JP2019004259A - Communication device and robot system - Google Patents

Abstract

To provide a communication device capable of suppressing collision of communication signals and suppressing delay in communication.SOLUTION: A communication device (a robot controller 1, a lifting controller 21, a turning controller 22, a first arm controller 23, and a second arm controller) that performs half-duplex communication, comprises: a communication unit 12 (212, 222, 232, and 242) that transmits/receives a communication signal; and a controller 13 (213, 223, 233, and 243) that controls the communication unit 12 (212, 222, 232, and 242). The controller 13 (213, 223, 233, and 243), at transmission of the communication signal, switches between a first state in which the communication signal is transmitted after a lapse of a collision detection time that is a random time for collision detection, and a second state in which the communication signal is transmitted without waiting the lapse of the collision detection time.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication device that performs half-duplex communication and a robot system including the communication device.

  In order to reduce the number of connection lines between the robot and the controller, a system is known in which communication is performed by power line carrier communication using only power lines as connections. For example, Patent Document 1 discloses an industrial robot in which a first control unit on the operating device side and a second control unit on the end effector side communicate with each other by power line communication using a power cable.

  FIG. 6 is a block diagram showing an outline of an industrial robot including two end effectors. A power supply line 300 connected to the power supply unit 110 of the controller device 100 branches in the middle and is connected to the power supply unit 210 of the first end effector 200 and the power supply unit 260 of the second end effector 250. The power supply unit 110 supplies power to the power supply unit 210 and the power supply unit 260 via the power supply line 300. The communication unit 120 of the controller device 100 communicates with the communication unit 220 of the first end effector 200 and the communication unit 270 of the second end effector 250 by power line carrier communication via the power line 300. The control unit 130 of the operating device 100 transmits an operation signal of the first end effector 200 to the control unit 230 via the communication unit 120 and the communication unit 220, and the control unit 280 via the communication unit 120 and the communication unit 270. The operation signal of the second end effector 250 is transmitted to Therefore, it is possible to greatly reduce the number of connection lines connecting between the operating device 100 and the first and second end effectors 200 and 250.

  The communication unit 120 and the communication units 220 and 270 perform half-duplex communication using the same frequency band for transmission and reception. Since the communication unit 120 and each of the communication units 220 and 270 communicate via the same power line 300, communication signal collision may occur. In order to suppress a collision of communication signals, the control unit 130 and the control units 230 and 280 wait for a random time for collision detection (hereinafter referred to as “collision detection time”) to elapse before transmission. After that, the communication signal is transmitted. For example, when the controller device 100 transmits a communication signal to the first end effector 200 and the second end effector 250 by simultaneous communication, if the collision detection time is not provided, the first end effector 200 and the second end effector 250 Since a reply signal for the received communication signal is transmitted at the same time, a communication signal collision occurs. The first end effector 200 and the second end effector 250 wait for transmission of a reply signal during the collision detection time, and delay transmission if another reply signal is transmitted at the time of transmission. Since the collision detection time is set at a random time, the transmission timings rarely overlap. Thereby, collision of communication signals is suppressed.

JP2013-129003A

  However, since the controller device 100, the first end effector 200, and the second end effector 250 transmit a communication signal after the collision detection time has elapsed, there is a problem that communication takes time. The communication delay for suppressing the collision of communication signals becomes a problem not only in the communication for operating the industrial robot, but also in a communication device that performs half-duplex communication. This problem is not limited to power line carrier communication, but also occurs in wireless communication.

  The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide a communication apparatus that can suppress collision of communication signals and suppress communication delay.

  The communication device provided by the first aspect of the present invention is a communication device that performs half-duplex communication, and includes a communication unit that transmits and receives communication signals, and a control unit that controls the communication unit, The control unit waits for the elapse of a collision detection time, which is a random time for collision detection, to transmit the communication signal after transmitting the communication signal, and the elapse of the collision detection time. Switching to the second state in which the communication signal is transmitted without waiting. According to this configuration, communication can be performed by switching between the first state and the second state. Therefore, when performing communication that may cause communication signal collision, perform communication in the first state, and when performing communication that does not cause communication signal collision, perform communication in the second state. Can do. In communication in the first state, the communication signal is transmitted after waiting for the collision detection time to elapse, so that collision of communication signals can be suppressed. Further, when performing communication without causing a collision of communication signals, the communication signal is transmitted as the second state without waiting for the collision detection time to elapse, so that communication delay can be suppressed.

  In a preferred embodiment of the present invention, the control unit switches from the first state to the second state based on transmission or reception of a predetermined signal. According to this configuration, a signal that becomes a boundary between communication in which communication signal collision may occur and communication in which communication signal collision does not occur is set as a predetermined signal, so that the first state is appropriately changed to the second state. Can be switched.

  In a preferred embodiment of the present invention, the communication unit performs power line carrier communication. According to this configuration, there is no need to provide a dedicated communication connection line.

  A robot system provided by the second aspect of the present invention includes a robot including a plurality of communication apparatuses provided by the first aspect of the present invention, and a communication apparatus provided by the first aspect of the present invention. And a robot controller for operating the robot. According to this configuration, in communication between the robot controller of the robot system and the robot, collision of communication signals can be suppressed and communication delay can be suppressed.

  In a preferred embodiment of the present invention, the communication device included in the robot controller, and the control unit of each communication device included in the robot receive an activation signal transmitted from the robot controller to the robot. Based on this, the first state is switched to the second state. According to this configuration, when the activation signal becomes a boundary between communication in which communication signal collision may occur and communication in which communication signal collision does not occur, it is possible to appropriately switch from the first state to the second state. .

  In a preferred embodiment of the present invention, the robot is a transfer robot that transfers a workpiece. According to this configuration, in communication between the robot controller and the transfer robot, collision of communication signals can be suppressed and communication delay can be suppressed.

  According to the present invention, communication can be performed by switching between the first state and the second state. Therefore, when performing communication that may cause communication signal collision, perform communication in the first state, and when performing communication that does not cause communication signal collision, perform communication in the second state. Can do. In communication in the first state, the communication signal is transmitted after waiting for the collision detection time to elapse, so that collision of communication signals can be suppressed. Further, when performing communication without causing a collision of communication signals, the communication signal is transmitted as the second state without waiting for the collision detection time to elapse, so that communication delay can be suppressed.

It is a whole external view which shows the outline of the conveyance robot system which concerns on 1st Embodiment. It is a block diagram which shows the outline of the conveyance robot system which concerns on 1st Embodiment. It is a sequence diagram for demonstrating two communication sequences. It is a flowchart for demonstrating the communication process which a control part and a 1st axis | shaft control part perform. It is a block diagram which shows the outline of the conveyance robot system which concerns on 2nd Embodiment. It is a block diagram which shows the outline of the conventional industrial robot.

  Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the accompanying drawings, taking as an example a case where a communication device according to the present invention is used in a transport robot system.

  1 to 4 are diagrams for explaining the transfer robot system according to the first embodiment. FIG. 1 is an overall external view showing an outline of the transfer robot system according to the first embodiment. FIG. 2 is a block diagram illustrating an outline of the transfer robot system according to the first embodiment. FIG. 3 is an example of a sequence diagram for explaining two communication sequences in the transfer robot system according to the first embodiment. FIG. 4 is a flowchart for explaining communication processing performed by the control unit 13 and the first axis control unit 213.

  As shown in FIG. 1, the transfer robot system A1 connects the transfer robot 2, the robot controller 1 that supplies power to the transfer robot 2, and operates the transfer robot 2, and connects the transfer robot 2 and the robot controller 1. Power supply line 3 is provided.

  The transfer robot 2 is a robot that takes out a work such as a semiconductor substrate stored in multiple stages in a cassette, and stores the work in a cassette. As shown in FIG. 1, the transfer robot 2 includes a support unit 4, a turning unit 5, a first arm mechanism 6, and a second arm mechanism 7. The support unit 4 is fixed to a floor surface or a vacuum chamber, and supports the swivel unit 5 so as to be movable up and down and swivelable. The swivel unit 5 is disposed inside the support unit 4. The turning part 5 is provided so as to be movable up and down so as to protrude from the opening of the support part 4. Further, the swivel unit 5 is provided so as to be able to swivel about a vertical axis with respect to the support unit 4. The first arm mechanism 6 is a link mechanism, and extends in the vertical direction with respect to the lower arm provided to be rotatable about an axis extending in the vertical direction with respect to the turning unit 5 and the tip portion of the lower arm. An upper arm provided to be rotatable about an axis, and a hand provided to be rotatable about an axis extending in a vertical direction with respect to a tip portion of the upper arm. As the lower arm, the upper arm, and the hand rotate in conjunction with each other, the hand moves in a predetermined direction (left-right direction in FIG. 1). The second arm mechanism 7 has the same structure as the first arm mechanism 6. The first arm mechanism 6 and the second arm mechanism 7 are controlled independently of each other.

  The transfer robot 2 changes the moving direction of each hand by turning the turning unit 5, changes the vertical position of each hand by moving the turning unit 5 up and down, and changes each part of the first arm mechanism 6. Is rotated to move the hand of the first arm mechanism 6, and each part of the second arm mechanism 7 is rotated to move the hand of the second arm mechanism 7. The transport robot 2 takes out the work in the cassette or stores the work in the cassette by each of these operations.

  A drive mechanism for moving the swivel unit 5 up and down is, for example, a ball screw mechanism. By controlling a first axis servo motor (not shown) that drives the ball screw mechanism, the ascending / descending position of the turning unit 5 is controlled. The ball screw mechanism and the first axis servo motor are disposed on the support portion 4, for example. The drive mechanism for turning the turning unit 5 is, for example, a gear mechanism. The turning position of the turning unit 5 is controlled by controlling a second axis servo motor (not shown) that drives the gear mechanism. The gear mechanism and the second axis servo motor are disposed on the support portion 4, for example. By controlling a third axis servo motor (not shown) that drives the first arm mechanism 6, the position of the hand movement direction of the first arm mechanism 6 is controlled. The third axis servo motor is disposed in the turning unit 5, for example. By controlling a fourth axis servo motor (not shown) that drives the second arm mechanism 7, the position of the hand of the second arm mechanism 7 in the moving direction is controlled. The fourth axis servo motor is disposed in the turning unit 5, for example.

  As shown in FIG. 2A, the transfer robot 2 includes a lifting controller 21, a turning controller 22, a first arm controller 23, and a second arm controller 24. The elevation controller 21 is disposed near the first axis servo motor (for example, the support unit 4) and controls the first axis servo motor. The elevator controller 21 includes a power supply unit 211, a communication unit 212, and a first axis control unit 213. The power supply unit 211 supplies power to the first axis control unit 213. The communication unit 212 communicates with the communication unit 12 of the robot controller 1. The first axis control unit 213 controls the first axis servo motor, and is realized by a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like. The turning controller 22 is arranged near the second axis servo motor (for example, the support unit 4) and controls the second axis servo motor. The turning controller 22 includes a power supply unit 221, a communication unit 222, and a second axis control unit 223. The power supply unit 221 supplies power to the second axis control unit 223. The communication unit 222 communicates with the communication unit 12 of the robot controller 1. The second axis control unit 223 controls the second axis servo motor and is realized by a microcomputer.

  The first arm controller 23 is arranged near the third axis servo motor (for example, the turning unit 5), and controls the third axis servo motor. The first arm controller 23 includes a power supply unit 231, a communication unit 232, and a third axis control unit 233. The power supply unit 231 supplies power to the third axis control unit 233. The communication unit 232 communicates with the communication unit 12 of the robot controller 1. The third axis control unit 233 controls the third axis servo motor and is realized by a microcomputer. The second arm controller 24 is arranged near the fourth axis servo motor (for example, the turning unit 5), and controls the fourth axis servo motor. The second arm controller 24 includes a power supply unit 241, a communication unit 242, and a fourth axis control unit 243. The power supply unit 241 supplies power to the fourth axis control unit 243. The communication unit 242 communicates with the communication unit 12 of the robot controller 1. The fourth axis control unit 243 controls the fourth axis servo motor and is realized by a microcomputer. The transfer robot 2 includes a power supply unit for supplying power for driving each servo motor, but the description thereof is omitted. The power supply unit may be supplied with power directly from an external power supply, or may be supplied from the robot controller 1 through a power supply line provided separately from the power supply line 3.

  The first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 are respectively a first axis servo motor, a control signal input from the robot controller 1, respectively. Encoder detection signals that drive the second axis servo motor, the third axis servo motor, and the fourth axis servo motor and detect the rotation position of each servo motor are output to the communication units 212, 222, 232, and 242, respectively. To send. In addition, a response signal to the signal input from the robot controller 1 and data corresponding to the data transmission command are transmitted.

  As shown in FIG. 2A, the robot controller 1 includes a power supply unit 11, a communication unit 12, and a control unit 13. The power supply unit 11 converts the voltage supplied from the external power supply into a predetermined voltage and supplies the voltage to the control unit 13. The power supply unit 11 also supplies power to the transfer robot 2 via the power supply line 3. The power supply line 3 branches inside the transfer robot 2 and is connected to the power supply units 211, 221, 231, and 241. Thereby, the power supply unit 11 supplies power to the power supply units 211, 221, 231, and 241 of the controllers 21 to 24 of the transport robot 2.

  The communication unit 12 communicates with the communication units 212, 222, 232, and 242 of the transport robot 2. The communication unit 12 and the communication units 212, 222, 232, and 242 of the transfer robot 2 perform power line transfer communication via the power line 3. The communication unit 12 modulates the signal input from the control unit 13 and superimposes the signal on the power supply line 3, thereby transmitting the signal to the transport robot 2. The communication unit 12 receives a signal superimposed on the power supply line 3, demodulates it, and outputs it to the control unit 13. Similarly, the communication units 212, 222, 232, and 242 of the transfer robot 2 are input from the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, respectively. The received signal is transmitted and the received signal is output.

  The control unit 13 controls the robot controller 1 and is realized by a microcomputer. The control unit 13 controls the robot controller 1 by executing a control program stored in advance in the ROM. In addition, the control unit 13 transmits and receives signals to and from the transfer robot 2 via the communication unit 12 in order to operate the transfer robot 2 in accordance with a preset processing procedure. Specifically, the control unit 13 conveys a control signal for driving the first axis servo motor, the second axis servo motor, the third axis servo motor, and the fourth axis servo motor via the communication unit 12. Transmit to the robot 2. Then, the detection signal detected by each encoder is received, and the state of the transfer robot 2 is recognized. Further, the control unit 13 is a program or data for controlling the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 when the transfer robot system A1 is activated. Is transmitted, and an activation signal is transmitted. In addition, the control unit 13 individually transmits initial parameters to be set in the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, respectively. In addition, the control unit 13 transmits an end signal when the work of the transfer robot system A1 ends. And a data transmission command is transmitted and the data which the 1st axis control part 213, the 2nd axis control part 223, the 3rd axis control part 233, and the 4th axis control part 243 transmitted are received.

  As shown in FIG. 2B, the control unit 13 includes a collision detection switching unit 131, a collision detection time setting unit 132, and a collision detection time standby unit 133 as functional blocks.

  The collision detection switching unit 131 transmits a communication signal via the communication unit 12 in a first state in which the collision detection time is transmitted after waiting for the collision detection time to elapse and a first state in which transmission is performed without waiting for the collision detection time to elapse. Switch between 2 states.

  The collision detection time setting unit 132 sets the collision detection time when the collision detection switching unit 131 is switched to the first state. Specifically, a random number is generated when communication is performed, and a time within a predetermined range is set as a collision detection time according to the generated random number. Thereby, a random time is set as the collision detection time. The collision detection time standby unit 133 counts the passage of the collision detection time set by the collision detection time setting unit 132.

  When the communication is performed, the control unit 13 causes the collision detection time setting unit 132 to set the collision detection time and the collision detection time standby unit 133 sets the collision when the collision detection switching unit 131 switches to the first state. After the elapse of the detection time, the communication signal is output to the communication unit 12 and transmitted. On the other hand, when the collision detection switching unit 131 is switched to the second state, a communication signal is immediately output to the communication unit 12 for transmission.

  Similarly to the control unit 13, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 are configured as functional blocks such as a collision detection switching unit 131, a collision detection time setting. Unit 132 and a collision detection time standby unit 133. In the present embodiment, the robot controller 1, the elevation controller 21, the turning controller 22, the first arm controller 23, and the second arm controller 24 correspond to the “communication device” of the present invention.

  Communication sequences between the robot controller 1 and the elevation controller 21, the turning controller 22, the first arm controller 23, and the second arm controller 24 are roughly classified into “communication sequence 1” and “communication sequence 2”. The communication sequence 1 is a communication sequence in which the robot controller 1 transmits communication signals all at once and waits for a reply from the elevating controller 21, the turning controller 22, the first arm controller 23, and the second arm controller 24. The communication sequence 2 is a communication sequence in which the robot controller 1 transmits a communication signal to the controllers 21 to 24 and receives a reply, and then transmits the next communication signal.

  When the transfer robot system A1 is activated, the robot controller 1 transmits a program or data and transmits an activation signal, or at the end of the operation of the transfer robot system A1, the robot controller 1 transmits an end signal to send a data transmission command. The communication sequence when transmitting data and receiving data corresponds to the communication sequence 1. In the case of communication in the communication sequence 1, if no collision detection time is provided, a reply signal is simultaneously transmitted from each of the controllers 21 to 24, and a collision of communication signals occurs. Therefore, the control unit 13, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 communicate in the first state during communication in the communication sequence 1. Do.

  As shown in the upper side of FIG. 3, in the case of communication in the communication sequence 1, even if the robot controller 1 transmits communication signals all at once, the elevating controller 21, the turning controller 22, the first arm controller 23, and the second The arm controller 24 sets the collision detection time at the time of transmission of the reply signal, and transmits the reply signal after waiting for the collision detection time to elapse. Therefore, communication signal collision is unlikely to occur. In FIG. 3, the elevation controller 21 sets the collision detection time t1, the turning controller 22 sets the collision detection time t2, the first arm controller 23 sets the collision detection time t3, and the second arm controller 24 detects the collision. A time t4 is set and a reply signal is transmitted. Since the collision detection times t1 to t4 are set at random, the collision times are rarely the same. Therefore, collision of communication signals can be suppressed.

  On the other hand, when the robot controller 1 transmits initial parameters to be set to each of the controllers 21 to 24, or for the operation of the transfer robot 2, a control signal for driving each servo motor is transmitted and detected by the encoder. A communication sequence when receiving a signal corresponds to communication sequence 2. In the case of communication in the communication sequence 2, since communication collision does not occur, communication is performed in the second state.

  As shown in the lower side of FIG. 3, in the case of communication in the communication sequence 2, the robot controller 1 transmits a communication signal to, for example, the lift controller 21 and receives a reply signal from the lift controller 21. A communication signal is transmitted to the turning controller 22. Therefore, collision of communication signals does not occur. Moreover, since the raising / lowering controller 21 does not set the collision detection time and transmits a reply signal immediately, the time from reception to transmission is short. Similarly, since the robot controller 1 does not set the collision detection time and immediately transmits the next communication signal, the time from reception to transmission is short. Therefore, the time required for communication can be shortened and communication delay can be suppressed.

  Next, the processing procedure of communication processing will be described with reference to the flowchart shown in FIG.

  FIG. 4 is a flowchart for explaining communication processing performed by the control unit 13 of the robot controller 1 and the first axis control unit 213 of the elevation controller 21. The communication processing performed by the second axis control unit 223 of the turning controller 22, the third axis control unit 233 of the first arm controller 23, and the fourth axis control unit 243 of the second arm controller 24 is performed by the first axis of the elevation controller 21. This is the same as the communication process performed by the control unit 213. These communication processes are started when the transfer robot system A1 is activated. At the start of each communication process, the state is switched to the first state.

  First, the control unit 13 transmits a program (S1). This program is a program for the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 to control each servo motor. The control unit 13 sets all of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 as reception targets and transmits them. At this time, the control unit 13 transmits after the collision detection time has elapsed in the first state. The first axis control unit 213 determines whether or not this program has been received (S21), and waits for reception. If received (S21: YES), a reply signal is transmitted to the control unit 13 (S22). At this time, the first axis control unit 213 transmits after waiting for the collision detection time to elapse in the first state. The control unit 13 determines whether or not all reply signals have been received (S2), and if there is an unreceived signal (S2: NO), it waits for reception. That is, the control unit 13 waits until a return signal is received from each of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 that has transmitted the program. . When the predetermined time has passed in a state where reception is not possible, the control unit 13 performs Step S1 again. When all the reply signals are received (S2: YES), the process proceeds to the next. Although not shown in FIG. 4, in actuality, the control unit 13 transmits a plurality of programs and data, so that the processes of steps S1, S2, S21, and S22 are repeated the number of times, and the process proceeds to step S3. .

  Next, the control unit 13 transmits an activation signal (S3). The activation signal is a signal for activating the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243. The control unit 13 sets all of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 as reception targets and transmits them. At this time, the control unit 13 transmits after the collision detection time has elapsed in the first state. The first axis control unit 213 determines whether an activation signal has been received (S23) and waits for reception. If received (S23: YES), a reply signal is transmitted to the control unit 13 (S24). At this time, the first axis control unit 213 transmits after waiting for the collision detection time to elapse in the first state. Moreover, the 1st axis | shaft control part 213 will be in the state which controls a servomotor by receiving a starting signal. Thereafter, the first axis control unit 213 switches from the first state to the second state (S25). That is, the collision detection switching unit 131 of the first axis control unit 213 switches from the first state to the second state at the timing when the reply signal to the activation signal is transmitted with the reception of the activation signal as a signal. The control unit 13 determines whether or not all reply signals have been received (S4), and if there is an unreceived signal (S4: NO), it waits for reception. That is, the control unit 13 waits until it receives a return signal from each of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 that has transmitted the activation signal. To do. When the predetermined time has passed in a state where reception is not possible, the control unit 13 returns to step S1 and resumes processing. At this time, the first axis control unit 213 has switched to the second state when the reply signal has been transmitted (S25), but the first state control unit 213 starts from the second state with the reception of the program in step S1 as a cue. Switch to the state. When the restart of the process is continued a predetermined number of times (for example, 3 times), the control unit 13 determines that an error has occurred, performs an error process, and ends the communication process. When all the reply signals are received (S4: YES), the control unit 13 switches from the first state to the second state (S5). That is, the collision detection switching unit 131 of the control unit 13 switches from the first state to the second state at the timing when all the return signals for the activation signal are received with the transmission of the activation signal as a signal. The state may be switched at the timing when the activation signal is transmitted. In this case, when returning to step S1 and restarting the process when no return signal is received, it is necessary to switch from the second state to the first state. In this embodiment, the “activation signal” corresponds to the “predetermined signal” of the present invention.

  Next, the control unit 13 transmits initial parameters (S6). The initial parameters are parameters individually set in the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, and are transmitted individually. The control unit 13 receives the first axis control unit 213 as a reception target, and transmits initial parameters of the first axis control unit 213. At this time, the control unit 13 transmits immediately without setting the collision detection time in the second state. The first axis control unit 213 determines whether or not an initial parameter has been received (S26), and waits for reception. If received (S26: YES), a reply signal is transmitted to the control unit 13 (S27). At this time, the 1st axis | shaft control part 213 transmits immediately, without setting collision detection time by a 2nd state. The first axis control unit 213 sets the received initial parameter. The control unit 13 determines whether or not a reply signal has been received (S7) and waits for reception. If received (S7: YES), proceed to the next. Although not shown in FIG. 4, in actuality, the control unit 13 transmits initial parameters to the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, respectively. Processing similar to S6, S26, S27, and S7 is performed between the control unit 13, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, and the process proceeds to step S8. .

  In the operation sequence of step S8 and step S28, processing for operating the transfer robot 2 is performed according to a preset processing procedure. Specifically, the control unit 13 transmits a control signal for driving the first axis servo motor to the first axis control unit 213. The first axis control unit 213 drives the first axis servo motor according to the received control signal. Next, the first axis control unit 213 transmits the detection signal of the encoder of the first axis servo motor to the control unit 13. The control unit 13 performs processing according to the received detection signal. The control unit 13 also performs these processes on the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243, thereby causing the transport robot 2 to perform one operation. The control unit 13 repeats these processes according to a preset processing procedure. In transmission of these signals, the control unit 13, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 determine the collision detection time according to the second state. Send immediately without setting.

  Next, the control part 13 transmits the completion | finish signal for work completion | finish (S9). The control unit 13 sets all of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 as reception targets and transmits them. At this time, the control unit 13 transmits immediately without setting the collision detection time in the second state. The first axis control unit 213 determines whether an end signal has been received (S29) and waits for reception. When received (S29: YES), the second state is switched to the first state (S30). That is, the collision detection switching unit 131 of the first axis control unit 213 switches from the second state to the first state at the timing of receiving the end signal, with the reception of the end signal as a signal. Then, the first axis control unit 213 transmits a reply signal to the control unit 13 (S31). At this time, the first axis control unit 213 transmits after waiting for the collision detection time to elapse in the first state. The control unit 13 determines whether or not all reply signals have been received (S10), and if there is an unreceived signal (S10: NO), it waits for reception. That is, the control unit 13 waits until receiving a return signal from each of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 that has transmitted the end signal. To do. When all the reply signals are received (S10: YES), the control unit 13 switches from the second state to the first state (S11). That is, the collision detection switching unit 131 of the control unit 13 switches from the second state to the first state at the timing when all the return signals for the end signal are received, with the transmission of the end signal as a signal. The state may be switched at the timing when the end signal is transmitted.

  Next, the control unit 13 transmits a data transmission command (S12). The control unit 13 sets all of the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 as reception targets and transmits them. At this time, the control unit 13 transmits after the collision detection time has elapsed in the first state. The first axis control unit 213 determines whether a data transmission command has been received (S32) and waits for reception. If received (S32: YES), the accumulated data is transmitted to the control unit 13 (S33), and the communication process is terminated. At this time, the first axis control unit 213 transmits after waiting for the collision detection time to elapse in the first state. The control unit 13 determines whether or not all data has been received (S13), and if there is any data that has not been received (S13: NO), the control unit 13 waits for reception. That is, the control unit 13 waits until data is received from the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 that have transmitted the data transmission command. To do. When all the data is received (S13: YES), the control unit 13 ends the communication process.

  In addition, each communication process shown in the flowchart of FIG. 4 is an example, and each communication process is not limited to what was mentioned above.

  Next, operations and effects of the transfer robot system A1 according to this embodiment will be described.

  According to the present embodiment, the control unit 13 (the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, the fourth axis control unit 243) Communication is performed in the state. That is, the collision detection time is set and the communication signal is transmitted after waiting for the collision detection time to elapse. Therefore, collision of communication signals is suppressed. The control unit 13 (the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243) communicates in the second state during communication in the communication sequence 2. I do. In other words, the communication signal for transmitting the reply signal is transmitted immediately without setting the collision detection time. Therefore, the time required for communication can be shortened. Thereby, collision of communication signals can be suppressed and communication delay can be suppressed.

  Since the time required for communication can be shortened when transmitting the control signal for driving each servo motor and the detection signal by the encoder, the operation of the transfer robot 2 can be made smooth. For one operation of the transfer robot 2, transmission of a control signal from the control unit 13 to the first axis control unit 213, transmission of a detection signal from the first axis control unit 213 to the control unit 13, from the control unit 13 Transmission of control signal to second axis control unit 223, transmission of detection signal from second axis control unit 223 to control unit 13, transmission of control signal from control unit 13 to third axis control unit 233, third axis Transmission of a detection signal from the control unit 233 to the control unit 13, transmission of a control signal from the control unit 13 to the fourth axis control unit 243, and transmission of a detection signal from the fourth axis control unit 243 to the control unit 13 8 communications are required. According to the experiments by the inventors, the communication time for one operation can be shortened by about 20% compared with the case of performing collision detection. As a result, the transport robot 2 can be operated smoothly.

  According to the present embodiment, the collision detection switching unit 131 switches from the first state to the second state based on transmission / reception of the activation signal, and switches from the second state to the first state based on transmission / reception of the end signal. . Therefore, it is not necessary to separately transmit and receive a signal for switching between the first state and the second state.

  In the present embodiment, the collision detection switching unit 131 switches from the first state to the second state based on transmission / reception of the activation signal, and from the second state to the first state based on transmission / reception of the end signal. Although the case where it switches to is demonstrated, it is not restricted to this. A signal for switching between the first state and the second state different from the start signal or the end signal may be transmitted and received, and the state may be switched based on this signal. In the present embodiment, in the entire communication process of the transfer robot system A1, the communication at the start and end is a communication that may cause a communication collision, and the communication between them is a communication that does not cause a communication collision. Therefore, the first state and the second state are switched at the boundary line. Thus, the state switching timing may be set as appropriate based on the entire communication process. At this time, it is not always necessary to switch based on signal transmission / reception, and switching may be performed based on other triggers.

  In the present embodiment, the control unit 13 of the robot controller 1 and the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 of the transfer robot 2 are both In both cases, the case where the collision detection switching unit 131 switches between the first state and the second state has been described, but the present invention is not limited thereto. For example, the controller 13 of the robot controller 1 may always switch to the first state without switching between the first state and the second state. Further, the controller 13 of the robot controller 1 may always be in the second state. Even in this case, during the communication in the communication sequence 1, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 of the transfer robot 2 communicate in the first state. Therefore, collision of communication signals is suppressed. Further, during communication in the communication sequence 2, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 of the transfer robot 2 perform communication in the second state. Therefore, communication delay can be suppressed.

  Conversely, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 of the transfer robot 2 perform switching between the first state and the second state. Instead, it may always be in the first state. Even in this case, during the communication in the communication sequence 1, the first axis control unit 213, the second axis control unit 223, the third axis control unit 233, and the fourth axis control unit 243 of the transfer robot 2 communicate in the first state. Therefore, collision of communication signals is suppressed. Further, at the time of communication in the communication sequence 2, the control unit 13 of the robot controller 1 performs communication in the second state, so that communication delay can be suppressed. That is, if at least one of the switching between the first state and the second state is performed by the collision detection switching unit 131, it is possible to suppress the collision of communication signals and to suppress the delay of communication. be able to.

  In the present embodiment, the case where the transfer robot 2 includes four servo motors has been described, but the present invention is not limited to this. Two or three may be sufficient and five or more may be sufficient. In the present embodiment, the case where the robot controller 1 communicates with the controller that controls the servo motor of the transport robot 2 has been described, but the present invention is not limited to this. Each hand of the transfer robot 2 includes, for example, a holding mechanism for holding a workpiece and a sensor for detecting the workpiece. Each hand may be provided with a controller for controlling the holding mechanism or transmitting a detection signal of the sensor, and the robot controller 1 may communicate with the controller.

  In the first embodiment, the case where power line carrier communication is performed has been described. However, the present invention is not limited to this. A case where wireless communication is performed will be described below as a second embodiment.

  FIG. 5 is a block diagram showing an outline of the transfer robot system A2 according to the second embodiment. In FIG. 5, the same or similar elements as those in the transfer robot system A1 (see FIG. 2 (a)) according to the first embodiment are denoted by the same reference numerals. As shown in FIG. 5, the transfer robot system A <b> 2 has a transfer according to the first embodiment in that each communication unit 12, 212, 222, 232, and 242 performs wireless communication instead of performing power line transfer communication. Different from the robot system A1. In the second embodiment, the same effect as that of the first embodiment can be obtained.

  In the first or second embodiment, the case where the communication apparatus according to the present invention is used in the transfer robot system has been described, but the present invention is not limited to this. The communication apparatus according to the present invention can also be used in other robot systems (for example, a welding robot system). The communication device according to the present invention can also be used in various systems that perform communication.

  The present invention can also be applied to a communication apparatus that performs only communication. In a communication device that performs half-duplex communication with another communication device, when performing communication that may cause a communication signal collision, communication is performed in the first state (the communication signal is transmitted after waiting for the collision detection time to elapse). When communication is performed without causing collision of communication signals, communication is performed in the second state (communication signal is transmitted without setting the collision detection time), thereby suppressing communication signal collision. And the delay of communication can be suppressed.

  The communication device and the robot system according to the present invention are not limited to the above-described embodiments. The specific configuration of each part of the communication device and the robot system according to the present invention can be varied in design in various ways.

A1, A2: Conveying robot system 1: Robot controller 11: Power supply unit 12: Communication unit 13: Control unit 131: Collision detection switching unit 132: Collision detection time setting unit 133: Collision detection time standby unit 2: Transport robot 21: Lift Controller 211: Power supply unit 212: Communication unit 213: First axis control unit 22: Turning controller 221: Power supply unit 222: Communication unit 223: Second axis control unit 23: First arm controller 231: Power supply unit 232: Communication unit 233 : Third axis control unit 24: second arm controller 241: power supply unit 242: communication unit 243: fourth axis control unit 4: support unit 5: swivel unit 6: first arm mechanism 7: second arm mechanism 3: power supply line

Claims (6)

A communication device that performs half-duplex communication,
A communication unit for transmitting and receiving communication signals;
A control unit for controlling the communication unit;
With
The control unit waits for the elapse of a collision detection time, which is a random time for collision detection, to transmit the communication signal after transmitting the communication signal, and the elapse of the collision detection time. Switching between the second state in which the communication signal is transmitted without waiting,
A communication device. The control unit switches from the first state to the second state based on transmission or reception of a predetermined signal.
The communication apparatus according to claim 1. The communication unit performs power line carrier communication.
The communication device according to claim 1 or 2. A robot comprising a plurality of communication devices according to any one of claims 1 to 3,
A communication apparatus according to any one of claims 1 to 3, comprising a robot controller for operating the robot;
A robot system characterized by comprising: The communication device provided in the robot controller, and the control unit of each communication device provided in the robot, from the first state based on an activation signal transmitted from the robot controller to the robot Switch to the second state,
The robot system according to claim 4. The robot is a transfer robot that transfers workpieces.
The robot system according to claim 4 or 5.

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