| Popis: |
Rapid and consistent turning of running legged robots on surfaces with moderate friction is challenging due to leg slip and uncertain dynamics. A tail is proposed as a method to effect turns at higher yaw frequencies than can be obtained by differential velocity drive of alternate sides. Here we introduce a 100 mm scale dynamic robot - OctoRoACH - with differential-drive steering and a low-mass tail to investigate issues of yaw rate control. The robot without tail is underactuated with only 2 drive motors and mass of 35 grams including battery and control electronics. For some surface conditions, OctoRoACH can maintain heading or turning rate using only leg velocity control, and a basic rate-gyro-based heading control system can respond to disturbances, with a closed-loop bandwidth of approximately 1 Hz. Using a modified off-the-shelf servo for the tail drive, the robot responds to turning commands at 4 Hz and up to 400°/sec. |
