Road antenna apparatus with speed determining means
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMasaki Terashima, Yoshiteru Hirano, Makoto Takemoto, Akihiro Inui
Life of this patent
Estimating the term…
Abstract
A road antenna apparatus includes a road antenna 104 which is mounted on a post 103 and at an elevated position on a road R and via a radio wave establishes radio communication with an on-vehicle radio device 102 mounted in a vehicle 101 which is traveling over the road; and a determining device provided in the antenna and determining whether the travel speed of the vehicle is appropriate for a speed limit imposed on a road, on the basis of the travel speed of the vehicle based on a signal corresponding to a reflected wave, the reflected wave being produced as a result of the radio wave emitted from the antenna being reflected by the vehicle.
Claims6
A travel-speed support system comprising:
- an on-vehicle radio device mounted in a vehicle;
- an antenna mounted above a road and establishing radio communication with the on-vehicle radio-device via a radio wave emitted from the antenna;
- and
- determining means provided in the antenna and determining whether the travel speed of the vehicle is appropriate for a speed limit imposed on a road, on the basis of the travel speed of the vehicle based on a signal corresponding to a reflected wave, the reflected wave being produced as a result of said radio wave emitted from the antenna being reflected by the vehicle.
An antenna for use with a travel-speed support system, comprising:
- on-vehicle radio device mounted in a traveling vehicle;
- an antenna disposed at a position above a road, and establishing radio communication with the on-vehicle radio device via a radio wave emitted from the antenna;
- and
- a speed detector which measures the speed of the traveling vehicle on the basis of a signal corresponding to a reflected wave by means of the Doppler effect when the vehicle approaches or departs from the antenna, the reflected wave being produced when said radio wave is reflected by the vehicle, wherein the road includes both a turnpike and an ordinary road.
Dependencies are inferred from the claim text.