戶用超聲波水表的研究與設(shè)計(jì)
發(fā)布時(shí)間：2019-01-09 14:51
【摘要】：隨著階梯水價(jià)政策的實(shí)施,一個(gè)以水表計(jì)量性能提升、無(wú)線網(wǎng)絡(luò)接入和融入互聯(lián)網(wǎng)應(yīng)用為標(biāo)志的“互聯(lián)網(wǎng)+智能水表2.0”時(shí)代已經(jīng)到來(lái)。超聲波水表無(wú)機(jī)械運(yùn)動(dòng)部件、壓力損失小、始動(dòng)流量低、誤差特性曲線可修正,而且可實(shí)現(xiàn)數(shù)據(jù)遠(yuǎn)傳,具備下一代智能水表的基本特征和功能。研究超聲波水表,不僅可以推動(dòng)階梯水價(jià)制度的建立,而且可以實(shí)現(xiàn)智能水表的轉(zhuǎn)型升級(jí),對(duì)我國(guó)水表產(chǎn)業(yè)的發(fā)展具有重要意義。針對(duì)時(shí)差法接收到超聲波信號(hào)的時(shí)刻難以精確捕獲,小流速的流量計(jì)量精度低等問(wèn)題,本文設(shè)計(jì)了一種相差法超聲波水表,可以實(shí)現(xiàn)家庭用水的精確計(jì)量。根據(jù)超聲波在水中的傳播速度和溫度的對(duì)應(yīng)關(guān)系實(shí)現(xiàn)水溫的檢測(cè)。然后針對(duì)相差法測(cè)得的流量值隨溫度呈非線性變化的問(wèn)題,提出了基于最小二乘曲面擬合的溫度補(bǔ)償算法。主要研究?jī)?nèi)容如下:1.在分析和比較幾種常用的超聲波流量檢測(cè)方法的基礎(chǔ)上,采用相差法檢測(cè)流量。通過(guò)對(duì)相位比較結(jié)果累加積分,不僅可以實(shí)現(xiàn)微小流量的檢測(cè),還可以減小干擾信號(hào)的影響。針對(duì)流速檢測(cè)過(guò)程中采集到的數(shù)據(jù)波動(dòng)大的問(wèn)題,采用限幅濾波、算術(shù)平均值濾波和滑動(dòng)平均值濾波相結(jié)合的復(fù)合濾波算法來(lái)對(duì)采集的數(shù)據(jù)進(jìn)行處理,改善了流速檢測(cè)結(jié)果的穩(wěn)定性。2.針對(duì)流量值隨溫度呈非線性變化這一問(wèn)題,進(jìn)一步研究對(duì)檢測(cè)流量進(jìn)行溫度補(bǔ)償?shù)姆椒�。采用檢測(cè)超聲波在水中的傳播速度推算出溫度、而非常規(guī)的溫度傳感器檢測(cè)溫度的方法。實(shí)驗(yàn)表明,溫度檢測(cè)檢測(cè)誤差在±2℃以內(nèi),并且降低了儀表的成本。3.提出了基于最小二乘曲面擬合的溫度補(bǔ)償算法,根據(jù)溫度和流量擬合得到的曲面對(duì)流量進(jìn)行預(yù)測(cè)和補(bǔ)償。在實(shí)現(xiàn)溫度補(bǔ)償后,針對(duì)超聲波水表自身計(jì)量特性的差異,進(jìn)一步提出多溫度點(diǎn)流量計(jì)量誤差二次補(bǔ)償算法,根據(jù)相鄰溫度點(diǎn)的流量計(jì)量誤差和權(quán)值計(jì)算當(dāng)前溫度和瞬時(shí)流量下的流量計(jì)量誤差,然后對(duì)誤差進(jìn)行補(bǔ)償,可以實(shí)現(xiàn)流量檢測(cè)的全局優(yōu)化。實(shí)驗(yàn)表明,流量計(jì)量誤差在±2.0%以內(nèi)。經(jīng)過(guò)實(shí)驗(yàn)驗(yàn)證,本文設(shè)計(jì)的超聲波水表可以實(shí)現(xiàn)家庭用水的流量精確檢測(cè),達(dá)到高精度、低功耗、低成本的目的。
[Abstract]:With the implementation of ladder water price policy, an era of "Internet Intelligent Water Meter 2.0", marked by the improvement of metering performance, wireless network access and integration into Internet applications, has arrived. Ultrasonic water meter has no mechanical moving parts, small pressure loss, low starting flow rate, correction of error characteristic curve, and can realize remote data transmission. It has the basic characteristics and functions of the next generation intelligent water meter. The study of ultrasonic water meter can not only promote the establishment of stepped water price system, but also realize the transformation and upgrading of intelligent water meter, which is of great significance to the development of water meter industry in China. In order to solve the problem that the time of receiving ultrasonic signal by moveout method is difficult to capture accurately and the measurement accuracy of flow rate of small velocity is low, a ultrasonic water meter with phase difference method is designed in this paper, which can be used to measure household water accurately. The detection of water temperature is realized according to the relationship between the velocity and temperature of ultrasonic wave propagation in water. Then a temperature compensation algorithm based on least square surface fitting is proposed to solve the problem that the flow rate measured by phase difference method is nonlinear with temperature. The main contents are as follows: 1. Based on the analysis and comparison of several ultrasonic flow detection methods, the phase difference method is used to detect the flow. By summing up the results of phase comparison, not only the detection of micro flow can be realized, but also the influence of interference signal can be reduced. Aiming at the problem of large fluctuation of data collected in the process of velocity detection, a composite filtering algorithm, which combines amplitude limiting filter, arithmetic average filter and sliding average filter, is used to process the collected data. Improved the stability of velocity detection results. 2. In order to solve the problem that the flow rate is nonlinear with the temperature, the method of temperature compensation for the detection flow rate is further studied. The temperature is calculated by measuring the velocity of ultrasonic wave in water, but not by conventional temperature sensor. The experimental results show that the temperature measurement error is within 鹵2 鈩，
本文編號(hào)：2405769
[Abstract]:With the implementation of ladder water price policy, an era of "Internet Intelligent Water Meter 2.0", marked by the improvement of metering performance, wireless network access and integration into Internet applications, has arrived. Ultrasonic water meter has no mechanical moving parts, small pressure loss, low starting flow rate, correction of error characteristic curve, and can realize remote data transmission. It has the basic characteristics and functions of the next generation intelligent water meter. The study of ultrasonic water meter can not only promote the establishment of stepped water price system, but also realize the transformation and upgrading of intelligent water meter, which is of great significance to the development of water meter industry in China. In order to solve the problem that the time of receiving ultrasonic signal by moveout method is difficult to capture accurately and the measurement accuracy of flow rate of small velocity is low, a ultrasonic water meter with phase difference method is designed in this paper, which can be used to measure household water accurately. The detection of water temperature is realized according to the relationship between the velocity and temperature of ultrasonic wave propagation in water. Then a temperature compensation algorithm based on least square surface fitting is proposed to solve the problem that the flow rate measured by phase difference method is nonlinear with temperature. The main contents are as follows: 1. Based on the analysis and comparison of several ultrasonic flow detection methods, the phase difference method is used to detect the flow. By summing up the results of phase comparison, not only the detection of micro flow can be realized, but also the influence of interference signal can be reduced. Aiming at the problem of large fluctuation of data collected in the process of velocity detection, a composite filtering algorithm, which combines amplitude limiting filter, arithmetic average filter and sliding average filter, is used to process the collected data. Improved the stability of velocity detection results. 2. In order to solve the problem that the flow rate is nonlinear with the temperature, the method of temperature compensation for the detection flow rate is further studied. The temperature is calculated by measuring the velocity of ultrasonic wave in water, but not by conventional temperature sensor. The experimental results show that the temperature measurement error is within 鹵2 鈩，
本文編號(hào)：2405769
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