DE20310075U1 - Device for the underwater localization of objects - Google Patents

Description

GOEPT03135 J ? ··? · &idigr;&Igr; .* · · ·* 06/30/03

Applicant:
Dr. Philipp Goedeking

Grillparzerstr. 57 60320 Frankfurt am Main

Device for underwater localization of objects

Description

The invention relates to a device for determining objects located below the water surface. In particular, the invention relates to a locating device for divers.

Scope of the invention:

The rule in recreational diving is that the divers in a group should always be within sight of each other, but no more than "one breath" away from each other. If the divers lose sight of each other for more than about a minute, especially in murky waters and if the divers involved do not have enough stress resistance or experience, this often leads to serious, sometimes fatal diving accidents.

Previous applications or patents (see in particular US 6,272,073 Bl: Underwater Location and Communication Device; DE 19914380 Al: Communication and search system for divers) use ultrasound to indicate the direction and, if applicable, the distance to the diving partner in continuous operation during the entire dive. These designs have the following essential features:

GOEPT03135

30.06.03

• The permanent display of direction and distance to each other gives divers a false sense of security. Occasionally losing sight of each other is wrongly perceived as tolerable and reduces the discipline of correct, safe diving. A failure of the direction indicator device in this situation would be fatal. These devices therefore pose the fundamental problem of latently increasing risk instead of supposedly reducing it.

· The constant transmission of ultrasound places a heavy load on the energy source (in US 6,272,073 Bl: button cells!). Long-term operation is not possible. By the time rescue operations begin with a systematic search for a lost diver, the battery can easily be exhausted. The device is then useless. The low energy supply and high energy consumption due to constant transmission also limits the energy and thus the range and signal-to-noise ratio of the transmission signals. A successful search over long distances under water is therefore significantly impaired.

Overall, the devices are usually superfluous (or even dangerous) and not powerful enough in an emergency. These two shortcomings have probably contributed significantly to the previously unrecorded market success of such designs.

The Japanese invention (publication number: 09292455 A: "Detecting apparatus for position of underwater target") calculates, in combination with a gyrocompass, the azimuth angle to a loud sound source in the audible frequency range at a distance in the water. This apparatus is unsuitable for the intended purpose here, as the lost diver would have to actively "honk" so that the searching divers could locate him using the invention in question. The possibility

·

·

·

·

GOEPT03135 · -J 3 ·- · · . ; ? · June 30, 2003

However, an active and controlled action is unlikely or even impossible with panicked or even unconscious divers. The need for a gyrocompass also makes the application complex and vulnerable. This invention is therefore also not suitable for use in an emergency.

The object of the present invention is to provide a device which does not have the aforementioned disadvantages.

This problem is solved by a device having the features of the independent claim.

klO In the following, a transponder-based device is presented, with the help of which a diver who has been lost from sight for a dangerously long time can be safely located without his intervention.

The present construction, which is preferably designed for emergencies, should therefore consume as little power as possible in normal operation, i.e. be able to be activated via transponder in an emergency. This ensures that sufficient electrical energy is available for longer search operations in an emergency. Furthermore, the present invention works with "loud or high-energy" acoustic signals, which are * preferably (but not necessarily) in the audible range, in order to carry far underwater, to ensure a high signal-to-noise ratio to other noises underwater, to be able to immediately check the function of the locating devices during the search and rescue operation and to be able to trigger the responder with any underwater horn in an emergency by the rescue team and thus receive an automatic response signal from the lost diver. On the other hand, the frequency of the signal must not be reduced so low (infrasound) that the propagation time differences can no longer be measured reliably enough due to the signals' rising edges being too flat.

·

GOEPT03135 * &Ggr;"~l<? ·■··*, J · · 06/30/03

Furthermore, it is preferred that the invention works with short signal pulses instead of continuous signals in order not to consume more energy than is necessary for reliable positioning.

The following describes a construction in which a transmitter ("interrogator") is integrated into an integrated, compact, portable and water and pressure-resistant system which, at the push of a button by the searching diver, emits a single, high-energy, short signal or several short signal pulses, whereby the signals are emitted with the highest possible sound pressure for safety reasons and preferably, but not necessarily, must be in the audible range.

A further component of the invention is a transponder which responds to the high-energy signal (or signal sequence) with a high-energy, short ¹ response signal. This signal is also preferred for safety reasons, but not necessarily arranged in the audible range.

To determine the position of the diver, a receiver is required that measures the time differences of the transponder signal as it reaches the microphones via an arrangement of ^k underwater microphones. In principle, it is possible to use one or more microphones.

With the help of a microprocessor-driven logic (MCU, Microcomputer Unit), the relative direction of the sound source is trigonometrically calculated from the time differences, which is then visually displayed on a display.

The transponder logic ensures that the device consumes very little power in normal mode, because only the power-saving microphones and the microprocessor are activated, but not the high-power transmitter.

· · · · · · · &bull; ·· ·· · · · · ·· t · &bull; · · · I · · · · &lgr; * * m · I » · &bull; * &bull; · · it· m · * ■ &bull; ■ · I · · · · ···

GOEPT03135 &ugr; - 5* ·· · · · YY · 06/30/03

In an emergency, there is then enough electrical energy available for very high-energy, short signals. The device is therefore primarily designed for emergencies in order to have a safe and powerful search system on hand. It represents an additional tool for safe diving practices.

In the following, the invention is explained in more detail using embodiments which are shown schematically in the figure. In detail:

.0 Fig. 1 is a schematic diagram of a possible embodiment.

Figure 1 describes a technical implementation option. The most advantageous is the integration of the functionalities of interrogator, transponder, receiver, etc. into a single technical device (see figure): This device preferably knows at least the following basic states:

1. Transponder mode:

} This is the basic state of the device. The device is in this mode whenever and as long as it is not briefly switched to interrogator mode. In transponder mode, the device "waits" for a "wake-up signal" (sound signal) from another, distant device. If such a signal arrives (regardless of which microphone), the loudspeaker responds with a short, high-energy tone (as an alternative to a loudspeaker ("beeper"), a commercially available underwater horn operated by air pressure can also be triggered). The device then goes back into the wait state.

2 . Interrogator mode:

GOEPT03135

At any time, the MCU can be triggered by pressing a button to activate the loudspeaker or underwater horn and to emit a short, high-energy tone (or a sequence of tones). At the same time, the previous basic transponder mode is exited. Immediately afterwards (i.e. after the signal has ended), the device switches to receiver mode and waits for the response signal from the remote counterpart. The differences in the runtime of the incoming response signal are evaluated by the MCU. The calculated direction of the received response signal is shown on a display, controlled by the MCU. The device then switches back to the basic transponder mode.

Claims (7)

1. Device for locating objects, in particular persons in water, - with a housing designed to be portable and to accommodate one or more of the following components, - with a transmitter that emits a high-energy signal (single tone or sequence of tones) at the push of a button; - with a transponder that responds to the signal with a high-energy signal; - with a receiver that measures the time differences of the transponder signal as it arrives at the microphones via an arrangement of one or more underwater microphones, - with a computer that determines the direction of the sound source. 2. The device according to the preceding claim, characterized in that the computer is a microprocessor-driven logic which trigonometrically calculates the relative direction of the sound source from the transit time differences. 3. The device according to one or more of the preceding claims, characterized in that the direction is indicated optically, in particular on a display. 4. The device according to one or more of the preceding claims, characterized in that a high-energy, short signal or a short sequence of such signals is used as the "wake-up signal" of the interrogator. 5. The device according to one or more of the preceding claims, characterized in that the high-energy signal is emitted in the audible range. 6. The device according to one or more of the preceding claims, characterized in that the signal can also be generated by a preferably pressure-operated underwater horn. 7. The device according to one or more of the preceding claims, characterized by an integrated, compact, portable and water and pressure resistant design.