JP7826760B2 - Time synchronization method, robot controller, and robot system - Google Patents

Description

The present invention relates to a time synchronization method, a robot controller, and a robot system.

For example, Patent Document 1 describes an integrated control system for a work robot that includes a robot control CPU, a first work tool control CPU, a second work tool control CPU, a common memory, and a system bus that integrates these CPUs and memories.

Japanese Patent Application Publication No. 9-323279

However, in such integrated control systems for work robots, time discrepancies can occur between CPUs. If time discrepancies occur between CPUs, the robot's drive characteristics may be degraded, for example, such as the work tool not starting to drive even though the robot has assumed a predetermined posture, or conversely, the work tool starting to drive before the robot has assumed a predetermined posture.

A time synchronization method of the present invention is a method for synchronizing the time of a first processing unit and a second processing unit connected to the first processing unit via a first bus, the second processing unit being included in a robot controller that controls driving of a robot, the method comprising:
a synchronization command instruction step in which a third processing unit, connected to the second processing unit via a second bus and including a clock circuit, transmits a synchronization command to the first processing unit and the second processing unit, and holds the time when the synchronization command is transmitted as a reference time;
a first processing unit time correction step in which the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit based on the reference time and the time required from when the synchronization command is received until acquisition of the reference time is completed;
The method includes a second processing unit time correction step in which the second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit based on the reference time and the time required from receiving the synchronization command to completing the acquisition of the reference time.

The robot controller of the present invention includes a first processing unit and
A second processing unit;
a third processing unit including a clock circuit;
a first bus connecting the first processing unit and the second processing unit;
a second bus connecting the second processing unit and the third processing unit;
the third processing unit transmits a synchronization command to the first processing unit and the second processing unit, and holds a time when the synchronization command is transmitted as a reference time;
the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit based on the reference time and a time required from receiving the synchronization command to completing acquisition of the reference time;
The second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit based on the reference time and the time required from receiving the synchronization command to completing the acquisition of the reference time.

The robot system of the present invention comprises: a robot;
a robot controller that controls the driving of the robot,
The robot controller includes a first processing unit and
A second processing unit;
a third processing unit including a clock circuit;
a first bus connecting the first processing unit and the second processing unit;
a second bus connecting the second processing unit and the third processing unit;
the third processing unit transmits a synchronization command to the first processing unit and the second processing unit, and holds a time when the synchronization command is transmitted as a reference time;
the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit based on the reference time and a time required from receiving the synchronization command to completing acquisition of the reference time;
The second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit based on the reference time and the time required from receiving the synchronization command to completing the acquisition of the reference time.

1 is an overall configuration diagram of a robot system according to a preferred embodiment. FIG. 1 is a block diagram of a robot controller. 10 is a flowchart showing a time synchronization process. 10 is a timing chart showing a time synchronization process. 10 is a timing chart showing a time synchronization process. FIG. 3 is a modified example of the block diagram of the robot controller of FIG. 2 .

The time synchronization method, robot controller, and robot system of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

Figure 1 is a diagram of the overall configuration of a robot system according to a preferred embodiment. Figure 2 is a block diagram of a robot controller. Figure 3 is a flowchart showing the time synchronization process. Figures 4 and 5 are timing charts showing the time synchronization process. Figure 6 is a modified version of the block diagram of the robot controller in Figure 2.

The robot system 1 shown in Figure 1 includes a robot 2 and a robot controller 3 that controls the driving of the robot 2.

-Robot 2-
The robot 2 is a robot that performs tasks such as supplying, removing, transporting, and assembling precision equipment and the components that make up the equipment. However, the use of the robot 2 is not particularly limited. The robot 2 is a six-axis robot having six rotation axes. The robot 2 has a base 21 and a robot arm 22 rotatably connected to the base 21, and an end effector 23 is attached to the tip of the robot arm 22.

The robot arm 22 is a robotic arm in which multiple arms 221, 222, 223, 224, 225, and 226 are rotatably connected, and is equipped with six joints J1 to J6. Of these, joints J2, J3, and J5 are bending joints, and joints J1, J4, and J6 are torsion joints. Each of the joints J1, J2, J3, J4, J5, and J6 is equipped with a motor M as a drive source and an encoder E for detecting the amount of rotation of the motor M. A control point that indicates the position of the robot arm 22 and is the object of control is provided at the end of arm 226, which is the tip of the robot arm 22. By independently driving the motors M of each joint J1, J2, J3, J4, J5, and J6, the control point of the robot arm 22 can be moved along a desired trajectory.

An end effector 23 is also connected to the arm 226. The end effector 23 is detachable from the arm 226, allowing the robot 2 to be selectively fitted to the task it is to perform.

The robot 2 has been described above, but the configuration of the robot 2 is not particularly limited. For example, the robot 2 may be a SCARA robot (horizontal articulated robot), a dual-arm robot, etc. Furthermore, the robot 2 may be fixed to the floor or the like and be immobile, or may be fixed to a mobile device such as an automated guided vehicle (AGV) and be mobile.

-Robot Controller 3-
The robot controller 3 is housed, for example, in the base 21. However, the location of the robot controller 3 is not particularly limited, and for example, it does not have to be housed in the robot 2. As shown in FIG. 2 , the robot controller 3 has a first processing unit 4, a second processing unit 5, a third processing unit 6, a first bus 7 connecting the first processing unit 4 and the second processing unit 5, and a second bus 8 connecting the second processing unit 5 and the third processing unit 6.

The first processing unit 4 is also connected to the host computer HPC and receives the robot 2 program from the host computer HPC. The first processing unit 4 has the program execution function of the robot controller 3, analyzes the received program, and acquires target position information for the robot arm 22 specified in the program. The target position information is information about the target position P1, which is the target point to which the control point of the robot arm 22 is to be moved, and is, for example, data indicating the coordinates of the target position P1. Other information such as the distance traveled by the control point of the robot arm 22 from its current position to the target position P1 may also be used.

The first processing unit 4 transmits the acquired target position information to the second processing unit 5 via the first bus 7. The second processing unit 5 has the function of generating robot motion, i.e., the trajectories of each joint J1 to J6, based on the target position information received from the first processing unit 4. With this configuration, these functions can be assigned to separate processing units, allowing each function to be executed smoothly and improving the performance of the robot controller 3, particularly its real-time performance.

However, the functions assigned to the first and second processing units 4 and 5 are not particularly limited. For example, contrary to this embodiment, the first processing unit 4 may have the function of generating robot motion, and the second processing unit 5 may have the function of executing the program of the robot controller 3. In this case, the second processing unit 5 may simply be connected to the host computer HPC.

The first processing unit 4 integrates all necessary functions onto a single board, and includes a printed wiring board 40, a first control unit 41, a main memory 42, and a system bus 43 connecting the first control unit 41 and the main memory 42.

The printed wiring board 40 includes an insulating substrate and wiring, and electrically connects the attached first control unit 41, first main memory 42, and first system bus 43. The first control unit 41 includes a processor 44, a cache memory 46, and a timer counter 47 (system timer) as a clock circuit. The first control unit 41 executes a program loaded in the main memory 42 to realize the functions of the first processing unit 4. The hardware configuration of the first control unit 41 is a system-on-chip (SoC). This allows for the first control unit 41 to be smaller, more power-efficient, and less expensive. It also simplifies the manufacture of the first processing unit 4. However, the hardware configuration of the first control unit 41 is not particularly limited; for example, the processor 44 and cache memory 46 may be integrated on a single board.

The first control unit 41 may be configured without a cache memory 46. The main memory 42 stores programs and data. The system bus 43 is a system bus that connects the processor 44 and the main memory 42. In this specification, the transmission path that connects to the processor and transmits data is referred to as the system bus, regardless of whether the hardware configuration of the control unit 41 is a system-on-chip.

The processor 44 can read and execute programs stored in the main memory 42. The processor 44 uses the general-purpose OS Linux (registered trademark) as its OS (operating system). This facilitates program execution and external communication. The cache memory 46 temporarily stores programs and data read from the main memory 42. The cache memory 46 has a smaller storage capacity than the main memory 42 but can operate at high speeds. The cache memory 46 is a multi-stage cache memory and includes at least a primary cache memory and a secondary cache memory that is slower than the primary cache memory but has a larger storage capacity. It may also include a tertiary or higher cache memory. It may also be a single cache memory that does not have multiple stages.

The processor 44 can also be a multi-core processor having multiple cores. In this case, the execution of different application programs can be assigned to each core, allowing each application program to be executed smoothly and improving the performance of the robot controller 3, particularly its real-time capabilities. A dedicated primary cache memory can also be provided for each core. In this case, a secondary cache memory can be provided so that it can be shared by multiple cores. Sharing the secondary cache memory allows for effective use of the secondary cache memory. Similarly to the primary cache memory, a dedicated secondary cache memory can also be provided for each core. By dedicating a cache memory to each core, processing delays can be reduced.

The timer counter 47 also counts the number of pulses in the input signal to measure time.

With the first processing unit 4 configured as described above, the first control unit 41 can occupy the main memory 42 and system bus 43, thereby reducing processing delays and improving the performance of the robot controller 3, particularly its real-time capabilities.

The second processing unit 5 has the same configuration as the first processing unit 4. Therefore, the following will provide a brief description of the second processing unit 5. The second processing unit 5 integrates all necessary functions on a single board, and includes a printed wiring board 50, a second control unit 51, a main memory 52, and a system bus 53 connecting the second control unit 51 and the main memory 52.

The second control unit 51 is a system-on-chip and includes a processor 54, cache memory 56, and a timer counter 57 (system timer) as a clock circuit. The processor 54 can read and execute programs stored in the main memory 52. With a second processing unit 5 configured in this way, the second control unit 51 can occupy the main memory 52 and system bus 53, thereby reducing processing delays and improving the performance of the robot controller 3, particularly its real-time capabilities.

The timer counter 57 also counts the number of pulses in the input signal to measure time.

The third processing unit 6 integrates all necessary functions onto a single board and includes a printed wiring board 60, a control unit 61, a main memory 62, and a system bus 63 connecting the control unit 61 and the main memory 62. The control unit 61 includes elements such as an FPGA (Field-Programmable Gate Array) equipped with a timer counter 67 (system timer) as a clock circuit. The control unit 61 also has functions such as generating timing signals at predetermined time intervals, and generating a synchronization command Ss along with the timing signal and sending it to the first and second processing units 4 and 5.

The first bus 7 connects the first processing unit 4 and the second processing unit 5. The second bus 8 connects the second processing unit 5 and the third processing unit 6. The first and second buses 7 and 8 are transmission paths for transmitting data. This allows information to be transmitted between the first processing unit 4, the second processing unit 5, and the third processing unit 6. For example, the first processing unit 4 can write information to be shared with the second processing unit 5 to the main memory 52 via the first bus 7, and the second processing unit 5 can write information to be shared with the first processing unit 4 to the main memory 52 via the first bus 7. This allows the first processing unit 4 to obtain the necessary information without accessing the main memory 52, thereby improving processing speed. The same is true for the second processing unit 5.

The standards for the first and second buses 7 and 8 are not particularly limited, and may be, for example, ISA, PCI, PCI Express (PCIe), AGP, etc. In the above description, the first processing unit 4, second processing unit 5, and third processing unit 6 are each configured on a single board, but as shown in Figure 6, the processing units 4, 5, and 6 may also be provided on a single board on a printed wiring board 9.

The circuit configuration of the robot controller 3 has been described above. Next, the software configuration of the robot controller 3, particularly the synchronization method between the first processing unit 4 and the second processing unit 5, will be described with reference to Figures 3 and 4. The horizontal axis in Figure 4 is the time axis, with time progressing from left to right. In Figure 4, the first period is period Q1, the next period is period Q2, and these periods are repeated cyclically thereafter. The lengths of each period are equal. Note that the same processing is performed during each period, so the following description will focus on period Q1, and descriptions of the other periods will be omitted.

As shown in FIG. 3, during period Q1, a synchronization command instruction step S1, a first processing unit time correction step S2, and a second processing unit time correction step S3 are performed. In the synchronization command instruction step S1, the third processing unit 6 transmits a synchronization command Ss to the first processing unit 4 and the second processing unit 5, and stores the time at which the synchronization command Ss is transmitted as the reference time Tref. In the first processing unit time correction step S2, the first processing unit 4 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the first processing unit 4 based on the reference time Tref and the time T1 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. In the second processing unit time correction step S3, the second processing unit 5 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the second processing unit 5 based on the reference time Tref and the time T2 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. Note that these times are system times. A detailed explanation is provided below.

<Synchronization command instruction step S1>
4, during period Q1, first, based on one timing signal St generated by the third processing unit 6, the third processing unit 6 simultaneously transmits a synchronization command Ss to the first processing unit 4 and the second processing unit 5. The third processing unit 6 also holds the time at which the synchronization command Ss is transmitted as a reference time Tref. Note that, because the synchronization command Ss is an interrupt signal, the actual time at which the synchronization command Ss is transmitted and the actual time at which the first and second processing units 4 and 5 receive the synchronization command Ss are the same.

<First processing unit time correction step S2>
When the first processing unit 4 receives the synchronization command Ss, it stores the time at which the synchronization command Ss is received as a reception time Ts1, and accesses the third processing unit 6 to acquire the reference time Tref stored in the third processing unit 6. The first processing unit 4 also stores the time at which it finishes acquiring the reference time Tref as an end time Te1. These times Ts1 and Te1 are each stored as count values of the timer counter 47.

Next, the first processing unit 4 calculates the time T1 from the reception time Ts1 to the end time Te1, i.e., the time T1 required from reception of the synchronization command Ss to completion of acquisition of the reference time Tref, based on the retained reception time Ts1 and end time Te1. The time T1 can be easily calculated from the count number of the timer counter 47. However, the method for calculating the time T1 is not particularly limited.

Next, the first processing unit 4 corrects its own time based on the acquired reference time Tref and the calculated time T1. Specifically, it corrects (updates) its own time to the reference time Tref plus the time T1, and stores this in the main memory 42. This synchronizes the first processing unit 4 with the third processing unit 6. Note that if the processor 44 is multi-core, each core is driven based on the time stored in the main memory 42. This makes it easy to synchronize the cores.

<<Second processing unit time correction step S3>>
When the second processing unit 5 receives the synchronization command Ss, it stores the time at which the synchronization command Ss is received as a reception time Ts2, and accesses the third processing unit 6 to acquire the reference time Tref stored in the third processing unit 6. The second processing unit 5 also stores the time at which acquisition of the reference time Tref is completed as an end time Te2. These times Ts2 and Te2 are each stored as count values of the timer counter 57.

Next, the second processing unit 5 calculates the time T2 from the reception time Ts2 to the end time Te2, i.e., the time T2 required from reception of the synchronization command Ss to completion of acquisition of the reference time Tref, based on the retained reception time Ts2 and end time Te2. The time T2 can be easily calculated from the count number of the timer counter 57. However, the method for calculating the time T2 is not particularly limited.

Next, the second processing unit 5 corrects its own time based on the acquired reference time Tref and the calculated time T2. Specifically, it corrects (updates) its own time to the reference time Tref plus the time T2, and stores this in the main memory 52. This synchronizes the second processing unit 5 with the third processing unit 6. Note that if the processor 54 is multi-core, each core is driven based on the time stored in the main memory 52. This makes it easy to synchronize the cores.

In the example described above, the second processing unit time correction step S3 is performed after the first processing unit time correction step S2, but this is not limited to this, and the second processing unit time correction step S3 may be performed before the first processing unit time correction step S2. The first party to access the third processing unit 6 has priority, and the second party to access the third processing unit 6 will wait to access the third processing unit 6 until the first party has acquired the reference time Tref.

By performing steps S1 to S3 above, the first processing unit 4 and the second processing unit 5 are synchronized with respect to the third processing unit 6. This method allows for easy synchronization of the first processing unit 4 and the second processing unit 5. Synchronizing the first and second processing units 4 and 5 improves the controllability of the robot 2, allowing the robot 2 to perform tasks more accurately. Because the first processing unit 4 and the second processing unit 5 access the third processing unit 6 via the second bus 8, while one of the first processing unit 4 and the second processing unit 5 occupies the second bus 8, the other cannot access the third processing unit 6 and only accesses the third processing unit 6 after the occupancy ends. Therefore, since the time required for the first processing unit 4 and the second processing unit 5 to complete acquisition of the reference time Tref differs, a time discrepancy will occur even if the first and second processing units 4 and 5 each correct their own time to the reference time Tref. However, because the correction is made using the times T1 and T2 required for the first and second processing units 4 and 5 to complete acquisition of the reference time Tref, respectively, the first and second processing units 4 and 5 can be synchronized without time deviation.

Furthermore, with this method, the time of the third processing unit 6 is used as the reference, so synchronization between the first processing unit 4 and the second processing unit 5 is possible even if their operating cycles (number of clocks) are different. Furthermore, because a real-time clock is not required for the first and second processing units 4 and 5, the configuration of the first and second processing units 4 and 5 is simplified.

The period of periods Q1 and Q2 is not particularly limited, but is set, for example, to be longer than the time Tm required to complete steps S1 to S3, and less than the maximum value of the timer counters 47 and 57, i.e., less than the time required for the counters to complete one cycle. This ensures that the time corrections of the first and second processing units 4 and 5 can be performed reliably for each period.

In addition, while the method described above involves correcting the time of the first and second processing units 4 and 5 for each period, time correction can also be performed at different times. For example, as shown in FIG. 5 , if the first processing unit 4 wishes to correct the time at time Tx during period Q1, the first processing unit 4 first retains the count value of the timer counter 47 at time Tx. Next, the first processing unit 4 calculates the time T3 from the reception time Ts1 to time Tx based on the retained reception time Ts1 and time Tx. Next, the first processing unit 4 corrects the time of the first processing unit 4 based on these times Ts1 and Tx. Specifically, the first processing unit 4 corrects (updates) its own time to the time obtained by adding time T3 to time Ts1, and stores this in the main memory 42. This allows the time of the first processing unit 4 to be corrected even during a period.

The above describes the robot system 1. As mentioned above, the time synchronization method used in such a robot system 1 is a method for synchronizing the time of the first processing unit 4 and the second processing unit 5 connected to the first processing unit 4 via the first bus 7, both of which are included in the robot controller 3 that controls the driving of the robot 2. The method includes a synchronization command instruction step S1 in which the third processing unit 6, which is connected to the second processing unit 5 via the second bus 8 and has a timer counter 67 that is a clock circuit, transmits a synchronization command Ss to the first processing unit 4 and the second processing unit 5 and holds the time at which the synchronization command Ss is transmitted as a reference time Tref; In response to the synchronization command Ss, the first processing unit 4 acquires the reference time Tref from the third processing unit 6 and corrects the time of the first processing unit 4 based on the reference time Tref and the time T1 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref (a first processing unit time correction step S2); and in response to the synchronization command Ss, the second processing unit 5 acquires the reference time Tref from the third processing unit 6 and corrects the time of the second processing unit 5 based on the reference time Tref and the time T2 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref (a second processing unit time correction step S3). This method makes it easy to synchronize the first processing unit 4 and the second processing unit 5.

As mentioned above, the robot controller 3 included in the robot system 1 has a first processing unit 4, a second processing unit 5, a third processing unit 6 equipped with a timer counter 67 which is a clock circuit, a first bus 7 connecting the first processing unit 4 and the second processing unit 5, and a second bus 8 connecting the second processing unit 5 and the third processing unit 6. The third processing unit 6 transmits a synchronization command Ss to the first processing unit 4 and the second processing unit 5, and holds the time at which the synchronization command Ss is transmitted as a reference time Tref. The first processing unit 4 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the first processing unit 4 based on the reference time Tref and the time T1 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. The second processing unit 5 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the second processing unit 5 based on the reference time Tref and the time T2 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. With this configuration, the first processing unit 4 and the second processing unit 5 can be easily synchronized.

Furthermore, as mentioned above, the first processing unit 4 and the second processing unit 5 each have timer counters 47 and 57, which are clock circuits. This makes it possible to easily calculate the times T1 and T2.

As mentioned above, the first processing unit 4 includes a first control unit 41, and the second processing unit 5 includes a second control unit 51, with the first control unit 41 and second control unit 51 each being a system-on-chip. This allows for the first and second control units 41, 51 to be made smaller, more energy-efficient, and less expensive. Furthermore, the first and second control units 41, 51 can be manufactured more easily.

Furthermore, as mentioned above, one of the first processing unit 4 and the second processing unit 5 has the program execution function of the robot controller 3, and the other has the function of generating robot motion. This allows the program execution function and the robot motion generation function to be assigned to separate processing units, allowing each function to be executed smoothly and improving the performance of the robot controller 3, particularly its real-time performance.

As mentioned above, the robot system 1 also includes a robot 2 and a robot controller 3 that controls the operation of the robot 2. The robot controller 3 also has a first processing unit 4, a second processing unit 5, a third processing unit 6 equipped with a timer counter 67 which is a clock circuit, a first bus 7 connecting the first processing unit 4 and the second processing unit 5, and a second bus 8 connecting the second processing unit 5 and the third processing unit 6. The third processing unit 6 transmits a synchronization command Ss to the first processing unit 4 and the second processing unit 5, and holds the time at which the synchronization command Ss is transmitted as a reference time Tref. The first processing unit 4 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the first processing unit 4 based on the reference time Tref and the time T1 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. The second processing unit 5 acquires the reference time Tref from the third processing unit 6 in response to the synchronization command Ss, and corrects the time of the second processing unit 5 based on the reference time Tref and the time T2 required from receiving the synchronization command Ss to completing acquisition of the reference time Tref. This configuration makes it easy to synchronize the first processing section 4 and the second processing section 5, improving the controllability of the robot 2 and enabling more accurate work.

The time synchronization method, robot controller, and robot system of the present invention have been described above based on the illustrated embodiments, but the present invention is not limited to this, and the configuration of each part can be replaced with any configuration that has similar functions. Furthermore, any other components may be added to the present invention.

1...Robot system, 2...Robot, 21...Base, 22...Robot arm, 221...Arm, 222...Arm, 223...Arm, 224...Arm, 225...Arm, 226...Arm, 23...End effector, 3...Robot controller, 4...First processing unit, 40...Printed wiring board, 41...First control unit, 42...Main memory, 43...System bus, 44...Processor, 46...Cache memory, 47...Timer counter, 5...Second processing unit, 50...Printed wiring board, 51...Second control unit, 52...Main memory, 53...System bus, 54...Processor, 56...Cache memory, 57...Timer counter, 6...Third processing unit, 60...Print Circuit board, 61...controller, 62...main memory, 63...system bus, 67...timer counter, 7...first bus, 8...second bus, 9...printed circuit board, E...encoder, HPC...host computer, J1...joint, J2...joint, J3...joint, J4...joint, J5...joint, J6...joint, M...motor, Q1...period, Q2...period, S1...synchronization command instruction step, S2...first processing unit time correction step, S3...second processing unit time correction step, Ss...synchronization command, St...timing signal, T1...time, T2...time, T3...time, Tm...time, Te1...end time, Te2...end time, Tm...time, Tref...reference time, Ts1...received time, Ts2...received time, Tx...time

Claims (6)

A method for synchronizing the time of a first processing unit and a second processing unit connected to the first processing unit via a first bus, the method comprising:
a synchronization command instruction step in which a third processing unit, connected to the second processing unit via a second bus and including a clock circuit, transmits a synchronization command to the first processing unit and the second processing unit, and holds the time when the synchronization command is transmitted as a reference time;
a first processing unit time correction step in which the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding the time required from receipt of the synchronization command to completion of acquisition of the reference time;
a second processing unit time correction step in which the second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding the time required from receiving the synchronization command to completing acquisition of the reference time. a first processing unit;
A second processing unit;
a third processing unit including a clock circuit;
a first bus connecting the first processing unit and the second processing unit;
a second bus connecting the second processing unit and the third processing unit;
the third processing unit transmits a synchronization command to the first processing unit and the second processing unit, and holds a time when the synchronization command is transmitted as a reference time;
the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding a time required from receipt of the synchronization command to completion of acquisition of the reference time to the reference time;
The second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding the time required from receiving the synchronization command to completing acquisition of the reference time to the reference time. The robot controller described in claim 2, wherein the first processing unit and the second processing unit each have a clock circuit. the first processing unit includes a first control unit,
the second processing unit includes a second control unit,
The robot controller according to claim 2 or 3, wherein the first control unit and the second control unit are each a system-on-chip. A robot controller according to any one of claims 2 to 4, wherein one of the first processing unit and the second processing unit has a program execution function for the robot controller, and the other has a function for generating robot motion. Robots and
a robot controller that controls the driving of the robot,
The robot controller includes a first processing unit and
A second processing unit;
a third processing unit including a clock circuit;
a first bus connecting the first processing unit and the second processing unit;
a second bus connecting the second processing unit and the third processing unit;
the third processing unit transmits a synchronization command to the first processing unit and the second processing unit, and holds a time when the synchronization command is transmitted as a reference time;
the first processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the first processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding a time required from receipt of the synchronization command to completion of acquisition of the reference time to the reference time;
The second processing unit acquires the reference time from the third processing unit in response to the synchronization command, and corrects the time of the second processing unit so that the time at which acquisition of the reference time is completed is the time obtained by adding the time required from receiving the synchronization command to completing acquisition of the reference time to the reference time.