Auto balancing hydrofoil watercraft

Abstract

A motorized hydrofoil watercraft using auto-balancing technology to dynamically balance the watercraft using acceleration in response to pitch changes, and to automatically maintain the watercraft at a desired elevation. The speed of the watercraft can be controlled by shifting of the rider's weight, or by fore-aft translation of the hydrofoil relative to the hull.

1 . A watercraft device comprising:
 at least one hydrofoil;   an above-water member rigidly coupled to the at least one hydrofoil and supported above the water surface by the at least one hydrofoil while the watercraft device is traveling;   a propulsion member for propelling the watercraft device;   at least one position sensor; and   a control circuit that drives the propulsion member toward maintaining a preset angle of attack of the hydrofoil based on data from the position sensor.   
     
     
         2 . The watercraft device of  claim 1 , further comprising an elevation sensor, wherein the set angle of attack is adjusted by the control circuit based on data from the elevation sensor to maintain the above-water member at a set elevation. 
     
     
         3 . The device of  claim 2 , wherein the elevation sensor is a pressure sensor. 
     
     
         4 . The device of  claim 2 , wherein the elevation sensor is an ultrasonic sensor. 
     
     
         5 . The device of  claim 1 , further comprising a strut that connects the hydrofoil and the propulsion member to the above-water member. 
     
     
         6 . The device of  claim 1 , wherein the hydrofoil is movable in the fore-aft direction relative to the center of gravity of the above-water member. 
     
     
         7 . The device of  claim 1 , further comprising a weight which is movable in the fore-aft direction relative to the center of gravity of the above-water member. 
     
     
         8 . The device of  claim 1 , wherein the position sensor includes at least a gyrosensor. 
     
     
         9 . A watercraft device comprising:
 at least one hydrofoil;   an above-water member rigidly coupled to the at least one hydrofoil and supported above the water surface by the at least one hydrofoil while the watercraft device is traveling;   a propulsion member for propelling the watercraft device;   at least one elevation sensor; and   a control circuit that drives the propulsion member toward maintaining a preset depth of the hydrofoil based on data from the elevation sensor.   
     
     
         10 . The device of  claim 9 , wherein the elevation sensor is a pressure sensor. 
     
     
         11 . The device of  claim 9 , wherein the elevation sensor is an ultrasonic sensor. 
     
     
         12 . The device of  claim 9 , further comprising a strut that connects the hydrofoil and the propulsion member to the above-water member. 
     
     
         13 . The device of  claim 9 , wherein the position sensor includes at least a gyrosensor.