A Universal Planar Manipulator

Dan S. Reznik & Prof. John Canny

UC-Berkeley

July, 2000

1 horizontal, rigid plate enough?

(x,y,)

1 2 3 4 5 6

-1

-0.5

0.5

Velocity Asymmetry

1 2 3 4 5 6

-1.5

-1

-0.5

0.5

Bang-bang

62%56%mg

mg

cos t + 0.5 cos 2t

Coulomb Pump

5 10 15 20 25 30

-1.5

-1

-0.5

0.5

Straight-Line Feeding

Anything Goes

Interesting Apps

• Novel tangible UI’s– Force feedback with viscous feel– Active desk

• Fancy product displays– Rotate wine bottles

• Fluid-based micro manipulation

From 1d feedingto

2d parallel manipulation

Force: not closed!

Parallel Manipulation

N parts => 2N constraints

Our Idea

• Horizontal Plate: 3 dof• Task: move N-parts• Proposal: Generate local fields

– Move parts almost one-by-one

“Local” Field

C-C

f1+f2

1f

Radial Jamming

Radial jamming Field

The System

50 lbfvoice coils

Teklam1” H/C

NewportOptical Table

B/W camera

PC Interface

videocapture

A/D

signalgeneration

Image Processing

• Plate edges

• Coin positions– Initial– tracking

Bowtie

(vhs)

Sorter

Summary

• Motivation: simplest possible manipulator

• Use non-linearity of friction and asymmetric motion (few harmonics)

• Very general parallel manipulator

• Other suggested apps?