Tom applies external forces to demonstrate the movement repertoire of his tensegrity models, either manipulating the model directly with his hands or pushing/pulling on control rods and cables attached to the model. Simulated tensegrity structures can similarly be set into motion by applying external forces over time. This type of simulated tensegrity movement suffices for applications such as Computer Generated Imagery.
Context: Tom Flemons Archive
Tom demonstrates the movement repertoire of his models
Direct manipulation of a tensegrity leg and arm
(Sept 4, 2012 youtube video of a tensegrity leg) This bio-mechanical representation of the leg and foot employs articulating tensegrity joints. No compression components (i.e. bones) pass forces across a joint directly – All forces are mediated by a web of tension equivalent to the fascia that wraps and contains the muscles, ligaments and tendons and their attachments to the bones.
(Sept 4, 2012 youtube video of a tensegrity arm) This version of a tensegrity arm demonstrates pronation of the forearm utilizing a basic tensegrity ‘elbow’. The two fingered ‘gripper’ is controlled by two actuator lines which are engaged when the arm extends and continues to operate during pronation. The gripper is built from ‘tensegrity joints’ – all forces are pin loaded with no shear or torque and are mediated by the tension system. This model is controlled by human manipulation but could of course be actuated by computer algorithms.
Pushing a control rod to move a tensegrity torso
(Sept 4, 2012 youtube video of a tensegrity torso) This is a tensegrity representation of the torso demonstrating basic movement patterns including gait, rotation, flexion and extension and also expansion and contraction. While this iteration is elementary, all the components are present that someday will be present in an autonomous robotic biped.
It is impressive that one control rod is enough to allow Tom to demonstrate such a big range of movement patterns of the tensegrity torso.
Pulling control cables to move a tensegrity mast
(Sept 4, 2012 youtube video of a tensegrity mast) This tensegrity mast is animated by three actuator lines that control its orientation in three dimensions. The three fingered ‘gripper’ is controlled separately by a single actuator. The gripper is built from ‘tensegrity joints’. All forces are pin loaded with no shear or torque and are mediated by the tension system. This model is controlled by human manipulation but could of course be actuated by computer algorithms.
Simulated tensegrity structures pushed into motion
A simulated tensegrity structure can be pushed into motion with no need to attach control rods or cables: the physics engine can “reach” any part of the model and apply force there. The challenge is to find a pattern of external forces that makes the tensegrity structure move in a desired way; machine learning might help with this. See related discussion in Tensegrity in Computer Generated Imagery.