October 21, 2009
Furukawa Electric has recently succeeded in developing “Onboard UWB (Note 1) Radar for Vehicles,” a compact radar for obstacle detection using quasi-millimeter band (26-GHz). It features a significant reduction of carrier leakage (Note 2), and is conformity with worldwide radio wave regulations (Note 3). Moreover, we have obtained an experimental radio station license for the developed radar from the Ministry of Internal Affairs and Communications.
The acquisition of the license allows us to carry out evaluation experiments on this radar for radio wave propagation and detection performance, while driving a vehicle with this radar onboard. We plan hereafter, by accumulated technologies and data obtained through the experiments, to develop new products with higher reliability.
We consider this “Onboard UWB Radar for Vehicles” significantly enhances capability of driving assistance and comfort for car driving.
Developmental Background
As the use of air-bag systems gains in popularity and the wearing of seat belt became compulsory, the number of fatalities due to car accidents tends to decrease. However, the number of car accidents and injuries stands still large due to the increase in aged drivers and some other reasons.
Recently, sensors for driving assistance that can detect obstacles located near one's car are drawing interest, and those such as ultrasonic sensors, cameras and millimeter-wave radars are already commercialized. See Appendix Table.
Accordingly, we have been promoting the development of a compact “Onboard UWB Radar for Vehicles,” which is capable of high-precision, wide azimuthal view detection of obstacles while satisfying both weather resistance and low costs.
Onboard UWB Radar for Vehicles
Application example of onboard UWB radar for Vehicles
| Performance/System | UWB radar | Millimeter wave radar | Laser radar | Ultrasonic sensor | Camera | Infrared camera |
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| Extremely short-range detection (~2m) |  |
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| Short- to medium-range detection (~30m) | |
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| Long-range detection(~150m) | |
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| Range resolution | |
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| Detection of azimuthal angle range(>30°) | |
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| Relative velocity direct detection | |
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| Weather resistance (fog, rain, snow) | |
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| Night-time (in-darkness) detection | |
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Legend : Suitable : Applicable : Not applicable
Acquisition of Experimental Radio Station License
Currently, the Information and Communication Council of the Ministry of Internal Affairs and Communications is formulating radio wave regulations concerning UWB radar. Thus since radio wave regulations are not prepared at present, it is necessary to acquire an experimental radio station license in order to make radio wave radiation experiments domestically. The developed “Onboard UWB Radar for Vehicles,” having acquired an experimental radio station license, is in compliance with the new regulations scheduled to be laid down in 2010.
Features of the Developed Product
UWB radar is a sensor that transmits short pulse signals of less than several nano seconds in width (one nano second is one billionth of a second), and receives the reflected signals from objects. Then it detects the distance, relative velocity and angle of obstacles in high precision. While advanced technologies are needed to realize such a sensor, Furukawa Electric has applied the elemental technologies that have been accumulated, and has developed the “Onboard UWB Radar for Vehicles” with the following features.
Elemental Technologies
- Antenna design technology
Technology that satisfies both wide bandwidth (frequency coverage) and wide coverage (radio wave radiation area) - Downsizing and high-density mounting technology for high-frequency (RF) module
Technology of selection, arrangement and wiring of RF parts, thereby realizing their mixed mounting with the antenna - Technology for designing ultra-wideband signal processing circuitry
Technology that can generate and process ultra-wideband signals
Features
- Carrier leakage has been significantly reduced.
- Compliant with the radio wave regulation in the U.S., and the one in Japan that is under formulation.
- Switching to different operational modes is possible depending on applications, such as the mode for high-precision (error: ±7.5 cm) and short range detection (less than 0.1 meter to several meters), and the one with slightly lower precision and medium range detection (up to several tens of meters).
- Wide azimuthal view angle (±60°).
- Stabilized detection of relative velocity is possible based on the analysis of Doppler shift.
- Less susceptible to adverse weather conditions like rain, wind and fog.
- Downsizing to palm-sized dimensions has been achieved, measuring W: 110 mm, H: 75 mm, D: 25 mm.
Glossary
(Note 1)UWB (Ultra Wide Band)
Wireless system using a wide bandwidth in excess of 450 MHz.Back to Main Content
(Note 2)Carrier leakage
Carrier signal component, being originally not intended to be transmitted, that leaks from a device to be radiated.Back to Main Content
(Note 3)Worldwide radio wave regulations
Refer to:
http://www.soumu.go.jp/main_sosiki/joho_tsusin/policyreports/joho_tsusin/uwb_wlsystem/pdf/061226_1_si3.pdf
Europe: The 24-GHz band has already been opened for UWB radar applications. Opening of 26-GHz band is under study.
U.S.: The 24-GHz band and 26-GHz band have been opened, with and without restrictions respectively, for UWB radar applications.
Japan: No frequency band is opened for UWB radar applications. Currently, the Information and Communication Council of the Ministry of Internal Affairs and Communications is studying to open the 24-GHz band and 26-GHz band, with and without restrictions respectively, for UWB radar applications. Moreover, public comments are being called for concerning the assignment of these bands to UWB radars, and it is expected that the radio wave regulations will be revised to make UWB radars available in 2010. Refer to:
http://www.soumu.go.jp/menu_news/s-news/19926.html
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