KR20220159620A - Camera lift with double safety structure for autonomous forklift - Google Patents

Abstract

According to the present invention, in a camera lift for an autonomous forklift having a double safety device, the camera lift is disposed on the side of a carriage configured to support a forklift of the autonomous forklift and move up and down. The camera lift for an autonomous forklift includes: a camera part that is movable up and down on the side of a mast assembly having a mast rail, which is a path for the carriage to move up and down, and includes a camera; and a camera movement control part configured to control the movement of the camera part. An objective of the present invention is to provide the method and a forklift structure for safely controlling a recognition camera to load pallets in multiple stages using an autonomous forklift.

Description

Camera lift for autonomous forklift with double safety structure {CAMERA LIFT WITH DOUBLE SAFETY STRUCTURE FOR AUTONOMOUS FORKLIFT}

The present invention relates to a structure of a camera lift for an autonomous forklift having a double safety structure and a method for controlling camera movement. More specifically, it relates to a method and structure for safely and efficiently controlling movement of a recognition camera required for an autonomous forklift to stack pallets in multiple stages.

A forklift is an industrial vehicle used to lift or transport heavy loads, and is mainly used to move loads to a short distance in an indoor workshop or construction site, or to load or unload loads from a vehicle. These forklifts can be classified into standard type forklifts in which the mast assembly only lifts and lowers, and reach type forklifts in which the mast assembly can move forward and backward.

For example, a standard forklift has a mast rail disposed vertically, a carriage capable of moving up and down along the mast rail, and a counterweight is provided at the rear of the vehicle body. In addition, the reach type forklift does not include a counterweight, but instead includes a pair of legs protruding forward of the forklift. Reach-type forklifts generally adopt a rear-wheel drive and rear-wheel steering method, and have a structure in which an operator can operate the forklift while standing.

In general, a pallet is widely used to lift bulky and heavy cargo with a forklift to load or unload or to support cargo during transportation and storage. A forklift is mainly used to move such a pallet, and research and development on an unmanned forklift or an autonomously driven forklift is being conducted as the demand for an autonomous guided vehicle is expanding according to the trend of logistics automation.

At this time, a recognition camera is essential for recognizing multi-stage loading and large-sized pallets of autonomous forklifts. The conventional method uses a method of obtaining data by fixing a recognition camera on the forklift mast or top of the forklift, or usually lowers by a mechanical spring, and when the fork or fork comes down, a stopper under the forklift is used. It was a way to configure and accept the recognition data of the camera.

However, it is difficult to obtain image recognition data corresponding to the forklift foot of a forklift only with the position fixing method of the camera module or the mechanical spring structure. In addition, since these methods have clear structural limitations, it is difficult to acquire image data required for autonomous forklifts.

Republic of Korea Patent Publication No. 10-2013-0099596

An object of the present invention is to provide a method and a forklift structure for safely controlling a recognition camera to load pallets in multiple stages using an autonomous forklift.

Another object of the present invention is to provide a forklift structure capable of receiving accurate data by efficiently controlling the position of a recognition camera through an actuator.

In addition, the present invention can be protected by hiding inside the case when the recognition camera is not in use through a recognition camera structure having a double safety structure, and is composed of a mechanical spring structure device even when the power is cut off, so that external impact It is an object of the present invention to provide a forklift truck including a mobile camera control device that is not damaged.

In addition, an object of the present invention is to provide a forklift capable of safely controlling a recognition camera in a model capable of switching between an unmanned automatic mode and a manned manual mode of an autonomous forklift.

Solving problems of the present invention are not limited to the contents mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In one embodiment of the present invention, in the camera lift for an autonomous forklift having a double safety device, the camera lift is disposed on the side of a carriage configured to support the forklift of the autonomous forklift and move vertically , A camera unit including a camera and movable up and down on the side of the mast assembly having a mast rail, which is a path along which the carriage moves up and down; and a camera movement controller configured to control movement of the camera unit.

In addition, the self-driving forklift may include a pair of legs extending parallel to the front side of the forklift, and the camera may move up and down on at least one of the pair of legs.

The camera movement controller may include an electric linear actuator for controlling vertical movement of the camera, and the electric linear actuator may include a sliding block capable of moving up and down along a linear guide.

Also, the sliding block of the camera movement controller may be coupled to the camera unit through a pair of shafts.

Further, a pair of springs surrounding the pair of shafts are further included, and the pair of shafts are configured to pass through an upper surface of the sliding block by downward pressure, thereby providing a distance between the camera unit and the sliding block. may be variable.

Also, the camera unit may be disposed within a case of the electric linear actuator before moving down.

The camera unit may include a case coupled to the pair of shafts and supporting the camera, and the case may include a bottom portion to protect the camera from collision with a floor.

Also, the camera may be coupled to the case of the camera unit through a camera support coupling unit.

According to the present invention, it is possible to provide a forklift structure and a method for safely controlling a recognition camera to load pallets in multiple stages using an autonomous forklift.

In addition, according to the present invention, it is possible to provide a forklift structure capable of receiving accurate data by efficiently controlling the position of a recognition camera through an actuator.

In addition, according to the present invention, when the recognition camera is not in use through the recognition camera structure having a double safety structure, it is possible to hide it inside the case for protection, and even when the power is cut off, it is composed of a mechanical spring structure device A forklift including a mobile camera control device that is not damaged by external shocks may be provided.

In addition, according to the present invention, it is possible to provide a forklift including a moving camera structure that secures high mechanical stability through a mechanical spring structure and an electric actuator structure and at the same time enables more accurate data acquisition of a recognition camera.

In addition, according to the present invention, it is possible to provide a forklift capable of safely controlling a recognition camera in a model capable of switching between an unmanned automatic mode and a manned manual mode of an autonomous forklift.

Effects of the present invention are not limited to the contents mentioned above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is an exemplary diagram for explaining the configuration of an autonomous forklift according to an embodiment of the present invention.
2 is an exemplary diagram for explaining a structure of a movable camera according to an embodiment of the present invention.
3A to 3C are exemplary diagrams for explaining the operation of a linear actuator and a bumper spring according to an embodiment of the present invention.
4 is an exemplary view for explaining the configuration of a camera unit according to an embodiment of the present invention.
5 is a flowchart illustrating a camera control method of an autonomous forklift in an automatic mode according to an embodiment of the present invention.
6 is a flowchart illustrating a method of controlling a camera in a manual mode of an autonomous forklift truck according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the embodiment of the present invention in the drawings, parts irrelevant to the description are omitted.

Terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions may include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as "include", "have" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one Or it may be understood that it does not exclude in advance the possibility of the existence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof.

In addition, the components appearing in the embodiments of the present invention are shown independently to represent different characteristic functions, and it does not mean that each component is made of separate hardware or a single software component unit. That is, each component is listed and described as each component for convenience of description, and at least two components of each component may be combined to form one component, or one component may be divided into a plurality of components to perform a function. An integrated embodiment and a separate embodiment of each of these components are also included in the scope of the present invention unless departing from the essence of the present invention.

In addition, the following embodiments are provided to more clearly explain to those with average knowledge in the art, and the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the accompanying drawings.

1 is an exemplary view for explaining the configuration of an autonomous forklift according to an embodiment of the present invention.

The self-driving forklift 100 according to an embodiment of the present invention may be configured as, for example, a reach type or a counterbalance type, and in the case of the reach type, the fork of the forklift truck can be inserted and removed back and forth, which is advantageous for multi-level loading in a narrow space. can have advantages.

The self-driving forklift 100 includes a pair of forks 140 for lifting pallets or objects, a carriage 120 configured to support the forks 140 and move vertically, and a forklift. The mast assembly 110, which includes an arm 130 having a structure for coupling the 140 to the carriage 120 and a mast rail 111, which is a path in which the carriage 120 moves, is provided in front of the forklift configuration can be included.

The autonomous forklift 100 according to the present invention may include a camera lift 200 for an autonomous forklift having a double safety device, and the camera lift 200 for an autonomous forklift includes a camera movement control unit 210 and a camera unit 220, and the camera lift 200 is disposed on the side of the carriage 120 and moves up and down together with the forklift 140 moving up and down.

The self-driving forklift 100 according to the present invention also includes a camera unit 220 that is movable up and down on the side of the mast assembly 110 and includes a camera 221 and a camera configured to control the movement of the camera unit 220 A movement control unit 210 may be included. For example, the camera movement control unit 210 may be attached to both sides or one side of the carriage 120, and the camera unit 220 may be controlled by the camera movement control unit 210 to be movable up and down. can

The recognition camera 221 disposed in the camera unit 220 may include, but is not limited to, a 3D depth camera and a lidar sensor. In the case of a 3D depth camera, it can be installed at a lower cost than a 3D lidar sensor, and has an advantage because the accuracy of distance information is higher than that of other distance sensors such as ultrasonic sensors. In addition, since only pallets located in the front are required for pallet detection, manufacturing costs can be reduced by using a 3D camera sensor instead of a 3D lidar sensor capable of omnidirectional 360 degrees. By recognizing both the top pallet loaded on the self-driving forklift 100 and the bottom pallet located in the front through the recognition camera 221 disposed on the self-driving forklift 100, double loading and boxing Palette image recognition is possible.

In addition, the self-driving forklift 100 may include a pair of legs 150 extending parallel to the front side of the forklift 140, and the camera unit 220 and the camera movement control unit 210 ) is disposed on the upper side of the at least one leg 150, so that the recognition camera 221 can move vertically on the at least one leg 150.

In addition, the camera movement control unit 210 can control the movement of the camera unit 230 by interlocking with the camera unit 230 through a pair of shafts 230, and the camera unit through a spring structure surrounding the shaft 230. When the shaft 230 moves downward and touches the upper surface of the leg 150, the camera unit 230 may be prevented from being damaged by an external impact through the action of the mechanical safety bumper spring.

2 is an exemplary view for explaining a structure of a movable camera according to an embodiment of the present invention.

Referring to FIG. 2 , the camera movement controller 210 configured to control the movement of the camera unit 220 is composed of an electric linear actuator 211 for controlling vertical movement of the recognition camera 221, and the electric linear actuator 211 ) may include a sliding block 214 movable up and down along the linear guide 213.

The sliding block 214 of the camera movement control unit 210 is coupled to the camera unit 220 through a pair of shafts 230 to control the movement of the camera unit 220 up and down.

In addition, when the camera unit 220 is in contact with the bottom surface due to the bumper spring 231 surrounding the shaft 230, the pair of shafts 230 move the upper hole of the sliding block 214 by downward pressure. The distance between the camera unit 220 and the sliding block 214 may be configured to be variable by being configured to pass through the upper side through the. Accordingly, when the forklift forklift 140 is lowered to the floor of the work surface in the event of failure of the electric actuator, failure of control communication, or power outage, which is a specific situation, the bumper spring 231 surrounding the shaft 230 operates to mechanically By raising the shaft 230 upward, the camera unit 220 may be protected from external impact.

3A to 3C are exemplary diagrams for explaining the operation of a linear actuator and a bumper spring according to an embodiment of the present invention.

First, referring to FIG. 3A , the camera unit 220 connected through the shaft 230 can be moved up and down according to the drive radius of the electric cylinder of the linear actuator 211 of the camera movement control unit 210 according to the present invention, , When the camera unit 220 is located at the top, the camera unit 220 is disposed in the case of the linear actuator 210 to be protected from the outside, and when the recognition camera 221 is used, the linear actuator 210 You can move down through the control action. In addition, when the forklift fork 140 descends to the floor of the work surface, the camera unit 220 may be moved upward so as not to collide with the floor through a control operation of the linear actuator 210 .

On the other hand, when the forklift forklift 140 is lowered to the floor of the working surface in the event of a failure of the electric actuator, failure of control communication, or power outage, which is a specific situation, the bumper spring 231 surrounding the shaft 230 operates and mechanically The camera unit 220 can be protected from impact by raising the 230 upward. At this time, when the forklift forklift 140 moves upward from the bottom of the working surface again, the camera unit 220 may return to its original position while the shaft 230 is lowered by the elastic force of the compressed bumper spring 231 .

When only a mechanical spring guide or electric actuator is used, there is a mechanical limit in lowering the recognition camera down the forklift forklift, and there is a problem that mechanical instability doubles as the movement length increases. By adding the configuration, it is possible to secure higher mechanical stability and at the same time acquire more accurate image data by controlling the recognition camera. In particular, the disadvantage of using only electric actuators is that when the power of the camera module is cut off, there is a risk of damage due to external impact because the structural safety device for this module is not configured. In particular, in the case of self-driving forklifts, in the case of models that can switch to both unmanned and manned, more weaknesses were revealed in this area.

In order to compensate for this, the double safety structure of the recognition camera 221 according to the present invention enables the position of the recognition camera 221 to be adjusted more widely, thereby obtaining more accurate data. In addition, the mechanical spring safety bumper structure, which consists of a double safety structure device, is composed of a mechanical spring bumper that is safe from external impact that may occur when the forklift of a forklift is lowered arbitrarily when there is no power to the electric actuator. The risk of damage to the module can be prevented.

In addition, referring to FIG. 3B, when the camera unit 220 is located at the top before operation in the left drawing, the camera unit 220 is disposed in the case of the linear actuator 210, and the recognition camera 221 in the right drawing When used, it can move downward through the control operation of the linear actuator 210 .

In addition, referring to FIG. 3C, in the drawing on the left, when the forklift fork 140 is lowered to the floor of the work surface in the event of a breakdown of the electric actuator, inability of control communication, or power failure, which is a specific situation, the camera unit 220 also touches the floor. As shown in the drawing on the right, when the camera unit 220 touches the bottom surface, the bumper spring 231 surrounding the shaft 230 operates, and the shaft 230 mechanically rises, and the camera unit 220 is moved. It can protect you from impact. At this time, when the forklift fork 140 moves up from the bottom of the working surface again, the camera unit 220 may return to its original position while the shaft 230 is lowered by the compressed bumper spring 231 .

4 is an exemplary view for explaining the configuration of a camera unit according to an embodiment of the present invention.

Referring to FIG. 4 , the camera unit 220 has a structure of a camera unit case 222 for protecting the recognition camera 221, and the camera unit case 222 prevents the recognition camera 221 from colliding with the floor. Including the configuration of the bottom portion 223 for protection, the recognition camera 221 is attached to the inner upper surface of the camera unit case 222 through the camera support coupling portion 224, so that the bottom portion 223 of the case It can be arranged to be separated by a certain distance from

5 is a flowchart illustrating a camera control method of an autonomous forklift in an automatic mode according to an embodiment of the present invention.

Referring to FIG. 5 , a method of controlling a recognition camera in an auto mode of an autonomous forklift is illustrated.

First, the self-driving forklift can be moved to the pallet loading position. (S510)

In the automatic mode, the electric linear actuator 213 is operated at the loading position to move the position of the recognition camera 221 downward, so that it can hide in the case and come out (S520).

Control through image recognition can be performed by transmitting image data captured through the recognition camera 221 moving downward. (S530)

Transfer loading can be completed after successful pallet entry through image recognition (S540).

After completion of the transfer operation at the corresponding location, transfer to another location may be attempted (S550), and at this time, steps S530 and S540 may be repeated.

When the transfer operation is completed, the recognition camera can be returned to its original position by operating the electric linear actuator (S560).

6 is a flowchart illustrating a camera control method of an autonomous forklift in a manual mode according to an embodiment of the present invention.

Referring to FIG. 6 , a method of controlling a recognition camera in a manual mode of an autonomous forklift is illustrated.

First, the self-driving forklift can be moved to the pallet loading position. (S610)

In the manual mode, the forklift can be operated manually to enter the pallet. (S620)

When the forklift forklift 140 is manually lowered to the floor of the work surface, such as when an electric actuator malfunctions, control communication is disabled, or a power failure occurs, the camera unit 220 is controlled through the mechanical safety operation of the bumper spring 231. (S630) Also, when the forklift foot 140 moves up from the bottom of the work surface, the camera unit 220 can be returned to its original position by the bumper spring 231 that has been compressed. .

After successfully entering the pallet manually, the loading and unloading can be completed (S640).

After completion of the transfer operation at the corresponding location, transfer to another location may be attempted (S650), and at this time, steps S620, S630, and S640 may be repeated.

Various embodiments described in this specification may be implemented by hardware, middleware, microcode, software, and/or combinations thereof. For example, various embodiments may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), , processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions presented herein, or combinations thereof.

Also, for example, various embodiments may be embodied or encoded in a computer-readable medium containing instructions. Instructions embodied or encoded on a computer-readable medium can cause a programmable processor or other processor to perform a method, for example when the instructions are executed. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. For example, such computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage medium, magnetic disk storage medium or other magnetic storage device, or instructions or data accessible by a computer that contains desired program code. any other medium that can be used to transport or store in the form of structures.

Such hardware, software, firmware, etc. may be implemented within the same device or within separate devices to support the various operations and functions described herein. Additionally, components, units, modules, components, etc., described as "-units" in the present invention may be implemented together or separately as separate but interoperable logic devices. Depiction of different features for modules, units, etc. is intended to highlight different functional embodiments and does not necessarily mean that they must be realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components.

While actions are depicted in the drawings in a particular order, it should not be understood that these actions need to be performed in the specific order shown, or in a sequential order, or that all depicted actions need to be performed to achieve a desired result. . In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the division of various components in the above-described embodiments should not be understood as requiring such division in all embodiments, and the described components may generally be integrated together into a single software product or packaged into multiple software products. It should be understood that it is possible

Although the present invention has been described with reference to the embodiments shown in the drawings, this is only exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: autonomous forklift
110: mast assembly
120: carriage
130 cancer
140: forklift
150: leg
200: camera lift
210: camera movement controller
211: electric linear actuator
212: step motor
213: linear guide
214: sliding block
220: camera unit
221: recognition camera
222: camera unit case
223: bottom
224: camera support joint
230: shaft
231: bumper spring

Claims (8)

In the camera lift for an autonomous forklift having a double safety device,
The camera lift is disposed on the side of a carriage configured to support a forklift of an autonomous forklift and to be movable up and down,
a camera unit including a camera and movable up and down on a side surface of a mast assembly having a mast rail, which is a path along which the carriage moves up and down; and
Camera movement controller configured to control movement of the camera unit
A camera lift for an autonomous forklift comprising a. The method of claim 1, wherein the self-driving forklift includes a pair of legs extending parallel to the front side of the forklift, and the camera moves up and down on at least one of the pair of legs. A possible camera lift for an autonomous forklift. The autonomous forklift of claim 1, wherein the camera movement controller includes an electric linear actuator for controlling vertical movement of the camera, and the electric linear actuator includes a sliding block capable of moving vertically along a linear guide. For camera lift. The camera lift of claim 3, wherein the sliding block of the camera movement control unit is coupled to the camera unit through a pair of shafts. 5. The method of claim 4, further comprising a pair of springs surrounding the pair of shafts, wherein the pair of shafts are configured to pass through an upper surface of the sliding block by a downward pressure, so that the camera unit and the sliding block are formed. A camera lift for an autonomous forklift, in which the distance between blocks is variable. The camera lift for an autonomous forklift according to claim 3, wherein the camera unit is disposed within a case of the electric linear actuator before moving down. 5 . The autonomous camera of claim 4 , wherein the camera unit includes a case coupled to the pair of shafts and supporting the camera, and the case includes a bottom portion to protect the camera from collision with a floor surface. Camera lift for driving forklift. The camera lift for an autonomous forklift according to claim 5, wherein the camera is coupled to a case of the camera unit through a camera support coupling unit.

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