(fall 2002)

 

MIKE is a 2D pneumatically activated biped with knees, weighing only 6 kg. The actuation is realized with McKibben muscles. This prototype walks fully autonomously on a flat floor. The McKibben muscles provide just enough energy to maintain the natural pendulum motion of the legs. The structure of MIKE is very close to McGeer's (passive) prototype, a copy of which can be found at Andy Ruina's lab at Cornell University. MIKE is designed and built by Jan van Frankenhuyzen, while Martijn Wisse has worked on the principal thoughts behind the design and testing them with computer simulations.

Actuation

MIKE is fully autonomous by the use of small, lightweight and energy efficient components. The pneumatic McKibben muscles are powered by a small 58 bar CO2 container, which is enough for a couple of minutes of continuous walking. (If MIKE were able to start, stop, and turn autonomously, it would pay off to use a larger CO2 container, but that's for the next prototype.) The 58 bar is reduced in two steps to 4 bar through our specially developed miniature pneumatics as shown in the page about Baps. For the experimental phase MIKE is equipped with a versatile though very low power (< 1 Watt) linux machine (the LART which was developed at TUDelft), although we aim at a controller so simple that no computer is necessary. The LART board communicates with the muscles and sensors through two PIC -based Universal Processor Boards from Multi Motions. The muscles are switched between 2 and 4 bar (off-line adjustable) with low-power valves from SMC ("USA branch here"):http://www.smcusa.com/.

    

Pneumatics and electronics in Mike.

   

Foot and knee of Mike.

Movies

These first movies are taken from the development and tuning period of Mike:

These last movies show Mike in full autonomous operation:

Obviously (from watching the movies), MIKE could use some direction control, it keeps running into walls or on the lawn. Martijn is a little anxious that MIKE would fall.