Transport carrier and transport system including the same

Abstract

The invention provides a transport vehicle and a transport system including the same. A transport system for compensating for a distance difference caused by a slip phenomenon between a drive wheel and a track when a plurality of transport vehicles executing a queue travel are simultaneously traveling, includes: a first transport vehicle; a second transport vehicle; a host controller to control the transport vehicle, the host controller configured to provide transport instructions to the first transport vehicle and the second transport vehicle, the first motion controller to provide a first position instruction to the first driver and the second motion controller to provide a second position instruction to the second driver according to the transport instructions, when a first interval between the first transport vehicle and the second transport vehicle becomes wider than a first reference, the first motion controller provides a third position command indicating a position closer to the first position command to the first driver. And the second transport vehicle provides a fourth position command indicating a position closer to the second position command to the second driver.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to and all benefits under 35 U.S.C. 119 from Korean Patent Application No. 10 - 2023 - 0179367, filed with the Korean Intellectual Property Office on December 12, 2023, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present disclosure relates to a transport vehicle and a transport system including the transport vehicle. Background art

[0004] In the process of manufacturing semiconductor devices, substrates can be transported by an unmanned transport system. Specifically, the unmanned transport system may include transport vehicles (e.g., overhead hoist transport (OHT), rail guided vehicle (RGV), etc.) configured to be movable along a travel track installed on the ceiling or floor of a clean room. The operation control of the transport vehicle can be controlled by an upper controller such as an OHT control server (OCS) device. Summary of the invention

[0005] Aspects of the present disclosure provide a transport system for compensating for a distance difference caused by a slip phenomenon between driving wheels and a track when multiple transport vehicles performing platoon driving travel simultaneously.

[0006] Aspects of the present disclosure also provide a transport vehicle for compensating for a distance difference caused by a slip phenomenon between driving wheels and a track when multiple transport vehicles performing platoon driving travel simultaneously.

[0007] Aspects of the present disclosure are not limited to the aspects mentioned above, and other aspects not mentioned will be clearly understood by those skilled in the art from the following description.

[0008] According to one aspect of the present disclosure, a transportation system is provided, which includes: a first transportation vehicle that moves along a track and includes a first motion controller and a first driver for rotating a first driving wheel; a second transportation vehicle that moves in a queue with the first transportation vehicle along the track, and the second transportation vehicle includes a second motion controller and a second driver for rotating a second driving wheel; and an upper controller that controls the first transportation vehicle and the second transportation vehicle. Wherein, the upper controller provides a transportation command to the first transportation vehicle and the second transportation vehicle. According to the transportation command, the first motion controller provides a first position command to the first driver, and the second motion controller provides a second position command to the second driver. And when a first interval between the first transportation vehicle and the second transportation vehicle becomes wider than a first reference, the first motion controller provides a third position command indicating a position closer than the first position command to the first driver, and the second transportation vehicle provides a fourth position command indicating a position closer than the second position command to the second driver.

[0009] According to another aspect of the present disclosure, a transportation vehicle is provided, which includes: a memory configured to store a reference acceleration; a motion controller configured to generate a position command based on the reference acceleration; a driver configured to receive the position command and rotate a driving wheel; and a communicator configured to communicate with a fellow transport vehicle belonging to a queue driving group. Wherein, the motion controller includes: generating a position command based on the reference acceleration and providing the position command to the driver, receiving an interval between fellow transport vehicles through the communicator, reducing the reference acceleration when the interval becomes wider than a first reference, and generating a position command based on the decreased reference acceleration and providing the position command to the driver.

[0010] According to another aspect of the present disclosure, a transport vehicle is provided, which includes: a memory configured to store a reference acceleration; a motion controller configured to generate a position command based on the reference acceleration; a driver configured to receive the position command and rotate a drive wheel; a communicator configured to communicate with a slave transport vehicle belonging to a platooning group; and a distance sensor configured to measure an interval from a slave transport vehicle positioned directly ahead, wherein the motion controller includes generating a position command based on the reference acceleration and providing the position command to the driver, the communicator includes transmitting the interval measured by the distance sensor to a master transport vehicle, the communicator includes receiving an instruction from the master transport vehicle to adjust the reference acceleration, the motion controller includes adjusting the reference acceleration, and the motion controller includes generating a position command based on the adjusted reference acceleration and providing the position command to the driver.

[0011] Details of other exemplary embodiments are included in the detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] With reference to the drawings, the above and other aspects and features of the present disclosure will become more apparent from the following detailed description of exemplary embodiments of the present disclosure, in which:

[0013] Figure 1 is a conceptual schematic diagram for describing a transport system according to some exemplary embodiments of the present disclosure;

[0014] Figure 2 is for describing Figure 1 the transport vehicle shown in

[0015] Figure 3 is a conceptual schematic diagram for describing the operation of a transport system according to some exemplary embodiments of the present disclosure;

[0016] Figure 4 is a conceptual schematic diagram for describing the operation of a transport system according to some exemplary embodiments of the present disclosure;

[0017] Figure 5 is for describing Figure 3 the block diagram of the transport vehicle shown in the transport system of

[0018] Figure 6 is for describing Figure 5 the motion controller of

[0019] Figure 7 is a flowchart for describing a method for operating a transport system according to some exemplary embodiments of the present disclosure;

[0020] Figure 8 is a schematic diagram for describing the operation of a transportation system according to some exemplary embodiments of the present disclosure;

[0021] Figure 9 is a schematic diagram for describing the operation of a transportation system according to some exemplary embodiments of the present disclosure;

[0022] Figure 10 is a schematic diagram for describing the operation of a transportation system according to some exemplary embodiments of the present disclosure; and

[0023] Figure 11 is a schematic diagram for describing the operation of a transportation system according to some exemplary embodiments of the present disclosure. Detailed Description

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The advantages and features of the present disclosure, as well as the methods for achieving these advantages and features, will become apparent from the following detailed description of the exemplary embodiments with reference to the accompanying drawings. However, the present disclosure is not limited to the exemplary embodiments disclosed below, but can be implemented in various different forms. These exemplary embodiments are provided only to make the present disclosure complete and to allow those skilled in the art to fully understand the scope of the present disclosure, and the present disclosure is only defined by the scope of the claims. Throughout the specification, the same reference numerals denote the same components.

[0025] Spatial relative terms (such as "beneath", "below", "under", "above", and "over", etc.) may be used to describe the relationship between one element or component and another (other) element or component shown in the drawings. Spatial relative terms should be understood to include terms for different directions of an element in addition to the directions shown in the drawings when in use or operation. For example, when the element shown in the figure is flipped, an element described as "below" or "beneath" another element will be positioned "above" the other element. Thus, the exemplary term "below" can include both upward and downward directions. The element can also be oriented in other directions, and thus the spatial relative terms can be interpreted according to that direction.

[0026] Terms such as "first" and "second" are used to describe various elements, components, and / or sections, but these elements, components, and / or sections are not limited by these terms. These terms can be used only to distinguish one element, component, and / or section from another element, component, and / or section. Thus, within the spirit of the present disclosure, a first element, first component, or first section mentioned below can also be a second element, second component, or second section.

[0027] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the exemplary embodiments of the present disclosure with reference to the accompanying drawings, components that are the same or corresponding to each other will be denoted by the same reference numerals, and overlapping descriptions thereof will be omitted.

[0028] Figure 1 is a conceptual schematic diagram for describing a transportation system according to some exemplary embodiments of the present disclosure. Figure 2 is for describing Figure 1 a schematic diagram of the transportation vehicle shown in

[0029] First, referring to Figure 1 , a transportation system according to some exemplary embodiments of the present disclosure includes an upper controller (OHT control system (OCS)) 10 and a plurality of transportation vehicles 110.

[0030] The transportation vehicle 110 may be an overhead hoist transporter (OHT) that travels along a track installed on the ceiling or floor of a semiconductor manufacturing factory (i.e., FAB), but is not limited thereto. The transportation vehicle 110 may be an automated guided vehicle (AGV) or an autonomous mobile robot (AMR) installed on the floor instead of on a track.

[0031] The upper controller 10 communicates with the plurality of transportation vehicles 110 (e.g., via wireless communication) and controls the plurality of transportation vehicles 110. The upper controller 10 provides a transportation instruction to each transportation vehicle 110. The transportation instruction may include information such as a starting position (node A), a destination position (node B), and a payload (transportation item). The transportation instruction may include a queue driving instruction for the plurality of transportation vehicles to form a queue driving group G to transport the payload, or a single driving command for one of the transportation vehicles to transport the payload alone.

[0032] Here, referring to Figure 2 , the transportation vehicle 110 may transport a container 100 (such as a Front Opening Unified Pod (FOUP)) that stores wafers when moving along a track 102 within a semiconductor manufacturing factory.

[0033] Such a transportation vehicle 110 includes a housing 142, a driving module 120, and a lifting module 140.

[0034] The drive module 120 is mounted on the housing 142 and is mounted to be movable along the track 102. The drive module 120 includes a drive wheel 122 and a motor 124 for rotating the drive wheel 122. In the present specification, the "drive wheel" refers to at least one of a front drive wheel and a rear drive wheel, and the "motor" refers to at least one of a front motor for driving the front drive wheel and a rear motor for driving the rear drive wheel.

[0035] The lifting module 140 is installed in the internal space of the housing 142 and moves up and down in the case of gripping the container 100.

[0036] The lifting module 140 may include a lifting unit 144 for raising and lowering the container 100, a slide unit 148 for moving the lifting unit 144 in the left - right direction, and a hand unit 146 connected to the lifting unit 144 and for holding the container 100.

[0037] Refer again to Figure 1 , the upper controller 10 can provide platooning instructions to multiple transport vehicles 110. That is, the upper controller 10 can instruct multiple transport vehicles 110 to form a separate platooning group G and transport the allocated load from the starting position to the destination.

[0038] Figure 3 and 4 are conceptual schematic diagrams for describing the operation of a transport system according to some exemplary embodiments of the present disclosure.

[0039] First, referring to Figure 3 , the transport system may include multiple transport vehicles 110M, 110S1, 110S2, and 110S3 that form a platooning group G.

[0040] One of the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 may be a main transport vehicle 110M, and the rest may be slave transport vehicles 110S1, 110S2, and 110S3. As shown, the transport vehicle at the front of the platooning group G is the main transport vehicle 110M, but the present disclosure is not limited thereto. For example, the last transport vehicle in the platooning group G may also be the main transport vehicle 110M.

[0041] When multiple transport vehicles 110M, 110S1, 110S2, and 110S3 move while forming a queue driving group G, the intervals between adjacent transport vehicles 110M, 110S1, 110S2, and 110S3 need to be kept substantially constant. For example, the interval W1 is measured from the transport vehicle 110S1 to the main transport vehicle 110M positioned directly in front of the transport vehicle 110S1, the interval W2 is measured from the transport vehicle 110S2 to the slave transport vehicle 110S1 positioned directly in front of the transport vehicle 110S2, and the interval W3 is measured from the transport vehicle 110S3 to the slave transport vehicle 110S2 positioned directly in front of the transport vehicle 110S3.

[0042] Each of the multiple slave transport vehicles 110S1, 110S2, and 110S3 provides interval information WS1, WS2, and WS3 corresponding to the measured intervals W1, W2, and W3 to the main transport vehicle 110M.

[0043] The main transport vehicle 110M checks the provided interval information WS1, WS2, and WS3 and determines whether to adjust the reference acceleration. For example, the main transport vehicle 110M can determine whether to adjust the reference acceleration by calculating the average value of the intervals W1, W2, and W3 and then comparing the average value with a preset reference. Alternatively, the main transport vehicle 110M can also compare each of the intervals W1, W2, and W3 with a preset reference. Alternatively, at least two of the references compared with the interval W1, the reference compared with the interval W2, and the reference compared with the interval W3 can be different from each other.

[0044] The main transport vehicle 110M can provide instructions AC1, AC2, and AC3 based on the inspection results to adjust the reference acceleration.

[0045] Each of the transport vehicles 110M, 110S1, 110S2, and 110S3 generates a position instruction based on the reference acceleration and controls the rotational speed of the drive wheels through position / velocity / current control according to the position instruction. Here, the initial reference acceleration is set by considering various factors such as the performance of the motor used to rotate the drive wheels. Since the position instruction is generated based on the reference acceleration, when the reference acceleration is high, the position instruction can indicate a relatively far position, and when the reference acceleration is low, the position instruction can indicate a relatively near position. Therefore, the position instruction can be adjusted by adjusting the reference acceleration.

[0046] Sometimes, the intervals W1, W2, and W3 between the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 forming the platooning group G may increase. For example, when the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 start accelerating simultaneously at the beginning of platooning, slippage may occur between the drive wheels and the track, which may increase the intervals W1, W2, and W3 between the multiple transport vehicles 110M, 110S1, 110S2, and 110S3.

[0047] As Figure 4 shown, before acceleration, the intervals W1, W2, and W3 between the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 are W, but after acceleration, the intervals W1, W2, and W3 between the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 can increase (see, for example, W+a, W+b, and W+c).

[0048] In this case, according to the transport system of some exemplary embodiments of the present disclosure, the main transport vehicle 110M can receive interval information WS1, WS2, and WS3 related to the intervals W+a, W+b, and W+c from the slave transport vehicles 110S1, 110S2, and 110S3, and can provide commands AC1, AC2, and AC3 for reducing the reference acceleration to the slave transport vehicles 110S1, 110S2, and 110S3. The main transport vehicle 110M also reduces the reference acceleration.

[0049] In this way, the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 generate position commands indicating positions closer than before. As a result, the actual accelerations of the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 are reduced, and the intervals W1, W2, and W3 between the multiple transport vehicles 110M, 110S1, 110S2, and 110S3 are decreased.

[0050] Figure 5 is a block diagram of the transport vehicle shown in the transport system for describing Figure 3 this. Figure 6 is a block diagram of the motion controller for describing Figure 5 this.

[0051] First, referring to Figure 5 this, the main transport vehicle 110M includes a first motion controller 170, a first memory 171, a first driver 128, a first motor 124, a first encoder 126, a first communicator 160, and a first distance sensor 190.

[0052] The first motion controller 170 can be based on the transport instruction provided by the upper controller (seeFigure 1 10), provide a position command PC1 to the first driver 128 at a preset time (or according to a cycle).

[0053] As described above, the transportation command includes information such as a start position, a destination position, and a payload. The position command PC1 is generated based on the transportation command and indicates an intermediate path position to reach the destination. That is, the position command PC1 can indicate how far the transportation vehicle needs to move within each preset time (e.g., 1 millisecond) to reach the destination. For example, if the transportation command indicates that the transportation vehicle needs to start at position 1 and move to position 30, the position command PC1 can indicate that the transportation vehicle needs to move to position 5 within the preset time.

[0054] In addition, the first motion controller 170 performs position planning in advance based on a reference acceleration. In the above example, the first motion controller 170 can plan that the transportation vehicle needs to move to positions 5, 10, 15, 20, 25, and 30 within the preset time. If the main transportation vehicle 110M moves according to the plan, the first motion controller 170 generates position commands PC1 corresponding to positions 5, 10, 15, 20, 25, and 30 in a preset time sequence.

[0055] However, the position planning is modified considering the current position of the main transportation vehicle 110M. For example, if the main transportation vehicle 110M fails to move to position 5 within the preset time and only moves to position 4, the plan can be modified so that the transportation vehicle needs to move in the following order at a predetermined time: positions 4, 9, 14, 19, 24, 29, and 30.

[0056] Meanwhile, if the reference acceleration decreases, the distance that the transportation vehicle can move within the preset time decreases. In this case, the first motion controller 170 can plan that the transportation vehicle needs to move to positions 3, 6, 9, 12, 15, 18, 21, 24, 27, and 30 within the preset time.

[0057] The reference acceleration is stored in the first memory 171. The first motion controller 170 can adjust the reference acceleration. That is, the first motion controller 170 can increase or decrease the reference acceleration.

[0058] The first driver 128 generates a first current I1 for controlling the first motor 124 connected to the first drive wheel based on the position command PC1.

[0059] The first motor 124 is connected to the drive wheel and adjusts the angular velocity of the drive wheel as the rotation speed changes according to the magnitude of the current I1 provided by the first driver 128.

[0060] The first encoder 126 measures the rotational speed of the first motor 124. The measurement result (i.e., the encoder signal R1) is provided to the first motion controller 170 and the first driver 128. The first motion controller 170 and the first driver 128 can check the position of the main transport vehicle 110M based on the encoder signal R1.

[0061] The first communicator 160 may include a plurality of communication modules for communicating with a plurality of objects. For example, the first communicator 160 may include a communication module for communicating with the upper controller OCS, a communication module for organizing the internal state of the main transport vehicle 110M and reporting it to the diagnostic server, and a communication module for communicating with other transport vehicles (e.g., transport vehicles belonging to the platooning group). Hereinafter, the communication method for communicating with adjacent vehicles is referred to as vehicle-to-vehicle communication. Through vehicle-to-vehicle communication, communication with the second communicator 260 of the slave transport vehicle 110S1 can be performed.

[0062] The first distance sensor 190 measures the distance to the transport vehicle positioned in front and reports the measured distance DD1 to the first motion controller 170. The type of the first distance sensor 190 can be changed and may include, for example, an ultrasonic sensor, an infrared sensor, a lidar (LIDAR) sensor, a radar sensor, a camera sensor, etc.

[0063] The slave transport vehicle 110S1 includes a second motion controller 270, a second memory 271, a second driver 228, a second motor 224, a second encoder 226, a second communicator 260, and a second distance sensor 290.

[0064] The slave transport vehicle 110S1 and the main transport vehicle 110M are basically the same in structure and operation principle. The second motion controller 270 can be based on the transfer instruction provided by the upper controller (see Figure 110), provide a position command PC2 to the second driver 228 at a preset time (or according to a period). The reference acceleration is stored in the second memory 271. The second motion controller 270 can increase or decrease the reference acceleration. The second driver 228 generates a second current I2 for controlling the second motor 224 connected to the second drive wheel based on the position command PC2. The second motor 224 is connected to the drive wheel and adjusts the angular velocity of the drive wheel as the rotational speed changes according to the magnitude of the second current I2 provided from the second driver 228. The second encoder 226 measures the rotational speed of the second motor 224. The measurement result (i.e., the encoder signal R2) is provided to the second motion controller 270 and the second driver 228. The second communicator 260 includes a plurality of communication modules for communicating with a plurality of objects (superior controller, diagnostic server, other transport vehicles, etc.). The second distance sensor 290 measures the distance to the transport vehicle positioned in front and reports the measured distance DD2 to the second motion controller 270.

[0065] Hereinafter, the first driver 128 will be described with reference to Figure 6 description.

[0066] The first driver 128 includes a position controller 1281, a speed controller 1282, and a current controller 1283, and can be controlled in a feedback manner.

[0067] Specifically, the calculator 1285 receives the position command PC1 provided from the first motion controller 170 and the encoded signal R1 provided from the first encoder 126, and calculates the difference between them.

[0068] The position controller 1281 generates a speed command VC1 corresponding to the output of the calculator 1285. That is, the position controller 1281 can detect whether the position of the main transport vehicle 110M detected by the encoder signal R1 is an appropriate position when compared with the position command PC1. That is, when checking the result calculated by the calculator 1285, if the position of the main transport vehicle 110M is at an appropriate position, the position controller 1281 keeps the speed of the main transport vehicle 110M unchanged. On the other hand, if the position of the main transport vehicle 110M does not reach the position specified in the position command PC1, the position controller 1281 increases the speed of the main transport vehicle 110M. Conversely, if the position of the main transport vehicle 110M exceeds the position specified in the position command PC1, the position controller 1281 needs to decrease the speed of the main transport vehicle 110M.

[0069] The differentiator 1289 differentiates the encoder signal R1 provided by the encoder 126 and supplies the result to the calculator 1285. The calculator 1286 receives the speed command VC1 and the result value of the differentiator 1289, and calculates the difference therebetween.

[0070] The speed controller 1282 generates a current command TC1 corresponding to the output of the calculator 1286. If it is necessary to increase the speed of the main carrier vehicle 110M, it is necessary to increase the angular acceleration of the drive wheels, so that the current command TC1 changes accordingly. Conversely, if it is necessary to decrease the speed of the main carrier vehicle 110M, it is necessary to decrease the angular acceleration of the drive wheels, so that the current command TC1 changes accordingly.

[0071] The calculator 1287 receives the current command TC1 and the first current I1, and calculates the difference therebetween.

[0072] The current controller 1283 generates a first current I1 corresponding to the output of the calculator 1287.

[0073] The first motor 124 is operated by the first current I1 and rotates the drive wheels connected to the first motor 124.

[0074] Although not separately described, the second driver 228 is also substantially the same as the first driver 128.

[0075] Here, referring again to Figure 5 , the main carrier vehicle 110M and the sub-carrier vehicle 110S1 belonging to the platooning group receive a transport command from the upper controller 10.

[0076] According to the transmission command, the first motion controller 170 supplies a first position command to the first driver 128, and the second motion controller 270 supplies a second position command to the second driver 228. The first motion controller 170 generates the first position command based on the first reference acceleration stored in the first memory 171. The second motion controller 270 generates the second position command based on the second reference acceleration stored in the second memory 271. The first reference acceleration and the second reference acceleration may be preset values obtained by respectively considering the performances of the first motor 124 and the second motor 224. The first reference acceleration and the second reference acceleration may be equal to each other.

[0077] The second distance sensor 290 measures the interval between the main carrier vehicle 110M and the sub-carrier vehicle 110S1. The second communicator 260 transmits information related to the measured interval (see Figure 1The interval information WS1) in is sent to the first communicator 160. The first motion controller 170 checks whether the interval W1 between the main transport vehicle 110M and the slave transport vehicle 110S1 is wider than the first reference based on the interval information WS1.

[0078] If the first motion controller 170 determines that the interval W1 is wider than the first reference, the first motion controller 170 generates a third position command indicating a position closer than the first position command and provides the third position command to the first driver 128. The second motion controller 270 generates a fourth position command indicating a position closer than the second position command and provides the fourth position command to the second driver 228.

[0079] Specifically, the first motion controller 170 determines whether to change the reference acceleration based on the interval information WS1.

[0080] If it is determined that the interval W1 is wider than the first reference, the first motion controller 170 changes the first reference acceleration stored in the first memory 171 to a third reference acceleration less than the first reference acceleration. In addition, the first motion controller 170 generates a third position command based on the third reference acceleration.

[0081] In addition, the first motion controller 170 sends a command to reduce the reference acceleration to the second communicator 260 through the first communicator 160.

[0082] The second motion controller 270 changes the second reference acceleration stored in the second memory 271 to a fourth reference acceleration less than the second reference acceleration according to the command. In addition, the second motion controller 270 generates a fourth position command based on the fourth reference acceleration.

[0083] Here, the third reference acceleration and the fourth reference acceleration may be equal to each other.

[0084] In this way, when the interval between the main transport vehicle 110M and the slave transport vehicle 110S1 increases, the speeds of the main transport vehicle 110M and the slave transport vehicle 110S1 can be slowed down by reducing the reference acceleration.

[0085] For example, slippage may occur in the slave transport vehicle 110S1, which may cause an increase in the interval between the main transport vehicle 110M and the slave transport vehicle 110S1. In this case, if the slave transport vehicle 110S1 is accelerated indiscriminately through the feedback control of the second driver 228 to reduce the interval, the slippage phenomenon may easily occur. In addition, by continuously increasing the second current I2 to accelerate, the battery consumption or power consumption may become very serious.

[0086] On the other hand, according to a transportation system according to some exemplary embodiments of the present disclosure, both the main transportation vehicle 110M and the slave transportation vehicle 110S1 generate position commands indicating a proximity position by reducing a reference acceleration, and accordingly, the distances of both the main transportation vehicle 110M and the slave transportation vehicle 110S1 that need to be moved are reduced. Therefore, the main transportation vehicle 110M and the slave transportation vehicle 110S1 can slowly escape from the section where the slip phenomenon occurs.

[0087] Figure 7 is a flowchart for describing a method for operating a transportation system according to some exemplary embodiments of the present disclosure. Hereinafter, for convenience of description, the use of Figures 3 to 6 will be omitted.

[0088] Referring to Figure 7 , once a transportation instruction is received from the upper controller 10, the first transportation vehicle and the second transportation vehicle are started (S510). Hereinafter, the first transportation vehicle corresponds to the main transportation vehicle, and the second transportation vehicle corresponds to the slave transportation vehicle immediately behind the main transportation vehicle. The main transportation vehicle or the slave transportation vehicle can be determined by the upper controller 10. Alternatively, the main transportation vehicle or the slave transportation vehicle can be determined based on the ID number of the transportation vehicle. For example, the transportation vehicle with the fastest ID number can be determined as the main transportation vehicle. Alternatively, the transportation vehicle in front of or behind the queue driving group can be determined as the main transportation vehicle.

[0089] Next, the first transportation vehicle and the second transportation vehicle start to accelerate (S520). As described above, the first transportation vehicle generates a first position command based on a preset reference acceleration, and the second transportation vehicle generates a second position command based on the preset reference acceleration.

[0090] Next, the interval between the first transportation vehicle and the second transportation vehicle is sensed (S530). For example, the interval can be sensed by sensing the distance between the second transportation vehicle and the first transportation vehicle directly in front of the second transportation vehicle. The sensed interval is transmitted to the first transportation vehicle.

[0091] Next, the first motion controller of the first transportation vehicle checks whether the interval increases (S540).

[0092] For example, skidding may occur in the second transport vehicle. Therefore, if the interval increases and exceeds the first reference (see "Yes" in S540), the reference acceleration of the first transport vehicle is decreased, and the reference acceleration of the second transport vehicle is decreased (S550). The first transport vehicle and the second transport vehicle generate new position commands based on the decreased reference acceleration. That is, new motion is generated (S560). The first transport vehicle generates a third position command based on the decreased reference acceleration, and the second transport vehicle generates a fourth position command based on the decreased reference acceleration.

[0093] If the interval does not increase (see "No" in S540), it is checked whether the interval remains constant (see S542).

[0094] If the interval is maintained (see "Yes" in S542), the reference acceleration of the first transport vehicle is increased, and the reference acceleration of the second transport vehicle is increased (S552). The first transport vehicle and the second transport vehicle generate new position commands based on the increased reference acceleration. That is, new motion is generated (S560).

[0095] For example, if the interval is maintained after the interval becomes wider than the first reference, the first transport vehicle generates a seventh position command indicating a position closer than the third position command based on the increased reference acceleration, and the second transport vehicle generates an eighth position command indicating a position closer than the fourth position command based on the increased reference acceleration.

[0096] If the interval is not maintained (see "No" in S542), driving continues without changing the reference acceleration (S570).

[0097] Figure 8 and Figure 9 are schematic diagrams for describing the operation of a transport system according to some exemplary embodiments of the present disclosure. For ease of explanation, descriptions identical to those using Figures 3 to 7 will be omitted.

[0098] In Figure 8 , the x-axis represents time, and the y-axis represents the reference acceleration. In Figure 9 , the x-axis represents time, and the y-axis represents the speed of the second transport vehicle. The second transport vehicle may be a following transport vehicle immediately behind the first transport vehicle (main transport vehicle).

[0099] Referring to Figure 8 and Figure 9 , at time t0, the first transport vehicle and the second transport vehicle start platooning. The second transport vehicle starts to accelerate. From time t0 to time t1, the reference acceleration may be, for example, 3 m / s2 The slope of line segment L1 from time t0 to time t1 represents the actual acceleration of the second transport vehicle.

[0100] Although for ease of illustration, the speed of the second transport vehicle is shown as line segment L1, since the speed of the second transport vehicle is controlled by feedback control, the speed of the second transport vehicle may actually have a curved shape.

[0101] At time t1, it can be determined that slip has occurred in the second transport vehicle. For example, it is determined that the interval between the first transport vehicle and the second transport vehicle is wider than a first reference. If it is determined that slip has occurred, the reference acceleration can be reduced. After time t1, the reference acceleration can be, for example, 2 m / s 2 The slope of line segment L2 after time t1 represents the actual acceleration of the second transport vehicle.

[0102] It can be seen that the slope of line segment L2 is less than the slope of line segment L1 centered at point a.

[0103] Figure 10 and Figure 11 are schematic diagrams for describing the operation of a transport system according to some exemplary embodiments of the present disclosure. For ease of illustration, descriptions the same as those using Figures 3 to 9 will be omitted.

[0104] In Figure 10 , the x-axis represents time, and the y-axis represents the reference acceleration. In Figure 11 , the x-axis represents time, and the y-axis represents the speed of the second transport vehicle. The second transport vehicle can be a following transport vehicle immediately behind the first transport vehicle (main transport vehicle).

[0105] Referring to Figure 10 and Figure 11 , at time t0, the first transport vehicle and the second transport vehicle start platooning. The second transport vehicle starts to accelerate. From time t0 to time t1, the reference acceleration can be, for example, 3 m / s 2 .

[0106] At time t1, it can be determined that slip has occurred in the second transport vehicle. For example, it is determined that the interval between the first transport vehicle and the second transport vehicle is wider than a first reference. If it is determined that slip has occurred, the reference acceleration can be reduced. After time t1, the reference acceleration can be, for example, 2 m / s 2 .

[0107] Meanwhile, even if the reference acceleration decreases, it is possible to determine that additional slippage has occurred in the second transport vehicle at time t2. For example, it can be determined that the gap between the first transport vehicle and the second transport vehicle is wider than a second reference greater than a first reference. If slippage is determined to have occurred, the reference acceleration can be additionally decreased. After time t1, the reference acceleration can be, for example, 1 m / s 2 .

[0108] Here, the slope of line segment L1 from time t0 to time t1, the slope of line segment L2 from time t1 to time t2, and the slope of line segment L3 after time t2 represent the actual acceleration of the second transport vehicle.

[0109] It can be seen that the slope of line segment L2 is less than the slope of line segment L1 centered at point a. Additionally, it can be seen that the slope of line segment L3 is less than the slope of line segment L2 centered at point b.

[0110] For example, the first transport vehicle generates a first position command based on a first reference acceleration, and the second transport vehicle generates a second position command based on a second reference acceleration.

[0111] However, if slippage occurs, the first reference acceleration is decreased to a third reference acceleration, and the second reference acceleration is decreased to a fourth reference acceleration. Thus, the first transport vehicle (i.e., the first motion controller) generates a third position command indicating a position closer than the first position command, and the second transport vehicle (i.e., the second motion controller) generates a fourth position command indicating a position closer than the second position command.

[0112] If additional slippage occurs, the third reference acceleration is decreased to a fifth reference acceleration, and the fourth reference acceleration is decreased to a sixth reference acceleration. Thus, the first transport vehicle (i.e., the first motion controller) generates a fifth position command indicating a position closer than the third position command, and the second transport vehicle (i.e., the second motion controller) generates a sixth position command indicating a position closer than the fourth position command.

[0113] Thereafter, if the gap between the first transport vehicle and the second transport vehicle becomes wider than a third reference greater than the second reference, the first transport vehicle and the second transport vehicle can stop. That is, the first transport vehicle (i.e., the first motion controller) receives interval information from the second transport vehicle and analyzes the interval information. As a result of the analysis, if it is determined that the gap has become too wide, the first motion controller can stop performing reference acceleration control and can generate a command to stop the first transport vehicle and the second transport vehicle.

[0114] Although the exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, those of ordinary skill in the art to which the present disclosure pertains will understand that the present disclosure can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and not restrictive.

Claims

1. A transport system, comprising: a first transport vehicle that moves along the track and includes a first motion controller and a first driver for rotating a first drive wheel; a second transport vehicle that moves in a queue with the first transport vehicle along the track, and that includes a second motion controller and a second driver for rotating a second drive wheel; as well as a host controller, the host controller controls the first transport vehicle and the second transport vehicle, The upper controller is configured to provide transport instructions to the first transport vehicle and the second transport vehicle. According to the transport instruction, the first motion controller provides a first position instruction to the first driver, and the second motion controller provides a second position instruction to the second driver, and When a first interval between the first transport vehicle and the second transport vehicle becomes wider than a first reference, the first motion controller provides a third position instruction to the first driver indicating a position closer than the first position instruction, and the second transport vehicle provides a fourth position instruction to the second driver indicating a position closer than the second position instruction.

2. The conveying system according to claim 1, wherein: The first motion controller generates the first position instruction based on a first reference acceleration, and the second motion controller generates the second position instruction based on a second reference acceleration, and When the first interval between the first transport vehicle and the second transport vehicle becomes wider than the first reference, the first motion controller generates the third position instruction based on a third reference acceleration that is less than the first reference acceleration, and the second motion controller generates the fourth position instruction based on a fourth reference acceleration that is less than the second reference acceleration.

3. The conveying system according to claim 2, wherein: When the first interval between the first transport vehicle and the second transport vehicle becomes wider than the first reference, the first transport vehicle provides an instruction to the second transport vehicle to decrease the second reference acceleration to the fourth reference acceleration.

4. The conveying system according to claim 2, wherein: The second transport vehicle measures the first interval from the first transport vehicle positioned in front and provides the first interval to the first transport vehicle, and The first transport vehicle determines whether to change the reference acceleration based on the provided first interval.

5. The conveying system according to claim 2, wherein: The first reference acceleration is the same as the second reference acceleration, and the third reference acceleration is the same as the fourth reference acceleration.

6. The conveying system according to claim 2, wherein: The first transport vehicle further includes a first memory, and when the first interval becomes wider than the first reference, the first reference acceleration stored in the first memory is changed to the third reference acceleration, and The second transport vehicle further includes a second memory, and when the first interval becomes wider than the first reference, changes the second reference acceleration stored in the second memory to the fourth reference acceleration.

7. The conveying system according to claim 1, wherein: When the first interval between the first transport vehicle and the second transport vehicle becomes wider than a second reference that is greater than the first reference, the first motion controller provides a fifth position instruction to the first driver indicating a position closer than the third position instruction, and the second transport vehicle provides a sixth position instruction to the second driver indicating a position closer than the fourth position instruction.

8. The conveying system according to claim 7, wherein: When the first interval between the first transport carrier and the second transport carrier becomes wider than a third reference greater than the second reference, the first transport carrier and the second transport carrier stop.

9. The conveying system according to claim 1, wherein: When the first interval is maintained after becoming wider than the first reference, the first motion controller provides a seventh position instruction to the first drive indicating a position closer than the third position instruction, and the second transport vehicle provides an eighth position instruction to the second drive indicating a position closer than the fourth position instruction.

10. The transport system according to claim 1, further comprising a third transport vehicle, the third transport vehicle forming a queue with the first transport vehicle and the second transport vehicle. in, the second transport vehicle measuring the first interval from the first transport vehicle positioned directly in front of the second transport vehicle and providing the first interval to the first transport vehicle, the third transport vehicle measuring the second interval from the second transport vehicle positioned directly in front of the third transport vehicle and providing the second interval to the first transport vehicle, The first transport vehicle determines whether to change the reference acceleration based on the first interval and the second interval, and The first transport vehicle instructs the second transport vehicle and the third transport vehicle to change the reference acceleration.

11. The conveying system according to claim 1, wherein: The interval between the first transport carrier and the second transport carrier becoming wider than the first reference includes slippage occurring in the second transport carrier.

12. A transport vehicle, comprising: a memory configured to store a reference acceleration; a motion controller configured to generate a position command based on the reference acceleration; a driver configured to receive the position instruction and rotate the drive wheel; as well as a communicator configured to communicate with slave transport vehicles belonging to the platoon driving group, Wherein, the motion controller comprises: generating a position command based on the reference acceleration and providing the position command to the driver, receiving the intervals between the slave transport vehicles through the communicator, When the interval becomes wider than the first reference, decreasing the reference acceleration, and A position command is generated based on the reduced reference acceleration, and the position command is provided to the driver.

13. The transport vehicle according to claim 12, wherein: The motion controller also includes: After lowering the reference acceleration, when the interval becomes wider than a second reference greater than the first reference, additionally lowering the reference acceleration, and A position command is generated based on the additionally reduced reference acceleration, and the position command is provided to the driver.

14. The transport vehicle according to claim 12, wherein: The motion controller also includes: When the interval is maintained after decreasing the reference acceleration, increasing the reference acceleration, and A position command is generated based on the increased reference acceleration, and the position command is provided to the driver.

15. The transport vehicle according to claim 12, wherein: When the interval becomes wider than the first reference, the motion controller transmits an instruction to reduce the reference acceleration to the slave transport vehicle through the communicator.

16. The transport vehicle according to claim 12, wherein: The interval becoming wider than the first reference includes slippage occurring in the slave transport vehicle.

17. A transport vehicle, comprising: a memory configured to store a reference acceleration; a motion controller configured to generate a position command based on the reference acceleration; a driver configured to receive the position instruction and rotate the drive wheel; A communicator configured to communicate with slave transport vehicles belonging to the platoon driving group; as well as a distance sensor configured to measure a distance from the slave transport vehicle positioned directly in front, wherein the motion controller generates a position command based on the reference acceleration and provides the position command to the driver, The communicator includes transmitting the interval measured by the distance sensor to a main transport vehicle, The communicator includes receiving instructions from the main transport vehicle to adjust the reference acceleration, The motion controller includes adjusting the reference acceleration, and The motion controller generates a position command based on the adjusted reference acceleration and provides the position command to the driver.

18. The transport vehicle according to claim 17, wherein: When the interval becomes wider than a first reference, the motion controller includes decreasing the reference acceleration according to an instruction of the main transport vehicle.

19. The transport vehicle according to claim 18, wherein: When the interval becomes wider than a second reference greater than the first reference after lowering the reference acceleration, the motion controller additionally lowers the reference acceleration according to the instruction of the main transport vehicle.

20. The transport vehicle according to claim 18, wherein: When the interval is maintained after reducing the reference acceleration, the motion controller increases the reference acceleration according to the instruction of the main transport vehicle.

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