JP2002148094A - Method and equipment for measuring water level - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an equipment in which measurement of water level can be continued through image processing even if a battery can not be charged by a solar battery. SOLUTION: When the voltage of a battery 6 being charged by a solar battery 7 is lower than a set level, the period for measuring the water level by means of a camera 2 and an image processor 3 is increased. More specifically, the period for supplying power to the water level measuring equipment is increased when the voltage of the battery 6 is lower than the set level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring a water level in a dam, a river or the like by image processing.

[0002]

2. Description of the Related Art Generally, water levels (tidal levels) of dams, rivers, etc.
Is measured by providing a water mark (also referred to as a water plate) with a scale at a water level measurement point and reading it visually by a human.

In order to measure the water level mechanically, there is known a method in which a float is floated on a water surface and the displacement of the float is measured mechanically.

However, it is difficult to measure the water level by visual observation at a remote place, and mechanical measurement has a problem that reliability is lacking due to a failure such as a float.

[0005] In order to solve such problems, it has been proposed to perform image processing of an image of a water mark captured by an imaging device such as a camera to measure a water level, and it has already been put to practical use.
This is described in, for example, JP-A-7-33039 and JP-A-8-145765.

[0006] As described above, a water level measuring device that performs image processing of an image of a water mark to measure a water level includes an image capturing device such as a camera that captures an image of the water mark, and an image processing device that processes an image captured by the image capturing device. An image processing device for measuring the water level and a communication device for transmitting the measured water level measured by the image processing device to the monitoring station are required.

A power supply is required to operate the imaging device, image processing device, and communication device that constitute the water level measuring device. The power of the water level measuring device that measures the water level by image processing is 1
It is about 2V. 2. Description of the Related Art Conventionally, a power source of a water level measuring apparatus for measuring a water level by performing image processing is obtained by stepping down a voltage of a commercial power source.

By the way, it is required to install a water level measuring device for measuring a water level by image processing in a remote place where commercial power cannot be obtained. In such a case, a battery (storage battery) is used as a power source, and the battery is charged with a solar cell.

[0009]

When a battery (rechargeable battery) charged by a solar cell is used as a power source of the water level measuring device, the battery cannot be charged by the solar cell due to long-term irregular weather. If the battery cannot be charged by the solar cell, the battery voltage decreases, and the water level measurement device cannot be operated, and the water level cannot be measured.

[0010] Therefore, there is a strong demand that the water level can be continuously measured even if the battery cannot be charged by the solar cell due to irregular weather.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a water level measurement method and apparatus capable of continuously measuring a water level by image processing without charging a battery with a solar cell. Is to do.

[0012]

A feature of the present invention is that the water level measurement cycle is increased when the voltage of a battery charged by a solar cell is smaller than a set value.

Specifically, when the voltage of the battery is smaller than the set value, the period for supplying power to the water level measuring device is increased.

According to the present invention, when the voltage of the battery is smaller than the set value, the water level is measured by increasing the water level measurement period, so that the power consumption of the battery can be reduced and the water level can be measured continuously. When the weather recovers, the battery will be charged by solar cells.

[0015]

FIG. 1 shows an embodiment of the present invention.

In FIG. 1, a water mark 1, which is graduated at a measuring point of water level and is installed vertically to the water surface, is imaged by a camera 2. In order to accurately determine the water level in the vicinity of the water mark 1, for example, Japanese Patent Application Laid-Open No.
An unillustrated inclined plate as described in Japanese Patent No. 2370 is arranged.

The camera 2 is installed at a position where the water surface boundary 20 of the water mark 1 can be photographed. The distance between the camera 2 and the water mark 1 is about 100 m. Ideally, the camera 2 covers the entire measurement range with one scene (one shooting screen). However, usually, one scene is about 4 m from the resolution of the camera 2 and the required measurement accuracy. Covers the entire measurement range. For this reason, the camera 2 sets a preset scene in advance so as to match the preset scene determined by the water surface position, and the camera angle (shooting angle) is controlled according to the water surface position.

An image (water mark image) including the water mark 1 and the water surface boundary 20 taken by the camera 2 is processed by the image processing device 3.
Is taken in. The image processing device 3 analyzes the water surface boundary portion 20 of the water mark 1 to specify the water surface position, and calculates the water level using the reference scale of the water mark 1. The water level measurement value as the measurement result of the image processing device 3 is added to the communication device (wireless communication device) 4 and transmitted to the monitoring station.

The camera 2, the image processing device 3, and the communication device 4 are supplied with power from a battery 6 via a power supply circuit (switch) 5. The rated voltage of the battery 6 is 12V. Battery 6 is charged by solar cell 7.

The voltage Vo of the battery 6 is detected by a voltage detection circuit 8
And compared with the set value Vs. The set value Vs is, for example, 1
It is set to 1V. When Vs> Vo, the voltage detection circuit 8 gives a cycle change command to the measurement cycle control circuit 9. The measurement cycle control circuit 9 changes the cycle of turning on and off the switch of the power supply circuit 5 when the cycle change command is input.

The image processing device 3 comprises a central processing unit (CPU), a main memory, a bus, a dedicated image processor, an image memory, an external interface, and the like.

Next, the operation will be described.

When the voltage Vo of the battery 6 is higher than the set value Vs, the measurement cycle control circuit 9 turns on the switch 5 at a predetermined cycle. Usually, this period is about 10 minutes. When the switch 5 is turned on, the camera 2, the image processing device 3, and the communication device 4 are powered by the battery 6 and start operating.

An image (water mark image) including the water mark 1 and the water surface boundary 20 taken by the camera 2 is processed by the image processing device 3.
Is taken in. The image processing device 3 analyzes the water surface boundary portion 20 of the water mark 1 to specify the water surface position, and calculates the water level using the reference scale of the water mark 1.

The water level measurement of the image processing device 3 is performed as follows. The water level measurement program is stored in the main memory, and the CPU executes a water level measurement process according to the program. The image dedicated processor has a processing algorithm implemented as an LSI or hardware to execute the image processing function at high speed, and the image from the camera 2 and the image processing result of the image dedicated processor are stored in the image memory.

The water level measurement processing of the image processing apparatus 3 is performed a plurality of times in one measurement cycle, and the average is taken to create a ripple.

The measured water level measured by the image processing device 3 in this manner is applied to a communication device (wireless communication device) 4 and transmitted to a monitoring station. The measurement cycle control circuit 9 turns off the switch 5 when one cycle of measurement is completed. The time during which the switch 5 is turned on is about 2 minutes. In this state,
Battery 6 is charged by solar cell 7.

As described above, when the water level is measured,
It is assumed that the solar cell 7 does not sufficiently charge the battery 6 due to irregular weather, and the voltage Vo becomes smaller than the set value Vs. When Vo <Vs, the voltage detection circuit 8 gives a cycle change command to the measurement cycle control circuit 9. Upon input of the cycle change command, the measurement cycle control circuit 9 changes the cycle of turning on the switch of the power supply circuit 5 to be longer. The measurement cycle control circuit 9 sets, for example, 60 minutes.

When the voltage Vo of the battery 6 becomes smaller than the set value Vs, the switch 5 is turned on at a measurement cycle of 60 minutes,
The water level measurement is similarly performed in the image processing device 3. The camera 2, the image processing device 3, and the communication device 4 operate when the voltage supplied from the battery 6 is, for example, 9 V or more.

Thereafter, when the weather recovers and the battery 6 is charged from the solar cell 7 and the voltage Vo becomes larger than the set value Vs, the measurement cycle control circuit 9 sets the cycle of turning on the switch of the power supply circuit 5 to a normal cycle. Return to smaller.

The water level is measured as described above. When the battery voltage is smaller than the set value, the water level is measured by increasing the water level measurement cycle, so that the power consumption of the battery is reduced and the water level measurement is continued. You can do it. Thereafter, when the weather recovers, the battery is charged by the solar cell, so that the water level measurement can be continued.

In the above embodiment, the image pickup means such as a camera, the image processing means, and the communication means are activated and deactivated by turning on / off the power supply. However, it is also possible to directly turn on / off each means. It is clear.

Although the water level measurement cycle is changed to two, it goes without saying that the water level measurement cycle may be changed to a plurality of cycles according to the battery voltage.

[0034]

According to the present invention, when the battery voltage is smaller than the set value, the water level is measured by increasing the water level measurement cycle, so that the power consumption of the battery can be reduced and the water level measurement can be continued. . Thereafter, when the weather recovers, the battery is charged by the solar cell, so that the water level measurement can be continued.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

[Brief description of reference numerals]

DESCRIPTION OF SYMBOLS 1 ... Water mark, 2 ... Camera, 3 ... Image processing device, 4 ... Communication device, 5 ... Power supply circuit (switch), 6 ... Battery, 7 ...
Solar cell, 8: voltage detection circuit, 9: measurement cycle control circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoichi Takagi 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Akio Tsujikawa 5-chome Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Information Control Systems Division (72) Inventor Takumi Ebisawa 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture F-term (reference) 2F014 FA04 GA10 5F051 BA05 BA11 JA17 JA20 KA03 KA10

Claims (5)

[Claims] 1. A water mark indicating a water surface position is photographed by an image pickup means, and an image photographed by the image pickup means is subjected to image processing by an image processing means to measure a water level and is communicated by a communication means. A water level measurement method, characterized in that a water level measurement cycle is increased when a voltage of a battery charged by a battery and supplied to the imaging means, the image processing means and the communication means is smaller than a set value. 2. A water mark indicating a water surface position is photographed by an image pickup means, and an image taken by the image pickup means is subjected to image processing by an image processing means to measure a water level and communicate by a communication means. When the voltage of the battery that is charged by the battery and supplies power to the imaging unit, the image processing unit, and the communication unit is smaller than a set value, the water level measurement cycle for supplying power to the imaging unit, the image processing unit, and the communication unit to measure the water level is increased. A water level measurement method characterized in that the water level is measured. 3. An image pickup means for picking up a water mark indicating a water surface position, an image processing means for processing an image picked up by the image pickup means to measure a water level, and a water level measurement value measured by the image processing means. A communication means for transmitting a signal, a battery charged by a solar cell and supplying power to the imaging means, the image processing means and the communication means, and a measurement cycle control means for increasing a water level measurement cycle when the voltage of the battery is smaller than a set value. A water level measuring device comprising: 4. An image pickup means for picking up a water mark indicating a water surface position, an image processing means for processing an image picked up by the image pickup means to measure a water level, and a water level measurement value measured by the image processing means. And a battery that is charged by a solar cell and supplies power to the imaging unit, the image processing unit, and the communication unit. When the voltage of the battery is smaller than a set value, the imaging unit, the image processing unit, and the communication unit A water level measurement device comprising: a measurement cycle control unit that increases a water level measurement cycle for measuring a water level by supplying power. 5. A camera for picking up a water mark indicating a water surface position, image processing means for image-processing a water mark image picked up by said camera to measure a water level, and water level measurement measured by said image processing means. Wireless communication means for transmitting a value, a battery charged by a solar cell, opening and closing means for supplying power to the imaging means, image processing means and communication means from the battery, and opening and closing when the voltage of the battery is smaller than a set value. A measuring cycle control means for increasing a water level measuring cycle for turning on the means.