Stewart platforms actuate Doc Ock tentacle

Octopus tentacles are, primarily, lengthy steady muscular tissues — a bit like your tongue. That anatomy offers octopuses unbelievable dexterity, however it is extremely troublesome to duplicate in robots. Synthetic “muscle” fiber isn’t very sensible but, which is why roboticists flip to extra standard technique of actuation. Cable-driven tentacles are well-liked, however they require many highly effective cable motors. For his latest undertaking, James Bruton took a unique method and utilized Stewart platforms.

Stewart platforms are considerably frequent in industrial settings, as a result of they’ll work with hydraulic pistons that deal with a whole lot of weight. Six linear actuators organized between two plates let the second plate transfer at any angle relative to the primary plate, with the precise angle relying on the present lengths of the actuators. By chaining collectively a number of Stewart platforms, Bruton created a tentacle-like construction with full freedom in each joint.

The present prototype solely has three Stewart platforms, however these are sufficient to exhibit the idea. Bruton used servos as an alternative of linear actuators to maintain the prices down. An Arduino Mega 2560 board controls these: a complete of 18 servo motors. Your entire construction is made up of 3D-printed components.

However increasing this design right into a full Doc Ock tentacle (a lot much less 4 of them) would include challenges. As with all robotic arm, the motors nearer to the bottom expertise extra load as the burden and the size of the arm improve. These would most likely have to be changed with beefier fashions. And with six servos for each joint, even an Arduino Mega 2560 would shortly run out of pins. That might, nevertheless, be solved by utilizing a number of Arduino boards or an IO expander.