JP5267722B2 - Laser radar equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser radar apparatus that allows detection of the periphery of the apparatus and also allows three-dimensional detection. <P>SOLUTION: This laser radar apparatus 1 includes a laser diode 10 for generating a laser beam, a photodiode 20 for detecting reflected light of the laser beam that has been reflected by a detecting object when the laser beam is generated from the laser diode 10, a deflecting section 41 constituted turnably about a predetermined center axis 42a, a turn deflecting mechanism 40 for deflecting the laser beam toward a space with the deflecting means 41 and deflecting the reflected light toward the photodiode 20, and a motor 50 for rotating and driving the rotation deflecting mechanism 40. The laser radar apparatus further comprises a rocking mirror 31 for changing the direction of the laser beam from the deflecting means 41 with respect to the direction of the center axis 42a by relatively changing the incidence direction of the laser beam to the deflecting section 41, and a controlling means for controlling the rocking mirror 31. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a laser radar device.

  Conventionally, for example, an apparatus as disclosed in Patent Document 1 is provided as a technique for detecting the distance and direction to a detection object using a laser beam. In the apparatus of Patent Document 1, an optical isolator that transmits laser light and reflects reflected light from a detection object toward the detection means is provided on the optical axis of the laser light from the laser light generation means. Furthermore, a concave mirror that rotates about the central axis in the optical axis direction is provided on the optical axis of the laser light that passes through the optical isolator. The concave mirror reflects the laser light toward the space and reflects it from the detection object. Reflecting light toward the optical isolator enables 360 ° horizontal scanning.

Japanese Patent No. 2789741

  By the way, in the technique of Patent Document 1, 360 ° horizontal scanning is possible by rotating the concave mirror, and the detection area (area where scanning with laser light is performed) is expanded to the entire periphery of the apparatus. There is a problem that the detection area is limited to a plane. That is, since the laser beam reflected from the concave mirror toward the space is scanned within a predetermined plane (scanning plane), it is impossible to detect a region outside the scanning plane. Therefore, a detected object that deviates from the scanning plane cannot be detected, and even if the detected object exists in the scanning plane, the detected object cannot be grasped in three dimensions.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a laser radar apparatus that can detect the surroundings of the apparatus and can also perform three-dimensional detection.

In order to achieve the above object, a first aspect of the present invention provides a laser radar device, wherein a laser beam generating means for generating laser light, and when the laser light is generated from the laser light generating means, are reflected by a detection object. A light detecting means for detecting reflected light of the laser light and one or a plurality of deflecting means configured to be rotatable about a predetermined central axis, and directing the laser light to the space by the deflecting means. And rotating the deflection means for deflecting the reflected light toward the light detection means, the drive means for rotating the rotation deflection means, and the incident direction of the laser light relative to the deflection means relative to each other. By changing the direction of the laser beam from the deflecting means with respect to the direction of the central axis, and a control means for controlling the direction changing means. Wherein the is provided.
Further, the direction changing means comprises laser light deflecting means configured to deflect the laser light from the laser light generating means toward the rotation deflecting means and configured to be swingable, and the control The means comprises swing control means for controlling the swing of the laser beam deflecting means. The laser beam deflecting means swings the deflecting member for deflecting the laser light and swingingly supports the deflecting member. A mechanism, and an actuator for driving the deflection member supported by the swing mechanism;
The deflecting means is a mirror having a surface that is inclined with respect to the central axis and reflects the laser light, and the direction of the central axis is a Y-axis direction, and is a predetermined perpendicular to the Y-axis direction. When the direction is the X-axis direction and the direction orthogonal to the X-axis direction and the Y-axis direction is the Z-axis direction, the laser beam from the laser beam generating means is deflected from one side in the X-axis direction. The deflection member is deflected by the deflection member toward the deflection unit disposed on one side in the Y-axis direction with respect to the deflection member, and the swing control unit is configured to rotate the deflection unit. When the moving position does not fall within the predetermined rotation range, the direction of the laser beam from the deflecting member toward the deflecting means is changed along the XY plane, and the rotating position of the deflecting means is the predetermined rotating position. In the case of a range, The driving state of the deflection member by the actuator is controlled so as to change the direction of the laser beam from the member toward the deflection unit along a plane intersecting the XY plane, and the predetermined rotation range Is a range in which an angle formed between a virtual straight line parallel to the X-axis direction and a virtual plane parallel to a surface of the deflecting unit that reflects the laser light is equal to or less than a predetermined threshold value. .

The invention according to claim 2 is characterized in that a deflection area for deflecting the reflected light in the deflection means is configured to be larger than a deflection area for deflecting the laser light in the laser light deflection means.

According to a third aspect of the present invention, a condensing unit that condenses the reflected light toward the light detecting unit is provided on an optical path of the reflected light from the rotation deflecting unit to the light detecting unit. It is characterized by being.

According to a fourth aspect of the present invention, there is provided a light selecting unit that transmits the reflected light and removes light other than the reflected light on an optical path of the reflected light from the rotation deflecting unit to the light detecting unit. It is provided.

  According to the first aspect of the present invention, the deflecting means for deflecting the laser light toward the space and deflecting the reflected light from the detection target toward the light detecting means is rotatable about a predetermined central axis. Therefore, the detection over the periphery of the device is possible. In addition, since there is provided a direction changing means for changing the direction of the laser light from the deflecting means with respect to the direction of the central axis, the direction of the laser light is changed not only in the plane direction orthogonal to the central axis but also in the direction of the central axis. Therefore, detection can be performed three-dimensionally.

In addition, a configuration capable of changing the direction of the laser beam from the deflection unit with respect to the direction of the central axis can be suitably realized by the laser beam deflection unit.

Further, the deflection member supported by the swing mechanism is configured to be driven by an actuator, and the drive state of the deflection member by the actuator is controlled by the swing control means. In this way, it is possible to satisfactorily control the oscillation of the part that deflects the laser beam.

In addition, the swing control of the laser beam deflecting unit can be performed appropriately according to the rotation position of the deflecting unit.

According to the second aspect of the present invention, the deflection area for deflecting the reflected light in the deflecting means is larger than the deflection area for deflecting the laser light in the laser light deflecting means. It can be used for detection, and the detection accuracy can be effectively increased.

In the invention of claim 3 , since the light collecting means for collecting the reflected light toward the detecting means is provided on the optical path of the reflected light from the rotation deflecting means to the light detecting means, the detecting means is A wide range of reflected light can be used for detection without increasing the size.

According to the fourth aspect of the present invention, there is provided a light selecting means for transmitting the reflected light and removing light other than the reflected light on the optical path of the reflected light from the rotation deflecting means to the light detecting means. , Noise light can be suitably removed.

FIG. 1 is a cross-sectional view schematically illustrating a laser radar device according to a first embodiment of the invention. FIG. 2 is an explanatory diagram schematically illustrating a displacement mechanism for displacing the oscillating mirror. FIG. 3 is a cross-sectional view schematically illustrating a laser radar device according to the second embodiment of the invention. FIG. 4 is an explanatory view for conceptually explaining a swing mechanism, an actuator, and the like used in the laser radar apparatus of FIG. FIG. 5 is an explanatory diagram for conceptually explaining a mirror to which a piezo actuator is attached from the back side (opposite side of the reflecting surface), and FIG. 5 (b) is a conceptual view of the mirror to which the piezo actuator is attached. It is a perspective view shown in FIG. Figure 6 is a flow chart illustrating the detection process in the laser radar apparatus of FIG.

[First embodiment]
Hereinafter, a first embodiment of a laser radar device according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically illustrating a laser radar device 1 according to the first embodiment.

  As shown in FIG. 1, the laser radar device 1 includes a laser diode 10 and a photodiode 20 that receives reflected light L2 from a detection object, and is configured as a device that detects the distance and direction to the detection object. Yes. The laser diode 10 corresponds to an example of laser light generation means, and is supplied with a pulse current from a drive circuit (not shown) and projects pulsed laser light (laser light L1). The photodiode 20 corresponds to an example of a detection unit, and when the laser light L1 is generated from the laser diode 10, the reflected light L2 of the laser light L1 reflected by the detection object is detected and converted into an electric signal. It has a configuration. The reflected light from the detection object is configured to be captured in a predetermined region. In the example of FIG. 1, when the laser light L1 passes through the path indicated by the solid line, Reflected light in the area between the lines is taken in.

  A lens 60 is provided on the optical axis of the laser beam L1. The lens 60 is configured as a collimating lens and has a function of converting the laser light L1 from the laser diode 10 into parallel light.

  On the optical path of the laser beam L1 that has passed through the lens 60, an oscillating mirror 31 is disposed as a laser beam deflecting unit. The oscillating mirror 31 corresponds to an example of “direction changing means”, and is configured to deflect the laser light L1 from the laser diode 10 toward the rotation deflection mechanism 40 and is configured to be oscillated. ing. The oscillating mirror 31 functions to change the direction of the laser beam from the deflection unit 41 with respect to the direction of the central axis 42a by relatively changing the incident direction of the laser beam with respect to the deflection unit 41.

  In addition, a mirror driving unit that drives the oscillating mirror 31 with multiple degrees of freedom is provided. Since the technique for driving the mirror with multiple degrees of freedom is well known in the field of galvano mirrors and the like, details thereof will be omitted, but for the mirror driving unit, for example, the oscillating mirror 31 is supported by a gimbal, a pivot bearing or the like. Thereby, it can be set as the structure made to rotationally move to two directions. In FIG. 2, as an example, a displacement mechanism 33 that displaces the oscillating mirror 31 is illustrated. The displacement mechanism 33 is a frame (not shown) disposed at a predetermined position in the case 3, and rotates on the frame. And a mirror support frame 34 that can be held. The swing mirror 31 is supported by a first shaft 33a and a second shaft 33b (the second shaft 33b is a first shaft 33a). It is configured to perform a rotational movement in two directions centered on (orthogonal to). With this configuration, the three-dimensional positional relationship of the reflecting surface 31a of the oscillating mirror 31 is determined. In FIG. 1, the emission direction of the laser light L1 from the laser diode 10 is the X-axis direction, the direction of the central axis 42a of the rotation changing mechanism 40 is the Y-axis direction, and the directions orthogonal to the X-axis direction and the Y-axis direction are It is described as the Z-axis direction. In such a definition, when the angle between the reflecting surface 31a and the XY plane is α, the angle between the reflecting surface 31a and the YZ plane is β, and the angle between the reflecting surface 31a and the XZ plane is γ, the control circuit By controlling the actuator 36 by 70, the values of α, β, and γ are freely determined.

  The displacement mechanism 33 is driven by an actuator 36 schematically shown in FIG. The actuator 36 includes a first actuator such as a motor that sets the relative position of the mirror support frame 34 with respect to the apparatus main body, and a second actuator such as a motor that sets the relative position of the swing mirror 31 with respect to the mirror support frame 34. Based on the control amount from the control circuit 70, the first actuator (motor or the like) sets the position of the mirror support frame 34, and the second actuator (motor or the like) sets the position of the oscillating mirror 31 relative to the mirror support frame 34. Thus, the tilt of the oscillating mirror 31 with respect to the laser beam L1 is set. The control circuit 70 is configured by a microcomputer equipped with a CPU. In the present embodiment, the control circuit 70 corresponds to an example of “control means”.

  A rotation deflection mechanism 40 is provided on the optical axis of the laser beam L1 reflected by the oscillating mirror 31. The rotation deflection mechanism 40 corresponds to an example of a rotation deflection unit. The deflection unit 41 includes a mirror having a flat reflecting surface 41a, a support base 43 that supports the deflection unit 41, and the support. A shaft portion 42 connected to the base 43 and a bearing (not shown) that rotatably supports the shaft portion 42 are provided. The deflecting portion 41 deflects the laser light toward the space, and reflects the reflected light to the photodiode. It functions to deflect towards 20. The deflection unit 41 constituting a part of the rotation deflection mechanism 40 is rotatable about the central axis 42a, and corresponds to an example of a deflection unit.

  In the laser radar device 1 according to the present embodiment, the deflection region (the region of the reflection surface 41a in the deflection unit 41) that deflects the reflected light in the deflection unit 41 is the deflection region (the region of the reflection surface 41a in the deflection unit 41) that deflects the laser light. It is configured to be larger than the area of the reflecting surface 31a in the oscillating mirror 31).

  Further, a motor 50 is provided so as to rotationally drive the rotation deflection mechanism 40. The motor 50 corresponds to an example of a driving unit, and is configured to rotate and drive the deflection unit 41 connected to the shaft unit 42 by rotating the shaft unit 42. Here, the motor 50 is constituted by a step motor. Various step motors can be used. If a step motor having a small angle for each step is used, precise rotation is possible. Further, driving means other than the step motor may be used as the motor 50. For example, a servo motor or the like may be used, or a motor that rotates regularly and a pulse laser beam is output in synchronization with the timing when the deflecting unit 41 faces the direction to be measured, thereby enabling detection of a desired direction. Also good. In the present embodiment, as shown in FIG. 1, a rotation angle position sensor 52 that detects the rotation angle position of the shaft portion 42 of the motor 50 (that is, the rotation angle position of the deflection unit 41) is provided. The rotation angle position sensor 52 can be of various types as long as it can detect the rotation angle position of the shaft portion 42 such as a rotary encoder, and the type of the motor 50 to be detected is not particularly limited. It can be applied to various types.

  A condensing lens 62 that condenses the reflected light toward the photodiode 20 is provided on the optical path of the reflected light from the rotation deflection mechanism 40 to the photodiode 20. A filter 64 is provided between the diodes 20. The condensing lens 62 condenses the reflected light from the deflection unit 41 and guides it to the photodiode 20 and corresponds to an example of a condensing unit. The filter 64 transmits reflected light and removes light other than reflected light on the optical path of reflected light from the rotation deflection mechanism 40 to the photodiode 20 and corresponds to an example of a light selection unit. doing. Specifically, it can be configured by a wavelength selection filter that transmits only light with a specific wavelength corresponding to the reflected light L2 (for example, light with a wavelength in a certain region) and blocks other light.

  In the present embodiment, the laser diode 10, the photodiode 20, the laser beam deflecting unit 30, the lens 60, the rotation deflection mechanism 40, the motor 50, and the like are housed in the case 3, and dust and impact protection are achieved. . Around the deflection unit 41 in the case 3, a light guide unit 4 that allows the laser light L <b> 1 and the reflected light L <b> 2 to pass is formed so as to surround the deflection unit 41. The light guide 4 is formed in an annular shape centering on the optical axis of the laser beam L1 incident on the deflecting unit 41 and is substantially 360 °, and the glass plate is closed in the form of closing the light guide 4. A laser light transmission plate 5 made of a material such as the like is arranged to prevent dust. The laser beam transmitting plate 5 is configured to be inclined over the entire circumference with respect to a virtual plane orthogonal to the optical axis of the laser beam L1 entering the deflection unit 41. That is, the plate surface is inclined with respect to the laser beam L1 from the deflection unit 41 toward the space. Therefore, even if the laser beam L1 traveling from the deflection unit 41 to the space is reflected by the laser beam transmitting plate 5, it is difficult to become noise light.

  Next, the operation of the laser radar device 1 will be described. In the laser radar device 1 shown in FIG. 1, when a pulse current is supplied to the laser diode 10, the laser diode 10 outputs a pulse laser beam (laser beam L1) at a time interval corresponding to the pulse width of the pulse current. The The laser light L1 is projected as diffused light having a certain spread angle, and is converted into parallel light by passing through the lens 60. The laser beam L1 that has passed through the lens 60 is reflected by the oscillating mirror 31 provided in the laser beam deflecting unit 30, enters the deflecting unit 41, is reflected by the deflecting unit 41, and is irradiated toward the space.

  The laser beam L1 reflected by the deflecting unit 41 is reflected by the detection object, and a part of the reflected light (see the reflected light L2) is incident on the deflecting unit 41 again. The deflecting unit 41 reflects the reflected light L2 toward the photodiode 20 side. The reflected light L <b> 2 reflected by the deflecting unit 41 is collected by the condenser lens 62, passes through the filter 64, and enters the photodiode 20.

  The photodiode 20 outputs an electrical signal corresponding to the received reflected light L2 (for example, a voltage value corresponding to the received reflected light L2). In this configuration, the distance to the detection object can be obtained by measuring the time from when the laser light L1 is output by the laser diode 10 until the reflected light L2 is detected by the photodiode 20. Further, the azimuth can be obtained from the displacement of the oscillating mirror 31 and the displacement of the deflecting unit 41 at that time. That is, the angle α formed between the reflecting surface 31a of the oscillating mirror 31 and the XY plane, the angle β formed between the reflecting surface 31a and the YZ plane, and the angle γ formed between the reflecting surface 31a and the XZ plane are determined, and the rotation of the deflection unit 41 is determined. When the position is determined, the direction in which the laser beam L1 travels from the deflecting unit 41 is determined as one azimuth, so that the azimuth of the detected object can be accurately grasped.

  The path change of the laser light accompanying the displacement of the oscillating mirror 31 is as follows. FIG. 1 shows an example in which the rotation deflection mechanism 40 is in a predetermined rotation state. When the swing mirror 31 is in the swing state of FIG. L1 passes through the path indicated by the solid line, and the reflected light in the region between the two lines indicated by reference numeral L2 is captured. On the other hand, when the oscillating state of the oscillating mirror 31 is changed, the incident angle of the laser beam L1 with respect to the deflecting unit 41 is relatively changed as indicated by a broken line L1 ′. That is, when the oscillating mirror 31 is displaced, the reflection angle of the laser beam on the oscillating mirror 31 changes, and the path shown by the solid line changes to the path shown by the broken line L1 ′. Thereby, the laser beam which goes to the space from the deflection | deviation part 41 will change to the direction of the central axis 42a. In this case, the path of the reflected light also changes as indicated by the broken line L2 ′, and after being reflected by the deflecting unit 41, is taken into the photodiode 20 via the condenser lens 62 and the filter 64.

  As described above, according to the laser radar device 1 according to the present embodiment, the deflection unit 41 that deflects the laser light L1 toward the space and deflects the reflected light L2 from the detection target toward the photodiode 20 is provided. Since it can be rotated about a predetermined central axis, detection over the periphery of the apparatus is possible. In addition, since the oscillating mirror 31 that can change the direction of the laser light L1 from the deflection unit 41 with respect to the direction of the central axis 42a is provided, the direction of the laser light L1 is a planar direction orthogonal to the central axis 42a ( Since it can be changed not only in the XZ plane direction) but also in the direction of the central axis 42a (Y direction), detection can be performed three-dimensionally.

  In addition, a configuration capable of changing the direction of the laser light L1 from the deflection unit 41 with respect to the direction of the central axis 42a can be suitably realized by the oscillating mirror 31 without using a complicated configuration.

  In addition, since the deflection area for deflecting the reflected light L2 in the deflecting unit 41 is configured to be larger than the deflection area for deflecting the laser light L1 in the oscillating mirror 31, the reflected light in a relatively wide area can be detected. It can be used, and the detection accuracy can be effectively increased.

  Further, since the condensing lens 62 that condenses the reflected light L2 toward the photodiode 20 is provided on the optical path of the reflected light L2 from the rotation deflection mechanism 40 to the photodiode 20, the photodiode 20 is provided. It becomes possible to use a wide range of reflected light for detection without increasing the size.

  In addition, since the filter 64 that transmits the reflected light L2 and removes light other than the reflected light is provided on the optical path of the reflected light L2 from the rotation deflection mechanism 40 to the photodiode 20, noise light is provided. Can be suitably removed.

[ Second Embodiment]
Next, a second embodiment will be described.
FIG. 3 is a cross-sectional view schematically illustrating a laser radar device according to the second embodiment of the invention. Figure 4 is an explanatory diagram conceptually illustrating the swinging mechanism and an actuator or the like for use in laser radar apparatus of FIG. FIG. 5 is an explanatory diagram for conceptually explaining a mirror to which a piezo actuator is attached from the back side (opposite side of the reflecting surface), and FIG. 5 (b) is a conceptual view of the mirror to which the piezo actuator is attached. It is a perspective view shown in FIG. Figure 6 is a flow chart illustrating the detection process in the laser radar apparatus of FIG.

As shown in FIG. 3 , the laser radar device 400 of this embodiment also uses parts similar to those of the first embodiment. That is, the case 3, the light guide 4, the laser light transmission plate 5, the laser diode 10, the lens 60, the photodiode 20, the filter 64, the condenser lens 62, the rotation deflection mechanism 40, the motor 50, the rotation angle position sensor 52, The control circuit 70 and the like have the same configuration as that of the first embodiment and have the same functions as those of the first embodiment. Accordingly, parts having the same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted. In the present embodiment, the direction of the central axis 42a of the rotation deflection mechanism 40 is the Y-axis direction, the predetermined direction orthogonal to the Y-axis direction is the X-axis direction, and the direction orthogonal to the X-axis direction and the Y-axis direction. Is the Z-axis direction. In the present embodiment, the emission direction of the laser light from the laser diode 10 is the X-axis direction.

  Also in the present embodiment, when the laser beam L1 is generated from the laser diode 10 (laser beam generation unit), the reflected light of the laser beam L1 reflected by the detection object is detected by the photodiode 20 (light detection unit). There is no. Further, the rotation deflection mechanism 40 includes a deflection unit 41 (deflection means) configured to be rotatable about a central axis 42a, and deflects the laser light L1 toward the space by the deflection unit 41, and The configuration is such that reflected light from the detection object is deflected toward the photodiode 20. Furthermore, the rotation deflection mechanism 40 is configured to be driven by a motor 50 (drive means).

  The laser beam deflecting unit 430 (the laser beam deflecting unit 430 corresponds to an example of “direction deflecting unit” or “laser beam deflecting unit”) deflects the laser beam from the laser diode 10 toward the rotating deflection mechanism 40. It has a configuration and is configured to be swingable. Then, the function of changing the incident direction of the laser light L1 relative to the deflecting unit 41 and changing the direction of the laser light from the deflecting unit 41 with respect to the direction of the central axis 42a (that is, the vertical direction (Y-axis direction)). have.

As shown in FIGS. 4 and 5A and 5B , the laser beam deflection unit 430 includes a mirror 431 that reflects the laser beam, a swing mechanism 435 that supports the mirror 431 so as to be swingable, and a swing mechanism. Piezo actuators 432a, 432b, 432c, and 432d that drive a mirror 431 supported by 435 are provided. The mirror 431 corresponds to an example of a “deflection member” that deflects laser light. The piezo actuators 432a, 432b, 432c, and 432d correspond to an example of an “actuator”.

  Each of the four piezo actuators 432a, 432b, 432c, and 432d is configured as a known piezo actuator that expands and contracts in accordance with an applied voltage, and each corner of the rectangular mirror 431 is opposite to the reflecting surface 431a. One end is attached in the vicinity (the vicinity of the corner of the mirror 431 corresponds to an example of a “specific part”), and the other end is fixed to the holding portion 438. The holding portion 438 is fixed to the case 3 and positioned at a predetermined position in the case 3. The piezoelectric actuators 432 a, 432 b, 432 c, and 432 d fixed to the holding portion 438 correspond to the applied voltage. By extending and contracting, the holder 438 is displaced relative to the holding portion 438 (that is, displaced relative to the case 3). The position in the vicinity of the part can be changed.

  The control circuit 70 (the control circuit 70 corresponds to an example of “control means” and “swing control means”) controls the driving state of the mirror 431 by the piezoelectric actuators 432a, 432b, 432c, and 432d, thereby deflecting the laser beam. The swing of the part 430 is controlled. Piezo actuator drive circuits (hereinafter also referred to as drive circuits) 436a, 436b, 436c, and 436d are electrically connected to the piezoelectric actuators 432a, 432b, 432c, and 432d, respectively. Each of these drive circuits 436a, 436b, 436c, 436d is configured to receive a control amount command from the control circuit 70, and from each drive circuit 436a, 436b, 436c, 436d, each piezoelectric actuator 432a, 432b, 432c, A voltage corresponding to the control amount from the control circuit 70 is output to 432d. In this way, the control circuit 70 controls the expansion and contraction of the piezoelectric actuators 432a, 432b, 432c, and 432d, and controls the attitude of the mirror 431 with respect to the laser light L1.

  The swing mechanism 435 is configured by a ball joint that connects the mirror 431 and the holding portion 438 that holds the mirror 431 in a spherical pair structure, and the ball portion 434 that is connected to the mirror 431 and the holding portion 438 are connected to each other. And a spherical shell portion 433 to be connected. In this configuration, the center 434a of the sphere portion 434 is always set at one position, and the sphere portion 434 can rotate in multiple directions while being accommodated in the spherical shell portion 433. The swing mechanism 435 configured as described above is adapted to the laser beam L1 while keeping the distance between the reflecting surface 431a and the center 434a of the ball portion 434 constant according to the expansion and contraction of the piezoelectric actuators 432a, 432b, 432c, and 432d. The tilt state of the mirror 431 is changed.

Next, detection processing in the laser radar device 400 will be described.
The detection process in FIG. 6 is started, for example, when the power is turned on or a predetermined operation is performed. First, the mirror 431 and the deflecting unit 41 are set to initial positions (S1). In the present embodiment, the position indicated by the solid line in FIGS . 3 and 4 is the initial position, and the motor 50 and the piezoelectric actuators 432a, 432b, 432c, and 432d are controlled so that the mirror 431 is at the position. Note that the deflecting unit 41 and the mirror 431 can be set to the initial positions in the standby state before the detection process. In such a configuration, the process of S1 can be omitted.

  Next, an object detection process is performed in the current setting state (a state where the initial position is set immediately after the start of the detection process) (S2). Specifically, the control circuit 70 controls the laser diode 10 to emit laser light, and the control circuit 70 reads an electric signal output from the photodiode 20 to read the current piezoelectric actuators 432a, 432b, 432c, and 432d. Whether there is an object to be detected in the direction corresponding to the setting (that is, the current setting of the mirror 431). When an electrical signal of a certain level or more is output from the photodiode 20, the distance to the detection object is calculated based on the time from the laser light projection by the laser diode 10 to the reception of the reflected light by the photodiode 20. . Further, based on the current setting of the piezo actuators 432a, 432b, 432c, and 432d, the direction in which the laser beam L1 is directed from the deflection unit 41 is calculated. Note that the calculated distance and direction can be output to a display unit (not shown).

  Thereafter, it is determined whether the mirror 431 has rotated by a predetermined range (S3). In the present embodiment, the motor 50 is configured to rotate the deflecting unit 41 by a predetermined angle (1 ° in the example of the present embodiment) by the control of the control circuit 70, and the deflecting unit 41 is constant. As the mirror 431 rotates over a “predetermined range” each time the angle (1 °) is rotated, the direction of the central axis (along the central axis 42a) is set at every constant angle (1 °) of the motor 50. (Vertical direction) scanning is performed. In the process of S3, it is determined whether or not the mirror 431 has been rotated by the “predetermined range” in the current setting state of the deflection unit 41. If the rotation has been completed, the current deflection unit is determined. Since the scanning in the vertical direction (that is, the direction of the central axis 42a) in the setting state 41 is completed, the process proceeds to Yes in S3.

  On the other hand, if the mirror 431 has not been rotated by the “predetermined range” in the current setting state of the deflection unit 41, the process proceeds to No in S3, and the deflection unit 41 is set to the “predetermined rotation range”. It is judged whether it is in. In this embodiment, an angle α formed by an imaginary straight line parallel to the laser beam emission direction from the laser diode 10 and an imaginary plane parallel to the reflecting surface 41a of the deflecting unit 41 is less than a predetermined threshold value. If the moving range is used as an example of the “predetermined rotating range” and the deflection unit 41 corresponds to the rotating range having such a relationship, the process proceeds to Yes in S4. On the other hand, if the deflection unit 41 does not fall within the predetermined rotation range, the process proceeds to No in S4.

The control circuit 70 that performs the swing control changes the swing control of the laser beam deflecting unit 430 based on the rotation position of the deflecting unit 41. That is, when the deflection unit 41 does not fall within the “predetermined rotation range” (a virtual straight line parallel to the emission direction of the laser light L1 from the laser diode 10 and a virtual plane parallel to the reflection surface 41a of the deflection unit 41) , when) the angle α of exceeds a predetermined threshold (e.g., 10 °), the process proceeds to No in S4, constant mirror 431 rotating shaft of the Z-axis direction (first axis 437a) around The expansion and contraction of the piezoelectric actuators 432a, 432b, 432c, and 432d is controlled so as to rotate at an angle. More specifically, when the deflection unit 41 does not correspond to the “predetermined rotation range”, the mirror 431 is rotated in the Z-axis direction (first axis 437a) with the reflecting surface 431a orthogonal to the XY plane. , And the direction of the laser beam L1 from the mirror 431 toward the deflecting unit 41 is changed along the XY plane. In FIG. 4 , the position of the mirror 431 rotated around the first axis 437a from the solid line position is indicated by a two-dot chain line. Further, the path of the laser beam at that time is indicated by a broken line L1 ′ (see FIGS. 3 and 4 ).

  In order to perform the control to rotate the mirror 431 around the first axis 437a, for example, the expansion / contraction amount of the piezoelectric actuators 432a and 432c is made the same, and the expansion / contraction amount of the piezoelectric actuators 432b and 432d is made the same, and the piezoelectric actuator 432a. Control may be performed such that the piezo actuators 432b and 432d are contracted by an amount corresponding to the extension of 432c, or the piezo actuators 432a and 432c are contracted by an amount corresponding to the extension of the piezo actuators 432b and 432d.

  On the other hand, when the deflection unit 41 is in the “predetermined rotation range” (the virtual straight line parallel to the laser beam emission direction from the laser diode 10 and the virtual plane parallel to the reflection surface 41a of the deflection unit 41). If the angle α is equal to or smaller than a predetermined threshold value), the process proceeds to Yes in S4, and the piezo actuator is rotated so that the mirror 431 rotates by a certain angle around the second axis 437b (axis intersecting the first axis 437a). The expansion and contraction of 432a, 432b, 432c, and 432d is controlled. The second axis 437b is an axis that intersects any of the XY plane, the YZ plane, and the ZX plane. In the present embodiment, the second axis 437b is set along the diagonal line of the mirror 431. By rotating around the second axis 437b as described above, the direction of the laser beam from the mirror 431 toward the deflecting unit 41 is changed along a plane intersecting the XY plane.

  When the mirror 431 is rotated about the first axis 437a extending in the Z-axis direction, a virtual straight line parallel to the laser beam emission direction (X-axis direction) from the laser diode 10 and the reflecting surface 41a of the deflecting unit 41 are parallel. The smaller the angle α formed with the virtual plane, the smaller the change in the direction (vertical direction) of the central axis 42a of the laser light from the deflecting unit 41 toward the space. Therefore, in the present embodiment, when the deflection unit 41 is in the “predetermined rotation range”, the mirror 431 is not rotated around the first axis 437a, but the second axis along the diagonal line of the mirror 431. The mirror 431 is rotated around 437b, so that the laser beam changes greatly in the direction of the central axis 42a (vertical direction) even when the angle α is small. In order to perform such control, for example, the amount of expansion and contraction of the piezo actuators 432bc and 432c is the same, and the piezo actuator 432a is contracted by the amount that the piezo actuator 432a is expanded, or the amount that the piezo actuator 432d is expanded. Control may be performed so that the piezoelectric actuator 432a is contracted.

Returning to FIG. 6 , when the process proceeds to Yes in S <b> 3, the motor 50 is driven to further rotate the deflection unit 41 by a certain angle (1 °) under the control of the control circuit 70 (S <b> 7). The process after S2 is repeated in the setting state of the subsequent deflection unit 41. That is, the scanning in the vertical direction is performed again in a state where the deflection unit 41 is set to a new position. In the above example, “1 °” is illustrated as an example of the “constant angle”. However, the “constant angle” that is the rotation step of the deflection unit 41 may be a smaller angle or a larger angle. There may be.

  In the present embodiment, the mirror 431 supported by the swing mechanism 435 is driven by the piezoelectric actuators 432a, 432b, 432c, and 432d, and the driving state of the mirror 431 by the piezoelectric actuators 432a, 432b, 432c, and 432d is Control is performed by the control circuit 70. In this way, the part that deflects the laser light can be controlled to be swinging with high accuracy. Further, the entire laser beam deflecting unit 430 can be reduced in size.

  Further, by controlling the four piezo actuators 432a, 432b, 432c, and 432d, the position of the vicinity of the corner (specific part) of the mirror 431 is changed, and the attitude of the mirror 431 with respect to the laser light is controlled. In this way, a configuration capable of controlling the swing of the mirror 431 can be realized with a simple and small configuration.

  Further, a ball joint is provided for connecting the mirror 431 and the holding portion 438 for holding the mirror 431 in a spherical pair structure. In this way, the mirror 431 can be stably held in the apparatus and can be smoothly swung.

  Further, the swing control of the laser beam deflection unit 430 is changed based on the rotation position of the deflection unit 41. In this way, the swing control of the laser beam deflecting unit 430 can be controlled appropriately according to the rotational position of the deflecting unit 41.

  In addition, a condensing lens 62 (condensing means) that condenses the reflected light toward the photodiode 20 is provided on the optical path of the reflected light from the rotation deflection mechanism 40 to the photodiode 20. A wide range of reflected light can be used for detection without increasing the size of the detection means.

  Also, a filter 64 (light selection means) that transmits the reflected light and removes light other than the reflected light is provided on the optical path of the reflected light from the rotation deflection mechanism 40 to the photodiode 20. , Noise light can be suitably removed.

[Other Embodiments]
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  In the above embodiment, the light collecting means for collecting the reflected light toward the light detecting means is provided on the optical path of the reflected light from the rotation deflecting means to the light detecting means. The light means may be omitted and the detection may be performed by a relatively large light detection means.

  In the above embodiment, the light selection means for transmitting the reflected light and removing the light other than the reflected light is provided on the optical path of the reflected light from the rotation deflecting means to the light detecting means. Such light selection means can be omitted.

In the second embodiment, the “actuator” is configured by four piezo actuators that change the position of a specific portion of the deflecting unit, but may be a plurality other than four, or may be only one. .

  The laser laser apparatus of any of the above embodiments is extremely useful when used as an area sensor or safety sensor in a factory.

DESCRIPTION OF SYMBOLS 1 , 400 ... Laser radar apparatus 10 ... Laser diode (laser light generation means)
20 ... Photodiode (light detection means)
31 ... Oscillating mirror (laser beam deflecting means, direction changing means)
40 ... Turning deflection mechanism (turning deflection means)
41 ... Deflection part (deflection means)
50 ... Motor (drive means)
62 ... Condensing lens (condensing means)
64. Filter (light selection means)
70 ... Control circuit (control means, swing control means )
210, 310 ... Actuator (tilting means)
430 ... Laser beam deflecting section (laser beam deflecting means, direction changing means)
431 ... Mirror (deflection member)
432a, 432b, 432c, 432d ... Piezo actuator (actuator)
435 ... Swing mechanism

Claims (4)

Laser light generating means for generating laser light;
Light detection means for detecting reflected light of the laser light reflected by a detection object when the laser light is generated from the laser light generation means;
One or a plurality of deflecting means configured to be rotatable about a predetermined central axis is provided, the laser light is deflected toward the space by the deflecting means, and the reflected light is directed to the light detecting means. Rotating deflection means for deflecting
Drive means for rotationally driving the turning deflection means;
Direction changing means for changing the direction of the laser light from the deflecting means with respect to the direction of the central axis by relatively changing the incident direction of the laser light with respect to the deflecting means;
Control means for controlling the direction changing means;
It is the composition provided with
The direction changing means comprises a laser light deflecting means configured to deflect the laser light from the laser light generating means toward the rotation deflecting means, and configured to be swingable.
The control means comprises a swing control means for controlling the swing of the laser beam deflecting means,
The laser beam deflecting means is
A deflecting member for deflecting the laser beam;
A swing mechanism for swingably supporting the deflection member;
An actuator for driving the deflection member supported by the swing mechanism;
With
The deflecting means is a mirror having a surface that is inclined with respect to the central axis and reflects the laser light;
The laser beam when the direction of the central axis is the Y-axis direction, the predetermined direction orthogonal to the Y-axis direction is the X-axis direction, and the direction orthogonal to the X-axis direction and the Y-axis direction is the Z-axis direction. The laser light from the generation unit enters the deflection member from one side in the X-axis direction, and is deflected by the deflection member toward the deflection unit disposed on one side in the Y-axis direction with respect to the deflection member. It is supposed to
When the rotation position of the deflection unit does not fall within a predetermined rotation range, the swing control unit changes the direction of the laser beam from the deflection member toward the deflection unit along the XY plane, When the rotation position of the deflection unit is within a predetermined rotation range, the actuator is configured to change the direction of the laser beam from the deflection member toward the deflection unit along a plane intersecting the XY plane. The configuration for controlling the drive state of the deflection member by
The predetermined rotation range is a range in which an angle formed between a virtual straight line parallel to the X-axis direction and a virtual plane parallel to the laser light reflecting surface of the deflecting unit is equal to or less than a predetermined threshold. There is a laser radar device. 2. The laser radar device according to claim 1 , wherein a deflection area for deflecting the reflected light in the deflection means is configured to be larger than a deflection area for deflecting the laser light in the laser light deflection means. The condensing means for condensing the reflected light toward the light detecting means is provided on an optical path of the reflected light from the rotating deflection means to the light detecting means. The laser radar device according to claim 1 or 2 . A light selection unit that transmits the reflected light and removes light other than the reflected light is provided on an optical path of the reflected light from the rotation deflecting unit to the light detecting unit. The laser radar device according to any one of claims 1 to 3 .

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