JP2013003025A - Laser distance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a distance measuring error with a simple structure.SOLUTION: A laser transmitting/receiving portion (a laser optical scanning portion 103 and a receiving portion 104) is installed at a predetermined position, opposes to a predetermined distance measuring object surface at a predetermined elevation angle, emits a laser beam to the distance measuring object surface while changing an emission angle, and receives reflection light. A reference reflection plate 6 is disposed at a position irradiated with the laser beam, and reflects the laser beam. A phase detector 9 detects a phase value at each reflection point reflecting the laser beam on the distance measuring object surface on the basis of the reflection light, and detects a phase value on the reference reflection plate 6. A distance correcting device 11 calculates the phase value at each reflection point on the basis of a position relationship between the laser transmitting/receiving portion and the distance measuring object surface, an elevation angle of the laser transmitting/receiving portion, and an emission angle of each laser beam emission, and calculates a correction value by using the phase value at each reflection point which is detected by the phase detector 9, the phase value on the reference reflection plate 6, and the calculated phase value at each reflection point.

Description

  The present invention relates to a technique for correcting a ranging error that occurs in laser ranging.

In a conventional laser image measurement device (for example, Patent Document 1), a reference point of a certain distance is provided inside the device to calibrate the distance measurement value.
The reference point of a certain distance is a mechanism that reflects the transmission laser existing inside the apparatus to the reception optical system or turns it back using an optical fiber.

JP 2007-10636 A

In the laser image measurement device of Patent Document 1, when a reference point of a certain distance is provided inside the device and the distance measurement value is calibrated, the optical value is changed by multipath or the like from the change of the environment such as the temperature or vibration of the device or the reference point. There is a problem that a difference occurs in the target path and electrical characteristics, resulting in a ranging error.
For example, in the laser image measuring device of Patent Document 1, the scanned transmission light is received as a “reference point of a certain distance” by the transmission / reception optical unit through the calibration optical unit and the calibration fiber.
When the modulated light passes through the calibration fiber, the length of the calibration fiber changes under the influence of heat, and the phase changes when receiving the modulated light.
As a result, a distance error occurs at the “fixed distance reference point”.

  Further, when the apparatus is installed, there is a problem that if the distance of the connection wiring from the modulator to the laser scanning optical system is changed, a distance error occurs and adjustment is required.

In addition, when a reference point is provided inside the apparatus, it is necessary to use an object having a special reflectance as the reference point in consideration of the dynamic range of the received beam, and there is a problem that the cost increases.
The “special reflectance object” arranged as the reference point is a calibration optical unit and a calibration fiber in the configuration of Patent Document 1.

  The main object of the present invention is to solve the above-mentioned problems, and to realize an apparatus capable of deriving an accurate distance by correcting a ranging error with a simple configuration. And

The laser distance measuring device according to the present invention is:
It is installed at a predetermined position, faces a predetermined distance measurement target surface at a predetermined elevation angle, emits laser light to the distance measurement target surface while changing the laser light emission angle, and measures the measured laser light. A laser transmitting / receiving unit that receives reflected light from a distance target surface;
A reference reflector disposed at a position where the laser beam from the laser transmitting / receiving unit is irradiated and reflecting the irradiated laser beam to the laser transmitting / receiving unit;
Based on the reflected light received by the laser transmitting / receiving unit, the phase value of the laser light at each reflection point where the laser light is reflected on the surface to be measured is detected, and the phase value of the laser light at the reference reflecting plate is determined. A phase value detector to detect;
Based on the positional relationship between the laser transmission / reception unit and the surface to be measured, the elevation angle of the laser transmission / reception unit, and the emission angle when each laser beam is emitted, the phase value of the laser beam at each reflection point is calculated. A phase value calculator,
Using the phase value at each reflection point detected by the phase value detection unit, the phase value at the reference reflector, and the phase value at each reflection point calculated by the phase value calculation unit, the reflection point And a correction value calculation unit for calculating a correction value used for calculation of the distance value between.

  According to the present invention, the correction value is calculated using the phase value obtained by the calculation based on the known installation conditions, and the accurate distance can be derived by correcting the ranging error with a simple configuration.

FIG. 3 is a diagram illustrating a configuration example of a laser image measurement device according to the first embodiment. FIG. 3 is a diagram for explaining an operation principle of the laser image measurement device according to the first and second embodiments. FIG. 3 is a diagram illustrating a laser transmission / reception unit and a laser beam scanning range according to the first embodiment. FIG. 3 is a flowchart showing a distance correction procedure according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a laser image measurement device according to a second embodiment. FIG. 9 is a flowchart showing a distance correction procedure according to the second embodiment. FIG. 3 is a diagram illustrating a hardware configuration example of a signal processing unit according to the first and second embodiments.

Embodiment 1 FIG.
In the present embodiment and the second embodiment, a laser image measurement device that performs distance correction on the phase value of a reception beam reflected from a known installation environment by a transmission beam transmitted from a laser beam scanning optical system will be described.

FIG. 1 shows a configuration example of a laser image measurement apparatus 100 according to the present embodiment.
The laser image measuring device 100 is an example of a laser distance measuring device.

As shown in FIG. 1, the laser image measurement device 100 includes a reference signal generation unit 101, a laser beam transmission unit 102, a laser beam scanning unit 103, a reception unit 104, a signal processing unit 105, and a reference reflection plate 6. .
The reference signal generator 101 includes an oscillator 1 and a distributor 2.
The laser beam transmission unit 102 includes a laser device 3 and a modulator 4.
The laser beam scanning unit 103 includes the laser beam scanning optical system 5.
The receiving unit 104 includes a receiving optical system 7 and a light receiver 8.
The signal processing unit 105 includes a phase detector 9, a distance calculation device 10, a distance correction device 11, and a three-dimensional image processing device 12.
A combination of the laser beam scanning unit 103 and the receiving unit 104 is referred to as a laser transmitting / receiving unit.

The oscillator 1 has a function of generating a reference sine wave modulation signal, and the distributor has a function of branching the modulation signal into two.
The laser device 3 has a function of emitting laser light, and the modulator 4 has a function of modulating the laser light based on the modulation signal.
The laser beam scanning optical system 5 has a function of shaping the beam shape and irradiating and scanning the laser beam in the space.
The reference reflector 6 is installed at a fixed distance from the laser beam scanning optical system 5 and has a function of reflecting the laser beam.
The receiving optical system 7 has a function of receiving the laser light reflected by the object and condensing it on the light receiver 8.
The light receiver 8 has a function of converting received light into an electrical signal.
The phase detector 9 has a function of receiving a modulation signal output from the reference signal generation unit 101 and a reception signal from the reception unit 104, performing phase detection, and outputting an electric signal corresponding to the phase signal.
The distance calculation device 10 has a function of calculating a distance value based on an electrical signal corresponding to the phase signal.
The distance correction device 11 has a function of correcting the distance value based on the calculated distance value of the reference reflector 6.
The three-dimensional image processing device 12 has a function of generating a three-dimensional image based on the correction distance value and the scanning angle signal.

In addition, the reference | standard reflecting plate 6 which concerns on this Embodiment needs to satisfy | fill the following conditions.
(1) The laser beam scanned by the laser beam scanning optical system 5 is reflected within the reception visual field of the reception optical system 7.
(2) The light received by the light receiver 8 can be reflected so that the power of the light is in an appropriate range (the power is not too small or too small) (if the power is too large, the light receiver 8 saturates, If it is too small, it will be a noise level and the distance cannot be measured accurately).

In laser image measurement apparatus 100 of the present embodiment, the modulation signal may be a pulse instead of a sine wave.
In this case, in order to measure the arrival time of the pulse from the transmission system to the reception system and derive the distance, for example, a time difference measurement circuit is used instead of the phase detector 9.
Further, in the laser light transmitting unit 102, the modulated light may be directly input to the laser device 3 instead of applying intensity modulation to the laser light using the modulator 4 to obtain the modulated light directly.
For example, a laser diode is used for the laser device 3 and a drive current synchronized with the modulation signal is injected to obtain directly modulated light.

  FIG. 3 shows a laser transmission / reception unit (laser beam scanning unit 103 and reception unit 104) and a laser beam scanning range according to the present embodiment.

The angle in FIG. 3A represents twice the beam scanning half angle θ of the laser transmitting / receiving unit.
The laser beam is reflected by the scanner mirror and irradiates the reference reflecting plate 6, and the laser beam emission direction changes within a range twice the beam scanning half angle θ by changing the angle of the laser beam.
As will be described later, the laser transmission / reception unit emits laser light toward a predetermined distance measurement target surface.

As shown in FIG. 3B, the laser transmitter / receiver scans the laser beam up and down in the j direction (data numbers 0 to n-1) and outputs data for m lines (here, one line in the i direction). The laser beam is transmitted / received.
Note that one line of scanning includes n times (data numbers 0 to n−1) of laser light emission and n times of reflected light reception.
Scanning in the j direction is performed by changing the laser beam emission angle (beam scanning angle α _j ).
In FIG. 3B, for example, if n = 10 (data numbers 0 to 9) and the data number 4 that is an intermediate data number is used as a reference (beam scanning angle α ₄ = 0 degree), the data number 0 And the data number 4 correspond to the beam scanning angle α ₀ with respect to the data number 0.
As described above, the laser light emission angle (beam scanning angle α _j ) is changed for each of the data numbers j = 0 to n−1, and the laser light is irradiated to a plurality of points on the surface to be measured. .
Here, n = 10 is set for simplicity of explanation, and in actual operation, for example, it is about 512 (n = 512) as shown in FIG.

3B corresponds to twice the beam scanning half angle θ of the laser transmitting / receiving unit.
Further, the reference reflector 6 is irradiated with laser light in the upper region of the intensity image / distance image.
In FIG. 3B, only the laser beam in the area of data number 0 is irradiated on the reference reflecting plate 6, but a wider range of laser light may be irradiated on the reference reflecting plate 6.

  Here, before explaining the details of the operation of the laser image measuring apparatus 100 according to the present embodiment, the principle of deriving the correction value in the signal processing unit 105 will be outlined.

The laser transmission / reception unit according to the present embodiment sequentially applies lasers to the reference reflector 6 and the distance measurement target surface (for example, a road surface) while changing the laser light emission angle (that is, the beam scanning angle α _j ). Light is irradiated, and reflected light from the reference reflector 6 and the distance measurement target surface is received.
The laser transmitting / receiving unit faces the distance measurement target surface at a predetermined elevation angle.
The number of measurement targets on the surface to be measured, that is, the number of reflection points that reflect the laser light is a predetermined value (= n).
Here, each of the n reflection points is represented as a reflection point j (j = 0 to n−1).
Then, the phase detector 9 detects the phase value (φ ′ _j ) of the laser light at the reflection point j based on the reflected light from the reflection point j.
Further, the phase detector 9 detects the phase value (φ _r ) of the laser light at the reference reflector 6 based on the reflected light from the reference reflector 6.
In addition, the distance correction device 11 has a reflection point j based on the positional relationship between the laser transmitter / receiver and the surface to be measured, the elevation angle of the laser transmitter / receiver, and the emission angle (beam scanning angle α _j ) when each laser beam is emitted. The phase value (φ _j ) of the laser beam is calculated.
This phase value (φ _j ) is a logical value derived from the positional relationship between the laser transmission / reception unit and the distance measurement target surface, the elevation angle of the laser transmission / reception unit, and the geometric relationship with the beam scanning angle α _j. is there.
Further, the distance correction device 11 includes the phase value (φ ′ _j ) at the reflection point j detected by the phase detector 9, the phase value (φ _r ) at the reference reflector 6, and the calculated reflection point j. Using the phase value (φ _j ), the correction value (φ ₀ ) of the phase value in the reference reflector 6 is calculated.
Then, the distance correction device 11 uses the phase value (φ ′ _j ) at the reflection point j detected by the phase detector 9, the phase value (φ _r ) at the reference reflector 6, and the calculated reference reflector 6. Using the correction value (φ ₀ ) of the phase value, an accurate distance (correction distance value zc _j ) to the reflection point j is obtained.

The phase detector 9 corresponds to an example of a phase value detection unit.
The distance correction device 11 corresponds to an example of a phase value calculation unit, a correction value calculation unit, and a distance value calculation unit.

Next, the operation of the laser image measurement apparatus 100 according to the present embodiment will be described in detail with reference to FIGS.
FIG. 2 is a diagram for explaining the operation principle of the laser image measurement apparatus 100, and FIG. 4 is a flowchart showing a distance correction procedure.

In FIG. 2, the head unit (including the laser transmitting / receiving unit) of the laser image measurement device 100 is installed at a predetermined height on the sidewalk (head unit installation height: H), and is a distance measurement target surface. An example is shown in which a plurality of points on the road surface are irradiated with laser light to determine the distance to each point on the road surface.
FIG. 2 shows a state in which laser light is irradiated in the j direction of FIG.
The black circles in FIG. 2 represent the data after the initial phase calibration, that is, the accurate position of the reflection point on the road surface (the position after the distance measurement error is corrected).
The white circles in FIG. 2 represent the data before the initial phase calibration, that is, the position of the reflection point before the distance measurement error is corrected.
Of the values shown in FIG. 2, the mounting elevation angle δ of the head portion, the beam scanning half angle θ, the road surface inclination angle Θ, the modulation frequency f, the speed of light c, the circumference ratio π, and the head portion installation height H are known. is there.
The measured phase value φ ′ _j of the reflection point j is detected from the reflected light by the phase detector 9, and the measured phase value φ _r of the reference reflector 6 is detected from the reflected light by the phase detector 9.
The beam scanning angle α _j is calculated from the beam scanning half angle θ by the distance correction device 11.
The correction value φ _{0 is} also calculated by the distance correction device 11.
The correction distance value zc _j to the reflection point j is also calculated by the distance correction device 11.

In the laser image measuring apparatus 100, the laser light generated from the laser apparatus 3 is intensity-modulated by the modulator 4 based on the modulation signal generated by the oscillator 1, and the laser light scanning optical system 5 performs one-dimensional scanning of the laser light. To do.
The reflected light from the object (the reference reflector 6 and the road surface in FIG. 2) is collected by a receiving optical system 7 having a corresponding reception field of view, and then converted into an electrical signal by a light receiver 8.
Thereafter, the phase detector 9 performs phase detection with the reference modulation signal, and outputs the reception intensity of the reflected light and an electric signal corresponding to the phase difference between the modulation signal and the reception signal.
Electrical signals obtained phase value from the reflected light from the reference reflection plate 6 corresponds to the phase value phi _r, an electric signal obtained phase value from the reflected light from each point of the road surface is the phase value phi _'j Equivalent to.

The distance calculation device 10 calculates the distance za _j in the line-of-sight direction of the reflection point j from the phase signal.
Specifically, assuming that the speed of light is c, the phase difference is Δφ _j , and the frequency of the modulation signal is f, the distance za _j is derived by the following equation (1).
za _j = (c × Δφ _j ) / (4 × π × f) (1)

The distance correction device 11 corrects the distance value and calculates a corrected distance value zc _j in order to obtain the distance accurately.
Specifically, the correction distance value zc _j is calculated according to the operation flow of FIG.

The distance correction device 11 calculates the provisional distance value zb _j using the installation conditions (elevation angle δ, installation height H, road surface inclination Θ) and beam scanning half angle θ (beam scanning angle α _j ) (S101) and stores it. .
The provisional distance value zb _j may be calculated by the three-dimensional image processing device 12.
In this case, the three-dimensional image processing device 12 corresponds to an example of a phase value calculation unit.
For example, when the beam scanning is a sine wave, it is calculated by the following equation.

Instead of calculating by the equation (3), each fixed value of the beam scanning angle α _j may be held as a table.

Then, the distance correction device 11, from the calculated provisional distance value zb _j, the following equation phase value phi _j of the laser beam in the reflection point j, is calculated (S102).

Further, the distance correction device 11 obtains an accurate phase value correction value φ ₀ up to the reference reflector 6 by the following equation (S103).

Incidentally, the correction value phi ₀ calculated, thereafter, used as a fixed value.

Next, the distance correction device 11 obtains a correction distance value zc _j by the following equation, and transmits the correction distance value zc _j to the three-dimensional image processing device 12 (S104).

This correction distance value zc _j corresponds to the data (black circle) after the initial phase configuration in FIG.
Note that the data (white circles) before the initial phase configuration in FIG. 2 corresponds to the following distance value zd _j .

  The distance correction device 11 repeats the process of S104 until the phase detector 9 stops transmitting the phase value (S105).

Taking FIG. 3B as an example, the processing of S101 to S103 of FIG.
The line number 1 subsequent scan of FIG. 3 (b), using the correction value phi ₀ calculated in S103 with respect to the scanning line number 0 _(correction value calculated by the equation (5)), S104 procedures ( That is, the correction distance value zc _j is calculated by the calculation according to the equation (6).

In the above description, the example in which the distance zb _j is calculated by the equation (2) when the head portion installation height H is known has been described.
If the head portion installation height H is unknown, the distance zb _j may be obtained by the following equation if X _j = jth depth measurement distance is known.
zb _j = X _j / sin (α _j + δ + Θ) (8)
Note that X _j = jth depth measurement distance is a horizontal distance from the head unit (laser transmission / reception unit) to the reflection point j, as shown in FIG.

  According to the present embodiment, the correction value is calculated using the logical value of the phase value obtained by the calculation based on the known installation conditions, and the accurate distance is corrected by correcting the ranging error with a simple configuration. Can be requested.

Embodiment 2. FIG.
In the present embodiment, a laser image measurement apparatus 100 that does not use the reference reflector 6 described in the first embodiment will be described.

The configuration of the laser image measurement apparatus 100 according to the present embodiment is as illustrated in FIG.
That is, the configuration is the same as that of FIG. 1 except that the reference reflector 6 is not used.
Each element is the same as that shown in FIG.

Further, the operation principle of the laser image measurement device 100 according to the present embodiment is also as shown in FIG.
For this reason, description of each element shown in FIG. 2 is also omitted.
As shown in FIG. 2, in this embodiment, the reference reflector 6 is not used, and therefore the expression of the correction distance value zc _j is different from that of the first embodiment.

Also in this embodiment, the modulation signal may be a pulse instead of a sine wave.
In this case, in order to measure the arrival time of the pulse from the transmission system to the reception system and derive the distance, for example, a time difference measurement circuit is used instead of the phase detector 9.
Further, in the laser light transmitting unit 102, the modulated light may be directly input to the laser device 3 instead of applying intensity modulation to the laser light using the modulator 4 to obtain the modulated light directly.
For example, a laser diode is used for the laser device 3 and a drive current synchronized with the modulation signal is injected to obtain directly modulated light.

  Next, the operation of the laser image measurement device 100 according to Embodiment 2 will be described.

In the laser image measuring apparatus 100, the laser light generated from the laser apparatus 3 is intensity-modulated by the modulator 4 based on the modulation signal generated by the oscillator 1, and the laser light scanning optical system 5 performs one-dimensional scanning of the laser light. To do.
The reflected light from the object (the road surface in FIG. 2) is collected by the receiving optical system 7 having a corresponding reception field of view, and then converted into an electric signal by the light receiver 8.
Thereafter, the phase detector 9 performs phase detection with the reference modulation signal, and outputs the reception intensity of the reflected light and an electric signal corresponding to the phase difference between the modulation signal and the reception signal.
An electric signal having a phase value obtained from the reflected light from each point on the road surface corresponds to the phase value φ ′ _j .

The distance calculation device 10 calculates the distance za _j in the line-of-sight direction of the reflection point j from the phase signal.
Specifically, assuming that the speed of light is c, the phase difference is Δφ _j , and the frequency of the modulation signal is f, the distance za _j is derived by the following equation (1).
za _j = (c × Δφ _j ) / (4 × π × f) (1)

The distance correction device 11 corrects the distance value and calculates a corrected distance value zc _j in order to obtain the distance accurately.
Specifically, the correction distance value zc _j is calculated according to the operation flow of FIG.

The distance correction device 11 calculates the provisional distance value zb _j using the installation conditions (elevation angle δ, installation height H, road surface inclination Θ) and beam scanning half angle θ (beam scanning angle α _j ) (S201) and stores it. .
The provisional distance value zb _j may be calculated by the three-dimensional image processing device 12.
In this case, the three-dimensional image processing device 12 corresponds to an example of a phase value calculation unit.
For example, when the beam scanning is a sine wave, it is calculated by the following equation.

Instead of calculating by the equation (3), each fixed value of the beam scanning angle α _j may be held as a table.

Then, the distance correction device 11, from the calculated provisional distance value zb _j, the following equation phase value phi _j of the laser beam in the reflection point j, is calculated (S202).

The distance correcting apparatus 11, by the following equation correction value phi ₀ of correct phase value, determined (S203).

It should be noted that the correction value φ ₀ is regularly updated.

Next, the distance correction device 11 obtains a correction distance value zc _j by the following equation, and transmits the correction distance value zc _j to the three-dimensional image processing device 12 (S204).

This correction distance value zc _j corresponds to the data (black circle) after the initial phase configuration in FIG.
The data (white circle) before the initial phase configuration in FIG. 2 corresponds to the following distance value zd _j .

The distance correcting apparatus 11, after the lapse update time correction value phi ₀ in phase (S205), and updates the correction value phi ₀ by the processing of S203.
Moreover, the process of S204 is repeated until the phase detector 9 stops transmission of a phase value (S206).

Taking FIG. 3B as an example, the processing of S201 to S203 of FIG. 6 is performed for the scan of line number 0.
For the scan after line number 1 in FIG. 3B, if the update time of the correction value φ ₀ has not elapsed, the correction value φ ₀ calculated in S203 for the scan of line number ₀ (formula (9)) in using the calculated correction value), in S204 the procedure (i.e., formula (10) calculated by), and calculates the correction distance value zc _j.

Further, as described in the first embodiment, when the head portion installation height H is unknown, the distance zb _j may be obtained using X _j = j-th depth measurement distance.

Further, when the laser image measurement apparatus 100 repeatedly emits the laser beam to the reflection point j a plurality of times, the phase value φ ′ _j used in the equation (9) is moved by the phase value obtained by the measurement a plurality of times. It can be an average value.
That is, the phase detector 9 detects the phase value at each reflection point j at each of a plurality of times, and the distance correction device 11 calculates a moving average value of the phase values obtained by the plurality of times of measurement, The correction value φ ₀ may be calculated using a moving average value instead of the phase value φ ′ _{j in} the equation (9).
Also in Equation (10), a moving average value may be used instead of the phase value φ ′ _j .

  As described above, according to the present embodiment, the correction value is calculated using the logical value of the phase value obtained by the calculation based on the known installation environment without using the reference reflector, and with a simple configuration, An accurate distance can be obtained by correcting the distance measurement error.

Finally, a hardware configuration example of the signal processing unit 105 described in Embodiments 1 and 2 will be described.
FIG. 7 is a diagram illustrating an example of hardware resources of the signal processing unit 105 illustrated in the first and second embodiments.
The configuration in FIG. 7 is merely an example of the hardware configuration of the signal processing unit 105, and the hardware configuration of the signal processing unit 105 is not limited to the configuration illustrated in FIG. Also good.

In FIG. 7, the signal processing unit 105 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a display device 901, a keyboard 902, a mouse 903, and a magnetic disk device 920 via a bus 912, and these hardware devices. To control.
Furthermore, the CPU 911 may be connected to a communication board, an FDD (Flexible Disk Drive), a compact disk device (CDD), a printer device, a scanner device, or the like.
Further, instead of the magnetic disk device 920, a storage device such as an SSD (Solid State Drive), an optical disk device, or a memory card (registered trademark) read / write device may be used.

The magnetic disk device 920 stores an operating system 921 (OS), a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911 using the operating system 921.

The RAM 914 temporarily stores at least part of the operating system 921 program and application programs to be executed by the CPU 911.
The RAM 914 stores various data necessary for processing by the CPU 911.

  The program group 923 stores a program for executing each function of the signal processing unit 105. The program is read and executed by the CPU 911.

In the file group 924, in the description of the first and second embodiments, “calculation of”, “calculation of”, “detection of”, “update of”, “input of”, “output of” Information, data, signal values, variable values, and parameters indicating the results of the processing described as “.” Are stored as items “˜file” and “˜database”.
The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory.

In addition, the arrows in the flowcharts described in the first and second embodiments mainly indicate input / output of data and signals.
Data and signal values are recorded on a recording medium.
Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

  Further, the processing of the signal processing unit 105 can be regarded as a signal processing method by the steps, procedures, and processes shown in the flowcharts described in the first and second embodiments.

  1 oscillator, 2 distributor, 3 laser device, 4 modulator, 5 laser beam scanning optical system, 6 reference reflector, 7 receiving optical system, 8 light receiver, 9 phase detector, 10 distance calculation device, 11 distance correction device , 12 3D image processing device, 100 laser image measurement device, 101 reference signal generation unit, 102 laser light transmission unit, 103 laser light scanning unit, 104 reception unit, 105 signal processing unit.

Claims (7)

It is installed at a predetermined position, faces a predetermined distance measurement target surface at a predetermined elevation angle, emits laser light to the distance measurement target surface while changing the laser light emission angle, and measures the measured laser light. A laser transmitting / receiving unit that receives reflected light from a distance target surface;
A reference reflector disposed at a position where the laser beam from the laser transmitting / receiving unit is irradiated and reflecting the irradiated laser beam to the laser transmitting / receiving unit;
Based on the reflected light received by the laser transmitting / receiving unit, the phase value of the laser light at each reflection point where the laser light is reflected on the surface to be measured is detected, and the phase value of the laser light at the reference reflecting plate is determined. A phase value detector to detect;
Based on the positional relationship between the laser transmission / reception unit and the surface to be measured, the elevation angle of the laser transmission / reception unit, and the emission angle when each laser beam is emitted, the phase value of the laser beam at each reflection point is calculated. A phase value calculator,
Using the phase value at each reflection point detected by the phase value detection unit, the phase value at the reference reflector, and the phase value at each reflection point calculated by the phase value calculation unit, the reflection point And a correction value calculation unit for calculating a correction value used for calculation of the distance value between. The correction value calculation unit
For each reflection point, the difference value obtained by subtracting the phase value at the reference reflector from the phase value at the reflection point detected by the phase value detection unit is the phase at the reflection point calculated by the phase value calculation unit. Calculate by subtracting from the value,
2. The laser distance measuring device according to claim 1, wherein the correction value is calculated by taking an average of the calculated values for each reflection point obtained. The laser distance measuring device further includes:
Using the phase value at the reflection point detected by the phase value detection unit, the phase value at the reference reflector, and the correction value calculated by the correction value calculation unit, for each reflection point, The laser distance measuring device according to claim 1, further comprising a distance value calculating unit that calculates the distance value of the distance. It is installed at a predetermined position, faces a predetermined distance measurement target surface at a predetermined elevation angle, emits laser light to the distance measurement target surface while changing the laser light emission angle, and measures the measured laser light. A laser transmitting / receiving unit that receives reflected light from a distance target surface;
A phase value detection unit that detects a phase value of the laser beam at each reflection point that reflects the laser beam on the surface to be measured based on the reflected light received by the laser transmitting and receiving unit;
Based on the positional relationship between the laser transmission / reception unit and the surface to be measured, the elevation angle of the laser transmission / reception unit, and the emission angle when each laser beam is emitted, the phase value of the laser beam at each reflection point is calculated. A phase value calculator,
Correction value used to calculate the distance value from the reflection point using the phase value at each reflection point detected by the phase value detection unit and the phase value at each reflection point calculated by the phase value calculation unit And a correction value calculation unit for calculating the laser range finder. The correction value calculation unit
For each reflection point, perform a calculation to subtract the phase value detected by the phase value detection unit from the phase value calculated by the phase value calculation unit,
5. The laser distance measuring device according to claim 4, wherein the correction value is calculated by taking an average of the calculated values for each obtained reflection point. The laser range finder is
Repeatedly emitting laser light to each reflection point multiple times,
The phase value detector
In each of the plurality of times, the phase value of the laser beam at each reflection point is detected,
The correction value calculation unit
For each reflection point, calculate the average value of the phase value detected by the phase value detector in the plurality of times,
The correction value is calculated using the average value of the calculated phase values of each reflection point and the phase value at each reflection point calculated by the phase value calculation unit. The laser distance measuring device described. The laser distance measuring device further includes:
A distance value calculation unit that calculates a distance value from the reflection point for each reflection point using the phase value detected by the phase value detection unit and the correction value calculated by the correction value calculation unit. The laser range finder according to any one of claims 4 to 6.

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