JPS63134980A - Detector for object in water channel - Google Patents

Abstract

PURPOSE:To prevent an erroneous alarm when one ultrasonic sensor has executed an erroneous detection, by raising an alarm by a deciding circuit, when a detecting signal has been sent out in order and at time intervals which are set in advance from plural ultrasonic sensors. CONSTITUTION:When an invasion object 5 exists in a water channel 4, first of all, a reflection type sensor 1 detects it, and a detecting signal is sent out to a deciding circuit 3. The deciding circuit 3 outputs an alarm signal, only when a detecting signal has been received from a cutoff type sensor 2 within a time set in advance based on the time when a detecting signal from the reflection type sensor 1 has been received, as a reference. When the detecting signal is not outputted from the cutoff type sensor 2 within said time, it is regarded as an erroneous detection due to a reflected wave, etc. in the water channel 4, and no alarm signal is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting intruders in a waterway, such as a waterway or an intake waterway, and generating an alarm signal.

[Conventional technology]

Generally, in order to prevent foreign objects and other intruders from entering a waterway such as a waterway or an intake channel, it is sufficient to attach a device to the waterway to detect intruders. No such device is available.

An example of such a device could be an active sonar for searching for target objects in open water.

[Problem that the invention seeks to solve]

However, when the above-mentioned active sonar is attached to a waterway, there is a problem that reliable operation cannot be expected because the waterway is an environment where there are many reflected waves of ultrasonic waves.

In view of such problems, an object of the present invention is to provide a highly reliable detection device for detecting an intruder in a waterway.

[Means for solving problems]

The present invention includes a plurality of ultrasonic sensors that monitor a plurality of isolated positions in a waterway, and outputs an alarm signal when detection signals are received from the plurality of ultrasonic sensors in a certain order and at a certain time interval. The object of the present invention is to provide an object detection device in a waterway, which is equipped with a determination circuit for detecting an object in a waterway.

[Effect]

If there is an intruder in the waterway, the plurality of ultrasonic sensors detect the intruder when it reaches the monitoring position, and send a detection signal to the determination circuit. As mentioned above, in waterways, ultrasonic sensors have a high risk of false detection due to reflected waves in the waterway, but if an intruder actually exists, these ultrasonic sensors will detect signals in a certain order and time interval. This means that a detection signal will be sent out.

The determination circuit outputs an alarm signal when the detection signals are sent out in a preset order and time interval. Therefore, even if there is a false detection in each ultrasonic sensor, this can be eliminated.

〔Example〕

An embodiment of the present invention will be explained based on Fig. 1 fal (b) (cl. Fig. 1 fa) The configuration diagram shown in FIG.

As shown in these figures, a reflective sensor 1 equipped with a transducer TR is attached to a side wall of a waterway.

The beam of the transducer TR has a slight angle with respect to the longitudinal direction of the waterway, and is set in a direction that crosses the waterway.

Further, the cut-off type sensor 2 includes a transmitter T and a receiver R, which are attached opposite to both side walls of the waterway. The determination circuit 3 is
This is a circuit to which the detection signal of the reflection type sensor 1 and the detection signal of the cutoff type sensor 2 are sent. It sends out an alarm signal only when the

In the above configuration, when there is an intruder 5 in the waterway 4,
First, the reflective sensor 1 detects this and sends a detection signal to the determination circuit 3.

When a detection signal is sent from the reflective sensor 1, the determination circuit 3 processes the detection signal for a set period of time in order to determine whether the detection signal is due to an intruder 5 or a false detection due to reflected waves in the waterway 4. Of these, the cut-off type sensor 2 is monitored.

If the detection signal from the reflective sensor 1 is correct and an intruder 5 is present, the intruder 5 will after a while invade to a position where it blocks the transmitter T and receiver R of the cut-off sensor 2.
The cutoff type sensor 2 detects this and sends out a detection signal.

The determination circuit 3 sends out an alarm signal only when there is a signal from the cut-off type sensor 2 within a preset time period based on the time when the detection signal from the reflection type sensor 1 is received. During this time period, reflective sensor 1 and blocking sensor 2
It is set in advance in consideration of the interval between the two, the angle of the beam of the transducer TR, the speed of the water flow, etc. In cases other than the above, 3.
It is assumed that this is a false detection due to reflected waves in the waterway 4, etc., and no alarm signal is output. Note that the alarm signal is sent to an alarm device, a gate opening/closing control device, or the like.

In this way, an alarm signal is sent only when there is a detection signal from both the reflective sensor 1 and the blocking sensor 2 at a predetermined time interval, so if either sensor makes a false detection, there is no chance that an error will occur. It does not send out alarm signals and can be expected to operate with high reliability.

Furthermore, although this embodiment shows a mode in which two sensors are used, it is also possible to adopt a mode in which three or more sensors are used, and as the number of sensors increases, the reliability will further improve. .

In addition, if the configuration is a combination of a reflection type sensor and a blocking type sensor as in this example, it is possible to monitor isolated locations in the waterway without installing the sensors in isolation. This has the advantage of being easy to install.

〔Effect of the invention〕

As explained above, according to the present invention, when detection signals are sent from a plurality of ultrasonic sensors in a preset order and time interval, the determination circuit outputs an alarm (g), so that individual Even if there is a false detection in the ultrasonic sensor, this can be eliminated, and an extremely reliable detection device can be provided.

[Brief explanation of the drawing]

1(a), (b), and (c) are diagrams showing one embodiment of the present invention, in which (a) is a configuration diagram showing an outline of the device;
C1 is a sectional view and a plan view of a waterway showing a state in which sensors are attached. 1...Reflection type sensor, 2...Block type sensor, 3...
- Judgment circuit, 4... Waterway, 5... Invading object, T... Transmitter, R... Receiver, TR... Transducer/receiver. (a) Diagram showing one embodiment Whistle 1 M (b) (C) Diagram showing one embodiment

Claims (1)

[Claims] A plurality of ultrasonic sensors (1, 2) each monitor a plurality of isolated positions in a waterway, and an alarm signal is issued when detection signals are received from these plurality of ultrasonic sensors in a certain order and at a certain time interval. An object detection device in a waterway, comprising: a determination circuit (3) for outputting an output.