JP2010060309A - Laser radar and method of monitoring boundary by same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser radar capable of eliminating a dead angle generated at either the inside or outside of a conventional boundary fence section by reducing an increase in monitoring costs when using the laser radar for monitoring a boundary, and to provide a boundary monitoring method by the laser radar. <P>SOLUTION: The laser radar includes: two light projection sections 2A, 2B; a scanning section 3 for performing scanning by laser beams LT emitted from the projection sections 2A, 2B; and two light reception sections 4A, 4B for receiving reflection laser beams LR that have returned after being reflected by a measurement target region. The scanning section 3 includes: one polygon mirror 31 rotating around a horizontal axis; and two rocking mirrors 32, 32 that are disposed inside and outside a fence F, scan the inside and outside of the fence F by two lines of laser beams LT from the two light projection sections 2A, 2B reflected by the polygon mirror 31, and return the two lines of reflection laser beams LR that have returned after being reflected by mutually different measurement targets inside and outside the fence F to the two light reception sections 4A, 4B each via the polygon mirror 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser radar and a boundary monitoring method using a laser radar that are used to monitor the inside and outside of a fence that partitions a boundary fence section that partitions an area, for example, a facility area such as a factory and the outside.

Conventionally, as a laser radar that monitors the inside and outside of the boundary fence that partitions the above-described region, for example, a light projecting unit that emits laser light, and a scanning unit that two-dimensionally scans the laser light emitted from the light projecting unit, In some laser radars, the scanning unit horizontally receives the laser light emitted from the light projecting unit. The light receiving unit receives a laser beam reflected and returned from the measurement target by the laser beam scanning by the scanning unit. A polygon mirror that scans in the direction and a oscillating mirror that scans laser light from the polygon mirror in the vertical direction are provided (see, for example, Patent Document 1).
JP 2005-69975 A

However, when using this laser radar to monitor the boundary fence part that divides the area, for example, the inside and outside of the fence, this fence will inevitably become an obstacle and a blind spot will be generated either inside or outside, and effective monitoring will be performed. There was a problem that the performance would be lowered.
In order to eliminate such a blind spot, it has been proposed to use two sets of the above laser radars. In this case, however, there is a problem that the monitoring cost is increased, and these problems are solved. This has been a conventional problem.

  The present invention has been made by paying attention to the above-described conventional problems. When used for boundary monitoring, the present invention can be applied to either the inside or the outside of the conventional boundary fence portion while suppressing an increase in monitoring cost. It is an object of the present invention to provide a laser radar and a boundary monitoring method using the laser radar that can eliminate the blind spot that has occurred.

  The invention according to claim 1 of the present invention includes two light projecting units that emit laser light, a scanning unit that two-dimensionally scans two lines of laser light emitted from these light projecting units, and the scanning unit. The laser beam scanning unit comprises two light-receiving units that individually receive two reflected laser beams reflected and returned from different measurement targets through the scanning unit, and the scanning unit includes one polygon mirror, The two laser beams reflected from the two light projecting units reflected by the polygon mirror are respectively scanned on the different measurement objects, and the two reflected laser beams reflected and returned by the different measurement objects are returned. In order to solve the above-described conventional problems, the structure of the laser radar is characterized in that it includes two oscillating mirrors that individually return to the two light receiving units via a polygon mirror. It is a means.

  The invention according to claim 2 of the present invention is a laser radar that monitors the inside and outside of the boundary fence part that partitions the area, and includes two light projecting parts that emit laser light and two light emitted from these light projecting parts. A scanning unit that two-dimensionally scans each of the muscle laser beams, and two reflected laser beams that are reflected and returned from different measurement targets by the laser beam scanning by the scanning unit are individually received via the scanning unit. The light scanning unit includes two light receiving units, and the scanning unit includes two polygon mirrors that rotate around a horizontal axis and two light projecting units that are arranged inside and outside the boundary fence unit and reflected by the polygon mirror. The laser beam of the streak is scanned in and out of the boundary fence part, and the reflected laser light of the two lines reflected and returned by different measurement objects inside and outside the boundary fence part is individually passed through the polygon mirror. two And characterized in that a structure that comprises two oscillating mirrors back to the light receiving portion of, and the configuration of the laser radar as a means for solving the conventional problems described above.

Furthermore, a laser radar according to a third aspect of the present invention includes a single control unit that issues a laser beam projection command to the two projection units at a predetermined period and controls scanning by the scanning unit. A laser light projection command is issued from the control unit to the two light projecting units with a half cycle shift.
On the other hand, in the invention according to claim 4 of the present invention, when the inside and outside of the boundary fence part that partitions the area is monitored by the laser radar according to claim 1 or 3, the central axis of the polygon mirror of the scanning part is set in the horizontal direction. The polygon mirrors are arranged along the two lines, and the two laser beams from the two light projecting parts reflected by the polygon mirrors are respectively scanned in and out of the boundary fence part, and are mutually inside and outside the boundary fence part. Two oscillating mirrors are respectively arranged inside and outside the boundary fence to return the two reflected laser beams reflected and returned by different measurement targets to the two light receiving parts individually via the polygon mirror, While rotating the polygon mirror of the scanning unit, project the laser light from the two light projecting units, respectively, scan the laser light in and out of the boundary fence through the two swing mirrors, The two reflected laser beams reflected and returned by different measurement objects inside and outside the boundary fence portion by the laser beam scanning by the scanning portion of the scanning portion individually through the two oscillating mirrors and the polygon mirror of the scanning portion. It is characterized in that it is configured to be received by two light receiving sections, and the configuration of the boundary monitoring method using this laser radar is a means for solving the above-described conventional problems.

In the laser radar and the boundary monitoring method using the laser radar according to the present invention, a semiconductor laser, a solid-state laser, a gas laser, or the like can be used as the laser light emitted from the light projecting unit. The formed laser beam is used.
In the laser radar of the present invention, when monitoring the inside and outside of the boundary fence part that divides the area, for example, as shown in FIG. 2, the polygon mirror 31 of the scanning part 3 has a rotation axis 31a in the longitudinal direction of the boundary fence part F ( Along the boundary fence portion F along the horizontal direction), the two oscillating mirrors 32 and 32 are installed inside and outside the boundary fence portion F with the polygon mirror 31 interposed therebetween.

  At this time, the pivot shafts 32a and 32a of the two oscillating mirrors 32 and 32 are aligned with the height direction (vertical direction) of the boundary fence portion F, and as shown in FIG. A portion positioned outside the boundary fence portion F in the polygon mirror 31 with one light projecting portion 2A of the two light projecting portions 2A and 2B and the light receiving portion 4A paired with the light projecting portion 2A facing the inner portion The other light projecting unit 2B of the two light projecting units 2A and 2B and the light receiving unit 4B paired therewith are directed.

  In this laser radar, the polygon mirror 31 and the two oscillating mirrors 32 and 32 of the scanning unit 3 are operated, and the pulsed or phase-modulated sinusoidal laser light LT is emitted from the two light projecting units 2A and 2B. When each light is projected, as shown in FIG. 5A, the laser light LT is scanned two-dimensionally inside and outside the boundary fence portion F, and these laser lights LT are inside and outside the boundary fence portion F. By measuring and processing the time until the light is reflected and returned by different measurement objects in each of the monitoring areas A and B, the distance to the measurement object can be obtained.

  At this time, in the laser beam scanning inside the boundary fence portion F, as shown in FIG. 5 (b), a dead angle Da corresponding to the thickness of the boundary fence portion F is generated outside the boundary fence portion F. In the laser beam scanning outside the part F, as shown in FIG. 5C, a dead angle Db corresponding to the thickness of the boundary fence part F is generated inside the boundary fence part F, but a dead angle Da outside the boundary fence part F is generated. Is eliminated by laser beam scanning outside the boundary fence portion F, and the dead angle Db inside the boundary fence portion F is eliminated by laser beam scanning inside the boundary fence portion F, so that highly effective monitoring is performed. Become.

As described above, in the laser radar according to the present invention, the scanning unit includes one polygon mirror and two oscillating mirrors. Therefore, when used for boundary monitoring, an increase in monitoring cost can be suppressed to a minimum. .
Further, in the case where the two projectors are provided with one control unit that issues a laser beam projection command at a predetermined cycle, the lasers are shifted from each other by a half cycle with respect to the two projectors. When the light projection command is issued, the power consumption timing and the distance calculation timing of the two light projecting units can be shifted. Therefore, in addition to one control unit, two high voltage power supplies for the light projecting unit and Only one distance calculation unit is required.

Since the laser radar according to claim 1 of the present invention has the above-described configuration, when used for boundary monitoring, it is possible to perform high-efficiency monitoring without blind spots while suppressing an increase in cost. This is a very good effect.
Further, since the boundary monitoring method using the laser radar according to claim 2 and the laser radar according to claim 4 of the present invention has the above-described configuration, high-efficiency monitoring without blind spots can be performed while suppressing an increase in monitoring cost. It has a very good effect that it can be done.

  Furthermore, since the laser radar according to claim 3 of the present invention has the above-described configuration, it is possible to achieve a very excellent effect that it is possible to further reduce the monitoring cost.

Hereinafter, a laser radar and a boundary monitoring method using the laser radar according to the present invention will be described with reference to the drawings.
1 to 5 show an embodiment of a laser radar according to the present invention. In this embodiment, a fence (boundary fence) that partitions the laser radar according to the present invention from a facility area such as a factory and the outside. The case where it is used to monitor the inside and outside of the case will be described as an example.

  As shown in FIG. 1, the laser radar 1 includes two light projecting units 2A and 2B that emit pulsed laser light LT, and two laser beams LT and LT emitted from these light projecting units 2A and 2B. The two-dimensional reflected laser beams LR and LR reflected and returned from different measurement objects within the scanning range by scanning the laser beams LT and LT by the scanning unit 3 respectively. Two light receiving units 4A and 4B received individually via the scanning unit 3, a control unit 5 that issues a light projection command of the laser light LT to the light projecting units 2A and 2B, and controls scanning by the scanning unit 3, and this control A distance calculation unit 6 that acquires distance information of a measurement target based on the light projection timing of the laser beams LT and LT given from the unit 5 and the light reception timing of the reflected laser beams LR and LR given from the light receiving units 4A and 4B. And throw Parts 2A, 2B is configured for projecting laser light LT respectively by power supplied from a common high-voltage power supply 7.

  As shown in FIG. 2, the scanning unit 3 includes a polygon mirror 31 that is rotated by the output of the motor 30 and two light projecting units 2 </ b> A and 2 </ b> B that are oscillated by the output of the motor 33 and reflected by the polygon mirror 31. The two laser beams LT are scanned on different measurement targets, and the two reflected laser beams LR reflected and returned from these measurement targets are individually passed through the polygon mirror 31 to the two light receiving units 4A, 4A, The polygon mirror 31 is installed above the fence F so that the rotating shaft 31a is along the longitudinal direction (horizontal direction) of the fence F. On the other hand, the two oscillating mirrors 32 and 32 are installed inside and outside the fence F with the polygon mirror 31 interposed therebetween.

  In this case, the respective oscillating shafts 32a, 32a of the two oscillating mirrors 32, 32 are aligned with the height direction (vertical direction) of the fence F, and as shown in FIG. One light projecting unit 2A of the two light projecting units 2A and 2B and the light receiving unit 4A paired with the light projecting unit 2A are directed to the position, and two light projecting units 2A and 2B are disposed on the part located outside the fence F in the polygon mirror 31. The other light projecting unit 2B of the light units 2A and 2B and the light receiving unit 4B paired therewith are directed.

  In the laser radar 1, as shown in FIG. 4, the control unit 5 that issues a light projection command of the laser light LT to the light projecting units 2A and 2B at a predetermined command cycle projects the light to the light projecting unit 2A. The command A and the light projection command A to the light projecting unit 2B are emitted with a half cycle shift, and the light reception timings A and B of the light receiving units 4A and 4B are also shifted with each other by a half cycle.

  In this laser radar 1, while operating the polygon mirror 31 and the two oscillating mirrors 32 of the scanning unit 3, a pulsed laser beam LT is transmitted from the two light projecting units 2 A and 2 B according to a command from the control unit 5. When the light is projected with a period and shifted from each other by a half period, the laser beams LT are scanned two-dimensionally inside and outside the fence F as shown in FIG. The time until the laser light LT is reflected by different measurement objects in the areas A and B inside and outside the fence F and returned is measured by the distance calculation unit 6 and processed. The distances dA and dB to the object are obtained, and the control unit 5 obtains the angle information obtained from the polygon mirror 31 and the two oscillating mirrors 32 and 32 of the scanning unit 3 and the distance obtained from the distance calculation unit 6. And a distribution, which is assumed to be output to the outside to generate three-dimensional data.

  At this time, in the region A by the two-dimensional scanning of the laser beam LT inside the fence F, a dead angle Da corresponding to the thickness of the fence F is generated outside the fence F, as shown in FIG. In the region B by the two-dimensional scanning of the laser beam LT outside the fence F, a dead angle Db corresponding to the thickness of the fence F is generated inside the fence F as shown in FIG. The outside blind spot Da is eliminated by laser beam scanning outside the fence F, and the dead zone Db inside the fence F is eliminated by laser beam scanning inside the fence F. Therefore, highly effective monitoring is performed.

In the laser radar 1 according to this embodiment, since the scanning unit 3 includes one polygon mirror 31 and two oscillating mirrors 32 and 32, the monitoring cost increases when used for boundary monitoring. It can be suppressed to a small extent.
In the laser radar 1 described above, the control unit 5 uses the light projection command A for one of the two light projection units 2A and 2B and the light projection command A for the other light projection unit 2B. Are emitted by being shifted by a half cycle from each other, so that the timing at which the two light projecting units 2A and 2B consume power can be shifted as shown in the broken line ellipse in FIG. 4, and the solid line in FIG. As shown in the ellipse, the distance calculation timing can also be shifted. Therefore, in addition to the control unit 5, only one high-voltage power supply 7 and distance calculation unit 6 are required, and the increase in monitoring cost can be suppressed to a minimum. It will be.

In the above-described embodiment, the case where the laser radar according to the present invention is used to monitor the inside and outside of a fence that separates a facility area such as a factory from the outside has been described as an example, but the present invention is not limited to this. Absent.
The configuration of the laser radar according to the present invention is not limited to the configuration of the laser radar 1 according to the above-described embodiment.

1 is a block diagram showing an embodiment of a laser radar according to the present invention. It is a perspective explanatory view from the fence inner side which shows each positional relationship of the scanning part of the laser radar in FIG. 1, a light projection part, and a light-receiving part. FIG. 2 is a perspective view (a) from above the fence showing a positional relationship among the scanning unit, light projecting unit, and light receiving unit of the laser radar in FIG. 1 and a perspective view (b) from above the fence and from behind the polygon mirror. It is a graph explaining the light projection command timing to the light projection part by the control part of the laser radar shown in FIG. It is plane explanatory drawing (a) which shows the monitoring area | region by the laser radar in FIG. 1, visual field image explanatory drawing (b) of a fence inner side monitoring area | region, and visual field image explanatory drawing (c) of a fence outer side monitoring area | region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser radar 2A, 2B Light projection part 3 Scan part 31 Polygon mirror 31a Rotating shaft of a polygon mirror 32 Swing mirror 32a Swing axis of a rocking mirror 4A, 4B Light receiving part 5 Control part 6 Distance calculating part F Fence (boundary fence) Part)
LR Reflected laser beam LT Projected laser beam

Claims (4)

Two light emitting parts emitting laser light,
A scanning unit that two-dimensionally scans two laser beams emitted from these light projecting units,
Two light-receiving units that individually receive the two reflected laser beams reflected and returned by different measurement objects by the laser beam scanning by the scanning unit through the scanning unit,
The scanning unit scans two different laser beams from one polygon mirror and the two light projecting units reflected by the polygon mirror on the different measurement targets, and reflects on the different measurement targets. A laser radar, comprising: two oscillating mirrors that return the two reflected laser beams returned to the two light receiving parts individually via the polygon mirror. A laser radar that monitors the inside and outside of the boundary fence that partitions the area,
Two light emitting parts emitting laser light,
A scanning unit that two-dimensionally scans two laser beams emitted from these light projecting units,
Two light-receiving units that individually receive the two reflected laser beams reflected and returned by different measurement objects by the laser beam scanning by the scanning unit through the scanning unit,
The scanning unit includes one polygon mirror that rotates about a horizontal axis, and two laser beams from the two light projecting units that are respectively disposed inside and outside the boundary fence unit and reflected by the polygon mirror. Each of the two reflected laser beams that have been scanned inside and outside the fence portion and reflected and returned from different measurement objects inside and outside the boundary fence portion is individually returned to the two light receiving portions via the polygon mirror. A laser radar comprising two oscillating mirrors.   A laser light projection command is issued to the two light projecting units at a predetermined cycle, and a control unit that controls scanning by the scanning unit is provided. 3. The laser radar according to claim 1, wherein a laser beam projection command is issued with a half cycle shift. When monitoring the inside and outside of the boundary fence part that divides the area by the laser radar according to claim 1 or 3,
The polygon mirror is arranged with the central axis of the polygon mirror of the scanning unit in the horizontal direction, and two laser beams from the two light projecting parts reflected by the polygon mirror are placed inside and outside the boundary fence. In order to return the two reflected laser beams respectively scanned and reflected by different measurement objects inside and outside the boundary fence part to the two light receiving parts individually via the polygon mirror, the inside and outside of the boundary fence part Two oscillating mirrors are placed in
Rotating the polygon mirror of the scanning unit to project laser light from the two light projecting units, respectively, scan the laser light in and out of the boundary fence through the two swing mirrors,
The two reflected laser beams reflected and returned by different measurement objects inside and outside the boundary fence by the laser beam scanning by the scanning unit are individually transmitted through the two oscillating mirrors and the polygon mirror of the scanning unit. A boundary monitoring method using a laser radar, which is received by two light receiving units.

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