Traffic system to prevent from accidents

• US 6,472,978 B1
• Filed: 11/24/2000
• Issued: 10/29/2002
• Est. Priority Date: 11/24/2000
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology, Yokogawa Electric Corporation
• Original Assignee: Massachusetts Institute of Technology, Yokogawa Electric Corporation
• Inventors: Masaki, Ichiro, Takagi, Masahito
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): TANG, SON M
• Application Number:
  US09/721,807
• Time in Patent Office: 704 Days
• Field of Search: 340/435, 340/944, 340/903, 340/904, 340/902, 340/905, 340/925, 340/907, 340/568.1, 340/436, 340/437, 340/438
• US Class Current: 340/435
• CPC Class Codes: G08G 1/005 including pedestrian guidance indicator
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

An improved traffic accident preventing system to alarm both a driver on vehicle and pedestrian each other using a radio communication unit when they are located close. This system also provides a traffic monitoring and control system using communication between vehicle, pedestrian with communication unit and radio unit equipped by roadside, in which a traffic management center can send information to a specific vehicle and pedestrian with communication unit, and also receive information from them.

Claims

1. A communication system for preventing accidents between a pedestrian and a vehicle, said system comprising:

portable tag means to be carried by said pedestrian for receiving a first signal, and for providing and transmitting a second signal; and

vehicle means to be installed in said vehicle for generating and transmitting said first signal, and for receiving said second signal from said portable tag means only when said pedestrian carrying said portable tag means is close to said vehicle and for not receiving said second signal when said pedestrian is not close to said vehicle, and for producing an alarm when receiving said second signal.

2. The system of claim 1, wherein said vehicle means comprises:

first means for generating and transmitting said first signal modulated by a pseudo noise which is unique for each different vehicle so that said first signal is reflected back by a portable tag means as said second signal;

second means for receiving said reflected second signal and for demodulating said reflected second signal using said pseudo noise and for not demodulating said reflected second signal when there is a difference in pseudo noise which identifies said reflected second signal as being originated from a different vehicle, said second means further comprising means for generating a trigger signal when said reflected second signal comprises the pseudo noise assigned to said vehicle;

alarm means for receiving said trigger signal and in response thereto for generating an alarm.

3. The system of claim 2, wherein said second means receives said second signals having a Doppler shift frequency corresponding to said vehicle;

and further comprising;

detector means for receiving said second signals from said second means and for detecting frequency thereof and for generating a second trigger signal when said frequency corresponds to that assigned to said vehicle; and

wherein said alarm means receives said second trigger signal and in response thereto generates an alarm.

4. The system of claim 1, wherein said vehicle means comprises:

transmitter means for transmitting said first signals having a fixed frequency;

receiver means for receiving said second signal having a Doppler shift frequency corresponding to said vehicle;

detector means for receiving said second signals from said receiver means and for detecting frequency thereof and for generating a trigger signal when said frequency corresponds to that assigned to said vehicle; and

alarm means for producing an alarm in response to said trigger signal.

5. The system of claim 1, further comprising;

recording means for recording said alarm.

6. A communication system for preventing accidents between a pedestrian and a vehicle, said system comprising:

portable means to be carried by said pedestrian for receiving a first signal, and for generating and transmitting a low power second signal, and for producing an alarm only when receiving said first signal;

vehicle means to be installed in said vehicle for generating and transmitting said first signal of low power, and for receiving said second signal from said portable means only when said pedestrian carrying said portable means is close to said vehicle and for not receiving said second signal when said pedestrian is not close to said vehicle.

7. The system of claim 6, wherein said portable means and said vehicle means comprise:

vehicle ID code means for identifying each different vehicle;

first means for transmitting first signals modulated by psuedo noise corresponding to said vehicle ID code means;

second means for receiving said first signal transmitted by said first means and for detecting said pseudo noise therein, and for generating a first trigger signal in response to the detected pseudo noise;

first alarm means for receiving said first trigger signal and for producing in response thereto an alarm only when said second means receives said first signal

third means for modulating said second signal using said pseudo noise and for transmitting said second signal only when receiving said first signal;

fourth means for receiving said second signal and for de-modulating said second signal using said pseudo noise and for not demodulating said second signal when said second signal comprises differences in pseudo noise; and

second alarm means for receiving a second trigger signal from said fourth means only when said fourth means demodulates said second signal using said pseudo noise and in response thereto for producing an alarm.

8. The system of claim 7, wherein said portable means further comprises:

means for converting pseudo noise to said vehicle ID code means; and

means for displaying said vehicle ID code means.

9. The system of claim 7, wherein said portable means and said vehicle means comprise:

pedestrian ID code means for identifying each different pedestrian;

fifth means contained in said portable means for generating said pedestrian ID code means, and for modulating said pedestrian ID code means and for transmitting by said second means;

sixth means contained in said vehicle means for converting demodulated signals into said pedestrian ID code means; and

display means contained in said vehicle for displaying said pedestrian ID code means.

10. The system of claim 7, wherein said portable means and said vehicle means further comprise:

first detector means for detecting frequency of said second signal having a Doppler shift frequency corresponding to velocity of said vehicle and for supplying predetermined first trigger signals depending on said detected frequency to said first alarm means when said fourth means demodulates said second signal by said pseudo noise and for not supplying said predetermined first trigger signals to said first alarm means when said fourth means does not demodulate said second signal because of differences in pseudo noise; and

second detector means for detecting frequency of said first signal having a Doppler shift frequency corresponding to said velocity of said vehicle and for supplying predetermined second trigger signals depending on said detected frequency to said second alarm means.

11. The system or claim 7, further comprising

vehicle recording means installed in said vehicle for recording said alarm produced by said first alarm means portable recording means carried by said pedestrian for recording said alarm produced by said second alarm means.

12. The system of claim 7, further comprising:

first detector means for detecting frequency of said signals

received from said first means and having a Doppler shift frequency; and

second detector means for detecting vehicle speed from said frequency detected by said first detector means.

13. The system of claim 6, wherein said portable means and said vehicle means comprise:

first means for transmitting signals having a fixed frequency;

second means for receiving Doppler signal having a frequency deviation from said fixed frequency corresponding to velocity of said vehicle;

third means for transmitting a signal having same frequency as that of said Doppler signal;

fourth means for receiving a response signal having a Doppler shift frequency corresponding to said velocity of said vehicle;

first detector means contained in said fourth means for detecting frequency response signals and for providing a first trigger signal in response thereto;

first alarm means for producing an alarm in response to said first trigger signal;

second detector means contained in said second means for detecting frequency of said Doppler signal and for providing a second trigger signal in response thereto; and

second alarm means for producing an alarm in response to said second trigger signal.