EP-4737075-A1 - OBJECT DETECTION SYSTEM

Abstract

An object detection system (1) includes a robot (10), laser sensors (30), and a control apparatus (20). The robot (10) includes a capacitive proximity sensor (110) disposed on an articulated arm (11) of the robot (10). The capacitive proximity sensor (110) detects an interfering object (2). The laser sensors (30) irradiate laser to detect the interfering object (2). The control apparatus (20) is programmed to stop or decelerate operation of the robot (10) based on a detection of the interfering object (2) by at least one of the capacitive proximity sensor (110) and the laser sensors (30).

Inventors

• ONO, Jotaro

Assignees

• Nachi-Fujikoshi Corp.

Dates

Publication Date

20260506

Application Date

20251027

Claims (4)

1. An object detection system (1) characterized by comprising: a robot (10) including a base (12), an articulated arm (11) connected to the base (12), and a capacitive proximity sensor (110) disposed on the articulated arm (11), wherein the capacitive proximity sensor (110) is operable to detect an interfering object (2); a pair of laser sensors (30) located at positions opposite with respect to the base (12), wherein the pair of laser sensors (30) are operable to irradiate laser approximately in parallel to an installation surface (S1) of the robot (10) for detection of the interfering object (2) and a control apparatus (20) programmed to stop or decelerate operation of the robot (10) based on a detection of the interfering object (2) by at least one of the capacitive proximity sensor (110) and the laser sensors (30).
2. The object detection system (1) according to claim 1, characterized in that the control apparatus (20) is programmed to stop or disable the laser sensors (30) from performing detection when a part of the articulated arm (11) is detected to be present in a detection range in which the laser sensors (30) can detect an interfering object (2).
3. The object detection system (1) according to claim 2, characterized in that the control apparatus (20) is programmed to operate the laser sensors (30) to perform detection of the interfering object (2) when no part of the articulated arm (11) is detected to be present in the detection range of any of the laser sensors (30).
4. The object detection system (1) according to claims 1 to 3, characterized in that the control apparatus (20) is programmed to calculate a distance between the interfering object (2) and the robot (10) based on the detection of the interfering object (2) by the capacitive proximity sensor (110) and the laser sensors (30) and to stop or decelerate the operation of the robot (10) in response to the calculated distance less than a specific distance.

Description

Technical Filed The present invention relates to an object detection system including a robot and a control apparatus. Background Art Robots equipped with non-contact proximity sensors for detecting interfering objects and robot systems including such robots have been known. Japanese Patent Application Laid-Open No. 2018-155712 discloses an autonomous apparatus (robot) equipped with a sensor device that includes a first sensor, and second and third sensors located closer to a moving section of the apparatus than the first sensor. The disclosure also teaches that the first sensor comprises a laser sensor, and the second and third sensors comprise proximity sensors. Summary Technical Problem The detection ranges of the proximity sensors have a blind area formed by limitation to the laser irradiation angles of the proximity sensors, and the proximity sensors may fail to detect an approaching interfering object if the approaching interfering object is outside the coverages of the detection ranges. Moreover, the sensing directions of some proximity sensors are sometimes fixed. The inventor of the present invention has thus recognized that these proximity sensors have the limited detection coverage that falls short of detecting an interfering object approaching toward the robot from every conceivable direction. Solution to Problem The embodiments of the present application provide an object detection system that can detect an interfering object approaching a robot with high accuracy and within a wide range of detection coverage. To solve the foregoing issues, an object detection system according to the present invention comprises a robot including a base, an articulated arm connected to the base, and a capacitive proximity sensor disposed on the articulated arm. The capacitive proximity sensor is configured to detect an interfering object. The object detection system according to the present invention further comprises a pair of laser sensors located at positions opposite to each other with respect to the base. The pair of laser sensors are each configured to irradiate laser approximately in parallel to the installation surface of the robot and detect an interfering object. The object detection system according to the present invention further comprises a control apparatus programmed to stop or decelerate the operation of the robot based on a detection of the interfering object by at least one of the capacitive proximity sensor and the laser sensors. The control apparatus is further programmed to operate the laser sensors to stop or disable the detection by the laser sensors when a part of the articulated arm is positioned in one of the detection ranges that are set for the laser sensors to detect an interfering object. The control apparatus is further programmed to operate the laser sensors to allow the detection of an interfering object when no part of the articulated arm is positioned within any of the detection ranges of the laser sensors. The control apparatus is further programmed to calculate a distance between the detected interfering object and the robot from the detection results from the capacitive proximity sensor and the laser sensors, and to stop or decelerate the operation of the robot if the calculated distance is less than a specific distance. Advantageous Effect of Invention The object detection system according to the present invention can detect an interfering object approaching the robot with high accuracy and within a wide range of detection coverage. Brief Description of the Drawings Fig. 1 is a diagram showing an overall configuration of an object detection system according to an embodiment of the present invention;Fig. 2 is a top view of a robot and laser sensors shown in Fig. 1;Fig. 3 is a diagram showing a functional configuration of a control apparatus shown in Fig. 1;Fig. 4 is a flowchart showing an exemplary processes performed by the object detection system shown in Fig. 1;Fig. 5A is a diagram showing one instance where the object detection system shown in Fig. 1 detects an interfering object; andFig. 5B is a diagram showing another instance where the object detection system shown in Fig. 1 detects an interfering object. Detailed Description of Embodiments An embodiment of the present invention (hereinafter, referred to as a "present embodiment") will be described with reference to the accompanying drawings. To facilitate understanding of the present embodiment, similar or the like components and steps in the drawings are denoted by the same reference signs where appropriate, and redundant descriptions will be omitted. Fig. 1 is a diagram showing an overall configuration of an object detection system 1 according to the present embodiment. Fig. 1 shows the object detection system 1 that includes in its main part a robot 10, a control apparatus 20, and laser sensors 30A and 30B. In the present embodiment, the up-and-down direction in Fig. 1 is defined by the Z-axis direction. In the p