Guard rail detecting device

• US 5,223,907 A
• Filed: 02/14/1992
• Issued: 06/29/1993
• Est. Priority Date: 02/18/1991
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Asayama, Yoshiaki
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US07/835,485
• Time in Patent Office: 501 Days
• Field of Search: 356/1, 356/4, 358/105, 358/126
• US Class Current: 356/3.14
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves

Abstract

A guard rail detecting device mounted on a motor vehicle has: two image sensors spaced vertically to sense a scene in front of the motor vehicle; a window setting device for setting a plurality of windows on the display screen at predetermined positions; a distance calculating device for calculating the distances from the vehicle to the parts of the guard rail which are held as images in the windows; and a device for calculating the curvature of the guard rail from the distances thus calculated.

Claims

1. A guard rail detecting device in which upper and lower image signals representing images formed on image sensors through a pair of upper and lower optical systems are compared with each other, to electrically detect the deviation of said two images from each other thereby to measure a distance from a vehicle to a plurality of points on a guard rail located ahead of said vehicle according to the principle of trigonometrical measurement, said guard rail detecting device comprising:

window setting means for setting a plurality of windows on one of said upper and lower image signals at predetermined positions;

distance calculating means for calculating the distance from said vehicle to said guard rail for each of said windows, by detecting deviation between an image signal in each window as a reference signal and another image signal corresponding to said reference signal; and

curvature calculating means for calculating the curvature of said guard rial from the distances calculated by the distance calculating means.

2. A guard rail detecting device as claimed in claim 1 further comprising display means for displaying the image sensed by one of said image sensors.

3. A guard rail detecting device as claimed in claim 1 further comprising alarm means for informing the driver of the vehicle that the road is sharply curved, before the vehicle reaches the sharp turn, based on a result calculated by said curvature calculating means.