NO147225B - PROCEDURE AND DEVICE FOR SIGNALIZATION OF NAVIGATION HAZARDS - Google Patents

Description

The invention relates to a method for automatically determining facilities and devices that approach a seagoing vessel and that may cause collisions or be damaged themselves, using an arbitrary navigation system that automatically indicates the current vessel position, and an automatically read data memory that contains the position coordinates for all danger points or danger zones, and in which the current vessel position calculated by the navigation system is compared with the previously stored positions and a first signal is provided when the distance reaches a first predetermined value, and a second signal is provided when the distance reaches a second value, as the alignment operation occurs between, on the one hand, the vessel position and, on the other hand, numerical values that correspond to the danger points or danger fields. Furthermore, the invention relates to a device for carrying out the method.

In a method of the specified type known from FR-PS 2 191 099, both the position of a vessel and the position of previously entered obstacles or sources of danger located in the relevant navigation zone are indicated. The successive positions of the vessel indicated on a picture screen indicate its course line,

as the obstacles also appear on the screen at the same time. It is left to the helmsman of the vessel to maneuver it in the usual way to circumvent the obstacles. The known method also complements the possibility of changing the scale on the picture screen.

From US-PS 3 899 769 there is further known a method for displaying on the screen of a cathode ray tube the positions of reference points and the running position and previous positions of a body in motion, so that the speed of the moving body becomes obvious. When it concerns a ship, the master must assess whether there is any danger. Likewise, it is from GB-PS 1 360 012

known a device which displays a representation of a ship together with a representation of objects not under the control of the ship, and a representation of predetermined, safe boundaries around a preferred course for the ship.

The master must also keep an eye on such information.

The purpose of the invention is to provide a method for indicating the approach of areas at sea to be navigated by a vessel, which method proceeds completely automatically and by triggering an alarm indication makes it possible for the navigation staff in each case to sail around an obstacle with sufficient safety or at a sufficient distance in front of the obstacle.

The above-mentioned purpose is achieved with a method of the type indicated at the outset which, according to the invention, is characterized by the fact that after reading the points and fields to be bypassed in the form of numerical characteristics for zones, signaling areas and alarm areas that contain these points and fields, all characteristics for zones are automatically and repeatedly read until they match the characteristics for the vessel position provided by the navigation system, that all characteristics for the signaling areas contained within the zone are then read systematically one after the other until the corresponding characteristics provided to the zone, from the navigation system and from the memory, are identical, that the a signal is provided as soon as the characteristics supplied by the navigation system match one of the characteristics read successively and systematically, after which all stored characteristics within the zone traversed by the vessel are read and the same operations are performed for the following following zones or areas when the ship enters another zone or another area, that furthermore all stored alarm areas located within the stored zone whose characteristics are provided using the navigation system are systematically and repeatedly read, and that an alarm signal is provided as soon as one of the read characteristics for alarm areas is identical to the characteristic for the area of residence determined by the navigation system.

Instead of the state-of-the-art indication of the positions of the ship and the danger points on the picture screen of a cathode ray tube, for the observation and assessment of which the constant presence of the navigational staff who must take into account the ship's speed at the start of rounding maneuvers is necessary, it becomes the method according to the invention at a sufficient distance in front of the obstacle in question or the point of danger in question provided for an automatic signal release which is implemented by simple means by comparing stored, numerical values for the obstacles with numerical values in accordance with the relevant ship position.

A device for carrying out the specified method includes devices for converting and storing analogue values indicated by a navigation system into numerically coded values, devices for automatically reading stored characteristics of zones, signaling areas and alarm areas in which there are points or fields which to be circumnavigated, and devices for comparing the characteristics supplied by the navigation system with the characteristics read in, and is characterized according to the invention in that it also includes control circuits for repeating the continuous reading of all characteristics for zones, and a control circuit for stopping the characteristics reading operation and for switching on the repeated reading operation for the sequence of characteristics for the zones, the control circles being controlled by means of the comparison device.

With the aid of the device according to the invention, the stored characteristics for all zones or the signaling areas for a zone can be systematically read in a relatively simple manner.

A device comprising a magnetic tape reader which contains devices for controlling tape stop, tape feed, tape rewind and fast-forward, which devices can be operated via comparison circuits, according to an embodiment of the invention can be structured so that the comparison circuit comprises a first control circuit for successive orders for tape rewind with consecutive read-forward, and a second control circuit for consecutive fast-forward orders with subsequent read-forward. This embodiment allows either to restart a reading from the beginning to systematically monitor a given surface area, or to very quickly go over

for monitoring another or subsequent surface re-

advise.

The invention shall be described in more detail below

in connection with a non-limiting embodiment example with reference to the drawings, where fig. 1 shows a schematic representation of two hyperbolic networks in a navigation aid chain for determining a ship's positions and its two devices for indicating the coordinates of its position, fig. 2 shows a schematic representation of the registrations of coordinates on a magnetic tape with four tracks, fig. 3 shows an assembly of the tape reader and of a navigation assistance system which is connected to a part of the signaling device, fig. 4-9 show the circuits included in the one in fig. 3 shows part of the device, fig. 10 shows a detailed

is a diagram of a detector device DR1 in fig. 6, and shows the beginning of the registrations relating to an unused chain,

fig. 11 shows a detailed diagram of a circuit for detecting

ring of preparation and alarm signaling areas in fig.

4 and 5, and fig. 12 shows the connection diagram for Figures 4-9.

Due to the widespread use of navigation aid systems that use position coordinates represented by two networks of hyperbolas where each hyperbola is determined by equal phase differences between signals received from two stations for retransmission of a reference wave, it is in fig. 1 shows a vessel 1 which is located at the intersection between the hyperbola 2 with the coordinate D35-80 which represents its phase difference in the network determined by a transmitter 3 and a slave station 4, and the hyperbola 5 with the coordinate

ten 116-30 in the network determined by the transmitter 3 and a second slave station 6, the coordinates of each of these being indicated by means of display devices 9 and 8 in the receiver device mounted on the vessel. Some parts of band-

ne D31 - D47 are shown at 10 to indicate that they form region D. Likewise, those shown at 11 form bands II - 123

area I. In practice, each receiver is provided with a third device for indicating the phase difference, as a device

ning is used to measure the phase difference between the waves

which is emitted by two transmitters, each chain comprising three transmitters. When the ship leaves the area served by the chain of stations 3, 4 and 6, it then uses the stations in a second chain.

The registration of all the coordinates defining the preliminary signaling zones and the alarm signaling zones can be carried out using only whole bands that are not subdivided. Instead of taking as coordinates for ship 1 its exact position 116-30, D35-80, it is thus possible to define only the intersection between bands 116 and D35, and to transform these values into binary data by giving each letter a given numerical value, such as a value denoting its place in the alphabet.

In order to facilitate the description of the device for carrying out the method according to the invention, a magnetic tape 16 has been chosen as the recording medium, the arrangement of the data being shown schematically in fig. 2. In this example, the tape 16 is of the type that has four reading tracks, the tracks 12, 13 and 14 being designated or assigned to the coordinates of tapes that each relate to the phase differences between two stations, and the track 15 serves for recording the synchronization pulses during the reading of the tape.

An indication of the beginning of the tape is introduced at 17 and appears in the form of the registration of 0 in the first

16 positions arranged in series on each of the tracks

12 - 14, but which, for the sake of clarity, are schematically shown to be arranged in parallel. This indication is followed by binary recordings of the call signals for all chains for which the hazards to be avoided have been recorded on the tape. These registrations appear at 18 in track 12.

The area 18 of the tape is followed by an indication RI of the position of the information relating to an area or zone covered by a given chain ("chain") whose identity is given in coded numerical form at 19 in the track 12.

The subsequent area corresponds to the indication R2 of the position of all coordinates of the intersections of bands constituting the preliminary or preparatory signaling zones of the chain identified at 19.

In area 20, each intersection point is therefore determined by data entered in at least two of the three tracks 12 - 14. An end indication for area 20 is given at 21 in track 12, and is followed by an indication R3 of all coordinates for the intersections of bands constituting the alarm signaling zones in the chain indicated at 19, these coordinates being recorded at 22.

An end-of-record indication R4 followed by a cycle-end signal at 23 terminates the recording of all the data associated with the first chain.

Similar rows of records, each addressed by the indications RI, R2, R3 and R4, provide the coordinates for the preparation and alarm signaling zones for each of the relevant chains, the order of these chains preferably corresponding to passages between two adjacent chains.

In the embodiment shown as an example, the magnetic strip reader, which can be of any type, is shown in the form of a block 24 in fig. 3, the output circuits for the reading heads for tracks 12 - 14 being of a similar type to those shown at 25 and feeding the serial register 26 for a comparator C16. The outputs, such as the output 27 from the register 26, are each connected to a device similar to the comparison device 28 which is shown on a larger scale at the bottom of the figure and which via conductors, such as W2, receives binary information coming from the position of the same rank of the parallel outputs W from a decoder device 29. The decoder 29 converts the analog data indicating the chain numbers and which is transmitted by a device 30 in a navigation system shown at 34, into numerical values. Similarly, decoders 31, 32 and 33 provide output signals X, Y and Z which provide the numerical values, for example binary numerical values,

of the position coordinates for the ship provided at 35, 36 and 37 by means of the navigation system 34. The output signals X, Y, Z are supplied to other similar comparators which are denoted by reference numbers C19-C24.

Each comparison device 28 for comparing binary elements emits an output signal to the corresponding output conductor 38 whenever the two binary input values are identical, i.e. when a binary 1 is present on each of conductors 27 and W2, or by the simultaneous presence of a binary 0 on these conductors. A coincidence circuit 39 emits an output signal at 40 when there is coincidence between the information derived from the register 26 and the output of the decoder 29. This output signal is only available in the presence on one side of the coincidence or coincidence between the binary values which are present on the inputs El and E2, the conductor 41 which feeds the logic circuit 39, and the conductor 42 which is connected to the input D and serves to block the comparator in accordance with the applied voltage. During the comparator's operation, the control inputs El and E2 and the blocking input D are connected to different circuits, as will be described in more detail later.

To facilitate understanding of the various circuits connected to the assembly of comparators C1 - C26, each comparator is shown schematically in the form of blocks. Fig. 4-10 shows all circuits for detecting the vessel's entry into a signaling zone and the circuit for controlling the reading of the recorded data.

A manual control of the device is shown at 45 in fig. 5, and the purpose of this is to set all the used trigger circuits in a reset state with the exception of Bil in fig. 8, the output of which controls the operation of the tape 16 via the circuit 52 and the connection 49. The trigger circuit can obviously be of any type. In the embodiment shown, in each case the letter S denotes a setting input of a trigger circuit, the letter R denotes a reset input of a trigger circuit, Q denotes an output available from a trigger circuit after setting the trigger circuit, and Q denotes the output available at reset . The internal control circuits in the tape reader 24 in fig. 3 is not shown as the reader used can be a commercially available reader. In fig. 3 is therefore only shown, together with the conductor 49, a conductor 46 for controlling the tape stop, a conductor 47 which transmits a signal sent from the reader 24 after receiving the stop instruction, a conductor 48 for controlling rapid feed and a conductor 50 for rewind control.

Starting the reader 24 results in a first pulse being transmitted via a connection 15 to the circuit for the reading head for reading the synchronization track on the tape to a trigger circuit Tl (Fig. 6) in a clock circuit 43. This clock circuit, which consists of four trigger circuits Tl , T2, T3

and T4, and by a trigger circuit D9 for controlling the reset of the circuit 43 to its output state, makes a gate P18 conductive when the trigger circuits T1 - T4 have all been switched on, i.e. every 16 pulses. The zero position is controlled by a conductor 44 which is connected via diodes to a manual start-control line 45' and to a line 56 which transmits the stop instructions for the reader 24 for which the assembly 68 of control and stop control circuits is shown in fig. 7-9.

Since the registration of the areas on the tape 16 is carried out by means of the indications RI, R2, R3, R4 which are carried on the tracks 12, 13 and 14, detection circuits DR1, DR2, DR3, DR4 are arranged (fig. 6). Each detection circuit consists of three comparators in a similar manner to the detector DR1 shown in fig. 10.

This circuit comprises three comparators C4, C5 and C6, each of which receives the synchronization pulse E2 emitted by the clock circuit 43, and the signal indicating the code for the indication RI, which in this example is 1111111001111111. Furthermore, each of the comparators C4, R5 and C6 receives the values that are read on tracks 12, 13 and 14. The output signals 60, 61 and 62 from these comparators are transferred to a logic circuit 63 which emits an output signal Ri, which has the same designation as the indication Ri detected on the tape, whenever any two of the comparators Cl, C2 and C3, or all three, detect a coincidence with the code RI. This code can be fed to the comparators by means of sixteen wires, each of which is connected to the selected, representative voltage.

Each of the detectors DR2, DR3 and DR4 also comprises three comparators (not shown), namely comparators C7, C8, C9 for DR2, CIO, C11, C12 for DR3 and C13, C14 and C15 for DR4. For the sake of clarity, these comparators are not shown in the drawings. The codes R2, R3 and R4 supplied to DR2, DR3 and DR4 are symmetrical codes 1111110000111111, 1111100000011111 and 1111000000001111, so that they can be detected on the tape during rewind or rewind. In order to standardize the various detection circuits, including those shown at DR5, DR6 and DR7 to be described later, the circuit 63 can be replaced with the circuit for the gate P14 shown in Fig. 11, if inputs 105, 106, 107 are replaced of the wires 60, 61 and 62. At the output 92, there are thus available signals that represent coincidence between the signals on any two of the three inputs and on all three inputs, and it is also possible to extract directly an arbitrary intermediate signal on which preferably clamp in the standard unit, such as the output signals for each comparator.

In order to avoid untimely influence of the signaling devices 80, 81 and 82 (fig. 4 and 5), respective comparators Cl, C2 and C3 of the detector DR7 (fig. 6) compare the values detected on the reading tracks 12, 13 and 14, with the beginning of the band code 17 (Fig. 2) represented by sixteen zeros, so that an output signal is available at 71, 72 and 73 whenever the corresponding comparator detects sixteen consecutive zeros on each of these tracks. The outputs 71, 72 and 73 of the comparators are further connected to a port P2 whose output 73 emits a signal whenever the assembly Cl, C2, C3 simultaneously detects the signal indicating the tape start code at 17 on the tape. This signal switches the trigger Dl whose output El enables the operation of C16 (fig. 4), as the reset of the trigger D2 in the circuit for detecting the list of chain codes, and of the trigger D5 in the circuit for detecting the last signaling zone, has been able to be controlled by means of C18, D2 and D5 being controlled directly by output 74.

The device's operation must be described in the following.

The output 76 from port P1 in fig. 6 leads to control or setting of the trigger circuits B2 and B7 in fig. 7. The output signal 96 from B2 is then supplied over a conductor

96' to effect switching of B10 (fig. 8) whose output 98

makes gate V4 conductive while gate V5 remains blocked due to the inverted signal on wire 95.

The output signal 56 from B7 is transmitted to the reader

24 by means of the connection'^ to stop the tape drive, to the reset input for Bil to suppress the signal for controlling the tape drive on connection 49, and to the reset circuit 44 for that of FIG. 6 shown counts 43.

The output signal 96 from B2 opens gates VI and V3 and blocks gate V5 in fig. 8.

Upon receipt of a signal denoting the stop of the tape via connection 47 (Fig. 7), this signal, transmitted via wire 55, makes gates V3 and VI conductive to set B8 and reset B2 and B7 via wires 94, 94' and 94", the port V5 (Fig. 8) remaining blocked. The output signal from B8 is transmitted on the one hand via wire 54 to connection 50 to effect rewinding of the reader 24, and on the other hand via a wire 6 7 to the circuit for detecting the tape's records to disconnect their comparators C during the rewind operation.

On the other hand, the detection of the signal indicating the tape start code results in a signal on line 74 (Fig. 6) which is transmitted via V4 to reset V8 and set B7. Thus, a new signal is transmitted over line 56 to connection 46 to stop the tape while the signal for starting rewind via line 50 is suppressed.

At the moment when a tape stop signal coming from the reader 24 and transmitted via the line 55 appears on the connection 47, the gates V3 and VI are blocked due to the previous reset of B2. Since on the other hand the gate V5 is open, the signal is transmitted via V5 to set Bil via a wire 101 and to reset both B10 and B7. The setting of Bli causes a signal to be applied via the output line 52 and connection 49 to the tape reader to initiate operation of the tape, while the zero setting of B7 causes suppression of the stop signal on line 56.

In the event of a match between the chain code read on track 12 and on decoder 29 coupled to C16 via line W, the output signal from C16 is applied over line 65 to set D2. The Q output from D2, which is connected via a wire 69 to the inputs of C17 and C18, then enables later use of these comparators. The output signal on the conductor 65 is inhibited by the absence of read signals due to the connection 66 in the case of rewinding, or by the absence of fast drive signals due to a signal received over the connection 67 from the general circuits 68 (Fig. 7) for the initiation of operation of the tape reader 24.

In the case of non-coincidence, since trigger circuit D2 is not set, detection of the indication RI leads to opening of gate P5 and setting of D3 via gate P4 which is opened by a signal received across connection 78 from the Q output of D2 which is not been set. The output from D3 then causes operation of a faulty band signaling device 80, and the signal from P4 is also applied over line 84 to produce a stop signal on connection 46 and a rewind signal on connection 50 until automatic tape end stop occurs. For this purpose, the signal applied over wire 84 sets the triggers B1 and B7 (Fig. 7), and the output signal from B7 is applied across connection 46 to stop the reader 24. The output signal from Cl is applied over wires 95 and 95' to open the gates VI and V3. After stopping reader 24, connector 47 transmits a signal via ports VI and V3 to set trigger B8, the output of which is applied across wire 54 and connector 50 to start the tape rewind circuit. The output signal from B8 also causes a signal to appear on a wire 6 7 which blocks the operation of the comparators and signaling detectors. The signaling from the device 80 ends as soon as D3 is reset by means of the manual operation control 45 and after changing bands. Port P5 is blocked due to wire 6 7 polarity during rewind and fast forward operations.

When D2 has been set, the comparator C17 can detect a coincidence between the chain code read from the track 12 and the code provided on a connection W by means of the navigation system. In this case, the output signal from C17 is applied across line 85 to set D4 whose output signal is applied across line 86 to enable the operation of comparators C19 - C24.

If, on the other hand, C17 does not detect a coincidence, the indication R2 read on the tape passes through the gates P7, P6 and P8, the gate P6 being open since D4 has not been set, and the gate P8 not being blocked by the setting of D5 for control of the detection of the code for the last chain Under these circumstances, a signal R2 appears from the detector DR2 on the wire 87 and causes the stop of the tape, fast advance as far as the next indication RI, new stop and then normal advance. The signal transmitted on wire 87 controls triggers B6 and B7 (Figs. 7 and 8), with the output signal from B7 applied across wire 56 and connection 46 to stop the tape, and the output signal from B6 applied across wire 99 to open gate V2, and via a diode and a wire 95" to open the gates V3 and V6, and further via an inverter to block the gate V5. The signal on the wire 99 is further supplied via a diode to a wire 102 to set B10 whose output signal is supplied above a wire 98 to set ports V4 and V5. Upon receipt across connection 47 of the signal emitted by the reader stop circuit 24, this signal is transmitted via ports V3 and V2 to set trigger B9 and reset trigger B7. The output signal from B9 on wire 53 is supplied across connector 48 to produce fast operation of reader 24, and fed via a diode to supply a block instruction on wire 67. The reset of B7 suppresses the stop control on the connector 46. When the tape is driven, the signal RI is supplied via gate V6 and a diode to a line 103 by means of which it is supplied via a diode to set B7 which produces the stop command on connection 46, and via another diode to reset B9 which suppresses the fast-forward command on connector 48, and via wire 104 to reset trigger B6 whose output signal is applied to block gates V2, V3 and V6. The stop command is sent back via line 56 and via a diode to line 44 to reset the clock counter 43. The stop signal received on connection 47 can then only pass through the one port V5 and is supplied via a line 100 and via a diode to a line 101 for to set Bli whose output signal is applied over line 52 to command operation of the tape via connection 49. The signal transmitted by V5 further resets B7 and B10 which suppresses the stop command. The comparator C17 works in the same way until the coincidence between the chain indicated by W and the chain read on track 12 is detected.

It compares C18 which operates after setting D2, enabling the signal indicating the last chain to be detected, which in the considered example is 110011001100 and is located in area 70 of the band. If a coincidence is detected, the output signal from C18 is applied over line 88 to set D5, and if there is indeed a coincidence between the chain read on the tape and that indicated by W by the navigation system, comparators C22 - C26 are used. In the opposite case, detection of indication R2, when D4 is not set and D5 is set, results in a stop command on line 46 and a rewind command on line 50 until automatic stop is followed by normal operation. On detection of the indication at the beginning of the tape, D5 is reset and the tape is read again.

If the comparator C18 does not detect the signal indicating the last chain, D5 remains unset and the non-coincidence of the chain code leads again to a stop command on line 46, fast operation until the new indication Ri, a stop command of 46 and a normal-progress command of 49.

The detector for the coordinates of the preparatory signaling zones comprises three comparators C19, C20 and C21 which are connected to each of the circuits for reading the tracks 12, 13 and 14 by means of connections s5, s6 and s7 via the normally closed contacts of a switch 89 which is controlled by the trigger D7. These detectors operate when D4 is set and blocked during non-detection of signals, during rewind and during fast operation.

If any two of the comparators, . or all three f detect coincidence with the coordinates of a preparatory signaling zone, the coincidence circuit P10 is opened and causes the setting of a trigger D6 which operates the signaling device 81. The device stops signaling only when the ship leaves the preparatory signaling zone and a new indication RI is detected.

When D6 has not been set, gate P3 is opened on reading the indication R3, and the output signal from Pil, which is not blocked by D6, is applied over a wire 90 to set B7 so as to obtain the stop command of 46, rewind as far as the indication RI, then stop and normal operation with a view to continuing the previous operations. The stop command is obtained by setting B3 and B7 (fig. 7) as the output signal on wire 56 is transmitted via connection 46 to the circuit for stopping the reader. The output signal from B3 on line 97 opens gate VI to command rewind, gate V3 to accept the first stop signal received over connection 47 from the reader, and gate V6 to receive signal Ri. The signal on wire 97 is fed via successive diodes to wire 96', wire 95' and wire 95" to block V5, and also from wire 96' via a diode to set B10 whose output signal is applied across wire 98 to open the gates V4 and V5 After stopping the reader and transmitting the subsequent signal on connection 47, setting B8 via V3 and VI and zeroing B7 using V5, the output signal from B8 on wire 54 opens gate V4, and the output signal is supplied via connection 50 to command rewind, and via a diode to wire 67 to cause blocking of the detection unit. The reset of B7 suppresses the stop command. When signal RI is detected, gate V6 opens and sets

again B7 which causes the belt to stop via connection 46. The output signal from V6 also causes zero

gene of B8 which causes suppression of the unwind command of 49 and blocking of gates VI, V3 and V6. The signal received on connection 47 that the reader has stopped passes via V5 which leads to the setting of Bil, and with the help of the output signal from Bil which passes over wire 52 and connection 49, to command the circuit for operating the tape in the reader 24. The trigger circuits B7 and B10 are reset to suppress the stop control and to be ready to respond to the subsequent control pulse.

The switch 89 is affected by the setting of D7 when the code 1010101010101010 is read at 21 on the tape and this code coincides with the one that determines the input to the comparator C25. When the switch 89 is actuated, its contacts bring the reading traces 12, 13 and 14 into connection with the respective connections s8, s9 and s10, so that the comparators C22, C23 and C24 are enabled to detect coincidences between the vessel's position coordinates and the coordinates of the alarm signaling zone . During this period, the comparators C19, C20 and C21 are no longer connected to the reading tracks 12, 13 and 14, the normally closed contacts connected to s5, s6 and s7 being open.

When comparator C26 detects coincidence between the code 0101010101010101 read at 23 on track 12 and that indicated by connections, it outputs a signal on line 91 which is applied to reset D7 to its output state, causing switch 89 to trip. as a result, tracks 12, 13 and 14 are again connected to connections s5, s6 and s7.

The comparators C22, C23 and C24 for detecting the coordinates of the alarm signaling zone can operate when the trigger circuit D4 has been set. These emit their coin-side signal only on receipt of a synchronization pulse E2 and are blocked both in the absence of signals and during the rewind and fast-forward operations. When a coincidence is detected, i.e. when the vessel is in an area or a point to be avoided, port P14 supplies a signal over line 92, leading to a stop command on connection 46, rewinding until indication R3 is detected, stop and normal forward. The signal from P14 causes simultaneous setting of D8 which activates the alarm signaling device 82. During this period the coordinates of the alarm signaling zones are read again on the tape as long as the detected coincidence is maintained.

If, on the other hand, a coincidence is not detected, i.e. if the vessel, even though it is still in a preparation signaling zone, is not close to any point in the alarm signaling zone, there is no signal at the output of P14 and the trigger circuit D8 is not set. At the end of the reading of the area 22 of the tape, the signal 23, whose code is 0101010101010101, is recognized by C26 whose output signal is supplied via the line 91 and the gates P16 and P15 in order, to energize the line 93 and thus initiate a stop command on the connection 46, a rewind command on connection 50 until signal R2 is detected, then a stop command on 46 and the normal-forward command on 49. Under these circumstances, comparators C19, C20 and C21 detect coincidence between the vessel's position and the coordinates of the preparation signaling zone.

It is obvious that the circuits described are only given as an example as the construction of the circuits only depends on the components used. In particular, the tape could cover only one track as the coordinates could be registered in the form of words of 48 bits. Although the tape reader 24 comprises circuits which enable a pulse to be supplied for a new command and a stop command, any other reader with suitable control devices could also be used. The same applies with regard to the other interconnection circuits.

In general, the device works in the following way:

Influence of a first manual control device 45

in the computer reader leads to stopping and resetting of the alarm signaling device, progress and reading of the registration start code located at 17 on the tape 16, and switching on of the comparator Cl. This controls a first circuit for influencing the device 80 to signal faulty tape, stopping the tape 16 in the reader 24, rewinding the tape until an automatic stop occurs, and there-

after operation of the tape for a new reading, and a second circuit which via C16 controls the reading of the area 18 of the tape until the indication RI is detected by the comparator C4. This indication controls a first circuit which leads to complete rewinding of the tape and stopping it if C16 does not detect any correspondence between the chain coordinates registered at 18 and the coordinates transmitted by means of the circuits W to indicate the navigation chain used by the vessel, since a second circuit maintains the feed and reading of the tape with a view to the detection, by means of the comparator C17, of a chain call signal which is contained in the area 19 of the tape and which coincides with the vessel's chain call signal.

This comparator is connected to two circuits. In the case of non-coincidence, the first circuit 87 initiates the rapid advance of the tape until a first indication RI is detected which determines the repetition of this sequence of operations and consequently the reading of only the areas 19 of the tape until coincidence between chains occurs - the call signs. The second circuit 86 then leads to the maintenance of the feed and of the successive reading of the coordinates of the preparatory signaling zones by means of the comparators C19, C20 and C21.

These comparators are likewise connected to two circuits. In case of non-coincidence, the first circuit 90, after complete reading of the preparatory signaling zone coordinates, initiates rewinding of the tape as far as the first indication RI, i.e. as far as the chain call sign corresponding to the preparatory signaling zones which has just been read, and then resuming tape feed and reading. The result is a repetition of the operations for verification of the chain already described, and a repetition of the operation of reading these preparatory signaling zones in case of detection of chain coincidence by means of C17.

In case of detection of coincidence, by means of P10, with a preparatory signaling zone, the second circuit maintains the feed and reading of the tape, which, after detecting the indication R3 denoting the beginning of records indicating the alarm signaling zones, leads to comparison, by means of comparators C22, C23 and C24, of the coordinates for these zones with the vessel's position coordinates. As in the previous cases, these comparators are also connected to two circuits, the first circuit, via line 93, in the case of non-coincidence leads to rewind as far as the first indication R2, i.e. to the beginning of the recording of the preparation -signaling zones that correspond to the alarm zones that have just been read, and possible repetition of these readings, as this repetition or repetition is designed to, when the ship leaves the corresponding chain, lead to the development of the chain-scanning operations already described.

In case of detection of correspondence between the vessel's coordinates and the coordinates of an alarm signaling zone, the second circuit leads, via P14, to repeat the reading and maintain the alarm signaling, so that the vessel is still able to avoid a possible collision.

It is thus not outside the scope of the invention to replace the magnetic tape, which is a movable recording medium, with a fixed storage or memory, as the data recorded in the memory is read either by permanent scanning or by indicating the address for the position of the recorded information. In reality, it is sufficient to register the preparatory signaling zones and alarm signaling zones for each of the relevant chains and to continuously read all coordinates for the preparatory signaling zones and alarm signaling zones for the chain used by the ship, in order to automatically detect a possible entry into and any exit of the ship from one of these zones in accordance with the described procedure. In particular, the coordinates of the preparation and alarm signaling zones can be placed in the memory in a given or ungiven order, provided that the coordinates of the preparation-signaling zones are first compared with the position coordinates of the ship, and that this comparison is completed by the comparison of the coordinates of the alarm zones and of the ship as soon as a coincidence in position has been detected in a preparation signaling zone. In reality, numerous detailed modifications can be applied to the method, and the contours of the areas or zones can vary depending on the characteristics of the sea hazards to be signalled.

Claims (7)

1. Procedure for the automatic determination of facilities and devices approaching a sea-going vessel and which may cause collisions or may themselves be damaged, using an arbitrary navigation system which automatically indicates the relevant vessel position, and an automatically read data memory which contains the position coordinates of all danger points or danger zones, and in which the current vessel position calculated by the navigation system is compared with the previously stored positions and a first signal is provided when the distance reaches a first predetermined value, and a second signal is provided when the distance reaches a second value, as the comparison operation takes place between on the one hand the vessel position and on the other hand numerical values that correspond to the danger points or danger fields, characterized by the fact that after reading the points and fields to be navigated in the form of numerical characteristics for zones, signaling areas and alarm areas that contain these points and fields, all characteristics for zones are automatically and repeatedly read until they match the characteristics for the vessel position provided by the navigation system - that all characteristics for the signaling areas contained within the zone are then read systematically one after the other until the corresponding ones for the zone, from the navigation system and the characteristics supplied from the memory are identical, that a signal is provided as soon as the characteristics supplied from the navigation system agree with one of the successive and systematically read characteristics, after which all stored characteristics within the zone traversed by the vessel are read and the same operations are carried out for the subsequent zones or areas when the ship enters another zone or another area, that further, all stored alarm areas located within the stored zone whose characteristics are provided by the navigation system are systematically and repeatedly read, and that an alarm signal is provided as soon as one of the read characteristics for alarm areas is identical to the characteristic for the area of residence determined by the navigation system. 2. Device for carrying out the method according to claim 1, comprising devices for converting and storing analogue values indicated by a navigation system into numerically coded values, devices for automatically reading stored characteristics for zones, signaling areas and alarm areas in which there are points or fields to be navigated, and devices for comparing the characteristics provided by the navigation system with the characteristics read in, characterized in that it also includes control circuits (90) for repeating the consecutive reading of all characteristics for zones, and a control circuit (92) for stopping the characteristic reading operation and for switching on the repeated reading operation for the sequence of characteristics for the zones, the control circuits being controlled by means of the comparison device (C17). 3. Device according to claim 2, comprising a magnetic tape reader which contains devices for controlling tape stop, tape feed, tape rewind and fast-forward, which devices can be operated via comparison circuits, characterized in that the comparison circuits comprise a first control circuit (87) for successive orders for tape rewind with successive read-forward, and a second control circuit (86) for successive orders of fast-forward with subsequent read-forward. 4. Device according to claim 2 or 3, characterized in that on each magnetic tape, in addition to the list (12, 13, 14) of the surface coordinates for the signaling area in question, there is at least a registration of characteristics (RI, R2) for the transmitter chains that cover -ker areas' surfaces, as the registrations of all signaling areas covered by the same transmitter chain are inscribed in groups on the magnetic tape (16) in accordance with the characteristic of the chain in question. 5. Device according to claim 4, characterized in that each preliminary signaling area is inscribed on the registration tape according to the characteristic of the relevant transmitter chain and before the stored values for the alarm areas located within the range of the same transmitter chain. 6. Device according to one of the claims 2-5, characterized in that the comparison device (C16) exclusively contains a transmitter chain assigned to the characteristics of the different signaling areas, which exhibits a first control circuit for the fast forwarding of the tape to look up the registration of the first signaling area to to which the transmitter chain specified with the help of the navigation system is assigned, and a second control circuit for tape feed and for reading the list of the signaling areas assigned to the transmitter chain which is both registered on the tape and determined with the help of the navigation system. 7. Device according to claim 6, characterized by a first comparison device for the numerically coded coordinates for the preliminary signaling areas from the memory and the ship position provided from the navigation system, with a first control circuit for band rewinding up to the characteristic (R2) for the first registration of a preliminary signaling area and for subsequent tape feed and reading, and with a second control circuit for reading the subsequent coordinates for the preliminary signaling areas, and. ) for the first recording of a preliminary signaling area, and for subsequent feeding and reading, and with a second control circuit for tape rewinding up to the characteristic (R3) for the first alarm area, and subsequent feeding and reading.