Patent Publication Number: US-2023152775-A1

Title: Transport device inspection system including diagnostic server and method of operation thereof

Description:
CROSS-REFERENCE TO THE RELATED APPLICATION 
     This U.S. non-provisional patent application claims priority from Korean Patent Application No. 10-2021-0159158, filed on Nov. 18, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field 
     The exemplary embodiments of the disclosure relate to a transport device inspection system for inspecting a transport device, and a method of operation thereof. 
     2. Description of the Related Art 
     A transport device, which is movable along a rail installed on a ceiling, is used in order to transport a wafer for manufacture of a semiconductor between pieces of processing equipment. Since the transport device is disposed at the rail installed on the ceiling, there is no method of checking a state of the transport device during operation of the transport device. For this reason, generally, maintenance of the transport device may be performed after breakdown of the transport device occurs. As such, the absence of a method for checking a state of the transport device before it breaks down may influence productivity of the semiconductor manufacturing facility and process. In addition, the transport device is configured to always move along the rail and, as such, stopping of any individual transport devices may interfere with movement of the remaining transport devices. 
     SUMMARY 
     The exemplary embodiments of the disclosure provide a transport device inspection system for efficiently inspecting a transport device, and a method of operation thereof. 
     A transport device inspection system according to an exemplary embodiment of the disclosure may include a plurality of transport devices, a diagnostic server, an inspector, and a transport device controller. The plurality of transport devices are configured to move along a transport path. The diagnostic server is configured to create inspection schedule information for the plurality of transport devices. The inspector is configured to receive the inspection schedule information from the diagnostic server and to sequentially inspect the plurality of transport devices in accordance with the inspection schedule information. The transport device controller is configured to receive the inspection schedule information from the inspector and to control the plurality of transport devices to sequentially move to an inspection position in accordance with the inspection schedule information. 
     A transport device inspection system according to an exemplary embodiment of the disclosure may include a plurality of transport devices, a diagnostic server, an inspector, and a transport device controller. The plurality of transport devices are configured to move along a transport path. The diagnostic server is configured to create inspection schedule information for the plurality of transport devices. The inspector is configured to receive the inspection schedule information from the diagnostic server and to sequentially inspect the plurality of transport devices in accordance with the inspection schedule information. The transport device controller is configured to receive the inspection schedule information from the inspector and to control the plurality of transport devices to sequentially move to an inspection position in accordance with the inspection schedule information. The inspector may include an inspection module configured to inspect a transport device having arrived at the inspection position. The diagnostic server may include a diagnostic unit configured to receive inspection results obtained after the inspector inspects the transport device and to analyze the inspection results, thereby diagnosing whether or not the transport device is abnormal. 
     A method of operation of a transport device inspection system according to an exemplary embodiment of the disclosure may include creating inspection schedule information for a plurality of transport devices, sequentially moving the plurality of transport devices to an inspection position in accordance with the inspection schedule information, inspecting the transport device having arrived at the inspection position, analyzing inspection results for the transport device, thereby diagnosing whether or not the transport device is abnormal, and moving the transport device to a transport path or moving the transport device to an exit of an inspector in accordance with diagnosis results for the transport device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of a transport device inspection system according to an exemplary embodiment of the disclosure. 
         FIG.  2    is a flowchart explaining a method of operation of the transport device inspection system of  FIG.  1   . 
         FIG.  3    is a block diagram illustrating a configuration of the transport device of  FIG.  1   . 
         FIG.  4    is a sectional view illustrating the transport device of  FIG.  1   . 
         FIG.  5    is a block diagram illustrating a configuration of the diagnostic server of  FIG.  1   . 
         FIG.  6    is a block diagram illustrating a configuration of the inspector of  FIG.  1   . 
         FIG.  7    is a view explaining a transport device inspection system according to an exemplary embodiment of the disclosure. 
         FIG.  8    is a view showing inspection schedule information created by a diagnostic server according to an exemplary embodiment of the disclosure. 
         FIG.  9    is a view showing movement of a transport device in an inspector according to an exemplary embodiment of the disclosure. 
         FIG.  10    shows inspection of a transport device using a distance sensor included in an inspector according to an exemplary embodiment of the disclosure. 
         FIG.  11    shows inspection of a transport device using a camera included in an inspector according to an exemplary embodiment of the disclosure. 
         FIG.  12    shows inspection of a transport device using an inspection measurer included in an inspector according to an exemplary embodiment of the disclosure. 
         FIG.  13    shows operation of a lifter included in an inspector according to an exemplary embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       FIG.  1    is a schematic view of a transport device inspection system according to an exemplary embodiment of the disclosure. 
     Referring to  FIG.  1   , a transport device inspection system  10  may include a plurality of transport devices  100 , a transport device controller  200 , an inspector  300 , and a diagnostic server  400 . The transport devices  100  are devices configured to carry materials in a factory and, for example, may be overhead hoist transfer (OHT) devices that include wheels or other mechanisms for moving. The materials may be a sealed container for receiving a wafer and, for example, may be a front open unified pod (FOUP). 
     Before proceeding, it should be clear that Figures herein, including  FIG.  1    as described below, show and reference elements that are or include circuitry with labels such as “controller”, “unit” including “control unit”, “diagnostic unit”, “scheduling unit”, “interface unit” and “display unit”, as well as “inspection module” or similar terms analogous to “circuit” or “block”. As is traditional in the field of the inventive concept(s) described herein, examples may be described and illustrated in terms of such labelled elements which carry out a described function or functions. These labelled elements, or the like, are physically implemented by analog and/or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by firmware and/or software. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting such labelled elements may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the labelled element and a processor to perform other functions of the labelled element. Each labelled element of the examples may be physically separated into two or more interacting and discrete circuits without departing from the scope of the present disclosure. 
     The transport devices  100  may move along a transport path installed in a factory. The transport path may be generally installed at a factory ceiling, and may be formed by a rail so that the transport devices  100  are suspended at or below the factory ceiling by the rail. As described herein, the rail may include multiple sections of rails, such as a first rail and a second rail, and the rail may include diverging paths. The transport devices  100  may load materials, and may then unload the materials at a desired position after moving along the transport path. For example, the transport devices  100  may transport materials to suitable semiconductor processing equipment in accordance with a semiconductor process sequence while passing through the transport path. In addition, when inspection of the transport devices  100  is required, the transport devices  100  may move to an inspection position, at which inspection may be performed, along the transport path. 
     The transport device controller  200  may manage overall movement and transport of the transport devices  100 . That is, the transport device controller  200  controls the plurality of transport devices  100 , including a transport device corresponding to a current inspection order from among the plurality of transport devices  100 . The transport device controller  200  may include, for example, a memory that stores instructions and a processor that executes the instructions to implement the functions attributed herein to the transport device controller  200 . The transport device controller  200  may also include other circuit elements such as a transmitter, a receiver, and/or a transceiver, as well as interface circuits for interfacing with other electronic systems, devices and/or components. The transport devices  100  may move in accordance with a control command of the transport device controller  200  and, as such, may transport materials. The transport device controller  200  may control the transport devices  100  to move to suitable semiconductor processing equipment in accordance with a semiconductor process sequence and then to load or unload materials. In addition, the transport device controller  200  may control the transport devices  100  to move to an inspection position, at which the transport devices  100  may be subjected to appropriate inspection, in accordance with inspection schedule information for the transport devices  100 . The transport device controller  200  may operate in accordance with knowledge of a plurality of inspection positions, such as distances between a sequence of inspection positions, and/or location information specifying the locations of each inspection position. 
     The inspector  300  may perform inspection to check whether or not the transport devices  100  have one or more abnormality. The transport devices  100  may sequentially arrive at the inspection position after moving along the transport path in accordance with the control command of the transport device controller  200 . For example, the inspection position may correspond to the position of the inspector  300 . The inspector  300  may inspect the transport device  100  having arrived at the inspection position. For example, the inspector  300  may inspect the appearance of the transport device  100  or may inspect driving of the transport device  100 . The inspector  300  may also inspect information from the transport device  100 , such as from a control unit  140  and/or from a sensor unit  130 . 
     The diagnostic server  400  may diagnose whether or not an abnormality exists in each of the transport devices  100 . The diagnostic server  400  may receive inspection results for the transport devices  100  from the inspector  300 , and may diagnose whether or not the abnormality exists in each of the transport devices  100 , through the inspection results. The diagnostic server  400  may store inspection results and/or diagnosis results. 
     The diagnostic server  400  may manage inspection of checking whether or not the transport devices  100  have one or more abnormality. The diagnostic server  400  may create inspection schedule information for the transport devices  100 . Inspection schedule information may be or include information as to an inspection order of the transport devices  100  to be subjected to inspection by the inspector  300 . Details of creation of the inspection schedule information by the diagnostic server  400  will be described later. The diagnostic server  400  may transmit the inspection schedule information to the transport device controller  200  via the inspector  300 . The transport device controller  200  may control the transport devices  100  in accordance with the inspection schedule information received thereto. The inspector  300  may inspect the transport devices  100  in accordance with the inspection schedule information. 
     The diagnostic server  400  may create the inspection schedule information for the transport devices  100  based on information stored in the diagnostic server  400  or based on state information of each of the plurality of transport devices  100  received from the plurality of transport devices  100 . Also, or alternatively, the diagnostic server  400  may create the inspection schedule information by receiving information used to execute the inspection from the user. For example, the user may provide the diagnostic server  400  with an inspection object and/or an inspection schedule. 
       FIG.  2    is a flowchart explaining a method of operation of the transport device inspection system of  FIG.  1   . 
     Referring to  FIG.  2   , the diagnostic server  400  may create inspection schedule information for the transport devices  100  (S 101 ). The diagnostic server  400  may transmit an inspection request for the transport devices  100  to the inspector  300  while transmitting inspection schedule information to the inspector  300  (S 102 ). The inspector  300  may receive the inspection schedule information and the inspection request from the diagnostic server  400 . In response to the inspection request, the inspector  300  may transmit the inspection schedule information to the transport device controller  200 , and may request that the transport device controller  200  control the transport devices  100  to move to the inspector  300  (S 103 ). For example, the request may include a sequence and/or times at which the transport devices  100  are to be controlled to move to the inspector  300 . The transport device controller  200  may control the transport devices  100  to move to the inspector  300  (that is, an inspection position) in response to a movement request from the inspector  300  (S 104 ). The transport device controller  200  may receive the inspection schedule information, and may control the transport devices  100  to move to the inspector  300  in accordance with the inspection schedule information. 
     When at least one of the transport devices  100  arrives at the inspection position or an entrance of the inspector  300  (S 105 ), the arrived transport device  100  may inform the inspector  300  of arrival thereof at the inspection position or the entrance, through communication with the inspector  300  (S 106 ). For example, the arrived transport device  100  may include a wireless communication module such as for Bluetooth or near-field communication (NFC) to wirelessly communicate with a wireless module of the inspector  300 . The entrance of the inspector  300  may be any position of the transport device  100  before the transport device  100  arrives at the inspection position, and may be a position adjacent to the inspector  300 . When the transport device  100  arrives at the entrance of the inspector  300 , the inspector  300  may identify arrival of the transport device  100 , and may then control the transport device  100  to move to the inspection position. The inspector  300  may inspect the transport device  100  having arrived at the inspection position (S 107 ). After performing the inspection of the transport device  100 , the inspector  300  may transmit inspection results to the diagnostic server  400  (S 108 ). As noted above, for example, the inspector  300  may include a wireless communication module such as for Bluetooth or near-field communication (NFC) to wirelessly communicate with a wireless module of the diagnostic server  400 . 
     The diagnostic server  400  may receive the inspection results, and may analyze the inspection results, thereby diagnosing whether or not the inspected transport device  100  is abnormal (S 109 ). After performing diagnosis through analysis of the inspection results, the inspector  300  may request that the inspector  300  move the transport device  100 , based on the diagnosis results (S 110 ). For example, the diagnostic server  400  may request movement of the transport device  100  by transmitting the diagnosis results to the inspector  300 . 
     When the transport device  100  is diagnosed as normal or is to be requested to appear for inspection, the diagnostic server  400  may request that the inspector  300  move the transport device  100  from the inspector  300  (that is, the inspection position) to the outside (S 110 ). In accordance with the movement request, the inspector  300  may request that the transport device controller  200  move the transport device  100  to the outside of the inspector  300  (S 111 ). In addition, the inspector  300  may request that the transport device controller  200  control the transport device  100  to move once outside of the inspector  300 . In accordance with the movement request and the control request, the transport device controller  200  may move the transport device  100  to the outside of the inspector  300 , and may control movement and transport of the transport device  100  at the outside of the inspector  300  (S 112 ). That is, the transport device controller  200  may control the transport device  100 , which has been diagnosed as normal or which is to be requested for inspection, to transport materials along the transport path after departing from the inspector  300 . 
     When the transport device  100  is diagnosed as abnormal (or is to be urgently inspected), the diagnostic server  400  may request that the inspector  300  move the transport device  100  to an exit through a lifter (S 110 ). In accordance with the movement request, the inspector  300  may move the transport device  100  to an exit thereof through the lifter. For example, the transport device  100  moved to the exit may be subjected to inspection or repair for a configuration which has one or more abnormality. 
     In an embodiment, when the transport device  100  has been diagnosed and is to be requested for inspection, the diagnostic server  400  may output diagnosis results to the user, may then receive control information for the transport device  100  from the user, and may then control the transport device  100  in accordance with the control information. For example, the user may control the transport device  100 , which has been diagnosed and is to be requested for inspection, to move to the outside of the inspector  300  for transport of materials, or to move to the exit through the lift for inspection. 
       FIG.  3    is a block diagram illustrating a configuration of the transport device of  FIG.  1   .  FIG.  4    is a sectional view illustrating the transport device of  FIG.  1   . 
     Referring to  FIG.  1   ,  FIG.  3   , and  FIG.  4   , the transport device  100  may be hanging on and suspended from a rail RA forming a transport path. The transport device  100  may include a body  101 , a driving device  110 , a hoist  120 , a sensor unit  130 , and a control unit  140 . The driving device  110 , the hoist  120 , the sensor unit  130 , and the control unit  140  may be connected to the body  101 . An equipment name ID of the transport device  100  may be indicated at a portion of a surface of the body  101 , and may be used in communications and processing to identify each instance of the transport device  100 . 
     The driving device  110  may include a driving unit  111  configured to enable the transport device  100  to move along the transport path. For example, the driving unit  111  may include a wheel  111   a , a motor  111   b  configured to drive the wheel  111   a , and a steering unit  111   c  configured to adjust a direction of the wheel  111   a . The driving device  110  may further include a drive signal generator  112 . The drive signal generator  112  may generate driving information for the driving unit  111 . For example, the driving information may include velocity (angular velocity) and/or torque of the motor  111   b . The steering unit  111   c  may be used to adjust the direction of travel of the transport device  100 , such as to move along one of two or more potential segments of the transport path. 
     The hoist  120  may include a handler  122  disposed at an inside of the body  101 , and configured to load or unload materials, and a hoist driver  121  configured to enable the handler  122  to move in a vertical direction or to move in a horizontal direction. Although not shown, the hoist  120  may further include a hoist drive signal generator. For example, the hoist drive signal generator may generate driving information such as velocity (angular velocity) and/or torque of a motor included in the hoist driver  121 . 
     The sensor unit  130  may be attached to the body  101 , and may sense a driving state of the transport device  100  or a peripheral environmental state of the transport device  100 . For example, the sensor unit  130  may include a carrier sensor  131 , an obstacle sensor  132 , a material sensor  133 , a tag recognition sensor  134  and/or another type of sensor. The carrier sensor  131  may sense whether or not another transport device  100  is in front of the transport device  100 . The obstacle sensor  132  may sense whether or not there is an obstacle on a track on which the transport device  100  will travel. The material sensor  133  may sense whether or not materials have been loaded in the handler  122  of the hoist  120 . The tag recognition sensor  134  may recognize a tag TA attached to the rail RA (that is, the transport path). In addition to the above-described sensors, the sensor unit  130  may include sensors configured to sense and measure a driving state of the transport device  100  such as vibration, noise, speed, etc. of the driving unit  111  or the hoist driver  121 . 
     The control unit  140  may control the driving device  110 , the hoist  120  and the sensor unit  130  in accordance with a control command of the transport device controller  200 . The control unit  140  may move the transport device  100  along the transport path by controlling the driving unit  111  of the driving device  110 . The control unit  140  may move the handler  122  upwards and downwards or left and right and may control the handler  122  to load materials or to provide materials to processing equipment by controlling the hoist driver  121 . The control unit  140  may control the sensor unit  130  to sense a driving state of the transport device  100  or a peripheral environmental state of the transport device  100 . 
     The control unit  140  may receive state information including at least one of a drive signal of the driving unit  111 , a drive signal of the hoist driver  121 , a driving state of the transport device  100 , and tag recognition information from the drive signal generator  112  of the driving device  110 , the hoist drive signal generator of the hoist  120 , and the sensor unit  130 . The control unit  140  may transmit the received state information to the diagnostic server  400 . Although not shown, the transport device  100  may further include a communication unit, and the control unit  140  may transmit the state information to the diagnostic server  400  via the communication unit. A communication unit may include a wireless communication module that communicates via Bluetooth, near-field communication (NFC) or another type of protocol, and/or may include a wired interface that communicates such as by ethernet. 
       FIG.  5    is a block diagram illustrating a configuration of the diagnostic server of  FIG.  1   . 
     Referring to  FIG.  1    and  FIG.  5   , the diagnostic server  400  may include a diagnostic unit  401 , a database  402 , a scheduling unit  403 , a display unit  404 , and an interface unit  405 . The diagnostic server  400  may further include a communication unit that communicates wirelessly and/or over a wire. 
     The diagnostic server  400  may receive pieces of state information for the transport devices  100  from the transport devices  100  via the communication unit thereof, respectively. The diagnostic unit  401  may analyze the received state information pieces, thereby diagnosing whether or not the respective transport devices  100  have one or more abnormality. 
     The diagnostic unit  401  may receive inspection results for the transport devices  100  from the inspector  300  via the communication unit. The diagnostic unit  401  may analyze the received inspection results, thereby diagnosing whether or not the respective transport devices  100  have one or more abnormality. 
     Diagnosis results obtained through diagnosis by the diagnostic unit  401  may be stored in the database  402 , together with the inspection results. The diagnostic unit  401  may output the diagnosis results to the user through the display unit  404 . Diagnosis results may be stored in the database  402 , and may subsequently be used when the scheduling unit  403  creates inspection schedule information. 
     The database  402  may store information as to the transport devices  100 . The database  402  may store state information received from the transport devices  100  and inspection results previously obtained through inspection of the transport devices  100  by the inspector  300 , as described above, and may also store diagnosis results obtained after the diagnostic unit  401  analyzes the state information and the inspection results and diagnoses whether or not the respective transport devices  100  have one or more abnormality, based on analysis results. For example, the database  402  may store usage (for example, period(s) of use) of each of the transport devices  100 , the number of times when each of the transport devices  100  was subjected to inspection, the number of times when each of the transport devices  100  was diagnosed as abnormal, and/or information as to a configuration which has one or more abnormality, etc. in each of the transport device  100 . The database  402  may store at least one of state information, inspection results and diagnosis results for each transport device  100 , corresponding to the equipment name ID of the transport device  100 . 
     The scheduling unit  403  may create inspection schedule information for the transport devices  100 . For example, the inspection schedule information may include equipment name IDs of inspection objects to be inspected from among the transport devices  100 , and an inspection order of the inspection objects. The scheduling unit  403  may provide the inspection schedule information to the inspector  300  via the communication unit. 
     In an embodiment, the scheduling unit  403  may receive diagnosis results from the diagnostic unit  401 , and may create inspection schedule information based on the diagnosis results. For example, when the diagnostic unit  401  receives state information of the transport devices  100  from the transport devices  100 , and then analyzes the state information, thereby generating diagnosis results, the scheduling unit  403  may receive the diagnosis results from the diagnostic unit  401 , and may create inspection schedule information based on the diagnosis results. When the diagnostic unit  401  receives inspection results for the transport devices  100  from the inspector  300 , and then analyzes the inspection results, thereby creating diagnosis results, the scheduling unit  403  may receive the diagnosis results from the diagnostic unit  401 , and may then create inspection schedule information based on the diagnosis results. For example, the scheduling unit  403  may create inspection schedule information for the transport devices  100  diagnosed as abnormal from among the transport devices  100  transmitting state information, in accordance with the diagnosis results. The scheduling unit  403  may determine an inspection order in which the transport devices  100  diagnosed as abnormal are subjected to inspection through the inspector  300 . 
     In an embodiment, the scheduling unit  403  may create inspection schedule information based on information stored in the database  402 . The scheduling unit  403  may determine an inspection order of the transport devices  100  based on the information stored in the database  402 . For example, the scheduling unit  403  may create inspection schedule information such that inspection is performed, starting from the transport device  100  having the greatest length of time since the transport device  100  was previously diagnosed as abnormal among a plurality of transport devices  100 . Also, or alternatively, the order may be created based on the number of inspections elapsed since the transport devices  100  were previously diagnosed as abnormal, so that transport devices  100  with the largest number of successful inspections may still be prioritized for future inspections. For example, in the case in which the number of inspection times when a first transport device  100   a  was previously diagnosed as abnormal is three, the number of inspection times when a second transport device  100   b  was previously diagnosed as abnormal is two, and the number of inspection times when a third transport device  100   c  was previously diagnosed as abnormal is five, the scheduling unit  403  may determine the inspection order of the third transport device  100   c  to be first, may determine the inspection order of the first transport device  100   a  to be second, and may determine the inspection order of the second transport device  100   b  to be third. 
     Alternatively, the order may be created so that the transport devices  100  with the smallest number of successful inspections may be prioritized for future inspections. For example, the scheduling unit  403  may create inspection schedule information such that inspection is performed, starting from the transport device  100  having a smaller number of inspection times since the transport device  100  was previously diagnosed as abnormal compared to the remaining transport devices  100 . For example, in the case in which the number of inspection times when the first transport device  100   a  was previously diagnosed as abnormal is five, the number of inspection times when the second transport device  100   b  was previously diagnosed as abnormal is three, and the number of inspection times when the third transport device  100   c  was previously diagnosed as abnormal is one, the scheduling unit  403  may determine the inspection order of the third transport device  100   c  to be first, may determine the inspection order of the second transport device  100   b  to be second, and may determine the inspection order of the first transport device  100   a  to be third. 
     Alternatively, the order may be created based on the total number of times the transport devices  100  were diagnosed as abnormal and the total number of inspection times of the transport devices  100 . For example, the scheduling unit  403  may create inspection schedule information based on the numbers of inspection times when the transport devices  100  were previously diagnosed as abnormal, respectively, and the numbers of times when the transport devices  100  were previously subjected to inspection, respectively. For example, the scheduling unit  403  may determine an inspection order of the transport devices  100  in accordance with the numbers of times when the transport devices  100  were previously diagnosed as abnormal, respectively, and when multiple of the transport devices  100  have equal numbers of times when the transport devices  100  were previously diagnosed as abnormal, respectively, in accordance with the numbers of times when the transport devices  100  were previously subjected to inspection, respectively. Alternatively, the scheduling unit  403  may not only determine an inspection order of the transport devices  100  in accordance with the numbers of times when the transport devices  100  were previously subjected to inspection, respectively, and when multiple of the transport devices  100  have equal numbers of times when the transport devices  100  were previously subjected to inspection, respectively, in accordance with the numbers of times when the transport devices  100  were previously diagnosed as abnormal, respectively. 
     In an embodiment, the scheduling unit  403  may create inspection schedule information based on information received from the user. The scheduling unit  403  may receive information for creation of inspection schedule information from the user via the interface unit  405 . The user may designate, through the interface unit  405 , inspection objects to be subjected to inspection from among the transport devices  100 , and may determine an inspection order of the inspection objects. The display unit  404  may output information as to the transport devices  100  based on information stored in the database  402 , and the user may identify the information as to the transport devices  100  through the display unit  404  and may input inspection objects and an inspection order through the interface unit  405  based on the identified information. The scheduling unit  403  may crease inspection schedule information in accordance with the inspection objects and the inspection order input by the user through the interface unit  405 . 
       FIG.  6    is a block diagram illustrating a configuration of the inspector of  FIG.  1   . 
     Referring to  FIG.  1    and  FIG.  6   , the inspector  300  may include a control unit  301 , an inspection module  302 , a display unit  303 , an interface unit  304 , and a lifter  305 . The inspector  300  may further include a communication unit. 
     The control unit  301  may include a memory that stores instructions and a processor that executes the instructions to implement the functions attributed herein to the control unit  301 . The control unit  301  may also include other circuitry and circuit elements, such as a transmitter, receiver or transceiver configured to communicate. The control unit  301  may receive inspection schedule information from the diagnostic server  400 . The control unit  301  may receive the inspection schedule information via the communication unit thereof. The control unit  301  may transmit the received inspection schedule information to the transport device controller  200 . Through transmission of the inspection schedule information to the transport device controller  200 , the control unit  301  requests that the transport device controller  200  move the transport devices  100  in accordance with the inspection schedule information. 
     When the transport device  100  arrives at the inspection position or the entrance of the inspector  300 , the control unit  301  may communicate with the transport device  100 , thereby identifying arrival of the transport device  100 . After identifying arrival of the transport device  100 , the control unit  301  may check, through the inspection module  302 , whether or not the transport device  100  is a current inspection object. For example, the control unit  301  may control a camera  302   a  included in the inspection module  302  and, as such, the camera  302   a  may photograph the equipment name (for example, ID) of the transport device  100  having arrived at the inspection position. The control unit  301  may analyze a photographed image, thereby recognizing the equipment name, and may then compare the recognized equipment name with the inspection schedule information. The control unit  301  may check whether or not the transport device  100  having the recognized equipment name is a transport device corresponding to an inspection order for execution of a current inspection. Alternatively, the control unit  301  may receive the equipment name of the transport device  100  having arrived at the inspection position or the entrance of the inspector  300 , through communication with the transport device  100 , and, as such, may check whether or not the transport device  100  is a transport device corresponding to a current inspection order. 
     When the transport device  100  having arrived at the inspection position or the entrance of the inspector  300  is the transport device corresponding to the inspection order for execution of the current inspection, the control unit  301  may control the inspection module  302 , thereby performing inspection of the transport device  100 . For example, when the transport device  100  having arrived at the entrance of the inspector  300  is the transport device corresponding to the inspection order for execution of the current inspection, the control unit  301  may control the transport device  100  to move from the entrance to the inspection position, through communication with the transport device  100 , and inspection may then be performed. 
     The inspection module  302  may operate in accordance with a control signal of the control unit  301  and, as such, may perform inspection of the transport device  100  having arrived at the inspection position. For example, the inspection module  302  may include at least one of a camera  302   a , a measurer  302   b , and a distance sensor  302   c . Of course, the exemplary embodiments of the disclosure are not limited to the above-described case, and, otherwise, the inspection module  302  may include another inspection device capable of observing a state of the transport device  100 . 
     The control unit  301  may receive, from the inspection module  302 , inspection results obtained through inspection of the transport device  100 , and may transmit the inspection results to the diagnostic server  400  via the communication unit. Alternatively, the inspection module  302  may directly transmit the inspection results to the diagnostic server  400  via the communication unit. The control unit  301  may receive diagnosis results obtained after the diagnostic server  400  diagnoses whether or not the transport device  100  is abnormal, based on the inspection results. The control unit  301  may output the received diagnosis results to the display unit  303 . The display unit  303  may be configured to output the diagnosis results. The user may identify the diagnosis results not only through the display unit  404  of the diagnostic server  400 , but also through the display unit  303  of the inspector  300 . 
     The inspector  300  may receive control information for the transport device  100  which has completed inspection from the user via the interface unit  304 . The user may identify diagnosis results for the transport device  100  which has completed inspection through the display unit  303 , and may input, to the inspector  300  via the interface unit  304 , control information as to how the transport device  100  should be controlled in accordance with the diagnosis results. The control unit  301  may receive the control information via the interface unit  304 , and may then control the transport device  100  in accordance with the control information. Alternatively, the control unit  301  may receive the control information via the interface unit  304 , and may then transmit the received control information to the transport device controller  200  via the communication unit. 
     The lifter  305  may move the transport device  100  which has completed the inspection. The lifter  305  may move the transport device  100  downwards, thereby moving the transport device  100  to the exit. The control unit  301  controls the lifter  305  in accordance with the diagnosis results for the transport device  100  received from the diagnostic server  400 . For example, when the diagnosis results for the transport device  100  received from the diagnostic server  400  represent one or more identified abnormality, the control unit  301  may control the lifter  305 , thereby moving the transport device  100  to the exit. When the diagnosis results for the transport device  100  received from the diagnostic server  400  represent normal, the control unit  301  may not operate the lifter  305 . When the diagnosis results for the transport device  100  received from the diagnostic server  400  represent normal, the transport device controller  200  may control the transport device  100 . The transport device controller  200  may control the transport device  100  to move to the outside of the inspector  300 . The transport device controller  200  may control the transport device  100  to move in accordance with a process sequence. Alternatively, the control unit  301  may control the lifter  305  in accordance with the control information received through the interface unit  304 . 
       FIG.  7    is a view explaining a transport device inspection system according to an exemplary embodiment of the disclosure.  FIG.  8    is a view showing inspection schedule information created by a diagnostic server according to an exemplary embodiment of the disclosure. 
     Referring to  FIG.  1   ,  FIG.  4   , and  FIG.  7   , transport devices  100  may move along a transport path RA. A plurality of tags T may be installed on the transport path RA. Each of the transport devices  100  may recognize the tag TA through a tag recognition sensor  134  included therein. For example, the tag TA may be constituted by a barcode, text, an image, or a combination thereof. Each of the transport devices  100  may recognize the tag T, and may then create position information representing a position at which the transport device  100  is disposed, on the transport path RA. A transport device controller  200  may receive the position information from the transport device  100  and, as such, may identify the position, at which the transport device  100  is disposed, on the transport path RA and may control movement of the transport device  100  in accordance with the position information. 
     The transport path RA may include a first path RA 1  and a second path RA 2 . For example, the first path RA 1  may be installed to enable the transport devices  100  to transport materials to processing equipment, etc. while passing through the first path RA 1 , and the second path RA 2  may be installed to enable the transport devices  100  to be inspected by an inspector  300  while passing through the second path RA 2 . The inspector  300  may be installed on the second path RA 2 . For example, the second path RA 2  may be branched from the first path RA 1 . The transport device controller  200  may control the transport devices  100  to transport materials to suitable processing equipment while moving along the first path RA 1 . 
     Referring to  FIG.  1   ,  FIG.  7   , and  FIG.  8   , the transport devices  100  may move on the first path RA 1  and the second path RA 2  in accordance with inspection schedule information  1 . When the transport device controller  200  receives the inspection schedule information  1  from the inspector  300 , the transport device controller  200  may control the transport devices  100  to move on the first path RA 1  and the second path RA 2  in accordance with the inspection schedule information  1 . The transport device controller  200  may control the transport devices  100  to sequentially enter the second path RA 2  and then to move to the inspector  300  (that is, the inspection position) in accordance with an inspection order of the transport devices  100  included in the inspection schedule information  1 . The transport device controller  200  may control the transport devices  100 , which do not correspond to a current inspection order, not to enter the second path RA 2  or not to arrive at the inspector  300  while the transport device  100  corresponding to the current inspection order is inspected by the inspector  300  after moving to the inspector  300  in accordance with the inspection schedule information  1 . In addition, the transport device controller  200  may control the transport devices  100 , which are not included, as inspection objects, in the received inspection schedule information  1 , to transport materials to suitable processing equipment while continuously moving on the first path RA 1 . 
     In an embodiment, the transport device inspection system may include a first transport device  100   a , a second transport device  100   b , a third transport device  100   c , a fourth transport device  100   d , and a fifth transport device  100   e . Of course, this case is only illustrative, and the number of transport devices is not limited thereto. For example, an equipment name ID of the first transport device  100   a  is ST 01 , an equipment name ID of the second transport device  100   b  is ST 02 , an equipment name ID of the third transport device  100   c  is ST 03 , an equipment name ID of the fourth transport device  100   d  is ST 04 , and an equipment name ID of the fifth transport device  100   e  is ST 05 . 
     The transport device controller  200  may move the first transport device  100   a , the second transport device  100   b , the third transport device  100   c  and the fourth transport device  100   d  to the inspector  300  in an order of the fourth transport device  100   d , the second transport device  100   b , the third transport device  100   c  and the first transport device  100   a  in accordance with the inspection schedule information  1 . First, the transport device controller  200  may move the fourth transport device  100   d , the inspection order of which is first, to the inspector  300  or the entrance of the inspector  300 . The fourth transport device  100   d  may arrive at a first position, at which a first tag TA 1  is disposed, in the middle of movement thereof along the first path RA 1 . For example, the first position, at which the first tag TA 1  is disposed, may be a branch point of the first path RA 1  and the second path RA 2 . The fourth transport device  100   d  may recognize the first tag TA 1  through a tag recognition sensor thereof and, as such, may create tag recognition information. The transport device controller  200  may receive the tag recognition information and, as such, may recognize that the fourth transport device  100   d  has arrived at the first position. The transport device controller  200  may control the fourth transport device  100   d  having arrived at the first position to enter the second path RA 2 . The fourth transport device  100   d  may move toward the inspector  300  disposed on the second path RA 2 . A second tag TA 2  may be installed at the inspection position of the inspector  300 . Alternatively, the fourth transport device  100   d  may arrive at the entrance of the inspector  300  first. The fourth transport device  100   d  having arrived at the entrance of the inspector  300  may communicate with the inspector  300  and, as such, may inform the inspector  300  of arrival at the entrance. The inspector  300  may check whether or not the fourth transport device  100   d  is equipment corresponding to the current inspection order, and may then move the fourth transport device  100   d  to the inspection position. In an embodiment, the fourth transport device  100   d  may, at the first position, inform the inspector  300  of arrival at the first position. The inspector  300  may check whether or not the fourth transport device  100   d  having arrived at the first position is the equipment corresponding to the current inspection order, and may then move the fourth transport device  100   d  to the inspection position. 
     The transport device controller  200  may control the first transport device  100   a , the second transport device  100   b , and the third transport device  100   c  not to enter the second path RA 2  while the fourth transport device  100   d  is subjected to inspection at the inspection position. For example, when the second transport device  100   b , which corresponds to an order (for example, a second order) just next to the current inspection order (for example, a first order), arrives at the first portion, the transport device controller  200  may control the second transport device  100   b  to wait at the first position. When the third transport device  100   c , the first transport device  100   a  or the fifth transport device  100   e , which does not correspond to the order just next to the current inspection order (for example, corresponding to a third order or a fourth order or not being an inspection object), arrives at the first position, the transport device controller  200  may control the third transport device  100   c , the first transport device  100   a  or the fifth transport device  100   e  to move to a position, at which a third tag TA 3  is disposed, on the first path RA 1 . 
     In an embodiment, after the inspection of the fourth transport device  100   d  is completed, the transport device controller  200  may align the first transport device  100   a , the second transport device  100   b , and the third transport device  100   c  in the vicinity of the first position in advance in accordance with an inspection order in order to enable the first transport device  100   a , the second transport device  100   b  and the third transport device  100   c  to move in accordance with the inspection order. 
     After completion of the inspection of the fourth transport device  100   d , the fourth transport device  100   d  may depart from the inspection position. The inspector  300  may move the fourth transport device  100   d  to the exit through the lifter, or the transport device controller  200  may control the fourth transport device  100   d  to again enter the first path RA 1 . When the fourth transport device  100   d  is moved to the exit through the lifter, the inspector  300  may move the fourth transport device  100   d  to a position, at which a fourth tag TA 4  is disposed, on the second path RA 2 . 
     When the fourth transport device  100   d  departs from the inspection position, the transport device controller  200  may move the second transport device  100   b , the inspection order of which is second, to the inspection position. The procedure of moving the second transport device  100   b  to the inspection position may be performed in the same manner as the above-described procedure of moving the fourth transport device  100   d  to the inspection position. Thereafter, the above-described procedure may be sequentially applied to the third transport device  100   c , the inspection order of which is third, and the first transport device  100   a , the inspection order of which is fourth, in the same manner. 
       FIG.  9    is a view showing movement of a transport device in an inspector according to an exemplary embodiment of the disclosure.  FIG.  10    shows inspection of a transport device using a distance sensor included in an inspector according to an exemplary embodiment of the disclosure.  FIG.  11    shows inspection of a transport device using a camera included in an inspector according to an exemplary embodiment of the disclosure.  FIG.  12    shows inspection of a transport device using an inspection measurer included in an inspector according to an exemplary embodiment of the disclosure.  FIG.  13    shows operation of a lifter included in an inspector according to an exemplary embodiment of the disclosure. 
     Referring to  FIG.  7    and  FIG.  9   , the second path RA 2  may include a first rail R 1  and a second rail R 2 . The first rail R 1  may be branched from the first path RA 1 . The first rail R 1  may be spaced apart from the first path RA 1  and, as such, vibration from the first path RA 1  may not be transmitted to the first rail R 1 . The second rail R 2  may be branched from the first path RA 1 . The second rail R 2  may be disposed between the first rail R 1  and the first path RA 1 . The second rail R 2  may be spaced apart from the first path RA 1  and, as such, vibration from the first path RA 1  may not be transmitted to the second rail R 2 . The second rail R 2  may also be spaced apart from the first rail R 1 , or may be separably connected to the first rail R 1 . 
     Referring to  FIG.  9    to  FIG.  13   , an inspector  300  may include a panel P, a port  310 , a camera  302   a , a measurer  302   b , a lifter  305 , and an exit  390 . The panel P may be disposed on the second path RA 2 . The panel P may surround at least parts of the first rail R 1  and the second rail R 2  of the second path RA 2 . The panel P may be disposed on a top surface and opposite side surfaces of the second path RA 2 , and may be open downwards. A transport device  100  may pass through an inside of the panel P while moving along the second path RA 2 . The panel P may prevent light from leaking outwards when the inspector  300  photographs the transport device  100  using the camera  302   a.    
     Referring to  FIG.  6   ,  FIG.  9   , and  FIG.  10   , the port  310  may be disposed under the first rail R 1 . A distance sensor  302   c  may be provided at the port  310 . The distance sensor  302   c  may check whether or not a handler  122  of the transport device  100  is horizontally maintained during vertical movement thereof. For example, the distance sensor  302   c  may be disposed in plural on the port  310  such that the plurality of distance sensors  302   c  are spaced apart from one another, and each of the plurality of distance sensors  302   c  may measure a distance therefrom to a bottom surface of the handler  122 . A control unit  301  of the inspector  300  may transmit the measured distance to a diagnostic server  400 , and a diagnostic unit  401  of the diagnostic server  400  may check whether or not the handler  122  is horizontally maintained, based on the measured distance, thereby diagnosing whether or not the transport device  100  is abnormal. 
     Referring to  FIG.  6   ,  FIG.  9   , and  FIG.  11   , the inspector  300  may include the camera  302   a . The camera  302   a  may be disposed at the inside of the panel P, and may further be disposed at the outside of the panel P. The camera  302   a  may photograph the appearance of a transport device  100  having arrived at the first rail R 1 . Cameras  302   a  may be installed at positions where the cameras  302   a  can easily photograph configurations of the transport device  100  having arrived at the first rail R 1 , respectively. 
     In an embodiment, materials may be provided on the port  310 . The transport device  100  may load the materials provided on the port  310 . Otherwise, the transport device  100  may unload, on the port  310 , materials loaded therein. The camera  302   a  may photograph a shape of the transport device  100  loading or unloading materials. 
     The control unit  301  of the inspector  300  may transmit, to the diagnostic server  400 , a video or image photographed by the camera  302   a , and the diagnostic unit  401  of the diagnostic server  400  may then analyze the photographed video or image, thereby diagnosing whether or not the transport device  100  is abnormal. 
     Referring to  FIG.  6   ,  FIG.  9   , and  FIG.  12   , the inspector  300  may include the measurer  302   b . The measurer  302   b  may be disposed at the inside of the panel P, and may further be disposed at the outside of the panel P. The measurer  302   b  may inspect states of multiple instances of the sensor unit  130  included in a transport device  100  having arrived at the first rail R 1 . The measurer  302   b  may receive light emitted from each instance of the sensor unit  130  and, as such, may measure an amount of light or may identify positions irradiated with light by each of the sensor unit  130 . 
     The control unit  301  of the inspector  300  may transmit measurement results for light from each instance of the sensor unit  130  to the diagnostic server  400 , and the diagnostic unit  401  of the diagnostic server  400  may then analyze the light measurement results, thereby diagnosing whether or not the transport device  100  is abnormal. 
     Referring to  FIG.  1    and  FIG.  9    to  FIG.  12   , the inspector  300  may perform inspection of a transport device  100  having arrived at the first rail R 1 . The inspector  300  may inspect whether or not the transport device  100  is abnormal, using the camera  302   a , the measurer  302   b  and the distance sensor  302   c . After completing the inspection of the transport device  100 , the inspector  300  may move the transport device  100  to the second rail R 2 . After completing the inspection of the transport device  100 , the inspector  300  may transmit inspection results to the diagnostic server  400 , and may then receive, from the diagnostic server  400 , diagnosis results obtained after the diagnostic server  400  diagnoses whether or not the transport device  100  is abnormal. When the diagnosis results represent normal, the inspector  300  may control the transport device  100  to again enter the first path RA 1  after passing through the second rail R 2 . 
     Referring to  FIG.  13   , the lifter  305  may move the second rail R 2  upwards and downwards. For example, the lifter  305  may have a configuration in which a belt  305   b  or a chain is connected to a rotational body  305   a  rotatable by a motor, and the second rail R 2  may be connected to the belt  305   b  or the chain. The lifter  305  may move the second rail R 2  upwards and downwards in accordance with movement of the belt  305   b  or the chain. For example, the control unit  301  may be configured to control the lifter  305  to move the second rail downwards when the diagnosis results represent abnormal. 
     Of course, the configuration of the lifter  305  is not limited to the above-described configuration, and another embodiment capable of moving the second rail R 2  upwards and downwards may be applied. 
     In an embodiment, when the transport device  100  is determined to be abnormal, the lifter  305  may move the second rail R 2  downwards. The second rail R 2  may move downwards through the lifter  305  and, as such, may be aligned with a third rail RA 3  disposed at the exit  390 . The transport device  100  may move to the exit  390  through the third rail RA 3 . 
     In accordance with an exemplary embodiment of the disclosure, a transport device inspection system capable of automatically inspecting transport devices in accordance with a predetermined inspection order may be provided and, as such, it may be possible to efficiently and safely inspect a transport device and to prevent degradation of productivity of a semiconductor production line caused by failure of a transport device. 
     While the embodiments of the disclosure have been described with reference to the accompanying drawings, it should be understood by those skilled in the art that various modifications may be made without departing from the scope of the disclosure and without changing essential features thereof. Therefore, the above-described embodiments should be considered in a descriptive sense only and not for purposes of limitation.