Mechanism for direct actuation of the tail of a self-trimming wingsail

Abstract

A self-trimming wingsail system, comprising a wingsail body mounted on a mast and configured to rotate freely around the mast, an adjustable tail connected to the wingsail body, and a tail control mechanism configured to adjust an angle of the adjustable tail. The tail control mechanism comprising a motor, and a slidable collar connected to the motor via a collar cable and connected to the adjustable tail via a tail cable. Movement of the slidable collar transmits a linear force via the tail cable to the adjustable tail to adjust the angle of the adjustable tail.

What is claimed is: 
     
         1 . A self-trimming wingsail system, comprising:
 a wingsail body mounted on a mast and configured to rotate freely around the mast;   an adjustable tail connected to the wingsail body; and   a tail control mechanism configured to adjust an angle of the adjustable tail, the tail control mechanism comprising:
 a motor, and 
 a slidable collar connected to the motor via a collar cable, and connected to the adjustable tail via a tail cable, 
   wherein movement of the slidable collar transmits a linear force via the tail cable to the adjustable tail to adjust the angle of the adjustable tail.   
     
     
         2 . The self-trimming wingsail system of  claim 1 , wherein the adjustable tail is mechanically attached to a frame of the wingsail body via a rigid frame structure. 
     
     
         3 . The self-trimming wingsail system of  claim 1 , wherein the slidable collar, the collar cable and the tail cable are internal to the wingsail body. 
     
     
         4 . The self-trimming wingsail system of  claim 1 , wherein the tail control mechanism further comprises a series of pulleys configured to facilitate a change in direction of the force applied to the slidable collar and the adjustable tail. 
     
     
         5 . The self-trimming wingsail system of  claim 1 , wherein the tail control mechanism further comprises a series of linkages configured to translate a linear motion of the collar into an angular adjustment of the tail. 
     
     
         6 . The self-trimming wingsail system of  claim 1 , wherein the tail control mechanism further comprises a collar bearing positioned around the mast, the collar bearing facilitating free rotation of the slidable collar around the mast. 
     
     
         7 . The self-trimming wingsail system of  claim 1 , wherein the tail cable includes a first tail cable attached to a first side of the slidable collar and a second cable attached to a second side of the slidable collar. 
     
     
         8 . The self-trimming wingsail system of  claim 1 , further comprising a controller configured to control the motor based on sensor data to adjust the angle of the adjustable tail. 
     
     
         9 . The self-trimming wingsail system of  claim 8 , wherein the sensor data includes at least one of data related to the angle of attack of the wingsail, wind direction and speed of the wingsail system. 
     
     
         10 . The self-trimming wingsail system of  claim 8 , wherein the controller is configured to monitor the sensor data and make adjustments to the tail angle based on the sensor data to maintain a desired angle of attack of the wingsail. 
     
     
         11 . A method of adjusting an angle of attack of a wingsail, comprising:
 controlling, by a controller, a motor of a tail control mechanism to move a slidable collar along a mast, the slidable collar connected to the motor via a collar cable, and connected to an adjustable tail via a tail cable;   applying, by the slidable collar via the collar cable, a linear force via the tail cable to the adjustable tail to adjust the angle of the adjustable tail; and   applying by the adjustable tail, an adjustment force to a freely rotating wingsail body mounted on the mast.   
     
     
         12 . The method of  claim 11 , further comprising:
 applying the adjustment force to the wingsail body via a rigid frame structure connecting the wingsail body to the adjustable tail.   
     
     
         13 . The method of  claim 11 , further comprising:
 controlling, by the controller, the slidable collar and the adjustable tail via a set of pulleys and linkages.   
     
     
         14 . The method of  claim 11 , further comprising:
 controlling, by the controller, the motor based on sensor data to adjust the angle of the adjustable tail.   
     
     
         15 . The method of  claim 14 , wherein the sensor data includes at least one of data related to the angle of attack of the wingsail, wind direction and speed of the wingsail. 
     
     
         16 . The method of  claim 14 , further comprising:
 making adjustments, by the controller, to the tail angle based on the sensor data to maintain the angle of attack of the wingsail.   
     
     
         17 . The method of  claim 14 , further comprising:
 controlling, by the controller, the motor based on a combination of the sensor data and predetermined sailing parameters to adjust the angle of the adjustable tail.   
     
     
         18 . The method of  claim 17 , wherein the predetermined sailing parameters include navigation parameters. 
     
     
         19 . The method of  claim 11 , further comprising:
 receiving, by a wireless transceiver, instructions for instructing the controller in adjusting the angle of attack of the wingsail.   
     
     
         20 . The method of  claim 19 , wherein the instructions provide autonomous control to the wingsail.