Conveyor control device, conveyor control program and conveyor control method

Abstract

To provide a conveyor control device which enables control of a conveyance speed of cargoes by a conveyor without requiring a sensor for detecting the cargoes, to provide a conveyor control program and to provide a conveyor control method.SOLUTION: A conveyor control device (20) includes: a target rotational frequency setting part (21) for setting target rotational frequency of a motor (11) for driving a conveyor (10); a theoretical conveyance number calculation part (23) for calculating the theoretical conveyance number per unit time of cargoes by the conveyor (10) based on the target rotational frequency set by the target rotational frequency setting part (21); an electric current information acquisition part (24) for acquiring information showing an electric current value supplied to the motor (11); and an actual conveyance number estimation part (25) for estimating the actual conveyance number per unit time of the cargoes by the conveyor (10) based on the information acquired by the electric current information acquisition part (24). The target rotational frequency setting part (21) sets the target rotational frequency of the motor (11) based on a comparison result of the actual conveyance number and the theoretical conveyance number.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a conveyor control device, a conveyor control program, and a conveyor control method. [Background technology]

[0002] Conventionally, a conveying device has been disclosed that calculates the workpiece conveying pitch based on the detection results of the workpieces on the conveyor by a photoelectric sensor, and controls the workpiece conveying speed based on the workpiece conveying pitch (see, for example, Patent Document 1). The conveying device described in Patent Document 1 controls the conveying speed based on the workpiece conveying pitch, thereby suppressing motor overload caused by excessive blockage of the workpiece conveying pitch. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-073666 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional conveying devices such as those described in Patent Document 1 require a photoelectric sensor to detect the workpiece in order to control the conveying speed, which makes it difficult to reduce the number of parts compared to conveying devices that do not use photoelectric sensors.

[0005] The present disclosure was made in response to the recognition of the above-mentioned problems, and aims to provide a conveyor control device, a conveyor control program, and a conveyor control method that enable control of the speed at which luggage is transported by a conveyor without requiring a sensor to detect luggage. [Means for solving the problem]

[0006] The conveyor control device according to the present disclosure comprises a target rotation speed setting unit that sets a target rotation speed of a drive source that drives the conveyor, a theoretical transport number calculation unit that calculates the theoretical number of packages transported by the conveyor per unit time based on the target rotation speed set by the target rotation speed setting unit, a current information acquisition unit that acquires information indicating the current value supplied to the drive source, and an actual transport number estimation unit that estimates the actual number of packages transported by the conveyor per unit time based on the information acquired by the current information acquisition unit, and is characterized in that the target rotation speed setting unit sets the target rotation speed of the drive source based on the result of comparing the actual transport number with the theoretical transport number. [Effects of the Invention]

[0007] The conveyor control device disclosed herein estimates the actual number of packages transported per unit time based on information indicating the current value supplied to the drive source, and sets the target rotation speed of the drive source based on the results of comparing the actual number of packages transported per unit time with the theoretical number of packages transported, making it possible to control the speed at which packages are transported by the conveyor without the need for a sensor to detect the packages. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram of a conveyor system according to a first embodiment. [Figure 2] 1 is a block diagram showing a schematic configuration of a conveyor system according to a first embodiment. [Figure 3] 1 is a schematic side view of a conveyor according to a first embodiment. FIG. [Figure 4] 4A, 4B, 4C, and 4D are graphs showing examples of changes over time in the value of the current supplied to the motor acquired by the current information acquisition unit according to the first embodiment. [Figure 5] 1 is a block diagram showing an example of a hardware configuration of a conveyor control device according to a first embodiment. [Figure 6] 1 is a block diagram showing an example of a hardware configuration of a conveyor control device according to a first embodiment. [Figure 7]5 is a flowchart showing an example of a process for controlling a conveying speed performed by the conveyor control device according to the first embodiment. [Figure 8] 5 is a flowchart showing an example of a process for controlling a conveying speed performed by the conveyor control device according to the first embodiment. [Figure 9] 4 is a graph showing an example of a change over time in the value of a current supplied to a motor acquired by a current information acquisition unit according to the first embodiment. [Figure 10] 4 is a graph showing an example of a change over time in the value of a current supplied to a motor acquired by a current information acquisition unit according to the first embodiment. [Figure 11] FIG. 11A is a diagram showing a current display screen that the conveyor control device according to the first embodiment causes the display device to display, and FIG. 11B is a diagram showing a setting screen that the conveyor control device according to the first embodiment causes the display device to display. [Figure 12] 5 is a flowchart showing an example of a process for controlling a display device performed by the conveyor control device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1 First, the overall configuration of a conveyor system 1 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is an overall configuration diagram of the conveyor system 1 according to the first embodiment. The conveyor system 1 includes a conveyor 10, a conveyor control device 20 for controlling the conveyor 10, an input device 30, and a display device 40, and is configured such that the conveyor control device 20, the conveyor 10, the input device 30, and the display device 40 are electrically connected to each other so as to be able to transmit information to each other. Note that the conveyor control device may be electrically connected to a plurality of conveyors 10 and configured to control these plurality of conveyors 10 in parallel.

[0010] The conveyor 10 includes a motor 11 as a drive source that operates upon receiving a current supply from the conveyor control device 20, and a rotation speed sensor 12. The motor 11 includes, for example, a rotor (not shown) that rotates in response to the current supply, a reducer 11a that reduces the rotation of the rotor before transmitting it, and a rotating shaft 11b to which the rotation of the rotor reduced by the reducer 11a is transmitted. The rotation speed sensor 12 is a sensor for detecting the rotation speed of the rotor, and outputs a signal corresponding to the rotation speed of the rotor to the conveyor control device 20. Note that in the first embodiment, the "rotor rotation speed per unit time" is also referred to as the "rotation speed of the motor 11."

[0011] The conveyor 10 includes, for example, an input pulley 13, an output pulley 14, and a transmission belt 15. The input pulley 13 is fixed to the rotary shaft 11b of the motor 11, and receives the rotational force of the motor 11. The output pulley 14 is supported rotatably about a rotation axis 14a that is parallel to the rotary shaft 11b of the motor 11. The transmission belt 15 is wound around the input pulley 13 and the output pulley 14, and transmits the rotational force of the input pulley 13 to the output pulley 14. For example, the transmission belt 15 is formed by a timing belt, and the input pulley 13 and the output pulley 14 are formed by timing pulleys that mesh with the transmission belt 15.

[0012] The conveyor 10 also includes, for example, a drive roller 16, a driven roller 17, and a conveyor belt 18. The drive roller 16 is formed integrally with the output pulley 14 and rotates together with the output pulley 14 around a rotation axis 14a of the output pulley 14. The driven roller 17 is supported so as to be rotatable around a rotation axis 17a that is parallel to the rotation axis 14a of the output pulley 14. The conveyor belt 18 is wound around the drive roller 16 and the driven roller 17, and transmits the rotational force of the drive roller 16 to the driven roller 17, while conveying the objects placed on its upper surface.

[0013] In the conveyor 10 configured as described above, when the rotating shaft 11b of the motor 11 receives a current supply from the conveyor control device 20 and rotates in the A1 direction shown in FIG. 1, the conveyor belt 18 rotates in the A2 direction shown in FIG. 1, and transports packages as transported objects on the conveyor belt 18 in the A2 direction, while the rotation speed sensor 12 outputs a signal corresponding to the rotation speed of the rotor to the conveyor control device 20. Note that the rotation speed sensor 12 may be any sensor that detects the rotation speed of a part that rotates with the rotation of the rotor, and may be, for example, a sensor that outputs a signal corresponding to the rotation speed of any of the rotating shaft 11b of the motor 11, the input pulley 13, the output pulley 14, the transmission belt 15, the drive roller 16, the driven roller 17, and the conveyor belt 18. Alternatively, instead of including the rotation speed sensor 12, the conveyor system 1 may be configured such that the conveyor control device 20 estimates the rotation speed of the motor 11 based on the value of the current supplied to the motor 11 by the conveyor control device 20. For example, the conveyor system 1 may be configured such that the conveyor control device 20 estimates the rotation speed of the motor 11 based on the current value supplied to the motor 11 by the conveyor control device 20 and the measured value of the speed electromotive voltage of the motor when current is supplied to the motor 11.

[0014] The conveyor 10 is used, for example, as a devanning assist device that assists unloading work by transporting packages from a worker performing unloading work (devanning work) to a worker performing sorting work, or as a vanning assist device that assists loading work by transporting packages from a worker performing sorting work to a worker performing loading work (vanning work). Hereinafter, the work of transporting packages by the conveyor 10 in devanning work or vanning work will be collectively referred to as transport work. The configuration of the conveyor is not limited to the above, and the conveyor may be configured to be capable of transporting cargo using the rotational force of a drive source, and may be, for example, a drive roller conveyor that rotates rollers using the rotational force of a drive source to transport cargo on the rotating rollers.

[0015] The conveyor control device 20 sets a target rotation speed of the drive source (motor 11) that drives the conveyor 10, calculates the theoretical number of units to be transported by the conveyor 10 per unit time based on the set target rotation speed, acquires information indicating the value of current supplied to the drive source (motor 11), estimates the actual number of units to be transported by the conveyor 10 per unit time based on the acquired information, and sets the target rotation speed of the drive source based on the result of comparing the actual number of units to the theoretical number of units to be transported. The conveyor control device 20 may also control the display device 40. Details of the conveyor control device 20 will be described later.

[0016] The input device 30 accepts input operations by an operator who operates the input device 30. For example, the input device 30 is configured with devices that allow input operations by the operator, such as a keyboard, a mouse, a touch panel, a microphone, and various switches. The input device 30 accepts input operations by the operator and outputs a signal according to the input operation to the conveyor control device 20, thereby inputting information to the conveyor control device 20 that is used when the conveyor control device 20 performs various processes.

[0017] The display device 40 acquires information from the conveyor control device 20 and displays the acquired information as visual information to notify the viewer of the display device 40. For example, the display device 40 is configured with a liquid crystal display panel, an organic or inorganic EL (Electroluminescence) panel, a dot matrix display, an LED (Light Emitting Diode), or other display device. The display device 40 may be configured integrally with the input device 30 configured as a touch panel or a keyboard.

[0018] The operator of the input device 30 and the viewer of the display device 40 may be the same or different. The operator of the input device 30 and the viewer of the display device 40 may be, for example, a worker who transports luggage using the conveyor 10, a worker who receives luggage transported by the conveyor 10, a manager of the transport work, or other relevant parties. In the first embodiment, "a worker who transports luggage using the conveyor 10, a worker who receives luggage transported by the conveyor 10, a manager of the transport work, and other relevant parties" are also referred to as "workers, etc." The input device 30 and the display device 40 may be formed integrally with the conveyor 10 or the conveyor control device 20, or may be formed independently of the conveyor 10 or the conveyor control device 20, or may be configured as a mobile terminal that can be carried by a worker, etc.

[0019] Next, the schematic configuration of the conveyor control device 20 will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a block diagram showing the schematic configuration of the conveyor system 1 according to the embodiment 1. As shown in Fig. 2, the conveyor control device 20 includes a target rotation speed setting unit 21, a drive source control unit 22, a theoretical conveyance number calculation unit 23, a current information acquisition unit 24, an actual conveyance number estimation unit 25, a threshold setting unit 26, a display control unit 27, and a storage unit 28.

[0020] (Target rotation speed setting section) The target rotation speed setting unit 21 sets a target rotation speed of the motor 11, which is a drive source that drives the conveyor 10. The target rotation speed is a numerical value that is set as a target value for the rotation speed of the motor 11. In addition, the target rotation speed setting unit 21 sets the target rotation speed based on a comparison result between the actual number of packages conveyed by the conveyor 10 estimated by the actual conveyance number estimation unit 25 and the theoretical number of packages conveyed by the conveyor 10 calculated by the theoretical conveyance number calculation unit 23. The target rotation speed setting unit 21 sets the target rotation speed using various information depending on the usage state of the conveyor 10, which is the control target of the conveyor control device 20. For example, when an initial value is set for the target rotation speed before the start of a conveying operation, the target rotation speed setting unit 21 sets the target rotation speed based on a signal from the input device 30 or information stored in the memory unit 28. Furthermore, the target rotation speed setting unit 21 sets the target rotation speed based on the comparison result described above during the conveying operation. Furthermore, the target rotation speed setting unit 21 sets the target rotation speed based on the current value supplied to the motor 11 during the conveying operation, for example. Details of the process by which the target rotation speed setting unit 21 sets the target rotation speed will be described later.

[0021] The target rotation speed setting unit 21 may be configured to set the target rotation speed by selecting one of a plurality of rotation speed values ​​previously set and stored in the storage unit 28, or may be configured to set the target rotation speed by selecting one of a plurality of stages to which a plurality of target rotation speed values ​​previously set and stored in the storage unit 28 are respectively associated, or may be configured to set the target rotation speed as a free value other than the above. Furthermore, the target rotation speed setting unit 21 may be configured to refer to information stored in the storage unit 28 and set the new target rotation speed based on information on the setting conditions of the target rotation speed stored in the storage unit 28 when setting a new target rotation speed to replace the target rotation speed previously set by the target rotation speed setting unit 21 and used in the transport operation. In other words, the target rotation speed setting unit 21 may be configured to refer to information stored in the storage unit 28 and set the new target rotation speed based on information on the setting conditions of the target rotation speed stored in the storage unit 28 when setting a new target rotation speed to replace the target rotation speed already set at a specific observation time point (a time point when a specific process is performed) and used in the transport operation. The conditions for setting the target rotation speed include, for example, the minimum and maximum values ​​of the target rotation speed, the amount of fluctuation in the target rotation speed per one rotation, etc. The target rotation speed setting unit 21 stores the set target rotation speed of the motor 11 in the storage unit 28.

[0022] (Drive source control unit) The drive source control unit 22 controls the value of the current supplied to the motor 11, which is the drive source, based on the target rotation speed set by the target rotation speed setting unit 21. The drive source control unit 22, for example, acquires the target rotation speed set by the target rotation speed setting unit 21 from the storage unit 28, and controls the value of the current supplied to the motor 11 based on the acquired target rotation speed. When the conveyor system 1 includes the rotation speed sensor 12 as in this embodiment 1, the drive source control unit 22 also acquires a signal from the rotation speed sensor 12 and controls the value of the current supplied to the motor 11 so that the rotation speed of the motor 11 indicated by the signal becomes the target rotation speed set by the target rotation speed setting unit 21. The drive source control unit 22 supplies the motor 11 with a current controlled by, for example, PWM (Pulse Width Modulation) control as a PWM signal. Furthermore, for example, the drive source control unit 22 stops and resumes the supply of current to the motor 11 based on the value of the current supplied to the motor 11. Details of the process by the drive source control unit 22 to stop and resume the supply of current to the motor 11 will be described later.

[0023] (Theoretical transport volume calculation section) The theoretical conveyance number calculation unit 23 calculates the theoretical number of units to be conveyed by the conveyor 10 per unit time based on the target rotation speed set by the target rotation speed setting unit 21. The theoretical conveyance number calculation unit 23 calculates the theoretical number of units to be conveyed by the conveyor 10 per unit time based on, for example, the conveying speed of the conveyor 10 calculated based on the target rotation speed of the motor 11. The conveying speed V [m / sec] of the conveyor 10 is calculated, for example, by the following formula (1). Conveying speed V = (N / I) × (Z1 / Z2) × (2 × π × r / 60) (1) In equation (1), N represents the target rotation speed [RPM] of the motor 11, I represents the reduction ratio of the reducer 11a, Z1 represents the number of teeth of the input pulley 13, Z2 represents the number of teeth of the output pulley 14, and r represents the radius [m] of the drive roller 16.

[0024] Fig. 3 is a schematic side view of the conveyor 10 according to the first embodiment. Fig. 3 shows a state in which, for example, X [units] (two units in Fig. 3) units of cargo M1 are loaded and transported on the conveyor 10 having a transport length L1 [m]. Here, if the transport speed V is the transport speed [m / sec] of the cargo M1 in the A2 direction when the drive roller 16 rotates in the A1 direction, the theoretical transport number W [units / min] can be calculated, for example, by the following formula (2): Theoretical conveyance quantity W=V×(X / L1)×60 (2) The value of X may be a preset value, or may be a value set for each transport task based on information from the input device 30. Furthermore, when the theoretical transport number calculated by formula (2) includes a decimal, the theoretical transport number calculation unit 23 may be configured to convert the result to an integer by truncating or rounding off the decimal point, and treat the result as the calculation result of the theoretical transport number per unit time. Furthermore, in the first embodiment, the "theoretical transport number per unit time" may also be simply referred to as the "theoretical transport number."

[0025] (Current information acquisition section) The current information acquiring unit 24 acquires information indicating the value of a current supplied to the motor 11 as a drive source. The current information acquiring unit 24 acquires, for example, information indicating a change over time in the value of a current supplied to the motor 11, which is control information of the current value by the drive source control unit 22.

[0026] 4A, 4B, 4C, and 4D are graphs showing an example of temporal changes in the value of the current supplied to the motor 11 acquired by the current information acquiring unit 24 according to the first embodiment. Assume that a conveyor table (not shown) or another conveyor, such as a free roller conveyor without a drive source, is connected to the downstream end of the conveyor 10 (the right end of the conveyor belt 18 in FIG. 3 ) next to the downstream end of the conveyor 10 in the conveying direction. In this case, a parcel conveyed to the downstream end by the conveyor 10 is pushed onto the conveying surface of the conveyor table by the rotational force of the conveyor 10. The pushed parcel remains on the conveying surface of the conveyor table when the rotational force of the conveyor 10 ceases to act on it. The parcel remaining on the conveying surface of the conveyor table is then pushed by the next parcel conveyed to the downstream end by the conveyor 10, and moves downstream in the conveying direction on the conveying surface of the conveyor table.

[0027] FIG. 4A is a graph showing an example of the change over time in the current supplied to motor 11 when a 12 kg load is being conveyed and there are no other loads on the conveying surface, such as the conveying table. In FIG. 4A, the load on motor 11 increases and a peak current appears when the conveyed load reaches the end of conveyor 10 between 6.5 and 7 seconds. FIG. 4B is a graph showing an example of the change over time in the current supplied to motor 11 when a 24 kg load is being conveyed and there are no other loads on the end of conveyor 10. In FIG. 4B, a peak current appears when the conveyed load reaches the end of conveyor 10 around 9 seconds. The peak current in FIGS. 4A and 4B is due to the increased load on motor 11 caused by contact between the conveyed load and the conveying surface, such as the conveying table, when the conveyed load reaches the end of conveyor 10. In order to push a load onto the conveying surface of a conveyor that does not have a conveying table or a driving source, the motor 11, which is the driving source of the conveyor 10, must generate a force sufficient to resist the frictional force and other forces that the load experiences from the conveying surface. This means that, compared to the torque generated by the motor 11 while the load is being transported up to the end of the conveyor 10, a larger torque must be generated to further push the load onto the conveying surface, such as the conveying table, after the load has reached the end. The greater the torque generated, the greater the current value required to drive the motor 11.

[0028] FIG. 4C is a graph showing an example of the change over time in the current supplied to motor 11 when a 12 kg load is being conveyed and there are 140 kg of other loads on the conveying surface, such as the conveying table. In FIG. 4C, the load on motor 11 increases and a peak current appears when the conveyed load reaches the end of conveyor 10 around 3 seconds. FIG. 4D is a graph showing an example of the change over time in the current supplied to motor 11 when a 32 kg load is being conveyed and there are 140 kg of other loads on the conveying surface, such as the conveying table. In FIG. 4C, the load on motor 11 increases and a peak current appears when the conveyed load reaches the end of conveyor 10 between 7.5 seconds and 8 seconds. The peak current in FIGS. 4C and 4D is due to the increase in the load on motor 11 caused by contact between the conveyed load and other loads on the conveying surface, such as the conveying table, when the conveyed load reaches the end of conveyor 10. As described above, compared to the torque generated by motor 11 while conveying a package before it reaches the end of conveyor 10, a larger torque must be generated to push the package further onto the conveying surface, such as a conveying table, after the package has reached the end, and if there is another package on the conveying surface, an even larger torque is required to push it out. Therefore, compared to when there is no other package on the conveying surface, when there is another package on the conveying surface, such as a conveying table, the torque generated by motor 11 is larger and the peak current value is also larger. 4A to 4D, it is expected that a peak in the current value occurs each time an item reaches the end of the conveyor 10. As will be described later, the actual conveyed number estimation unit 25 can estimate the actual conveyed number by utilizing the occurrence of this peak in the current value.

[0029] (Actual transport number estimation part) The actual conveyance number estimation unit 25 estimates the actual number of parcels conveyed per unit time by the conveyor 10 based on the information acquired by the current information acquisition unit 24. In other words, the actual conveyance number estimation unit 25 calculates an estimate of the actual number of parcels conveyed per unit time by the conveyor 10 based on the information acquired by the current information acquisition unit 24. For example, the actual conveyance number estimation unit 25 detects peaks of the current value supplied to the motor 11 based on the information acquired by the current information acquisition unit 24, and estimates the actual number of parcels conveyed per unit time by the conveyor 10 based on the detection results. Specifically, the actual conveyance number estimation unit 25 detects peaks of the current value supplied to the motor 11 that exceed a preset threshold value stored in the memory unit 28 based on the information acquired by the current information acquisition unit 24, and estimates the actual number of parcels conveyed per unit time by the conveyor 10 based on the number of peaks of the current value detected in a specific period. For example, the estimated value of the actual conveyance number R [pieces / min] is calculated using the following formula (3): Actual transport volume R=P / T (3) In formula (3), P represents the number of peaks of the current value detected in a specific period, and T represents the specific period (minutes) during which the peaks are detected. When the actual number of conveyed items calculated by formula (3) includes a decimal point, the actual number of conveyed items estimation unit 25 may be configured to convert the actual number of conveyed items calculated by formula (3) to an integer by truncating or rounding off the decimal point, and treat the converted integer as the estimated result of the actual number of conveyed items per unit time. In the first embodiment, the "actual number of conveyed items per unit time" may also be simply referred to as the "actual number of conveyed items."

[0030] (Threshold setting section) The threshold setting unit 26 sets thresholds used when the conveyor control device 20 performs each process. For example, the threshold setting unit 26 sets thresholds used in the process for the drive source control unit 22 to control the supply of current to the motor 11. Furthermore, for example, the threshold setting unit 26 sets thresholds for current values ​​used when the actual conveyed number estimation unit 25 estimates the actual number of packages conveyed by the conveyor 10. For example, the threshold setting unit 26 sets each threshold based on a signal from the input device 30. The threshold setting unit 26 stores the set thresholds in the memory unit 28. The thresholds set by the threshold setting unit 26 will be described in detail later.

[0031] (Display control unit) The display control unit 27 controls the display device 40 to display information related to information used when the conveyor control device 20 performs each process and information indicating the results of each process on the display device 40. Details of the information that the display control unit 27 causes the display device 40 to display and details of the process by which the display control unit 27 controls the display device 40 will be described later.

[0032] (Storage part) The storage unit 28 stores information acquired by the conveyor control device 20 from external devices, information used when the conveyor control device 20 performs each process, and information indicating the results of each process. The storage unit 28 stores, for example, information acquired from the conveyor 10 and the input device 30, initial values ​​and setting values ​​of numerical values ​​used when the conveyor control device 20 performs each process, threshold values ​​used when the conveyor control device 20 performs each process, and calculation results and estimation results of each process of the conveyor control device 20. Each component of the conveyor control device 20 references the information stored in the storage unit 28 as necessary, acquires the information stored in the storage unit 28, and performs each process.

[0033] Next, the hardware configuration of the conveyor control device 20 will be described with reference to Figures 5 and 6. Figure 5 is a diagram showing an example of the hardware configuration of the conveyor control device 20, and Figure 6 is a diagram showing an example of the hardware configuration of the conveyor control device 20 that is different from that shown in Figure 5. For example, as shown in Figure 5, the conveyor control device 20 is a computer having a processor 20a, a memory 20b, and an I / O port 20c, and is configured so that the processor 20a reads and executes a program stored in the memory 20b.

[0034] 6, the conveyor controller 20 is a computer that has a processing circuit 20d, which is dedicated hardware, and an I / O port 20c, and executes a program. The processing circuit 20d is configured, for example, by a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each function of the conveyor controller 20 is realized by the processor 20a or the processing circuit 20d, which is dedicated hardware, executing a program. The conveyor controller 20 may also have hardware other than those described above, such as a hardware timer, a current sensor, or other electronic components.

[0035] Next, a process performed by the conveyor control device 20 will be described with reference to FIGS. 1, 2, and 7. FIG. 7 is a flowchart showing an example of a process for controlling the conveying speed performed by the conveyor control device 20. As shown in FIG. 7, when the conveyor control device 20 starts the process for controlling the conveying speed, the conveyor control device 20 first sets an initial value for the target rotation speed of the motor 11 (step ST01). In this process, the conveyor control device 20, for example, refers to information stored in the storage unit 28, and sets the initial value of the target rotation speed stored in the storage unit 28 as the target rotation speed of the motor 11 by the target rotation speed setting unit 21. The initial value of the target rotation speed may be, for example, a value acquired from the input device 30 and stored in the storage unit 28, a value acquired from another device (not shown) and stored in the storage unit 28, a value previously stored in the storage unit 28, or a value acquired by the target rotation speed setting unit 21 from the input device 30 or another device without going through the storage unit 28.

[0036] After performing the process of step ST01, the conveyor control device 20 starts the motor 11 (step ST02). In this process, the conveyor control device 20 starts supplying current to the motor 11 by the drive source control unit 22 based on the initial value of the target rotation speed set by the target rotation speed setting unit 21. Note that the conveyor control device 20 may be configured to automatically start the motor 11 after performing the process of step ST02, or may be configured to start the motor 11 based on another trigger. For example, the conveyor control device 20 may be configured to start the motor 11 when a motor start signal for starting the motor 11 is input from the input device 30 or a sensor or device (not shown).

[0037] After performing the process of step ST02, the conveyor control device 20 calculates (step ST03) the theoretical number of conveyances based on the current target rotation speed of the motor 11. In this process, the conveyor control device 20 calculates the theoretical number of conveyances of packages at the time of performing step ST03 using the theoretical number of conveyances calculation unit 23 so that the theoretical number of conveyances can be used when determining whether or not the target rotation speed of the motor 11 should be changed in subsequent processes.

[0038] After performing the process of step ST03, the conveyor control device 20 estimates the actual number of conveyed packages based on the value of the current supplied to the motor 11 (step ST04). In this process, the conveyor control device 20 calculates an estimate of the actual number of conveyed packages at the time of performing the process of step ST04 using the actual number of conveyed packages estimation unit 25 based on information indicating the current value acquired by the current information acquisition unit 24 so that the estimate can be used when determining whether or not the target rotation speed of the motor 11 should be changed in subsequent processes. For example, the actual number of conveyed packages estimation unit 25 estimates the actual number of conveyed packages of the conveyor 10 based on the number of times the number of conveyed packages exceeds a preset threshold value (hereinafter referred to as a "third threshold value") during a specific period in the past.

[0039] 9 is a graph showing an example of a change over time in the value of the current supplied to the motor 11, acquired by the current information acquiring unit 24 according to the first embodiment. For example, when the information showing the change in the current value shown in FIG. 9 is acquired by the current information acquiring unit 24, the actual conveyed number estimating unit 25 detects peaks in the current value that are equal to or greater than the third threshold value of 3 [A] during the immediately preceding one minute, which is a specific period, and estimates the actual conveyed number of the conveyor 10 to be 10 [items / minute] based on the fact that the number of detected peaks is 10 [items / minute].

[0040] After performing the process of step ST04, the conveyor control device 20 determines whether the current value supplied to the motor 11 is in an excessively large overload state (step ST05). In this process, the conveyor control device 20 determines whether the load on the motor 11 is excessive based on the current value supplied to the motor 11 by the drive source control device 22, in order to determine whether to stop the supply of current to the motor 11 by the drive source control device 22. Note that the conveyor control device 20 may be configured to perform the process of step ST04 before the process of step ST03.

[0041] For example, in the processing of step ST05, the conveyor control device 20 determines whether or not the value of the current supplied to the motor 11 has reached a preset threshold value (hereinafter referred to as the "first threshold value") based on the information acquired by the current information acquisition unit 24. Also, for example, in the processing of step ST05, the conveyor control device 20 determines whether or not the period during which the value of the current supplied to the motor 11 is equal to or greater than the first threshold value has continued for a preset period threshold value (hereinafter referred to as the "period threshold value") or more based on the information acquired by the current information acquisition unit 24.

[0042] In the process of step ST05, if the current value supplied to the motor 11 is in an overload state (YES in step ST05), the conveyor control device 20 temporarily stops the motor 11 (step ST06). For example, if an item conveyed by the conveyor 10 is stuck on a carrier or the like at the end of the conveyor 10, the load on the motor 11 may increase, causing the current value supplied to the motor 11 to be in an overload state. In addition, for example, if the total weight of the items being conveyed by the conveyor 10 is excessive, the current value supplied to the motor 11 may be in an overload state. In the process of step ST06, the conveyor control device 20 stops the supply of current from the drive source control unit 22 to the motor 11 based on the fact that the current value supplied to the motor 11 is in an overload state, thereby suppressing the continuation of the excessive load on the motor 11 and suppressing power consumption.

[0043] 10 is a graph showing an example of a change over time in the value of the current supplied to motor 11, acquired by current information acquiring unit 24 according to embodiment 1. For example, when information showing the change in the current value shown in FIG. 10 is acquired by current information acquiring unit 24, drive source control unit 22 stops the supply of current to motor 11 based on the fact that the period during which the value of the current supplied to motor 11 is equal to or greater than the first threshold value has continued for the period threshold value or longer. Specifically, when information showing the change in the current value shown in FIG. 10 is acquired by current information acquiring unit 24, drive source control unit 22 stops the supply of current to motor 11 based on the fact that the period during which the value of the current supplied to motor 11 is equal to or greater than the first threshold value of 5 [A] has continued for the period threshold value of 40 [seconds] or longer. In addition, the conveyor control device 20 may be configured so that when the current value supplied to the motor 11 is in an overload state, the drive source control unit 22 stops the supply of current to the motor 11 regardless of the set target rotation speed, or so that the target rotation speed setting unit 21 temporarily sets the target rotation speed to 0, thereby stopping the supply of current from the drive source control unit 22 to the motor 11.

[0044] After performing the process of step ST06, the conveyor control device 20 reduces the target rotation speed by one step (step ST07). In this process, the conveyor control device 20 sets a new target rotation speed that is lower than the target rotation speed that has already been set by the target rotation speed setting unit 21, thereby reducing the load on the motor 11. Note that, if the conveyor control device 20 temporarily set the target rotation speed to 0 in the process of step ST06, the conveyor control device 20 sets a new target rotation speed in the process of step ST07 based on the target rotation speed immediately before the target rotation speed was temporarily set to 0.

[0045] After performing the process of step ST07, the conveyor control device 20 determines whether or not a start signal for starting the motor 11 has been input (step ST08). In this process, the conveyor control device 20 determines whether or not a start signal has been input, which is a signal for restarting the temporarily stopped conveyor 10 by resuming the supply of current to the motor 11. The start signal may be, for example, a signal obtained from the input device 30 indicating that an operator or the like has performed an input operation on the input device 30 to start the conveyor 10, or a signal indicating that the drive source control unit 22 has determined that the temporary stop time of the conveyor 10 has reached or exceeded a preset time threshold for ending the temporary stop of the conveyor 10.

[0046] For example, if the total weight of packages being transported by the conveyor 10 is excessive, causing the current supplied to the motor 11 to be in an overload state, a worker or the like performs an input operation on the input device 30 to start the conveyor 10 when the worker or the like determines that the cause of the overload state has been resolved by removing some or all of the packages from the conveyor 10. Also, if the current supplied to the motor 11 is in an overload state due to packages being transported by the conveyor 10 temporarily stagnating on a conveying table or the like at the end of the conveyor 10, the cause of the overload state can be expected to be resolved by transporting the packages on the conveying table or the like downstream. Therefore, for example, the threshold time for ending the temporary stop of the conveyor 10 described above is set taking into consideration the time it takes for the packages temporarily stagnating on the conveying table or the like to be transported.

[0047] In the process of step ST08, if a start signal is not input (NO in step ST08), the conveyor control device 20 waits until a start signal is input. In the process of step ST08, if a start signal is input (YES in step ST08), the conveyor control device 20 resumes supplying current to the motor 11 to start the motor 11 (step ST09).

[0048] In the process of step ST05, if the current value supplied to the motor 11 is not in an overload state (NO in step ST05), the conveyor control device 20 determines whether the actual number of conveyed units is greater than the theoretical number of conveyed units (step ST10). In this process, in order to control the rotation speed of the motor 11, the conveyor control device 20 compares the estimated value of the actual number of conveyed units by the conveyor 10 at the time of performing the process of step ST10 with the calculated value of the theoretical number of conveyed units to determine whether to increase the target rotation speed.

[0049] In the process of step ST10, if the actual number of conveyed units is greater than the theoretical number of conveyed units (YES in step ST10), the conveyor control device 20 increases the target rotation speed by one step (step ST11). For example, in this process, the conveyor control device 20 increases the target rotation speed, which is preset among a plurality of steps, by one step from the stage at the time of performing the process of step ST10 so that one step of the target rotation speed corresponds to the amount of change in the rotation speed of the motor 11 that changes the theoretical number of conveyed units by one. In this process, the conveyor control device 20 sets a target rotation speed higher than the preset target rotation speed by the target rotation speed setting unit 21 based on the fact that the actual number of conveyed units by the conveyor 10 is greater than the theoretical number of conveyed units.

[0050] For example, if the number of packages loaded onto the conveyor 10 per unit time by workers performing unloading work is greater than the number of packages transported by the conveyor 10 per unit time, and the number of packages processed by workers downstream of the conveyor 10 per unit time is greater than the number of packages transported by the conveyor 10 per unit time, the actual number of packages transported by the conveyor 10 will be greater than the theoretical number. In other words, if the theoretical number of packages transported by the conveyor 10 is less than the number of processes upstream of the conveyor 10 and the number of processes downstream of the conveyor 10 per unit time, the actual number of packages transported by the conveyor 10 will be greater than the theoretical number. In such cases, increasing the transport speed of the conveyor 10 may improve work efficiency. Therefore, in processing step ST11, the conveyor control device 20 increases the target rotation speed based on the fact that the actual number of packages transported by the conveyor 10 is greater than the theoretical number of packages transported, thereby reducing the difference between the number of packages loaded on the conveyor 10 per unit time, the number of packages transported by the conveyor 10 per unit time, and the number of packages processed downstream of the conveyor 10 per unit time, thereby improving the work efficiency of transportation by the conveyor 10.

[0051] In the process of step ST10, if the actual number of conveyed units is not greater than the theoretical number of conveyed units (NO in step ST10), the conveyor control device 20 determines whether or not the actual number of conveyed units is less than the theoretical number of conveyed units (step ST12). In this process, the conveyor control device 20 compares the estimated value of the actual number of conveyed units by the conveyor 10 at the time of performing the process of step ST12 with the calculated value of the theoretical number of conveyed units in order to determine whether or not to reduce the target rotation speed when controlling the rotation speed of the motor 11.

[0052] In the process of step ST12, if the actual number of conveyed units is less than the theoretical number of conveyed units (YES in step ST12), the conveyor control device 20 reduces the target rotation speed by one step (step ST13). For example, in this process, the conveyor control device 20 reduces the target rotation speed, which is set in advance among a plurality of steps, by one step from the step at the time of performing the process of step ST12 so that one step of the target rotation speed corresponds to the amount of change in the rotation speed of the motor 11 that changes the theoretical number of conveyed units by one. In this process, the conveyor control device 20 sets a new target rotation speed lower than the preset target rotation speed by the target rotation speed setting unit 21 based on the fact that the actual number of conveyed units by the conveyor 10 is less than the theoretical number of conveyed units.

[0053] For example, if the number of packages per unit time loaded onto the conveyor 10 by workers performing unloading work is smaller than the number of packages transported by the conveyor 10, or if the number of packages per unit time processed by workers downstream of the conveyor 10 is smaller than the number transported by the conveyor 10, and packages transported by the conveyor 10 are stuck at the end of the conveyor 10, the actual number of packages transported by the conveyor 10 will be smaller than the theoretical number. In such cases, reducing the transport speed of the conveyor 10 may make it possible to reduce the power consumption of the conveyor 10. For this reason, in the processing of step ST13, the conveyor control device 20 reduces the target rotation speed based on the fact that the actual number of packages transported by the conveyor 10 is smaller than the theoretical number, thereby reducing the difference between the number of packages loaded onto the conveyor 10 per unit time, the number of packages transported by the conveyor 10 per unit time, and the number of packages processed downstream of the conveyor 10 per unit time, thereby reducing the power consumption of the conveyor 10.

[0054] If the actual conveyance number is not less than the theoretical conveyance number in the process of step ST12 (NO in step ST12), the conveyor control device 20 determines not to change the target rotation speed (step ST14). In other words, if the actual conveyance number is not less than the theoretical conveyance number in the process of step ST12, the conveyor control device 20 maintains the target rotation speed until a new target rotation speed is set. This is because, since it has already been determined in the process of step ST10 that the actual conveyance number is not greater than the theoretical conveyance number, and since it has been determined in the process of step ST12 that the actual conveyance number is not less than the theoretical conveyance number, the actual conveyance number and the theoretical conveyance number are equal, and one of them is neither greater nor less than the other. In this process, the conveyor control device 20 determines to maintain the already set target rotation speed, assuming that the target rotation speed of the motor 11 at the time of performing the process of step ST12 is an appropriate value taking into account power consumption and work efficiency. In addition, when the actual conveying number and the theoretical conveying number are equal, the conveyor control device 20 may be configured to increase the target rotation speed as in the processing of step ST11, or may be configured to decrease the target rotation speed as in the processing of step ST13.

[0055] After performing the process of step ST09, the process of step ST11, the process of step ST13, or the process of step ST14, the conveyor control device 20 performs the process of step ST03 again.

[0056] As described above, the conveyor control device 20 may be configured to start the motor 11 when a motor start signal for starting the motor 11 is input from the input device 30 or a sensor or device (not shown). FIG. 8 is a flowchart showing an example of a process for controlling the conveying speed performed by the conveyor control device 20 when the conveyor control device 20 is configured to start the motor 11 based on the input of a motor start signal. Some of the processes in the flowchart shown in FIG. 8 are similar to those in the flowchart shown in FIG. 7, and the same processes as those in the flowchart shown in FIG. 7 are denoted by the same reference numerals as those in FIG. 7, and description thereof will be omitted.

[0057] 8, after performing the processing of step ST01, the conveyor control device 20 determines whether or not a motor start signal has been received (step ST21). In this processing, the conveyor control device 20 determines whether or not a motor start signal for starting the motor 11 has been input to the conveyor control device 20 while the motor 11 is stopped. For example, if the input device 30 is a switch that outputs a motor start signal for starting the motor 11 and a motor stop signal for stopping the motor 11 based on an operation by a worker or the like, the conveyor control device 20 determines in the processing of step ST21 whether or not a motor start signal has been input to the conveyor control device 20 from the input device 30.

[0058] In the process of step ST21, if there is a motor start signal (YES in step ST21), the conveyor control device 20 starts the motor 11 (step ST22). In this process, based on the fact that there is a motor start signal in the process of step ST21, the conveyor control device 20 starts supplying current to the motor 11, making the conveyor 10 ready to transport packages.

[0059] When the conveyor control device 20 has performed the process of step ST22, or when there has been no motor start signal in the process of step ST21 (NO in step ST21), the conveyor control device 20 determines whether or not there has been a motor stop signal (step ST23). In this process, the conveyor control device 20 determines whether or not there has been an input of a motor stop signal to the conveyor control device 20 for stopping the motor 11. For example, if the input device 30 is a switch that outputs a motor start signal to start the motor 11 and a motor stop signal to stop the motor 11 based on an operation by a worker or the like, in this process, the conveyor control device 20 determines whether or not there has been an input of a motor stop signal from the input device 30 to the conveyor control device 20.

[0060] In the process of step ST23, if there is a motor stop signal (YES in step ST23), the conveyor control device 20 stops the motor 11 (step ST24). In this process, the conveyor control device 20 stops the supply of current to the motor 11 based on the fact that there is a motor stop signal in the process of step ST23, and ends the transport of goods by the conveyor 10.

[0061] When the conveyor control device 20 performs the process of step ST24, or when there is no motor stop signal in the process of step ST23 (NO in step ST23), the conveyor control device 20 determines whether the motor 11 is operating (step ST25). In this process, the conveyor control device 20 determines whether the motor 11 is in an operating state where current is being supplied to the motor 11, or in a stopped state where current is not being supplied to the motor 11. In the process of step ST25, if the motor 11 is not operating (NO in step ST25), the conveyor control device 20 returns the process to step ST21.

[0062] In the process of step ST25, if the motor 11 is operating (YES in step ST25), the conveyor control device 20 acquires the current value (step ST26). In this process, the conveyor control device 20 acquires information indicating the value of the current supplied to the motor 11 from the current information acquisition unit 24.

[0063] After performing the process of step ST26, the conveyor control device 20 determines whether or not a current value for a preset specified time has been acquired (step ST27). In this process, the conveyor control device 20 determines whether or not a current value for a specific period (specified time, for example, one minute) for estimating the actual number of conveyances per unit time has been acquired by the current information acquisition unit 24. After performing the process of step ST27, the conveyor control device 20 performs the process of step ST03.

[0064] After performing the process of step ST07, the process of step ST11, the process of step ST13, or the process of step ST14, the conveyor control device 20 performs the process of step ST21 again.

[0065] Next, details of information that the conveyor control device 20 causes the display device 40 to display will be described with reference to Fig. 11 and Fig. 12. Fig. 11A is a diagram showing a current display screen that the conveyor control device 20 according to the first embodiment causes the display device 40 to display, and Fig. 11B is a diagram showing a setting screen that the conveyor control device 20 according to the first embodiment causes the display device 40 to display.

[0066] 11A, the current display screen is an image showing a current target rotation speed 10A1, a current theoretical conveyance speed 10A2, a current actual conveyance speed 10A3, and a display setting button 10A4. For example, the display control unit 27 updates the information shown on the current display screen each time the processing from step ST03 to step ST09, step ST11, step ST13, and step ST14 shown in FIG. 7 is performed. Furthermore, for example, when the current display screen shown in FIG. 11A is displayed on the display device 40, the display control unit 27 changes the image displayed on the display device 40 to the setting screen shown in FIG. 11B based on receiving a signal from the input device 30 indicating that the display setting button 10A4 has been selected and operated.

[0067] 11B, the setting screen is an image showing display input field 10B1 for accepting input of each setting value, display update button 10B2 for confirming the input of each setting value, and display back button 10B3 for returning the image displayed on display device 40 to the current display screen. For example, display input field 10B1 has an initial rotation speed input field for accepting input of an initial rotation speed that is an initial value of the target rotation speed of motor 11, a minimum rotation speed input field for accepting input of a minimum rotation speed that is the minimum value of the target rotation speed of motor 11, and a maximum rotation speed input field for accepting input of a maximum rotation speed that is the maximum value of the target rotation speed of motor 11. Furthermore, for example, display input field 10B1 has an increase / decrease rotation speed input field for accepting input of an increase / decrease rotation speed that is a setting value for the amount of fluctuation in the target rotation speed per rotation when target rotation speed setting unit 21 sets a new target rotation speed that is different from the previously set target rotation speed of motor 11. In other words, the display input field 10B1 has an increase / decrease rotation speed input field that accepts input of a setting value for the amount of fluctuation in the target rotation speed by one step when the target rotation speed setting unit 21 sets a new target rotation speed that is different from the target rotation speed of the motor 11 that has been previously set.

[0068] For example, when the initial rotation speed input field, minimum rotation speed input field, maximum rotation speed input field, or increase / decrease rotation speed input field of the display input field 10B1 is selected while the setting screen shown in FIG. 11B is displayed on the display device 40, the display control unit 27 causes the display device 40 to display a software keyboard for inputting a setting value corresponding to the selected field. When the display update button 10B2 is selected while an input operation on the software keyboard is being performed, the input device 30 outputs a signal corresponding to the input operation on the software keyboard to the conveyor control device 20. The target rotation speed setting unit 21 acquires a signal corresponding to the input operation on the software keyboard from the input device 30 and stores each setting value corresponding to the acquired signal in the storage unit 28. When the display control unit 27 acquires a signal from the input device 30 indicating that the display back button 10B3 has been selected while the setting screen shown in FIG. 11B is displayed on the display device 40, the display control unit 27 causes the display device 40 to display the current display screen shown in FIG. 11A.

[0069] Fig. 12 is a flowchart showing an example of a process for controlling the display device 40 as a touch panel, which is performed by the conveyor control device 20 according to the first embodiment. As shown in Fig. 12, when the conveyor control device 20 starts the process for controlling the display device 40, it first causes the display device 40 to display a current display screen (step ST31). In this process, the conveyor control device 20 causes the display control unit 27 to output, for example, image data for displaying the current display screen shown in Fig. 11A and information indicating the current target rotation speed, the current theoretical transport count, and the current actual transport count to the display device 40, and causes the display device 40 to display the current display screen.

[0070] After performing the process of step ST31, the conveyor control device 20 acquires the latest data to be displayed on the display device 40 as a current display screen (step ST32). In this process, the conveyor control device 20, for example, references information stored in the memory unit 28 to acquire the latest values ​​of the target rotation speed, the theoretical conveyance number, and the actual conveyance number. Note that the conveyor control device may be configured to acquire the latest values ​​of the target rotation speed, the theoretical conveyance number, and the actual conveyance number using the target rotation speed setting unit 21, the theoretical conveyance number calculation unit 23, and the actual conveyance number estimation unit 25 in the process of step ST32. Furthermore, the conveyor control device may be configured to acquire one or more values ​​of the target rotation speed, the theoretical conveyance number, and the actual conveyance number in the process of step ST32, or may be configured to acquire only values ​​that have changed from the previously acquired values.

[0071] After completing the process of step ST32, the conveyor control device 20 displays the latest data in the display fields on the screen of the display device 40 (step ST33). In this process, the conveyor control device 20 outputs information indicating the values ​​of the target rotation speed, theoretical conveyance number, and actual conveyance number acquired in the process of step ST32 to the display device 40, and displays, for example, the values ​​of the target rotation speed, theoretical conveyance number, and actual conveyance number acquired in the process of step ST32 in each display field on the current display screen of the display device 40.

[0072] After performing the process of step ST33, the conveyor control device 20 determines whether or not the display setting button 10A4 has been touched (step ST34). In this process, the conveyor control device 20 determines whether or not a touch operation of the display setting button 10A4 by a worker or the like as a user of the display device 40 has been detected by the touch panel.

[0073] In the process of step ST34, if the display setting button 10A4 has not been touched (NO in step ST34), the conveyor control device 20 returns the process to step ST32.

[0074] In the process of step ST34, if the display setting button 10A4 is touched (YES in step ST34), the conveyor control device 20 displays a setting screen on the display device 40 (step ST35). In this process, based on the fact that the touch operation of the display setting button 10A4 by an operator or the like is detected by the touch panel, the conveyor control device 20 outputs image data for displaying the setting screen shown in FIG. 11B for changing each setting value to the display device 40, and displays the setting screen on the display device 40.

[0075] After performing the process of step ST35, the conveyor control device 20 acquires the set values ​​(step ST36). In this process, the conveyor control device 20 refers to information stored in the storage unit 28, for example, to acquire the set values ​​of the initial rotation speed, the minimum rotation speed, the maximum rotation speed, and the increase / decrease rotation speed.

[0076] After performing the process of step ST36, the conveyor control device 20 displays the set values ​​in the input fields on the screen of the display device 40 (step ST37). In this process, the conveyor control device 20 outputs information indicating the set values ​​of the initial rotation speed, the minimum rotation speed, the maximum rotation speed, and the increase / decrease rotation speed, which were acquired in the process of step ST36, to the display device 40, and displays the set values ​​of the initial rotation speed, the minimum rotation speed, the maximum rotation speed, and the increase / decrease rotation speed in the input fields on the setting screen of the display device 40.

[0077] After performing the process of step ST37, the conveyor control device 20 determines whether or not the display update button 10B2 has been touched (step ST38). In this process, the conveyor control device 20 determines whether or not the touch operation of the display update button 10B2 for confirming each setting value displayed in the process of step ST37 has been detected by the touch panel.

[0078] In the process of step ST38, if the display update button 10B2 is touched (YES in step ST38), the conveyor control device 20 updates the set values ​​to the values ​​displayed in the input fields on the screen of the display device 40 (step ST39). In this process, the conveyor control device 20 stores the set values ​​of the initial rotation speed, the minimum rotation speed, the maximum rotation speed, and the increase / decrease rotation speed, which were displayed in the process of step ST37, in the storage unit 28 as the latest set values.

[0079] In the process of step ST38, if the display update button 10B2 has not been touched (NO in step ST38), the conveyor control device 20 determines whether or not the display back button 10B3 has been touched (step ST40). In this process, the conveyor control device 20 determines whether or not the touch panel has detected a touch operation of the display back button 10B3 by an operator or the like in order to switch the image displayed on the display device 40 to the current display screen.

[0080] In the process of step ST40, if there is no touch operation of the display back button 10B3 (NO in step ST40), the conveyor control device 20 determines whether there is a touch operation of the display input field 10B1 (step ST41). In this process, the conveyor control device 20 determines whether there is a touch operation of the display input field 10B1 by an operator or the like to change a setting value, by using the touch panel.

[0081] In the process of step ST41, if there is a touch operation on the display input field 10B1 (YES in step ST41), the conveyor control device 20 accepts input from the user (step ST42). In this process, the conveyor control device 20 detects, by the touch panel, an input operation performed by a worker or the like who is the user of the display device 40 to input one or more setting values ​​of the initial rotation speed, the minimum rotation speed, the maximum rotation speed, and the increase / decrease rotation speed into each input field (display field) of the display input field 10B1, obtains information indicating each setting value according to the input operation, and stores each obtained setting value in the storage unit 28.

[0082] When the conveyor control device 20 has performed the process of step ST42, or when there is no touch operation on the display input field 10B1 in the process of step ST41 (NO in step ST41), the conveyor control device 20 returns the process to step ST38.

[0083] When the conveyor control device 20 has performed the process of step ST39, and when the display back button 10B3 is touched in the process of step ST40 (YES in step ST40), the conveyor control device 20 returns the process to step ST31.

[0084] As described above, the conveyor control device 20 according to embodiment 1 comprises a target rotation speed setting unit 21 that sets a target rotation speed of the motor 11 that drives the conveyor 10, a theoretical conveyance speed calculation unit 23 that calculates the theoretical number of packages to be conveyed per unit time by the conveyor 10 based on the target rotation speed set by the target rotation speed setting unit 21, a current information acquisition unit 24 that acquires information indicating the current value supplied to the motor 11, and an actual conveyance speed estimation unit 25 that estimates the actual number of packages to be conveyed per unit time by the conveyor 10 based on the information acquired by the current information acquisition unit 24, and the target rotation speed setting unit 21 is configured to set the target rotation speed of the motor 11 based on the result of comparing the actual conveyance speed with the theoretical conveyance speed.

[0085] With this configuration, the conveyor control device 20 estimates the actual number of units transported per unit time based on information indicating the current value supplied to the motor 11, and sets the target rotation speed of the motor 11 based on the result of comparing the actual number of units transported with the theoretical number of units transported, making it possible to control the speed at which units are transported by the conveyor 10 based on the target rotation speed without requiring a sensor to detect units. Also, because the conveyor control device 20 does not require a sensor to detect units, it is possible to reduce the number of parts in the conveyor system 1 compared to a system that includes a sensor to detect units.

[0086] Moreover, the conveyor control device 20 according to the first embodiment includes a drive source control unit 22 that controls the value of the current supplied to the motor 11 based on the target rotation speed set by the target rotation speed setting unit 21. With this configuration, the conveyor control device 20 can control the transport speed of the goods by the conveyor 10 by controlling the value of the current supplied to the motor 11 based on the target rotation speed, without requiring a sensor for detecting the goods.

[0087] Furthermore, the conveyor control device 20 according to the first embodiment is configured to set a target rotation speed higher than the preset target rotation speed of the motor 11 when the actual conveyance number per unit time is greater than the theoretical conveyance number. With this configuration, the conveyor control device 20 can improve the efficiency of conveyance work by the conveyor 10 by increasing the target rotation speed when the actual conveyance number is greater than the theoretical conveyance number.

[0088] Furthermore, the conveyor control device 20 according to the first embodiment is configured to set a target rotation speed that is lower than the preset target rotation speed of the motor 11 when the actual conveyance number per unit time is smaller than the theoretical conveyance number. With this configuration, the conveyor control device 20 can suppress power consumption by the conveyor 10 by reducing the target rotation speed when the actual conveyance number is smaller than the theoretical conveyance number.

[0089] Furthermore, the conveyor control device 20 according to the first embodiment is configured to determine not to change the preset target rotation speed of the motor 11 when the actual number of conveyances per unit time is equal to the theoretical number of conveyances per unit time. With this configuration, the conveyor control device 20 aims to reduce the processing load of the conveyor control device 20 by determining not to change the target rotation speed when it is not necessary to change the target rotation speed.

[0090] Furthermore, the conveyor control device 20 according to the first embodiment is configured to stop the supply of current to the motor 11 when the current value acquired by the current information acquiring unit 24 is equal to or greater than a preset threshold value. With this configuration, the conveyor control device 20 can reduce the load on the motor 11 and suppress power consumption by stopping the supply of current to the motor 11 when the load on the motor 11 is excessive.

[0091] Furthermore, the conveyor control device 20 according to the first embodiment is configured to stop the supply of current to the motor 11 when the actual number of conveyed packages is less than a preset second threshold value. With this configuration, the conveyor control device 20 can reduce the power consumption of the motor 11 by stopping the supply of current to the motor 11 when the number of packages being conveyed by the conveyor 10 is small.

[0092] Furthermore, the conveyor control device 20 according to the first embodiment is configured to estimate the actual number of transported units per unit time based on the number of times that the current value acquired by the current information acquiring unit 24 exceeds a preset threshold value in a specific period. Thus configured, the conveyor control device 20 can estimate the actual number of transported units per unit time based on the change in the current value over time. Furthermore, thus configured, the conveyor control device 20 can estimate the actual number of transported units per unit time even when the magnitude of the load on the motor 11 due to the transported units is unclear.

[0093] Furthermore, the conveyor control device 20 according to the first embodiment includes a display control unit 27 that controls the display device 40, and the display control unit 27 is configured to display the current target rotation speed, the current theoretical conveyance number, and the current actual conveyance number on the display device 40. With this configuration, the conveyor control device 20 can notify a worker or the like of the details of the control of the conveyor 10 by the conveyor control device 20 by displaying information related to the conveyance speed on the display device 40.

[0094] Furthermore, the conveyor control device 20 according to the first embodiment is configured to display on the display device 40 an input acceptance image for accepting input of at least one of the initial value, minimum value, and maximum value of the target rotation speed of the motor 11, and the amount of fluctuation in the target rotation speed per cycle when the target rotation speed setting unit 21 sets a new target rotation speed that is different from the target rotation speed of the motor 11 that has been preset. With this configuration, the conveyor control device 20 allows an operator or the like to input each setting value of the initial value, minimum value, maximum value of the target rotation speed of the motor 11, and the amount of fluctuation in the target rotation speed while viewing the image displayed on the display device 40, thereby improving operability when inputting each setting value.

[0095] Furthermore, for example, by making it possible to set in advance the minimum value of the target rotation speed set by the target rotation speed setting unit 21, it is possible to prevent the conveyor 10 from transporting packages at a speed that is undesirable for the transport work. Furthermore, for example, by making it possible to set in advance the maximum value of the target rotation speed set by the target rotation speed setting unit 21, it is possible to prevent excessive burdens from being placed on workers who transport packages using the conveyor 10 and workers who receive packages transported by the conveyor 10.

[0096] In the first embodiment, the conveyor control device 20 includes a drive source control unit 22 that controls the value of the current supplied to the motor 11 based on the target rotation speed set by the target rotation speed setting unit 21, but is not limited to this. The conveyor control device may be configured to set the target rotation speed of the motor 11 based on the result of comparing the actual conveyance number with the theoretical conveyance number, and may be configured, for example, to output the target rotation speed of the motor 11, set based on the result of comparing the actual conveyance number with the theoretical conveyance number, to an external device, for example, an external device that functions as the drive source control unit 22, and cause the external device to supply current to the motor 11 based on the target rotation speed. Specifically, the conveyor control device may be configured to include a microcomputer that sets a target rotation speed of the motor 11 based on the comparison result between the actual conveyance number and the theoretical conveyance number, and to output the set target rotation speed of the motor 11 to a motor driver serving as a drive source control unit 22 that has the function of supplying current to the motor 11 by PWM control and controlling the operation of the motor 11 to stop or switch between forward and reverse rotation by a digital input signal, and to cause the motor driver to supply current to the motor 11 based on the target rotation speed.

[0097] Furthermore, in the first embodiment, the conveyor control device 20 is configured to calculate the transport speed of the goods by the conveyor 10 and the theoretical number of goods to be transported per unit time by substituting the target rotation speed set by the target rotation speed setting unit 21 into formula (1), but is not limited to this. The conveyor control device may be configured to calculate the theoretical number of goods to be transported per unit time by the conveyor 10 based on the target rotation speed set by the target rotation speed setting unit, for example, the conveyor control device may be configured to detect the rotation speed of the motor 11 controlled based on the target rotation speed set by the target rotation speed setting unit using the rotation speed sensor 12, and calculate the transport speed of the goods by the conveyor 10 by performing a calculation using the detected result.

[0098] Furthermore, in the first embodiment, the conveyor control device 20 is configured to estimate the actual number of units transported per unit time by the conveyor 10 based on the value of the current supplied to the motor 11, but is not limited thereto. The conveyor control device may be configured to acquire information indicating the value of the current supplied to the motor 11 using a current information acquisition unit, and estimate the actual number of units transported per unit time by the conveyor 10 using the actual number of units transported estimation unit based on the information acquired by the current information acquisition unit. For example, the conveyor control device may be configured to acquire information indicating which level the current value supplied to the motor 11 corresponds to when current values ​​are classified into a plurality of levels according to the magnitude of the current value, using the current information acquisition unit, and estimate the actual number of units transported per unit time by the conveyor 10 using the actual number of units transported estimation unit based on the information acquired by the current information acquisition unit, or may be configured to acquire information on the value of the current consumed by the motor 11 using the current information acquisition unit, and estimate the actual number of units transported per unit time by the conveyor 10 using the actual number of units transported estimation unit based on the information acquired by the current information acquisition unit.

[0099] Furthermore, in the first embodiment, the conveyor control device 20 is configured to set a target rotation speed one step higher than the preset target rotation speed of the motor 11 when the actual conveyance number per unit time is greater than the theoretical conveyance number, and to set a target rotation speed one step lower than the preset target rotation speed of the motor 11 when the actual conveyance number per unit time is less than the theoretical conveyance number. However, this is not limited to this. The conveyor control device may be configured to set the target rotation speed of the motor 11 based on the results of comparing the actual conveyance number with the theoretical conveyance number. For example, the conveyor control device may be configured to change the amount of change in the target rotation speed depending on the difference between the actual conveyance number and the theoretical conveyance number. Specifically, the conveyor control device may be configured to change the target rotation speed by a larger amount as the difference between the actual conveyance number and the theoretical conveyance number increases. This configuration enables the conveyor control device to optimize the target rotation speed in a short time in response to a sudden change in the actual conveyance number.

[0100] Furthermore, for example, the conveyor control device may be configured to change the preset target rotation speed of the motor 11 when the difference between the actual conveyance number and the theoretical conveyance number becomes equal to or greater than a preset threshold value. Specifically, the conveyor control device may be configured to set a target rotation speed higher than the preset target rotation speed of the motor 11 when the actual conveyance number is higher than the theoretical conveyance number by equal to or greater than a preset threshold value, or to set a target rotation speed lower than the preset target rotation speed of the motor 11 when the actual conveyance number is lower than the theoretical conveyance number by equal to or greater than a preset threshold value. With this configuration, the conveyor control device can prevent the target rotation speed from repeatedly fluctuating around a specific value when the difference between the actual conveyance number and the theoretical conveyance number is small enough that changing the target rotation speed is not necessary. Note that these threshold values ​​may be the same or different values.

[0101] Furthermore, in the first embodiment, the conveyor control device 20 is configured to determine not to change the preset target rotation speed of the motor 11 when the actual conveyance number and the theoretical conveyance number per unit time are equal, but this is not limiting. The conveyor control device may be configured to set the target rotation speed of the motor 11 based on the result of comparing the actual conveyance number and the theoretical conveyance number. For example, the conveyor control device may be configured to determine not to change the preset target rotation speed of the motor 11 when the difference between the actual conveyance number and the theoretical conveyance number is less than a preset threshold. With this configuration, the conveyor control device can prevent the target rotation speed from repeatedly fluctuating around a specific value when the difference between the actual conveyance number and the theoretical conveyance number is small enough that it is not necessary to change the target rotation speed.

[0102] Furthermore, in the first embodiment, the conveyor control device 20 is configured to stop the supply of current to the motor 11 based on the fact that the period during which the value of the current supplied to the motor 11 is equal to or greater than a predetermined threshold continues for the predetermined period, but is not limited to this. The conveyor control device may be configured to stop the supply of current to the motor 11 when the current value acquired by the current information acquisition unit is equal to or greater than a predetermined threshold. For example, the conveyor control device may be configured to stop the supply of current to the motor 11 when the value of the current supplied to the motor 11 becomes equal to or greater than a predetermined threshold, regardless of the length of the period during which the value of the current supplied to the motor 11 is equal to or greater than a predetermined threshold, or may be configured to stop the supply of current to the motor 11 when the result of integrating the value of the current supplied to the motor 11 over time for a specific period is equal to or greater than a predetermined threshold, or may be configured to stop the supply of current to the motor 11 when the average value of the current over the specific period is equal to or greater than a predetermined threshold.

[0103] Furthermore, the conveyor control device may be configured to stop the supply of current to the motor 11 regardless of either the value of the current supplied to the motor 11 or the theoretical conveyance number. For example, the conveyor control device may be configured to set a target rotation speed of the motor 11 based on a comparison result between the actual conveyance number and the theoretical conveyance number, and to stop the supply of current from the drive source control unit 22 to the motor 11 when the actual conveyance number estimated by the actual conveyance number estimation unit 25 is less than a preset threshold value (second threshold value) regardless of either the value of the current supplied to the motor 11 or the theoretical conveyance number. With this configuration, the conveyor control device can control the motor 11 based on the comparison result between the actual conveyance number and the theoretical conveyance number, while stopping conveyance by the conveyor 10 when the actual conveyance number is low, thereby reducing power consumption.

[0104] Furthermore, in the first embodiment, the conveyor control device 20 is configured to estimate the actual number of packages transported per unit time based on the number of times that the current value acquired by the current information acquiring unit 24 exceeds a preset threshold value in a specific period, but is not limited to this. The conveyor control device only needs to be configured to estimate the actual number of packages transported per unit time by the conveyor based on the information acquired by the current information acquiring unit, and may be configured to estimate the actual number of packages transported per unit time by the conveyor based on, for example, an average value of the current value in a specific period.

[0105] Furthermore, in the first embodiment, the conveyor control device 20 is configured to display the current target rotation speed, the current theoretical transport speed, and the current actual transport speed on the display device 40, but is not limited to this. The conveyor control device may be configured to display at least one of the target rotation speed, the theoretical transport speed, and the actual transport speed on the display device 40. For example, the conveyor control device may be configured to display one or two of the current target rotation speed, the current theoretical transport speed, and the current actual transport speed on the display device 40, or may be configured to display an average value of at least one of the target rotation speed, the theoretical transport speed, and the actual transport speed over a specific period on the display device 40, or may be configured to display a total value of the theoretical transport speed and the actual transport speed over at least one specific period on the display device 40, or may be configured to display a total value of the theoretical transport speed and the actual transport speed for a plurality of conveyors 10 over at least one specific period on the display device 40.

[0106] In addition, in the present disclosure, any component of the embodiments may be modified or any component of the embodiments may be omitted. [Industrial Applicability]

[0107] The conveyor control device, conveyor control program, and conveyor control method according to the present disclosure can be used, for example, to control the conveying speed according to the actual number of packages being conveyed by the conveyor. [Explanation of symbols]

[0108] 1. Conveyor System 10 Conveyor 10A1 Target RPM 10A2 Theoretical transport number 10A3 Actual number of transports 10A4 Display Settings Button 10B1 Display input field 10B2 Display refresh button 10B3 Display back button 11 Motor 11a Reducer 11b Rotation axis 12 RPM sensor 13 Input pulley 14 Output pulley 14a Rotation axis 15 Transmission Belt 16 Drive roller 17 Driven roller 17a Rotation axis 18 Conveyor Belt 20 Conveyor control device 20a processor 20b memory 20c I / O port 20d Processing circuit 21 Target rotation speed setting section 22 Drive source control unit 23 Theoretical transport quantity calculation section 24 Current information acquisition section 25 Actual transport number estimation unit 26 Threshold setting section 27 Display control unit 28 Memory section 30 Input Devices 40 Display device M1 Luggage R Actual number of deliveries V Conveying speed W Theoretical number of conveyances

Claims

1. a target rotation speed setting unit that sets a target rotation speed of a drive source that drives the conveyor; a theoretical conveyance number calculation unit that calculates a theoretical number of units to be conveyed by the conveyor per unit time based on the target rotation speed set by the target rotation speed setting unit; a current information acquisition unit that acquires information indicating a current value supplied to the driving source; an actual conveyance number estimation unit that estimates an actual number of packages conveyed by the conveyor per unit time based on the information acquired by the current information acquisition unit, The target rotation speed setting unit sets a target rotation speed of the drive source based on a comparison result between the actual conveyance number and the theoretical conveyance number. A conveyor control device characterized by:

2. a drive source control unit that controls the value of the current supplied to the drive source based on the target rotation speed set by the target rotation speed setting unit; 2. The conveyor control device according to claim 1.

3. When the actual conveyance number is greater than the theoretical conveyance number, the target rotation speed setting unit sets a target rotation speed higher than a preset target rotation speed of the drive source.

2. The conveyor control device according to claim 1.

4. When the actual conveyance number is smaller than the theoretical conveyance number, the target rotation speed setting unit sets a target rotation speed lower than a preset target rotation speed of the drive source.

2. The conveyor control device according to claim 1.

5. The target rotation speed setting unit determines not to change the target rotation speed of the drive source that is set in advance when the actual conveyance number and the theoretical conveyance number are equal.

2. The conveyor control device according to claim 1.

6. The drive source control unit stops supplying current to the drive source when the current value acquired by the current information acquisition unit is equal to or greater than a preset first threshold value.

3. The conveyor control device according to claim 2.

7. The drive source control unit stops supplying current to the drive source when the actual transport number is less than a preset second threshold value.

3. The conveyor control device according to claim 2.

8. The actual conveyance number estimation unit estimates the actual conveyance number based on the number of times that the current value acquired by the current information acquisition unit becomes equal to or greater than a third threshold value set in advance within a specific period.

2. The conveyor control device according to claim 1.

9. a display control unit that controls the display device; The display control unit causes the display device to display at least one of the target rotation speed of the drive source, the theoretical transport number, and the actual transport number.

9. The conveyor control device according to claim 1, wherein the conveyor control device is a control device for controlling a conveyor.

10. The display control unit causes the display device to display an input acceptance image for accepting input of at least one of an initial value, a minimum value, a maximum value of the target rotation speed of the drive source, and a fluctuation amount of the target rotation speed per rotation when the target rotation speed setting unit sets a new target rotation speed that is different from the target rotation speed of the drive source that is preset.

10. The conveyor control device according to claim 9.

11. Computer, a target rotation speed setting unit that sets a target rotation speed of a drive source that drives the conveyor; a theoretical conveyance number calculation unit that calculates a theoretical number of conveyances per unit time by the conveyor based on the target rotation speed set by the target rotation speed setting unit; a current information acquisition unit that acquires information indicating a current value supplied to the driving source; and an actual conveyance number estimation unit that estimates the actual number of packages conveyed by the conveyor per unit time based on the information acquired by the current information acquisition unit; The target rotation speed setting unit sets a target rotation speed of the drive source based on a comparison result between the actual conveyance number and the theoretical conveyance number. A conveyor control program comprising:

12. A conveyor control method performed by an apparatus including a target rotation speed setting unit, a theoretical conveyance speed calculation unit, a current information acquisition unit, and an actual conveyance speed estimation unit, a step in which the target rotation speed setting unit sets a target rotation speed of a drive source that drives a conveyor; a step in which the theoretical conveyance number calculation unit calculates a theoretical conveyance number of units per unit time by the conveyor based on the target rotation number set by the target rotation number setting unit; a current information acquiring unit acquiring information indicating a current value supplied to the driving source; the actual conveyance number estimation unit estimating the actual number of packages conveyed by the conveyor per unit time based on the information acquired by the current information acquisition unit, The target rotation speed setting unit sets a target rotation speed of the drive source based on a comparison result between the actual conveyance number and the theoretical conveyance number. A conveyor control method comprising:

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