壓實點網(wǎng)格選項字段和按鈕
Settling Time estimate (from model)（從模型中設(shè)定估計時間） 指示達到穩(wěn)態(tài)所需要的時間（子控制器周期的倍數(shù)，分鐘或秒）。
Calculator（計算器） 根據(jù)用戶指定的輸入時域和設(shè)定時間（見下文）重新計算壓實點。
輸入
ControlPeriod ×dT（控制周期×dT） 子控制器周期中的輸入壓實點列表。
Minutes/Seconds（分/秒） 表示成時間單位的輸入壓實點列表。
輸出
ControlPeriod×dT（控制周期×dT） 子控制器周期中的輸出壓實點列表。
Minutes/Seconds（分/秒） 表示成時間單位的輸出壓實點列表。
Reset to Default（重置為默認） 將壓實點重置為從操作輸入與被控輸出響應(yīng)的動態(tài)模型中自動計算的結(jié)果。
注：穩(wěn)態(tài)時間被限制為1000個子控制器周期以內(nèi)。對較慢的子控制器動態(tài)，請增加子控制器周期。
用戶可以通過在壓實點表格相應(yīng)欄中手動輸入所需值來分配輸入和輸出壓實點。這些值可以根據(jù)時間單位（mins/secs）或子控制器周期（Control Period × dT)的格式輸入和/或查看。從mins/secs到子控制器周期單位間轉(zhuǎn)換是自動的（反之亦然）。計算出的值將自動進行四舍五入，以圓整為子控制器周期的整數(shù)倍。
另一個可供用戶使用的工具是壓實點計算器，可通過單擊Calculator按鈕進入。這個工具可根據(jù)用戶指定的輸入時域和設(shè)定時間來確定合適的壓實點。用戶將打開下述輸入框：
這兩個可修改的字段分別是：
? Input Horizon（輸入時域）- 該值作為一個（未來）時間窗口將用于生成預(yù)測動作規(guī)劃。此外，該數(shù)也限定了最后輸入壓實點的位置。
? Settling Time（穩(wěn)態(tài)時間） - 該值表示達到穩(wěn)態(tài)所需的時間。該值與預(yù)估值（從模型中）相比較越大，動態(tài)控制過程將把更大重心放在穩(wěn)態(tài)處理上。
注：輸入時域是向動作計劃提供自由度的一個有用手段。這個量對“浪潮控制”非常重要。
靜態(tài)約束
在子控制器層，被控變量被定義為子控制器的MV和/或POVs的線性組合。在它的觀點中，定義整個子控制器的控制目標（CV）是不允許的。子控制器使用它們的子模型（與其它子控制器的前饋一起）來優(yōu)化動態(tài)目標?？缭阶涌刂破鞯目刂颇繕吮惶幚沓伸o態(tài)目標，并執(zhí)行為穩(wěn)態(tài)下的動態(tài)子控制器約束。
Compaction Points Grid Tab Fields and Buttons
Settling Time estimate (from model) An indication of the time needed to reach steady state (in number of sub-control periods, and minutes or seconds).
Calculator Recalculates the compaction points on the basis of user-defined input horizon and settling time (see below).
Input
*ControlPerioddT **The list of input compaction points in the sub-controller period.
Minutes/Seconds A list of input compaction points in time units.
**Output **
*ControlPerioddT **The list of output compaction points in the sub-controller period.
**Minutes/Seconds **A list of output compaction points in time units.
Reset to Default Reset the compaction points to those computed automatically computed from the response of dynamic model from the manipulated inputs to the controlled outputs.
NOTE: The time for steady state is limited to 1000 subcontrol periods. For slower sub-controller dynamics, increase the subcontrol period.
The user may assign input and output compaction points manually by entering the desired values in the corresponding cells in the compaction points grid. These values may be entered and/or viewed in either time-units (minutes/seconds) or in sub-controller periods (Control Period × dT). The conversion between the fields from minutes/seconds to sub-controller periods (or vice-versa) is automatic. The calculated numbers will automatically be rounded up so that the conversion gives an exact multiple of the sub-controller period.
Another tool available to the user is the Compaction Point Calculator accessed by clicking the Calculator button. This tool determines suitable compaction points based on user specified entries for the input horizon and settling time. The following input box opens:
The two modifiable fields are:
? Input Horizon – This value is the (future) time window over which a forecast of the plan of action is generated. In addition, this quantity also defines the location of the last input compaction point.
? Settling Time – This value denotes the time required to reach steady-state conditions. The larger this value is compared to its estimate (from model), the more emphasis is put on the steady state during dynamic control.
NOTE: The input horizon is a useful handle for providing freedom to the plan of action. This quantity is important for “surge volume control.”
Static Constraints
At the sub-controller level, the controlled variables are defined as linear combinations of that sub-controller’s MVs and/or POVs. At his point, defining a control objective (CV) across sub-controllers is not allowed. Sub-controllers optimize their dynamic objectives using their sub-model (together with feed forward from other sub-controllers). Control objectives across sub-controllers are processed as static objectives and are enforced as constraints on the dynamic sub-controllers at steady state.
2016.9.29
