Chapter 8 Robotic Systems

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Chapter 8Robotic Systems
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Agenda

• Definition of an Industrial Robot
• Fundamentals of Robotics and Robotics Technology
• The Robotic Joints
• Robot Classification and Robot Reach
• Robot Programming and Languages
• Robot Selection
• Robot Applications
• Economic Justification of Robots

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Definition of an Industrial Robot

• An industrial robot is a , designed to
  move materials, parts, tools, or special devices
  through variable programmed motions for the
  performance of a variety of tasks

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Robotics Robotics Technology

• The basic components of a robot , , and
• Power sources for robots
• Hydraulic drive
• Electric drive
• Pneumatic drive
• Robotic sensors
• Position sensors
• Range sensors
• Velocity sensors
• Proximity sensors
• The hand of a robot end-effector
• Grippers mechanical grippers (single, double),
  vacuum or suction cups, magnetic grippers,
  adhesive grippers, double grippers ? Interval and
  external
• Tools the tool itself acts as end-effector. E.g,
  welding tools, drilling, etc.

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Robotics Robotics Technology

• Robot movement and precision
• Speed of responsegtltstability (least amount of
  oscillation)
• The precision of robot movement
• spatial resolution of movement into which
  the robot can divide its work volume. Total
  range/(Number of increments 2n), n no. of
  bits in memory
• Accuracy ability to its wrist end at a
  desired point within its reach. one-half
  of the control resolution
• Repeatability ability to its end-effector at
  a point that had been tight to the robot

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Accuracy and Repeatability
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The Robotic Joints

• A robot joint is a mechanism that permits
  between parts of a robot arm
• Robot basic movements
• movement
• movement
• movement
• The joints movement relative motion of adjoining
  links
• Prismatic joints (L) as well as joints
• Revolute joints ( motion) rotational joint
  (R), Twisting joint (T), Revolving joint (V)
• The join notation from the body ? base joint

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The Robotic Joints
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Robot Classification and Robot Reach

• Classification based on physical
• Cartesian configuration
• Cylindrical configuration
• Polar configuration
• Joined-arm configuration
• Classification based on
• Point-to-point (PTP) control robot
• Continuous-path (CP) control robot
• Controlled-path robot
• Robot Reach ( ) reaching space of the robot
  arm or the of the end-effector or tool
  (range)

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Robot Classification and Robot Reach
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Robot Programming and Languages

• Objective make the robot understand its work
  cycle
• The program teaches the robot
• The it should take
• The it should reach precisely
• How to interpret the
• How and when to actuate the
• How to parts from one location to another

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Robot Programming and Languages

• Teaching methods
• Teach-by-showing power leadthrough or discrete
  point programming, manual leadthrough or
  walk-through or continuous path programming
• Textual language programming
• Programming languages
• Objective instruct the robot in how to ,
  the end-effector, and signal from
  sensors.
• Robot programming languages combination of
  textual and teach-pendant programming
• Properties like computer programming languages,
  provide robots with limited intelligence (error
  recovery, necessary actions, etc.), extenable by
  user
• Example WAVE, VAL, VALII

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Robot Selection

• Selection technical features
• Degrees of freedom
• Control system
• Work envelope
• Load-carry capacity
• Accuracy and repeatability
• Robot characteristics considered in a selection
  process
• 1. Size of the robot max dimension of the robot
  (x) micro (x 1m) small (1ltx 2m)
  medium (2ltx 5m)large (xgt 5m)
• 2. Degrees of freedom 1,2,3
• 3. Velocity affected by arm structure, divided
  into ranges
• 4..Actuator type
• 5. Control mode non servo, servo PTP, servo CP,
  combined PTP and CP
• 6. Repeatability divided into ranges
• 7. Lift capacity divided into ranges
• 8. Right-left-traverse, Up-down-traverse, in-out
  traverse
• 9. Yaw, Pitch, Roll
• 10. weight of the robot divided into ranges

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Robot Selection

• Selection method
• Identify all required features
• Give score for the desirability of the features
  on the scale of 1-10
• Assign the weight for each feature
• Rank the available robot that have these features
  based on cost and quality consideration

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Example
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Robot Applications

• Loading and unloading parts
• The robot unloading parts from die-casting
  machines
• The robot loading a raw hot billet into a die,
  holding it during forging and unloading it from
  the forging die
• The robot loading sheet blanks into automatic
  presses, with the parts falling out of the back
  of the machine automatically after the press
  operation is performed
• The robot unloading molded parts formed in
  injection molding machines
• The robot loading raw blanks into NC machine
  tools and unloading the finished parts from the
  machine
• A single- machine robotic cell application
• The incoming conveyor delivers the parts to a
  fixed position
• The robot picksupt a part from the conveyor and
  moves to the machine
• The robot loads the part onto the machine
• The part is processed on the machine
• The robot unloads the part from the machine
• The robot puts the part on the outgoing conveyor
• The robot moves from the output conveyor to the
  input conveyor

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Robot Applications

• A single-machine cell with a double-griper robot
• Move to conveyor
• Deposit a part and pickup a new part
• Move to the machine
• Multi-machine robotic cell applications
• Welding
• Spray painting
• Assembly
• Other applications material handling,
  inspection, firefighting, filling, sealing,
  packaging, etc.

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Example
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Economic Justification of Robots

• Payback period
• n NIC/net annual cash flows
• Where
• NIC total investment cost of robot and
  accessories investment tax credit available
  from the government, if any
• Net annual cash flows annual anticicpated
  revenues from robot installation including direct
  labor and material cost savings annual
  operating costs including labor, matrial, and
  maintenance cost of the robot system

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Example