Grow-hose-I: A hose shaped actuator growing just like a plant root

Hideyuki Tsukagoshi, Nobuhiko Aarai, Ichiro Kiryu


At the disastrous site, the fiber scope and the pole equipped with a camera on its head have been previously used to search victims inside debris. However, these tools were available only for the straight route or the short path. Generally, the longer it travels, the larger friction is caused.


We propose a hose type actuator named “Grow-Hose-I” which draws out its own inner body to move with its reducing friction between the hose surface and the environment. Additionally, it can actively steer the direction while carrying the camera and the microphone (Fig.1).
To realize it, the urethane tube flattened by heat-treatment was adopted, shown in Fig.2. The flat tube has the following property: the propelling force can be generated on the buckling part of the tube when its inside is pressurized by pneumatics, since the fluid passage can be closed at the buckling part. Furthermore, if 2 flat tubes are put to be faced symmetrically, the inner tube can be drawn out while the upstream sides are kept staying at the same point, shown in Fig.3. Since no friction is generated between the upstream sides and the ground, it’s possible to propel smoothly even in the rough debris. This movement is similar to the growing process of the plant root.
To steer the direction, the metallic grippers are set on the surface of the hose at constant intervals (Fig.4). If the one side of the tube get swollen by increasing the inner pressure, because the grippers fixes the tube to the cover. As a result, the spans among the grippers are fixed and then the hose can keep curving(Fig.5, Fig.6). The movies can be seen in bellow.

Fig.1 Application of Grow-hose-I to rescue operation to search survivors at disastrous site. 

Fig.2 Flat tube.

Fig.3 How to propel by pneumatics.

Fig.4 How to steer actively. 

Fig.5 Scene of the prototypesteering through narrow path.

Fig.6 Grow-hose-I.

>>movie1 : Fast linear motion
>>movie2 : Active steering
>>movie3 : Grow-hose-I equipped with a camera