JP5823367B2 - measuring device - Google Patents

Description

  The present invention relates to a measuring apparatus that performs measurement by projecting on an object.

  For mobile robots that run on a flat surface, measure the distance to an object that exists in the moving space as needed, and control its own travel based on the measurement results whenever they are obtained. It is. As a measuring device that measures the distance to an object, it is necessary to be able to measure time quickly and to have high measurement accuracy. However, in order to apply it to a mobile robot, the scanning range is wide. In addition, it is important that the device is small.

  As such a measurement device, a measurement device that scans laser light in two dimensions has been developed. However, a mobile robot can sufficiently cope with a three-dimensional object only with measurement results obtained from a two-dimensional plane. There wasn't.

Therefore, Patent Document 1 described later discloses the following measuring apparatus.
That is, a scanning two-dimensional distance measuring device that rotates and scans the measurement light output from the light projecting unit around one axis and calculates the distance to the target unit based on the reflected light from the target, and the scanning two-dimensional distance measuring device A rotation mechanism that rotates the distance measuring device around the other axis that is obliquely crossed with the one axis that rotates and projects the light projecting unit, and the rotation mechanism rotates the scanning two-dimensional distance measuring device, thereby The roll angle and the pitch angle are changed. The scanning two-dimensional distance measuring device performs two-dimensional measurement by rotating and scanning around the one axis, and performs three-dimensional measurement because the rotating mechanism swings in the axial direction of the other axis. Can do.

  Further, in Patent Document 2 to be described later, a deflecting mirror that is inclined with respect to a reference plane, a scanning mechanism that rotates the change mirror around an axis perpendicular to the reference plane, and an axis around the vertical axis A plurality of light projecting portions arranged to project light at different angles with respect to the deflection mirror, a condensing optical system for condensing the reflected light from the object, and the condensed reflection There is disclosed a measuring apparatus that includes a light receiving unit that detects light, and projects light from each light projecting unit at different timings while rotating a deflection mirror by the scanning mechanism. The measurement light output from each light projecting unit is projected to different positions in the axial direction of the vertical axis, and the measurement light from each light projecting unit is radiated in a 360 ° direction by a rotating deflection mirror. Since it is deflected, three-dimensional measurement can be performed in the entire circumferential direction.

JP 2008-134163 A JP 2009-236774 A

  However, in the former measuring device, since the scanning two-dimensional distance measuring device is rotated around the other axis obliquely intersecting with one axis to be rotated and scanned by the light projecting unit by the rotation mechanism, rattling is likely to occur. There was a risk of causing a large measurement error.

  On the other hand, in the latter measuring apparatus, since the angle of each light projecting unit is fixed, the three-dimensional measurement density is low. For this reason, it is conceivable to increase the number of light projecting parts. However, since it is necessary to change the angles of the light projecting parts, the mounting operation is complicated and the assembly cost increases. In addition, since the deflection mirror arranged to be inclined with respect to the reference plane is rotated, there is a problem that the backlash is likely to occur as before.

  This invention is made | formed in view of such a situation, Comprising: Generation | occurrence | production of play can be prevented and the measuring apparatus which can perform a high-density three-dimensional measurement is provided.

  (1) A measuring apparatus according to the present invention includes a sensor that scans measuring light around a predetermined rotation axis and receives reflected light from an object, and a reflecting mirror that reflects the measuring light from the sensor. In the case where the measurement light reflected by the reflecting mirror is reflected by the object and is measured based on the result of entering the sensor, one or a plurality of the reflecting mirrors are arranged around the sensor. The reflecting surfaces of the reflecting mirrors are reflected in the first plane parallel to the plane constituted by the optical paths of the plurality of measuring beams scanned around the rotation axis at different positions in the scanning direction, In addition, the measurement light is inclined so that the reflection direction of the measurement light is different in a second plane parallel to the other plane orthogonal to the first plane.

  In the measuring apparatus of the present invention, it comprises a sensor that scans the measuring light around a predetermined rotation axis and receives the reflected light from the object, and a reflecting mirror that reflects the measuring light from the sensor, Measurement is performed based on the result of the measurement light reflected by the reflecting mirror being reflected by the object and incident on the sensor.

  One or a plurality of the reflecting mirrors are disposed around the sensor. The mirror surfaces of the reflecting mirrors reflect the measuring light in a first plane parallel to a plane constituted by a plurality of optical paths of the measuring light scanned around the rotation axis at different positions in the scanning direction, and It is inclined so that the reflection directions of the measurement light on the second plane parallel to the other plane orthogonal to the first plane are different. That is, the mirror surface of the reflecting mirror has an arc shape having a predetermined curvature in the scanning direction of the measurement light, and the inclination with respect to the second plane is varied in the scanning direction of the measurement light.

  As a result, the measurement light scanned on the reflecting mirror is continuously reflected in a spiral shape by the mirror surface of the reflecting mirror. Therefore, high-density three-dimensional measurement can be performed. On the other hand, when the reflecting mirror is fixed without being driven to rotate, no play occurs.

Further, in the measurement equipment according to the present invention, the mirror surface in the first plane, the optical path of each reflected light scanned measurement light reflected respectively, on the tangent of the base circle which is set around the rotating shaft It is inclined so that it may be located in.

In this way, the mirror surface of the reflecting mirror is positioned on the tangent line of the reference circle set with the rotation axis as the center, on the first plane described above, the optical path of each reflected light reflected from the scanned measuring light. It is tilted. Accordingly, each reflected light reflected by the mirror surface of the reflecting mirror is emitted radially outward from the sensor without being interfered with the sensor, so that high-density three-dimensional measurement can be maintained.

( 2 ) The measuring apparatus according to the present invention is characterized in that the inclination of the mirror surface is determined based on both the following equations.
α _{m (k)} = 45 ° + (θ _mc + θ _{m (k)} ) / 2
γ _{m (k)} = θ _{m (k)} / n
Where α _{m (k)} : inclination of the mirror surface with respect to the X _m axis at the k th reflection point
γ _{m (k)} : inclination of the mirror surface with respect to the Z _m axis at the k th reflection point
θ _mc : Angle from the X _m axis around the Z _m axis of the contact point with respect to the reference circle of the optical path of each reflected light
θ _{m (k)} : Angle of the k-th measurement light from the X _m axis around the Z _m axis
n: Appropriate number

  In the measuring apparatus of the present invention, the inclination of the mirror surface of the reflecting mirror is designed based on the above two formulas, so that the measurement light scanned on the reflecting mirror is continuously reflected by the mirror surface of the reflecting mirror. Each reflected light reflected in a spiral shape and reflected by the mirror surface of the reflecting mirror is emitted radially outward of the sensor without being interfered by the sensor. Therefore, as before, high-density three-dimensional measurement can be performed.

( 3 ) The measuring apparatus according to the present invention is characterized in that the mirror surface is inclined smoothly.

  In the measuring apparatus of the present invention, the mirror surface of the reflecting mirror is inclined smoothly. Such a smoothing process is, for example, a line segment that passes through the position and is perpendicular to the mirror surface at each position in the scanning direction of the mirror surface, and is arranged in the same height region from the first plane described above. This is realized by setting reflection lines to be connected and smoothly connecting adjacent reflection lines. When the measurement light is reflected by the object and incident on the sensor, the diameter of the light incident on the sensor may be wider than the diameter of the light emitted from the sensor, but the mirror surface of the reflector is tilted smoothly. In some cases, all of the light can be incident on the sensor, thus preventing a decrease in measurement sensitivity.

( 4 ) The measuring apparatus according to the present invention further includes a rotating plate that rotates concentrically with the rotating shaft, and a motor that rotationally drives the rotating plate, and the reflecting mirror is attached to the rotating plate. It is characterized by.

  The measuring apparatus of the present invention includes a rotating plate that rotates concentrically with a rotating shaft that scans the measuring light, and a motor that rotates the rotating plate, and a reflecting mirror is attached to the rotating plate. Then, the measurement light is scanned around the rotation axis from the sensor while rotating the rotating plate by the motor. At this time, the scanning speed of the measurement light and the rotation speed of the rotating plate are preferably different from each other.

  As a result, the measurement light scanned around the rotation axis faces the reflecting mirror at a different position in the rotation direction every time scanning around the rotation axis, so that a higher density three-dimensional measurement can be performed.

( 5 ) The measuring apparatus according to the present invention is characterized in that a plurality of reflecting mirrors are attached to the rotating plate so as to be rotationally symmetric.

  In the measuring apparatus of the present invention, a plurality of reflecting mirrors are attached to the rotating plate so as to be rotationally symmetric, thereby achieving balance of the rotating plate. Therefore, it is possible to prevent backlash from occurring on the rotating plate during rotation.

It is a typical perspective view showing the example of composition of the measuring device concerning the present invention. FIG. 2 is a schematic plan view of a rotating plate, a reflecting mirror, and a laser light sensor shown in FIG. 1. FIG. 2 is a schematic side view of the rotating plate, reflecting mirror, and laser light sensor shown in FIG. 1. It is explanatory drawing explaining the design method of the mirror surface of a reflective mirror. X-axis of the fixed coordinate system of the laser beam sensor, and is an explanatory diagram for explaining each parameter in the X _m-axis of the rotating coordinate system of the rotating plate and a reflecting mirror. It is the graph which showed the position of each reflective point on the target object measured by one scan.

  FIG. 1 is a schematic perspective view showing a configuration example of a measuring apparatus according to the present invention, in which 2 is a base. A plurality of support columns 21, 21,... Are erected on the base 2 at appropriate positions, and the flat base member 3 is separated from the base 2 at an appropriate distance by the support columns 21, 21,. It is supported in parallel with the table 2.

  On one side of the pedestal member 3, a first rotating shaft 81 that penetrates the pedestal member 3 is rotatably provided by a bearing (not shown) fixed to the pedestal member 3. A pulley 82 is fitted on the end of the first rotary shaft 81 on the base 2 side, and the rotary plate 8 is between the base member 3 and the end of the first rotary shaft 81 on the opposite side. The outer fitting is fixed with an appropriate gap. On the other side of the pedestal member 3, the motor 4 is attached in such a manner that the second rotating shaft 41 connected to the drive shaft of the motor 4 penetrates the pedestal member 3. The rotational driving force of the motor 4 is passed through an annular belt 6 wound around a pulley 42 fitted around the second rotary shaft 41 and a pulley 82 fitted around the end of the first rotary shaft 81. Thus, the rotation plate 8 fixed to the first rotation shaft 81 is rotationally driven. Further, an encoder 5 for detecting the rotational speed of the rotating plate 8 is disposed in the vicinity of the rotating plate 8, and the detection result of the encoder 5 is given to the control unit 1 described later.

  On the rotating plate 8, a pair of arc-shaped reflecting mirrors 83, 83 having appropriate height dimensions are arranged at different positions by 180 ° in the circumferential direction of the rotating plate 8, and both reflecting mirrors 83, 83 are arranged. Is fixed at a position spaced from the rotating plate 8 by a fixed leg 84, 84, 84, 84 erected on the rotating plate 8.

  On the first rotation shaft 81 of the rotating plate 8, a laser light sensor that emits laser light radially around the central axis of the first rotation shaft 81 at a predetermined scanning period and receives reflected light from the object. 9 is suspended from one end of the support arm 32 so that the central axis is coaxial with the rotation axis of the rotary plate 8, and the other end of both the support arms 32 is supported on the base member 3. It is being fixed to the members 31 and 31, respectively. As a result, laser light is emitted from the laser light sensor 9 in a direction perpendicular to the central axis of the first rotation shaft 81. As the laser light sensor 9, for example, the side area sensor UTM-30LX (manufactured by Hokuyo Electric Co., Ltd.) can be used, but is not limited thereto, and may be further downsized. When the side area sensor UTM-30LX is used as the laser beam sensor 9, the laser beam scanning range is 270 °, and therefore the laser is arranged so that the support members 31, 31 described above are located in a range where the laser beam is not scanned. The mounting posture of the optical sensor 9 is adjusted in advance.

  The above-described reflecting mirrors 83 and 83 are arranged on the optical path of the laser light emitted from the laser light sensor 9. The mirror surfaces of the reflecting mirrors 83 and 83 are twisted in an axial direction passing through the center of the mirror surface and parallel to the axis orthogonal to the first rotation axis 81, and from the laser light sensor 9 to the first rotation axis 81. In the region facing the reflecting mirrors 83 and 83, the laser light scanned around the central axis of the laser beam is scanned by the reflecting mirrors 83 and 83 from the direction oblique to the central axis to the direction perpendicular to the central axis, or From the direction orthogonal to the central axis to the direction oblique to the central axis, the reflection angle with respect to the axial length direction is reflected and emitted to the target, and the reflected light from the target is reflected by the corresponding reflecting mirror 83, The light is reflected by 83 and is incident on the laser light sensor 9.

  On the other hand, the laser light emitted from the laser light sensor 9 is emitted in a direction orthogonal to the central axis of the first rotation shaft 81 in a region not facing the reflecting mirrors 83, 83, and the reflected light from the object is laser. The light enters the optical sensor 9.

  Further, a control unit 1 is provided outside the laser light sensor 9 or inside the laser light sensor 9 (in FIG. 1, outside the laser light sensor 9). The object is measured based on the drive control of the motor 4 and the detection result of the laser light sensor 9 described above. The controller 1, the laser light sensor 9, and the motor 4 are supplied with power from the outside.

  In such a measuring apparatus, when the rotating plate 8 and the reflecting mirrors 83 and 83 fixed to the rotating plate 8 are driven to rotate in a predetermined direction by the motor 4, the encoder 5 changes the rotating state of the rotating plate 8. The detected result is given to the control unit 1. A value of the scanning speed of the laser light from the laser light sensor 9 is given in advance to the control unit 1, and the control unit 1 determines the rotation period of the rotating plate 8 based on the detection result given from the encoder 5. The output of the motor 4 is adjusted so as to have a predetermined value different from the scanning cycle.

  When the rotational speed of the rotating plate 8 reaches a predetermined value, the control unit 1 operates the laser light sensor 9 to cause the laser light to rotate around the central axis of the first rotating shaft 81 in the same direction as the rotating direction of the rotating plate 8. Let it scan. The laser light scanned from the laser light sensor 9 is reflected and emitted to the object as described above in the region facing the reflecting mirrors 83 and 83, and the reflected light from the object corresponds to the corresponding reflecting mirrors 83 and 83. And is incident on the laser light sensor 9. Further, in a region not facing the reflecting mirrors 83, 83, the light is emitted in a direction orthogonal to the central axis of the first rotation shaft 81, and reflected light from the object enters the laser light sensor 9. The laser light sensor 9 is provided with a light receiving portion on which the laser light reflected from the object is incident, and the light receiving portion photoelectrically converts the incident laser light to generate an incident signal. ing.

  The laser light sensor 9 emits laser light in a pulse shape, and the difference between the laser light emission timing and the timing at which the light receiving unit generates an incident signal by reflected light from the object is determined by the control unit. Give to 1. The control unit 1 calculates the position of the reflection point by the object based on the given difference as will be described later.

  2 and 3 are a schematic plan view and a schematic side view of the rotary plate 8, the reflecting mirrors 83 and 83, and the laser light sensor 9 shown in FIG. In both figures, the same numbers are assigned to parts corresponding to those in FIG.

  As shown in FIGS. 2 and 3, the laser beam sensor 9 is suspended from the rotating plate 8 with an appropriate gap, and the center O where the laser beam sensor 9 scans the laser beam is fixed to the rotating plate 8. It is located on the central axis Z of the first rotation shaft 81.

  Both reflecting mirrors 83 and 83 are arranged so as to be symmetric about the central axis Z. As a result, the mass of the reflecting mirrors 83 and 83 applied to the rotating plate 8 is balanced in the rotating plate 8, so that play is prevented when the rotating plate 8 is rotationally driven.

  As described above, the laser light sensor 9 emits laser light in a direction orthogonal to the central axis Z, and the laser light scanned around the central axis Z is a region facing the reflecting mirrors 83 and 83. Then, the light is reflected in a predetermined direction by the reflecting mirrors 83 and 83. At this time, the reflecting mirrors 83 and 83 are arranged so as to obliquely intersect with the concentric circle of the center O, and the mirror surfaces of the reflecting mirrors 83 and 83 receive the laser light scanned by the laser light sensor 9 in plan view. Each of the reflected optical paths L, L,... Is positioned on the tangent line of the reference circle C with the center O as the center, as shown in FIG.

In addition, the mirror surfaces of the reflecting mirrors 83 and 83 have optical paths L, L,... That reflect the laser beams scanned by the laser beam sensor 9 when viewed from the side, as shown in FIG. The inclination angle is smoothly inclined in the longitudinal direction so that the first optical path L _{1 has} an appropriate angle with respect to the first optical path L ₁ and gradually changes from the m-th optical path L _m to the first optical path L _1. It is. The angle formed by the first optical path L ₁ and the m-th optical path L _m described above can be set to an appropriate angle of more than 0 ° and less than 90 °, but is preferably set to an appropriate angle of 30 ° or less. It is.

The laser light reflected by the reflecting mirrors 83 and 83 in this manner is reflected by the target object when the target object is present within an appropriate distance, and is reflected by the reflecting mirrors 83 and 83 again to be laser light sensor 9. Is incident on. That is, the laser beam reflected by the object is incident on the laser beam sensor 9 with the direction reversed on the optical paths L _{1 to} L _m .

  Here, the longitudinal dimensions of the reflecting mirrors 83 and 83 are determined in such a range that the reflected light at both edges in the longitudinal direction of one reflecting mirror 83 is not incident on the reflecting mirror 83 and the other reflecting mirror 83, respectively. deep. In addition, the dimension in the height direction of the reflecting mirrors 83 and 83 is a dimension that can receive all of the light reflected by the object, and is determined to be as small as possible.

  Thus, since the laser light scanned from the laser light sensor 9 is gradually raised from the direction orthogonal to the central axis Z by the reflecting mirrors 83 and 83 in the axial direction of the central axis Z, the laser light is three-dimensional. The space will be scanned. At this time, as described above, since the mirror surfaces of the reflecting mirrors 83 and 83 are smoothly changed in inclination angle in the longitudinal direction, the laser beams scanned from the laser beam sensor 9 are continuously different at different angles. The density of the laser light that is launched and thus scanned in the three-dimensional space is high.

Next, a method for designing the mirror surface of the reflecting mirror 83 shown in FIG. 1 will be described.
4A and 4B are explanatory diagrams for explaining a method of designing the mirror surface of the reflecting mirror, in which FIG. 4A shows the X _m -Y _m plane from which the laser light is emitted from the laser light sensor, and FIG. 4B shows the laser light by the reflecting mirror. It shows _X m -Z _m plane rises. In FIG. 4, the arrows indicate the optical path of the laser beam, and the black dots indicate the reflection point on the mirror surface of the laser beam.

Now, the spread of the laser beam is not taken into consideration, the reflection point of the laser beam is a point, and the optical path of the laser beam is a line. As shown in FIG. 4, the reflection point on the mirror surface of the laser beam scanned in the circumferential direction from the rotation center O _{m of the} laser beam scanned in the circumferential direction on the X _m -Y _m plane. distance and _{r m,} the angle from the _{X m-axis} and theta _m to _{Z m} axis, the coordinates of the reflection point and _{(x m, y} m). Further, the inclination of the mirror surface with respect to the X _m axis at the reflection point is α _m , the reflection angle of the laser light on the X _m -Y _m plane is β _m, and the inclination of the mirror surface with respect to the Z _m axis is γ _m. The reflection angle on the X _m -Z _m plane is δ _m .

In order to cause the laser light to travel radially outward from the laser light sensor and the reflecting mirror, as described above, a reference circle C having a radius r _mc is set from the rotation center O _m of the laser light in the X _m -Y _m plane, The optical path of the laser beam reflected by the reflecting mirror is set to be tangent to the reference circle C. At this time, the coordinates of the contact point where the optical path of the laser beam is in contact with the reference circle C is (x _mc , y _mc ), and a line segment connecting the coordinates (x _mc , y _mc ) and the rotation center O _{m of the} laser beam, When the angle formed between the X _m-axis and theta _mc, coordinates of the contact can be represented by the following formula (1) and (2) below.
x _mc = r _mc cos θ _mc (1)
y _mc = r _mc sin θ _mc (2)

Here, the first reflection point the edges overlapping the _{X m-axis} of the mirror, theta _mc the direction k-1 th reflection point coordinates _{(x m (k-1)} , y m (k-1) ) Can be expressed by the following equations (3) and (4) using the distance rm _(k-1) and the direction θm _(k-1) .
x _{m (k−1)} = r _{m (k−1)} cos θ _{m (k−1)} (3)
y _{m (k−1)} = r _{m (k−1)} sin θ _{m (k−1)} (4)

Similarly, the coordinates (x _{m (k)} , y _{m (k)} ) of the _kth reflection point are expressed by the following equation (5) and (5) using the distance r _{m (k)} and the direction θ _{m (k).} 6) It can be expressed by the formula.
x _{m (k)} = r _{m (k)} cos θ _{m (k)} (5)
y _{m (k)} = r _{m (k)} sin θ _{m (k)} (6)

The distance between the coordinates (xm _(k) , ym _(k) ) of the reflection point and the coordinates (xm _(k-1) , ym _(k-1) ) of the reflection point is _{expressed as wm (k- 1),} and the inclination of the mirror surface with respect to the X _m axis at the _(k−1) th reflection point is α _{m (k−1)} , the coordinates (x _{m (k)} , y _{m (k)} ) of the reflection point are It can be expressed by the equations (7) and (8).
x _{m (k)} = x _{m (k-1)} + w _{m (k-1)} cos α _{m (k-1)} (7)
y _{m (k)} = y _{m (k-1)} + w _{m (k-1)} sin α _{m (k-1)} (8)

When rm _(k) is obtained from the above-described equations (3) to (8), the following equation (9) is obtained.

Here, the value of θ _{m (k)} can be expressed by the following equation (10), where n is the number of laser beams emitted radially from the laser beam sensor.
θ _{m (k)} = (360 ° / n) k (10)

  Since the optical path of the laser beam reflected by the mirror surface is in contact with the reference circle C, the relationship of the following equation (11) is established.

When θ _mc is obtained from the above formulas (1), (2), (5), (6) and (11), the following formula (12) is derived.
θ _mc = cos ⁻¹ (r _mc / r _{m (k)} ) + θ _{m (k)} (12)

This theta _mc, inclination with respect to _{X m-axis} of the mirror in the k th reflection point alpha _m to _(k), and the reflection angle at _X m -Y _m plane of the laser beam in the k th reflection point beta _{m (k)} If it calculates | requires, it can represent with following (13) Formula and (14) Formula.
α _{m (k)} = 45 ° + (θ _mc + θ _{m (k)} ) / 2 (13)
β _{m (k)} = 90 ° −θ _mc + θ _{m (k)} (14)

Further, the inclination γ _{m (k)} of the mirror surface with respect to the Z _m axis at the k-th reflection point and the reflection angle δ _{m (k)} of the laser beam at the k-th reflection point on the X _m -Z _m plane are, for example, reflection If the slope γ _{m (k)} is changed in proportion to ¼ of the angle θ _{m (k)} from the X _m axis of the point, it can be expressed by the following equations (15) and (16). .
γ _{m (k)} = θ _{m (k)} / 4 (15)
δ _{m (k)} = θ _{m (k)} / 2 (16)

Such calculation is sequentially performed from the first to the kth to obtain the inclination α _m of the mirror surface with respect to the X _m axis at each reflection point and the inclination γ _m of the mirror surface with respect to the Z _m axis at each reflection point.

Then, each at each reflection point, through the reflection point, a line segment perpendicular to the mirror surface has a height h _m, distribution of X _m -Y _m plane at the same height region from each other By setting a reflection line to be connected and smoothly connecting adjacent reflection lines, a mirror surface having a required curved surface is generated.

Furthermore, in the actual machine, the following conditions are added to the mirror surface design.
That is, the value of the radius r _mc of the reference circle C is such that the laser beam reflected by the reflecting mirror passes between the laser beam sensor and the reflecting mirror, and the laser beam reflected by the object enters the laser beam sensor. Set as possible. Specifically, a mirror surface of the reflecting mirror and the first reflection point at the edge overlapping the X _m-axis, the distance of the reflection point and r _{m (1),} and the angle and theta _{m (1),} The value of rm ₍₁₎ is set so that the laser beam reflected by the reflecting mirror passes between the laser beam sensor and the reflecting mirror, and the laser beam reflected by the object can enter the laser beam sensor. Set.

The value of the slope alpha _m aforementioned _(1), the value of the combined reflection angle [delta] _m in the reflection angle beta _m and _X m -Z _m plane in _X m -Y _m plane of laser light at the reflection point Set to be approximately constant. On the other hand, the number n of laser beams is set with reference to the use of a laser beam sensor for a scanning range of 360 °. Furthermore, theta _m direction in the range of the mirror surface of the reflector is set to a range where the laser light reflected by the mirror surface does not interfere with the mirror surface of the other reflector. The value of the mirror surface of the height h _m is the height of the light receiving window of the laser beam sensor.

Next, a method in which the control unit 1 shown in FIG. 1 determines the position of the object will be described.
The position of the object is calculated separately when the laser light is reflected by the reflecting mirror and when the laser light is projected directly on the object without being reflected by the reflecting mirror.

Now, the ranges in which the laser light is reflected by the two reflecting mirrors are set to 0 ° ≦ θ _li −θ _t <60 ° and 180 ° ≦ θ _li −θ _t <240 °, and as shown in FIG. When the angle formed by the reflected laser beam between the optical path L before being reflected and the X axis is θ _li , the following equation is derived.
θ _lr = θ _li + 180 ° −β _m (17)
However, theta _lr: of the laser beam reflected by the reflecting mirror, the angle between the optical path X _m-axis after being reflected

Each when the error of measured distance caused by reflecting the laser beam by the reflecting mirror in the laser light sensor and e _m, the X-Y-Z coordinate system, the scanned laser light is reflected by the object The coordinates (x, y, z) of the reflection point are expressed by the following equations (18) to (20). Incidentally, the error e _m described above is determined in advance by the tests in each of actual equipment.
x = r _m cos θ _li + (d ₁ −r _m −e _m ) cos θ _lr (18)
y = r _m sin θ _li + (d ₁ −r _m −e _m ) sin θ _lr (19)
z = (d ₁ −r _m −e _m ) sin δ _m (20)

Here, as shown in FIG. 5, _dl is the distance from the laser light source to the object, and θ _t is around the Z axis of the fixed coordinate system of the laser light sensor 9 from the X axis of the fixed coordinate system. respectively show angle to X _m-axis of the rotating coordinate system of the rotating plate 8 and the reflector 83.

On the other hand, in the above case, the ranges in which the laser beam is not reflected by the reflecting mirror are 60 ° ≦ θ _li −θ _t <180 ° and 240 ° ≦ θ _li −θ _t <360 °. The coordinates (x, y, z) of the reflection point reflected by the object are expressed by the following equations (21) to (23).
x = d ₁ cos θ _li (21)
y = d ₁ sin θ _li (22)
z = 0 (23)

  In this way, the laser light is reflected by the object in a range where the scanned laser light is reflected by the reflecting mirror and in a range where the laser light is projected directly on the object without being reflected by the reflecting mirror. The coordinates (x, y, z) of each reflection point to be reflected are obtained.

  The control unit 1 shown in FIG. 1 performs such calculation every time the laser beam is scanned by the laser beam sensor 9, and stores the coordinates of each obtained reflection point in a memory (not shown) for each scan. ), The coordinates of each reflection point are output for each scan.

  In such a measuring apparatus, the measurement light scanned on the reflecting mirrors 83 and 83 is continuously reflected in a spiral shape by the mirror surfaces of the reflecting mirrors 83 and 83. Therefore, high-density three-dimensional measurement can be performed. Further, the mirror surfaces of the reflecting mirrors 83 and 83 are inclined so that the optical paths of the respective laser beams reflected on the scanned laser beams are positioned on the tangent line of the reference circle C described above on the XY plane. Therefore, each laser beam reflected by the mirror surfaces of the reflecting mirrors 83 and 83 is emitted radially outward from the laser beam sensor 9 without being interfered with the laser beam sensor 9. Therefore, high density three-dimensional measurement can be maintained.

  Further, since the mirror surfaces of the reflecting mirrors 83 and 83 are smoothly tilted, even when the diameter of the laser light incident on the laser light sensor 9 is larger than the diameter of the laser light emitted from the laser light sensor 9. All the light can be incident on the laser light sensor 9. Therefore, it is possible to prevent a decrease in measurement sensitivity.

  On the other hand, a plurality of (two in the present embodiment) reflecting mirrors 83, 83 are attached to the rotating plate 8 so as to be rotationally symmetric, thereby balancing the rotating plate 8. Therefore, it is possible to prevent the play of the rotating plate 8 during rotation.

  In the present embodiment, the case where two reflecting mirrors 83 and 83 are used has been described. However, the present invention is not limited to this, and one or three or more reflecting mirrors may be used. When a plurality of reflecting mirrors are used, the reflecting mirrors are evenly arranged on the rotating plate. On the other hand, when a single reflecting mirror is used, a weight for maintaining balance at a rotationally symmetric position may be provided. This prevents backlash from occurring on the rotating plate 8 during driving of the rotating plate 8.

  In the present embodiment, the reflecting mirrors 83 and 83 are attached to the rotating plate 8, and the rotating plate 8 and the reflecting mirrors 83 and 83 are rotated by the motor 4. However, the present invention is not limited to this, and the reflecting plate The fixing legs 84 and 84 of the mirrors 83 and 83 and the support members 31 and 31 are fixed to the base 2, and the mechanism for rotating the reflecting mirrors 83 and 83 such as the rotating plate 8, the motor 4 and the belt 6 is omitted. Also good. In this case, three or more reflecting mirrors may be used in order to increase the position for acquiring the three-dimensional data. In addition, since the reflecting mirror is fixed to the base 2 and there is no possibility of looseness, when using one or a plurality of reflecting mirrors, each reflecting mirror can be arranged at an arbitrary position.

  On the other hand, in the present embodiment, an annular shape in which the rotational driving force of the motor 4 is hung between a pulley 42 externally fitted to the second rotary shaft 41 and a pulley 82 externally fitted to the end of the first rotary shaft 81. However, the present invention is not limited to this, and the output shaft of the motor 4 is connected to the first rotating shaft 81, and the motor 4 rotates the rotating plate 8. It is also possible to adopt a configuration in which the is directly rotated.

  In the present embodiment, the case where laser light is used as measurement light has been described. However, the present invention is not limited to this, and any light having the same intensity and straightness as the laser light may be used.

  Next, the results of measuring an object using a commercially available sensor as the laser light sensor will be described.

  The measuring apparatus has the configuration shown in FIG. 1, and a side area sensor UTM-30LX (manufactured by Hokuyo Electric Co., Ltd.) is used as the laser light sensor 9 with a scanning period of 10 milliseconds. The rotation period of the rotating plate 8 was 30 milliseconds.

  Two reflectors having the parameters shown in Table 1 below were used.

Then, an object is installed so as to surround the periphery of the laser light sensor 9 at a distance of 5000 mm from the laser light sensor 9, and each object on the object measured by one scan by the laser light sensor 9. The position of the reflection point is shown on the XYZ coordinate axis. It should be noted that the error _{e m} was set to zero.

FIG. 6 is a graph showing the position of each reflection point on the object measured in one scan.
As is apparent from FIG. 6, the reflection points on the object of the laser light reflected by the two reflecting mirrors are arranged on two optical paths spiraling around an axis parallel to the Z axis. This shows that the three-dimensional space can be measured with high density.

  On the other hand, each reflection point on the object of the laser light not reflected by the two reflecting mirrors is arranged on one optical path forming a ring partially broken in a plane parallel to the XY plane. It can be seen that the two-dimensional space is also measured simultaneously.

DESCRIPTION OF SYMBOLS 1 Control part 2 Base 3 Base member 4 Motor 8 Rotating plate 9 Laser light sensor 41 2nd rotating shaft 81 1st rotating shaft 83 Reflecting mirror C Reference | standard circle

Claims (5)

A measuring light is scanned around a predetermined rotation axis, and a sensor on which reflected light from an object is incident and a reflecting mirror that reflects the measuring light from the sensor are provided, and the measuring light reflected by the reflecting mirror is If the measurement is based on the result reflected by the object and incident on the sensor,
One or more reflectors are arranged around the sensor;
The mirror surfaces of the reflecting mirrors reflect the measuring light in a first plane parallel to a plane constituted by a plurality of optical paths of the measuring light scanned around the rotation axis at different positions in the scanning direction, and the first Tilted so that the reflection direction of the measurement light in a second plane parallel to another plane orthogonal to the plane is different ;
Further, the mirror surface is inclined on the first plane so that the optical path of each reflected light reflected from the scanned measurement light is positioned on the tangent line of the reference circle set around the rotation axis < A measuring device characterized by the above. The measuring apparatus according to claim 1, wherein the inclination of the mirror surface is determined based on both the following equations.
α _{m (k)} = 45 ° + (θ _mc + Θ _{m (k)} ) / 2
γ _{m (k)} = Θ _{m (k)} / N
Where α _{m (k)} : Specular X at the kth reflection point _m Tilt to axis
γ _{m (k)} : Mirror surface Z at the kth reflection point _m Tilt to axis
θ _mc   : Z of the contact point with respect to the reference circle of the optical path of each reflected light _m X around the axis _m Angle from axis
θ _{m (k)} : Z of the kth measurement light _m X around the axis _m Angle from axis
n: Appropriate number The measuring apparatus according to claim 1, wherein the mirror surface is inclined smoothly. The measurement according to any one of claims 1 to 3, further comprising: a rotating plate that rotates concentrically with the rotating shaft; and a motor that rotationally drives the rotating plate, and the reflecting mirror is attached to the rotating plate. apparatus. The measuring apparatus according to claim 4, wherein a plurality of reflecting mirrors are attached to the rotating plate so as to be rotationally symmetric.

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