JPH05186189A - Device for detecting approach of long-size body to obstacle - Google Patents

Abstract

PURPOSE:To detect the approach or a long-size body to an obstacle with high accuracy by providing a sound wave generator to be mounted on the long-size body, sound wave receivers to be installed in three positions, a measuring instrument for the parameters of the environment, a position detecting device and an alarm generator. CONSTITUTION:A device for detecting the approach of a long-size body to an obstacle includes a sound wave generator 1 mounted on a long-size body such as a crane 10 to transmit ultrasonic or sound waves, sound wave receivers 2a-2c installed in three spaced positions including a transmission line 9 as an obstacle and receiving sound waves from the sound wave generator 1, and a parameter measuring instrument 13 for measuring the parameters of the environment which fluctuate the sound waves. The difference in the time required for the sound waves to arrive among the sound wave receivers 2a-2c is measured from the timing of transmission and the timing of reception of the sound waves and a position detecting device 3 calculates the position of the sound wave generator 1 according to the data on the time difference and to the sound waves corrected according to parameter data, and the calculated position is compared with a set value and an alarm generator 7 generates an alarm when the crane 10 is within the set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an obstacle length approaching device for issuing an alarm when an obstacle such as a crane approaches an obstacle.

[0002]

2. Description of the Related Art Generally, monitoring of the approach of a crane to an obstacle such as a power line is carried out by visual inspection by a human at the site,
Alternatively, a method is used in which a TV camera is installed and the image is transmitted to a construction office or the like, where it is viewed by a human through a monitor TV. However, in both cases, since humans visually monitor the approach of the crane to the power transmission line, there is a problem that it requires a great deal of labor, time, and cost.

Therefore, conventionally, an ultrasonic sensor for transmitting and receiving ultrasonic waves and an electric field sensor for detecting the strength of an electric field are attached to the tip of a crane boom, and the ultrasonic sensor monitors the echo from the structure. Has been proposed (for example, Japanese Utility Model Laid-Open No. 63-200589) to detect the approach of the high voltage electric wire by monitoring the electric field from the high voltage electric wire with an electric field sensor. According to this, since the machine automatically monitors the approach of the crane without human eyes, the labor and time can be greatly reduced, and the cost can be reduced.

[0004]

However, in the conventional detection device, the ultrasonic sensor is designed to detect the echo reflected from the structure, but the echo is the disturbance or the reflection surface of the structure. Since it is strongly influenced, there is a lot of noise, and it is very difficult to accurately extract only the reflection echo of the structure from it. The electric field sensor has the same detection accuracy and cannot be used for DC power transmission. In addition, it can be said that both sensors are affected by environmental parameters such as wind direction, wind speed, temperature, and atmospheric pressure, but the effects are not taken into consideration at all. However, there is a problem that the measurement accuracy is not good because it is a one-point measurement. Further, since there are two types of sensors, that is, an ultrasonic sensor and an electric field sensor, there is a drawback that the device on the crane becomes large-scale. These are common not only to cranes but also to other long bodies.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and detect the approach of a long object to an obstacle with high accuracy by receiving and detecting at three points instead of detecting an echo from one point. An object is to provide a device for detecting a long object approaching an obstacle that is capable of performing the above.

[0006]

SUMMARY OF THE INVENTION An obstacle long-distance approaching apparatus of the present invention includes a sound wave generator which is attached to a long object such as a crane and intermittently emits ultrasonic waves or sound waves to the surroundings. A sound wave receiver attached to any three points spaced apart from each other including the vicinity of an object to independently receive sound waves emitted from a sound wave generator, and a parameter measuring device for measuring surrounding environmental parameters that cause fluctuations in sound velocity. , The sound wave arrival time difference between each sound wave receiver is measured from the transmission timing of the sound wave generator and the reception timing received by each sound wave receiver, and the sound velocity corrected based on the measured time difference data and the parameter data from the parameter measuring device. And a position detection device that obtains the position of the sound wave generator from the and a alarm that issues an alarm when the position of the elongated body falls within the set value by comparing the position obtained by the position detection device with the set value. It is constructed by a generator.

[0007]

When ultrasonic waves or sound waves are transmitted from the sound wave generator attached to the elongated body, the sound waves are received by the sound wave receivers installed at three points. The reception involves a delay in arrival time according to the distance from the long body. The position detecting device multiplies the arrival time difference between the two sound wave receivers by the speed of sound to obtain the difference in the distance from the two sound wave receivers to the position of the elongated body. To do. The speed of sound used when calculating the difference in distance is the wind direction detected by the parameter measuring device,
Since it is corrected based on environmental parameters such as temperature,
Accurate distance calculation is performed. If this is similarly calculated between other sound wave receivers, three hyperbolas that connect points where the difference in distance from the two fixed points is constant are formed. The point where at least two hyperbolas intersect is the position of the elongated body. When the position of the elongated body is detected in this way, the alarm generator makes a comparative determination as to whether or not the detected value is within the preset abnormal proximity distance, and determines that it is within the abnormal proximity distance. Then, the alarm sounds automatically from the alarm generator. As a result, the long worker can know the danger.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a crane approach detection device for a power transmission line according to this embodiment. At the boom tip of the crane 10,
A sound wave generator 1 that intermittently emits ultrasonic waves or sound waves is attached so that sound waves can be emitted around the crane 10. The sound wave receivers 2 spaced apart from each other are provided at arbitrary three points around the crane 10, and the sound waves emitted from the sound wave generator 1 are independently received. Although the three locations where the sound wave receiver 2 is arranged are arbitrary, in the illustrated example, the crane 10 is a crane for power transmission line construction, and the power transmission line 9 is assumed as an obstacle to the crane 10.
The points are located on adjacent steel towers 8a and 8b that suspend and support the power transmission line 9, and their sound wave receivers are designated as 2a and 2b. If possible, it may be directly attached to the power transmission line 9. Also,
The remaining 1 point is on the ground, and 2 sound wave receivers are installed there.
c.

The signal received by each sound wave receiver 2 is sent to the position detecting device 3 installed on the ground by wire, wireless or optical fiber. The position detection device 3 detects the position of the crane, and the position detection device 3 receives not only the signal from the sound wave receiver 2 but also the signal from the environmental parameter measurement device 13. .. The environmental parameter measuring device 13 is composed of an anemometer / anemometer 4, a thermometer 5 and a barometer 6, which are attached to arbitrary points on the ground or in the air, and respectively locate the anemometer / wind speed, temperature and atmospheric pressure data. It is designed to be sent to the detection device 3. Only a part of these parameters may be sent to the position detecting device 3.

As shown in FIG. 2, the position detector 3 comprises a time difference measuring device 11 and a position calculator 12. The time difference measuring device 11 receives the reception signal from each of the sound wave receivers 2 and calculates the arrival time difference of the sound waves from the sound wave generator 1 from each timing. The position calculator 12 corrects and obtains an accurate sound speed in the current environment from the wind direction / wind speed, temperature, and atmospheric pressure data, and determines the position of the sound wave generator 1 from the corrected sound speed and the arrival time difference of the sound waves calculated previously. Calculate as described below. When it is determined from the calculation result that the sound wave generator is approaching the power transmission line 9, the position calculator 12 sends an alarm signal to the alarm generator 7, and the alarm generator 7 issues an alarm. The determination is made by comparing a preset abnormal approach distance with the calculation result, and the alarm generator 7 can be configured by a comparison / determination device and an alarm lamp, an alarm buzzer, or the like.

Next, the principle of position calculation executed by the position calculator 12 will be described. The difference in distance between the two sound wave receivers 2 and the sound wave generator 1 can be calculated from the speed of sound and the arrival time difference of the sound waves at any two sound wave receivers 2.
In FIG. 3, sound velocity is now v, two receivers are 2a, 2
b, two wave receivers 2a, sound waves arrival time to 2b t _a, When t _b, the difference D _ab distance to the two wave receiver 2 _a, 2 _b are, D _ab = v · ( t _a -t _b) represented by (1). Therefore, when a curve is drawn by calculating so that the difference in distance to the two sound wave receivers 2a and 2c is constant,
A hyperbola ac is obtained. Similarly, for other combinations of the two sound wave receivers 2a and 2c and 2b and 2c, a curve is drawn by calculating so that the difference in distance is constant.
c and bc are obtained. The intersection of these three hyperbolas is the position of the sound wave generator 1, that is, the position of the crane. It should be noted that the intersection of two hyperbolas of the three hyperbolas is sufficient to specify the position of the crane, but three installation points of the sound wave receiver are required as can be seen from the above calculation. Most 4
The points may be set, or the three-point measurement may be set in duplicate.

According to this embodiment, the difference in the arrival time of the signals from the sound wave transmitters attached to the crane to the three points is measured, so that the approach of the crane to the power transmission line can be automatically detected without human visual inspection. Can be detected. In particular, since the measurement is performed at three points, it is possible to improve the detection accuracy without being affected by noise and reflection as in the case of measuring one point. Also,
Since the receiver is attached to the power transmission line side, the electric field sensor is not required and the device attached to the crane can be downsized, and it can be used for DC transmission. Moreover, wind direction, wind speed,
Since the sound velocity is corrected by measuring environmental parameters such as temperature and atmospheric pressure, the measurement accuracy can be significantly improved.

[0013]

According to the present invention, the arrival time difference of sound waves at three points is measured, and the position of the elongated body is obtained using this time difference and the sound velocity corrected in accordance with the environment. It is possible to detect various positions, and it is possible to detect a long object approaching an obstacle with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an apparatus for detecting a crane approaching an obstacle according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a signal processing system according to the present embodiment.

FIG. 3 is an explanatory diagram showing a position calculation method of the present embodiment.

[Explanation of symbols]

 1 sound wave generator 2, 2a, 2b, 2c sound wave receiver 3 position detection device 4 wind direction and anemometer 5 air temperature meter 6 barometer 7 alarm generator 8 steel tower 9 transmission line 10 crane 11 time difference measuring device 12 position calculator 13 parameters Measuring instrument

Claims (1)

[Claims] 1. A sound wave generator which is attached to a long body and intermittently transmits ultrasonic waves or sound waves to the surroundings, and a sound wave generator which is attached to any three points separated from each other including the vicinity of an obstacle and transmits from the sound wave generator. Between the sound wave receiver that receives sound waves, a parameter measuring device that measures ambient environmental parameters that give fluctuations in the speed of sound, and the sound wave generator's transmission timing and the reception timing received by each sound wave receiver. The position detection device that determines the position of the sound wave generator from the measured time difference data and the sound velocity corrected based on the measured time difference data and the parameter data from the parameter measurement device, and the position that is determined by the position detection device are set. An apparatus for detecting the approach of a crane to an obstacle, comprising: an alarm generator that issues an alarm when the position of the elongated body falls within a set value compared with a value.