Whisking With Robotics

Joe Fazzino

Whisking

Whisking - the controlled sweeping movements of vibrissae more commonly known as whiskers

Animals such as Rats, Seals and Shrews all use their whiskers for different and highly complicated tasks

Tactile Perception

Tactile perception has never been seen as an importance for robotic sensors

Seen more often as a 'last resort' when all other sensors have failed

This is bad

The Importance of Touch

• Distinguishing Shapes
• Determining texture i.e. how hard of soft a surface is
• Determining if something is in a state of motion
• Determining if something is living or nonliving
• Feeling and processing Braille

Touch Receptors

• A rat's whiskers have been proven to be as good at determining the texture of a surface as a human fingertip.
• A seal's whiskers are used to track the hydrodynamic trails left by fish
• A Pygmy shrew's whiskers are used as a multi purpose tool in the hunting and catching of prey

Rat's Whiskers

• Whisking has been measured to occur between 5 and 25 times/s
• The opposing sets of whiskers move largely in a synchronous and symmetrical manner
• They can be forced to move asymmetrically however if the rat decides to move it's head or turn it's body

Robot Whiskers

(a) Real rat whiskers glued to electret microphones

(b) Steel wires that spin round a pipe to try and sculpt the shape they touch

(c) Metal at tips is flexible enough to bend when touching an object helping to determine texture

(d) Each whisker was controlled by an actuator and the robot to rotate to face the object that it was trying to model

(e) Flexible sets of steel whiskers that could be rotated independently to try and model shape and texture

(f) Rigid whiskers could be rotated independently to determine the shape of an object

Room for Improvement

• More degrees of freedom
• Shape/Size
• Greater understanding of rat's neural processing required

Questions?