JP2002107452A - Two-dimensional scanning type optical radar sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional scanning type optical radar sensor capable of monitoring an object while confirming normal operation. SOLUTION: A scanning mirror 13 is rockingly driven around axes 13a and 13b by driving circuits 14 and 15, and a light beam from a light emitting element 11 is two-dimensionally scanned on the range of a scanning area A including a monitoring area B. A normal operation confirming means 19 confirms whether or not the reflected light from reflectors m1 to m4 for inspection are being received on the basis of scanning information from the driving circuits 14 and 15 and received light output R1 obtained via a light receiving element 16 and a light receiving circuit 17. A nonexistence judging means 18 judges the existence of the object in the monitoring area B on the basis of the received light output R1. When S=1 for indicating the nonexistence of the object is generated from the nonexistence judging means 18 and N=1 for indicating the normal operation is generated from the normal operation confirming means 19, Z=1 for indicating safety is generated from an AND gate 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional scanning optical radar sensor capable of monitoring an object in a three-dimensional area, and more particularly to a two-dimensional scanning optical radar sensor capable of monitoring an object while confirming that the sensor is normal.

[0002]

2. Description of the Related Art For example, according to the international safety standard for automatic guided vehicles, an optical radar sensor for monitoring an object on a route is provided at a predetermined height or less from the floor in consideration of the discovery of a person lying on the route. It is stipulated that it should be attached to the automatic guided vehicle at the location. However, if a two-dimensional scanning optical radar sensor that monitors a three-dimensional space by scanning a light beam two-dimensionally is used, the scanning beam can be directed also toward the floor surface even when the installation height is equal to or more than a specified value. Therefore, the requirements of the above standard can be substantially satisfied, and the degree of freedom in mounting the optical radar sensor can be increased.

A two-dimensional scanning optical radar sensor is described in, for example, IEICE, Vol. 99, No. 516, "Development of two-dimensional scanning radar", and JP-A-11-306485.
And others disclosed in Japanese Patent Publication No. The former two-dimensional scanning optical radar sensor reflects a light beam emitted from a laser diode by a polygon mirror and radiates the light beam into space. If an object exists on the optical axis of the scanning beam, the reflected light from the object is reflected. The presence of an object is reported by light reception. Since the polygon mirror has a truncated pyramid shape and different angles of inclination of the respective reflection surfaces, the scanning of the light beam reflected by the polygon mirror and emitted to space becomes two-dimensional. As a result, the radiation area of the scanning beam becomes a three-dimensional shape with the light beam reflection point at the top, and the object can be monitored in a three-dimensional area.

In the latter two-dimensional scanning optical radar sensor, a light beam from a light emitting section is reflected by a galvanomirror and projected into a predetermined area. If there is an object in the predetermined area, the reflected light is received. The light is received by the means and it is determined that there is an object. The galvanometer mirror is known in Japanese Patent Application Laid-Open Nos. 7-175005, 7-218857, and the like. The two movable parts that are respectively supported by rotating shafts orthogonal to each other are independently swung by driving means. The mirror is tilted by dynamic driving. Thereby, the scanning of the light beam becomes two-dimensional, and the radiation area of the scanning beam becomes three-dimensional.

[0005]

According to the international safety standard, in consideration of the seriousness of a collision accident between an automatic guided vehicle and a person, it is required that an optical radar sensor to be mounted is not mistaken for danger when a failure occurs. In this case, a function for confirming that the sensor is normal is required. However, any of the above 2
The two-dimensional scanning optical radar sensor does not show a function for confirming the normal operation of the sensor.

A one-dimensional scanning optical radar sensor having a function of confirming normal operation is disclosed in, for example,
It is publicly known in, for example, JP-A-1-144161. This one-dimensional scanning optical radar sensor scans a light beam emitted from a laser diode one-dimensionally by a galvanometer mirror having one rotation axis, and if an object exists on the optical axis of the scanning beam,
The presence of the object is notified by receiving the reflected light. In this one-dimensional scanning optical radar sensor, an inspection reflector for confirming normal operation is provided near an end of the object monitoring area,
The normal operation of the sensor is confirmed by the normal operation confirmation means based on the reflected light from the inspection reflector.

When the radiation direction of the light beam from the galvanomirror is the direction in which the inspection reflector is present, the normal operation checking means determines that the light is normal if the reflected light is received and abnormal if the light is not received. Then, when a sensor normality confirmation output (logical value 1) is generated from the normal operation confirmation means,
When the absence determination means outputs a determination output indicating no object (logical value 1), a notification output indicating no object is generated (logical value 1). Thus, the presence or absence of an object is monitored while confirming that the sensor is normal.

However, when the above-described one-dimensional scanning optical radar sensor normal operation confirmation method is applied to the two-dimensional scanning optical radar sensor, the vertical and horizontal scanning of the light beam is structurally difficult. Although it is applicable to an optical radar sensor using an inseparable polygon mirror as a scanning mirror, it may be applied to an optical radar sensor using a scanning mirror such as a galvanometer mirror that performs scanning in two directions independently. There is a possibility that the sensor cannot be checked normally.

That is, as shown in FIGS. 24A and 24B, based on the above-mentioned method for confirming the normal operation of the one-dimensional scanning optical radar sensor, the scanning area A of the light beam (the area surrounded by the dotted line). Suppose that reflectors 1 and 2 are provided near the end of the monitoring area B (the area surrounded by the solid line), and that the light reflected from the reflectors 1 and 2 is received periodically to confirm normality.
In this case, for example, even if the scanning of the light beam becomes one-dimensional as shown by the scanning region A 'in the drawing due to the failure of one of the scanning driving mechanisms, the scanning beam is reflected by the reflectors 1, 2 near the end of the monitoring region B
In such a failure mode, the reflected light from the reflectors 1 and 2 is periodically received in the same manner as in the normal state, and the abnormality cannot be reported.

The present invention has been made in view of the above problems, and has as its object to provide a two-dimensional scanning optical radar sensor capable of monitoring an object while confirming normal operation. It is another object of the present invention to provide a two-dimensional scanning optical radar sensor capable of monitoring an object while confirming normal operation even in a scanning method in which light beam scanning in two directions is independently performed.

[0011]

According to a first aspect of the present invention, there is provided a two-dimensional scanning optical radar sensor including a light beam generating means and a light beam from the light beam generating means including an object monitoring area. Light beam scanning means capable of two-dimensional scanning;
A light receiving unit that receives reflected light from a scanning space of a scanning beam emitted from the light beam scanning unit; an absence determining unit that determines absence of an object in the monitoring area based on at least an output of the light receiving unit; Normal operation checking means for checking the normal operation of the light beam generating means, light beam scanning means and light receiving means; and safety information based on the logical product of the output of the absence determining means and the output of the normal operation checking means. And a gate means for outputting the same.

In this configuration, the light beam generated by the light beam generating means is two-dimensionally scanned by the light beam scanning means, including the monitoring area of the object. As a result, the scanning beam is emitted into a three-dimensional space, and the object monitoring space becomes three-dimensional. The absence determining means determines the absence of the object based on the presence or absence of a light receiving output of the light receiving means based on the reflected light from the predetermined monitoring area. The normal operation checking means checks the normal operation of at least the light beam generating means, light beam scanning means and light receiving means. The safety information is output from the gate means when a determination output indicating the absence of an object is generated from the absence determination means and a determination output indicating normal operation is generated from the normal operation confirmation means.

The normal operation confirmation means confirms the normal operation based on the light reception output of the light reception means by the reflected light from the inspection reflector arranged in the scanning area of the scanning beam. Configuration. In such a configuration,
The normal operation checking means arranges a reflector for inspection at a predetermined position in the scanning area in advance, and confirms that the reflected light from the reflector for inspection is received by the light receiving means to confirm the normal operation.

According to a third aspect of the present invention, the reflector for inspection is
It is preferable that the correspondence between the scanning beam radiation information obtained from the sensor operating state and the light receiving output result of the light receiving means is different between an assumed abnormal operation and a normal operation. According to this configuration, even when using the light beam scanning means in which scanning in each direction of the scanning beam is performed independently, the scanning beam radiation information and the light receiving output result of the light receiving means at the time of an assumed abnormal operation are used. Since the correspondence relationship with is different from that during normal operation, normal operation can be confirmed.

The normal operation confirmation means confirms normal operation based on a light receiving output result of the light receiving means when the scanning beam information is information indicating the position of the inspection reflector. Configuration. In such a configuration, if there is a light reception output when the reflected light from the inspection reflector should be received, the scanning beam is scanned normally and the normal operation is confirmed.

The normal operation checking means may include a light receiving output result of the light receiving means when the scanning beam information is information indicating the position of the inspection reflector and the scanning beam information. It is preferable that the normal operation is confirmed based on the light receiving output result of the light receiving means when the information indicates a position other than the inspection reflector position. According to this configuration, the normal operation is performed based on the determination result that the reflected light from the inspection reflector is received when it should be received and that the reflection light from the inspection reflector should not be received when it should not be received. , The reliability of normal operation confirmation is further improved.

The information indicating the position of the inspection reflector may include the direction of the inspection reflector as viewed from the sensor and the distance from the sensor to the inspection reflector. With this configuration, the object monitoring can be performed by defining the range of the monitoring area. If the inspection reflector is arranged in the vicinity of a corner of the scanning area as in claim 7, the reflected light from the inspection reflector is received, and the scanning beam scans the entire monitoring area. Is being scanned. Further, when there are a plurality of monitoring areas in the scanning area, there is no need to arrange an inspection reflector for each monitoring area.

According to the present invention, the reflector for inspection is
A configuration may be adopted in which the monitor area is arranged near the corner of the monitor area outside the monitor area. If the inspection reflector is arranged in the vicinity of the azimuth indicated by the maximum vertical angle and the maximum left and right angle of the scanning beam with respect to the outer edge of the monitoring area, the monitoring area may be, for example, spherical. However, it is suitable.

According to a tenth aspect of the present invention, in the case where a two-dimensional scanning optical radar sensor is mounted on the movable body, the inspection reflector is monitored by the monitor when the movable body moves within a predetermined range. The arrangement is such that there is at least one or more in the region. In such a configuration, the moving body can move while confirming that the scanning beam is emitted to the area to be monitored.

According to the eleventh aspect, if the reflector for inspection is arranged so as to be continuously present along the moving direction of the moving body, it is always possible to confirm the normal operation even while the moving body is moving. It can be performed in the same scanning beam emission range. The non-existence determining unit determines the presence or absence of an object by excluding, from the light receiving output of the light receiving unit, the light receiving output by the reflected light from the inspection reflector in the monitoring area, as in claim 12. did.

The inspection reflector may be configured to modulate the light intensity frequency of the incident scanning beam as in claim 13, or to modulate the wavelength of the incident scanning beam as in claim 14. It may be. According to this configuration, it is easy to distinguish the reflected light from the inspection reflector from the reflected light from the object.

According to a fifteenth aspect, if the inspection reflector is used for information display means, display information can be transmitted by the inspection reflector.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a first embodiment of a two-dimensional scanning optical radar sensor according to the present invention. In FIG. 1, a light emitting element 11 is driven by a light emitting element driving circuit 12 to generate a light beam. The scanning mirror 13 reflects the light beam from the light emitting element 11 and emits it as a scanning beam to the object monitoring space. The scanning mirror 13 is
For example, a semiconductor galvanomirror, which will be described later, is periodically driven to swing around a rotation axis 13a by a first drive circuit 14, and is rotated about a rotation axis 13b orthogonal to the rotation axis 13a by a second drive circuit 15. Swings periodically. A scanning beam A (a region surrounded by a dotted line in the figure) includes a monitoring region B (a region surrounded by a solid line in the figure) in a horizontal direction and a vertical direction in the figure with the swing of the scanning mirror 13. Is scanned two-dimensionally. Thereby, the scanning beam is transmitted to the scanning mirror 13.
The light beam is reflected into a pyramid-shaped three-dimensional space indicated by a two-dot chain line in FIG. Inspection reflectors m1 to m4 for confirming normal operation are provided outside the monitoring area B and near the four corners of the monitoring area in the scanning area A. The reflected light from inside the pyramid-shaped scanning beam radiation space is received by the light receiving element 16, converted into an electric signal, and subjected to processing such as amplification and detection by the light receiving circuit 17, and then, as the light receiving output R1, the absence determining means 18 and It is input to the normal operation check means 19. The AND gate 20 as a gate means is provided with each output S of the absence determination means 18 and the normal operation confirmation means 19,
An AND operation is performed on N and the operation result is output as an output Z.
Here, the light emitting element 11 and the light emitting element driving circuit 12 constitute light beam generating means, and the scanning mirror 13, the first and second driving circuits 14 and 15 constitute light beam scanning means. The light receiving circuit 17 forms light receiving means.

FIG. 2 shows a semiconductor galvanometer mirror used as the scanning mirror 13. Semiconductor galvanometer mirrors
JP-A-7-175005, JP-A-7-21885
It is known in, for example, Japanese Patent Publication No. 7 and the like, and its configuration and operation principle will be briefly described here. FIG.
This is a configuration example described in Japanese Patent Publication No. 005. Center movable plate 3
One surface has a mirror 32 formed of a deposited metal film or the like.
The movable plate 31 is supported in a movable frame 34 by a first torsion bar 33A, and the movable frame 34 is further supported in a fixed frame 35 by a second torsion bar 33B. The movable plate 31 and the movable frame 34 are provided with drive coils 36A and 36B, respectively, and supply a drive current to a pair of electrode terminals 37A and 37B at both ends of the drive coils 36A and 36B. A static magnetic field is applied to the drive coils 36A and 36B by a static magnetic field generating means such as a permanent magnet (not shown).

The operation is performed by applying a static magnetic field in a direction traversing each of the drive coils 36A and 36B along the plane of both ends of the movable plate 31 and the movable frame 34, and
When a current is supplied to the movable plate 36B, an electromagnetic force acts on both ends of the movable plate 31 and the movable frame 34 in a direction according to Fleming's left-hand rule, and the movable plate 31 and the movable frame 34 rotate. When the movable plate 31 and the movable frame 34 rotate, each torsion bar 3
3A and 33B (corresponding to the rotating shafts 13a and 13b in FIG. 1) are twisted and generated torsion bars 33A and 33B.
The movable plate 31 and the movable frame 3 reach a position where the respective spring reaction forces of B and the respective electromagnetic forces acting on the movable plate 31 and the movable frame 34 are balanced.
4 rotates. The electromagnetic force is applied to each drive coil 36A, 36A.
B, the displacement angles of the movable plate 31 and the movable frame 34 are respectively proportional to the drive coils 36A and 36B.
Is proportional to the current flowing through Therefore, each drive coil 36
By controlling the current flowing through A and 36B, the displacement angle of the movable plate 31 and the movable frame 34, that is, the mirror 32, can be controlled two-dimensionally. If the relationship between the current amount of the drive coils 36A and 36B and the displacement angles of the movable plate 31 and the movable frame 34 is determined in advance, information on the displacement angle of the mirror 32 can be obtained from the current amount.

Accordingly, in the present embodiment, the displacement angle of the mirror based on the driving current, that is, the radiation azimuth of the scanning beam is indicated from each of the driving circuits 14 and 15 for supplying a driving current to the driving coils 36A and 36B, respectively. Information signals p1,
p2 is determined by the absence determination means 18 and the normal operation confirmation means 19
Is being entered. As disclosed in Japanese Patent Application Laid-Open No. 7-218857, if a detection coil for detecting the displacement of the movable plate is provided, the mirror displacement angle can be detected by the detection coil. Information signals p1, p
If it is used instead of 2, it becomes possible to directly monitor whether or not the scanning state of the mirror is normal from the output of the displacement detection coil.

The absence judging means 18 stores the scanning beam direction corresponding to the monitoring area B.
The presence / absence of an object in the monitoring space corresponding to the monitoring area B is determined by determining the presence or absence of the light receiving output R1 of the light receiving circuit 17 when the scanning beam directions indicated by the signals p1 and p2 of the signals 4 and 15 match the stored information. Is determined, and when no object is present, S =
1. Output S = 0 when an object is present.

The normal operation check means 19 stores the direction in which the inspection reflectors m1 to m4 are present, and as will be described later, the scanning beam radiation direction indicated by the signals p1 and p2 of the driving circuits 14 and 15 as described later. When the information matches the stored information, the presence or absence of the light-receiving output is determined, and the normal operation of the sensor is confirmed. When the sensor is determined to be normal, N = 1 is output. When the sensor is determined to be abnormal, N = 0 is output.

FIG. 3 shows the normal operation checking means 1 of the present embodiment.
9 shows a circuit configuration. In FIG. 3, the normal operation check unit 19 of the present embodiment includes an angle detection circuit 19A, a reflection check circuit 19B, a period check circuit 19C, and an AND gate 19D. The angle detecting circuit 19A are respectively the azimuth (θ _1, ψ ₁₎ of the inspection reflector m1~m4 which are prearranged ~ (θ _4, ψ ₄₎ stores a signal p1, p2 to enter When the indicated scanning beam azimuth (θ, ψ) information matches the stored azimuth information, a light reception presence / absence instruction signal Sr = 1 is output as instruction information indicating that it is time to determine the presence or absence of light reception. The orientation (θ ₁ , ψ ₁ ) ~
Except for (θ ₄ , ψ ₄ ), the light reception presence / absence instruction signal Sr = 0.

The reflection presence / absence confirmation circuit 19B confirms the presence / absence of the light reception output R1 during the period of the light reception presence / absence instruction signal Sr = 1. If the light reception output R1 is input, the output NS = 1 is continued, and the light reception output R1 is input. If not, set NS = 0. The period checking circuit 19C checks the generation period of the signal Sr = 1, that is, the scanning speed of the scanning beam, and if the generation period of the signal Sr = 1 is a predetermined period, determines that the scanning speed is normal and continues the output NT = 1,
If the period is not the predetermined period, the scanning speed is determined to be abnormal and NT = 0 is set.

The AND gate 19D outputs the signals NS = 1 and N
When T = 1 is input together, it generates an output N = 1 indicating that the sensor is normal. Incidentally, the scanning beam direction (θ, ψ) is, as shown in FIG.
The light beam azimuths in the left-right direction (x direction) and the up-down direction (y direction) are defined with the origin (which is also the center of the scanning region A).

In this case, even when a scanning mirror that performs scanning in each direction independently, such as a galvanometer mirror, is used as well as a polygon mirror, an inspection reflector that can confirm the normal operation of the two-dimensional scanning optical radar sensor. Will be described. The normal operation checking means 19 stores the azimuth information (reflector existence range) of the inspection reflector arranged in advance in the scanning region A of the scanning beam, and further stores the scanning region A of the scanning beam.
Orientation information (gap range) of the area where the inspection reflector does not exist is stored, and whether or not there is a light-receiving output to be input is determined by judging whether the orientation information is normal. That is, the relationship between the azimuth (scanning beam azimuth) in the scanning area A and the output logical value of the light receiving circuit 17 (logical value 1 with light receiving, logical value 0 without light receiving) is stored in advance in the normal operation checking means 19,
The result of the azimuth-logical value actually obtained at the time of beam scanning is
When the information matches the stored information, the operation is determined to be normal, and when the information does not match, the operation is determined to be abnormal.

The gap range is a range where there is no reflector for inspection and is a range where there is no light reception when an object is absent, and may include the monitoring area B. However, when the monitoring area B is included, if an object is present in the monitoring area B, the reflected light from the object is received. Therefore, the object absence determining means 18 not only detects the object but also checks the normal operation. In No. 19, the result of the azimuth-logic value does not match the stored information, and an abnormality is determined. Therefore, it is desirable that the gap range be within the scanning area A and outside the monitoring area B.

In the assumed abnormal state, the logical value 1
If the inspection reflector can be configured so as to be erroneously set to the logical value 0 (no light reception) when it should be (with light reception), the normal operation checking means 19 determines the orientation of the inspection reflector in the scanning area A of the scanning beam. Only the information (reflector existence range) may be stored, and only the logical value of the light reception output at the time of the azimuth information may be confirmed.

In the case of a semiconductor galvanometer mirror, an abnormal state in which the scanning of the scanning beam becomes one-dimensional as in the above-described scanning area A 'in FIG. In this case, the output state of the drive circuit differs from the actual movement of the mirror movable unit. For this reason, in the configuration in which the bar-shaped inspection reflectors 1 and 2 are simply arranged near the end of the monitoring area B as shown in FIG. 24, even when the scanning becomes abnormal one-dimensionally (scanning area A '), the monitoring area B Since reflected light is always obtained near the end, the result of the azimuth-logical value obtained at the time of this abnormality is the same as the result of the azimuth-logical value obtained at the time of normal, and the abnormality cannot be detected. Therefore, in order to surely confirm the normal operation of the two-dimensional scanning optical radar sensor, the result of the azimuth-logic value obtained at the time of the assumed scanning abnormality must always be the same as the result of the azimuth-logic value actually obtained at the normal time. It is necessary to configure the inspection reflector differently.

FIG. 5 shows an example of the configuration of such a reflector for inspection, and the principle of confirming the normal operation of the two-dimensional scanning optical radar sensor will be described. In FIG. 5, the inspection reflector 1 is divided into a reflector 1a and a reflector 1b, and a gap 3 is provided between the reflectors 1a and 1b. (Reflector existence range) and a section (gap range) where the logical value is 0 exist.

According to such a configuration, when the above-mentioned scanning is abnormal in one-dimensional scanning, reflected light is always obtained near the end of the monitoring area B, and the azimuth information p1 and p2 of the scanning beam are in the gap range (normal). (The section where the logical value becomes 0 at the time), the received light output becomes the logical value 1, so that the result of the azimuth-logical value obtained at the time of the scanning abnormality is different from the normal state, and the abnormality can be detected. Even in the case of a radar sensor, normal operation can be confirmed. In the case where the scanning beam is not projected due to a failure of the light emitting element 11 or the like, the received light output becomes the logical value 0 even when the azimuth information p1 and p2 indicate the reflector existence range (the section where the logical value is 1 in a normal state). Therefore, the result of the azimuth-logic value obtained at the time of abnormal scanning is different from that at the time of normal scanning, and abnormalities can be detected.

The arrangement of the inspection reflectors 1m to 4m in the first embodiment shown in FIG. 1 is based on the configuration principle shown in FIG. In the configuration in which the inspection reflectors 1m to 4m are arranged in the vicinity of the four corners of the monitoring area B as shown in FIG.
When p2 indicates the direction in which the inspection reflectors 1m to 4m are present (when the received light output R1 should have a logical value of 1), the received light output R1 has a logical value of 0. Therefore, the azimuth information p1 and p2 of the scanning beam.
The normality can be confirmed by detecting the presence or absence of the light receiving output R1 when indicates the direction of existence of the inspection reflectors 1m to 4m.

If the reflected light from the inspection reflector is obtained outside the monitoring area B, it is possible to confirm that at least the entire monitoring area B is scanned.
4m is preferably arranged to protrude from the upper end and the lower end of the monitoring area B in FIG. Next, the normality checking operation of the first embodiment will be described with reference to the time chart of FIG.

Information signals p1 and p2 indicating the azimuths (θ, ψ) of the scanning beam are input to the angle detection circuit 19A in the normal operation confirmation means 19 from the driving circuits 14 and 15 for driving the scanning mirror 13 to swing. . Angle detection circuit 19A are respectively the azimuth (θ _1, ψ ₁₎ of the inspection reflectors m1 to m4 ~ (theta
_4, stores [psi _4). The angle detection circuit 19A determines whether or not the azimuths indicated by the input information signals p1 and p2 match the stored information. Each time the matching azimuth information (inspection reflector existence azimuth information) is input, the figure is changed. As shown in FIG. 6, information indicating the light reception presence / absence confirmation period is output as Sr = 1 to the reflection presence / absence confirmation circuit 19B and the period confirmation circuit 19C. The reflection presence / absence confirmation circuit 19B determines whether or not the light receiving output R1 is input during the period when Sr = 1 is input,
When the light receiving output R1 = 1 is input, NS = 1 is generated. As shown in FIG. 6, if the relationship of inputting R1 = 1 when Sr = 1 is maintained, NS = 1 from the reflection presence / absence confirmation circuit 19B.
Continue. Further, the period checking circuit 19C continues NT = 1 when the scanning speed of the scanning mirror 13 is normal and the signal Sr = 1 is generated at a predetermined interval. Thus, the presence azimuth (θ _1, ψ ₁₎ of the inspection reflectors _{m1~m4 ~ (θ 4, ψ 4} ) reflected light is received when the scanning beam is emitted (NS =
1) The scanning speed of the scanning mirror 13 is normal (NT =
If 1), the normal operation check means 19 continuously outputs N = 1 indicating that the sensor is normal. On the other hand, for example, FIG.
As shown by the dotted line f1, the light receiving output R when Sr = 1
If 1 = 0, NS = 0 and normal operation check means 19
Is N = 0.

The absence determining means 18 determines that there is no object and outputs S = 1 if there is no light reception output R1 = 0 when the azimuth information of the monitoring area stored therein is input during the period of Sr = 0. Occurs continuously. On the other hand, for example, in FIG.
As shown by the dotted line f2, when the received light output R1 = 1 in the beam direction corresponding to the monitoring area, it is determined that the light is reflected from the object, and the output of the absence determination means 18 is S =
It becomes 0.

The AND gate 20 in FIG. 1 generates an output of Z = 1 only when S = 1 is generated from the non-existence judging means 18 and N = 1 is generated from the normal operation checking means 19 to notify the safety. I do. As described above, according to the first embodiment, in an assumed abnormal state in which scanning is one-dimensional, the scanning beam direction information obtained from the drive system of the scanning mirror 13 is the inspection reflector existing direction. Sometimes, reflected light is not received, and the logical value to be obtained during normal operation differs from the actually obtained logical value, and an abnormality can be detected. Further, even when the light beam is not radiated to the area that should be radiated due to the improper mounting of the optical radar sensor, at least a part of the reflected light in the radiation azimuth where the reflected light of the inspection reflectors m1 to m4 should exist. Since no light is received, an abnormality is reported.

The angle detection circuit 19A has a monitoring area B
Is stored for all scanning regions except for the scanning direction, and based on the azimuth information p1 and p2, the scanning beam azimuth is defined as the azimuth (reflector existence range) at which the logical value should be 1 (with light reception). Is present and scan beam orientation is logical 0
The signal Sr indicates to the reflection presence / absence confirmation circuit 19B that the orientation (gap range) should be (no light reception),
If the reflection presence / absence confirmation circuit 19B is configured to confirm the presence / absence of light reception in all scanning regions except the monitoring region B, for example, the light beam reciprocates between the inspection reflectors m1 and m2 due to a failure or the like. Even when the light receiving output should be R1 = 0, it is detected that R1 = 1 and NS = 0
Can be output, and abnormality can be detected, so that the reliability of the normal operation check function can be further improved.

Further, as shown by a dotted line in FIG.
Area B 'except for the inspection reflectors m1 to m4
If there is reflected light from the area B ', the absence determining means 18 considers the reflected light from the object to be the output S = 0, so that the angle detection circuit 19A
And the reflection presence / absence confirmation circuit 19B is provided with inspection reflectors m1 to m
Since the danger can be reported even in the configuration in which the relationship between the azimuth and the logical value is monitored only for the existence azimuth of No. 4, the reliability of the sensor can be further improved as described above.

For example, a threshold value is set for the received light intensity of the reflected light, and when the received light intensity is equal to or higher than the threshold value, it is determined that there is light reception, and the reflectance of the inspection reflectors m1 to m4 is determined by the reflected light. If the light receiving intensity is adjusted to slightly exceed the threshold value, the light beam intensity decreases due to the deterioration of the light emitting element 11 or the reflected light receiving intensity decreases due to the light-electric conversion efficiency deterioration due to the deterioration of the light receiving element 16. There is an advantage that defects such as can be detected early. The reflectance of the inspection reflectors m1 to m4 can be adjusted by the material and color of the reflection surface.

Also, in FIG.
And the signals p1,
p2 is determined by the absence determination means 18 and the normal operation confirmation means 19
, And the same information signal may be transmitted to the other via the means to which the signals p1 and p2 are input. For example, the light receiving output R1 is determined by
And transmitting an information signal equivalent to the received light output R1 to the normal operation checking means 19 via the non-existence judging means 18, it is necessary that at least the non-existence judging means 18 receives the output R1. Can be confirmed, and the absence determination means 1
It is also possible to confirm whether or not the processing operation of the output R1 of No. 8 is normal.

Next, a case where the optical radar sensor has a distance measuring function will be described as a second embodiment of the present invention. In the present embodiment, as shown by the dotted line in FIG. 1, a signal K indicating the light emitting state output from the light emitting element driving circuit 12 in synchronization with the light emitting pulse is sent to the absence determining means 18 and the normal operation checking means 19, respectively. input. Normal operation check means 19
Has a configuration in which a delay circuit 19E of FIG. 8 is provided in addition to the configuration of FIG. 3, and the signal K is input to the delay circuit 19E. It is known that the distance to the object can be calculated by the time difference between the emission of the light beam and the reception of the reflected light, the phase difference between the emission beam and the reception beam, and the details of the distance calculation method are omitted here. Since the distances from the optical radar sensor to the inspection reflectors m1 to m4 are respectively known, each time ΔT from when the signal K is input to when the reflected light from each of the inspection reflectors m1 to m4 is received is: It can be calculated in advance. The ΔT differs depending on the distance from each of the inspection reflectors m1 to m4. Information on the time ΔT for each of the inspection reflectors m1 to m4 is stored in the delay circuit 19E. In the present embodiment, it is assumed that the signal Sr from the angle detection circuit 19A includes identification information of the scanning beam direction corresponding to each of the inspection reflectors m1 to m4.

Therefore, the delay circuit 19E outputs the signal Sr output from the angle detection circuit 19A as shown in FIG.
Indicates that it is the confirmation period of the presence or absence of light reception (when Sr = 1), the delay time ΔT for the corresponding inspection reflector is selected based on the azimuth information included in the signal Sr, and the signal K is input. Delays the selected delay time ΔT from the signal S
r ′ = 1 is output.

As a result, as shown in FIG.
If R1 = 1 is input at the time of 1, the reflection check circuit 19
B determines NS = 1 as the received light output R1 from the inspection reflectors m1 to m4 and continues NS = 1. On the other hand, for example, as shown by a dotted line f1 in FIG. 9, when Sr ′ = 1, the light receiving output R1 =
If 0, NS = 0. Further, in the scanning range of the monitoring area B during the period of Sr ′ = 0, the light receiving output R1 =
If 0, the absence determining means 18 continuously generates the output S = 1 as there is no object, but if the light receiving output R1 = 1 as shown by a dotted line f2 in FIG. The output of the judging means 18 is S = 0 indicating that there is an object.

In this configuration, in addition to the same effects as in the first embodiment, when the operation delay of the light receiving element 16 or the light receiving circuit 17 increases, the time difference between the signal Sr 'and the generation time of the light receiving output R1 on the time axis. Is generated, so that there is an advantage that notification can be made as a sensor abnormality. Further, since the monitoring area B can be set by defining the monitoring distance from the optical radar sensor, the object can be monitored by setting a desired space area.

Next, another example of arrangement of the inspection reflector applicable to the first and second embodiments will be described with reference to FIGS. When it is arranged near the four corners of the monitoring area B as in FIG. 1, it may be arranged as shown in FIG. Further, as shown in FIG. 11, at the outer edge of the monitoring area B, the maximum angle θmax and the minimum angle θmin are identified for the azimuth θ (azimuth angle of the scanning beam) about the rotation axis 13 a by the first drive circuit 14. The maximum angle 方位 max and the minimum angle ψmin are identified for the azimuth ψ around the rotation axis 13b by the two-drive circuit 15, and the azimuths (θmax, ψmax), (θmin, ψ
max), (θmax, ψmin), (θmin, m
Inspection reflectors m1 to m4 may be arranged near the (in) direction. Such an arrangement method is particularly suitable when the monitoring area B is, for example, spherical.

Further, as shown in FIG. 12, a part of the reflector for inspection m may be arranged on the floor. In this case, as the inspection reflector m, for example, a Braille mat attached to the floor surface or the like can be considered. The arrangement of the inspection reflector on the floor or the like is described in detail in Japanese Patent Application Laid-Open No. 2000-162306 by the present applicant. As in the case of the galvanomirror shown in FIG. 2, when the rotations of the rotation shafts 13a and 13b are independent, it is possible to omit some of the inspection reflectors.

For example, as shown in FIG.
With respect to the azimuth θ around a, the reflector m having the maximum angle θmax
3 and the reflector m4 having the minimum angle θmin,
Reflector m with maximum angle ψmax for azimuth ψ around b
2 (may be m1) and the reflector m3 having the minimum angle ψmin is selected. The reflector not selected at this time can be omitted. In FIG. 13, the inspection reflector m1 (or m2) can be omitted.

When such an arrangement method is applied, FIG.
In the case of 0, one of the diagonal inspection reflectors, that is, the inspection reflectors m1 and m4 or m2 and m3 can be omitted. In addition, the galvanomirror as shown in FIG. 2 has a structure in which the swing angle is considered to be symmetric both up and down and left and right, so that the inspection reflector having the maximum absolute value | θ | The inspection reflector having the maximum absolute value | ψ | with respect to the angles ± ψ is selected, and the others can be omitted. FIG.
When applied to the arrangement configuration of FIG.
Any one of m4 may be provided.

When a polygon mirror is used as the scanning mirror 13, the normality of scanning of the light beam is replaced with the normality of the rotation operation, so that only one inspection reflector is required. Also, if it is arranged near the four corners of the scanning area A,
Since it is confirmed that the scanning area A is being scanned, it is also possible to simultaneously confirm that the monitoring area B in the scanning area A is being scanned. In addition, even if there are a plurality of monitoring areas B in the scanning area A, there is an advantage that it is not necessary to arrange an inspection reflector for each monitoring area B.

Next, a case where the two-dimensional scanning optical radar sensor is mounted on a moving body will be described. When an optical radar sensor is mounted on a moving object, the normal operation of the sensor is checked,
It is necessary to confirm that the scanning beam is emitted to the area to be monitored. Confirmation of normal operation is as follows.If the inspection reflector for normal operation confirmation described above is fixed to the sensor, the relative position between the scanning mirror and the reflector is constant, and regardless of the movement of the moving body as described above. The normal operation can be confirmed (the traveling range of the moving object is not limited by the sensor).
Further, when confirming that the scanning beam is radiated to the area to be monitored, an inspection reflector for radiation area confirmation is arranged in the monitoring area, and the presence or absence of reflected light from the inspection reflector is checked. You just need to check. In addition, it is preferable that the radiation region checking inspection reflector is arranged near an outer edge portion (a region corresponding to a monitoring region to be monitored by the sensor) where a dangerous state is expected to occur due to traveling of the moving body.

FIG. 14 shows an example of the arrangement of the reflectors for inspection when the optical radar sensor is mounted on a moving body. (A) is a top view and (B) is a side view. In FIG. 14, the moving body 1
The two-dimensional scanning optical radar sensor 101 attached at 00 has inspection reflectors EaU and Eb for normal operation confirmation in the same arrangement as in FIG. 1, for example, in front of a scanning mirror (not shown).
U, EaL and EbL are attached. The optical radar sensor 101 uses these reflectors EaU, EbU, EaL, E
Based on the bL reflected light, the normal operation check means 19 checks the normal operation of the sensor 101 in the same manner as described above.

In addition, at the four corners near the outer edge of the moving space of the moving body 100, a certain interval is provided along the traveling path 102 as shown in the figure to provide inspection reflectors a1U to a4 for checking the radiation area.
U, a1L to a4U, b1U to b4U, b1L to b4L
Is arranged. Each of the above-mentioned inspection reflectors has a retroreflective property. Inspection reflectors a1U to a4U, a1L to a4U, b1U to b4U,
The signals b1L to b4L are identified by the signals p1 and p2 and the light reception output R
The reflector position pattern and the reflector azimuth (and distance) information in the image obtained from step 1 are estimated from the current position of the moving body and the reflector position stored in advance and the reflector's predicted position pattern and prediction. What is necessary is just to compare with azimuth (and distance) data.

FIGS. 15A to 15C show the optical radar sensor 1 when the moving body 100 moves in the direction of the arrow in FIG.
The change of the image based on the radiation azimuth information 01 and the light receiving output R1 is shown. The area surrounded by the dotted line indicates the scanning area A of the scanning beam. FIG. 15A shows an image at the position shown in FIG. 14, and the reflectors a2U, a2L, b2U, and b2 for inspection are used.
L and a3U, a3L, b3U, b3L are detected. The inspection reflectors a4U, a4L, b4U, and b4L are not detected because they are far away. According to the movement of the moving body 100, as shown in FIG.
The a2L, b2U, and b2L are outside the scanning area and disappear from the image, and only the inspection reflectors a3U, a3L, b3U, and b3L are detected. Moving further, FIG.
Inspection reflectors a4U, a4L, b4U, as shown in FIG.
b4L starts to be detected. As described above, when the moving body 100 moves along the traveling path 102, the inspection reflectors a1U to a1a
4U, a1L to a4U, b1U to b4U, b1L to b4
By detecting L, it can be confirmed that the scanning beam is radiated to the original area to be monitored.

With the configuration shown in FIG. 14, it is possible to omit the inspection reflectors EaU, EbU, EaL and EbL for checking the normal operation. In this case, confirmation of scanning by the scanning beam is limited to a range surrounded by an inspection reflector for confirming a radiation area detected at the outermost edge. That is, in FIGS. 15A and 15C, scanning confirmation of the scanning beam is performed in a range surrounded by the inspection reflectors a2U, a2L, b2U, b2L and the inspection reflectors a3U, a3L, b3U, b3L. In FIG. 15B, the measurement is performed in a range surrounded by the inspection reflectors a3U, a3L, b3U, and b3L.

Therefore, the inspection reflector Ea for checking the normal operation is used.
When U, EbU, EaL, and EbL are omitted, the normal operation can be confirmed in the same scanning range as when these inspection reflectors EaU, EbU, EaL, and EbL are used. Reflectors a1U-a4U, a1L-
Immediately before the frames a4L, b1U to b4U, and b1L to b4L are out of the frame, that is, at the four corners of the image in FIG. 15, each of the inspection reflectors a1U to a4U, a1L to a4U, and b1U to b4.
It is a time point when U, b1L to b4L are located, and is not continuous but periodic with the movement of the moving body.

Inspection reflectors EaU, Eb for checking normal operation
U, EaL, EbL are omitted, and the reflectors for inspection EaU, E
In order to continuously confirm normal operation in a scanning range substantially the same as that in the case of using bU, EaL, and EbL, each of the inspection reflectors a1U to a4U, a1L to a4L, and b1 for confirming the radiation area are used.
U to b4U and b1L to b4L may be configured, for example, as shown in FIG.

As shown in FIGS. 16A and 16B, the inspection reflectors aU, aL, bU, and bL are continuously arranged along the traveling path 102 at the four corners near the outer edge of the moving space of the moving body 100. I do. With this configuration, as shown in FIGS. 17A to 17C, even if the moving body 100 moves, the inspection reflector a
The range surrounded by U, aL, bU, and bL does not change, and normal operation can be continuously confirmed in the same scanning range as when the inspection reflectors EaU, EbU, EaL, and EbL are provided.
H2, h3 and h4 in FIG. 17 are positions h2 and h in FIG.
3, h4.

The moving body on which the two-dimensional scanning optical radar sensor is mounted is not limited to the traveling vehicle shown, but may be a robot arm or the like. Further, when the scanning mirrors, such as galvanometer mirrors, having independent mirror rotation operations in the scanning direction are employed, a part of the inspection reflector can be omitted as described with reference to FIG. is there. FIG. 14, FIG.
In the case of No. 6, since the inspection reflector for radiation area confirmation is included in the monitoring area B, the absence determining means 18 needs to determine the presence or absence of an object except for the light reception output R1 from the reflector for inspection. is there. For this reason, the absence determining means 18 is provided with a circuit similar to the angle detecting circuit 19A in the normal operation checking means 19 described above, uses the same instruction signal as the signal Sr, and operates when the signal Sr = 1 is input. The presence or absence of an object is determined except for the light reception output.

FIGS. 18 and 19 show the difference between the case where the optical radar sensor does not have the distance measuring function and the case where the optical radar sensor has the distance measuring function when the inspection reflector existing area is excluded from the monitoring area. FIG. 18 shows a case without a distance measuring function, and FIG. 19 shows a case with a distance measuring function. (A) of both figures shows a top view, and (B) shows a side view. The dotted line in the figure is the scanning area A of the scanning beam.

When the distance measuring function is not provided, the monitoring area B and the non-monitoring area C (the area where the reflected light from the inspection reflector is received) are as shown in the figure, and the object 105 is inspected as shown in the figure. If the object exists in the direction of the reflector for inspection, the reflected light of the object 105 and the reflected light of the reflector for inspection may not be distinguished from each other. Since the light is limited to the surroundings of the body, it is possible to distinguish the reflected light from the object 105 and the reflected light from the inspection reflector behind it. It is needless to say that the above-described area dividing method can be similarly applied to each of the embodiments described above.

Even in the case as shown in FIG. 18, FIGS.
With the inspection reflector having the configuration shown in FIG. 1, the reflected light from the inspection reflector and the reflected light from the object can be distinguished. FIG.
0 (A) and (B) are configuration examples of the movable inspection reflector configured to modulate the light intensity frequency of the reflected light. FIG.
The inspection reflector 200 in (A) has a configuration in which a mirror 202 is mounted on a shaft 201 that is rotated by a driving unit (not shown). Assuming that the mirror 202 has low retroreflectivity,
The incident light beam is reflected in an azimuth corresponding to the rotation angle of the inspection reflector 200. Therefore, the reflected light from the inspection reflector 200 is modulated by the rotation frequency of the inspection reflector 200 and received by the light receiving element of the optical radar sensor. The modulation information is included in the light reception output R1 and input to the reflection presence / absence confirmation circuit 19B of the normal operation confirmation means 19. When the modulated light reception output R1 is input, the reflection presence / absence check circuit 19B can regard the reflection light from the inspection reflector 200 as the reflection light from the object. For example, the fact that the light receiving signal is modulated at a specific frequency can be detected by providing a band-pass filter that passes that frequency.

The inspection reflector 210 shown in FIG.
The mirror 212 pivotally supports the mirror 212 so as to be able to swing around the axis 211, and a spring 213 is connected to the mirror 212.
This is a configuration in which vibration energy is supplied from outside to the wafer 12 to swing it. In particular, when the oscillation frequency is a resonance frequency determined by the mass of the inspection reflector 210 and the spring constant, the oscillation can be largely performed. In such a configuration, for example, if the optical radar sensor is provided with a sound wave generating unit and the vibration energy is supplied to the inspection reflector 210 by the sound wave from the sensor, the inspection reflector 210 does not need to have a driving unit in itself, and becomes unnecessary. There is an advantage that can be converted to a power supply.

FIG. 21 shows an example of a wavelength conversion type inspection reflector configured to modulate the wavelength of reflected light. The wavelength conversion type inspection reflector 220 of FIG. 21 has a configuration in which a wavelength conversion layer 222 is provided on the front surface of a mirror 221 and converts an incident light beam into reflected light of a different wavelength. In the present embodiment, for example, a blue incident light beam is converted into a red light beam and reflected. Such a wavelength conversion technology is described in Mamiya et al., 13th Human Interface Symposium, Human Interface Subcommittee, Japan Society of Automatic Control, 1996, p. 49
It is known as 3-500.

When the wavelength conversion type inspection reflector 220 is used, for example, a light receiving element provided with an optical filter having a characteristic of transmitting only a red light beam and blocking a blue light beam, and a light receiving output based on an output from the light receiving element The generated light receiving circuit is separately provided in the optical radar sensor having the configuration shown in FIG. As a result, the reflected light of the red light beam wavelength-converted by the inspection reflector 220 is received only by the light receiving element with the optical filter, and the light receiving circuit outputs a light reception output only when the reflection light of the inspection reflector 220 exists. appear. Therefore, the received light output becomes information indicating the presence of the reflected light of the inspection reflector.
The normal operation can be confirmed by judging the presence or absence of the light reception output R1 in the light reception presence / absence confirmation circuit 19B of No. 9.

By using the inspection reflector as shown in FIGS. 20 and 21, it is easy to distinguish the reflected light of the inspection reflector from the reflected light of the object, and the distance measuring function can be performed even in the state shown in FIG. The two can be identified without providing them. Further, it is possible to omit the signals p1 and p2 indicating the orientation of the inspection reflector. It is also possible to use a reflector for inspection for confirming a radiation area as information display means. FIG. 22 shows an example.
FIGS. 22A and 22B show an example in which traveling information of the moving body 100 is displayed, for example, where FIG. 22A is a top view and FIG. 22B is a side view.
The same components as those in FIG. 14 are denoted by the same reference numerals.

In FIG. 22, the inspection reflectors a to c are
For example, it is installed on the traveling path 102 and used for confirming the radiation area of the light beam of the optical radar sensor 101 mounted on the moving body 100 and for displaying information at the same time. The information is displayed by changing the basic shape of the non-informational reflector (reflection characteristic) to a predetermined shape (reflection characteristic) corresponding to the information. For example, in the present embodiment, no information is used as the inspection reflector c, and the information is displayed by transforming the basic shape into a barcode shape. The shapes (reflection characteristics) of the inspection reflectors a to c are extracted based on the signal R1, and based on the correspondence relationship between the reflectance and the information stored in advance, the signal R is used.
The information is decoded from the output state of No. 1.

FIGS. 23A to 23C show the optical radar sensor 1 when the moving body 100 moves in the direction of the arrow in FIG.
The change of the image based on the light reception output of No. 01 is shown.
The image of (A) shows a state in which the decoding and execution of the display information of the inspection reflector a have already been completed and the image is approaching the inspection reflector b. In this image, the inspection reflector b is surrounded by a dotted line, which indicates that the inspection reflector b is recognized as an inspection reflector for confirming the emission area of the light beam.
This confirms that the light beam is emitted to the monitoring area. Assuming that the reflector b for inspection is displaying, for example, “running speed” information, the display information of the reflector b for inspection is (B)
When the inspection reflector b overlaps the horizontal line I on the image as described above, the decoding is executed, and the moving body 100 travels based on the “running speed” information indicated by the inspection reflector b. In (C), the inspection reflector c with no information is confirmed, and it is confirmed only that the light beam is emitted to the monitoring area.

With this configuration, for example, when applied to a railway vehicle, the inspection reflector is arranged on, for example, a sleeper,
The inspection reflector enables information to be provided to the vehicle. The information to be provided includes, for example, "speed limit",
In addition to fixed information such as "track slope" and "distance to railroad crossing", if the above-mentioned barcode shape can be made variable, variable information such as "forward signal indication" and "point opening direction" can be used. Can also be displayed. If the stop position information is displayed, it can be used for fixed point stop control.

Incidentally, the identification of the inspection reflector and the reading of the information are not limited to the method based on the image as in the present embodiment, but can also be performed by the azimuth / distance information as described above. Needless to say, the arrangement position of the inspection reflector is not limited to the traveling path. Further, information may be displayed by a combination of a plurality of inspection reflectors.

[0076]

As described above, according to the first and second aspects of the present invention, a two-dimensional scanning optical radar sensor capable of two-dimensionally scanning a scanning beam and monitoring an object in a three-dimensional space is provided. Since the object monitoring can be performed while confirming the condition, the degree of freedom in mounting the optical radar sensor on an automatic guided vehicle or the like can be increased.

According to the third and fourth aspects of the present invention, in addition to the above-described effects, the normal operation of the light beam scanning means, such as a galvanometer mirror, which performs scanning in each direction of the scanning beam independently, is used. Confirmation can be assured. According to the invention of claim 5, the reliability of the function for confirming the normal operation can be enhanced. According to the invention of claim 6, since the position of the inspection reflector is determined not only by the azimuth but also by the distance from the sensor, it is possible to identify the inspection reflector and the object even when the object overlaps. In addition, the reliability of the object monitoring function can be improved.

According to the invention of claim 7, when there are a plurality of monitoring areas in the scanning area, it is not necessary to arrange the inspection reflector for each monitoring area. According to the ninth aspect of the present invention,
It is preferable that the monitoring area has a spherical shape, for example. According to the tenth and eleventh aspects, the moving body can move while confirming that the scanning beam is radiated to the area to be monitored.

According to the twelfth aspect of the present invention, the reliability of the object monitoring function when the moving object is mounted can be improved. Claims 13 and 1
According to the fourth aspect, since it is easy to distinguish the reflected light from the inspection reflector and the reflected light from the object, the reliability of the normal operation checking function and the object monitoring function can be further improved.

According to the fifteenth aspect, the reflector for inspection can be used not only for confirming normal operation but also for transmitting information.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a two-dimensional scanning optical radar sensor according to the present invention.

FIG. 2 is a main part configuration diagram of a semiconductor galvanometer mirror applied to the embodiment;

FIG. 3 is a configuration diagram of a normal operation check unit.

FIG. 4 is an explanatory diagram of a scanning beam direction.

FIG. 5 is an explanatory diagram of an arrangement principle of a reflector for inspection of a two-dimensional scanning optical radar sensor.

FIG. 6 is a time chart for explaining the operation of the normal operation check means of the first embodiment;

FIG. 7 is a diagram showing a setting example of a monitoring area;

FIG. 8 is a configuration diagram of a main part of a normal operation checking unit having a distance measuring function according to a second embodiment of the present invention;

FIG. 9 is a time chart for explaining the operation of the normal operation check means of the second embodiment.

FIG. 10 is a diagram showing another arrangement example of the inspection reflector;

FIG. 11 is a diagram showing another example of the arrangement of the reflector for inspection.

FIG. 12 is a view showing another arrangement example of the inspection reflector;

FIG. 13 is a diagram showing another example of the arrangement of the reflector for inspection.

14A and 14B show a configuration example of an inspection reflector when a moving body is mounted, where FIG. 14A is a top view and FIG.

15 is a diagram showing a change state of a moving body traveling direction screen detected by the sensor of FIG. 14;

16A and 16B show another configuration example of the inspection reflector when the moving body is mounted, where FIG. 16A is a top view and FIG. 16B is a side view.

17 is a diagram showing a change state of a moving body traveling direction screen detected by the sensor of FIG. 16;

FIG. 18 is an explanatory diagram excluding the position of an inspection reflector in a monitoring area when a distance measuring function is not provided, (A) is a top view,
(B) is a side view

FIGS. 19A and 19B are explanatory diagrams excluding a position of a reflector for inspection in a monitoring area when a distance measuring function is provided, and FIG.
(B) is a side view

FIG. 20 is a diagram illustrating a configuration example of an inspection reflector configured to modulate the light intensity frequency of a scanning beam.

FIG. 21 is a diagram illustrating a configuration example of an inspection reflector configured to modulate the wavelength of a scanning beam;

22A and 22B are diagrams illustrating a configuration example of an inspection reflector provided with an information display function, where FIG. 22A is a top view and FIG.

FIG. 23 is a diagram showing a change state of a moving body traveling direction screen detected by the sensor of FIG. 22;

FIG. 24 is a diagram for explaining a problem when a method for confirming normal operation of a one-dimensional scanning optical radar sensor is applied to a two-dimensional scanning optical radar sensor.

[Explanation of symbols]

Reference Signs List 11 light emitting element 12 light emitting element driving circuit 13 scanning mirror 14 first driving circuit 15 second driving circuit 16 light receiving element 17 light receiving circuit 18 non-existence determining means 19 normal operation checking means 20 AND gates m1 to m4 inspection reflectors EaU, EbU , EaL, EbL Inspection reflector a1U-a4U, a1L-a4U, b1U-b4U, b
1L to b4L Reflectors for inspection a, b, c Reflectors for inspection 200, 210, 220 Reflectors for inspection, A scanning area B monitoring area

Claims (15)

[Claims] 1. A light beam generating means, a light beam scanning means capable of two-dimensionally scanning a light beam from the light beam generating means including a monitoring area of an object, and a scanning radiated from the light beam scanning means Light receiving means for receiving light reflected from a beam scanning space; at least absence determining means for determining absence of an object in the monitoring area based on at least an output of the light receiving means; at least the light beam generating means and light beam scanning means And normal operation checking means for checking the normal operation of the light receiving means, and gate means for outputting safety information based on the logical product of the output of the absence determining means and the output of the normal operation checking means. A two-dimensional scanning optical radar sensor, characterized in that: 2. The apparatus according to claim 1, wherein said normal operation checking means checks a normal operation based on a light receiving output of said light receiving means by a reflected light from an inspection reflector arranged in a scanning area of said scanning beam. Item 2. A two-dimensional scanning optical radar sensor according to item 1. 3. The inspection reflector according to claim 1, wherein a correspondence between scanning beam radiation information obtained from a sensor operating state and a light receiving output result of said light receiving means is different between an assumed abnormal operation and a normal operation. The two-dimensional scanning optical radar sensor according to claim 2, wherein the two-dimensional scanning optical radar sensor is disposed at a position other than the above. 4. A normal operation confirming means for confirming a normal operation based on a light receiving output result of said light receiving means when said scanning beam information is information indicating said inspection reflector position. Item 4. A two-dimensional scanning optical radar sensor according to item 3. 5. The normal operation confirming means includes: a light receiving output result of the light receiving means when the scanning beam information is information indicating the inspection reflector position; and the scanning beam information indicating the inspection reflector position. 4. The two-dimensional scanning optical radar sensor according to claim 3, wherein a normal operation is confirmed based on a light receiving output result of the light receiving unit when the information indicates information other than the above. 6. The two-dimensional scanning according to claim 4, wherein the information indicating the position of the reflector for inspection includes the direction of existence of the reflector for inspection as viewed from the sensor and the distance from the sensor to the reflector for inspection. Type optical radar sensor. 7. The two-dimensional scanning optical radar sensor according to claim 2, wherein the reflector for inspection is arranged near a corner of the scanning area. 8. The monitoring reflector according to claim 2, wherein the inspection reflector is arranged outside the monitoring area and near a corner of the monitoring area.
7. The two-dimensional scanning optical radar sensor according to any one of 6. 9. The inspection reflector according to claim 2, wherein the inspection reflector is arranged near an azimuth indicated by a maximum vertical angle and a maximum left and right angle of the scanning beam with respect to the outer edge of the monitoring area. 2D scanning optical radar sensor. 10. In a case where a two-dimensional scanning optical radar sensor is mounted on a moving body, when the moving body moves within a predetermined range, at least one inspection reflector is placed in the monitoring area. The two-dimensional scanning optical radar sensor according to any one of claims 2 to 6, wherein the two-dimensional scanning optical radar sensor is arranged so as to exist. 11. The two-dimensional scanning optical radar sensor according to claim 10, wherein the inspection reflector is arranged so as to be continuously present along the moving direction of the moving body. 12. The apparatus according to claim 1, wherein said absence determining means determines the presence or absence of an object by excluding a light receiving output of said inspection reflector within said monitoring area from a light receiving output of said light receiving means. Item 12. A two-dimensional scanning optical radar sensor according to item 10 or 11. 13. The inspection reflector for modulating the light intensity frequency of an incident scanning beam.
A two-dimensional scanning optical radar sensor according to any one of the above. 14. The two-dimensional scanning optical radar sensor according to claim 2, wherein the inspection reflector is configured to modulate a wavelength of an incident scanning beam. 15. A two-dimensional scanning optical radar sensor according to claim 2, wherein said reflector for inspection is used for information display means.