The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 1977
Filed:
Jul. 21, 1975
David A Cooke, Saratoga, CA (US);
David M Edison, Murrysville, PA (US);
Subsea Equipment Associates Limited, Hamilton, BM;
Abstract
A position control system, for use in positioning relative to a subsea well a subsea vehicle or a re-entry tool having thrusters, including a Doppler sonar system connected to the vehicle and operable for generating a Doppler pulse train signal having a pulse rate substantially proportional to the Doppler frequency produced by a change in the spatial position of the vehicle along a predetermined linear coordinate, whereby the occurrence of each pulse signal in the Doppler pulse train signal corresponds substantially to a predetermined linear distance, velocity measurement means coupled to the Doppler pulse train signal and operable for converting it into an equivalent velocity amplitude, a pulse generator operable for producing a predetermined number of pulse signals equivalent to a certain linear distance along the coordinate, up/down counter means operable for counting up from one signal and down from another signal, connection means operable for connecting the up/down counter means to the Doppler pulse train signal and the pulse generator for opposite counting therein, and drive means connected to the up/down counter means and operable for supplying the count therein as an error signal for controlling one of the thrusters.