AIDAPro可用于鑒定轉(zhuǎn)換域（線性）的模型。AIDAPro擁有一個(gè)可執(zhí)行各種變換的計(jì)算引擎。然而，AIDAPro不具有直接將變換表（查找表）自動(dòng)傳遞給SMOCPro的能力。因此，用戶必須將AIDAPro和SMOCPro中的變換表保持一致。此外，必須仔細(xì)確認(rèn)變換表囊括了整個(gè)操作范圍。變換表中的值可以被復(fù)制粘貼到Microsoft Excel?電子表格。
注：我們建議不要將轉(zhuǎn)換應(yīng)用于中間POVs。
為了說明SMOCPro中的變換功能，我們考慮自AIDAPro中導(dǎo)入一個(gè)精餾塔模型。所得模型如下圖所示。
在本例中，再沸和回流量通過調(diào)節(jié)頂部和底部溫度中間變量來調(diào)節(jié)塔頂和塔釜質(zhì)量。我們需要對(duì)回流進(jìn)行適當(dāng)?shù)淖儞Q（本例中是對(duì)數(shù)）以更好地實(shí)現(xiàn)我們的控制目標(biāo)。建立模型后，你需要對(duì)感興趣的變量指定變換。本例中要做到這一點(diǎn)，可雙擊回流模塊，并單擊Add Transform（添加變換）按鈕。
接下來你需要在變換模塊中輸入分段線性變換。下圖顯示了變換表。記住變換表格可以從Microsoft Excel?電子表格復(fù)制粘貼。值得注意的是在進(jìn)行這些變換時(shí)，用戶必須保持值與所辨識(shí)的模型一致。最后，在轉(zhuǎn)化的MV,DV和/或POV模塊的左上角將顯示一個(gè)綠色三角形，以證明其是變換變量。
該變換表具有以下重要特征：
?坐標(biāo)X是工程單位→即測(cè)量值；
?坐標(biāo)Y是變換單位→即變換值；
?每對(duì)X-Y都定義了一個(gè)內(nèi)插值（或外插值）數(shù)據(jù)點(diǎn)；
?變換表最多可包含10個(gè)點(diǎn)；
?可通過設(shè)置點(diǎn)數(shù)為0刪除變換；
?兩個(gè)相同的連續(xù)值是不允許的，因?yàn)樗鼈兊哪孀儞Q不能確定；
?最后非常重要的是X和Y坐標(biāo)系的所有值必須嚴(yán)格單調(diào)（請(qǐng)參閱以下的允許函數(shù)例子）。
變換表的最后一個(gè)要求是單調(diào)性。對(duì)給定的函數(shù)，單調(diào)性具有當(dāng)自變量（X）增加時(shí)，因變量始終保持持續(xù)增加或持續(xù)減小的特性。變換表允許的函數(shù)如下圖所示。
原文：
To identify the model in the transformed (linearized) domain, AIDAPro can be used. AIDAPro has a calculation engine that can perform all kinds of transforms. However, AIDAPro does not have the ability to automatically pass the transform table (lookup table) directly to SMOCPro. Therefore, the user must keep the transform tables in AIDAPro and SMOCPro consistent. In addition, careful consideration must be taken so that the transform table covers the entire range of operations. The values in the transform table can be copied and pasted from a Microsoft Excel? spreadsheet.
NOTE: It is our recommendation that the transforms NOT be applied to intermediate POVs.
To illustrate the transform functionality in SMOCPro, consider the distillation column example as imported from AIDAPro. The resulting model is shown in the figure below.
In this example, the reboil and reflux regulate the column’s top and bottom qualities with the top and bottom temperatures being intermediate variables. We need to transform the reflux with a suitable transformation (in this example, logarithmic) to better achieve our control objectives. After building the model, you need to specify the transform for the variables of interest. To do this in this example, double click on the reflux block and click on the Add Transform button.
Next, you need to enter the piecewise linear transform in the transform block. The figure below shows the transform table. Remember that the transform table can be copied and pasted from a Microsoft Excel? spreadsheet. It is worth noting that while entering these transforms the user must keep the values consistent with the identified model. Lastly, a green triangle is added to the left corner of the transformed MV, DV and/or POV blocks to indicate a transformed variable.
The transform table has the following important characteristics:
?The X-coordinate is in engineering units → this is the measurement
?The Y-coordinate is in transformed units → this is the transformation
? Each X-Y pair defines an interpolation (or extrapolation) data point.
? The transform table can have a maximum of 10 points.
? A transform can be deleted by setting the number of the points to zero.
? Two identical consecutive values are not allowed because they make the inverse transform undefined.
? Lastly, (extremely important) all values in the X- and Y-coordinates must be strictly monotonic (see below for examples of allowed functions).
The last requirement in the transform table is that of monotonicity. For a given function, monotonicity is having the property of never increasing or of never decreasing as the values of the independent (X) variable increases. The allowed functions for the transform table are illustrated in the following figure.
2016.9.8
