JP2020147418A - Image display device - Google Patents

Abstract

To stably provide peripheral information useful for the operation of a forklift to an operator by performing stable radio communication.SOLUTION: An image display device 20 includes: a peripheral information acquisition unit 20a mounted on a moving unit of a movable body; and a main body processing device 20b mounted on a main body of the movable body to perform radio communication with the peripheral information acquisition unit 20a by radio wave with directivity. The peripheral information acquisition unit 20a includes a first radio communication unit 23 including a first antenna 231. The main body processing device 20b includes: a second radio communication unit 26 including a second antenna 261; a main body control unit 25 generating an image based on the received peripheral information; a display unit 28 arranged in a position where it can be visually recognized by an operator from a driver's seat of the main body to display the image generated by the main body control unit 25; and a changing unit 27 changing a direction of directivity of radio wave of the second antenna 261 of the main body processing device 20b according to a position of the moving unit.SELECTED DRAWING: Figure 4

Description

The present invention relates to an image display device.

The forklift moves by placing the luggage on the pallet on the fork. For example, in a seat-type forklift in which the driver faces the direction of travel and sits in the driver's seat, a blind spot is created in the front when the fork is loaded higher than the driver's line of sight. When traveling, the driver moves while moving the forklift backward. However, at the time of cargo handling, it is necessary to move forward, and the driver has no choice but to lean out to the side and visually recognize.

In addition, there is a demand for accurate and easy positioning of the fork or the pallet insertion port on the fork even in the loading / unloading work on a high-altitude shelf where it is difficult for the driver to see the front of the fork. In the image processing device for a forklift disclosed in Patent Document 1 to solve such a problem, a camera for photographing the front is provided on the fork, and the photographed image is reduced to represent a fork or a part of a palette on the fork. The image is superimposed and displayed on the display.

Japanese Unexamined Patent Publication No. 2003-246597 (paragraph 0015, FIG. 1)

In the technique disclosed in Patent Document 1, a camera is provided at the tip of a fork that moves up and down, and is connected to a display in the driver's seat by a coaxial cable to transmit video.

However, when connecting a moving body such as a fork that moves up and down and a display unit of the driver's seat with a wired cable, it is necessary to consider entanglement due to looseness of the cable. In Patent Document 1, the cord telescopic reel prevents the cable from loosening. However, if a component such as a cord telescopic reel is used to transmit camera image data to the display unit, the degree of freedom in design is reduced. Further, if the cable is repeatedly wound and expanded and contracted by the cord telescopic reel, the cable is deteriorated due to the repeated operation, so that the durability is lowered and maintenance work is required.

The present invention has been made in view of the above circumstances, and data is transmitted by wireless communication between a peripheral information acquisition unit mounted on a moving unit of a moving body and a main body processing device mounted on the main body of the moving body. It is an object of the present invention to provide an image display device capable of stably providing information useful for operating a moving body to a driver by performing stable wireless communication at the time of transmission.

The above object of the present invention is achieved by the following means.

(1) Around information acquisition unit mounted on the moving unit of the moving body,
An image display device that is mounted on the main body of the moving body and includes a main body processing device that wirelessly communicates with the surrounding information acquisition unit by radio waves having directivity.
The surrounding information acquisition unit
With the first wireless communication unit including the first antenna,
As the surrounding information, an image in front of the moving body or a sensor that acquires the position information of the object in front is provided.
The main body processing device is
A second wireless communication unit that includes a second antenna and wirelessly communicates with the first wireless communication unit,
A main body control unit that generates an image based on the surrounding information transmitted from the first wireless communication unit and received by the second wireless communication unit.
A display unit that is arranged at a position visible to the driver from the driver's seat of the main body and displays an image generated by the main body control unit.
An image display device including a changing unit that changes the direction of radio wave directivity of the second antenna according to the position of the moving unit.

(2) The main body processing device further includes an acquisition unit that acquires relative position information between the moving unit and the main body of the moving body.
The image display device according to (1) above, wherein the changing unit changes the direction of the radio wave directivity of the second antenna according to the position information acquired from the acquiring unit.

(3) The image display device according to (1) or (2) above, wherein the moving body is a forklift and the moving portion is a fork.

(4) The fork is provided on the front side of the main body.
The image display device according to (3) above, wherein the second antenna of the second wireless communication unit is arranged on the front side surface of the main body of the forklift or on the front side of the upper part of the main body.

(5) The image display device according to (3) or (4) above, wherein the sensor is an image sensor of a camera attached to a tip end portion of the fork.

(6) The image display device according to any one of (1) to (5) above, wherein the wireless communication system is a WirelessHD system and the frequency band is 60 GHz.

(7) The image display according to any one of (1) to (6) above, wherein the changing unit changes the direction of the radio wave directivity by mechanically changing the direction of the second antenna. apparatus.

(8) The changing unit is a direction changing mechanism that mechanically changes the direction of the second antenna by rotating the rotation axis provided at one end of the second antenna as a rotation center. The image display device according to (7) above.

(9) The image display device according to (8) above, wherein the orientation changing mechanism has a plurality of rotation stop positions and rotates the second antenna at multiple rotation angles.

(10) The image display device according to (8) above, wherein the orientation changing mechanism rotates the second antenna at a continuous rotation angle.

(11) The image according to any one of (1) to (10) above, wherein the main body control unit detects an object in front based on the acquired surrounding information and generates an image corresponding to the detected object. Display device.

(12) The image display device according to any one of (1) to (11) above, wherein the display unit is a head-up display or a transmissive liquid crystal display.

The image display device according to the present invention includes a peripheral information acquisition unit mounted on a moving unit of a moving body and a main body processing device mounted on the main body of the moving body and wirelessly communicating with the surrounding information acquisition unit by radio waves having directivity. , The ambient information acquisition unit includes a first wireless communication unit including a first antenna, and the main body processing device includes a second wireless communication unit including a second antenna and a main body that generates an image based on received ambient information. The control unit, the display unit that is arranged at a position visible to the driver from the driver's seat of the main unit and displays the image generated by the main unit control unit, and the second antenna of the main unit processing device according to the position of the moving unit. It is equipped with a change unit that changes the direction of radio wave directivity. By using such an image display device, it is possible to stably provide the driver with information useful for operating the moving body by performing stable wireless communication.

It is a side view which shows the appearance of a forklift. It is a schematic diagram which shows the state which the 1st and 2nd cameras are attached to the tip | tip portion of one fork. It is an enlarged view of a fork. It is a block diagram which shows the hardware configuration and the functional configuration of the image display device which concerns on 1st Embodiment. It is a schematic diagram for demonstrating the structure of the antenna direction change mechanism. It is a schematic diagram which shows the relationship between the height position of a fork, and the radio wave directivity of a 2nd antenna. This is an example of the display screen displayed on the display. It is a figure which shows the state which attached the surrounding information acquisition part including the 1st and 2nd cameras to the tip part of a sheath fork.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios. Further, in the drawing, the vertical direction is the Z direction, the traveling direction of the forklift is the X direction, and the direction orthogonal to these is the Y direction.

(forklift)
FIG. 1 is a side view showing the appearance of a forklift. The image display device 20 according to the first embodiment is attached to the forklift 10. The forklift 10 has a main body (body) 11, a driver's seat 12, a mast 13, a finger bar 14, a pair of forks 15 and 16, and a head guard 17.

Here, the forklift 10 corresponds to a moving body. Further, the main body 11 and the head guard 17 are collectively referred to as a “main body”. The forks 15, 16 and the finger bar 14 that moves integrally with them correspond to the "moving part" of the moving body. The forklift 10 will be described as an example of the moving body in the following embodiments, but the moving body is not limited to this, and other types may be used as long as the vehicle can be moved by the drive source in the own device. Alternatively, the moving body may be a crane that moves along a rail. Excavators and cranes are examples of vehicles other than forklifts. Further, the main body has a driver's seat 12 of the driver. The moving part moves together with the main body, but it can also be moved so as to change the relative positional relationship with the main body.

A pallet 91 and a load 92 on the pallet 91 are loaded on the forks 15 and 16. A mast 13 that can be expanded and contracted in the vertical direction is provided in front of the main body 11. The forks 15 and 16 are supported by the finger bar 14, and are attached to the mast 13 via the finger bar 14 so as to be vertically movable. The forks 15 and 16 are positioned in the vertical direction by moving the finger bar 14 up and down along the mast 13 via a chain (not shown) attached to the mast 13 and a wheel. Further, the inclination angle (tilt) of the forks 15 and 16 with respect to the ground (running surface), the opening angle between the forks 15 and 16, and the interval are within a predetermined range by the hydraulic cylinder (not shown) in the finger bar 14. It can be changed.

(Camera 21a, 21b)
FIG. 2 is a schematic view showing a state in which the first and second cameras 21a and 21b are attached to the tip end portion of one fork. FIG. 3 is an enlarged plan view of the fork.

As shown in FIG. 2, of the two forklifts 15 and 16 of the forklift 10, two cameras 21a and 21b for stereo viewing (also referred to as compound eyes) are attached to the tip of one fork 15 as a main body. It is attached so that the front of 11 is the photographing area. Further, in the width direction (Y direction) of the fork 15, both cameras 21a and 21b are separated by a predetermined interval (baseline length). In the example shown in the figure, two cameras are attached to the fork 15 on the left side, but the present invention is not limited to this, and the fork 16 on the right side may be attached. The control unit 22 on the cameras 21a and 21b side and the main body control unit 25 on the display 28 side, which will be described later, are wirelessly connected, and a video signal (image signal) is transmitted to the main body control unit 25 by wireless communication. The first and second cameras 21a and 21b each include an image sensor (imaging sensor) having sensitivity in the visible light region such as CCD or CMOS, and an optical system such as a lens, and photograph the front of the forklift 10 to obtain an image (image). Image) is generated. In the following, when the two cameras 21a and 21b are not distinguished, they are collectively referred to simply as "camera 21".

As an example of the size of the fork 15, the thickness is 10 mm, the width is 100 mm, the tapered portion is R (radius) 60 mm, and the tapered portion is from the tip s1 to 40 mm in the X direction and from the side surface to 40 mm in the Y direction. .. As another application example, when a fork 15 having a tapered surface provided not only on the side surface but also on the lower surface side is used, the cameras 21a and 21b may be arranged on the tapered portion.

Cylindrical holes are provided on both the left and right sides of the tapered portion of the fork 15, and the cameras 21a and 21b are embedded in the holes, respectively. It is preferable to arrange the cameras 21a and 21b so that the front surface of the lens slightly protrudes from the outer peripheral surface of the tapered portion in that a wide angle of view can be secured, but due to a collision of the fork 15 with the floor surface or the like during use. From the viewpoint of breakage, it is more preferable to arrange it inside the opening surface of the columnar hole.

When viewing an object in stereo (stereoscopic view) for distance measurement, it is necessary to overlap the imaging areas of the two cameras 21a and 21b. In order to secure a wide field of view (angle of view) and allow more regions to overlap, it is preferable to provide cameras 21a and 21b on the tapered portion on the side surface or the lower surface. As shown in FIG. 3, the two cameras 21a and 21b arranged in the tapered portion on the side surface side can secure a wide angle of view toward the front side of the fork 15. The two cameras 21a and 21b arranged in this way and the main body control unit 25 (described later) cooperate to detect the distance to the object, and the distance measurement point cloud data (also referred to as "three-dimensional distance map"). To generate.

(Configuration of image display device 20)
Next, the configuration of the image display device 20 will be described with reference to FIG. 1 and FIG. FIG. 4 is a block diagram showing a hardware configuration of the image display device 20 and a functional configuration of the main body control unit 25.

As shown in FIGS. 1 and 4, the image display device 20 includes a surrounding information acquisition unit 20a and a main body processing device 20b. The surrounding information acquisition unit 20a is mounted on the moving portion side (fork 15, 16, or finger bar 14), and the main body processing device 20b is mounted on the main body side (main body portion 11 and head guard 17) of the forklift 10.

(Around information acquisition unit 20a)
The surrounding information acquisition unit 20a includes a control unit 22, a first wireless communication unit 23, and a position information detection unit 24, in addition to the fork camera 21 described above. Power is supplied to these electronic components on the ambient information acquisition unit 20a side by a battery (not shown). The control unit 22, the first wireless communication unit 23, the position information detection unit 24, etc. are housed in a sensor box 29a made of a radio wave transmitting material, and between the sensor box 29a and the cameras 21a, 21b, Wired connection by cable 212. The cable 212 is arranged inside a groove provided on the lower surface of the fork 15. The sensor box 29a (first wireless communication unit 23) is mounted on the base of the fork 15 or the finger bar 14, and moves up and down together with the fork 15.

(Control unit 22)
The control unit 22 includes a CPU (Central Processing Unit) and a memory, and the CPU executes a control program stored in the memory to perform various controls on the entire surrounding information acquisition unit 20a. Further, the control unit 22 controls the entire image display device 20 in cooperation with the main body control unit 25.

(1st wireless communication unit 23)
The first wireless communication unit 23 includes the first antenna 231 and wirelessly communicates with the main body processing device 20b side by a radio wave having directivity. Examples of the wireless communication method include wirelessHD using radio waves in the 60 GHz band and WiGig according to the IEEE standard. Since these wireless communication methods have a high frequency of radio waves, they are radio waves having high straightness and directivity. Therefore, in order to perform stable high-speed communication, it is necessary to align the radio wave directivity of the antenna with the second wireless communication unit 26 of the main body processing device 20b within a short distance of several meters.

In the wireless communication between the first wireless communication unit 23 and the second wireless communication unit 26 described later of the main body processing device 20b, the amount of data communication from the first wireless communication unit 23 to the second wireless communication unit 26 is large. Overwhelmingly many. Specifically, the uncompressed data of the video captured by the camera 21 and the detection data of the position information detection unit 24 are continuously transmitted to the second wireless communication unit 26. The main body processing device 20b processes the received video data in real time to detect an object, or displays the received video on the display 28. The video transmitted from the surrounding information acquisition unit 20a may be an HD resolution video or a full HD resolution video. The amount of data communication for video only is approximately 165 MB / when transmitting video with HD resolution (1280 x 720 pixels, 3 bytes per pixel) at 30 fps without compression using two cameras 21a and 21b. A large transfer rate of sec is required. In addition, in forklift work, a fine image or a wide range of images is required for assistance (useful information), and the data size of the image becomes large. If the image is delayed due to the large data size, there will be a time lag between the display and the actual work, for example, when placing luggage on a shelf where there is not enough space or when loading and unloading luggage in a high position that is not directly visible. For example, there is a risk that the worker may make a mistake in the work and the luggage or the fork may hit the shelf. High-speed communication is required to prevent such problems. In order to make the data to be communicated as light as possible, the control unit 22 may compress the compressed data according to a standard such as MPEG or JPEG, and transmit the compressed data.

(Position information detection unit 24)
The position information detection unit 24 functions as a position information acquisition unit and acquires relative position information between the forks 15 and 16 and the main body 11. Specifically, the position information detection unit 24 acquires the position information of the heights of the forks 15 and 16 with respect to the mast 13, that is, the height with respect to the ground. The position information detection unit 24 is composed of, for example, an acceleration sensor and / or a gyro sensor. As another example, the forklift 10 and the image display device 20 may be electrically connected, and the position information of the heights of the forks 15 and 16 may be acquired from the control signal regarding the height received from the forklift 10. In this case, the input / output interface of the image display device 20 functions as a position information acquisition unit.

(Main body processing device 20b)
The main body processing device 20b includes a main body control unit 25, a second wireless communication unit 26, an antenna orientation changing mechanism 27, and a display 28. Electronic components other than the display 28 are housed in the main body box 29b. Before explaining the main body control unit 25, first, the second wireless communication unit 26 and the antenna orientation changing mechanism 27 that functions as the changing unit will be described.

(2nd wireless communication unit 26)
The second wireless communication unit 26 includes a second antenna 261 and a radio wave intensity detection unit 262, and wirelessly communicates with the first wireless communication unit 23 of the ambient information acquisition unit 20a by a radio wave having directivity. By mechanically changing the direction of the second antenna 261 by the antenna direction changing mechanism 27, the direction of the radio wave directivity of the second antenna 261 is changed. In addition, the radio wave strength detection unit 262 detects the strength of the received radio wave. The main body box 29b is made of a material such as a radio wave transmitting resin. The main body box 29b (that is, the second antenna 261) is arranged on the front side surface of the main body of the forklift 10 or on the front side of the upper part of the main body. Specifically, as shown in FIG. 1, it is arranged on the front side of the head guard 17 constituting the upper part of the main body. Alternatively, it may be arranged on the front side of the main body 11.

(Antenna orientation changing mechanism 27)
FIG. 5 is a schematic diagram for explaining the configuration of the antenna orientation changing mechanism 27. In the example shown in FIGS. 5A and 5B, the second antenna 261 is a directional loop-shaped antenna. As shown in FIG. 5A, the antenna orientation changing mechanism 27 is a rotation mechanism composed of a motor 271, a gear 272, a claw 273, and a solenoid 274. When the motor 271 rotates by a predetermined amount, one end of the second antenna 261 is attached to the rotation shaft a1 of the gear 272, and the second antenna 261 rotates in the direction of the arrow with the rotation shaft a1 as the center of rotation. Further, the rotation of the gear 272 is stopped by the claw 273 that is urged toward the gear 272 by the spring. Further, when the angle is changed, the main body control unit 25 turns on the solenoid 274 to temporarily move the claw 273 to the retracted position while rotating the gear 272 by a predetermined amount by the motor 271. The second antenna 261 is rotated. The second antenna 261 rotates around the rotation axis a1 along the Y-axis direction in multiple stages at a rotation stop position corresponding to the position of the gear 272. The number of stages is, for example, about several stages. By making it possible to change the rotation constant stop position step by step, the accuracy of the angle at the time of stop is improved. Not limited to such a configuration, if the motor 271 is a motor with an encoder function, the angle of the second antenna 261 can be changed steplessly (continuously) by rotating the motor 271 by a predetermined angle. May be good. In the example shown in FIG. 5, by rotating the second antenna 261 around the Y axis, the first and second antennas are opposed to each other. For example, the first and second antennas are arranged at the same position in the Y direction.

(Main body control unit 25)
Like the control unit 22, the main body control unit 25 includes a CPU and a memory, performs various controls, and functions as an object detection unit 251 and an image processing unit 252. These functions will be described later.

The main body control unit 25 obtains height information of the forks 15 and 16 with respect to the mast 13 from the detection data of the position information detection unit 24. As a result, the relative position information between the first antenna 231 and the second antenna 261 can be known. The main body control unit 25 grasps the height position of the first antenna 231 from the detection data of the position information detection unit 24. It is preferable that the detection data is transmitted before the wireless communication between the first wireless communication unit 23 and the second wireless communication unit 26 is interrupted or the communication speed is lowered. The transmission cycle of the detection data can be appropriately set according to the maximum ascending / descending speed of the forks 15 and 16. The main body control unit 25 receives the height position detection data, controls the antenna orientation changing mechanism 27, and changes the orientation of the second antenna 261 toward the first antenna 231. Specifically, the second antenna 261 is rotated by a predetermined angle with the rotation axis a1 as the rotation center so that the center of the loop surface of the loop-shaped second antenna 261 faces the first antenna 231. The association table (or relational expression) between the height position detected by the position information detection unit 24 and the rotation angle (stop position) of the second antenna 261 is preset and stored in the memory of the main body control unit 25. ing. The main body control unit 25 may set the angle of the second antenna 261 by using the detection data of the radio wave intensity detection unit 262. For example, the angle of the second antenna 261 may be appropriately adjusted so that the radio field intensity from the radio wave intensity detection unit 262 is maximized each time the height position of the first antenna 231 changes. Alternatively, the main body control unit 25 records the adjustment angle (stop position) of the second antenna 261 that maximizes the radio wave intensity from the radio wave intensity detection unit 262 at the height positions of the first antenna 231 in a plurality of stages. The table may be created at the time of introduction or on a regular basis.

FIG. 6 is a schematic view showing the relationship between the height position of the forks 15 and 16 and the radio wave directivity of the second antenna 261 when the forks 15 and 16 are moved up and down. The arrow in FIG. 6 indicates the direction of the radio wave directivity of the second antenna 261. As shown in FIG. 6, the main body control unit 25 controls the antenna orientation changing mechanism 27 according to the height position of the first antenna 231 moving together with the forks 15 and 16, so that the orientation is appropriate. The direction of the second antenna 261 is changed. By doing so, when the surrounding information acquisition unit 20a and the main body processing device 20b are configured as separate bodies and the two are wirelessly connected by wireless communication, stable and high-speed communication can be performed. As a result, it is possible to stably provide the driver with information useful for operating the forklift regarding surrounding information.

(Object detection unit 251 and image processing unit 252)
Next, the functions of the object detection unit 251 and the image processing unit 252 of the main body control unit 25 will be described.

(Object detection unit 251)
The object detection unit 251 acquires the position information of the object in front by cooperating with the first and second cameras 21a and 21b. In this case, the first and second cameras 21a and 21b function as sensors for acquiring the position information of the object in front. The object detection unit 251 extracts common corresponding points from the extracted feature points of a set of images, and calculates the distance to each of the feature points using the conversion parameters from those corresponding points. For example, in a pair of cameras 21a and 21b arranged on the left and right, the distance value of each pixel is calculated according to the amount of deviation of the left and right pixel values of the same corresponding point using the baseline length (distance measurement), and three-dimensional. Generate a distance map.

Further, the object detection unit 251 detects an object in front of the forklift 10 and detects the position of the detected object in the three-dimensional space by using the generated distance map. Objects to be detected include luggage 92, pallets 91, people (workers), and other objects such as shelves and obstacles on aisles. The detection of this object may be performed, for example, by clustering the pixels according to the similarity of the distance values of the pixels. Further, clustering may be performed by combining the similarity of the distance values with the similarity of the color of the pixels. Calculate the size of each cluster determined from clustering. For example, the vertical dimension, the horizontal dimension, the total area, and the like are calculated. The "size" referred to here is an actual size, and is different from the apparent size (angle of view, that is, the spread of pixels), and a block of pixel groups is determined according to the distance to the object. For example, the object detection unit 251 determines whether or not the calculated size is equal to or larger than a predetermined size threshold value for identifying the object to be analyzed to be extracted. The size threshold can be arbitrarily set depending on the measurement location, the behavior analysis target, and the like. If the behavior is analyzed by tracking the passing workers, the minimum value of the size of a normal person may be used as the size threshold value for clustering. Objects below the size threshold are excluded. Further, if the environment in which the forklift 10 travels is limited in a specific warehouse or the like, a size threshold value corresponding to an object existing in that environment may be applied. Further, the object detection unit 251 displays a three-dimensional distance map including information on the size and position of each object of a predetermined size or larger in front of the generated forklift 10 (main body unit 11) in the internal memory of the image display device 20 or Accumulate in external memory such as server.

Further, as the type of the object, machine learning may be used or proportion discrimination (aspect ratio) may be used for discriminating between a human being and another object. In machine learning, a computer repeats learning using the obtained three-dimensional distance map data and correct label data. Especially in the work space, it is important to discriminate the worker in order to prevent a serious accident, and it is expected that the discriminating accuracy will be improved by using these.

Further, the distance measurement may be performed by one camera 21a instead of the configuration in which the distance measurement is performed by the images of the pair of cameras 21a and 21b. For example, by arranging a floodlight at the position of the camera 21b and irradiating the floodlight with a pattern light composed of a plurality of grid-like lines or dots at a predetermined timing, the distance is measured and the focus point cloud group data is generated. You may try to do it.

(Image processing unit 252)
The image processing unit 252 forms an image that assists the driver's work of the forklift 10 according to the type of the object in front detected by the object detection unit 251 and the relative position (distance) to the object.

The image processing unit 252 determines whether or not to issue a warning to the object or person detected by the object detection unit 251. For example, if a person exists within a predetermined distance in the moving direction of the main body 11, the driver is warned. The warning is given through the display 28, but may be given by a warning light or a speaker (neither shown) provided on the forklift 10.

Further, the image processing unit 252 creates an additional image (annotation image) for assisting the work according to the type of the object detected forward by the object detection unit 251 and displays it on the display 28. An example of the display screen will be described later. As the additional image, there is a distance ladder showing the distance to an object such as a luggage 92 in front, and a numerical display. In addition, the additional image may be a rectangular frame whose color or mode is changed according to the type and distance of the object, or a mark or text for alerting the driver when there is an object requiring attention. Good. Further, as the additional image, it may be information on the inclination angle, the inclination angle, or the height from the ground in the horizontal plane or the XY plane in front of the pallet of the fork.

(Display 28)
The display 28 functions as a display unit. The display 28 is attached at a position visible from the driver's seat 12 of the forklift 10. As the display 28, for example, a HUD (head-up display) can be applied. When the HUD is applied, the display 28 comprises a combiner that is a semitransparent concave or plane mirror and projects a virtual image onto the combiner. The virtual image is a display image generated by the image processing unit 252 described above. This combiner is arranged on the front side of the driver's seat 12, and the driver sitting in the driver's seat 12 can see the real image (forks 15, 16, luggage 92, etc.) ahead of the combiner through the combiner, and the combiner reflects. You can recognize virtual images at the same time. By using the HUD, even if the combiner is placed in front of the driver's seat, the combiner becomes transparent when no image is projected, so that the forward visibility is not obstructed.

Further, as another example of the display 28, a transmissive liquid crystal display may be applied. The transmissive liquid crystal display does not obstruct the forward view as much as the HUD. However, the present invention is not limited to this, and a normal liquid crystal display may be applied as yet another example of the display unit. In this case, it is preferable to arrange the liquid crystal display diagonally above the driver's seat 12 at a position that does not obstruct the front view, for example, a head guard 17. By using a normal liquid crystal display, it is possible to display a high-resolution image even at a low cost. Further, when applying a normal liquid crystal display, a stitch process of pasting a high-resolution image taken by one of the first and second cameras 21a and 21b or a set of images in a positional relationship according to the baseline length. The image with the stitches may be continuously displayed in real time.

FIG. 7 is an example of the display screen 280 displayed on the display 28. A truck 95 as an object, a pallet 91 on the pallet 91, a luggage 92, and a worker 96 are present in front of the forklift 10, and show a situation in which the forklift 10 is approaching the loading platform of the truck 95. The pallet 91, the luggage 92, the truck 95, and the worker 96 are real images and are viewed by the driver through the transparent display 28.

The object detection unit 251 of the main body processing device 20b detects an object in front of the object based on the images acquired by the cameras 21a and 21b as ambient information. Further, the image processing unit 252 generates information according to the object detected by the object detection unit 251 and displays this on the display 28.

In the display screen 280 of FIG. 7, the additional images 401 to 406 are information generated by the main body control unit 25 according to the detected object.

The additional image 401 is an illustration image (animation image) corresponding to the forks 15 and 16. The additional images 402 and 403 are images showing a line in which the forks 15 and 16 are extended forward and the periphery of the contact position thereof. As a result, the driver can recognize the position where the forks 15 and 16 hit (insert). The additional images 404 and 405 are images showing the distance to the object in front of the forklift 10. The additional images 404 and 405 are also referred to as a distance ladder together with the additional image 403. The additional image 406 shows the distances of the forks 15 and 16 to the upper surface of the truck bed in the height direction. The additional image 407 is a mark that calls attention to the driver when a person (worker 96) approaches in front of the forklift 10.

In the additional images 401 to 406, if the distance between the pair of forks 15 and 16 and the inclination angle of the forks 15 and 16 with respect to the ground are changeable forklift 10, the distance and the inclination angle can be changed. The shape, size, and orientation may be changed. For example, when the fork 15 is tilted upward, the additional images 403 to 406 are changed according to the tilt angle. The interval distance and the inclination angle may be obtained by processing of the object detection unit 251 based on the image acquired from the camera 21, or may be detected by the position information detection unit 24.

In the first embodiment, as shown in FIG. 7, by displaying the information corresponding to the detected object on the display 28, it is possible to provide an index useful for operating the forklift 10. A sensor for detecting the presence or absence of luggage on the forks 15 and 16 is included in the sensor box 29a, so that when the forks 15 and 16 have luggage and the heights of the forks 15 and 16 are equal to or more than a predetermined value. , The front view is obstructed. Therefore, in such a situation, the image from the camera 21 received wirelessly may be displayed as it is on the display 28. Further, an image in which the above-mentioned additional image is superimposed may be displayed on this image. By doing so, even if the front view is obstructed by the luggage 92, the front can be confirmed by the image from the camera 21 displayed, so that the driver can stably provide information useful for forklift operation regarding surrounding information. Can be provided.

The configuration of the image display device 20 for a forklift described above is not limited to the above configuration, and various modifications are made within the scope of claims, as the main configuration has been described in explaining the features of the above-described embodiment. can do. Moreover, the configuration provided in a general image display device is not excluded.

(Modification example 1)
FIG. 8 is a schematic view showing a state in which the entire surrounding information acquisition unit 20a including the first and second cameras 21a and 21b is attached to the tip end portion of one sheath fork. The sheath fork 19 is mounted so as to cover the fork 15 (or fork 16) and is fixed by a holder (not shown) such as a screw.

As shown in FIG. 8, the sheath fork 19 has a main body portion 191 and a lid portion 192, a transparent plate 193, an impact mitigation member 194, and an aluminum plate 195.

The first and second cameras 21a and 21b and the substrate unit 29c are arranged on the aluminum plate 195. The board unit 29c includes the control unit 22, the first wireless communication unit 23, and the position information detection unit 24 described above, as well as the battery for supplying power. By fixing the lid portion 192 to the main body portion 191 with a bolt b1 or the like, each electronic component on the aluminum plate 195 is housed in the space of the main body portion 191.

The main body 191 is made of steel. The lid portion 192 is made of a material such as a radio wave transmitting resin. The transparent plate 193 is a member that transmits light, and is made of, for example, polycarbonate. The first and second cameras 21a and 21b photograph the outside through the transparent plate 193. The shock absorbing member 194 is made of an elastic body such as silicon rubber or a gelled material.

The shock absorbing member 194 is attached on the inner surface of the main body portion 191. By the shock absorbing member 194, the camera and the electronic components constituting the detection sensor are indirectly connected to the main body via the shock absorbing member 194. Connect with part 191. Specifically, in the example of FIG. 8, all the electronic components are covered with the shock absorbing member 194, and the impact caused by the collision of the object with the sheath fork 19 is alleviated and transmitted to each electronic component. By using such a sheath fork 19, the orientation of the second antenna 261 is changed when the surrounding information acquisition unit 20a is wirelessly connected to the main body processing device 20b by wireless communication even if the configuration is separate from the main body processing device 20b. As a result, stable and high-speed communication can be performed.

(Modification 2)
In the first embodiment described above and the example of the first modification, the direction of the radio wave directivity is changed by mechanically changing the direction of the second antenna 261 by the antenna direction changing mechanism 27. Not limited to this, the orientation of the first antenna 231 may also be changed. Specifically, a mechanism similar to the antenna orientation changing mechanism 27 is provided on the first antenna 231 side, whereby the direction of the radio wave directivity of the first antenna 231 also depends on the relative position with respect to the second antenna 261. You may change it.

(Modification 3)
Further, in the above-described embodiment, the antenna orientation changing mechanism 27 that mechanically changes the orientation of the antenna is shown as an example of the changing portion. However, the present invention is not limited to this, and may be a change part that electrically changes the direction of the radio wave directivity of the second antenna (or both the first antenna 231 and the second antenna 261) rather than mechanically. .. It is especially useful when beamforming by applying the Wigig communication method.

For example, each of the first antenna 231 and the second antenna 261 is composed of a plurality of antennas (antenna groups), and the second antenna 261 (or the first antenna 231 is also) is electrically formed by beamforming by MIMO technology. Change the direction of the radio wave directivity of. For example, by explicit feedback, the change unit adjusts the phase and amplitude of the radio waves from each antenna constituting the antenna group of the first antenna 231 and / or the second antenna 261 so that the first antenna 231 and / or the second antenna 261 and / Or change the direction of the radio wave directivity of the second antenna 261. Specifically, the channel state is calculated on the second wireless communication unit 26 side based on the sounding frame transmitted from the first wireless communication unit 23 side, and this is fed back to the first wireless communication unit 23 side. As a result, the first wireless communication unit 23 adjusts the phase and amplitude of the radio waves from each antenna of the antenna group. Alternatively, the phase and amplitude of the radio waves from each antenna of the antenna group of the second wireless communication unit 26 are adjusted by the same processing using the sounding frame from the second wireless communication unit 26 side.

The means and methods for performing various processes in the image display device according to the above-described embodiment can be realized by either a dedicated hardware circuit or a programmed computer. The program may be provided by a computer-readable recording medium such as a USB memory or a DVD (Digital Versaille Disc) -ROM, or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. Further, the above program may be provided as a single application software, or may be incorporated into the software of the device as a function of the image display device.

10 Fork lift 11 Main body 12 Driver's seat 13 Mast 14 Finger bar 15, 16 Fork 17 Head guard 19 Sheath fork 20 Image display device 20a Ambient information acquisition unit 21a, 21b Camera 22 Control unit 23 1st wireless communication unit 231 1st antenna 24 position Information detection unit 20b Main unit processing device 25 Main unit control unit 251 Object detection unit 252 Image processing unit 26 Second wireless communication unit 261 Second antenna 262 Radio wave strength detection unit 27 Antenna orientation change mechanism 28 Display 280 Display screen 29a Sensor box 29b Main unit box 91 Pallet 92 Luggage 95 Truck 96 Workers 401-407 Additional information

Claims (12)

Around information acquisition unit mounted on the moving part of the moving body,
An image display device that is mounted on the main body of the moving body and includes a main body processing device that wirelessly communicates with the surrounding information acquisition unit by radio waves having directivity.
The surrounding information acquisition unit
With the first wireless communication unit including the first antenna,
As the surrounding information, an image in front of the moving body or a sensor that acquires the position information of the object in front is provided.
The main body processing device is
A second wireless communication unit that includes a second antenna and wirelessly communicates with the first wireless communication unit,
A main body control unit that generates an image based on the surrounding information transmitted from the first wireless communication unit and received by the second wireless communication unit.
A display unit that is arranged at a position visible to the driver from the driver's seat of the main body and displays an image generated by the main body control unit.
An image display device including a changing unit that changes the direction of radio wave directivity of the second antenna according to the position of the moving unit. The main body processing device further includes an acquisition unit that acquires relative position information between the moving unit and the main body of the moving body.
The image display device according to claim 1, wherein the changing unit changes the direction of the radio wave directivity of the second antenna according to the position information acquired from the acquisition unit. The image display device according to claim 1 or 2, wherein the moving body is a forklift and the moving part is a fork. The fork is provided on the front side of the main body.
The image display device according to claim 3, wherein the second antenna of the second wireless communication unit is arranged on the front side surface of the main body of the forklift or on the front side of the upper part of the main body. The image display device according to claim 3, wherein the sensor is an image sensor of a camera attached to a tip end portion of the fork. The image display device according to any one of claims 1 to 5, wherein the wireless communication system is a WirelessHD system and the frequency band is 60 GHz. The image display device according to any one of claims 1 to 6, wherein the changing unit changes the direction of the radio wave directivity by mechanically changing the direction of the second antenna. 7. The changing portion is a direction changing mechanism that mechanically changes the direction of the second antenna by rotating the rotation axis provided at one end of the second antenna as a rotation center. The image display device described in 1. The image display device according to claim 8, wherein the orientation changing mechanism has a plurality of rotation stop positions and rotates the second antenna at a plurality of rotation angles. The image display device according to claim 8, wherein the orientation changing mechanism rotates the second antenna at a continuous rotation angle. The image display device according to any one of claims 1 to 10, wherein the main body control unit detects an object in front based on the acquired surrounding information and generates an image corresponding to the detected object. The image display device according to any one of claims 1 to 11, wherein the display unit is a head-up display or a transmissive liquid crystal display.