JP2005209161A - Optimal conveyance control method of unmanned conveyance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a more efficient unmanned conveyance system by drastically reducing travel amount and communication amount of an unmanned conveyance vehicle through the optimal conveyance scheduling in an unmanned conveyance system which operates the unmanned conveyance vehicle having two hands. <P>SOLUTION: The optimal conveyance system has the unmanned conveyance vehicle having two hands and the unmanned conveyance vehicle simultaneously implements at least two work instructions having one and the same destination using the two hands at the destination. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an unmanned transport system, and more particularly to a control method for an unmanned transport system that transports wafers, LCD substrates, and the like according to a predetermined work schedule between a stocker and process equipment.

  In general, the automatic transport system is for automating the loading and transport of loads, and uses an automatic guided vehicle. An automated guided vehicle (AGV), that is, an AGV (Automatic Guided Vehicle) moves along a guideline laid on the floor, or transports a load while moving to a target position using a separate position measurement system. Here, the guideline is constructed by continuously laying magnetic tape on the floor, and AGV uses a magnetic sensor to detect the magnetism from this guideline to confirm the position of the guideline. Drive along the guidelines. On the other hand, RGV (Rail Guided Vehicle) conveys a load while moving along a rail laid on the floor.

  An automatic guided vehicle that transports a wafer, an LCD substrate, or the like in a semiconductor manufacturing process is provided with a hand for gripping the wafer or the LCD substrate, but a conventional automatic guided vehicle has been provided with only one hand. For this reason, the conventional automatic guided vehicle uses only one hand when loading and unloading the wafer while reciprocating between the process equipment and the stocker, so that the loading and unloading operations can be freely performed. Since it is difficult to carry out and it is impossible to carry out loading and unloading at the same position at the same time, there is a problem that the number of times of reciprocation between the process equipment and the stocker and the moving distance thereof are extremely large. In particular, since the conventional automatic guided vehicle has to perform loading and unloading work separately, the number of communication and the communication amount between the main controller and the automatic guided vehicle increase as well as the work time increases. There was also a problem.

  The present invention provides an automated guided vehicle system that operates two automated guided vehicles with a large amount of movement and communication amount of the automated guided vehicle through optimized conveyance scheduling, thereby realizing a more efficient automated transport system. For that purpose.

  In order to achieve the above object, an automatic guided vehicle according to the present invention includes an automatic guided vehicle having two hands, and the automatic guided vehicle receives at least two work orders having the same destination in accordance with the corresponding destination. Perform with two hands at the same time.

  An automatic guided system according to the present invention includes an automatic guided vehicle having a buffer and two hands, and the automatic guided vehicle transports an object while moving between a plurality of first work positions and a plurality of second work positions. However, the control method of the automatic transport system according to the present invention is the same as the combination of the loading command and the unloading command with the same work position as the destination when the buffer has a spare space. A first pattern is set and stored in the memory so that at least one of the combinations of two loading instructions with the work position as the destination is included. When there is room in the buffer and the first pattern loading instruction is not executed, each single work instruction not included in the first pattern is set as the second pattern and stored in the memory. . When there is no room in the buffer, only the loading command for loading the object loaded in the buffer to the corresponding destination is retrieved and stored in the memory.

  The automatic transport system according to the present invention includes a main controller that generates a work command and an automatic guided vehicle that receives the work command and performs the work. Select a pattern to be used from among multiple patterns consisting of combinations of work instructions generated from the main control unit, determine the execution order and overall execution time of each selected pattern, and select the selected pattern as one pattern It registers as a set, determines the execution order between each registered pattern set, and performs the work according to the determined execution order.

  According to the present invention, since the transfer operation is performed using the automatic guided vehicle having two hands, the loading and unloading are performed more efficiently. It is possible to significantly reduce the number of communications and the amount of communication with the apparatus, and to realize a more efficient unmanned conveyance system.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a perspective view showing an automatic guided vehicle having two hands according to an embodiment of the present invention. As shown in FIG. 1, the RGV 100 of the automatic guided vehicle according to the embodiment of the present invention transports a substrate 128 and a wafer (not shown) between a process equipment 124 and a stocker 126. The RGV 100 is installed so as to be linearly movable along the rail 102 and can be rotated 360 ° on the XY plane. The length of the rail 102 can be extended as necessary. Use of the two hands 114 and 118 attached to the RGV 100 is more efficient because two substrates or wafers can be loaded or unloaded in one cycle of operation. The RGV 100 is provided with a buffer (not shown) which is a temporary storage space, and a large number of wafers or LCD substrates are loaded into the buffer and transported.

  FIG. 2 is a block diagram showing a configuration of the unmanned conveyance system according to the embodiment of the present invention. As shown in FIG. 2, the RGV 204 moves along a rail 206 laid in advance, and process equipment 202 a to 202 j, a stocker 208, a stocker table 210, and the like are disposed around the rail 206. The RGV 204 conveys a wafer or a substrate between the process equipment 202 a to 202 j and the stocker 208 while moving along the rail 206.

  FIG. 3 is a flowchart showing an optimum transport control method of the unmanned transport system according to the embodiment of the present invention. As shown in FIG. 3, it is confirmed whether there is a margin space in the buffer of the RGV 204 (step 302). Therefore, an unloading instruction and a loading instruction (that is, the load in the buffer of the RGV 204 is loaded into the target process equipment 202a to 202j or the stocker 208). The operation command to be taken down is retrieved, and an unloading-loading pattern is set for the components related to each other (step 304).

  On the other hand, if the buffer of the RGV 204 is full of wafers and there is no room, no further unloading work is possible. Therefore, the wafers currently in the buffer of the RGV 204 are replaced with the process equipment 202a to 202j or the stocker. A loading command for loading in 208 is retrieved and stored (step 324).

  After unloading-loading pattern setting (step 304), a loading-loading pattern is set (step 306). The EQ-loading command (EL) having the same destination (equipment) is searched from the EQ-loading commands (EL) that are not set as the pattern when setting the unloading-loading pattern described above. A loading-loading pattern is set (step 306). Here, EQ means process equipment (Equipment).

  Subsequently, it is confirmed again whether there is room in the buffer of the RGV 204 (step 308), and it is confirmed whether the loading operation has already started (step 310). If the loading operation has not yet started in a state where there is a margin space in the buffer of the RGV 204, the wafer is unloaded from the stocker table 210 in order to further load the wafer into the margin space of the buffer of the RGV 204. Whether or not there is an ST-unloading instruction (SU) is stored and stored in the memory (step 312). Here, ST means a stocker table.

At this time, the number of ST-unloading instructions (SU) stored in the memory is limited to a preset maximum value, and the number of ST-unloading instructions (SU) in the memory satisfies the following condition. If any one is satisfied, the retrieval and storage of the ST-unloading instruction (SU) is interrupted.
(1) nSU = nMax (SU): When the number of stored ST-unloading instructions (SU) reaches the preset maximum allowable storage number (nMaxSU) (2) nSU = nBufferLeft: Stored When the number of ST-unloading instructions (SU) reaches the number of free buffer spaces (nBufferLeft) (3) nSU = nTCQty: The number of stored ST-unloading instructions (SU) is the main control When the number of work instructions sent from the apparatus (nTCQty) is reached If there is no room in the buffer of the RGV 204, or loading into the process equipment 202a to 202j or the stocker table 210 has already started, the stocker As additional unloading from the table 210 is impossible or inefficient, the stocker table 210 or process equipment 202a-202j may be Loading instruction stores to search whether there for loading Eha (step 324).

  On the other hand, if there is room in the memory while searching for and storing whether or not an ST-unloading instruction (SU) exists, that is, the number of work instructions (nMemoryJob) stored in the memory is preset. If it is less than the maximum window value (nMaxWindow) (step 314) and the number of work commands sent from the main controller (nTCQty) is not reached (step S316), an EQ-unloading command (EU) ), EQ-loading instruction (EL), ST-loading instruction (SL) are additionally searched in order and stored (step 318, step 320, step 322).

  On the other hand, if there is not enough memory, that is, the number of work instructions sent from the main controller because the number of work instructions stored in the memory (nMemoryJob) exceeds the preset maximum window value (nMaxWindow) When (nTCQty) is reached, the search for the EQ-unloading instruction (EU) is omitted, and only the EQ-loading instruction (EL) and the ST-loading instruction (SL) are searched and stored (ie, step 314). And if it is determined “NO” in steps 316, only steps 320 and 322 are performed).

  Further, after the loading command search and storage operation (step 324), it is determined whether or not an ST-unloading command (SU) not set as a pattern exists in the work commands sent from the main controller. Search is performed (step 326). If there is no ST-unloading instruction (SU) that has not been set as a pattern, the scheduling is terminated. On the other hand, if there is an ST-unloading instruction (SU) that has not been set as a pattern, the ST-unloading instruction (SU) is searched and work scheduling is performed again. Since this rescheduling should be performed only once, it is determined whether the current rescheduling is the first rescheduling, and if it is the first rescheduling, ST-unloading instruction (SU) search operation (step 312). If it is determined that rescheduling has already been performed, scheduling is terminated without performing further rescheduling (step 328).

  FIG. 4 is a diagram for explaining setting of an unloading-loading pattern in the optimum transfer control method of the unmanned transfer system shown in FIG. 3, and is sent from the main controller for more efficient transfer work. FIG. 5 is a diagram showing a method for analyzing a work order, setting mutually related components as at least one pattern, and performing work according to the set pattern.

  As shown in FIG. 4, when there is room in the buffer of the RGV 204, a wafer is extracted from the process equipment 202 a to 202 j in all the wafer transfer commands sent from the main controller to the RGV 204. First, it is searched whether or not an EQ-unloading instruction (EU_a to EU_j) exists (for example, in FIG. 4, an EQ-unloading instruction (EU_b) for unloading the wafer W1 mounted on the process equipment 202b). Is assumed to have been searched).

  Subsequently, it is searched whether there is an EQ-loading command (EL_b) for transporting and loading the wafer on the process equipment 202b. That is, whether or not there is a new wafer (for example, an EQ-loading command (EL_b) for the wafer W2 or W3 in FIG. 4) to be loaded into the vacant process equipment 202b after unloading the wafer W1 from the process equipment 202b. Search for. The EQ-unloading instruction (EU) and the EQ-loading instruction (EL) searched in this way are set as one unloading-loading pattern.

  In order to load the wafer W2 or W3 onto the process equipment 202b, the wafer W2 or W3 should be first unloaded from the stocker table 210 or the process equipment 202j. Therefore, an unloading command for unloading the wafer W2 or W3 is retrieved and stored in the memory as a set with the previously set unloading-loading pattern. The instruction for unloading the wafer is an ST-unloading instruction (SU) for unloading the wafer W2 from the stocker table 210, or an EQ for unloading the wafer W3 from the process equipment 202j. -Unloading instruction (EU_J).

  In order to set the pattern of work orders, work orders are searched in the order of EU_b-EL_b-SU (EU_j), but the actual work is performed in the order of SU (EU_j) -EL_b-EU_b. That is, the RGV 204 unloads the wafer W2 close to the stocker table 210, or unloads the wafer W3 close to the process equipment 202j, and transports the unloaded wafer W2 or W3 to the process equipment 202b. To do. Since the RGV 204 adjacent to the process equipment 202b has two hands, after unloading the wafer W1 from the process equipment 202b using an empty hand other than the hand holding the wafer W2 or W3. Then, the transferred wafer W2 or W3 is loaded onto the process equipment 202b (EL_b). Thus, loading and unloading are performed by the two hands of the RGV 204, so that the working time and the moving distance can be greatly reduced, and the unloading and loading are performed as one pattern. Therefore, the amount of communication that occurs when sending work results to the main control device is also greatly reduced.

  FIG. 5 is a diagram for explaining the setting of the loading-loading pattern in the optimum transfer control method of the unmanned transfer system shown in FIG. 3, and a given work command is given for more efficient transfer work. It is a figure which shows the scheduling method for performing the operation | work according to this set pattern which analyzes and sets mutually related components as one pattern.

  As shown in FIG. 5, when two EQ-loading instructions (EL_e1, EL_e2) for loading two wafers W4 and W5 are retrieved in the process equipment 202e, the two loading instructions are converted into one loading- Set as loading pattern.

  Further, an ST-unloading instruction (SU) for unloading the wafer W4 from the stocker table 210 and an EQ-unloading instruction (EU_h) for unloading the wafer W5 from the process equipment 202h are retrieved, and Then, it is stored in the memory as a set with the previously set loading-loading pattern.

  In this case, the RGV 204 unloads the wafer W4 of the stocker table 210 and the wafer W5 of the process equipment 202h according to the work priority order and loads them into its own buffer, and then moves to the destination process equipment 202e and moves to its own. The two wafers W4 and W5 loaded in the buffer are loaded onto the process equipment 202e.

  Since RGV 204 according to the embodiment of the present invention includes two hands, two wafers W4 and W5 can be simultaneously loaded onto process equipment 202e. Therefore, compared with RGV using one hand, the loading time is greatly shortened, and the entire transport time is also greatly shortened.

  FIG. 6 is a flowchart showing a pattern set operation method of the automatic transport system according to the embodiment of the present invention, in which a pattern to be used is determined and registered as one pattern set, and these pattern sets are operated in order. Shows a method for improving the conveyance efficiency. In the pattern setting according to the embodiment of the present invention, each work instruction is classified according to priority, and among the work instructions having the same priority, work instructions related to each other are set as one pattern. In addition, the work at the nearest place is performed first, and then the work forcibly specified by the main controller is performed. The order of each pattern and the order of each pattern set are also determined so as to satisfy this.

  As shown in FIG. 6, first, a pattern to be used is selected from the work instruction patterns (UL, LL, U, L) (step 602). When the pattern to be used is selected, the order in which the patterns are operated in each pattern set is determined, and the execution time of the pattern set is also determined (step 604). Here, the execution time of the pattern set is the total time for executing one pattern set, and is determined by the system operator as the time expected to be the most efficient. For example, if any one pattern set is determined and the execution time is determined to be 20 minutes, the transportation of the physical distribution is performed for 20 minutes according to the corresponding pattern set. When the pattern order and execution time within the pattern set are determined in this way, the corresponding pattern set is registered in the system (step 606). When registration of the pattern set is completed, the order of each pattern set is determined and applied to the system (step 608). As a result, each pattern set is executed according to a predetermined order during a set unique execution time. At this time, whether or not the specific execution time of the currently executed pattern set elapses is checked at regular time intervals (for example, at intervals of 1 second) (step 610). For example, the pattern set in the next order is executed during the corresponding set time (step 612).

It is a perspective view which shows the automatic guided vehicle provided with the two hands according to embodiment of this invention. It is a block diagram which shows the structure of the unmanned conveyance system according to embodiment of this invention. It is a flowchart which shows the optimal conveyance control method of the unmanned conveyance system according to embodiment of this invention. It is a figure for demonstrating the setting of an unloading-loading pattern in the optimal conveyance control method of the unmanned conveyance system shown in FIG. It is a figure for demonstrating the setting of a loading-loading pattern in the optimal conveyance control method of the unmanned conveyance system shown in FIG. It is a flowchart which shows the pattern set operation method of the automatic guided system according to embodiment of this invention.

Explanation of symbols

100, 204 RGV
102, 206 Rail 114, 118 Hand 124, 202a-202j Process equipment 126, 208 Stocker 128 Substrate 210 Stocker table 250 Main controller

Claims (11)

It has an automated guided vehicle with two hands,
The automatic guided vehicle performs at least two work orders having the same destination at the same destination using the two hands at the same time.   Although at least two work instructions having the same destination are set as one pattern and work is performed according to the pattern, the pattern includes a loading instruction and an unloading instruction having the same destination. The unmanned conveyance system according to claim 1, wherein a combination of at least one command is included in a combination and a combination of two loading commands having the same destination.   The pattern is set so as to include only one of the loading instruction and the unloading instruction when at least two work instructions having the same destination do not exist. Item 4. The unmanned conveyance system according to item 1. A control method for an unmanned transport system that includes an automatic guided vehicle having a buffer and two hands and transports an object while moving between a plurality of first work positions and a plurality of second work positions,
When there is room in the buffer, at least one of a combination of a loading command and an unloading command with the same work position as the destination, and a combination of two loading commands with the same work position as the destination Set a first pattern to contain one instruction combination and store it in memory;
When there is room in the buffer and the loading command of the first pattern is not executed, each single work command not included in the first pattern is set as a second pattern. Storing in said memory;
An unmanned conveyance system characterized in that when there is no room in the buffer, only a loading instruction for loading an object loaded in the buffer to a corresponding destination is searched and stored in the memory. Control method. When there is room in the buffer and the loading command of the first pattern is not executed,
Retrieving and storing an unloading instruction with the plurality of first work positions as destinations;
When there is room in the memory for work instructions, an unloading instruction and a loading instruction for the plurality of second work positions as destinations, and a loading instruction for the plurality of first work positions as destinations in order 5. The method for controlling an unmanned conveyance system according to claim 4, wherein retrieval and storage are performed. The automatic guided system further includes a main control device that transfers a work command to the automatic guided vehicle;
When the number of work instructions stored in the memory is equal to or less than a preset maximum window value and smaller than the total number of work instructions sent from the main control device, the memory has a margin. 5. The method for controlling an unmanned conveyance system according to claim 4, wherein the method is determined to be present.   When there is not enough room in the memory, a loading command for the plurality of second work positions as a destination and a loading command for the plurality of first work positions as a destination are sequentially searched and stored. The method for controlling an unmanned conveyance system according to claim 4.   When there is no room in the buffer, a plurality of first working positions are searched after only loading instructions for loading an object loaded in the buffer to a corresponding destination are retrieved and stored in the memory. If there is a work command that is not set as a pattern among the work commands having the destination as a destination, by executing rescheduling once, an unloading command having the plurality of first work positions as the destination is obtained. 5. The method for controlling an unmanned conveyance system according to claim 4, wherein retrieval and storage are performed. A control method for an unmanned transport system comprising a main controller that generates a work command and an automatic guided vehicle that receives the work command and performs a work,
A pattern to be used is selected from among a plurality of patterns composed of combinations of the work instructions generated from the main controller;
Determining the execution order and overall execution time of each selected pattern;
Registering the selected patterns as one pattern set;
A control method for an unmanned conveyance system, wherein an execution order between each registered pattern set is determined, and an operation is performed according to the execution order. The work commands generated from the main controller are classified according to priority, and among the work commands having the same priority, work commands having the same or close destination are set as one pattern;
The control method of the unmanned conveyance system according to claim 9, wherein an execution order of the respective patterns and pattern sets is determined so as to satisfy a preset condition.   The method for controlling an unmanned conveyance system according to claim 9, wherein an execution time of each pattern set is determined by an operator of the unmanned conveyance system as a time when an optimum conveyance efficiency is expected to be obtained. .

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