(1997 ~) At the time of natural disasters like earthquakes, people who are trapped in broken buildings must be rescued immediately. But, it is very difficult and dangerous to creep into the debris to find sufferers. So it is desired to develop some machine that can maneuver in this environment in order to find these victims by TV camera and microphone.

In this study we developed "Souryu I" for this purpose and this vehicle is composed shown in Fig.1. Souryu has 3 parts: 1) front body, 2) center body, and 3) rear body, and each body is equipped with a crawler on each side. The front body includes a CCD camera and a microphone to find victims, the center body includes the driving actuators and batteries, and the rear body includes the radio receiver. So this vehicle is a self-contained system and tele-operated by a remote operator. All crawlers are driven all at once by the motor of center body via torque tubes connected by a universal joint and makes a motion to move forward and back. The front and rear bodies are connected to the center body by the special 2 dimensional joint mechanisms shown in Fig.2 and posture is changed symmetrically around the yaw and the pitch axis by two motors of center body shown in Fig.3. So, this vehicle has only 3 degrees of freedom, but can change posture to fit for the terrain and it can do roll over motion shown in Photo.1. In short this vehicle has high mobility peculiar to snaky vehicle and it wold help rescue operation.

"Souryu II" is practical model. It is designed to separate three bodies easily so as to make it portable and to make it possible to add segments with special functions. Souryu II is exhibited at "National Museum of Emerging Science and Innovation".

Fig.1 Total Mechanism of Souryu-I	Fig.2 Comparison of 2D Joint Mechanisms
Fig.3 Posture Driving Mechanism	Photo.1 Roll Over Motion

Photo.2 Total View of Souryu-II