  Inflated continuum robots are promising for a variety of navigation tasks,
but controlling their motion with a small number of actuators is challenging.
These inflated beam robots tend to buckle under compressive loads, producing
extremely tight local curvature at difficult-to-control buckle point locations.
In this paper, we present an inflated beam robot that uses distributed
stiffness changing sections enabled by positive pressure layer jamming to
control or prevent buckling. Passive valves are actuated by an electromagnet
carried by an electromechanical device that travels inside the main inflated
beam robot body. The valves themselves require no external connections or
wiring, allowing the distributed stiffness control to be scaled to long beam
lengths. Multiple layer jamming elements are stiffened simultaneously to
achieve global stiffening, allowing the robot to support greater cantilevered
loads and longer unsupported lengths. Local stiffening, achieved by leaving
certain layer jamming elements unstiffened, allows the robot to produce
"virtual joints" that dynamically change the robot kinematics. Implementing
these stiffening strategies is compatible with growth through tip eversion and
tendon-steering, and enables a number of new capabilities for inflated beam
robots and tip-everting robots.
