JRC REVIEW No.73 2022 Technical Reports

- Special Issues : Mobility -

The collision avoidance support system aims to support the safe navigation of ships by avoiding collisions between ships and to lighten the burden on the ship operator due to the complexity of conventional collision avoidance maneuvers. For safe collision avoidance, it is essential to develop generation technology of collision avoidance routes. We are working on the development of an collision avoidance support system based on our original algorithm for generating collision avoidance routes, which employs Obstacle Zone by Target (OZT) devised by Professor Emeritus Hayama Imazu of the Tokyo University of Marine Science and Technology to calculate collisions with other ships. The algorithm will enable us to avoid OZT, comply with the Act on Preventing Collisions at Sea, avoid collisions with other vessels earlier before the risk of collision increases, and ensure that other vessels are aware of our avoidance actions. By realizing this system, we aim to reduce marine accidents, prevent marine pollution, improve fuel efficiency, and solve the shortage of seafarers.

Kengo Toeda
Takanori Akiike
Mikihisa Ishii
Jun Satsumabayashi

- Special Issues : Mobility -

Unmanned aerial vehicles are expected to be utilized for various purposes, and the number of operations is increasing. On the other hand, the realization of collision avoidance technology with manned aerial vehicles such as helicopter ambulances is an urgent issue for safe utilization. Against this background, JRC has developed a non-cooperative collision avoidance system in cooperation with private companies, commissioned and subsidized by the New Energy and Industrial Technology Development Organization (hereafter NEDO), a National Research and Development Agency. We installed this system on a single-rotor medium-sized unmanned aerial vehicle, have conducted the world's first autonomous collision avoidance test using the collision avoidance system, and have successfully avoided a collision with a manned helicopter at a relative speed of 100 km/h. Furthermore, we have conducted research and development to reduce the size, weight, and power consumption of the sensor in consideration of mounting it on a small-sized unmanned aerial vehicle, and have successfully avoided a collision at a relative speed of 200 km/h.

Naoya Hiraki
Akira Itakura

- Special Issues : Mobility -

Based on the positioning technology and the sensing technology accumulated over years, JRC Mobility has achieved high precision positioning technology mainly by GNSS receiver, and advanced sensing technology mainly by surround-monitoring radar. The high precision positioning technology is comprised of centimeter-class precision positioning by GNSS receiver and high precision dead reckoning. The dead reckoning, taking over the GNSS positioning, maintains the positioning precision even in a tunnel, urban canyon, etc. The advanced sensing technology is comprised of surround-monitoring radar providing sensing function of high resolution and wide viewing angle, and sensor fusion. As for sensor fusion, JRC Mobility has achieved the sensing ability to predict collision risks by combining the information from surround-monitoring radar and camera. Those sophisticated technologies are expected to contribute actively to the future mobility society.

Tamaki Honda
Taku Yamane
Yukinobu Tokieda
Masahiro Hoshi
Satoshi Tsuchiya

- Technical articles -

As an alternative approach for measuring the directivity of large aperture parabolic antennas, JRC has developed a method that combines measurement using scale model and directivity analysis including the effects of manufacturing errors. This approach is to combine “measurement using the scale model” which was used in the past without requiring massive facility investment and “directivity analysis including the effects of manufacturing errors”. This is a method of adding the effects of the manufacturing errors of the test antenna obtained by the directivity analysis to the measured directivity of the scale model as a correction value. This time, JRC predicted the directivity of the actual parabolic antenna using this approach and compared and verified with the measured directivity. As a result, it has been confirmed that the directivity obtained by this approach predicts the worst value of the measured directivity and is effective for directivity inspection.

Keiichi Natsuhara
Shinya Hasegawa
Erhao Shang
Takanori Noro
Hideki Tamura

- Technical articles -

The ultra-multilevel modulation technique, which advances to be introduced into microwave radio systems, enables the high efficiency transmission of digital signals. However, when the ultra-multilevel modulation technique is realized, the essential issues are to minimize the effects of phase noise generated in the local oscillator of the radio unit, non-linear distortion of the power amplifier, and multipath fading that occurs in the process of radio wave propagation. To solve each issue, JRC has developed to improve the performance of phase noise compensation technology, DPD (Digital Pre-Distortion: Technology that estimates the distortion of the output signal of a power amplifier using digital signal processing technique and corrects the distortion by giving the distortion of the inverse characteristics in advance) and adaptive equalization technology by utilizing the technology cultivated over many years, and has realized the application to the ultra-multilevel modulation technique. Moreover, JRC applied each technology to existing products (radio systems) and conducted a comprehensive evaluation, and confirmed that the 4096QAM system also obtained high comprehensive characteristics. Through the development of each technology, JRC has realized the high performance of the existing product group and has laid the foundation for large-capacity transmission using a microwave radio system.

Yasuhide Tanaka
Takuya Funayama
Akihiro Yamakita
Masaaki Kato

- Technical articles -

According to the national seismic survey [reference⁽¹⁾], a large-scale Nankai Trough earthquake of magnitude 8-9 class is predicted to occur with a probability of 70-80 % within 30 years. When a huge tsunami caused by a large-scale earthquake occurs, the fishing vessels on the sea need to decide to avoid the tsunami in a short time. For this purpose, the mechanism that the information about an earthquake and tsunami should be provided to the fishing vessels on the sea quickly and reliably is indispensable. Moreover, it is the same about the information over the weather phenomenon which threatens safe navigation. A coastal fishery radio network system conducts the collection and analysis of emergency information about earthquakes, tsunamis, and weather phenomena, that distributes emergency information to fishing vessels in real-time using 27 MHz band DSB radio equipment, and that contributes to safe and secure fishing greatly. JRC has developed the system that distributes such emergency information automatically using existing fishery radio equipment and supplied it for the fisheries cooperative association of Kochi prefecture.

Toshiyuki Ipponyari
Daisuke Takada
Masahiko Takamatsu
Yumiko Noro

- Technical articles -

In maritime satellite communication, depending on the position and heading of the ship, communication may be interrupted due to blocking caused by the presence of an onboard structure between the antenna and the satellite. Our Inmarsat FB and Inmarsat GX satellite communication equipment had a function to notify the blocking condition, but improvements were required for the difficulty of creating a blocking chart and the low visibility of the notification. In response to this requirement, JRC has developed an accurate and simple method of creating blocking charts, a function to notify the occurrence of blocking with the existing ECDIS / radar, and a function to predict the occurrence of future blocking, by utilizing the know-how related to satellite communication technology and navigation aids developed over many years.

Hideki Mino
Katsunori Ando
Yusuke Yagi

- Technical articles -

Instead of the conventional alert management for navigation equipment, the alert management (centralized processing operation and integrated display) based on the requirements of the Bridge Alert Management (BAM) specified in International Maritime Organization (IMO) resolution MSC.302 (87) is implemented, by expanding the target equipment to be managed and increasing the certainty of recognition of alerts, the burden on crew members involved in handling alerts will be reduced. By conforming JRC navigation equipment to the BAM requirements, and connecting it to JRC CONNING Display that incorporates the Alert Management System (AMS) function, alert management of the target equipment is centralized. In addition, by using the J-Marine Cloud Smart Ship Viewer, which JRC provides as a Web service, alert management information of navigation equipment can be shared with land (ship management companies, JRC engineers, etc.).

Koji Inoue
Takashi Kawabata
Minoru Akatsuka

- Technical articles -

In the generation of three-dimensional (hereafter 3D) spatial data of a visual system required for a driving simulator (hereafter simulator), in the past, it took a lot of time to generate data in order to enhance the reality of the 3D space to be created. However, JRC has succeeded in generating high-reality 3D spatial data in a short time using the 3D spatial data generation software developed by JRC. This software automates a series of processes of two-dimensional (hereafter 2D) road data conversion, base data generation for 3D conversion, and data generation of 3D drawing, and automatically generates 3D spatial data from existing 2D road data. Through these, high-reality road images for which needs have been increasing in recent years will be reproduced in the simulator.

Masato Sasaki
Masaru Ishikawa
Yuta Igarashi

- Technical articles -

When a natural disaster such as localized torrential rain or an earthquake occurs, it is important to promptly deliver information related to evacuation and information on the damage situation to the residents in order to maintain the safety and security of the residents. However, the method of externally controlling the broadcasting radio system, which plays this role, differs depending on the system manufacturer and has not been unified, which has been a factor that hindered the speed of information delivery. For this reason, by adopting the J-ALERT automatic activation equipment for the broadcasting radio, JRC has unified the control method of the broadcasting radio system and has developed a system that works in conjunction with the automatic broadcasting from the disaster prevention information system maintained by prefectures to the broadcasting radio system maintained by municipalities, thereby has constructed a system supporting management when a disaster occurred.

Hiroaki Yamamoto
Yutaka Suenaga
Sadaharu Hashimoto
Toshihiko Koyama
Yuki Fukushima

- Technical articles -

JRC has developed in collaboration with Electronic Navigation Research Institute (ENRI) “an optically connected multilateration system”, which is an improved version of the Multilateration System (hereafter MLAT), one of the radar systems used to survey the position of aircraft taxiing on the ground in airport premises. In the conventional MLAT, the positioning accuracy of aircraft and vehicles tends to deteriorate due to the influence of buildings in airport premises on radio wave propagation, and this countermeasure has been an issue. JRC’s newly developed optically connected MLAT realizes high-precision surveying of aircraft and vehicles by converting radio signals received outdoors into optical signals, transmitting them, and performing batch decoding indoors. As a result of evaluating the positioning accuracy of this system introduced at Phu Quoc Airport in Vietnam, it has been confirmed that the performance of this system greatly exceeded the international standard (ED-117A).

Koichi Nakahara
Hanayo Fujimoto

- Technical articles -

The Association of Electricity and Telecommunication Engineering for Land and Infrastructure participated in the excitation experiment of a full-scale building, and JRC participated in the experiment in which the “excitation experiment for telecommunications equipment installed in a building” was conducted. In the experiment, an excitation facility called “E-Defense”, which is the world’s largest three-dimensional shaking table was used. As a result of the excitation experiment, there was no damage to the “post-installed anchor bolt" that installs the telecommunications equipment to the building. The maximum values of acceleration generated on the floor and equipment of the test specimen were generally within the standard values specified in the “Construction Common Specifications for Telecommunication Facilities” (2021 edition, Electricity and Telecommunication Office, Engineering Affairs Division, Minister’s Secretariat, Ministry of Land, Infrastructure, Transport and Tourism), since JRC could confirm that the current installation method of telecommunications equipment is appropriate, it will be reported.

Toshitsugu Ono
Shinji Nakamoto
Jun Muta
Hironobu Hamada
Hirofumi Sugamura
Masaharu Okawa

- Group Companies Technical articles -

Autonomous driving for small vehicles (mobility) is expected to be realized for labor-saving in farms, factories, etc., as well as for transportation in mountainous areas. As for autonomous driving for mobility, millimeter-wave radar is expected as an environmental recognition sensor because of its ability of detecting the distance with high accuracy and of monitoring wide angular range instantly. Millimeter-wave radar is suitable for detection collision hazards because of its measurement capability of distance, azimuth, and instantaneous speed. Advantageously, the radar is hardly disturbed by ambient light and weather conditions, unlike cameras and lidar easily affected by backlight and rainfall outdoors. For an environmental recognition sensor for mobility, JRC Mobility has developed a surround-monitoring radar on the 79 GHz band. The radar realizes environmental recognition by azimuth detection with multiple-input multiple-output (MIMO) technology, digital beamforming (DBF), and by high accuracy of distance and speed due to 79 GHz band. Regarding the radar function as an environmental recognition sensor for mobility, JRC Mobility conducted an experiment in a farm field with rows of fruit trees including narrow passages in between. Throughout the experiment of detecting passages and persons, sufficient capability has been confirmed in the typical evaluation condition for mobility use. Based on the evaluation results, the surroundmonitoring radar is expected to contribute to environmental recognition for mobility.

Yukinobu Tokieda
Kazutoshi Tsuda
Masahiro Hoshi
Kuniaki Yano

- Group Companies Technical articles -

In order to satisfy a wide range of needs related to the autonomation of production lines, NJRC has newly constructed the “Smart ProductWay”, which is a concept model of next-generation production lines that combines our strengths in wireless and mechatronics technologies. The elemental technologies of the Smart ProductWay are “wireless power transmission”, “E-Paper Tag”, “IoT platform”, and “system integration”. By combining these technologies to propose a production line model that matches the market where DX (digital transformation) is accelerating, and by standardizing product planning, NJRC will realize the provision of production equipment products that have both versatility and expandability in a short delivery time and at low cost. In the future, for the purpose of process progress management and monitor and abnormality detection of equipment, NJRC aims to construct a predictive maintenance system by realizing visualization that integrates traceability management data of parts assuming actual products, inspection data of products, and various equipment data.

Takeshi Ichikawa