Detection device

• US 20060244978A1
• Filed: 04/25/2006
• Published: 11/02/2006
• Est. Priority Date: 04/27/2005
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamada, Masato, Ichiura, Shuichi
• Granted Patent: US 7,566,861 B2
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4972 Alignment of sensor

Abstract

An irradiation pattern of a laser beam within a target region is controlled based on external signals each related to a driving direction and a driving speed, a result obtained by detection of an obstacle, and signals related to distances to the obstacle. For example, at the time of a right turn, an irradiation pattern for increasing irradiation frequency on a portion shifted in a right-turn direction from a center axis in a driving direction is set. At the time of high-speed driving, an irradiation pattern for increasing irradiation frequency on a center portion of a forward region in the driving direction is set. When the obstacle is detected and a distance to the obstacle is shorter than a threshold distance, an irradiation pattern for increasing irradiation frequency in the vicinity of the obstacle is set. Detection of the obstacle and monitoring of a state thereof are adequately and smoothly performed at the time of changing of the driving direction, the time of high-speed driving, and the time of detection of the obstacle.

Claims

1. A detection device for detecting an obstacle within a target region by emitting a laser beam to the target region, comprising:

target region setting means for setting the target region;

scan trajectory setting means for setting a scan trajectory of the laser beam within the target region; and

irradiation pattern setting means for setting a pattern of an irradiation position of the laser beam within the target region based on a signal related to a moving state of the detection device or a moving object on which the detection device is mounted.

2. A detection device according to claim 1, wherein

the irradiation pattern setting means sets the pattern based on at least one of a signal related to a traveling direction of the detection device or the moving object on which the detection device is mounted and a signal related to a traveling speed thereof.

3. A detection device according to claim 2, wherein

the irradiation pattern setting means sets, as the pattern of the irradiation position of the laser beam within the target region, a pattern for increasing irradiation frequency on a portion shifted in a direction to which the traveling direction is changed from a center of the target region, based on the signal related to the traveling direction of the detection device or the moving object on which the detection device is mounted.

4. A detection device according to claim 3, wherein

the target region setting means shifts the target region in the direction to which the traveling direction is changed from a center axis in the traveling direction, based on the signal related to the traveling direction of the detection device or the moving object on which the detection device is mounted.

5. A detection device according to claim 2, wherein

the irradiation pattern setting means sets, as the pattern of the irradiation position of the laser beam within the target region, a pattern for increasing irradiation frequency on a center portion of a forward region in the traveling direction, based on the signal related to the traveling speed of the detection device or the moving object on which the detection device is mounted.

6. A detection device according to claim 5, wherein

the target region setting means reduces the target region toward the center portion of the forward region in the traveling direction, based on the signal related to the traveling speed of the detection device or the moving object on which the detection device is mounted.

7. A detection device according to claim 6, wherein

the target region setting means reduces the target region toward the center portion of the forward region in the traveling direction with an increase of the traveling speed, based on the signal related to the traveling speed of the moving object.

8. A detection device according to claim 1, further comprising;

separation means for separating a part of the laser beam irradiated to the target region;

detection means for receiving the laser beam separated by the separation means and detecting a beam receiving position of the separated beam on a beam receiving face; and

correction means for correcting a scan position of the laser beam irradiated to the target region based on the beam receiving position detected by the detection means.

9. A detection device for detecting an obstacle within a target region by emitting a laser beam to the target region, comprising:

a beam source for emitting a laser beam;

an actuator for changing an irradiation direction of the laser beam;

a target region setting circuit for setting the target region by controlling the actuator;

a scan trajectory setting circuit for setting a scan trajectory of the laser beam within the target region by controlling the actuator; and

an irradiation pattern setting circuit for setting a pattern of an irradiation position of the laser beam within the target region based on a signal related to a moving state of the detection device or a moving object on which the detection device is mounted and for controlling irradiation timing of the laser beam within the target region based on the pattern set.

10. A detection device according to claim 9, wherein

the irradiation pattern setting circuit sets the pattern based on at least one of a signal related to a traveling direction of the detection device or the moving object on which the detection device is mounted and a signal related to a traveling speed thereof.

11. A detection device according to claim 10, wherein

the irradiation pattern setting circuit sets, as the pattern of the irradiation position of the laser beam within the target region, a pattern for increasing irradiation frequency on a portion shifted in a direction to which the traveling direction is changed from a center of the target region, based on the signal related to the traveling direction of the detection device or the moving object on which the detection device is mounted.

12. A detection device according to claim 11, wherein

the target region setting circuit shifts the target region in the direction to which the traveling direction is changed from a center axis in the traveling direction, based on the signal related to the traveling direction of the detection device or the moving object on which the detection device is mounted.

13. A detection device according to claim 10, wherein

the irradiation pattern setting circuit sets, as the pattern of the irradiation position of the laser beam within the target region, a pattern for increasing irradiation frequency on a center portion of a forward region in the traveling direction, based on the signal related to the traveling speed of the detection device or the moving object on which the detection device is mounted.

14. A detection device according to claim 13, wherein

the target region setting circuit reduces the target region toward the center portion of the forward region in the traveling direction, based on the signal related to the traveling speed of the detection device or the moving object on which the detection device is mounted.

15. A detection device according to claim 14, wherein

the target region setting circuit reduces the target region toward the center portion of the forward region in the traveling direction with an increase of the traveling speed, based on the signal related to the traveling speed of the moving object.

16. A detection device according to claim 9, further comprising;

an optical element for separating a part of the laser beam irradiated to the target region;

a photo detector for receiving the laser beam separated by the optical element and outputting a signal according to a beam receiving position of the separated beam on a beam receiving face;

a detection circuit for detecting the beam receiving position of the separated beam on the beam receiving face based on the signal from the photo detector; and

a correction circuit for correcting a scan position of the laser beam irradiated to the target region based on the beam receiving position detected by the detection circuit.