Week 8: An Introduction to Robotics 1)What is a robot ? 2)The historical development of robotics 3)Industrial robot systems and components 4)Industrial robot configurations 5)Kinematic classification 6)Industrial applications, usage and world

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Week 8 An Introduction to Robotics1) What is a
robot ? 2) The historical development of
robotics3) Industrial robot systems and
components4) Industrial robot configurations
5) Kinematic classification 6) Industrial
applications, usage and world markets
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• Suggested reading to find out more
• textbooks
• Craig Introduction to Robotics, 1986
• Fu, Gonzalez and Lee Robotics, 1987
• Groover et al Industrial Robotics, McGraw Hill,
  1986
• periodicals and journals
• IEEE Robotics Magazine
• IEEE Transactions on Robotics Automation
• Industrial Robot
• Internet
• Internet Robotics Resource Page (URL)
• comp.robotics.misc and comp.robotics research

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What is a robot ?

• A robot is a re-programmable, multifunctional
  machine designed to manipulate materials, parts,
  tools,or specialized devices, through variable
  programmed motions for the performance of a
  variety of tasks."
• Robotics Industries
  Association
• "A robot is an automatic device that performs
  functions normally ascribed to humans or a
  machine in the form of a human."
• Websters Dictionary

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• Historical development I - the beginning
• The word 'robot' was coined in the early 1920s
  by the Czech playwright Karel Capek (pronounced
  "chap'ek") from the Czech word for forced labor
• The term 'robotics' refers to the study and use
  of robots and was coined and first used by the
  Russian-born American scientist and writer Isaac
  Asimov (1942). Asimov also created the Three
  Laws of Robotics.
• in the early 1940s MIT developed a numerically
  controlled (NC) milling machine (the first NC
  machine tool)
• In 1961 George Devol created his patent for parts
  transfer machines. Joe Engelberger teamed with
  Devol to form Unimation and was the first to
  market robots. As a result, Engelberger has been
  called the 'father of robotics.'
• The first industrial modern robot - the Unimate -
  developed by Devol and Engelberger - was
  installed at GM (New Jersey) in 1961.

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A Unimate serves Devol and Engelberger with a
cocktail
A Unimate employed more profitably
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• Historical development II - computers sensors
• In 1964 Artficial Intelligence (AI) Labs open at
  MIT, Stanford (SRI) and University of Edinburgh
• The mobile robot Shakey was developed at
  Stanford in the late sixties.It had a camera and
  touch sensors and could move about the lab floor
• SRI develop the Stanford Arm - an electrically
  powered manipulator and then WAVE - the first
  robot programming language. This was subsequently
  developed into VAL for use with Unimation robots
• In 1974 ASEA introduce the all electric drive
  IRb6. Cincinnati Milacron also introduce computer
  controlled T3 (The Tomorrow Tool) robot. Kawasaki
  use Unimation machines to weld motorbike frames.
• In 1976 Viking I II space crafts equipped with
  robot arms land on Mars
• Unimate PUMAs introduced in 1978. SCARAs
  (Selective Compliance Articulated Robot Arm)
  introduced in 1979.
• Vision based workcell demonstrated at University
  of Rhode Island in 1980 (Kirsch).

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• Evolution of computing power

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• Historical development III - the latest
• New Techniques
• walking robots
• co-operating arms or AGVs
• biomedical engineering
• teleoperation
• Internet robotics
• micro and nanorobotics
• New Applications
• teleoperated robotics (space, surgery)
• service robots (teaching, retail, fast food
  outlets, bank tellers, garbage collection,
  security guards, cleaning vehicles etc etc)
• UGVs and UAVs for hazardous environments

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• Historical development IV - science fiction
• early perception of robots was that they were the
  tools of scientists or aliens bent on world
  domination (The Day the Earth Stood Still, The
  Forbidden Planet)
• some robots even wanted to take over the world
  themselves (Dr. Who), or quite often went berserk
  (RUR, 2001, Westworld, Saturn 3)
• later they were viewed in more sympathetic light
  as often humaniod-like companions (Star Wars, Dr.
  Who, Short Circuit, Hitch Hikers Guide, Red
  Dwarf).
• we still however best enjoy the notion that
  robots are basically very scary (Terminator,
  Bladerunner, RoboCop)
• end result is that robots and their capabilities
  are still very poorly understood by the general
  public

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• Robots in sci-fi seminal films I
• 1951 - The Day the Earth Stood Still (sci-fi
  drama) Michael Rennie, Patricia Neal. Story about
  aliens who come to Earth with an all-powerful
  robot called Gort.
• 1956 - Forbidden Planet (sci-fi drama) Leslie
  Nielsen. Classic movie robot Robby.
• 1965 - Dr. Who and the Daleks (sci-fi drama) Dr.
  Who helps humans on a distant planet overcome
  their robot masters.
• 1968 - 2001 A Space Odyssey (cult sci-fi drama)
  Not strictly a robot, but an intelligent computer
  who kills members of his crew.
• 1973 - Sleeper (Comedy) - Woody Allen comedy with
  household robots of the future.
• 1973 - Westworld (sci-fi drama) - cult story
  about an entertainment park filled with androids.
  Yul Brynner stars as an android gunslinger who
  goes berserk and starts killing the guests.

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• Robots in sci-fi seminal films II
• 1977 - Star Wars (sci-fi epic)- Harrison Ford,
  Carrie Fisher. R2D2 robot C3PO android steal
  the show.
• 1980 - Saturn 3 (sci-fi horror)- Kirk Douglas,
  Farah Fawcett, Harvey Keitel. Story about a
  couple on a space outpost who are about to be
  replaced by a robot - which predictably goes
  berserk.
• 1982 - Blade Runner (sci-fi drama) - Harrison
  Ford is hired to track down and kill several
  androids including Rutger Hauer who steals the
  show.
• 1984 - The Terminator (sci-fi drama) - Arnold
  Schwartzenegger. A time-travelling cyborg comes
  back from the future to kill the mother of its
  nemesis.
• 1986 - Short Circuit (sci-fi drama) Ludicrously
  cute military robot (Johnny 5) gets hit by
  lightning and comes alive.
• 1987 - Robocop (sci-fi drama) Poor story of a
  cyborg cop - though well worth seeing for the
  ED-209 go beserk at the beginning.
• 1997 - Titanic (drama) Subsea ROV with stereo
  vision is overshadowed by the tragic drowning of
  Leonardo de Caprio.

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• Robots in sci-fi

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• Terminology
• Some Definitions
• 1) Robot An electromechanical machine with more
  than one degrees-of-freedom
• (DOF) which is programmable to perform a variety
  of tasks.
• 2) Anthropomorphic Similar to Humans.
• 3) Manipulator - mechanical arm, with several
  DOF.
• 4) Degrees-of-Freedom - the number of
  independently controllable motions in a
• mechanical device. The number of motors in a
  serial manipulator.
• 5) Mechanism - a 1-DOF machine element.
• 6) Fixed Automation - designed to perform a
  single repetitive task.
• 7) Flexible Automation - can be programmed to
  perform a variety of tasks.
• 8) Robot system - manipulator(s), sensors,
  actuators, communication, computers,
• interface, hand controllers to accomplish a
  programmable task.
• 9) Actuator - motor that drives a joint
  generally rotary (revolute) or linear
  (prismatic)
• electric, hydraulic, pneumatic, piezoelectric.
• 10) Cartesian Coordinate frame - dextral,
  orthogonal, XYZ

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• Terminology
• 11)Kinematics - the study of motion without
  regard to forces. Cartesian Pose position
• and orientation of a coordinate frame.
• a) Forward Kinematics - given the joint
  variables, calculate the Cartesian pose.
• b) Inverse Kinematics - given the Cartesian
  pose, calculate the joint variables.
• 12) Position (Translation) - measure of location
  of a body in a reference frame.
• 13) Orientation (Rotation) - measure of attitude
  of a body (e.g. Roll, Pitch, Yaw) in a
• reference frame.
• 14) Singularity - a configuration where the
  manipulator momentarily loses one or more
• degrees-of-freedom due to its geometry.
• 15) Actuator Space - vector of actuator commands,
  connected to joint through gear train
• or other drive.
• 16) Joint Space - vector of joint variables
  basic control parameters.
• 17) Cartesian Space - Position vector and
  orientation representation of end-effector
• natural for humans.

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• Terminology
• 18) End-effector - tool or hand at the end of a
  robot.
• 19) Workspace - The volume in space that a
  robots end-effector can reach, both in
• position and orientation.
• 20) Dynamics - the study of motion with regard to
  forces (the study of the relationship
• between forces/torques and motion). Composed of
  kinematics and kinetics.
• a) Forward Dynamics (simulation) - given the
  actuator forces and torques, compute the motion.
• b) Inverse Dynamics (control) - given the
  desired motion, calculate the actuator forces and
  torques.
• 21) Control - causing the robot system to perform
  the desired task. Different levels.
• a) Teleoperation - human moves master, slave
  manipulator follows.
• b) Automation - computer controlled (using
  sensors).
• c) Telerobotics - combination of the b) and c)
• 22) Haptics - From the Greek, meaning to touch.
  Haptic interfaces give human
• operators the sense of touch and forces from the
  computer, either in virtual or real,
• remote environments. Also called force reflection.

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• industrial robot systems overview
• Today 90 of all robots used are found in
  factories and they are referred to as industrial
  robots.
• An industrial robot typically has the following
  component parts
• controller
• arm
• drive
• end-effector
• sensors

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• Components of an industrial robot system
• Controller
• Every robot is connected to a computer
  controller, which regulates the components of the
  arm and keeps them working together.
• The controller also allows the robot to be
  networked to other systems, so that it may work
  together with other machines, processes, or
  robots.
• Almost all robots are pre-programmed using
  "teaching" devices or off-line software programs
  (OLP).
• In the future, controllers with artificial
  intelligence (AI) could allow robots to think on
  their own, or even program themselves. This could
  make robots more self-reliant and independent.

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• Components of an industrial robot system
• Arm
• The arm is the part of the robot that positions
  the end-effector and sensors to do their
  pre-programmed business.
• Many are built to resemble human arms, and have
  shoulders, elbows, wrists, even fingers.
• Each joint is said to give the robot 1 degree of
  freedom. A simple robot arm with 3 degrees of
  freedom could move in 3 ways up and down, left
  and right, forward and backward.
• Most working robots today have 6 degrees of
  freedom to allow them to reach any possible point
  in space within its work envelope (or working
  volume).

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• Components of an industrial robot system
• Drive
• The links (the sections between the joints) are
  moved into their desired position by the drive.
• Typically, a drive is powered by pneumatic or
  hydraulic pressure, or, most commonly,
  electricity.
• hydraulic drives powerful, deliver large forces,
  require pumps
• pneumatic cheap, practical (most factories have
  air lines), safe, difficult to control.
• electric good precision, good accuracy, stepper
  or DC servo (most common),

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• Components of an industrial robot system
• End-effector (or tool)
• The end-effector could be thought of as the
  "hand" on the end of the robotic arm.
• There are many possible end-effectors including a
  gripper, a vacuum pump, tweezers, scalpel,
  blowtorch, welding gun, spray gun, axe, hair
  clippers, or just about anything that helps it do
  its job.
• Some robots can change end-effectors, and be
  reprogrammed for a different set of tasks.

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• Components of an industrial robot system
• Sensors
• A sensor sends information, in the form of
  electronic signals back to the controller.
• Sensors also give the robot controller
  information about its surroundings and lets it
  know the exact position of the arm, or the state
  of the world around it.
• One of the more interesting areas of sensor
  development is in the field of computer vision
  and object recognition.
• Other types of sensors include ultrasonic,
  lasers, force/touch etc.

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• Components of an industrial robot system
• Classification of joint types
• R - revolute (1 DOF)
• P - prismatic (1 DOF)
• helical (2 DOF)
• cylindrical ((2 DOF)
• universal (2 DOF)
• spherical (3 DOF)

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• Kinematic Robot Arm Classifications
• In a serial design joints disposed
  sequentially the total number of DOFs is the
  sum of the DOF of all joints
• Parallel design a closed-loop linkage (most
  well known Stewart platform)
• Robot arms are usually classified by the design
  of their mechanical system and by the shape of
  their working volume.
• Generally, there are five common robot
  configurations
• 1) Cartesian (or rectangular),
• 2) cylindrical,
• 3) spherical,
• 4) jointed arm
• 5) SCARA.
• Robots may also be categorised as being either
  articulated (bending about an elbow to perform
  the task) or non-articulated (retracting/
  extending a boom).
• A further way of describing a robot is by its
  number of DoF.

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• Cartesian coordinate robots I
• CCRs are highly configurable, rectilinear robot
  systems which, in a basic configuration, include
  an X and Y axis.
• Three-axis CCRs, incorporating an X, Y, and Z
  axis, are also common for positioning tools, such
  as dispensers, cutters, drivers, and routers.

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• Cartesian coordinate robots II
• Each of the axis lengths are selectable
• Payloads and speeds vary based on axis length and
  support structures.
• CCRs are typically very repeatable, have better
  inherent accuracy than a SCARA or jointed arm,
  and perform 3D path-dependent motions with
  relative ease.
• However,the CCRs key feature is its
  configurability the ability you have to
  configure and size the CCR to best meet your
  application needs.
• A gantry robot is a special type of Cartesian
  robot whose structure resembles a gantry. This
  structure is used to minimize deflection along
  each axis. Many large robots are of this type.

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• Cylindrical Coordinate Robots
• A cylindrical robot has two linear axes and one
  rotary axis.
• The robot derives its name from the operating
  envelope
• The Z axis is located inside the base, resulting
  in a compact end-of-arm design that allows the
  robot to "reach" into tight work envelopes
  without sacrificing speed or repeatability.

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• Spherical (or Polar) Coordinate Robots
• A spherical robot has one linear axis and two
  rotary axes
• Spherical robots are used in a variety of
  industrial tasks such as welding and material
  handling.

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• Jointed Arm Robots
• A Jointed Arm robot has three rotational axes
  connecting three rigid links and a base.
• An Jointed Arm robot is frequently called an
  anthropomorphic arm because it closely
  resembles a human arm. The first joint above the
  base is referred to as the shoulder. The shoulder
  joint is connected to the upper arm, which is
  connected at the elbow joint.
• Jointed Arm robots are suitable for a wide
  variety of industrial tasks, ranging from welding
  to assembly.

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• SCARA Robots I
• The acronym SCARA stands for Selective Compliance
  Assembly Robot Arm, a particular design developed
  in the late 1970's in the laboratory of Professor
  Hiroshi Makino of Yamanashi University, located
  in Kofu, Japan.
• SCARA robots are a blend of the articulated and
  cylindrical robots, providing the benefits of
  each.
• The basic configuration of a SCARA is a four
  degree-of-freedom robot with horizontal
  positioning accomplished much like a shoulder and
  elbow held perfectly parallel to the ground. The
  robot consists of three R and one P joints
• The robot arm unit can move up and down, and at
  an angle around the axis of the cylinder just as
  in a cylindrical robot, but the arm itself is
  jointed like a revolute coordinate robot to allow
  precise and rapid positioning.
• SCARAs are know for their fast cycle times,
  excellent repeatability, good payload capacity
  and a large workspace, shaped somewhat like a
  donut.
• SCARAs can be referred to as swivel robots

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• SCARA Robots II
• SCARA robots are a combination of the articulated
  arm and the cylindrical robot.
• They are used widely in electronic assembly.
• The rotary axes are mounted vertically rather
  than horizontally minimising the robot's
  deflection when it carries an object while moving
  at speed. The load is carried by the joint frame
  NOT the motor.

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• Summary of classifications in terms of joint
  types
• Cartesian P-P-P
• Cylindrical R-P-P
• Spherical R-R-P
• SCARA R-R-R-P
• Jointed/articulated/revolute R-R-R

See Pg 73 Figure 6.2 in Lecture notes
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Examples of robot kinematic configurations
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Advantages and limitations of different
configs Cartesian Pros Position control is
easy. Rigid structure so high payloads are
possible Cons Occupies a large volume (low
robot to workspace ratio) All 3 axes exposed
to environment Used for pick and place,
machine tool loading, electronics Cylindrical
Pros Rigid structure and realtively easy
position control. High payloads are
possible. Cons Can only operate close to base
(or floor) Used for Pick and place,
palletizing, laboratory testing
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Advantages and limitations of different
configs Polar Pros Versatile - large
working envelope. Cons More difficult to
control end effector position Large space near
the base that cannot be reached Used for
applications where a small number of vertical
actions is required loading a press, spot
welding etc. Articulated Pros Extremely
flexible - can reach anywhere within
workspace. Joints can be completely
sealed. Cons Difficult to program - controller
must be complex Payload can be low depending
on build Used for Almost anything - but good
in harsh or clean room conditions.
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Advantages and limitations of different
configs SCARA Pros Fast (3 m/s), high
repeatability (0.02mm), Compact and can
operate through 360 degrees (plan). Cons Medium
to low payload Limited vertical movement Used
for Soldering, welding, drilling, electronics
assembly. Almost any table-top application.
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• Components of an industrial robot system
• Classification of end effectors grippers

An end effector is the device that is fixed to
the end of the robot manipulator mounting
flange. N.B. Typically the manipulator also has
a wrist (often R-R-R).
see page 75, Fig 6.4 for gripper types.
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• Other types of robot
• Stewart platforms - parallel linkages
• Mobile vehicles
• Crawlers
• biologically inspired systems

A robotic camera head
Is this a robot ?
Stewart platform
A planeatry Rover vehicle
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• Uses of robots
• Today 90 of all robots used are found in
  factories and they are referred to as industrial
  robots.
• Ten years ago, 9 out of 10 robots were being
  bought by auto companies - now, only 50 of
  robots made today are bought by car
  manufacturers.
• Robots are slowly finding their way into
  warehouses, laboratories, research and
  exploration sites, energy plants, hospitals, even
  outer space.
• Robots are useful in industry for a variety of
  reasons. Installing robots is often a way
  business owners can be more competitive, because
  robots can do some things more efficiently than
  people.

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• Distribution of robots installed in the UK during
  1996

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• Distribution of robots installed in the UK during
  1996

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Week 8 Summary1) What is a robot ? 2) The
historical development of robotics3) Industrial
robot systems and components4) Industrial robot
configurations 5) Kinematic classification
6) Industrial applications, usage and world
markets

Week 9 Robot control programming ...