KR20230119286A - Transfer vehicle system and controlling method thereof - Google Patents

Abstract

A transfer truck system capable of increasing the amount of transported goods per hour is provided. The transfer cart system is a transfer cart system including a rail device and a transfer cart moving along the rail device, wherein the transfer cart includes a body capable of carrying a container in which a substrate is stored, and at least a sensor installed on the body. And, a first wheel and a second wheel installed in the front of the body, a third wheel and a fourth wheel installed in the rear of the body, a first motor installed in the body and connected to the first wheel, the first A second motor connected to two wheels, a third motor connected to the third wheel, and a fourth motor connected to the fourth wheel, a controller for controlling the first to fourth motors, and communicating with the controller. A memory, wherein first to fourth hysteresis curves corresponding to the first to fourth motors are stored in the memory, and the controller controls the stored first to fourth hysteresis curves. Torques of the first to fourth motors are individually controlled according to the hysteresis curve.

Description

Transfer vehicle system and control method thereof {Transfer vehicle system and controlling method thereof}

The present invention relates to a transfer balance system and a control method thereof.

In a manufacturing process of a semiconductor device, a substrate may be transported through an unmanned transport system. In particular, the unmanned transport system may include a transport cart (eg, Overhead Hoist Transport (OHT), Rail Guided Vehicle (RGV), etc.) configured to be movable along running rails installed on the ceiling or floor of a clean room. Operation control of the transfer cart may be controlled by an upper control device such as OCS (OHT Control Server) device.

On the other hand, when the transfer cart travels on the curved rail at high speed, there is concern about damage to the transfer cart and the curved rail. Therefore, when the transfer cart enters the curved rail from the straight rail, the speed of the transfer cart is lowered. Accordingly, a bottleneck phenomenon of the transfer cart may occur on the curved rail. In addition, the transport amount of logistics per hour is lowered.

The problem to be solved by the present invention is to provide a transfer truck system capable of increasing the transport amount per hour.

The problem to be solved by the present invention is to provide a control method of a transfer truck system capable of increasing the transport amount per hour.

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

One aspect (aspect) of the transfer balance system of the present invention for achieving the above object is a transfer balance system including a rail device and a transfer balance moving along the rail device, wherein the transfer balance is a substrate is accommodated A body capable of carrying a container, at least a sensor installed on the body, a first wheel and a second wheel installed in front of the body, a third wheel and a fourth wheel installed in the rear of the body, installed, a first motor connected to the first wheel, a second motor connected to the second wheel, a third motor connected to the third wheel, and a fourth motor connected to the fourth wheel; A controller for controlling a fourth motor, and a memory communicating with the controller, wherein first to fourth hysteresis curves corresponding to the first to fourth motors are stored in the memory, The controller individually controls torques of the first to fourth motors according to the stored first to fourth hysteresis curves.

The sensors include a speed sensor, a weight sensor, and a position sensor, and the sensor values of the sensors include speed information of the transfer cart measured by the speed sensor, weight information of the transfer cart measured by the weight sensor, and , includes node information of the transfer cart measured by the position sensor.

The sensor does not include an inertial sensor.

Based on the speed information, weight information, and node information, the current yaw rate of the transfer truck is calculated, and based on the calculated current yaw rate, the control mode of the first to fourth motors change When the calculated current yaw rate is less than the reference value, the first to fourth motors are controlled in a first control mode, wherein the first motor and the second motor are controlled by the first wheel. and providing the same torque to the second wheel, and providing the same torque to the third wheel and the second wheel by the third motor and the fourth motor. When the calculated current yaw rate is greater than the reference value, the first to fourth motors are controlled in a second control mode, wherein the first to fourth motors are stored in the second control mode. Torques of the first to fourth motors are individually controlled according to the first to fourth hysteresis curves.

The first hysteresis curve to the fourth hysteresis curve are configured to minimize the difference between the desired yaw rate and the measured yaw rate of the transfer vehicle through a pre-experiment

One aspect of the control method of the transfer cart system of the present invention for achieving the other object is to include a rail device, a transfer cart moving along the rail device, a controller for controlling the transfer cart, and a memory, The transfer cart includes a body capable of transporting a container in which a substrate is stored, at least a sensor installed in the body, a first wheel and a second wheel installed in front of the body, a third wheel installed in the rear of the body, and A fourth wheel, a first motor installed on the body, connected to the first wheel, a second motor connected to the second wheel, a third motor connected to the third wheel, and a fourth connected to the fourth wheel. A transfer cart system is provided that includes a motor, and the sensor includes a speed sensor, a weight sensor, and a position sensor, and the speed information of the transfer cart measured by the speed sensor and the transfer measured by the weight sensor Acquiring weight information of the bogie and node information of the transfer bogie measured by the position sensor, and calculating a current yawrate of the transfer bogie based on the speed information, weight information, and node information, , and changing control modes of the first to fourth motors based on the calculated current yaw rate.

Changing the control mode is to control the first to fourth motors in a first control mode when the calculated current yaw rate is smaller than the reference value, and in the first control mode, the first motor and the The second motor provides the same torque to the first wheel and the second wheel, the third motor and the fourth motor provide the same torque to the third wheel and the fourth wheel, and the calculated current When the yaw rate is greater than the reference value, the first to fourth motors are controlled in a second control mode, and in the second control mode, the first to fourth motors are stored in the first hysteresis curve to the fourth motor. and individually controlling the torque of each of the first to fourth motors according to the fourth hysteresis curve.

Details of other embodiments are included in the detailed description and drawings.

1 is a conceptual diagram for explaining a transfer balance system according to some embodiments of the present invention.
FIG. 2 is a conceptual diagram for explaining a transfer cart moving on the curved rail S1 shown in FIG. 1 .
Figure 3 is a block diagram for explaining the transfer cart shown in Figure 2;
Figure 4 is a block diagram for explaining the operation of the transfer cart shown in Figure 2.
5 is a flowchart illustrating a control method of a transfer balance system according to some embodiments of the present invention.
6 is a flowchart for explaining step S240 of FIG. 3 in detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms, only the present embodiments make the disclosure of the present invention complete, and the common knowledge in the art to which the present invention belongs It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

The spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between elements or components and other elements or components. Spatially relative terms should be understood as encompassing different orientations of elements in use or operation in addition to the orientations shown in the figures. For example, when flipping elements shown in the figures, elements described as “below” or “beneath” other elements may be placed “above” the other elements. Thus, the exemplary term “below” may include directions of both below and above. Elements may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Although first, second, etc. are used to describe various elements, components and/or sections, it is needless to say that these elements, components and/or sections are not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Accordingly, it goes without saying that the first element, first element, or first section referred to below may also be a second element, second element, or second section within the spirit of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same or corresponding components regardless of reference numerals are given the same reference numerals, Description is omitted.

1 is a conceptual diagram for explaining a transfer balance system according to some embodiments of the present invention. FIG. 2 is a conceptual diagram for explaining a transfer cart moving on the curved rail S1 shown in FIG. 1 .

Referring to FIGS. 1 and 2 , a transfer cart system 1000 according to some embodiments of the present invention includes a transfer cart 1 and a rail device 200 .

The rail device 200 may be installed in a semiconductor manufacturing line. The rail device 200 may include two rails 201 and 202 disposed parallel to each other, but is not limited thereto.

In addition, the rail device 200 includes a first linear rail L1 extending in a first direction, a second linear rail L2 extending in a second direction different from the first direction, and a first linear rail L1. And it may include a curved rail (S1) connecting the second straight rail (L2).

The transfer cart 1 moves along the rail device 200 and transports the container in which the substrate is stored. The transfer cart may be, for example, OHT (Overhead Hoist Transport), but is not limited thereto. The transported container may be, for example, a Front Opening Unified Pod (FOUP), but is not limited thereto.

As shown, the transfer cart 1 includes a first wheel 11 and a third wheel 13 rotating along a rail 201 and a second wheel 12 rotating along a rail 202 Includes 4 wheels (14). That is, the first wheel 11 and the second wheel 12 are disposed in the front relative to the moving direction of the transfer cart 1, and the third wheel 13 and the fourth wheel 14 are the transfer cart 1 ) can be arranged at the rear based on the direction of movement of ).

On the other hand, since the transfer cart system 1000 is installed in a semiconductor manufacturing line, the transfer cart system 1000 is operated within fairly limited conditions. For example, the transfer cart system 100 is not affected by weather and can maintain a constant temperature. In addition, since the transfer cart 1 moves along the rail device 200, the friction coefficient is constant, and the objects to be loaded are limited to substrate storage containers and the like.

Therefore, in the transfer cart system 1000 according to some embodiments of the present invention, several driving scenarios are prepared and the transfer cart 1 is controlled accordingly. Although described in detail later, the current yaw rate of the transfer cart 1 entering the curved rail S1 may be calculated, and the control mode of the transfer cart 1 may be changed according to the calculated current yaw rate. That is, a driving scenario to be followed is determined according to the current yaw rate, and the transfer cart 1 is controlled accordingly. The yaw rate corresponds to the lateral component (or rotational angular velocity) of the transfer bogie 1.

Hereinafter, the structure of the transfer cart will be described using FIGS. 3 and 4. Figure 3 is a block diagram for explaining the transfer cart shown in Figure 2; Figure 4 is a block diagram for explaining the operation of the transfer cart shown in Figure 2.

3 and 4, the transfer cart 1 includes a body 101, a plurality of wheels 11, 12, 13, and 14, a plurality of motors 110, 120, 130, and 140, a plurality of sensors ( S1, S2, S3), memory 160 and controller 150.

The body 101 may carry a container in which a substrate is stored.

A plurality of wheels (11, 12, 13, 14) are installed on the body (101). As described above, the first wheel 11 and the second wheel 12 may be disposed at the front, and the third wheel 13 and the fourth wheel 14 may be disposed at the rear.

The first motor 110 is connected to the first wheel 11, the second motor 120 is connected to the second wheel 12, and the third motor 130 is connected to the third wheel 13 , the fourth motor 140 is connected to the fourth wheel 14. Torque of each of the first motor 110 to the fourth motor 140 is controlled according to the control of the controller 150 . The controller 150 corresponds to a torque distribution controller.

The plurality of sensors S1 , S2 , and S3 provide sensing results (ie, sensor values VI, WI, and RI) to the controller 150 . The controller 150 may control torque of the first motor 110 to the fourth motor 140 based on the sensor values VI, WI, and RI.

The plurality of sensors S1 , S2 , and S3 may include a speed sensor S1 , a weight sensor S2 , and a position sensor S3 .

The sensor values (VI, WI, RI) are the speed information (VI) of the transfer cart 1 measured by the speed sensor S1 and the weight information of the transfer cart 1 measured by the weight sensor S2 (WI) and the node information (RI) of the transfer trolley 1 measured by the position sensor S3.

The speed information VI is the measured speed of the transfer cart 1 while the rail device 200 is moving. In particular, the speed information VI may include the speed of the transfer cart 1 when entering the curved rail S1. The speed information VI may be the longitudinal speed of the transfer cart 1.

The weight information (WI) is the weight applied to the front wheels (the first wheel 11 and the second wheel 12) (or the weight applied to the front axle), the rear wheels (the third wheel 13 and the fourth wheel 14). ) (or the weight on the rear axle).

The location information RI may be, for example, the location of the transfer cart 1 obtained by communicating with a tag installed in the rail device 200 by the location sensor S3.

The memory 150 includes a first hysteresis curve H1 corresponding to the first motor 110 , a second hysteresis curve H2 corresponding to the second motor 120 , and a third hysteresis curve H2 corresponding to the third motor 130 . The hysteresis curve H3 and the fourth hysteresis curve H4 corresponding to the fourth motor 140 may be stored. For example, the first hysteresis curve H1 corresponds to measured speed information VI, weight information WI, and node information RI, and is a table composed of torque values to be provided to the first motor 110. can be implemented in the form Similarly, the second hysteresis curve H2 corresponds to the measured speed information VI, weight information WI, node information RI, etc., in the form of a table consisting of torque values to be provided to the second motor 120. can be implemented

A method of generating the first to fourth hysteresis curves H1 to H4 will be described later.

The controller 150 receives sensor values VI, WI, and RI from the plurality of sensors S1, S2, and S3. That is, speed information VI, weight information WI, and node information RI are obtained from the speed sensor S1, weight sensor S2, and position sensor S3. Using these, the controller 150 controls the current yaw rate at the current location ( ) is calculated.

Current yaw rate ( ) is equal to Equation 1 below. In Equation 1, Is the longitudinal speed of the transfer cart (1), L is the distance between the axes of the front and rear wheels of the transfer cart (1), is the weight on the front and rear axles, is the stiffness coefficient of the front and rear wheels, g is the gravitational acceleration, represents the average of the left and right wheel steering angles.

(Equation 1)

Here, due to the nature of the transfer cart 1 moving along the rail device 200, can be approximated as in Equation 2 according to the Ackerman turning geometry.

(Equation 2)

According to Equations 1 and 2, the current yaw rate ( ) is arranged as in Equation 3. The controller 150 uses Equation 3 to determine the current yaw rate ( ) is calculated.

(Equation 3)

The controller 150 determines the current yaw rate ( ) is compared with the reference value, and the control mode of the first motor 110 to the fourth motor 140 is changed.

Specifically, the current yaw rate ( ) is less than the reference value, the first motor 110 to the fourth motor 140 are controlled in the first control mode. In the first control mode, the first motor 110 and the second motor 120 provide the same torque to the first wheel 11 and the second wheel 12, and the third motor 130 and the fourth motor 140 provides the same torque to the third wheel 13 and the fourth wheel 14 . Since the transfer bogie 1 enters the curved rail S1 at low speed, the two wheels 11 and 12 corresponding to the current are controlled with the same torque, and the two wheels 13 and 14 corresponding to the rear wheels It is controlled with the same torque (ie, torque control for each front/rear wheel).

Current yaw rate ( ) is greater than the reference value, the first motor 110 to the fourth motor 140 are controlled in the second control mode. In the second control mode, the first motor 110 to the fourth motor 140 operate according to the stored first hysteresis curves H1 to fourth hysteresis curves H4. The torque of each of the motors 140 is individually controlled. Since the transfer bogie 1 enters the curved rail S1 at high speed, each of the four wheels 11, 12, 13, 14 is individually torque controlled. For example, torque provided to the inner wheels (eg, 12 and 14) and the outer wheels 11 and 13 is distributed differently.

The current yaw rate ( ) is calculated, and the current yaw rate ( ) Based on this, the torque control of the motors 110 to 140 is performed. That is, (based on a previously prepared driving scenario), when the transfer bogie 1 travels on the curved rail S1 at low speed, torque control for each front/rear wheel is performed, and the transfer bogie 1 moves the curved rail S1 at high speed. During driving, sensorless individual torque control can be performed through open-loop control.

Therefore, since it is not necessary to reduce the speed of the transfer cart 1 entering the curved rail S1, the amount of transported goods per hour can be increased. That is, by widening the speed band in which the transfer cart 1 travels on the curved rail S1, it is possible to increase the transport amount of logistics per hour. In addition, the generation of particles can be minimized due to friction reduction.

Hereinafter, a method of generating the hysteresis curves H1 to H4 will be described.

The hysteresis curves H1 to H4 may be configured to minimize the difference between the desired yaw rate and the measured yaw rate of the transfer cart 1 through a preliminary experiment.

In the experiment, a separate inertial sensor (or yaw rate sensor) is mounted on the transfer cart 1, and the actual yaw rate ( ) is measured.

In addition, the reference yaw rate ( ) is calculated by Equation 4. The description of Equation 4 is replaced with the description of Equation 3.

(Equation 4)

Then, as shown in Equation 5, the reference yaw rate ( ) and the actual measured yaw rate ( ), hysteresis (H1 to H4) is configured in the direction of minimizing the difference.

(Equation 5)

5 is a flowchart illustrating a control method of a transfer balance system according to some embodiments of the present invention. 6 is a flowchart for explaining step S240 of FIG. 3 in detail.

First, referring to FIGS. 4 and 5 , a transfer balance system 1000 is provided (S210).

Specifically, the transfer cart system 1000 includes a rail device 200 and a transfer cart 1 moving along the rail device 200 .

Here, the transfer cart 1 includes a body 101 capable of transporting a container in which substrates are stored, at least sensors S1 to S3 installed in the body 101, and a first wheel installed in front of the body 101. (11) and the second wheel 12, the third wheel 13 and the fourth wheel 14 installed on the rear of the body 101, installed on the body 101, and the first wheel 11 The first motor 110 connected, the second motor 120 connected to the second wheel 12, the third motor 130 connected to the third wheel 13, and the fourth motor connected to the fourth wheel 14 (140). The sensors S1 to S3 include a speed sensor S1, a weight sensor S2, and a position sensor S3. In addition, the transfer cart 1 includes a controller 150 for controlling the first to fourth motors 110, 120, 130, and 140, and a memory 160 communicating with the controller 150.

Then, speed information (VI), weight information (WI), and node information (RI) are acquired (S220).

The speed information (VI) of the transfer cart (1) measured by the speed sensor (S1), the weight information (WI) of the transfer cart (1) measured by the weight sensor (S2), and the position sensor (S3) Obtain node information (RI) of the transfer truck 1 measured by

Next, the current yaw rate of the transfer cart 1 ( ) is calculated (S230). Current yaw rate ( ) can be calculated by the above equation (Equation 3).

Then, the calculated current yaw rate ( ), the control mode is changed (S240).

Specifically, referring to FIGS. 4 and 6, the current yaw rate ( ) and the reference value (S241).

Current yaw rate ( ) is smaller than the reference value, the first motor 110 to the fourth motor 140 are controlled in the first control mode (S242). In the first control mode, the first motor 110 and the second motor 120 provide the same torque to the first wheel 11 and the second wheel 12, and the third motor 130 and the fourth motor 140 provides the same torque to the third wheel 13 and the fourth wheel 14 . Since the transfer bogie 1 enters the curved rail S1 at low speed, the two wheels 11 and 12 corresponding to the current are controlled with the same torque, and the two wheels 13 and 14 corresponding to the rear wheels It is controlled with the same torque (ie, torque control for each front/rear wheel).

Current yaw rate ( ) is greater than the reference value, the first motor 110 to the fourth motor 140 are controlled in the second control mode (S243). In the second control mode, the first motor 110 to the fourth motor 140 operate according to the stored first hysteresis curves H1 to fourth hysteresis curves H4. The torque of each of the motors 140 is individually controlled. Since the transfer bogie 1 enters the curved rail S1 at high speed, each of the four wheels 11, 12, 13, 14 is individually torque controlled.

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features. You will understand that there is Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

1: transfer truck 11: first wheel
12: second wheel 13: third wheel
14: fourth wheel 101: body
110: first motor 120: second motor
130: third motor 140: fourth motor
200: rail device 1000: transfer cart system
S1: speed sensor S2: weight sensor
S3: position sensor

Claims (9)

A transfer cart system including a rail device and a transfer cart moving along the rail device,
The transfer truck,
A body capable of carrying a container in which a substrate is stored;
At least a sensor installed on the body;
A first wheel and a second wheel installed in front of the body;
A third wheel and a fourth wheel installed at the rear of the body;
A first motor installed in the body, connected to the first wheel, a second motor connected to the second wheel, a third motor connected to the third wheel, and a fourth motor connected to the fourth wheel;
A controller for controlling the first to fourth motors;
a memory in communication with the controller;
First to fourth hysteresis curves corresponding to the first to fourth motors are stored in the memory,
Wherein the controller individually controls the torque of each of the first to fourth motors according to the stored first to fourth hysteresis curves. According to claim 1,
The sensor includes a speed sensor, a weight sensor and a position sensor,
The sensor value of the sensor includes speed information of the transfer cart measured by the speed sensor, weight information of the transfer cart measured by the weight sensor, and node information of the transfer cart measured by the position sensor. Including, transfer balance system. According to claim 1,
The sensor does not include an inertial sensor, the transfer bogie system. According to claim 2,
Based on the speed information, weight information, and node information, a current yawrate of the transfer cart is calculated,
Based on the calculated current yaw rate, the control mode of the first to fourth motors is changed. According to claim 4,
If the calculated current yaw rate is smaller than the reference value, controlling the first to fourth motors in a first control mode;
In the first control mode, the first motor and the second motor provide the same torque to the first wheel and the second wheel, and the third motor and the fourth motor provide the same torque to the third wheel and the second wheel. A transfer bogie system comprising providing equal torque to two wheels. According to claim 4,
If the calculated current yaw rate is greater than the reference value, controlling the first to fourth motors in a second control mode;
In the second control mode, the first to fourth motors individually control the torque of the first to fourth motors according to the stored first to fourth hysteresis curves, transfer truck system. According to claim 1,
The first hysteresis curve to the fourth hysteresis curve are configured to minimize the difference between the desired yaw rate and the measured yaw rate of the transfer cart through a pre-experiment. A rail device and a transfer cart moving along the rail device, wherein the transfer cart includes a body capable of carrying a container in which a substrate is stored, at least a sensor installed in the body, and a first body installed in front of the body. A wheel and a second wheel, a third wheel and a fourth wheel installed on the rear of the body, a first motor installed on the body and connected to the first wheel, a second motor connected to the second wheel, A transfer cart system is provided, including a third motor connected to three wheels and a fourth motor connected to the fourth wheel, wherein the sensors include a speed sensor, a weight sensor, and a position sensor,
Obtaining speed information of the transfer cart measured by the speed sensor, weight information of the transfer cart measured by the weight sensor, and node information of the transfer cart measured by the position sensor,
Based on the speed information, weight information, and node information, a current yawrate of the transfer cart is calculated,
Based on the calculated current yaw rate, the control method of the transfer cart system comprising changing the control mode of the first to fourth motors. The method of claim 8, wherein changing the control mode,
When the calculated current yaw rate is less than the reference value, the first to fourth motors are controlled in a first control mode, wherein the first motor and the second motor are controlled by the first wheel. and providing the same torque to the second wheel, wherein the third motor and the fourth motor provide the same torque to the third wheel and the fourth wheel;
If the calculated current yaw rate is greater than the reference value, the first to fourth motors are controlled in a second control mode, wherein the first to fourth motors are stored in the second control mode. A method of controlling a transfer cart system, comprising individually controlling torque of each of the first to fourth motors according to a first hysteresis curve to a fourth hysteresis curve.

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