TWI883765B - Control device for an automatic guided vehicle and control method for the same - Google Patents

Abstract

A control device for an automatic guided vehicle is disclosed, suitable for controlling the movement of an automatic guided vehicle, where the control device includes at least two optical sensors, a camera circuit and a processing circuit. The at least two optical sensors configured to detect a first distance between the automated guided vehicle and a pallet. The processing circuit configured to perform following steps: controlling the automatic guided vehicle to move toward the pallet until the first distance is equal to a first safety threshold; detecting respective coordinate sets of both sides of the pallet from at least one image of the pallet; calculating an offset parameter based on the respective coordinate sets on the both sides of the pallet; and controlling the automatic guided vehicle to move toward the pallet based on the offset parameter.

Description

Control device and control method for automatic guided vehicle

This disclosure relates to the technology of automatic guided vehicle applications, and in particular to the control device and control method of the automatic guided vehicle.

In recent years, automated guided vehicles (AGVs) have played an important role in the field of factory or warehouse automation, and the advancement of their technology has improved the autonomy of AGVs, which can perform their functions almost without human intervention. Mature sensing and perception technologies facilitate navigation in complex environments, and intelligent control algorithms enable AGVs to perform more complex tasks.

When an AUV is transporting goods, it mainly moves the pallet carrying the goods. However, the fork of the AUV sometimes cannot be accurately inserted into the pallet hole of the pallet, which causes the AUV to be unable to transport the goods. Therefore, how to control the fork of the AUV to accurately insert into the pallet hole to move the goods is a problem that technicians in this field are eager to solve.

The main purpose of this disclosure is to provide a control device and control method for an automatic guided vehicle, which can greatly increase the accuracy of controlling the fork of the automatic guided vehicle to insert into the platform hole.

In order to achieve the above-mentioned purpose, the control device of the automatic guided vehicle disclosed in the present invention is arranged on an automatic guided vehicle and is suitable for controlling at least two forks of the automatic guided vehicle to be inserted into at least two holes of a pallet, comprising: at least two optical sensors, respectively arranged on the at least two forks of the automatic guided vehicle, configured to detect a first distance between the automatic guided vehicle and the pallet; a photographic circuit, arranged at a position at the geometric center of a carrying part of the automatic guided vehicle, configured to photograph the pallet; and a processing circuit, coupled to the at least two optical sensors and the photographic circuit, configured to perform the following steps: controlling the automatic guided vehicle to move toward the pallet until the pallet is A relay position at which the first distance is equal to a first safety threshold value; capturing at least one image of the pallet by the photographic circuit, and detecting from the at least one image a set of coordinates of each of two vertical edges corresponding to a thickness of the pallet on a plane of the pallet close to the at least two optical sensors; calculating an offset parameter according to the respective sets of coordinates of the two vertical edges, wherein the offset parameter includes a lateral offset distance, a longitudinal offset distance and an offset angle of the automatic guided vehicle relative to the pallet; and controlling the automatic guided vehicle to move from the relay position toward the pallet according to the offset parameter to insert the at least two teeth of the automatic guided vehicle into the at least two pallet holes of the pallet.

In order to achieve the above-mentioned purpose, the control method of the automatic guided vehicle disclosed in the present invention comprises: controlling the automatic guided vehicle to move toward the pallet until the first distance is equal to a relay position of a first safety threshold value by a processing circuit, wherein the first distance is the distance between the automatic guided vehicle and the pallet detected by at least two optical sensors; capturing at least one image of the pallet by a photographing circuit, and detecting from the at least one image a plane of the pallet close to the at least two optical sensors and the first distance between the automatic guided vehicle and the pallet; A coordinate set of each of two vertical edges corresponding to a thickness of the pallet; the processing circuit calculates an offset parameter according to the coordinate set of each of the two vertical edges, wherein the offset parameter includes a lateral offset distance, a longitudinal offset distance and an offset angle of the automatic guided vehicle relative to the pallet; and the processing circuit controls the automatic guided vehicle to move from the intermediate position toward the pallet according to the offset parameter so as to insert at least two teeth of the automatic guided vehicle into at least two pallet holes of the pallet.

Compared with related technologies, the technical effect that can be achieved by this disclosure is to use three-dimensional vision technology to calculate the offset parameters between the automatic guided vehicle and the pallet. In this way, the offset parameters can be used to accurately control the fork of the automatic guided vehicle to insert into the pallet to move the goods to the destination.

100: Control device

110a~110b: Optical sensor

120a~120b: Photography circuit

130: Processing circuit

140a~140b: Optical radar

VC:Automated Guided Vehicle

fk: tooth fork

cr: passenger department

mt:mast

vd: vertical distance

S310~S340, S910~S930, S1010: Steps

GS: Goods

PT: Pallet

FS1~FS2: front part

d1~d2: Actual distance

MD: moving direction

HL1~HL2: Parallel lines

N1~N2: Normal vector

CC: Location

a: lateral offset distance

b: Longitudinal offset distance

θ: offset angle

O_GS: cargo object

O_PT: Pallet object

R_FS: Part of the front area

CP: Point cloud

IMG: 3D Image

s1: First sub-point cloud collection

s2: Second sub-point cloud collection

s3: cargo point cluster

s4: A large number of pallets are gathered

INS:Inner wall

D1~D2: minimum distance

FIG1 is a schematic diagram of an automatic guided vehicle in some embodiments

FIG2 shows a block diagram of a control device for an automated guided vehicle in some embodiments

FIG3 is a flow chart showing a control method of an automatic guided vehicle in some embodiments.

FIG. 4 shows an oblique view of an automated guided vehicle moving toward a pallet in some embodiments.

FIG. 5 shows a top view of an automated guided vehicle and a pallet in some embodiments.

FIG. 6 shows a top view of an automatic guided vehicle and a pallet in other embodiments.

FIG7 is a schematic diagram of a three-dimensional image in some embodiments.

FIG8 is a schematic diagram of a point cloud image in some embodiments.

FIG9 is a flow chart showing the steps further included in the control method of the automatic guided vehicle in some embodiments.

FIG10 is a flow chart showing the steps further included in the control method of the automatic guided vehicle in other embodiments.

FIG. 11 shows an oblique view of controlling an automated guided vehicle to enter a container in some embodiments.

FIG. 12 shows a top view of controlling an automated guided vehicle to enter a container in some embodiments.

Referring to FIG. 1 and FIG. 2 at the same time, FIG. 1 is a schematic diagram of an automated guided vehicle (AGV) VC in some embodiments, and FIG. 2 is a block diagram of a control device 100 of an automated guided vehicle VC in some embodiments, wherein the automated guided vehicle VC can be implemented by any omnidirectional (i.e., an automated forklift with omnidirectional wheels (Omni wheels) or Mecanum wheels (Mecanum wheels)) automated forklift, and can receive tasks assigned by the management system (e.g., a server system or cloud processing system that can implement a logistics control system (warehouse control system), etc., not shown) (e.g., moving goods at a specific location in a warehouse). In some embodiments, the management system manages the control devices 100 of multiple automated guided vehicles VC.

As shown in FIG. 1 and FIG. 2 , the control device 100 includes at least two optical sensors 110a-110b, a photographic circuit 120a, and a processing circuit 130. The at least two optical sensors 110a-110b and the photographic circuit 120a are coupled to the processing circuit 130. In this embodiment, the optical sensors 110a-110b are respectively disposed on the tips of at least two forks fk of the automatic guided vehicle VC. Such a setting position can more accurately detect the first distance between the automatic guided vehicle VC and the pallet in the subsequent section to prevent the at least two forks fk of the automatic guided vehicle VC from colliding with the pallet. In some embodiments, the number of optical sensors 110a-110b can also be other positive integers greater than two, and the number of teeth forks fk can also be any positive integer that matches the number of bottom leads of the pallet carrying the goods. The present disclosure does not have any special restrictions on the number of optical sensors 110a-110b and the number of teeth forks fk. It is worth noting that the management system will transmit the specifications of the pallet and the height of the pallet to the processing circuit 130 in advance, so that the processing circuit 130 can pre-set the distance between the two teeth forks fk and the height between the teeth forks fk and the ground.

In this embodiment, the optical sensors 110a-110b detect a first distance between the automatic guided vehicle VC and the pallet. More specifically, the optical sensors 110a-110b are disposed at the tip of the two forks fk and detect toward the outside, and the first distance refers to the vertical distance of the tip of the two forks fk (i.e., the location of the optical sensors 110a-110b) relative to a plane of the pallet close to one side of the optical sensors 110a-110b. In detail, when the automatic guided vehicle VC is assigned to a specific location to transport goods, the automatic guided vehicle VC needs to insert at least the two forks fk into at least two pallet holes of the pallet. Before the processing circuit 130 controls the automatic guided vehicle VC to insert at least two forks fk into at least two pallet holes of the pallet, at least two optical sensors 110a~110b will instantly detect the distance between the automatic guided vehicle VC and the pallet, so that the automatic guided vehicle VC can be positioned before inserting the two forks fk into the at least two pallet holes. In some embodiments, the optical sensors 110a~110b can be implemented by any laser sensor that performs light sensing ranging or electromagnetic sensing ranging.

In this embodiment, the camera circuit 120a is controlled by the processing circuit 130 to shoot the pallet in front of the automatic guided vehicle VC. In some embodiments, the camera circuit 120a is set at the geometric center of the carrier cr of the automatic guided vehicle VC. Such a setting can clearly capture the pallet directly in front of the automatic guided vehicle VC and the goods on the pallet. In some embodiments, the control device 100 further includes a camera circuit 120b. In some embodiments, the camera circuit 120b is set at the center point of the vertices on both sides of the mast mt of the automatic guided vehicle VC, and there is a vertical distance vd between this center point and the camera circuit 120a. In some embodiments, when the automated guided vehicle VC needs to move cargo at a higher position, the camera circuit 120b can replace the camera circuit 120a to photograph the pallet (because the pallet is too high and the camera circuit 120a cannot photograph the pallet). In some embodiments, the camera circuits 120a~120b can be implemented by any three-dimensional camera.

In some embodiments, the control device 100 further includes at least two optical radars (light detection and ranging, LIDAR) 140a~140b. In some embodiments, the optical radars 140a~140b are respectively arranged at the tops of the two sides of the mast mt of the automatic guided vehicle VC, wherein the number of the optical radars 140a~140b can also be other positive integers greater than two, and there is no special limitation. Such a setting method can more accurately detect the two second distances between the two sides of the automatic guided vehicle VC and the two inner walls of the container in the subsequent paragraphs. The subsequent paragraphs will further explain how to use the optical radars 140a~140b, which will not be further elaborated here.

In this embodiment, the processing circuit 130 executes the control method of the automatic guided vehicle VC in the subsequent paragraphs. In some embodiments, the processing circuit 130 can be implemented by a central processing unit (CPU), a micro control unit (MCU), a programmable logic controller (PLC), a system on chip (SoC) or a field programmable gate array (FPGA), etc., but is not limited thereto.

Referring to FIG. 3 , FIG. 3 is a flow chart of a control method of an automatic guided vehicle VC in some embodiments. This control method is applicable to the control device 100 shown in FIG. 1 and FIG. 2 .

As shown in FIG3 , the control method includes steps S310 to S340. First, in step S310, the processing circuit 130 controls the automatic guided vehicle VC to move toward the pallet until a relay position where the first distance is equal to the first safety threshold. In one embodiment, the automatic guided vehicle VC will first pause after moving to the relay position, and will first be positioned by the control method disclosed herein. In other words, when the first distance is equal to the first safety threshold, the processing circuit 130 controls the automatic guided vehicle VC to stop moving toward the pallet. In another embodiment, the automatic guided vehicle VC continues to be positioned by the control method disclosed herein during the process of moving to the relay position, so it is not necessarily necessary to stop moving at the relay position. The following is an actual example to illustrate the movement of the automatic guided vehicle VC. In some embodiments, the first safety threshold can be pre-set by the user and recorded in the processing circuit 130.

Referring to Fig. 4 and Fig. 5, Fig. 4 shows an oblique view of the automatic guided vehicle VC moving toward the pallet PT in some embodiments, and Fig. 5 shows a top view of the automatic guided vehicle VC and the pallet PT in some embodiments. As shown in Fig. 4, assuming that the goods GS in the warehouse are all placed on the pallet PT, and the management system assigns the automatic guided vehicle VC to move the goods GS in the warehouse (not the goods in the container), the management system transmits the coordinates of the goods GS in the warehouse to the processing circuit 130, and the processing circuit 130 controls the automatic guided vehicle VC to move to the front of the pallet PT where the goods GS are placed according to the coordinates of the goods GS in the warehouse. Next, the processing circuit 130 controls the front part FS2 (i.e., the front face) of the automatic guided vehicle VC to turn toward the front part FS1 of the pallet PT according to the two distances respectively detected by the optical sensors 110a~110b, so that the front part FS2 of the automatic guided vehicle VC and the front part FS1 of the pallet PT are in a horizontal state (i.e., the automatic guided vehicle VC is controlled to turn until the distance detected by the optical sensor 110a is equal to the distance detected by the optical sensor 110b), and then controls the automatic guided vehicle VC to move slowly toward the pallet PT along a moving direction MD.

Next, when the automatic guided vehicle VC slowly moves toward the pallet PT along the moving direction MD, the optical sensors 110a-110b continuously detect the distance between the automatic guided vehicle VC and the pallet PT (i.e., the first distance mentioned above), and continuously move to a position where the distance is equal to the first safety threshold (i.e., the intermediate position mentioned above). However, due to the detection accuracy of the optical sensors 110a-110b, the two actual distances d1-d2 between the optical sensors 110a-110b on the automatic guided vehicle VC and the pallet PT may not be equal. As shown in FIG5 , since the actual distances d1 and d2 are not equal, there is an offset angle θ between the parallel line HL2 perpendicular to the normal vector N2 of the front part FS2 of the automatic guided vehicle VC and the parallel line HL1 perpendicular to the normal vector N1 of the front part FS1 of the pallet PT. Therefore, the automatic guided vehicle VC needs to rotate counterclockwise by the offset angle θ with the position CC of the camera circuit 120a as the center to make the normal vector N2 parallel to the normal vector N1.

Referring to FIG6 , FIG6 shows a top view of the automatic guided vehicle VC and the pallet PT in other embodiments. As shown in FIG6 , after the automatic guided vehicle VC rotates counterclockwise by an offset angle θ with the position CC of the camera circuit 120a as the center, the position CC of the camera circuit 120a of the automatic guided vehicle VC needs to move a lateral offset distance a and a longitudinal offset distance b to reach the center point FC of the front part FS1 of the pallet PT. When the position CC of the camera circuit 120a reaches the center point FC of the front part FS1 of the pallet PT, it means that the two forks of the automatic guided vehicle VC have been correctly inserted into the two pallet holes of the pallet PT. In one embodiment, the lateral offset distance a is an offset distance perpendicular to the normal direction N2 of the front portion FS2 and parallel to the ground, and the longitudinal offset distance b is an offset distance parallel to the normal direction N2 of the front portion FS2 and parallel to the ground. The following paragraphs will further explain how to calculate the offset angle θ, the lateral offset distance a, and the longitudinal offset distance b, which will not be further elaborated here.

Returning to FIG. 3, in step S320, the processing circuit 130 captures at least one image of the pallet PT through the camera circuit 120a, and detects from the at least one image the respective coordinate sets of two vertical edges corresponding to the thickness of the pallet PT on the plane of the pallet PT close to the optical sensors 110a~110b (i.e., the edges perpendicular to the ground on which the pallet PT is placed). In step S330, the processing circuit 130 calculates the offset parameters according to the respective coordinate sets of the two vertical edges, wherein the offset parameters include the lateral offset distance a, the longitudinal offset distance b, and the offset angle θ of the automatic guided vehicle VC relative to the pallet PT.

In some embodiments, at least one image may be a three-dimensional image or a plurality of continuous images. In some embodiments, the processing circuit 130 generates a point cloud map from at least one image, wherein the point cloud map includes a pallet point cloud set corresponding to the pallet (i.e., a point cloud set of the pallet PT in at least one image). Then, the processing circuit 130 selects a first sub-point cloud set and a second sub-point cloud set corresponding to the two vertical edges respectively from the pallet point cloud set (i.e., all point clouds at positions on both sides of the pallet PT in at least one image). Then, the processing circuit 130 uses the coordinate set of the first sub-point cloud set and the coordinate set of the second sub-point cloud set (i.e., the coordinates of all point clouds in the first sub-point cloud set and the coordinates of all point clouds in the second sub-point cloud set) as the coordinate sets of the two vertical edges respectively. In some embodiments, the point cloud map CP further includes a cargo point cloud set corresponding to the cargo GS. In some embodiments, the processing circuit 130 uses any point cloud generation algorithm commonly used in the field (for example, the structure from motion (SFM) algorithm of SLAM (simultaneous localization and mapping) technology) to generate the above point cloud map.

In some embodiments, the processing circuit 130 calculates the lateral offset distance a, the longitudinal offset distance b, and the offset angle θ of the automatic guided vehicle VC relative to the pallet PT based on the average lateral component and the average longitudinal component of the coordinate sets of the two vertical edges (i.e., the x component and the y component in the camera coordinate system).

The generation of the offset parameter is described below with an actual example. Referring to FIG. 7 and FIG. 8 , FIG. 7 is a schematic diagram of a three-dimensional image IMG in some embodiments, and FIG. 8 is a schematic diagram of a point cloud image CP in some embodiments. As shown in FIG. 7 and FIG. 8 , the three-dimensional image IMG includes a cargo object O_GS and a pallet object O_PT. When calculating the offset parameters, the processing circuit 130 converts the three-dimensional image IMG into a point cloud image CP, and selects a plurality of point clouds on two vertical edges corresponding to the thickness of the front partial area R_FS of the pallet object O_PT as the first sub-point cloud set s1 (i.e., all point clouds on one side of the front partial area R_FS corresponding to the thickness of the pallet object O_PT) and the second sub-point cloud set s2 (i.e., all point clouds on the other side of the front partial area R_FS corresponding to the thickness of the pallet object O_PT). In one embodiment, the processing circuit 130 may, for example, use an object detection algorithm to identify the area corresponding to the front partial area R_FS of the pallet object O_PT, and then use a corner detection algorithm and an edge detection algorithm to detect two edges corresponding to the thickness of this area, and then select all point clouds on these two edges respectively).

The processing circuit 130 calculates the average value of the transverse components of the camera coordinates (i.e., coordinate set) of all point clouds in the first sub-point cloud set s1 as the average transverse component of the coordinate set corresponding to the thickness of the front partial area R_FS of the pallet object O_PT, and calculates the average value of the longitudinal components of the camera coordinates of all point clouds in the first sub-point cloud set s1 as the average longitudinal component of the coordinate set corresponding to the thickness of the front partial area R_FS of the pallet object O_PT. Next, the processing circuit 130 calculates the average value of the horizontal components of the camera coordinates of all point clouds in the second sub-point cloud set s2 as the average horizontal component of the coordinate set of the other side corresponding to the thickness of the front partial area R_FS of the pallet object O_PT, and calculates the average value of the vertical components of the camera coordinates of all point clouds in the second sub-point cloud set s2 as the average vertical component of the coordinate set of the other side corresponding to the thickness of the front partial area R_FS of the pallet object O_PT.

The processing circuit 130 calculates the average transverse component of the coordinate set of one side corresponding to the thickness of the front partial area R_FS and the average transverse component of the coordinate set of the other side corresponding to the thickness of the front partial area R_FS as the transverse offset distance a, and calculates the average longitudinal component of the coordinate set of one side corresponding to the thickness of the front partial area R_FS and the average longitudinal component of the coordinate set of the other side corresponding to the thickness of the front partial area R_FS as the longitudinal offset distance b. Then, the processing circuit 130 calculates the offset angle θ according to the transverse offset distance a and the longitudinal offset distance b, and uses the transverse offset distance a, the longitudinal offset distance b and the offset angle θ as offset parameters.

Referring to FIG. 9 , FIG. 9 is a flowchart of steps S910 to S930 further included in the control method of the automatic guided vehicle VC in some embodiments. As shown in FIG. 9 , in step S910, the processing circuit 130 determines whether the cargo GS is tilted (for example, tilted to the right or tilted to the left) according to the cargo point cloud s3. Specifically, taking the cargo GS as a space bag as an example, because the space bag is large in size and heavy in weight, various deformations may occur when stacking, and this deformation may cause the automatic guided vehicle VC to cause the cargo GS to fall when transporting the cargo GS. When it is determined that the cargo GS is tilted to the right, step S920 is entered. In step S920, the processing circuit 130 controls the automatic guided vehicle VC to move rightward by a deviation amount to compensate for the weight distribution of the cargo GS shifting toward the right side. On the contrary, when it is determined that the cargo GS is tilted to the left, the process proceeds to step S930. In step S930, the processing circuit 130 controls the automatic guided vehicle VC to move leftward by a deviation amount to compensate for the weight distribution of the cargo GS shifting toward the left side. In this way, the processing circuit 130 prevents the cargo from tipping over when transporting the cargo by moving a deviation amount. It is worth mentioning that the processing circuit 130 can compensate for the tilt of the cargo GS according to the above technical means before controlling the two forks of the automatic guided vehicle VC to insert into the two pallet holes of the pallet PT, or can compensate for the tilt of the cargo GS according to the above technical means after controlling the two forks of the automatic guided vehicle VC to insert into the two pallet holes of the pallet PT.

For example, as shown in FIG8 , the processing circuit 130 selects a cargo point cloud set s3 corresponding to the cargo object O_GS (e.g., using an object recognition algorithm to recognize the region corresponding to the cargo object O_GS and selecting all point clouds in the region) and a pallet point cloud set s4 corresponding to the pallet object O_PT (e.g., using an object recognition algorithm to recognize the region corresponding to the pallet object O_PT and selecting all point clouds in the region) from the point cloud image CP. The processing circuit 130 executes a PCL (point cloud library) point cloud centroid algorithm on the camera coordinates of the multiple point clouds in the cargo point cloud set s3 and the camera coordinates of the multiple point clouds in the pallet point cloud set s4 to generate the centroid coordinates of the cargo point cloud set s3 and the centroid coordinates of the other multiple point clouds. Next, the processing circuit 130 determines whether the cargo GS is tilted to the right or to the left based on the centroid coordinates of the cargo point cloud set s3 and the centroid coordinates of multiple other point clouds, and then controls the automatic guided vehicle VC to move to the left or to the right based on the deviation according to the judgment result.

Returning to FIG. 3 , in step S340, the processing circuit 130 controls the automatic guided vehicle VC to move toward the pallet PT from the intermediate position according to the offset parameter, so as to insert at least two forks fk of the automatic guided vehicle VC into at least two pallet holes of the pallet PT. In some embodiments, the processing circuit 130 controls the automatic guided vehicle VC to rotate counterclockwise by an offset angle θ with the camera circuit 120a as the center, and then controls the automatic guided vehicle VC to move a lateral offset distance a along a direction perpendicular to the normal vector N2 of the front part FS2 of the automatic guided vehicle VC, and finally controls the automatic guided vehicle VC to move a longitudinal offset distance b along the normal vector N2 of the front part FS2 of the automatic guided vehicle VC. At this time, the at least two forks fk of the automatic guided vehicle VC have been inserted into the at least two pallet holes of the pallet PT. After at least two forks fk are inserted into at least two holes of the pallet PT, the processing circuit 130 can control the automatic guided vehicle VC to lift the two forks fk upward, thereby starting to transport the pallet PT and the goods GS on the pallet PT.

Referring to FIG. 10 , FIG. 10 is a flow chart of step S1010 further included in the control method of the automatic guided vehicle VC in other embodiments. As shown in FIG. 10 , in step S1010, when the processing circuit 130 controls the automatic guided vehicle VC to enter the container, the optical radars 140a-140b detect the two second distances between the two sides of the mast of the automatic guided vehicle VC and the two inner walls of the container, and control the left and right movement of the automatic guided vehicle VC, so that the two second distances between the two sides of the mast and the two inner walls of the container are both greater than the second safety threshold. In detail, when the automatic guided vehicle VC is assigned to transport the cargo GS to a specific container, the optical radar 140a~140b will instantly detect the two distances between the two sides of the mast of the automatic guided vehicle VC and the two inner walls of the container, and transmit the two distances to the processing circuit 130 (because the camera circuit 120a is blocked by the transported cargo GS, only the optical radar 140a~140b can be used to detect the distance). In some embodiments, the second safety threshold value can also be pre-set by the user and recorded in the processing circuit 130. The following is an actual example to illustrate the control of the automatic guided vehicle VC entering the container.

Referring to FIG. 11 and FIG. 12 , FIG. 11 is an oblique view of controlling the automatic guided vehicle VC to enter the container CT in some embodiments, and FIG. 12 is a top view of controlling the automatic guided vehicle VC to enter the container CT in some embodiments. As shown in FIG. 11 and FIG. 12 , when the automatic guided vehicle VC is assigned to the container CT, the automatic guided vehicle VC moves toward the container CT along the moving direction MD. When the automatic guided vehicle VC moves, the optical radar 140a-140b detects two minimum distances D1-D2 (i.e., two second distances) between the top ends of the two sides of the mast of the automatic guided vehicle VC and the two inner side walls INS of the container CT in real time. The processing circuit 130 continuously controls the movement of the automatic guided vehicle VC so that the two minimum distances D1-D2 between the two sides of the mast and the two inner walls INS of the container CT are both greater than a second safety threshold value to prevent the two sides of the automatic guided vehicle VC from colliding with the two inner walls INS of the container CT when entering the container CT.

In some embodiments, when the processing circuit 130 controls the automatic guided vehicle VC to transport the goods GS in the container CT, the processing circuit 130 detects whether there is another goods in front of the automatic guided vehicle VC by at least two optical sensors 110a~110b (because the camera circuit 120a is blocked by the transported goods GS and the optical radar 140a~140b may be too high, only the optical sensors 110a~110b can be used to sense whether there is another goods in front). In this way, the method of the processing circuit 130 using at least two optical sensors 110a~110b to detect obstacles in front can prevent the automatic guided vehicle VC from placing the goods GS in the container CT to the position of another existing goods.

In summary, the control device and control method of the automatic guided vehicle proposed in the present disclosure can use the point cloud map of the pallet to generate the coordinate sets of the two sides of the pallet, and calculate the average transverse component and longitudinal component of the coordinate sets of the two sides of the pallet, and then calculate the offset parameter according to the average transverse component and longitudinal component of the coordinate sets of the two sides of the pallet. In this way, the offset parameter can be used to accurately control the fork of the automatic guided vehicle to insert into the pallet hole of the pallet, so that the pallet can be moved to transport the goods to the destination, thereby overcoming the problem of insufficient accuracy of the optical sensor. In addition, the control device and control method of the automatic guided vehicle proposed in the present disclosure can further identify whether the goods are placed crookedly according to the point cloud map. In this way, when the cargo is tilted, the control device and control method of the automatic guided vehicle proposed in the present disclosure can slightly adjust the position of the fork in the pallet hole to prevent the cargo from falling. On the other hand, when the automatic guided vehicle is about to enter the container, the control device and control method of the automatic guided vehicle proposed in the present disclosure can use the method of optical radar detection distance to control the movement of the automatic guided vehicle, so that the distance between the mast and the inner wall of the container is maintained in a safe range. When the automatic guided vehicle is unloading cargo in the container, the control device and control method of the automatic guided vehicle proposed in the present disclosure can use the method of optical sensor detection distance to control the automatic guided vehicle to move to a position where no other cargo is placed to place the cargo. In this way, the occurrence of collision can be avoided even when the cargo blocks the camera circuit.

The above is only a specific example of this disclosure, and does not limit the scope of the patent application of this disclosure. Therefore, all equivalent changes made by applying the content of this case are also included in the scope of this disclosure and are hereby stated.

100: Control device

110a~110b: Optical sensor

120a~120b: Photography circuit

130: Processing circuit

140a~140b: Optical radar

Claims (12)

A control device for an automatic guided vehicle is provided on the automatic guided vehicle and is suitable for controlling at least two prongs of the automatic guided vehicle to be inserted into at least two pallet holes of a pallet, comprising: at least two optical sensors, respectively provided on the at least two prongs of the automatic guided vehicle, and configured to detect a first distance between the automatic guided vehicle and the pallet; a photographic circuit, provided at a position at a geometric center of a carrying portion of the automatic guided vehicle, and configured to photograph the pallet; and a processing circuit, coupled to the at least two optical sensors and the photographic circuit, and configured to perform the following steps: controlling the automatic guided vehicle to move toward the pallet until the first distance is equal to a relay position of a first safety threshold; capturing at least one image of the pallet by the photographic circuit, and detecting from the at least one image a set of coordinates of two vertical edges corresponding to a thickness of the pallet on a plane of the pallet close to the at least two optical sensors; calculating an offset parameter according to the respective coordinate sets of the two vertical edges, wherein the offset parameter includes a lateral offset distance, a longitudinal offset distance and an offset angle of the automatic guided vehicle relative to the pallet; and controlling the automatic guided vehicle to move from the relay position toward the pallet according to the offset parameter to insert the at least two teeth of the automatic guided vehicle into the at least two pallet holes of the pallet. A control device for an automatic guided vehicle as described in claim 1, wherein the at least one image is a three-dimensional image or a plurality of continuous images, wherein in the step of detecting the coordinate sets of the two vertical edges corresponding to the thickness of the pallet on the plane of the pallet close to the at least two optical sensors from the at least one image, the processing circuit is configured to perform the following steps: generating a point cloud image from the at least one image, wherein the point cloud image includes a pallet point cloud corresponding to the pallet; selecting a first sub-point cloud and a second sub-point cloud corresponding to the two vertical edges from the pallet point cloud; and using the coordinate sets of the first sub-point cloud and the coordinate sets of the second sub-point cloud as the coordinate sets of the two vertical edges. The control device of the automatic guided vehicle as described in claim 1, wherein in the step of calculating the offset parameter according to the coordinate set of each of the two vertical edges, the processing circuit is configured to perform the following steps: calculating the lateral offset distance, the longitudinal offset distance and the offset angle of the automatic guided vehicle relative to the pallet according to an average lateral component and a longitudinal component of the coordinate set of each of the two vertical edges. A control device for an automated guided vehicle as described in claim 2, wherein the point cloud map further includes a cargo point cloud corresponding to a cargo, wherein the processing circuit is further configured to perform the following steps: judging whether the cargo is tilted to the right or to the left according to the cargo point cloud; when judging that the cargo is tilted to the right, controlling the automated guided vehicle to move to the right by a deviation; and when judging that the cargo is tilted to the left, controlling the automated guided vehicle to move to the left by the deviation. The control device of the automatic guided vehicle as described in claim 1 further comprises: at least two optical radars, respectively disposed at the top of the two sides of a mast of the automatic guided vehicle, configured to detect two second distances between the two sides of the automatic guided vehicle and the two inner walls of a container, wherein the processing circuit is further configured to perform the following steps: When controlling the automatic guided vehicle to enter the container, the processing circuit controls the movement of the automatic guided vehicle so that the two second distances between the two sides and the two inner walls of the container are both greater than a second safety threshold. The control device of the automated guided vehicle as described in claim 5, wherein the processing circuit is further configured to perform the following steps: when the processing circuit controls the automated guided vehicle to move in the container, the at least two optical sensors are used to detect whether there is another cargo in front of the automated guided vehicle. A control method for an automatic guided vehicle comprises: controlling the automatic guided vehicle to move toward a pallet by a processing circuit until a relay position at which a first distance is equal to a first safety threshold, wherein the first distance is a distance between the automatic guided vehicle and the pallet detected by at least two optical sensors; capturing at least one image of the pallet by a photographic circuit, and detecting from the at least one image a thickness of the pallet on a plane of the pallet close to the at least two optical sensors. The processing circuit calculates an offset parameter according to the coordinate sets of the two vertical edges, wherein the offset parameter includes a lateral offset distance, a longitudinal offset distance and an offset angle of the automatic guided vehicle relative to the pallet; and the processing circuit controls the automatic guided vehicle to move from the intermediate position toward the pallet according to the offset parameter so as to insert at least two teeth of the automatic guided vehicle into at least two pallet holes of the pallet. The control method of the automatic guided vehicle as described in claim 7, wherein the at least one image is a three-dimensional image or a plurality of continuous images, wherein the step of detecting the coordinate sets of the two vertical edges corresponding to the thickness of the pallet on the plane of the pallet close to the at least two optical sensors from the at least one image comprises: generating a point cloud image from the at least one image by the processing circuit, wherein the point cloud image comprises a pallet point cloud corresponding to the pallet; selecting a first sub-point cloud and a second sub-point cloud corresponding to the two vertical edges respectively from the pallet point cloud by the processing circuit; and using the coordinate sets of the first sub-point cloud and the coordinate sets of the second sub-point cloud as the coordinate sets of the two vertical edges respectively by the processing circuit. The control method of the automatic guided vehicle as described in claim 7, wherein the step of calculating the offset parameter according to the coordinate sets of the two vertical edges comprises: calculating the lateral offset distance, the longitudinal offset distance and the offset angle of the automatic guided vehicle relative to the pallet according to an average lateral component and a longitudinal component of the coordinate sets of the two vertical edges by the processing circuit. A control method for an automated guided vehicle as described in claim 8, wherein the point cloud map further includes a cargo point cloud corresponding to a cargo, wherein the control method further includes: judging by the processing circuit whether the cargo is tilted right or left according to the cargo point cloud; when judging that the cargo is tilted right, controlling the automated guided vehicle to move rightward by a deviation amount by the processing circuit; and when judging that the cargo is tilted leftward, controlling the automated guided vehicle to move leftward by the deviation amount by the processing circuit. The control method of the automatic guided vehicle as described in claim 7 further includes: detecting two second distances between the two sides of the automatic guided vehicle and the two inner walls of a container by at least two optical radars; and When the processing circuit controls the automatic guided vehicle to enter the container, the processing circuit controls the two second distances between the two sides of the automatic guided vehicle and the two inner walls of the container to be greater than a second safety threshold. The control method of the automatic guided vehicle as described in claim 11 further includes: when the processing circuit controls the automatic guided vehicle to move in the container, the at least two optical sensors detect whether there is another cargo in front of the automatic guided vehicle.

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