# Presentation: 108848

## Industrial Robots in Radiation FieldsHerschel B. Smartt, Ph.D.

***July 1, 2004***

## Industrial Robots in Radiation Fields

*What problem do we want to solve?*
*Examples industrial robots*
*Robot coordinate systems*
*How do robots work?*
*Degrees-of-freedom; axes-of-motion*
*Motors, encoders, resolvers, limit and home switches*
*Radiation*
*Radiation hardening*
*Quick disconnects*
*End effectors*
*Robotics research*

- Slide 1

## Industrial Robots in Radiation Fields

*We want to use industrial robots to weld lids on certain radioactive waste materials storage canisters.*
*We need to use robots because the radioactive exposure is too great in this specific application for personnel to be present. *

- Slide 2

- Storage canister

- Robot 1

- Robot 1

## Articulated Arm Robot

- Floor mounted

- Tool end

- Slide 3

- 6-axis motion

## Cartesian robots

- Linear slides

- Slide 4

## "Selective Compliant Assembly Robot Arm". 

- SCARA robots

- Slide 5

## Slide 6

- X

- Y

- Z

- P1

- P2

- 3 Translation axes

## Slide 7

- X

- Y

- Z

- P1

- P2

## Slide 8

- X

- Y

- Z

- P1

- P2

- θ1

- θ2

- θ3

- 3 Translation axes
- 3 Rotation axes

## Slide 9

- 6 axis

- 3 or 4 axis

- 3 to 5 axis

## 6 degrees-of-freedom

- Axis 6

- Axis 5

- Axis 4

- Axis 3

- Axis 2

- Axis 1

- Slide 10

## θ6

- θ6

- θ5

- θ4

- θ3

- θ2

- θ1

- Slide 11

- Forward kinematics:
- for a specific robot geometry,
- given θ1, θ2, θ3, θ4, θ5, θ6
- find P
- Inverse kinematics:
- for a specific robot geometry,
- given P
- find θ1, θ2, θ3, θ4, θ5, θ6

- P

- See, for example:
- P. J. McKerrow, _Introduction to Robotics_, Addison-Wesley, ISBN 0-201-18240-8, 1991.
- W. Khalil & E. Dombre, _Modeling, Identification & Control of Robots_, Taylor & Francis, ISBN 1-56032-983-1, 2002.

## Robot exposure

- 10 to 1000 rem/hr gamma radiation

- Slide 12

- Radiation environments

## Motor 5

- Motor 4

- Motor 3

- Motor 1

- Motor 2

- Slide 13

## Slide 14

- Servo motors and drives

- Radiation hardened motors are available.

## Slide 15

- Optical encoders

## Incremental

- encoder disk

- Absolute
- encoder disk

- Encoder disks

- Slide 16

- Plastic disk and sensing electronics are not radiation hardened.

## Slide 17

- Encoder signals

## Resolvers

- Slide 18

- Radiation hardened resolvers are available.

## Internal drive by precision gear boxes and timing belts

- Toothed belt

- sprockets

- Slide 19

- Radiation hardened timing belts are available.

## Tool quick disconnect & collision detection

- Slide 20

## Welding End Effector

- Tool Quick Disconnect

- Seam Tracker/Profile Measurement

- Wire Feed Positioner

- TIG Torch

- Wire Guide

- Video Camera

- Automatic Voltage
- Control Axis

- Video Camera

- Oscillation Axis

- Mounting Plate

- Slide 21

## Video Camera

- Clear view of cold wire TIG process operating at 350A
- View area of 3⁄4–1in. square at tip of tungsten
- Arc on and off viewing modes with commanded switching
- Camera position 4-7in. range from tip of tungsten
- Viewing angles 40-55deg from torch axis
- Minimum depth of focus of 1”
- NTSC (color) or RS-170 (B&W) video output
- Same camera system for leading and trailing cameras
- Standard environmental requirements

- Slide 22

## Video Camera

* **Camera Views*

-  Leading Camera View

-  Trailing Camera View

- Slide 23

## Video Camera

- Remote head camera system with out of cell CCU
- 2/3” Radiation tolerant CID imager
- 750 x 512 Imager pixels
- Resolution: 450 TVL Horizontal, 400 TVL Vertical
- RS-170, 30FPS, 2:1 Interlaced Video Output
**1x10****6**** rad total exposure (at 7x10****5**** rad/hr)**
**7x10****5**** rad/hr maximum field strengths**
- Less rad damage when device is not energized
- Camera Weight = 9.7 oz

- Slide 24

## Slide 25

## Slide 26

## Robot welding cell: 8-axis motion

- Linear slide

- Top linear slide

- robot

- Slide 27

## Linear slide

- robot

- Weld torch

- Slide 28

## electrode

- molten steel drop

- weld pool

- molten steel drop

- Drops of molten steel moving down the arc plasma.

## Spot  weld

- Slide 29

- Weld torch

## X-axis motor

- Y-axis motor

- Z-axis motor

- power supply

- wire feeder

- operator

- GUI

- arc length
- to
- voltage

- volume
- to
- wfs & time

- Weld quality

- Slide 30

- bus

## digital

- analog

- rules of behavior

- dead man

- Agent Block Diagram

- high level messages

- serial port

- com
- port

- state

- dead man

- mid-level motion control

- tasks,
- state

- Ethernet/TCP-IP

- I

- Slide 31

## X-axis motor

- Y-axis motor

- Z-axis motor

- power supply

- wire feeder

- operator

- GUI

- arc length
- to
- voltage

- volume
- to
- wfs & time

- Weld quality

- Slide 32

## Industrial Robots in Radiation Fields

*Discussed some aspects of using robots in radiation fields*
*Looked at some various types of industrial robots*
*Considered robot coordinate systems*
*Examined some aspects of the internal technology of robots*
*Considered problem of radiation hardening robots*
*Discussed some research on agent-based robot control*

- Slide 33