【正文】 ringe period. The selftrigger function is acplished by the Schmitt circuit. The threshold voltage of the Schmitt circuit is set according to experiments to distinguish the real fringe signal caused by vehicles and the pseudo fringe signal caused by small vibration in the test environment. In practical application, this could be caused by the passing vehicles in adjoining lanes. System software based on Labview Windows/CVI is designed to set measurement parameters, control the test procedure and display results. Fullsize image (14K) Fig. 1. Dynamic fiber optic pressure sensor setup. . Sensor principle One arm of the Michelson interferometer is subjected to a distributing dynamic load Ld(t). The generalized stress–optic relationship between the optical path change Δl and the strain induced over the gauge length can be derived as Eq. (1) [6]: (1) and (2) where P11 and P12 are the Pockels constant。 t the loading time, approximately equal to the duration time of the optic fiber fringe. 3. Experimental procedures and results . Experimental setup The experimental setup is shown in Fig. 2. A steel chamber is designed to contain the optical fiber. The optic fiber is sandwiched between two 1 cm thick stiff rubber pads and glued to one of the two pieces. Rubber pads are necessary for the protection of fiber from damage. The crosssectional area of the loading surface for the steel chamber is mm 24 mm. The gauge length of the optical fiber pressure sensor is mm. A closedloop materials testing system (MTS) is used for the application of pressure. Ramp function load with different loading rates and magnitudes are chosen as dynamic loads to simulate the weight loads caused by moving vehicles on road. Fullsize image (45K) Fig. 2. Experimental setup. Fig. 3 shows a typical loading profile and fringe output of the interferometer during the duration of the applied ramp function load. As can be seen, the number of fringes at left corner of Fig. 3 is so great that it is hard to distinguish each fringe. Thus, another figure on the right is used. The figure is the enlargement of the circled area to show clearly the fringes. Because of the polarization effect, the amplitudes of fringes slightly vary. But will not influence the fringe count and period, thus neglected in this paper. In the experiment, the pressure load is applied to the chamber at MPa increments up to the maximum pressure level of 30 MPa, corresponding to load increments from kN to a maximum of 178 kN. The loading time is applied starting from 1 to 6 s with an increment of 1 s. Fullsize image (46K) Fig. 3. Typical loading procedure and fiber optic sensor output waveform. . Experimental data Fig. 4 shows the experimental results of the fringe number and fringe period readouts of the sensor output under different loads. Lines with different signs represent relations between the sensor39。 摘要： 在這里描述一種光纖為基礎(chǔ)的動(dòng)態(tài)壓力傳感裝置來測(cè)量車輛荷載的方法。該調(diào)查結(jié)果顯示，在這些研究開發(fā)的干涉下的動(dòng)態(tài)壓縮應(yīng)力狀態(tài)傳感器的作用是了解基本的在光纖應(yīng)用的方案 — 光纖傳感器監(jiān)測(cè)車車輛荷載。壓電和電容墊技術(shù)會(huì)使成本大幅降低，但卻不太準(zhǔn)確（ 515％），在速度低于二十公里每小時(shí) [2]和 [3]的無法正常工作。納瓦雷特和伯納烏報(bào)告是對(duì)多光纖干涉儀的馬赫 曾德爾干涉儀結(jié)構(gòu)組成用另一馬赫曾德爾干涉儀取代作為研究?jī)?nèi)容 [4]。傳感器的動(dòng)態(tài)響應(yīng)進(jìn)行研究時(shí)，受到了不同程度的負(fù)荷率和動(dòng)態(tài)壓縮載荷的影響。該干涉儀的光電組件包括一個(gè) 長(zhǎng)度 在 1550 納米 的 激光隔離器和一個(gè)光電二極管激光波長(zhǎng)。（ 2）提供消除低頻干擾的功能，如溫度的影響而 使 該元素的變化 緩慢 ， 。 一個(gè)零點(diǎn)檢測(cè)電路的設(shè)計(jì)更改計(jì)算機(jī)中的數(shù)據(jù)采集系統(tǒng)反正弦表邊緣，以脈沖信號(hào)進(jìn)行計(jì)數(shù)的條紋數(shù)和測(cè)量的邊緣時(shí)期。 圖 1 光纖壓力傳感器的動(dòng)態(tài)設(shè)置 3 實(shí)驗(yàn)程序和結(jié)果 實(shí)驗(yàn)裝置 實(shí)驗(yàn)裝置如圖 2所示。該室的裝載鋼材表面的橫截面面積為 毫米 24 毫米。 圖 2 實(shí)驗(yàn)裝置。因此，數(shù)字 有 另一個(gè) 用途， 這個(gè)數(shù)字是該圈的地方擴(kuò)大，顯示清晰的邊緣的數(shù) 字 。裝 載 時(shí)間是從 1 開始 從第 1 至 6 秒遞增 。不同的標(biāo)志線代表不同加載速率之間的傳感器的輸出和負(fù)載的最大振幅的關(guān)系。雖然雙方的條紋數(shù)及附 加 時(shí)期敏感的動(dòng)態(tài)負(fù)載，其敏感范圍是不同的 ， 加載 時(shí) 靈敏度是在整個(gè)測(cè)試范圍不變。這兩個(gè)參數(shù)可以一起使用提供了更精確的 荷載 指標(biāo)進(jìn)行測(cè)試。該傳感器的校準(zhǔn) 根據(jù)條紋數(shù)和光纖傳感器的輸出期間，可從動(dòng)態(tài)車輛載荷和靜載荷傳遞的過程 中 校準(zhǔn)。采取以下步 第 1 步：使用函數(shù)方法測(cè)量數(shù)據(jù)時(shí)，經(jīng)歷了不同的傳感器適用于具有相同的靜態(tài)負(fù)荷率 時(shí) 。 第 3 步：使用 ksn1 = F1 類（噸）， ksn2 = f2類（噸）， kst1 =三級(jí)方程式（ t）和 kst2 = F4 類（噸）均衡器，從步驟 2 一起獲得（ 7）及（ 8）校準(zhǔn)條紋數(shù)及附帶期間測(cè)得靜載荷。 6。 動(dòng)態(tài)校準(zhǔn) 權(quán)重 的 開發(fā) 是 基于以下的假設(shè)。如圖 7 所示。 要讀出邊緣時(shí)期以 外的數(shù)據(jù) ，參數(shù) Ksp1 和 Ksp2 不是常數(shù)時(shí)，以 不同的動(dòng)態(tài)負(fù)載傳感器的經(jīng)驗(yàn)，它不能被使用上述方法校準(zhǔn)。 通過 校正技術(shù) 來 開發(fā)校