JP2020148617A - Object detector - Google Patents

Abstract

To provide an object detector with which it is possible to suppress the occurrence of a non-detectable area in an object detection range.SOLUTION: An optical scan unit of the object detector scans measurement light emitted by a light emitting unit in a prescribed range while reflecting it at reflection planes on the surface and reverse side of a rotating mirror, and guides reflected light from an object to a light receiving unit while reflecting it at each reflection plane. A plurality of photodiodes PD1 to PD16 provided in a photodiode (PD) array 21 of the light receiving unit are arrayed in a vertical direction Y so as to correspond to the incidence direction of reflected light. When measurement light or reflected light reflects on each reflection plane, a control unit of the object detector selects a prescribed photodiode from among the plurality of photodiodes PD1 to PD16 in accordance with the direction of each reflection plane of the mirror relative to a reference scan plane to which the scan direction of measurement light or reflected light belongs so as not to cause an object non-detectable area to occur, and enables the selected photodiode so as to receive reflected light and output a received light signal.SELECTED DRAWING: Figure 10

Description

The present invention relates to an object detection device that detects an object by projecting measurement light from a light emitting unit and receiving the reflected light from the object by the light receiving unit.

For example, a vehicle having a collision prevention function is equipped with an object detection device such as a laser radar. This object detection device detects other vehicles, people, roads, and other objects existing in the vicinity of the vehicle as an object, and detects the distance to the object (Patent Documents 1 to 5). reference).

The object detection device of Patent Documents 1 to 5 includes a light emitting unit, a light receiving unit, an object detection unit, a control unit for controlling these, and the like. A light emitting element such as a laser diode is provided in the light emitting unit. A light receiving element such as a photodiode or an avalanche photodiode is provided in the light receiving portion. In order to widen the detection range of the object, a plurality of light emitting elements may be provided in the light emitting unit, or a plurality of light receiving elements may be provided in the light receiving unit.

In addition, the object detection devices of Patent Documents 1 to 4 also include an optical scanning unit. By rotating the mirror, the optical scanning unit emits light from the light emitting element and reflects the measurement light emitted from the light emitting unit on the reflecting surface of the mirror to scan it within a predetermined detection range, or the detection range of the measurement light. The reflected light from the object in the mirror is reflected by the reflecting surface of the mirror and scanned so as to be guided to the light receiving portion. The direction in which the optical scanning unit scans light and the reference scanning surface to which the direction belongs are perpendicular to the rotation axis of the mirror. In order to widen the detection range of the object, the mirror of the optical scanning unit is provided with a plurality of reflecting surfaces. Further, each reflecting surface may be provided at the same angle with respect to the rotation axis of the mirror (Patent Documents 1 to 3), or may be provided at a different angle (Patent Document 4).

The light receiving element of the light receiving unit outputs a light receiving signal according to the light receiving state of the reflected light. The object detection unit detects an object or detects the distance to the object based on the light receiving signal output from the light receiving element.

When the measurement light is projected from the object detection device into a predetermined detection range, the reflected light from the object is incident on the object detection device from the direction opposite to the projection direction of the measurement light. In consideration of this, the plurality of light receiving elements are arranged in a predetermined direction so as to correspond to the incident direction of the reflected light (Patent Documents 4 and 5). Therefore, the reflected light of the measurement light projected by the light emitting unit by the object is received by the light receiving element corresponding to the incident direction, and the object detecting unit picks up the object based on the light receiving signal output from the light receiving element. To detect.

In addition, the detection range is divided by switching the light emitting element or the light receiving element to be operated, or by changing the angle of each reflecting surface of the mirror of the optical scanning unit, and the object is detected for each divided area. There is also a detector.

JP-A-2018-115995 JP-A-2017-15404 JP-A-2017-227569 Japanese Unexamined Patent Publication No. 2014-71029 Japanese Unexamined Patent Publication No. 2014-209878

In the object detection device as described above, the relative angle of each reflecting surface of the mirror may deviate from the design angle due to the shape error of the mirror of the optical scanning unit. Further, the angle of the rotation axis of the mirror may deviate from the design angle due to an assembly error of the optical scanning unit. In these cases, the direction of the reflection surface of the mirror deviates from the design orientation, and the direction of projection of the measurement light reflected by the reflection surface, the direction of incidence of the reflected light from the object, or after being reflected by the reflection surface. The traveling direction of the reflected light deviates from each design direction.

When the object is detected by reflecting the measurement light or the reflected light on each reflecting surface in such a state of deviation, the region where the object is detected by reflecting the light on one reflecting surface and the reflection of the other. There may be a non-detection area where the object cannot be detected between the area where the object is detected by reflecting light on the surface. If this non-detection region occurs in the central portion of the detection range of the object, it is not possible to accurately detect an obstacle or the like in front of the vehicle, and the performance of the object detection device is greatly impaired.

An object of the present invention is to provide an object detection device capable of suppressing the occurrence of a non-detection region in the detection range of an object.

In the object detection device according to the present invention, the light emitting element emits light and projects from the light emitting unit by rotating a light emitting unit having a light emitting element, a light receiving unit having a light receiving element, and a mirror provided with a plurality of reflecting surfaces. The measured light is reflected by each reflecting surface and scanned into a predetermined detection range, or the reflected light of an object within the detection range of the measurement light is reflected by each reflecting surface and guided to the light receiving portion. An optical scanning unit to scan, an object detection unit that detects an object based on a light receiving signal output by the light receiving element according to the light receiving state of the reflected light, a light emitting unit, a light receiving unit, an optical scanning unit, and an object detecting unit. It is provided with a control unit that controls the operation of. A plurality of light receiving elements are provided, and these plurality of light receiving elements are arranged in a predetermined direction so as to correspond to the incident direction of the reflected light. The control unit sets a predetermined light receiving element among the plurality of light receiving elements according to the orientation of each reflecting surface with respect to the reference scanning surface to which the scanning direction of the measurement light or the reflected light belongs so that an undetected region of the object does not occur. It is selected, and when the measured light or the reflected light is reflected by each reflecting surface, the selected light receiving element is enabled to receive the reflected light and output the received light signal.

According to the above, when the measurement light or the reflected light is reflected by each reflecting surface provided in the mirror of the optical scanning unit, a light receiving element that does not generate an undetected region of the object according to the direction of each reflecting surface is effective. Then, the object detection unit detects the object based on the light receiving signal output from the effective light receiving element. Therefore, the measurement light or the reflected light is reflected by each reflecting surface, and the reflected light is received by a light receiving element effective for each reflecting surface, so that the object is between the detection regions for detecting the object. It is possible to suppress the occurrence of an undetected region in which the light cannot be detected.

In the present invention, when the first reflecting surface is tilted to one side of the second reflecting surface with respect to the reference scanning surface among the plurality of reflecting surfaces, the control unit uses the measurement light on the first reflecting surface or When the reflected light is reflected, the first light receiving element corresponding to the first incident direction of the reflected light is enabled among the plurality of light receiving elements, and the object detection unit determines the light receiving signal output from the first light receiving element. Detect an object. Further, when the measurement light or the reflected light is reflected on the second reflecting surface, the second light receiving element corresponding to the second incident direction inclined to one side of the first incident direction of the reflected light among the plurality of light receiving elements is effective. Then, the object is detected by the object detection unit based on the light receiving signal output from the second light receiving element.

Further, in the present invention, a plurality of the first light receiving element and the second light receiving element are provided to form a first light receiving element group and a second light receiving element group, and the first light receiving element group and the second light receiving element are provided. Adjacent to the group, one detection area where the object detection unit detects an object based on the reflected light received by the first light receiving element group, and the object based on the reflected light received by the second light receiving element group. The other detection area in which the detection unit detects the object may partially overlap.

Further, in the present invention, the control unit expands the detection range to a plurality of detection regions by switching a light receiving element that receives the reflected light and outputs a light receiving signal when the measured light or the reflected light is reflected on each reflecting surface. It may be divided and the result of the object detection unit detecting the object may be synthesized for each detection area.

Further, in the present invention, the control unit may determine the orientation of each reflection surface based on the angle of each reflection surface with respect to the reference scanning surface that has been measured in advance and stored in the storage unit.

Further, in the present invention, the object detection unit detects the direction of the object or the distance to the object based on the received signal, and determines the angle of each reflecting surface with respect to the reference scanning surface that has been measured in advance and stored in the storage unit. Based on this, a correction unit that corrects the detection result of the object detection unit may be further provided.

Further, in the present invention, the first incident direction and the second incident direction are the incident angles of the reflected light with respect to the vertical direction, the scanning direction is the horizontal direction intersecting the vertical direction, and the first light receiving element is: The second light receiving element is provided so as to correspond to the first incident direction tilted downward from the second incident direction with respect to the reference scanning surface, and the second light receiving element is tilted upward from the first incident direction with respect to the reference scanning surface. It may be provided so as to correspond to the second incident direction. Then, when the first reflecting surface is tilted downward from the second reflecting surface, the control unit receives the reflected light incident from the first incident direction when the measurement light or the reflected light is reflected by the first reflecting surface. 1 The light receiving element may receive light, and when the measurement light or the reflected light is reflected by the second reflecting surface, the reflected light incident from the second incident direction may be received by the second light receiving element.

Further, in the present invention, one of the first light receiving element and the second light receiving element receives the reflected light incident in the horizontal direction, and the other light receiving element is incident obliquely above or diagonally below the horizontal direction. The reflected light may be received.

According to the present invention, it is possible to provide an object detection device capable of suppressing the occurrence of a non-detection region in the detection range of an object.

It is an electric block diagram of the object detection apparatus by embodiment of this invention. It is a front view of the vehicle equipped with the object detection device of FIG. It is a figure which looked at the optical system of the object detection apparatus of FIG. 1 from the rear. It is a figure which looked at the light projection optical system of FIG. 3 from above. FIG. 3 is a view of the light receiving optical system of FIG. 3 as viewed from above. It is a figure which showed the LD module and PD array of FIG. It is a figure which showed the light-receiving principle of the object detection device of FIG. It is a figure explaining the conventional problem. It is a figure explaining the conventional problem. It is a figure explaining the conventional problem. It is a figure which showed an example of the conventional detection field of view. It is a figure which showed an example of the conventional detection range. It is a figure which showed an example of the detection field of view by this invention. It is a figure which showed an example of the detection range by this invention. It is a figure which showed the other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same parts or corresponding parts are designated by the same reference numerals.

FIG. 1 is an electrical configuration diagram of the object detection device 100 of the embodiment. FIG. 2 is a front view of the vehicle 30 on which the object detection device 100 is mounted.

The object detection device 100 includes an in-vehicle laser radar. As shown in FIG. 2, the object detection device 100 is installed at the front of the vehicle 30 made of a four-wheeled vehicle. The object detection device 100 transmits and receives light to a predetermined detection range in front of the vehicle 30 to detect an object in the detection range. The object is another vehicle, person, road, or other object within the detection range.

As another example, the object detection device 100 is installed at the rear portion or the left and right side portions of the vehicle 30, and emits and receives light to a predetermined detection range located behind or on the left and right sides of the vehicle 30 to project and receive light on the object. May be detected.

As shown in FIG. 1, the object detection device 100 includes a light emitting unit 1, a light receiving unit 2, an optical scanning unit 3, an encoder 4, a signal processing unit 5, a control unit 6, a storage unit 7, and an interface 8. ing.

The light emitting unit 1 includes an LD module 11 and an LD drive circuit 12. The LD module 11 is composed of a plurality of LDs (laser diodes). The LD drive circuit 12 supplies a drive current to each LD of the LD module 11 to make each LD emit light. Each LD emits measurement light (laser light) by emitting light. The light emitting unit 1 causes each LD to emit light by the LD drive circuit 12, and projects the measurement light. The LD is an example of the "light emitting device" of the present invention.

The light receiving unit 2 includes a PD array 21. The PD array 21 is composed of a plurality of PDs (photodiodes). Each PD receives light and outputs a light receiving signal (electrical signal) according to the light receiving state. The light receiving unit 2 receives the reflected light of the measurement light projected from the light emitting unit 1 by the object by each PD of the PD array 21 and outputs a light receiving signal. PD is an example of the "light receiving element" of the present invention.

The optical scanning unit 3 includes a motor 3f and a motor drive circuit 3m. The motor 3f is an actuator for rotating a mirror 3a (FIG. 3 or the like) described later. The motor drive circuit 3m drives the motor 3f. The optical scanning unit 3 scans the measurement light and the reflected light by driving the motor 3f by the motor drive circuit 3m and rotating the mirror 3a.

The encoder 4 outputs a pulse signal according to the driving state of the motor 3f. The control unit 6 detects the driving state of the motor 3f, the rotation angle of the mirror 3a, and the like based on the pulse signal output from the encoder 4.

The signal processing unit 5 includes a TIA (transimpedance amplifier) 5a, a MUX (multiplexer) 5b, a VGA (variable gain amplifier) 5c, an ADC (analog-digital converter) 5d, and the like. A plurality of TIA5a are provided so as to correspond to a plurality of PDs. One or more MUX5b, VGA5c, and ADC5d are provided.

Each TIA5a converts the current (light receiving signal) flowing through the corresponding PD according to the light receiving state into a voltage signal. The MUX5b selects the voltage signal output from each TIA5a. The VGA 5c amplifies the voltage signal selected by the MUX 5b. The ADC 5d converts the analog voltage signal amplified by the VGA 5c into a digital signal at high speed. In this way, the signal processing unit 5 processes the light receiving signal corresponding to the light receiving state of each PD of the PD array 21 by the respective units 5a to 5d, and outputs the signal to the control unit 6.

The control unit 6 is composed of a CPU and a memory, and controls the operation of each unit of the object detection device 100. The control unit 6 includes an object detection unit 6a and a correction unit 6b. Each function of the object detection unit 6a and the correction unit 6b is realized by a software program executed by the CPU of the control unit 6.

The object detection unit 6a detects the presence / absence of the object, the direction of the object, and the distance to the object based on the output signal from the signal processing unit 5. Specifically, the object detection unit 6a projects the measurement light based on the light emission state of each LD of the light emitting unit 1, the rotation angle of the mirror 4a of the light scanning unit 3, and the light receiving state of each PD of the light receiving unit 2. The direction and the incident direction of the reflected light are detected. Then, the object detection unit 6a compares the level of the received light signal output from each PD via the signal processing unit 5 with a predetermined threshold value, and if the level of the received light signal is less than the threshold value, there is no object. Judge.

Further, the object detection unit 6a determines that there is an object if the level of the received light signal is equal to or higher than the threshold value, and the direction of the object is based on the incident direction of the reflected light received by the PD that outputs the received signal. To judge. Further, the object detection unit 6a detects the peak value of the light receiving signal whose level is equal to or higher than the threshold value, and detects the light receiving time of the reflected light by the object based on the peak value. Then, the object detection unit 6a calculates the distance to the object based on the reception time of the reflected light and the projection time of the measurement light from the LD module 11 (TOF (Time of Flight) method).

The storage unit 7 is composed of a memory or the like. The storage unit 7 stores data and information for the control unit 6 to control each unit of the object detection device 100, data and information for detecting the object, and the like. As an example of data for detecting an object, the angle of each reflecting surface of the mirror 3a of the optical scanning unit 3 measured in advance is stored in the storage unit 7. The control unit 6 reads and writes data and information to and from the storage unit 7. The correction unit 6b of the control unit 6 corrects the detection result of the object detected by the object detection unit 6a based on the angle of each reflecting surface of the mirror 3a stored in the storage unit 7.

The interface 8 includes a communication circuit for communicating with a vehicle-side ECU (electronic control unit) mounted on the vehicle 30 (not shown). The control unit 6 transmits and receives various control information to the vehicle-side ECU and outputs the detection result of the object via the interface 8.

FIG. 3 is a view of the optical system of the object detection device 100 as viewed from the rear (opposite side of the object 50 in FIG. 4A). FIG. 4A is a view of the projection optical system of FIG. 3 as viewed from above (upper side in FIG. 3). FIG. 4B is a view of the light receiving optical system of FIG. 3 as viewed from above. The orientation of the mirror 3a is different between FIG. 3 and FIG. 4A. In FIGS. 4A and 4B, the orientations of the mirrors 3a are the same. FIG. 5 is a diagram showing the LD module 11 and the PD array 21.

As shown in FIG. 3, the optical system of the object detection device 100 includes an LD module 11, a light projecting lens 13, a mirror 3a of the light scanning unit 3, a transmission cover 18, a light receiving lens 23, a reflecting mirror 22, and a PD array 21. It is composed of. Of these, the LD module 11, the light projecting lens 13, the mirror 3a, and the transmission cover 18 are light projecting optical systems. Further, the transmission cover 18, the mirror 3a, the light receiving lens 23, the reflecting mirror 22, and the PD array 21 are light receiving optical systems.

As shown in FIGS. 3 to 4B, these optical systems are housed in the housing 19 of the object detection device 100. The housing 19 is provided with a window 19a that opens toward the object 50 side. A transparent cover 18 is fitted so as to close the window 19a. The transmissive cover 18 is made of a translucent plate material. The object detection device 100 is installed in the front part of the vehicle 30 so that the transmission cover 18 faces the front of the vehicle 30.

As shown in FIG. 5, the LD module 11 is provided with _four LDs ₁ to LD ₄ . These LDs ₁ to LD ₄ are vertical so as to correspond to each projection angle of the measurement light with respect to the vertical direction Y and the reference scanning surfaces Sb and Sc (FIGS. 7A to 7C) described later, that is, each projection direction of the measurement light. They are arranged in the direction Y. Then, LDs _{1 to} LD ₄ project measurement light in directions at different angles with respect to the vertical direction Y and the reference scanning surfaces Sb and Sc.

The PD array 21 is provided with ₁₆ PDs _{1 to 16} . These PDs ₁ to PD ₁₆ are arranged in the vertical direction Y so as to correspond to each incident angle of the reflected light from the object 50 with respect to the vertical direction Y and the reference scanning surfaces Sb and Sc, that is, each incident direction of the reflected light. Has been done. PDs _{1 to} PD ₁₆ correspond to each of LDs _{1 to} LD 4 by _four . Specifically, PD _{1 to} PD ₄ correspond to LD ₁ , PD ₅ to PD ₈ correspond to LD ₂ , PD ₉ to PD ₁₂ correspond to LD ₃ , and PD ₁₃ to PD ₁₆ correspond to LD _4. ing. PDs _{1 to 16} receive reflected light incident on the vertical direction Y and the reference scanning surfaces Sb and Sc from different angles.

In FIG. 3 and the like, the floodlight lens 13 is composed of a collimator lens. The floodlight lens 13 is arranged between the LD module 11 and the mirror 3a. The light receiving lens 23 is composed of a condensing lens. As shown in FIG. 4B, the reflecting mirror 22 is arranged so as to be tilted at a predetermined angle with respect to the light receiving lens 23 and the PD array 21.

The mirror 3a of the optical scanning unit 3 is formed in a plate shape. Reflective surfaces 3b and 3c are provided on both plate surfaces (front surface and back surface) of the mirror 3a. In FIG. 3, the upper half of each reflection surface 3b and 3c is a light projection reflection region, and the lower half is a light reception reflection region.

A motor 3f is provided below the mirror 3a. A mirror 3a is fixed to the upper end of the rotation shaft 3j of the motor 3f. The mirror 3a rotates in conjunction with the rotation shaft 3j of the motor 3f. The alternate long and short dash line Q passing through the center of the mirror 3a is the axis of rotation of the mirror 3a. The rotation axis Q and the rotation axis 3j of the motor 3f are on the same straight line and are parallel to the vertical direction Y. The reflecting surfaces 3b and 3c of the mirror 3a are designed to be parallel to the rotation axis Q.

A floodlight lens 13, an LD module 11, a light receiving lens 23, a reflector 22, and a PD array 21 are arranged on one side of the mirror 3a (one side in the left-right direction X). The floodlight lens 13 and the LD module 11 are arranged at positions equivalent to the upper half of the mirror 3a. Each of the LDs _{1 to} LD ₄ (FIG. 5) of the LD module 11 is arranged so that its light emitting surface faces the mirror 3a.

The light receiving lens 23, the reflecting mirror 22, and the PD array 21 are arranged at the same height as the lower half of the mirror 3a. Each of PDs _{1 to 16} (FIG. 5) of the PD array 21 is arranged so that its light receiving surface faces the reflector 22 side.

As the mirror 3a rotates about the rotation axis Q, the upper halves of the reflecting surfaces 3b and 3c face the projection lens 13 and the LD module 11 (FIGS. 3 and 4A). Further, the lower halves of the reflecting surfaces 3b and 3c face the light receiving lens 23, the reflecting mirror 22, and the PD array 21 (FIGS. 3 and 4B).

As shown in FIG. 3, the inside of the housing 19 is vertically partitioned by a light-shielding plate 17. The LD module 11, the light projecting lens 13, and the upper half of the mirror 3a are arranged in the light projecting space above the light shielding plate 17. A PD array 21, a reflecting mirror 22, a light receiving lens 23, and a lower half of the mirror 3a are arranged in a light receiving space below the light shielding plate 17.

The light emitting / receiving path when detecting the object 50 is as shown by the arrows of the one-dot chain line and the two-dot chain line in FIGS. 3 to 4B. The mirror 3a shown in FIG. 3 shows a state in which the long side of the mirror 3a in FIGS. 4A and 4B is perpendicular to the left-right direction X so that its shape is most easily understood. In the state of the mirror 3a of FIG. 3, the measurement light and the reflected light cannot actually be projected and received on the object 50. In the state of the mirror 3a shown in FIGS. 4A and 4B, the measurement light and the reflected light can actually be projected and received on the object 50.

As shown by the arrow of the one-point chain line in FIGS. 3 and 4A, the measurement light projected from each of the LDs _{1 to} LD ₄ (FIG. 5) of the LD module 11 is converted into parallel light in a predetermined direction by the projection lens 13. It is converted and incident on any of the reflecting surfaces 3b and 3c of the mirror 3a. At this time, by driving the motor 3f, the mirror 3a rotates about the rotation axis Q, so that any of the reflecting surfaces 3b and 3c has a predetermined angle facing the object 50 side (for example, FIGS. 4A and 4B). The state of the mirror 3a shown in (1). As a result, the measurement light is reflected in the light projection reflection region of the upper half of any of the reflection surfaces 3b and 3c, passes through the transmission cover 18, and reaches a predetermined detection range Z (hatched portion) outside the housing 19. It is flooded. Further, the rotation of the mirror 3a changes the directions of the reflecting surfaces 3b and 3c, so that the measurement light is scanned in the left-right direction X intersecting the vertical direction Y.

The measurement light projected on the detection range Z as described above is reflected by the object 50 in the detection range Z. The reflected light travels toward the object detection device 100, passes through the transmission cover 18, and transmits the reflected light to any of the reflecting surfaces 3b of the mirror 3a, as shown by the two-dot chain arrow in FIGS. 4A and 4B. It is incident on 3c (Fig. 4B).

At that time, by driving the motor 3f, the mirror 3a rotates about the rotation axis Q, so that any of the reflecting surfaces 3b and 3c has a predetermined angle facing the object 50 side (for example, FIGS. 4A and 4B). The state of the mirror 3a shown in (1). As a result, the reflected light from the object 50 is reflected by the lower half of any of the reflecting surfaces 3b and 3c and is incident on the light receiving lens 23 (see also FIG. 3). Then, the reflected light is collected by the light receiving lens 23, then reflected by the reflecting mirror 22, and received by each of PDs _{1 to 16} of the PD array 21. That is, the mirror 3a scans the reflected light from the object 50 in the left-right direction X by the reflecting surfaces 3b and 3c, and guides the reflected light to the PD array 21 via the light receiving lens 23 and the reflecting mirror 22.

FIG. 6 is a diagram showing the light emitting / receiving principle of the object detection device 100. FIG. 6A schematically shows a state in which the LD module 11, the light projecting lens 13, and the mirror 3a of the optical scanning unit 3 are viewed from the side. FIG. 6B schematically shows a state in which the PD array 21, the light receiving lens 23, and the mirror 3a of the optical scanning unit 3 are viewed from the side.

Further, in FIG. 6A, the measurement lights projected from LDs ₁ to LD ₄ of the LD module 11 are indicated by arrows L _{1 to} L ₄ of the alternate long and short dash line. The alternate long and short dash line represents the optical axis of each measurement light. Also shown in FIG. 6 (b) in the light reflected by the object 50 of measurement light _L 1 ~L _4, arrows _{L 1} of the two-dot chain line '~L _4'. The alternate long and short dash line represents the optical axis of each reflected light.

As shown by the arrow of the one-point chain line in FIG. 6A, the measurement lights L _{1 to} L ₄ emitted from each of the LDs _{1 to} LD ₄ of the LD module 11 pass through the floodlight lens 13 and perform optical scanning. It is incident on any of the reflecting surfaces 3b and 3c of the mirror 3a of the part 3. Then, the measurement lights L _{1 to} L ₄ are reflected by any of the reflecting surfaces 3b and 3c and projected onto the detection range Z.

The LD provided at a position lower than the vertical direction Y projects the measurement light emitted from the LD to a position higher in the detection range Z (see FIG. 5).

Specifically, in FIG. 6A, the measurement light L ₁ emitted from the LD ₁ provided at the bottom of the LD module 11 and the measurement light L emitted from the LD ₂ provided second from the bottom. A part of L ₂ is projected in a predetermined angle diagonally upward with respect to the horizontal direction H (the direction in which the vertical angle in FIG. 5 is 0 °). Projection angle with respect to the horizontal direction H of the measurement light L ₂ from the LD ₂ is set to be smaller than the projection angle with respect to the horizontal direction H of the measurement light L ₁ from the LD _1. The other part of the measurement light _{L 2} from the LD _2, is projected in a horizontal direction H (see FIG. 5).

Further, the measurement light L ₄ emitted from the LD ₄ provided at the top of the LD module 11 and the measurement light L ₃ emitted from the LD ₃ provided second from the top are in the horizontal direction H. It is projected diagonally downward at a predetermined angle. Projecting with respect to the horizontal direction H of the measurement light L ₃ from the LD ₃ angle is set to be smaller than the projection angle with respect to the horizontal direction H of the measurement light L ₄ from the LD _4.

The measurement light _L 1 ~L ₄ projected into the detection range Z as described above, when it is reflected by the object 50 in the detection range Z, the reflected light _{L 1} '~L _4' measurement light _L 1 ~ the opposite direction to the projection direction of L _4, enters the transparent cover 18 (FIG. 4A, etc.). Then, the reflected light _{L 1} '~L _4', as shown by an arrow indicated by the two-dot chain line in FIG. 6 (b), one of the reflecting surface 3b, enters the 3c. Further, the reflected light _{L 1} '~L _4' is one of the reflecting surface 3b, and is reflected by 3c, it is received by _PD 1 _{-PD 16} of PD array 21.

PD ₁ -PD ₁₆ so as to correspond to the incident direction of the reflected light _{L 1} '~L _4', are arranged in the vertical direction Y. The PD provided at a position lower than the vertical direction Y corresponds to the incident direction of the reflected light incident from the position where the detection range Z is higher.

Specifically, the sequence in FIG. 6 (b), so as to correspond to the incident direction of the reflected light _{L 1} 'incident from obliquely with respect to the horizontal direction _H, PD 1 -PD ₄ at the bottom of the PD array 21 Has been done. Reflected light L _{1 'is} a light reflected by the object 50 of measurement light L _1. Also, so as to correspond to the incident direction of the _'part of the reflected light L ₂ incident from an obliquely upward at a smaller incident _angle' reflected light L ₁ with respect to the horizontal direction H, PD ₅ and PD ₆ are arranged .. Further, PD ₇ and PD ₈ are arranged so as to correspond to the incident direction of some other reflected light L ₂ ′ incident from the horizontal direction H. Reflected light L _{2 'is} the light reflected by the object 50 of measurement light L _2. PDs _{5 to 8} are adjacent to PDs _{1 to 4} above.

Also, so as to correspond to the incident direction of the reflected light L _{3 'incident} obliquely from below with respect to the horizontal direction H, PD ₉ ~PD ₁₂ are arranged. Reflected light L _{3 'is} a light reflected by the object 50 of measurement light L _3. PDs _{9 to 12} are adjacent to PDs _{5 to 8} above. Furthermore, so as to correspond to the incident direction of the _'reflected light L ₄ incident obliquely from below in greater incident _angle' reflected light L ₃ with respect to the horizontal direction H, PD ₁₃ ~PD ₁₆ are arranged. Reflected light L _{4 'is} the light reflected by the object 50 of measurement light L _4. PDs _{13 to 16} are adjacent to PDs ₉ to PD ₁₂ .

That is, the PD array 21, the reflected light _{L 1} entering from above the horizontal H ', _{L 2'} so as to correspond to the incident direction of, one of the PD group _PD 1 -PD ₈ is provided horizontally It reflected light _{L 3} incident from below H ', _{L 4'} so as to correspond to the incident direction of the is provided with the other of PD group _PD 9 _{-PD 16.}

Control unit 6 in FIG. 1, each reflecting surface 3b of the mirror 3a, upon reflection of the measurement light _L 1 ~L ₄ and the reflected light _{L 1} '~L _4' in 3c, the _LD 1 to Ld ₄ for emitting, receiving By switching PD ₁ to PD ₁₆ to be performed, the detection range Z is divided into a plurality of detection areas. Then, the control unit 6 detects the object 50 by the object detection unit 6a for each detection region, and synthesizes the detection result.

In the object detection device 100, the reflection surface 3b and the reflection surface 3c of the mirror 3a of the optical scanning unit 3 are parallel to each other, and the rotation axis Q of the mirror 3a and the reflection surfaces 3b and 3c are parallel to the vertical direction Y. It is designed to be. That is, the rotation axis with respect to the reference scanning surfaces Sb and Sc (FIGS. 7A to 7C) to which the scanning direction (horizontal direction X in FIGS. 4A and 4B) in which the optical scanning unit 3 scans the measurement light and the reflected light belongs. It is designed so that Q and the reflecting surfaces 3b and 3c are both vertical. Further, the scanning direction X of the optical scanning unit 3 is designed to be a horizontal plane. However, due to manufacturing problems, the orientation of the reflective surfaces 3b and 3c may deviate from the design orientation.

7A to 7C are diagrams for explaining problems that occur in manufacturing in the mirror 3a of the optical scanning unit 3.

Due to the shape error of the mirror 3a at the time of manufacture, the relative angles of the reflecting surfaces 3b and 3c deviate from the design angles, and as shown in FIGS. 7A and 7B, the reflecting surfaces 3b and the reflecting surfaces 3c are not parallel to each other. There is. When the mirror 3a is connected to the rotating shaft 3j of the motor 3f and fixed in the housing 19, at least one of the reflecting surfaces 3b and 3c becomes a reference scanning surface Sb for the measurement light of the optical scanning unit 3. It is not perpendicular to the reference scanning surface Sc for reflected light, and is displaced diagonally upward or diagonally downward. That is, at least one of the reflecting surfaces 3b and 3c is tilted so as to face one side or the other side with respect to the reference scanning surfaces Sb and Sc. (In FIGS. 7A and 7B, the inclinations of the reflecting surfaces 3b and 3c are exaggerated more than they actually are for the sake of clarity.) The reference scanning surfaces Sb and Sc of the optical scanning unit 3 are set to be horizontal planes. It is designed.

In the examples of FIGS. 7A and 7B, one of the reflecting surfaces 3b is slightly inclined downward with respect to the reference scanning surfaces Sb and Sc. Further, in the example of FIG. 7A, the other reflecting surface 3c is perpendicular to the reference scanning surfaces Sb and Sc and parallel to the vertical direction Y. In the example of FIG. 7B, the other reflecting surface 3c is slightly inclined upward with respect to the reference scanning surfaces Sb and Sc. That is, in the examples of FIGS. 7A and 7B, at least one of the reflecting surfaces 3b and 3c is not perpendicular to the reference scanning surfaces Sb and Sc, but is inclined at an angle.

Further, even if there is no shape error in the mirror 3a (the reflecting surface 3b and the reflecting surface 3c are parallel), as shown in FIG. 7C, due to an assembly error of the optical scanning unit 3 and an attachment error to the housing 19. The rotation axis Q of the mirror 3 may be tilted with respect to the rotation axis 3j of the motor 3f, and the rotation axis Q may not be perpendicular to the reference scanning surfaces Sb and Sc. Also in this case, the reflecting surfaces 3b and 3c are not perpendicular to the reference scanning surfaces Sb and Sc, but are inclined at an angle. In the example of FIG. 7C, one of the reflecting surfaces 3b is slightly inclined downward with respect to the reference scanning surfaces Sb and Sc. Further, the other reflecting surface 3c is inclined obliquely upward with respect to the reference scanning surfaces Sb and Sc.

As another example, one reflecting surface 3b may be designed to be inclined with respect to the other reflecting surface 3c. Further, the reflecting surfaces 3b and 3c of the mirror 3a or the rotation axis Q may be set to be tilted at a predetermined angle with respect to the vertical direction Y. Further, the reflecting surfaces 3b and 3c may be designed to face diagonally upward or diagonally downward with respect to the reference scanning surfaces Sb and Sc. Further, the angles of the reflecting surfaces 3b and 3c with respect to the reference scanning surfaces Sb and Sc may be designed to be different. Even in these cases, the orientation of the reflecting surfaces 3b and 3c may deviate from the design orientation due to the shape error of the mirror 3a, the assembly error of the optical scanning unit 3, the mounting error, and the like.

When the reflecting surfaces 3b and 3c are inclined obliquely with respect to the reference scanning surfaces Sb and Sc in this way, the problems shown in FIGS. 8 and 9 occur. FIG. 8 shows the relationship between the conventional PD array 21 and the field of view detected by the reflecting surfaces 3b and 3c. FIG. 9 shows the detection range Z of the conventional object 50. In FIG. 8, the arrangement of PDs _{1 to 16} shown in the field of view detected by the reflecting surfaces 3b and 3c is reversed from that in FIGS. 5 and 6 (b). This is due to the following reasons. The light receiving regions Rb'and Rc'(described later) in FIG. 8 correspond to the detection regions Zb'and Zc' (described later) in FIG. 9, respectively. The detection area Zb'is the area on the lower side of the field of view when the occupant of the vehicle 30 looks ahead, and the detection area Zc'is the area on the upper side of the field of view. Therefore, the light receiving region Rb'(PD _{9 to} PD ₁₆ ) of FIG. 8 is positioned on the lower side in accordance with the detection region Zb' of FIG. 9, and the light receiving region Rc'(PD _{1 to} PD ₈ ) of FIG. By locating it on the upper side according to the detection area Zc'of, the correspondence relationship is made easy to understand. In FIGS. 10 and 12, which will be described later, the arrangement of PDs _{1 to 16} is reversed from that in FIGS. 5 and 6 (b) for the same reason.

As described above, when the orientation of the reflecting surfaces 3b and 3c deviates from the design orientation, the projection direction of the measurement light reflected by the reflection surfaces 3b and 3c and the incident direction of the reflected light also become the design projection direction and the incident direction. It deviates from. For example, as shown in each (a) of FIGS. 7A to 7C, when the measurement light (one-point chain line arrow) or the reflected light (two-point chain line arrow) is reflected by the reflecting surface 3b tilted diagonally downward. , The projection direction of the measurement light and the incident direction of the reflected light are shifted so as to be inclined downward from the design projection direction and the incident direction parallel to the reference scanning surfaces Sb and Sc. Further, as shown in each (b) of FIGS. 7B and 7C, when the measurement light or the reflected light is reflected by the reflecting surface 3c inclined diagonally upward, the projection direction of the measurement light or the incident direction of the reflected light is changed. It shifts so as to tilt upward from the design projection direction and incident direction.

As a result, as shown in FIG. 8, the detection visual field of the object 50 (the region of PD ₁ to PD ₁₆ in FIG. 8A) by reflecting the measurement light or the reflected light on one of the reflecting surfaces 3b, and the other. The detection visual field of the object 50 (the region of PD ₁ to PD ₁₆ in FIG. 8B) due to the reflection of the measured light or the reflected light on the reflecting surface 3c of the above is displaced in the vertical direction Y. In the example of FIG. 8, the detection field of view of the object 50 by the reflection surface 3b downward from the reflection surface 3c (FIG. 8A) is larger than the detection field of view of the object 50 by the reflection surface 3c (FIG. 8B). It is in a state of being displaced downward.

In the conventional object detection device, for example, when the measurement light or the reflected light is reflected by one of the reflecting surfaces 3b, the LD ₃ and LD ₄ are made to emit light, and the lower part of the detection range Z (with respect to the reference scanning surfaces Sb and Sc). When projecting the measurement light (measurement light L ₃ , L _{4 in} FIG. 6 (a)) to the lower side), the reflected light from the lower part of the detection range Z (reflected light L ₃ ', L in FIG. 6 (b)). _The other PD groups PD _{9 to} PD ₁₆ corresponding to the incident direction of ₄ ') were enabled (FIG. 8 (a)). Then, the reflected light incident from the lower part of the detection range Z is received by PDs ₉ to PD ₁₆ , and the object detection unit 6a detects the object 50 based on the light receiving signals output from PDs ₉ to PD ₁₆ . ..

Further, when the measurement light or the reflected light is reflected by the other reflection surface 3c, the LD ₁ and LD ₂ are made to emit light, and the measurement light (upper side with respect to the reference scanning surfaces Sb and Sc) of the detection range Z (FIG. the measurement light _L 1 of 6 (a), _{L 2)} when projecting a, corresponding to the incident direction of the reflected light from the top of the detection range Z reflected light _{L 1} (FIG. _{6 (b) ', L 2} ') , One of the PD groups PD _{1 to} PD ₈ was effective (Fig. 8 (b)). Then, the reflected light incident from the upper part of the detection range Z is received by PDs ₁ to PD ₈ , and the object detection unit 6a detects the object 50 based on the light receiving signals output from PDs ₁ to PD ₈ . ..

Therefore, as shown in FIGS. 7A to 7C, when one reflecting surface 3b is tilted downward from the other reflecting surface 3c, the light received from one reflecting surface 3b is received as shown in FIG. The region Rb'(PD _{9 to} PD ₁₆ ) and the light receiving region Rc'(PD _{1 to} PD ₈ ) of the reflected light from the other reflecting surface 3c are separated from each other. That is, a non-light receiving region Rx that cannot receive the reflected light from the object 50 is generated between the light receiving region Rb'and the light receiving region Rc'.

Then, as shown in FIG. 9A, when the object detection device faces the detection range Z in front of the vehicle, the object detection unit 6a receives the light reception signals from PDs ₉ to PD ₁₆ of the light reception area Rb'. The detection region Zb'that detects the object based on the object occupies almost the lower half of the detection range Z. Further, as shown in FIG. 9B, the detection region Zc'where the object detection unit 6a detects an object based on the light receiving signals from PDs ₁ to PD ₈ of the light receiving region Rc'is approximately the detection range Z. It occupies the upper half.

Therefore, as shown in FIG. 9C, when the detection region Zb'and the detection region Zc'are combined, the detection region Zb'and the detection region Zc' are combined based on the non-light receiving region Rx in FIG. In between, a band-shaped non-detection region Zx in which the object cannot be detected is generated. Further, as shown in FIG. 9C, when the non-detection region Zx occurs in the central portion of the detection range Z, the object exists in the central portion of the detection range Z and hinders the running of the vehicle (not shown). ) Cannot be accurately detected by the object detection unit 6a, and the performance of the object detection device is greatly impaired.

FIG. 10 is a diagram showing an example of a detection field of view according to the present invention. FIG. 11 is a diagram showing an example of the detection range Z according to the present invention.

As shown in FIGS. 7A to 7C, when one reflecting surface 3b is tilted downward from the other reflecting surface 3c, as shown in FIG. 10, the detection field of view of the object 50 by one reflecting surface 3b ( FIG. 10A) shifts downward from the detection field of view (FIG. 10B) of the object 50 by the other reflecting surface 3c.

However, in the object detection device 100 of the present invention, the angles of the reflection surfaces 3b and 3c of the mirror 3a with respect to the reference scanning surfaces Sb and Sc (FIGS. 7A to 7C) of the optical scanning unit 3 are measured in advance and stored in the storage unit. It is stored in 7. Then, the control unit 6 determines the orientation of the reflective surfaces 3b and 3c with respect to the reference scanning surfaces Sb and Sc of the optical scanning unit 3 based on the angles of the reflective surfaces 3b and 3c stored in the storage unit 7. .. Further, the control unit 6 sets LD ₁ to LD ₄ and PD ₁ to PD ₁₆ which are effective when scanning the measurement light or the reflected light on the reflecting surfaces 3b and 3c according to the orientation of the reflecting surfaces 3b and 3c. select.

Specifically, for example, as shown in FIGS. 7A to 7C, when one reflecting surface 3b is tilted downward from the other reflecting surface 3c, the control unit 6 controls the measurement light on one reflecting surface 3b. And when the reflected light is reflected, LD ₁ and LD ₂ are made to emit light, and the measurement light (measurement lights L ₁ and L in FIG. 6A) is moved to the upper part of the detection range Z (upper side with respect to the reference scanning surfaces Sb and Sc). ₂ ) is projected. Then, the reflected light from the top of the detection range Z (reflected light _{L 1} in FIG. _{6 (b) ', L 2} ') to enable one of the PD group _PD 1 -PD ₈ corresponding to the incident direction (FIG. 10 (A)). Therefore, the reflected light incident from the detection range Z (reflected light _{L 1} in FIG. _{6 (b) ', L 2} ') is, after being reflected by one reflecting surface _3b, and is received by PD 1 -PD ₈ , The object detection unit 6a detects the object 50 based on the light receiving signals output from the PDs _{1 to 8} .

Further, the control unit 6 receives the measurement light (FIG. 6 (a)) to the lower part of the detection range Z (lower side with respect to the reference scanning surfaces Sb and Sc) when the measurement light or the reflected light is reflected by the other reflection surface 3c. ), The LD ₃ and LD ₄ corresponding to the projection direction of the measurement light L ₃ and L ₄ ) are enabled. Then, the reflected light from the lower part of the detection range Z (reflected light _{L 3} of FIG. _{6 (b) ', L 4} ') to enable the other PD group _PD 9 _{-PD 16} corresponding to the incident direction (FIG. 10 (B)). Therefore, the reflected light incident from the detection range Z (reflected light _{L 3} of FIG. _{6 (b) ', L 4} ') is, after being reflected by the other reflecting surface _3c, and is received by PD 9 _{-PD 16} , The object detection unit 6a detects the object 50 based on the light receiving signals output from the PDs _{9 to 16} .

The reflected light incident on the horizontal direction H is reflected by any of the reflecting surfaces 3b and 3c, and then received by any of PD _{7 to} PD ₁₀ . The reflected light incident from above the horizontal H is reflected by the reflecting surface _3b, or is received by the _{PD 7, PD 8, PD 1} ~PD 6 ( FIG. 5 adjacent to the lower side of the PD 7, PD ₈ (See) may receive light. The reflected light incident from below the horizontal H is reflected by the reflecting surface _3c, or is received by the _{PD 9, PD 10, PD 11} ~PD 16 adjacent above the PD 9, _{PD 10} (FIG. 5 (See) may receive light.

As can be seen from FIG. 10, in the object detection device 100 of the present invention, the light receiving region Rb of the reflected light from one reflecting surface 3b and the light receiving region Rc of the reflected light from the other reflecting surface 3c are partially. Duplicate. That is, the overlapping light receiving region Ry is generated between the light receiving region Rb and the light receiving region Rc, and the non-light receiving region Rx of FIG. 8 is not generated.

On the other hand, as shown in FIG. 11A, when the object detection device 100 faces the detection range Z in front of the vehicle 30, the object detection unit 6a receives the light receiving signals from PDs ₁ to PD ₈ of the light receiving region Rb. The detection region Zb that detects the object based on it occupies almost the upper half of the detection range Z. Further, as shown in FIG. 11B, the detection region Zc in which the object detection unit 6a detects an object based on the light receiving signals from PDs ₉ to PD ₁₆ of the light receiving region Rc is substantially the lower half of the detection range Z. Occupy.

However, as shown in FIG. 11C, when the detection region Zb and the detection region Zc are combined, the detection region Zb and the detection region Zc are partially due to the presence of the overlapping light receiving region Ry shown in FIG. Duplicate. That is, an overlapping detection region Zy is generated between the detection region Zb and the detection region Zc, and the non-detection region Zx shown in FIG. 9C is not generated. Further, since the non-detection region Zx does not occur in the central portion of the detection range Z, the object detection unit 6a uses the object detection unit 6a to detect an object (not shown) that exists in the central portion of the detection range Z and interferes with the running of the vehicle 30. It can be detected accurately.

Further, in the object detection device 100 of the present invention, the detection result (presence / absence of the object, the direction of the object, the distance to the object) of the object in the detection area Zb detected by the object detection unit 6a and the object detection unit The detection result (same as above) of the object in the detection area Zc detected by 6a is corrected by the correction unit 6b (FIG. 1). Specifically, the correction unit 6b measures the detection results of the objects in the detection areas Zb and Zc detected by the object detection unit 6a based on the angles of the reflection surfaces 3b and 3c that have been measured in advance and stored in the storage unit 7. To correct. At this time, the correction unit 6b corrects the detection result of the object in the detection regions Zb and Zc so as to eliminate the deviation angle between the design orientation of each reflection surface 3b and 3c and the measured orientation.

Then, the control unit 6 synthesizes the detection result of the object in the detection area Zb corrected by the correction unit 6b and the detection result of the object in the detection area Zc corrected by the correction unit 6b. As a result, the duplication of the detection results of the objects in the overlap detection region Zy shown in FIG. 11 (c) is eliminated, and the detection results of the objects in the entire detection range Z shown in FIG. 11 (d) can be obtained. The control unit 6 outputs the detection result of the synthesized object to the vehicle side ECU by the interface 8.

According to the above embodiment, when the measurement light or the reflected light is reflected by the reflecting surfaces 3b and 3c provided on the mirror 3a of the optical scanning unit 3, PDs ₁ to 3c are reflected according to the orientation of the reflecting surfaces 3b and 3c. Of the PD _16, a predetermined PD that does not generate a non-detection region becomes effective, and the object detection unit 6a detects the object 50 based on the light receiving signal output from the valid PD. Therefore, the object 50 is detected by reflecting the measurement light or the reflected light on the reflecting surfaces 3b and 3c and receiving the reflected light on the PDs ₁ to PD ₁₆ effective for the reflecting surfaces 3b and 3c. It is possible to suppress the occurrence of a non-detection region Zx in which the object 50 cannot be detected between the detection regions Zb and Zc.

Further, in the above embodiment, when the reflected light is reflected by the reflecting surface 3b downward from the reflecting surface 3c of the mirror 3a, the reflected light incident on the reference scanning surfaces Sb and Sc of the optical scanning unit 3 from above (FIG. 6 reflected light _{L 1} of _{(b) ', L 2'} ) one of the PD group _PD 1 -PD ₈ corresponding to the incident direction of is enabled and receives the reflected light from the object 50. Then, the object detection unit 6a detects the object 50 based on the light receiving signals output from the PDs _{1 to 8} . Further, when reflected light at relatively upward reflection surface 3c of the reflecting surface 3b, the reference scanning surface Sb, the reflected light incident from the lower side of the Sc (reflected light L ₃ of FIG. 6 (b) ' , L ₄ '), the other PD group PD _{9 to} PD ₁₆ corresponding to the incident direction is enabled and receives the reflected light from the object 50. Then, the object detection unit 6a detects the object 50 based on the received light signals output from the PDs _{9 to 16} . As a result, the detection region Zb that detects an object by receiving the reflected light reflected by the reflecting surface 3b on one PD group PD _{1 to} PD ₈ and the reflected light reflected by the reflecting surface 3c on the other PD. The detection area Zc that detects an object by receiving light in groups PD _{9 to} PD ₁₆ partially overlaps (FIG. 11 (c)). Therefore, even if the direction of the reflecting surface 3b or the reflecting surface 3c deviates from the design direction due to an error during manufacturing or the like, the object cannot be detected between the detection area Zb and the detection area Zc. The non-detection region Zx (FIG. 9 (c)) does not occur.

Further, in the above embodiment, one PD group PD _{1 to} PD ₈ that receives the reflected light reflected by the reflecting surface 3b and the other PD group PD ₉ to that receive the reflected light reflected by the reflecting surface 3c. The PD ₁₆ is adjacent to the vertical direction Y. Therefore, a part of the detection region Zb that detects the object by the reflected light from the reflecting surface 3b and a part of the detection region Zc that detects the object by the reflected light from the reflecting surface 3c are surely overlapped. be able to. Then, it is possible to reliably prevent the non-detection region Zx from being generated between the two detection regions Zb and Zc.

Further, in the above embodiment, when the light is reflected by the reflecting surfaces 3b and 3c, the control unit 6 switches the light emitting LD ₁ to LD ₄ and the light receiving PD ₁ to PD ₁₆ to detect the object. The detection range Z of 100 is divided into a plurality of detection regions Zb and Zc. Therefore, information about the object 50, such as the presence / absence of the object, the direction of the object, and the distance to the object, is reliably detected by the object detection unit 6a for each detection area Zb and Zc, and the detection accuracy is determined. Can be improved. Further, since the control unit 6 synthesizes the detection result of the object 50 by the object detection unit 6a for each of the detection areas Zb and Zc, the information about the object 50 is detected in the entire detection range Z of the object detection device 100. , The detection accuracy can also be improved.

Further, in the above embodiment, the control unit 6 has the reflection surfaces 3b and 3c of the reflection surfaces 3b and 3c based on the angles of the reflection surfaces 3b and 3c with respect to the reference scanning surfaces Sb and Sc that have been measured in advance and stored in the storage unit 7. The orientation with respect to the reference scanning surfaces Sb and Sc is determined. Therefore, the control unit 6 receives the reflected light from the object 50 and outputs a light receiving signal according to the orientation of the reflecting surfaces 3b and 3c (PD ₁ to PD ₈ or PD _{9 to} PD _16). ) Can be selected appropriately. Then, the object detection unit 6a can reliably detect the object in the detection range Z based on the received signal from each PD group.

Further, in the above embodiment, the detection result of the object 50 detected by the object detection unit 6a is corrected by the correction unit 6b based on the angles of the reflection surfaces 3b and 3c stored in the storage unit 7. Therefore, even if the orientations of the reflecting surfaces 3b and 3c deviate from the design orientation, the detection accuracy such as the position of the object 50 and the distance to the object 50 can be improved.

Furthermore, in the embodiment shown in FIG. 10, the reflected light incident in the horizontal direction H is received by any of the _PD 7 _{-PD 10,} based on the light reception signal output from the PD 7 _{-PD 10,} the object The detection unit 6a can detect the object 50 in the horizontal direction H. Further, since the reflected light incident from below the horizontal H is received by the _PD 1 -PD _8, based on the light reception signal output from the PD 1 -PD _8, the object detection unit 6a is lower than the horizontal H It is possible to reliably detect an object 50 that is located in and near the vehicle 30. Further, it is possible to surely prevent the non-detection region Zx from being generated in the center of the detection range Z of the object detection device 100, and improve the detection performance of the object detection device 100.

In the present invention, various embodiments other than those described above can be adopted.

For example, in the above embodiment, the control unit 6 determines the orientation of the reflection surfaces 3b and 3c based on the angles of the reflection surfaces 3b and 3c of the mirror 3a measured in advance and stored in the storage unit 7. , However, the present invention is not limited to this, although PDs ₁ to PD ₁₆ that are effective when light is reflected by the reflecting surfaces 3b and 3c are set according to the orientation. In addition to this, for example, a staff member at the manufacturing stage determines the orientation of each reflecting surface 3b, 3c based on the angle of each reflecting surface 3b, 3c with respect to the measured reference scanning surfaces Sb, Sc (FIGS. 7A to 7C). You may. In this case, the clerk sets PDs ₁ to PD ₁₆ to be enabled when light is reflected by the reflecting surfaces 3b and 3c according to the determined orientations of the reflecting surfaces 3b and 3c, and stores the set contents in the storage unit 7. To memorize. Then, during operation, the control unit 6 reads the stored contents of the storage unit 7 and validates PDs ₁ to PD ₁₆ set at the time of light reflection on the reflecting surfaces 3b and 3c.

In the above embodiments, as shown in FIG. 10, by dividing the _PD 1 _{-PD 16} of PD array 21 into two PD groups _(PD 1 -PD ₈ and _PD 9 _{-PD 16),} PD array 21 Although the detection range Z of the object detection device 100 is divided into two detection areas Zb and Zc by dividing the light receiving region of the above into two, the present invention is not limited to this. By dividing PD ₁ to PD ₁₆ of the PD array 21 into three or more PD groups and dividing the light receiving area of the PD array 21 into three or more, the detection range Z is divided into three or more detection areas. May be good.

For example, in another embodiment shown in FIG. 12, PDs ₁ to PD ₁₆ of the PD array 21 are divided into four groups, and the light receiving region is divided into four light receiving regions Rd, Re, Rf, and Rg. In this case, for example, when the measurement light or the reflected light is reflected by the reflecting surface 3b obliquely downward from the reflecting surface 3c of the mirror 3a of the optical scanning unit 3, the control unit 6 causes LD ₂ and LD ₄ to emit light. The measurement lights L ₂ and L ₄ (FIG. 6 (a)) are projected. Then, the control unit 6, the measuring light _L 2, light reflected by the object 50 of _{L 4 L 2 ', L 4} ' ( FIG. 6 (b)) PD group _PD 5 which corresponds to the incident direction of -PD ₈ (light receiving Region Rd) and PD groups PD ₁₃ to PD ₁₆ (light receiving region Re) are enabled. As a result, the object detection unit 6a detects the object 50 based on the light receiving signals output from PDs ₅ to PD ₈ and PD ₁₃ to PD ₁₆ .

Further, when the measurement light or the reflected light is reflected by the reflecting surface 3c, the control unit 6 causes LD ₁ and LD ₃ to emit light and projects the measurement lights L ₁ and L ₃ (FIG. 6 (a)). Then, the control unit 6, the measurement light _L 1, _L reflected light _{L 1} by the object 50 of ₃ ', _{L 3'} (FIG. 6 (b)) PD group _PD 1 -PD ₄ corresponding to the incident direction of the (light-receiving The region Rf) and the PD groups PD ₉ to PD ₁₂ (light receiving region Rg) are enabled. As a result, the object detection unit 6a detects the object 50 based on the light receiving signals output from PDs ₉ to PD ₁₂ and PDs ₁ to PD ₄ .

As a result, the light receiving region Rd of the reflected light from the reflecting surface 3b and the light receiving region Rg of the reflected light from the reflecting surface 3c partially overlap. The partially overlapping partial Ry corresponds to the center of the detection range Z. Therefore, it is possible to prevent an undetected region Rx from which the object 50 cannot be detected from being generated between the light receiving region Rd corresponding to the center of the detection range Z and the light receiving region Rg. In addition, the object 50 in the vicinity of the horizontal direction H can be reliably detected.

A non-detection region Rx is generated between the light receiving region Rf and the light receiving region Rd. Further, a non-detection region Rx is also generated between the light receiving region Rg and the light receiving region Re. However, since these non-detection regions Rx are not located in the center of the detection range Z, there is not much trouble in detecting the object 50 in the vicinity of the horizontal direction H. Further, for example, when the reflection surface 3b reflects the measurement light or the reflected light, the PD ₁₂ is enabled instead of the PD ₁₆ , or when the reflection surface 3c reflects the measurement light or the reflected light, the PD ₅ is used instead of the PD _1. The undetected region Rx may be eliminated by enabling it. Therefore, also in the embodiment of FIG. 12, it is possible to suppress the occurrence of the non-detection region Zx (FIG. 8) in the detection range Z of the object 50.

Further, in the above embodiment, the mirror 3a is provided with two reflecting surfaces 3b and 3c, but the mirror 3a may be provided with three or more reflecting surfaces. Further, the angles of the reflecting surfaces of the optical scanning unit 3 with respect to the reference scanning surfaces Sb and Sc may be intentionally made different, or may be designed to be a predetermined angle other than vertical. Further, the angle of the rotation axis Q of the mirror 3a with respect to the reference scanning surfaces Sb and Sc is designed to be a predetermined angle other than vertical, and the angle of the rotation axis Q is designed to be perpendicular to or tilted with respect to the vertical direction Y. You may do it. Further, the orientation of the optical scanning unit 3 may be appropriately selected to scan the measurement light or the reflected light in a predetermined direction other than the left-right direction X.

Further, in the above embodiment, the object detection unit 6a determines the presence / absence of the target unit 50, the direction of the target unit 50, and the target objects 50 based on the light receiving signals output by the PDs _{1 to 16} according to the light receiving state. Although an example of detecting a distance is shown, the present invention is not limited to this. In addition to this, the object detection unit 6a determines at least one of the presence / absence of the target unit 50, the direction of the object 50, or the distance to the object 50 based on the light receiving signals output from PDs _{1 to 16.} It may be detected. In addition, the object detection unit 6a may detect other information regarding the object 50.

Further, in the above embodiments, an example in which LD is used as the light emitting element and PD is used as the light receiving element is shown, but the present invention is not limited to these. An appropriate number of light emitting elements other than the LD may be used. Further, for example, an APD (Avalanche Photo Diode), a SPAD (Single Photon Avalanche Diode), an MPPC (Multi-Pixel Photon Counter), or the like may be used as the light receiving element. Further, an appropriate number of light emitting elements and light receiving elements may be provided and arranged in a direction other than the vertical direction Y. That is, the number of light emitting elements and the light receiving elements installed and the arrangement form may be appropriately selected. Further, the number of light emitting elements corresponding to the projection direction of the measurement light and the number of light receiving elements corresponding to the incident direction of the reflected light may be set to an appropriate number of one or more. Further, the number of light receiving elements to be effective when the measurement light or the reflected light is reflected on the reflecting surfaces 3b and 3c of the light scanning unit 3 may be one or more as appropriate.

Further, in the above embodiment, the measurement light emitted from the light emitting unit 1 is reflected by the reflecting surfaces 3b and 3c of the mirror 3a and scanned into the detection range Z, and the reflected light from the object 50 in the detection range Z is scanned. Although an example is shown in which an optical scanning unit 3 is used which scans the light on the reflecting surfaces 3b and 3c so as to be reflected and guided to the light receiving unit 2, the present invention is not limited to this. Instead of this, an optical scanning unit that scans one of the measurement light and the reflected light may be used.

Further, in the above embodiments, the present invention has been applied to the object detection device 100 composed of an in-vehicle laser radar, but the present invention is also applied to the object detection device for other uses. It is possible.

1 Light emitting part 2 Light receiving part 3 Optical scanning part 3a Mirror 3b, 3c Reflective surface (first reflective surface or second reflective surface)
6 control unit 6a object detection unit 6b correcting unit 7 storing unit 50 object 100 object detecting device H horizontal L ₁ ~L ₄ measurement light L ₁ '~L _4' reflected light LD ₁ to Ld ₄ laser diode (light emitting element )
PD _{1 to} PD ₁₆ photodiode (light receiving element)
PD _{1 to} PD ₈ , PD _{9 to} PD ₁₆ PD group (first light receiving element group, second light receiving element group)
Sb, Sc Reference scanning surface X Left-right direction (scanning direction)
Y Vertical direction (predetermined direction)
Z detection range Zb, Zc detection area

Claims (8)

A light emitting part having a light emitting element and
A light receiving part having a light receiving element and
By rotating a mirror provided with a plurality of reflecting surfaces, the light emitting element emits light, and the measurement light projected from the light emitting unit is reflected by each of the reflecting surfaces and scanned into a predetermined detection range, or An optical scanning unit that scans the reflected light of the measurement light from an object within the detection range so as to be reflected by each of the reflecting surfaces and guided to the light receiving unit.
An object detection unit that detects an object based on a light receiving signal output by the light receiving element according to the light receiving state of the reflected light.
The light emitting unit, the light receiving unit, the optical scanning unit, and a control unit that controls the operation of the object detection unit are provided.
In an object detection device in which a plurality of the light receiving elements are provided and the plurality of light receiving elements are arranged in a predetermined direction so as to correspond to the incident direction of the reflected light.
The control unit
Depending on the orientation of each reflecting surface with respect to the reference scanning surface to which the scanning direction of the measurement light or the reflected light belongs, a predetermined light receiving element among the plurality of light receiving elements is provided so that an undetected region of the object does not occur. When the measured light or the reflected light is reflected by each of the reflecting surfaces, the selected light receiving element is enabled to receive the reflected light and output the received signal. Object detection device. In the object detection device according to claim 1,
Of the plurality of reflecting surfaces, the first reflecting surface is inclined to one side of the second reflecting surface with respect to the reference scanning surface.
The control unit
When the measurement light or the reflected light is reflected on the first reflecting surface, the first light receiving element corresponding to the first incident direction of the reflected light is enabled among the plurality of light receiving elements, and the first light receiving element is enabled. Based on the light receiving signal output from the element, the object detection unit detects the object.
When the measurement light or the reflected light is reflected by the second reflecting surface, the second of the plurality of light receiving elements corresponds to the second incident direction inclined to one side of the first incident direction of the reflected light. An object detection device characterized in that the light receiving element is enabled and the object is detected by the object detecting unit based on the light receiving signal output from the second light receiving element. In the object detection device according to claim 1 or 2.
A plurality of the first light receiving element and the second light receiving element are provided to form a first light receiving element group and a second light receiving element group.
The first light receiving element group and the second light receiving element group are adjacent to each other.
Based on the reflected light received by the first light receiving element group, the object detection unit detects one of the objects, and based on the reflected light received by the second light receiving element group, the object is detected. An object detection device characterized in that the object detection unit partially overlaps with the other detection region for detecting the object. In the object detection device according to any one of claims 1 to 3.
The control unit detects a plurality of the detection ranges by switching the light receiving element that receives the reflected light and outputs the light receiving signal when the measured light or the reflected light is reflected on each reflecting surface. An object detection device characterized in that it is divided into regions and the result of detecting the object by the object detection unit is synthesized for each detection region. In the object detection device according to any one of claims 1 to 4.
The object detection device is characterized in that the control unit determines the orientation of each reflection surface based on the angle of each reflection surface with respect to the reference scanning surface that has been measured in advance and stored in the storage unit. In the object detection device according to any one of claims 1 to 5.
The object detection unit detects the direction of the object or the distance to the object based on the received signal.
An object detection characterized by further including a correction unit for correcting the detection result of the object detection unit based on the angle of each reflection surface with respect to the reference scanning surface measured in advance and stored in the storage unit. apparatus. In the object detection device according to any one of claims 1 to 6.
The first incident direction and the second incident direction are incident angles of the reflected light with respect to the vertical direction.
The scanning direction is a horizontal direction that intersects the vertical direction.
The first light receiving element is provided so as to correspond to the first incident direction inclined downward from the second incident direction with respect to the reference scanning surface.
The second light receiving element is provided so as to correspond to the second incident direction inclined upward from the first incident direction with respect to the reference scanning surface.
When the first reflecting surface is tilted downward from the second reflecting surface, the control unit is incident from the first incident direction when the measurement light or the reflected light is reflected by the first reflecting surface. The reflected light is received by the first light receiving element, and when the measured light or the reflected light is reflected by the second reflecting surface, the reflected light incident from the second incident direction is received by the second light receiving element. An object detection device characterized by receiving light. In the object detection device according to claim 7,
Of the first light receiving element and the second light receiving element, one light receiving element receives the reflected light incident in the horizontal direction, and the other light receiving element receives reflection obliquely above or diagonally below the horizontal direction. An object detection device characterized by receiving light.

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