JPH0694458A - Structure level measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain a high accuracy structure level measuring apparatus with a small measurement error by detecting a change of light emission level of a laser radiator to every predetermined unit and calculating the level of a measuring point from the above detected value and an average of the number of outputs of light receiving signals from a light receiver for each of light emission levels. CONSTITUTION:A light receiver 2 for outputting a light receiving signals in response to light reception of a laser beam is placed at a measuring point of a structure. A laser radiator 1 is horizontally rotated at a predetermined velocity while radiating the laser beam in the horizontal direction and moved up and down at a predetermined velocity by an elevation device 15. An upper and lower position detector 19 detects a change of the light emission level of the laser radiator 1 to every predetermined unit to output a height signal. A control device 20 drives a motor in accordance with a tilt angle signal depending on a tilt angle detected by a tilt sensor provided on a level adjuster 4 so as to keep the laser radiator 1 horizontally and drive the elevation device 15. The control device 20 simultaneously calculates a level at the measuring point from the change of the light emission level detected by the detector 19 and the average of the number of outputs of the light receiving signals from the light receiver 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a measuring device for measuring the level of a large number of points of a structure by using a laser beam.

[0002]

2. Description of the Related Art Recently, as a method of knowing the level change of a large number of measurement points installed in a structure such as measurement of uneven settlement of a structure, electronic measurement using a laser beam emitter and a receiver Many measurement methods are used.

For example, in Japanese Patent Laid-Open No. 60-25413, a laser beam light emitter is installed at a reference point, a light receiver is attached to a measurement site, and a large number of light receiving elements are arranged vertically. It has been proposed that the level of the measurement site is judged from the position of the light-receiving element by irradiating the laser beam on. When there are many measurement points such as uneven settlement of the structure, and moreover, periodical measurement is required, set the photoreceiver at that position and input the output to the computer to improve the efficiency. Good measurements can be performed.

[0004]

However, in this case, in order to improve the accuracy (resolution) of the level measurement, it is necessary to increase the array density of the light receiving elements vertically arranged in the light receiver, but there are many measurement points. In this case, since the number of light receivers installed may increase, it is necessary to prepare a large number of light receivers having such a high element density, which makes the measuring device very expensive and further increases the resolution. For this reason, it is necessary to detect and eliminate measurement errors due to ambient vibrations and disturbances such as work vehicles and personnel.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a highly accurate structure level measuring apparatus with few measurement errors.

[0006]

A first aspect of the present invention is to provide a light receiver 2 installed in a measuring point of a structure in FIG. 1 for outputting a light receiving signal by receiving a laser beam, and a laser beam. A laser irradiator 1 that horizontally swirls at a predetermined speed while irradiating in the horizontal direction, an elevating device that raises and lowers the laser irradiator 1 at a predetermined speed, and a change in emission level of the laser irradiator 1. Is detected for each predetermined unit, and the average value of the number of times the light receiving signal of the light receiving device 2 is output at each laser emission level detected by the detecting device 19 The light receiving position calculating means 30 for calculating the level and the level distribution comparing means 32 for judging the measurement abnormality when the difference between the maximum value and the minimum value of the light receiving level exceeds a preset allowable value.
Further, at the time of the abnormality judgment of the comparison means 32, at least the control means 31 for displaying invalidity of the level calculation result of the calculation means 30 and re-measurement is provided.

In the second invention, in FIG. 1, a light receiver 2 which is installed at a measuring point of a structure and outputs a light receiving signal by receiving a laser beam, and a laser beam is emitted in a horizontal direction. Laser irradiator 1 that horizontally turns at a predetermined speed, and this laser
A lifting device for moving the irradiator 1 up and down at a predetermined speed;
Means 19 for detecting a change in the light emission level of the laser irradiator for each predetermined unit, a change in the laser light emission level detected by the detecting means 19, and the light receiver 2 at each of these levels.
A light receiving position calculating means 30 for calculating the level of the measuring point where the light receiver 2 is arranged, from the average value of the number of times the light receiving signal is output,
A reciprocating value comparison means 33 for judging a measurement abnormality when the difference between the result of the calculation means 30 in the ascending direction of the elevating device and the result of the calculation means 30 in the descending direction exceeds a preset allowable value; At the time of judging the abnormality of the comparison means 33, at least the invalidity of the level calculation result of the calculation means 30 is displayed,
The control means 31 which measures again is provided.

[0008]

According to the first aspect of the invention, the light receiving position calculation means divides the sum of the products of the respective light emitting levels of the laser beam and the number of times of light reception of the light receiver at that level by the total number of times of light reception to obtain a measurement level, and the level distribution The comparing means compares the difference between the maximum value and the minimum value of the level at which the light receiving signal is generated in the light receiving position calculating means with a preset allowable value, and when the difference between the maximum value and the minimum value exceeds the allowable value, It is determined that the measurement value is abnormal and the calculation result of the light receiving position calculation means is invalidated, and the measurement control means displays the abnormality of the measurement value, the lifting device is returned to the origin, and the measurement is performed again. Eliminate abnormalities.

According to a second aspect of the present invention, the light receiving position calculation means divides the sum of products of the respective light emitting levels of the laser beam and the number of times of light reception of the light receiver at that level, by dividing the result by the total number of times of light reception, and this measurement level is obtained. The level is calculated in each of the ascending and descending directions of the lifting device, and the difference between these levels is further calculated by the reciprocating value comparison means, and the calculated difference is compared with a preset allowable value. When it exceeds the value, the calculation result of the light receiving position calculation means is invalidated, the measurement value is judged to be abnormal and the measurement control means displays the abnormality of the measured value on the display device, and the lifting device is returned to the origin to measure again. Perform to eliminate abnormal measurement values due to disturbance.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a laser irradiator 1 for irradiating a laser beam, and a large number of light receivers 2 for receiving the laser beam are arranged at respective measuring points around the laser irradiator. To be done.

The light receiver 2 has a single light receiving element which outputs an electric signal by receiving a laser beam. A phototransistor or a photodiode is used for this light receiving element, for example.

The laser irradiator 1 is supported by a lifting device 15 and horizontally oscillates at a predetermined speed while emitting a laser beam in a horizontal direction.

For this purpose, the laser irradiator 1 is equipped with a turning motor which rotates at a predetermined constant speed. Also, the lifting device 1
A leveling device 4 is provided between the device 5 and the device. The level adjuster 4 is arranged around the orthogonal horizontal rotation axes, and the laser irradiator 1 is provided.
And a tilt sensor for detecting the tilt angle of the laser irradiator 1 around each axis, and the controller 20 drives each motor based on the angle detected by the tilt sensor, thereby irradiating the laser. Keep vessel 1 horizontal.

The elevating device 15 is composed of, for example, a screw mechanism which is fed by rotation of a motor, and expands and contracts at a predetermined constant speed. The lifting device 15 can also be configured by a hydraulic cylinder or the like.

A vertical position detector 19 in parallel with the lifting device 15.
Is provided. Each time the light emission level of the laser irradiator 1 changes by a predetermined measurement unit Δh, the vertical position detector 19 detects the level and outputs it to the controller 20 as a height signal.

The control unit 20 drives the motor based on the tilt signal output from the tilt sensor to drive the laser irradiator 1.
Is kept horizontal and the elevating device 15 is driven, and at the same time, the level of the measurement point is calculated based on the outputs of the vertical position detector 19 and the photodetector 2, and it is determined whether or not this measurement is normally performed. If an error occurs, the error is displayed and remeasurement is performed.

The control device 20 detects the laser light emission levels detected by the vertical position detector 19 during the light receiving period of the laser beam by the light receiver 2 and the average value of the number of times the light receiving signal is output at each of these levels. Then, the level of the measuring point where the light receiver 2 is installed is calculated. That is, the product of the laser emission level and the number of times the light receiving signal is output at that level is summed for each level, and this is divided by the total number of outputs of the light receiving signal to calculate the level at the measurement point.

Then, for each level at which the light receiving signal is generated in the light receiving position calculating means, the difference between the highest value and the lowest value of these levels is calculated, and it is compared whether or not the calculation result is within a predetermined range. In the case of, it is determined that the measurement is abnormal, and the measurement is performed again.

Further, the difference between the measurement level calculated while the laser irradiator 1 is rising and the measurement level calculated when the laser irradiator 1 is descending is calculated, and it is judged whether or not the calculation result is within a predetermined range.
When it is out of the range, it is judged that the measurement is abnormal as in the above case, an error is displayed and the measurement is performed again.

A more detailed description will be given with reference to the flowchart of FIG.

When the measurement is started in step 50, the laser irradiator 1 supported by the elevating device 15 rises from a lowest position (hereinafter referred to as an origin) at a predetermined speed and turns at a predetermined speed. Meanwhile, the laser beam is emitted in the horizontal direction, and when this laser beam enters the photodetector 2, the photodetector 2 outputs a photodetection signal to the control device 20.

By the way, the laser emitted by the laser irradiator 1
Since the laser beam is a parallel laser beam having a circular cross section, the center of the laser beam of the photodetector 2 has a height h as shown in FIG.
When it falls within the range of a ± α, it receives the laser beam and outputs a received light signal.

As a result, while the laser beam is in this height range, the photodetector 2 outputs a photodetection signal to the controller 20 at a constant interval according to the turning speed of the laser irradiator 1. The laser emission level of the laser irradiator 1 is Δ shown in FIG.
A height signal indicating a new laser emission level is input from the vertical position detector 19 to the control device 20 every time the height is increased by h.

That is, since the laser emission level detected by the vertical position detector 19 changes subtly even within the output range of the light receiving signal, the level of the light receiving device 2 can be accurately determined with only one height signal. You cannot do it.

Therefore, the control unit 20 calculates the level of the photodetector 2 by the following method based on the input signal.

First, the number of pulses n ₁ , n ₂ , n ₃ , ... Of the light receiving signals input from the same light receiving device 2 at each laser light emitting level different by unit height Δh shown in FIG. ． ． n _n is counted, and then, for each unit height Δh, the center values h ₁ , h ₂ , h ₃ ,. ． ． Find h _n . Then, based on these values, the following calculation is performed to obtain the level of the light receiver 2.

[0028]

[Equation 1]

However, the photodetector 2 obtained by the above equation
The level ha is only the variation in the detected height based on the radius of the parallel laser beam, such as the measured value in the normal state shown in FIG. 7, is eliminated, and the measurement error due to the disturbance is not eliminated.

Therefore, in step 51, the measurement disturbance due to the disturbance is removed. For example, when a large vehicle or the like passes near a structure during level measurement in the ascending direction, the laser beam also vibrates due to the vibration of the laser irradiator 1 as shown in FIG. The level range in which the received light signal is generated is more disturbed than in the normal state shown in FIG. 7, and if the level of the light receiver 2 is obtained by the above equation as it is, a calculation result different from the actual level is obtained.

The minimum value h ₁ and the maximum value h _n of the height signal h _i are detected, and ΔHi which is the distribution range of the height signal is obtained by the following equation.

[0032] _{ΔHi = | h n - h 1} |

Next, in step 51, ΔHi obtained by the above equation is compared with a preset value ΔHl of the distribution range of the height signal, and the calculated level is invalidated if ΔHi exceeds the allowable value ΔHl. At the same time, a signal indicating that the measured value is abnormal is output, an error is displayed on a display device (not shown) of the control device 20 (step 60), the elevating device 15 is returned to the origin, and measurement is performed again.

If there is no abnormality in the measured value at step 51, the level is measured in the ascending direction and the descending direction respectively, and the measurement is completed after returning to the origin (step 52).

However, the abnormality in the measured value due to the disturbance that can be eliminated by the level distribution comparison is when the laser beam is disturbed by vibration or the like, and the abnormality in the measured value when the laser beam is blocked by an obstacle is not eliminated. .

For example, during measurement of the laser irradiator 1 in the ascending direction, the laser beam is temporarily passed between the laser irradiator 1 and the light receiver 2 by a work vehicle or a worker passing therethrough. When it is cut off, the portion indicated by the solid line in FIG. 5 becomes the measured value.

That is, since the laser beam is cut off, the maximum value of the level at which the light receiving signal is detected by the photodetector 2 becomes h _n , and the measured values up to the maximum value h _n ′ of the level that can be measured originally. Outputs a measurement level that is missing and has an error.

Therefore, the level of the photodetector 2 is set to ha _U in the measurement in the ascending direction and the level of the photodetector 2 is set to ha _D in the measurement in the descending direction (steps 53 and 54). The error ΔMi of the level is calculated by the following equation.

ΔMi = | ha _U −ha _D |

Next, at step 55, the error ΔMi obtained by the above equation is compared with a preset allowable error range ΔMl. If ΔMi exceeds the allowable value ΔMl,
The calculated ha _U and ha _D are invalidated, a signal indicating that the measured value is abnormal is output, an error is displayed on the display device (not shown) of the control device 20 (step 60), and the lifting device 15 is returned to the origin. And measure again.

From the level of the photodetector 2 calculated in this way, an abnormality in the measured value due to vibration or the like is excluded, and further, an abnormality in the measured value due to the interruption of the laser beam is excluded. The level of the photodetector 2 can be measured with high accuracy.

[0042]

As described above, according to the first invention,
Determine whether the output frequency of the received light signal at each laser emission level during the light receiving period and the distribution of that level are appropriate,
If the judgment result is incorrect, the calculated level is invalidated, and the control device displays an anomaly in the measured value, and the lifting device is returned to the origin to measure again. It becomes possible to perform high-accuracy and reliable level measurement by eliminating.

According to the second aspect of the invention, the level is calculated for each of the light receivers at one location in the ascending and descending directions of the laser beam, and it is judged whether the difference between these levels is appropriate. If is not appropriate, the calculated level is invalidated, and the control device displays an abnormality in the measured value, and the lifting device is returned to the origin to perform measurement again, so that the laser beam is accidentally cut off. It becomes possible to eliminate abnormalities in measured values and perform level measurement with high accuracy and reliability.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a light receiving range of a light receiver 2.

FIG. 4 is a graph showing a relationship between a received light signal pulse disturbed by a disturbance and a height signal.

FIG. 5 is a graph showing a relationship between a light receiving signal pulse partially lacking and a height signal.

FIG. 6 is a flowchart of control in the control device.

FIG. 7 is a graph showing a relationship between a normal light receiving signal pulse and a height signal.

[Explanation of Codes] 1 laser irradiator 2 light receiver 15 lifting device 19 vertical position detector 20 control device 30 light receiving position calculation means 32 reciprocating value comparison means 33 level distribution comparison means

Claims (2)

[Claims] 1. A light receiver which is installed at a measuring point of a structure and outputs a light reception signal by receiving a laser beam, and a laser which horizontally turns at a predetermined speed while irradiating the laser beam in a horizontal direction.
A laser irradiator, an elevating device for moving the laser irradiator up and down at a predetermined speed, a means for detecting a change in the light emission level of the laser irradiator for each predetermined unit, and a means for detecting each by the detecting means. The light receiving position calculating means for calculating the level of the measuring point where the light receiver is arranged from the average value of the number of times the light receiving signal of the light receiver is output at the laser light emitting level, and the difference between the highest and lowest light receiving levels are previously A level distribution comparing means for determining a measurement abnormality when the set allowable value is exceeded and a control means for displaying and invalidating the level calculation result of at least the calculating means at the time of abnormality determination of the comparing means are provided. Characteristic structure level measuring device. 2. A light receiver which is installed at a measuring point of a structure and outputs a light reception signal by receiving a laser beam, and a laser which horizontally turns at a predetermined speed while irradiating the laser beam in a horizontal direction.
A laser irradiator, an elevating device for moving the laser irradiator up and down at a predetermined speed, a means for detecting a change in the light emission level of the laser irradiator for each predetermined unit, and a laser for detecting by this detecting means. -The light receiving position calculation means for calculating the level of the measurement point at which the light receiver is arranged based on the change in the light emission level and the average value of the number of times of the light reception signal output from the light receiver at each of these levels, and the elevating device. Direction comparison means for determining a measurement abnormality when the difference between the result of the calculation means in the direction and the result of the calculation means in the descending direction exceeds a preset allowable value, and at least the above-mentioned value at the time of the abnormality determination of the comparison means. A structure level measuring device comprising a control means for displaying invalidity of a level calculation result of the calculation means and re-measurement.