System for determining the distance traveled by an underwater vehicle launched
from an underwater device
5 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
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
10 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
exchange information between the submarine and the torpedo in order to ensure
guiding of this torpedo.
15 These information transmission means can for example include at least one
optical fiber.
Of course, other types of transmission means can be considered.
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
20 submarine.
This fiber and this sheath are indeed coiled in the form of a hollow spool of turns
for example in a casing positioned in a weapon tube of the underwater device, this
hollow spool, that is to say the fiber and the sheath, unwinding during the movement
of the underwater vehicle, from the underwater device.
25 It is known that today, the detection of the departure of the torpedo from the
tube is for example based on the use of a contact released during the departure from
the launch tube, this contact being coupled with a velocimeter.
However, it remains very difficult to obtain information on the distance traveled
by the vehicle, correlated with the movement of the underwater vehicle relative to the
30 underwater device.
Furthermore, it is not possible today to detect whether the torpedo has also left
a front tube of some submarines.
The aim of the invention is therefore to address these problems.
To that end, the invention relates to a system for determining the distance
35 traveled by an underwater vehicle launched from an underwater device and
connected thereto by information transmission means, at least a portion of which is
2
housed in a protective sheath, the transmission means and the sheath being coiled
in the form of a hollow spool of turns unwinding during the movement of the
underwater vehicle, characterized in that it includes means for determining the
decoiled length of sheath in order to determine the distance traveled by the
5 underwater vehicle.
According to other features of the device according to the invention, considered
alone or in combination:
- the determining means comprise light reflection photosensor means activated
by the sheath during the decoiling of each turn;
10 - the determining means comprise light barrier means cut by the sheath during
the decoiling of each turn;
- the determining means comprise inductive sensor means activated by the
sheath during the decoiling of each turn;
- the determining means comprise decoiling sensors of certain turns of the
15 spool;
- the decoiling sensors comprise a sensor for detecting the decoiling of the first
turn of the sheath in order to detect the beginning of the movement of the vehicle;
- the decoiling sensors comprise at least one sensor in order to detect the
decoiling of a predetermined turn of the sheath to detect the crossing of a
20 predetermined distance by the vehicle;
- the decoiling sensors comprise a sensor for detecting the decoiling of the last
turn of the sheath in order to detect the end of the decoiling of the sheath;
- the sensors each comprise a state change switch controlled by the release of
a pin driven by the sheath during its decoiling;
25 - the underwater vehicle is a torpedo, the information transmission means
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
30 which figures 1, 2, 3 and 4 show schematic perspective and sectional views of a rear
part of an underwater vehicle such as a torpedo, illustrating four example
embodiments of a determination system according to the invention.
These figures in fact shows several example embodiments of a system for
determining the distance traveled by an underwater vehicle launched from an
35 underwater device.
3
In these figures, the underwater device, which may for example be made up of
a submarine strictly speaking, is designated by general reference 1 in these figures.
The underwater vehicle is in turn not shown and may for example be made up
of a torpedo launched from the submarine.
5 As previously indicated, the torpedo and the submarine are connected by
information transmission means.
These information transmission means for example comprise at least one
optical fiber.
At least one portion of this optical fiber is housed in a protective sheath in a
10 conventional manner, this sheath being designated by general reference 2 in these
figures.
As also illustrated in these figures, these information transmission means and
the protective sheath thereof are coiled in the form of a spool of turns designated by
general reference 3 in these various figures.
15 This spool of turns then empties during the movement of the underwater vehicle,
as illustrated.
In the system according to the invention, means are provided for determining
the decoiled length of sheath in order to determine the distance traveled by the
underwater vehicle.
20 Different possible embodiments of these means for determining the length of
the decoiled sheath can be considered.
Thus for example in figure 1, the use has been illustrated of light barrier means
cut by the transmission means during the decoiling of each turn.
In figure 1, the barrier is then formed between a light beam transmitter
25 designated by general reference 4 and a corresponding receiver designated by
general reference 5, the light beam being cut by the transmission means during the
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
30 photosensor means activated by the transmission means during the decoiling of each
turn.
These photosensor means are designated by general reference 6 in this figure
2.
Of course, still other embodiments of these determining means can be
35 considered.
4
Thus for example, inductive sensor means activated by the transmission means
during the decoiling of each turn can be considered if the sheath is for example
metallic.
This is for example illustrated in figure 3, in which the inductive sensor is
5 designated by reference 7.
Still other embodiments thereof can be considered, for example the use of
decoiling sensors of certain turns of the spool.
Thus for example, the spool and the turns can be associated with sensors such
as switches, for example, making it possible to detect the decoiling of the spool.
10 Thus for example, the system can include a sensor associated with the first turn
of the sheath, in order to detect the beginning of the movement of the underwater
vehicle.
The system can also include at least one sensor for detecting the decoiling of a
predetermined turn of the sheath, in order to detect the crossing of a predetermined
15 distance by the vehicle, and for example another sensor for detecting the decoiling of
the last turn of the sheath, in order to detect the end of the decoiling of this sheath.
As an example, these sensors can each include a state change switch
controlled by the release of a pin driven by the sheath during its decoiling.
One example embodiment of this type of structure is illustrated in figure 4.
20 In this figure, four devices with pin and switch are shown and designated by
references 8, 9, 10 and 11. The latter are associated with determined turns of the
spool.
The operating principle of this system is then based on the detection and
counting of the passage of a turn of the sheath being decoiled.
25 The length of a sheath turn 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.
One can then see that such a system has a certain number of advantages, in
particular in terms of the possibility of determining, for example, whether a torpedo
30 has left the tube, or even the front tube in some submarines.

CLAIMS
1. A system for determining the distance traveled by an underwater vehicle
5 launched from an underwater device and connected thereto by information
transmission means, at least a portion of which is housed in a protective sheath (2),
the transmission means and the sheath being coiled in the form of a hollow spool of
turns (3) unwinding during the movement of the underwater vehicle, characterized in
that it includes means (4, 5; 6; 7; 8, 9, 10, 11) for determining the decoiled length of
10 sheath in order to determine the distance traveled by the underwater vehicle.
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 (6) activated
15 by the sheath during the decoiling of each turn.
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 sheath
20 during the decoiling of each turn.
4. 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 inductive sensor means (7) activated by the
25 sheath during the decoiling of each turn.
5. 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 decoiling sensor (8, 9, 10, 11) for certain turns
30 of the spool (3).
6. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 5, characterized in
that the decoiling sensors (8, 9, 10, 11) comprise a sensor for detecting the decoiling
35 of the first turn of the sheath in order to detect the beginning of the movement of the
vehicle.
6
7. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 5 or 6, characterized
in that the decoiling sensors (8, 9, 10, 11) comprise at least one sensor in order to
detect the decoiling of a predetermined turn of the sheath to detect the crossing of a
predetermined distance by the vehicle. 5
8. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 5, 6 or 7,
characterized in that the decoiling sensors comprise a sensor (8, 9, 10, 11) for
10 detecting the decoiling of the last turn of the sheath in order to detect the end of the
decoiling of the sheath.
9. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to claim 5, 6, 7 or 8,
15 characterized in that the sensors (8, 9, 10, 11) each comprise a state change switch
controlled by the release of a pin driven by the sheath during its decoiling.
10. The system for determining the distance traveled by an underwater
vehicle launched from an underwater device according to any one of the preceding
20 claims, characterized in that the underwater vehicle is a torpedo, the information
transmission means (2) comprise at least one optical fiber and the underwater device
is a submarine strictly speaking