Methods and systems for determining heave and heave rate of...

Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Marine vehicle

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C114S230100, C114S230270, C340S984000, C073S17800T, C414S138100, C414S138300, C166S355000, C441S003000, C441S021000

Reexamination Certificate

active

06836707

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates generally to navigation of vessels, and more specifically, to determination of and compensation for heave and heave rates for vessels.
Heave is the vertical distance of motion relative to sea-level. and a vertical motion of a vessel riding waves at sea, relative to sea level, is generally referred to as heave rate. For a vessel riding the waves, the vertical motion is simply an oscillation about sea-level, having a zero long-term average of earth-relative displacement and velocity. Heave and heave rate values are utilized in controlling various operations, such as, to control a tether to a submerged diver, submarine, and for other underwater operations, as well as to define a motion of a sonar transmitter, and to define deck motion at a point for landing operations of a helicopter.
Some known inertial systems are used to measure heave and heave rate. However, a vertical channel of a pure inertial system typically has divergent errors. A global positioning satellite (GPS) system can be used to compensate for such divergence, but the GPS system itself may introduce errors into the heave and heave rate determinations.
BRIEF SUMMARY OF THE INVENTION
In one aspect, a method for determining heave and heave rate for a vessel is provided. In an exemplary embodiment, the vessel is equipped with an inertial navigation system (INS), and sensors for the INS are located at a selected point of the vessel, e.g. point A. The vessel further has a zero heave reference point B. The method is utilized to determine heave and heave rate at a point C of the vessel, where point C is a different point than points A and B. More particularly, the method comprises determining reference coordinates for points A, B, and C of the vessel, generating a signal representative of velocity at a point on the vessel, generating a heave rate signal based upon the velocity signal, and generating a heave signal based upon the heave rate signal.
In another aspect, an inertial navigation system (INS) for determining a heave and a heave rate for a vessel is provided. The INS system comprises, in an exemplary embodiment, a main unit, a user interface, a global positioning satellite (GPS) receiver, and a sensor unit. The sensor unit comprises an inertial sensor assembly located at a point A of the vessel. The main unit comprises interfaces for communication of inertial navigation information to other control systems on the vessel. The INS is configured to determine reference coordinates for points A, B, and C of the vessel, a heave, and a heave rate for the vessel.
In a further aspect, a filter is provided which comprises a first stage and a second stage. The first stage is configured to generate an output signal representative of a heave rate based, at least in part on a velocity signal input. The second stage is configured to generate an output signal representative of heave by filtering the heave rate signal output by the first stage.


REFERENCES:
patent: 3896755 (1975-07-01), Marbury
patent: 4000646 (1977-01-01), Mott et al.
patent: 4021019 (1977-05-01), Sanders
patent: 4039177 (1977-08-01), Person et al.
patent: 4091356 (1978-05-01), Hutchins
patent: 4104608 (1978-08-01), Melling et al.
patent: 4210897 (1980-07-01), Hutchins
patent: 4236695 (1980-12-01), Morrison
patent: 4349179 (1982-09-01), Barber
patent: 4448396 (1984-05-01), Delago
patent: 4547857 (1985-10-01), Alexander
patent: 4576517 (1986-03-01), McCann et al.
patent: 4582014 (1986-04-01), Patel
patent: 4697253 (1987-09-01), Lind et al.
patent: 4932248 (1990-06-01), Delignieres
patent: 4986121 (1991-01-01), Luscombe
patent: 5098226 (1992-03-01), Venugopal
patent: 5135327 (1992-08-01), White et al.
patent: 5190107 (1993-03-01), Langner et al.
patent: 5317542 (1994-05-01), Konopelski
patent: 5452674 (1995-09-01), Melville et al.
patent: 5535690 (1996-07-01), Bystedt et al.
patent: 5577874 (1996-11-01), Olsen
patent: 5894895 (1999-04-01), Welsh
patent: 6064924 (2000-05-01), Fleischmann
patent: 6216789 (2001-04-01), Lorsignol et al.
patent: 6382022 (2002-05-01), Martinez et al.
patent: 6390012 (2002-05-01), Watt et al.
patent: 6505574 (2003-01-01), Naud et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Methods and systems for determining heave and heave rate of... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Methods and systems for determining heave and heave rate of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods and systems for determining heave and heave rate of... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3331286

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.