MICHIBIKI (QZSS) has become a hot topic! Autonomous driving's key "error number cm" service front line
Positioning technology, which is counted as one of the elemental technologies that make up autonomous driving. Based on information from satellites and electronic reference points, this technology enables precise positioning of the vehicle and enables precise driving.
Conventional GPS, which is familiar with car navigation systems, can have an error of several tens of meters depending on the location. Before you know it, you may be driving on the next road, so an error of a few meters is considered an acceptable range.
However, in autonomous driving, an error of several meters is fatal. The permissible error in positional information such as vehicle position and lane must be within a few centimeters. High-precision positioning technology is required, including in tunnels, mountains, and built-up areas where satellite signals are difficult to reach.
Currently, with the commercialization of Japan's quasi-zenith satellite system "Michibiki (QZSS)", it has become possible to perform more accurate positioning. Research and development to suppress it is underway, and the development of positioning technology seems to be heating up.
This time, we will pick up domestic companies that challenge the error of a few centimeters and introduce their technologies and services.
Article table of contents
■NTT DoCoMo: Provides a GNSS position correction information distribution platform service with an error of 2 centimeters
In March 2019, NTT DoCoMo used GNSS to measure positions with high accuracy with an error of several centimeters. announced that it has started technical verification for the construction of a system "GNSS position correction information distribution platform" that can
Install DOCOMO's own fixed station near the mobile station to be verified, and build a location correction information distribution server for technical verification. By verifying the positioning data actually obtained from the mobile station, we verified the quality of the position accuracy, the radio wave interference of the antenna, the quality and operability of the position correction information distribution server, etc. from various angles.
As a result of the verification, it was confirmed that the positioning accuracy converged within the target error of about ± 2 cm could be achieved with the DOCOMO's own fixed station and the position correction information distribution server constructed by DOCOMO. We have started providing location correction information distribution infrastructure service.
About 1,300 electronic reference points installed nationwide by the Geospatial Information Authority of Japan and data observed from GNSS by DOCOMO's own fixed stations are collected and processed in the location correction information distribution server, and the location correction information is processed by the mobile phone network. By distributing high-precision location information to mobile stations that require it, it enables high-precision positioning with an error of a few centimeters.
In January 2020, we are conducting a demonstration experiment of a residential complex / suburban model in Himakajima, Aichi Prefecture as an autonomous driving social implementation demonstration project. is installed, and experiments are also being conducted to grasp the position of autonomous buses and the traffic conditions of driving routes with high accuracy and in real time.
■Softbank: Provides high-precision positioning service from over 3,300 unique reference points nationwide
In June 2019, Softbank began providing a service that enables positioning with an error of several centimeters using RTK positioning in the same year. It was announced that it will start nationwide for corporations from the end of November. By using mobile phone base stations and establishing unique reference points in over 3,300 locations, it is possible to receive services nationwide.
By performing RTK positioning using signals received from GNSS such as Michibiki, it is possible to perform positioning with an error of several centimeters. Generates information and distributes correction information to GNSS receivers (mobile stations) installed in agricultural machinery, construction machinery, self-driving vehicles, drones, etc. through SoftBank's mobile network.
In addition to developing a dedicated GNSS receiver that can be introduced at a low cost and promoting its introduction, we are also developing a service that allows RTK positioning on the cloud without a GNSS receiver.
The service is provided by ALES, a joint venture with Enabler.
In addition, prior to the start of the service, from July of the same year, in cooperation with Yanmar Agri, Kajima Corporation, and BOLDLY, construction site management using automatic operation of agricultural machinery and automatic control of drones, automatic operation of buses and other vehicles We are conducting joint demonstrations.
[Reference] See also "Softbank provides positioning service with an error of several centimeters for self-driving cars" as a related article.
■KDDI: Partnering with Jenova to provide high-precision positioning information distribution service
In April 2020, KDDI and Jenova, which handles high-precision positioning information distribution by GNSS, and real-time positioning with an error of several centimeters. announced that it has signed a business alliance agreement to provide a high-precision positioning information distribution service that enables
Jenova owns patented technology related to the distribution of correction information for GNSS surveying and positioning. It collects and analyzes data on the GNSS system and distributes network-type correction data suitable for GNSS positioning.
On the other hand, KDDI is conducting demonstration experiments in areas where location positioning is important, such as autonomous driving, which is expected to utilize IoT and 5G, and remote control of construction equipment, and is creating new value by combining location information. In addition to working on the creation of , we provide the Geographical Survey Institute with a communication network that supports the distribution of real-time data from electronic reference points installed throughout the country.
By utilizing these technical platforms, the two companies will realize a high-precision positioning information distribution service that enables real-time positioning with an error of a few centimeters, and IoT such as agriculture, automatic driving, disaster prevention/crime prevention, disaster recovery, and infrastructure inspection.・We are aiming for early provision in various new areas where 5G is expected to be used.
[Reference] For KDDI's efforts, see also "A few centimeters of error! The self-driving industry is keen on real-time high-precision positioning KDDI and Jenova are tagging together".
■Mitsubishi Electric: Commercialization of high-precision positioning terminal "AQLOC" for mobiles
Mitsubishi Electric, which designed and manufactured Michibiki's satellite bus system, launched the world's first in September 2017. We are actively promoting development in the field of high-precision positioning, such as starting demonstration experiments of autonomous driving using CLAS signals from quasi-zenith satellites.
CLAS is positioning augmentation information for obtaining high-precision positioning values distributed free of charge throughout Japan from the Quasi-Zenith Satellite System developed by the Cabinet Office. In the demonstration experiment, we confirmed the feasibility of infrastructure-type driving using CLAS signals and high-precision 3D maps. We are aiming to make
The satellite positioning receiver "AQLOC" has already been commercialized as a high-precision positioning terminal for mobile units that provides centimeter-level positioning results by using augmentation information, and it can be used for positioning information from conventional GNSS. Receiving centimeter-level high-precision and stable positioning augmentation information delivered by Kazami Michibiki will support the development and application of applications in a variety of fields.
It is said that autonomous positioning can be performed by the gyro and vehicle speed pulse installed in the receiver even in places where positioning signals from positioning satellites cannot be received, such as tunnels and underpasses while moving.
■ Global positioning service: commercialization by 2020
To create various services that utilize high-precision location information, Denso, Hitachi Zosen, Development Bank of Japan, Japan Radio , Global Positioning Service, established by Hitachi Automotive Systems in 2017, aims to commercialize centimeter-level global high-precision positioning augmentation services by 2020 through technical demonstrations using the high-precision positioning correction technology MADOCA.
MADOCA is software based on precision satellite orbit and clock estimation technology being developed by JAXA (Japan Aerospace Exploration Agency). In addition to precisely calculating the error of the satellite clock, QZSS "L6E signal" is used to distribute correction information to users on the ground. By performing positioning calculations using the distributed data, it is possible to perform centimeter-level positioning around the world.
Correction information for technology demonstration has already been distributed from the L6E signal of the Quasi-Zenith Satellite, and anyone can use it. In addition, prior to MADOCA's commercial distribution service, beta distribution service has started on January 22, 2020. You can use it by registering as a user.
■Japan Radio: Starts development of GNSS chip for autonomous driving
Japan Radio, a major telecommunications manufacturer, began development of centimeter-level GNSS chip "JG11" for autonomous driving systems in January 2017. announced it had started.
JG11 enables centimeter-class high-precision position accuracy by performing positioning using L6 signal augmentation data. Supports satellites such as GPS L1C/A/L2C, QZSS L1C/A/L2C/L6, GLONASS G1C, BDS B1, Galileo E1, etc. Uses external correction data through communication networks outside of overseas quasi-zenith satellite service areas Enables centimeter-class accuracy with RTK positioning.
In addition to supporting dead-reckoning to identify positions even in environments where GPS signals are blocked in tunnels and urban areas, it also satisfies in-vehicle quality standards in preparation for incorporation into autonomous driving systems, which are expected to be put into practical use in the future. It says.
■Enabler: Specializing in GNSS technology development High-precision positioning technology for indoors and underground is also under development
Enabler, which handles location information and satellite positioning technology development, is a product specialized in GNSS. We focus on development, production and sales.
In the automotive field, a system that measures the vertical and horizontal gradients of roads with high precision and visualizes them intuitively and in three dimensions has been adopted by major automobile manufacturers. We have also succeeded in developing "iPNT", which realizes seamless provision of location information and time information.
We are also conducting demonstration experiments of high-precision self-localization of automobiles in places where GPS is not available, such as underground parking lots, and we are using multiple sensor data such as GNS / IMES receivers, acceleration sensors, gyro sensors, and laser Doppler speedometers. We conducted an experiment to fuse with our own algorithm in collaboration with a major domestic system integrator.
In the experiment, the car meandered around an indoor parking lot where GPS positioning was not possible, and the error between the start point and the goal point was measured. It says.
Self-positioning technology in tunnels and indoor parking lots is an important technology not only for car navigation but also for automatic driving systems, so I would like to pay attention to future development.
■ALES: Position correction information generation and distribution service with an error of a few centimeters
ALES, which was jointly established by SoftBank and Enabler in July 2018, generates highly accurate position correction information.・Delivery service started in December 2019.
Correction information is generated based on the signal received by SoftBank's own reference point, and the correction information is distributed to GNSS receivers (mobile stations) installed in agricultural machinery, construction machinery, self-driving vehicles, drones, etc. .
By performing RTK positioning using the correction information generated/distributed by the positioning core system and the signal received by the GNSS receiver (mobile station), highly accurate positioning with an error of several centimeters is possible in real time. It is said that
SoftBank's own reference points are installed in more than 3,300 locations nationwide, eliminating the need for users to set up reference points themselves and ensuring redundancy.
Panasonic: RTK-GNSS with 10 cm error Michibiki-compatible car navigation
Panasonic, which is familiar with car navigation systems, has been commercializing a single-frequency RTK-GNSS high-precision positioning system from early on. Proprietary satellite positioning technology enables positioning with an error of about 10 centimeters. Since the single-frequency RTK-GNSS function involves a huge amount of calculation, it takes time to calculate the positioning, but we have developed an algorithm that quickly derives results on a high-performance CPU and abundant memory, making it practical.
In the car navigation field, Michibiki-compatible products are being released to the market one after another. This makes it possible to determine the position of the vehicle more accurately. In addition, submeter-level positioning augmentation service and centimeter-level positioning augmentation service are not supported.
According to the company, positioning accuracy depends on the positioning method, so using Michibiki does not necessarily mean that positioning can be done with an error of a few centimeters.
Michibiki emits GPS supplementary signals and supplementary signals, and supplementary signals have the same effect as increasing the number of GPS satellites, shortening the positioning time but not improving the positioning accuracy.
In addition, augmentation signals are positioning correction data, and there are L1S (L1-SAIF) for single-frequency receivers and L6 (LEX) for dual-frequency receivers. Using an antenna that can receive three types of radio waves, L1, L2, and L6, and a dedicated receiver, it is possible to determine positioning with an average accuracy of 6 to 12 centimeters.
There is a strong image that positioning with an error of several centimeters will become possible with the advent of Michibiki, but the importance of positioning methods and new technologies does not seem to change.
■Spacelink: Developing a 3-frequency multi-GNSS receiver
In November 2018, Spacelink, a venture company engaged in research and development of energy devices aiming to innovate in the battery area, started centimeter-class real-time We announced a high-performance positioning receiver "3-frequency multi-GNSS receiver" that enables positioning. It is planned to be used in various fields such as industrial drones and self-driving vehicles.
It is possible to perform positioning by capturing positioning signals in three different frequency bands output by the US GPS, Japan's QZS (Quasi-Zenith Satellite), and Europe's Galileo. It is said that high-precision positioning is possible regardless of urban areas or mountainous areas.
In addition to enabling ultra-high-precision positioning with positioning accuracy reduced to the centimeter level, it is possible to perform positioning once every 0.1 seconds at maximum with its unique signal processing and positioning calculation technology. Approximately 10 times the real-time performance has been achieved.
As a use case, it is assumed that it will be used in the autonomous flight of drones, air traffic control, and self-driving vehicles, which require high real-time performance and stability.
■ [Summary] Situation of a multitude of companies, a battle for leadership? Although it was conspicuous, efforts that make use of location information technology, which is closely related to mobile communication, are likely to become popular in the future.
In addition, it is a field where ventures are participating one after another, including long-established companies such as Hitachi, Mitsubishi, and Japan Radio, and it seems likely that partnerships and collaborations among companies will progress.
How will high-precision positioning technology be incorporated into autonomous driving systems in the future? It seems that the day will soon come when the struggle for leadership that is progressing behind the scenes will emerge and develop into a full-scale development competition.
[Reference] See also "Automatic driving, summary of 40,000 characters that can be understood from scratch" as a related article.