JPS62194992A - Supervision device for passenger - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation in which an alarm signal is transmitted in spite of the fact that a passenger does not fall into the sea by installing a switching device which alternately switches a plurality of antennas in the sufficiently shorter time than the continuation time of the electric waves of a transmitter and connects the antenna with a receiver. CONSTITUTION:A subsidiary machine 1 as transmitter transmits electric waves intermittently in a certain cycle. Two antennas 2a and 2b are installed at different positions so that the electric waves can be received at a certain level by either of the antennas 2a and 2b even if the position or the attitude of a passenger having the subsidiary machine changes. Further, a switching device 3 is connected to a receiver 4 by alternately switching the output of the antennas 2a and 2b, and a detection part 13 receives the output signal of the receiver 4 and outputs an alarm signal which shows the cut-off of the electric waves transmitted from the subsidiary machine 1. Since the switching time by the device 3 is sufficiently shorter than the continuation time of the electric waves transmitted by the subsidiary machine 1, the presence of the electric waves can be certainly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a monitoring device for people on a ship, etc., for issuing an alarm when a person on a ship falls into the water or into the sea.

(Prior Art and its Problems) Conventionally, a distress signal transmitting device has been proposed that detects when a passenger on a ship falls into the sea and automatically takes rescue measures. . For example, as shown in Japanese Patent Application Laid-open No. 103735/1983, when a passenger carrying a handset that is a transmitter falls into the sea,
When the radio waves from the handset are cut off, the reception input of the receiver installed on the ship decreases, so a monitoring device is used that detects this and issues a W@i signal, and this alarm signal is used to alert the ship. The engine is stopped and a transceiver sends a distress signal to notify of the occurrence of an emergency situation. In order for such devices to carry out complete rescue operations and ensure safety, it is necessary to ensure that a distress signal is issued only when a passenger actually falls, and that it is not issued at any other time. It is necessary to increase the reliability of the monitoring device so that the engine is not stopped.

However, in the conventional device, since the radio waves of the handset are received by seven antennas, deficiencies occur due to the th tropism of the handset and interference from nearby obstacles. For this reason, depending on the position and posture of the person on board carrying the handset, the receiving input of the receiver may drop and issue a warning signal, which may cause the engine to stop and a distress signal to be issued even though there is no emergency situation. There was a problem.

(Technical means for solving the problem) In view of the above-mentioned problem, the present invention is designed to prevent the reception input from decreasing as much as possible even if the position or posture of the passenger carrying the handset, which is a transmitter, changes. The purpose is to prevent as much as possible the malfunction of a warning signal being issued even though no passenger has fallen.The technical means for this purpose is to carry a warning signal carried by the passenger and emit radio waves intermittently. It has a transmitter 1, antennas 2a and 2b installed on a ship, etc., and a receiver 4, and the receiver'v
i4 is a monitoring device for passengers, etc., which emits an alarm signal when the received input from the transmitter 1 falls below a certain level, and a plurality of the antennas 2a and 2b are installed, and the plurality of antennas 2a;
2b is provided with a switching device 3 which alternately disconnects the radio waves 2b and connects them to the receiver 4 in a time sufficiently shorter than the duration of the radio waves emitted by the transmitter l.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, the slave unit l, which is a transmitter, has a
The amplitude of a carrier wave of approximately MIIZ is varied by a modulation pulse as shown in FIG. 4a, and radio waves are emitted intermittently at a constant period as shown in the figure. In the figure a, for example, t 1 = 100 m5ec.

It is assumed that t 2 = 300 m5ec. The two antennas 2a and 2b are installed at different positions so that radio waves can be received at a certain level by either antenna 2a or 2b even if the position or posture of the passenger carrying the handset l changes. ing. These are usually installed at intervals of 2 m or more, and for example, in the case of a small boat, they are installed in a place with good visibility, such as on the front and rear bridges. Switching device'f! , 3 are both antennas 2a, 2
This is for alternately switching the outputs of the output terminals b and connecting them to the receiver 4, and includes a switch section 5, a switch drive section 6, and an oscillation section 7. As shown in FIG. 4C, the oscillating unit 7 generates a signal for a time sufficiently shorter than the duration (modulation pulse width) 1 of the radio waves emitted by the handset 1, for example, L 3 =
It oscillates a switching pulse with a duty ratio of 50% with a cycle of romsec, which activates the switch driving section 6 to drive the switch section 5. FIG. 2 shows a more specific example of the switching device 3. The switch section 5 is composed of diodes DI + D2, and a positive potential is alternately applied to the diodes -FDt and D2 by a switch drive section 6 including a transistor TRI. can now be added. In addition, in the same figure, the high frequency preamplifier 8
is provided.

The output from the switching device r11.3 is sent by cable 9 to the receiver IO of the receiver 4 and is demodulated there. When both antennas 2a and 2b are receiving radio waves of sufficient strength from the slave unit 1, the output from the receiving unit 10 has a pulse waveform for modulation at the slave unit 1, as shown in Fig. 4d. A waveform similar to (a) in the same figure can be obtained, but if this is not the case, for example, if there is no reception input to one of the antennas 2a and 2b, the pulse waveform is the same as that in a), as shown in (e) in the same figure. A waveform similar to an AND with the switching pulse waveform shown in Figure C is obtained.

The integrator 11 is for integrating the output of the receiving section 10 and smoothing the switching pulse component, so that the waveform shown in FIG. 4C becomes the waveform shown in FIG. 4F. The waveform shaping section 12 is composed of, for example, a Schmitt trigger element, and outputs the waveform shown in g in the figure when there is an input shown in f in the figure. Figure 3 shows receiver 4
A more specific example is shown in which the switching circuit SWG detects the level of the received carrier wave from the detector DBT, and outputs a high-level logic signal when this level is above a certain value.

The detection unit 13 receives the output signal of the receiver 4 and outputs an alarm signal indicating that the radio waves from the handset 1 have been interrupted, and detects the pulse time width of the pulse signal output from the waveform shaping unit 12. and the period is measured, and the time width t! of the *tonal pulse of child ta1! and period t2 to detect whether the period is within a certain allowable range.

For example, if the pulse period of the signal is 240m5ec or less,
The signal passes through three pulse period g1 recognition means of 0 m5 ec or less and 5 sec or less, and the signal is 300 m5 ec ± 2.
If the signal is out of 0%, the interference indicator lamp will blink, and if the signal is interrupted for 5 seconds, an alarm signal will be output. Such a detection unit 13 can be realized by a program using a microcomputer.

When an alarm signal is output from the detection unit 13, the alarm unit 14 emits an alarm sound by, for example, a buzzer or audio broadcast, stops the ship's engine after a certain period of time has elapsed, and also turns on a wireless transmitter after a certain period of time has elapsed. This system sends a distress signal to notify of the occurrence of an emergency situation.

According to the above embodiment, the antennas 2a and 2b of 2111 are installed at different positions to receive the radio waves emitted by the slave unit 1, so the position and posture of the person on board carrying the slave unit 1 changes. Even if the antenna 2a, 2b is connected to the receiver 4, it is possible to receive radio waves at a certain level or higher using either antenna 2a, 2b. A constant receiving input can be obtained regardless of the position of the receiver. Since the switching time by the switching device 3 is sufficiently shorter than the connection time of the radio waves emitted by the child fit, the two antennas 2a, 2
Even if only one of b has receiving input,
The signal waveform can be easily restored using the integrator 11 or the like, and the presence or absence of radio waves from the handset 1 can be easily and reliably detected. Therefore, if a passenger carrying handset 1 falls into the sea and the radio waves are cut off, the W alarm signal will be reliably emitted, and even if the passenger has not fallen and is still on the ship, the position and posture of the passenger will be It is possible to prevent a malfunction in which an alarm signal is issued due to a malfunction, thereby improving the reliability of the device. Since the handset 1 emits radio waves intermittently, it consumes less power and has a longer battery life, and by varying the duration and cycle, it is possible to identify multiple handsets. .

In the above embodiment, two antennas 2a and 2b are provided, but three or more antennas may be used.
They may be connected to the receiver one by one, or they may be connected to a receiver by making a set of two and switching between each set.
The time width t1 and period t2 of the modulation pulse of the handset I, the period t3 of the switching pulse, etc. can be determined as appropriate. The radio waves of the handset 1 may be modulated at a low frequency, and various circuits such as the switching device 3 and the receiver 4 may be employed. can be used for monitoring.

(Effects of the Invention) According to the present invention, it is possible to prevent the reception input from dropping below a certain level depending on the position and posture of the person on board carrying the handset, which is a transmitter, and to prevent the person on board from falling. It is possible to prevent as much as possible a malfunction in which the 1i notification signal is issued even though the 1i notification signal is not in use. Therefore, the reliability of the entire device is improved, and as a result, more rapid rescue operations can be expected, and the safety of passengers and others can be protected.

The switching time by the switching device is sufficiently shorter than the connection time of the radio waves emitted by the handset, so even if only one of the two antennas has a receiving input, the signal waveform can be easily restored using an integrator, etc. The presence or absence of radio waves from the handset can be easily and reliably detected. Also, since the f# transmitter emits radio waves intermittently, the life of the battery is extended, and the continuous use time of the transmitter is extended accordingly.
Reliability is improved by reducing the possibility that radio wave emission will unexpectedly stop during use.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall block diagram, FIG. 2 is a circuit diagram showing an example of a switching device in detail, and FIG. 3 is a circuit diagram showing an example of a receiver in detail. , FIG. 4 is a diagram showing signal waveforms of each part. 1... Handset (transmitter), 2a, 2b... Antenna, 3... Switching device, 4... Receiver.

Claims (1)

[Claims] It has a transmitter that is carried by passengers on board and emits radio waves intermittently, and an antenna and receiver that are installed on the ship, etc., and the receiver receives input from the transmitter when the reception input from the transmitter falls below a certain level. A monitoring device for passengers, etc., which sometimes emits an alarm signal, in which a plurality of said antennas are installed, and said plurality of antennas are activated for a sufficiently shorter time than the duration of radio waves emitted by said transmitter. 1. A monitoring device for persons on board, etc., characterized in that a switching device is provided to alternately switch and connect to the receiver.