Vehicle surroundings monitor with obstacle avoidance lighting

• US 6,285,778 B1
• Filed: 06/06/1995
• Issued: 09/04/2001
• Est. Priority Date: 09/19/1991
• Status: Expired due to Fees

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Akita, Hiroya, Tsuji, Yoshihiro, Yamaguchi, Junichi, Ishikawa, Naoto, Sasaki, Kazuyuki, Nakajima, Masato
• Primary Examiner(s): PATEL, JAYANTI K
• Application Number:
  US08/468,231
• Time in Patent Office: 2,282 Days
• Field of Search: 382/104, 382/107, 382/106, 382/154, 382/199, 364/424.02, 364/436, 180/166-170, 250/559.16, 250/559.2, 318/568.12, 318/568.19, 318/587, 340/901-904, 340/443, 342/70, 342/457, 348/113-118, 761/1, 761/117, 761/207, 761/300, 761/301, 761/302
• US Class Current: 382/104
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 20/10 Terrestrial scenes scenes under surveillance with static cameras G06V20/52; scenes perceived from the exterior of a vehicle G06V20/56; scenes perceived from the interior of a vehicle G06V20/59
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads

Abstract

The vehicle surroundings monitor detects the sizes and positions of obstacles, ditches and humans as well as the depths of the ditches to provide the driver with sufficient information to secure safety during driving. The pattern light projector receives an incoming laser beam and projects a light spot matrix in the form of a regular grating onto the monitored area. The camera photographs the light spot pattern on the monitored area and sends image signals to the data processor which processes the image signals to detect the presence of any obstacle, ditch or human. Based on the steering angle detected by the steering angle sensor, the path the car will take is predicted and a possible contact or collision of the car with the obstacle is detected beforehand. The buzzer, voice synthesizer and display device are used to alert the driver and indicate the presence of the obstacles, the possible contact with them and the location where the possible contact will occur.

Claims

1. A surroundings monitor for a vehicle moving over a supporting surface comprising:

a two-dimensional matrix pattern light projector which receives a laser beam and projects a two-dimensional light spot matrix pattern downward onto a monitored area within said supporting surface located in closed proximity to vehicle;

a camera for photographing the light spot matrix pattern; and

a data processor which processes image signals supplied from the camera to detect the presence of obstacles and depressions in the monitored area within said supporting surface, wherein said data processor further comprises;

a reference data generating means which extracts a light spot pattern from pixel data, the pixel data including a coordinate position of the light spot baricenter which is obtained from the image signals supplied by the camera that photographed the light spot pattern projected upon a flat road surface when a sensing means is first mounted on a vehicle;

a detecting means which compares the light spots of the reference data with light spots which are extracted from pixel data, the pixel data being produced from the image signals supplied by the camera that photographed the light spot pattern projected upon a road surface being examined, in order to detect the presence of obstacles and depressions; and

a height correction means which corrects the three-dimensional coordinates of the road surface according to changes in the camera height from the road surface, wherein said height correction means first detects displacements of the three-dimensional coordinates of light spots at several predetermined points from those at the same points of said reference data with passengers on board the vehicle, determines a height correction value by the amount of sinkage of the vehicle caused by a weight of the passengers, said amount being calculated from said detected displacements, and subtracts said height correction value from the actual three-dimensional coordinates of the road surface for obtaining the actual road surface being examined.

2. A surrounds monitor for a vehicle as claimed in claim 1, wherein said data processor further comprises:

a brightness correction means which corrects the threshold values for individual light spots recorded in the reference data to extract light spots from the pixel data, which is produced from image signals supplied by the camera that photographed the light spot pattern projected upon the road surface being examined, according to a difference between the brightness of a background other than the light spots and the background brightness of the reference data.

3. A surroundings monitor for a vehicle as claimed in claims 1 or 2, further comprising:

a vehicle path prediction means for calculating the path the vehicle will take and thereby predicting a possible contact or collision of the vehicle with obstacles.

4. A surroundings monitor for a vehicle as claimed in claim 3, further comprising:

at least one of a buzzer, voice synthesizer and display device to inform a driver of the vehicle of the presence of obstacles, wherein said voice synthesizer and said display device are also capable of informing the driver of the location in which the vehicle is predicted to contact the obstacles along said path.

5. A surroundings monitor for a vehicle as claimed in claim 1, wherein said two-dimensional matrix pattern light projector comprises a fiber grating.

6. A surroundings monitor for a vehicle as claimed in claim 1, wherein said two-dimensional matrix pattern light projector comprises a multi-beam projector consisting of a plurality of microlenses integrated onto a thin transparent plate.

7. A surroundings monitor for a vehicle as claimed in claim 1, wherein said height correction means determines said height correction value only when the road surface is detected to be a horizontal plane.

8. A surroundings monitor for a vehicle as claimed in claim 7, wherein said height correction means operates only when the travel speed of the vehicle is within a predetermined speed range.