This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2014-054147, filed on Mar. 17, 2014, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a setting update system and a vehicle control system.
Conventionally, vehicles which travel in an area including a plurality of zones in response to a traveling request are employed in a plant or the like. Generally, a range of the number of vehicles in each zone (which will be called “number of vehicles” below) is set and the number of vehicles in each zone is controlled within the set range. Conventionally, the range of the number of vehicles is manually set, and a proper range is difficult to set. Therefore, there is a problem that an upper limit value of the number of vehicles is improperly set, which causes a clog of the vehicles in the area and reduces a working efficiency of the plant.
Embodiments will now be explained with reference to the accompanying drawings. The present invention is not limited to the embodiments.
A setting update system according to one embodiment updates an upper limit value of the number of vehicles, which travel in an area including a plurality of zones in response to a traveling request, set per zone depending on the number of the traveling requests in each of the zones.
A vehicle control system and a setting update system according to a first embodiment will be first described with reference to
The vehicles may be automated guided vehicles (AGV) which autonomously and dispersively travel according to information on an inter-vehicular distance relative to an ahead-vehicle, or manned vehicles such as carriers or transportation (including buses and taxies) driven by a driver.
The traveling request designates a traveling route of the vehicle. The vehicle travels through the traveling route designated in the traveling request. The traveling request may designate the departure point and arrival point of the vehicle, and the route therebetween may be previously determined depending on the departure point and the arrival point.
When the vehicle is an AGV, the vehicle autonomously travels down to the arrival point in response to a traveling request. When the vehicle is a manned vehicle, the vehicle is driven by a driver down to the arrival point in response to a traveling request. The area where the vehicle travels may or may not be provided with a trajectory rail configuring the traveling route of the vehicle. The traveling request may or may not be assigned with a vehicle.
In the present embodiment, a range of the number of vehicles in each zone is set, and the vehicle control system controls the number of vehicles in each zone within the set range.
The vehicle controller 1 is mounted on each vehicle traveling within an area, and wirelessly communicates with the zone controller 2. The vehicle controller 1 transmits positional information of the vehicle to the zone controller 2, and receives a traveling instruction from the zone controller 2. The traveling instruction is a traveling request assigned with a vehicle, and is generated and transmitted per vehicle. When a traveling request is previously assigned with a vehicle, the traveling request may be transmitted to the vehicle controller 1.
When the vehicle is an AGV, the vehicle controller 1 controls the vehicle to autonomously travel based on information on an inter-vehicular distance relative to an ahead-vehicle until receiving a traveling instruction, and when receiving a traveling instruction, controls the vehicle to travel through a traveling route designated by the traveling instruction.
When the vehicle is a manned vehicle, the vehicle controller 1 notifies the driver of a route to be travelled by the vehicle until receiving a traveling instruction, and when receiving a traveling instruction, notifies the driver of the arrival point or traveling route designated in the traveling request.
The vehicle controller 1 can be configured of a computer device.
The CPU 101 controls other components, and sequentially executes the programs stored in the storage medium 102. The storage medium 102 is configured of HDD or SSD, and stores the programs required to control the vehicle therein. The RAM 103 is configured of SRAM, DRAM, or a flash memory, and reads and temporarily stores the programs stored in the storage medium 102 as needed when the CPU 101 executes the programs, respectively. The wireless communication interface 104 wirelessly communicates with the zone controller 2, receives a traveling instruction from the zone controller 2 and transmits positional information on the vehicle to the zone controller 2. When the vehicle is a manned vehicle, the computer device may comprise a display for displaying a traveling instruction thereon.
The zone controller 2 is installed per zone in the area, wirelessly communicates with the vehicle controller 1 of the vehicle traveling in each zone, and communicates with the host system 3 via a LAN constructed in the area.
The zone controller 2 receives a traveling request from the host system 3, assigns a vehicle traveling in a zone to the received traveling request to generate a traveling instruction, and transmits the generated traveling instruction to the vehicle controller 1 of each vehicle. When the traveling request is previously assigned with a vehicle, the zone controller 2 transmits the traveling request received from the host system 3 to each vehicle controller 1.
The zone controller 2 receives positional information from the vehicle controllers 1 on all the vehicles traveling in the zone, generates traveling performance information in each zone based on the received positional information, and transmits the generated information to the host system 3. The traveling performance information includes the number of vehicles in each zone, positional information on each vehicle, and the like.
The zone controller 2 can be configured of a computer device.
The CPU 201 controls other components, and sequentially executes the programs stored in the storage medium 202. The storage medium 202 is configured of HDD or SSD, and stores the programs required to generate a traveling instruction or traveling performance information therein. The RAM 203 is configured of
SRAM, DRAM or a flash memory, and reads and temporarily stores the programs stored in the storage medium 202 as needed when the CPU 201 executes the programs, respectively. The communication interface 204 communicates with the host system 3 via a LAN, receives a traveling request from the host system 3, and transmits traveling performance information to the host system 3. The user interface 205 is configured of a display, a keyboard, a mouse, and the like, and can accept user inputs and output information to the user. The wireless communication interface 206 wirelessly communicates with the vehicle controller 1, receives positional information from the vehicle controller 1, and transmits a traveling instruction to the vehicle controller 1. The zone controller 2 and the vehicle controller 1 can be configured to communicate with each other in a wired manner.
The host system 3 communicates with the zone controllers 2 and the setting update system 4 via a LAN constructed in the area.
The host system 3 receives traveling performance information from all the zone controllers 2 in the area. That is, the host system 3 collects the traveling performance information on all the vehicles in the area.
The host system 3 issues a traveling request based on traveling performance information received from the zone controllers 2 or a range of the number of vehicles updated in the setting update system 4. The traveling request is issued such that the number of vehicles in each zone is within the set range. The host system 3 transmits the issued traveling request to each zone controller 2 thereby to control the number of vehicles in each zone within the set range. For example, the host system 3 moves a vehicle from a zone in which more vehicles beyond the set ranges travels to other zone, and controls the number of vehicles in each zone within the set range.
The host system 3 transmits the generated traveling request, or the traveling performance information received from the zone controllers 2 to the setting update system 4, and receives an updated range of the number of vehicles, and the like from the setting update system 4.
The host system 3 can be configured of a computer device.
The CPU 301 controls other components, and sequentially executes the programs stored in the storage medium 302. The storage medium 302 is configured of HDD or SSD, and stores the programs required to generate a traveling request therein. The RAM 303 is configured of SRAM, DRAM or a flash memory, and reads and temporarily stores the programs stored in the storage medium 302 as needed when the CPU 301 executes the programs, respectively. The communication interface 304 receives traveling performance information from the zone controllers 2 via a LAN and transmits a traveling request to the zone controllers 2, as well as transmits traveling request information or the like to the setting update system 4 and receives an updated range of the number of vehicles from the setting update system 4. The user interface 305 is configured of a display, a keyboard, a mouse and the like, and can accept user inputs and output information to the user.
A subsystem or sub-controller having a different control range may be provided between the zone controllers 2 and the host system 3 or at a higher order than the host system 3. The vehicle controller 1 of each vehicle may wirelessly communicate with the host system 3 without providing the zone controller 2. In this case, the host system 3 comprises a wireless communication interface, receives traveling performance information from the vehicle controller 1, and transmits a traveling request assigned with a vehicle to the vehicle controller 1.
The setting update system 4 communicates with the host system 3 via a LAN constructed in the area. The setting update system 4 receives traveling performance information or traveling request information from the host system 3, and updates a range of the number of vehicles set in each zone based on the received information. The setting update system 4 transmits the updated range of the number of vehicles to the host system 3. The host system 3 generates a traveling request based on the range of the number of vehicles received from the setting update system 4.
The setting update system 4 can be configured of a computer device.
The CPU 401 controls other components, and sequentially executes the programs stored in the storage medium 402. The storage medium 402 is configured of HDD or SSD, and stores the programs required to update a range of the number of vehicles in each zone. The RAM 403 is configured of SRAM, DRAM or a flash memory, and reads and temporarily stores the programs stored in the storage medium 402 as needed when the CPU 401 executes the programs, respectively. The communication interface 404 receives traveling performance information and traveling request information from the host system 3 via a LAN, and transmits an updated range of the number of vehicles, and the like to the host system 3. The user interface 405 is configured of a display, a keyboard, a mouse, and the like, and can accept user inputs and output information to the user.
As illustrated in
The load rate calculation unit 41 (which will be called “calculation unit 41” below) calculates a load rate ρ in each zone. The load rate ρ is a parameter indicating a likelihood of a clog, and a clog is easily caused in a zone with a higher load rate ρ. The load rate ρ is a rate of performance traveling rate QA relative to critical traveling rate QCR, and is calculated at ρ=QA/QCR. The traveling rate described herein indicates the number of vehicles passing beyond a border in each zone per certain time. The traveling rate may employ the number of vehicles entering each zone or the number of vehicles exiting each zone per certain time.
The performance traveling rate QA is a performance value of the traveling rate. A vehicle is moved in response to a traveling request, and the performance traveling rate QA in each zone matches with the number of the traveling requests in each zone. The calculation unit 41 acquires the number of the traveling requests in each zone as performance traveling rate QA in each zone. The number of the traveling requests in each zone can be acquired from traveling request information received from the host system 3.
The critical traveling rate QCR is a maximum value of the traveling rate assumed for each zone. The calculation unit 41 acquires the critical traveling rate QCR from a vehicle number/traveling rate relationship stored in the vehicle number/traveling rate relationship storage unit 42 (which will be called “storage unit 42” below).
The vehicle number/traveling rate relationship indicates a correspondence between the number of vehicles and a traveling rate. The storage unit 42 stores a vehicle number/traveling rate relationship per zone therein.
The upper limit traveling rate calculation unit 43 (which will be called “calculation unit 43” below) calculates an upper limit traveling rate QB which is an upper limit value of the traveling rate in each zone based on a performance traveling rate QA in each zone and a maximum load rate ρMAX calculated by the calculation unit 41. The upper limit traveling rate QB is calculated by dividing the performance traveling rate QA in each zone by the maximum load rate ρMAX(QB=QA/ρMAX).
The upper limit vehicle number update unit 44 (which will be called “update unit 44” below) updates an upper limit number of vehicles MB as an upper limit value of the number of vehicles based on the upper limit traveling rate QB and the vehicle number/traveling rate relationship. Specifically, as illustrated in
The calculation unit 41 preferably adjusts the load rate ρ in each zone such that when the calculated maximum load rate ρMAX is higher than 1, the load rates
in all the zones are uniformly reduced and the load rate ρMAX is 1 or less. This is because when the maximum load rate ρMAX is higher than 1, the upper limit traveling rate QB (QB=QA/ρMAX) is lower than the performance traveling rate QA in all the zones.
Such a method for adjusting a load rate ρ may employ a method for integrating the load rates ρ in all the zones by a predetermined value (<1), or a method for subtracting a predetermined value from the load rates ρ in all the zones, but is not limited thereto. The load rate ρ may be adjusted such that the maximum load rate ρMAX takes any setting value.
A setting update processing by the setting update system 4 according to the present embodiment will be described below with reference to
The calculation unit 41 acquires the number of the traveling requests in each zone based on the traveling request information as in
The traveling rate is not limited thereto, and may employ the number of vehicles entering a zone or the number of vehicles exiting a zone. For example, when the traveling rate employs the number of vehicles entering a zone, the performance traveling QA of zone 5 is the number of vehicles traveling in response to the traveling request A (see
The calculation unit 41 then calculates a load ρ in each zone based on the number of the traveling requests and the vehicle number/traveling rate relationship (step S2). The calculation unit 41 first acquires a vehicle number/traveling rate relationship in each zone stored in a form such as equation or table in the storage unit 42 in order to calculate a load rate ρ.
The calculation unit 41 acquires a critical traveling rate QCR in each zone based on the vehicle number/traveling rate relationship. When the vehicle number/traveling rate relationship is discrete as in the vehicle number/traveling rate table of
The calculation unit 41 calculates a load rate ρ in each zone by dividing the performance traveling rate QA by the critical traveling rate QCR.
in all the zones such that the maximum load rate ρMAX is 1 or less.
The calculation unit 43 then calculates an upper limit traveling rate QB in each zone (step S3). The upper limit traveling rate QB is calculated by dividing the number of the traveling requests QA in each zone by the maximum load rate ρMAX. The calculation unit 43 acquires the number of the traveling requests QA and the maximum load rate ρMAX from the calculation unit 41.
The update unit 44 acquires the number of vehicles corresponding to the upper limit traveling rate QB in each zone calculated by the calculation unit 43 with reference to the vehicle number/traveling rate relationship in each zone, and updates the upper limit number of vehicles MB to the acquired number of vehicles (step S4). When the vehicle number/traveling rate relationship is an equation, the update unit 44 updates the upper limit number of vehicles MB to the number of vehicles acquired by substituting the upper limit traveling rate QB into the equation. When the vehicle number/traveling rate relationship is discrete, the update unit 44 updates the upper limit number of vehicles MB to the number of vehicles corresponding to a closest traveling rate to the upper limit traveling rate QB, or the number of vehicles calculated by use of an approximate equation generated from the vehicle number/traveling rate relationship.
The setting update system 4 performs the setting update processing periodically or at any timing, thereby updating an upper limit number of vehicles MB set in each zone.
The host system 3 monitors the number of vehicles in each zone based on traveling performance information received from the zone controllers 2. The host system 3 issues a traveling request to a zone in which the number of vehicles exceeds an upper limit number of vehicles MB, and moves some vehicles in the zone to other zone. Thereby, the number of vehicles in each zone is controlled at the upper limit number of vehicles MB or less.
As described above, the setting update system 4 according to the present embodiment can automatically update an upper limit number of vehicles MB set in each zone to a critical number of vehicles MCR or less based on the number of the traveling requests in each zone. The host system 3 controls the vehicles in each zone to be equal to or less than an upper limit number of vehicles MB updated by the setting update system 4, and the number of vehicles in each zone is controlled at a critical number of vehicles MCR or less. Therefore, the vehicle control system according to the present embodiment can prevent a clog in the area from occurring.
The setting update system 4 according to the present embodiment sets an upper limit number of vehicles MB in a zone other than the zones with a maximum load rate ρMAX to be smaller than a critical number of vehicles MCR in each zone. Thereby, the number of vehicles in a zone around the zone with the maximum load rate ρMAX is limited, which prevents a vehicle from entering the zone with the maximum load rate ρMAX from the surrounding zone. Thereby, a clog can be further prevented from occurring.
A vehicle control system and a setting update system according to a second embodiment will be described below with reference to
The lower limit vehicle number update unit 45 (which will be called “update unit 45” below) updates a lower limit number of vehicles MA as a lower limit value of the number of vehicles in each zone based on the number of the traveling requests in each zone and a vehicle number/traveling rate relationship. The number of the traveling requests in each zone is acquired from the calculation unit 41, and the vehicle number/traveling rate relationship is acquired from the storage unit 42. The update unit 45 acquires the number of vehicles (see
The setting update system 4 performs the setting update processing periodically or at any timing, thereby updating a lower limit number of vehicles MA set in each zone.
The host system 3 monitors the number of vehicles in each zone based on traveling performance information received from the zone controllers 2. If there is a zone in which the number of vehicles is lower than the lower limit number of vehicles MA, the host system 3 issues a traveling request to vehicles in other zones, and moves the vehicles to the zone in which the number of vehicles is lower than the lower limit number of vehicles MA. Thereby, the number of vehicles in each zone is controlled at the lower limit number of vehicles MA or more.
As described above, the setting update system 4 according to the present embodiment can automatically update a lower limit number of vehicles MA set in each zone to the number of vehicles corresponding to the number of the traveling requests (performance traveling rate QA ) based on the number of the traveling requests in each zone. The host system 3 controls the vehicles in each zone at the lower limit number of vehicles MA updated in the setting update system 4 or more, and the number of vehicles in each zone is controlled at the number of vehicles corresponding to the number of the traveling requests or more. Therefore, the vehicle control system according to the present embodiment can prevent an opportunity loss for a traveling request issued to each zone. The opportunity loss described herein indicates that there is no vehicle corresponding to an issued traveling request due to a lack of vehicles in a zone.
A vehicle control system and a setting update system according to a third embodiment will be described below with reference to
The priority setting unit 46 (which will be called “setting unit 46” below) acquires a load rate ρ in each zone from the calculation unit 41, and sets a priority for each zone according to the load rate in each zone. The host system 3 controls the number of vehicles according to the priority set by the setting unit 46.
The setting unit 46 selects a bottleneck zone based on a load rate ρ, for example, and sets a higher priority in the bottleneck zone than other zones. The bottleneck zone described herein is a zone with a higher load rate ρ, or a zone in which a clog is easily caused. A bottleneck zone may be arbitrarily selected, but the setting unit 46 selects, as a bottleneck zone, a zone with a maximum load rate ρ, a zone with a load rate ρ at a predetermined threshold or more, or zones at predetermined orders in descending order of load rate ρ, and sets a higher priority therein than other zones.
The setting unit 46 may set a higher priority in a neighboring zone than other zones. The neighboring zone is a zone having a higher impact on the bottleneck zone in which a clog is easily caused. The setting unit 46 employs any neighboring zone selection method, but the setting unit 46 selects, as a neighboring zone, a zone adjacent to the bottleneck zone, a zone positioned within a predetermined range from the bottleneck, or a zone with a high association with the number of vehicles in the bottleneck. The setting unit 46 sets a higher priority in order of bottleneck zone, neighboring zone, and other zone in this order.
As described above, the setting update system 4 according to the present embodiment sets a high priority to a bottleneck zone in which a clog is easily caused or a neighboring zone which has a higher impact on the bottleneck zone depending on a load rate ρ in each zone. The host system 3 controls the number of vehicles according to a priority, and when the numbers of vehicles in the bottleneck zone (neighboring zone) and other zones exceed an upper limit number of vehicles, the host system 3 controls the number of vehicles in the bottleneck zone (neighboring zone). In this way, the vehicle control system according to the present embodiment preferentially controls the number of vehicles in a zone in which a clog is easily caused or a zone having a higher impact on an occurrence of a clog ahead of the number of vehicles in a zone in which a clog is rarely caused, thereby efficiently preventing a clog from occurring.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2014-054147 | Mar 2014 | JP | national |