Course Overview: Introduction to automation and control

1. Course Overview: Introduction to automation and control

2. CO1 • Ability to identify control system requirements • CO2 • Ability to describe the operation of simple controllers • CO3 • Ability to configure simple controllers in a system. • CO4 • Ability to identify transducers and sensors requirements for control systems Course Outcomes (CO)

3. CO5 • Ability to troubleshoot simple controllers • CO6 • Ability to repair simple controllers • CO7 • Ability to describe process actuators • CO8 • Ability to describe control system layout Course Outcomes (CO)

4. Final Examination : 60% • Test#1 : 10% • Test#2 : 10% • Test#3 : 10% • Assignments : 10% Total Mark : 100% Course Evaluation

5. References • Banister B. R et al (1986) “Transducers and Interfacing” Van Nostrand Reinhold ii.Barney G.G (1988) “Intelligent Instrumentation Microprocessor Applications in Measurement and Control”-Prentice-Hall iii.Dorf R.C., Bishop R.H. (2001). Modern Control Systems (9th Ed), Prentice Hall. iv.Ruosco S.R (1987) “Robot sensors and Transduces”Open University Press List of References

6. Instructor Mohamed MAGANGA • Contact : mohamedmaganga@hotmail.com

7. Teaching Plan

8. Teaching Plan

9. Lab Sessions

10. Introduction to Automation and Control CoED

11. Basic Concepts Control System Examples Control System Design Contents

12. System • A collection of components which are coordinated together to perform a function. • Dynamic System • A system with a memory. • For example, the input value at time t will influence the output at future instant. • A system interact with their environment through a controlled boundary. Basic Concepts

13. The interaction is defined in terms of variables. • System input • System output • Environmental disturbances Basic Concepts

14. The system’s boundary depends upon the defined objective function of the system. The system’s function is expressed in terms of measured output variables. The system’s operation is manipulated through control input variables. The system’s operation is also affected in an uncontrolled manner through disturbance input variables. System Variables

15. Control is the process of causing a system variable to conform to some desired value. ManualcontrolAutomatic control (involving machines only). A control system is an interconnection of components forming a system configuration that will provide a desired system response. Control System Output Signal Input Signal Control System Energy Source

16. Control is a process of causing a system variable such as temperature or position to conform to some desired value or trajectory, called reference value or trajectory. • For example, driving a car implies controlling the vehicle to follow the desired path to arrive safely at a planned destination. • If you are driving the car yourself, you are performing manual control of the car. • If you use design a machine, or use a computer to do it, then you have built an automatic control system. Manual Vs Automatic Control

17. Transient response: • Gradual change of output from initial to the desired condition • Steady-state response: • Approximation to the desired response • For example, consider an elevator rising from ground to the 4th floor. Response Characteristics

18. Component or process to be controlled can be represented by a block diagram. • The input-output relationship represents the cause and effect of the process. • Control systems can be classified into two categories: • Open-loop control system • Closed-loop feedback control system Block Diagram Process Input Output

19. An open-loop control system utilizes an actuating device to control the process directly without using feedback. A closed-loop feedback control system uses a measurement of the output and feedback of the output signal to compare it with the desired output or reference. Control System Classification Desired Output Response Comparison Controller Process Output Actuating Device Measurement Desired Output Response Process Output Single Input Single Output (SISO) System

20. Control System Classification Missile Launcher System Open-Loop Control System

21. Control System Classification Missile Launcher System Closed-Loop Feedback Control System

22. Control System Classification Desired Output Response Controller Process Output Variables Multi Input Multi Output (MIMO) System Measurement

23. Power Amplification (Gain) • Positioning of a large radar antenna by low-power rotation of a knob • Remote Control • Robotic arm used to pick up radioactive materials • Convenience of Input Form • Changing room temperature by thermostat position • Compensation for Disturbances • Controlling antenna position in the presence of large wind disturbance torque Purpose of Control Systems

24. Ancient Greece (1 to 300 BC) • Water float regulation, water clock, automatic oil lamp • Cornellis Drebbel (17th century) • Temperature control • James Watt (18th century) • Flyball governor • Late 19th to mid 20th century • Modern control theory Historical Developments

25. Watt’s Flyball Governor

26. Human System The Vetruvian Man

27. Pancreas • Regulates blood glucose level • Adrenaline • Automatically generated to increase the heart rate and oxygen in times of flight • Eye • Follow moving object • Hand • Pick up an object and place it at a predetermined location • Temperature • Regulated temperature of 36°C to 37°C Human System

28. Figure shows a schematic diagram of temperature control of an electric furnace. The temperature in the electric furnace is measured by a thermometer, which is analog device. The analog temperature is converted to a digital temperature by an A/D converter. The digital temperature is fed to a controller through an interface. This digital temperature is compared with the programmed input temperature, and if there is any error , the controller sends out a signal to the heater, through an interface, amplifier and relay to bring the furnace temperature to a desired value. Temperature Control

29. Car and Driver Objective: To control direction and speed of car Outputs: Actual direction and speed of car Control inputs: Road markings and speed signs Disturbances: Road surface and grade, wind, obstacles Possible subsystems: The car alone, power steering system, breaking system Transportation

30. Functional block diagram: Time response: Transportation Actual course of travel Desired course of travel Steering Mechanism Automobile Driver + Error Measurement, visual and tactile -

31. Consider using a radar to measure distance and velocity to autonomously maintain distance between vehicles. Automotive: Engine regulation, active suspension, anti-lock breaking system (ABS) Steering of missiles, planes, aircraft and ships at sear. Transportation

32. Control used to regulate level, pressure and pressure of refinery vessel. • For steel rolling mills, the position of rolls is controlled by the thickness of the steel coming off the finishing line. Process Industry Coordinated control system for a boiler-generator.

33. Consider a three-axis control system for inspecting individual semiconducting wafers with a highly sensitive camera Manufacturing Industry

34. CD Players • The position of the laser spot in relation to the microscopic pits in a CD is controlled. • Air-Conditioning System • Uses thermostat and controls room temperature. Homes

35. System, plant or process • To be controlled • Actuators • Converts the control signal to a power signal • Sensors • Provides measurement of the system output • Reference input • Represents the desired output Control System Components

36. General Control System Set-point or Reference input Disturbance Actual Output Controlled Signal Manipulated Variable Error + + Process Actuator + + + Controller - Sensor Feedback Signal

37. Control System Design Process If the performance does not meet specifications, then iterate the configuration and actuator

38. Application: CD player, computer disk drive Requirement: Constant speed of rotation Open loop control system: Block diagram representation: Turntable Speed Control

39. Closed-loop control system: Block diagram representation: Turntable Speed Control

40. Goal of the system: Position the reader head in order to read data stored on a track. • Variables to control: Position of the reader head Disk Drive Read System

41. Specification: • Speed of disk: 1800 rpm to 7200 rpm • Distance head-disk: Less than 100nm • Position accuracy: 1 µm • Move the head from track ‘a’ to track ‘b’ within 50ms • System Configuration: Disk Drive Read System

42. Describe the principle of operation for Watt’s Flyball Governor. Include the relevant block diagram and indicate the functional components of the system. Your report should be no more than 2 pages long. The report should be submitted on Wednesday (21/10/2000) during the tutorial session. Assignment 1

43. “The right half of the brain controls the left half of the body. This means that only left handed people are in their right mind…” The End…