JP2020043382A - Forklift remote control system - Google Patents

Abstract

To provide a forklift remote control system that makes it easy to understand a relationship with an interference object when a forklift turns.SOLUTION: The forklift remote control system includes: cameras 71, 72, 73, mounted on a reach-type forklift 20, for imaging the periphery of the reach-type forklift 20; a display unit 63, provided on the remote control device 40 for displaying images captured by the cameras 71, 72, 73; and a controller 61 for generating an expected trajectory of a rear corner of a machine opposite to a turning direction on the basis of a current steering angle prior to turning of the reach-type forklift 20 and superimposing it on the images captured by the cameras 71, 72, 73 to display the image on the display unit 63.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a forklift remote control system.

  In the rear periphery monitoring device for a work vehicle disclosed in Patent Document 1, a turning center of a vehicle body is obtained based on a steering angle of a rear wheel, and a traveling locus of left and right rear wheels is calculated based on data of the turning center. A bird's-eye view image having a rear image portion, a left image portion, and a right image portion arranged corresponding to the periphery of the vehicle body image is formed from the captured image data. Then, the traveling trajectory is superimposed on the bird's-eye view image to create a composite image, and the back-around monitor device arranged in the cockpit displays the composite image as enlarged images of the left and right rear wheels.

JP 2014-239357 A

  By the way, in the forklift remote control system, when the technique of Patent Literature 1 is used, interference with a structure (an obstacle) is difficult to recognize only by superimposing the traveling trajectory of the rear wheel advanced by a predetermined distance.

  An object of the present invention is to provide a remote control system for a forklift, which makes it easy to understand the relationship with an interference object when the forklift turns.

  A forklift remote control system for solving the above-mentioned problems includes a forklift including a cargo handling device on a machine base and a vehicle communication unit, and an operation device communication unit for performing wireless communication with the vehicle communication unit. A remote control device for remotely controlling travel of the cargo handling and cargo handling by the cargo handling device, a remote control system for a forklift, which is mounted on the forklift and captures an image of a periphery of the forklift, A display unit provided on a remote control device, for displaying an image captured by the camera, and, prior to the turning of the forklift, a rear corner of the machine base opposite to the turning direction based on the current steering angle. A trajectory superimposing unit that generates an expected trajectory, superimposes the predicted trajectory on an image captured by the camera, and displays the predicted trajectory on the display unit. The gist of the door.

  According to this, prior to the turning of the forklift, an expected trajectory of the rear corner of the machine on the opposite side to the turning direction is generated based on the current steering angle, and is superimposed on the image captured by the camera, and is displayed on the display unit. Is displayed. Therefore, it is possible to easily understand the relationship with the interference target when the forklift turns.

  In addition, regarding the forklift remote control system, the trajectory superimposing unit may be configured such that, prior to the turning of the forklift, the tip or turning direction of the fork on the opposite side to the turning direction of the pair of left and right forks based on the current steering angle. It is preferable to further generate an expected trajectory of the front corner of the pallet on the opposite side and superimpose the trajectory on the image captured by the camera, and display it on the display unit.

  In addition, regarding the forklift remote control system, when the pallet sensor detects a pallet on the fork, the trajectory superimposing unit predicts a pallet front corner on the opposite side to the turning direction based on the current steering angle prior to turning of the forklift. It is preferable that a trajectory is further generated and superimposed on an image captured by the camera and displayed on the display unit.

  Further, regarding the forklift remote control system, the forklift is a reach-type forklift, and the trajectory superimposing unit includes a pair of right and left reach legs arranged on the front side of the machine based on a current steering angle prior to turning of the forklift. The expected trajectory of the front corner of the reach leg opposite to the turning direction, or the axial center of the front wheel opposite to the turning direction among the left and right front wheels provided on the pair of left and right reach legs arranged on the front of the machine May be further generated and superimposed on an image captured by the camera and displayed on the display unit.

  In addition, regarding the forklift remote control system, the trajectory superimposition unit may include an area between the predicted trajectory of the front corner of the pallet in the turning direction and the predicted trajectory of the rear corner of the machine opposite to the turning direction, It is preferable that the information is displayed on the display unit so as to be distinguished from other areas.

  Further, regarding the remote control system for a forklift, the trajectory superimposing portion includes an expected trajectory of a front corner portion in a reach leg in a turning direction or an expected trajectory of an axial center of a front wheel in a turning direction, and a machine rear angle opposite to the turning direction. The region sandwiched between the predicted trajectory of the unit and the other region may be displayed on the display unit so as to be distinguished from other regions.

  Further, regarding the remote control system for a forklift, the forklift is a counter-type forklift, and the trajectory superimposing portion is opposite to the turning direction of the left and right front wheels based on a current steering angle prior to the turning of the forklift. It is preferable to further generate an expected trajectory of the front wheel axis center and superimpose it on an image captured by the camera and display the trajectory on the display unit.

  ADVANTAGE OF THE INVENTION According to this invention, when turning a forklift, the relationship with an interference object can be made easy to understand.

FIG. 2 is a block diagram showing an electric configuration of a forklift remote control system. The schematic side view which shows a reach type forklift. FIG. 1 is a schematic perspective view showing a part of a reach type forklift in a cutaway manner. The top view which shows a reach type forklift typically. 5 is a flowchart according to the first embodiment. The top view which shows a reach type forklift typically. The top view which shows a reach type forklift typically. 7A and 7B are diagrams showing display contents on a display unit. (A) is a plan view schematically showing a reach-type forklift, (b) is a plan view schematically showing a reach-type forklift, and (c) is a view showing display contents on a display unit. 9 is a flowchart according to the second embodiment. The top view which shows a reach type forklift typically. The top view which shows a reach type forklift typically. (A), (b), (c) is a figure which shows the display content on a display part. (A) is a plan view schematically showing a reach-type forklift, (b) is a plan view schematically showing a reach-type forklift, and (c) is a view showing display contents on a display unit. The top view which shows the reach type forklift and its periphery typically. The top view which shows the reach type forklift and its periphery typically. The top view which shows typically the reach type forklift in 3rd Embodiment, and its periphery. (A), (b) is a top view which shows typically the reach type forklift in 3rd Embodiment. The top view showing typically the reach type forklift in a 4th embodiment. (A), (b), (c) is a figure which shows the display content on a display part. (A) is a plan view schematically showing a reach-type forklift, (b) is a plan view schematically showing a reach-type forklift, and (c) is a view showing display contents on a display unit. The top view which shows the reach type forklift and its periphery typically. The top view which shows the reach type forklift and its periphery typically. The top view which shows typically the reach type forklift in 5th Embodiment, and its periphery. The top view which shows typically the reach type forklift in 5th Embodiment, and its periphery. The schematic side view which shows the counter type forklift of another example. The top view which shows a counter type forklift typically.

(First embodiment)
An embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the remote control system 10 for a forklift includes a reach type forklift 20 and a remote control device 40 used to remotely control the traveling of the reach type forklift 20 and cargo handling by the loading / unloading device. . The reach type forklift 20 is arranged in a work place. Then, the reach type forklift 20 in the workplace can be remotely controlled from the operation room using the remote control device 40.
A reach type forklift 20 is located at a place away from a pallet or the like in a work place. From this state, the operator remotely operates the reach-type forklift 20 to bring the reach-type forklift 20 closer to a pallet or the like and to perform an operation of inserting a fork into a pallet hole.

  As shown in FIGS. 2 and 3, the reach type forklift 20 includes a machine base 21. A pair of left and right reach legs 22a and 22b are arranged on the front side of the machine base 21, and the reach legs 22a and 22b extend forward. Specifically, the reach leg 22a is provided on the right side in the traveling direction, and the reach leg 22b is provided on the left side in the traveling direction. Front wheels 23a and 23b are provided in front of the reach legs 22a and 22b. Specifically, the right front wheel 23a is provided on the right reach leg 22a in the traveling direction, and the left front wheel 23b is provided on the left reach leg 22b in the traveling direction. As described above, a pair of left and right front wheels 23a and 23b is provided on the front side of the machine base 21.

  A rear wheel 24 and caster wheels (auxiliary wheels) 25 are provided at the rear of the machine base 21. The rear wheel 24 is provided on the left side of the machine base 21, and the caster wheel 25 is provided on the right side of the machine body 21. The rear wheels 24 are driving wheels and steering wheels.

  As shown in FIG. 2, the reach type forklift 20 runs on three front wheels 23 a and 23 b and one rear wheel 24. The machine base 21 is mounted with a traveling motor 26 serving as a driving source of the reach type forklift 20 and a battery 27 serving as a power source of the traveling motor 26. Then, the rear wheel 24 is driven to rotate by the traveling motor 26.

  The reach type forklift 20 includes a cargo handling device 28 in front of the machine base 21. The cargo handling device 28 includes a mast 29 that moves back and forth along each of the reach legs 22a and 22b by driving a reach cylinder (not shown). In front of the mast 29, a pair of left and right forks 30a, 30b is provided via a lift bracket 31. The forks 30a and 30b move up and down along the mast 29.

The reach-type forklift 20 of the present embodiment is configured so that a driver can sit and operate it. Note that an unmanned reach type forklift having no driver's seat may be used.
As shown in FIG. 3, the reach type forklift 20 includes a standing-type cab 32 at the rear of the machine base 21. In front of and in the left of the cab 32, steering tables 33a and 33b are provided. A steering table 33a located in front of the cab 32 is provided with a direction lever 34 for operating the reach type forklift 20 and a plurality of cargo handling levers 35 for operating the cargo handling device 28. The direction lever 34 is operated to drive the rear wheel 24 to rotate and drive the vehicle. On a steering table 33b located to the left of the cab 32, a steering wheel 36 for steering the rear wheels 24 is provided. A brake pedal 37 is provided on the floor of the cab 32.

The cab 32 is surrounded by two pillars 38 erected on the machine base 21 and a head guard 39 fixed to an upper end of the pillar 38.
As shown in FIG. 1, the reach type forklift 20 includes a controller 51, a wireless unit 52 as a vehicle communication unit, an image processing unit 53, a wireless device 54 as a vehicle communication unit, and a camera as the forklift mounted device 50. 71, 72 and 73.

  The remote operation device 40 includes a controller 61, an operation unit 62, a display unit (monitor) 63, and wireless devices 64 and 65 as operation device communication units. The remote control device 40 includes a controller 61, an operation unit 62, and a display unit (monitor) 63 as the operation room side device 60.

  The wireless device 64 of the remote control device 40 is arranged in a work place. Further, the wireless device 65 of the remote control device 40 is arranged at the work place. The controller 61 arranged in the operation room is connected to a wireless device 64 arranged in the work place by a wire L1. The controller 61 is connected by a wire L2 to a wireless device 65 arranged in the work place.

  In the workplace, the wireless device 64 of the remote control device 40 and the wireless unit 52 of the forklift-mounted device 50 can perform two-way wireless communication. In the workplace, the wireless device 54 of the forklift-mounted device 50 can wirelessly communicate with the wireless device 65 of the remote control device 40.

  Thus, the reach type forklift 20 has the wireless unit 52 and the wireless device 54, and the remote control device 40 has the wireless devices 64 and 65 that perform wireless communication with the wireless unit 52 and the wireless device 54.

  The controller 61 of the remote operation device 40 is connected to an operation unit 62 and a display unit (monitor) 63. The operation unit 62 is for remotely controlling the reach type forklift 20 by an operator. The operation contents of the reach type forklift 20 (lift, reach, tilt operation command values, speed, acceleration, steering, etc.) Angle operation command value, etc.) is sent to the controller 61. The controller 61 wirelessly transmits lift, reach, and tilt operation command values and vehicle control signals such as speed, acceleration, and steering angle operation command values to the wireless unit 52 of the forklift-mounted device 50 via the wireless device 64. I do.

  In the forklift mounted device 50, the controller 51, the wireless unit 52, and the image processing unit 53 are connected so as to be able to communicate with each other (for example, CAN communication). The controller 51 can drive a travel system actuator (the travel motor 26, a steering motor (not shown), etc.) and a cargo handling actuator (a lift cylinder, a reach cylinder, a tilt cylinder, etc., not shown) according to an instruction from the remote control device 40 side.

The wireless unit 52 wirelessly transmits vehicle information such as the vehicle speed of the reach type forklift 20 and abnormality information (obstacle detection information and the like) to the controller 61 via the wireless device 64.
In FIG. 1, the controller 61 can remotely control the traveling of the reach-type forklift 20 and the cargo handling by the cargo handling device 28 via the wireless device 64, the wireless unit 52, and the controller 51. That is, instead of the operation units (the direction lever 34, the cargo handling lever 35, the handle 36, the brake pedal 37, and the like) in FIG. 3, the remote operation can be performed by the operation unit 62 of the remote operation device 40.

  Then, in the remote control device 40, when the operator performs a desired operation using the operation unit 62, the operation content is sent by the controller 61 to the reach type forklift 20 via the wireless device 64. In the reach type forklift 20, the operation content from the remote control device 40 is received by the wireless unit 52, and the controller 51 drives the actuator unit to execute a desired operation.

As shown in FIG. 4, the reach type forklift 20 has a right rear corner P1 and a left rear corner P2 in the machine base 21.
As shown in FIGS. 2 and 4, a camera 71 is attached to the front part of the head guard 39 of the reach type forklift 20 so as to face forward and downward. The camera 71 captures an image around the reach type forklift 20. Specifically, the camera 71 captures an image of a floor surface ahead of the reach type forklift 20 in the traveling direction. A camera 72 is attached to the right rear portion of the head guard 39 of the reach type forklift 20 so as to face downward. The camera 72 captures an image around the reach type forklift 20. Specifically, the camera 72 images the vicinity of the right rear corner P1 of the machine base 21 from above. In the reach type forklift 20, a camera 73 is attached to the left rear portion of the head guard 39 so as to face downward, and the camera 73 captures an image around the reach type forklift 20. Specifically, the camera 73 images the vicinity of the left rear corner P2 of the machine base 21 from above.

  As shown in FIG. 1, in the reach type forklift 20, images captured by the cameras 71, 72, and 73 are sent by the controller 51 to the remote control device 40 via the image processing unit 53 and the wireless device 54. In the remote control device 40, a camera image from the reach type forklift 20 is received by the wireless device 65 and displayed on the display unit 63 by the controller 61. The display unit 63 is, for example, a desktop type display.

  On the display unit 63 provided in the remote control device 40, images captured by the cameras 71, 72, 73 are displayed. The operator operates while viewing the images of the cameras 71, 72, and 73 on the display unit 63.

Next, the operation will be described.
As shown in FIG. 5, when turning at the maximum steering wheel angle (when turning on the spot) in step S101, the controller 61, as shown in FIG. Circles C1 and C2 as predicted trajectories to pass are represented in a world coordinate system. The turning radius when turning right is based on the right front wheel 23a. The turning radius when turning left is based on the left front wheel 23b. The circle having the largest turning radius is the circle drawn by the rear corners P1 and P2, which are the outermost rear portions of the reach of the reach type forklift.

  In step S102 in FIG. 5, the controller 61 detects the relative positions of the circles C1, C2 in step S101 and the cameras 71, 72, 73 as shown in FIG. 7, and converts the circles C1, C2 in step S101 into a world coordinate system. Is converted to the camera coordinate system. In step S103 of FIG. 5, the controller 61 converts the coordinates of the circles C1 and C2 in step S102 from the camera coordinate system to the monitor coordinate system. In step S104 of FIG. 5, the controller 61 superimposes the circles C1 and C2 of step S103 on the camera image, and displays the machine rear corner P1 and P1 on the display 63 as shown in FIGS. 8A and 8B. Display around P2.

  More specifically, when turning left, as shown in FIG. 9A, the circle C1 passing through the rear corner P1 of the machine is expressed in a world coordinate system, and as shown in FIG. 9B. , The relative position between the circle C1 and the cameras 72 and 73 is detected, and the circle C1 is coordinate-transformed from the world coordinate system to the camera coordinate system. Further, the circle C1 is coordinate-transformed from the camera coordinate system to the monitor coordinate system, the circle C1 is superimposed on the camera image, and further displayed on the display unit 63 as shown in FIG. 9C. That is, a circle C1 is generated and displayed as an expected trajectory of the machine rear corner P1 on the opposite side to the turning direction in which there is a possibility of interference when turning left. This makes it easier for the operator to determine whether or not interference occurs.

  On the other hand, when turning right, the circle C2 passing through the rear corner P2 of the machine is expressed in the world coordinate system, the relative position between the circle C2 and the cameras 72 and 73 is detected, and the circle C2 is moved from the world coordinate system to the camera. The coordinates are converted to a coordinate system, and the circle C2 is further converted from the camera coordinate system to the monitor coordinate system, and the circle C2 is superimposed on the camera image and displayed on the display unit 63. That is, a circle C2 is generated and displayed as an expected trajectory of the machine rear corner P2 on the opposite side to the turning direction in which there is a possibility of interference when turning right. This makes it easier for the operator to determine whether or not interference occurs.

  As described above, prior to the turn of the reach type forklift 20, the controller 61 determines the circles (C1, C2) as the expected trajectory of the machine rear corners (P1, P2) on the opposite side to the turning direction based on the current steering angle. ). Then, the controller 61 causes the display unit 63 to display the image superimposed on the images captured by the cameras 71, 72, and 73.

  More specifically, the controller 61 as a trajectory superimposing unit prior to the in-place turn of the reach type forklift 20 turning at the maximum steering wheel angle, based on the current steering angle, the machine rear corner (P1, The circle (C1, C2) as the predicted trajectory of P2) is generated and superimposed on the images captured by the cameras 71, 72, 73 and displayed on the display unit 63.

The details will be described below.
Circles C1 and C2 as predicted trajectories of the rear corners P1 and P2 of the machine are superimposed and displayed on the camera image. The reach-type forklift 20 is often used in a relatively narrow place because of a small turning radius in rear wheel steering. Therefore, if the turning radius is not correctly predicted and judged, there is a possibility that the turning object may come into contact with a surrounding object at the time of turning. In particular, when operating the reach-type forklift 20 by remote operation, the operator must predict and judge the turning radius of the reach-type forklift 20 from the camera image, and it is difficult to make a correct judgment as compared with the manned operation. . Therefore, when the reach type forklift 20 is turned at the maximum steering wheel angle from the current position, that is, when the so-called in-situ turn is performed, the circles C1 and C2 passing through the machine rear corners P1 and P2 are superimposed on the camera image as a guide display. To display.

  In this way, when turning the reach-type forklift with the maximum handle angle from the current position, that is, when turning on the spot, circles C1 and C2 as predicted trajectories through which the machine rear corners P1 and P2 pass are displayed as guides. Is displayed superimposed on the camera image. Therefore, it is easy to recognize the circles C1 and C2 (turning radii) as the expected trajectories of the rear corners P1 and P2 of the machine stand, and safety during turning by remote control is improved.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the forklift remote operation system 10, the machine platform 21 is provided with the cargo handling device 28 and the reach type forklift 20 is provided with the wireless unit 52 and the wireless device 54 as a vehicle communication unit. In addition, there are wireless devices 64 and 65 as operating device communication units that perform wireless communication with the wireless unit 52 and the wireless device 54 as a vehicle communication unit, and remotely operate the traveling of the reach-type forklift 20 and cargo handling by the cargo handling device 28. A remote control device 40 used for Cameras 71, 72, 73 mounted on the reach-type forklift 20 to capture images around the reach-type forklift 20, and provided on the remote control device 40 for displaying images captured by the cameras 71, 72, 73. The display unit 63 is provided. Prior to the turn of the reach type forklift 20, circles (C1, C2) are generated as expected trajectories of the rear corners (P1, P2) of the machine opposite to the turning direction based on the current steering angle, and the camera (71). , 72, 73) is provided with a controller 61 as a trajectory superimposing unit to be superimposed on the image captured by the display unit 63 and displayed on the display unit 63. Therefore, when turning the reach type forklift 20, it is possible to easily understand the relationship with the interference target (such as an obstacle).

  (2) The turn of the reach type forklift 20 is an in-situ turn. Therefore, prior to the turn, the circles C1 and C2 are displayed as the predicted trajectories of the rear corners P1 and P2 of the machine, so that the relationship between the reach type forklift 20 and the object to be interfered during the turn of the reach forklift 20 can be understood. It can be easier.

(Second embodiment)
Next, a second embodiment will be described focusing on differences from the first embodiment.
As shown in FIG. 4, the reach type forklift 20 has a tip P11 of a right fork 30a and a tip P12 of a left fork 30b.

  As shown in FIG. 10, in step S201, when turning at the maximum steering wheel angle (when turning on the spot), the controller 61 passes through the machine rear corners P1 and P2 as shown in FIG. The circles C1 and C2 as the expected trajectories and the circles C11 and C12 as the expected trajectories through which the fork tips P11 and P12 pass are expressed in the world coordinate system. The turning radius when turning right is based on the right front wheel 23a. The turning radius when turning left is based on the left front wheel 23b. The circles C11 and C12 through which the fork tips P11 and P12 pass vary depending on the in-out state of the reach (position in the front-rear direction of the mast 29).

  The controller 61 detects the relative positions of the circles C1, C2, C11, and C12 in Step S201 and the cameras 71, 72, and 73 in Step S202 in FIG. , C11, C12 from the world coordinate system to the camera coordinate system. In step S203, the controller 61 converts the coordinates of the circles C1, C2, C11, and C12 in step S202 from the camera coordinate system to the monitor coordinate system. In step S204, the controller 61 superimposes the circles C1, C2, C11, and C12 in step S203 on the camera image, and displays the machine image on the display unit 63 as shown in FIGS. 13A, 13B, and 13C. The front and the vicinity of the rear corners P1, P2 of the machine are displayed.

  More specifically, when turning left, as shown in FIG. 14A, a circle C1 passing through the rear corner P1 of the machine and a circle C11 passing through the tip P11 of the fork are expressed in the world coordinate system. Then, as shown in FIG. 14B, the relative positions of the circles C1, C11 and the cameras 71, 72, 73 are detected, and the coordinates of the circles C1, C11 are transformed from the world coordinate system to the camera coordinate system. Further, the circles C1 and C11 are coordinate-transformed from the camera coordinate system to the monitor coordinate system, and the circles C1 and C11 are superimposed on the camera image and displayed on the display unit 63 as shown in FIG. On the other hand, during a right turn, the circles C2 and C12 through which the machine rear corner P2 and the fork tip P12 pass are represented in the world coordinate system, and the relative positions of the circles C2 and C12 and the cameras 71, 72 and 73 are determined. The circles C2 and C12 are detected and coordinate-transformed from the world coordinate system to the camera coordinate system. Further, the coordinates of the circles C2 and C12 are converted from the camera coordinate system to the monitor coordinate system, and the circles C2 and C12 are superimposed on the camera image and displayed on the display unit 63.

The guide display of the machine turning range in the present embodiment will be described with reference to FIGS.
When turning the forklift at the maximum steering wheel angle from the current position (when turning on the spot), the circle passing through the rear corners P1, P2 of the machine stand and the tip ends P11, P12 of the fork is superimposed on the camera image as a guide display. indicate. That is, the turning radius of the turning radius at the time of turning left (based on the front left wheel) and the turning radius at the time of turning right (based on the front right wheel) is the largest at the rear corner P1 which is the outermost rear portion of the forklift. , P2.

  In the case where the machine base is turned 360 degrees, a clearance with an obstacle around the machine base is required by the turning radius of the rear corners P1 and P2 of the machine base. On the other hand, in other cases (for example, when the machine is turned 90 degrees), a clearance corresponding to the turning radius of the machine rear corners P1 and P2 is not necessarily required, and the machine rear corners P1 and P2 are not necessarily required. In the area where does not pass, there is no problem as long as there is a clearance corresponding to the turning radius of the fork tips P11 and P12. Therefore, not only the circle passing through the machine rear corners P1 and P2 but also the circle passing through the fork tip portions P11 and P12 are displayed as guides.

  As shown in FIG. 15, when turning left by 360 degrees, the turning radius (circle C1) of the rear corner P1 of the machine is displayed, and the turning radius of the rear corner P1 of the machine is displayed in all directions of the machine. Clearance with other obstacles is required.

  As shown in FIG. 16, at the time of turning 90 degrees to the left, the turning radius (circle C1) of the rear corner P1 and the turning radius (circle C11) of the fork tip P11 are displayed. In the area where the machine rear corner P1 passes, clearance with the surrounding obstacle is required by the turning radius (circle C1) of the machine rear corner P1, but in the area where the machine rear corner P1 does not pass, the clearance of the fork tip P11 is reduced. It is sufficient if there is a clearance corresponding to the turning radius (circle C11).

  In other words, when turning 90 degrees in place and directly facing the position of the pallet, the turning radius is the largest at the rear corner P1 of the machine, so that the machine is located in the area where the rear corner P1 of the machine passes. A clearance is required for the turning radius (circle C1) of the rear corner P1. On the other hand, in an area where the rear corner P1 of the machine does not pass, it is sufficient that there is a clearance corresponding to the turning radius (circle C11) of the fork tip P11. In this way, the predicted turning trajectory (circles C1, C11) of the machine base rear corner P1 and the fork tip P11 is displayed. By performing the guide display in this way, it is possible to easily determine whether or not facing is possible without interference (contact) with an obstacle.

According to the present embodiment, the following effects can be obtained in addition to the above (1).
(3) Prior to the turning of the reach type forklift 20, the controller 61 as the trajectory superimposing unit uses the tip of the fork (P11) of the pair of left and right forks 30a, 30b opposite to the turning direction based on the current steering angle. , P12) are further generated as circles (C11, C12) as predicted trajectories, and are superimposed on images captured by the cameras (71, 72, 73) and displayed on the display unit 63. Therefore, the circles C11 and C12 are displayed as the predicted trajectories of the tips P11 and P12 of the forks 30a and 30b, so that the relationship with the interference object can be more easily understood when the reach type forklift 20 turns. .

(Third embodiment)
Next, a third embodiment will be described focusing on differences from the second embodiment.
In the present embodiment, as shown in FIG. 17, prior to turning of the reach type forklift 20, the controller 61 determines a circle as an expected trajectory of the machine rear corner P1 on the opposite side to the turning direction based on the current steering angle. A circle C51 is generated as an expected trajectory of C1 and the reach leg front corner P51 (or the center of the front wheel axis). Then, the controller 61 superimposes the images captured by the cameras 71, 72, 73 on the display unit.

  Here, in FIG. 18A, when the front wheels 23a and 23b do not protrude from the reach legs 22a and 22b, circles C51 and C52 are displayed as the expected turning trajectories of the reach leg front corners P51 and P52. On the other hand, as shown in FIG. 18B, when the front wheels 23a, 23b are protruding from the reach legs 22a, 22b, circles C61, C62 are displayed as predicted turning trajectories of the front wheel axis centers P61, P62.

  Specifically, for example, as shown in FIG. 17, when turning around by 180 degrees to change the direction, the turning radius is the largest at the machine rear corner P1 and the machine rear corner P1 The circle C1 is displayed as the expected turning trajectory of the vehicle. By performing the guide display in this way, it is possible to easily determine whether or not the direction can be changed without interference (contact) with an obstacle.

According to the present embodiment, the following effects can be obtained in addition to the above (1).
(4) Prior to turning of the reach type forklift 20, the controller 61 serving as a trajectory superimposing unit is a side opposite to the turning direction of the pair of left and right reach legs 22a and 22b arranged on the front side of the machine based on the current steering angle. Circle (C51, C52) as an expected trajectory of the front corner portion (P51, P52) of the reach leg or the left and right front wheels 23a, 23b provided on the pair of left and right reach legs 22a, 22b arranged on the front side of the machine base. A circle (C61, C62) is further generated as an expected trajectory of the axis center (P61, P62) of the front wheel on the side opposite to the turning direction, and is superimposed on an image captured by the camera (71, 72, 73). It is displayed on the display unit 63. Therefore, the expected trajectory of the reach legs 22a and 22b or the expected trajectory of the front wheels 23a and 23b is displayed, so that the relationship with the interference target can be more easily understood when the reach type forklift 20 turns.

(Fourth embodiment)
Next, a fourth embodiment will be described focusing on differences from the second embodiment.
As shown in FIG. 2, the lift bracket 31 is provided with a pallet sensor Sp for detecting the pallet 80 (see FIG. 19). In the controller 61, the pallet sensor Sp detects that the forks 30a, 30b are inserted into the pallet 80 (see FIG. 19). As the pallet sensor Sp, for example, a contact sensor that is turned on when the pallet comes into contact can be used.

  As shown in FIG. 19, when turning at the maximum steering wheel angle (when turning on the spot), the controller 61 controls the circles C1, C2 through which the machine rear corners P1, P2 pass and the front corner of the pallet 80. Circles C21 and C22 as predicted trajectories through which P21 and P22 pass are expressed in a world coordinate system. The controller 61 detects the relative positions of the circles C1, C2, C21, C22 and the cameras 71, 72, 73, and converts the coordinates of the circles C1, C2, C21, C22 from the world coordinate system to the camera coordinate system. The controller 61 converts the coordinates of the circles C1, C2, C21, and C22 from the camera coordinate system to the monitor coordinate system. The controller 61 superimposes the circles C1, C2, C21, and C22 on the camera image, and displays the front of the machine base and the rear corner of the machine base on the display unit 63 as shown in FIGS. 20A, 20B, and 20C. The vicinity of P1 and P2 is displayed.

  More specifically, when turning left, as shown in FIG. 21A, a circle C1 passing through the rear corner P1 of the machine base and a circle C21 passing through the front corner P21 of the pallet 80 are represented in the world coordinate system. Expressed by Then, as shown in FIG. 21 (b), the relative positions of the circles C1, C21 and the cameras 71, 72, 73 are detected, and the circles C1, C21 are coordinate-transformed from the world coordinate system to the camera coordinate system, and the circle C1 is detected. , C21 are converted from the camera coordinate system to the monitor coordinate system, and the circles C1 and C21 are superimposed on the camera image and displayed on the display unit 63 as shown in FIG. On the other hand, when turning right, the circles C2 and C22 passing through the rear corner P2 of the machine and the front corner P22 of the pallet are represented in the world coordinate system, and the relative positions of the circles C2 and C22 and the cameras 71, 72 and 73 are determined. Is detected, and the coordinates of the circles C2 and C22 are converted from the world coordinate system to the camera coordinate system. Then, the coordinates of the circles C2 and C22 are converted from the camera coordinate system to the monitor coordinate system, and the circles C2 and C22 are superimposed on the camera image and displayed on the display unit 63.

  As described above, when the pallet 80 is being conveyed, the circles C21 and C22 that the pallet front corners P21 and P22 pass during turning instead of the fork tip ends P11 and P12 are displayed as guides. The presence or absence of the pallet 80 is confirmed by the pallet sensor Sp at the root of the forks 30a, 30b. Since the size of the pallet 80 is determined by JIS (Japanese Standard), the turning radii of the front corners P21 and P22 of the pallet can be calculated. It is also assumed that the forks 30a, 30b have been inserted into the pallet 80 up to the root. Therefore, the turning radius can be easily recognized even during pallet conveyance. Even if the pallet is out of standard, the circles C21 and C22 can be generated and displayed if the size is known in advance.

  More specifically, as shown in FIG. 22, when turning around by 180 degrees to change the direction, the turning radius is the largest at the machine rear corner P1, and the machine rear corner P1 A circle C1 is displayed as a predicted turning trajectory. By performing the guide display in this way, it is possible to easily determine whether or not the direction can be changed without interference (contact) with an obstacle.

  Here, as shown by a broken line in FIG. 22, as a guide display, a tangent Lg to a position Pm where the rear corner of the machine swells most in a locus (C1 in FIG. 22) through which the rear corner of the machine passes is displayed. Is also good.

  As shown in FIG. 23, when turning 90 degrees in place and directly facing the pallet arrangement position, the turning radius (circle C1) is the largest at the rear corner P1 of the machine, so that the machine rear angle. In the area where the portion P1 passes, clearance is required by the turning radius (C1) of the machine rear corner P1. On the other hand, in an area where the rear corner P1 of the machine does not pass, it is sufficient if there is a clearance corresponding to the turning radius (circle C21) of the front corner P21 of the pallet. In this way, the circles C1 and C21 are displayed as predicted turning trajectories of the machine base rear corner P1 and the pallet front corner P21. By performing the guide display in this way, it is possible to easily determine whether or not facing is possible without interference (contact) with an obstacle.

According to the present embodiment, the following effects can be obtained in addition to the above (1).
(5) Prior to turning of the reach-type forklift 20, the controller 61 as a track superimposing unit determines a circle (P21, P22) as a predicted track of the pallet front corners (P21, P22) on the opposite side to the turning direction based on the current steering angle. C21, C22) are further generated and superimposed on the images captured by the cameras (71, 72, 73) and displayed on the display unit 63. Therefore, since the circles C21 and C22 are displayed as the predicted trajectories of the pallet front corners P21 and P22, the relationship with the interference object can be more easily understood when the reach type forklift 20 turns.

  (6) When the pallet sensor Sp detects the pallet 80 on the forks 30a and 30b, the controller 61 serving as the trajectory superimposing unit precedes the turning of the reach-type forklift 20 and, based on the current steering angle, the front of the pallet opposite to the turning direction. Circles (C21, C22) as predicted trajectories of the corners (P21, P22) are further generated, and are superimposed on images captured by the cameras (71, 72, 73) and displayed on the display unit 63. Therefore, when the pallet 80 is detected as the forks 30a, 30b are inserted into the pallet 80, circles C21, C22 are displayed as the expected trajectories of the pallet front corners P21, P22. It is possible to make the relationship with the object easier to understand.

(Fifth embodiment)
Next, a fifth embodiment will be described focusing on differences from the first to fourth embodiments.
When steering while traveling, for example, when making a gentle turn, as shown in FIG. 24, the controller 61 controls the rear of the machine on the opposite side to the turning direction according to a turn (steering angle) command value. A circle (C1, C2) is generated as an expected trajectory of the corner (P1, P2). Further, the controller 61 generates circles (C51, C52) as expected trajectories of front corners (P51, P52) of the reach legs in the turning direction in the pair of left and right reach legs 22a, 22b arranged on the front side of the machine base 21. Then, the controller 61 causes the display unit 63 to display the image superimposed on the images captured by the cameras 71, 72, and 73.

  That is, when making a gentle turn to avoid the obstacle M, the turning radius becomes the largest at the machine rear corners (P1, P2) on the opposite side to the turning direction and the turning radius becomes the smallest. Are the front corners (P51, P52) of the reach leg in the turning direction, or the front wheels (see FIGS. 18A and 18B). An expected turning trajectory of the rear corners of the machine (P1, P2) opposite to the turning direction and the front corners (P51, P52) of the reach leg in the turning direction or the axis center of the front wheel is generated and displayed.

  The circles C51, C52 (or circles C61, C62) as the expected turning trajectories of the reach leg front corners P51, P52 (or the front wheel shaft centers P61, P62) and the estimated turning trajectories of the machine rear corners P1, P2. The region Z1 sandwiched between the circles C1 and C2 is displayed on the display unit 63 so as to be distinguished from other regions. For example, by giving the area Z1 a different color than the other areas or adding a different shade to the other areas, the area Z1 is an area through which the machine passes, and the determination of interference (contact) with an obstacle is made. Make it easier to do.

By performing the guide display in this manner, it is possible to easily determine whether or not the vehicle can proceed without interfering with (touching) an obstacle at the current steering angle.
Similarly, as shown in FIG. 25, the turning radius is maximum at the machine rear corners (P1, P2) opposite to the turning direction, and the turning radius is minimum at the turning direction. It is a pallet front corner (P21, P22). The controller 61 predicts the turning trajectory of the machine rear corners (P1, P2) opposite to the turning direction and the pallet front corners (P21, P22) in the turning direction according to the turning (steering angle) command value. Circles C1, C2, C21, and C22 are generated and displayed.

  An area Z2 sandwiched between circles C21 and C22 as predicted turning trajectories of pallet front corners P21 and P22 and circles C1 and C2 as predicted turning trajectories of machine rear corners P1 and P2 is different from other areas. The information is displayed on the display unit 63 so as to be distinguished. For example, by giving a different color to the area Z2 than to the other areas, or by adding a shade to the other areas, the area Z2 is an area through which the machine passes, and the determination of interference (contact) with an obstacle is made. Make it easier to do.

According to the present embodiment, the following effects can be obtained instead of the above (2).
(7) As described with reference to FIG. 25, the controller 61 as the trajectory superimposing unit includes the circle (C21, C22) as the predicted turning trajectory of the pallet front corners (P21, P22) in the turning direction, and the turning direction. The area Z2 sandwiched between the circles (C1, C2) as the expected trajectory of the rear corners (P1, P2) of the machine on the opposite side is displayed on the display unit 63 so as to be distinguished from other areas. Therefore, when the reach type forklift 20 turns, the relationship with the interference target can be more easily understood.

  (8) As described with reference to FIG. 24, the controller 61 serving as the trajectory superimposing unit determines the circles (C51, C52) as the predicted trajectories of the front corners (P51, P52) in the reach legs (22a, 22b) in the turning direction. ) Or a circle (C61, C62) as an expected trajectory of the axis center (P61, P62) of the front wheel (23a, 23b) in the turning direction, and a machine rear corner (P1, P2) opposite to the turning direction. The region Z1 sandwiched between the circles (C1, C2) as the expected trajectory is displayed on the display unit 63 so as to be distinguished from other regions. Therefore, when the reach type forklift 20 turns, the relationship with the interference target can be more easily understood.

The embodiment is not limited to the above, and may be embodied as follows, for example.
Regarding (3) and (5) above, before the forklift turns, the trajectory superimposition unit determines whether the tip or the turning direction of the fork on the opposite side of the turning direction of the pair of left and right forks is based on the current steering angle. May be generated by further generating an expected trajectory of the front corner of the pallet on the opposite side and superimposing the trajectory on the image captured by the camera, and displaying the same on the display unit.

○ The number of cameras does not matter.
The forklift is a reach type forklift, but is not limited thereto, and may be a forklift other than the reach type forklift. For example, in the case of a counter-type forklift, since there is no reach leg, an expected turning trajectory around the front wheel axis is always displayed.

  That is, as shown in FIG. 26, the counter-type forklift 90 includes a machine base 91 and a cargo handling device 92. The counter type forklift 90 includes a right front wheel 93a, a left front wheel 93b, a right rear wheel 94a, and a left rear wheel 94b. As shown in FIG. 27, the right front wheel 93a has an axial center P71. The left front wheel 93b has an axial center P72. Then, prior to the turning of the forklift, the controller 61 as a trajectory superimposing unit determines, based on the current steering angle, a circle as an expected trajectory of the axial center of the front wheel of the left and right front wheels 93a and 93b that is opposite to the turning direction. C71, C72) may be further generated and superimposed on the images captured by the cameras 71, 72, 73 and displayed on the display unit 63.

  DESCRIPTION OF SYMBOLS 10 ... Forklift remote control system, 20 ... Reach type forklift, 21 ... Machine stand, 22a, 22b ... Reach leg, 23a, 23b ... Front wheel, 28 ... Cargo handling equipment, 30a, 30b ... Fork, 40 ... Remote control device, 52 ... Wireless unit, 54 ... Wireless device, 61 ... Controller, 63 ... Display unit, 64, 65 ... Wireless device, 71, 72, 73 ... Camera, 80 ... Pallet, 90 ... Counter type forklift, 91 ... Machine stand, 92 ... Cargo handling Apparatus, 93a, 93b: Front wheel, C1, C2, C11, C12, C21, C22, C51, C52, C61, C62, C71, C72: Circle, P1, P2: Rear corner of machine stand, P11, P12: Fork tip P21, P22: Pallet front corner, P51, P52: Reach leg front corner, P61, P62: Shaft center, P71, P72 ... Center, Sp ... pallet sensor, Z1, Z2 ... area.

Claims (7)

A forklift having a vehicle communication unit while having a cargo handling device on a machine stand,
A remote control device that has an operating device communication unit that performs wireless communication with the vehicle communication unit, and is used to remotely control the traveling of the forklift and cargo handling by the cargo handling device;
A forklift remote control system comprising:
A camera mounted on the forklift and imaging an area around the forklift,
A display unit provided on the remote control device for displaying an image captured by the camera,
Prior to the turning of the forklift, a predicted trajectory of the rear corner of the machine on the opposite side to the turning direction is generated based on the current steering angle and is superimposed on an image captured by the camera and displayed on the display unit. A trajectory superimposing unit;
A remote control system for a forklift, comprising:   Prior to the turning of the forklift, the trajectory superimposing portion is configured to include a tip portion of a fork on a side opposite to a turning direction of a pair of left and right forks or a pallet front corner on a side opposite to the turning direction based on a current steering angle. The remote operation system for a forklift according to claim 1, wherein an expected trajectory is further generated and superimposed on an image captured by the camera and displayed on the display unit.   When the pallet sensor detects a pallet on the fork, the trajectory superimposing unit further generates an expected trajectory of a pallet front corner on the opposite side to the turning direction based on the current steering angle, prior to turning of the forklift, and transmits the trajectory to the camera. The remote operation system for a forklift according to claim 1, wherein the display unit superimposes the image on the captured image and displays the image on the display unit. The forklift is a reach-type forklift,
Prior to turning of the forklift, the trajectory superimposing unit is configured to calculate a predicted trajectory of the front corner of the front leg of the reach leg opposite to the turning direction of the pair of left and right reach legs arranged on the front side of the machine based on the current steering angle. An expected trajectory of the axis center of the front wheel on the side opposite to the turning direction of the left and right front wheels provided on the pair of left and right reach legs arranged on the front side is further generated and superimposed on the image captured by the camera. The remote control system for a forklift according to any one of claims 1 to 3, wherein the display is displayed on the display unit.   The trajectory superimposing unit is configured to distinguish an area interposed between an expected trajectory of a pallet front corner in a turning direction and an expected trajectory of a machine rear corner in a direction opposite to the turning direction from the other areas. The remote control system for a forklift according to claim 3, wherein the display is displayed on a display unit.   The trajectory superimposition portion is sandwiched between an expected trajectory of a front corner portion in a reach leg in a turning direction or an expected trajectory of an axial center of a front wheel in a turning direction, and an expected trajectory of a rear corner of a machine body opposite to the turning direction. The remote control system for a forklift according to claim 4, wherein an area is displayed on the display unit so as to be distinguished from other areas. The forklift is a counter-type forklift,
Prior to the turning of the forklift, the trajectory superimposing unit further generates an expected trajectory of the axis center of the front wheel on the opposite side of the turning direction of the left and right front wheels based on the current steering angle and is imaged by the camera. The remote control system for a forklift according to any one of claims 1 to 3, wherein the remote control system is displayed on the display unit so as to be superimposed on the displayed image.