The KSI tentacle manipulator

Robotic tentacles provide an interesting alternative to conventional rigid-link robotic arms; in certain situations, they may even be more capable. Kinetic Sciences Inc. has developed a hybrid electric-pneumatic tentacular robot called the KSI tentacle manipulator. It has variable compliance, can bend independently in two or more regions, and can extend to more than five times its contracted length. In total, the Tentacle has six degrees of freedom-or seven with the addition of a distal wrist-rotate joint. The Tentacle's unusual kinematics and inherent compliance demand new approaches to control. Three schemes are considered here: joystick-based teleoperation, inverse kinematics-based tendon length control, and machine vision-based fine position control. Under control, the Tentacle has broad potential in many applications, including teleoperated vacuuming and spray washing (for nuclear hot cell decontamination), general materials handling, agricultural harvesting, robotic refueling, and endoscopy.