KR102389494B1 - Autonomous Forklift Truck - Google Patents

Abstract

The present invention relates to an unmanned forklift system capable of accurately recognizing its own position within a work area and the position of obstacles during loading and unloading of cargo. a position recognition sensor that continuously irradiates the radar and detects the self-position of the unmanned forklift through the laser reflected from the reflective mark provided on the structure defining the space of the work area; a first sensor provided at the lower end of the front of the unmanned forklift to detect an obstacle near the ground of the work area; a second sensor provided on the upper end of the front of the unmanned forklift to detect an obstacle at a predetermined height from the ground that is not detected by the first sensor; a fork laser sensor provided at a lift point between two cantilever beams constituting the fork to measure a distance from a shelf on which the pallet is loaded or a distance from the pallet; a first fork photoelectric sensor and a second fork photoelectric sensor provided on the front side of each cantilever constituting the fork; and a control computer that processes sensing signals input from sensors provided in the front and rear parts of the unmanned forklift and controls the driving and working devices of the unmanned forklift.

Description

Unmanned Forklift Truck {Autonomous Forklift Truck}

The present invention relates to an automated forklift system, and more particularly, to an unmanned forklift system capable of automatically transporting and unloading a forklift by means of a computer and a network system without a human boarding or direct manipulation.

As the production system of the logistics industry system becomes automated and unmanned, the use of AGVs (Autonomous Guided Vehicles) that transport products in buildings or factories is increasing. Autonomous forklift trucks (autonomous forklift trucks or unmanned forklifts) require autonomous judgment ability and accurate and safe working ability for any work environment. Due to these characteristics, the unmanned forklift can have a variety of work environments, unlike the existing unmanned transport vehicle, which can only travel/transport a limited work area or limited range, and can have flexibility. For this reason, unmanned forklift trucks can be used in hazardous environments where human access is difficult, and can be used to automate material handling and material handling in existing warehouse systems.

In addition, in recent years, a lot of research has been done in the field of element technologies such as surrounding environment recognition, route planning, collision avoidance, and location recognition technology to implement an intelligent unmanned forklift.

Unmanned forklifts require location recognition technology to periodically grasp the current location while moving, and also require a function of regenerating an appropriate path to avoid collision with these obstacles by judging fixed or moving obstacles by themselves. Through these functions, the driverless forklift can judge and drive itself without human assistance, and perform the given task. Due to this, it is possible to increase the efficiency of the production line without replacement or change. In addition, the big role of the unmanned forklift is to have its own power and perform the given repetitive work precisely and safely for the accuracy of transportation, and it is still being applied and used in many industrial field fields. Research on the development/application of unmanned forklifts and various methods for their implementation have been studied, and the industrial utility and economic effect of unmanned forklifts have been proven from many studies above, and the scope of application in industrial fields using them has been gradually expanded and there is. However, there has been a problem in that the entire working environment is understood and the autonomous operation of the unmanned forklift is not clearly expressed yet.

Korean Patent No. 1784567

An object of the present invention is to provide an unmanned forklift system capable of automating transport and unloading operations within a working space within a working area.

The unmanned forklift system according to the present invention for achieving the above object is provided on the upper side of the unmanned forklift and irradiates a laser, and reflects the reflective mark provided on the structure defining the space of the work area or the geometrical features of the fixed indoor terrain. a position recognition sensor that detects the position of the unmanned forklift during driving and rotational operation of the unmanned forklift through a laser scan reflected by the vehicle; a third sensor provided on the left and right sides of the unmanned forklift to detect the presence or absence of obstacles on the rotational path during the rotational operation of the unmanned forklift, and detect two shelf pillars during the unloading operation to guide the position where the pallet is to be loaded; It is provided at one point of the lift between the two cantilever beams constituting the fork to measure the distance to the shelf on which the pallet is loaded or the distance to the pallet, and the laser is irradiated to the reflective mark for detecting the pallet hole provided on the pallet during the loading operation. and a fork laser sensor receiving <position information and reflectance data> of the reflected laser; a control computer that processes detection signals input from sensors provided in the front and rear parts of the unmanned forklift and controls the driving, rotating, loading and unloading operations of the unmanned forklift in conjunction with the unmanned forklift control server; It is characterized in that it comprises a.

The fork laser sensor receives a plurality of <location information and reflectance data> by repeatedly irradiating the laser within a predetermined time toward the pallet provided with the reflective mark for detecting the pallet hole, and the position information is 2 of the position where the laser is irradiated It is dimensional coordinate information, and the reflectance data is quantitative light and dark data of the position where the laser is irradiated, and the position information of the position where the laser is irradiated for each reflectivity data is received together, and the control computer receives each reflectance data for the reflectivity data above a certain reference value. The average position information is calculated by averaging the position information of

During the unloading operation, a third sensor provided on the left and right sides of the unmanned forklift detects the two shelf posts, and the control computer detects the position between the shelf posts and the shelf posts based on the position information of the shelf posts detected by the third sensor. Specifies the shelf position on which the pallet will be loaded.

The driving operation is a process in which the control computer receives the shape map-based destination node information required for driving from the unmanned forklift control server, and the control computer determines a route to the destination node on the shape map based on the received destination node information. It is configured to include the process of generating the vehicle, and the control computer controlling the driving motor and the steering motor of the unmanned forklift to drive the unmanned forklift along the generated path.

The rotating operation includes a process in which the control computer receives arrival angle information from the unmanned forklift control server, and the control computer controls the steering motor based on the arrival angle information to rotate the unmanned forklift by the arrival angle. During the rotational operation of the unmanned forklift, the presence or absence of an obstacle on the rotational path is detected by the third sensor.

The loading operation includes a process in which the control computer receives shelf height information of a position where pallets are loaded from the unmanned forklift control server, a process of detecting the position of the pallet hole, left and right movement of the fork so that the fork is located in the pallet hole, and Configuration including the process of adjusting the distance between the two cantilever beams forming the fork, measuring the distance between the fork and the pallet hole using a fork laser sensor, and moving the fork forward based on that and inserting the fork into the pallet hole In the process of detecting the position of the pallet hole, the fork laser sensor repeatedly irradiates the laser within a predetermined time toward the pallet provided with the reflective mark for detecting the pallet hole to receive a plurality of <location information and reflectance data>, The control computer calculates the average value of position information by averaging the position information of each reflectivity data for the reflectivity data above a certain reference value, and detects the position of the pallet hole by specifying the calculated average value of the position information as the point where the reflective marker for detecting the pallet hole is located. .

The unloading operation includes a process in which the control computer of the unmanned forklift receives shelf height information from the unmanned forklift control server and raises the lift by the corresponding shelf height based on the received shelf height information, and determines the position of the shelf on which the pallet will be loaded. With the process of specifying and the position of the shelf on which the pallet is to be loaded, the control computer measures the distance between the unmanned forklift and the shelf column through the third sensor, and based on that It consists of a process of locating the upper part of the shelf to be loaded, and a process of loading the pallet on the shelf by lowering the lift. The third sensor detects the two shelf posts, and the control computer specifies the position of the shelf where the pallet is to be loaded between the shelf posts and the shelf posts based on the position information of the shelf posts detected by the third sensor.

a first sensor provided at the lower end of the front of the unmanned forklift to detect an obstacle near the ground of the work area; It may further include; a second sensor provided at the upper end of the front part of the unmanned forklift to detect an obstacle at a predetermined height from the ground.

and a first fork photoelectric sensor and a second fork photoelectric sensor provided on the front side of each cantilever constituting the fork, wherein the first fork photoelectric sensor is disposed on the center side of the working device, and the second fork photoelectric sensor The sensor is disposed on the outside of the working device, the first fork photoelectric sensor detects whether there is a pallet hole during the loading operation, and the second fork photoelectric sensor detects the presence of a pallet hole during the unloading operation. It detects whether there is an obstacle in front.

A first wire sensor for measuring the height of the lift, a second wire sensor for measuring the shifted position when the two cantilevers are shifted to the left or right, and a third wire sensor for measuring the forward movement distance of the fork; may further include there is.

The unmanned forklift system according to the present invention has the following effects.

It is possible to improve the working stability of racks and pallets during loading and unloading of cargo while accurately recognizing their position and direction within the work area.

1 and 2 are reference views showing a front part of an unmanned forklift according to an embodiment of the present invention.
3 and 4 are reference views showing the rear portion of the unmanned forklift according to an embodiment of the present invention.
5 is a flowchart for explaining a driving operation.
6 is a flowchart for explaining a rotation operation.
7 is a flowchart for explaining a loading operation.
8 is a flowchart for explaining an unloading operation.
9 is a reference diagram showing an example of using an editing operation for a shape map.
Figure 10 is a reference diagram showing that a reflective mark is provided on the pallet for detecting the pallet hole.
11 is a reference view showing a reflection mark of a shelf column.

The present invention can improve work stability by accurately recognizing its own position within a work area based on a plurality of LiDAR sensors and accurately measuring the distance to obstacles during cargo loading and unloading such as transfer. We present the technology for the unmanned forklift system.

Hereinafter, an unmanned forklift system according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 to 4, an unmanned forklift system according to an embodiment of the present invention includes a plurality of sensors and a control computer that processes detection signals input from these sensors and controls the driving and working devices of the unmanned forklift. (not shown) is included.

A plurality of sensors provided in the unmanned forklift system generates a detection signal for recognizing the position of the unmanned forklift within the work area and a detection signal for measuring the distance to obstacles and surrounding objects during work.

The unmanned forklift is divided into a rear portion where the work device is provided and a front portion in the opposite direction. The above-described plurality of sensors are provided on the front and rear portions of the unmanned forklift, and depending on the function of each sensor, it is installed on the front or rear portion of the unmanned forklift. is mounted For reference, the direction of the front part of the unmanned forklift corresponds to the running direction, and the direction of the rear part corresponds to the reverse direction.

First, the sensor mounted on the front part of the unmanned forklift is as follows. A position recognition sensor 1 is provided at the upper end of the front of the unmanned forklift. The position recognition sensor 1 is for detecting the magnetic position of the unmanned forklift within the work area, and may be configured as a LiDAR. In detail, the lidar may be composed of a laser transmitter, a receiver, a driving and data processing module.

In order to determine the self-position of the unmanned forklift, a reflective marker that reflects a laser is required in addition to the lidar, and the reflective marker is disposed at intervals of several m to tens of m on the structure defining the space of the work area. When the unmanned forklift moves, the location recognition sensor 1 of the unmanned forklift continuously irradiates the laser, and the self-position of the unmanned forklift can be determined through the laser reflected from the reflective mark provided on the structure defining the space of the work area. In addition, this technology is possible without the installation and setting of a separate reflective mark, and it is possible through location recognition processing within the computer through information about the shape map composed based on the boundary wall and fixed structure of the indoor warehouse.

Next, in the front part of the unmanned forklift, the first sensor 2 and the second sensor 9 are provided on the lower and upper sides, respectively. The first sensor 2 provided on the lower side of the front part of the unmanned forklift is provided on one side of the front shock bumper 10 of the unmanned forklift and serves to detect obstacles near the ground of the work area. In addition, the second sensor 9 provided at the upper end of the front part of the unmanned forklift serves to detect an obstacle at a predetermined height from the ground that is not detected by the first sensor 2 . In one embodiment, when an obstacle near the ground is detected by the first sensor 2 within 100 to 200 cm, the unmanned forklift can be emergency stopped, and when the obstacle is located within 1 m by the second sensor 9 Unmanned forklift trucks can be stopped in an emergency.

In addition, a warning light 3 and an alarm lamp 4 may be provided on one side of the front part of the unmanned forklift. The warning light (3) generates a warning sound when an obstacle is detected by the first sensor (2) or the second sensor (9) while driving, and the alarm lamp (4) is green when the unmanned forklift is operating normally, and yellow when attention is required. , Red is displayed when an error occurs. At the same time, a wireless transmission/reception system 11 for communication with the unmanned forklift control server is provided on one side of the front part of the unmanned forklift, and a touch screen display 6 capable of grasping the operation status and work status of the unmanned forklift is provided. can In addition, a manual/automatic operation switch 7 for converting manual operation and automatic operation, an emergency stop switch 8 for emergency stop, a joystick 5 for manual operation, and a front shock bumper 10 will be provided. can In addition, a battery charging system (not shown) capable of charging and discharging is provided on one side of the unmanned forklift.

The sensors installed on the rear part of the driverless forklift are as follows. Sensors mounted on the rear part of the unmanned forklift generate sensing signals related to the operation of the work device of the unmanned forklift. The working devices of the driverless forklift are largely divided into lifts and forks. The lift refers to a structure extending a certain length in the vertical direction, such as a ladder structure of a ladder truck, and the fork is two cantilever beams arranged side by side in the form of chopsticks, and is fixed to one side of the lift and moved together according to the vertical movement of the lift. Loads eg pallets can be loaded on the forks or pallets on reach can be unloaded. For loading and unloading cargo, the fork can move forward and backward in addition to moving up and down with the lift.

As described above, the fork consists of two cantilever beams arranged side by side, and a fork laser sensor 12 is provided at a lift point between the two cantilever beams. The fork laser sensor 12 serves to measure the distance to the shelf on which the pallet is loaded or the distance to the pallet, and the laser scan layer of the fork laser sensor 12 is several mm for the upper surfaces of the two cantilevers constituting the fork. It is preferably located on a plane within a height range of more than 1 cm. When the fork enters the pallet hole to load the pallet, it detects the pallet hole or the center of the pallet through the analysis and algorithm processing of the reflected laser points, and induces two fork cantilevers to safely enter the pallet hall do Pallet hole detection by the fork laser sensor 12 is performed based on <location information and reflectivity data>, which will be described in detail in the description of the 'loading operation' to be described later.

In addition, a first fork photoelectric sensor 13 and a second fork photoelectric sensor 14 are provided on the front side of each cantilever constituting the fork. The first fork photoelectric sensor 13 is provided on the inside, and the second fork photoelectric sensor 14 is provided on the outside. Here, the first fork photoelectric sensor 13 and the second fork photoelectric sensor 14 are provided on the same line. The inner side means a direction toward the center of the working device, and the outer side faces the outside of the working device. means direction.

The first fork photoelectric sensor 13 is a sensor capable of on/off output by setting the obstacle detection distance. Depending on the working environment, whether or not an obstacle is encountered during the fork entering the pallet hole during the loading operation or the shelf during the unloading operation It is used for the procedure of reconfirming for safety whether there is an already existing load in the target shelf space just before loading the pallet. Of the two photoelectric sensors existing in each cantilever, the outer side sets the distance sensitivity to 1m or more to detect overlapping loading, and the inner side detects the safety of entering the pallet hall by setting the distance sensitivity to a minimum of less than 10 cm. That is, the second fork photoelectric sensor 14 serves to sense whether there is an obstacle in the front while the fork moves forward for pallet loading, and the second fork photoelectric sensor 14 detects the obstacle. When this is detected, the driverless forklift stops emergency.

A first wire sensor 15, a second wire sensor (not shown), and a third wire sensor (not shown) are provided. The first wire sensor 15 measures the height of the lift, the second wire sensor measures the shifted position when the two cantilevers are shifted to the left or right, and the third wire sensor measures the forward movement distance of the fork. measure The first wire sensor 15, the second wire sensor, and the third wire sensor are provided on one side of the working device, and in one embodiment, may be provided on one side of the lift or one side of the mast.

In addition, third sensors 16 are respectively provided on the left and right rear bumpers 17 in the rear part of the unmanned forklift truck. In order to calculate the moving distance of the unmanned forklift to the shelf when the pallet on the fork is unloaded on the shelf, a reflective mark is provided on the shelf and the shelf column (refer to FIGS. 10 and 11 ), and the third sensor 16 is a reflective mark The relative position and direction between the unmanned forklift and the shelf can be measured by examining the distance and intensity of the laser scan data, and securing a strong shelf position recognition rate so that it is not easily mistaken for the environment.

The control computer processes sensing signals input from various sensors provided on the front and rear parts of the unmanned forklift and controls the driving and working devices of the unmanned forklift through interworking with the unmanned forklift control server.

The control computer is mounted on the unmanned forklift together with the wireless transmission/reception system and transmits the detection signals input from the above-described sensors to the unmanned forklift control server through the wireless transmission/reception system, along with map information such as work routes from the unmanned forklift control server. and a control signal for operation of the unmanned forklift.

By interlocking the control computer with the unmanned forklift control server, the unmanned forklift can perform four major unit operations, namely, a driving operation, a rotating operation, a loading operation, and an unloading operation. The movement of the unmanned forklift and the loading and unloading of pallets are made possible through the driving operation, rotation operation, loading operation, and unloading operation.

In each unit operation, the control computer mounted on the unmanned forklift receives the destination node information required for driving, the arrival angle information required for rotation, and shelf height information required for loading and unloading from the unmanned forklift control server, along with the overall system mounted on the unmanned forklift truck. Obstacle detection based on a detection signal input from a sensor and controlling whether an operation proceeds or not, each of the four unit operations is specifically performed as follows.

First, the driving operation proceeds as follows (refer to FIG. 5).

The control computer mounted on the unmanned forklift receives the shape map-based destination node information required for driving from the unmanned forklift control server (S501). The work space, the activity space of the unmanned forklift, is defined as a two-dimensional shape map composed of a plurality of nodes (points), and the destination node information, which is the final destination of the unmanned forklift, is generated by the unmanned forklift control server and transmitted to the unmanned forklift control computer. do.

The control computer of the unmanned forklift generates a path to the destination node on the shape map based on the received destination node information (S502) (refer to FIG. 9). The generation of the path to the destination node may use a known path algorithm, for example, the Djikstra algorithm.

The control computer controls the driving motor and the steering motor of the unmanned forklift to drive the unmanned forklift along the generated path (S503) (S504). At this time, as the generated path connects nodes, the path is updated every time it passes through each node.

In the process of driving the unmanned forklift along the generated path, the presence or absence of obstacles is detected, and accordingly, continuous driving or stopping of the unmanned forklift is required. It is sensed by the sensor 9 . As described above, the first sensor 2 is provided on one side of the front shock bumper 10 of the unmanned forklift and serves to detect obstacles near the ground in the work area, and the second sensor 9 is the first sensor ( It serves to detect obstacles at a certain height from the ground that are not detected by 2). When an obstacle is detected on the driving path by the first sensor 2 or the second sensor 9, the control computer temporarily stops the driving operation of the unmanned forklift, and resumes the driving operation when the obstacle is released.

The rotation operation proceeds as follows.

Rotational operation refers to the operation in which the unmanned forklift is rotated in place, and rotational operation is required when loading or unloading pallets.

For the rotation operation of the unmanned forklift, first, the control computer receives arrival angle information from the unmanned forklift control server (S601). The arrival angle means the target rotation angle of the unmanned forklift.

The control computer controls the steering motor based on the arrival angle information to rotate the unmanned forklift by the arrival angle (S602) (S603). In the process of rotating the unmanned forklift toward the arrival angle, it is necessary to detect the presence of obstacles, and the detection of the presence of obstacles during rotation is performed by the third sensor 16 . The third sensor 16 is provided on the left and right rear bumpers 17 as described above, and the third sensors 16 respectively provided on the left and right rear bumpers 17 are clockwise or counterclockwise of the unmanned forklift. It plays a role in detecting obstacles on the turning path when turning.

When an obstacle is detected on the rotation path by the third sensor 16, the control computer temporarily stops the rotation operation of the unmanned forklift, and restarts the rotation operation when the obstacle is released.

The third sensor 16 serves to recognize the point at which the pallet is loaded during the unloading operation in addition to the role of detecting an obstacle on the rotation path, which will be described in the description of the unloading operation to be described later.

The loading operation proceeds as follows.

The loading operation refers to the operation of loading the pallets loaded on the shelves of the driverless forklift onto the fork of the unmanned forklift. The unloading operation, which will be described later, refers to the operation of loading the pallet loaded on the fork of the unmanned forklift onto the shelf. Both the loading and unloading operations are carried out on the basis of the lifting and lowering of the lift and the forward and backward movement of the fork.

For the loading operation, information on the height of the shelf on which the pallet is loaded is required. Accordingly, the control computer receives the shelf height information of the position where the pallet is loaded from the unmanned forklift control server (S701).

In the state in which the shelf height information is received, the control computer raises the lift by the shelf height (S702). Then, it is required to accurately insert the fork into the pallet hole in order to load the pallet. In order to accurately insert the fork into the pallet hole, it is necessary to accurately detect the position of the pallet hole.

In order to detect the position of the pallet hole, the present invention applies the following method (S703).

The pallet hole is provided at the lower ends of both ends of the pallet, and a reflective mark for detecting the pallet hole is pre-mounted in the center between the two pallet holes (see FIG. 10). In this state, the recognition process for the reflective mark for detecting the pallet hole by the fork laser sensor 12 is in progress. The fork laser sensor 12 is provided at the center of the lift between the fork, that is, the two cantilever beams, as described above. Two cantilever beams constituting the fork are inserted into the two pallet holes, and as the fork laser sensor 12 is located in the center between the two cantilevers, the fork laser sensor 12 and the reflective mark for detecting the pallet hole are on the same line. If positioned, two cantilever beams can be accurately inserted into the two pallet holes.

The fork laser sensor 12 irradiates a laser toward the pallet provided with a reflective mark for detecting the pallet hole, and receives <location information and reflectance data> through the reflected laser. Here, the position information is two-dimensional coordinate information of the position where the laser is irradiated, the reflectivity data is the contrast data of the position where the laser is irradiated, and when the laser irradiation is performed once, the position information and the reflectivity data are received. That is, for each reflectance data, the position information of the laser irradiated position is received together. The reflectivity data is quantitative numerical data, and may be divided into, for example, steps of 0 to 255. The closer it is to 0, the darker it is, and the closer to 255, the brighter it is.

The fork laser sensor 12 receives a plurality of <position information and reflectance data> by repeatedly irradiating the laser within a predetermined time. The control computer filters the received plurality of <location information and reflectivity data>. For example, only reflectance data of 250 or more reflectance data is left, and the remaining reflectivity data and location information corresponding thereto are deleted. Next, the position information average value is calculated by averaging the position information of each of the reflectivity data 250 or more of the reflectivity data. The calculated average value of location information is specified as the point where the reflective marker for detecting the pallet hole is located.

When the point at which the reflective mark for detecting the pallet hole is located is specified through the above process, the control computer adjusts the left and right movement of the fork and the distance between the two cantilevers constituting the fork so that the fork is located in the pallet hole (S704). In addition, the control computer measures the distance between the fork and the pallet hole using the fork laser sensor 12 and moves the fork forward based on it (S705) (S706). In this process, the first wire sensor 15 measures the height of the lift, the second wire sensor measures the shifted position when the two cantilevers are shifted to the left or right, and the third wire sensor measures the height of the fork. Measure the forward travel distance.

In the process of moving the fork forward and inserting the fork into the pallet hole, the first fork photoelectric sensor detects the presence of an obstacle inside the pallet hole.

With the fork inserted into the pallet hole, the control computer raises the lift (S707), then moves the fork backward (S708), and then lowers the lift to a certain point (S709), and the loading operation is completed.

The unloading operation proceeds as follows.

The unloading operation refers to the process of loading the pallet loaded on the fork onto the shelf as described above.

For the unloading operation, information on the shelf height of the location where the pallet will be loaded is required. Accordingly, the control computer receives shelf height information from the unmanned forklift control server (S801), and raises the lift by the corresponding shelf height based on the received shelf height information (S802).

Shelf posts are arranged at regular intervals on the shelf, and pallets are loaded on the shelves between the shelf posts. In order to accurately load the pallets on the shelves between the shelf posts, a detection process by the third sensor 16 is performed. (S803).

As described above, the third sensor 16 is provided on the left and right rear bumpers 17, respectively. Accordingly, the position of the shelf post is detected through the third sensor 16 provided on the left and right rear bumpers 17, respectively, through the detection of the reflective patch provided on the shelf post in advance (refer to FIG. 11), and the third sensor The position of the shelf on which the pallet is to be loaded is specified by the control computer based on the position information of the shelf column detected by the system.

When the position of the shelf on which the pallet is to be loaded is specified by the third sensor 16, the control computer moves the fork left and right to the corresponding position (S804). Then, the control computer measures the distance between the unmanned forklift truck and the shelf column through the third sensor 16 (S805), and based on it, moves the fork forward to position it on the top of the shelf on which the pallet is loaded (S806). Then, by lowering the lift to load the pallet on the shelf (S807), and after moving the port backward (S801) and lowering the lift (S809), the unloading operation is completed. At this time, in the process of moving the fork forward, the presence or absence of an obstacle on the top of the shelf is detected by the second fork photoelectric sensor.

Above, the four unit operations of the unmanned forklift, that is, the driving operation, the rotation operation, the loading operation, and the unloading operation have been described. Each of the driving operation, the rotation operation, the loading operation, and the unloading operation is performed independently, and the four unit operations may be overlapped. For example, the loading operation may be performed at the time the rotation operation is finished.

1: position recognition sensor 2: first sensor
3: warning light 4: alarm lamp
5: joystick 6: touch screen monitor
7: Manual/automatic operation switch 8: Emergency stop switch
9: second sensor 10: front shock bumper
11: wireless transmit/receive antenna 12: fork laser sensor
13: first fork photoelectric sensor 14: second fork photoelectric sensor
15: wire sensor 16: third sensor
17: rear bumper

Claims (10)

It is provided on the upper side of the unmanned forklift and irradiates the laser, and the driving and rotating operation of the unmanned forklift is through the laser scan reflected by the reflective mark provided on the structure defining the space of the work area or the geometrical features of the stationary indoor topography. a location recognition sensor that detects the location of an unmanned forklift truck;
a third sensor provided on the left and right sides of the unmanned forklift to detect the presence of obstacles on the rotational path during the rotational operation of the unmanned forklift and detect two shelf pillars during the unloading operation to guide the location where the pallet is to be loaded;
It is provided at one point of the lift between the two cantilever beams constituting the fork to measure the distance to the shelf on which the pallet is loaded or the distance to the pallet, and also irradiates a laser to the reflective mark for detecting the pallet hole provided on the pallet during the loading operation. and a fork laser sensor receiving <position information and reflectance data> of the reflected laser;
a control computer that processes detection signals input from sensors provided in the front and rear parts of the unmanned forklift and controls the driving, rotating, loading and unloading operations of the unmanned forklift in conjunction with the unmanned forklift control server; is made, including
A first fork photoelectric sensor and a second fork photoelectric sensor provided on the front side of each cantilever constituting the fork; further comprising:
The first fork photoelectric sensor is disposed on the center side of the working device, and the second fork photoelectric sensor is disposed on the outside of the working device,
The first fork photoelectric sensor detects whether there is a pallet hole during the loading operation, and the second fork photoelectric sensor detects whether an obstacle exists in front of the fork in the process of moving the fork forward during the unloading operation. Unmanned forklift system, characterized in that.
According to claim 1, wherein the fork laser sensor receives a plurality of <position information and reflectivity data> by repeatedly irradiating the laser within a predetermined time toward the pallet provided with the reflective mark for detecting the pallet hole,
The position information is two-dimensional coordinate information of the position where the laser is irradiated, the reflectivity data is quantitative contrast data of the position where the laser is irradiated, and the position information of the position where the laser is irradiated is received together for each reflectivity data,
The control computer calculates an average value of position information by averaging the position information of each reflectivity data with respect to the reflectivity data above a certain reference value, and specifies the calculated average value of position information as a point where the reflection mark for detecting the pallet hole is located. driverless forklift system.
According to claim 1, wherein the third sensor respectively provided on the left and right sides of the unmanned forklift during the unloading operation to detect the two shelf pillars,
The control computer specifies the position of the shelf on which the pallet is to be loaded between the shelf column and the shelf column based on the position information of the shelf column detected by the third sensor.
According to claim 1, wherein the driving operation,
A process in which the control computer receives the destination node information based on the shape map required for driving from the unmanned forklift control server;
A process in which the control computer generates a path to the destination node on the shape map based on the received destination node information;
The unmanned forklift system, characterized in that it comprises a process in which the control computer controls the driving motor and the steering motor of the unmanned forklift so that the unmanned forklift runs along the generated path.
According to claim 1, wherein the rotation operation,
The process of the control computer receiving the arrival angle information from the unmanned forklift control server;
The control computer controls the steering motor based on the arrival angle information to rotate the unmanned forklift by the arrival angle.
An unmanned forklift system, characterized in that when the unmanned forklift rotates, the presence or absence of an obstacle on the rotational path is detected by a third sensor.
According to claim 1, wherein the loading operation,
A process in which the control computer receives the shelf height information of the location where the pallets are loaded from the unmanned forklift control server;
The process of detecting the position of the pallet hole,
The process of adjusting the distance between the two cantilever beams constituting the fork and moving the fork left and right so that the fork is located in the pallet hole;
It measures the distance between the fork and the pallet hole using a fork laser sensor, and based on that, moves the fork forward and inserts the fork into the pallet hole.
In the process of detecting the position of the pallet hole, the fork laser sensor repeatedly irradiates the laser toward the pallet provided with the reflective mark for detecting the pallet hole within a predetermined time to receive a plurality of <location information and reflectance data>, and a control computer Detects the position of the pallet hole by averaging the position information of each reflectivity data for the reflectivity data above a certain reference value, calculating the average value of the position information, and specifying the calculated average value of the position information as the point where the reflective marker for detecting the pallet hole is located Unmanned forklift system, characterized in that.
The method of claim 1, wherein the unloading operation comprises:
A process in which the control computer of the unmanned forklift receives shelf height information from the unmanned forklift control server and raises the lift by the corresponding shelf height based on the received shelf height information;
The process of specifying the position of the shelf on which the pallet will be loaded;
With the position of the shelf on which the pallet is to be loaded, the control computer measures the distance between the unmanned forklift and the shelf column through the third sensor, and based on that, moves the fork in the left and right directions and forwards to the upper part of the shelf on which the pallet is to be loaded the process of placing it in
It consists of lowering the lift and loading the pallet on the shelf,
In the process of specifying the position of the shelf on which the pallet is to be loaded, the third sensors respectively provided on the left and right sides of the unmanned forklift detect the two shelf posts, and the control computer collects the position information of the shelf posts detected by the third sensor. The unmanned forklift system, characterized in that it specifies the position of the shelf on which the pallet is to be loaded between the shelf column and the shelf column based on the base.
The method of claim 1, further comprising: a first sensor provided at the lower end of the front part of the unmanned forklift to detect an obstacle near the ground of the work area;
The unmanned forklift system further comprising a; a second sensor provided at the upper end of the front of the unmanned forklift to detect an obstacle at a predetermined height from the ground.
delete The method of claim 1, wherein the first wire sensor for measuring the height of the lift, the second wire sensor for measuring the shifted position when the two cantilevers are shifted to the left or right, and the third wire sensor for measuring the forward movement distance of the fork ; Unmanned forklift system, characterized in that it further comprises.

Images