System for determining the distance traveled by an underwater vehicle from
5 an underwater device
The present invention relates to a system for determining the distance traveled
by an underwater vehicle launched from an underwater device.
Such a determining system is for example applicable to determine the distance
10 traveled by a weapon such as a torpedo, launched from a submarine strictly speaking.
It is known that in general, a torpedo of this nature is launched from a torpedo
tube of the submarine and can be connected at least in a first stage of its movement,
to the rest of the circuits of the submarine via information transmission means.
These information transmission means for example make it possible to
15 exchange information between the submarine and the torpedo in order to ensure
guiding of this torpedo.
These information transmission means can for example include at least one
optical fiber.
Of course, other types of transmission means can be considered.
20 At least part of this optical fiber is then housed in a protective sheath.
This makes it possible to avoid any damage of this fiber against parts of the
submarine.
This fiber and this sheath are indeed coiled in the form of a hollow spool of turns
for example in a casing behind the torpedo, this spool of turns, that is to say the fiber
25 and the sheath, unwinding from its center during the movement of the underwater
vehicle, behind the latter.
Several means are currently known for determining the distance traveled by the
vehicle after it is launched.
Thus for example, it is possible to count the number of drive shaft or propeller
30 turns of the vehicle.
It is also possible to measure the movement of the vehicle, or even its
movement speed relative to the bottom.
Means for optical counting of marks carried by the transmission means are also
known, to make it possible to determine the distance traveled.
35 However, all of these means are relatively complex to implement and require
the use of costly means.
2
The aim of the invention is therefore to address these problems.
To that end, the invention relates to a system for determining the distance
traveled by an underwater vehicle launched from an underwater device and
connected thereto by information transmission means, coiled in the form of a hollow
5 spool of turns unwinding from its center during the movement of the underwater
vehicle, characterized in that it includes means for determining the number of decoiled
turns in order to determine the distance traveled by the underwater vehicle.
According to other features of the device according to the invention, considered
alone or in combination:
10 - the determining means comprise light reflection photosensor means activated
by the transmission means during the decoiling of each turn;
- the determining means comprise light barrier means cut by the transmission
means during the decoiling of each turn;
- the underwater vehicle is a torpedo, the information transmission means
15 comprise at least one optical fiber and the underwater device is a submarine
strictly speaking.
The invention will be better understood upon reading the following description,
provided solely as an example, and done in reference to the appended drawings, in
which figures 1 and 2 show schematic sectional views of a rear part of an underwater
20 vehicle such as a torpedo, illustrating two example embodiments of a determination
system according to the invention.
These figures in fact shows two example embodiments of a system for
determining the distance traveled by an underwater vehicle launched from an
underwater device.
25 In these figures, the underwater device, which may for example be made up of
a submarine strictly speaking, is not shown.
The underwater vehicle is in shown schematically and designated by general
reference 1 in these figures, and may for example be made up of a torpedo launched
from the submarine.
30 As previously indicated, the torpedo and the submarine are connected by
information transmission means designated by general reference 2 in these figures.
These information transmission means for example comprise at least one
optical fiber.
At least one portion of this optical fiber is for example housed in a protective
35 sheath in a conventional manner.
3
As also illustrated in these figures, these information transmission means and
the protective sheath thereof are coiled in the form of a hollow spool of turns
designated by general reference 3 in these figures.
This hollow spool of turns then unwinds from its center during the movement of
5 the underwater vehicle, as illustrated.
In the system according to the invention, means are provided for determining
the number of decoiled turns in order to determine the distance traveled by the
underwater vehicle.
Different possible embodiments of these determining means can be considered.
10 Thus for example in figure 1, the use has been illustrated of light barrier means
cut by the information transmission means during the decoiling of each turn.
In figure 1, the light barrier is then formed between a light beam transmitter
designated by general reference 4 and a corresponding receiver designated by
general reference 5, the light beam being cut by the transmission means 2 during the
15 decoiling of each turn.
Of course, other embodiments of these determining means can be considered.
Thus for example in figure 2, the use has been illustrated of light reflection
photosensor means activated by the transmission means during the decoiling of each
turn.
20 These photosensor means are designated by general reference 6 in this figure
2.
Of course, still other embodiments of these determining means can be
considered.
The operating principle of this system is then based on the detection and
25 counting of the passage of a turn of the information transmission means being
decoiled.
The length of a turn of these means being known or being able to be determined
with a known precision, it is then possible to calculate the distance traveled by the
vehicle by counting the number of turns decoiled.
30 The movement speed of the vehicle can also be estimated.
One can then see that such a system has a certain number of advantages, in
particular in terms of its simplicity

CLAIMS
1. A system for determining the distance traveled by an underwater vehicle
(1) launched from an underwater device and connected thereto by information
5 transmission means (2), coiled in the form of a hollow spool of turns (3) unwinding
from its center during the movement of the underwater vehicle, characterized in that
it includes means (4, 5; 6) for determining the number of decoiled turns in order to
determine the distance traveled by the underwater vehicle.
10 2. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 1, characterized in
that the determining means comprise light reflection photosensor means (4, 5)
activated by the transmission means (2) during the decoiling of each turn.
15 3. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 1, characterized in
that the determining means comprise light barrier means (4, 5) cut by the transmission
means during the decoiling of each turn.
20
4. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to any one of the preceding
claims, characterized in that the underwater vehicle (1) is a torpedo, the information
transmission means (2) comprise at least one optical fiber and the underwater device
25 is a submarine strictly speaking.