Sistem Kendali dan Mekanika

Transcription

1 Sistem Kendali dan Mekanika

2 Automatic Control Periods The history of automatic control divides conveniently into four main periods as follows: Early Control: To 1900 The Pre-Classical Period: The Classical Period: Modern Control: Post-1955

3 Early Control to 1900 Mead s speed regulator Boulton & Watt steam engine with centrifugal governor

4 Pre Classical Period : Torpedo servomotor as fitted to Whitehead torpedoes around 1900

5 Classical Period: Black s feedback amplifier

6 Modern Control: Post-1955 The Modicon 084 PLC

7 The History of Control System (Video)

8 Introduction A control system is Collection of components working together under the direction of some machine intelligence. Electronic circuits provide the intelligence Electromechanical components (sensors and motors) provide the interface to the physical world

9 Natural Control System Example : Human body If the body need to heat itself, food calories are converted to produce heat If temperature sensors in the body notice a drop in temperature, they signal the body to burn more fuel If the sensors indicate too high temperature, they signal the body to sweat

10 Man-made Control System Example : Toilet

11 Electrical Control System Example : Electromechanical relays and switches Used as simple logic gates to implement intelligence Development : Solid-state devices replace the power relays Transistors and IC op-amps became available for analog controllers Digital integrated circuits replaced bulky relay logic Microprocessor

12 Subject of Control System Electronics (both analog and digital) Power-control devices Sensors Motors Mechanics Control system theory Control system is interesting because it deals with applications of much of the theory!!

13 Block Diagram Set point : signal representing the desired output Actuator, example : electric motor, electric valve, heating element

14 Open-Loop Control System Controller independently calculates exact voltage or current needed by the actuator to do the job No feedback

15 Closed-Loop Control System Output of the process (controlled variable) is constantly monitored by a sensor Receice a feedback

16 Transfer Function Background : Control system is a collection of components and circuits connected together Each component in the system converts energy from one form to another Example : Temperature sensor converting degrees to volts Motor converting volts to revolutions per minute

17 Example A potentiometer is used as a position sensor. The pot is configured in such a way that 0 of rotation yields 0 V and 300 yields 10 V. Find transfer function of the pot. Solution The transfer function is output divided by input. In this case, the input to the pot is position in degrees, and output is volt. output TF input 10 volt 300 0,0333 V/deg

18 Combined Transfer Function

19 Example

20 Example Motor : TF output 100 rpm m m 100 rpmm/vm input 1Vm Gear train : TF g output input 1rpm 2 rpm w m 0,5 rpm w /rpm m Winch : TF m output input 3in./min 1rpm w 3in./min/rpm w

21 Analog & Digital Control System Physical world is basically an "analog place" Natural events take time to happen, and they move in a continuous fashion from one position to the next Digital control system must first convert real-world analog input data into digital form before it can be used in calculation Output from the digital controller must be converted from digital form back into analog form

22 Analog & Digital Control System

23 Classification of Control System Process Control : Control system that oversees some industrial process so that a uniform, correct output is maintained Monitoring and adjusting the control parameters (such as temperature or flow rate) to ensure that the output product remains as it should Example : Closed-loop system maintaining a specified temperature in an electric oven

24 Classification of Control System

25 Classification of Control System Process Control can be classified into : Continuous process There is a continuous flow of material or product Example, paint-mixing machine Batch process There is a beginning and an end (which is usually performed over and over) Example, mixing a batch of bread dough and loading boxes on a pallet

26 Classification of Control System Sequentially Controlled System : Series of tasks to be performed that is, a sequence of operations, one after the other Based on its properties : Time-driven (open-loop) Do it for a certain amount of time. Example, traffic light Event-driven (closed-loop) Do it until the task is finished. Example, automatic washing machine

27 Classification of Control System Multiprocess Control :

28 Classification of Control System Multiprocess Control :

29 Classification of Control System Multiprocess Control :

30 Open & Close Loops (Video)

31 Reference : c1.pdf?SGWID= p Randy E. Saputra : Introduction to Control System

32 Terima Kasih