TRAFFIC ACCIDENT DETECTION DEVICE AND METHOD OF DETECTING TRAFFIC ACCIDENT

• US 20130204515A1
• Filed: 10/19/2011
• Published: 08/08/2013
• Est. Priority Date: 10/28/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Emura, Koichi
• Granted Patent: US 9,704,391 B2
• Time in Patent Office: Days
• US Class Current: 701/119
• CPC Class Codes: G07C 5/085 using electronic data carriers
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/0133 for classifying traffic situation
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P
• CPC Class Codes: G08G 1/0968 Systems involving transmission of navigation instructions to the vehicle

Abstract

The present invention provides a traffic accident detection device of detecting traffic accident that estimates a precise speed variation for a vehicle, and detects dangerous events similar to traffic accidents. A time series estimation unit (202) chronologically estimates a speed from a detected speed of a vehicle that a sensor unit (102) has detected, and acquires a first estimated value; and a reverse time series estimation unit (204) reverse chronologically estimates a speed from the detected speed, and acquires a second estimated value. An integration estimation unit (206) estimates the speed and the speed shift of the vehicle by defining the first estimated value as an integrated estimated value until a time when the distance between the first estimated value and the second estimated value is at maximum, and defining the second estimated value as the integrated estimated value at the time the distance is at maximum and thereafter.

Claims

1. A traffic accident detection apparatus comprising:

a sensor section that observes a vehicle and obtains speed observation values of the vehicle;

a time-series/reverse-time-series combined estimation section that obtains the speed observation values from the sensor section, computes time-series speed estimate values and reverse-time-series speed estimate values, and computes speed estimate values based on the time-series speed estimate values and the reverse-time-series speed estimate values, the time-series speed estimate values being estimated in a time-series fashion based on the speed observation values, the reverse-time-series speed estimate values being estimated in a reverse-time-series fashion based on the speed observation values;

an acceleration computation section that computes acceleration values in a time-series fashion based on an amount of change in the speed estimate values per unit time; and

a sudden braking determination section that compares the acceleration values and a pre-defined determination threshold in a time-series fashion, and determines a time at which the acceleration values are less than the determination threshold to be a sudden braking time of the vehicle

2. The traffic accident detection apparatus according to claim 1, wherein the time-series/reverse-time-series combined estimation section extracts a time at which a difference between the time-series speed estimate values and the reverse-time-series speed estimate values becomes greatest, and computes the speed estimate values by combining the time-series speed estimate values preceding the time with the reverse-time-series speed estimate values following the time.

3. The traffic accident detection apparatus according to claim 1, wherein:

the determination threshold varies according to a corresponding per-hour-speed; and

the sudden braking determination section obtains the speed estimate values in a time-series fashion, determines a determination threshold for each observation time based on the obtained speed estimate values, and determines the sudden braking time based on the determination thresholds that have been defined and the acceleration values.

4. The traffic accident detection apparatus according to claim 3, wherein the determination thresholds decrease in absolute value in accordance with how slow the corresponding per-hour-speed is, and increase in absolute value in accordance with how fast the corresponding per-hour-speed is.

5. The traffic accident detection apparatus according to claim 1, wherein the time-series/reverse-time-series combined estimation section computes the time-series speed estimate values based on the speed observation values read out in a time-series fashion, respective observation times, and a Kalman gain value derived from a Kalman filter, and computes the reverse-time-series speed estimate values based on the speed observation values read out in a reverse-time-series fashion, respective observation times, and a Kalman gain value derived from a Kalman filter.

6. The traffic accident detection apparatus according to claim 1, wherein:

the sudden braking determination section performs a comparative determination with respect to the determination threshold only when the acceleration values are greater than a predetermined threshold; and

the predetermined threshold is determined by at least one of an error distribution computed by a Kalman filter, a SN ratio obtained by the sensor section, and a vehicle count observed by the sensor section.

7. The traffic accident detection apparatus according to claim 1, wherein a range for the speed observation values used to compute the time-series speed estimate values or the reverse-time-series speed estimate values at the time-series/reverse-time-series combined estimation section is broader than a range for the time-series speed estimate values or reverse-time-series speed estimate values as computation results.

8. A traffic accident detection method, wherein:

a sensor section observes a vehicle and obtains speed observation values of the vehicle;

a time-series/reverse-time-series combined estimation section obtains the speed observation values from the sensor section, computes time-series speed estimate values and reverse-time-series speed estimate values, and computes speed estimate values based on the time-series speed estimate values and the reverse-time-series speed estimate values, the time-series speed estimate values being estimated in a time-series fashion based on the speed observation values, the reverse-time-series speed estimate values being estimated in a reverse-time-series fashion based on the speed observation values;

an acceleration computation section computes acceleration values in a time-series fashion based on an amount of change in the speed estimate values per unit time; and

a sudden braking determination section compares the acceleration values and a pre-defined determination threshold in a time-series fashion, and determines a time at which the acceleration values are less than the determination threshold to be a sudden braking time of the vehicle.