Robotics Automation in production

Computer vs. Human
 Machine
 Performs precisely defined tasks with speed and
accuracy
 Not gifted with common sense
 Human
 Capable of understanding and reasoning
 More likely to understand the results and
determine what to do next
 Not gifted with complex computations

Humanlike Computer
 The ideal hybrid
 Continues without human intervention when
faced with unforeseen situations
 Possesses or simulate the ability to reason

Robotics History
"Where did the word 'robot' come from?
In fact, the term "robot" was first used in
1920 in a play called "R.U.R." Or
"Rossum's universal robots" by the Czech
writer Karel Capek. The plot was simple:
man makes robot then robot kills man!
Many movies that followed continued to
show robots as harmful, menacing
machines

Robotics Terminology
Robot - Mechanical device that performs
human tasks, either automatically or by
remote control. (From the Czech word
robota.)
Robotics - Study and application of robot
technology.
Telerobotics - Robot that is operated
remotely.

Definitions
What is the definition of a ‘robot’?
􀂄 “A reprogrammable, multifunctional manipulator
designed to move material, parts, tools, or specialized
devices through various programmed motions for
the performance of a variety of tasks."
Robot Institute of America,
1979
􀂄 “Force through intelligence.”
􀂄 “Where AI (Artificial Intelligence) meet the real world.”
􀂄 “An automatic device that performs functions
normally
ascribed to humans or a machine in the form of a
human.”
Webster’s Dictionary

Law Of Robotics
 Asimov proposed three “Laws of Robotics”
 Law 1: A robot may not injure a human being or through
inaction, allow a human being to come to harm
 Law 2: A robot must obey orders given to it by human beings,
except where such orders would conflict with a higher order law
 Law 3: A robot must protect its own existence as long as such
protection does not conflict with a higher order law

Types of Robots
 Industrial Robots –
–materials handling
–welding
–inspection
–improving productivity
–Laboratory applications
 Mobile Robots
–Robots that move around on legs, tracks or
wheels.
 In 1979 a nuclear accident in the USA caused a
leak of radioactive material
 Led to production of special robot –teleoperator to
handle the radioactive material

• Educational Robots – robotic kits are used
extensively in education. Examples are
Robolab and Lego and RoboCup Soccer
 Domestic Robots – 2 types – those designed
to perform household tasks and modern toys
which are programmed to do things like
talking, walking and dancing

Hardware- Robots
 Robots are programmable computers designed to
perform a variety of tasks by moving parts, tools or
specialized devices.
• Non- adaptive robots - no way of sensing the environment,
so do the job regardless of any environmental factors
• Adaptive Robots - get feedback from a sensor to alter the
operation of the device.
 Robots can also be classified according to whether they are
stationary or mobile. Mobile robots are free to move around,
but stationary robots remain in 1 place but have arms that move.

Robot Components
 1. Manipulator or Rover: Main body of robot
(Links, Joints, other structural element of the robot)
 2. End Effecter: The part that is connected to the last joint hand)
of a manipulator
 3. Actuators: Muscles of the manipulators (servomotor, stepper
motor, pneumatic and hydraulic cylinder)
 4. Sensors: To collect information about the internal state of the
robot or To communicate with the outside environment
 5. Controller: Similar to cerebellum. It controls and coordinates the
motion of the actuators.
 6. Processor: The brain of the robot. It calculates the motions and
the velocity of the robot’s joints, etc.
 7. Software: Operating system, robotic software and
the collection of routines.

Sensors
 Sensors that tell the robot position/change of
joints: odometers, speedometers, etc.
 Force sensing: Enables compliant motion--
robot just maintains contact with object
 Sonar: Send out sound waves and measure
how long it takes for it to be reflected back.
Good for obstacle avoidance.
 Vision systems

Why Do Robots Need Sensors?
 Provides “awareness” of surroundings
 What’s ahead, around, “out there”?
 Allows interaction with environment
 Robot lawn mower can “see” cut grass
 Protection & Self-Preservation
 Safety, Damage Prevention, Stairwell sensor
 Gives the robot capability to goal-seek
 Find colorful objects, seek goals
 Makes robots “interesting”

Sensors - What Can Be Sensed?
 Light
 Presence, color, intensity, content (mod), direction
 Sound
 Presence, frequency, intensity, content (mod), direction
 Heat
 Temperature, wavelength, magnitude, direction
 Chemicals
 Presence, concentration, identity, etc.
 Object Proximity
 Presence/absence, distance, bearing, color, etc.
 Physical orientation/attitude/position
 Magnitude, pitch, roll, yaw, coordinates, etc

Sensors - What Can Be Sensed?
 Magnetic & Electric Fields
 Presence, magnitude, orientation, content (mod)
 Resistance (electrical, indirectly via V/I)
 Presence, magnitude, etc.
 Capacitance (via excitation/oscillation)
 Inductance (via excitation/oscillation)

What Sensors Are Out There?
 Visual – Cameras & Arrays (Active & Passive)
 Color Sensors (Active & Passive)
 Magnetic (Active & Passive)
 Orientation (Pitch & Roll)
 GPS (location, altitude)
 Compass (orientation, bearing)
 Voltage – Electric Field Sensors
 Current – Magnetic Field Sensors
 Chemical – Smoke Detectors, Gas Sensors

What Sensors Are Out There?
 Feelers (Whiskers, Bumpers) – Mechanical
 Photoelectric (Visible) – Active & Passive
 Infrared (light) – Active & Passive
 Ultrasonic (sound) – Active & Passive
 Sonic – Active & Passive
 Resistive/Capacitive/Inductive – Active &
Passive

Sensors – Feelers
 Whiskers
 Piano wire suspended through conductive “hoop”
 Deflection causes contact with “hoop”
 Springy wire that touches studs when deflected
 Reaches beyond robot a few inches
 Simple, cheap, binary output
 Bumpers & Guards
 Impact/Collision sensor, senses pressure/contact
 Microswitches & wires or framework that moves
 Simple, cheap, binary output, easy to read

Feelers - Bumpers & Guards
From Kevin Ross’s “Getting Started Article (SRS Website)

Sensors – IR
 Active (emitting)
 Oscillator generates IR reflections off objects
 Filtered receiver looks for “reflections”
 Pulses may be encoded for better discrimination
 Typically frequencies around 40KHz
 Doesn’t work well with dark, flat colored objects
 Passive (sensor only)
 Pyro-electric (heat sensor)
 Look for IR emissions from people & animals
 Used in security systems & motion detectors

Sensors – Ultrasonic
 Active
 Emit pulses & listen for echos
 Times round trip sound travel (~1ft/mS)
 Reaches far fairly beyond robot (inches to 30-50’)
 Relatively simple, not cheap, analog output
 Directional; not everything reflects sound well
 Passive (listens only)
 Sensor listens for ultrasonic sounds
 Electronics may translate frequency or modulation
 Software may perform signal analysis (FFTs, etc.)

Effectors
 Converts software commands into physical
motion
 Typically electrical motors or
hydraulic/pneumatic cylinders

Actuators
 Locomotion
 Manipulation

Locomotion
 Legs
 Wheels
 Other exotic means

Legs
 Two legs seems the most obvious configuration
 but in fact balance is an incredibly difficult problem
 e.g. the Honda Humanoid Project
 need knees, ankles and hips in order to move around
 two legs are inherently unstable: difficult to stand still
 Six legs are much easier to balance and move
 stable when not moving
 can work with simple cams and rigid legs
 Brooks et al. (1989) evolved the walking Genghis robot

Manipulations
 Degrees of freedom
 independently controllable components of motion
 Arms
 convenient method to allow full movement in 3D
 more often used in fixed robots due to power & weight
 even more difficult to control!
 due to extra degrees of freedom
 Grippers
 may be very simple (two rigid arms) to pick up objects
 may be complex device with fingers on end of an arm
 probably need feedback to control grip force

Manipulation Actuator Types
 Electric
 DC motor is the most common type used in mobile robots
 stepper motors turn a certain amount / applied voltage
 Pneumatic
 operate by pumping compressed air through chambers
 Hydraulic
 pump pressurized oil: usually too heavy, dirty and expensive
to be used on mobile robots
 Shape memory alloys (SMA’s)
 metallic alloys that deform under heat and then return to
their previous shape: used for artificial muscles
 see http://www.sma-inc.com/SMAPaper.html

Measuring Motion: Odometers
 If wheels are being used, then distance
traveled can be calculated by measuring
number of turns
 dead-reckoning or odometry is the name given to the
direct measure of distance (for navigation)
 Motor speed and timing are very inaccurate
 measuring the number of wheel rotations is better
 shaft encoders, or rotation sensors, measure this
 Different types & technologies of shaft encoder

The robot control loop
 Sense Think
 Act

Output information Move, Speech
Text, Visuals Wheels Legs
Arms Tracks
Speech, Vision
Acceleration,
Temperature
Position ,Distance
Touch, Force
Magnetic field ,Light
Sound ,Position
Task planning
Plan Classification
Learn
Process data
Path planning
Motion planning
Sense Think
Act

Mobility Considerations
A number of issues impact selection of drive
 Maneuverability - ability to alter direction/speed
 Controllability - practical and not too complex
traction sufficient to minimize slippage
 climbing ability - traversal of minor
discontinuities, slope rate, surface type, terrain
 stability - must not fall over!
 efficiency - power consumption reasonable
 maintenance - easy to maintain, reliable
 environmental impact - does not do damage
 navigation - accuracy of dead-reckoning

Degrees of Freedom
Degrees of freedom -
Each plane in which a
robot can maneuver.
 ROTATE BASE OF ARM
 PIVOT BASE OF ARM
 BEND ELBOW
 WRIST UP AND DOWN
 WRIST LEFT AND
RIGHT
 ROTATE WRIST

Different Degrees of freedom
1 DOF 2 DOF
3 DOF

HOW ROBOTS WORK
 “The inspiration for the design of a robot manipulator is the
human arm, but with some differences. For example, a robot arm
can extend by telescoping—that is, by sliding cylindrical sections
one over another to lengthen the arm. Robot arms also can be
constructed so that they bend like an elephant trunk. Grippers, or
end effectors, are designed to mimic the function and structure of
the human hand. Many robots are equipped with special purpose
grippers to grasp particular devices such as a rack of test tubes
or an arc-welder. The joints of a robotic arm are usually driven
by electric motors. In most robots, the gripper is moved from one
position to another, changing its orientation. A computer
calculates the joint angles needed to move the gripper to the
desired position in a process known as inverse kinematics.
Some multi-jointed arms are equipped with servo, or feedback,
controllers that receive input from a computer. Each joint in the
arm has a device to measure its angle and send that value to the
controller

contd.
 If the actual angle of the arm does not equal the computed angle
for the desired position, the servo controller moves the joint until
the arm's angle matches the computed angle. Controllers and
associated computers also must process sensor information
collected from cameras that locate objects to be grasped, or they
must touch sensors on grippers that regulate the grasping force.
Any robot designed to move in an unstructured or unknown
environment will require multiple sensors and controls, such as
ultrasonic or infrared sensors, to avoid obstacles. Robots, such
as the National Aeronautics and Space Administration (NASA)
planetary rovers, require a multitude of sensors and powerful
onboard computers to process the complex information that
allows them mobility. This is particularly true for robots designed
to work in close proximity with human beings, such as robots that
assist persons with disabilities and robots that deliver meals in a
hospital. Safety must be integral to the design of human service
robots.”

First Commercial Robot
• After the 1950’s the first commercial robot
nicknamed the ‘Unimate‘, was created.
• The first Unimate was installed at a General
Motors plant to work with heated die-casting
machines .

The Purpose of Robots
- Repetitive tasks that robots can do 24/7.
- Robots never get sick or need time off.
- Robots can do tasks considered too dangerous for
humans.
- Robots can operate equipment to much higher precision
than humans.
-May be cheaper over the long term
- May be able to perform tasks that are impossible for
humans
Robots are also used for the following reasons

The Purpose of Robots
• Robots are also used for the following tasks:
• Dirty Tasks
• Repetitive tasks
• Dangerous tasks
• Impossible tasks
• Robots assisting the handicapped

Advantages VS. Disadvantages of Robots
 ♦ Robots increase productivity, safety, efficiency, quality, and
 consistency of products.
 ♦ Robots can work in hazardous environments without the need.
 ♦ Robots need no environmental comfort.
 ♦ Robots work continuously without experiencing fatigue of problem.
 ♦ Robots have repeatable precision at all times.
 ♦ Robots can be much more accurate than human.
 ♦ Robots replace human workers creating economic problems.
 ♦ Robots can process multiple stimuli or tasks simultaneously.
 ♦ Robots lack capability to respond in emergencies.
 ♦ Robots, although superior in certain senses, have limited
 capabilities in Degree of freedom, Dexterity, Sensors, Vision
 system, real time response.
 ♦ Robots are costly, due to Initial cost of equipment, Installation
 costs, Need for Peripherals, Need for training, Need for
 programming

Robotic Applications
 EXPLORATION-
– Space Missions
– Robots in the Antarctic
– Exploring Volcanoes
– Underwater Exploration
 MEDICAL SCIENCE
– Surgical assistant
 ASSEMBLY- factories Parts handling
- Assembly
- Painting
- Surveillance
- Security (bomb disposal … really telecherics
rather than robotics)
- Home help (grass cutting, nursing)

Neural networks and AI
 After initial training - neural network may be
used to control robot platform. It can learn by
itself reacting to real world objects
 In neural networks we have two subjects:
“knowledge” and “learning”. This means that
intelligent systems has some knowledge, or
so called experience and ability to learn and
improve

An example
 In general neural network is a set of
interconnected elements where each of them
has their own input signals and outputs some
resulting signal. For instance simple robot
platform:

Robotics Automation in production

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