Control System Introduction PDF

Control System -the study of control system involves how components are integrated together to control a parameter such as velocity, torque, and pressure to force an output parameter to remain at a specific value. -control system consists of subsystems and processes ( or plants ) a...

Control System -the study of control system involves how components are integrated together to control a parameter such as velocity, torque, and pressure to force an output parameter to remain at a specific value. -control system consists of subsystems and processes ( or plants ) assembled for the purpose of obtaining a desired output with desired performance, given a specified input.  Example of Control System(s) Radar system Satellite system Rover ( moon explorations) Elevators Mobile robots ( mobot ) last sem project Regulated power supply dvd players/cd players/ vhs/ legendary betamax ( wala pa kayo noon, pero meron na ako) Smartphones ( not so smart ) And many others  Wait there’s more… Within our bodies are numerous control systems, such as the pancreas, which regulates our blood sugar. In time of “ flight or fight ,” our adrenaline increases along with our heart rate, causing more oxygen to be delivered to our cells. Our eyes follow a moving object to keep it in view; our hands grasp the object and place it precisely at a predetermined location.  Transient response & steady-state response Transient response – for the elevator, if this response is too fast, passenger comfort is sacrificed; if too slow, passenger patience is sacrificed. Steady-state response – if the elevator did not properly level passenger safety and convinience would be sacrificed. Eto na un oh! Elevator noon  We build CS for 4 primary reasons 1. Power amplification 2. Remote Control 3. Convenience of input form 4. Compensation for disturbances  History of control system The Greeks began engineering feedback systems around 300 BC. The water clock invented by Ktesibios used a float regulator. Oil lamp devised by Philon for maintaining a constant level of fuel oil. First feedback system to be invented in modern Europe was the temperature regulator of Cornelis Drebbel( 1572- 1633)  History part 2 Flyball Governor – first automatic feedback controller used in an industrial process was developed by James Watt in 1769  History pa more… First historical feedback system, claimed by Russia , is the water –level float regulator invented by I. Polzunov in 1765. The float detects the water level and controls the valve that covers the water inlet in the boiler Flyball governor Water-level float regulator  Shortcut na lang tayo sa history para mabilis ha During Worl War II the design of and construction od automatic airplane pilots, gun positioning systems, radar antenna control systems, and other military systems based on the feedback control approach. During 1940’s, mathematical and anlytical methods increased in number and utility, and control engineering became an engineering discipline in its own right.  Following the World War II the frequency domain techniques continued to dominate the field of control with the increased use of Laplace Transform and the complex frequency plane. During the 1950’s, the emphasis in control engineering theory was on the development and the use of the s-plane methods and particularly , the root locus approach. During the 1980’s, the utilization of digital computers for control components became routine.  Today, control systems find widespread application in the guidance system, navigation and control of missiles and spacecrafts, as well as planes and ships at sea. Modern developments have seen widespread used of digital computer as part of control systems. For example , computers in control systems are for industrial robots, spacecraft, and the process control industry.  Pics dito  Two Types of Control System ❑Open-loop system ❑Closed-loop System  Open-loop system open-loop control does not measure the output variable, and no correction of the actuating signal is made to cause the output to conform to the reference input. It generally requires human intervention to assure the proper operation of the system Example of open-loop  Open-loop systems are simply commanded by the input. Example: toasters  Closed-loop system The output is measured and feedback is used to cause the output signal to conform to the reference input. The closed-loop system compensates for the disturbances by measuring the output response, feeding that measurement back through a feedback path, and comparing that response to the input at the summing junction. If there is any difference between the two responses , the system drives the plant , via the actuating signal, to make correction. Example of Close-loop System One more example..  Advantages of Closed-loop system Greater accuracy Less sensitive to noise, disturbances, and changes in the environment Transient response and steady-state error can be controlled more conveniently and with greater flexibility often by simple adjustment of gain in the loop and sometimes by redesigning the controller.  Disadvantage of CL system More complex More expensive Advantage of open-loop system Cheap Easier to implement Easier to maintain Good for applications that require set parameters Example of open and closed-loop