

A kind of ultrasonic precision ranging system in low-speed wind tunnel

Technical field

The present invention relates to wind tunnel test field, especially relate to the ultrasonic precision ranging system in a kind of low-speed wind tunnel.

Background technology

Low-speed wind tunnel is processed system and dynamical system etc. formed by hole body, model supporting system, DATA REASONING, and the measurement of modal position and attitude is model supporting system and the key component of data measurement processing system, its precision is to ensure that the important step of wind tunnel test data accuracy.Modal position conventional at present and attitude measurement method include indirectly measuring and noncontact directly measurement etc., and the accurately measurement of space length is as the basis of low-speed wind tunnel test modal position and attitude measurement, the precision of its measurement is most important to the certainty of measurement of modal position and attitude.

Ultrasound wave is a kind of mechanical wave, and ultrasound wave, also known as ultrasonic, belongs to sound wave, refers to that frequency is higher than the sound wave of 20kHz.At present, ultrasonic communication theory comparative maturity in gas and fluid, application mainly includes detection ultrasonic, power ultrasonic and medical ultrasonic etc..Wherein ultrasound detection is to utilize super sonic propagation and information carrier characteristic, extracted the information of reflection medium internal structure or medium self character by certain means, reach the purpose of detection internal structure or fault of construction, Measuring Object physical dimension and medium physical function parameter.Such as ultrasonic inspection, ultrasonic thickness measurement, ultrasonic survey thing position, supersonic sounding etc..Supersonic sounding is to determine a kind of ultrasonic detecting technology of detected space distance by measurement the ultrasound wave time of a certain spatial transmission and the velocity of sound in this medium in medium.Ultrasonic distance-measuring method includes phase-detection method, magnitudes of acoustic waves detection method and transit time method etc., and current supersonic sounding generally uses transit time method.Transit time method includes again the direct method of measurement and reflectrometry.The velocity of sound in use, is generally all processed by these measuring methods as constant.But it practice, the velocity of sound certain change can occur along with the change of the conditions such as the density of propagation medium, temperature, pressure and humidity, thus the error of measurement result can be caused due to the change of the velocity of sound, thus reducing certainty of measurement.Having certain flow rate additionally, due to air as propagation medium in low-speed wind tunnel, supersonic sounding result can be brought error by the Doppler effect in propagation process of sound wave.

Summary of the invention

It is an object of the invention to provide the ultrasonic precision ranging system in a kind of low-speed wind tunnel, it is to avoid the impact on supersonic sounding such as air velocity, density, temperature, pressure and humidity in low-speed wind tunnel test section.

For achieving the above object, the present invention adopts the following technical scheme that

Ultrasonic precision ranging system in a kind of low-speed wind tunnel, including controller and sonac one (B₁), sonac two (B₂), sonac three (S), sonac four (B_i), sonac five (P_j), wherein sonac one (B₁), sonac two (B₂) be fixedly installed on wind-tunnel inwall, an other sonac three (S) is arranged in wind-tunnel for mobile terminal, sonac four (B_i), sonac five (P_j) be each fixedly installed on two testees, described testee is placed in wind-tunnel, and described five sonacs are transmitting-receiving integrated sensor, and the signal output part of described five sonacs is connected respectively to controller；

Described system adopts distance-finding method to be made up of gap method and bi-directional probing method two parts, as follows:

Gap method

Two sonac being fixedly installed on wind-tunnel inwall one (B are recorded by conventional method₁), sonac two (B₂) between distance d；

Ultrasound wave launched by ultrasonic transducer in wind-tunnel, and controller gathers ultrasound wave and is transmitted into sonac one (B from sonac three (S)₁) reception duration be t₁, controller gathers ultrasound wave from sonac one (B₁) the reception duration that is transmitted into sonac three (S) is t₁'；

By the movement of sonac three (S), controller gathers the distance d of sonac three (S) movement₂, then gathered ultrasound wave by controller and launch ultrasound wave to sonac one (B from sonac three (S)₁) reception duration be t₂, device processed gathers ultrasound wave from sonac one (B₁) the reception duration that is transmitted into sonac three (S) is t₂'；

Controller gathers ultrasound wave from sonac two (B₂) it is transmitted into sonac one (B₁) reception duration be t, controller gathers ultrasound wave from sonac one (B₁) it is transmitted into sonac two (B₂) reception duration be t '；

By can be calculated:

$d=\frac{t\·t^{\′}}{t+t^{\′}}\·\frac{d_2\·(t_1+{t_1}^{\′})\·(t_2+{t_2}^{\′})}{t_2\·{t_2}^{\′}\·(t_1+{t_1}^{\′})-t_1\·{t_1}^{\′}\·(t_2+{t_2}^{\′})}$

And velocity of sound c is in real time:

$c=\frac{d}{2}\·(\frac{1}{t}+\frac{1}{t^{\′}});$

Bi-directional probing method

It is arranged on the sonac four (B on testee_i), sonac five (P_j) mutually launch ultrasound wave, controller gathers ultrasound wave by B_iIt is transmitted into P_jThe duration received is t_ji1, ultrasound wave is by P_jIt is transmitted into B_iThe duration received is t_ji2Sonac B_iWith sensor P_jBetween distance be designated as d_ji,

By can be calculated

$d_{ji}=\frac{2\×c}{\frac{1}{t_{ji1}}+\frac{1}{t_{ji2}}}.$

In technique scheme, described sonac three (S) is linearly moved in wind-tunnel.

In technique scheme, described sonac one (B₁), sonac three (S) and mobile after sonac three (S) on the same line.

In technique scheme, the measurement between described each two sonac needs timesharing to measure, namely from receive transmitting measure one by one.

In technique scheme, the ultrasound wave that described ultrasonic transducer sends has the constant amplitude cosine wave of one fixed width.

In technique scheme, the complete cycle that the cycle is wind-tunnel low frequency pulsating of ultrasonic propagation duration sampling during described supersonic sounding.

In technique scheme, the integral multiple that frequency is power frequency of ultrasonic propagation duration sampling during supersonic sounding.

In sum, owing to have employed technique scheme, the invention has the beneficial effects as follows:

The velocity of sound is easily subject to the impact of environmental condition such as density, temperature, pressure and humidity etc. and changes, and generally the velocity of sound processes as constant, and this can cause corresponding error.In the present invention, by adopting gap method to realize the real-time measurement of the velocity of sound in low-speed wind tunnel, it is to avoid the velocity of sound is processed, as constant, the error caused；

In the present invention, utilize bi-directional probing method to obtain the space length of two articles in low-speed wind tunnel test section, it is to avoid the impact on range measurement such as air velocity (Doppler effect can be produced) in low-speed wind tunnel test section, improve the precision of measurement；

In the present invention, have employed non-cpntact measurement means, it is to avoid measure the instrument impact on low-speed wind tunnel test section flow field and experimental enviroment, the accuracy improving test efficiency and data is benefited.

Accompanying drawing explanation

Examples of the present invention will be described by way of reference to the accompanying drawings, wherein:

Fig. 1 is gap method schematic diagram；

Fig. 2 is bi-directional probing method schematic diagram.

Detailed description of the invention

The present invention is made up of two parts content: one is the real-time velocity of sound adopting gap method to obtain in low-speed wind tunnel test section；Two is utilize to measure the real-time velocity of sound arrived, and adopts bi-directional probing method to obtain the Accuracy Space distance between two articles to be measured in low-speed wind tunnel test section.In order to realize this two parts function, sonac one (B₁), sonac two (B₂), sonac three (S), sonac four (B_i), sonac five (P_j), wherein sonac one (B₁), sonac two (B₂) be fixedly installed on wind-tunnel inwall, an other sonac three (S) is arranged in wind-tunnel can move in wind-tunnel for mobile terminal, sonac four (B_i), sonac five (P_j) be each fixedly installed on two testees, described testee is placed in wind-tunnel, certain distance is there is between two testees, described five sonacs are transmitting-receiving integrated sensor, present invention additionally comprises a controller, the effect of controller is the duration gathering five sonac ultrasonic propagations each other, and therefore controller needs and sonac connection, and controller is calculated in real time by the data collected.

In real process, the velocity of sound can change a lot along with the circumstances (such as the density of medium, temperature, pressure and humidity etc.) of medium, if being applied to the velocity of sound measure, just should obtain the velocity of sound under conditions present in real time.In order to obtain the real-time velocity of sound, set forth herein gap method.Namely problem is measured for the velocity of sound c real-time high-precision under test section current environment, gap method can be adopted to obtain, as it is shown in figure 1, for gap method schematic diagram.

Sonac B₁And B₂Between space length be definite value, if this distance is d；The distance that sonac S is moved to S ' by initial position S is d₂, by general length measurement method d in moving process₂Can accurately obtain, t₁It is transmitted into B from S for ultrasound wave₁The duration received, t₁' for ultrasound wave from B₁It is transmitted into the S duration received, t₂It is transmitted into B from S ' for ultrasound wave₁The duration received, t₂' for ultrasound wave from B₁Being transmitted into the S ' duration received, t is ultrasound wave from B₂It is transmitted into B₁The duration received, t ' for ultrasound wave from B₁It is transmitted into B₂The duration received.Adopt existing various test and technology can realize t completely₁、t₁′、t₂、t₂', the accurate measurement of t and t ', the present invention is adopted and is directly gathered data by controller.

In test gap, by measuring t₁、t₁′、t₂And t₂', sensor B can be obtained₁And B₂Between fixed range d be:

$d=\frac{t\·t^{\′}}{t+t^{\′}}\·\frac{d_2\·(t_1+{t_1}^{\′})\·(t_2+{t_2}^{\′})}{t_2\·{t_2}^{\′}\·(t_1+{t_1}^{\′})-t_1\·{t_1}^{\′}\·(t_2+{t_2}^{\′})}$

In process of the test, can measure t and t ' as required at any time, then velocity of sound c is in real time:

$c=\frac{d}{2}\·(\frac{1}{t}+\frac{1}{t^{\′}})$

As in figure 2 it is shown, be bi-directional probing ratio juris schematic diagram, in order to avoid the air in test section flows the impact on Precision of Ultrasound Distance Measurement of the Doppler effect that causes, set forth herein that bi-directional probing method is for ultrasonic precision ranging, measuring method is as follows:

On the object that to be separately mounted in low-speed wind tunnel by two sonacs measured, sonac is integral type sonac, namely can launch ultrasonic signal, also can detect received ultrasonic signal, corresponding data is obtained, by can be calculated by the data acquisition of controller:

$d_{ji}=\frac{2\×c}{\frac{1}{t_{ji1}}+\frac{1}{t_{ji2}}}$

D in formula_jiIt is sonac B_iWith sensor P_jBetween distance；

t_ji1It is that ultrasound wave is by B_iIt is transmitted into P_jThe duration received；

t_ji2It is that ultrasound wave is by P_jIt is transmitted into B_iThe duration received；

C is the real-time velocity of sound adopting above-mentioned gap method to obtain.

Wherein t_ji1And t_ji2Measurement error include synchronization trigger error when duration measurement error and duration are measured, t can be realized completely by the method for testing of existing advanced person and technology_ji1And t_ji2Accurate measurement, as long as therefore can accurately record real-time velocity of sound c, so that it may avoid Doppler effect and the environmental condition (such as Media density, temperature, pressure and the humidity etc.) impact on range accuracy, thus obtaining accurate sensor B_iAnd P_jBetween distance, i.e. accurate distance between two objects under test.

Adopt ultrasonic carry out precision ranging time, for the precision avoiding the phenomena impair such as hyperacoustic transmitting and diffraction to measure, it should be noted that problems with:

The sonac of arbitrary pairing range finding should adopt timesharing measurements technology, namely time history, often between group sonac the range measurement of transmitting terminal and receiving terminal for measure one by one successively.

The ultrasound wave that ultrasonic transducer sends is the constant amplitude cosine wave with one fixed width, for avoiding interference, the transmitting terminal often organizing sonac measured for pairing and receiving terminal, should determine that the same point in ultrasonic signal is as time detecting point, and properly increase the threshold value of comparator.

During supersonic sounding, the cycle of transonic duration sampling should be the complete cycle of wind-tunnel low frequency pulsating, to avoid the model vibration impact on measurement result.

The integral multiple that frequency is power frequency of transonic duration sampling during supersonic sounding, to avoid the power supply impact on measurement data.

The invention is not limited in aforesaid detailed description of the invention.The present invention expands to any new feature disclosed in this manual or any new combination, and the step of the arbitrary new method disclosed or process or any new combination.

Claims (7)

1. the ultrasonic precision ranging system in a low-speed wind tunnel, it is characterised in that include controller and sonac one (B₁), sonac two (B₂), sonac three (S), sonac four (B_i), sonac five (P_j), wherein sonac one (B₁), sonac two (B₂) be fixedly installed on wind-tunnel inwall, an other sonac three (S) is arranged in wind-tunnel for mobile terminal, sonac four (B_i), sonac five (P_j) be each fixedly installed on two testees, described testee is placed in wind-tunnel, and described five sonacs are transmitting-receiving integrated sensor, and the signal output part of described five sonacs is connected respectively to controller.

2. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 1, it is characterised in that described sonac three (S) is linearly moved in wind-tunnel.

3. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 2, it is characterised in that described sonac one (B₁), sonac three (S) and mobile after sonac three (S) on the same line.

4. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 1, it is characterised in that the measurement between described each two sonac needs timesharing to measure, namely from receive transmitting measure one by one.

5. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 4, it is characterised in that the ultrasound wave that described ultrasonic transducer sends has the constant amplitude cosine wave of one fixed width.

6. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 5, it is characterised in that the complete cycle that the cycle is wind-tunnel low frequency pulsating of ultrasonic propagation duration sampling during described supersonic sounding.

7. the ultrasonic precision ranging system in a kind of low-speed wind tunnel according to claim 6, it is characterised in that the integral multiple that frequency is power frequency of ultrasonic propagation duration sampling during supersonic sounding.