Download ME 4135 * Robotics and Control An Introduction

ME 4135 – Robotics and Control
An Introduction
Dr. Richard Lindeke
203 Engineering Building
726-7947; [email protected]
Outline
 Some General Thoughts
• uses and statistics
 Project Management for automated Systems & Machines
– What to consider
– Working intelligently with the systems
 The Overriding “Tenets of Automation”
• Pose Control – Fixed Vs Flexible Automation
• System Synchronization
• System Balance
 The Robot as a System – by definition!
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Manipulator
Power System
Controller Schemes
End of Arm Tooling
Sensors (environmental)
Just Consider This:
Thank goodness robots are now at the point where using
them is nearly the business equivalent of upgrading from a
typewriter to a personal computer. Price has virtually been
eliminated from the cost justification exercise. Today you get so
much value in terms of software and technology, reliability and
accuracy, that robots are affordable at any size.
Just as Joe Engelberger, the ‘‘Father of Robotics,’‘ has said so
many times – when looking at solving manufacturing
problems, ask the question: ‘‘Do you think a robot could …?’‘ It
was a good question 40 years ago, and even better today with
all the new technology.
Just Consider This:
(from The British Automation & Robot Association)
Search by [Automation/Robot] Application Area: Arc / Gas / Laser / Spot
Welding Assembling Bio-Chemistry and Hazardous Applications Cutting / Grinding /
Polishing Dispensing / Painting / Sealing / Spraying Handling Operations / Machine
Tending / Moulding Inspection / Measurement / Testing Laser / Water Jet Cutting
Loading / Unloading Packaging / Palletizing
Search by [User] Industry: Aerospace Agriculture / Hunting / Forestry / Fishing
Basic Metals / Fabricated Metal Products Beverages / Food / Tobacco Products
Ceramics Chemicals / Fuels Clocks / Medical / Optical / Precision / Watches
Communications / Radio / Television Computing / Electronics / Software Construction
Cork / Wood (excluding furniture) Education Electric / Gas / Water Supply Furniture
Minerals (non-metallic) Mining / Quarrying Motor Vehicles Paper / Printing /
Publishing / Recorded Media Pharmaceuticals Plastic / Rubber Research &
Development Textiles
North American Robotics Companies Post Best Year Since
2007
by: Robotic Industries Association (Posted 02/07/2011)
Ann Arbor, MI – North American based robotics companies
reported strong growth in 2010, posting the best year since
2007, according to new statistics released by Robotic
Industries Association (RIA), the industry’s trade group.
North American robot suppliers reported orders of 13,174
robots valued at $845.6 million from North American based
companies, increases of 39% in units and 49% in
dollars. When orders from customers outside North America
are included, the totals are 15,860 robots valued at $993.2
million, gains of 52% in units and 58% in dollars.
2010 Robot Sales (U.S.A.)
The automotive industry, including OEMs and their suppliers,
accounted for 51% of the North American orders in
2010. Orders to this sector, the largest user in North America,
were up 34% in units.
 Non-automotive orders jumped 46%, fueled by large gains in
orders from metalworking (+90%),
semiconductor/electronics/photonics (+66%), plastics & rubber
(+57%), food & consumer goods (+47%), and life
sciences/pharmaceuticals/biomedical/medical devices (+26%).
Now in 2011 …
North American Robot Orders Jump 41% in First Half of
2011
Robotic Industries Association Posted 07/29/2011 Second
quarter is strongest quarter in six years: Fueled by its best quarter
in six years, the North American robotics industry jumped 41% in
the first half of 2011.
A total of 8879 robots valued at $577.8 million were ordered by
North American companies in the first six months of the
year. When orders from outside North America are added, the
totals are 10,476 robots valued at $667.9 million.
The second quarter was particularly strong, posting gains of 50%
in units and 55% in dollars over the same period in 2010.
U.S.A.’s Robotic Usage
RIA estimates that some 200,000 industrial
robots are now used in the United States,
placing the United States second only to
Japan in overall robot use. More than one
million industrial robots are used worldwide.
Project Management for Automated Systems
Defining Automation:
– Automation is the technology concerned
with the application of complex mechanical,
electronic and computer-based (computercontrolled) systems to the operation and
control of production
Project Management for Automated Systems
Automation includes:
– Automatic Machine Tools, Forges and Molder for
workpiece processing (CNC & DNC)
– Material Handling Equipment (ASRS’s, AGV’s, Reactive
Conveyors)
– Automated Assembly Machines
– Feedback Control Systems/System Sensors
– Process Controllers (PLC’s)
– Automated Data Collection Systems (AIDC)
– Automated Data Reporting Systems (MRP)
Project Management for Automated Systems –
what to consider
The development of an Automated System is a 4
step process:
– System problem analysis for overall needs
– Determination of special needs
– Design of control hierarchy
– Building/programming of individual
components
Working Intelligently with a Production
System
Does Variety (types) or Piece Count (volume)
dominate?
• Consider Fixed Automation vs. Flexible Automation
Should we Consider Humans?
• Typically, making it easier for automation makes it easier
for humans (especially true for assembly)
Cost Justification of the system
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Productivity Gains
Labor Replacement
Improved Quality, Repeatability & Reliability
Increased Production Capabilities
Quicker Changeovers
Project Management for Automated Systems –
what to consider
STEP 1
Quantify Overall System Needs:
– Number of Parts per hour (Production Rate!)
– Product Variety
– Part Size
– Part Shape
– Part Weight, etc
Project Management for Automated Systems –
what to consider
STEP 2
Find Special Needs:
– Robot Tooling and Machine Fixturing
– Sensors for Pose Control or Decision-making
– Communication Requirements (Machine to
Machine)
Project Management for Automated Systems –
what to consider
STEP 3
Determine Control Hierarchy:
– Isolated Actions
– Master/Slave(s)
– Event Driven Response – under higher or parallel
control
Project Management for Automated Systems –
Final Actions
STEP 4:
Build and/or Program Individual Units:
– Robot Path Control
– Machine Tool Codes
– AGV Paths/Controls
– ASRS Designs/Controls
– Communication Network
– Relays/Sensors, etc.
“Tenets of Automation” – Or what must be assured
when Machines replace Humans
Pose Control: is a principle that states that each degree
of freedom of a machine, tool, product or process
must be fully known or accounted for at all times
for the (high quality) production systems to
operate.
Degree of Freedom is (in this physical sense):
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a set of positional bits (X, Y or Z)
a set of Rotational bits (Roll, Pitch or Yaw)
Full POSE Control Requires 6 dof from the machine!
“Tenets of Automation”
• System Synchronization (timing control) of
operations must be maintained:
– this requires that the sequence and timing
of each movement during the process
activity must be known and controlled.
– This includes part counting, machine and
product arrivals and departures, completed
and closed communication sequences, etc.
“Tenets of Automation”
• System Balance:
– Each step in a process must be
appropriately sized to complete its tasks
within the overall system processing
requirements.
– Thus, no process should be slower/smaller
(or faster/larger) than its predecessor or
followers without accounting for product
accumulation within the system.
Achieving Automation – Fixed vs Flexible
• In Fixed Automation Systems
– POSE CONTROL is imposed by stops, cams,
rotators, etc
– SYNCHRONIZATION is controller by in-feed supply,
part feeders, hoppers, pallet movers, etc
– BALANCE is controlled by (Overall System) design
Achieving Automation – Fixed vs Flexible
• In Flexible Automation Systems
– POSE CONTROL is achieve by sensing and
adaptation by the machines and product in the
system
– SYNCHRONIZATION is by adapting to the changing
needs of the feed stock and throughput demand
– BALANCE is by design over extended time horizon,
machines can be reprogrammed (on-line in Real
Time) for changing part mix
The Robot System Contains 5 Major Subsystems
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Manipulator
Power System
Control
End-of-Arm Tooling
Environmental Sensors
The Robot System
• The Manipulator
– consists of joints (revolute or prismatic),
actuators, and kinesthetic (positional) sensors
– Types:
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Cartesian
Cylindrical
Spherical
SCARA (selectively compliant assembly robots)
Articulating Arms
The Robot System
• The Power Systems
– Pneumatic for light loads at elevated speed
– Hydraulic for heavy loads or very high speeds
– Electric Servo for general applications
The Robot System
• The Controllers
– Bang-Bang: are mechanically programmed (movement to stops) and
usually one-axis-at-a-time
– Point-to-point servo: feedback of joints positions as moves from
point A to B are run – no control of the path between A and B only
end points are assured
– Servo w/ Path Control: the motion is controlled completely between
point pairs including positions and orientation to follow desired
space curves
– Autonomous Control: Device control that allows paths to be
determined in ‘real time’ as the devices moves and interprets various
sets of sensory inputs to create ‘intelligent’ paths as it moves
The Robot System
• The End of Arm Tooling -- their complexity of task
dictates the type of control scheme that is required
– Grippers/Hands/spot welders
– Sensor Arrays (static reading)
– Sensors (active scanning)
– Ladle/Hooks
– Routers/Grinders/Drills
– Spray Guns/Torches
The Robot System
• Environmental Sensors
– devices that give higher level information for
program control and or path planning
• Thus, Robots are Systems requiring design
choices at 5 levels!