WO2020045474A1

WO2020045474A1 - Sensor unit and mobile body

Info

Publication number: WO2020045474A1
Application number: PCT/JP2019/033644
Authority: WO
Inventors: 裕多堀; 佐伯　哲夫; 和穂江川; 智浩江川; 岡本　修治; 石丸　裕
Original assignee: 日本電産株式会社
Priority date: 2018-08-30
Filing date: 2019-08-28
Publication date: 2020-03-05

Abstract

This sensor unit (1), which is mounted in a mobile body (100), comprises a first sensor (2) having a first light-emitting part (21) and a first light-receiving part (22), and a second sensor (3) having a second light-emitting part (31). The first light-receiving part (22) is disposed between the first light-emitting part (21) and the second light-emitting part (31), and light incident from the first light-emitting-part (21) is detected by the first light-receiving part (22).

Description

Sensor unit, moving body

The present disclosure relates to a sensor unit and a moving body.

2. Description of the Related Art In recent years, mobile objects such as unmanned transport vehicles that transport goods have been introduced into factories and warehouses. A plurality of sensors that detect surrounding objects are mounted on the moving object in order to identify its own position and avoid collision with surrounding objects. For example, Japanese Unexamined Patent Application Publication No. 2014-186694 discloses an automatic guided vehicle having a laser range finder and an ultrasonic sensor. The laser range finder scans the laser light around the laser range finder, and acquires the position of the object by detecting an object within the scanning range of the laser light. The ultrasonic sensor transmits an ultrasonic wave having directivity, and detects a surrounding object based on a detection result of a reflected wave of the ultrasonic wave.

However, the responsiveness and reliability of the ultrasonic sensor are lower than those of a sensor using light as a detection medium, such as a laser range finder.

Japanese Unexamined Patent Publication: JP-A-2014-186694

When a plurality of sensors are mounted on the same device, the frequency of the detection medium used by some of the sensors may be the same as or close to the frequency of the detection medium used by some of the other sensors. For this reason, there is a possibility that the other part of the sensors may erroneously detect the reflected wave of the detection medium used by some of the sensors, thereby erroneously detecting the reflected wave.

An object of the present disclosure is to prevent a first sensor from erroneously detecting reflected light of light emitted from a second sensor.

An exemplary sensor unit according to the present disclosure includes a first sensor having a first light irradiation unit and a first light receiving unit, and a second sensor having a second light irradiation unit. The first light receiving unit is disposed between the first light irradiating unit and the second light irradiating unit, and detects light incident from the first light irradiating unit side of the first light receiving unit.

An exemplary moving object of the present disclosure includes the above-described sensor unit.

According to the exemplary sensor unit and the moving body of the present disclosure, it is possible to prevent the first sensor from erroneously detecting the reflected light of the light emitted from the second sensor.

FIG. 1 is a perspective view illustrating a configuration example of the automatic guided vehicle according to the embodiment. FIG. 2 is a top view illustrating the automatic guided vehicle according to the embodiment together with external objects. FIG. 3 is a side view showing the automatic guided vehicle according to the embodiment together with an external object. FIG. 4A is a cross-sectional view illustrating a configuration example of the first light receiving unit of the obstacle sensor. FIG. 4B is a cross-sectional view illustrating another configuration example of the first light receiving unit of the obstacle sensor. FIG. 5 is a cross-sectional view illustrating a configuration example of the distance measurement unit. FIG. 6 is a block diagram illustrating an example of an electrical configuration of the distance measurement unit. FIG. 7 is a timing chart of the laser emission pulse and the measurement data. FIG. 8 is a block diagram illustrating an electrical configuration example of the automatic guided vehicle. FIG. 9 is a timing chart of the irradiation light pulse and the corrected detection signal. FIG. 10 is a side view showing an automatic guided vehicle according to a modification together with an external object.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

In the present specification, the first direction from the first light receiving unit 22 of the obstacle sensor 2 described later toward the first light irradiation unit 21 in the vertical direction D1 is referred to as “downward D1d”. The direction toward the first light receiving unit 22 is referred to as “upper D1t”. Note that the upper direction D1t is in a direction opposite to the lower direction D1d. In each of the constituent elements, an end in the lower portion D1d is referred to as a “lower end”, and a position of the lower end in the vertical direction D1 is referred to as a “lower end”. Furthermore, the end in the upper part D1t is called “upper end”, and the position of the upper end in the vertical direction D1 is called “upper end”. Further, of the end surfaces of the respective components, a surface facing downward D1d is referred to as “lower surface”, and a surface facing upward D1t is referred to as “upper surface”.

A second direction perpendicular to the lower side D1d and in which the automatic guided vehicle 100 described later moves forward is referred to as “front direction D2f”, and a direction opposite to the front direction D2f is referred to as “rear direction D2b”. In each component, the end in the front direction D2f is referred to as “front end”, and the position of the front end in the front direction D2f is referred to as “front end”. Further, the end in the rear direction D2b is referred to as a “rear end”, and the position of the rear end in the rear direction D2b is referred to as a “rear end”. In addition, a surface facing the front direction D2f is referred to as a “front surface”, and a surface facing the rear direction D2b is referred to as a “back surface”.

A third direction perpendicular to both the lower direction D1d and the front direction D2f is referred to as a “lateral direction D3”. In the left-right direction D3, a direction from a driving wheel 105R described later to a driving wheel 105L described later is referred to as “left D3L”, and a direction from the driving wheel 105L to the driving wheel 105R is referred to as “right D3R”. In each component, an end in the left side D3L is called a "left end", and a position of the left end in the left-right direction D3 is called a "left end". Further, an end in the right D3R is called a “right end”, and a position of the right end in the left / right direction D3 is called a “right end”. Further, in the side surfaces of the respective components, a surface facing the left D3L is called a "left surface", and a surface facing the right D3R is called a "right surface".

In a distance measuring unit 3 described later, a direction parallel to the rotation axis J is referred to as an “axial direction”. In the axial direction, the direction from the second light receiving element 324 described later to the LD 311 described later is referred to as “axially upper”, and the direction from the LD 311 to the second light receiving element 324 is referred to as “axially lower”. Note that the axial direction is parallel to the vertical direction D1 in the present embodiment. However, the present invention is not limited to the example of the present embodiment, and the axial direction may be a direction that intersects the vertical direction D1. The direction perpendicular to the rotation axis J is referred to as “radial direction”. Of the radial directions, the direction toward the rotation axis J is referred to as “radially inward”, and the direction away from the rotation axis J is referred to as “radially outward”. In addition, a circumferential direction around the rotation axis J is referred to as a “rotation direction”. In each component of the distance measuring unit 3, the lower end is referred to as “axial lower end”, and the position of the lower end is referred to as “axial lower end”. Further, the upper end is referred to as “axial upper end”, and the position of the upper end is referred to as “axial upper end”. Further, of the end faces of the respective components in the distance measurement unit 3, a face facing downward is referred to as a "lower face", and a face facing upward is referred to as an "upper face".

It should be noted that the names of the directions, ends, positions, surfaces, and the like described above do not indicate the positional relationship, the directions, and the like when incorporated in actual equipment.

<1. Embodiment> <1-1. Automatic guided vehicle> FIG. 1 is a perspective view showing a configuration example of an automatic guided vehicle 100 according to the embodiment. FIG. 2 is a top view illustrating the automatic guided vehicle 100 according to the embodiment together with an external object OJ. FIG. 2 is a diagram of the automatic guided vehicle 100 as viewed from above D1t.

The automatic guided vehicle 100 is an example of a moving object including the sensor unit 1 and is generally called an AGV (Automatic Guided Vehicle). In the present embodiment, the automatic guided vehicle 100 autonomously travels on the road surface G by two-wheel drive and transports a load. However, the moving object exemplified by the automatic guided vehicle 100 is not limited to this example, and may be used for purposes other than the conveyance of luggage.

The sensor unit 1 mounted on the automatic guided vehicle 100 has two types of optical sensors (that is, the obstacle sensor 2 and the distance measurement unit 3). That is, not only the distance measurement unit 3 but also the obstacle sensor 2 uses an optical sensor with good responsiveness and high reliability. The automatic guided vehicle 100 detects the object OJ1 located near the automatic guided vehicle 100 as an obstacle by the obstacle sensor 2. Accordingly, for example, when there is an obstacle in the front direction D2f of the automatic guided vehicle 100, the automatic guided vehicle 100 stops moving. Further, the automatic guided vehicle 100 detects the object OJ2 located outside the automatic guided vehicle 100 by the distance measuring unit 3, and the position of the object OJ2 is determined with respect to the distance to the object OJ2 and the position of the automatic guided vehicle 100. Direction to be detected. Note that the distance measurement unit 3 can detect an object OJ2 located farther than the object OJ1 that can be detected by the obstacle sensor 2. Thereby, the automatic guided vehicle 100 can perform map information creation and self-position identification, which will be described later. In the sensor unit 1 and the automatic guided vehicle 100 of the present embodiment, as described later, the obstacle sensor 2 erroneously detects the reflected light Lb in which the light emitted from the distance measuring unit 3 is reflected by an external object. Can be suppressed or prevented. Therefore, the automatic guided vehicle 100 can prevent the automatic guided vehicle 100 from stopping even though there is no obstacle OJ1 around the automatic guided vehicle 100 due to the erroneous detection described above. A more detailed configuration of the sensor unit 1 will be described later.

As shown in FIGS. 1 and 2, the automatic guided vehicle 100 includes a vehicle body 101, a carrier 102,

support portions

103L and 103R, drive

motors

104L and 104R, drive

wheels

105L and 105R, and driven wheels 106F. , 106R, a battery 107, a communication unit 108, and a control unit 109.

The vehicle body 101 houses a battery 107, a communication unit 108, a control unit 109, and the like. 1, five obstacle sensors 2 of the sensor unit 1 are provided at the front end and the rear end of the vehicle body 101. In addition, the site | part in which the obstacle sensor 2 is provided, and the number thereof are not limited to the illustration of FIG. The configuration of the obstacle sensor 2 will be described later.

A plate-shaped carrier 102 is fixed to the upper surface of the vehicle body 101. Luggage can be placed on the upper surface of the loading platform 102. Further, on the upper surface of the vehicle body 101, the distance measuring unit 3 of the sensor unit 1 is disposed in the forward direction D2f. The configuration of the distance measuring unit 3 will be described later.

The support portion 103L is fixed to the left end of the vehicle body 101, and supports the drive motor 104L. For example, an AC servomotor is used as drive motor 104L. The drive motor 104L incorporates a speed reducer (not shown). The drive wheel 105L is attached to a shaft (not shown) of the drive motor 104L, and contacts the road surface G. The drive wheel 105L is rotatable with the shaft by the rotational drive of the drive motor 104L.

The support portion 103R is fixed to the right end of the vehicle body 101, and supports the drive motor 104R. As the drive motor 104R, for example, an AC servomotor is used. The drive motor 104R incorporates a speed reducer (not shown). The drive wheel 105R is attached to a shaft (not shown) of the drive motor 104R and contacts the road surface G. The drive wheel 105R is rotatable with the shaft by the rotational drive of the drive motor 104R.

The driven wheel 106F is rotatably attached to the front end of the vehicle body 101. The driven wheel 106R is rotatably mounted at the rear end of the vehicle body 101. The driven

wheels

106F and 106R come into contact with the road surface G and rotate passively according to the rotation of the

drive wheels

105L and 105R.

By driving the

drive wheels

105L and 105R to rotate by the

drive motors

104L and 104R, the automatic guided vehicle 100 can be moved forward and backward on the road surface G. In addition, by controlling the rotational speeds of the

drive wheels

105L and 105R to provide a difference, the automatic guided vehicle 100 can be rotated clockwise or counterclockwise to change the direction.

The battery 107 is a power source of the automatic guided vehicle 100, and supplies power to, for example, the distance measurement unit 3, the communication unit 108, the control unit 109, and the like. As the battery 107, for example, a lithium ion battery is used.

The communication unit 108 performs communication with a tablet terminal (not shown) outside the automatic guided vehicle 100, for example, in compliance with Bluetooth (registered trademark). Thus, the automatic guided vehicle 100 can be remotely controlled by an external information device such as a tablet terminal.

The control unit 109 is connected to the

drive motors

104L and 104R, the communication unit 108, and the like. The control unit 109 controls the drive of the

drive motors

104L and 104R. The control unit 109 is further connected to the obstacle sensor 2 and the distance measurement unit 3 and receives various signals from the obstacle sensor 2 and the distance measurement unit 3 to perform various controls.

<1-2. Sensor Unit> Next, the sensor unit 1 mounted on the automatic guided vehicle 100 will be described with reference to FIG. 3 in addition to FIGS. 1 and 2. FIG. 3 is a side view showing the automatic guided vehicle 100 according to the embodiment together with an external object OJ. In FIG. 3, the front end of the automatic guided vehicle 100 is viewed from the left D3L.

The sensor unit 1 includes the obstacle sensor 2 and the distance measurement unit 3 as described above.

<1-2-1. Obstacle Sensor> The obstacle sensor 2 is a first sensor included in the sensor unit 1 and is an optical sensor that detects an object OJ1 located around the first sensor. In this case, for example, an optical sensor having higher responsiveness and reliability than a sensor using an ultrasonic wave as a detection medium can be used as the obstacle sensor 2. As shown in FIG. 3, the obstacle sensor 2 is provided below the distance measurement unit 3 at D1d.

The obstacle sensor 2 includes a first light irradiation unit 21 and a first light receiving unit 22. The first light irradiation unit 21 irradiates the outside of the automatic guided vehicle 100 with irradiation light Lra. The first light receiving unit 22 receives the incident light, and particularly receives the reflected light Lrb. The reflected light Lrb is light in which the irradiation light Lra is reflected by the object OJ1 located outside the automatic guided vehicle 100. The obstacle sensor 2 detects, for example, an object OJ1 located outside the automatic guided vehicle 100 as an obstacle based on the light reception result of the first light receiving unit 22.

In the vertical direction D1, the first light receiving unit 22 is disposed between the first light irradiation unit 21 and the second light irradiation unit of the distance measurement unit 3. Further, the first light receiving unit 22 detects light incident from the first light irradiation unit 21 side of the first light receiving unit 22. On the other hand, the first light receiving unit 22 does not detect light incident from the distance measuring unit 3 side more than the first light receiving unit 22. In other words, when viewed from the left-right direction D3, the first light receiving unit 22 detects only light incident from the lower side D1d than the front direction D2f, and does not detect light incident from the upper side D1t than the front direction D2f.

As described above, the first light receiving unit 22 does not detect light incident from the distance measuring unit 3 side than the first light receiving unit 22 does, and detects the light from the first light irradiation unit 21 side rather than the first light receiving unit 22. Only the light that emits light. As a result, in the first light receiving unit 22, the reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2 is detected, and the detection of the reflected light Lb of the laser light La emitted from the distance measurement unit 3 is prevented. . Therefore, it is possible to prevent the obstacle sensor 2 from erroneously detecting the reflected light Lb of the laser light La emitted from the distance measuring unit 3. This effect is particularly effective when the wavelength bands of the laser light La and the irradiation light Lra are the same.

Further, the first light irradiating unit 21 is disposed below the first light receiving unit 22 in the axial direction. In the present embodiment, the first light irradiation unit 21 of the obstacle sensor 2 is disposed below the first light receiving unit 22 at D1d. In this case, the distance measurement unit 3 can be arranged above the obstacle sensor 2 that detects the surrounding object. Therefore, the obstacle sensor 2 that detects a surrounding object does not detect the light that enters the first light receiving unit 22 from the distance measurement unit 3 side (that is, the D1t side above the horizontal direction), so that the distance measurement unit 3 Detection of the reflected light Lb of the emitted laser light La can be prevented.

When the laser light La emitted from the distance measuring unit 3 is reflected on the road surface G or the like, the reflected light Lb may enter the first light receiving unit 22 from the lower side D1d. In this case, the obstacle sensor 2 erroneously detects the reflected light Lb of the laser light La emitted from the distance measuring unit 3 reflected on the road surface G. However, the intensity of the reflected light Lb incident on the first light receiving unit 22 from the first light irradiation unit 21 side is lower than the intensity of the reflected light Lb incident on the first light receiving unit 22 from the distance measurement unit 3 side. For example, the intensity of the reflected light Lb reflected by the road surface G is lower than the intensity of the reflected light Lb reflected by a portion on the D1t side above the first light receiving unit 22 of the external object OJ2. Therefore, in the present embodiment, as to the erroneous detection by the obstacle sensor 2 as described above, when the light receiving intensity of the incident light received by the first light receiving unit 22 is less than the first threshold, the incident light is detected as described later. The light detection result is invalidated. In other words, when the intensity of the incident light received by the first light receiving unit 22 is equal to or greater than the first threshold, the detection result of the incident light is valid. Thereby, for example, the detection of the reflected light Lb reflected on the road surface G as described above is invalidated. Therefore, the obstacle sensor 2 can more reliably prevent the reflected light Lb of the laser light La emitted from the distance measuring unit 3 from being erroneously detected.

The first light irradiation unit 21 has an LED (Light Emitting Diode) not shown in the present embodiment. The LED is an example of a light source that emits the irradiation light Lra. The first light irradiating unit 21 irradiates the irradiation light Lra having lower directivity than the laser light La emitted from the distance measuring unit 3. In this case, a relatively inexpensive light emitting element such as an LED can be used as the light source of the first light irradiation unit 21. The irradiation light Lra is an infrared ray in the present embodiment. In this case, an inexpensive infrared light emitting element can be used as the light source of the first light irradiation unit 21. However, the irradiation light Lra is not limited to this example, and may be light in a wavelength band other than the infrared band.

In the present embodiment, the first light irradiation unit 21 causes the LED to emit the irradiation light Lra intermittently in response to the irradiation light pulse Pi input periodically. That is, the first light irradiation unit 21 irradiates the irradiation light Lra intermittently. However, the present invention is not limited to this example, and the first light irradiation unit 21 may continuously emit the irradiation light Lra during the operation of the automatic guided vehicle 100.

Next, the configuration of the first light receiving unit 22 will be described. FIG. 4A is a cross-sectional view illustrating a configuration example of the first light receiving unit 22 of the obstacle sensor 2. FIG. 4A corresponds to the cross-sectional structure of a portion A surrounded by an elliptical broken line in FIG.

As shown in FIG. 4A, the first light receiving unit 22 includes a first light receiving element 221 and a condenser lens 222. The first light receiving element 221 detects incident light from outside the first light receiving unit 22 at each incident angle θ based on the light receiving position on the light receiving surface 221a. The condenser lens 222 condenses the incident light on the light receiving surface 221a of the first light receiving unit 22. The incident angle θ is the forward direction D2f of the incident light as viewed from both the lower direction D1d from the first light receiving unit 22 toward the first light irradiating unit 21 and the front direction D2f perpendicular to the lower direction D1d and the right and left direction D3 perpendicular to the lower direction D1d. Is the angle with respect to As described above, the first light receiving unit 22 can use the first light receiving element 221 of a PSD (position sensitive) device that detects the distance to the first object OJ1 by triangulation.

More specifically, as shown in FIG. 4A, the first light receiving element 221 is provided inside the vehicle body 101. The light receiving surface 221a of the first light receiving element 221 intersects the front direction D2f, and in the present embodiment, is orthogonal to the front direction D2f. In the present embodiment, the condenser lens 222 is fitted into openings provided on the front and back surfaces of the vehicle body 101. In the vertical direction D1, the light receiving surface 221a of the first light receiving element 221 is located D1t above the center position of the condenser lens 222 in the vertical direction D1.

When viewed from the left side D3L, the condenser lens 222 includes light that enters the condenser lens 222 from the front direction D2f and light that enters the condenser lens 222 from the side D1t above the front direction D2f (for example, a distance measurement unit). The reflected light Lb) of the laser light La emitted from 3 is condensed below the first light receiving element 221 toward the side D1d. Therefore, the collected light does not enter the light receiving surface 221a of the first light receiving element 221 and is not received by the first light receiving element 221.

On the other hand, when viewed from the left side D3L, the condenser lens 222 is a light incident on the condenser lens 222 from a side D1d below the front direction D2f (for example, a reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2). Is focused toward the upper D1t side than the front direction D2f. Therefore, the condensed light enters the light receiving surface 221a of the first light receiving element 221 and is received by the first light receiving element 221.

The light condensed on the light receiving surface 221a is received at a position away from the lower end of the light receiving surface 221a toward the upper part D1t as the incident angle θ is larger. At this time, the first light receiving element 221 detects the light receiving intensity of the light collected on the light receiving surface 221a for each light receiving position on the light receiving surface 221a in the vertical direction D1. In other words, the first light receiving element 221 detects the incident light condensed on the light receiving surface 221a for each incident angle θ based on the light receiving position on the light receiving surface 221a. Therefore, the first light receiving element 221 receives the reflected light Lrb reflected by the external obstacle as described above and the reflected light incident from the object OJ located at a known distance from the first light receiving unit 22. The distance from the obstacle sensor 2 to the obstacle can be obtained by calculation based on the light receiving result of Lrb.

4A, the first light receiving unit 22 may include a light blocking member 223. FIG. 4B is a cross-sectional view illustrating another configuration example of the first light receiving unit 22 of the obstacle sensor 2. FIG. 4B corresponds to the cross-sectional structure of the portion A surrounded by the elliptical broken line in FIG. In FIG. 4B, in the vertical direction D1, the lower end of the light receiving surface 221a is on the D1d side below the front direction D2f. The light blocking member 223 is provided between the first light receiving element 221 and the condenser lens 222 inside the vehicle body 101, and shields light condensed from the condenser lens 222 toward the lower side D1d than the front direction D2f. This prevents the light from entering the light receiving surface 221a. 4B, the first light receiving element 221 can detect only light incident from the side of D1d below the front direction D2f when viewed from the left and right direction D3, similarly to the configuration of FIG. 4A. Further, the first light receiving element 221 can detect incident light from outside the first light receiving unit 22 at each incident angle θ based on the light receiving position on the light receiving surface 221a.

<1-2-2. Distance measuring unit> Distance measuring unit 3 is a second sensor provided in sensor unit 1, and measures a distance between the distance measuring unit 3 and an object located outside. The distance measurement unit 3 is disposed axially above the obstacle sensor 2. Further, in the present embodiment, as shown in FIG. 3, the distance measurement unit 3 is disposed above the obstacle sensor 2 at D1t. The distance measuring unit 3 in the present embodiment is a so-called LRF (Laser \ Range \ Finder). FIG. 5 is a cross-sectional view illustrating a configuration example of the distance measuring unit 3. FIG. 5 shows a cross-sectional structure when the distance measurement unit 3 is virtually cut along a plane including the rotation axis J.

As shown in FIG. 5, the distance measurement unit 3 includes a housing 30, a second light irradiating unit 31, a second light receiving unit 32, a rotating housing 33, and a motor 34.

The housing 30 has a hollow cylindrical shape extending in the up-down direction, and accommodates the second light irradiation unit 31, the second light receiving unit 32, the rotating housing 33, and the motor 34 in the internal space. Further, the housing 30 has a light transmitting portion 301. The light-transmitting portion 301 is provided on the radial side surface of the housing 30 using a material such as a light-transmitting resin or glass in the middle in the vertical direction. The light transmitting portion 301 is provided in an annular shape around the rotation axis J. In addition, the ring here has a shape that is continuously connected over the entire circumference in the rotation direction around the rotation axis J as shown in FIG. 5, and a shape that is intermittently connected over the entire circumference in the rotation direction as shown in FIG. Including.

The second light irradiating unit 31 irradiates the laser light La to the outside of the automatic guided vehicle 100. In the present embodiment, the laser light La is irradiated in the horizontal direction. That is, the optical axis of the laser beam La is parallel to the horizontal direction. In the present embodiment, the laser light La is light in the same infrared band as the irradiation light Lra. In the present embodiment, since only the light incident from the lower side D1d than the front direction D2f is detected by the first light receiving unit 22, the obstacle sensor 2 erroneously detects the reflected light Lb in the same wavelength band as the irradiation light Lra. Can be prevented. However, the present invention is not limited to this example, and the laser light La may be light in a wavelength band different from the irradiation light Lra. For example, the laser light La may be light in a wavelength band other than the infrared band.

The intensity of the laser light La emitted from the second light emitting unit 31 is stronger than the intensity of the emitted light Lra emitted from the first light emitting unit 21 of the obstacle sensor 2. In this way, for example, by invalidating the detection result of light having an intensity less than the second threshold value in the second light receiving unit 32 of the distance measurement unit 3, the distance measurement unit 3 reflects the irradiation light Lra of the obstacle sensor 2 It is possible to prevent the light Lrb from being erroneously detected.

As shown in FIG. 5, the second light irradiation unit 31 includes an LD (Laser @ Diode) 311, a substrate 312, a collimating lens 313, and a light projecting mirror 314. The LD 311 is an example of a light source that emits laser light La. The substrate 312 is mounted with an LD driver 311a (see FIG. 6 described later) that controls light emission of the LD 311. In this embodiment, the LD 311 and the substrate 312 are fixed to the lower end surface of the upper end of the housing 30. The collimating lens 313 is arranged below the LD 311. The light projecting mirror 314 is arranged below the collimating lens 313 and is fixed to the upper end surface of the upper end of the rotating housing 33.

The LD 311 emits the laser light La downward. The laser light La emitted from the LD 311 is collimated by the collimator lens 313. The laser light La emitted downward from the collimating lens 313 is reflected by the light projecting mirror 314, passes through the light transmitting unit 301, and is emitted to the outside of the housing 30.

Here, in the present embodiment, the laser light La is intermittently emitted by the LD 311 according to the laser emission pulse Pe. At this time, the period during which the laser light La is irradiated from the second light irradiation unit 31 preferably does not overlap with the period during which the irradiation light Lra is irradiated. In other words, the irradiation light Lra emitted from the first light irradiation unit 21 and the laser light La emitted from the second light irradiation unit 31 are preferably emitted to the outside of the sensor unit 1 at mutually different timings. .

In this way, even if the reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2 enters the second light receiving unit 32 of the distance measurement unit 3, the reflected light Lrb is emitted from the distance measurement unit 3. The laser light La enters the second light receiving unit 32 at a timing different from that of the reflected light Lb. At this time, for example, the detection result of the light incident on the second light receiving unit 32 a predetermined time after the time when the laser light La is irradiated to the outside is valid. Note that the predetermined time is determined in consideration of the TOF (Time @ of @ Flight) of the laser light La and the reflected light Lb. Further, the detection result of the light incident on the second light receiving unit 32 a predetermined time after the irradiation light Lra is irradiated to the outside is invalidated. The predetermined time is determined in consideration of the TOF (Time @ of @ Flight) of the irradiation light Lra and the reflected light Lrb. Thus, it is possible to prevent the second light receiving unit 32 of the distance measuring unit 3 from erroneously detecting the reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2.

Furthermore, even if the reflected light Lb of the laser beam La emitted from the distance measuring unit 3 is incident on the first light receiving unit 22 of the obstacle sensor 2, the reflected light Lb is irradiated light emitted from the obstacle sensor 2 The light enters the first light receiving unit 22 at a different timing from the reflected light Lrb of Lra. For example, the detection result of the light incident on the first light receiving unit 22 a predetermined time after the irradiation light Lra is irradiated to the outside is valid. The predetermined time is determined in consideration of the TOF (Time @ of @ Flight) of the irradiation light Lra and the reflected light Lrb. Further, the detection result of the light incident on the first light receiving unit 22 a predetermined time after the time when the laser light La is irradiated to the outside is invalidated. Note that the predetermined time is determined in consideration of the TOF (Time @ of @ Flight) of the laser light La and the reflected light Lb. Accordingly, it is possible to more reliably prevent the first light receiving unit 22 of the obstacle sensor 2 from erroneously detecting the reflected light Lb of the laser light La emitted from the distance measuring unit 3.

The present invention is not limited to the above example, and at least a part of the period in which the laser light La is irradiated from the second light irradiation unit 31 may overlap with the period in which the irradiation light Lra is irradiated. For example, the laser light La may be irradiated to the outside of the sensor unit 1 at the same timing as the irradiation light Lra intermittently irradiated from the first light irradiation unit 21.

Next, the second light receiving unit 32 receives the incident light, and in particular, receives the reflected light Lb of the laser light La reflected by the object OJ2 located outside the automatic guided vehicle 100, for example. If the intensity of the incident light received by the second light receiving unit 32 is less than the second threshold, the detection result of the incident light is invalidated.

As shown in FIG. 5, the second light receiving section 32 includes a light receiving lens 321, a light receiving mirror 322, a wavelength filter 323, and a second light receiving element 324. The light receiving lens 321 is fitted and fixed in an opening 33 a provided on a radial side surface of the rotating housing 33. The light receiving mirror 322 is fixed to the lower end surface of the upper end of the rotating housing 33. The wavelength filter 323 is arranged below the light receiving mirror 322. The second light receiving element 324 is disposed below the wavelength filter 323 and is fixed to the upper end surface of the lower end of the rotating housing 33.

The laser light La emitted from the distance measurement unit 3 is reflected by an object OJ2 outside the distance measurement unit 3 and becomes diffused light. Part of the diffused light passes through the light transmitting portion 301 and enters the second light receiving portion 32 as reflected light Lb. The reflected light Lb first enters the light receiving lens 321. The reflected light Lb transmitted through the light receiving lens 321 is reflected downward by the light receiving mirror 322 and transmitted through the wavelength filter 323. At this time, the wavelength filter 323 transmits, for example, only light in the same wavelength band as the laser light La. Thereafter, the reflected light Lb is received by the second light receiving element 324. The second light receiving element 324 photoelectrically converts the received reflected light Lb into an electric signal such as a measurement pulse Pm to be described later, and outputs the electric signal.

The rotating housing 33 has a hollow cylindrical shape extending in the vertical direction, and accommodates the light receiving mirror 322, the wavelength filter 323, and the second light receiving element 324 in the internal space. The rotating housing 33 is fixed to a shaft 34 a of a motor 34 and can be driven to rotate by the motor 34. Due to the rotation of the rotating housing 33, the light projecting mirror 314 is also driven to rotate about the rotation axis J. Therefore, the irradiation direction of the laser beam La reflected by the light projecting mirror 314 rotates around the rotation axis J. In other words, the laser beam La is irradiated to the outside of the housing 30 while changing the irradiation direction within a range of 360 ° around the rotation axis J. Therefore, the laser light La emitted from the second light emitting unit 31 is scanned in the rotation direction about the rotation axis J in accordance with the rotation of the motor 34.

Here, the scanning range Rs in the rotation direction of the laser beam La is a measurement range in which the distance measurement unit 3 can measure the distance to the external object OJ (see FIG. 2), and the laser beam La rotates around the rotation axis. It is formed by doing. Note that the scanning range Rs changes according to the output level of the laser light La. When the laser beam La applied to the measurement range is reflected by the object OJ located within the scanning range Rs, the reflected light Lb passes through the light transmitting unit 301 and enters the light receiving lens 321.

The motor 34 rotates the rotating housing 33 at a predetermined rotation speed by rotating the shaft 34a. The rotation of the motor 34 causes the laser beam La to scan in the rotation direction. That is, the motor 34 is a scanning mechanism of the laser beam La.

<1-3. Electrical Configuration of Distance Measuring Unit> Next, the electrical configuration of the distance measuring unit 3 will be described. FIG. 6 is a block diagram showing an electrical configuration of the distance measurement unit 3. As shown in FIG.

As shown in FIG. 6, the distance measuring unit 3 includes a measuring unit 35, an arithmetic processing unit 36, and a motor driving unit 37, in addition to the above-described second light irradiation unit 31, second light receiving unit 32, and motor 34. , A communication I / F 38. In addition, the second light receiving unit 32 further includes a comparator 325. In the present embodiment, the measuring unit 35 and the arithmetic processing unit 36 are functional components of one or a plurality of microcomputers (not shown) provided in the distance measuring unit 3. However, the present invention is not limited to this example, and at least one of the measuring unit 35 and the arithmetic processing unit 36 may be a physical component realized by an electric circuit, an element, an electric device, or the like.

The comparator 325 is mounted on, for example, a substrate (not shown) in the housing 30 and compares the level of an electric signal output from the second light receiving element 324 with a second threshold. The electric signal indicates a result of light reception by the second light receiving element 324. The second threshold value is greater than the intensity of the reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2 incident on the second light receiving unit 32. Thereby, even if the reflected light Lrb of the irradiation light Lra emitted from the obstacle sensor 2 is incident on the second light receiving unit 32, the distance measurement unit 3 emits the reflected light Lrb from the laser emitted from the distance measurement unit 3. Erroneous detection as the reflected light Lb of the light La can be more reliably prevented.

The comparator 325 outputs a high-level or low-level measurement pulse Pm according to the above-described comparison result. For example, when the level of the electric signal is lower than the second threshold, the comparator 325 invalidates the detection result of the incident light by the second light receiving element 324 and outputs the measurement pulse Pm of the Low level. When the level of the electric signal is equal to or higher than the second threshold, the comparator 325 validates the result of detection of the incident light by the second light receiving element 324 and outputs a high-level measurement pulse Pm.

The arithmetic processing unit 36 outputs a laser light emission pulse Pe to the second light irradiation unit 31. At this time, the second light irradiation unit 31 causes the LD 311 to emit pulsed laser light La using the laser emission pulse Pe as a trigger. When outputting the laser emission pulse Pe, the arithmetic processing unit 36 outputs the reference pulse Ps and the laser emission pulse Pe to the measurement unit 35.

The measurement pulse Pm output from the comparator 325 and the reference pulse Ps output from the arithmetic processing unit 36 are input to the measurement unit 35. The measurement unit 35 acquires the distance to the object OJ by measuring the elapsed time from the rising timing of the reference pulse Ps to the rising timing of the measurement pulse Pm. That is, the measuring unit 35 measures the distance by a so-called TOF (Time @ of @ Flight) method. The measurement unit 35 outputs the measurement result of the distance to the arithmetic processing unit 36 as measurement data Dm.

The motor driving unit 37 controls driving of the motor 34. The motor 34 is driven to rotate at a predetermined rotation speed by a motor drive unit 37. At this time, the arithmetic processing unit 36 outputs a laser emission pulse Pe every time the motor 34 rotates by a predetermined unit angle. Thus, the second light irradiator 31 irradiates the laser beam La each time the rotating housing 33 and the light projecting mirror 314 rotate by a predetermined unit angle.

The arithmetic processing unit 36 uses the distance measurement unit 3 as a reference based on the rotation angle position of the motor 34 at the timing when the laser emission pulse Pe is output and the measurement data Dm obtained corresponding to the laser emission pulse Pe. Generate position information on a rectangular coordinate system. That is, the position of the object OJ is acquired based on the rotation angle position of the light projecting mirror 314 and the measured distance. The position information acquired in this way is output from the arithmetic processing unit 36 as measured distance data Dd. Thus, the position information of the object OJ is obtained by the scanning of the laser beam La within the rotation scanning angle range.

The communication I / F 38 transmits the measured distance data Dd output from the arithmetic processing unit 36 to the automatic guided vehicle 100 (see FIG. 8 described later).

The communication I / F 38 preferably transmits the laser emission pulse Pe to the automatic guided vehicle 100 and receives the irradiation light pulse Pi from the automatic guided vehicle 100. At this time, the measuring unit 35 determines validity / invalidity of the measurement pulse Pm for a predetermined time according to the laser emission pulse Pe and the irradiation light pulse Pi, and outputs measurement data Dm based on the determined measurement pulse Pm. FIG. 7 is a timing chart of the laser emission pulse Pe and the measurement data Dm.

In FIG. 7, the laser beam La is irradiated at a time point t1 when the laser emission pulse Pe rises. At time t2 when the same time as TOF (Time @ of @ Flight) of the laser light La and its reflected light Lb has elapsed from time t1, the reflected light Lb is received by the second light receiving unit 32. At time t3 when the irradiation light pulse Pi rises, the irradiation light Lra is irradiated. At time t5 when the same time as TOF (Time @ of @ Flight) of the irradiation light Lra and its reflected light Lrb has elapsed from time t3, the reflected light Lrb is received by the second light receiving unit 32. The period of the laser emission pulse Pe (the period from t1 to t6 in FIG. 7) is, for example, 8.6 [μsec], whereas the TOF of the irradiation light Lra and the reflected light Lrb is, for example, 0.2 [μsec]. μsec]. Here, the measurement unit 35 validates the measurement pulse Pm during the predetermined time Te from the time t2 to the time t4, and invalidates the measurement pulse Pm during the period Tu from the time t4 to the time t6 when the next laser emission pulse Pe rises. . The time point t4 is a time point after the predetermined time Te from the time point t2 and before the time point t5. That is, t2 <t4 <t5. Then, the measurement unit 35 generates the measurement data Dm based on the valid measurement pulse Pm. By doing so, the measuring unit 35 prevents the second light receiving unit 32 from erroneously detecting the reflected light Lrb of the irradiation light Lra.

<1-4. Next, the electrical configuration of the automatic guided vehicle 100 other than the distance measurement unit 3 will be described. FIG. 8 is a block diagram illustrating an electrical configuration example of the automatic guided vehicle 100.

The control unit 109 of the automatic guided vehicle 100 includes a control unit 4 and a storage unit 5, as shown in FIG.

The control unit 4 communicates with an information device (not shown) such as a tablet terminal via the communication unit 108. For example, control unit 4 receives, via communication unit 108, an operation signal indicating the content of the operation input on the information device. In the present embodiment, one or more CPUs (illustration omitted) are used for the control unit 4. However, the present invention is not limited to this example, and at least a part of the control unit 4 may be an electric circuit, an element, an electronic device, or the like other than the CPU.

In addition, the control unit 4 includes a drive control unit 41, a determination unit 42, a map creation unit 43, a position identification unit 44, and a light emission control unit 45. In this embodiment, the drive control unit 41, the determination unit 42, the map creation unit 43, the position identification unit 45, and the light emission control unit 45 are functional components of the above-described CPU. However, the present invention is not limited to this example, and at least one of the drive control unit 41, the determination unit 42, the map creation unit 43, the position identification unit 45, and the light emission control unit 45 is an electric circuit, an element, an electric device, or the like. It may be a realized physical component.

The drive control unit 41 controls the rotational drive of the

drive motors

104L and 104R, and controls the rotational speed and the rotational direction of the

drive wheels

105L and 105R, for example.

The determination unit 42 performs various determinations. For example, the determination unit 42 determines whether there is an obstacle near the vehicle body 101 based on the detection signal Sd output from the obstacle sensor 2. When the level of the detection signal Sd is lower than the first threshold level, the determination unit 42 determines that there is no obstacle near the vehicle body 101. When the level of the detection signal Sd is equal to or higher than the first threshold level, the determination unit 42 determines that there is an obstacle near the vehicle body 101. When the determining unit 42 determines that there is an obstacle such as the object OJ1 (for example, see FIGS. 2 and 8), the drive control unit 41 stops or reversely rotates the

drive motors

104L and 104R. Thereby, contact between the vehicle body 101 and an obstacle such as the object OJ1 is avoided.

The map creating unit 43 creates map information based on the measured distance data Dd output from the distance measuring unit 3 and stores the map information in the storage unit 5. The map information is position information of an object placed at a place where the automatic guided vehicle 100 travels, and indicates a relative position of each object located outside the distance measuring unit 3 with respect to a predetermined reference position. For example, when the automatic guided vehicle 100 travels in a warehouse, it is a wall of the warehouse, shelves arranged in the warehouse, luggage loaded on a road surface G in the warehouse, and the like.

The position identification unit 44 compares the measured distance data Dd output from the distance measurement unit 3 with the map information stored in the storage unit 5, and specifies the position of the automatic guided vehicle 100 itself based on the comparison result. Self-position identification. By performing the self-position identification, the control unit 4 can control the autonomous traveling of the automatic guided vehicle 100 along a predetermined route.

The storage unit 5 is a non-transitory storage medium that can retain storage even when power supply is stopped. The storage unit 5 stores programs and information used by the control unit 109 or the control unit 4.

The light emission control unit 45 outputs an irradiation light pulse to the obstacle sensor 2 and controls light emission of the obstacle sensor 2. Here, the light emission control unit 45 preferably transmits the irradiation light pulse Pi to the distance measurement unit 3 and receives the laser light emission pulse Pe from the distance measurement unit 3. At this time, the light emission control unit 45 determines the validity / invalidity of the detection signal Sd output from the obstacle sensor 2 for a predetermined time according to the laser light emission pulse Pe and the irradiation light pulse Pi, and based on the determination result, Modify Sd. FIG. 9 is a timing chart of the irradiation light pulse Pi and the corrected detection signal. Note that reference symbol Sda in FIG. 9 indicates the corrected detection signal.

In FIG. 9, the irradiation light Lra is applied at a time point tr1 when the irradiation light pulse Pi rises. At time tr2 when the same time as the TOF (Time @ of @ Flight) of the irradiation light Lra and the reflected light Lrb has elapsed from the time tr1, the reflected light Lrb is detected by the first light receiving unit 22. Further, at time tr3 at which the laser emission pulse Pe rises, the laser light La is irradiated. At time tr5 when the same time as TOF (Time @ of @ Flight) of the laser light La and the reflected light Lb has elapsed from the time t3, the reflected light Lb is detected by the first light receiving unit 22. Note that the reflected light Lb detected at the time point tr5 is light in which the laser light La is reflected by an object D1d below the first light receiving unit 22 (for example, below the external object OJ2, the road surface G, and the like). That is, the light is incident on the first light receiving unit 22 from the side D1d below the front direction D2f. Here, the light emission control unit 45 validates the detection signal Sd during the predetermined time Tre from the time point tr2 to the time point tr4. Therefore, the light emission control unit 45 does not modify the detection signal Sd at the predetermined time Tre. Further, the light emission control unit 45 invalidates the detection signal Sd in the period Tru from the time point tr4 to the time point tr6 at which the next irradiation light pulse Pi rises, and corrects the detection signal Sd. For example, the light emission control unit 45 removes a light receiving pulse from the detection signal Sd in the period Tru. Note that the time point tr4 is a time point after the predetermined time Tre from the time point tr2 and before the time point tr5. That is, tr2 <tr4 <tr5. By doing so, the light emission control unit 45 more reliably prevents the first light receiving unit 22 from erroneously detecting the reflected light Lb of the laser light La.

<2. Modified Example> Next, a modified example of the embodiment will be described, which is different from the above-described embodiment. FIG. 10 is a side view showing an automatic guided vehicle 100 according to a modification together with an external object OJ. In FIG. 10, the front end of the automatic guided vehicle 100 is viewed from the left D3L. In the following, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

In a modified example, the second light irradiating unit 31 of the distance measuring unit 3 irradiates the laser light La to a side opposite to the first light receiving unit 22 with respect to the second light irradiating unit 31. In other words, the second light irradiating unit 31 irradiates the laser beam La on the D1t side above the forward direction D2f. That is, the optical axis of the laser light La is directed upward D1t as it moves forward D2f. In this way, for example, in the vertical direction D1, the reflection of the laser beam La on an object D1d below the second light irradiation unit 31 of the distance measurement unit 3 (for example, below the external object OJ2, on the road surface G, etc.). Can be suppressed or prevented. Therefore, it is possible to more reliably prevent the obstacle sensor 2 that detects the surrounding object OJ from erroneously detecting the reflected light Lb of the laser light La emitted from the distance measuring unit 3.

The elevation angle between the optical axis of the laser beam La and the horizontal plane is preferably larger than half the spread angle of the laser beam La in the direction in which the optical axis extends. In this way, the laser beam La can be prevented from irradiating the object on the D1d side below the second light irradiating unit 31, so that, for example, the reflection at the lower part of the external object OJ2, the road surface G, etc. can be further effectively reduced. Can be suppressed or prevented.

<3. Others> The exemplary embodiments of the present disclosure have been described above. Note that the scope of the present invention is not limited to the above disclosure. The present disclosure can be implemented with various modifications without departing from the spirit of the invention. In addition, matters described in the present disclosure can be arbitrarily combined as appropriate without causing contradiction.

INDUSTRIAL APPLICABILITY The present disclosure is useful for a sensor unit having a plurality of optical sensors and a moving body on which the sensor unit is mounted.

100: automatic guided vehicle, 101: body, 102: carrier, 103L, 103R: support, 104L, 104R: drive motor, 105L, 105R: drive wheel, 106F, 106R ... follower wheel, 107 ... battery, 108 ... communication unit, 109 ... control unit, 1 ... sensor unit, 2 ... obstacle sensor, 21 ... first light irradiation unit , 211 ... LED, 22 ... first light receiving unit, 221 ... first light receiving element, 221a ... light receiving surface, 222 ... condenser lens, 223 ... light shielding member, 3 ...・ Distance measurement unit, 30 ・・・ Case, 301 ・・・ Transparent part, 31 ・・・ Second light irradiation part, 311 ・・・ LD, 311a ・・・ LD driver, 312 ・・・ Substrate, 313・・・ Collimate lens, 314 ・・・ Emission ,..., 321, a light receiving lens, 322, a light receiving mirror, 323, a wavelength filter, 324, a second light receiving element, 325, a comparator, 33,.・ Rotating housing, 33a ・・・ Opening, 34 ・・・ Motor, 34a ・・・ Shaft, 35 ・・・ Measurement unit, 36 ・・・ Calculation processing unit, 37 ・・・ Motor drive unit, 38 ・・・Communication I / F, 4 control unit, 41 drive control unit, 42 determination unit, 43 map creating unit, 44 position identification unit, 45 light emission control unit 5, storage unit, J: rotation axis, La: laser light, Lra: irradiation light, Lb, Lrb: reflected light, G: road surface, OJ, OJ1, OJ2 · ..Object, θ: Incident angle, Rs: Scanning range, D1: Vertical direction, D1d: Downward, D1t ..Upward, D2f: forward direction, D2r: rearward direction, D3: left / right direction, D3L: left, D3R: right

Claims

A first sensor having a first light irradiating unit and a first light receiving unit; and a second sensor having a second light irradiating unit. {The first light receiving unit is} the first light irradiating unit and the second light A sensor unit that is disposed between the first light receiving unit and the first light receiving unit and that is disposed between the first light receiving unit and the first light receiving unit;
2. The sensor unit according to claim 1, wherein the intensity of light emitted from the second light emitting unit is higher than the intensity of light emitted from the first light emitting unit. 3.
The sensor unit according to claim 1, wherein the second light irradiating unit irradiates a laser beam, and the first light irradiating unit irradiates a light having lower directivity than the laser light.
The sensor unit according to claim 3, wherein the second light irradiating unit irradiates the laser light to a side opposite to the first light receiving unit with respect to the second light irradiating unit.
The first sensor is an optical sensor that detects an object located around the first sensor, and the second sensor is a distance measurement that measures a distance between the first sensor and an object located outside the second sensor. The sensor unit according to any one of claims 1 to 4, which is a unit.
The sensor unit according to claim 5, wherein the distance measuring unit is disposed above the optical sensor, and the first light irradiation unit of the optical sensor is disposed below the first light receiving unit.
The first light receiving unit includes: (1) a light receiving element that detects incident light from the outside of the first light receiving unit at each incident angle based on a light receiving position on a light receiving surface; A condenser lens for condensing light on a light receiving surface, wherein the incident angle is both in a first direction from the first light receiving portion toward the first light irradiating portion and in a second direction perpendicular to the first direction. The sensor unit according to claim 1, wherein the angle is an angle of the incident light with respect to the second direction when viewed from a third direction perpendicular to the second direction.
The light emitted from the first light emitting unit and the light emitted from the second light emitting unit are respectively emitted to the outside of the sensor unit at different timings. 2. The sensor unit according to claim 1.
A moving body on which the sensor unit according to any one of claims 1 to 8 is mounted.