Automated Precision Machines

1. Automated Precision Machines Team 2 Nicholas Neumann Ralph Prewett Jonathan Brouker Li Tian Felix Adisaputra November 5th, 2010

2. Contents • Servo Motor • Stepper Motor • Sensors for Precision Control • Robotic Programming Languages • Automated Machines

3. What is a Servo Motor? • Closed-Loop System • Precise position control

4. Servo Motor • Servo Mechanism • 1 : Position Sensor • 2: Electric Motor • 3: Reduction Gears

5. Servo Motor • Closed-Loop System

6. Servo Motor • Example • No Control • No Feedbacks

7. Servo Motor • Proportional-Integral-Derivative Control • Overshoot = 0 • Rise Time • Settling Time • Steady-State Error = 0

8. Servo Motor • Applications • Labelling Machine

9. Stepper Motor • Brushless, Synchronous Electric Motor • Open-Loop System • (No Feedback) • Full Rotation Divided into • Large Number of Steps • Torque Decreases as Speed Increases.

10. Stepper Motor • Permanent Magnet Stepper Motor • “Tin-Can” or “Canstock” • Low Cost • Low Resolution • 7.5o to 15o step angles • 48-24 steps/revolution • Rotor Magnetized with Alternating Poles • More Magnetic Flux Provides More Torque

11. Stepper Motor • Hybrid Stepper Motor • More Expensive • Better Performance • Torque • Speed • Higher Resolution • 3.6o to 0.9o step angles • 100-400 steps/revolution • Rotor • Multi-Toothed • Axially Magnetized Concentric Magnet

12. Stepper Motor • Two-Phase Stepper Motor • Bipolar Drive • Single Winding per Phase • Half the Power Loss • Unipolar Drive • Two Windings per Phase • One for Each Magnetic Field Direction • Fewer Switches

13. Stepper Motor • Applications • Film-Advance

14. Stepper Motor • Applications • Conveyor

15. Servo Motor vs Stepper Motor

16. Sensors for Precision Control • Hall Effect Sensor • Voltage Transducer • Response to Changes in Magnetic Field • Applications: • Switching, Positioning, Speed Detection, Current Sensing

17. Sensors for Precision Control Advantage: • They are immune to dirt, dust and water, • They are capable of switching at high frequencies. • They can be used for a wide variety of applications.

18. Sensors for Precision Control • Rotary Potentiometer • Position Transducer • Three-Terminal Resistor • Adjustable Voltage Divider

19. Sensors for Precision Control • Potentiometer If RL >> (R1 and R2),

20. Sensors for Precision Control • Linear Potentiometer • Displacement Transducer • Voltage Division • Hybrid Conductive Film

22. Sensors for Precision Control • Rotary Encoder • Electromechanical Device • Angle Transducer • Angular Position Analog/Digital Code • Types: • Absolute Rotary Encoder • Incremental Rotary Encoder Gray Code

23. Sensors for Precision Control • Rotary Encoder • Gray Code

24. Robotic Programming Languages • C Language • Pros: • Speed of Resulting Application • Application in Firmware Programming • Compatible with Many Other Languages • Code is Compacted into Executable Instruction • Cons: • No Runtime Checking • No Strict Type Checking • Can Pass Integer Value for Floating Data Type • Very Difficult to Fix Bugs as Program Extends

25. Robotic Programming Languages • RobotC Language • Pros: • More Functions than Regular Graphical Language • Easy to Navigate Through Program • Suitable for More Complicated Programs • Cons: • Text-Based Language • Hard for Beginners • Must be Bought Separately from Kit

26. Robotic Programming Languages • Ladder Logic • Pros: • Familiar Programming Language • Relay Logic (Widely Used) • Cost-Effective Equipment • Reliable Parts • Simple Circuits • Cons: • Difficult Integration with Third Party Software

27. BASIC Pros: User Friendly and Interactive Simple and Easy Rapid Development Powerful Front-End Tool Multiple Vendor Support Cons: Memory Leakage Passing Value by Reference Only for Windows Sluggish Performance Robotic Programming Languages

28. Robotic Programming Languages • LabVIEW • Pros: • User Friendly Graphical Interface • Universal Platform for Numerous Applications • Compatible with Other Languages • Execution Highlighting Feature • Cons: • Expandability Problem • Depends on How Well the Original Program was Written • Memory Management • Difficult Memory Allocation • Expensive

29. Robotic Programming Languages • LEGO Mindstroms NXT • Pros: • Icon-Based Drag and Drop • Graphical Language • Easy Maintenance • Simple Programs • Cons: • Lack of Complex Features in the Compiler

30. Which Language to pick? Previous Experience How much time and effort you intend to invest Your goals Availability Robotic Programming Languages

31. Automated Machines • Control Systems • Information Technologies • Reduce Human Work

32. Automated Machines • Programmable Logic Controller (PLC) • Digital Computer • Automation of Electromechanical Processes • Multiple Input-Output Arrangements • Armored for Severe Conditions • User Interface

33. Automated Machines • Supervisory Control and Data Acquisition (SCADA) • Centralized Systems • Monitor and Control • Human-Machine Interface (HMI) • Alarm Conditions

35. Automated Machines • Main Advantages • Replacing Human Operators in Monotonous Work • Performing Tasks that are Beyond Human Capabilities • Size, Weight, Speed • Dangerous Environment • Space, Underwater, Nuclear Facilities • Economy Improvement

36. Automated Machines • Main Disadvantages • Technology Limits • Unable to Automate All Desired Tasks • High Initial Cost • Unpredictable Development Costs

37. Questions