barcode reader using c#.net I Conventional control II Cascade control in Software

Make Code 128 Code Set B in Software I Conventional control II Cascade control

I Conventional control II Cascade control
Code 128 Code Set C Scanner In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Painting Code 128B In None
Using Barcode maker for Software Control to generate, create Code 128 image in Software applications.
FIGURE 18-6 Responses to step change in set point for single-loop control and cascade control for Example 18.1. I Conventional control with K, = 2.84, r1 = 5; II Cascade control with Kci = 1.0, r1 = 0.63, KEZ = 10.
Decode Code 128 In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Code 128B Encoder In Visual C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create Code 128B image in .NET framework applications.
ADVANCED cQNTR0L STRATEGIES
Encoding Code 128A In Visual Studio .NET
Using Barcode printer for ASP.NET Control to generate, create Code 128B image in ASP.NET applications.
Code 128 Code Set A Generation In VS .NET
Using Barcode printer for .NET Control to generate, create Code 128 Code Set C image in .NET applications.
FlGURE 18-7 Responses to step change in load for Example 18.1. I no control; II conventional control with K, = 2.84, TI = 5; III cascade control with K,, = 1.0, rl = 0.63, Kc* = 10.
Create Code 128 Code Set A In VB.NET
Using Barcode maker for .NET Control to generate, create Code 128 Code Set A image in Visual Studio .NET applications.
UPC-A Supplement 2 Creator In None
Using Barcode generator for Software Control to generate, create UPC Code image in Software applications.
The choice of control action and tuning of the primary and secondary controllers for a cascade control system must be given careful consideration. The control action for the inner loop is often proportional with the gain set to a high value. The rationale for the use of proportional contml rather than two- or threemode control is that tuning is simplified and any offset associated with proportional control of the inner loop can be handled by the presence of integral action in the primary controller. The gain of the secondary controller should be set to a high value to give a tight inner loop that responds quickly to load disturbance; however, the gain should not be so high that the inner loop is unstable. Although the primary control loop can provide stable control even when the inner loop is unstable, it is considered unwise to have an unstable inner loop because the system will go unstable if the primary controller is placed in manual operation or if there is a break in the outer loop. The action for the primary controller is generally PI or PID. The integral action is needed to reduce offset when sustained changes in load or set point occur. The problem of adjusting a primary controller is essentially the same as for a single-loop control system. Since the addition of the inner loop can change the dynamics of the outer loop significantly, the primary controller must be retuned when the inner loop is closed or when the secondary controller settings are changed. The microprocessor-based controllers available today can implement cascade control very easily. A discussion of such controllers will be given in a later chapter.
EAN 13 Generation In None
Using Barcode drawer for Software Control to generate, create EAN-13 image in Software applications.
Drawing Code 128 Code Set A In None
Using Barcode printer for Software Control to generate, create Code 128A image in Software applications.
Example 18.2. The claim is often made that cascade control gives a better response
Data Matrix ECC200 Encoder In None
Using Barcode maker for Software Control to generate, create Data Matrix image in Software applications.
Bar Code Generation In None
Using Barcode encoder for Software Control to generate, create barcode image in Software applications.
than conventional control because the lags in the outer loop are reduced. To illustrate this benefit, consider the conventional control and the cascade control of a third-order plant in Figs. 18.8~ and b. The inner loop of the cascade system surrounds two of
2 Of 5 Interleaved Creation In None
Using Barcode encoder for Software Control to generate, create ANSI/AIM I-2/5 image in Software applications.
Code 128B Creation In Objective-C
Using Barcode encoder for iPad Control to generate, create Code-128 image in iPad applications.
PROCESS
Printing Matrix 2D Barcode In VS .NET
Using Barcode generator for VS .NET Control to generate, create 2D Barcode image in Visual Studio .NET applications.
Generate Code 39 Full ASCII In Objective-C
Using Barcode printer for iPhone Control to generate, create Code 39 Full ASCII image in iPhone applications.
APPLICATIONS
Barcode Printer In Java
Using Barcode generator for Java Control to generate, create bar code image in Java applications.
GS1-128 Decoder In Visual C#
Using Barcode scanner for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
FIGURE 18-8
Scanning DataMatrix In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Making Code 39 Extended In None
Using Barcode maker for Font Control to generate, create Code39 image in Font applications.
Block diagram for Example 18.2.
the first-order blocks in the plant. To simplify the discussion, the load disturbance is not shown since we are interested only in the closed-loop dynamics. The equivalent single-loop control system of the cascade system, shown in Fig. I8 AC, was obtained by the usual method for reducing a loop to a single block. Comparing Fig. 18.8~ with Fig. 18.8~ shows that the use of cascade contro1 has replaced a second-order critically damped system represented by the first two bIocks of the plant [I/(s + 1)2] with the following underdamped second-order system: K T2S2 + 2579 + 1 where K = lo/11 7=JVii t= J i m This second-order underdamped system, for which T and 5 am small, responds much faster than the critically damped second-order transfer function of the first two blocks of the open-loop system. Consequently, the cascade system will respond faster with a higher frequency of oscillation as we have already seen in the simulated response of Fig. 18.6.
ADVANCED CONTROL STRAI EGlES
FEEDFORWARD
CONTROL
If a particular load disturbance occurs frequently in a control process, the quality of control can often be improved by the addition of feedforward control. Consider the composition control system shown in Fig. 18.9~~ in which a concentrated stream of control reagent containing water and solute is used to control the concentration of the stream leaving a three-tank system. The stream to be processed passes through a preconditioning stirred tank where composition fluctuations are smoothed out before the outlet stream is mixed with control reagent. A three-tank system has been chosen for ease of computation in a numerical example that follows. In the conventional feedback control system shown in Fig. 18.9a, the measurement of composition in the third tank is sent to a controller, which generates
Copyright © OnBarcode.com . All rights reserved.