JP4196826B2 - Rear view display device for turning work vehicle - Google Patents

Description

  The present invention relates to a swivel work vehicle such as a hydraulic excavator, in which a camera is provided at the rear position of the upper swivel body, and a rear view image obtained from the camera is displayed on a monitor installed in a cab. The present invention relates to a rear visual field display device, and more particularly to a rear visual field display device that can accurately detect a distance to an object or the like located in the rear visual field when a monitor is viewed.

  As an example of a working vehicle, a hydraulic excavator is composed of a lower traveling body having a crawler type traveling means and an upper turning body installed via a turning device. The upper turning body has a front as a driver's cab and working means. A work machine is installed. These cab and front working machine are arranged in front of the upper swing body. Moreover, the building which comprises a machine room is provided in the rear part side of the cab in an upper revolving structure, and the counterweight is installed in the rearmost position.

  A hydraulic excavator is mainly used for excavation of earth and sand. A driver's seat on which an operator is seated is installed in the driver's cab, and an operating lever, an operating pedal, and the like as operating means are provided on the left and right sides and the front of the driver's seat. Therefore, the operator sits in the driver's seat and operates each operation means. During the operation, the front and side conditions of the driver's cab can be confirmed with the naked eye of the operator, but faced forward. In the posture, the visual field of the rear and the oblique rear cannot be obtained. Here, from the viewpoint of work safety and smoothness, it is extremely important to obtain a rear view.

In particular, when the operator enters the work site where the excavator is operating and is doing some work, or when there are structures around it, it is very important to confirm the safety of the rear. come. Here, the rear view is necessary mainly when the lower traveling body is moving backward and when the upper rotating body is turning.When performing operations such as excavating earth and sand and loading the dump truck, the backward and Since turning is performed frequently, getting off frequently for safety confirmation is extremely disadvantageous and troublesome in terms of work efficiency. From the above, a monitoring camera is installed behind the upper revolving unit so that the operator can check the safety even when the operator is facing forward in the cab, and the video from this camera is displayed. A device that obtains a rear visual field by displaying on a monitor provided in a driver's cab is conventionally known as disclosed in Patent Document 1, for example.
JP 2002-371595 A

  By the way, in a work vehicle such as a hydraulic excavator, the target of safety confirmation is a person such as an operator and an object such as a structure or a machine tool, and therefore, within a range where it interferes with the work vehicle, that is, from the ground. If a field of view up to the height position of the upper surface of the upper swing body is obtained, the object is substantially achieved. Therefore, the camera installed at the rear position of the upper revolving body of the work vehicle has a visual field centered obliquely downward, so that the distance to these human or physical obstacles can be grasped to some extent around the work vehicle. It is common to do so.

  Now, as shown in FIG. 8, the camera C is arranged at a position of height h from the ground G, and the visual field center A of the camera C is directed obliquely downward, from the position p to the position s on the ground G. Suppose you have a field of view. When the image obtained by the camera C is displayed on the monitor M as shown in FIG. 9, the image close to the position p is naturally large, and the image becomes small as the position approaches the position s. That is, when the distance from the position p to the position s is decomposed into fixed intervals (interval a shown in FIG. 8), in the image on the monitor M, the interval d is wider on the position p side, and the position s It is displayed so that a space | interval becomes narrow continuously toward the side. Therefore, it is not always easy to grasp the exact distance from the vehicle to the position where the obstacle exists only by visually observing the monitor M. In addition, when the upper swing body is swung, it may not be possible to accurately determine from the image on the monitor M whether or not there is an obstacle at a position that may interfere with the upper swing body. That is, since the image is expressed two-dimensionally on the monitor M, even if the visual field center A of the camera C is directed obliquely downward, sufficient information in the depth direction of the image shown in the image cannot be obtained. Perspective may not always be accurately grasped.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to more accurately grasp the distance from the upper swing body of the image appearing in the image displayed on the monitor. is there.

To achieve the above object, in the present invention, it provided at a rear portion of the upper rotating body to a working vehicle which pivotally instrumentation wearing upper swing structure to the lower traveling body, get rear-view of the swivel body And a monitor for displaying an image obtained by the camera , wherein the camera is provided on the upper swing body so that the center of the field of view is obliquely downward toward the rear. , and the said monitor, said camera graduations are formed toward the rear of the end portion from this position as the origin of the upper rotating body as arcuate distance display lines around the rotation center of the upper rotating body This is characterized in that it is configured to display the image superimposed on the image acquired in (1).

  Here, the distance display line can be formed as a plurality of scales for displaying the distance from the turning center, may be a turning line for displaying the turning radius, and further, working means installed in the vehicle. It is also possible to display the trajectory at the time of turning. It is particularly preferable that the scale and the turning line are displayed, and the turning line is displayed by changing the color, thickness, line type, and the like.

  The distance display line is most suitable to be superimposed on the image at the stage of image signal processing. However, this line is inserted through a transparent film or the like that displays the line on the imaging side, for example, the objective optical system. Can be displayed at the same time, or it can be set so that a line is displayed in advance on the display side, for example, a monitor.

  By configuring as described above, at a predetermined height position in the upper swing body, the distance from the upper swing body of the image included in the image obtained from the camera installed with the field of view directed obliquely downward is accurately determined. There are effects such as being able to be determined.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a hydraulic excavator will be described as an example of a swivel work vehicle. However, the work vehicle to which the rear view display device of the present invention is applied is not limited to this hydraulic excavator. Needless to say.

  FIG. 1 shows a hydraulic excavator that is a turning work vehicle. In the figure, a hydraulic excavator 1 includes a lower traveling body 2 having a pair of left and right crawler traveling means, and an upper revolving body 4 connected to the lower traveling body 2 via a revolving device 3. Accordingly, the entire vehicle can be driven by the lower traveling body 2 such as moving forward and backward, and the upper swing body 4 can be swung with respect to the lower traveling body 2. The turning center at the time of turning of the upper turning body 4 is indicated by O in the figure.

The upper swing body 4, an operator aboard, the cab 10 for operating the entire machine is installed, also as a working mechanism, the boom 11, arm 12 and bucket 13 (the bucket 13 is in the other A multi-joint front work machine 14 is attached. A building 15 in which equipment such as an engine, a hydraulic pump, and a control valve are installed is provided at a site behind the installation section of the cab 10 and the front work machine 14, and a hydraulic oil tank and a fuel tank are provided. Such tanks are also installed. Further, a counterweight 16 is installed at the rearmost position of the upper swing body 4.

  When the excavator 1 is operated to perform excavation such as earth and sand, the operator operates operation means such as an operation lever and an operation pedal in the cab 10, but the front work machine 14 operates in front of the operator. Therefore, the operator can confirm safety by directly viewing the operating state. Further, when the vehicle is running and when the upper turning body 4 is turning, it is possible to confirm the safety in the front, it is difficult to confirm the safety in the rear, and the field of view is blocked by the building 15 or the like, so-called blind spots. There are also directions. Therefore, when the vehicle is moved backward or when the upper turning body 4 is turned, a camera is mounted on the counterweight 16 located at the rearmost part of the upper turning body 4 in order to supplementarily obtain a visual field behind it. 20 is installed, and the rear side is photographed by the camera 20 so that the operator can visually recognize it. Here, the camera 20 can be configured to shoot a still image at predetermined time intervals, but is preferably configured to be a moving image state, that is, a television camera.

  The rear view image obtained by the camera 20 is displayed on a monitor 21 installed in the cab 10. The monitor 21 is installed at a position that is easy to see when the operator is seated in the driver's seat provided in the cab 10 and that does not obstruct the front vision as much as possible. As a result, when a rear view is required, such as when the vehicle is moving backward or when the upper turning body 4 is turning, the operator can check the safety of the rear and diagonally rear by viewing the monitor 21. .

  As shown in FIG. 2, the camera 20 is installed at an intermediate position in the width direction of the counterweight 16 and at a certain height. Here, the visual field center A of the camera 20 is obliquely downward toward the rear as shown in FIG. That is, the reason for acquiring the rear visual field is to ensure the safety of the person and the object, and the information above the height position of the counterweight 16 is not necessary, and the image existing on the ground becomes a problem. It is necessary to acquire an image standing on the road surface over a wide range. As described above, the visual field of the camera 20 is directed obliquely downward so that a certain degree of distance is given to the two-dimensional expression display monitor 21, but the perspective of the image displayed on the monitor 21 is reduced. The feeling cannot always be accurately grasped.

Therefore, as shown in FIG. 4, the scale 22 as the distance display line is displayed on the screen of the monitor 21 so as to be superimposed on the image from the camera 20. The scale 22 has an arc shape centered on the turning center O of the upper swing body 4 on which the camera 20 is installed, and an arc whose radius is the rear end T of the counterweight 16 which is the rearmost part of the upper swing body 4. scale 22 ₀ is the origin of the scale 22 as (this scale 22 ₀ becomes the pivot line of the upper frame 4), sequentially scale 22 ₁ toward the rear from the position of the origin scale 22 _0, 22 _2, ... _-A plurality of lines such as 22 _n are formed. Here, the intervals of the scales 22 are formed every time a constant pitch interval is increased, for example, every 1 m. In addition, the monitor 21 may indicate the distance to each scale 22 with a numerical value together with the scale 22 as necessary.

  By configuring as described above, the operator is displayed on the screen of the monitor 21 in order to confirm the safety of the rear when the vehicle is moved backward by the lower traveling body 2 or when the upper turning body 4 is turned. When the image of the camera 20 is viewed, the operator can easily and accurately recognize the distance from the counterweight 16 such as a person or an object reflected in the image with the scale 22. Therefore, it is possible to accurately determine whether or not the collision must be avoided, and whether or not there is a possibility of collision when the operation is continued as it is. In addition, when an avoidance operation is necessary, it is possible to determine what operation should be performed according to which procedure and the like. As a result, work safety is ensured.

  Here, in order to superimpose and display the scale 22 on the image from the camera 20, for example, a technique of interposing a transparent plate displaying the scale 22 in the optical system of the camera 20 may be used. Since the mounting position and the turning center position of the upper turning body 4 are not necessarily constant, and the pitch interval of the scale 22 can be arbitrarily set, as shown in FIG. The scale setting means 31 is connected to the image signal processing circuit 30 and the scale 22 arbitrarily set by the scale setting means 31 is superimposed on the image of the camera 20. Can be configured to.

  This makes it possible to perform accurate scale display at a desired pitch interval when setting to which position the camera 20 is attached and how much the visual field center is inclined is set. Further, in order to accurately measure the distance from the rear end portion T of the counterweight 16, it is desirable to increase the number of scales 22, but when a large number of scales 22 are displayed, the camera 20 It becomes difficult to see the image. Therefore, in order to set the pitch interval of the scale 22 to an arbitrary interval, it is desirable that the scale setting unit 31 can freely set the pitch interval of the scale 22.

  Here, the hydraulic excavator 1 shown in FIG. 1 is a standard machine, and the hydraulic excavator 1 as the standard machine has a distance from the turning center O to the rear end T of the counterweight 16 in the width of the lower traveling body 2. It is longer than the dimension, that is, the interval between the outer end portions of the left and right crawler belts, and the rear side protrudes more greatly on the front side and the rear side with the turning center O as a boundary. Therefore, in this type of machine, the rear end T of the counterweight 16 becomes the turning radius of the upper turning body 4. On the other hand, in the excavator 101 shown in FIG. 6, when the upper swing body 104 is swung, the rear end portion of the upper swing body 104 is outside the left and right crawler tracks of the lower traveling body 102. A so-called rear small turning type having a length that does not protrude outward from the end portion has been put into practical use. In the case of this hydraulic excavator 101, when comparing the length LF from the turning center O to the front end of the revolving structure 104 with the length LB to the rear end, the length LF on the front end side is more Therefore, the turning radius of the turning upper turning body 104 is the front end portion of the upper turning body 104.

  As described above, the monitor 21 as the rear visual field display device provided in the rear small turning type hydraulic excavator 101 displays the turning radius in addition to the plurality of scales 22 as shown in FIG. As a distance display line formed in an arc shape, the turning line 23 can also be displayed. Here, when displaying the turning line 23 on the monitor 21, it is desirable to change the color or the line type so that it can be distinguished from the scale 22. In particular, it is more desirable that the swivel line 23 changes color and line type with the scale 22. Thus, by displaying the turning line 23 together, it is possible to determine whether the turning line 23 is a reference line and whether a human or physical obstacle is inside or outside the turning line 23. .

  In the case of a configuration having a pivotable upper swing body such as a hydraulic excavator, the upper swing body is normally capable of 360 ° swing. Therefore, when the turning radius is larger at the front end of the upper swing body 104 than at the rear end, when the upper swing body 104 is to be swung largely by displaying the swing line 23, the upper swing body is displayed. Since it becomes possible to predict in advance the possibility that 104 will collide with human and physical obstacles, higher safety is ensured.

1 is an overall configuration diagram of a hydraulic excavator as a turning work vehicle provided with a rear visual field display device showing an embodiment of the present invention. It is a structure explanatory view which shows the installation position of the camera in the upper revolving body of FIG. It is composition explanatory drawing which shows the visual field direction of a camera. It is explanatory drawing which shows the one aspect | mode on the monitor screen of a back visual field display apparatus. It is a figure which shows the circuit structure for superimposing a scale on a camera image, and displaying it on a monitor. It is a whole block diagram which shows the back small turning type hydraulic excavator as another turning type working vehicle. It is explanatory drawing which shows the one aspect | mode of the display of the monitor screen of the back visual field display apparatus in the hydraulic shovel of FIG. It is explanatory drawing which shows a visual field range when arrange | positioning a camera in a certain height position from the ground and directing the visual field center of this camera to diagonally downward. It is explanatory drawing which shows the relationship between a distance when a video acquired with the camera which has a visual field of FIG. 8 is displayed on a monitor, and a display area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Hydraulic excavator 2,102 Lower traveling body 4,104 Upper turning body 10 Driver's cab 16 Counterweight 20 Camera 21 Monitor 22, 22 ₀ , 22 ₁ , 22 ₂ ,... 22 _n scale 23 Turning line 30 Image signal Processing circuit 31 Scale setting means

Claims (4)

Wherein the working vehicle which pivotally instrumentation wearing upper swing structure to the lower traveling body provided at a rear portion of the upper frame, and displays the camera to obtain a rear-view of the swing body, an image obtained by the camera In the thing with the monitor,
The camera is provided on the upper swing body so that the center of the visual field is obliquely downward toward the rear ,
In the monitor, a graduation formed backward from this position with the rearmost part of the upper swing body as the origin is acquired by the camera as an arc-shaped distance display line centering on the swing center of the upper swing body. A rear visual field display device for a swivel work vehicle, characterized by being configured to display the image superimposed on the image. 2. The rear visual field display device for a turning work vehicle according to claim 1 , wherein the scale as the distance display line includes a plurality of arc-shaped lines indicating distances from the turning center on a road surface. 2. The rear visual field display device for a turning work vehicle according to claim 1, wherein the distance display line is a turning line for displaying a turning radius of the upper turning body. The distance display line includes a plurality of scales indicating the distance from the turning center on the road surface, and a turning line for displaying a turning radius of the upper turning body formed by a line distinguishable from the scales. The rear visual field display device for a turning work vehicle according to claim 1.

Images