JP-2026074683-A - Robot system

Abstract

[Problem] To provide a robot system that can calibrate sensor values that have an offset component that fluctuates due to environmental factors. [Solution] The robot system 10 comprises a robot 1, a sensor 2 provided on the robot 1 that outputs a sensor value corresponding to the capacitance generated between it and an object, a monitoring sensor 3 that monitors objects around the sensor 2, and a control device 4 that determines the presence or absence of objects around the sensor 2 based on the monitoring results of the monitoring sensor 3, and performs calibration of the sensor value when it is determined that there are no objects around the sensor 2. [Selection Diagram] Figure 1

Inventors

• 柴 徹

Assignees

• 株式会社不二越

Dates

Publication Date

20260507

Application Date

20241021

Claims (5)

1. Robots and, A sensor provided on the robot that outputs a sensor value corresponding to the capacitance generated between it and an object, A monitoring sensor that monitors objects around the aforementioned sensor, A control device that determines the presence or absence of objects around the sensor based on the monitoring results of the aforementioned monitoring sensor, and performs calibration of the sensor value when it is determined that there are no objects around the sensor, A robot system characterized by having the following features.
2. The robot system according to claim 1, characterized in that the control device performs zero-point adjustment of the sensor value when it determines that there are no objects around the sensor.
3. The sensor has a bridge circuit including a detection electrode that generates an electric field in a predetermined direction. The robot system according to claim 1 or 2, characterized in that the control device adjusts the balance state of the bridge circuit and performs calibration for the sensor value.
4. The bridge circuit includes a first resistor and a second resistor. The robot system according to claim 3, characterized in that the control device adjusts the resistance value of at least one of the first resistor and the second resistor to perform zero-point adjustment of the sensor value.
5. The robot system according to claim 1 or 2, characterized in that the control device switches between a detection mode, in which object detection is performed using the sensor value, and a calibration mode, in which the sensor value is calibrated, based on the result of determining whether or not there is an object around the sensor.

Description

This invention relates to a robot system comprising a robot and a control device. There are cases where humans and robots work together to perform tasks on a workpiece. Robots used in such cases are called collaborative robots. For example, collaborative robots may be equipped with capacitive sensors to detect nearby objects. Furthermore, Patent Document 1 describes a capacitive sensor for measuring the amount of an object stored in a container, wherein zero point adjustment is performed by separating the sensor electrode and the ground electrode by a certain distance. Japanese Patent Application Publication No. 09-033317 This is a schematic diagram showing an example of the overall configuration of a robot system according to an embodiment of the present invention.This figure shows an example of the specific configuration of the sensor shown in Figure 1.This figure shows an example of various functions in the control device shown in Figure 1.Figure 1 is a flowchart showing an example of processing by the control device. The embodiments of the present invention will be described below with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing, and redundant explanations are omitted as appropriate. ===Implementation=== <Overall Structure> Figure 1 is a schematic diagram showing an example of the overall configuration of a robot system 10 according to one embodiment of the present invention. The robot system 10 is an industrial robot that performs tasks on a workpiece, such as processing and transporting. Furthermore, the robot system 10 is a collaborative robot that works in the same space as a human, for example. As shown in Figure 1, the robot system 10 mainly consists of a robot 1, a sensor 2, a monitoring sensor 3, and a control device 4. Robot 1 is a multi-joint robot with multiple arms and multiple joints. Specifically, Robot 1 comprises a base 7, a first arm A1, a second arm A2, a third arm A3, and a fourth arm A4. The number of arms is not limited. The base 7 is the base of Robot 1. The base 7 is fixed to, for example, a floor or wall, and supports the entire robot 1. The first arm A1 is connected to the base 7 via a pivot axis. The first arm A1 rotates around this pivot axis relative to the base 7 by a motor (not shown). The second arm A2, third arm A3, and fourth arm A4 rotate around their respective pivot axes by motors (not shown), similar to the first arm A1. A tool or the like is attached to the tip of the fourth arm A4. In this way, the arms are connected to other arms, etc., via pivot axes as joints, making them movable. The robot 1 performs predetermined actions through the movement of each joint. Sensor 2 is a capacitive sensor that detects objects such as people without contact. Sensor 2 outputs a sensor value corresponding to the capacitance generated between it and the object. In this embodiment, "object" is a broad concept including people, workpieces, and other objects. For example, Sensor 2 detects the proximity of an object. Alternatively, Sensor 2 may detect the displacement of an object. This embodiment uses the case where Sensor 2 detects the proximity of an object as an example. The sensor value is, for example, the output voltage output from Sensor 2. Sensor 2 is installed on the robot 1. Specifically, sensor 2 is installed on the arm of the robot 1. In this embodiment, the case in which sensor 2 is installed on the fourth arm A4 is described as an example. Note that the installation position and number of sensors 2 on the robot 1 shown in Figure 1 are just an example, and the installation position and number of sensors 2 are not limited to the specific example shown in Figure 1. Figure 2 shows an example of the specific configuration of sensor 2. Sensor 2 comprises an arbitrary waveform generator 21, a first resistor 22, a capacitance 23, a second resistor 24, a detection electrode 25, an instrumentation amplifier 26, a lock-in amplifier 27, and an A/D converter 28. The first resistor 22, the capacitance 23, the second resistor 24, and the detection electrode 25 form a bridge circuit 29. The bridge circuit 29 is, for example, an RC bridge circuit. The arbitrary waveform generator 21 is an oscillator circuit that generates a sinusoidal voltage or square wave voltage of a predetermined frequency, using the ground potential (GND potential) as the reference potential. The signal generated by the arbitrary waveform generator 21 is input to the bridge circuit 29. Specifically, one end of the first resistor 22 is electrically connected to the arbitrary waveform generator 21, and the other end is electrically connected to the capacitance 23. One end of the capacitance 23 is electrically connected to the first resistor 22, and the other end is electrically connected to the reference potential of the arbitrary waveform generator 21. The point between the first resistor 22 and the c