Hoist communication device for transport platform in automated transport system

Abstract

To provide a hoist communication apparatus for a carriage of an automatic transfer system, capable of individually communicating with a motor in an inner part of a gripper and various sensors by a carriage control machine.SOLUTION: A hoist communication apparatus for a carriage contains: a master communication unit that assigns transfer frequencies which are different in each gripper device identification information, modulates them, and transfers at least one modulated control signal to a slave communication apparatus via a power supply line formed in a belt by being superposed on a power supply; and a slave communication unit that supplies the power supply provided from the master communication unit to a gripper unit that carries out a hoist operation, demodulates the modulated control signal by using the transfer frequency, transfers the demodulated control signal to the gripper device corresponding to identification information, and transfers to the master communication unit the signal applied from each gripper device after the different transfer frequency is assigned and modulated, via the power supply line formed in the belt.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a technology in which a master communication unit and a slave communication unit of a hoist device perform power line communication through a single power line installed on a belt, and a transport vehicle controller connected to the master communication unit performs individual communication with a plurality of gripper devices connected to the slave communication unit using different carrier frequencies. [Background technology]

[0002] Generally, in the manufacturing process of semiconductor devices or liquid crystal display devices, an automated material handling system (AMHS) is used to transport manufactured items to manufacturing equipment for each manufacturing process, so that the items are manufactured according to the process of each manufacturing equipment. Such an automated material handling system transports carriers containing semiconductor substrates or liquid crystal substrates to each manufacturing equipment installed on the manufacturing process line, and uses a transport cart to store the items that have completed the process in the manufacturing equipment and transport them to the manufacturing equipment for the next process.

[0003] Depending on the transportation method, the transport vehicle includes AGV (Automated Guided Vehicle) that runs automatically by wheels, RGV (Rail Guided Vehicle) that runs along guide rails installed on the bottom, and OHT (Overhead Hoist Transport) that runs along guide rails installed on the ceiling. The transport vehicle moves to the manufacturing equipment using its own wheels or along guide rails installed on the bottom or ceiling, and then transports / loads carriers into the manufacturing equipment using an operating arm or a hoist and gripper.

[0004] Fig. 1 is a diagram for explaining a transport vehicle of a conventional automatic transport system, and shows the process of performing a hoist operation on the transport vehicle. In Fig. 1, (A) is a step in which the transport vehicle (10) carries a carrier (3) and moves along a rail (1) to the position of the manufacturing equipment (2), (B) is a step in which the transport vehicle (10) lowers the belt (12) to seat the carrier (3) on the manufacturing equipment (2), and (C) is a step in which the transport vehicle (10) places the carrier (3) on the manufacturing equipment (2) and raises and lowers the belt (12) to perform the corresponding process operation on the carrier (3) in the manufacturing equipment (2).

[0005] As shown in FIG. 1, the transport vehicle (10) includes a hoist (11), a belt (12), and a gripper unit (gripper (13)). When the transport vehicle (10) moves along the rails (1) and is positioned at the location of the manufacturing equipment (2), it raises and lowers the gripper unit (13) via the belt (12) to carry the carrier (3) in or out of the manufacturing equipment (2).

[0006] 2, the transport vehicle (10) includes a transport vehicle controller (15), a hoist (11), and a gripper unit (13), and the gripper unit (13) includes a gripper controller (13-1), a gripper (13-2), and at least one motor and a sensor for operating the gripper (13-2). The hoist (11) is configured such that the master communication unit (11-1) performs power line communication with the slave communication unit (11-2) through a wired power line (L) formed on the belt (12) using a communication system, for example, a cyclic communication method.

[0007] In other words, in the above-mentioned transport vehicle (10), when each device such as a motor or a sensor located in the gripper unit (13) attempts to transmit certain information to the transport vehicle controller (15), it first communicates with the gripper controller (13-1), the gripper controller (13-1) communicates with the slave communication unit (11-2), the slave communication unit (11-2) communicates with the master communication unit (11-1) via PLC, and the master communication unit (11-1) communicates with the transport vehicle controller (15). In addition, when the transport vehicle controller (15) controls each device such as a motor, a sensor, etc. in the gripper unit (13) or transmits information, the transport vehicle controller (15) communicates with the master communication unit (11-1) in the opposite manner to the above-mentioned communication flow, and the master communication unit (11-1) communicates with the slave communication unit (11-2) via PLC, and the slave communication unit (11-2) communicates with the gripper unit (13). The gripper unit (13) then performs a process of communicating with the motor, the sensor, etc. located inside the gripper (13-2) through the gripper controller (13-1).

[0008] The motors and various sensors located inside the gripper (13-2) constantly transmit information to the gripper controller (13-1) and receive commands through the gripper controller (13-1). The gripper controller (13-1) also issues commands to the motors and various sensors inside the gripper (13-2), collects information received from the motors and various sensors of the gripper (13-2) and transmits it to the upper side.

[0009] At this time, the motors and various sensors inside the gripper each have a different control and require a different communication system, while the hoist (11) communicates only through one communication system using one wired transmission line, so the gripper controller (13-1) must collect and integrate information from the internal devices of the gripper (13-2) into one communication system and transmit it. The transport vehicle controller (15) must have one communication system and transmit commands and information to the gripper controller (13-1) through the master communication unit (11-1) and the slave communication unit (11-2).

[0010] In such a structure where communication is performed through a single transmission line, periodic communication is generally performed in which devices communicate with each other at regular time intervals. Therefore, all devices that need real-time control and communication to notify of emergencies and devices that need to be controlled and communicated at regular intervals must be in one communication system, which not only causes various control problems but also creates communication delays because the communication performance required for each communication system is subordinate to the "communication system that transmits after gathering," and when real-time data transmission is required in a periodic communication system, it can cause limitations in system operation, such as operational delays. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Korean Patent No. 10-2020662 (Title: Communication method between master communication device and slave communication device for controlling gripper unit in hoist device for transport cart) Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been created in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a hoist communication device for a transport cart of an automatic transport system, in which a master communication unit and a slave communication unit of a hoist device perform power line communication using a single power line provided on a belt, but form multiple communication paths using different carrier frequencies, thereby enabling a transport cart controller to perform individual communication with motors and various sensors inside a gripper. [Means for solving the problem]

[0013] According to the present invention, there is provided a hoist communication device for a transporting platform of an automatic transporting system, in which a master communication unit connected to a transporting platform controller is connected to a slave communication unit connected to a gripper unit through a belt and the gripper unit is operated in response to a control signal from the transporting platform controller to perform a hoist operation. The hoist communication device for a transporting platform of an automatic transporting system includes: a master communication unit that, when a control signal including gripper device identification information corresponding to a destination is received from the transporting platform controller, assigns different carrier frequencies to the gripper device identification information, modulates the signal, and superimposes at least one modulated control signal on a power source to transmit the superimposed signal to a slave communication device through a power source line formed on the belt; and a slave communication unit that supplies power provided from the master communication unit to a gripper unit having a plurality of gripper devices performing a hoist operation, demodulates the modulated control signal using the carrier frequency, transmits the demodulated control signal to each gripper device corresponding to the identification information, and assigns different carrier frequencies to modulate signals applied from each gripper device, and transmits the modulated control signal to the master communication unit through a power source line formed on the belt.

[0014] The gripper device includes a gripper controller, at least one motor and at least one sensor connected to the gripper, and the slave communication unit communicates with the motor and sensor connected to the gripper through the gripper controller, directly with the motor and sensor, or communicates with the gripper device in a mixed form.

[0015] The master communication unit and the slave communication unit are characterized in that they simultaneously perform real-time communication and periodic communication with different gripper devices using different carrier frequencies.

[0016] The master communication unit and the slave communication unit divide and set carrier frequency sections according to the communication system, and are characterized in that the carrier frequency section allocated to real-time communication and the carrier frequency section allocated to periodic communication are set to different frequency sections.

[0017] The master communication unit and the slave communication unit analyze a signal transmission / reception waveform of the carrier frequency when transmitting and receiving each other through the carrier frequency, detect a transmission level and a reception level, and transmit the detected levels to the other side, respectively. The master communication unit and the slave communication unit set their own transmission signal level and reception gain for the carrier frequency based on a difference between the transmission level and reception level of the other side.

[0018] The master communication unit and the slave communication unit analyze a transmission / reception waveform of the carrier frequency to detect a noise level for the carrier frequency, and if the detected noise level is less than a reference value, further adjust a transmission signal level and a reception gain in proportion to the current noise level, and if the detected noise level exceeds the reference value, reallocate the carrier frequency for the destination to another carrier frequency in a dormant state, or adjust the transmission signal level and the reception gain.

[0019] The master communication unit or the slave communication unit adds checksum information to a signal transmitted through a power line in order to detect an error in the signal, modulates the signal, and transmits the signal. If an error occurs in the checksum information when demodulating a received signal, the master communication unit or the slave communication unit performs a data recovery process by analyzing a received signal strength indicator (RSSI) pattern of the waveform of the received signal and changing bit data at a position where a difference of a reference level or more occurs between the previous RSSI pattern and the signal.

[0020] The master communication unit and the slave communication unit are each configured with a motion sensor that detects the degree of movement of each position, and the slave communication unit transmits slave motion information received from its own motion sensor to the master communication unit, and the master communication unit compares the master motion information received from its own motion sensor with the slave motion information to determine whether there is an abnormality in the gripper unit or the guide rail. When the master communication unit is stopped and a certain amount of movement or more is detected in the gripper communication unit, it is determined that there is an abnormality in the gripper unit, and when the master communication unit detects movement and the gripper communication unit detects a certain amount of movement or more, it is determined that there is an abnormality in the movement of the transport vehicle and an abnormality in the guide level. Effect of the Invention

[0021] According to the present invention, control signals required for hoisting operations are transmitted and received in the form of modulated signals through a single power line embedded in the belt, and multiple devices provided in the transport vehicle controller and gripper unit perform individual communication with each other, allowing the transport vehicle controller to perform optimal communication with each device having a different communication protocol provided in the gripper. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a transport vehicle in a conventional automatic transport system. [Diagram 2] 2 is a block diagram showing the internal configuration of the transport vehicle shown in FIG. 1 in a functionally separated manner. FIG. [Diagram 3] 1 is a diagram illustrating a schematic configuration of a hoist communication device for a transporting carriage of an automatic transport system according to the present invention; [Figure 4] 4 is a diagram showing the internal configuration of the master communication unit in FIG. 3 in a functionally separated manner. [Diagram 5] 5 is a diagram illustrating a signal measuring method performed in a first signal measuring unit of FIG. 4; [Figure 6] 5 is a diagram for explaining a method of automatically restoring data based on checksum information in a first control unit of FIG. 4; [Figure 7] 4 is a diagram showing the internal configuration of the slave communication unit in FIG. 3 in a functionally separated manner. [Figure 8] 1 is a diagram illustrating a hoist communication method for a transport vehicle of an automatic transport system according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hoist communication device for a transport platform of an automatic transport system according to the present invention will be described in detail with reference to the accompanying drawings.

[0024] In the drawings, the same components are indicated by the same reference numerals whenever possible. Meanwhile, the terms and words used in the present specification and claims should not be interpreted limitedly to their ordinary or dictionary meanings, but should be interpreted to have meanings and concepts that correspond to the technical ideas of the present invention, based on the principle that the inventor can appropriately define the concepts of terms in order to best describe his / her invention. Therefore, the embodiments described in the present specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention, and do not represent the entire technical ideas of the present invention, and various equivalents and modifications that can be substituted therefor are possible at the time of filing this application.

[0025] Fig. 3 is a diagram illustrating the main components of a hoist communication device in rail car of an automated material handling system according to the present invention. As shown in Fig. 3, the hoist communication device in rail car of an automated material handling system according to the present invention includes a master communication unit (100) that communicates with a transport vehicle controller (30) and a slave communication unit (200) that communicates with a gripper unit (50), and the master communication unit (100) and the slave communication unit (200) perform power line communication through one power line (L) provided on the belt.

[0026] At this time, the transport vehicle controller (30) controls the overall operation of the transport vehicle, transmits information for power supply and gripper control to the gripper unit (50) through the hoist communication device, and the gripper unit (50) collects information related to gripper operation through the hoist communication device. The master communication unit (100) is a device provided on the master side of the hoist communication device, and transmits power supply and control signals for carrier transfer or transportation to the slave communication unit (200) through the power line (L) provided on the belt. At this time, the master side is provided with a lifting body (not shown) including a motor for lifting and lowering the belt.

[0027] The slave communication unit 200 is a device provided on the slave side of the hoist communication device, and provides power supplied through a power line L provided on the belt to the driving power source of the gripper unit 50, and also provides a control signal for carrier transfer or transportation received from the master communication unit 100 to the gripper unit 50, thereby operating the gripper 52 in response to the control signal. Also, the slave communication unit 200 transmits status information of the gripper unit 50 to the master communication unit 100.

[0028] The gripper unit (50) includes a gripper controller (51) and a number of gripper devices including at least one motor (52-1) and at least one sensor (52-2) provided in the gripper (52), and may include a number of additional devices required when the gripper (52) transports a carrier. At this time, the motor (52-1) is not a simple motor, but is a device that includes a control device required for motor control and is controlled by the transport vehicle controller, and the sensor (52-2) is not a simple sensor, but is a device that includes a control device for controlling gripper peripheral devices using the sensor and is controlled by the transport vehicle controller.

[0029] The motor 52-1 and the sensor 52-2 may have different communication protocols, and may be set to different communication systems for transmitting information in real time or periodically depending on the position of the motor 52-1 and the type of the sensor 52-2. For example, the motor 52-1 may transmit driving information to the transport vehicle controller 30 through the hoist communication device in real time, and the first to third sensors 52-2 may transmit gripper status information to the transport vehicle controller 30 periodically through the hoist communication device.

[0030] That is, the present invention has a main feature in that the master communication unit (100) and the slave communication unit (200) perform power line communication through one power line (L) installed on the belt, but perform individual communication with a number of gripper devices using different communication systems, and the master communication unit (100) and the slave communication unit (200) can simultaneously perform real-time communication and periodic communication with different gripper devices using different carrier frequencies.

[0031] In addition, when communicating with the gripper unit (50), the transport vehicle controller (30) controls only one motor (52-1) in the gripper device, controls multiple motors (52-1), receives sensing information from one sensor (52-2), or receives sensing information from multiple sensors (52-2), and performs communication with the gripper unit (50) in various combinations depending on the purpose of use.

[0032] In other words, the present invention can be applied to and implemented in all of the following structures: a transport vehicle controller (30) communicates with a gripper device via a gripper controller (51) through a hoist communication device as shown in FIG. 3(A); a transport vehicle controller (30) communicates with a gripper device via a gripper controller (51) through a hoist communication device as shown in FIG. 3(B) and also communicates directly with a gripper device including a motor (52-1) and a sensor (52-2); or a transport vehicle controller (30) only communicates directly with a gripper device via a hoist communication device as shown in FIG. 3(C).

[0033] In addition, in the present invention, the master communication unit (100) and the slave communication unit (200) may perform one-way communication using the same carrier frequency, or the master communication unit (100) and the slave communication unit (200) may perform bidirectional communication through one power line (L) by setting different frequency ranges for the carrier frequency assigned to the master communication unit (100) and the carrier frequency assigned to the slave communication unit (200).

[0034] Fig. 4 is a block diagram showing the internal configuration of the master communication unit (100) shown in Fig. 3, separated functionally. As shown in Fig. 4, the master communication unit (100) includes a first communication unit (110), a first carrier allocation unit (120), a first modulation / demodulation unit (130), a first power supply unit (140), a first transmission / reception unit (150), a first filter unit (160), a first signal measurement unit (170), a first sensor (180), and a first control unit (190).

[0035] The first communication unit (110) is an interface means for communicating with the transport vehicle controller (30), and includes a parallel communication unit having a number of communication ports (Port#1 to Port#n) for performing parallel communication, and a serial communication unit having a number of communication ports (Port#1 to Port#n) for performing serial communication. The first carrier wave allocation unit (120) allocates a carrier frequency for modulating a signal to be transmitted to the gripper unit (50) under the control of the first control unit (190), and also allocates a carrier frequency for demodulating a demodulated signal received through the power line (L).

[0036] The first modulation / demodulation unit (130) modulates a signal applied from the first control unit (190) using a carrier frequency selected by the first carrier allocation unit (120) and outputs the modulated signal to the first transceiver unit (150), and also demodulates the modulated signal received from the first transceiver unit (150) and transmits it to the transport vehicle controller (30). The first power supply unit (140) supplies power supplied from the outside including the transport vehicle controller (30) to the driving power of the master communication unit (100) and also to the gripper unit (50) through the power line (L). At this time, the first power supply unit (140) can measure the voltage level of the signal transmitted through the transmission line (L) and transmit it to the first control unit (190).

[0037] The first transceiver (150) transmits at least one modulated signal modulated by the first modem (130) to a first filter (160) and transmits a modulated signal received from the first filter (160) to the first modem (130). The first filter (160) transmits a master modulated signal, which is carried on a carrier frequency different from that of the first transceiver (150), to a transmission line (L) and filters a slave modulated signal received through the transmission line (L) according to the carrier frequency and transmits it to the first transceiver (150). At this time, a number of first filters (160) are provided corresponding to the allocatable carrier frequencies. For example, when power line communication is performed using first to Nth carrier frequencies through the power line (L), first to Nth filters are provided.

[0038] The first signal measuring unit (170) measures the signal level and noise level of each carrier frequency for the slave modulated signal received through the power line (L) and the master modulated signal transmitted through the transmission line (L) in real time, and provides them to the first control unit (190). That is, as shown in Fig. 5, the communication period (25 ms) of the modulated signal transmitted and received through the power line (L) includes a transmission signal (T), a reception signal (R) and a standby period (S), and the first signal measuring unit (170) repeatedly measures a Received Signal Strength Indicator (RSSI) at position (1) of Fig. 5 during each communication between the master communication unit (100) and the slave communication unit (200) and detects a transmission signal level in real time based on the average value, repeatedly measures the RSSI at position (2) of Fig. 5 and detects a reception signal level in real time based on the average value, and repeatedly measures the RSSI at position (3) of Fig. 5, extracts the maximum and minimum values, and detects the noise level using the difference value.

[0039] The first sensor 180 may be composed of at least one sensor for detecting the hoist state on the master side, and in particular includes a motion sensor for detecting the movement state. The first control unit 190 controls the overall operation of the master communication unit 100, and includes a memory for storing various reference information including carrier frequency bands and whether each carrier frequency is assigned, and various information processed by the first control unit 190.

[0040] The first control unit (190) modulates the data to be transmitted to the slave communication unit (200) using different carrier frequencies according to the destination of the data, and then transmits the modulated data to the slave communication unit (200). The first control unit (190) provides, in the header area of ​​the transmission packet, one identification code corresponding to a destination among a number of gripper devices provided in the gripper unit (50).

[0041] At this time, the first control unit 190 sequentially assigns one of the currently paused carrier frequencies, obtains a noise level for each carrier frequency of the signal being transmitted and received, and if the noise level is above a certain level, assigns another currently paused carrier frequency or adjusts the transmission level and reception gain to perform data transmission. Here, if a communication leak occurs during periodic communication, the first control unit 190 checks the noise level for the corresponding carrier frequency after stopping the communication, and if the noise level is below a preset reference level, resumes communication, and if the noise level is above the reference level, assigns a new carrier frequency to the periodic communication.

[0042] In addition, the first control unit 190 receives slave transmission level, slave reception level and noise level information for each carrier frequency currently being transmitted and received from the slave communication unit 200, and adjusts the transmission level and reception gain based on the difference between the slave transmission level and the slave reception level. For example, if the slave transmission level is greater than the slave reception level by a preset reference level or more, the first control unit 190 adjusts the master transmission signal level and reception gain to be weak, and if the slave transmission level is less than the slave reception level by a preset reference level, the first control unit 190 adjusts the master transmission signal level and the slave reception gain to be strong, so that the transmitted and received signals in the slave communication unit 200 have the same signal strength even in an environment where the power supply level state and the power line communication environment change from time to time due to belt movement, etc.

[0043] In addition, the first control unit 190 can finely adjust the strength of the master transmission signal in consideration of the electrical safety of the device, including circuit damage, when adjusting the master transmission signal level and the reception gain. The first control unit 190 can also cumulatively analyze the difference between the slave transmission level and the slave reception level to distinguish between a noiseless state and a noisy state, and can finely adjust the master transmission signal, change the carrier frequency, or finely adjust the reception gain depending on the presence or absence of noise.

[0044] Also, the first control unit (190) generates checksum information for error detection for the control signal provided to the slave communication unit (200), provides it to the first modem unit (140), and controls it to be added to the data packet of the control signal for modulation. If an error occurs in the checksum information received from the slave communication unit (200), the first control unit (190) analyzes the signal waveform of the received signal to automatically restore the data. That is, the first control unit (190) first measures the power line transmission / reception waveform (FIG. 6(1)) when transmitting / receiving a signal from the slave communication unit (200), analyzes the RSSI value pattern (FIG. 6(2)) from the power line transmission / reception waveform (FIG. 6(1)) when a checksum error occurs, checks the noise position bit (circled symbols a, b in FIG. 6(2)) with a high relative difference from the previously checked RSSI value in the RSSI value, and changes the data of the bit (0⇔1). For example, if the bit data corresponding to the noise position of the received signal is "1," it is changed to "0," and if it is "0," it is changed to "1." Then, after restoring the received data by referring to the previously received data, the checksum information is checked, and if the checksum is normal, a reception success process is performed.

[0045] Also, the first control unit (190) provides the transport vehicle controller (30) with a demodulated signal from the first modem unit (130). At this time, the demodulated signal can be a response signal for the hoist operation received from the slave communication unit (200), communication status information, operation status information, etc. In addition, the first control unit (190) monitors the status of the transport vehicle or the guide rail by comparing master motion information collected from the first sensor (180), more specifically, the motion sensor, with slave motion information received from the slave communication unit (200). That is, if the slave communication unit (200) detects a certain amount of movement, such as a left-right swing or impact, while the master communication unit (100) is stopped, it can be determined that the gripper unit (50) is in an abnormal state, and if the slave communication unit (200) detects a certain amount of movement, such as a downward movement or left-right swing, while the master communication unit (100) detects a movement, it can be determined that the transport vehicle is in an abnormal state and the guide level is in an abnormal state or above. If it is determined that an abnormality has occurred in the transport vehicle or the guide rail, this can be reported to the manager's terminal or a higher level, and a request can be made to perform maintenance on any parts that may cause problems in the movement of the transport vehicle at a timely manner.

[0046] Fig. 7 is a block diagram showing the internal configuration of the slave communication unit (200) shown in Fig. 4 in a functionally separated manner. As shown in Fig. 7, the slave communication unit (200) includes a second communication unit (210), a second carrier allocation unit (220), a second modulation / demodulation unit (230), a second power supply unit (240), a second transmission / reception unit (250), a second filter unit (260), a second signal measurement unit (270), a second sensor (280), and a second control unit (290), and has the same components as the master communication unit (100), except that the second communication unit (210) is configured to communicate with a plurality of gripper devices or gripper controllers provided in the gripper unit (50). Hereinafter, the configuration and function of devices performing the same functions as the master communication unit (100) will be omitted.

[0047] In FIG. 7, the second sensor (280) may include a motion sensor as well as a gyro sensor, an acceleration sensor, a tilt sensor, etc., and may detect the belt's travel distance, travel speed, left / right sway, impact, etc., using these sensors, and provide the information to the second control unit (290).

[0048] The second control unit (290) sets up communication paths between the multiple gripper devices and the transport vehicle controller (30) using different carrier frequencies, similar to the first control unit (190) of the master communication unit (100), and controls to perform power line communication through the power line (L) by allocating a carrier frequency in a dormant state. At this time, the second control unit (290) controls to modulate various slave information including slave communication state information including slave transmission level, slave reception level and noise level for each carrier frequency, slave state information sensed by the second sensor unit (280), and response information corresponding to a control signal received from the master communication unit (100) using different carrier frequencies, and then transmits the modulated information to the master communication unit (100) through the power line (L).

[0049] In addition, the second control unit (290) demodulates the control signal for operating the gripper unit (50) applied from the master communication unit (100) according to the carrier frequency, extracts an identification code corresponding to the destination from the demodulated data packet, and directly transmits the data packet to the gripper device corresponding to the extracted identification code.

[0050] Next, the operation of the hoist communication device for the transporting carriage in the automatic transport system having the above-mentioned configuration will be described with reference to the flow chart shown in FIG.

[0051] In the following, the communication method between the master communication unit (100) and the slave communication unit (200) will be described by applying it to the lowering operation of the gripper unit (50).

[0052] When the transport vehicle moves along the rails and stops at the manufacturing facility where the work is to be performed, the master communication unit (100) drives the belt to lower the gripper unit (50) to the manufacturing facility. In the above-mentioned state, the master communication unit (100) supplies a constant level of power supplied from the outside through the power line (L) formed on the belt to the slave communication unit (200) under the control of the transport vehicle controller (30), and the slave communication unit (200) sets the gripper unit (50) to an operation standby state (ST10).

[0053] In the above-mentioned state, when the master communication unit (100) receives master information for a hoist operation from the transport vehicle controller (30), it assigns one of the carrier frequencies in the pause state, for example, the first carrier frequency, modulates the master information using the assigned first carrier frequency, superimposes the modulated master information on the power supply, and transmits it to the slave communication unit (200) through the power supply line (L) (ST20, ST30). At this time, the transport vehicle controller (30) provides gripper control information including a gripper device ID for receiving the data to the master communication unit (100), and the master communication unit (100) transmits the master information including the gripper device ID to the slave communication unit (200).

[0054] At this time, the carrier frequency band can be preset so that the carrier frequency range is divided into a first section and a second section according to the communication system, and in step ST20, the master communication unit (100) assigns a pause carrier frequency of a section corresponding to the communication system corresponding to the gripper device ID. For example, the first section can be set as a carrier frequency range set when performing real-time communication with the motor of the gripper unit (50), and the second section can be set as a carrier frequency range set when performing periodic communication with the sensor of the gripper unit (50).

[0055] Also, the master communication unit 100 can add checksum information for checking errors to a packet including the master information and transmit it to the slave communication unit 200. Also, the master communication unit 100 transmits data through the power line L in step ST30 and detects a master transmission level by analyzing a transmission signal waveform for the first carrier frequency (ST40).

[0056] Meanwhile, the slave communication unit 200 demodulates the master information received through the power line L to the carrier frequency and transmits the demodulated gripper control signal to the gripper device corresponding to the ID to operate the gripper unit 50 (ST50). For example, the slave communication unit 200 can transmit the demodulated data to the motor 52-1, the sensor 52-2, or the gripper controller 51.

[0057] In step ST50, the slave communication unit (200) checks the checksum information of the packet, and when a checksum error occurs, analyzes the RSSI pattern of the waveform of the master reception signal and changes the bit data at a position having an RSSI difference value greater than a preset reference level, thereby automatically restoring the master information.

[0058] In addition, the slave communication unit 200 detects a slave reception level by analyzing the waveform of the reception signal for the carrier frequency received through the power line L in step ST50 (ST60). The slave communication unit 200 also assigns a carrier frequency in a dormant state to modulate the slave information, and transmits it to the master communication unit 100 through the power line L (ST70). At this time, the slave information is response information to the master information received in step ST30, or includes gripper status information detected by the sensor 52-2.

[0059] In step ST70, the slave communication unit (200) generates and transmits a packet including a gripper device ID, and can transmit in real time or periodically according to the gripper device ID, and a dormant carrier frequency is assigned in a pre-set carrier frequency region based on this communication system. Then, the master communication unit (100) demodulates the slave information received through the slave communication unit (200) using the carrier frequency, and transmits it to the transport vehicle controller (30) (ST80).

[0060] Meanwhile, the slave communication unit 200 transmits slave information through the power line L in step ST70 and detects a slave transmission level by analyzing a transmission signal waveform for the carrier frequency (ST90). The slave communication unit 200 then transmits the slave reception level for the carrier frequency detected in step ST60 and the slave transmission level information for the carrier frequency detected in step ST90 to the master communication unit 100 (ST100). At this time, the slave communication unit 200 can transmit the slave transmission level and reception level information to the master communication unit 100 at a first carrier frequency corresponding to the transmission / reception level information.

[0061] The master communication unit 100 detects a master reception level for the carrier frequency by analyzing a slave signal waveform received through the slave communication unit 200 (ST110). The master communication unit 100 determines a master transmission signal level to be transmitted to the carrier frequency using the slave reception level and transmission level received in step ST100 (ST120). At this time, the master communication unit 100 can set a transmission level and a reception gain so that a signal level transmitted and received through the carrier frequency is kept constant based on a difference between the slave transmission level and the slave reception level for the carrier frequency.

[0062] In addition, in step ST120, the master communication unit (100) detects the noise level for the carrier frequency, and if no noise is detected, sets the signal transmission level based on the difference between the slave transmission level and the slave reception level, and if a noise level is detected, further adjusts the transmission signal level higher in proportion to the noise level.

[0063] In step ST120, if the noise level of the carrier frequency exceeds a preset standard, the master communication unit 100 can assign a new idle carrier frequency to the destination or adjust the transmission level and reception gain.

[0064] In addition, the master communication unit 100 transmits the master transmission level of the carrier frequency detected in step ST40 and the master reception level information detected in step ST110 to the slave communication unit 200 (ST130). At this time, the master communication unit 100 transmits the master transmission / reception level information at the transmission level of the corresponding carrier frequency set in step ST120. Meanwhile, the slave communication unit 200 sets the slave transmission level and reception gain so that the transmission / reception level is maintained constant based on the difference between the master transmission level and the master reception level for the corresponding carrier frequency received in step ST130, and thereafter transmits slave information based on the previously set slave transmission level for the corresponding carrier frequency (ST140).

[0065] In step ST140, the slave communication unit 200, like the master communication unit 100, can reset the slave transmission level and reception gain or reallocate the carrier frequency, taking into account the noise level of the carrier frequency.

[0066] In addition, the slave communication unit (200) receives a status detection signal provided from the second sensor unit (280) and transmits the status detection signal level to the master communication unit (100) using a carrier frequency at a fixed period, and the master communication unit (100) detects an abnormal state of the transport vehicle or the guide rail by analyzing the slave status information received from the slave communication unit (200) and the master status information sensed through the first sensor unit (180). When an abnormal state is detected, the master communication unit (100) can perform an abnormal state alarm process by transmitting the abnormal state to the transport vehicle controller (30). [Explanation of symbols]

[0067] 1 Rail 2 Manufacturing equipment 3. Career 10 Transport cart 11 Hoist 11-1 Master communication unit 11-2 Slave communication unit 12 Belt 13 Gripper unit 13-1 Gripper controller 13-2 Gripper 15 Transport vehicle controller 30 Transport vehicle controller 50 Gripper Unit 51 Gripper controller 52 Gripper 52-1 Motor 52-2 Sensor 100 Master Communication Unit 200 Slave communication unit 110, 210 Communications Department 120, 220 Carrier allocation section 130, 230 Modulation and demodulation section 140, 240 Power supply section 150, 250 Transmitter / Receiver 160, 260 Filter section 170, 270 Signal measurement section 180, 280 Sensor 190, 290 Control unit L Power line

Claims

1. A hoist communication device for a transport vehicle of an automatic transport system, in which a master communication unit connected to a transport vehicle controller is connected to a slave communication unit connected to a gripper unit through a belt, and the gripper unit is operated according to a control signal from the transport vehicle controller to perform a hoist operation, a master communication unit that, when a control signal including gripper device identification information is received from the transport vehicle controller, assigns different carrier frequencies to the gripper device identification information, modulates the carrier frequencies, and transmits at least one modulated control signal to a slave communication device through a power line formed on a belt by superimposing the control signal on a power source; a slave communication unit that supplies power provided from the master communication unit to a gripper unit having a plurality of gripper devices performing a hoisting operation, demodulates a modulated control signal using the carrier frequency, transmits the demodulated control signal to each gripper device corresponding to the identification information, and assigns different carrier frequencies to signals applied from each gripper device to modulate the signals, and then transmits the signals to the master communication unit through a power line formed on the belt; A hoist communication device for a transport cart of an automatic transport system, characterized in that the transport cart controller and a plurality of gripper devices provided in the gripper unit perform individual communication with each other.

2. the gripper device includes a gripper controller, at least one motor coupled to the gripper, and at least one sensor; 2. The hoist communication device for a transport vehicle of an automatic transport system according to claim 1, wherein the slave communication unit communicates with a motor and a sensor connected to a gripper through a gripper controller, directly communicates with the motor and the sensor, or communicates with a gripper device in a mixed form.

3. 2. The hoist communication device for a transport vehicle of an automatic transport system according to claim 1, wherein the master communication unit and the slave communication unit simultaneously perform real-time communication and periodic communication with different gripper devices using different carrier frequencies.

4. 4. A hoist communication device for a transport vehicle of an automatic transport system as described in claim 3, characterized in that the master communication unit and the slave communication unit divide and set carrier frequency sections according to the communication system, and the carrier frequency section allocated to real-time communication and the carrier frequency section allocated to periodic communication are set to different frequency sections.

5. When the master communication unit and the slave communication unit transmit and receive signals to each other through a carrier frequency, the master communication unit and the slave communication unit analyze a signal transmission / reception waveform of the corresponding carrier frequency to detect a transmission level and a reception level, and then transmit the detected levels to the other side, 2. A hoist communication device for a transport platform of an automatic transport system as described in claim 1, wherein the master communication unit and the slave communication unit set their own transmission signal level and reception gain for the carrier frequency based on the difference between the transmission level and reception level of the other side.

6. The master communication unit and the slave communication unit analyze the signal transmission and reception waveform of the carrier frequency to respectively detect the noise level for the carrier frequency; If the detected noise level is less than the reference value, the transmission signal level and the reception gain are further adjusted in proportion to the current noise level; The hoist communication device for a transport cart in an automatic transport system as described in claim 5, characterized in that if the detected noise level exceeds a reference value, the carrier frequency is reallocated to another carrier frequency in a dormant state, or a transmission signal level and a receiving gain are adjusted.

7. The master communication unit or the slave communication unit adds checksum information to the signal to be transmitted through the power line in order to detect errors in the signal, modulates the signal, and transmits the signal.

2. The hoist communication device for a transport platform of an automatic transport system according to claim 1, wherein, when an error occurs in checksum information when demodulating a received signal, an RSSI (Received Signal Strength Indicator) pattern of the waveform of the received signal is analyzed, and bit data at a position where a difference of a reference level or more occurs with respect to a previous RSSI pattern is changed to perform data restoration processing.

8. The master communication unit and the slave communication unit each include a motion sensor for detecting the degree of movement of the respective positions, The slave communication unit transmits slave motion information received from its motion sensor to the master communication unit; 2. The hoist communication device for a transport vehicle of an automatic transport system according to claim 1, wherein the master communication unit compares the master motion information and the slave motion information received from its own motion sensor to determine whether there is an abnormality in the gripper unit or the guide rail, and when the gripper communication unit detects a certain amount of movement while the master communication unit is stopped, it determines that there is an abnormality in the gripper unit, and when the gripper communication unit detects a certain amount of movement while the master communication unit detects movement, it determines that there is an abnormality in the transport vehicle movement and the guide level.

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