JP7617050B2 - Device control device, control system, and control method - Google Patents

Description

The present invention relates to a control device, a control system, and a control method for industrial equipment.

Customer demands are becoming more diverse in every industry, and in the manufacturing industry, there is an urgent need to shorten development cycles and respond to mass production and the manufacturing of complex products. For this reason, when controlling equipment such as industrial robots, there is a demand to control a large number of devices simultaneously in order to improve productivity. When controlling multiple devices simultaneously, synchronization between the devices being controlled is necessary. For example, to use multiple robots to manufacture a single product, the timing of each robot's movements must be synchronized with high precision.

An example of a conventional technique for synchronizing multiple devices is described in Patent Document 1. The control system described in Patent Document 1 performs synchronization control by correcting the phase difference and period difference of timing signals generated by each control device that is connected by a communication path and constitutes a master unit and a slave unit.

JP 2007-219642 A

As mentioned above, when controlling multiple devices such as industrial robots, synchronized control between the multiple devices is necessary. In particular, when multiple types of devices are used, such as devices of different models or devices manufactured by different manufacturers, synchronization between such multiple devices is necessary.

When controlling multiple devices, the controllers and devices that control the devices each execute the control commands they receive at different times. For this reason, even if the same control command is input to the controllers and devices, the timing at which the command is executed (command execution timing) differs from one another, resulting in discrepancies in operation. Therefore, when controlling multiple devices, control is required that absorbs the difference in command execution timing and causes each device to execute synchronized operations. For example, by adjusting the cycle and phase that generates the timing signals for the devices and synchronizing the command execution timing of each device, synchronized operations can be executed.

However, when controlling multiple types of devices, such as devices from different manufacturers, it is not always possible to adjust the timing signals and command execution timing of all devices and controllers as expected. For this reason, with conventional technologies such as the technology described in Patent Document 1, if such devices, whose internal operations and settings cannot be easily changed, are present as control targets, it is difficult to execute synchronized operations between the devices.

The object of the present invention is to provide an equipment control device, an equipment control system, and an equipment control method that can synchronize the operation of one or more equipment.

The device for controlling an appliance according to the present invention includes a communication unit capable of communicating with one or more appliances, a command generation unit that generates commands for the appliance, a command execution time difference acquisition unit that acquires a command execution time difference that is the time difference between when the command is transmitted from the communication unit to the appliance and when the appliance executes the command, a period calculation unit that uses the command execution time difference to calculate a command execution period that is the period during which the appliance executes the command, a phase calculation unit that uses the command execution time difference to calculate a phase that is a reference point for the command execution period of the appliance, and a command correction unit that calculates a command execution timing that is the timing at which the appliance executes the command from the command execution period and the phase, and corrects the command by determining a command value at the next command execution timing.

The device control system according to the present invention is characterized by comprising a control device according to the present invention and one or more devices that are controlled by the control device and can communicate with the communication unit provided in the control device.

The method for controlling an appliance according to the present invention is executed by a control device having a communication unit capable of communicating with one or more appliances, and includes a command generation step for generating a command for the appliance, a command execution time difference acquisition step for acquiring a command execution time difference, which is the time difference between when the command is transmitted from the communication unit to the appliance and when the appliance executes the command, a period calculation step for calculating a command execution period, which is the period during which the appliance executes the command, using the command execution time difference, a phase calculation step for calculating a phase, which is a reference point of the command execution period of the appliance, using the command execution time difference, and a command correction step for calculating a command execution timing, which is the timing at which the appliance executes the command, from the command execution period and the phase, and correcting the command by determining a command value at the next command execution timing.

According to the present invention, it is possible to provide an equipment control device, an equipment control system, and an equipment control method that can synchronize the operation of one or more equipment.

FIG. 2 is a functional block diagram of a control device according to the first embodiment of the present invention. FIG. 11 is a diagram illustrating an example of an operation flow of a command generating unit. FIG. 11 is a diagram illustrating an example of an operation flow of a command correction unit. FIG. 2 is a time chart showing the command execution period T and phase α of the robot calculated by a period calculation unit and a phase calculation unit. 11A and 11B are diagrams illustrating an example of a trajectory command corrected by a command correction unit and a trajectory command corrected by the command correction unit. FIG. 11 is a time chart showing elements used when calculating a command execution time difference Δt, a command execution period T, and a phase α. FIG. 11 is a diagram illustrating an example of an operation flow of a communication unit. FIG. 11 is a functional block diagram of a control device according to a second embodiment of the present invention. FIG. 11 is a functional block diagram of a control device according to a third embodiment of the present invention. FIG. 11 is a functional block diagram of a control device according to a fourth embodiment of the present invention. FIG. 4 is a functional block diagram of a calculation value update unit.

The device, control system, and control method for equipment according to the present invention can absorb differences in the timing at which multiple equipment (e.g., multiple types of equipment of different models or manufacturers) execute commands, and can control the operation of multiple equipment in a synchronized manner. Furthermore, when there is only one equipment to be controlled, the operation of the equipment can be adjusted by correcting the trajectory command taking into account the difference between the timing at which the command is sent and the timing at which the command is executed, thereby eliminating the discrepancy between ideal operation and actual operation.

According to the present invention, even if there is equipment in a production line or industrial system that controls one or more devices, whose internal operations or settings cannot be changed and are difficult to adjust, it is possible to synchronize and adjust the operation of the equipment, thereby realizing complex production processes and highly accurate and efficient production.

The following describes an equipment control device, an equipment control system, and an equipment control method according to an embodiment of the present invention, with reference to the drawings. In the present invention, the equipment to be controlled includes devices such as robots (e.g., industrial robots), autonomous vehicles, and conveyor belts. In the following embodiment, multiple robots are exemplified as the equipment to be controlled. However, the present invention can also be applied to the case where there is only one equipment to be controlled (a robot in the following embodiment).

In the drawings used in this specification, the same or corresponding components are designated by the same reference numerals, and repeated explanations of these components may be omitted.

The device control device, device control system, and device control method according to the first embodiment of the present invention will be described with reference to Figures 1 to 7.

Figure 1 is a functional block diagram of a control device 101 according to this embodiment. The control device 101 according to this embodiment mainly comprises a command generation unit 102, a command correction unit 103, a period calculation unit 104, a phase calculation unit 105, a command execution time difference acquisition unit 106, and communication units 107a to 107c, and controls multiple robots 109a to 109c via robot controllers 108a to 108c. Figure 1 shows an example in which the control device 101 controls three robots 109a to 109c.

The robot controllers 108a to 108c are connected to the control device 101 and to the robots 109a to 109c, respectively, and control the robots 109a to 109c according to commands from the control device 101. The robot controllers 108a to 108c transmit commands from the control device 101 to the robots 109a to 109c, respectively.

The robots 109a to 109c are devices controlled by the control device 101, and periodically execute commands sent from the control device 101 via the robot controllers 108a to 108c, respectively. For example, the robots 109a to 109c drive their own joints (axes) according to commands from the control device 101. In the following description, the robots 109a, 109b, and 109c may also be referred to as robot A, robot B, and robot C, respectively.

The command generation unit 102 generates commands for the robots 109a to 109c. The command generation unit 102 generates commands based on the operations to be executed by the robots 109a to 109c. The operations to be executed by the robots 109a to 109c are, for example, operations instructed by a user, which are input from outside and stored in the control device 101.

The command correction unit 103 corrects the command generated by the command generation unit 102 according to the cycle and phase of the robots 109a to 109c. The cycle and phase of the robots 109a to 109c refer to the cycle and phase at which the robots 109a to 109c each executes a command.

The period calculation unit 104 calculates the command execution period T, which is the period during which each robot 109a to 109c executes a command. The command execution period T is calculated using the time difference between when the control device 101 sends a command to each robot 109a to 109c and when each robot 109a to 109c executes the command (the command execution time difference Δt, described later).

The phase calculation unit 105 calculates the phase α, which is the reference point (starting point) of the command execution period T of each of the robots 109a to 109c. The command execution time difference Δt, which will be described later, is used to calculate the phase α. The phase α determines the start time point at which the robots 109a to 109c start executing commands.

The command execution time difference acquisition unit 106 acquires the command execution time difference Δt, which is the time difference between when the control device 101 sends a command to the robots 109a to 109c and when each of the robots 109a to 109c executes the command.

The communication units 107a to 107c can communicate with the robots 109a to 109c via the robot controllers 108a to 108c. The communication units 107a to 107c are connected to the robot controllers 108a to 108c, respectively, and communicate with the robot controllers 108a to 108c to send commands to the robots 109a to 109c and receive information from the robots 109a to 109c. The communication units 107a to 107c can also send and receive commands and information to any external device other than the robots 109a to 109c.

The number of communication units 107a to 107c is determined according to the number of devices and equipment with which the control device 101 communicates. In addition, the number of robot controllers 108a to 108c is determined according to the number of robots controlled by the control device 101.

The device control system according to this embodiment includes a control device 101, robot controllers 108a-108c, and robots 109a-109c. The robots 109a-109c can communicate with the communication units 107a-107c of the control device 101 via the robot controllers 108a-108c, and are controlled by the control device 101.

Figure 2 is a diagram showing an example of the operation flow of the command generation unit 102. The operation of the command generation unit 102 will be explained using Figure 2.

In S201, the command generation unit 102 selects a target robot and an axis (joint) of the robot for which a command (trajectory command) is to be generated. The command generation unit 102 can select any robot from robots 109a to 109c, and can select any axis of the selected robot. In the following, the target robot for which a command is to be generated (the robot selected in S201) is referred to as the "target robot".

At S202, the command generation unit 102 generates a trajectory command for the selected axis of the robot at the current time in accordance with the next operation to be executed by the target robot.

In S203, the command generation unit 102 checks whether generation of trajectory commands has been completed for all axes of the target robot. If generation of trajectory commands has not been completed for all axes of the target robot, the process of S204 is executed, and if generation of trajectory commands has been completed, the process of S205 is executed.

In S204, the command generation unit 102 selects the axis for which the next trajectory command is to be generated for the target robot. After executing the process of S204, the process returns to S202.

In S205, the command generation unit 102 checks whether generation of trajectory commands has been completed for all robots 109a to 109c. If generation of trajectory commands has not been completed for all robots 109a to 109c, the process of S206 is executed.

In S206, the command generation unit 102 selects the next robot for which a trajectory command is to be generated (the next target robot). After executing the process of S206, the process returns to S202.

In S205, if the command generation unit 102 determines that trajectory command generation has been completed for all robots 109a to 109c, it ends the operation.

Figure 3 is a diagram showing an example of the operation flow of the command correction unit 103. The operation of the command correction unit 103 will be explained using Figure 3.

In S301, the command correction unit 103 selects a target robot and an axis (joint) of the robot for which the command (trajectory command) is to be corrected. The command correction unit 103 can select any robot from robots 109a to 109c, and can select any axis of the selected robot. In the following, the target robot for which the command is to be corrected (the robot selected in S301) is referred to as the "target robot."

In S302, the command correction unit 103 acquires the command execution period T and phase α for the target robot. The command execution period T and phase α are calculated by the period calculation unit 104 and phase calculation unit 105, respectively.

In S303, the command correction unit 103 corrects the trajectory command to match the timing at which the target robot executes the command (command execution timing). For example, the command correction unit 103 interpolates the value of the trajectory command for time with respect to time to obtain the value of the trajectory command at the next command execution timing. Then, the command correction unit 103 corrects the trajectory command by setting the obtained value of the trajectory command at the next command execution timing as the trajectory command (corrected trajectory command).

The next command execution timing of the target robot can be obtained from the command execution period T and phase α of the target robot. Therefore, once the command execution period T, which is the period for executing commands, and the phase α, which is the reference point (starting point) for executing commands, are known for the target robot, the command correction unit 103 can calculate the next command execution timing.

In S304, the command correction unit 103 checks whether the correction of the trajectory command has been completed for all axes of the target robot. If the correction of the trajectory command has not been completed for all axes of the target robot, the process of S305 is executed, and if the correction has been completed, the process of S306 is executed.

In S305, the command correction unit 103 selects the axis for which the trajectory command of the target robot is to be corrected next. After executing the process of S305, the process returns to S303.

In S306, the command correction unit 103 checks whether the correction of the trajectory command has been completed for all robots 109a to 109c. If the correction of the trajectory command has not been completed for all robots 109a to 109c, the process of S307 is executed.

In S307, the command correction unit 103 selects the next robot (next target robot) for which the trajectory command is to be corrected. After executing the process of S307, the process returns to S302.

In S306, if the command correction unit 103 determines that the correction of the trajectory commands for all robots 109a to 109c has been completed, the operation ends.

Figure 4 is a diagram showing a time chart showing the command execution period T and phase α of the robots 109a to 109c calculated by the period calculation unit 104 and the phase calculation unit 105. The command execution period T and phase α will be explained using Figure 4.

Figure 4 shows the timing (command transmission timing ts) at which the control device 101 sends commands to the robots 109a to 109c, and the timing (command execution timing te) at which the robots 109a to 109c (robots A to C) each execute the command. The control device 101 sends commands to each of the robots 109a to 109c at the same timing (command transmission timing ts). Robot 109a executes the command at command execution timing teA, robot 109b executes the command at command execution timing teB, and robot 109c executes the command at command execution timing teC.

The time difference (te-ts) between when a command is sent from the communication units 107a-107c to the robots 109a-109c, i.e., when the control device 101 sends a command, and when each of the robots 109a-109c executes the command, is called the command execution time difference Δt. In FIG. 4, the command execution time difference Δt for robot 109a is indicated as ΔtA (=teA-ts), the command execution time difference Δt for robot 109b is indicated as ΔtB (=teB-ts), and the command execution time difference Δt for robot 109c is indicated as ΔtC (=teC-ts).

As an example, FIG. 4 shows the command execution periods Tb and Tc of robots 109b and 109c (robots B and C) and the phases αa and αb of robots 109a and 109b (robots A and B). The command execution period T is the time interval during which robots 109a to 109c execute two successive commands. The phase α is the reference point (starting point) of the command execution period T of robots 109a to 109c.

As shown in FIG. 4, even if the control device 101 transmits trajectory commands to each of the robots 109a to 109c at the same timing (command transmission timing ts), the robots 109a to 109c execute the received commands at different times (command execution timings teA to teC).

The robots 109a to 109c receive commands from the control device 101 and execute the trajectory commands at regular intervals. This regular time (time interval) is the command execution cycle T.

In addition, even if the robots 109a to 109c have the same command execution period T, the command execution timing te may differ from one another. This is because the starting points of the command execution periods T of the robots 109a to 109c are different from one another. The starting points of these command execution periods T are the phase α.

The command correction unit 103 calculates the next command execution timing te for each of the robots 109a to 109c using the command execution period T and phase α, and corrects the trajectory command generated by the command generation unit 102 to a trajectory command to be executed at the calculated next command execution timing te. The command correction unit 103 can calculate the next command execution timing te from the command execution period T, which is the time interval for executing a command, and the phase α, which is the starting point of the command execution period T.

The period calculation unit 104 and phase calculation unit 105 acquire the command execution period T and phase α of each robot 109a to 109c (robots A to C) during the calibration period of the control device 101. The command correction unit 103 corrects the command generated by the command generation unit 102 during the robot control period in which the control device 101 controls the robots 109a to 109c.

Fig. 5 is a diagram showing an example of a trajectory command corrected by the command correction unit 103 and a trajectory command corrected by the command correction unit 103. The process of correcting a command by the command correction unit 103 will be described with reference to Fig. 5. The command correction unit 103 corrects the command in accordance with the timing of the next command execution of the target robot in the process of S303 in Fig. 3.

The table on the left of FIG. 5 shows an example of a trajectory command corrected by the command correction unit 103. This trajectory command is a command generated by the command generation unit 102, and is expressed, for example, by a value indicating the position of an axis with respect to time (time from reference time t0). As an example, FIG. 5 shows the angular positions (angles from a predetermined reference position) at each time for axis 1 and axis 2 of robot 109a (robot A) and axis 10 of robot 109c (robot C). For example, the table on the left of FIG. 5 shows an example of a trajectory command in which axis 1 of robot A is at a position of 20 degrees at time 10 ms and at a position of 10 degrees at time 20 ms.

The table on the right of FIG. 5 shows an example of a trajectory command corrected by the command correction unit 103. As an example, FIG. 5 shows the angular positions of axis 1, axis 2, and axis 10 of robot A at time 12 ms. For example, the table on the right of FIG. 5 shows an example of a trajectory command corrected so that axis 1 of robot A is at a position of 18 degrees at time 12 ms. Note that time 12 ms is an example of the next command execution timing te, which is obtained as the sum of phase α and command execution period T (= 4 ms + 8 ms) when, for example, phase α is 4 ms from reference time t0 and command execution period T is 8 ms.

The command correction unit 103 corrects the command generated by the command generation unit 102, for example, by interpolating the value of the command generated by the command generation unit 102 with respect to time. As described above, the command correction unit 103 calculates the next command execution timing te using the command execution period T and phase α. From the next command execution timing te, the command correction unit 103 can determine which two times (times 10 ms and 20 ms in the example of FIG. 5) of the commands generated by the command generation unit 102 should be interpolated, and at which time (time 12 ms in the example of FIG. 5) the command (angular position) should be obtained. That is, the command correction unit 103 derives the command execution timing te of the command for the next operation to be executed using the command execution period T and phase α, determines between which two times the command falls from the command execution timing te, and corrects the command by interpolating the commands of the two times obtained with respect to time.

The command correction unit 103 can correct the command by interpolating the command value over time using any interpolation method, such as linear interpolation or spline interpolation, to obtain the corrected command.

As already mentioned, even if the robots 109a to 109c have the same command transmission timing ts, their command execution timings teA to teC are different from one another. It is generally difficult to synchronize (match) the command execution timings teA to teC of the robots 109a to 109c.

In this embodiment, the command is corrected to match the next command execution timing teA to teC, so that the operation of the robots 109a to 109c is synchronized rather than the command execution timing teA to teC being synchronized. Therefore, even if the command execution timings teA to teC of the robots 109a to 109c are different from each other, the robots 109a to 109c can execute matching operations and synchronize their operations. This command correction is based on the command execution timings teA to teC of the robots 109a to 109c, so it takes into account the difference in the command execution timings teA to teC of the robots 109a to 109c, and is a correction that can synchronize the operation of the robots 109a to 109c.

Figure 6 is a diagram showing a time chart showing elements used when calculating the command execution time difference Δt, the command execution period T, and the phase α. Using Figure 6, the calculation method of the command execution time difference Δt, the command execution period T, and the phase α will be explained. The command execution time difference Δt is calculated by the command execution time difference acquisition unit 106, the command execution period T is calculated by the period calculation unit 104, and the phase α is calculated by the phase calculation unit 105.

As an example, FIG. 6 shows the command execution period Ta, phase αa, command execution timing teA, and command execution time difference ΔtA for robot 109a (robot A). The control device 101 periodically transmits commands to the robots 109a to 109c. The time difference between when the control device 101 transmits a command for the first time and when the robots 109a to 109c execute the command is represented as command execution time difference Δt_1, and the time difference between when the control device 101 transmits a command for the second time and when the robots 109a to 109c execute the command is represented as command execution time difference Δt_2. In FIG. 6, the command execution time difference Δt_1 and the command execution time difference Δt_2 for robot 109a are represented as command execution time difference ΔtA_1 and command execution time difference ΔtA_2, respectively.

The command execution time difference acquisition unit 106 acquires the time from when the control device 101 transmits a command to the robots 109a to 109c until each of the robots 109a to 109c executes the command. Specifically, the command execution time difference acquisition unit 106 receives and records the time when the control device 101 transmits a command (command transmission timing ts) and the time when the robots 109a to 109c execute the command (command execution timing te) from the communication units 107a to 107c. The command execution time difference acquisition unit 106 then calculates the command execution time difference Δt (= te - ts) from the difference between these times, and outputs the command execution time difference Δt to the period calculation unit 104 and the phase calculation unit 105.

Furthermore, FIG. 6 shows the period (command transmission period command_period) at which the control device 101 sends commands to the robots 109a to 109c, and the difference (command transmission time difference command_diff) between a predetermined reference time t0 and the command transmission timing ts of the control device 101.

The period calculation unit 104 calculates the command execution period T of each robot 109a to 109c, for example, using the command transmission period command_period and the command execution time difference Δt_1 and command execution time difference Δt_2 according to the following formula (1).

Command execution period T = command_period
-(Δt_1%(command_period×(Δt_1/command_period)))
+Δt_2 (1)
Note that formula (1) is an example where variables are expressed as integers (when performing an operation with integer type variables), the operator "/" represents division that truncates the quotient to the nearest integer, and the operator ""%" represents an operation to find the remainder of a division.

Equation (1) is constructed taking into account the case where the command execution period T differs by more than double the command transmission period command_period used for sampling, and uses the remainder obtained by dividing the command execution time difference Δt_1 by the command transmission period command_period. Note that the control device 101 transmits the second command in accordance with the command execution period T after the command execution timing te is returned. Note that in equation (1), if the denominator of the calculation expressed by the operators "/" and "%" is 0, this calculation is deleted or the denominator is replaced with 1 to avoid the occurrence of an error.

The phase calculation unit 105 calculates the phase α of each robot 109a to 109c according to the following formula (2), for example, using the command transmission time difference command_diff, the command execution time difference Δt_1, and the command execution period T.

Phase α = (command_diff + Δt_1)% T (2)
Like equation (1), equation (2) is an example in which variables are expressed as integers, and the operator "%" represents an operation to obtain a remainder of division.

The phase α is calculated using the command execution period T. The phase calculation unit 105 may input the command execution period T calculated by the period calculation unit 104 to calculate the phase α. In formula (2), if the denominator of the operation represented by the operator "%" is 0, this operation is deleted or the denominator is replaced with 1 for calculation.

The corrected trajectory command (trajectory command at time 12 ms) shown in the table on the right of Figure 5 is an example in which command_diff is 0 ms and command_period is 10 ms, and the command execution timing te after the time (command_diff + command_period) is the sum of the phase α (4 ms) and the command execution period T (8 ms). In other words, the command execution timing te after the time 10 ms is 12 ms. Therefore, the next command execution timing te is 2 ms (12 ms) after the timing (10 ms) when the control device 101 sends a command to the robot 109a (robot A).

Figure 7 is a diagram showing an example of the operation flow of the communication units 107a to 107c shown in Figure 1. The operation of the communication units 107a to 107c will be explained using Figure 7.

The communication units 107a to 107c are capable of communicating with the robots 109a to 109c via the robot controllers 108a to 108c, and have the function of transmitting commands to the robots 109a to 109c from the control device 101 to the robot controllers 108a to 108c, and the function of receiving information such as the responses of the robots 109a to 109c to the commands from the robot controllers 108a to 108c.

In S701, the communication units 107a to 107c determine whether the communication is a command transmission from the control device 101. If a command is being transmitted, the process of S702 is executed. If a response is being received instead of a command transmission, the process of S704 is executed.

At S702, the communication units 107a to 107c generate a packet based on the command to be sent.

In S703, the communication units 107a to 107c transmit the packets generated in S702.

In S704, the communication units 107a to 107c acquire packets received from the robots 109a to 109c via the robot controllers 108a to 108c.

In S705, the communication units 107a to 107c analyze the packets acquired in S704, and output the information obtained by analyzing the packets to the command execution time difference acquisition unit 106. The command execution time difference acquisition unit 106 can determine the command execution time difference Δt using the information acquired by the communication units 107a to 107c from the robots 109a to 109c.

When calculating the command execution time difference Δt, the command execution time difference acquisition unit 106 can calculate the time (time instant) at which the robots 109a to 109c executed the command by any method, such as the method shown below.

The time at which the robots 109a to 109c execute a command can be obtained, for example, by a method of obtaining a message from the robots 109a to 109c without the robots 109a to 109c moving. This method considers the time at which the robots 109a to 109c execute a command to be the time when the communication units 107a to 107c send a command to the robots 109a to 109c during the calibration period of the control device 101 and receive a response (message) from the robots 109a to 109c that they have recognized the command. When the robots 109a to 109c receive a command from the communication units 107a to 107c, they send a response (message) to the communication units 107a to 107c that they have recognized the command.

The time at which the robots 109a to 109c execute a command can also be found by, for example, having the robots 109a to 109c return a message indicating their current status before performing an action. In this method, before the robots 109a to 109c execute an action, they send any information, such as information that they are about to execute an action or the current time, as their current status, and the time at which the communication units 107a to 107c receive a message containing such information is considered to be the time at which the robots 109a to 109c execute a command.

The time at which the robots 109a to 109c execute a command can also be found by, for example, having the robot controllers 108a to 108c store the time difference between when the robots 109a to 109c receive a command and when they execute the command, or by having the robot controllers 108a to 108c record the time at which the robots 109a to 109c execute a command. The command execution time difference acquisition unit 106 can find the time at which the robots 109a to 109c execute a command by acquiring from the robot controllers 108a to 108c the time difference stored by the robot controllers 108a to 108c or the recorded command execution time.

The command correction unit 103 may calculate the command execution timing te one command execution period T later, or may calculate the command execution timing te multiple command execution periods T later. That is, the command correction unit 103 can correct the command by calculating the command execution timing te one or multiple command execution periods T later and determining the value of the command at the calculated command execution timing te. It is preferable that the robot controllers 108a to 108c are provided with a buffer that can store multiple commands so that they can receive commands at multiple command execution timings te.

As described above, the control device 101 according to this embodiment can absorb the difference in command execution timing te between multiple robots 109a to 109c that have different command execution timing te, and synchronize the operations of each of the robots 109a to 109c.

The control device 101 according to this embodiment can also be applied to cases where there is only one robot to be controlled. When there is only one robot to be controlled, the trajectory command can be corrected taking into account the command execution time difference Δt, which is the difference between the command transmission timing ts and the command execution timing te, thereby eliminating the discrepancy between the ideal operation and the actual operation.

The control device 101 according to the second embodiment of the present invention will be described with reference to FIG. 8.

Figure 8 is a functional block diagram of the control device 101 according to this embodiment. The control device 101 according to this embodiment has a similar configuration to the control device 101 according to embodiment 1 (Figure 1), but differs from the control device 101 according to embodiment 1 in that it includes a sensor communication unit 802 and a sensor value analysis unit 803. The following mainly describes the differences between the control device 101 according to this embodiment and the control device 101 according to embodiment 1.

The robots 109a to 109c, which are devices controlled by the control device 101, are equipped with sensors 801. The sensors 801 are installed on each axis of the robots 109a to 109c, and can be configured with any sensor that records the movement of each axis.

The sensor communication unit 802 is connected to the sensor 801 equipped on the robots 109a to 109c. The sensor communication unit 802 communicates with the sensor 801 and acquires the sensor value recorded by the sensor 801.

The sensor value analysis unit 803 acquires the sensor values from the sensor communication unit 802, analyzes and determines the time (time instant) when each of the robots 109a to 109c executes a command from the sensor values, and outputs the determined time to the command execution time difference acquisition unit 106. For example, the sensor value analysis unit 803 can determine the time when the axis of the robots 109a to 109c moves from the sensor values, and use this time instant as the time when the robots 109a to 109c execute a command.

The control device 101 according to this embodiment can obtain the time (time instant) at which the robots 109a to 109c execute a command more accurately even if the robots 109a to 109c do not return the command execution time or if the method for obtaining the command execution time differs depending on the robots 109a to 109c.

The control device 101 according to the third embodiment of the present invention will be described with reference to FIG. 9.

Figure 9 is a functional block diagram of the control device 101 according to this embodiment. The control device 101 according to this embodiment has a similar configuration to the control device 101 according to embodiment 1 (Figure 1), but differs from the control device 101 according to embodiment 1 in that it includes a camera communication unit 902 and an image analysis unit 903. The following will mainly describe the control device 101 according to this embodiment, focusing on the differences from the control device 101 according to embodiment 1.

The robots 109a to 109c, which are devices controlled by the control device 101, are photographed by the camera 901. The camera 901 is installed so as to photograph the robots 109a to 109c. The camera 901 can be any camera that records the movements of each axis of the robots 109a to 109c, for example a camera with a high frame rate such as 1000 fps. The device control system according to this embodiment can be equipped with the camera 901.

The camera communication unit 902 is connected to the camera 901. The camera communication unit 902 communicates with the camera 901 and obtains information about images captured by the camera 901.

The image analysis unit 903 acquires image information from the camera communication unit 902, analyzes and determines from this image information the time (time instant) at which each robot 109a to 109c executed a command, and outputs the determined time to the command execution time difference acquisition unit 106. For example, the image analysis unit 903 can determine from the image information the time instant at which the axis of the robot 109a to 109c moved, and regard this time instant as the time at which the robot 109a to 109c executed a command.

The control device 101 according to this embodiment can obtain the time (time) at which the robots 109a to 109c execute a command more accurately, even if the robots 109a to 109c do not return the command execution time, or if the method of obtaining the command execution time differs depending on the robots 109a to 109c. In addition, since there is no need to attach a sensor to the robots 109a to 109c to obtain the time at which the axis moved, the robots 109a to 109c can be easily replaced or repaired.

The control device 101 according to the fourth embodiment of the present invention will be described with reference to Figures 10 and 11.

Figure 10 is a functional block diagram of the control device 101 according to this embodiment. The control device 101 according to this embodiment has a similar configuration to the control device 101 according to embodiment 1 (Figure 1), but differs from the control device 101 according to embodiment 1 in that it includes a calculated value update unit 1001. Below, the control device 101 according to this embodiment will be described, focusing mainly on the differences from the control device 101 according to embodiment 1.

Figure 11 is a functional block diagram of the calculated value update unit 1001. The calculated value update unit 1001 includes a period holding unit 1101, a phase holding unit 1102, a counter 1103, and a median calculation unit 1104.

The cycle holding unit 1101 holds the command execution cycle T of each of the robots 109a to 109c calculated by the cycle calculation unit 104. The cycle calculation unit 104 calculates the command execution cycle T every time the control device 101 transmits a command. The cycle holding unit 1101 holds the command execution cycle T calculated multiple times by the cycle calculation unit 104 in this way, i.e., multiple command execution cycles T.

The phase holding unit 1102 holds the phase α of each robot 109a to 109c calculated by the phase calculation unit 105. The phase calculation unit 105 calculates the phase α every time the control device 101 transmits a command. The phase holding unit 1102 holds the phase α calculated multiple times by the phase calculation unit 105 in this way, i.e., multiple phases α.

The counter 1103 records the number of times the period calculation unit 104 calculates the command execution period T and the number of times the phase calculation unit 105 calculates the phase α. That is, the counter 1103 records the number of command execution periods T held by the period holding unit 1101 and the number of phases α held by the phase holding unit 1102. When the number of command execution periods T and phases α reaches a predetermined fixed number, that is, when the control device 101 communicates with the robots 109a to 109c a predetermined fixed number of times, the counter 1103 transmits a notification to that effect to the median calculation unit 1104 and clears the recorded number of command execution periods T and phases α. The counter 1103 transmits the above notification to the median calculation unit 1104 every time the number of command execution periods T and phases α reaches a certain number, that is, every time the control device 101 communicates with the robots 109a to 109c a certain number of times.

When the median calculation unit 1104 receives a notification from the counter 1103, it calculates the median of the command execution period T and the phase α. That is, when the median calculation unit 1104 receives a notification from the counter 1103, it receives from the period holding unit 1101 the multiple command execution periods T held by the period holding unit 1101 and receives from the phase holding unit 1102 the multiple phases α held by the phase holding unit 1102, and calculates the median of the multiple command execution periods T and the median of the multiple phases α. Then, the median calculation unit 1104 outputs the calculated median of the command execution periods T and the median of the phase α to the command correction unit 103.

The median calculation unit 1104 may calculate the median of either the command execution period T or the phase α instead of the median of both, and output the median to the command correction unit 103. The median calculation unit 1104 may also calculate the average value of the command execution period T and the phase α instead of the median value of the command execution period T and the phase α, and output the average value to the command correction unit 103.

In the control device 101 according to this embodiment, the calculation value update unit 1001 calculates the median (or average) of the command execution period T and phase α each time the control device 101 communicates with the robots 109a to 109c a predetermined number of times. The command correction unit 103 corrects the command generated by the command generation unit 102 using the command execution period T and phase α received from the calculation value update unit 1001. In other words, the command correction unit 103 periodically updates the command correction value by updating the command execution period T and phase α used for correction each time the control device 101 communicates with the robots 109a to 109c a predetermined number of times.

As described above, the control device 101 according to this embodiment updates the command corrections every certain number of communications, so that even if a time lag occurs in the timers of the robots 109a to 109c (or the robot controllers 108a to 108c), the robots 109a to 109c can continue to perform the desired operations.

The present invention is not limited to the above-mentioned examples, and various modifications are possible. For example, the above-mentioned examples have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment that includes all of the configurations described. It is also possible to replace part of the configuration of one example with the configuration of another example. It is also possible to add the configuration of another example to the configuration of one example. It is also possible to delete part of the configuration of each example, or to add or replace other configurations.

101...Control device, 102...Command generation unit, 103...Command correction unit, 104...Periodic calculation unit, 105...Phase calculation unit, 106...Command execution time difference acquisition unit, 107a to 107c...Communication unit, 108a to 108c...Robot controller, 109a to 109c...Robot, 801...Sensor, 802...Sensor communication unit, 803...Sensor value analysis unit, 901...Camera, 902...Camera communication unit, 903...Image analysis unit, 1001...Calculated value update unit, 1101...Periodic retention unit, 1102...phase holding unit, 1103...counter, 1104...median calculation unit, t0...reference time, ts...command transmission timing, te, teA to teC...command execution timing, T, Ta, Tb, Tc...command execution period, Δt, Δt_1, Δt_2, ΔtA, ΔtA_1, ΔtA_2, ΔtB, ΔtC...command execution time difference, α, αa, αb...phase, command_period...command transmission period, command_diff...command transmission time difference.

Claims (12)

A communication unit capable of communicating with one or more devices;
A command generating unit that generates a command for the device;
a command execution time difference acquisition unit that acquires a command execution time difference that is a time difference between when the command is transmitted from the communication unit to the device and when the device executes the command;
a period calculation unit that calculates a command execution period, which is a period during which the device executes the command, using the command execution time difference;
a phase calculation unit that calculates a phase that is a reference point of the command execution cycle of the device by using the command execution time difference;
a command correction unit that calculates a command execution timing, which is a timing at which the device executes the command, from the command execution cycle and the phase, and corrects the command by determining a command value at the next command execution timing;
A device control apparatus comprising: The cycle calculation unit calculates the command execution cycle by using a command transmission cycle, which is a cycle for transmitting the command to the device, and the command execution time difference.
The device according to claim 1 . the phase calculation unit calculates the phase using a command transmission time difference, which is a difference between a predetermined reference time and a time when a command is transmitted, the command execution time difference, and the command execution period.
The device according to claim 1 . the command execution time difference acquisition unit, when acquiring the command execution time difference, regards a time when the message is received from the device as a time when the device executed the command;
The device according to claim 1 . the command execution time difference acquisition unit, when acquiring the command execution time difference, acquires from the device a time difference between when the device receives the command and when the device executes the command, thereby determining a time at which the device executed the command.
The device according to claim 1 . the command execution time difference acquisition unit, when acquiring the command execution time difference, acquires, from the device, a time when the device executed the command, thereby determining the time when the device executed the command.
The device according to claim 1 . the command execution time difference acquisition unit acquires a value recorded by a sensor installed in the device when acquiring the command execution time difference, thereby determining the time when the device executed the command.
The device according to claim 1 . the command execution time difference acquisition unit, when acquiring the command execution time difference, acquires information on an image captured by a camera that captures the device, thereby determining the time at which the device executed the command;
The device according to claim 1 . The command correction unit updates the command execution period and the phase every time the control device communicates with the device a predetermined number of times.
The device according to claim 1 . the command correction unit calculates the command execution timing a plurality of command execution cycles later, obtains a command value at the command execution timing, and corrects the command.
The device according to claim 1 . The control device according to claim 1 ;
One or more devices controlled by the control device and capable of communicating with the communication unit included in the control device;
An equipment control system comprising: The method is executed by a control device having a communication unit capable of communicating with one or more devices,
A command generating step of generating a command for the device;
a command execution time difference acquisition step of acquiring a command execution time difference which is a time difference between when the command is transmitted from the communication unit to the device and when the device executes the command;
a period calculation step of calculating a command execution period, which is a period during which the device executes the command, using the command execution time difference;
a phase calculation step of calculating a phase that is a reference point of the command execution cycle of the device using the command execution time difference;
a command execution timing, which is a timing at which the device executes the command, is calculated from the command execution cycle and the phase, and a command correction step of correcting the command by determining a value of the command at the next command execution timing;
A method for controlling an apparatus, comprising:

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