JP5090294B2 - Wireless communication device - Google Patents

Description

  The present invention relates to a wireless communication apparatus, and more particularly to a wireless communication apparatus including a plurality of wireless communication modules using different wireless communication schemes using the same frequency band.

  Wireless communication is subject to legal regulations, and arbitrary frequencies and communication methods cannot be used freely. In addition, the development of a new wireless communication module takes an enormous period and cost. For this reason, in the development of a wireless communication device, it is desirable to use a ready-made wireless communication module that does not require a license. For example, Bluetooth (registered trademark), WLAN, or the like can be cited as a wireless communication method that is generally employed in a ready-made wireless communication module that does not require a license and that is easy to use.

  There are WLANs that use the 2.4 GHz band (IEEE802.11b / g) and those that use the 5 GHz band (IEEE802.11a). There are laws and regulations such as the prohibition of outdoor use for 5 GHz WLAN. Further, since the higher frequency radio waves have higher straightness, the 5 GHz band WLAN may be difficult to use due to the problem of radio wave interference due to the surrounding environment as compared to the 2.4 GHz band WLAN. For this reason, Bluetooth and 2.4 GHz band WLAN (IEEE802.11b / g) may be employed when a plurality of wireless communications of different wireless communication methods are required.

  Although Bluetooth and a 2.4 GHz band WLAN (IEEE802.11b / g) are different wireless communication systems, they use the same frequency band (2.4 GHz band). A Bluetooth wireless communication system that performs wireless communication with Bluetooth is a frequency hopping wireless communication system that avoids radio channels used in WLAN and automatically selects an available frequency to perform frequency hopping. A function to prevent interference is provided. However, it is not assumed that a Bluetooth wireless communication module that performs wireless communication with Bluetooth and a 2.4 GHz band WLAN wireless communication module that performs wireless communication with a 2.4 GHz band WLAN are incorporated in the same device. When a communication module and a 2.4 GHz band WLAN wireless communication module are incorporated in the same device, radio interference occurs because the Bluetooth wireless communication module and the 2.4 GHz band WLAN wireless communication module are too close together, and Bluetooth wireless communication Wireless communication may become impossible in both the module and the 2.4 GHz band WLAN wireless communication module.

  It is well known that there is time division multiplexing control as a method for avoiding radio wave interference caused by a plurality of wireless communication modules of different wireless communication systems using the same frequency band as described above being too close.

Japanese Patent Laying-Open No. 2007-143155 (FIG. 1, paragraph 0033)

  In the case of general time division multiplex control, since the ratio of time division is fixed, when applied to a wireless communication apparatus including a plurality of wireless communication modules of different wireless communication methods using the same frequency band, a certain wireless communication method There is a problem in that it is not possible to shorten the period from the start of wireless communication to the start of the next wireless communication in the certain wireless communication system.

  Note that the communication terminal apparatus proposed in Patent Document 1 is also an application of this time division multiplex control, and the ratio of time division can be changed to improve the throughput. The period from the start of wireless communication to the start of the next wireless communication in the certain wireless communication system cannot be shortened.

  In view of the above situation, the present invention includes a plurality of wireless communication modules of different wireless communication schemes using the same frequency band, and starts the wireless communication in a certain wireless communication method to the next in the certain wireless communication method. An object of the present invention is to provide a wireless communication apparatus that can shorten the period until the start of wireless communication.

  In order to achieve the above object, a wireless communication apparatus according to the present invention includes a first wireless communication module that performs wireless communication using a first wireless communication system that uses a predetermined frequency band, and the first wireless communication system. A second wireless communication module that performs wireless communication using a second wireless communication system that is a different wireless communication system and uses the predetermined frequency band, and a first period for wireless communication by the first wireless communication module. Assigning, assigning a second period to wireless communication by the second wireless communication module, so that wireless communication by the first wireless communication module and wireless communication by the second wireless communication module are performed alternately. A time division control unit that performs time division control of wireless communication by the first wireless communication module and wireless communication by the second wireless communication module, and the time division control unit includes: When the wireless communication by the first wireless communication module ends earlier than the first period, the wireless communication by the second wireless communication module is started without waiting for the first period to elapse. As described above, the wireless communication by the first wireless communication module and the wireless communication by the second wireless communication module are time-division controlled.

  According to such a configuration, when the wireless communication by the first wireless communication module ends earlier than the first period (the period assigned to the wireless communication by the first wireless communication module), the first period Since the wireless communication by the first wireless communication module and the wireless communication by the second wireless communication module are time-division controlled so as to start wireless communication by the second wireless communication module without waiting for the elapse of time, the first When wireless communication by the wireless communication module ends earlier than the first period (period assigned to wireless communication by the first wireless communication module), the first wireless communication system starts from the start of wireless communication. The period until the start of the next wireless communication in one wireless communication method can be shortened.

  The period from the start of wireless communication in the first wireless communication system to the start of the next wireless communication in the first wireless communication system is a standard setting (the total period of the first period and the second period From the viewpoint of preventing the time from becoming longer than), the time-sharing control unit does not end the wireless communication by the first wireless communication module even after the first period has elapsed. By the first wireless communication module, the wireless communication module continues the wireless communication, and performs the wireless communication by the second wireless communication module in the period obtained by subtracting the continued period from the second period. Wireless communication and wireless communication by the second wireless communication module may be time-division controlled. It should be noted that such a configuration includes a configuration in which the period obtained by subtracting the continued period from the second period becomes zero, and the wireless communication by the first wireless communication module is continuously performed. Further, in this configuration, from the viewpoint of preventing the stop of the upper application due to the delay in data transmission in the wireless communication by the second wireless communication module, the data is transmitted by the wireless communication by the second wireless communication module once. You may make it provide the memory | storage part which stores the data which could not be completed temporarily.

  Further, the first wireless communication method may be Bluetooth (registered trademark), and the second wireless communication method may be a 2.4 GHz band WLAN.

  According to the present invention, when the wireless communication by the first wireless communication module ends earlier than the first period (the period assigned to the wireless communication by the first wireless communication module), the first period elapses. The wireless communication by the first wireless communication module and the wireless communication by the second wireless communication module are time-sharing controlled so that wireless communication by the second wireless communication module is started without waiting for the first wireless communication module. When the wireless communication by the communication module ends earlier than the first period (the period assigned to the wireless communication by the first wireless communication module), the first time from the start of the wireless communication in the first wireless communication system A period until the start of the next wireless communication in the wireless communication system can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings. As a wireless communication apparatus according to the present invention, here, a wireless communication apparatus mounted on a teaching pendant of an industrial robot system including a robot and a teaching pendant will be described as an example.

  The industrial robot system shown in FIG. 1 includes a robot 1 and a teaching pendant 2 equipped with a wireless communication apparatus according to the present invention. An emergency stop switch 3 and a touch panel 4 are provided on the front surface of the teaching pendant 2, and an enable switch (not shown) is provided on the rear surface of the teaching pendant 2.

  In the industrial robot system shown in FIG. 1, it is necessary to perform an operation for causing the robot 1 to learn an operation, that is, a teaching operation, at the initial stage and at the time of adjustment. The robot 1 calls the teaching data taught by this teaching work and realizes automatic operation.

  The emergency stop switch 3 has a normal contact point ON, and the contact point of the emergency stop switch 3 is turned OFF, so that the robot 1 comes to an emergency stop. The touch panel 4 functions as a display device that displays various information of the robot 1 during teaching work, and also functions as an input device that inputs teaching data. The operation content of the touch panel 4 becomes valid when the enable switch is turned on, and the operation content of the touch panel 4 becomes invalid when the enable switch is turned off.

  In teaching work, the operator 5 enters the safety fence 6 with the teaching pendant 2 which is a mobile device, and moves the movable part of the robot 1 using the teaching pendant 2 while approaching the movable part of the robot 1. The teaching data necessary for the automatic operation is input by operating the touch panel 4.

  Between the robot 1 and the teaching pendant 2, two types of wireless communication, emergency communication and operation information communication, are performed. The emergency communication communicates the operation information of the emergency stop switch 3, the operation information of the enable switch, the information of the self-diagnosis result regarding the transmission processing circuit and program of the radio communication module for emergency communication. In the operation information communication, teaching data input to the touch panel 4 is transmitted from the teaching pendant 2 side to the robot 1 side, and display data for displaying various information of the robot 1 is transmitted from the robot 1 side to the teaching pendant 2 side. .

  In emergency communication, hardware and software independent of hardware and software used in operation information communication are used to increase the reliability. Further, for the communication path for emergency communication, a communication path that is independent from the communication path for operation information communication is used in order to increase the reliability of emergency communication.

  Bluetooth has a smaller amount of data that can be transmitted than WLAN, but has less transmission delay and stable communication. Since this characteristic is suitable for emergency communication, Bluetooth is used for emergency communication in this embodiment. Further, since the operation information communication has a large amount of data compared to the emergency communication, a WLAN having a large amount of data that can be transmitted to the operation information communication is used in this embodiment.

  Therefore, as shown in FIG. 2, the wireless communication device mounted on the teaching pendant 2 includes the Bluetooth wireless communication module 7 and the 2.4 GHz band WLAN wireless communication module 8, and the Bluetooth wireless communication module 7 performs emergency communication. Thus, the 2.4 GHz band WLAN wireless communication module 8 is configured to perform operation information communication. The wireless communication device mounted on the teaching pendant 2 also includes switches SW1 to SW3, a memory 9, and a time division control unit 10 as shown in FIG. The robot 1 includes a Bluetooth wireless communication module, a 2.4 GHz band WLAN wireless communication module, and a time division control unit in order to enable wireless communication with a wireless communication device mounted on the teaching pendant 2. ing.

  Hereinafter, time division multiplexing control executed by the wireless communication device mounted on the teaching pendant 2 will be described.

  When the industrial robot system performs normal operation during teaching work, the amount of emergency communication can be predicted, and the amount of communication is not so large. On the other hand, since emergency communication is performed for safety-related communication, it must always be performed at short time intervals.

  When an emergency stop switch or enable switch is operated, information on the operation of the emergency stop switch or enable switch is transmitted from the teaching pendant 2 to the robot 1 by subsequent emergency communication. The start of the response to the operation of the emergency stop switch or the enable switch is delayed until the start of emergency communication thereafter. The delay is maximized when the emergency stop switch or enable switch is operated immediately after the start of emergency communication. In this case, the delay time (the emergency stop switch or enable switch is operated immediately after the emergency communication is started). It is the time from the time point to the time point when the next emergency communication is started, and hereinafter referred to as the “maximum delay time”). If it is too long, it will cause a safety problem, so emergency communication must be performed at short intervals as described above. There is.

  Therefore, the emergency communication is assigned a time during which a normal amount of communication can be performed even when the radio station condition is bad. In this embodiment, 30 msec is assigned to emergency communication and 70 msec is assigned to operation information communication. Note that the operation information communication is normally set to have a longer time than emergency communication, as in this embodiment, but the operation information communication allocation time is not necessarily longer than the time allocated for emergency communication. It doesn't have to be long.

  Since emergency communication is assigned a time (30 msec) during which normal communication volume can be communicated even when the radio wave condition is bad, it is normal, that is, the radio wave condition is not bad and the communication volume is normal. For example, the emergency communication is completed in a time shorter than the allocated time. When the emergency communication ends earlier than the assigned time, the wireless communication device mounted on the teaching pendant 2 immediately starts the operation information communication without waiting for the emergency communication assigned time to elapse. And the radio | wireless communication apparatus mounted in the teaching pendant 2 starts emergency communication again after the allocation time of operation information communication passes. The wireless communication device mounted on the teaching pendant 2 always uses up the operation information communication allocation time.

  Therefore, when the radio wave condition is bad and the emergency communication is completed at the emergency communication allocation time, the communication status shown in FIG. 3 is obtained, the radio wave condition is good and the communication amount is normal, and the emergency communication allocation time is exceeded. If the emergency communication is completed in a short time, the communication status shown in FIG. 4 is obtained. Thus, when the radio wave condition is good and the communication amount is normal and the emergency communication is completed in a time shorter than the emergency communication allocation time, the period from the start of the emergency communication to the start of the next emergency communication T can be made shorter than the standard 100 msec, and the above-mentioned “maximum delay time” can be shortened.

  By the way, when an abnormality occurs in an industrial robot system, the amount of emergency communication increases, and emergency communication may not end within the time (30 msec) allocated for emergency communication. Therefore, in the wireless communication device mounted on the teaching pendant 2, if the emergency communication does not end within the allotted time (30 msec), the operation information communication is not switched even after the allotted time (30 msec) has passed. Continue emergency communications. The time eroded due to the continuation of emergency communication during the operation information communication allocation time is not compensated, and when the original time allocated for operation information communication (70 msec) has elapsed, emergency communication is started again as usual. If the operation information communication is not completed before the original time (70 msec) assigned to the operation information communication elapses, the operation information communication data D1 (see FIG. 5) that could not be transmitted is temporarily stored in the memory 9. Stored in the network and communicated by the next operation information communication. As a result, it is possible to prevent the upper application from being stopped due to a delay in the transmission of the operation information communication data.

  Therefore, when the communication amount of emergency communication increases when an abnormality occurs in the industrial robot system and the emergency communication does not end within the time allotted for emergency communication, the communication status shown in FIG. 5 is obtained. As a result, the amount of emergency communication increases when an abnormality occurs in the industrial robot system. Even if the emergency communication does not end within the time allotted to emergency communication (30 msec), the emergency communication starts. The period from the start of the next emergency communication to the start of communication can be prevented from exceeding the standard 100 msec, and the above-described “maximum delay time” can be prevented from becoming long.

  Here, the operation of one cycle of the time division control unit 10 that performs the above-described time division multiplexing control will be described with reference to the flowchart shown in FIG.

  First, the time division control unit 10 turns on the switch SW1, turns off the switches SW2 and SW3, operates the Bluetooth wireless communication module 7, and establishes emergency communication with the robot 1 (step S1). S10) Emergency communication is started (step S20).

  In emergency communication, first, the Bluetooth wireless communication module 7 receives a data packet (a data packet indicating that the robot 1 is operating normally) transmitted from the robot 1 side. When receiving the data packet transmitted from the robot 1, the Bluetooth wireless communication module 7 indicates the information indicating that the teaching pendant 2 is operating normally and the operation status of the emergency stop switch 3 and the like in the received data packet. Information is added and returned to the robot 1 side.

  Since the flow shown in FIG. 6 is 100 msec at the longest from the start to the end, when the emergency stop switch 3 is turned OFF, when the teaching pendant 2 determines that there is an abnormality through self-diagnosis, or when there is an abnormality in emergency communication In the worst case, the robot 1 can enter an emergency stop operation (fail-safe operation) within 100 msec.

  When the communication of the emergency communication data is completed and the emergency communication is finished (YES in step S30), the time division control unit 10 does not wait for the emergency communication allocation time to elapse, and the time division control unit 10 disconnects the emergency communication. The communication module 7 is controlled, and then the switch SW1 is turned off, the switches SW2 and SW3 are turned on with the contact a, the 2.4 GHz band WLAN wireless communication module 8 is operated, and the robot 1 Operation information communication is established (step S40), and operation information communication is started (step S50).

  On the other hand, when the communication of the emergency communication data is not completed and the emergency communication does not end (NO in step S30), even if the emergency communication allocation time has elapsed, 100 msec has not elapsed since the start of the flow (step S35). NO), the emergency communication is continued without switching to the operation information communication. When 100 msec has elapsed from the start of the flow (YES in step S35), the flow is terminated and emergency communication is continued in the flow of the next cycle.

  After the operation information communication is started in step S50, the time division control unit 10 determines whether or not the operation information communication data communication is completed and the operation information communication is ended (step S60).

  When the communication of the operation information communication data is completed and the operation information communication is completed (YES in step S60), the time division control unit 10 waits for the time allocated for the operation information communication to elapse (step S90). Then, the 2.4 GHz band WLAN wireless communication module 8 is controlled so as to disconnect the operation information communication (step S100), and the flow ends.

  On the other hand, when the communication of the operation information communication data is not completed and the operation information communication does not end (NO in step S60), if the time allocated for the operation information communication has not elapsed (NO in step S70), the operation information communication To continue. On the other hand, if the time allotted to the operation information communication has elapsed (YES in step S70), the time division control unit 10 sets the switches SW2 and SW3 to the on state at the contact point b and then does not transmit. Is temporarily stored in the memory 9 (step S80), and the flow ends.

These are figures which show the schematic structural example of an industrial robot system. These are figures which show the schematic structural example of the radio | wireless communication apparatus mounted in a teaching pendant. These are figures which show the communication condition in case radio wave condition is bad and emergency communication is complete | finished just in the allocation time of emergency communication. These are figures which show a communication condition when emergency communication is complete | finished in time shorter than the allocation time of emergency communication, when radio wave condition is favorable and communication volume is normal. These are figures which show the communication condition when emergency communication does not end within the time allotted for emergency communication, when the amount of emergency communication increases, when abnormality arises in an industrial robot system. These are flowcharts which show operation | movement of the time division control part with which the radio | wireless communication apparatus mounted in a teaching pendant is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot 2 Teaching pendant 3 Emergency stop switch 4 Touch panel 5 Worker 6 Safety fence 7 Bluetooth wireless communication module 8 2.4GHz band WLAN wireless communication module 9 Memory 10 Time division control part SW1-SW3 switch

Claims (4)

A first wireless communication module that performs wireless communication in a first wireless communication system that uses a predetermined frequency band;
A second wireless communication module that is different from the first wireless communication method and performs wireless communication in a second wireless communication method that uses the predetermined frequency band; and
A first period is assigned to wireless communication by the first wireless communication module, a second period is assigned to wireless communication by the second wireless communication module, and wireless communication by the first wireless communication module and the second A time-division control unit that time-division-controls the wireless communication by the first wireless communication module and the wireless communication by the second wireless communication module so that wireless communication by the wireless communication module is alternately performed,
When the time division control unit determines whether or not the wireless communication by the first wireless communication module is finished, and the wireless communication by the first wireless communication module is finished earlier than the first period The wireless communication by the first wireless communication module and the second wireless communication module so as to start wireless communication by the second wireless communication module without waiting for the elapse of the first period. A wireless communication apparatus characterized by time-division control of wireless communication.   If the time-division control unit does not end the wireless communication by the first wireless communication module even after the first period has elapsed, the time-division control unit continues the wireless communication by the first wireless communication module and continues the wireless communication. The wireless communication by the first wireless communication module and the wireless communication by the second wireless communication module are performed so that wireless communication by the second wireless communication module is performed in a period obtained by subtracting the amount of time from the second period. The wireless communication apparatus according to claim 1, wherein communication is time-division controlled.   The wireless communication apparatus according to claim 1, further comprising a storage unit that temporarily stores data that could not be transmitted by wireless communication by the second wireless communication module once.   The wireless communication according to any one of claims 1 to 3, wherein the first wireless communication method is Bluetooth (registered trademark), and the second wireless communication method is a WLAN of 2.4 GHz band. apparatus.

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