Smart City Construction Magnetics and Sustainability

On Saturday, February 10, 2018, I observed a demonstration test for the autonamous bus system near the Nagano Prefecture, Ina City roadside station (Ministry of Land, Infrastructure and Transport; Central Development Bureau). I had been invited by the Ministry of Land, Infrastructure, Transport and Tourism.

A system (Magnetic Positioning System: MPS) consisting of an MI sensor module (Aichi Steel) installed in the anterior lower part of the vehicle body of a 20-seat bus (Advanced Mobility, Inc.) which detects the weak magnetic field emitted by small ferrite magnets embedded in the road surface along the bus route had been created.

Along the 4km test course GPS was used along the comparatively simple straight sections of road, and MPS was used in the comparatively complicated sections of road with angular turns and in residential areas. Along the right-angle turn, ferrite magnetic markers (30mm in diameter and 35mm in length cylinder) are installed at 50cm intervals so that the bus can turn as expertly as a veteran driver.

The smooth and stable turning ability of the autonomous bus was confirmed by the test drive. It is a system that can cope with snow conditions.

The MPS has also been tested three times in 2017 (the Ministry of Land, Infrastructure, Transport and Technology): at a road side station in Shiga Prefecture (the Ministry of Land, Infrastructure, Transport and Technology), Hokkaido (snow covered road; the Ministry of Land, Infrastructure, Transport and Technology), and Okinawa Prefecture (precision docking; the Cabinet Office). The demonstration test in Nagano Prefecture is the fourth demonstration test of MPS. The results of these four large scale field demonstration tests are that this technology (MPS) is safe enough to entrust an autonomous bus with the lives of passengers. Other systems are limited to ideal conditions such as wide-open spaces, sunny days, no tree cover and outside tunnels and is not reliable enough to entrust with human lives. The MPS is capable of not only operating in ideal conditions but also operating on snow covered roads that have covered all road markings, leading to MPS reputation as a “super-human system” that is a very reliable automated driving technology.

The MPS was developed with the aim of overcoming the challenges of IMTS (Magnetic Guide System for Unmanned Operation of Buses) that was demonstrated at the 2005 Aichi Exposition. The magnetic markers used at that time were large NdFeB strong magnet cylindrical markers that become traffic obstacles when they inevitably attracted magnetic objects such as empty cans due to their strong residual magnetic field. Cost-wise it was impractical to implement widely due to the high installation cost, high maintenance cost and additional costs due to the necessity for a protective case on the markers to preventing moisture from leaking into the strong magnetic material, rendering them useless. In the background there were technical issues such as a lack of high-sensitivity micromagnetic sensor that could withstand the vibrations of a vehicle and could be used outdoors. Subsequently, Aichi Steel developed a system for mass producing amorphous wire based electronic compasses for devices such as smartphones and established a system to make full use of micro-magnetic sensors. Using this technology, the company challenged itself to detect ferrite market magnets, which are weak and inexpensive magnets that would lower the cost of materials and maintenance. They aimed to and succeeded in developing a new magnetic sensing system that detects only the minute magnetic field of marker magnets while canceling out the various disturbances in a road’s magnetic field.

The MPS technology, which exhibited this “life entrusting technology” in four autonomous bus demonstration test in fiscal 2017 (sponsored by Japanese government agencies), seems to be directly and indirectly inspiring social projects in each area. For example, as reported on February 15, autonomous buses would be a feature of Japan’s Ministry of Economy, Trade and Industry’s Vietnam Smart Town Construction Project. More than 20 corporations will be participating in the project. Without MPS, the autonomous bus system is unstable at night, in strong backlight situations, in rainy weather, etc, and is not yet accepted by society as a whole and is unlikely to become a central part of Smart Society Construction.

Under such circumstances, MPS creates a situation in which “Smart Town, Smart City, Smart Society” can be designed. In the above-mentioned media, the goal of the smart town is to construct a city that can reduce (or eliminate) environmental pollution, traffic congestion, traffic accidents and other common large city problems. The keyword “Smart” is spreading rapidly, along with I-o-T, but the image seems to have changed considerably. When smartphones were first released, the word seemed to invoke the image of “sophisticated, sharp, stylish, clever, high-tech, etc” but it seems now “Smart City, Smart Town” has an image more like “a high-tech, smart town with less traffic congestion and accidents due to autonomous bus systems, where the elderly can also live safely and reliably with less air pollution, water pollution and energy consumption with natural energy power generation.” This seems to indicate that in the last 10 years, the public’s consciousness has changed from personal, wearable technology, to social, security technologies with “environmental consciousness” through the influence of the internet. This is because the public’s expectations for technology have become more sophisticated as a result of metropolitanization due to living conditions having deteriorated due to urbanization and high population growth rate worldwide. In other words, in order for humans needs to be met, science and technology is necessary or their hopes and dreams for their lives will be unattainable.

MPS is a reliable and highly feasible science and technology for autonomous buses that is a necessary component for building a Smart Society. The results of tests and demonstrations show that autonomous bus systems are not a dream and show the scientific and technological capabilities of the modern era.

In terms of applications of the amorphous wire CMOS IC magnetic impedance-effect sensor, comprised of the modular magnetic sensor system of MPS (MI sensor), this is the following impression.

(1) Starting in 2002, Aichi Steel has developed and produced electronic compass chips for smart phones and portable devices that demonstrate that the MI sensors are a wearable high-performance micro magnetic sensor capable of keeping up with human movements.
(2) The above-mentioned MPS constitutes a magnetic guide system for autonomous buses which operates reliably and accurately at all times, regardless of the weather or lighting conditions. In a super competitive, worldwide automated driving system development race, even in snowy conditions or mountainous regions, regardless of time of day, MPS has succeeded in all demonstration tests sponsored by government agencies. The MI sensor functions as a magnetic sensor for MPS. The MI sensor is tough, reliable and sensitive, even when exposed to vehicle vibrations and electromagnetic wave disturbances in the road environment or temperature changes, drastic changes in weather and humidity including snowfall and snow cover, and road surface irregularities.
(3) At the same time as MPS, a professional baseball pitcher rotation analysis ball (MAQ; a joint development between Aichi Steel Co., Ltd. and Mizuno Co., Ltd.) was developed. Until now, the rotation measurement of an object has typically been performed by a "gyro sensor", but the throwing rotation speed of a professional baseball pitcher has a high-speed rotation reaching 50 rps, so the MEMS type gyro sensor that can be built into a hard baseball cannot be used because the maximum measurable rotational speed is 17 rps. The MAQ was developed by altering this concept. Aichi Steel built a 3-axis MI sensor chip for geomagnetic detection into a ball, and adopted a system for measuring the ball rotational speed from the measurement of the relative geomagnetic change due to the rotation of the magnetic sensor in the geomagnetic field. The high sensitivity characteristics and high-speed response (GHz possible) of geomagnetic detection of the MI sensor were utilized in the MAQ. Until now, there had been no magnetic sensor with both high enough sensitivity and a fast enough response time to a achieve a working rotation speed measuring ball.
(4) The creation of a "smart society" that aims to harmonize with the environment by reducing urban problems such as environmental pollution and traffic congestion will be large-scale global projects in the future, such as the Vietnam Smart Town Project by the Japanese government and companies.
Starting with the realization of autonomous driving buses through the development of MPS, MI sensors will continue to develop to include use cases such as tap water volume, using micro magnetic sensor chips, and electric leakage sensor chips, which are technologies for IoT high-tech infrastructure control and disaster prevention security in smart societies. (Amorphous wire MI sensors, which are high performance micromagnetic sensors, have become increasingly clear in their specificity and superiority, and the technology has been continuously grown and developed by Aichi Steel Corporation from "personal sensors" to "wearable sensors" and "smart sensors" and "bionic sensors" in response to the demands of society.)