Biologically Inspired Adaptation

I am only planning on doing one or two of these, but this is a good place to think about things

Time of Response

• Tap into a high EMG frequency muscle
• Measure the time of response to perturbation
• Same as old kugle setup, with similar directions and data acquisition

• Tells you
  • Lower limit of the time of response (so what?)

• Tasks
  • Locate high frequency muscle
  • Use current setup and code
    • apply perturbation at time interval from initiation of EMG
    • measure time of response (change from normal)

Reaction to cyclic perturbations

• Instead of applying perturbations in the vertical direction, apply them fore-aft (or maybe lateral)
• While excursions are about the same in the 3 directions, fore-aft power expenditure (and thus the changes in energy) are much greater in this direction
• This is also the main thing that changes when going from flat ground to vertical climbing
• Tells you
  • If perturbations in this direction are attended to
  • This may be a possible measure of how good the locomotion is
• Accelerometer on robot body (and in the foot)

• Tasks
  • Work out what adding a different frequency sinusoid looks like
  • Try again in the vertical direction
    • verify previous results?
  • Fore-aft direction
    • Verify
      • Excursions
      • Energy/power expenditure
      • Mathematics
  • Build new actuator/sensor
    • Laptop HDD
    • Laser sensor for position
    • Force sensor
      • Semiconductor straingage - design beam and flexures
      • Mouse pointer - sensitivity?
    • Electronics and interface to operate
    • Calibrate with known masses and compliances
  • New mounting design
    • prismatic slider
    • flexures
    • direct (like current)
  • Put accelerometer on back of
    • Animal
      • Verify flat running force patterns
      • New data on vertical or near vertical running
      • Need thin wire (order from company)
      • Need more animals!
    • Robot
      • See if there is a correlation between actually moving and force patterns
      • Ask Jonathan about fore-aft ground reaction forces
  • Voice coil on the back of a free-running animal
    • Use with EMGs for descending frequency
    • What is the lower limit of frequencies for a voice coil (need 10-25 Hz)
    • How much mass is there that it moves around?
  • Climbing
    • Simulate by using air jets
    • Relocate bug to being at an angle from the kugle

Ground reaction forces and sprawl angles up and across slopes

• The gecko seems to change strategy from flat ground to climbing, does the cockroach as well?
• Have the animal run up (and across slopes) with force sensors underneath and high speed video
• Do the same thing with an accelerometer glued to the back of the animal (whole body only)
• Tells us
  • Are insects’ strategies different than Geckos? (do they change from pushing outwards to pushing inwards?)
  • Ground reaction forces for different slopes and angles
  • Change in sprawled posture
  • Change in foot orientations
  • Overall variations in accelerations of the body

• Tasks
  • Have others done this work? Kellar? Others? Read Dan's paper... Look up vertical running
  • Ground reaction forces
    • Figure out the accelerations and the forces we expect to see
    • Research types of force sensors
      • Mouse pointer (piezo? Electronics, sensitivity)
      • Bought sensor
      • Homemade (with strain gages) – structure? flexures?
      • Full lab type - Heglund 1981
    • Whole body versus individual leg GRFs
    • Accelerometer on back? Gives whole body forces?
  • Sprawl angles
    • high speed video with a marker at foot and on body
  • Basic track design
    • Basic U channel
    • Flat plate (with bright light behind, or vaseline around)
    • Squashed cylinder (ala CGW)
    • What slopes and materials can the two types of cockroaches run up?

Convex and concave surfaces

• Have the animal run over convex/concave surfaces with embedded force sensors - does the strategy that insects adopt change with the surface they are running over?
• High speed video to look for changes in posture
• What path does it choose when given a corrugated roof surface?
• Tells us
  • If strategy is dependant on surface curvature

• Tasks
  • Run animal up corrugated surface - does it pick convex or concave?
  • Same as above