Toll collection system and its communication method
First Claim
1. A toll collection system communication method which charges a car passing through a communication area in a tollgate without a stop, by radio communication between a roadside antenna in the tollgate and an antenna mounted in the car, the method comprising the steps of:
- detecting a car passing through the communication area and a detection area including a given area just before the communication area to obtain the car position data;
calculating, when a car is present in the communication area, a plurality of electromagnetic wave beam paths of direct and reflected waves which connect the roadside antenna and the vehicle-mounted antenna in the car in the position (hereinafter the a plurality of electromagnetic wave beam paths are referred to as “
wave paths”
);
selecting the radiation direction of the radio path whose communication sensitivity is the highest among the wave paths as radiation direction 1; and
adjusting so as to have the directional pattern of the roadside antenna directed toward the radiation direction 1.
1 Assignment
0 Petitions
Accused Products
Abstract
An electronic toll collection system (ETCS) for use in a tollgate for charging a car without the need for the car to stop, in which communication failures or errors due to reflected waves from a structure or a passing car are prevented. A roadside communication antenna which communicates with a vehicle-mounted communication antenna for charging, and a car sensor which detects a car (cars) in an area wider than a designed communication area are installed at the tollgate. As an electromagnetic wave path judgment section obtains data on the profile and position of a car which has entered the tollgate, from a car data detector, it calculates electromagnetic wave paths of direct and reflected waves which connect the roadside communication antenna 21 and the vehicle-mounted antenna in each of the cars, and calculates the receiving electric field strength for each of the paths. The direction of the path which has the highest field strength among the paths to the car in the communication area is selected as radiation direction and the direction of the other paths as radiation direction; then the directional pattern which makes the radiant intensity in radiation direction the maximum and that in radiation direction null is determined to control the radiation direction of the antenna unit through a directivity controller.
22 Citations
14 Claims
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1. A toll collection system communication method which charges a car passing through a communication area in a tollgate without a stop, by radio communication between a roadside antenna in the tollgate and an antenna mounted in the car, the method comprising the steps of:
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detecting a car passing through the communication area and a detection area including a given area just before the communication area to obtain the car position data;
calculating, when a car is present in the communication area, a plurality of electromagnetic wave beam paths of direct and reflected waves which connect the roadside antenna and the vehicle-mounted antenna in the car in the position (hereinafter the a plurality of electromagnetic wave beam paths are referred to as “
wave paths”
);
selecting the radiation direction of the radio path whose communication sensitivity is the highest among the wave paths as radiation direction 1; and
adjusting so as to have the directional pattern of the roadside antenna directed toward the radiation direction 1. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A toll collection system comprising:
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a car sensor for detection of a car in a given area including a designed communication area in a tollgate; and
roadside communication antenna equipment having a roadside antenna and a directional pattern controller for changing its directional pattern, wherein charging is performed by radio communication between the roadside antenna and a vehicle-mounted antenna in an entering car without the need for the car to stop, the system further comprises;
an electromagnetic wave path judgment section for calculating wave paths between the roadside antenna and the vehicle-mounted antenna according to data on the structure of the tollgate, the car profile and car position detected by the car sensor, whereby allowing the directional pattern controller to work with priority given to the wave path to the car in the communication area. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification