Transport vehicle

Abstract

Provided is a transport vehicle that transports an article, the transport vehicle being provided with: a travel device that is provided with a travel drive unit; a control device that controls the travel device; and a power supply unit that receives power supply from the outside, supplies at least power to the traveling device and the control device, sets the voltage supplied from the power supply unit to the traveling device as a target voltage (V1), and sets a lower limit voltage necessary for operating the traveling device as a necessary lower limit voltage (Vs1), the control device monitors the target voltage (V1), and controls the traveling device to operate the traveling device. When the target voltage is less than or equal to a determination threshold value (Vt1) set to a value lower than the voltage during normal operation of the power supply unit and higher than the necessary lower limit voltage (Vs1) during traveling of the transport vehicle, a deceleration stop process is executed in which the traveling speed of the transport vehicle is reduced and the traveling of the transport vehicle is stopped.

Description

Technical Field

[0001] The invention relates to a conveying vehicle for conveying articles. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2022-003858 (Patent Document 1) discloses a technology related to a transport vehicle. In the following description of the background art, the reference numerals shown in parentheses are the reference numerals of Patent Document 1.

[0003] The conveying device (100) of Patent Document 1 comprises: a travel track (2) arranged along a travel path (1); and a transport vehicle (article transport vehicle 3) guided by the travel track (2) and traveling along the travel path (1). In addition, in the conveying device (100), a power supply line (11) is arranged along the travel path (1), and a plurality of article processing units (P) are provided. The transport vehicle receives driving power from the power supply line (11) in a non-contact manner, thereby traveling along the travel path (1) and transporting articles to the article processing units (P). Summary of the invention

[0004] Regarding the conveying equipment such as Patent Document 1, if the power supply line cannot be supplied with power due to a power outage or a failure of the power supply unit, for example, there is a case where the conveying vehicle suddenly stops on the travel track due to insufficient power required for travel. If the conveying vehicle suddenly stops like this, a large load is easily applied to the conveying vehicle itself, and a large acceleration is easily applied to the objects being conveyed. As a result, there is a possibility that the life of the conveying vehicle is shortened or the objects being conveyed are easily damaged.

[0005] Therefore, it is desired to realize a transport vehicle that can be stopped appropriately even when a failure occurs in power supply.

[0006] The transport vehicle involved in the present disclosure is a transport vehicle for transporting articles. The transport vehicle comprises: a travel device having a travel drive unit; a control device for controlling the travel device; and a power supply unit for receiving power supply from the outside and supplying power to at least the travel device and the control device. The voltage supplied from the power supply unit to the travel device is set as a target voltage, and the lower limit voltage required for the travel device to operate is set as a necessary lower limit voltage. The control device monitors the object voltage, and during the travel of the transport vehicle, when the object voltage becomes below a determination threshold value that is set to a value lower than the voltage in normal operation of the power supply unit and higher than the required lower limit voltage, a deceleration stop process is performed to reduce the travel speed of the transport vehicle and stop the travel of the transport vehicle.

[0007] According to this configuration, even if the voltage (target voltage) supplied to the travel device drops below the required lower limit voltage due to a power failure or a failure of the power supply unit, the transport vehicle can be decelerated at the stage where the voltage reaches the judgment threshold. Therefore, by making the target voltage lower than the required lower limit voltage, it is possible to avoid the travel device from being unable to operate and the transport vehicle from stopping suddenly. In this way, the transport vehicle can be prevented from stopping suddenly, and thus, for example, adverse effects such as a large acceleration acting on the article being transported can be alleviated.

[0008] Further features and advantages of the transport vehicle will become apparent from the following description of exemplary and non-limiting embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a front view schematically showing the transfer operation of the transport vehicle. Figure 2 It is a top view schematically showing the travel path of the transport vehicle and the processing device. Figure 3 It is a side view of the transport vehicle. Figure 4 It is a control block diagram. Figure 5 It is a diagram showing a stop pattern of the transport vehicle in the deceleration stop process. Figure 6 It is a control flow chart. Figure 7 It is a control flow chart. Figure 8 It is a control flow chart. Fig. 9 is a control flow chart of another implementation. DETAILED DESCRIPTION

[0010] Regarding the embodiment of the transport vehicle, an example applicable to transport equipment will be described.

[0011] like Figure 1 and Figure 2 As shown, the transport equipment 100 includes: a transport vehicle 1 that travels along a travel path 5; a travel track 4 that guides the transport vehicle 1; a plurality of processing devices 7; and an upper control system C that uniformly controls the entire transport equipment 100. The travel track 4 is arranged along the travel path 5. In addition, a plurality of processing devices 7 are arranged along the travel path 5.

[0012] In this embodiment, the transport vehicle 1 transports articles W. Specifically, the transport vehicle 1 travels along a travel path 5 and transfers articles W to a plurality of processing devices 7. In this embodiment, the travel path 5 is set along the ceiling of the transport equipment 100. Therefore, the travel track 4 is configured in a state of being suspended and supported from the ceiling. That is, the transport vehicle 1 is configured as a ceiling transport vehicle that travels along the travel path 5 set along the ceiling. In this example, a pair of travel tracks 4 is provided. Moreover, a plurality of transport vehicles 1 are arranged on a pair of left and right travel tracks 4 ( Figure 1 ) on. In addition, the transport vehicle 1 is not limited to a ceiling transport vehicle. The transport vehicle 1 may also be, for example, an unmanned transport vehicle that autonomously travels on a floor surface or the like.

[0013] The processing device 7 is a device that performs predetermined processing on the article W. Each of the multiple processing devices 7 is arranged below the travel track 4. Here, each processing device 7 is arranged on the bottom surface of the conveying equipment 100. In this example, the processing device 7 has a transfer object portion 7a for transferring the article W and a processing main body portion 7b for processing. Here, the transfer object portion 7a is set as a handover port. That is, the transfer object portion 7a is a port for handing over the article W with the conveying vehicle 1. In this embodiment, as the article W, for example, it can be set as a container for accommodating semiconductor wafers used in the manufacture of semiconductor devices or photomasks for processing. That is, as the article W, a FOUP for accommodating semiconductor wafers or a photomask box for accommodating photomasks can be exemplified. In the processing main body portion 7b, processing is performed on the contents accommodated in such an article W.

[0014] The upper control system C sends a transport command to each of the plurality of transport vehicles 1 traveling on the travel path 5. Each transport vehicle 1 transports the article W between the plurality of processing devices 7 based on the transport command issued by the upper control system C. The upper control system C includes an upper communication device 101. The upper communication device 101 is configured to communicate with a communication device 9 of the transport vehicle 1 described later.

[0015] like Figures 1 to 4 As shown, the transport vehicle 1 includes: a travel device 2 including a travel drive unit 21; a control device 10 for controlling the travel device 2; and a power supply unit 3 for receiving power supply from the outside and supplying power to at least the travel device 2 and the control device 10. In addition, in the present embodiment, the transport vehicle 1 further includes: a holding device 62 for holding an article W; a lifting device 72 for lifting and lowering the holding device 62; a sliding device 82 for advancing and retreating the holding device 62 in a specific advancing and retreating direction Y along the horizontal direction; and a communication device 9.

[0016] In the following description, the direction along the travel path 5 is referred to as the travel direction X, and the direction (track width direction) perpendicular to the travel direction X when viewed in the vertical direction is referred to as the forward and backward direction Y.

[0017] The travel device 2 includes a travel wheel 22 that rolls on the travel rail 4 and a travel motor M ( Figure 3 ). In this example, Figure 1 and Figure 3 As shown, the transport vehicle 1 further includes a vehicle body 11, a storage portion 17 for storing articles W, and a cover 16 covering the storage portion 17. Here, a plurality of running wheels 22 are provided on the vehicle body 11. The running motor M drives at least one of the plurality of running wheels 22 to provide a propulsion force for driving the vehicle body 11 along the running direction X. In addition, the running motor M may also be a linear motor, in which case the running wheels 22 may not necessarily be provided. In this example, the vehicle body 11 is arranged above the running track 4.

[0018] The storage section 17 is arranged below the travel rail 4. When the transport vehicle 1 transports the article W toward the transfer target portion 7a, the vehicle body 11 travels with the article W stored in the storage section 17. The cover 16 is suspended and supported by the vehicle body 11. The cover 16 covers the upper side of the storage section 17 and both sides in the travel direction X. In the example shown in the figure, the cover 16 is not arranged on both outer sides of the storage section 17 in the forward and backward direction Y, but is open.

[0019] The lifting device 72 is configured to lift the holding device 62 between a height corresponding to the transfer target portion 7a and a height corresponding to the storage portion 17. Figure 3 As shown, the lifting device 72 is arranged in the storage part 17. In this example, the lifting device 72 includes: a reel 73; a belt 74, which is wound around the reel 73 and connected to the holding device 62 at the front end; and a lifting motor (not shown). The reel 73 is rotated by driving the lifting motor to wind or unwind the belt 74, so that the holding device 62 and the article W held by the holding device 62 are lifted or lowered. The vehicle body 11 stops at a position corresponding to the transfer target portion 7a, and the lifting device 72 lifts and lowers the article W held by the holding device 62, so that the article W can be transferred between the transfer target portion 7a (here, the transfer port).

[0020] The slide device 82 includes a slide body 83 that moves relative to the storage portion 17 in the forward and backward direction Y (here, the track width direction) and a slide motor (not shown) that slides the slide body 83 in the forward and backward direction Y. The slide motor drives the slide body 83 to move, thereby enabling the lifting device 72, the holding device 62, and the article W held by the holding device 62 to move in the forward and backward direction Y. Figure 2As shown, when the transfer target portion 7a of the processing device 7 is arranged at a position separated from the travel path 5 in the forward and backward direction Y, the slide device 82 transfers the article W between the transfer target portion 7a by sliding the slide body 83. In this example, the slide device 82 is accommodated in the storage portion 17, and the slide body 83 is moved forward and backward relative to the storage portion 17 in the forward and backward direction Y as needed.

[0021] The holding device 62 includes a pair of gripping claws and a gripping motor that moves the pair of gripping claws closer and farther away. The holding device 62 is configured to switch between a gripping state in which the object W is gripped and a gripping release state in which the object W is released by moving the pair of gripping claws closer and farther away.

[0022] In this example, if Figure 3 As shown, the transport vehicle 1 includes a detection device 15. The detection device 15 detects a plurality of detected objects 43 ( Figure 2 ). The detected object 43 stores position information (address information) indicating the position where the detected object 43 is set, and the detection device 15 is configured to read the position information. The detected object 43 is set at a position corresponding to the transfer object portion 7a, in addition to the branch path or the converging path in the travel path 5. Here, the detected object 43 is set as a barcode label and is set on the lower surface of the travel track 4. In addition, the detection device 15 is set on the upper surface of the cover body 16 and is configured to read the barcode label facing it during the travel of the transport vehicle 1.

[0023] like Figure 4 As shown, the communication device 9 is configured to communicate with a host control system C that controls a plurality of transport vehicles 1. Examples of the function of the communication device 9 include receiving a transport instruction from the host control system C or transmitting position information or speed information of the transport vehicle 1 to the host control system C.

[0024] The power supply unit 3 includes a power receiving device 32 ( Figure 4 ). In this example, power is supplied from the power supply line to the power receiving device 32 in a contactless manner. The power receiving device 32 includes a pickup coil (not shown) and a power receiving unit (not shown) formed on a wiring substrate inside the transport vehicle 1. The power receiving unit is electrically connected to the pickup coil, and an electric load whose power consumption varies is electrically connected to the power receiving unit. The AC current and AC voltage induced by the pickup coil are converted into DC current and DC voltage in the power receiving unit by a rectifier circuit such as a full-wave rectifier circuit or a power receiving circuit such as a smoothing capacitor, and are supplied to the power load. Examples of the power load include the travel device 2, the holding device 62, the lifting device 72, and the sliding device 82 as described above.

[0025] In this embodiment, if Figure 4 As shown, the power supply unit 3 includes a power storage device 31 for temporarily storing electric power. And, it is configured in such a way that the voltage of the power storage device 31 is supplied to the traveling device 2. Here, the power storage device 31 is provided as a device for coping with an instantaneous voltage drop in the transport vehicle 1. That is, when the voltage supply to the traveling device 2 drops instantaneously due to a poor power supply condition caused by a power outage or a failure of the power supply unit 3, the power storage device 31 supplies voltage to the traveling device 2. In the present embodiment, the power storage device 31 is configured in such a way that it can supply electric power not only to the traveling device 2, but also to electric loads such as the holding device 62, the lifting device 72, and the sliding device 82. In addition, as the power storage device 31, it can be provided as a capacitor provided on the substrate of the power supply unit 3. In addition, as the power storage device 31, a small battery can also be provided.

[0026] like Figure 4 As shown, the control device 10 controls the travel device 2, the lifting device 72, the holding device 62, the sliding device 82, the detection device 15 and the power supply unit 3. In addition, the control device 10 is configured in a manner that can communicate with the upper control system C. The control device 10 and the upper control system C, for example, have a processor such as a microcomputer, a peripheral circuit such as a memory, etc. Moreover, each function is realized by the cooperation of these hardware and the program executed on the processor such as a computer. In the present embodiment, the control device 10 is configured in a manner that controls the travel device 2 based on the instruction from the upper control system C. In addition, the control device 10 controls the holding device 62 and the sliding device 82 according to the instruction from the upper control system C. In addition, the control device 10 can also be configured in a manner that controls only the travel device 2.

[0027] In the following, the voltage supplied from the power supply unit 3 to the travel device 2 is set to the first target voltage V1, and the lower limit voltage required for the travel device 2 to operate is set to the first necessary lower limit voltage Vs1. In addition, the voltage supplied from the power supply unit 3 to the lifting device 72 is set to the second target voltage V2, and the lower limit voltage required for the lifting device 72 to operate is set to the second necessary lower limit voltage Vs2. Similarly, the voltage supplied from the power supply unit 3 to the sliding device 82 is set to the third target voltage V3, and the lower limit voltage required for the sliding device 82 to operate is set to the third necessary lower limit voltage Vs3. Here, the first necessary lower limit voltage Vs1 corresponds to the "necessary lower limit voltage".

[0028] like Figure 5As shown, the control device 10 is configured to monitor the first object voltage V1. In addition, the control device 10 is configured to also monitor the second object voltage V2 and the third object voltage V3. In this example, the control device 10 monitors the voltage supplied to the driver (servo driver, etc., the same below) of the travel motor M of the travel device 2 as the first object voltage V1. In addition, the control device 10 monitors the voltage supplied to the driver of the lifting motor as the second object voltage V2. Furthermore, the control device 10 monitors the voltage supplied to the driver of the sliding motor as the third object voltage V3. In addition, the control device 10 may also monitor the voltage supplied to the motor body of each of the above-mentioned motors. Here, the first object voltage V1 is equivalent to the "object voltage".

[0029] In the present embodiment, the control device 10 performs normal conveying control. Normal conveying control is a control for conveying an article W between a predetermined transfer object part 7a based on a conveying instruction received from a superior control system C. Here, as an example of normal conveying control, a control for conveying an article W to a predetermined transfer object part 7a is described. If the control device 10 receives a conveying instruction, it controls the travel device 2 so that the transport vehicle 1 moves toward the position of the transfer object part 7a corresponding to the transport destination (here, the position on the travel track 4). If the transport vehicle 1 approaches this position, the control device 10 controls the travel device 2 so that the transport vehicle 1 slows down and can stop at an appropriate stop position. Alternatively, if the detection device 15 detects a detected object 43 in front of the transfer object part 7a configured at the transport destination, the control device 10 slows down the transport vehicle 1. If the transport vehicle 1 stops, the control device 10 sends the stop position to the superior control system C. In this example, the control device 10 calculates the stop position based on the position information obtained from the detection object 43 and the movement amount of the transport vehicle 1 from the detection object 43 to the stop position detected by the encoder of the travel motor M.

[0030] When the transfer target portion 7a of the transport destination is arranged directly below the travel rail 4, the control device 10 controls the lifting device 72 to lower the holding device 62 and the article W held by the holding device 62. In addition, when the transfer target portion 7a of the transport destination is arranged at a position offset in the forward and backward direction Y relative to the travel rail 4, the control device 10 controls the sliding device 82 to move the holding device 62 and the article W held by the holding device 62 to directly above the transfer target portion 7a. Thereafter, the control device 10 controls the lifting device 72 to lower the holding device 62 and the article W held by the holding device 62. If the article W is placed on the transfer target portion 7a, the control device 10 controls the holding device 62 to bring the pair of gripping claws into a gripping release state.

[0031] In normal transport control, when the transport vehicle 1 is traveling on the travel track 4, a properly set predetermined voltage (normal voltage V0) is continuously supplied to the travel device 2. In addition, when the transport vehicle 1 is stopped on the travel track 4 and the article W is transferred to the transfer target portion 7a, the normal voltage V0 is supplied to the slide device 82 and the lifting device 72 as needed. Figure 5 In the example of , the normal voltage V0 supplied to each of the travel device 2, the slide device 82, and the lifting device 72 is set to the same value. In addition, the normal voltage V0 supplied to each of the travel device 2, the slide device 82, and the lifting device 72 may be set to different values. In addition, it is also possible to set an upper limit value and a lower limit value for the normal voltage V0, and the voltage value from the lower limit value to the upper limit value is set as the range of the normal voltage V0.

[0032] On the other hand, if a fault occurs in the power supply, such as when power cannot be supplied to the power supply unit 3 due to a power outage, the first target voltage V1, the second target voltage V2, and the third target voltage V3 become values ​​dropped from the normal voltage V0 ( Figure 5 ). In addition, as the main reasons why these object voltages are lower than the required lower limit voltages (the first required lower limit voltage Vs1, the second required lower limit voltage Vs2, and the third required lower limit voltage Vs3), there can be cited the situation where each motor (travel motor M, lifting motor, and sliding motor) becomes short of power due to such a poor power supply condition or the situation where an error occurs in the driver of these motors.

[0033] like Figures 5 to 9 As shown in FIG. 1 , the control device 10 executes the first deceleration and stop process, the second deceleration and stop process, and the third deceleration and stop process. Figure 5 and Figure 6 As shown, the first deceleration and stop process is a process in which, during the travel of the transport vehicle 1, when the first object voltage V1 becomes less than the first determination threshold value Vt1 set to a value lower than the voltage (normal voltage V0) in the normal operation of the power supply unit 3 and higher than the first necessary lower limit voltage Vs1, the first deceleration and stop process is executed to reduce the travel speed of the transport vehicle 1 and stop the travel of the transport vehicle 1. Here, the first deceleration and stop process is equivalent to the "deceleration and stop process", and the first necessary lower limit voltage Vs1 is equivalent to the "necessary lower limit voltage".

[0034] like Figure 5As shown, the time required from the start to the completion of the first deceleration stop process is set as the first processing required time Ta, the decrease per unit time of the first object voltage V1 when an abnormality occurs in the power supply from the power supply unit 3 is set as the first voltage drop rate Ra, and the first determination threshold Vt1 is set to be greater than the value obtained by adding the value obtained by multiplying the first voltage drop rate Ra by the first processing required time Ta to the first required lower limit voltage Vs1. Figure 5 In the example, the first voltage drop rate Ra from the normal voltage V0 is constant, but is not limited to this. In this example, the difference E between the first determination threshold value Vt1 and the first required lower limit voltage Vs1 is set in a manner larger than the value obtained by multiplying the first voltage drop rate Ra by the first processing necessary time Ta. Thus, the first determination threshold value Vt1 is larger than the value obtained by adding the first required lower limit voltage Vs1 to the value obtained by multiplying the first voltage drop rate Ra by the first processing necessary time Ta. In this example, the first processing necessary time Ta is set to the time from the start of deceleration of the transport vehicle 1 to the completion of the stop of the movement of the transport vehicle 1 in the driving direction X. In addition, the first voltage drop rate Ra is equivalent to the "voltage drop rate", and the first processing necessary time Ta is equivalent to the "processing necessary time".

[0035] In this embodiment, if Figure 6 As shown, the control device 10 determines whether the first object voltage V1 is a value greater than the first determination threshold value Vt1 (S01). If the control device 10 determines that the first object voltage V1 is below the first determination threshold value Vt1 (S01: No), the first deceleration stop process is performed (S02). In this example, if the control device 10 detects that the first object voltage V1 is the same value as the first determination threshold value Vt1, the travel device 2 is controlled in such a manner as to decelerate the transport vehicle 1. Moreover, before the first object voltage V1 is lower than the first required lower limit voltage Vs1, the control device 10 controls the travel device 2 in such a manner as to stop the transport vehicle 1. Figure 5In the example of , the control device 10 stops the transport vehicle 1 when the first object voltage V1 becomes the same value as the first required lower limit voltage Vs1. In this way, the control device 10 controls the travel device 2 in the first deceleration and stop process, during the period when the first object voltage V1 is less than the first determination threshold value Vt1 and is greater than the first required lower limit voltage Vs1, so as to stop the transport vehicle 1. In this example, the control device 10 decelerates the transport vehicle 1 at a predetermined deceleration rate, and stops the transport vehicle 1 before the first object voltage V1 is lower than the first required lower limit voltage Vs1. In addition, in the example shown in the figure, the deceleration rate per unit time of the transport vehicle 1 is constant, but it is not limited to this. Here, the control device 10 can also send the stop position of the transport vehicle 1 to the upper control system C after the first deceleration and stop process. As a result, in the recovery operation after the poor condition of the power supply is eliminated, the upper control system C can easily calculate the correct stop position of the transport vehicle 1. Therefore, the period of the recovery operation can be shortened. In addition, the control device 10 can also be set to a configuration that does not originally monitor the first object voltage V1. In this case, the control device 10 may not execute the first deceleration and stop process.

[0036] like Figure 5 and Figure 7 As shown, the second deceleration and stop processing is the following processing: in the lifting and lowering action of the holding device 62 controlled by the lifting device 72, when the second object voltage V2 becomes below the second judgment threshold value Vt2 which is set to a value lower than the voltage in the normal operation of the power supply unit 3 and higher than the second required lower limit voltage Vs2, the second deceleration and stop processing is performed to reduce the lifting and lowering speed of the holding device 62 controlled by the lifting device 72 and stop the lifting and lowering of the holding device 62.

[0037] like Figure 5 As shown, the time required from the start to the completion of the second deceleration stop process is set as the second necessary processing time Tb, the decrease per unit time of the second object voltage V2 when an abnormality occurs in the power supply from the power supply unit 3 is set as the second voltage drop rate Rb, and the second determination threshold Vt2 is set to be greater than the value obtained by adding the value obtained by multiplying the second voltage drop rate Rb by the second necessary processing time Tb to the second necessary lower limit voltage Vs2. Figure 5In the example, the second voltage drop rate Rb from the normal voltage V0 is constant, but it is not limited to this. In this example, the difference F between the second determination threshold value Vt2 and the second required lower limit voltage Vs2 is set in a manner larger than the value obtained by multiplying the second voltage drop rate Rb by the second processing necessary time Tb. Thus, the second determination threshold value Vt2 is larger than the value obtained by adding the second required lower limit voltage Vs2 to the value obtained by multiplying the second voltage drop rate Rb by the second processing necessary time Tb. In this example, the second processing necessary time Tb is set to the time from the start of deceleration (reduction of the lifting speed) of the holding device 62 to the completion of the stop of the holding device 62.

[0038] In this embodiment, if Figure 7 As shown, the control device 10 determines whether the second object voltage V2 is a value greater than the second determination threshold value Vt2 (S11). If the control device 10 determines that the second object voltage V2 is below the second determination threshold value Vt2 (S11: No), the second deceleration stop process is performed (S12). In this example, if the control device 10 detects that the second object voltage V2 is the same value as the second determination threshold value Vt2, the lifting device 72 is controlled in such a manner as to decelerate the holding device 62. Furthermore, before the second object voltage V2 is lower than the second required lower limit voltage Vs2, the control device 10 controls the lifting device 72 in such a manner as to stop the lifting and lowering of the holding device 62. Figure 5 In the example of , the control device 10 stops the holding device 62 when the second object voltage V2 becomes the same value as the second required lower limit voltage Vs2. In this way, the control device 10 controls the lifting device 72 in the second deceleration stop process, during the period when the second object voltage V2 is less than the second determination threshold value Vt2 and is greater than the second required lower limit voltage Vs2, so as to stop the holding device 62. Here, the control device 10 may also send the stop position of the holding device 62 in the up-down direction (lifting direction) to the upper control system C after the second deceleration stop process. Thus, in the recovery operation after the poor condition of the power supply is eliminated, the upper control system C can easily calculate the correct stop position of the holding device 62. Therefore, the period of the recovery operation can be shortened. In addition, the control device 10 can calculate the position of the holding device 62 in the up-down direction, for example, by an encoder mounted on the lifting motor.

[0039] like Figure 5 and Figure 8As shown, the third deceleration and stop processing is the following processing: in the forward and backward movement of the holding device 62 controlled by the sliding device 82, when the third object voltage V3 becomes below the third judgment threshold value Vt3 which is set to a value lower than the voltage in the normal operation of the power supply unit 3 (normally the voltage V0) and higher than the third required lower limit voltage Vs3, the third deceleration and stop processing is performed to reduce the forward and backward speed of the holding device 62 controlled by the sliding device 82 and stop the forward and backward movement of the holding device 62.

[0040] like Figure 5 As shown, the time required from the start to the completion of the third deceleration stop process is set as the third necessary process time Tc, the decrease per unit time of the third object voltage V3 when an abnormality occurs in the power supply from the power supply unit 3 is set as the third voltage drop rate Rc, and the third determination threshold Vt3 is set to be greater than the value obtained by adding the third necessary lower limit voltage Vs3 to the value obtained by multiplying the third voltage drop rate Rc by the third necessary process time Tc. Figure 5 In the example, the third voltage drop rate Rc from the normal voltage V0 is constant, but it is not limited to this. In this example, the difference G between the third determination threshold value Vt3 and the third necessary lower limit voltage Vs3 is set in a manner larger than the value obtained by multiplying the third voltage drop rate Rc by the third processing necessary time Tc. Thus, the third determination threshold value Vt3 is larger than the value obtained by adding the third necessary lower limit voltage Vs3 to the value obtained by multiplying the third voltage drop rate Rc by the third processing necessary time Tc. In this example, the third processing necessary time Tc is set to the time from the start of deceleration (reduction of the forward and backward speed) of the holding device 62 to the completion of the stop of the movement of the holding device 62 in the forward and backward direction Y.

[0041] In this embodiment, if Figure 8 As shown, the control device 10 determines whether the third object voltage V3 is a value greater than the third determination threshold value Vt3 (S21). If the control device 10 determines that the third object voltage V3 is below the third determination threshold value Vt3 (S21: No), the third deceleration stop process is performed (S22). In this example, if the control device 10 detects that the third object voltage V3 drops to the same value as the third determination threshold value Vt3, the sliding device 82 is controlled in such a manner as to decelerate the holding device 62. Furthermore, before the third object voltage V3 falls below the third required lower limit voltage Vs3, the control device 10 controls the sliding device 82 in such a manner as to stop the sliding movement of the holding device 62. Figure 5In the example, the control device 10 stops the holding device 62 when the third object voltage V3 becomes the same value as the third required lower limit voltage Vs3. In this way, the control device 10 controls the sliding device 82 in the third deceleration stop process so as to stop the holding device 62 during the period when the third object voltage V3 is less than the third determination threshold value Vt3 and is greater than the third required lower limit voltage Vs3. Here, the control device 10 may also send the stop position of the holding device 62 in the forward and backward direction Y to the upper control system C after the third deceleration stop process. Thus, in the recovery operation after the poor condition of the power supply is eliminated, the upper control system C can easily calculate the correct stop position of the holding device 62. Therefore, the period of the recovery operation can be shortened. The control device 10 can calculate the position of the holding device 62 in the forward and backward direction Y, for example, by using an encoder mounted on the sliding motor. In addition, in this example, as Figure 5 As shown in FIG. 1 , the first determination threshold value Vt1 , the second determination threshold value Vt2 , and the third determination threshold value Vt3 are set to the same values, but these values ​​may be different from each other.

[0042] like Figure 5 As shown, when the first deceleration stop process, the second deceleration stop process, and the third deceleration stop process are not executed, if the first object voltage V1 becomes lower than the first necessary lower limit voltage Vs1, the travel of the transport vehicle 1 will suddenly stop. Similarly, if the second object voltage V2 becomes lower than the second necessary lower limit voltage Vs2, the lifting and lowering movement of the holding device 62 will suddenly stop. In addition, if the third object voltage V3 becomes lower than the third necessary lower limit voltage Vs3, the sliding movement of the holding device 62 will suddenly stop. Figure 5 In the example, when the normal voltage V0 is supplied, the travel speed of the transport vehicle 1, the lifting speed of the holding device 62, and the forward and backward speed are each set to a constant speed S1. Thereafter, if the respective object voltages drop to the required lower limit voltage (time T2), the travel speed of the transport vehicle 1, the lifting speed of the holding device 62, and the forward and backward speed are each decreased at a constant rate of decrease, and then become 0 (time T3). In addition, in Figure 5 , only schematically summarizes the changes in the travel speed of the transport vehicle 1, the lifting speed of the holding device 62, and the forward and backward speed. Therefore, the speed S1 does not mean that the travel speed of the transport vehicle 1, the lifting speed of the holding device 62, and the forward and backward speed become the same speed.

[0043] On the other hand, Figure 5In the example of , when the first deceleration and stop processing, the second deceleration and stop processing, and the third deceleration and stop processing are executed, if the first object voltage V1 becomes less than the first judgment threshold value Vt1 (time T1), the control device 10 controls the transport vehicle 1 to decelerate, and if the first object voltage V1 becomes the first necessary lower limit voltage Vs1, the transport vehicle 1 is stopped (time T2). Similarly, if the second object voltage V2 becomes less than the second judgment threshold value Vt2 (time T1), the control device 10 controls the lifting and lowering movement of the holding device 62 to decelerate, and if the second object voltage V2 becomes the second necessary lower limit voltage Vs2, the lifting and lowering movement of the holding device 62 is stopped (time T2). In addition, if the third object voltage V3 becomes less than the third judgment threshold value Vt3 (time T1), the control device 10 controls the sliding movement of the holding device 62 to decelerate, and if the third object voltage V3 becomes the third necessary lower limit voltage Vs3, the sliding movement of the holding device 62 is stopped (time T2). By executing the first deceleration and stop process, the second deceleration and stop process, and the third deceleration and stop process, the decreasing rates of the traveling speed of the transport vehicle 1, the lifting speed of the holding device 62, and the forward and backward speed become gentler than when the first deceleration and stop process, the second deceleration and stop process, and the third deceleration and stop process are not executed. Figure 5 In the example, by executing the first deceleration stop process, the second deceleration stop process and the third deceleration stop process, the stopping of the travel of the transport vehicle 1, the stopping of the lifting and lowering movement of the holding device 62 and the stopping of the sliding movement are completed earlier (time T2) compared to the case where these processes are not executed.

[0044] [Other implementation methods] (1) In the above embodiment, the transport vehicle 1 transports the articles W to the plurality of processing devices 7, but the present invention is not limited thereto. The transport vehicle 1 may transport the articles W to a storage rack or the like for storing the articles W.

[0045] (2) In the above-mentioned embodiment, the following configuration is used as an example to illustrate that by executing the first deceleration and stop processing, the second deceleration and stop processing, and the third deceleration and stop processing, the stop of the travel of the transport vehicle 1, the stop of the lifting and lowering movement of the holding device 62, and the stop of the sliding movement are completed in advance compared with the case where these processings are not executed, but it is not limited to this. For example, the period of completing the stop of the travel of the transport vehicle 1, the stop of the lifting and lowering movement of the holding device 62, and the stop of the sliding movement can also be the same when the first deceleration and stop processing, the second deceleration and stop processing, and the third deceleration and stop processing are executed and when these processings are not executed.

[0046] (3) In the above-mentioned embodiment, the following configuration is used as an example for explanation: the first determination threshold value Vt1 is set to be equal to or higher than the value obtained by adding the first required lower limit voltage Vs1 to the value obtained by multiplying the first voltage drop rate Ra by the first processing required time Ta, but the present invention is not limited thereto. The first determination threshold value Vt1 can be set to any value as long as it is greater than the first required lower limit voltage Vs1 and smaller than the normal voltage V0.

[0047] (4) In the above-mentioned embodiment, the following configuration is used as an example for explanation: if the first object voltage V1 becomes lower than the first judgment threshold value Vt1, the control device 10 controls the travel device 2 in a manner that decelerates and stops the transport vehicle 1 at a constant speed reduction rate as the first deceleration stop processing, and does not set the target stop position of the transport vehicle 1, but is not limited to this. The control device 10 can also set the target stop position in the deceleration stop processing, control the travel device 2 in a manner that stops the transport vehicle 1 at the target stop position, and execute a notification processing of notifying the superior control system C of the target stop position via the communication device 9. Fig. 9 Such an example is shown in FIG. Fig. 9 As shown, if the control device 10 determines that the first object voltage V1 is below the first determination threshold value Vt1 (S31: No), the first deceleration stop process (S32) is executed, and the notification process (S33) is executed. In this example, the control device 10 sets the target stop position of the transport vehicle 1 at the same period as the execution of the first deceleration stop process. Here, the target stop position can be set to a position that advances a specified distance from the position of the detected body 43 most recently detected by the detection device 15 of the transport vehicle 1 to the front in the driving direction X. For example, the deceleration rate of the transport vehicle 1 can be pre-set, and the specified distance is calculated based on the deceleration rate. In addition, the control device 10 can also store map information of the driving path 5 and use the map information to set the target stop position of the transport vehicle 1. When executing the first deceleration stop process, the control device 10 executes a notification process of sending the set target stop position to the upper control system C. In addition, the control device 10 can also execute the notification process after executing the first deceleration stop process and before completing the process. In addition, the control device 10 may notify the upper control system C of the deceleration start position of the transport vehicle 1 as a notification process. In this case, the upper control system C calculates the target stop position.

[0048] (5) In the above-described embodiment, the power supply unit 3 is described as an example in which the power supply unit 3 includes the power storage device 31 that temporarily stores electric power, but the present invention is not limited thereto. The power supply unit 3 may not necessarily include the power storage device 31 .

[0049] (6) In the above-mentioned embodiment, the configuration in which the control device 10 monitors the second object voltage V2 and executes the second deceleration and stop processing is described as an example, but the present invention is not limited thereto. It is also possible to set the configuration in which the control device 10 does not originally monitor the second object voltage V2. In this case, the control device 10 does not execute the second deceleration and stop processing. On the other hand, it is also possible that the control device 10 controls the lifting device 72 in a manner such that the holding device 62 is accommodated in the accommodating portion 17 when the second object voltage V2 becomes less than the second determination threshold value Vt2 during the second deceleration and stop processing, regardless of the position of the holding device 62.

[0050] (7) In the above-mentioned embodiment, the configuration in which the control device 10 monitors the third object voltage V3 and executes the third deceleration and stop process is described as an example, but the present invention is not limited thereto. It is also possible to set the configuration in which the control device 10 does not originally monitor the third object voltage V3. In this case, the control device 10 does not execute the third deceleration and stop process. On the other hand, it is also possible that the control device 10 controls the lifting device 72 in a manner such that the holding device 62 is accommodated in the accommodating portion 17 when the third object voltage V3 becomes less than the third determination threshold value Vt3 during the third deceleration and stop process, regardless of the position of the holding device 62 in the forward and backward direction Y.

[0051] (8) In addition, as long as no contradiction occurs, the configuration disclosed in each of the above-mentioned embodiments can also be combined with the configuration disclosed in other embodiments and applied (including the combination of the embodiments described as other embodiments). With regard to other configurations, the embodiments disclosed in this specification are merely illustrative in all aspects. Therefore, various changes can be appropriately made without departing from the scope of the present disclosure.

[0052] [Summary of the above-mentioned embodiments] Hereinafter, the transport vehicle described above will be generally described.

[0053] The transport vehicle involved in the present disclosure is a transport vehicle for transporting articles. The transport vehicle comprises: a travel device having a travel drive unit; a control device for controlling the travel device; and a power supply unit for receiving power supply from the outside and supplying power to at least the travel device and the control device. The voltage supplied from the power supply unit to the travel device is set as a target voltage, and the lower limit voltage required for the travel device to operate is set as a necessary lower limit voltage. The control device monitors the object voltage, and during the travel of the transport vehicle, when the object voltage becomes below a determination threshold value that is set to a value lower than the voltage in normal operation of the power supply unit and higher than the required lower limit voltage, a deceleration stop process is performed to reduce the travel speed of the transport vehicle and stop the travel of the transport vehicle.

[0054] According to this configuration, even if the voltage (target voltage) supplied to the travel device drops below the required lower limit voltage due to a power failure or a failure of the power supply unit, the transport vehicle can be decelerated at the stage where the voltage reaches the judgment threshold. Therefore, by making the target voltage lower than the required lower limit voltage, it is possible to avoid the travel device from being unable to operate and the transport vehicle from stopping suddenly. In this way, the transport vehicle can be prevented from stopping suddenly, and thus, for example, adverse effects such as a large acceleration acting on the article being transported can be alleviated.

[0055] Here, it is appropriate to define the time required from the start to the completion of the deceleration stop process as the necessary processing time, define the amount of decrease per unit time of the target voltage when an abnormality occurs in the power supply from the power supply unit as the voltage decrease rate, The determination threshold is set to be equal to or higher than a value obtained by adding the required lower limit voltage to a value obtained by multiplying the voltage drop rate by the required processing time.

[0056] According to this configuration, the deceleration and stop process can be completed after the target voltage becomes below the determination threshold and before it becomes the required lower limit voltage. Therefore, even if the voltage supplied to the travel device drops due to a poor power supply, the transport vehicle can be properly decelerated and stopped.

[0057] In addition, it is preferable to further include a communication device for communicating with a superior control system that controls the plurality of transport vehicles. The control device is configured to control the travel device based on instructions from the upper control system. The control device sets a target stop position in the deceleration stop process, controls the travel device so that the transport vehicle stops at the target stop position, and performs a notification process of notifying the upper control system of the target stop position via the communication device.

[0058] According to this configuration, the stop position of the transport vehicle can be grasped on the upper control system side, and thus the workload of the recovery process after the power supply failure is resolved can be reduced.

[0059] Furthermore, preferably, the power supply unit includes a power storage device that temporarily stores electric power, and is configured so that a voltage of the power storage device is supplied to the travel device.

[0060] According to this configuration, even when a power supply failure occurs, a rapid drop in the voltage supplied to the travel device can be avoided. Therefore, it is easy to ensure time for the control device to execute the deceleration stop process.

[0061] In addition, it is suitable to further include a holding device for holding the aforementioned article and a lifting device for lifting the aforementioned holding device. The voltage supplied from the power supply unit to the lifting device is set as a second target voltage, and the lower limit voltage required for the lifting device to operate is set as a second required lower limit voltage. The control device also monitors the second object voltage. During the lifting and lowering operation of the holding device controlled by the lifting device, when the second object voltage becomes below a second determination threshold value that is set to a value lower than the voltage in the normal operation of the power supply unit and higher than the second required lower limit voltage, the control device performs a second deceleration stop process to reduce the lifting and lowering speed of the holding device controlled by the lifting device and stop the lifting and lowering of the holding device.

[0062] According to this configuration, even when the voltage (second target voltage) supplied to the lifting device decreases due to a poor power supply condition such as a power outage or a failure of the power supply unit, the lifting speed of the holding device can be reduced at the stage where the voltage reaches the second judgment threshold. Therefore, by making the second target voltage lower than the second required lower limit voltage, it is possible to avoid the lifting device from being unable to operate and the holding device from stopping suddenly. In this way, it is possible to avoid a sudden stop of the holding device during the lifting operation, thereby alleviating adverse effects such as a large acceleration acting on the article being lifted and lowered.

[0063] In addition, it is suitable to further include a holding device for holding the aforementioned article and a sliding device for moving the aforementioned holding device forward and backward in a specific forward and backward direction, wherein the aforementioned specific forward and backward direction is along the horizontal direction. The voltage supplied from the power supply unit to the slide device is set as a third target voltage, and the lower limit voltage required for the slide device to operate is set as a third required lower limit voltage. The control device also monitors the third object voltage. During the forward and backward movement of the holding device controlled by the sliding device, when the third object voltage becomes below a third determination threshold value that is set to a value lower than the voltage in the normal operation of the power supply unit and higher than the third required lower limit voltage, the control device executes a third deceleration stop process for reducing the forward and backward speed of the holding device controlled by the sliding device and stopping the forward and backward movement of the holding device.

[0064] According to this configuration, even when the voltage (third target voltage) supplied to the sliding device decreases due to a poor power supply condition such as a power outage or a failure of the power supply unit, the forward and backward speed of the holding device can be reduced at the stage where the voltage reaches the third determination threshold. Therefore, by making the third target voltage lower than the third required lower limit voltage, it is possible to avoid the sliding device from being unable to operate and the holding device from stopping suddenly. In this way, it is possible to avoid a sudden stop of the holding device during the forward and backward movement, and thus, for example, it is possible to alleviate adverse effects such as a large acceleration acting on the moving article in the forward and backward direction.

[0065] The transport vehicle according to the present disclosure only needs to be able to achieve at least one of the above-mentioned effects.

Explanation of symbols

[0066] 1: Transport vehicle 2: Driving device 3: Power supply unit 9: Communication device 21: Travel drive unit 31: Power storage device 62: Holding device 72: Lifting device 82: Sliding device C: Superior control system Ra: 1st voltage drop rate (voltage drop rate) S: Target stop position Ta: First processing time (processing time) V1: 1st target voltage (target voltage) V2: Second target voltage V3: The third target voltage Vs1: 1st required lower limit voltage (required lower limit voltage) Vs2: Second required lower limit voltage Vs3: The third required lower limit voltage Vt1: First judgment threshold (judgment threshold) Vt2: Second judgment threshold Vt3: The third judgment threshold Y: forward and backward direction

Claims

1. A transport vehicle, which is a transport vehicle for transporting articles. The transport vehicle comprises: a travel device having a travel drive unit; a control device controlling the travel device; and a power supply unit receiving power supply from the outside and supplying power to at least the travel device and the control device. The transport vehicle has the following features: The voltage supplied from the power supply unit to the travel device is defined as a target voltage, and the lower limit voltage required for the travel device to operate is defined as a required lower limit voltage. The control device monitors the target voltage, and during the travel of the transport vehicle, when the target voltage becomes below a determination threshold value set to a value lower than the voltage in normal operation of the power supply unit and higher than the required lower limit voltage, performs a deceleration stop process to reduce the travel speed of the transport vehicle and stop the travel of the transport vehicle.

2. The transport vehicle according to claim 1, wherein: The time required from the start to the completion of the deceleration stop process is defined as the processing required time, the amount of decrease per unit time of the target voltage when an abnormality occurs in the power supply from the power supply unit is defined as the voltage decrease rate, The determination threshold is set to be equal to or greater than a value obtained by adding the required lower limit voltage to a value obtained by multiplying the voltage drop rate by the required processing time.

3. The transport vehicle according to claim 1, It also includes a communication device for communicating with a superior control system that controls the plurality of transport vehicles. The control device is configured to control the travel device based on a command from the upper control system. The control device sets a target stop position in the deceleration stop process, controls the travel device so that the transport vehicle stops at the target stop position, and performs a notification process of notifying the upper control system of the target stop position via the communication device.

4. The transport vehicle according to any one of claims 1 to 3, wherein: The power supply unit includes a power storage device for temporarily storing electric power. The configuration is such that the voltage of the power storage device is supplied to the travel device.

5. The transport vehicle according to any one of claims 1 to 3, It also includes a holding device for holding the article and a lifting device for lifting the holding device. The voltage supplied from the power supply unit to the lifting device is set as a second target voltage, and the lower limit voltage required for the lifting device to operate is set as a second required lower limit voltage. The control device also monitors the second object voltage, and during the lifting and lowering action of the holding device controlled by the lifting device, when the second object voltage becomes below a second judgment threshold value set to a value lower than the voltage in normal operation of the power supply unit and higher than the second required lower limit voltage, a second deceleration stop process is performed to reduce the lifting and lowering speed of the holding device controlled by the lifting device and stop the lifting and lowering of the holding device.

6. The transport vehicle according to any one of claims 1 to 3, The invention also comprises a holding device for holding the article and a sliding device for moving the holding device forward and backward in a specific forward and backward direction, wherein the specific forward and backward direction is along the horizontal direction. The voltage supplied from the power supply unit to the slide device is set as a third target voltage, and the lower limit voltage required for the slide device to operate is set as a third required lower limit voltage. The control device also monitors the third object voltage, and during the forward and backward movement of the holding device controlled by the sliding device, when the third object voltage becomes below a third judgment threshold value set to a value lower than the voltage in normal operation of the power supply unit and higher than the third required lower limit voltage, the control device executes a third deceleration stop process to reduce the forward and backward speed of the holding device controlled by the sliding device and stop the forward and backward movement of the holding device.

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