Article transport apparatus

Abstract

The transport vehicle control system limits the travel speed of the transport vehicle to a predetermined limit speed or less when the temperature (TH) of the regenerative resistor detected by the temperature sensor is a first temperature (TH1) or more, which is set to a temperature higher than a constant temperature range that is a temperature range of a constant state prescribed in advance, and cuts off the connection of the power supply unit to the travel motor by a switch when the temperature (TH) of the regenerative resistor detected by the temperature sensor is a second temperature (TH2) or more, which is set to a temperature higher than the first temperature (TH1).

Description

TECHNICAL FIELD

[0001] The present application relates to an article transport apparatus provided with an article transport vehicle that travels along a travel path and transports an article. BACKGROUND

[0002] As for the article transport vehicle, there is known an article transport vehicle that receives electric power supply from a power feeding line provided along a travel path and travels while driving a motor or the like. The motor functions as a generator at the time of deceleration, but since regenerated electric power by the generation cannot be returned to the power feeding line, sometimes the electric power is consumed by a resistor (regenerative resistor) or the like. In Japanese Patent Application Laid-Open No. 3-150083, a regenerative resistor (3) is provided on the direct current side of an inverter (7) that drives an alternating current rotary electric machine, and a regenerative current is caused to flow to the regenerative resistor (3), thereby causing the regenerated electric power to be consumed (in the background art, the symbols in parentheses are symbols of the document referred to.). The regenerative resistor heats up due to the flow of the regenerative current. If the temperature of the regenerative resistor rises exceeding a rated temperature, it is likely to cause a failure of the regenerative resistor or the like, and thus, for example, a control is considered in which the inverter is stopped by a temperature sensor detecting that the temperature of the regenerative resistor excessively rises. However, if the article transport vehicle stops due to the stop of the inverter, the article transport vehicle becomes to block the travel path, and thus, during the period until the article transport vehicle is removed, other article transport vehicles become unable to pass through the path thereof, and the efficiency of the system as a whole decreases. Therefore, in Japanese Patent Application Laid-Open No. 3-150083, a scheme is proposed in which the energization time of the regenerative resistor is metered, the temperature rise of the regenerative resistor is inferred, and the regenerated electric power of the inverter is suppressed. SUMMARY

[0003] The greater the regenerative current, the faster the temperature of the regenerative resistor rises; the longer the time during which the regenerative current flows, the faster the temperature of the regenerative resistor rises. In addition, even if the temperature rises are the same, if the ambient temperature is low, the time until the rated temperature is exceeded becomes long, and if the ambient temperature is high, the rated temperature is reached in a short time. Therefore, merely metering the energization time of the regenerative resistor is insufficient in properly inferring the temperature of the regenerative resistor.

[0004] In view of the above-described background, it is desirable to provide a technology that suppresses a decrease in the efficiency of the system and properly controls the system in accordance with the temperature of the regenerative resistor.

[0005] As one mode, in the above-described article transport apparatus provided with the article transport vehicle that travels along a travel path and transports an article, the article transport apparatus is provided with a transport vehicle control system that controls the article transport vehicle, the article transport vehicle is provided with: a travel motor that drives a wheel; a power supply section that supplies electric power to the travel motor; a regenerative resistor that is supplied with regenerative electric power generated when the travel motor regenerates; a temperature sensor that detects a temperature of the regenerative resistor; and a switch that is disposed in an electric connection path of the power supply section and the travel motor and can cut off supply of electric power from the power supply section to the travel motor, and the transport vehicle control system limits a travel speed of the article transport vehicle to be lower than a predetermined limit speed in a case where the temperature sensor detects that the temperature of the regenerative resistor is a first temperature or more that is set to be higher than a temperature range, i.e., a constant temperature range, of a constant state that is prescribed in advance, and cuts off connection of the power supply section and the travel motor by the switch in a case where the temperature sensor detects that the temperature of the regenerative resistor is a second temperature or more that is set to be higher than the first temperature.

[0006] According to the configuration, the temperature of the regenerative resistor including an influence of an ambient temperature is detected by the temperature sensor, and two different control states are selected and the article transport vehicle is controlled based on the detected temperature. That is, the control state is selected depending on whether the regenerative resistor is the first temperature or more or the second temperature or more that is higher than the first temperature. In a case where the temperature of the regenerative resistor is the second temperature or more, the electric connection of the power supply section and the travel motor is cut off by the switch. In a case where the temperature of the regenerative resistor is the first temperature or more and less than the second temperature, the electric connection of the power supply section and the travel motor is not cut off, and the article transport vehicle continues to travel in a state where the travel speed of the article transport vehicle is limited to be lower than the limit speed. As such, in a stage before the electric connection of the power supply section and the travel motor is cut off, the travel speed of the article transport vehicle is limited, and thus it is possible to maintain the travel of the article transport vehicle while suppressing an increase in the temperature of the regenerative resistor. Therefore, it is possible to reduce the possibility that the travel of the article transport vehicle is stopped due to an increase in the temperature of the regenerative resistor, and to suppress a decrease in the transport efficiency of the article transport apparatus. In addition, according to the present configuration, the actual temperature of the regenerative resistor is detected by the temperature sensor, not a predicted value, and thus it is possible to appropriately control the article transport vehicle depending on the temperature of the regenerative resistor even if the ambient temperature changes. As such, according to the present configuration, it is possible to suppress a decrease in the system efficiency while appropriately controlling the system depending on the temperature of the regenerative resistor.

[0007] Further features and advantages of the article transport apparatus will become apparent from the following description of embodiments with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1is a plan view of the article transport apparatus;

[0009] Figure 2 is a side view of the article transport vehicle;

[0010] Figure 3 is a front view of the article transport vehicle;

[0011] Figure 4 is a diagram showing an example of transferring an article by the article transport vehicle;

[0012] Figure 5 is a schematic block diagram showing the configuration of the article transport apparatus;

[0013] Figure 6 is a circuit block diagram showing one example of the power receiving portion and the traveling motor drive circuit;

[0014] Figure 7 is a flowchart showing one example of the relationship between the temperature of the regenerative resistor and the control of the article transport vehicle;

[0015] Figure 8 is a flowchart showing one example of the relationship between the temperature of the regenerative resistor and the control of the article transport vehicle. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment of the article transport apparatus will be described based on the drawings. As shown in Figures 1 to 5 the article transport apparatus 200 is provided with a traveling rail 2 suspended and supported by a ceiling, disposed along a traveling path 1, and an article transport vehicle 3 suspended and supported by the traveling rail 2, which travels along the traveling path 1 on the traveling rail 2 and transports an article W. The article transport vehicle 3 transports, for example, a FOUP (Front Opening Unified Pod) that houses a semiconductor substrate or a reticle that houses a photomask, as the article W. In the present embodiment, a FOUP is exemplified as the article W. In addition, in the following description, a direction along the traveling path 1 is taken as a traveling direction Y, and a direction along a horizontal plane and orthogonal to the traveling direction Y is taken as a width direction X. A vertical direction Z is a direction orthogonal to the traveling direction Y and the width direction X.

[0017] the article transport apparatus 200 is provided with a traveling rail 2 suspended and supported by a ceiling, disposed along a traveling path 1, and an article transport vehicle 3 suspended and supported by the traveling rail 2, which travels along the traveling path 1 on the traveling rail 2 and transports an article W. The article transport vehicle 3 transports, for example, a FOUP (Front Opening Unified Pod) that houses a semiconductor substrate or a reticle that houses a photomask, as the article W. In the present embodiment, a FOUP is exemplified as the article W. In addition, in the following description, a direction along the traveling path 1 is taken as a traveling direction Y, and a direction along a horizontal plane and orthogonal to the traveling direction Y is taken as a width direction X. A vertical direction Z is a direction orthogonal to the traveling direction Y and the width direction X. Figure 1As shown, the travel path 1 is provided with, for example, one main path 1M in a ring shape, a plurality of sub-paths 1S in a ring shape via a plurality of processing devices 202, and connection paths connecting the main path 1M and the sub-paths 1S. With respect to the article transport vehicle 3, the travel path 1 is one-way, and the article transport vehicle 3 travels in the travel path 1 from the upstream side toward the downstream side in the travel direction. In addition, in the travel path 1, there are included a transport area E1, which is an area through which the article W passes in a case where the article W is transported, and a maintenance area E2, which is an area through which the article transport vehicle 3 passes in a case where maintenance of the article transport vehicle 3 is performed. In the maintenance area E2, for example, a maintenance lift 204 for lowering the article transport vehicle 3 suspended from the travel rail 2 to the floor side is provided in order to perform maintenance.

[0018] As shown in Figure 2 and Figure 3 , the article transport vehicle 3 is provided with a travel portion 9 guided along the travel path 1 by a pair of travel rails 2 arranged suspended from a ceiling along the travel path 1, a vehicle body 10 located below the travel rail 2 and suspended supported by the travel portion 9, and a power receiving portion 4 that receives driving electric power from a power feeding line 11 provided along the travel path 1 without contact. In addition, in the vehicle body 10, there are provided an article holding portion 13 that suspends and holds the article W and a lifting portion 14 that lifts the article holding portion 13. As shown in Figure 2 and Figure 3 , the article transport vehicle 3 travels and transports the article W in a state in which the article holding portion 13 is lifted.

[0019] As shown in Figure 4 , the article transport apparatus 200 is provided with a load platform 203 provided on the floor surface 102 side and that loads the article W. The article transport vehicle 3 transfers the article W between the load platform 203 in a state in which the article holding portion 13 is lowered. The load platform 203 is provided at a plurality of locations of the article transport apparatus 200. For example, the load platform 203 is provided at each of the processing devices 202 or Figure 1 outside the article storage warehouse shown in the drawing.

[0020] In the present embodiment, as shown in Figure 3 , one article transport vehicle 3 is provided with two travel portions 9, and a common vehicle body 10 is suspended supported by each of the travel portions 9. The two travel portions 9 are of the same configuration, and, for example, each of the travel portions 9 is provided with a power receiving portion 4. The power receiving portion 4 corresponds to a power supply portion that supplies electric power to the article transport vehicle 3. Each of the travel portions 9 is arranged side by side along the travel direction Y of the article transport vehicle 3.

[0021] As shown in Figure 2 and Figure 3 , in each of the travel portions 9, there is provided an electrically driven travel actuator 35 (see Figure 5) a pair of traveling wheels 15 that are rotationally driven. The traveling actuator 35 is, for example, a motor (traveling motor). The traveling wheels 15 roll on traveling surfaces formed on respective upper surfaces of the traveling rails 2. In addition, in each traveling section 9, a pair of guide wheels 16 that freely rotate around an axis in the up-down direction Z (around an up-down axis) are provided in a state of abutting against inner side surfaces of the pair of traveling rails 2. In the conveyance vehicle body 10, as shown in Figure 5 FIG. 6, a lifting actuator 34 that lifts the article holding section 13, an article holding actuator 33 that drives the article holding section 13 that holds the article W by gripping, and the like, and a drive circuit that drives those actuators, and the like, are provided. These actuators are, for example, motors or solenoids, and the like.

[0022] The article conveyance vehicle 3 conveys the article W between different load tables 203 based on a conveyance instruction from a device control device H (MCP: Material Control Processor) that manages the entire article conveyance apparatus 200. In the present embodiment, the device control device H and each article conveyance vehicle 3 are configured so as to be able to communicate by wireless communication. Each article conveyance vehicle 3 is provided with a vehicle control section 31 that causes the article conveyance vehicle 3 to travel, stop above a designated load table 203, and lift the article holding section 13 by autonomous control based on the conveyance instruction, thereby transferring the article W.

[0023] In addition, in the traveling path 1, position markers B that show positions in the traveling path 1 are arranged along the traveling path 1. The article conveyance vehicle 3 is provided with a position detection sensor 32 (position detection section) that detects a position in the traveling path 1 using these plurality of position markers B. The position marker B can be, for example, a one-dimensional or two-dimensional bar code, or a marker on which numbers or letters are written. The position detection sensor 32 can be a bar code reader or an image recognition device, a letter recognition device that recognizes numbers or letters. Position information detected by the position detection sensor 32 is transmitted to the vehicle control section 31. The article conveyance vehicle 3 transmits the detected position information to the conveyance control section H1, and the conveyance control section H1 transmits a conveyance instruction generated based on the position information to the article conveyance vehicle 3.

[0024] As shown in Figure 5 In the present embodiment, as a conveyance vehicle control system 100 that controls the article conveyance vehicle 3, a conveyance control section H1 provided in a device control device H that controls conveyance of the article W by a plurality of article conveyance vehicles 3, and a vehicle control section 31 provided in each article conveyance vehicle 3 are included. Moreover, the device control device H and each article conveyance vehicle 3 are able to communicate bidirectionally.

[0025] In the present embodiment, the power receiving portion 4 supplies driving electric power to the article transport vehicle 3 using a wireless power feeding technology called HID (High Efficiency Inductive Power Distribution Technology). Specifically, a high-frequency current is caused to flow to the power feeding line 11 as an inductive line, causing a magnetic field to be generated around the power feeding line 11. The power receiving portion 4 is configured with a pickup coil 41 that is induced by electromagnetic induction from the magnetic field, or a magnetic core 42. The induced electric power is rectified by a full-wave rectification circuit 43 (refer to Figure 6 ). A smoothing capacitor 49 smoothes the pulsation generated by the full-wave rectification circuit 43.

[0026] In Figure 6 , an example is shown in which the travel actuator 35 for travel is driven by this electric power. That is, the power receiving portion 4 corresponds to a power supply portion that supplies electric power to the travel actuator 35 (travel motor). The travel actuator 35 is an alternating-current motor that is driven via the inverter 6, which converts direct-current electric power rectified by the full-wave rectification circuit 43 into alternating-current electric power. The inverter 6 is configured with a plurality of switching elements, and switches according to a switching control signal generated by the vehicle control portion 31 and input via a not-shown drive circuit, thereby converting electric power between direct current and alternating current.

[0027] The power receiving portion 4 and the inverter 6 are electrically connected via a contactor 90 disposed on the power receiving portion 4 side and a switch 8 disposed on the inverter 6 side. The contactor 90 is, for example, a circuit protector (circuit breaker), and the switch 8 is, for example, a magnetic contactor such as an electromagnetic relay. When at least one of the contactor 90 and the switch 8 is in an off state (cut-off state), the electrical connection of the power receiving portion 4 and the inverter 6 is cut off. Between the contactor 90 and the switch 8, for example, a DC / DC converter 48 is connected, which generates a voltage supplied to the vehicle control portion 31 or the position detection sensor 32 described later, and the like. If the contactor 90 is in an on state (on state), the DC / DC converter 48 is electrically connected to the power receiving portion 4, and can supply electric power to the vehicle control portion 31 or the position detection sensor 32 described later, and the like. Even if the contactor 90 is in an on state (on state), the switch 8 is disposed in the electrical connection path of the power receiving portion 4 and the travel actuator 35, and can cut off the supply of electric power from the power receiving portion 4 to the travel actuator 35.

[0028] However, if the transport vehicle 3 slows down, the driving motor, which acts as the driving actuator 35, functions as a generator, and regenerative current flows from the inverter 6 towards the power receiving unit 4. The regenerative current from the driving actuator 35, driven by power supplied from the feeder line 11, cannot return to the feeder line 11. Therefore, a regenerative resistor 5 is provided, which is supplied with the regenerative power generated during the regeneration of the driving actuator 35. The regenerative resistor 5 is connected between the positive and negative terminals of the DC side of the inverter 6, and the regenerative current is dissipated as heat.

[0029] Here, when a large amount of regenerative current is generated, the temperature of the regenerative resistor 5 rises. If the temperature of the regenerative resistor 5 exceeds its operating temperature range, there is a possibility of failure of the regenerative resistor 5 or its peripheral circuit. Therefore, a temperature sensor 7 is provided to detect the temperature of the regenerative resistor 5. In this embodiment, the temperature sensor 7 uses an NTC thermistor (whose resistance value decreases when the temperature rises). The temperature sensor 7 is connected in series with a voltage divider resistor 71 provided in the temperature detection circuit 70, and the voltage at the connection point of the temperature sensor 7 and the voltage divider resistor 71 is transmitted to the vehicle control unit 31 as a temperature detection value. As described above, the vehicle control unit 31 and the equipment control device H can communicate bidirectionally, and the temperature detection value can also be transmitted to the equipment control device H.

[0030] For example, if the temperature of the regenerative resistor 5 rises, the voltage of the temperature detection value increases. The vehicle control unit 31 can determine the state of the regenerative resistor 5 by comparing it with a predetermined threshold. Furthermore, if the temperature sensor 7 malfunctions, for example, if a short circuit occurs in the thermistor or its wiring, the resistance value of the temperature sensor 7 decreases, and the voltage of the temperature detection value increases. Conversely, if a break occurs in the thermistor or its wiring, the resistance value of the temperature sensor 7 increases, and the voltage of the temperature detection value decreases.

[0031] The transport vehicle control system 100 performs fail-safe control on the transport vehicle 3 based on temperature detection values. The temperature of the regenerative resistor 5, including the influence of ambient temperature, is appropriately detected by the temperature sensor 7, and the fail-safe control to be executed is selected based on the detected temperature value. When the temperature of the regenerative resistor 5 is detected by the temperature sensor 7 (TH (reference)... Figure 7When the temperature (TH) of the regenerative resistor 5 is set to be higher than a first temperature (TH1), which is higher than a predetermined constant temperature range, the transport vehicle control system 100 limits the travel speed of the transport vehicle 3 to a predetermined limit speed (first limit speed) or lower. Furthermore, when the temperature (TH) of the regenerative resistor 5 detected by the temperature sensor 7 is a second temperature (TH2), which is higher than the first temperature (TH1), the transport vehicle control system 100 disconnects the connection between the power receiving unit 4 and the travel actuator 35 using the switch 8. Additionally, when the temperature of the regenerative resistor 5 detected by the temperature sensor 7 is lower than a third temperature (TH3), which is lower than a predetermined constant temperature range, the transport vehicle control system 100 limits the travel speed of the transport vehicle 3 to a limit speed (second limit speed) or lower. Moreover, the first limit speed and the second limit speed can be the same speed or different speeds.

[0032] Figure 7 The flowchart illustrates an example of the relationship between the temperature (TH) of the regenerative resistor 5 and the control of the transport vehicle 3. The transport vehicle control system 100 (specifically, the vehicle control unit 31) determines whether the temperature (TH) of the regenerative resistor 5 is above a first temperature TH1 (#1). If it is determined to be above the first temperature TH1, it then determines whether the temperature (TH) of the regenerative resistor 5 is above a second temperature TH2 (#2). If it is determined that the temperature (TH) of the regenerative resistor 5 is below the second temperature TH2, the vehicle control unit 31 limits the travel speed, for example, to a first speed limit (#5). If it is determined in step #1 that the temperature is below the first temperature TH1, it then determines whether the temperature (TH) of the regenerative resistor 5 is below a third temperature TH3 (#3). If the temperature (TH) of the regenerative resistor 5 is below the third temperature TH3, the vehicle control unit 31 limits the travel speed, for example, to a second speed limit (#5). If the temperature is determined to be above the first temperature TH1 in step #1 and above the second temperature TH2 in step #2, the vehicle control unit 31 will disconnect the switch 8, cut off the connection between the power receiving unit 4 and the driving actuator 35, and cut off the power supply to the driving actuator 35 (#4).

[0033] When the temperature of the regenerative resistor 5 is above the second temperature TH2, the electrical connection between the receiving part 4 and the travel actuator 35 is cut off. However, when the temperature of the regenerative resistor 5 is above the first temperature TH1 but below the second temperature TH2, the electrical connection between the receiving part 4 and the travel actuator 35 is not cut off, and the transport vehicle 3 continues to travel while its speed is limited. Thus, by limiting the travel speed of the transport vehicle 3 before the electrical connection between the receiving part 4 and the travel actuator 35 is cut off, the travel of the transport vehicle 3 can be maintained, while simultaneously reducing the temperature of the regenerative resistor 5 or slowing down the rate at which its temperature rises. Therefore, the possibility of the transport vehicle stopping due to a rise in the temperature of the regenerative resistor can be reduced. Therefore, the decrease in the transport efficiency of the transport equipment 200 is suppressed.

[0034] Furthermore, as mentioned above, if a fault such as a broken wire occurs in the temperature sensor 7 or the temperature detection circuit 70, the temperature value obtained by the temperature sensor 7 may sometimes be significantly lower. In such a case, if the process is determined to be normal in step #1 and the transport vehicle 3 continues to travel, the temperature of the regenerative resistor 5 may rise beyond its rated range. If the temperature of the regenerative resistor 5 is below the third temperature TH3, such a temperature rise can be suppressed by limiting the travel speed of the transport vehicle 3.

[0035] However, if the speed-restricted transport vehicle 3 is allowed to operate as is, there is a possibility that the malfunction may develop to the point of near-immobility. Furthermore, if the speed-restricted transport vehicle 3 is in motion, it will become an obstacle to the movement of other speed-unrestricted transport vehicles 3, potentially causing congestion and reduced transport efficiency. Therefore, it is preferable to move the speed-restricted transport vehicle 3 to the maintenance area E2. However, when the transport vehicle 3 is transporting item W, it is preferable to move it to the maintenance area E2 after delivering the item W to its destination, so as to avoid the time required for the operator to transport item W to its destination or transfer item W to another transport vehicle 3.

[0036] Figure 8The flowchart illustrates an example of the relationship between the temperature (TH) of the regenerative resistor 5 and the control of the transport vehicle 3. Specifically, the transport vehicle control system 100 limits the travel speed of the transport vehicle 3 to below a certain speed limit (#5) based on the detection results of the temperature sensor 7. When the transport vehicle 3 is transporting item W (#6), after the item W has been transported to its destination (#7), the transport vehicle 3 is directed towards the maintenance area E2 (#8). Conversely, when the transport vehicle 3 is not transporting item W (#6), the transport vehicle control system 100 directs the transport vehicle 3 towards the maintenance area E2 as it was originally intended (#8).

[0037] As described above, the transport vehicle control system 100 includes a transport control unit H1 provided in the equipment control device H that controls the transport of items W using multiple transport vehicles 3, and a vehicle control unit 31 provided in each transport vehicle 3. The equipment control device H and each transport vehicle 3 are capable of bidirectional communication. The vehicle control unit 31 performs a determination based on the detection result of the temperature sensor 7, sends regenerative resistance information to the transport control unit H1 based on at least one of the detection result and the determination result based on the detection result, controls the travel speed of the transport vehicle 3 based on the determination result, and controls the switch 8 based on the determination result. The transport control unit H1 receives the regenerative resistance information and, if it determines based on the regenerative resistance information that the travel speed of the transport vehicle 3 is limited to below the speed limit, sends a transport command to the transport vehicle 3 with a location within the maintenance area E2 as the destination of the transport vehicle 3.

[0038] Since the vehicle control unit 31 of each transport vehicle 3 controls the travel speed of the transport vehicle 3 based on the temperature (TH) of the regenerative resistor 5, it can quickly control the transport vehicle 3 after the temperature of the regenerative resistor 5 is detected. Furthermore, the transport control unit H1 receives regenerative resistor information based on at least one of the detection results from the temperature sensor 7 and a determination result based on those detection results. Even if it is determined that the travel speed of the transport vehicle 3 is limited, the transport command for the item W is maintained while the transport vehicle 3 is transporting the item W. Therefore, the item W being transported can be transported to its destination without incurring the time required for an operation where the operator transports the item W to the destination or transfers the item W to another transport vehicle 3.

[0039] If the transport vehicle 3 is determined to be traveling at a restricted speed based on the received regenerative resistance information, and if the transport vehicle 3 is not currently transporting item W, the transport control unit H1 will send a transport command to the transport vehicle 3 with a location within the maintenance area E2 as its destination. The vehicle control unit 31 of the transport vehicle 3, upon receiving the transport command, will then move towards the maintenance area E2 based on the transport command. If the transport vehicle 3 is currently transporting item W, the transport command for item W will be maintained as described above. After the transport, a transport command will be sent to the transport vehicle 3 with a location within the maintenance area E2 as its destination. The vehicle control unit 31 of the transport vehicle 3, upon receiving the transport command, will then move towards the maintenance area E2 based on the transport command.

[0040] At this time, the transport control unit H1 generates a transport command toward the maintenance area E2 based on the position of the transport vehicle 3, the configuration shape of the travel path 1, and the positions of other transport vehicles 3, and sends it to the vehicle control unit 31. Therefore, the transport control unit H1 can ensure that the transport vehicle 3, whose travel speed is limited, travels toward the maintenance area E2 along an appropriate path. For example, even if the maintenance area E2 is located in multiple locations, the transport vehicle 3 can be directed toward the optimal maintenance area E2 based on the location information.

[0041] [Other Implementation Methods]

[0042] Other embodiments will be described below. Furthermore, the configurations of the embodiments described below are not limited to individual application; they can also be combined with the configurations of other embodiments, provided there is no contradiction.

[0043] (1) In the above, the example of the goods transport vehicle 3 is a roof transport vehicle that is suspended and supported on the roof side. However, as long as the goods transport equipment includes the transport area E1 and the maintenance area E2 in the travel path 1, the goods transport vehicle 3 can also be a transport vehicle that travels on the ground side.

[0044] (2) In the above, the item W that is being transported is exemplified as a FOUP or a mask, but the item W is not limited to these and can also be other items.

[0045] (3) As illustrated above, when a transport vehicle 3 with a limited travel speed is transporting an item W, after the item W is transported to its destination, the transport vehicle 3 is directed toward the maintenance area E2. However, even in this case, it is not imperative to direct the transport vehicle 3 toward the maintenance area E2 as it is originally intended.

[0046] (4) In the above, the example given is a power supply unit that has a power receiving unit 4 that receives power from the feeder line 11, but it is also possible for the power supply unit to have a battery or other energy storage device.

[0047] [Summary of Implementation Methods]

[0048] The following is a brief overview of the article conveying equipment described above.

[0049] As one approach, a goods transport device comprising a goods transport vehicle that travels along a travel path and transports goods includes a goods transport vehicle control system for controlling the goods transport vehicle. The goods transport vehicle comprises: a travel motor that drives the wheels; a power supply unit that supplies power to the travel motor; a regenerative resistor that is supplied with regenerative power generated during regeneration by the travel motor; a temperature sensor that detects the temperature of the regenerative resistor; and a switch disposed in the electrical connection path between the power supply unit and the travel motor, capable of cutting off the power supply from the power supply unit to the travel motor. When the temperature sensor detects that the temperature of the regenerative resistor is at or above a first temperature, which is higher than a predetermined constant temperature range, the goods transport vehicle control system limits the travel speed of the goods transport vehicle to below a predetermined limit speed. When the temperature sensor detects that the temperature of the regenerative resistor is at or above a second temperature, which is higher than the first temperature, the switch cuts off the connection between the power supply unit and the travel motor.

[0050] According to this configuration, a temperature sensor detects the temperature of the regenerative resistor, including the effect of ambient temperature, and selects two different control states to control the transport vehicle based on the detected temperature. Specifically, the control state is selected based on whether the regenerative resistor temperature is above a first temperature or above a second temperature, which is higher than the first temperature. If the regenerative resistor temperature is above the second temperature, the electrical connection between the power supply and the travel motor is cut off by a switch. If the regenerative resistor temperature is above the first temperature but below the second temperature, the electrical connection between the power supply and the travel motor is not cut off, and the transport vehicle continues to travel at a speed limited to a specified limit. Thus, by limiting the transport vehicle's speed before cutting off the electrical connection between the power supply and the travel motor, the transport vehicle's movement can be maintained while simultaneously suppressing the temperature rise of the regenerative resistor. Therefore, the possibility of the transport vehicle stopping due to a rise in the regenerative resistor temperature can be reduced, and the decrease in the transport efficiency of the transport equipment can be suppressed. Furthermore, according to this configuration, instead of predicting the value, the actual temperature of the regenerative resistor is detected by a temperature sensor. Therefore, even if the ambient temperature changes, the material transport vehicle can be appropriately controlled based on the temperature of the regenerative resistor. Thus, according to this configuration, the decrease in system efficiency can be suppressed while simultaneously controlling the system appropriately based on the temperature of the regenerative resistor.

[0051] In addition, it is preferable that the aforementioned transport vehicle control system limits the travel speed of the aforementioned transport vehicle to below the aforementioned limit speed when the temperature of the aforementioned regenerative resistor detected by the aforementioned temperature sensor is below a third temperature set to be lower than the aforementioned constant temperature range.

[0052] For example, if the temperature sensor malfunctions, such as a broken wire, the detected value may sometimes be significantly lower. In such cases, if the transport vehicle continues to move while the condition is deemed normal, the temperature of the regenerative resistor may rise beyond its rated range. As in this configuration, if the temperature of the regenerative resistor is below a third temperature lower than the constant temperature range, and the transport vehicle's speed is limited to a speed below a certain limit, such a temperature rise can be suppressed. Furthermore, the speed limit in this case can be the same as or different from the speed when the temperature of the regenerative resistor is above a first temperature.

[0053] Furthermore, it is preferable that the aforementioned travel path includes a transport area for passing through when transporting the aforementioned items and a maintenance area for passing through when performing maintenance on the aforementioned item transport vehicle. The aforementioned transport vehicle control system limits the travel speed of the aforementioned item transport vehicle to below the aforementioned speed limit based on the detection results of the aforementioned temperature sensor. When the aforementioned item transport vehicle is transporting the aforementioned items, after transporting the items to the transport destination, the item transport vehicle is directed toward the aforementioned maintenance area. When the aforementioned item transport vehicle is not transporting the aforementioned items, the item transport vehicle is directed toward the aforementioned maintenance area as it was originally.

[0054] If the speed-restricted transport vehicle is allowed to operate as is, there is a possibility that the malfunction may develop to the point of near-immobility. Furthermore, if the speed-restricted transport vehicle is in motion, it becomes an obstacle to the movement of the unrestricted transport vehicles, potentially causing congestion and reducing transport efficiency. Therefore, it is preferable that the speed-restricted transport vehicle be moved to the maintenance area. According to this configuration, when the transport vehicle is not carrying any items, it can be moved towards the maintenance area as is, allowing for rapid maintenance. Furthermore, when the transport vehicle is carrying items, after delivering the items to their destination, it can be moved towards the maintenance area, thus eliminating the need for operator time spent transporting the items to their destination or transferring them to other transport vehicles, allowing for timely delivery of items and appropriate maintenance of the transport vehicle.

[0055] Furthermore, the aforementioned transport vehicle control system includes a transport control unit of an equipment control device that controls the transport of the aforementioned items using multiple aforementioned transport vehicles, and a vehicle control unit of each of the aforementioned transport vehicles. The aforementioned equipment control device and each of the aforementioned transport vehicles are capable of bidirectional communication. The aforementioned vehicle control unit performs a determination based on the detection result of the aforementioned temperature sensor, sends regenerative resistance information to the aforementioned transport control unit based on at least one of the detection result and the determination result based on the detection result, controls the travel speed of the aforementioned transport vehicle based on the aforementioned determination result, and controls the aforementioned switch based on the aforementioned determination result. The aforementioned transport control unit receives the aforementioned regenerative resistance information, and when it determines based on the aforementioned regenerative resistance information that the travel speed of the aforementioned transport vehicle is limited to below the aforementioned speed limit, it sends a transport instruction to the transport vehicle with a location within the aforementioned maintenance area as the destination of the transport vehicle.

[0056] Based on this configuration, the vehicle control unit of the transport vehicle itself controls the travel speed of the transport vehicle based on the temperature of the regenerative resistor, thus enabling rapid control of the transport vehicle after the temperature of the regenerative resistor is detected. Furthermore, the transport control unit allows the transport vehicle, whose travel speed is limited, to proceed along an appropriate path towards the maintenance area.

[0057] In addition, the aforementioned goods transport vehicle preferably has a position detection unit that detects the position in the aforementioned travel path, and sends the detected position information to the aforementioned transport control unit. The aforementioned transport control unit sends the aforementioned transport command generated based on the aforementioned position information to the aforementioned goods transport vehicle.

[0058] Based on this configuration, even when maintenance areas are set in multiple locations, the transport vehicle can be directed toward the optimal maintenance area based on location information.

[0059] Symbol Explanation

[0060] 1: Driving route

[0061] 3: Goods transport vehicle

[0062] 4: Power receiving section (power supply section)

[0063] 5: Regenerative resistor

[0064] 7: Temperature sensor

[0065] 8: Switch

[0066] 31: Vehicle Control Department

[0067] 32: Position detection sensor (position detection unit)

[0068] 35: Driving actuator (driving motor)

[0069] 100: Transport vehicle control system

[0070] 200: Goods conveying equipment

[0071] E1: Transfer area

[0072] E2: Maintenance Area

[0073] H: Equipment control device

[0074] H1: Conveying Control Department

[0075] TH1: First Temperature

[0076] TH2: Second temperature

[0077] TH3: Third Temperature

[0078] W: Items

Claims

1. A goods conveying device, comprising a goods conveying vehicle that travels along a travel path and conveys goods. Equipped with a transport vehicle control system for controlling the transport vehicle carrying the aforementioned items. The transport vehicle for the goods is equipped with: A motor that drives the wheels; The power supply unit supplies power to the driving motor; A regenerative resistor is supplied with regenerative power generated during the regeneration of the driving motor; A temperature sensor that detects the temperature of the regenerative resistor; as well as A switch is disposed in the electrical connection path between the power supply unit and the travel motor, and is capable of cutting off the power supply from the power supply unit to the travel motor. The item conveying equipment has the following characteristics: The transport vehicle control system, If the temperature of the regenerative resistor detected by the temperature sensor is above a first temperature that is set higher than a predetermined constant temperature range, the travel speed of the goods transport vehicle is limited to below a predetermined speed limit. If the temperature of the regenerative resistor detected by the temperature sensor is a second temperature or higher than the first temperature, the switch disconnects the power supply unit from the driving motor.

2. The goods conveying equipment according to claim 1, wherein, When the temperature sensor detects that the temperature of the regenerative resistor is below a third temperature set lower than the constant temperature range, the transport vehicle control system limits the travel speed of the transport vehicle to below the limit speed.

3. The goods conveying equipment according to claim 1, wherein, The travel path includes a transport area, which is the area traversed when transporting the items, and a maintenance area, which is the area traversed when maintaining the item transport vehicle. The transport vehicle control system, The speed of the goods transport vehicle is limited to below the specified speed limit based on the temperature sensor readings. While the transport vehicle is carrying the item, after the item has been transported to its destination, the transport vehicle should be oriented towards the maintenance area. If the transport vehicle is not transporting the items, the transport vehicle shall be oriented toward the maintenance area as it was originally.

4. The goods conveying equipment according to claim 2, wherein, The travel path includes a transport area, which is the area traversed when transporting the items, and a maintenance area, which is the area traversed when maintaining the item transport vehicle. The transport vehicle control system, The speed of the goods transport vehicle is limited to below the specified speed limit based on the temperature sensor readings. While the transport vehicle is carrying the item, after the item has been transported to its destination, the transport vehicle should be oriented towards the maintenance area. If the transport vehicle is not transporting the items, the transport vehicle shall be oriented toward the maintenance area as it was originally.

5. The goods conveying equipment according to claim 3, wherein, The transport vehicle control system includes a transport control unit in an equipment control device that controls the transport of items using multiple transport vehicles, and a vehicle control unit in each of the transport vehicles. The equipment control device and each transport vehicle are capable of bidirectional communication. The vehicle control unit performs the following actions: making a determination based on the detection result of the temperature sensor; sending regenerative resistance information to the transport control unit based on at least one of the detection result and the determination result based on the detection result; controlling the travel speed of the goods transport vehicle based on the determination result; and controlling the switch based on the determination result. The transport control unit receives the regenerative resistance information, and if it determines based on the regenerative resistance information that the travel speed of the transport vehicle is limited to below the speed limit, it sends a transport instruction to the transport vehicle with a location within the maintenance area as the destination of the transport vehicle.

6. The goods conveying equipment according to claim 4, wherein, The transport vehicle control system includes a transport control unit in an equipment control device that controls the transport of items using multiple transport vehicles, and a vehicle control unit in each of the transport vehicles. The equipment control device and each transport vehicle are capable of bidirectional communication. The vehicle control unit performs the following actions: making a determination based on the detection result of the temperature sensor; sending regenerative resistance information to the transport control unit based on at least one of the detection result and the determination result based on the detection result; controlling the travel speed of the goods transport vehicle based on the determination result; and controlling the switch based on the determination result. The transport control unit receives the regenerative resistance information, and if it determines based on the regenerative resistance information that the travel speed of the transport vehicle is limited to below the speed limit, it sends a transport instruction to the transport vehicle with a location within the maintenance area as the destination of the transport vehicle.

7. The goods conveying equipment according to claim 5, wherein, The transport vehicle is equipped with a position detection unit that detects the position in the travel path and sends the detected position information to the transport control unit. The transport control unit then sends the transport command generated based on the position information to the transport vehicle.

8. The goods conveying equipment according to claim 6, wherein, The transport vehicle is equipped with a position detection unit that detects the position in the travel path and sends the detected position information to the transport control unit. The transport control unit then sends the transport command generated based on the position information to the transport vehicle.

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