Subminiature unmanned submarine comprising rotary artificial muscle motor and operating method thereof

Abstract

Provided are a propulsion device and a propulsion method of a subminiature unmanned submarine using an artificial muscle and a paddle. The propulsion device of the subminiature unmanned submarine may be actively utilized to implement a subminiature unmanned submarine by driving a paddle coupled to a rotary-type artificial muscle that generates a rotational force through repeated twisting and untwisting depending on whether a voltage is applied, and may reduce noise generation, thereby minimizing the likelihood of detection.

1 . A propulsion device of a subminiature unmanned submarine, comprising:
 an outer frame formed to extend from a submarine pressure hull and disposed to surround a seawater inflow space;   fixing members coupled to an inner wall of the outer frame and provided to face each other;   an artificial muscle motor part disposed in the seawater inflow space, having one end portion fixed by one of the fixing members, and configured to generate a rotational force by repeated twisting and untwisting;   an artificial muscle return part disposed apart from the artificial muscle motor part and having one end portion fixed by the other of the fixing members;   an insulating member having opposite end portions respectively attached to the other end portion of the artificial muscle motor part and the other end portion of the artificial muscle return part, and configured to connect the artificial muscle motor part and the artificial muscle return part to each other;   a paddle coupled to the insulating member and configured to perform a paddling function of pushing water by receiving rotational forces from the artificial muscle motor part and the artificial muscle return part;   a counter electrode disposed apart from the artificial muscle motor part and provided to be partially exposed in the seawater inflow space; and   a battery part electrically connected to the artificial muscle motor part and the counter electrode.   
     
     
         2 . The propulsion device of  claim 1 , wherein each of the artificial muscle motor part and the artificial muscle return part includes a mono-filament yarn having a single filament or a multi-filament yarn having a plurality of filaments. 
     
     
         3 . The propulsion device of  claim 1 , wherein the artificial muscle motor part includes a conductive material yarn. 
     
     
         4 . The propulsion device of  claim 3 , wherein the conductive material yarn includes a carbon nanotube yarn. 
     
     
         5 . The propulsion device of  claim 2 , wherein each of the artificial muscle motor part and the artificial muscle return part has one of a Z-twist twisted in a clockwise direction and an S-twist twisted in a counterclockwise direction. 
     
     
         6 . The propulsion device of  claim 5 , wherein the artificial muscle motor part and the artificial muscle return part have the same twist. 
     
     
         7 . The propulsion device of  claim 1 , further comprising a first paddle guide and a second paddle guide, each having opposite end portions coupled to the inner wall of the outer frame and disposed apart from each other within a region in which the paddle is positionable. 
     
     
         8 . A propulsion method of a subminiature unmanned submarine, comprising:
 providing an outer frame formed to extend from a submarine pressure hull and disposed to surround a seawater inflow space, fixing members coupled to an inner wall of the outer frame and provided to face each other, an artificial muscle motor part disposed in the seawater inflow space, having one end portion fixed by one of the fixing members, and configured to generate a rotational force by repeated twisting and untwisting, an artificial muscle return part disposed apart from the artificial muscle motor part and having one end portion fixed by the other of the fixing members, an insulating member having opposite end portions respectively attached to the other end portion of the artificial muscle motor part and the other end portion of the artificial muscle return part and configured to connect the artificial muscle motor part and the artificial muscle return part to each other, a paddle coupled to the insulating member and configured to perform a paddling function of pushing water by receiving rotational forces from the artificial muscle motor part and the artificial muscle return part, a counter electrode disposed apart from the artificial muscle motor part and provided to be partially exposed in the seawater inflow space, and a battery part electrically connected to the artificial muscle motor part and the counter electrode;   applying a driving voltage derived from the battery part to the artificial muscle motor part and the counter electrode;   rotating the artificial muscle motor part and the artificial muscle return part, to which the voltage is applied, in one direction;   allowing the paddle to perform a paddling function of pushing water in the one direction by transmitting the rotational forces of the artificial muscle motor part and the artificial muscle return part, which rotate in the one direction, to the paddle;   rotating the artificial muscle motor part and the artificial muscle return part in the other direction when the voltage applied to the artificial muscle motor part and the counter electrode is removed or a reference voltage lower than the driving voltage is applied; and   allowing the paddle to perform a paddling function of pushing water in the other direction by transmitting the rotational forces of the artificial muscle motor part and the artificial muscle return part, which rotate in the other direction, to the paddle.   
     
     
         9 . The propulsion method of  claim 8 , wherein each of the artificial muscle motor part and the artificial muscle return part of the propulsion device of the subminiature unmanned submarine has one of a Z-twist twisted in a clockwise direction and an S-twist twisted in a counterclockwise direction,
 the artificial muscle motor part and the artificial muscle return part have the same twist,   when the driving voltage is applied to the artificial muscle motor part and the counter electrode, an ion, either a cation or an anion, in seawater is adsorbed onto the counter electrode, and an ion having a charge opposite to that of the ion adsorbed onto the counter electrode penetrates into the artificial muscle motor part, thereby causing the artificial muscle motor part to expand in volume, rotate in a direction opposite to a twisting direction, and transition into an untwisted state, and   when the artificial muscle motor part rotates in the untwisted state, the artificial muscle return part also rotates in the direction opposite to the twisting direction and is further twisted.   
     
     
         10 . The propulsion method of  claim 9 , wherein no voltage is applied to the artificial muscle return part, so that the ion in the seawater does not penetrate into the artificial muscle return part. 
     
     
         11 . The propulsion method of  claim 9 , wherein when the voltage applied to the artificial muscle motor part and the counter electrode is removed or the reference voltage lower than the driving voltage is applied, the expanded artificial muscle motor part contracts, and the artificial muscle motor part, which had been untwisted, rotates in the original twisting direction, and
 when the artificial muscle motor part rotates in the twisted state, the artificial muscle return part also rotates in the twisting direction.   
     
     
         12 . The propulsion method of  claim 8 , wherein, when a fully-ON voltage and an OFF voltage are alternately applied to the artificial muscle motor part and the counter electrode, the submarine operates in a forward mode. 
     
     
         13 . The propulsion method of  claim 8 , wherein, when a half-ON voltage and an OFF voltage are alternately applied to the artificial muscle motor part and the counter electrode, the submarine operates in a left-turn mode. 
     
     
         14 . The propulsion method of  claim 8 , wherein, when a half-ON voltage and a fully-ON voltage are alternately applied to the artificial muscle motor part and the counter electrode, the submarine operates in a right-turn mode.