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  • 日本語トップ

Verification Project of Wireless Communication Technologies to Accelerate Factory IoT

-Harmonization and stabilization as keys to control various and mixed wireless systems-

  • 日本語
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March 1, 2017

National Institute of Information and Communications Technology
OMRON Corporation
Advanced Telecommunications Research Institute International
NEC Corporation
NEC Communication Systems, Ltd. 
Fujitsu Limited
Fujitsu Kansai-Chubu Net-Tech Limited
Sanritz Automation Co., Ltd.
Murata Machinery, Ltd.

Points

    • ‘Flexible Factory Project’ has started in Japan leading factories with various industry partners.
    • Wireless communication software configuration sets have been proposed as project results.
 

In a collaborative effort between private and public sectors, NICT, OMRON Corporation (OMRON), the Advanced Telecommunications Research Institute International (ATR), NEC Corporation (NEC), NEC Communication Systems, Ltd., Fujitsu Limited (Fujitsu), Fujitsu Kansai-Chubu Net-Tech Limited (Fujitsu KCN), Sanritz Automation Co., Ltd. (SANRITZ), and Murata Machinery, Ltd. teamed up to carry out a series of tests and evaluations for wireless communications technology in several currently-operating factory sites, for the purpose of promoting the integration of IoT on the factory floor.
Within a factory, there are potential instability issues in wireless communications when several different wireless systems running at the same time and location. In order to tackle these issues, the Flexible Factory Project has started in June, 2015.
Additionally, further cooperative relationship with end user factories, evaluations and tests have been carried out with information gathered from sensors such as sound, vibrations, temperature, humidity and current waveform, transmitted over wireless. The requirements for wireless communications from factories were also organized and classified by use, as outcomes of these verification, test results and validation such as hearings from user factories. Wireless communication software configuration sets have been proposed to stabilize various wireless systems with coordinated control in response to the issues discovered and the clarified communication requirements classified by use.
From here on, based on these results, we will evaluate risks of instabilities by simulating multiple and independent wireless communication systems of each facility in factories. In addition, we will also evaluate the effectiveness of this wireless communication software configuration by demonstration experiments with actual systems, and will further accelerate the project for the integration of factory IoT.

Background

While “visualizing” is proceeding as for production facilities and production status to increase productivity, the following needs were raised.
  • Introducing equipment such as sensors or RFID tags to be connected to the network.
  • Saving new cabling cost as well as cable relocation related expenses.
Wireless communication is one of effective methods to cover these requirements. Actuality, more and more wireless systems have becoming introduced to accompany manufacturing equipment. 
There are concerns such as communication instabilities or impact on the current equipment due to interference between wireless systems. However, so far there had not been any verifications to resolve these wireless communication issues at actual sites with multiple coexisting wireless systems.
NICT, OMRON, ATR, NEC, NEC Communication Systems, Ltd., Fujitsu, Fujitsu KCN, SANRITZ  and Murata Machinery, Ltd. have established the Flexible Factory Project. This project has been continued for over one year and is ongoing, to verify wireless environment and wireless communications in factories in operation.

Achievements

The project has been carried out at end user factory sites of Mitsubishi Heavy Industries Machine Tool’s Ritto factory and Toyota’s Tsutsumi and Takaoka factories. Project partners brought their own sensors to gather information such as data on sound, vibration, temperature, humidity and current waveform transmitted over wireless.
The following points were discovered after detail verifications as wireless resources not being used effectively.
  • Wireless systems being introduced rapidly.
  • Manage and control needed of all the wireless systems working in a factory as a whole since there are existing wireless systems introduced separately.
  • Noise from large motors spreading to wireless frequency bands.
  • Shielding effect of large machinery reducing the wireless transmission quality.
  • Receiving data delay caused by collision avoidance due to multiple machines running at the same time.
Risks were confirmed that wireless communications becoming unstable due to various wireless systems intermingled in the same factory site.
Also as a part of this project, we interviewed workers in different factories. Based on them, we categorized the communication requirements by the use of wireless communication devices, such as “quality, control, management, display, safety, and others” which are currently or will be used in factories, facilities and warehouses. These communications requirements can be used for purposes including simulation of complex wireless systems in factories, planning, destabilization risk assessment, and guidelines etc.
In case of being used in actual running factories, we proposed wireless communications software configuration as a wireless architecture for stabilization by harmonizing and managing wireless systems made independent of each facility. This architecture will make wireless network design easier by non-experts at networking and has following characteristics.
  • Covering frequency bands of 920MHz, 2.4GHz, 5GHz, or 60GHz.
  • Two design points
       usage-categorized wireless requirements in actual use
       differences of wireless environment of each factory
  • Well-established information exchange on the application software layer not to depend on physical layer.
 

Future Prospects

NICT, OMRON, ATR, NEC, NEC Communication Systems, Ltd., Fujitsu, Fujitsu KCN, SANRITZ, and Murata Machinery, Ltd. together with the users and the experts of communication, machinery, and systems, will propose solutions to resolve real issues related wireless communications in running factories through clarifying functional requirements for wireless communication devices utilizing own sensors and technologies such as IoT, wireless communication, security, cloud and AI.
This project will be continued to establish and standardize the technology to stabilize various wireless systems with coordinated control, and is to promote applications of wireless communications in manufacturing factories that is expected to accelerate wireless-connected devices to increase productivity.
NICT and project partners will proceed together to promote wireless communication acceleration and productivity visualization for factory IoT.

Information of each organization

-  National Institute of Information and Communications Technology (Headquarters: Koganei Tokyo, Acting president: Taihei Kurose)
-  OMRON Corporation (Headquarters: Shimogyo-ku Kyoto, Managing director CEO: Yoshihito Yamada)
-  Advanced Telecommunications Research Institute International (Headquarters: Souraku Kyoto, Managing director: Yasuo Hirata)
-  NEC Corporation (Headquarters: Minato-ku Tokyo, President and CEO: Takashi Niino)
-  NEC Communication Systems, Ltd. (Headquarters: Minato-ku Tokyo, Managing director and Executive officer: Masanobu Yamaguchi)
-  Fujitsu Limited (Headquarters: Minato-ku Tokyo, Managing director: Tatsuya Tanaka)
-  Fujitsu Kansai-Chubu Net-Tech Limited (Headquarters: Chuo-ku Osaka, Managing director: Toyoo Nomura)
-  Sanritz Automation Co, Ltd. (Headquarters: Machida Tokyo, Managing director: Kazuya Suzuki)
-  Murata Machinery, Ltd. (Headquarters: Fushimi-ku Kyoto, President and CEO: Daisuke Murata)

Appendix

Fig. 1. Various wireless environment evaluations and wireless communication tests carried out in a number of operating factories. 920MHz, 2.4GHz, 5GHz, and 60GHz frequency bands were used.

Fig. 2. Wireless environment evaluation conducted in factories.
Categorized by factory size, whether or not residential area is nearby, existence of shielding structures in factories, existence of facility noise, and stages of using wireless environments (Unwire Stage)

Fig. 3. Relationships among wireless communication usage and communication requirements, and frequencies/wireless standards.
In a factory, data size, data production frequency and node numbers are different in each system. Because of that, the frequency and wireless standard used are different depending on the system functions needed. It is expected to use higher frequency bands such as 60 GHz bands for systems which use a large amount of data (e.g. imaging inspection equipment). The 5 GHz and 2.4 GHz bands are used for sending control programs and/or mobile device control of systems in which data sizes and data producing frequencies are moderate. The 920 MHz and relatively low frequency bands are used for applications which need power saving (e.g. environment sensing).

Fig. 4. Permissible delay time for wireless usage categorized by control, quality, management, display, and safety.
Wireless communication systems used in factories have usually either relatively short permissible delay time (shorter than 100 milliseconds) for safety or control reasons or long permissible delay time (longer than 100 milliseconds). Most applications are required to have the permissible delay time between 10 milliseconds and 10 seconds. The first targeted delay time in this project is also within this range.

Fig. 5. Analogy for a communication situation improved by wireless stabilization. Since each existing application (e.g. existing automated conveyer system, sensor system, or assembly system using wireless torque wrench) uses its own frequency and timing to communicate, they interfere with each other and hence cause degradation of communication quality. Therefore, by coordinating those communications for inter and intra applications, the communication quality can be improved and applications and manufacturing equipment can function stably.

Fig. 6. Software configuration using wireless communication stabilization technology.
By unifying the methods of information exchange in the software applications, the software configuration is not dependent on the physical layer. We defined the required specification based on the studied 6 categories (control, quality, management, display, safety and others) in order to add this function to existing applications (existing automated conveyer systems, sensor systems or assembly systems using wireless torque wrenches).
The software configuration component added this time has application data abstraction function, wireless environment monitoring function and wireless routing function, and can comply with existing radio communication standards.
In the future, if another application in one of the above categories or a new category needs to be added, a different common information exchange scheme can also be added.

Glossary

IoT

Internet of Things

Flexible Factory Project

NICT-led wireless communication experiment project using different kinds of systems aimed at factories in operation, established for the promotion of use and application of wireless.

Wireless Architecture

Wireless technology specification organized according to use and wireless system configuration based on it

Physical Layer

Specifies a network’s physical connection and transmission systems

AI

Artificial Intelligence

Technical Contact

Satoko Itaya
Wireless Systems Laboratory
Wireless Networks Research Center
National Institute of Information and Communications Technology
Tel: +81-46-847-5101
E-mail:

Media Contact

Sachiko Hirota
Press Office
Public Relations Department
National Institute of Information and Communications Technology
Tel: +81-42-327-6923
Fax: +81-42-327-7587
E-mail: