JP2016040662A - Laser radar apparatus and laser radar method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce running costs and maintenance costs by reducing energy consumption.SOLUTION: A laser radar apparatus 100 comprises: a laser light emitter 110 for emitting laser light L to a predetermined first area and a second area which includes at least part of the first area and is larger than the first area; an object detector 178 for detecting an object on the basis of a reflection wave M generated by reflection of the laser light L; and a switching controller 180 for switching an area emitted by the laser light L from the first area to the second area by controlling the laser light emitter 110 when an object is detected while the first area is emitted by the laser light L.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laser radar apparatus and a laser radar method for detecting an object using laser light.

  Conventionally, a laser radar device has been used to monitor a predetermined target range such as in a room, a building, or a site. The laser radar device includes a laser light projecting unit that projects a laser beam while scanning the entire region of the target range, and a new object is generated in the target range based on a reflected wave generated by reflecting the projected laser beam. It is detected whether or not an intrusion has occurred (for example, Patent Documents 1 and 2).

JP 2009-110069 A JP2013-224915A

  In the above-described conventional laser radar apparatus, the laser beam is projected while constantly scanning the entire target range, so that the energy (power consumption) spent for the projection is large and the running cost is increased. There was a problem. Further, since the laser light projecting unit is always driven, the components constituting the laser light projecting unit are likely to be consumed, and the parts must be frequently replaced, resulting in a high maintenance cost.

  In view of the above problems, an object of the present invention is to provide a laser radar device and a laser radar method that can reduce energy consumption to reduce running costs and reduce maintenance costs.

  In order to solve the above problems, a laser radar device of the present invention projects laser light into a predetermined first range and a second range that includes at least part of the first range and is wider than the first range. A laser beam projecting unit that emits light, an object detection unit that detects an object based on a reflected wave generated by reflecting the laser beam, and an object detected while projecting the laser beam in the first range And a switching control unit that controls the laser light projecting unit to switch the laser light projecting range from the first range to the second range.

  In addition, when the laser beam scanning range is at least the second range and the light projection range is the first range, the switching control unit projects only the first range, and the light projection range is the second range. Alternatively, the laser light projecting unit may be controlled to project light over the second range.

  The laser beam projector scans the laser beam in one or both of the vertical direction and the horizontal direction while projecting the laser beam, and the switching control unit sets the projection range as the first range. In this case, when the first range is scanned in one direction and the projection range is set as the second range, the laser beam projecting unit may be controlled so as to scan the second range in both directions. .

  In order to solve the above-described problem, a laser radar method of the present invention includes a step of projecting a laser beam to a predetermined first range and detecting an object based on a reflected wave generated by reflecting the laser beam; When an object is detected, the projection range of the laser beam is switched from the first range to the second range that includes the first range and is wider than the first range, and based on the reflected wave generated by reflecting the laser beam. And a step of detecting an object.

  According to the present invention, energy consumption can be reduced to reduce running costs, and maintenance costs can be reduced.

It is a figure for demonstrating the usage pattern of the laser radar apparatus concerning 1st Embodiment. It is a figure for demonstrating the specific structure of the laser radar apparatus concerning 1st Embodiment. It is a flowchart for demonstrating the flow of a process of the laser radar method concerning 1st Embodiment. It is a figure for demonstrating the usage type of the laser radar apparatus concerning 2nd Embodiment. It is a figure for demonstrating the specific structure of the laser radar apparatus concerning 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First embodiment)
FIG. 1 is a diagram for explaining a usage pattern of the laser radar device 100 according to the first embodiment, and FIG. 1A is a perspective view of a target range 102 to be monitored by the laser radar device 100. FIG. 1 (b) is a top view of FIG. 1 (a). As shown in FIG. 1, in a predetermined target range 102 such as a room, a building, or a site, there is a place where there is a high possibility of entry such as a door, a window, and a vent (hereinafter referred to as “intrusion place”). At least a portion thereof. Therefore, the laser radar apparatus 100 monitors the intrusion of a new object such as an intruder into the target range 102 through the intrusion point 104.

  The laser radar apparatus 100 is driven in one of the monitoring mode and the locus grasping mode. The monitoring mode is an operation mode for detecting whether or not a new object has entered the target range 102. When a new object intrusion is detected in the monitoring mode, the operation mode is switched from the monitoring mode to the trajectory grasping mode. . The trajectory grasping mode is an operation mode for grasping (tracing) the trajectory of the new object detected in the monitoring mode in the target range 102. Hereinafter, a specific configuration of the laser radar device 100 that monitors the target range 102 and grasps a locus when a new object is detected will be described.

(Laser radar device 100)
FIG. 2 is a diagram for explaining a specific configuration of the laser radar device 100 according to the first embodiment. As shown in FIG. 2, the laser radar device 100 includes a laser beam projector 110 and a control unit 160. In FIG. 2, the laser light L and the reflected wave M are indicated by thick arrows, the moving directions of the polygon mirror 122 and the galvano mirror 132 are indicated by solid arrows, and the flow of control and data is indicated by broken arrows. The scanning direction of the light L is indicated by a one-dot chain line and two-dot chain arrow.

  The laser beam projecting unit 110 projects the laser beam L based on the monitoring mode or the locus grasping mode in response to a control command from the switching control unit 180 described later. The operation mode switching processing by the switching control unit 180 will be described in detail later. In the present embodiment, the laser beam projecting unit 110 includes a laser beam oscillator 112, a horizontal scanning unit 120, a vertical scanning unit 130, and a reflected wave light receiving unit 140.

  The laser light oscillator 112 includes, for example, a laser diode that is a light source of the laser light L, a light projecting lens that collimates the laser light L, and an LD driver that drives the laser diode, and emits the laser light L. Radiate. The LD driver drives the laser diode so that the laser light L is emitted based on a control command from an oscillation control unit 170 described later. In the present embodiment, the laser light oscillator 112 emits the laser light L in a pulse shape (pulse oscillation).

  The horizontal scanning unit 120 scans the laser beam L emitted from the laser beam oscillator 112 in the horizontal direction H. In the present embodiment, the horizontal scanning unit 120 is, for example, a polygon scanner, and includes a polygon mirror 122, a drive motor 124, and a housing 126.

  The polygon mirror 122 is a hexahedron (regular quadratic prism) and is driven by a drive motor 124 with the center of two opposite faces (hereinafter referred to as “axial faces”) among the six faces constituting the hexahedron as the rotation axis. It is rotated. Of the polygon mirror 122, four surfaces other than the axial surface are mirror-finished, and when the polygon mirror 122 is rotated by the drive motor 124, the mirror-finished four surfaces are in a predetermined direction (in FIG. 2, (Indicated by solid arrows). The drive motor 124 rotates the polygon mirror 122 based on a control command from a horizontal control unit 172 described later. The casing 126 supports the polygon mirror 122 and the drive motor 124.

  As described above, when the drive motor 124 rotates the polygon mirror 122, the angle in the horizontal direction H of the laser light L emitted in a pulse form from the laser light oscillator 112 is changed. Scanning is performed in the horizontal direction H.

  The vertical scanning unit 130 scans the laser light emitted from the laser light oscillator 112 in the vertical direction V. In the present embodiment, the vertical scanning unit 130 is, for example, a galvano scanner, and includes a galvano mirror 132 and a drive motor 134. The galvanometer mirror 132 is a plane mirror. The drive motor 134 rotates the mirror surface of the galvanometer mirror 132 based on a control command from the vertical control unit 174 described later.

  As described above, the drive motor 134 rotates the galvano mirror 132, thereby changing the angle of the laser beam L reflected by the polygon mirror 122 in the vertical direction V. The laser beam L is changed in the vertical direction V in the target range 102. It will be scanned.

  As described above, the laser beam L emitted from the laser beam oscillator 112 passes through the projection window 150 and is projected onto the target range 102 via the polygon mirror 122 and the galvanometer mirror 132.

  The reflected wave light receiving unit 140 includes, for example, a light receiving lens that collects the reflected wave M and a photoelectric conversion element (photodiode) that receives the collected reflected wave M and converts it into a voltage. A reflected wave M generated by reflecting the laser light L projected by the light projecting unit 110 is received.

  The reflected wave M generated when the object reflects the laser light L is transmitted through the light projection window 150 and guided to the reflected wave light receiving unit 140 through the galvano mirror 132 and the polygon mirror 122. After being converted to voltage, light reception information indicating the voltage value is output to the control unit 160.

  The control unit 160 includes a central control unit 162 and a storage unit 164. The central control unit 162 is composed of a semiconductor integrated circuit including a CPU (central processing unit), reads programs and parameters for operating the CPU itself from the ROM, and cooperates with the RAM as a work area and other electronic circuits. Thus, the entire laser radar apparatus 100 is managed and controlled. The storage unit 164 includes a ROM, a RAM, a flash memory, an HDD, and the like, and stores programs and various data used for the central control unit 162.

  In the present embodiment, the central control unit 162 also functions as an oscillation control unit 170, a horizontal control unit 172, a vertical control unit 174, a light reception control unit 176, an object detection unit 178, and a switching control unit 180.

  The oscillation control unit 170 controls the LD driver constituting the laser light oscillator 112 to drive or stop the laser diode.

  The horizontal control unit 172 controls the drive motor 124 included in the horizontal scanning unit 120 to control the rotation speed of the polygon mirror 122. The horizontal control unit 172 derives an angle in the rotation direction from the initial position of the polygon mirror 122 and causes the storage unit 164 to hold horizontal angle information indicating the derived angle in the rotation direction.

  The vertical control unit 174 controls the drive motor 134 constituting the vertical scanning unit 130 to control the rotation direction and rotation speed of the galvano mirror 132. Note that the vertical control unit 174 derives an angle in the rotation direction from the initial position of the galvanometer mirror 132, and causes the storage unit 164 to hold vertical angle information indicating the derived angle in the rotation direction.

  The light reception control unit 176 maintains or stops power supply to the photoelectric conversion elements that constitute the reflected wave light reception unit 140.

  The object detection unit 178 acquires the light reception information output from the reflected wave light reception unit 140, and detects whether a new object has entered the target range 102 based on the voltage value indicated by the light reception information. Specifically, the storage unit 164 stores in advance background information indicating the voltage value of the reflected wave M reflected by each object (for example, a wall) previously set in the target range 102, and the object The detection unit 178 compares the background information held in the storage unit 164 with the voltage value indicated by the acquired light reception information, and detects the difference, thereby grasping that a new object has entered.

  The switching control unit 180 switches the operation mode of the laser light projecting unit 110 between the monitoring mode and the locus grasping mode. Referring back to FIG. 1B, when the operation mode is set to the monitoring mode, the switching control unit 180 only lasers the first range 106 that is included in the target range (second range) 102 and includes the entry point 104. The laser beam projector 110 is controlled so that the light L is projected. Then, when a new object (intrusion of a new object) is detected in the monitoring mode, the switching control unit 180 switches the operation mode from the monitoring mode to the trajectory grasping mode, and the laser beam L is projected over the entire target range 102. The laser light projecting unit 110 is controlled so that the light is emitted. In addition, when a new object is no longer detected in the target range (second range) 102 (when a new object escapes) in the trajectory grasp mode, the switching control unit 180 switches the operation mode to the monitoring mode. That is, the monitoring mode is an operation mode in which the projection range of the laser light L is the first range 106, and the locus grasping mode is an operation mode in which the projection range of the laser light L is the target range (second range) 102. You can say that.

  More specifically, in this embodiment, the switching control unit 180 controls the horizontal control unit 172 and the vertical control unit 174 regardless of whether the mode is set to the monitoring mode or the track grasping mode. Thus, the driving of the horizontal scanning unit 120 and the vertical scanning unit 130 is maintained, and the scanning range of the laser light L is maintained in the target range 102.

  When the operation mode of the laser beam projecting unit 110 is set to the monitoring mode, the switching control unit 180 controls the oscillation control unit 170 so that the laser beam is emitted only during the period in which the laser beam L is emitted to the first range 106. The oscillator 112 is driven. On the other hand, when the switching control unit 180 sets the operation mode of the laser light projecting unit 110 to the locus grasping mode, the switching control unit 180 controls the oscillation control unit 170 over the period in which the laser light L is emitted to the target range 102. The laser light oscillator 112 is driven, that is, the laser light oscillator 112 is always driven.

  As described above, in the monitoring mode, the switching control unit 180 restricts the range in which the laser light L is projected to the first range 106, and when an intrusion of a new object is detected, the switching control unit 180 switches to the trajectory grasping mode. As a result, the driving time of the laser beam oscillator 112 is shortened compared to a conventional laser radar device that projects light while constantly scanning the laser beam over the entire target range. can do. Thereby, the energy consumption (power consumption) for driving the laser light oscillator 112 can be reduced, and the running cost can be reduced. In addition, since consumption of components such as a laser diode constituting the laser light oscillator 112 can be suppressed, the frequency of replacement of components can be reduced, and maintenance costs can be reduced.

(Laser radar method)
Next, a laser radar method using the laser radar device 100 will be described. FIG. 3 is a flowchart for explaining the flow of processing of the laser radar method according to the first embodiment. As shown in FIG. 3, the switching control unit 180 sets the operation mode of the laser light projecting unit 110 to the monitoring mode (monitoring mode setting process S110). Then, the laser beam projecting unit 110 projects the laser beam L onto the predetermined first range 106, receives the reflected wave M generated by reflecting the laser beam L, and the object detection unit 178 receives the laser beam L. Based on the reflected wave M received by the light projecting unit 110, it is detected whether or not there is a new object (whether or not it has entered).

  Subsequently, the switching control unit 180 determines whether or not a new object has been detected by the object detection unit 178 (object detection determination processing S120). Until a new object is detected (NO in S120), switching control unit 180 maintains the operation mode of laser light projecting unit 110 in the monitoring mode, and when a new object is detected (YES in S120). The switching control unit 180 switches the operation mode of the laser beam projecting unit 110 to the trajectory grasping mode (trajectory grasping mode switching process S130). Then, the laser beam projecting unit 110 projects the laser beam L to the second range including the first range 106 and wider than the first range 106, and receives the reflected wave M generated by reflecting the laser beam L. The object detection unit 178 grasps the locus of a new object based on the reflected wave M received by the laser light projecting unit 110.

  Then, until no new object is detected by the object detection unit 178 (NO in S140), the switching control unit 180 maintains the operation mode of the laser light projecting unit 110 in the locus grasping mode, and a new object is detected. When there is no more (YES in S140), the switching control unit 180 repeats the process from the monitoring mode setting process S110.

  As described above, according to the laser radar device 100 and the laser radar method using the same according to the present embodiment, it is possible to reduce energy consumption to reduce running costs and to reduce maintenance costs. .

(Second Embodiment: Laser Radar Device 200)
In the first embodiment, the horizontal scanning unit 120 and the vertical scanning unit 130 are kept driven, and the driving state of the laser light oscillator 112 is controlled, so that the monitoring mode (the laser light L projection range is the first). 1 range 106) and the laser radar device 100 that switches between the locus grasp mode (the projection range of the laser light L is the second range) has been described. However, when there is only one intrusion point 104, the monitoring mode and the trajectory grasping mode can be switched with other configurations. In the second embodiment, a laser radar device 200 that switches between a monitoring mode and a trajectory grasping mode with a configuration different from that of the first embodiment will be described.

  FIG. 4 is a diagram for explaining a usage pattern of the laser radar device 200 according to the second embodiment, and FIG. 4A is a perspective view of a target range 102 to be monitored by the laser radar device 200. FIG. 4 (b) is a top view of FIG. 4 (a). As shown in FIG. 4, the target range 102 (second range) monitored by the laser radar device 200 includes only one intrusion point 104. Therefore, when the laser radar device 200 is in the monitoring mode, it is only necessary to project the laser light L only to one first range 106 including the entry point 104. Hereinafter, a specific configuration of the laser radar device 200 that monitors the target range 102 and grasps a locus when a new object is detected will be described.

(Laser radar device 200)
FIG. 5 is a diagram for explaining a specific configuration of the laser radar apparatus 200 according to the second embodiment. As shown in FIG. 5, the laser radar device 200 includes a laser light projector 110 and a control unit 260. The control unit 260 includes a central control unit 262 and a storage unit 164. The central control unit 262 is composed of a semiconductor integrated circuit including a CPU (central processing unit), reads programs and parameters for operating the CPU itself from the ROM, and cooperates with the RAM as a work area and other electronic circuits. Thus, the entire laser radar apparatus 200 is managed and controlled. In the present embodiment, the central control unit 262 also functions as the oscillation control unit 170, the horizontal control unit 172, the vertical control unit 174, the light reception control unit 176, the object detection unit 178, and the switching control unit 280. Note that components that are substantially the same as those of the laser radar device 100 described above are denoted by the same reference numerals and description thereof is omitted. Here, the switching control unit 280 having a different configuration will be described in detail.

  The switching control unit 280 controls the oscillation control unit 170 to set the laser light oscillator whether the operation mode of the laser light projecting unit 110 is set to the monitoring mode or the locus grasping mode. The drive of 112 is maintained and the laser beam L is always emitted.

  Then, when setting the operation mode of the laser beam projector 110 to the monitoring mode, the switching controller 280 refers to the horizontal angle information indicating the angle in the rotation direction of the polygon mirror 122 held in the storage unit 164, The horizontal control unit 172 is controlled to drive the drive motor 124 and change the angle of the polygon mirror 122 so that the laser light L is projected onto the first range 106. When the polygon mirror 122 is rotated at an angle at which the laser beam L is projected onto the first range 106, the switching control unit 280 controls the horizontal control unit 172 to stop the drive motor 124 and The position in the horizontal direction H is fixed.

  Further, the switching control unit 280 controls the vertical control unit 174 to maintain the drive of the vertical scanning unit 130. Then, the laser beam projecting unit 110 scans the first range 106 with the laser beam L with only one axis in the vertical direction V. Even when scanning is performed with only one axis in the vertical direction V, it can be said that the projection range of the laser light L has a width in the horizontal direction H, and thus the first range 106 can be covered.

  On the other hand, the switching control unit 280 controls the horizontal control unit 172 to start driving the drive motor 124 and rotate the polygon mirror 122 when the operation mode of the laser beam projecting unit 110 is set to the locus grasping mode. The projection range (scanning range) of the laser light L is expanded to the target range 102.

  As described above, according to the laser radar device 200 according to the present embodiment, compared with the conventional laser radar device, the scanning by the horizontal scanning unit 120 is fixed and the drive target is limited to one axis. it can. Thereby, the energy consumption (power consumption) for driving the horizontal scanning unit 120 can be reduced, and the running cost can be reduced. In addition, since the consumption of components such as the drive motor 124 constituting the horizontal scanning unit 120 can be suppressed, the frequency of component replacement can be reduced and the maintenance cost can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the second embodiment, the switching control unit 280 has been described by taking as an example a configuration in which the driving of the horizontal scanning unit 120, that is, the scanning in the horizontal direction H is stopped in the monitoring mode. However, the switching control unit 280 scans the first range 106 in one of the vertical direction V and the horizontal direction H in the monitoring mode, and performs the first operation in both the vertical direction V and the horizontal direction H in the trajectory grasping mode. Two ranges may be scanned. For example, in the monitoring mode, the driving of the vertical scanning unit 130 may be stopped while the driving of the horizontal scanning unit 120 is maintained.

  The present invention can be used in a laser radar apparatus and a laser radar method for detecting an object using laser light.

100, 200 Laser radar device 102 Target range (second range)
106 1st range 110 Laser beam projection part 180,280 Switching control part

Claims (4)

A laser light projecting unit that projects laser light onto a predetermined first range and a second range that includes at least part of the first range and is wider than the first range;
An object detection unit that detects an object based on a reflected wave generated by reflecting the laser beam;
When the object is detected while projecting the laser beam on the first range, the laser beam projecting unit is controlled to change the projecting range of the laser beam from the first range to the second range. A switching control unit for switching to a range;
A laser radar device comprising: The switching controller is
The scanning range of the laser beam is at least the second range,
When the light projection range is the first range, only the first range is projected,
2. The laser radar device according to claim 1, wherein when the light projection range is the second range, the laser light projection unit is controlled to project light over the second range. . The laser light projecting unit scans the laser light in one or both of the vertical direction and the horizontal direction while projecting the laser light,
The switching controller is
When the projection range is the first range, the first range is scanned in the one direction,
2. The laser radar according to claim 1, wherein when the light projection range is the second range, the laser light projection unit is controlled to scan the second range in both directions. apparatus. Projecting a laser beam in a predetermined first range and detecting an object based on a reflected wave generated by reflecting the laser beam;
When the object is detected, the laser light projecting range is switched from the first range to the second range that includes the first range and is wider than the first range, and is generated by reflecting the laser light. Detecting an object based on the reflected wave;
A laser radar method comprising:

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