# US 5,708,626 A · Trajectory measurement system for underwater vehicles

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,708,626 A
- Document ID: US5708626A
- Status: Granted
- Kind: A
- Application number: 08/775,233
- Filed: 1996-12-30
- Granted: 1998-01-13
- Earliest claimed: 1996-12-30
- Assignees: The United States of America as represented by the Secretary of the Navy
- Inventors: J. Dana Hrubes
- Web page: https://patentgrep.com/patent/US5708626A

## CPC

- F41G 7/36: using inertial references
- B63G 8/14: Control of attitude or depth (of torpedoes F42B19/00)
- F41G: WEAPON SIGHTS; AIMING (optical aspects thereof G02B)
- B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H)

## Abstract

A system for determining the velocity and trajectory of an underwater vehe comprises a data acquisition processor coupled to a plurality of sensors providing depth, heading, pitch and yaw data for the underwater vehicle. The acquisition processor collects data from the sensors, correlates and assembles the collected data into batches and processes the batches to determine vehicle velocity and trajectory of the vehicle relative to an earth-fixed coordinate system.

## Claims

### Claim 1

A trajectory measurement system for an underwater vehicle comprising:
a depth sensor for measuring depth of the vehicle and generating a depth sensor signal, said depth sensor signal indicating depth of the vehicle;
a heading sensor for measuring an angular heading with respect to a reference point and generating a heading sensor signal indicating said angular heading;
a tilt sensor for sensing orientation of the vehicle about two mutually perpendicular axes and generating a tilt sensor signal; and
an acquisition processor, responsive to said depth sensor signal, said heading sensor signal and said tilt sensor signal, for determining vehicle velocity and vehicle trajectory.

### Claim 2 (depends on 1)

The system of claim 1 wherein said acquisition processor comprises:
a sensor interface, coupled to receive said depth sensor signal, said heading sensor signal and said tilt sensor signal, for generating a multiplexed digital sensor signal; and
a trajectory processor, responsive to said multiplexed digital sensor signal, for generating said vehicle trajectory and said vehicle velocity.

### Claim 3 (depends on 2)

The system of claim 2 wherein said sensor interface comprises:
a plurality of sensor bridges, each sensor bridge being connected across one of said depth sensor, said heading sensor and said tilt sensor for measuring a resistance of said sensor and converting said resistance to an analog voltage;
a multiplexer, coupled to receive said analog voltage from each one of said plurality of sensor bridges, for periodically passing the analog voltage from one of said plurality of sensor bridges; and
a converter, coupled to said multiplexer, for generating said multiplexed digital sensor signal.

### Claim 4 (depends on 3)

The system of claim 3 wherein said depth sensor comprises a plurality of pressure ports spaced circumferentially around said vehicle.

### Claim 5 (depends on 3)

The system of claim 3 wherein said heading sensor comprises a gimbaled magnetic compass.

### Claim 6 (depends on 3)

The system of claim 3 wherein said tilt sensor comprises a capacitance effect bubble sensor.

### Claim 7 (depends on 2)

The system of claim 2 wherein said depth sensor comprises a plurality of pressure ports spaced circumferentially around said vehicle.

### Claim 8 (depends on 2)

The system of claim 2 wherein said heading sensor comprises a magnetic compass.

### Claim 9 (depends on 2)

The system of claim 2 wherein said tilt sensor comprises at least two capacitance effect bubble sensors.