Vol. 73, No. 3, May 2018

  Special Reports 1

New Value Creation due to Technology Integration

Toward Realizing Innovations through Vertical Collaboration between Organizations and Horizontal Collaboration between Technologies
AKIYAMA Yasuhiro

Next-Generation SCiB™ Lithium-Ion Rechargeable Battery with High-Capacity Titanium-Niobium-Oxide Anode Capable of Ultrahigh-Speed Charging
HARADA Yasuhiro / ISE Kazuki / TAKAMI Norio
The movement toward conversion from gasoline-powered vehicles to electric vehicles (EVs) has recently accelerated worldwide. To enhance the convenience of EVs, both expansion of the cruising range per charge and shortening of the charging time are required.
Toshiba Corporation and Toshiba Infrastructure Systems & Solutions Corporation have developed and released a lineup of SCiB™ lithium-ion rechargeable batteries offering high-speed charging, high safety, and a long lifetime. We are now developing the next-generation SCiB™ for EV applications, featuring both ultrafast charging and higher energy density compared with the current SCiB™ lineup. This is achieved through the application of a titanium-niobium-oxide (TNO) anode that has double the volumetric capacity of graphite-based anodes generally used for lithium-ion batteries. Experiments on a prototype battery with a capacity of 49 Ah using the TNO anode have confirmed that it offers ultrahigh-speed charging of up to 90% of the nominal capacity in six minutes and can maintain 90% of the initial capacity after 5 000 charge/discharge cycles. This higher energy density battery makes it possible to expand the cruising range of compact EVs to 320 km per charge with a charging time of only six minutes, and is expected to improve the usability of EVs.

Technology for Reduction of Precious Metals Used in Anode Catalyst of PEM Electrolyzers
YOSHINAGA Norihiro / NAKANO Yoshihiko / MEI Wu
As the power generated by renewable energy sources such as wind and photovoltaic systems tends to vary according to the weather conditions, attention has become increasingly focused in recent years on power-to-gas, a system in which surplus electric power is converted into gaseous energy carriers including hydrogen and methane gases using an electrolyzer. Water electrolysis is a key power-to-gas technology, utilized for the conversion of electric power to hydrogen gas. The use of a polymer electrolyte membrane (PEM) electrolyzer has several advantages in such a system, including excellent response characteristics, a wide range of operating current densities, easy production of high-pressure hydrogen gas with high purity, and high durability in repeated start and stop operations. However, a large amount of precious metals is essential to achieve high efficiency and high durability in a PEM electrolyzer, leading to high costs. In conventional PEM electrolyzers, several mg/cm2 of precious metals are used for the powder catalyst and coating layer of the anode electrode.
To reduce the amount of these precious metals, Toshiba Corporation has developed an alternating catalyst layer structure (ACLS) for the anode of PEM electrolyzers based on its proprietary nanostructure control technology using a sputtering method. Experiments on a PEM electrolyzer cell using the ACLS anode catalyst have confirmed that it reduces the amount of precious metal to 0.1 mg/cm2, while achieving high efficiency and long-term durability despite the small amount of precious metal used.

Film-Based Perovskite PV Minimodule with High Energy Conversion Efficiency, Light Weight, and Flexibility
TODORI Kenji / OHKA Haruhi / MORI Shigehiko
In the photovoltaic (PV) power generation market, film-based PV modules that offer advantages including light weight and flexibility are now attracting attention as an alternative to silicon (Si) solar cells. However, the higher manufacturing cost and lower energy conversion efficiency of such modules are serious issues.
As a solution to these issues, Toshiba Corporation has been developing a perovskite solar cell using a thin-film fabrication method employing a printing process for PV power generation devices that can be installed on structures such as buildings with low load bearing capacity, walls, windows, and so on. We have now developed a proprietary film-coating technology, a technology to form transparent electrodes having low resistivity, and a scribing process technology, aimed at practical realization of this type of module. We have conducted experiments on a prototype perovskite PV minimodule fabricated on a polymer-film substrate with a size of about 5 cm square, and confirmed that it achieves an energy conversion efficiency of 13.7%.

Comprehensive Monitoring System for Yield Analysis Using Big Data in Semiconductor Manufacturing
Yield analysis contributes to improvements in the productivity of semiconductor manufacturing through identification of the causes of failures and provision of the appropriate countermeasures based on the results of product inspection and processing histories. However, the large volumes of complicated data collected in each process require a long processing time, making it difficult to manually extract useful information from raw data.
In order to resolve this issue, the Toshiba Group has developed a monitoring system for yield analysis in semiconductor manufacturing that is capable of comprehensively visualizing a summary of failure occurrences and inferring candidates for failure-causing machines by applying machine learning and data mining techniques to big data processing. This yield monitoring system automatically classifies distinctive types of wafer failures, thereby offering information on wafer failure maps and candidates for failure-causing machines. We have conducted simulation experiments using actual data from our semiconductor manufacturing factory and confirmed that this system reduces the average turnaround time of yield analysis from the conventional six hours to two hours.

High-Precision Depth Map Estimation Technology for Stereo Images Applying Deep Neural Networks
Technologies capable of precisely understanding three-dimensional (3D) environments are essential for self-driving cars and autonomous mobile robots and drones. In 3D measurement using a stereo camera system equipped with two cameras to generate binocular disparity, accurate correspondence of the identical points in the left- and right-hand images using a disparity map is important to estimate the distance to objects, providing a so-called depth map.
Toshiba Corporation has developed a deep neural network called SGM-Net that can achieve accurate dense correspondence of stereo images based on the semi-global matching (SGM) method, which is widely used as a regularization method. SGM-Net can automatically estimate the optimal parameters by more effectively removing noise, textureless areas , and occluded parts compared with conventional manual tuning methods. From the results of quantitative evaluation using an open dataset, we have confirmed that SGM-Net offers higher performance for depth map estimation than other reported methods.

Efforts for Standardization of Video Transfer and Content Protection Technologies with Start of 4K and 8K Satellite Broadcasting
SUZUKI Nobuaki / SATO Jun
Before the start of 4K (3 840 x 2 160 pixels) and 8K (7 680 x 4 320 pixels) satellite broadcasting services in Japan scheduled for December 2018, enhanced specifications for interface technologies including video transfer and content protection technologies necessary for transmitting high-resolution video images are required. As part of the efforts to standardize these technologies, version 2.1 of the HDMI® specification for 4K and 8K video image transmission was released in November 2017, the Digital Transmission Content Protection 2 (DTCP2) specification that defines a cryptographic protocol offering more robust content protection for higher resolution digital video formats as well as current audiovisual formats was released in June 2017, and the Advanced Access Content System 2 (AACS2) Recordable specification that provides content protection for the Ultra HD Blu-ray™ Recordable format was released in January 2018.
The Toshiba Group has been making efforts to promote standardization as a founding member of the related standards organizations and is actively contributing to the establishment of these specifications for licensing before the start of full 4K and 8K satellite broadcasting.

Standardization Activities for Next-Generation Wireless LAN and Development of Wireless Communication LSI Compliant with Draft Specifications
NABETANI Toshihisa / MITOMO Toshiya / SEKIYA Masahiro
With the advent of high-speed wireless LAN (WLAN) devices compliant with the Institute of Electrical and Electronics Engineers (IEEE) 802.11ac standard offering a higher communication speed of 1 Gbit/s, WLAN has become widely disseminated in a variety of fields in recent years. However, the expansion of WLAN devices has resulted in a reduction in communication speeds due to interference between multiple WLAN devices, particularly in areas of dense deployment. To address this issue, active efforts have been made since May 2013 toward realization of the IEEE 802.11ax next-generation WLAN standard.
Toshiba Corporation is contributing to the standardization of IEEE 802.11ax by making proposals on technologies for highly efficient wireless communication even in areas with dense deployment of WLAN devices. At the same time, we have been working to ensure the effectiveness of the IEEE 802.11ax standard, including improvement of the throughput when there are many WLAN devices, through the development of a wireless communication large-scale integration (LSI) complying with the draft specifications of IEEE 802.11ax.

Video Transmission Experiments Using Multiple Drones Based on Wireless Multihop Network Technology
In line with the progress of Internet of Things (IoT) technologies for the analysis of data collected from various sensors and other devices in the network, attention has recently been focused on wireless multihop networks in order to efficiently collect a broad range of information. However, such networks are not suitable for the transmission of large volumes of data, including video data.
With this as a background, Toshiba Corporation has been engaged in the research and development of a wireless multihop network technology to transmit video data to distant locations in real time. This technology facilitates the installation of surveillance camera systems outdoors and makes it possible to construct video surveillance systems in conjunction with multiple drones and robots. We have confirmed the transmission of full high-definition (Full-HD) video data to distant locations via drones through demonstration experiments on a video surveillance system using multiple drones equipped with cameras connected to a wireless multihop network.

System Test Automation Techniques for Software Development Capable of Reducing Testing Worker Hours and Shortening Testing Periods
NAKANO Takashi / TANAKA Yuta / DANG Thi Hong Yen
In addition to the development of new software for installation in various products, the creation of derivation software utilizing existing software accumulated as development assets has been increasing. This approach, referred to as derivation development, is effective for the refurbishment of existing software. However, a large number of test cases need to be examined in order to assure the quality of such software for a new product, making it difficult to reduce testing worker hours and shorten testing periods.
The Toshiba Group has been implementing a broad array of measures to rectify this situation through the development and introduction of system test automation techniques, as follows: (1) preparation of guidelines for the introduction and promotion of test automation, (2) development of test automation processes, (3) establishment of a test automation organization utilizing overseas resources, (4) maintenance of a unified management environment for test specifications and test scripts, and (5) development of a technique to generate test scripts with easy maintenance. We have conducted simulation experiments applying these techniques to a large-scale social infrastructure system and confirmed that the techniques make it possible to achieve a 30% reduction in the system testing costs of subsequent systems and a 40% reduction in initial introduction costs.

GridDB Scale-Out Database Adapted to Management of Ever-Increasing IoT Data
HATTORI Masakazu / KODA Kazuhisa
In line with the progress of Internet of Things (IoT) technologies connecting a wide variety of devices via the network, large volumes of data are continuously being generated in various fields including social infrastructure systems. These big data make it possible to create new services and values through a set of processes from data gathering and storage to analysis and visualization. Database systems have become increasingly important as a key element of IoT platforms. Although conventional relational database (RDB) systems are suitable for mission-critical systems due to the high level of data consistency that they provide, these systems pose several problems such as their high costs and difficulties with scalability.
To resolve these issues, Toshiba Digital Solutions Corporation has developed GridDB, a scale-out database that achieves data consistency as well as high scalability and high reliability, in consideration of the characteristics of IoT data. We are supplying GridDB databases for various applications, centering around the field of social infrastructure systems.

Unsupervised Method to Automatically Measure Lead Time of Repetitive Processes Using Acceleration Data from Wearable Sensor on Worker
Lead time, which is the time required to complete an operation in repetitive processes including assembly and inspection processes, is a key parameter in mass production corresponding to the productivity of a factory.
In cooperation with Osaka University, Toshiba has developed a method applying unsupervised method to automatically measure lead time in a mass production line using acceleration data obtained by a wearable sensor on a worker's wrist. This method can automatically extract a motif, which is a distinctive segment that occurs once in each operation period, from time-series acceleration data using only prior knowledge about a predefined standard takt time of the operation process, and consequently estimate the lead time from the interval of occurrence of the motif. We have confirmed the effectiveness of this method through application to final-assembly and inspection operations at our manufacturing sites.

Technologies to Achieve Reduction in Vibration and High Reliability Exemplified by High-Head and Large-Capacity Pumped Storage Power Station in China
KATO Masatoshi / KUROKAWA Toshifumi / WANG Qing / CHEN Hongyu
The Qingyuan Pumped Storage Power Station of China Southern Power Grid Co., Ltd. has four pumped storage units with a pumping head of more than 500 m and a capacity of 320 MW. Toshiba Hydro Power (Hangzhou) Co., Ltd., a subsidiary of Toshiba Energy Systems & Solutions Corporation in China, supplied the four main units and various balance-of-plant (BOP) systems. The final pumped storage unit started commercial operation in August 2016. We have confirmed that each unit offers a low-vibration condition, high reliability, and a high operation rate through the results of commercial operation since then.
A splitter runner consisting of long and short blades for the pump-turbine, which Toshiba Energy Systems & Solutions Corporation developed for pumped storage power generation ahead of its competitors in the world, has been employed to reduce pressure fluctuations and vibration, even during partial-load operation. Optimized methods for plant operation and pump-turbine control under the severe conditions of the water conduit system have also been established based on the results obtained from hydraulic transient analyses. As a result of these technologies, a simultaneous load rejection test on all four units was successfully conducted, the first time that such a test had been carried out at a pumped storage power station in China.


  Frontiers of  Research & Development

High-Accuracy Trajectory Estimation Technology for Plurality of People Based on Images Captured by Multiple Cameras
Accurate and Efficient Particle Method toward Practical Use of Multiphysics Simulations

* Company, product, and service names appearing in each paper include those that are trademarks or registered trademarks of their respective companies.