CN102749108B - Method of Reducing Working Blind Area of Ultrasonic Transducer Based on Excitation Energy Control - Google Patents

Abstract

The invention discloses a method for reducing a working blind zone of an ultrasonic transducer on the basis of excitation energy control. After an ultrasonic flow or object position measuring instrument is started or reset, the instrument sets an ultrasonic exciting pulse to generate an ultrasonic exciting signal, wherein the ultrasonic exciting pulse has excitation energy, and the number of the ultrasonic exciting pulse is one less than the number of the ultrasonic exciting pulse required for generating an ultrasonic exciting signal with a plateau characteristic; an ultrasonic echo signal corresponding to the ultrasonic exciting signal is utilized to measure the flow or object position; when the flow or object position is not changed, measurement is respectively carried for more than two times; a measurement result is compared with a preset value; ultrasonic excitation energy is regulated in a self-adaption mode by a result obtained by comparing the measurement result with the preset value so as to control the residual energy of the ultrasonic transducer; the working blind zone of the ultrasonic transducer is reduced; and the measurable acoustic-path range of the ultrasonic is widened.

Description

Based on excitation energy, control the method that reduces ultrasonic transducer work blind area

Technical field

The present invention relates to a kind of ultrasonic transducer work blind area minishing method, particularly relate to a kind of method that reduces ultrasonic transducer work blind area of controlling based on excitation energy.

Background technology

Supersonic technique in modern industry because of the advantages such as its measuring accuracy is high, broad quantum, good reliability be widely applied and highly approval.The key of supersonic technique is the detection of ultrasonic echo signal, so-called ultrasonic echo signal is for ultrasonic excitation signal, refer to that same ultrasonic transducer launched after ultrasonic excitation signal, ultrasonic excitation signal is through different medium interface (as water and air, water and metal etc.) ultrasonic signal reflecting to form or the ultrasonic signal oppositely firing back after another transducer receives this ultrasonic excitation signal.Utilize travel-time of ultrasonic excitation signal and ultrasonic echo signal to carry out flow or object position measurement is the time difference type supersonic technique generally adopting at present.

One of them common problem that time difference type supersonic technique faces is that ultrasonic transducer exists work blind zone problem.Ultrasonic transducer is converted to electric impulse signal by inner piezoelectric crystal the mechanical vibration of same frequency, and then inspires ultrasonic excitation signal, so ultrasonic transducer is a typical electromechanical vibration system.The same with other vibrational system, after removing pumping signal, due to inertia, ultrasonic transducer is by sustained vibration (free damping vibration) a period of time, until run out of residual amount of energy.If ultrasonic transducer aftershock amplitude not free damping to receiving ultrasonic echo signal than ultrasonic echo signal maximum amplitude urine, ultrasonic echo signal, by being submerged among the aftershock signal of ultrasonic transducer, causes detecting ultrasonic echo signal.We are decreased to the equal time of ultrasonic echo signal maximum amplitude by ultrasonic transducer free damping starting of oscillation to aftershock amplitude and are referred to as ultrasonic transducer work blind area, because the existence of ultrasonic transducer work blind area has limited the surveyed sound path scope of ultrasound wave when the information such as measuring flow, object space.For flow measurement, having limited it can measuring channel bore scope; For object position measurement, directly limited its range.

The typical method that solves at present ultrasonic transducer work blind zone problem comprises: many echoes detection technique that (1) patent CN93120461.5 proposes, this technology utilizes ultrasound wave between ultrasonic transducer and medium interface, to have the phenomenon of multiple reflections, the ultrasonic echo signal of usining after multiple reflections is as final measuring-signal, thereby effectively extend sound path, avoid the ultrasonic echo signal for measuring to fall in ultrasonic transducer work blind area.In actual applications, the method faces the problem that ultrasonic echo Signal-to-Noise obviously reduces after multiple reflections; (2) the change power shooting techniques of mentioning in patent 93120460.7, core concept is that the small-pulse effect of the multiple-pulse while realizing remote object position measurement by software approach while exciting with closer object position measurement excites.The above one-shot measurement result of this method is set next excitation pulse number, and adopt, proposed by the invention according to measuring result error, does not adjust adaptively pulse number, therefore can only be applicable to the situation that object space slowly changes; (3) by the structure to ultrasonic transducer, be optimized design, reduce excitation pulse aftershock later.Owing to will considering the performance of a series of performances such as ultrasonic transducer sensitivity, bandwidth of operation, design various aspects of performance all very excellent ultrasonic transducer still have difficulties.(4) in actual flow or object position measurement, conventionally ultrasonic transducer installation site is adjusted, to extend, measure sound path, avoid ultrasonic echo signal to fall in ultrasonic transducer work blind area, as: widen two distances between ultrasonic transducer when the flow measurement, when object position measurement, widen ultrasonic transducer and measure the distance between interface.This method can cause very large inconvenience for the flow of some closed conduit or container or object position measurement.

Summary of the invention

The object of the present invention is to provide a kind of method that reduces ultrasonic transducer work blind area of controlling based on excitation energy.

In order to achieve the above object, the technical solution used in the present invention is as follows:

The present invention is after ultrasonic flow or the start of object position measurement instrument or resetting, and instrument is set the ultrasonic excitation umber of pulse with excitation energy; When measuring flow, excitation-emission ultrasonic transducer produces ultrasonic excitation signal, utilizes reception ultrasonic transducer to receive the ultrasonic echo signal producing after this ultrasonic excitation signal and carries out flow measurement; When measuring object space, excitation-emission ultrasonic transducer produces ultrasonic excitation signal, and the ultrasonic echo signal that utilizes this ultrasonic excitation signal to reflect from body surface carries out object position measurement; In the situation that flow or object space do not change, carry out respectively more than twice measuring, measurement result and preset value compare; The result of utilization and preset value comparison, adaptive adjustment ultrasonic excitation energy, thus realize the control to ultrasonic transducer rudimental energy.

Described ultrasound wave work blind area refers to from ultrasonic transducer free damping starting of oscillation to aftershock amplitude and is decreased to the time equating with ultrasonic echo signal maximum amplitude.

If ultrasonic echo signal does not fall in transducer work blind area, and twice above measurement result conformity error of measuring be less than or equal to preset value, thinks that instrument carried out correct measurement;

If measurement result conformity error is greater than preset value, think that instrument do not carry out correct measurement, ultrasonic echo signal falls in ultrasonic transducer work blind area, now reduce one by one ultrasonic excitation umber of pulse, reduce gradually ultrasonic transducer work blind area, until measurement result conformity error is less than or equal to preset value, ultrasonic echo signal is positioned at outside ultrasonic transducer work blind area.

The number reducing for reducing ultrasonic excitation umber of pulse, while first requiring first measuring flow or object space, the ultrasonic excitation umber of pulse adopting than produce have one plateau feature ultrasonic excitation signal time required few 1 pulse of ultrasonic excitation umber of pulse, thereby realization not only guarantees excitation energy but also avoid the too much negative effect of excitation pulse number; Secondly, before measuring next time, first with last twice measurement result, carry out extrapolation and calculate the sound path of predicting that measure next time, according to prediction gained sound path, the required ultrasonic excitation umber of pulse of measurement next time is set.

The beneficial effect that the present invention has is:

The method that adopts excitation energy self-adaptation to adjust, by the control of ultrasonic transducer excitation energy is realized to the control to ultrasonic transducer rudimental energy, reduces ultrasonic transducer work blind area, widens hyperacoustic sound path scope of surveying.For flow measurement, widening it can measuring channel bore scope, mounting distance requirement between the ultrasonic transducer while reducing small-bore pipeline flow measurement; For object position measurement, directly widen its range, the mounting distance requirement between the ultrasonic transducer while reducing small distance object position measurement and measurement interface.

Accompanying drawing explanation

Fig. 1 is the ultrasonic transducer work blind area schematic diagram relating in the present invention.

Fig. 2 is that the excitation energy self-adaptation adopting in the present invention is adjusted process flow diagram.

Fig. 3 ultrasonic excitation umber of pulse schematic diagram during feature ultrasonic excitation signal that is the generation that relates in the present invention without plateau.

Fig. 4 is the ultrasonic excitation signal schematic representation without plateau feature relating in the present invention.

Fig. 5 is that the generation that relates in the present invention has the ultrasonic excitation umber of pulse schematic diagram of plateau during feature ultrasonic excitation signal.

Fig. 6 be in the present invention, relate to have one plateau feature ultrasonic excitation signal schematic representation.

In figure: 1, ultrasonic excitation signal, 2, aftershock signal, 3, aftershock signal amplitude envelope, 4, ultrasonic echo signal, 5, ultrasonic echo signal amplitude marking line, 6, amplitude is cut-off rule relatively, 7, ultrasonic transducer work blind area, 8, ultrasonic transducer aftershock area, 9, generation is ultrasonic excitation umber of pulse during feature ultrasonic excitation signal without plateau, 10, ultrasonic excitation signal without plateau feature, 11, there is the ultrasonic excitation umber of pulse of plateau during feature ultrasonic excitation signal, 12, have one plateau feature ultrasonic signal, 13, plateau.

Embodiment

Below in conjunction with accompanying drawing and example in detail the specific embodiment of the present invention.

Be illustrated in figure 1 ultrasonic transducer work blind area schematic diagram.The frequency of ultrasonic excitation signal 1 is identical with ultrasonic transducer resonance frequency.Therefore, ultrasonic excitation signal 1 enters after ultrasonic transducer, can make ultrasonic transducer produce resonance, and inspire ultrasonic excitation signal.But, after ultrasonic excitation signal 1 disappears, residual energy owing to exciting, ultrasonic transducer internal energy conversion element will be because of machinery inertial and electrical inertia sustained vibration (free damping vibration), generation aftershock signal 2.From aftershock signal amplitude envelope 3, can find out, the vibration ofaftershock signal 2 needs the regular hour just can run out of, if ultrasonic echo signal 4 arrives whenaftershock signal 2 amplitudes are greater than the maximum amplitude of ultrasonic echo signal 4, ultrasonic echo signal 4 will be submerged inaftershock signal 2, cannot be identified, make to measure unsuccessfully.In Fig. 1, provide ultrasonic echo signal amplitude marking line 5, in ultrasonic echo signal amplitude marking line 5 and the boundary of aftershock signal amplitude envelope 3, drawn relatively cut-off rule 6 of amplitude.If ultrasonic echo signal 4 falls into relatively cut-off rule 6 left part of amplitude, because of the amplitude of ultrasonic echo signal 4, be less than the amplitude None-identified ofaftershock signal 2; If ultrasonic echo signal 4 falls into relatively cut-off rule 6 right side parts of amplitude, the amplitude that can be greater than because of the amplitude of ultrasonic echo signal 4aftershock signal 2 is easily identified.Therefore, amplitude comparison cut-off rule 6 left part are called to ultrasonic transducer workblind area 7, ultrasonic transducer workblind area 7 is parts of whole ultrasonictransducer aftershock area 8.

Problem for the ultrasonic transducer work blind area shown in Fig. 1, the present invention proposes a kind of method that reduces ultrasonic transducer work blind area of controlling based on excitation energy, the method that adopts excitation energy self-adaptation to adjust, by the control of ultrasonic transducer excitation energy is realized to the control to ultrasound wave rudimental energy, shorten ultrasonic transducer aftershock amplitude and be decreased to the time equating with ultrasonic echo signal maximum amplitude, thereby reduce ultrasonic transducer work blind area, widen ultrasonic applications in flow, the sound path surveyed scope during the physical quantities such as object space.

Fig. 2 has provided the excitation energy self-adaptation adopting in the present invention and has adjusted process flow diagram.After ultrasonic flow or the start of object position measurement instrument or resetting, instrument is set the ultrasonic excitation umber of pulse with excitation energy, when measuring flow, excitation-emission ultrasonic transducer produces ultrasonic excitation signal 1, and the ultrasonic echo signal 4 that utilizes reception ultrasonic transducer to receive this ultrasonic excitation signal 1 rear generation carries out flow measurement; When measuring object space, excitation-emission ultrasonic transducer produces ultrasonic excitation signal 1, utilize the ultrasonic echo signal 4 that ultrasonic excitation signal 1 reflects from body surface to carry out object position measurement, in the situation that flow or object space do not change, carry out respectively more than twice measuring.

For the number that reduction ultrasonic excitation umber of pulse reduces, the measurement first except just start of instrument or after resetting, in all the other measuring processes, with last twice measurement result, carry out single order extrapolation calculating prediction and measure possible sound path next time, sound path predictor formula is as follows:

D_n+1=2×D_n－D_n-1 (1)

D in formula_n+1for predicted t+ △ t moment sound path, D_nfor measuring gained t sound path constantly, D_n-1for measuring gained t-△ t sound path constantly.Calculate D_n+1after, and then according to the data form that pre-deposits instrument, the required excitation pulse number of the inquiry institute sound path of predict correspondence, as the initial value of self-adaptation adjustment.Under different sound paths, the data form of corresponding required excitation pulse can be determined by experiment in advance.Because predict the umber of pulse initial value and the final ultrasonic excitation umber of pulse used that obtain can approach (its fine difference in umber of pulse be due to the difference of experiment condition and actual measurement operating mode due to) very much, therefore can reduce the number that ultrasonic excitation umber of pulse reduces.

Instrument start or reset after measure first the ultrasonic excitation umber of pulse that adopts than produce have one plateau feature ultrasonic excitation signal time required few 1 pulse of ultrasonic excitation umber of pulse, thereby realization not only guarantees excitation energy but also avoid the too much impact of excitation pulse number.As shown in Fig. 3, Fig. 4, Fig. 5, Fig. 6, along with ultrasonic excitation umber of pulse, from the generation of Fig. 3, without plateau, the ultrasonic excitation umber ofpulse 9 during feature ultrasonic excitation signal increases and becomes the generation shown in Fig. 5 a pulse and have the ultrasonic excitation umber ofpulse 11 of plateau during feature ultrasonic excitation signal, corresponding produced ultrasonic excitation signal by from without without plateau featureultrasonic excitation signal 10 become have one plateau feature excitation pulse signal 12.Wherein, the appearance ofplateau 13 not only can not increase the amplitude of ultrasonic excitation signal, strengthens signal sensitivity, can reduce because ultrasonic excitation umber of pulse too much causes excitation energy self-adaptation regulated efficiency on the contrary.

Claims (3)

Translated fromChinese

1.一种基于激发能量控制减小超声波换能器工作盲区的方法，其特征在于： 当超声波流量或物体位置测量仪表开机或复位后，仪表设定具有激发能量的超声波激发脉冲数；当测量流量时，激发发射超声波换能器产生超声波激发信号，利用接收超声波换能器接收到此超声波激发信号后产生的超声波回波信号进行流量测量；当测量物体位置时，激发发射超声波换能器产生超声波激发信号，利用此超声波激发信号从物体表面反射回来的超声波回波信号进行物体位置测量；在流量或物体位置未发生变化的情况下分别进行两次以上测量，测量结果与预设值进行比较；利用与预设值比较的结果，自适应的调整超声波激发能量，从而实现对超声波换能器残留能量的控制； 1. A method for reducing the working blind area of an ultrasonic transducer based on excitation energy control, characterized in that: After the ultrasonic flow or object position measuring instrument is turned on or reset, the instrument sets the number of ultrasonic excitation pulses with excitation energy; During the flow rate, the ultrasonic excitation signal is generated by the excitation and emission ultrasonic transducer, and the flow measurement is performed by the ultrasonic echo signal generated after the ultrasonic excitation signal is received by the receiving ultrasonic transducer; when the position of the object is measured, the excitation and emission ultrasonic transducer generates Ultrasonic excitation signal, using the ultrasonic echo signal reflected from the surface of the object to measure the position of the object; when the flow rate or the position of the object does not change, perform more than two measurements respectively, and compare the measurement results with the preset values ;Use the result compared with the preset value to adaptively adjust the ultrasonic excitation energy, so as to realize the control of the residual energy of the ultrasonic transducer;为降低超声波激发脉冲数减少的个数，首先要求初次测量流量或物体位置时，所采用的超声波激发脉冲数比产生具有一个平台期特征的超声波激发信号时所需的超声波激发脉冲数少1个脉冲，从而实现既保证激发能量又避免激发脉冲数过多的负面影响；其次，在下次测量前，先以最后两次测量结果进行外插计算预测下次测量的声程，根据预测所得声程设置下次测量所需的超声波激发脉冲数。In order to reduce the number of ultrasonic excitation pulses, it is first required that when measuring the flow or object position for the first time, the number of ultrasonic excitation pulses used is one less than the number of ultrasonic excitation pulses required to generate an ultrasonic excitation signal with a plateau characteristic. Pulse, so as to ensure the excitation energy and avoid the negative impact of too many excitation pulses; secondly, before the next measurement, the last two measurement results are used to extrapolate the sound path of the next measurement to predict the sound path of the next measurement, according to the predicted sound path Set the number of ultrasonic excitation pulses required for the next measurement.2.根据权利要求1所述的一种基于激发能量控制减小超声波换能器工作盲区的方法，其特征在于：所述超声波工作盲区是指从超声波换能器自由衰减振荡开始至余震幅值减小至与超声波回波信号最大幅值相等的时间。2. A method for reducing the working blind zone of an ultrasonic transducer based on excitation energy control according to claim 1, wherein the working dead zone of the ultrasonic wave refers to the time from the free attenuation oscillation of the ultrasonic transducer to the aftershock amplitude Decrease to the time equal to the maximum amplitude of the ultrasonic echo signal.3.根据权利要求1所述的一种基于激发能量控制减小超声波换能器工作盲区的方法，其特征在于：3. a kind of method based on exciting energy control to reduce the working blind area of ultrasonic transducer according to claim 1, is characterized in that:若超声波回波信号未落入换能器工作盲区内，且两次以上测量测量结果一致性误差小于或等于预设值，则认为仪表进行了正确的测量；If the ultrasonic echo signal does not fall into the working blind area of the transducer, and the consistency error of the measurement results of more than two measurements is less than or equal to the preset value, it is considered that the instrument has carried out correct measurement;若测量结果一致性误差大于预设值，则认为仪表未进行正确的测量，超声波回波信号落入超声波换能器工作盲区内，此时逐个减少超声波激发脉冲数，逐渐减小超声波换能器工作盲区，直至测量结果一致性误差小于或等于预设值，超声波回波信号位于超声波换能器工作盲区外。If the consistency error of the measurement result is greater than the preset value, it is considered that the instrument has not measured correctly, and the ultrasonic echo signal falls into the working blind area of the ultrasonic transducer. At this time, the number of ultrasonic excitation pulses is reduced one by one, and the ultrasonic transducer is gradually reduced. Working blind zone, until the consistency error of the measurement results is less than or equal to the preset value, the ultrasonic echo signal is located outside the working blind zone of the ultrasonic transducer.

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