robot classification

1. PARTS OF ROBOT

2. What are the parts
of a robot?
• Manipulator
• Pedestal
• Controller
• End Effectors
• Power Source

3. Manipulator
• Base
•Appendages
Shoulder
Arm
Grippers

4. Pedestal
(Human waist)
•Supports the
manipulator.
•Acts as a
counterbalance.

5. Controller
(The brain)
• Issues instructions to
the robot.
• Controls peripheral
devices.
• Interfaces with robot.
• Interfaces with
humans.

6. End Effectors
(The hand)
• Spray paint
attachments
• Welding attachments
• Vacuum heads
• Hands
• Grippers

7. Power Source
(The food)
• Electric
• Pneumatic
• Hydraulic

8. ROBOT JOINTS
Prismatic Joint: Linear, No rotation involved.
(Hydraulic or pneumatic cylinder)
Revolute Joint: Rotary, (electrically driven with stepper motor, servo motor)

9. ROBOT COORDINATES
• Cartesian/rectangular/gantry (3P) : 3 cylinders joint
• Cylindrical (R2P) : 2 Prismatic joint and 1 revolute joint
• Spherical (2RP) : 1 Prismatic joint and 2 revolute joint
• Articulated/anthropomorphic (3R) : All revolute(Human arm)
• Selective Compliance Assembly Robot Arm (SCARA): 2
paralleled revolute joint and 1 additional prismatic joint
• Delta : These spider like robots are built from jointed parallel
ograms connected to a common base.

12. Cartesian
Coordinate System

13. Cartesian
Coordinate System
X- Axis

14. Cartesian
Coordinate System
Y- Axis

15. Cartesian
Coordinate System
Z- Axis

16. Cartesian
Coordinate System

18. Cylindrical
Coordinate System

19. Cylindrical
Coordinate System
Y - Axis

20. Cylindrical
Coordinate System
Z - Axis

21. Cylindrical
Coordinate System
q - Axis

22. Cylindrical
Coordinate System

25. Polar (Spherical)
Coordinate System

26. Polar (Spherical)
Coordinate System
 - Axis

27. Polar (Spherical)
Coordinate System
q - Axis

28. Polar (Spherical)
Coordinate System
g - Axis

29. Polar (Spherical)
Coordinate System

31. Revolute (Joined-Arm)
Coordinate System

32. Revolute (Joined-Arm)
Coordinate System
a - Axis

33. Revolute (Joined-Arm)
Coordinate System
 - Axis

34. Revolute (Joined-Arm)
Coordinate System
q - Axis

35. Revolute (Joined-Arm)
Coordinate System

39. Robotics Joints

40. Robots degrees of freedom
• Degrees of Freedom: Number of
independent position variables which
would has to be specified to locate all
parts of a mechanism.
• In most manipulators this is usually the
number of joints.

41. Fig. 1.3 A Fanuc P-15 robot.
Reprinted with permission from Fanuc Robotics, North America, Inc.
Consider what is the degree of Fig. 3
1 D.O.F. 2 D.O.F. 3 D.O.F.
ROBOTS DEGREES OF FREEDOM

42. Degrees of Freedom
VS
Degrees of freedom (DOF) is a term used to describe a robot’s freedom of motion in
three dimensional space— specifically, the ability to move forward and backward, up
and down, and to the left and to the right. For each degree of freedom, a joint is
required.
A robot requires six degrees of freedom to be completely versatile.

46. Degrees of Freedom
• Rotating the base.

47. Degrees of Freedom
• Pivot the base of
the arm.

48. Degrees of Freedom
• Bending the elbow.

49. Degrees of Freedom
• Wrist up and down.

50. Degrees of Freedom
• Wrist left and right.

51. Degrees of Freedom
•Rotating the wrist.

52. ROBOT WORKSPACE
Fig. 1.7 Typical workspaces for common robot configurations

53. Cartesian
Cylindrical
Polar Revolute
SCARA

54. JOINT SYMBOL

55. FUNCTION BLOCK DIAGRAM

56. • Reach and Stroke
• Performance parameters

59. PERFORMANCE PARAMETERS :ACCURACY & REPEATABILITY
• Repeatability - is how well the robot will
return to a programmed position. This is not
the same as accuracy. It may be that when
told to go to a certain X-Y-Z position that it
gets only to within 1 mm of that position. This
would be its accuracy which may be improved
by calibration. But if that position is taught
into controller memory and each time it is
sent there it returns to within 0.1mm of the
taught position then the repeatability will be
within 0.1mm.
•Accuracy – is how closely a robot can reach a
commanded position.
•When the absolute position of the robot is measured
and compared to the commanded position the error is a
measure of accuracy.
•Accuracy can be improved with external sensing for
example a vision system or Infra-Red. See robot
calibration.
• Accuracy can vary with speed and position within the
working envelope and with payload (see compliance).

60. RESOLUTION
• Resolution The resolution of a robot is a feature
determined by the design of the control unit and is
mainly dependent on the position feedback sensor.
• It is important to distinguish the programming
resolution from the control resolution.
• The programming resolution is the smallest
allowable position increment in robot programs and
is referred to as the basic resolution unit (BRU).
• For IRB2000 ABB robot it is approximately 0,125 mm
on linear axis.
• The control resolution is the smallest
change in position that the feedback
device can sense.
• For example, assume that an optical
encoder which emits 1000 pulses per
revolution of the shaft is directly
attached to a rotary axis. This encoder
will emit one pulse for each of 0,36° of
angular displacement of the shaft.
• The unit 0,36° is the control resolution
of this axis of motion.

61. FIGURE: ERROR AFFECTING CONTROL RESOLUTION

62. ROBOT DRIVE SYSTEM

63. HYDRAULIC SYSTEM
Power Packs
1. Reservoir
2. Hydraulic
pump
3. Electric
motor
4. Valves
5. Hoses and
pipes

64. ROBOT REFERENCE FRAMES
Fig. 1.6 A robot’s World, Joint, and Tool
reference frames.
Most robots may be programmed
to move relative to either of these
reference frames.