초록 ▼

An anchorless boat positioning system for establishing and maintaining a boat at a selected geographic location without the use of a conventional anchor. In one embodiment, a steerable thruster is used whose thrust and steering direction are determined and controlled on the basis of position informa

An anchorless boat positioning system for establishing and maintaining a boat at a selected geographic location without the use of a conventional anchor. In one embodiment, a steerable thruster is used whose thrust and steering direction are determined and controlled on the basis of position information signals received from global positioning system (GPS) satellites, relative steering angle between the boat and the thruster and boat heading indication signals from a magnetic compass. The system continuously monitors the position and heading of the boat and compares it with the stored coordinates of the selected anchoring location(s) to generate control signals for the steerable motor. Several modes of operation are disclosed and Euler transformations for offset antenna placement for error reduction are taught. Proportional, integral, and derivative control (PID) of four constants of vessel control is also provided. Multiple thrusters in various arrangements are also provided to control either the orientation of the boat or a second point of interest on the boat at a second geographic location.

대표청구항 ▼

1. A system for substantially controlling the geographic position of the bow, or other part of a boat in water at a location selected by an operator of the boat thus virtually anchoring the boat, the system comprising: a thruster means located in proximity to the bow, or point of interest, of the

1. A system for substantially controlling the geographic position of the bow, or other part of a boat in water at a location selected by an operator of the boat thus virtually anchoring the boat, the system comprising: a thruster means located in proximity to the bow, or point of interest, of the boat, said thruster capable of producing a steerable thrust force to move the boat to the selected location, or virtual anchoring point, within the water, said thruster means providing a thruster heading signal equal to the relative angle between the heading of the boat and that of said thruster; a DGPS or WAAS enabled receiver and antenna located onboard the boat for receiving signals from differential correction sources and GPS satellites, said receiver providing information as to the geographical position of said antenna, said antenna being located at a second point of interest on the boat; an electronic means compass for providing current heading indication signals representative of the heading of the boat; a controller receiving the information signals from said GPS receiver, said compass and the thruster heading signal, said thruster providing output signals to said thruster to control the direction and magnitude of the thrust, these output signals being computed as based on the calculated range and bearing to the desired anchoring site and upon the rate of change of range to the anchoring site; a wireless manually activated remote control interface with which the operator of said boat can issue commands to said controller to control its mode of operation; whereby the system can be commanded to operate in a trolling mode, said controller calculating a straight course in a desired direction and continually calculating a new anchoring site along that course or track such that the bow of the boat is forced to continuously follow that track with little or no cross-track error and wherein said remote control can be used to issue commands to increase or decrease the apparent trolling speed of the boat by having the controller displace the continuous moving anchor site an appropriate distance each computation cycle, said remote control interface providing the operator a means of altering the trolling speed and direction. 2. A system as set forth in claim 1, wherein: the controller adjusts the magnitude of the thrust control signal based upon a long term average of range taken over an extended period of time and the thrust output signal is expressed substantially as: thrust=[K1*range]-[K2*range rate]+[K3*average range]