Platform monitoring system

• US 6,559,760 B2
• Filed: 05/29/2001
• Issued: 05/06/2003
• Est. Priority Date: 05/31/2000
• Status: Active Grant

• Current Assignee: Koito Industries Limited
• Original Assignee: Koito Industries Limited
• Inventors: Araki, Takayuki, Samejima, Akitaka
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/865,535
• Publication Number:
  US 20010050709A1
• Time in Patent Office: 707 Days
• Field of Search: 340/425.5, 340/426, 340/937, 340/506, 340/3.1, 340/539
• US Class Current: 340/425.5
• CPC Class Codes: B61C 17/00 Arrangement or disposition of parts; Details or accessories not otherwise provided for; Use of control gear and control systems
• CPC Class Codes: B61L 23/00 Control, warning or like safety means along the route or between vehicles or trains
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A platform monitoring system includes a camera for capturing a situation on a platform. An image captured by the camera is transmitted from a light emitter on the ground side as an optical signal and also transmitted from a transmission antenna on the ground side as a radio wave signal. These signals are received by an optical receiver and a reception antenna, respectively, mounted in a leading end portion of a vehicle. When the vehicle is positioned in a region around a stopping position, an image carried by the optical signal is selectively displayed on a monitor disposed near an operator'"'"'s seat in the vehicle. When the vehicle is positioned out of the region around the stopping position, an image carried by the radio wave signal is selectively displayed on the monitor near the operator'"'"'s seat in the vehicle.

Claims

1. A platform monitoring system comprising:

an imager device installed on the ground side for capturing a situation on a platform;

a wireless transmission unit for transmitting an image captured by said imager device to a vehicle side;

a display unit installed on the vehicle side for displaying an image transmitted by said wireless transmission unit,

wherein said wireless transmission unit includes;

an optical transmitter installed on the ground side for transmitting an image captured by said imager device as an optical signal;

a radio wave transmitter installed on the ground side for transmitting the image as a radio wave signal;

an optical receiver installed on the vehicle side for receiving an optical signal transmitted from said optical transmitter;

a radio wave receiver installed on the vehicle side for receiving a radio wave signal transmitted from said radio wave transmitter; and

a selector for selecting one of the optical signal received by said optical receiver and the radio wave signal received by said radio wave receiver,

said optical transmitter and said optical receiver are positioned such that a vehicle position range in which signal transmission through the optical signal can be achieved includes a region around a predetermined stopping position of the vehicle with respect to the platform,

said radio wave transmitter and said radio wave receiver are positioned such that a vehicle position range in which signal transmission through the radio wave signal can be achieved includes a range from a region around the stopping position to a predetermined position behind the stopping position in a vehicle running direction, and

an image represented by a signal selected by said selector is selectively displayed on said display unit.

2. A platform monitoring system according to claim 1, wherein:

said selector is responsive to a transmission state of an optical signal between said optical transmitter and said optical receiver for selecting the optical signal when the optical signal presents a good transmission state, and the radio wave signal when the optical signal does not present the good transmission state.

3. A platform monitoring system according to claim 1, wherein:

said selector includes an optical signal level detector for detecting a level of an optical signal received by said optical receiver, wherein said selector selects the optical signal when a level detected by said optical signal level detector is equal to or higher than a predetermined level, and selects the radio wave signal when the level detected by said optical signal level detector is lower than the predetermined level.

4. A platform monitoring system according to claim 1, wherein:

said selector is responsive to the position of the vehicle for selecting the optical signal when the vehicle is positioned in the region around the stopping position, and the radio wave signal when the vehicle is positioned out of the region around the stopping position.

5. A platform monitoring system according to claim 1, wherein:

said selector is responsive to a transmission state of an optical signal between said optical transmitter and said optical receiver and a transmission state of a radio wave signal between said radio wave transmitter and said radio wave receiver for selecting;

(a) the optical signal when the optical signal presents a good transmission state;

(b) the radio wave signal when the optical signal does not present the good transmission state and the radio wave signal presents a good transmission state; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the optical signal does not present the good transmission state and the radio wave signal does not present the good transmission state,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

6. A platform monitoring system according to claim 1, wherein:

said selector includes an optical signal level detector for detecting a level of an optical signal received by said optical receiver, and a radio wave signal level detector for detecting a level of a radio wave signal received by said radio wave receiver,

wherein said selector selects;

(a) the optical signal when a level detected by said optical signal level detector is equal to or higher than a first level;

(b) the radio wave signal when the level detected by said optical signal level detector is lower than the first level and a level detected by said radio wave signal level detector is equal to or higher than a second level; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the level detected by said optical signal level detector is lower than the first level and the level detected by said radio wave signal level detector is lower than the second level,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

7. A platform monitoring system according to claim 1, wherein:

said selector is responsive to a transmission state of an optical signal between said optical transmitter and said optical receiver and a transmission state of a radio wave signal between said radio wave transmitter and said radio wave receiver for selecting;

(a) the optical signal when the optical signal presents a good transmission state and the radio wave signal presents a good transmission state;

(b) the radio wave signal when the optical signal does not present the good transmission state and the radio wave signal presents the good transmission state; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the radio wave signal does not present the good transmission state,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

8. A platform monitoring system according to claim 1, wherein:

said selector includes an optical signal level detector for detecting a level of an optical signal received by said optical receiver, and a radio wave signal level detector for detecting a level of a radio wave signal received by said radio wave receiver,

wherein said selector selects;

(a) the optical signal when a level detected by said optical signal level detector is equal to or higher than a first level and a level detected by said radio wave signal level detector is equal to or higher than a second level;

(b) the radio wave signal when the level detected by said optical signal level detector is lower than the first level and the level detected by said radio wave signal level detector is equal to or higher than the second level; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the level detected by said radio wave signal level detector is lower than the second level,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

9. A platform monitoring system according to claim 1, wherein:

said selector is responsive to a position of the vehicle and a transmission state of a radio wave signal between said radio wave transmitter and said radio wave receiver for selecting;

(a) the optical signal when the vehicle is positioned in the region around the stopping position;

(b) the radio wave signal when the vehicle is positioned out of the region around the stopping position and the radio wave signal presents a good transmission state; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the vehicle is positioned out of the region around the stopping position and the radio wave signal does not present the good transmission state,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

10. A platform monitoring system according to claim 1, wherein:

said selector includes a radio wave signal level detector for detecting a level of a radio wave signal received by said radio wave receiver, wherein;

said selector selects;

(a) the optical signal when the vehicle is positioned in the region around the stopping position;

(b) the radio wave signal when the vehicle is positioned out of the region around the stopping position and a level detected by said radio wave signal level detector is equal to or higher than a predetermined level; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the vehicle is positioned out of the region around the stopping position and the level detected by said radio wave signal level detector is lower than the predetermined level,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

11. A platform monitoring system according to claim 1, wherein:

said selector is responsive to the position of the vehicle for selecting;

(a) the optical signal when the vehicle is positioned in the region around the stopping position;

(b) the radio wave signal when the vehicle is positioned out of the region around the stopping position and the vehicle positioned in the range from the region around the stopping position to the predetermined position behind the stopping position in the vehicle running direction; and

(c) a stop of displaying an image represented by the optical signal or the radio wave signal when the vehicle is positioned out of the region around the stopping position and the vehicle is positioned out of the range from the region around the stopping position to the predetermined position behind the stopping position in the vehicle running direction,

wherein an image represented by the optical signal or the radio wave signal is not displayed on said display unit when said selector selects the stop of displaying.

12. A platform monitoring system according to claim 1, wherein:

an image transmitted through the optical signal has a quality higher than an image transmitted through the radio wave signal.