Object detection system, transport vehicle, and object detection device

Patent metadata

Field	Value
Publication number	US-12298407-B2
Application number	US-202017440810-A
Country	US
Kind code	B2
Filing date	Jan 29, 2020
Priority date	Mar 25, 2019
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

An object detection device includes: a scanning optical system configured to scan a space by measurement light and guide reflected light from an object; a distance calculation circuit configured to calculate a distance and a direction to the object based on physical relationship between the measurement light and the reflected light; an object determination circuit configured to determine whether the distance and the direction to the object are within a predetermined monitoring region; a signal output circuit configured to output an object detection signal upon determination that the object is within the monitoring region; and a mode switching circuit configured to switch to either a first mode in which it is determined whether the object is within the monitoring region regardless of an intensity of the reflected light and a second mode in which such determination is performed only when the intensity is at or above a predetermined threshold.

First claim

The invention claimed is:

1. An object detection system comprising:
a transport vehicle including a traveling mechanism configured to travel along a predetermined route; and
an object detection device mounted on the transport vehicle, wherein
the object detection device includes:
a light emitting element;
a light receiving element;
a scanning optical system configured to scan a space by measurement light emitted from the light emitting element and guide reflected light from an object for the measurement light to the light receiving element; and
a first hardware processor configured to:
(i) calculate a distance and a direction to the object based on physical relationship between the measurement light emitted from the light emitting element and the reflected light detected by the light receiving element;
(ii) store a monitoring region in a memory;
(iii) determine whether the distance and the direction to the object are within the monitoring region stored in the memory;
(iv) output an object detection signal when the first hardware processor determines that the object is within the monitoring region; and
(v) switch to either a first mode or a second mode, the first mode being a mode in which the first hardware processor performs (i), (iii), and (iv) regardless of an intensity of the reflected light received by the light receiving element, the second mode being a mode in which the first hardware processor performs (i), (iii), and (iv) when the intensity of the reflected light received by the light receiving element is at or above a predetermined threshold and the first hardware processor is inhibited from performing any of (i), (iii), and (iv) when the intensity of the reflected light received by the light receiving element is below the predetermined threshold, and wherein

the transport vehicle includes:
a second hardware processor configured to:
control the traveling mechanism to control traveling of the transport vehicle to a predesignated station and to slow down or stop the transport vehicle based on the object detection signal output from the first hardware processor; and
output, to the first hardware processor, a mode switching signal to switch to either the first mode or the second mode.

2. The object detection system according to claim 1 , wherein
the second hardware processor is configured to output the mode switching signal to switch to the second mode when location information about a transport vehicle ahead is unavailable.

3. The object detection system according to claim 1 , wherein
the second hardware processor is further configured to:
monitor a traveling location along the route, and
output, to the first hardware processor, a mode switching signal to switch to either the first mode or the second mode based on the traveling location monitored by the second hardware processor.

4. The object detection system according to claim 3 , wherein
the first hardware processor is further configured to select the monitoring region from among a plurality of monitoring regions stored in the memory, and
the second hardware processor is further configured to output, to the first hardware processor, a region selection signal to select the monitoring region based on the traveling location monitored by the second hardware processor.

5. The object detection system according to claim 4 , wherein
the first hardware processor is further configured to be switchable to either the first mode or the second mode for each monitoring region selected.

6. The object detection system according to claim 4 , wherein
the second hardware processor is further configured to output, to the first hardware processor, the mode switching signal to switch to either the first mode or the second mode for each monitoring region corresponding to the region selection signal.

7. The object detection system according to claim 1 , further comprising
a particular highly reflective sheet disposed at a rear end of the transport vehicle, the light receiving element receiving reflected light from the sheet at an intensity at or above the predetermined threshold, wherein
in the second mode, the first hardware processor receives only a signal corresponding to light, reflected from the highly reflective sheet, of a transport vehicle ahead and received by the light receiving element.

8. An object detection device for detecting an object based on reflected light for measurement light emitted to scan a space, the object detection device comprising:
a light emitting element;
a light receiving element;
a scanning optical system configured to scan a space by measurement light emitted from the light emitting element and guide reflected light from an object for the measurement light to the light receiving element; and
a hardware processor configured to:
(i) calculate a distance and a direction to the object based on physical relationship between the measurement light emitted from the light emitting element and the reflected light detected by the light receiving element;
(ii) store a monitoring region in a memory;
(iii) determine whether the distance and the direction to the object are within the monitoring region stored in the memory;
(iv) output an object detection signal when the hardware processor determines that the object is within the monitoring region; and
(v) switch to either a first mode or a second mode, the first mode being a mode in which the hardware processor performs (i), (iii), and (iv) regardless of an intensity of the reflected light received by the light receiving element, the second mode being a mode in which the hardware processor performs (i), (iii), and (iv) when the intensity of the reflected light received by the light receiving element is at or above a predetermined threshold and the hardware processor is inhibited from performing any of (i), (iii), (iv) when the intensity of the reflected light received by the light receiving element is below the predetermined threshold.

9. The object detection device according to claim 8 , wherein
the hardware processor is further configured to:
store a plurality of monitoring regions,
select monitoring region from among the plurality of monitoring regions stored in the memory, and
be switchable to either the first mode or the second mode for each monitoring region selected.

10. The object detection device according to claim 9 , wherein
either the first mode or the second mode is set for each of the plurality of monitoring regions stored in memory, and
the hardware processor is further configured to switch to either the first mode or the second mode set for the monitoring region selected.

11. The object detection device according to claim 9 , wherein
the hardware processor receives the plurality of monitoring regions from an external controller in advance.

Assignees

• Hokuyo Automatic Co
• Daifuku Kk

Inventors

• Takagawa Natsuo
• Yamamoto Akihito
• Kasahara Takahiro

Classifications

• B65G2203/0283

  Position of the load carrier · CPC title

• G05D1/43

  Control of position or course in two dimensions [2D] · CPC title

• B65G35/06

  comprising a load-carrier moving along a path, e.g. a closed path, and adapted to be engaged by any one of a series of traction elements spaced along the path (effecting drive at two or more points spaced along the length of an endless conveyor B65G23/32) · CPC title

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G01S7/4817

  relating to scanning · CPC title