JP7540316B2 - Control device and transport system - Google Patents

Description

The present invention relates to a control device for controlling a transport robot and a transport system equipped with the same.

Self-propelled transport robots, such as automated guided vehicles (AGVs) and automated guided forklifts (AGFs), have been proposed for use in factories, warehouses, etc. A transport system that realizes the automation of transport in factories, etc., is configured by controlling multiple such transport robots by a control device via wireless communication.

JP 2019-48689 A

The control device assigns transport instructions to these multiple transport robots as appropriate to accomplish the desired transport task. However, transport systems in factories, warehouses, etc. typically deploy a large number of transport robots to handle the large number of objects to be transported. These transport robots are in various states, and even if the control device sends a transport instruction to a specific transport robot, there may be no response.

This could be due to a problem with communication quality, or it could be a problem specific to the transport robot itself. However, in the past, it was not clearly considered whether the problem was with communication quality or a problem specific to the transport robot, and no consideration was given to this point when issuing instructions to the transport robot.

As a result, it has not been easy for a control device to appropriately assign and transmit instructions to each of the many transport robots deployed. In one aspect, the present invention has been made in consideration of this situation, and aims to realize a control device for a transport system that can optimize the assignment of transport instructions to transport robots.

The present invention employs the following configuration to solve the above-mentioned problems. One aspect of the present invention is a control device that controls a transport robot, and includes a master communication unit that performs wireless communication with the transport robot, a communication quality determination unit that determines the quality of the wireless communication, an instruction generation unit that generates instructions to the transport robot, and an instruction state determination unit that determines an instruction state regarding whether or not to transmit the instruction based on the quality of the wireless communication, and the instruction states include a first state that permits transmission of an instruction to the transport robot, a second state that causes the transmission of an instruction to the transport robot to be put on hold, and a third state that causes the instruction transmitted to the transport robot to be reallocated to another transport robot for transmission, and the instruction generation unit generates the instruction to the transport robot according to the instruction state and controls the master communication unit to transmit the instruction at the transport robot.

The above configuration makes it possible to realize a control device for a transport system that can optimize the allocation of transport instructions to transport robots.

In the control device according to the above aspect, the communication quality determination unit may be configured to determine the quality of the wireless communication based on the communication state of the message generated by the transport robot and received by the master communication unit.

The above configuration makes it possible to realize a control device for a transport system that can evaluate the quality of communication between the control device and the transport robot in a manner suitable for the transport system, thereby optimizing the allocation of transport instructions.

In the control device according to the above aspect, the communication quality determination unit may be configured to determine the quality of the wireless communication by classifying the quality of the wireless communication based on the communication state of the telegram, which includes at least one of the number of occurrences of arrival time sequence errors in the telegram or the number of occurrences of error corrections in the telegram.

According to the above configuration, the quality of wireless communication is specifically evaluated based on the state of communication between the control device and the transport robot. Furthermore, such quality evaluation is an excellent measure for enabling the control device to appropriately control the transport robot, and a control device that can more appropriately assign transport instructions can be realized.

In the control device according to the above aspect, the communication quality determination unit may be configured to determine the quality of the wireless communication by reflecting the past and current communication states of the message.

The above configuration makes it possible to assign and transmit instructions to the transport robots in the transport system without being affected by minute fluctuations in the communication state.

A transport system according to one aspect of the present invention includes a plurality of transport robots each having a message generating unit that generates the message and a slave communication unit that performs the wireless communication, and any one of the control devices described above.

The above configuration makes it possible to realize a transport system that can optimize the allocation of transport instructions to transport robots.

The control device according to each aspect of the present invention may be realized by a computer. In this case, the control program of the control device of the transport system that causes the computer to operate as the control device and realize the control device by the computer, and the computer-readable recording medium on which the control program is recorded, also fall within the scope of the present invention.

The control device according to one aspect of the present invention can realize a control device for a transport system that can optimize the allocation of transport instructions to transport robots.

1 is a floor map showing a schematic example of a factory in which a conveyance system including a control device according to an application example of the present invention is installed. 1 is a block diagram showing a configuration of a control device according to a first embodiment of the present invention and a transport system including the control device; 11 is a table for explaining the operation of a quality classification unit in a control device according to the second embodiment of the present invention in comparison with the control device according to the first embodiment.

An embodiment of one aspect of the present invention will be described below with reference to the drawings.

An example of a scene to which the present invention is applied will be described with reference to Figures 1 and 2. Figure 1 is a diagram that illustrates a floor map of a factory 100, which is an example of an area such as a factory or warehouse to which a conveyance system 1 equipped with a control device 10 according to this application example can be applied.

The factory 100 is equipped with a transport robot 20 that transports objects to be transported, such as finished products, semi-finished products, parts, tools, raw materials, jigs, packaging materials, and cassettes for storing them. As an example, the transport robot 20 is a self-propelled transport robot equipped with a robot arm (manipulator) that grasps the objects to be transported. However, the transport robot 20 may also be an unmanned transport vehicle, an AGF, or another form of self-propelled transport device.

In the factory 100, shelves 30 are installed on which the objects to be transported can be placed. In addition, in the factory 100, production equipment is also installed that, when the objects to be transported are placed at a designated receiving port, performs the required processing such as assembly, processing, fitting, inspection, etc., and then places them at a designated unloading port. Note that, depending on the production equipment, the receiving port and the unloading port may be combined. The transport robot 20 of the transport system 1 equipped with the control device 10 according to this application example can transport the objects to be transported between these facilities.

Figure 2 is a block diagram showing the configuration of a transport system 1 equipped with a control device 10 according to this application example. The transport system 1 is equipped with multiple transport robots 20 and a control device 10 that controls the multiple transport robots 20. Note that the control device 10 according to this application example is not shown in the floor map of Figure 1.

The control device 10 according to this application example includes a master communication unit 11 that performs wireless communication with the transport robots 20, and a communication quality determination unit 12 that determines the quality of wireless communication with each transport robot 20. The control device 10 further includes an instruction generation unit 15 that generates instructions for each transport robot 20, and an instruction state determination unit 13 that determines an instruction state regarding whether or not to transmit an instruction to each transport robot 20 depending on the quality of wireless communication.

In the control device 10 according to this application example, the instruction states include a first state in which transmission of an instruction to the transport robot 20 is permitted, a second state in which transmission of an instruction to the transport robot 20 is put on hold, and a third state in which the instruction transmitted to the transport robot 20 is reallocated to another transport robot 20 for transmission. The instruction generation unit 15 generates an instruction to the transport robot 20 according to the instruction states, and controls the master communication unit 11 to transmit the instruction to the transport robot 20.

In the control device 10 according to this application example, the quality of the wireless communication between the control device 10 and the transport robot 20 is evaluated by the communication quality determination unit 12. Then, depending on the quality of the wireless communication, the instruction state for each transport robot 20 is differentiated into three types. Therefore, the evaluation related to the quality of the wireless communication is performed separately from any specific problems occurring in the transport robot 20, and the instruction state is changed, so that the transport system can be operated appropriately.

The control device 10 according to this application example also has a second state between the first state in which instructions can be given and the third state in which instructions cannot be given, in which the control device 10 waits to send a command to the transport robot 20. This prevents unnecessary operations in the transport system, such as unnecessary reassignment of jobs or multiple transport robots attempting to execute overlapping instructions. Therefore, the control device 10 according to this application example can realize a transport system that can optimize the assignment of transport instructions to transport robots.

§2 Configuration Example [Embodiment 1]
<Conveyor system overview>
A more specific configuration example and operation of the control device and the transport system will be described below. Fig. 2 is a block diagram showing the configuration of the control device 10 according to the first embodiment and the transport system 1 including the same. The transport system 1 includes the control device 10 and a transport robot 20. In Fig. 2, the configuration of one transport robot 20 is shown in detail, but the other robots also have the same internal configuration.

The control device 10 is an information processing system that is responsible for managing transportation, and is sometimes called a transportation system server (AMHS server: Automated Material Handling System Server). Based on commands from a higher-level information processing system, the control device 10 transmits more specific transportation instructions to the transport robot 20 in the transport system 1. The control device 10 need only be an information processing system that can execute such processing, and does not need to be a device physically contained in a single housing.

When the transport system 1 is applied to a production factory, the upper information processing system that manages the production of products in the production factory is sometimes called a manufacturing execution system server (MES server). When the transport system 1 is applied to a logistics warehouse, the upper information processing system that manages the entry and exit of stored items in the logistics warehouse is sometimes called a warehouse management system server (WMS server).

<Configuration of the transport robot>
2, the transfer robot 20 is provided with a slave communication unit 21, a message generation unit 22, a specific state monitoring unit 23, an instruction reception unit 24, an operation control unit 25, and a mechanism unit 26. The slave communication unit 21 is a communication interface that executes wireless communication with the control device 10.

The message generation unit 22 is a functional block that generates a message including information on the specific state of the transport robot 20 to be reported to the control device 10, and notifies the control device 10 through the slave communication unit 21. The specific state monitoring unit 23 is a functional block that acquires the specific state of the transport robot 20. Here, the specific state of the transport robot 20 refers to a state related to the individual transport robot itself, such as the current position, operating state, loading state of the transport object, remaining battery level, etc., and states related to the operation of the transport robot 20 and other internal states.

The instruction receiving unit 24 is a functional block that receives instructions from the control device 10 to the transport robot 20 regarding transport and the like through the slave communication unit 21. The operation control unit 25 is a functional block that controls the mechanism unit 26 based on the instructions received by the instruction receiving unit 24, and causes the transport robot 20 to perform the required operation.

The mechanism unit 26 is a mechanism for the transport robot 20 to perform the transport operation. The mechanism unit 26 includes at least a traveling mechanism for the transport robot 20 to move. Furthermore, the mechanism unit 26 may have a mechanism for picking up or placing the transport object, such as a robot arm.

<Configuration of the control device>
2 , the control device 10 is provided with a master communication unit 11, a communication quality determination unit 12, an instruction state determination unit 13, a slave monitoring unit 14, and an instruction generation unit 15. The master communication unit 11 is a communication interface that realizes wireless communication with a plurality of transport robots 20.

The communication quality determination unit 12 is a functional block that determines the quality of wireless communication with the transport robot 20 based on the communication state of the above-mentioned message from the transport robot 20 received by the master communication unit 11. The communication quality determination unit 12 has a time series determination unit 121, a reception determination unit 122, a reception success rate calculation unit 123, and a quality classification unit 124. The functions and operations of each of these units will be described later.

The instruction state determination unit 13 is a functional block that changes the instruction state regarding whether or not to send an instruction to control the transport robot based on the result of the wireless communication quality judgment by the communication quality judgment unit 12. The slave monitoring unit 14 is a functional block that monitors the inherent state of the transport robot 20 in the transport system 1. The slave monitoring unit 14 monitors the inherent state of the transport robot 20 based on at least the content of the above-mentioned telegram from the transport robot 20 received by the master communication unit 11.

The instruction generation unit 15 assigns jobs for transporting objects to the transport robots 20 in the transport system 1 based on commands from a higher-level information processing system, etc., taking into consideration the unique states of each transport robot 20 acquired by the slave monitoring unit 14. The instruction generation unit 15 further generates instructions for transport, etc. to the transport robots 20 to which the jobs have been assigned, and transmits them via the master communication unit 11.

At that time, the instruction generation unit 15 also takes into consideration the instruction state determined by the instruction state determination unit 13, and executes job allocation for transporting the transport object and sending instructions such as transport to the transport robot 20. The details will be described later. Here, examples of allocating a job while taking into consideration the unique state of the transport robot 20 include the following.

For example, when a transport object is to be moved, the job is assigned to a transport robot 20 that is not currently running a job and is located close to where the transport object is to be placed. Alternatively, a transport robot 20 with sufficient battery power remaining for transporting the object is selected and the job is assigned to it.

<Operation of the transport system>
The characteristic operations of the control device 10 and the transport system 1 according to the first embodiment will be described in detail below. The message generating unit 22 of the transport robot 20 creates a message including information on the inherent state of the transport robot 20 acquired by the inherent state monitoring unit 23 and time series information. At this time, information on the radio wave intensity of the wireless communication with the control device 10 may be further included. The time series information may be time information, or may be the order in which the message was created. In the specific example of the first embodiment, the time series information is time information.

The message generator 22 periodically generates the message to sequentially transmit the unique state of the transport robot 20 to the control device 10. The slave communication unit 21 of the transport robot 20 transmits the message to the control device as a message with an error correction code (so-called checksum). Any known method can be used for error correction as appropriate. For example, HMAC-SHA256 (Hash-based Message Authentication Code - Secure Hash Algorithm 256-bit) can be used as the error correction method.

When the master communication unit 11 of the control device 10 receives the above-mentioned message from a specific transport robot 20, it determines whether or not there is a communication error in the received message based on an error correction method, and extracts the contents of the message. When extracting the contents of the message, if there is an error, error correction may be performed. The contents of the message are acquired by the slave monitoring unit 14. The time series determination unit 121 refers to the time series information of the messages transmitted sequentially from the specific transport robot 20, and determines whether or not the time series of the received message differs from the arrival time series.

The reception determination unit 122 determines whether or not a message has been received successfully based on the determination result of the time series determination unit 121 and the determination result of the master communication unit 11 as to whether or not there is an error. The reception is determined to be successful if the time series of the message is not different from the arrival time series and there is no error, and is determined to be unsuccessful in all other cases.

The reception determination unit 122 counts the number of messages that are determined to have been successfully received within a specified period of time. The determination of whether reception was successful or not can also be made based solely on the determination result of the time series determination unit 121. Alternatively, it can also be made solely on the determination result of the master communication unit 11 as to whether or not there is an error.

In other words, the reception determination unit 122 may determine whether reception was successful or not based on the communication state of the message generated by the transport robot 20, which includes at least one of the number of occurrences of arrival time sequence errors in the message or the number of occurrences of error corrections in the message.

The reception success rate calculation unit 123 calculates the reception success rate from the ratio of the number of messages received from a specific transport robot 20 within the specified period to the number of messages that were determined to be successfully received. The reception success rate calculation unit 123 may further calculate the reception success rate by determining whether the time difference between the message creation time (time series information) included in the message and the message reception time is within a predetermined time. Alternatively, the reception success rate may also be calculated by determining whether the radio wave strength based on information regarding the radio wave strength of wireless communication with the control device 10 included in the message is equal to or greater than a predetermined value.

The quality classification unit 124 classifies and judges the communication quality for each predetermined period according to the value of the reception success rate calculated by the reception success rate calculation unit 123. For example, the communication quality is classified as the first category when the reception success rate is equal to or higher than the first threshold, as the third category when the reception success rate is equal to or lower than the second threshold, and as the second category when the reception success rate is between these two.

As another example, the first threshold value can be 70% and the second threshold value can be 30%. However, these threshold values are merely examples and are set appropriately depending on the transport system. In this way, the communication quality determination unit 12 determines the quality of communication depending on the communication state of the above-mentioned message from the transport robot 20 received by the master communication unit 11.

Next, the instruction state determination unit 13 of the control device 10 determines the instruction state of the control device 10 according to the quality of communication determined by the quality classification unit 124 of the communication quality judgment unit 12. The instruction state can take three states, for example, active (first state), pending (second state), and dead (third state), according to the first, second, and third classifications, respectively.

Active corresponds to a state that is considered to be a communication quality state in which the transport robot 20 can immediately receive instructions such as transport. When the instruction state is active, the control device 10 can execute instructions to the transport robot 20. In other words, the control device 10 allows instructions to the transport robot 20.

Dead corresponds to a state that is considered to be a communication quality state in which the transport robot 20 cannot receive instructions such as transport. When the instruction state is Dead, the control device 10 does not execute instructions to the transport robot 20. Furthermore, if a response to an instruction to the transport robot 20 is not received, the control device 10 reallocates the job for that instruction to another device and reissues the instruction.

Pending corresponds to a state that is considered to be an intermediate communication quality state between active and dead. When the instruction status is dead, the control device 10 waits for instructions to the transport robot 20. Then, when the instruction status changes to active and an instruction can be given, the control device 10 executes the instruction of the transport robot 20, and when the instruction status changes to dead, the control device 10 reallocates the job to another machine.

The instruction generation unit 15 assigns jobs to the multiple transport robots 20 in the transport system 1 according to the above instruction state, and transmits instructions to specific transport robots 20. Therefore, the control device 10 of embodiment 1 can optimize the assignment of transport instructions and the timing of the instructions based on the quality of communication between the control device 10 and the transport robots 20.

In a transport system, the state of wireless communication between a control device and a specific transport robot is not constant due to the existence of numerous sources of electromagnetic noise in a factory and the nature of the transport robot moving around within the factory. Conventionally, when assigning jobs and sending instructions to a large number of transport robots, the quality of communication between the control device and the transport robot was not taken into consideration.

The control device 10 of the first embodiment takes such communication quality into consideration, and also defines three instruction states according to the communication quality. Therefore, the control device 10 of the first embodiment can optimize the allocation of transport instructions and the timing of the instructions. In particular, the control device 10 has the above-mentioned pending state between the active instruction state in which instructions can be given and the dead instruction state in which instructions cannot be given.

This prevents unnecessary operations in the transport system, such as job reassignment being repeated more than necessary due to instability in wireless communication. Alternatively, it prevents unnecessary operations in the transport system, such as multiple transport robots attempting to execute overlapping instructions.

In addition, the evaluation of communication quality is not based on physical parameters such as radio wave strength or physical communication speed, but on the state of communication actually performed between the control device 10 and the transport robot 20 for the purpose of control. Therefore, such a method of evaluating communication quality is suitable as an evaluation measure for enabling the control device to appropriately control the transport robot 20.

[Embodiment 2]
Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

The control device 10 and transport system 1 according to the second embodiment have the same configuration as those of the first embodiment, and operate in the same manner, except that the operation of the quality classification unit 124 differs from that of the first embodiment. In the control device 10 according to the first embodiment, the quality classification unit 124 classifies and judges the communication quality according to the value of the reception success rate calculated by the reception success rate calculation unit 123. At that time, the quality classification unit 124 classifies the communication quality for each predetermined period according to the reception success rate for that period (current time).

However, in the second embodiment, as shown in the specific example below, the quality classification unit 124 determines the quality of wireless communication by reflecting the past and current communication states of the message, which is different from the first embodiment.

Figure 3 is a chart for explaining the operation results of the quality classification unit 124 in each of the first and second embodiments in a specific example of the reception success rate. The second column shows an example of the reception success rate P(t) calculated by the quality classification unit 124 at each time t. The third column shows the indication state in the case of the first embodiment, in which the communication quality is classified based on the reception success rate P(t) at time t. In the case of the first embodiment, if the reception success rate P(t) fluctuates significantly from time to time, such as after time t=5, a situation may occur in which the indication state fluctuates between active and dead.

On the other hand, in the control device 10 according to the second embodiment, the quality classification unit 124 of the communication quality determination unit 12 classifies and determines the communication quality by reflecting not only the reception success rate during the period (current time) but also the past reception success rates. The quality classification unit 124 of the second embodiment classifies the communication quality based on the reception success rate as follows:

The logarithmic odds L(t) are calculated by converting the reception success rate P(t) at time t using a logit function (fourth column in Figure 3). Next, the cumulative logarithmic odds Ls(t) are calculated, which is the accumulation of the logarithmic odds L(t) from the past to time t, with the initial value set to 0 (fifth column in Figure 3). The cumulative logarithmic odds Ls(t) is converted using the inverse function of the logit function to calculate the reception success likelihood P2(t) (sixth column in Figure 3). Then, instead of the reception success rate P(t) in the first embodiment, the communication quality is classified according to the value of the reception success likelihood P2(t) (seventh column in Figure 3).

When the communication quality is classified using the method of embodiment 2, the classification is made reflecting the past value of the reception success rate, so that even if the reception success rate P(t) varies greatly from time to time, the fluctuation of the instruction state is suppressed. As shown after time t=5 in FIG. 3, in the case of embodiment 2, even if the reception success rate P(t) varies greatly from time to time, a situation in which the instruction state fluctuates between active and dead is unlikely to occur. Therefore, according to the control device 10 of embodiment 2, it becomes possible to assign jobs and give instructions to the transport robot 20 in the transport system 1 in a more stable state than in embodiment 1, without being affected by small fluctuations in the communication state.

[Embodiment 3]
In each of the above embodiments, the first and second thresholds for classifying the communication quality must be appropriately determined so that the instruction state can be appropriately determined. The appropriate values for these thresholds can be determined by trial and error in a factory or the like to which the conveying system 1 is applied. However, this requires the work of acquiring a large amount of data and appropriately correcting the values to find the most suitable values.

In embodiment 3, a method that can support the determination of such a threshold value is described. In the threshold determination method according to embodiment 3, various locations (factories, warehouses, etc.) where the transport system is applied are grouped (classified) as locations with similar communication characteristics belonging to the same group, and appropriate threshold values are stored in advance for each location. Then, when the transport system is applied to a new location, the communication characteristics at that location are measured, and the threshold value of the group with the closest characteristics is adopted as the recommended threshold value for that location.

Such grouping (classification) in the third embodiment is characterized in that it is performed using various probabilities related to the parameters used to calculate the communication quality in each of the above embodiments as the data to be examined. In other words, the data to be examined includes the following:

Time series validity probability, which is the percentage of messages within a period that had no discrepancies in the reception time series. Reliability probability, which is the percentage of messages within a period that had no error correction using an error correction method. Within-time arrival probability, which is the percentage of messages within a period that had a time difference between the message creation time (time series information) included in the message and the message reception time within a predetermined time. Valid radio wave strength probability, which is the percentage of messages within a period that had a radio wave strength equal to or greater than a predetermined value, based on information included in the message on the radio wave strength of wireless communication with the control device 10.

As a method for grouping (classification), the subspace method can be applied. This method is a known statistical method, so it will be explained briefly. First, for each period k, a vector a(k) is defined, whose elements are the above-mentioned data to be considered (various probabilities). Furthermore, an intra-system communication value matrix Ad is defined, which arranges n vectors a(k) for the period k (k is an integer from 1 to n) in which measurements were taken.

The intra-system communication value matrix Ad is decomposed into eigenvalues to find the eigenvalues λ(k) and eigenvectors x(k). The average value vector b of n vectors a(k) is found. The inner product ω(k) of vector a(k)-b and eigenvector x(k) is found for each k. This inner product ω(k) is called the expansion coefficient of the eigenvector. A vector Ω is derived in which the expansion coefficients ω(k) of the eigenvectors are arranged up to an appropriate dimension m in descending order of eigenvalue λ(k). The vector Ω is called the intra-system communication feature vector.

The intra-system communication feature vector Ω is calculated for various locations (factories, warehouses, etc.) where the transport system is applied, and the locations are appropriately grouped by collection within the space in which the intra-system communication feature vectors Ω exist. A representative intra-system communication feature vector Ωg representing the group is calculated by a method such as finding the average vector of the intra-system communication feature vectors Ω for the locations belonging to a specific group.

When the transportation system is applied to a new site, the intra-system communication feature vector Ω is calculated in the same manner, and the group to which it belongs is determined based on which group's representative intra-system communication feature vector Ωg it is closest to. The threshold value set for that group is adopted as the recommended threshold value for the transportation system applied to the new site.

The control device according to the third embodiment includes the configuration of the control device described in the first embodiment with reference to FIG. 2, and further includes a threshold calculation unit that calculates a threshold value by the above-mentioned method. The threshold calculation unit holds in advance the representative intra-system communication feature vector Ωg of each group and the threshold value, and selects a recommended threshold value by acquiring the above-mentioned data to be considered and calculating the intra-system communication feature vector Ω. According to the third embodiment, it becomes easy to set a threshold value for classifying communication quality.

[Software implementation example]
The functional blocks of the control device 10 (particularly, the master communication unit 11, communication quality judgment unit 12, instruction state determination unit 13, slave monitoring unit 14, and instruction generation unit 15) or the functional blocks of the transport robot 20 (particularly, the slave communication unit 21, message generation unit 22, inherent state monitoring unit 23, instruction receiving unit 24, and operation control unit 25) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the control device 10 or the transport robot 20 is equipped with a computer that executes the instructions of a program, which is software that realizes each function. This computer is equipped with, for example, one or more processors, and a computer-readable recording medium that stores the program. The object of the present invention is achieved by having the processor in the computer read and execute the program from the recording medium.

The processor may be, for example, a CPU (Central Processing Unit). The recording medium may be a "non-transitory tangible medium" such as a ROM (Read Only Memory), as well as a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The device may further include a RAM (Random Access Memory) for expanding the program.

The program may be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves). One aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the disclosed technical means.

REFERENCE SIGNS LIST 1 Transport system 10 Control device 11 Master communication unit 12 Communication quality determination unit 121 Time series determination unit 122 Reception determination unit 123 Reception success rate calculation unit 124 Quality classification unit 13 Instruction state determination unit 14 Slave monitoring unit 15 Instruction generation unit 20 Transport robot 21 Slave communication unit 22 Telegram generation unit 23 Unique state monitoring unit 24 Instruction reception unit 25 Operation control unit 26 Mechanical unit 100 Factory

Claims (5)

A control device that controls a transport robot,
A master communication unit that wirelessly communicates with the transport robot;
a communication quality determination unit that determines a quality of the wireless communication;
An instruction generation unit that generates an instruction to the transport robot;
an instruction state determination unit that determines an instruction state regarding whether or not to transmit the instruction based on the quality of the wireless communication, the instruction state being:
a first state in which transmission of a command to the transport robot is permitted;
a second state in which the transmission of a command to the transport robot is waited for;
a third state in which the command transmitted to the transport robot is reallocated to another transport robot and transmitted thereto;
The instruction generation unit generates the instruction for the transport robot according to the instruction state, and controls the master communication unit to cause the transport robot to transmit the instruction. The control device according to claim 1, wherein the communication quality determination unit determines the quality of the wireless communication based on the communication state of the message generated by the transport robot and received by the master communication unit. The control device according to claim 2, wherein the communication quality determination unit determines the quality of the wireless communication by classifying the quality of the wireless communication based on the communication state of the telegram, which includes at least one of the number of occurrences of arrival time sequence errors in the telegram or the number of occurrences of error corrections in the telegram. The control device according to claim 2 or 3, wherein the communication quality determination unit determines the quality of the wireless communication by reflecting the past and current communication states of the message. A plurality of the transport robots each having a message generating unit that generates the message and a slave communication unit that performs the wireless communication; and
A transport system comprising the control device according to any one of claims 2 to 4.

Images