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Active Flexible Cables

Last-modified: Sun, 25 Mar 2007 10:22:21 GMT (2581d)


Stuck or tangled cables are large issue for scope cameras and wired robots when they are inserted into a narrow space. Proposed new actuation mechanism realizes active or semi-active mobility for flexible long cables. By adding actuation mechanism to flexible cables, it is expected that progress of the robot’s ability to approach into narrow spaces and realization of actively release of stuck cables.

  • Constitution method of actuation mechanism of active cables having devices which can generate distributional driving force
  • Development of ciliary vibration mechanism
  • Modeling of active flexible cables
  • Establishment of control method for flexible cables with distributional forces

Actuation of active flexible cables

Ciliary vibration mechanism


Ciliary vibration mechanisms were focused and examined for the following two advantages: 1) those having distributional driving force; 2) those that are attachable easily to existing cables. The ciliary vibration mechanism has plastic or metal thin wires called cilia and achieve driving power through cilia vibration. As the cilia are angled and planted, by adding vibration to the cables, bending and rapid recovery occurs at the front edge of the cilia, which touch the running surface. Using energy stored by bending the cilia, the body can move very short lengths as the cilia recover their original shape. Repeating this bending and recovery motion very rapidly, a body can move forward through a falling-down and standing-up motion. Changing the angle of planted cilia can control the object's velocity and climbing ability. The active cable with this mechanism is covered with cilia all around. Therefore, it has distributive mobility throughout its body and it can generate driving forces in all directions around its body.

Prototypes with ciliary vibration mechanism

Prototypes with ciliary vibration mechanism were produced to examine the capability of this mechanism.

A first prototype
using brass cilia
73 mm diameter
130 mm/s of driving speed

A second prototype
using nylon cilia
38 mm diameter
40 mm/s of driving speed
can be bent by about 30degrees in four directions

Movies of these prototypes (Flash)

Numerical analysis using model

To elucidate the actuation mechanism and optimize the designing, the actuation mechanism is analyzed using modeling.


Active scope camera developed


A prototype of an active scope camera was produced. The ciliary vibration mechanism was attached to a general industrial scope camera. The dimensions of the active scope camera are 30 mm diameter and 5 m in length. The driving speed is 11 mm/s and the maximum gradability was 11.5 degrees.

Movie of the active scope camera (Flash)

Publications about active flexible cables