An unmanned vehicle capable of tunneling into soft materials, such as sand, comprises a hollow, bullet-shaped forward outer body with a first drive screw thread integrated into its exterior, a hollow cylindrical rear outer body with a second drive screw thread integrated into its exterior but threaded in the opposed direction of the first drive screw thread, and an inner body that is rotatably coupled to the inside of the forward and rear outer bodies via mechanical gears, and including directional control fins mounted on a housing at the rear end of the inner body.

A robotic device for inspecting a pipe includes at least one pair of propulsion elements each including a rotary drum, an outer surface of which has a screw thread. The device also includes a body associated with at least one pair of propulsion elements and in which are inserted sensor, at least one pair of electric motors each capable of rotating a rotary drum, and at least one pair of electric power sources each capable of powering an electric motor. The body is shaped such that a ventral portion and a dorsal portion of the device are symmetrical with one another relative to a median frontal plane of the device, thus allowing the device to move indistinctly on the belly or on the back.

A water turbine propeller includes an optional turbine casing having forward and rearward openings, a rotational cylindrical unit, a plurality of rotating foil blades rigidly secured to the inner periphery of the rotational shaft on a common shaft, and an engine or motor which rotates the rotational shaft within the turbine casing. The operation of the engine causes the rotation of the rotational shaft and the helical blades direct water into the forward opening of the turbine casing and out the rearward openings of the turbine casing, thereby creating a focused torque (or vortex) effect on the water flow for a propulsive force.

A robotic device for inspecting a pipe includes at least one pair of propulsion elements each including a rotary drum, an outer surface of which has a screw thread. The device also includes a body associated with at least one pair of propulsion elements and in which are inserted sensor, at least one pair of electric motors each capable of rotating a rotary drum, and at least one pair of electric power sources each capable of powering an electric motor. The body is shaped such that a ventral portion and a dorsal portion of the device are symmetrical with one another relative to a median frontal plane of the device, thus allowing the device to move indistinctly on the belly or on the back.

Provided is a deformable variable helical cylinder fundamentally based on a helix in a space. The helix starts at a point in a space and rotates around a central axis to draw a trajectory, and has a similar shape to a common spring. The factors defining the helix are the radius, pitch, and height of the helix. A variable helix is a helix of which the radius and period are modified, and the variable helix is characterized by a form in which the radius at the lower end thereof decreases toward the top. A deformable variable helix (mVHC) is a variable helix that is deformed once further, and the biggest feature thereof is that the exit section of the variable helix is deformed to be almost parallel to the central axis of rotation.

Various aspects include a robot and method of using the robot, which includes a chassis and a forward propulsion auger. The chassis may include a forward section a rear section; and a maneuvering gimbal. The forward propulsion auger may be positioned on a leading end of the forward section and coupled to a first drive motor. The forward propulsion auger may include at least one fluid nozzle configured to eject a fluid therefrom.