Obstacle recognition system for vehicle

• US 5,798,727 A
• Filed: 12/24/1996
• Issued: 08/25/1998
• Est. Priority Date: 12/25/1995
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nishimura, Takao, Shirai, Noriaki, Hibino, Katsuhiko
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/777,967
• Time in Patent Office: 609 Days
• Field of Search: 342/70, 342/71, 342/72, 342/90, 342/106, 342/107, 342/115, 340/903, 340/435, 340/436
• US Class Current: 342/70
• CPC Class Codes: G01S 13/44 Monopulse radar, i.e. simultaneous lobing
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles

Abstract

In an obstacle recognition system for a vehicle, transmission wave is irradiated per given angle for recognizing an obstacle ahead of the subject vehicle based on angle/distance data obtained from received reflected wave. A position of the obstacle is estimated based on a previously recognized position of the obstacle. The estimated position of the obstacle and an actually recognized position of the obstacle are compared so as to determine whether the obstacle currently recognized is identical with the obstacle previously recognized. Relative acceleration is derived for the obstacle which has been determined plural times to be identical with the previously recognized obstacle. When the derived relative acceleration is outside a given range, the corresponding obstacle is excluded from objects of further obstacle recognition.

Claims

1. An obstacle recognition system for a vehicle, comprising:

radar means for irradiating transmission wave over a given angle around the subject vehicle and, based on reflected wave of the transmission wave, detecting angles and distances of a reflecting object relative to the subject vehicle;

recognition means for recognizing an obstacle around the subject vehicle based on the angles and the distances detected by said radar means;

position estimating means for estimating a position of the obstacle to be recognized by said recognition means, based on a position of the obstacle previously recognized;

identity determining means for comparing the position of the obstacle estimated by said position estimating means and a position of the obstacle recognized by said recognition means so as to determine whether the obstacle currently recognized by said recognition means is identical with the obstacle previously recognized;

acceleration deriving means for deriving relative acceleration of the obstacle determined plural times by said identity determining means to be identical with the previously recognized obstacle; and

excluding means for, when the relative acceleration derived by said acceleration deriving means is outside a given range, excluding the corresponding obstacle from objects of subsequent position estimation performed by said position estimating means and subsequent identity determination performed by said identity determining means.

2. The obstacle recognition system according to claim 1, wherein said acceleration deriving means derives relative accelerations of plural kinds with different sampling periods, and wherein said excluding means, when at least one of said relative accelerations is outside a corresponding given range which is set for each of said plural kinds of the relative accelerations, excludes the corresponding obstacle from the objects of the subsequent position estimation performed by said position estimating means and the subsequent identity determination performed by said identity determining means.

3. The obstacle recognition system according to claim 1, wherein said recognition means comprises point recognition means for recognizing the obstacle as points based on the angles and the distances detected by said radar means, unifying means for unifying neighboring points among the points recognized by said point recognition means, and segment recognition means for recognizing a set of the points unified by said unifying means, as a segment having only a length in a widthwise direction of the subject vehicle.

4. The obstacle recognition system according to claim 2, wherein said recognition means comprises point recognition means for recognizing the obstacle as points based on the angles and the distances detected by said radar means, unifying means for unifying neighboring points among the points recognized by said point recognition means, and segment recognition means for recognizing a set of the points unified by said unifying means, as a segment having only a length in a widthwise direction of the subject vehicle.