Position and highly oscillatory dynamics, which can easily be velocity control have been used successfully in changed by moving the propeller. The basic system Another popular process is a hairdryer with a consists of a motor with devices for measuring long pipe having thermistors that control the angular orientation and rotation speed. Some energy to the dryer. With a long pipe, this is an systems have two motors on the same shaft so excellent way to illustrate the effect of dead that disturbance torques can be added.
Several time. A commercial version is available from systems have a variable backlash and friction. Feedback Ltd. There are also more elaborate systems with 5. M anufacturing sy stems. Manufacturing several masses connected by springs. Such systems contain not only control systems, but systems are good for illustration of many aspects also a large amount of logic and sequencing that of linear and nonlinear control.
Many control is typically implemented in a programmable logic schemes can be applied to them, including controller PLC. It is possible to build up small simple lead-lag compensation and state- models of manufacturing systems by using feedback observers.
To do this well, it is advanced toy kits from Fisher Technique and important that the systems are designed in such a Lego. Such systems are very useful to illustrate way that the linear behavior dominates.
The many issues in manufacturing systems. Several servo systems can also be used to illustrate laboratories have also built more elaborate and backlash, and friction can make application of much more expensive test facilities for theory very complicated.
A very elegant implemen- built up around standard components like tation of the inverted pendulum has been electric teapots, valves and pumps.
They Technology. This allows demonstration of the are now available in many shapes over a wide difficulties in controlling an inherently unstable price range. Some of them have real control system.
With a proper design, an inverted systems in the joints while others have stepping pendulum on a cart can also be used to illustrate motors. The key problem here is to 5. Autonomous vehicles. The subject of introduce damping in an almost-unstable system. These kits. Remote control can easily be arranged systems are interesting because they are good using standard equipment for control of model devices to illustrate the inherent limitations in airplanes.
Position sensing can be done in a feedback; also see Kanzaki et al. Inexpensive cards for such mechatronics device that illustrates several cameras are available both for PCs and interesting measurement and control techniques. An interesting experiment is to Apart from positioning the ball on the beam, it reverse a truck with two or more trailers. The hovering ball is 5.
Curriculum issues another popular example; systems with multiple There are many curriculum issues involved in axes of motion have also been developed for the laboratory.
The standard way of using a illustration. Process control. We should, courses. An example of this is in Lund Astrom, however, be reluctant to put such a system into , where integrated laboratories are used the hands of a student who has not had some for classes with several hundred students. In this previous laboratory experience. The 6. Another ughs in computer-aided engineering is the advantage is that it is possible to refer to the continuing development of sophisticated laboratory in lectures with all students doing the software tools that allow control engineers to same experiments.
The best benefits are clearly design and analyze control systems in a friendly, obtained from open-ended laboratories where interactive environment. The underlying philo- students set up their own experiments. Such sophy of the software is to minimize program- laboratories do, however, require substantial ming effort on the part of the users and allow time and substantial supervision.
Computer-aided Laboratory engineering tools are an equipment is expensive to buy and costly to run important aspect of teaching, since they make it and maintain. Why not substitute it with possible to significantly increase the personal simulation, which is much cheaper? Simulation is efficiency in problem solving. They also make it certainly useful, but it cannot replace real possible to deal with realistic problems, which physical equipment.
It is important that students contributes to making teaching more interesting be exposed to the vagaries and perversities of and more realistic. Different aspects of CACE the real-world early-they need to deal with are found in Atherton Schaufelberger measurement noise, friction, saturating valves , , and Maier and Schaufelberger and motors. It is also very useful for them to A control laboratory should have software for 5. Logic and sequencing. Logic and Seq- computer-aided control engineering.
This in- uencing are important aspects of real automation cludes numerical linear algebra, computer systems that a control engineer should master. They are often not part of the ordinary control There should also be tools for modeling, system curriculum, but definitely should be.
In manu- identification and control system design simula- facturing systems, sequencing of parts is often tion. It is also advantageous if there are facilities essential. In cussed above. Most of the desired functions can Europe it is becoming increasingly popular to be put together with standard software available base courses on Grafset, which is a modified today. In this section the presentation will focus on 5. Real- time simulation. A simulator with the CACE software environment, the role of real-time facilities has many advantages.
It is software in teaching and learning, potential then possible to start with as simulation of a shortfalls of CACE software, and trends in process and controller. Once satisfactory simula- CACE software. CACE software environment by changing some connections. This also has an software is a smart technical computing environ- additional feature in terms of a code generator ment architecture where a user can interact with that generates real-time code in Modula II with the computer and build his or her applications calls to a real-time kernel Dahl, With this in a convenient way.
For instance, a user should system, it is possible to get better user interfaces be able to express technical concepts, design than with the real-time simulator. It can also be algorithms etc. The computer control them.
At the kernel of CACE software is scope. After setting up the necessary parameters normally a collection of callable mathematical, via GUI dialog windows, the model is complete scientific and engineering functions for delivering and a simulation can be run with a click of the high-performance numerical computation re- mouse button.
A click on the oscilloscope icon quired in control applications. It should also will display and update the results of the have an open architecture that easily allows a simulated output as the simulation crunches on. A of minutes. Of the above learning curve to overcome, since the block software, MATLAB appears to be the most diagram icons and graphics are similar to popular among academic institutions see Ather- textbook standards.
Once they have their model ton ef al. This can be attributed to its checked out, students usually find themselves pricing through a university support program exploring new variations and designs, and and its operability across PC, Macintosh, rediscovering or confirming the principles of workstations, minicomputers and supercompu- feedback and control system see Jorgl, Numerous control textbooks have been Simulink has over built-in block types of written based on the use of MATLAB Franklin simple and complex subsystem icons, and allows et al.
Simulink is a, b. The software is a general-purpose indeed a powerful interactive workbench for high-performance numerical computation engine dynamic system simulation for undergraduate with over callable kernel functions to and graduate courses as well as for research and support numerical and graphics applications development projects.
Its functiona- Control toolboxes are for the benefits of lity is extended by toolboxes for signal control engineers as well as engineering students. Its open architecture allows a on classical and modern control methodologies, third party to create his or her own toolbox It covers Laplace-transform, frequency-domain where necessary see Schaufelberger, , and state-space methods in the continuous-time Since it is imprac- Nichols chart, pole placements, linear quadratic tical to discuss all aspects of the software, we optimal control and estimators, etc.
Students shall briefly highlight only some of the powerful usually combine the calls to the toolbox with a functions in the control toolboxes and the use of call to the Simulink to evaluate their design, Simulink.
As an icons for a transfer function summation, signal example, a student only requires about half an generator and oscilloscope into a working hour of introduction by the instructor to be Simulink window. Using a few intuitive actions familiar with the MATLAB file setup and with the mouse, one can point, click and connect programming philosophy.
After another one-hour and application. Because of with the simulation capability of the software. Faculty and graduate 6. CACE software to highlight the essential aspects of dynamic systems and control. Potential shortfalls of CACE software tion analysis of system stability, effect of The shortfalls for relying heavily on CACE parameter variation, evaluation of feedback software are the potential ignorance of hidden control system, transient and steady-state analy- numerical computation that powers the software, sis, frequency response analysis, etc.
Labora- the deficiency of realizing the limitation of the tories should be designed to challenge students actual physical system being modeled and to correlate observations from the simulation simulated, and the lack of practical hands-on with the theory presented in the class see experience in dealing with actual physical control Kheir, , , , ; Gillet et al.
Numerical results uersus theoretical control engineering classes has never been validation. With a few integration algorithm, as long as the software has lessons on the basic necessary commands and a smart routine with variable integration step using the on-line help for the CACE software, size. The truth, however, is that users are still students can progress on their own through the the final people who must use their theoretical tutorials that accompany the software and the grounding and control background to confirm examples given in the class.
For 6. The ability to successfully simulate a instructor may ask them to first verify a control system provides a designer with con- pencil-and-paper example or a simple CACE fidence in his or her design and useful insights solution presented in the classroom.
Students into the problem and its potentials. The may then be challenged with problems that confidence and insights, however, are limited by highlight the theory they have learned in class. A main reason approaches to solve the problems. Control applications representation rather than physical component for illustrating and exposing students to different type representation. The following is a case in aspects of control theory are only limited by the point. A control scientist often views a DC motor imagination of the instructors, scope of the with voltage input and position output as a course and time factor.
The problems posed by laboratory assign- control engineer, who has to examine the actual ments occupy their thought and challenge them circuitry and mechanism, is confronted with to prove their ability to solve control engineering questions such as Coulomb friction, voltage and problems and demonstrate them using the current saturation, nonlinearities of amplifiers, CACE software.
The motivation and determina- backlashes, and limit stops that have not been tion to succeed often find students working carefully considered by the control scientist. The persistently on the computer, and learning more limitation of the behavioral models used in and more about the subject in their own time.
Practical hands- on laboratory ex- using the templates of the tentative physical perience. As described in Section 5, a laboratory component. The simulation can be used to control experiment or project is one of the most evaluate the suitability and statistical tolerance exciting, revealing and confidence-building en- of the components for the proposed design.
The gineering experiences to undergraduate and use of such physical object oriented modelling graduate students alike. Students derive satisfac- and simulation should be an excellent and tion in seeing working control systems that they natural extension for many control engineering have just successfully implemented.
A control curricula. Animated visualization of dy namic much of their previously acquired engineering sy stem motion. Computer simulation of a knowledge, including system theory, computer dynamic system traditionally produces some programming, electronics, mechanics, sensors form of time-response plots that show how the and instrumentation, to successfully complete system would respond to external excitation. Trends in CACE software Computer visualization, on the other hand, Over just a span of several years, computer can enhance the perception and understanding vendors have made tremendous breakthrough in of a system being simulated many fold, while, at the areas of simulation, graphics and visualiza- the same time, it brings the simulation to life tion technologies IEEE, ; Kheir, Visualization Virtual prototyping, which consists of interac- often confirms the more abstract or hidden tive visualization for physical component functi- information that would otherwise be missed or onality and virtual mockup model, is the current misinterpreted.
Animation is often the most thrust for many applications that involve natural form of visualization for simulating the multidiscipline engineering. The ultimate goal in a motion of a physical system.
CACE will interact with real-time simulation and animation be a part of such virtual prototyping simulation. As mentioned earlier, while empiri- applications, with varying breadth and depth cal behavioral models are sufficient to represent IEEE, A representative trend of the dynamics of a system, they lack the ability to visualization in the area where graphics predict the more realistic behavior of an actual animation is used to depict systems behavior is system.
CAE software for capturing detailed found in Kheir High-performance and models of physical components has recently been high-speed interactive video graphics technology developed in the field of electrical, electronics, is available today, and it will only be a matter of mechanical, thermal pneumatic and hydraulics time before the technology is utilized more systems, with minimal consultation with the field extensively in CACE.
One such software that is widely used 6. Real- time code generation and controller in the industry is the Saber Simulation Software hardware. Although computer simulation and a product of Analogy , which uses the concept visualization provide a convenient means for of component templates for various engineering verifying control concepts under investigation, parts. For example, its library consists of actual implementation of laboratory experiments comprehensive sets of templates for off-the-shelf offer the opportunity of validating the results.
The scheduling and management. The importance of port automatic generation of real-time code for continuing education and recently published implementing dynamic function of the system or textbooks is well documented.
We note that subsystem block developed in the simulation practical hands-on laboratory experience can be diagram. An automatically generated C-language complemented but cannot be replaced by the source code for a controller block, for example, exact world of CACE simulation environment.
Although some experience in C more real-world laboratory experiments with programming may be required, tremendous novel applications; development time and effort can be saved by increased reliance on computer-aided control eliminating the need to program and debug the engineering CACE ; software, or the use of low-level assembly language. Special digital signal processor-based broader education of control engineers and hardware, such as dSPACE DSP, is also more emphasis on interdisciplinary teamwork supported by these real-time code generators, to activities; enable real-time implementation of high-order and complex dynamical control systems.
Such closer ties between industry and academia, real-time software and hardware CACE support, particularly with regard to continuing which offer a quick mechanism to transfer education; theoretical simulation into actual implementa- tion, is an excellent tool for introducing students continued novelty in how textbooks in control to the world of computer-controlled systems.
It is a powerful computer tool continued sophistication in the laboratory that will play an even more useful role in the computer visualization, interactive and vir- control engineering education. The future trend tual environment as technology keeps ad- of CACE should capitalize on the rapid vancing rapidly; advances of computer technology toward inter- active virtual environment for analysis, design more programs expected to present newly and prototyping for CAE instruction, research, developed concepts of control in the form of development and engineering of control systems.
Trends in automatic control education in examine control systems engineering as an Japan. IV, pp. In this context, focus has Anderson, B. Moore Optimal been broadly placed on the control curriculum Control: Linear Quadratic M ethods.
Aris, A. M athemutical M odeling Techniques. Pitman, the United States , the significance of the London. Reglerteori Confrol Theory.
Unusalal in Swedish. Astram, K. Lundh, M. Lund control and learning. How the educational experience program combines theory with hands-on experience. Wittenmark Comparer engineer in the s and beyond. Attention has Controlled Systems, Theory und Design, 2nd ed. Atherton, D. The role of CAD in education and systems engineering, but also to the future, research. In Proc. Sorenson and A. Goucem t Auslander, D. Horowitz Mechanical Dickenson, B. Systems Analy sis, Design and engineering control system curriculum.
American Computation. Control Co. Dorato, P. Robust Control. Bagchi, A. Optimal Control Stochastic Systems. IEEE Trans. Balchen, J. Handlykken and A.
Tyss The need Dorato. Abdallah A survey of engineering for better laboratory experiments in control engineering education outside the United States: implications for the education. ASEE J. Engng Educ. Bagar, T. Bernhard H, Optimal Control and Dorf, R. M odern Conrrol Systems, 6th ed. Springer-Verlag, Berlin.
Dorny, C. Understanding Dy namic Systems: Bertekas, D. Prentice- Deterministic and Stochastic M odels. Sensible heat applied to a pot of water will raise its temperature until it boils. Once the substance reaches the necessary temperature at a given pressure to change state, the addition of latent heat causes the substance to change state.
Adding latent heat to the boiling water does not get the water any hotter, but changes the liquid water into a gas steam. One can state that a certain amount of heat is required to raise the temperature of a substance one degree. This means that if we add 1 BTU of heat to 1 lbm of water, the temperature will rise 1F. The specific heat value and the specific heat capacity value for water are equal. Other properties identified on the Mollier diagram are constant temperature, density and entropy lines.
The Mollier diagram8 is useful when analyzing the performance of adiabatic steady-flow processes. The chart is used to determine the state of an air-water vapor mixture when at least two properties are known. Mollier diagrams are named after Richard Mollier, a professor at Dresden University who pioneered the graphical display of the relationship of temperature, pressure, enthalpy, entropy and volume of steam and moist air. Reference www. Intersection Point Dewpoint. The point of intersection of the two lines indicates the condition of the given air.
As a result:. Linear Interpolation in Tables Linear interpolation is a convenient way to fill in holes in tabular data. The formula for linear interpolation is:. Once the waters boiling point is reached, the waters temperature ceases to rise and stays the same until all the water is vaporized. As the water goes from a liquid state to a vapor state it receives energy in the form of latent heat of vaporization. As long as there is some liquid water left, the steams temperature is the same as the liquid waters temperature.
This type of steam is called saturated steam. Industries normally use saturated steam for heating, cooking, drying and other processes. Steam heated beyond the saturated steam level is called superheated steam. Superheated steam is used almost exclusively for turbines. Turbines have a number of stages. The exhaust steam from the first stage is directed to a second stage on the same shaft, and so on.
This means that saturated steam would get wetter and wetter as it went through the successive stages. This is due to the fact that saturated steam has a greater volume of water in it as the pressure gets lower. Not only would this situation promote water hammer11, but the water particles would cause severe erosion within the turbine.
There is a good reason why superheated steam is not as suitable for process heating as is saturated steam. Superheated steam has to cool to saturation temperature before it can condense to release its enthalpy of evaporation.
The amount of heat given up by superheated steam as it cools to saturation temperature is relatively small in comparison to its enthalpy of evaporation.
Thus, if the steam has a large degree of superheat, it may take a relatively long time to cool, during which time the steam will release very little energy.
There are many free online tools available to calculate these values based upon the pressure in psig, www. Water hammer aka fluid hammer is a pressure surge that occurs when the fluid in motion is suddenly stopped or forced to change directions abruptly. This pressure wave then propagates throughout the equipment causing noise and vibration.
Properties of Superheated Steam12 Pressure Sat. Total Temperature F Temp psia psig. Standard Deviation is a measure of the spread of the data about the mean value. Reference Figure for the normal distribution curve between standard deviations. To calculate the population standard deviation, we compute the difference of each data point from the mean, and square the result:.
There are many free online tools available to calculate these values based upon the pressure and super- heat temperature, www. Six Sigma Six Sigma comes from the notion that if one has six standard deviations between the process mean and the nearest specification limit, there will be practically no items that fail to meet specifications. To achieve Six Sigma, a process must not produce more than 3. As a result of this performance, the number of sigmas that will fit between the process mean and the nearest specification limit is likely to drop over time, as compared to an initial short-term study.
To account for this real-life increase in process variation over time, an empirically-based 1. According to this concept, a process that fits Six Sigmas between the process mean and the nearest specification limit in a short-term study will, in the long term, only fit 4. Either the process mean will move over time, or the long-term standard deviation of the process will be greater than that observed in the short term, or possibly both.
Therefore, the widely accepted definition of a Six Sigma process is one that produces 3. Rating details. All Languages. More filters. Sort order. Davidt rated it really liked it Oct 27, Swapnil Pawar rated it it was ok Jul 17, B added it Apr 27, Galih Ardiyanto marked it as to-read Sep 02, Agustin Foglino marked it as to-read Jan 10, Ramy Zaki marked it as to-read Feb 19, Edmund marked it as to-read Sep 29, Felipe Restrepo is currently reading it Oct 10, Hamza Khalid marked it as to-read Apr 13, Christian Alford added it May 17, Water hammer aka fluid hammer is a pressure surge that occurs when the fluid in motion is suddenly stopped or forced to change directions abruptly.
This pressure wave then propagates throughout the equipment causing noise and vibration. Properties of Superheated Steam12 Pressure Sat. Total Temperature F Temp psia psig. Standard Deviation is a measure of the spread of the data about the mean value. Reference Figure for the normal distribution curve between standard deviations. To calculate the population standard deviation, we compute the difference of each data point from the mean, and square the result:.
There are many free online tools available to calculate these values based upon the pressure and super- heat temperature, www. Six Sigma Six Sigma comes from the notion that if one has six standard deviations between the process mean and the nearest specification limit, there will be practically no items that fail to meet specifications. To achieve Six Sigma, a process must not produce more than 3. As a result of this performance, the number of sigmas that will fit between the process mean and the nearest specification limit is likely to drop over time, as compared to an initial short-term study.
To account for this real-life increase in process variation over time, an empirically-based 1. According to this concept, a process that fits Six Sigmas between the process mean and the nearest specification limit in a short-term study will, in the long term, only fit 4. Either the process mean will move over time, or the long-term standard deviation of the process will be greater than that observed in the short term, or possibly both.
Therefore, the widely accepted definition of a Six Sigma process is one that produces 3. So the 3. This is done to prevent underestimation of the defect levels likely to be encountered in real-life operation.
Boyles law states that at constant temperature, the absolute pressure and the volume of a gas are inversely proportional. The law can also be stated in a slightly different manner: that the product of absolute pressure and volume is always constant. Charless law states that at constant pressure, the volume of a given mass of an ideal gas increases or decreases by the same factor as its temperature on the absolute temperature scale i.
The pressure of a fixed mass and fixed volume of a gas is directly proportional to the gas's temperature. Pascals Law Pascals Law states that a change in the pressure of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container.
Note: this is the principle used in the pressure factor table Table to convert between pressure and inches-WC, mm- Hg, etc.
Bernoullis Equation The Bernoulli equation states that as the speed of a moving fluid increases, the pressure within the fluid decreases:. This form of the Bernoulli equation ignores viscous effects. If the flow rate is high, or the flowing material has a very low viscosity, Bernoullis equation should not be used. For example, liquid flowing in a pipe may be more accurately described with Poiseuilles equation14 to account for flow rate, viscosity and pipe diameter.
Poiseuilles equation states:. The Joule-Thomson coefficient JT is the change of temperature per unit change of pressure. The rate of change of temperature T with respect to pressure P in a Joule-Thomson process that is, at constant enthalpy H is the Joule-Thomson Kelvin coefficient.
This coefficient can be expressed in terms of the gas's volume V, its heat capacity at constant pressure Cp, and its coefficient of thermal expansion as:. Open navigation menu. Close suggestions Search Search. User Settings. Skip carousel. Carousel Previous.
Carousel Next. What is Scribd? Uploaded by inglufer. Did you find this document useful? Is this content inappropriate? Report this Document. Flag for inappropriate content.
Download now. For Later. Related titles. Carousel Previous Carousel Next. Jump to Page.
0コメント