amp process control systems

... Ratio Control Systems 160 Selective Control Loops 167 Adaptive Control Systems 170 Summary 179 References 180 Problems 180 153 Contents I Multivariable Process Control 181 Choosing Controlled Variables ... On-off Controller 131 The Dual-mode Concept 136 Nonlinear Two-mode Controllers 144 Problems 149 PART MULTIPLE-LOOP 125 SYSTEMS Improved Control through Multiple Loops Cascade Control 154 Ratio Control ... Pairing Controlled and Manipulated Variables Decoupling Control Systems 198 Summary 202 References 202 Problems 203 Feedforward xiii - 188 Control 204 The Control System as a Model of the Process...

Ngày tải lên: 01/04/2014, 11:09

... Ratio Control Systems 160 Selective Control Loops 167 Adaptive Control Systems 170 Summary 179 References 180 Problems 180 153 Contents I Multivariable Process Control 181 Choosing Controlled Variables ... On-off Controller 131 The Dual-mode Concept 136 Nonlinear Two-mode Controllers 144 Problems 149 PART MULTIPLE-LOOP 125 SYSTEMS Improved Control through Multiple Loops Cascade Control 154 Ratio Control ... Pairing Controlled and Manipulated Variables Decoupling Control Systems 198 Summary 202 References 202 Problems 203 Feedforward xiii - 188 Control 204 The Control System as a Model of the Process...

Ngày tải lên: 27/06/2014, 05:20

... Ratio Control Systems 160 Selective Control Loops 167 Adaptive Control Systems 170 Summary 179 References 180 Problems 180 153 Contents I Multivariable Process Control 181 Choosing Controlled Variables ... On-off Controller 131 The Dual-mode Concept 136 Nonlinear Two-mode Controllers 144 Problems 149 PART MULTIPLE-LOOP 125 SYSTEMS Improved Control through Multiple Loops Cascade Control 154 Ratio Control ... Pairing Controlled and Manipulated Variables Decoupling Control Systems 198 Summary 202 References 202 Problems 203 Feedforward xiii - 188 Control 204 The Control System as a Model of the Process...

Ngày tải lên: 27/06/2014, 08:20

... of both process and controller are zero The loop cannot, therefore, sustain oscillations A Two-capacity Process Having established the ease with which a single-capacity process may be controlled, ... two-capacity process will be one where 72/~1 = 1.0 For >/4-amplitude damping, P would be 16 percent By comparison, the dead-time process is 209{,3 or 12.5 times more difficult to control than ... in that the characteristics of the same process under proportional control are improved tenfold For pi-amplitude damping with proportional-plus-derivative control, P = 1.672 i-1 D = 72 70 = 0.2572...

Ngày tải lên: 12/08/2014, 16:21

... derivat’ive are really the best control modes for every application For the easierto -control processes, their use can be justified A single-capacity process and some two-capacity processes need only narrow-band ... by ml-7-7gg+ Control er , Process I L - - - - - - - - - - - - - - - - - - l FIG 4.10 The complementary controller has a model of the process in its positive feedback loop Linear Controllers ... by sampling // c* Fast I 111 process - c I fi I 5[r -4’ ” = t/Al If a process can respond fast enough, its dynamic characteristics will be masked by the sampling system An extremely slow process, ...

Ngày tải lên: 12/08/2014, 16:21

... Secondary Controller Primary controller FIG 6.1 Cascade control resolves the process into two parts, each within a closed loop Improved Control through Multiple Loops FIG 6.2 The primary controller ... one control loop CASCADE CONTROL The output of one controller may be used to manipulate the set point of another The two controllers are then said to be cascaded, one upon the other Each controller ... labeled “zero damping, ” is superimposed on the curve in Fig 5.19 If the proportional gain of t’he linear controller were halved, the closed loop would exhibit >a-amplitude damping The controller...

Ngày tải lên: 12/08/2014, 16:21

... coupled process can produce essentially independent control loops 199 PO0 Multiple-loop Systems Consider how a decoupling control system might be designed for the blending process of Example 7.4 ... be defeated if either controller were placed in manual - Process - - :$eE’ FIG 7.9 The decoupling control system should be the image of the process Multivariable Process Control I Suppose the ... adjusting controllers on processes with variable dead time? CHAPTER u ntil now, discussion has been confined to control systems with a single manipulated variable Furthermore, only one controlled...

Ngày tải lên: 12/08/2014, 16:21

... variable Load components * * c Process I I FIG 8.1 The control system embodies a forward flow of information Controlled variable PO6 Multiple-loop Systems Although a single controlled variable is indicated ... Feedforward control should not, therefore, be construed as merely an elaborate form of programmed or open-loop control THE CONTROL SYSTEM AS A MODEL OF THE PROCESS In practice, the feedforward control ... nature of the process largely determines how well it can be controlled: the proportional band, reset and derivative times, and the period of cycling are all functions of the process Processes which...

Ngày tải lên: 12/08/2014, 16:21

... bias set into t.he controller The lead-lag unit is used t’o Control of Energy Transfer h FIG 9.11 The control system for a once-through boiler must be as closely knit as the process itself Set ... a heating medium, manipulation of its flow t’o bring about temperature control of the process fluid is effective If the process fluid is boiling, steam flow directly infers its rate of vaporization ... exchanger Thus without being directly controlled, the exit temperature of the process fluid will nonetheless be well regulated 240 Applications The flow of steam to a process heater or reboiler may...

Ngày tải lên: 12/08/2014, 16:21

... sampling controller is most effective and reliable for coping with dead time alone The control interval Al, should be set to a very low value, e.g., Answers to Problems I 0.1 min; then the sample ... without cascade control 6.P RP = 1.75 set; 70 = 5.0 sec 6.3 Two level controllers must be used, one set for high level, the other low The outputs of the flow controller and the high-level controller ... Because inventory control for vapor and liquid manipulate both effluent streams, as in an absorber, heat input is the only variable left for composit’ion control Since, in th is example, quality...

Ngày tải lên: 12/08/2014, 16:21

... Multicapacity process, 38-44 Multiple-loop control, 153-180 adaptive control systems, 170-179 cascade control, 154-160 ratio control, 160-167 selective control loops, 167-170 Multipliers, in adaptive systems, ... dual-mode control, 141 in sampling systems, 114, 115 Time-shared control, 110 (See also Direct digital control) Transfer, auto-manual, 98, 99 in digital control systems, 119 energy, control of ... 336-338 D Damping, amplitude-dependant, 125, 126 critical, 27 with complementary feedback, 105 with sampling controller, 115, 116 quarter-amplitude, variable, 52-54, 145 DDC (see Direct digital control) ...

Ngày tải lên: 12/08/2014, 16:21

... two water valves 10 E70 Climate Control Systems Air Flow Control/ Blower Speed Control Air flow control is dependent on the following settings and parameters Blower control automatic mode If automatic ... externally controlled control valve Screw fastening point of lines Pressure line to A/C condenser 40 E70 Climate Control Systems A/C Compressor Control The IHKA is the master for controlling ... Climate Control Systems Manual Air Distribution/Air Flap Control Settings The air distribution in the vehicle can be manually adjusted via the controller and/or the rocker button of the IHKA control...

Ngày tải lên: 19/10/2012, 13:50

Ngày tải lên: 05/03/2013, 17:01

... ot metsys eht htiw gnikrow yltcerid ot srefer ”smetsys ngiseD no sdnaH“ “Hands-on” Design of Control Systems metsys redro dnoces fo esnopseR petS :5 erugiF 0 20 40 60 time (secs) 80 100 120 0.2 ... eht naht rellams hcum eb ot sah emit gnilpmas eht taht ylevitiutni etats nac eW 6.3 Sampling Time with PID controllers sniag D dna P esaerced dna esaercni yletanretla dna pets tsrfi eht ot kcab ... no setarepo hcihw waL lortnoC a gningised ni detseretni era ew ,lortnoc kcabdeef nI 6.2 Feedback Control eulav derised lautca eht morf si esnopser pets eht ni dehcaer eulav lanfi eht raf woh fo...

Ngày tải lên: 12/12/2013, 07:15

... used in process control 1.4 Process modeling 1.5 Process dynamics and time constants 1.6 Types or modes of operation of process control systems 13 1.7 Closed loop controller ... in process control Most basic process control systems consist of a control loop as shown in Figure 1.1, having four main components: A measurement of the state or condition of a process A controller ... Disturbance inputs Controller Control input Setpoint + – Control action Actuator Output Process Measurement Process variable Figure 1.1 Block diagram showing the elements of a process control loop...

Ngày tải lên: 12/12/2013, 20:28

Ngày tải lên: 14/12/2013, 12:15

... SOFTWARE FOR DIGITAL CONTROL 28.12.1 Digital Control Hardware 28.12.2 Software for Digital Control 28.13 909 909 911 FUTURE TRENDS IN CONTROL SYSTEMS 28.13.1 Fuzzy Logic Control 28.13.2 Neural ... the design of a feedback amplifier Electronic Controllers 862 The operational amplifier (op amp) is a high-gain amplifier with a high input impedance A diagram of an op amp with feedback and input ... 28.5 CONTROL LAWS The control logic elements are designed to act on the error signal to produce the control signal The algorithm that is used for this purpose is called the control law, the control...

Ngày tải lên: 17/12/2013, 14:15

... in many real-life applications such as medical diagnosis [Slowinski, 1992], control algorithm acquisition and process control [Mrozek, 1992], and structural engineering [Arciszewski and Ziarko, ... chromosomes are produced During the process of reproduction, mutation may take place For example, the binary value of bit in Figure 19.3 has been changed from to The above process of fitness evaluation, ... examples classified correctly by the rule fitness of chromosome =   number of examples related to the rule   ©2001 CRC Press LLC The above fitness function favors rules that classify examples...

Ngày tải lên: 22/12/2013, 21:18