ROBOTICS COURSE NOTES©1981, 1991, 2001, 2011, 2017 Max Donath(Incorporates material from many sources)

DEPARTMENT OF MECHANICAL ENGINEERINGUNIVERSITY OF MINNESOTA

111 CHURCH ST. S.E. MINNEAPOLIS, MN 55455

Topics:1. Robotics: An Introduction2. Manipulator specifications and criteria for selection

- Resolution, repeatability, and accuracy3. Manipulation Tasks4. Mathematics of Coordinate Transformation5. Homogeneous transformations matrices

- Example: The Puma 5606. Inverse kinematics: The problem7. Robot Link transformation matrices8. Inverse kinematic solutions9. Velocity and path control: the Jacobian

10. Computation of the Jacobian11. Task primitives and programming: Computational aspects12. Determining path trajectories

- Interpolation and spline functions13. Static force analysis: Another role for the Jacobian14. Manipulator dynamics15. Inertial effects of drive and transmissions on dynamics16. Force based control

- Force vs. impedance control vs. position control17. Manipulator peripherals: the RCC18. Integrating sensors into robots19. The future

Robotics TechnologyMotivation: Replacement for limited function while maintaining “human” flexibilityv Manufacturing

Discrete ContinuousFlexible VS Hard Automation Transfer LinesBatch High Volume

ØHybrid circuit assemblyv Hazardous Environments

Ø SpaceØ UnderwaterØ RadioactiveØ ToxicØ Combat

v MedicalØ MicrosurgeryØ Rehabilitation

§ Upper extremity§ Lower Extremity

v Transportation

IN 1984:THE UNITED STATES MANUFACTURED 5500 ROBOTSVALUED AT $300 MILLION (1984 DOLLARS)

SOURCE: FIRST ROBOT CENSUS, AUGUST, 1985NATIONAL CENSUS BUREAU(AS REPORTED BY CNN, AUGUST 18, 1985)

IN 1985:ROBOTS VALUED AT $443 MILLION WERE SHIPPED.

IN 1995:10,198 UNITS VALUED AT $897.7 MILLION WERE SHIPPED.ROBOT SHIPMENTS MORE THAN DOUBLED SINCE 1991.

IN 2005: 18,228 ROBOTS WERE SOLD.

SOURCE: ROBOTICS INDUSTRY ASSOCIATION (RIA), ANN ARBOR, MI

IN 2016:

“Robot orders and shipments in North America set new records in the first nine months of 2016, according to Robotic Industries Association (RIA), the industry’s trade group.

A total of 23,985 robots valued at $1.3 billion were ordered from North American companies in the first nine months of 2016, an increase of 7% in units and 3% in dollars over the same period in 2015, which held the previous record.

Robot shipments to North American customers through September totaled 22,050 robots valued at $1.3 billion, breaking the previous record set in 2015 by 3% in units and 11% in dollars.

SOURCE: ROBOTICS INDUSTRY ASSOCIATION (RIA), ANN ARBOR, MI

“Record sales levels were driven primarily by strong growth in demand from automotive OEMs and component suppliers. Robot orders from these two sectors were up 14% through September. Outside of automotive, robots ordered into the food & consumer goods industry increased substantially by 40% year over year.

RIA estimates that some 269,000 robots are now at use in United States factories, placing the US third to only Japan and China.”

SOURCE: ROBOTICS INDUSTRY ASSOCIATION (RIA), ANN ARBOR, MI athttp://www.robotics.org/content-detail.cfm/Industrial-Robotics-News/North-American-Robotics-Market-Sets-New-Records-for-First-Nine-Months-of-2016/content_id/6298

MORE RECENT INDUSTRY STATISTICS CAN BE FOUND AT:http://www.robotics.org/Industry-Statistics

From: M. Muro and S. Andes,Robots Seem to Be Improving Productivity, Not Costing Jobs,Harvard Business Review, June 15, 2015https://hbr.org/2015/06/robots-seem-to-be-improving-productivity-not-costing-jobs

From: M. Muro and S. Andes,Robots Seem to Be Improving Productivity, Not Costing Jobs,Harvard Business Review, June 15, 2015https://hbr.org/2015/06/robots-seem-to-be-improving-productivity-not-costing-jobs

Robots: State of the Art?

Genius

Gifted

High Normal

Normal

Low Normal

Moron

Imbecile

Idiot

100. . . . . . . . . .

0. . . . . . . . . . . .

STUPID BEHAVIOR

◆ HITTING OBJECTS INADVERTENTLY AND THEN DOING IT AGAIN

◆ PICKING UP OBJECTS THAT AREN’T THERE

◆ CONTINUING WITH OPERATIONS THAT MAKE NO SENSEE.G., INSERTING SQUARE PEGS INTO ROUND HOLES

◆ REQUIRING DETAILED INSTRUCTIONS

◆ ALBERT EINSTEIN ONCE DEFINED INSANITY AS:“DOING THE SAME THING OVER AND OVER AGAIN ANDEXPECTING DIFFERENT RESULTS.”

ROBOT REQUIREMENTS:

SENSORY INPUT

INTELLIGENCE

MOTOR FUNCTION

HUMAN SENSES:

VISION

HEARING

TOUCH

BALANCE

PROPRIOCEPTIONMUSCLE LENGTHMUSCLE TENSION

TEMPERATURE

SMELL AND TASTE

PAIN

Human Intelligence

Cerebrum Complex Decisions

Cerebellum Coordination

Spinal Reflex Activity

Increasing precision and speed but decreasing complexity

HUMAN GROSS MOTOR ACTIVITY:

POSTURELOCOMOTION

HUMAN FINE MOTOR ACTIVITY:

MANIPULATION

Cylindrical

Rectangular

Spherical

See video on course web siteUNDER Manipulators/Resources LINK

Cobots or Collaborative Robots

From https://en.wikipedia.org/wiki/Cobot#cite_note-2

“A cobot or co-robot (from collaborative robot) is a robotintended to physically interact with humans in a shared workspace.

This is in contrast with other robots, designed to operate autonomously or with limited guidance, which is what mostindustrial robots were up until the decade of the 2010s.

Cobots were invented in 1996 by J. Edward Colgate and MichaelPeshkin, professors at Northwestern University.

A 1997 US patent filing describes cobots as "an apparatus and method for direct physical interaction between a person and a general-purpose manipulator controlled by a computer."

“The cobot's function was to allow computer control of motion, by redirecting or steering a payload, in a cooperative way with the human worker.”

A safety standard “ISO/TS 15066:2016, Robots and robotic devices -- Collaborative robots” was published in 2016. Seehttp://www.iso.org/iso/catalogue_detail?csnumber=62996

Yumi from ABB

Universal Robots

Baxter from Rethink Robotics

Kuka LBR iiwa

Possible kinematic configuration ofthree-jointed robot manipulators

From: Eugene I. Rivin,“Mechanical Design of Robots”McGraw-Hill, 1988.

* Characterized by some degree ofredundancy (points in workspacecan be reached by at least2 sets of joint coordinates)

The SCARA {Selective Compliant Articulated Robot for Assembly}

Parallelogram Robot Structure

Stewart Platforms

Hexapods

Many micropositioning applicationsSee http://www.pi-usa.us/products/Micropositioning_Stage_Hexapod/hexapod-6-axis-

stage.php

H-811 Miniature Hexapod 6-Axis Positioner

TYPES OF MANIPULATOR CONTROL

◆ POSITION

◆ VELOCITY

◆ PATH

◆ FORCE

CRITERIA FOR ROBOT MANIPULATOR CONTROL

◆ PROGRAMMABILITY

◆ MANEUVERABILITY

◆ REPEATABILITY

◆ ACCURACY

◆ PAYLOAD

◆ SPEED

◆ END EFFECTORS

◆ SENSORY INPUT

◆ The work volume of a manipulator is the set of points in space reachable by the working (or tool) frame of the manipulator

◆ Not all orientations may be accessible at all points in theworking volume.

Robot Manipulator Limitations

{PUMA 560}

◆ Cannot move from any arbitrary position/orientation to any other

◆ Path: Constant velocity

Ø Straight line

Ø Curved path limited to rotation

◆ On/off interrupts

◆ Payload/velocity combination

◆ On-line programming

CONTROL INFLUENCE ON RESOLUTION

€

Control Resolution =48 in. (1.22m)

4096 Control Increments= .012 in. (.305mm)

MANIPULATION TASKS

◆ LOCATION AND ORIENTATION OF:

– END EFFECTORS– OBJECT– APPLIED FORCES

◆ EACH TASK TYPICALLY INVOLVES SEVERAL SUBTASKS:

– APPROACH OBJECT WITH APPROPRIATE ORIENTATION

– POSITION GRIPPER ON OBJECT– GRIP OBJECT– DEPART WITH APPROPRIATE ORIENTATION

Tool Coordinate System

X2 behind Y2Z2 planeX3 behind Y3Z3 planeY4 behind X4Z4 plane