Road antenna apparatus with speed determining means

• US 6,646,590 B2
• Filed: 02/26/2002
• Issued: 11/11/2003
• Est. Priority Date: 06/29/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Terashima, Masaki, Hirano, Yoshiteru, Takemoto, Makoto, Inui, Akihiro
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US10/083,220
• Publication Number:
  US 20020101371A1
• Time in Patent Office: 623 Days
• Field of Search: 340/905, 340/936, 340/539.1, 342/104, 342/114, 701/117, 701/119
• US Class Current: 342/104
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G
• CPC Class Codes: H01Q 1/1242 Rigid masts specially adapted for supporting an aerial
• CPC Class Codes: H01Q 1/125 Means for positioning
• CPC Class Codes: H01Q 1/3225 Cooperation with the rails or the road
• CPC Class Codes: H01Q 17/008 with a particular shape H01Q17/007 takes precedence

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.

Claims

1. 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.

2. The travel-speed support system as described in claim 1, wherein the antenna includes:

a receiver which receives the reflected wave; and

a detector which detects a signal received by the receiver and the speed of the vehicle.

3. The travel-speed support system as described in claim 1, wherein the antenna includes:

speed warning means which compares the travel speed of the vehicle detected by the detector with a predetermined warning speed, determines whether the speed of the vehicle exceeds the warning speed, and issues a warning to the vehicle if the vehicle exceeds the warning speed.

4. 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.

5. The antenna as described in claim 4, wherein the antenna includes:

a receiver which receives the reflected; and

a detector which detects a signal received by the receiver and the speed of the vehicle.

6. The antenna as described in claim 4, wherein the antenna includes:

a speed detector which compares the travel speed of the vehicle as detected by the detection means with a predetermined warning speed, determines whether or not the speed of the vehicle exceeds the warning speed, and issues a warning to the vehicle if the vehicle exceeds the warning speed.