TRACK is a specialized controller for the All-Terrain Hex-Limbed Extra-Terrestrial Explorer Robot (ATHLETE), which has six limbs with six kinematic degrees of freedom each. TRACK is a 1/8-scale sensed but un-actuated model of one ATHLETE limb (see figure), designed to be used as a human-interface device to aid operations. TRACK is useful in cases where the whole-limb posture must be unambiguously commanded — for example, to maximize rigidity, available range of motion, or to avoid nearby obstacles. Because TRACK mimics the link lengths and geometry of ATHLETE as well as the joint angle limits, its kinematic workspace is representative of the actual ATHLETE limb workspace.
TRACK includes rotary sensors (potentiometers) for each ATHLETE kinematic degree-of-freedom (DoF) and an extra rotary sensor for the wheel rotation; spring-loaded friction bearings to hold joint pose against gravity; tri-color RGB LEDs (light emitting diodes) at each joint and the wheel; two momentary-contact tactile pushbuttons at each joint and the wheel; USB (universal serial bus) communications and power; onboard firmware with calibration storage and ASCII (American Standard Code for Information Interchange) monitor; and host-side Java interface library.
This work was done by Jeffrey S. Norris of Caltech and Marsette A. Vona of the Massachusetts Institute of Technology for NASA’s Jet Propulsion Laboratory. For more information, contact