DE2140035C3 - Measuring device for steering a ship - Google Patents

Description

The invention relates to a device accordingly the preamble of claim I.

From "Marine Engineering / 1.og", lull I9b9. Ropes 92 isi r> a measure of advance by making use of the double depth fects «. known Hei this procedure are on Ship's hull attached near the bow and stern electromagnetic transducers, which when receiving electrical Signals generate ultrasonic waves and when received s> o Emit electrical signals from sound waves. A transmitter is sent in four directions to the Secgrtind ultrasonic waves are radiated obliquely and the reflected waves are from a receiver recorded. it

The frequencies of the waves received are different from those of the transmitted waves due to the Doppler effect Waves different. The speed of the ship can be derived from the Doppler frequency deviation with a Accuracy of about 5 mm / sec. to be determined. The ship's course can be based on the four directions obtained information can be calculated. The disadvantage of this method is that for each Ship a separate measuring device is necessary. In addition, inaccuracies can occur during the measurement process arise due to the movement of the ship.

The invention is based on the object of creating a device with which the simple Structure that can control the docking and casting off of a ship with high accuracy.

This object is achieved according to the invention by the in the characterizing part of claim I. specified features. Since the entire device is at the anchorage, there is no need on the ship special measures are taken. The fixed arrangement of the ultrasound transducers means that the The speed of the ship can be measured very precisely because the transducers do not track the ship's movements are exposed. Another advantage is that the distance between the ship and the pier is at two different points Places is measured so that the position of the ship can be precisely determined.

The invention is explained below with reference to FIG. 1 and Fig. 2, for example. It shows

F i g. 1 a schematic representation of the device, and

F i g. 2 shows a block diagram of the evaluation device.

Fig. I shows a mooring 1 with a pier 2 and Anlegep ^f Aehle 3.4. which are attached to Pier 2 at a distance from each other. Fin ship 5 is to be brought up to anchorage 1 alongside. It is first stopped in a position about 100 m away from anchorage 1 and then controlled so that it is approximately parallel to line 6 which connects the front surfaces of the mooring piles 3 and 4. Then the ship is pulled by a tug parallel to / around anchorage 1 and finally tied to mooring piles 3 and 4 with ropes. The speed of the ship when approaching the anchorage can be controlled with an accuracy of 1 mul.

The proposed device includes transducers 7,8 which are attached to the mooring posts 3 and 4 and Transmit and receive ultrasonic waves that have a fixed angle of about 12, for example. Aiiswerieeinnehtungen 9, 10 are with the converters 7,8 connected by Koaxialkabc 'II, 12. It is also a display device 13 is present, which the Meßre siilt.it indicates still a (flour illustrated) Radio link that communicates the measurement result to a helmsman who is on the reeds.

The measuring device measures the time that the Transducers 7, 8 emitted I laser sound pulses benon until they are reflected on ship 5 again get back based on the measured line one d.inn taking into account the known propagation velocity of ultrasonic waves the distance between the transducer and the ship. To measure the approaching speed, the The time interval of the emission of the ultrasound pulses is precisely defined and the one measured at each point in time Distance subtracted from the reading of the previous measurement, which gives the ship's speed receives.

The following is the offshore and speed measurement explained on the assumption that the time interval of emission of the ultrasonic pulse I see.

amounts to.

It is assumed that the ship 5 is at a distance L from the pier at the time 1 = 0 and is approaching the pier at a speed V , furthermore that an ultrasonic pulse emitted at the time (= 0) at the ship 5 after a time At \ occurs. The time At ₁ is then given by the following equation:

Ifi =

L-V C.

III

This results in:

U ₁ =

C + V

Here, C is the speed of the ultrasonic waves in the water. Accordingly, the pulse emitted at the time / = 0 is picked up by the receiver _{after a time 2 ^ r 1.}

L ₀ =

C + V

If one takes C = 1500 m / sec. and V = 0.15 m / sec. at. so the difference between /. and at the same time 0.01 'Vo.

The distance L ₀ measured from the pulse emitted at time i = 0 is LCV (C '+ V); the distance Li, which is measured by the pulse emitted at time / = 1, is (L- W) CV (C + V). since the distance between the ship and the pier at time t = 1 is equal to (I. - W; bct.

Here, W corresponds to the path that the sound travels during an impulse.

The speed to be measured is therefore given by the following equation as the difference between the Landing; given in a second:

V =

^ ι, ■ / ι ^y

^ ^l \ ' c

If C =! 500 m / sec. and V = P ■ '5 m / sec. the measurement error is in the order of magnitude of 0.01%.

Fi g. 2 / Eigl the ejector 9, which is connected to the Llltraschallwandler 7 is connected. Elin Zeitgeber 21 generates a clock pulse at intervals of one second, a pulse generator 22 generates based on the in Taklimpiilscs an electrical transmission pulse every second, by means of which an ultrasonic pulse is emitted by the transducer 7. The one that spreads in the water Ultrasonic pulse hits the body of the ship 5 and is then reflected around transducer 7. The received pulse is converted into an electrical signal converted and by an f-.receiver amplifier 23 amplified, resulting in a stop signal for a Gate circuit 24 results in the .Send signal of the pulse generator 22 is via a delay circuit 25 of the Gate circuit 24 supplied and serves as the opening signal.

The transducer 7 is set back by one distance d from the front edge of the mooring pole 3 , but since the distance L to be measured is the distance L between the front edge of the mooring pole 3 and the ship 5, the aforementioned delay sound 25 serves to compensate for the time that the ultrasonic pulse takes required for traversing the distance d. If the Wandlei 7 is set back by a distance c / from the front edge of the mooring pole 3, as in the illustrated Ausführungsoei, there is no dead zone in which no measurements can be made due to the transmission pulse width. Damage to the ship and / or the pier as a result of a collision can therefore be prevented in that the entire zone in front of the leading edge of the mooring pole 3 can be measured.

A measuring pulse generator 26 generates a pulse of z. E.g. 750 kHz. Its pulse interval corresponds to the time in which the ultrasonic wave travels 1 mm back and forth in the water, ie the propagation time of the ultrasonic wave in the water for a distance of 2 mm. If you take the sound or ultrasound speed in water at 1500m / sec. is the time T required for the ultrasonic wave to propagate by 2 mm. given by the following equation:

65 T =

1 mm
1500 m lake.

2
1.5

10

lake.

The frequency of the ultrasound rush in the Walser is that above time F inversely proportional, i.e. H.

"f χ K)" see. '= 0.75 χ 10 "Hz = 750 kHz

As stated above, the gate circuit 24 is opened by a pulse emitted by the delay circuit 25 and closed by the pulse received from the amplifier 23. The gate circuit 24 leaves as long as it is open. the pulses of the measuring pulse generator 26 pass through. The distance to be measured between the ship and the mooring piles can therefore be displayed digitally by counting the pulses passing through the gate circuit 24. For this purpose, the gate circuit 24 passing pulses z. B. fed to a decimal counter 27, which carries out the pulse count. The output signal of the counter 27 is supplied to a memory 28 which holds its value for a second Ausgan the _t 'ssignal the memory 28 comes to a display device 29 which indicates the measured distance.

The speed of the ship as it approaches the anchorage is measured in the following way: On first pulse train which the gate circuit 24 traverses is fed to the minus side of a counter 30; at the same time, a signal from the timer 21 to the counter 30 and Stell! him back. The same he .te After passing through the gate circuit 24 and the feed to the counter 27, the pulse train is fed to the counter 30, namely shifted to the plus side, inden the counter 27 receives a signal from the timer 21 then a / further pulse train after passing through the gate scarf device 24 supplied to the minus side of the counter 30 and subtracted from the Impulsz'ig, the counter 30 from Counter 27 arrives. The subtraction result is fed through a memory 31 to a display device 32, which displays the measured value. The speed of the ship can be continuous in this way can be determined and displayed by repeating the above process.

The speed display can show the speeds of someone approaching the anchorage and a departing ship can be distinguished by the prefix "+" or "-". The Oenaniekpit

the speed display in the order of magnitude from cm / scc. can be increased by the fact that the Measurement on the order of 1 mm takes place. The measuring device) 0 of the converter 8 has the same Structure like the measuring device 9.

The output signals of the measuring devices 9 and 10 are fed to an electrical indicator 13 fed to the offshore of the ship from the berth and displays the berthing speed and the measurement results to one on the ship Helmsman notifies. The notification to the helmsman can also be done by punk.

For this purpose 2 13InIt drawings

Claims (4)

Patent claims: 1. Device for steering a ship when berthing or casting off using two ϊ Ultrasonic transducers and an evaluation device for calculating the speed and the Distance of the ship from the pier, thereby marked that (a) the ultrasound transducers (7, 8) at anchorage (1) in under water on two spaced mooring piles (3, 4) for the transfer of Ultrasonic beams to the ship and to receive the ultrasonic beams reflected from the ship are arranged (b) the evaluation device (9, 10) is arranged on the pier (2) and each has a counter (27, 30) for Determine the speed and the distance, and (C) a device for the transmission of the measured values> u te to the ship. 2. Device according to claim 1, characterized in that dall the front of the ultrasound transducers (7, 8) opposite the front edge of the mooring piles (3, 4) is so reset. that the time it takes for the ultrasonic beams to be sent out to the transducers need to make the distance between the front of the transducer and the leading edge of the mooring piles To go there and back, larger than the pulse width of one of the ultrasonic transducers - so led impuises is. 3. Device according to Anspn h., Characterized in that the switching device (9, 10) consists of two switching parts, each of which has a pulse generator for feeding a transducer (7, 8). ;> has a receiving amplifier (23) for the signal received by the transducer reflected from the ship, a measuring pulse generator (26) and a gate circuit (24) which is opened by the output signal of the pulse generator (22) via a delay circuit w (25) and is closed by the output signal of the amplifier (25) and, in the open state, allows the pulses of the measuring pulse generator (26) / u counters (27, 30) to pass through. 4. Apparatus according to claim 3 thereby marked -n indicates that the counters (27, 30) mn stores (28, 31) and these with display devices (29, 32) are connected