Goods handling equipment

Abstract

The aim is to provide a goods transport system that minimizes the decrease in the efficiency of goods transport by transport vehicles while also making it easier to reduce the energy consumption of the transport vehicles. [Solution] Each of the multiple transport vehicles is equipped with a speed detection unit that detects the current speed V and a distance detection unit that detects an inter-vehicle distance index D, which is an index corresponding to the distance to another transport vehicle located ahead in the direction of travel. The control system performs a first target speed determination process to determine the control target speed V2 based on the distance-corresponding target speed V1, which is set to increase as the inter-vehicle distance index D increases, the current speed V, and the inter-vehicle distance index D. The first target speed determination process includes an acceleration determination process to determine whether to perform an acceleration process to set the control target speed V2 to a distance-corresponding target speed V1 that is higher than the current speed V. In the acceleration determination process, the control system performs the acceleration process if the relationship between the current speed V and the distance-corresponding target speed V1 satisfies the acceleration condition and that state continues for a determination time T or longer.

Description

Technical Field

[0001] The present invention relates to an article conveying facility including a plurality of carrier vehicles that travel along a travel route to convey articles, and a control system that controls the plurality of carrier vehicles.

Background Art

[0002] An example of such an article conveying facility is disclosed in Patent Document 1 below. In the article conveying facility of Patent Document 1, each of the plurality of carrier vehicles includes a distance detection unit that detects the distance (inter-vehicle distance) from another carrier vehicle existing in front in the travel direction. The control system calculates the amount of change in the inter-vehicle distance (distance change amount) per unit time based on the inter-vehicle distance detected by the distance detection unit, and calculates the difference between a preset appropriate set distance and the inter-vehicle distance (distance difference). Then, the control system increases or decreases the acceleration of the carrier vehicle according to the distance change amount and the distance difference.

[0003] Thus, in the article conveying facility of Patent Document 1, the carrier vehicle is made to travel while changing the acceleration so as to maintain an appropriate inter-vehicle distance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the article transport equipment described in Patent Document 1, even when the transport vehicle is controlled to accelerate by increasing the acceleration due to factors such as a larger distance between vehicles, depending on the conditions of the transport vehicle's travel path, such as congestion ahead in the direction of travel, the acceleration of the transport vehicle may be wasted, potentially leading to increased energy consumption of the transport vehicle. To reduce the energy consumption of the transport vehicle, it is conceivable to reduce the frequency of acceleration of the transport vehicle, but this may lead to a decrease in the efficiency of article transport by the transport vehicle.

[0006] Therefore, there is a need to realize a material handling system that minimizes the decrease in the efficiency of material handling by transport vehicles while also easily reducing the energy consumption of the transport vehicles. [Means for solving the problem]

[0007] In light of the above, the characteristic configuration of the goods conveying equipment is: An article transporting system comprising: a plurality of transport vehicles that travel along a travel path to transport articles; and a control system that controls the plurality of transport vehicles, Each of the multiple transport vehicles is equipped with a speed detection unit that detects its current speed, which is its current driving speed, and a distance detection unit that detects an inter-vehicle distance index, which is an index corresponding to the distance to another transport vehicle located ahead in the direction of travel. The control system is configured to perform a first target speed determination process that determines a control target speed, which is a target value for controlling the driving speed, based on a distance-corresponding target speed, which is a target value for the driving speed, which is a target value for the driving speed, which is preset to increase as the inter-vehicle distance index increases, the current speed, and the inter-vehicle distance index. The first target speed determination process includes an acceleration determination process that determines whether or not to perform an acceleration process to set the control target speed to the distance-corresponding target speed which is higher than the current speed. In the acceleration determination process, the control system determines that it will execute the acceleration process if the relationship between the current speed and the distance-corresponding target speed is in an acceleration-adjusted state that satisfies a preset acceleration condition, and the acceleration-adjusted state continues for a preset determination time or longer.

[0008] With this feature configuration, even if the relationship between the current speed and the distance-corresponding target speed meets the pre-set acceleration conditions and results in an acceleration-compatible state, the acceleration process will not be executed unless the acceleration-compatible state continues for a pre-set duration or longer. This reduces unnecessary acceleration of the transport vehicle, allowing it to travel more efficiently. Therefore, it is easier to minimize the decrease in the efficiency of goods transported by the transport vehicle while keeping the energy consumption of the transport vehicle low. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram showing the overall configuration of the article conveying equipment according to this embodiment. [Figure 2] Side view of a transport vehicle included in the article transport equipment according to this embodiment. [Figure 3] Block diagram showing the configuration of the article conveying equipment according to the embodiment. [Figure 4] A flowchart illustrating an example of control processing by a control system. [Figure 5] Figure showing the inter-vehicle distance indicator according to other embodiments. [Figure 6] Figure showing the inter-vehicle distance indicator according to other embodiments. [Modes for carrying out the invention]

[0010] In the following, the article transport equipment 100 according to the embodiment will be described with reference to the drawings.

[0011] As shown in Figure 1, the goods transport equipment 100 is equipped with multiple transport vehicles 1 that travel along a travel path P to transport goods W (see Figure 2).

[0012] In this embodiment, the travel path P comprises a main path Pa formed in a ring shape, a plurality of secondary paths Pb formed in a ring shape, each passing through a plurality of stations S, and a plurality of connecting paths Pc that connect the main path Pa and the plurality of secondary paths Pb.

[0013] Station S is configured such that the carrier 1 stops at a position corresponding to the station S, and the delivery of the article W and the like is performed between the carrier 1 and the station S. The delivery target of the article W at the station S is, for example, the load port of a processing apparatus that processes the article W, the loading / unloading port of a storage apparatus that stores the article W, a storage shelf that temporarily stores the article W, and the like.

[0014] As shown in FIG. 2, in the present embodiment, the article conveying facility 100 further includes a traveling rail 2 suspended from the ceiling. The traveling rail 2 is arranged along the traveling path P. In the present embodiment, the carrier 1 is a ceiling carrier that is guided by the traveling rail 2 and travels along the traveling path P. The article W is, for example, a FOUP (Front Opening Unified Pod) that houses a semiconductor substrate, a glass substrate that is a material for a display, or the like.

[0015] In the present embodiment, the carrier 1 includes a traveling unit 11 and a transfer unit 12.

[0016] The traveling unit 11 includes a plurality of traveling wheels 11a that roll on the traveling rail 2. In the present embodiment, at least one of the plurality of traveling wheels 11a rotates by the driving force of a traveling motor (not shown) and rolls on the traveling rail 2, so that the traveling unit 11 travels along the traveling path P.

[0017] The transfer unit 12 transfers the article W between the station S. Although detailed description is omitted, the transfer unit 12 includes, for example, a holding unit that holds the article W and a lifting unit that moves the holding unit up and down with respect to the traveling unit 11. Further, the transfer unit 12 includes a horizontal movement unit that horizontally moves the holding unit with respect to the traveling unit 11 and a turning unit that rotates the holding unit with respect to the traveling unit 11 about a rotation axis along the vertical direction, as necessary. Note that the transfer unit 12 only needs to include a configuration necessary for transferring the article W between the station S, and is not limited to the above configuration.

[0018] In the following description, any carrier 1 is referred to as "target vehicle 1A", and another carrier 1 existing in front of the target vehicle 1A in the traveling direction (refer to the white arrow in FIG. 2) is referred to as "preceding vehicle 1B".

[0019] As shown in FIG. 3, the article conveying facility 100 includes a control system 10 for controlling a plurality of carriers 1. In this embodiment, the control system 10 includes a first control device 3 provided at a predetermined location of the article conveying facility 100, and a second control device 4 provided on each of the plurality of carriers 1. The first control device 3 and the plurality of second control devices 4 are configured to be capable of wireless communication with each other.

[0020] The first control device 3 outputs a control command to each of the plurality of second control devices 4. The first control device 3 includes a processing unit 31 that performs prescribed processing, and a storage unit 32 that stores various information.

[0021] The second control device 4 controls the operations of the traveling unit 11 and the transfer unit 12 based on the control command from the first control device 3.

[0022] Each of the plurality of carriers 1 includes a speed detection unit 13 that detects the current speed V, which is the current traveling speed of itself (target vehicle 1A), and a distance detection unit 14 that detects an inter-vehicle distance index D, which is an index corresponding to the distance from another carrier 1 (preceding vehicle 1B) existing in front in the traveling direction. In this embodiment, the inter-vehicle distance index D is the inter-vehicle distance between the target vehicle 1A and the preceding vehicle 1B.

[0023] In this embodiment, the second control device 4 transmits the current speed V detected by the speed detection unit 13 and the inter-vehicle distance index D detected by the distance detection unit 14 to the first control device 3.

[0024] The control system 10 is configured to perform a first target speed determination process that determines a target control speed V2, which is a target value for controlling the travel speed of the transport vehicle 1, based on the current speed V, the inter-vehicle distance index D, and the distance-corresponding target speed V1. In this embodiment, the control system 10 is further configured to perform a second target speed determination process that determines the control target speed V2. In this embodiment, the processing unit 31 of the first control device 3 performs control processing of the transport vehicle 1, including the first target speed determination process and the second target speed determination process.

[0025] The distance-corresponding target speed V1 is a target value for the travel speed of the transport vehicle 1, which is pre-set to increase as the inter-vehicle distance index D increases. In this embodiment, a target speed table in which the distance-corresponding target speed V1 for the inter-vehicle distance index D is registered is stored in the storage unit 32 of the first control device 3. The processing unit 31 of the first control device 3 then refers to the target speed table stored in the storage unit 32 and obtains the distance-corresponding target speed V1 corresponding to the inter-vehicle distance index D detected by the distance detection unit 14.

[0026] The control process by the control system 10 will be described below with reference to Figure 4. Figure 4 is a flowchart showing an example of the control process by the control system 10.

[0027] The control system 10 executes the following control processes at predetermined intervals.

[0028] As shown in Figure 4, the control system 10 first causes the speed detection unit 13 to detect the current speed V and acquires the detected current speed V (step #1). Note that the process of acquiring the current speed V (step #1) may be performed in parallel with the processes (steps #2 and #3) or after the processes (steps #2 and #3), rather than before the process of detecting the inter-vehicle distance index D (step #2) or the process of acquiring the distance-corresponding target speed V1 (step #3).

[0029] Next, the control system 10 causes the distance detection unit 14 to detect the inter-vehicle distance index D and acquires the detected inter-vehicle distance index D (step #2). Then, the control system 10 acquires the distance-corresponding target speed V1 corresponding to the inter-vehicle distance index D (step #3).

[0030] Next, the control system 10 determines whether the increase in the inter-vehicle distance index D per specified time (D(n)-D(n-1)) is less than or equal to a preset reference value R (step #4). Here, D(n) is the current inter-vehicle distance index D, and D(n-1) is the previously detected inter-vehicle distance index D. Note that if D(n) is less than D(n-1), the increase in the inter-vehicle distance index D per specified time will be a negative value. Also, as described above, in this embodiment, the inter-vehicle distance index D is the distance between the transport vehicle 1 and another transport vehicle 1 located in front of the transport vehicle 1 in the direction of travel. Therefore, in this embodiment, the reference value R is a value indicating distance (for example, 200 [mm]). Note that the reference value R can be used as a correction value and may be set to zero or a negative value, not just a positive value.

[0031] If the increase in the predetermined hourly interval distance index D (D(n)-D(n-1)) is less than or equal to the reference value R (Step #4: Yes), the control system 10 executes the first target speed determination process. For example, if the distance between the target vehicle 1A and the preceding vehicle 1B is approximately the same or has decreased, it is determined to be "Yes" in Step #4, and if the distance between the target vehicle 1A and the preceding vehicle 1B has increased to some extent, it is determined to be "No" in Step #4.

[0032] In the first target speed determination process, the control system 10 first determines whether the current speed V is less than the distance-corresponding target speed V1 (step #5).

[0033] If the current speed V is less than the distance-corresponding target speed V1 (Step #5: Yes), the control system 10 determines whether the difference between the current speed V and the distance-corresponding target speed V1 is less than or equal to a preset threshold TH (Step #6).

[0034] Here, the "difference between the current speed V and the distance-corresponding target speed V1" is, for example, the value obtained by simply subtracting the current speed V from the distance-corresponding target speed V1. In this case, the judgment threshold TH will be a value indicating speed (for example, 10 [m / min]). Alternatively, multiple speed ranges may be defined by numerical values ​​corresponding to the travel speed of the transport vehicle 1, and the value obtained by subtracting the speed range to which the current speed V belongs from the speed range to which the distance-corresponding target speed V1 belongs (a value representing the difference between speed range stages) may be used as the "difference between the current speed V and the distance-corresponding target speed V1". In this case, the judgment threshold TH will be a value indicating speed range (a value representing the speed range stage, for example, 1).

[0035] If the difference between the current speed V and the distance-corresponding target speed V1 is less than or equal to the determination threshold TH (Step #6: Yes), the control system 10 performs constant speed processing with the control target speed V2 set to the current speed V (Step #7).

[0036] On the other hand, if the difference between the current speed V and the distance-corresponding target speed V1 is greater than the judgment threshold TH (Step #6: No), the control system 10 determines whether the acceleration adaptation state has continued for a preset judgment time T or longer (Step #8).

[0037] Here, the "acceleration-adjusted state" is a state in which the relationship between the current speed V and the distance-corresponding target speed V1 satisfies the predetermined acceleration conditions. In this embodiment, when the increase in the predetermined inter-vehicle distance index D per unit time (D(n)-D(n-1)) is less than or equal to the reference value R (Step #4: Yes), the "acceleration conditions" are that the current speed V is less than the distance-corresponding target speed V1 (Step #5: Yes), and the difference between the current speed V and the distance-corresponding target speed V1 is greater than the judgment threshold TH (Step #6: No).

[0038] Furthermore, in this embodiment, the "determination time T" is a value corresponding to the number of times the control system 10 executes the control process (for example, a time equivalent to 10 control processes by the control system 10). For example, the number of times the distance detection unit 14 detects the inter-vehicle distance index D can be used as the number of times the control process is executed. In this case, the time of one cycle in the detection cycle of the inter-vehicle distance index D by the distance detection unit 14 corresponds to the time of one control process.

[0039] If the acceleration adaptation state continues for a judgment time T or longer (Step #8: Yes), the control system 10 sets the control target speed V2 to the distance-corresponding target speed V1 (Step #9). At this time, since the distance-corresponding target speed V1 is higher than the current speed V (Step #5: Yes), the acceleration process is executed.

[0040] Furthermore, in step #5 above, if the current speed V is greater than or equal to the distance-corresponding target speed V1 (step #5: No), the control system 10 sets the control target speed V2 to the distance-corresponding target speed V1 (step #9). In this case, if the distance-corresponding target speed V1 is lower than the current speed V, deceleration processing is performed, and if the distance-corresponding target speed V1 is equal to the current speed V, constant speed processing is performed.

[0041] On the other hand, if the time during which the acceleration adaptation state is continuous is less than the determination time T (Step #8: No), the control system 10 performs a constant speed process to set the control target speed V2 to the current speed V (Step #7).

[0042] In step #4 above, if the increase in the specified inter-vehicle distance index D per unit time (D(n)-D(n-1)) is greater than the reference value R (step #4: No), the control system 10 performs the second target speed determination process.

[0043] In the second target speed determination process, the control system 10 first determines whether the control target speed V2 was set as the distance-corresponding target speed V1 in the previous control process, that is, whether a deceleration process or an acceleration process was performed in the previous control process (step #10).

[0044] If deceleration or acceleration processing was performed in the previous control process (Step #10: Yes), the control system 10 will perform deceleration or acceleration processing, that is, it will continue the state in which the control target speed V2 is the distance-corresponding target speed V1 (Step #9).

[0045] On the other hand, if deceleration or acceleration processing was not performed in the previous control processing, that is, if constant speed processing was performed in the previous control processing (Step #10: No), the control system 10 determines whether the current speed V is less than the distance-corresponding target speed V1 (Step #11).

[0046] If the current speed V is less than the distance-corresponding target speed V1 (Step #11: Yes), the control system 10 determines whether the acceleration-adjusted state that satisfies the acceleration condition has continued for a judgment time T or longer (Step #8). In this embodiment, the "acceleration condition" when the increase in the inter-vehicle distance index D per specified time (D(n)-D(n-1)) is greater than the reference value R (Step #4: No) is that the current speed V is less than the distance-corresponding target speed V1 (Step #11: Yes).

[0047] If the acceleration-adjusted state continues for a judgment time T or longer (Step #8: Yes), the control system 10 sets the control target speed V2 to the distance-corresponding target speed V1 (Step #9). At this time, since the distance-corresponding target speed V1 is higher than the current speed V (Step #11: Yes), the acceleration process is executed.

[0048] On the other hand, if the time during which the acceleration adaptation state is continuous is less than the determination time T (Step #8: No), the control system 10 performs a constant speed process to set the control target speed V2 to the current speed V (Step #7).

[0049] In step #11 above, if the current speed V is greater than or equal to the distance-corresponding target speed V1 (step #11: No), the control system 10 sets the control target speed V2 to the distance-corresponding target speed V1 (step #9). In this case, if the distance-corresponding target speed V1 is lower than the current speed V, deceleration processing is performed, and if the distance-corresponding target speed V1 is equal to the current speed V, constant speed processing is performed.

[0050] As described above, the first target speed determination process includes an acceleration determination process (corresponding to steps #5, #6, and #8) that determines whether or not to execute an acceleration process (corresponding to step #9) to set the control target speed V2 to a distance-corresponding target speed V1 that is higher than the current speed V.

[0051] Then, in the acceleration determination process (corresponding to steps #5, #6, and #8), the control system 10 determines that the relationship between the current speed V and the distance-corresponding target speed V1 is in an acceleration-adjusted state that satisfies the preset acceleration conditions (corresponding to steps #5 and #6), and that this acceleration-adjusted state continues for a preset determination time T or longer (corresponding to step #8: Yes), and that it will execute the acceleration process (corresponding to step #9).

[0052] Thus, in the acceleration determination process (corresponding to steps #5, #6, and #8), even if the relationship between the current speed V and the distance-dependent target speed V1 reaches an acceleration-compatible state (corresponding to steps #5 and #6) that satisfies the preset acceleration conditions, the acceleration process (corresponding to step #9) will not be executed unless the acceleration-compatible state continues for a preset determination time T or longer (corresponding to step #8: Yes). This reduces unnecessary acceleration of the transport vehicle 1, allowing it to travel efficiently. Therefore, it is easier to keep the energy consumption of the transport vehicle 1 low while minimizing the decrease in the efficiency of transporting goods W by the transport vehicle 1.

[0053] Incidentally, congestion of the transport vehicle 1 is likely to occur at merging and crossing points on the travel route P (for example, the connection point between the main route Pa and the connecting route Pc in Figure 1), and consequently, the energy consumption of the transport vehicle 1 tends to increase. Therefore, the effect of reducing energy consumption by the above control processing is more likely to be seen when there are many merging and crossing points on the travel route P.

[0054] In this embodiment, the acceleration determination process (corresponding to steps #5, #6, and #8) includes a determination (corresponding to step #8) of whether or not to perform a constant speed process (corresponding to step #7) with the control target speed V2 set to the current speed V. Then, in the acceleration determination process (corresponding to steps #5, #6, and #8), the control system 10 determines that if the time during which the acceleration-adjusted state has been continuous is less than the determination time T (corresponding to step #8: No), it will perform the constant speed process (corresponding to step #7) without performing the acceleration process (corresponding to step #9).

[0055] Furthermore, in this embodiment, if the increase in the inter-vehicle distance index D per specified time (D(n)-D(n-1)) is less than or equal to the reference value R (corresponding to step #4: Yes), the control system 10 executes an acceleration determination process (corresponding to steps #5, #6, and #8) with the acceleration conditions being that the current speed V is less than the distance-corresponding target speed V1 (corresponding to step #5: Yes) and the difference between the current speed V and the distance-corresponding target speed V1 is greater than the determination threshold TH (corresponding to step #6: No).

[0056] Furthermore, in this embodiment, in the acceleration determination process (corresponding to steps #5, #6, and #8), the control system 10 determines that even if the current speed V is less than the distance-corresponding target speed V1 (corresponding to step #5: Yes), if the difference between the current speed V and the distance-corresponding target speed V1 is less than or equal to the determination threshold TH (corresponding to step #6: Yes), it will execute the constant speed process (corresponding to step #7) without executing the acceleration process (corresponding to step #9).

[0057] Furthermore, in this embodiment, the first target speed determination process further includes a deceleration determination process (corresponding to step #5) that determines whether or not to execute a deceleration process (corresponding to step #9) to set the control target speed V2 to a distance-corresponding target speed V1 that is lower than the current speed V.

[0058] Then, in the deceleration determination process (corresponding to step #5), the control system 10 determines that if the relationship between the current speed V and the distance-corresponding target speed V1 satisfies the pre-set deceleration conditions (corresponding to step #5: No), it will execute the deceleration process (corresponding to step #9).

[0059] Furthermore, in this embodiment, the control system 10 is configured to further execute a second target speed determination process (corresponding to steps #10 and #11) that determines the control target speed V2 when the increase in the inter-vehicle distance index D per specified time (D(n)-D(n-1)) is greater than the reference value R (corresponding to step #4: No).

[0060] In this embodiment, in the second target speed determination process (corresponding to steps #10 and #11), if the control system 10 has set the control target speed V2 to the distance-corresponding target speed V1 (corresponding to step #10: Yes), it continues to maintain the state in which the control target speed V2 is set to the distance-corresponding target speed V1.

[0061] Furthermore, if constant speed processing (corresponding to step #7) was being performed (corresponding to step #10: No), and the current speed V is higher than the distance-corresponding target speed V1 (corresponding to step #11: No), it is determined to perform deceleration processing (corresponding to step #9).

[0062] Then, if constant speed processing (corresponding to step #7) was being performed (corresponding to step #10: No), and the current speed V is less than the distance-corresponding target speed V1 (corresponding to step #11: Yes), the acceleration determination process (corresponding to steps #8 and #11) is executed, with the condition that the current speed V is less than the distance-corresponding target speed V1 (corresponding to step #11: Yes) being used as the acceleration condition.

[0063] [Other Embodiments] (1) In the above embodiment, the configuration in which the inter-vehicle distance index D is the distance between the target vehicle 1A and the preceding vehicle 1B was described as an example. However, the configuration is not limited to such an example. For example, as shown in Figures 5 and 6, multiple distance regions defined by numerical values ​​corresponding to the distance between the target vehicle 1A and the preceding vehicle 1B may be set, and the numerical value indicating the distance region in which the distance between the target vehicle 1A and the preceding vehicle 1B is located may be used as the inter-vehicle distance index D. In the example shown in Figures 5 and 6, five distance regions, from the first region D1 to the fifth region D5, are set in ascending order of numerical value. The numerical values ​​for the first region D1 to the fifth region D5 are defined as "1" to "5", respectively. Therefore, in this embodiment, the reference value R is a value indicating the distance region (for example, "0"). In this example, the range widens from the first region D1 to the fifth region D5.

[0064] In the example shown in Figure 5, a specified amount of time has elapsed since the distance between the target vehicle 1A and the preceding vehicle 1B was in the fifth region D5. Although the distance between the target vehicle 1A and the preceding vehicle 1B has decreased, the distance region in which this distance is located remains unchanged from the fifth region D5. In this case, the increase in the inter-vehicle distance index D per specified time (D(n)-D(n-1)) is "0". Note that in Figure 5, the distance region in which the distance between the target vehicle 1A and the preceding vehicle 1B is located is shown with hatching, and the same applies in Figure 6.

[0065] On the other hand, in the example shown in Figure 6, a specified amount of time has elapsed since the distance between the target vehicle 1A and the preceding vehicle 1B was in the fifth region D5. As a result, the distance between the target vehicle 1A and the preceding vehicle 1B decreases, and the distance region in which this distance is located changes from the fifth region D5 to the fourth region D4. At this time, the increase in the inter-vehicle distance index D per specified unit of time (D(n)-D(n-1)) is "-1".

[0066] (2) In the above embodiment, the transport vehicle 1 was described as an overhead transport vehicle that is guided by a travel rail 2 suspended from the ceiling and travels along a travel path P. However, the embodiment is not limited to such a configuration, and for example, the transport vehicle 1 may be a tracked transport vehicle that travels along rails provided on the floor. Alternatively, the transport vehicle 1 may be a trackless transport vehicle such as an AGV (Automated Guided Vehicle) or an AMR (Autonomous Mobile Robot). If the transport vehicle 1 is a trackless transport vehicle, the transport vehicle 1 travels along a virtually formed travel path P, rather than a physically formed travel path P using rails, etc. In this case, the travel path P can be formed by a plurality of detectable objects (for example, 2D codes, RF (Radio Frequency) tags, etc.) installed on the floor. It is also possible to have a configuration in which such detectable objects are not provided on the floor, and the travel path P is virtually formed by a route calculated based on the recognition results of the surrounding environment.

[0067] (3) In the above embodiment, the control system 10 was described as comprising a first control device 3 and a second control device 4 provided on each of the multiple transport vehicles 1, and the first control device 3 issued commands to the multiple second control devices 4 as an example. However, the system is not limited to such a configuration, and for example, the multiple second control devices 4 may operate independently of each other or cooperate with each other.

[0068] (4) In the above embodiment, the determination time T was described as a value corresponding to the number of times the control system 10 has executed control processing (for example, a time equivalent to 10 control processing operations by the control system 10). However, the configuration is not limited to such an example, and the determination time T may be set to a time independent of the number of times the control system 10 has executed control processing.

[0069] (5) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0070] [Summary of this embodiment] The following section provides an overview of the goods handling equipment described above.

[0071] The goods transport equipment comprises a plurality of transport vehicles that travel along a travel path to transport goods, and a control system that controls the plurality of transport vehicles, Each of the multiple transport vehicles is equipped with a speed detection unit that detects its current speed, which is its current driving speed, and a distance detection unit that detects an inter-vehicle distance index, which is an index corresponding to the distance to another transport vehicle located ahead in the direction of travel. The control system is configured to perform a first target speed determination process that determines a control target speed, which is a target value for controlling the driving speed, based on a distance-corresponding target speed, which is a target value for the driving speed, which is a target value for the driving speed, which is preset to increase as the inter-vehicle distance index increases, the current speed, and the inter-vehicle distance index. The first target speed determination process includes an acceleration determination process that determines whether or not to perform an acceleration process to set the control target speed to the distance-corresponding target speed which is higher than the current speed. In the acceleration determination process, the control system determines that it will execute the acceleration process if the relationship between the current speed and the distance-corresponding target speed is in an acceleration-adjusted state that satisfies a preset acceleration condition, and the acceleration-adjusted state continues for a preset determination time or longer.

[0072] With this configuration, even if the relationship between the current speed and the distance-corresponding target speed meets the pre-set acceleration conditions and results in an acceleration-compatible state, the acceleration process will not be executed unless the acceleration-compatible state continues for a pre-set duration or longer. This reduces unnecessary acceleration of the transport vehicle, allowing it to travel more efficiently. Therefore, it is easier to minimize the decrease in the efficiency of goods transported by the transport vehicle while keeping the energy consumption of the transport vehicle low.

[0073] Here, the acceleration determination process includes a determination of whether or not to perform a constant speed process where the control target speed is the current speed. In the acceleration determination process, it is preferable that the control system determines to execute the constant speed process without executing the acceleration process if the time during which the acceleration-adjusted state is continuous is less than the determination time.

[0074] With this configuration, even if the relationship between the current speed and the distance-corresponding target speed reaches an acceleration-compatible state that satisfies the acceleration conditions, if this acceleration-compatible state does not continue for longer than the judgment time, constant speed processing will be executed instead of acceleration processing. This makes it easier to minimize unnecessary acceleration of the transport vehicle. Therefore, it is easier to keep the energy consumption of the transport vehicle low.

[0075] In the above configuration, if the increase in the inter-vehicle distance index per specified time is less than or equal to a preset reference value, the control system preferably executes the acceleration determination process with the acceleration condition being that the current speed is less than the distance-corresponding target speed and the difference between the current speed and the distance-corresponding target speed is greater than a preset determination threshold.

[0076] With this configuration, if the increase in the specified inter-vehicle distance index per unit time is zero or negative, or if the increase is positive but relatively small, acceleration processing will not be performed even if the current speed is below the distance-corresponding target speed, as long as the difference between the current speed and the distance-corresponding target speed is relatively small. This makes it easier to minimize unnecessary acceleration of the transport vehicle. Consequently, it is easier to keep the energy consumption of the transport vehicle low.

[0077] In the above configuration, in the acceleration determination process, it is preferable that the control system determines to execute the constant speed process without executing the acceleration process if the difference between the current speed and the distance-corresponding target speed is less than or equal to the determination threshold, even if the current speed is less than or equal to the distance-corresponding target speed.

[0078] With this configuration, if the increase in the specified inter-vehicle distance index per unit time is zero or negative, or if the increase is positive but relatively small, even if the current speed is below the distance-corresponding target speed, constant speed processing will be performed instead of acceleration processing if the difference between the current speed and the distance-corresponding target speed is relatively small. This makes it easier to minimize unnecessary acceleration of the transport vehicle. Therefore, it is easier to keep the energy consumption of the transport vehicle low.

[0079] Furthermore, the first target speed determination process further includes a deceleration determination process that determines whether or not to perform a deceleration process to set the control target speed to the distance-corresponding target speed which is lower than the current speed. In the deceleration determination process, it is preferable that the control system determines to execute the deceleration process when the relationship between the current speed and the distance-corresponding target speed satisfies a preset deceleration condition.

[0080] This configuration allows for proper deceleration processing.

[0081] In the above configuration, the control system is configured to further execute a second target speed determination process for determining the control target speed when the increase in the inter-vehicle distance index per specified time is greater than the reference value. In the second target velocity determination process, the control system: If the control target speed is the distance-corresponding target speed, the state in which the control target speed is the distance-corresponding target speed is continued. If the constant speed processing described above is being performed and the current speed is higher than the distance-corresponding target speed, it is determined to perform the deceleration processing. If the constant speed processing described above is being performed and the current speed is less than the distance-corresponding target speed, it is preferable to perform the acceleration determination processing with the condition that the current speed is less than the distance-corresponding target speed as the acceleration condition.

[0082] With this configuration, if the increase in the specified inter-vehicle distance index per unit time is relatively large, the second target speed determination process is executed. If deceleration or acceleration processing was performed during the second target speed determination process, then deceleration or acceleration processing is executed. Furthermore, if constant speed processing was performed during the second target speed determination process and the current speed is higher than the distance-corresponding target speed, then deceleration processing is executed. If constant speed processing was performed and the current speed is less than the distance-corresponding target speed, then acceleration determination processing is executed without including the difference between the current speed and the distance-corresponding target speed being greater than the determination threshold as an acceleration condition. Thus, with this configuration, when the increase in the specified inter-vehicle distance index per unit time is relatively large, the transport vehicle can be driven efficiently without unnecessarily reducing the frequency of acceleration of the transport vehicle. [Industrial applicability]

[0083] The technology disclosed herein can be used in an article transport system comprising a plurality of transport vehicles that travel along a route to transport articles, and a control system that controls the plurality of transport vehicles. [Explanation of symbols]

[0084] 100: Goods handling equipment 10: Control System 1: Transport vehicle 13: Speed ​​detection unit 14: Distance detection unit P: Route W:Goods D: Inter-vehicle distance index V: Current speed V1: Distance-based target speed V2: Control target speed R: Reference value T: Judgment time TH: Judgment threshold

Claims

1. An article transporting system comprising: a plurality of transport vehicles that travel along a travel path to transport articles; and a control system that controls the plurality of transport vehicles, Each of the multiple transport vehicles is equipped with a speed detection unit that detects its current speed, which is its current driving speed, and a distance detection unit that detects an inter-vehicle distance index, which is an index corresponding to the distance to another transport vehicle located ahead in the direction of travel. The control system is configured to perform a first target speed determination process that determines a control target speed, which is a target value for controlling the driving speed, based on a distance-corresponding target speed, which is a target value for the driving speed, which is a target value for the driving speed, which is preset to increase as the inter-vehicle distance index increases, the current speed, and the inter-vehicle distance index. The first target speed determination process includes an acceleration determination process that determines whether or not to perform an acceleration process to set the control target speed to the distance-corresponding target speed which is higher than the current speed. In the acceleration determination process, the control system determines to execute the acceleration process when the relationship between the current speed and the distance-corresponding target speed is in an acceleration-adjusted state that satisfies a preset acceleration condition, and the acceleration-adjusted state continues for a preset determination time or longer.

2. The acceleration determination process includes a determination of whether or not to perform a constant speed process where the control target speed is the current speed. The article conveying equipment according to claim 1, wherein in the acceleration determination process, the control system determines that if the time during which the acceleration suitability state is continuous is less than the determination time, it will execute the constant speed process without executing the acceleration process.

3. The article transport equipment according to claim 2, wherein if the increase in the inter-vehicle distance index per specified time is less than or equal to a preset reference value, the control system executes the acceleration determination process with the current speed being less than the distance-corresponding target speed and the difference between the current speed and the distance-corresponding target speed being greater than a preset determination threshold as the acceleration condition.

4. The article transport equipment according to claim 3, wherein in the acceleration determination process, the control system determines to execute the constant speed process without executing the acceleration process if the difference between the current speed and the distance-corresponding target speed is less than or equal to the determination threshold, even if the current speed is less than or equal to the distance-corresponding target speed.

5. The first target speed determination process further includes a deceleration determination process that determines whether or not to perform a deceleration process to set the control target speed to the distance-corresponding target speed which is lower than the current speed, The article conveying equipment according to claim 3 or 4, wherein in the deceleration determination process, the control system determines to execute the deceleration process when the relationship between the current speed and the distance-corresponding target speed satisfies a preset deceleration condition.

6. The control system is configured to further perform a second target speed determination process for determining the control target speed when the increase in the inter-vehicle distance index per specified time is greater than the reference value. In the second target velocity determination process, the control system If the control target speed is the distance-corresponding target speed, the state in which the control target speed is the distance-corresponding target speed is continued. If the constant speed processing described above is being performed and the current speed is higher than the distance-corresponding target speed, it is determined to perform the deceleration processing. The article conveying equipment according to claim 5, wherein, in the case where the constant speed processing described above has been performed, if the current speed is less than the distance-corresponding target speed, the acceleration determination processing is performed with the condition that the current speed is less than the distance-corresponding target speed.

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