Robot system

Abstract

To provide a robot system that is able to prevent deterioration in the detection accuracy of an electrostatic capacity type sensor.SOLUTION: A robot system equipped with an electrostatic capacity type sensor 6 includes: a housing 31 constituting, for example, a fourth arm A4 as an arm of a robot and having an opening 33; an external cover 32 covering the opening 33 of the housing 31; a detection electrode 11 provided closer to the housing 31 than the external cover 32 and constituting a sensor 6; a circuit board 12 provided closer to the housing 31 than the detection electrode 11 and connected to the detection electrodes 11 to constitute the sensor 6; and a shield member 35 provided closer to the housing 31 than the circuit board 12, having the same potential as the housing 31, shielding the circuit board 12 from the housing 31 and also shielding the detection electrode 11 from the housing 31.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a robot system equipped with a capacitance type sensor. [Background technology]

[0002] There are cases where humans and robots work together to perform tasks on a workpiece. Robots used in such cases are called collaborative robots. Collaborative robots may be equipped with capacitance sensors.

[0003] For example, Patent Document 1 describes that a circuit shielding layer may be provided on a detection circuit board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Utility Model No. 211916890 Summary of the Invention [Problem to be solved by the invention]

[0005] However, noise generated inside the arm or the like can affect not only the circuit board but also the detection electrodes of the capacitance sensor, which can degrade the detection accuracy of the sensor.

[0006] In view of the above problems, an object of the present invention is to provide a robot system that can suppress deterioration in detection accuracy by a capacitance sensor. [Means for solving the problem]

[0007] In order to solve the above problems, the robot system of the present invention is a robot system equipped with a capacitance-type sensor, and includes: a housing that forms the arm of the robot and has an opening; an external cover that covers the opening of the housing; a detection electrode that is provided on the housing side of the external cover and forms the capacitance-type sensor; a circuit board that is provided on the housing side of the detection electrode and is connected to the detection electrode to form the capacitance-type sensor; and a shielding member that is provided on the housing side of the circuit board, has the same potential as the housing, and shields the circuit board from the housing and also shields the detection electrode from the housing.

[0008] In addition, in the robot system, a motor is provided inside the housing, and the shielding member shields the circuit board and the detection electrode from noise generated by the motor.

[0009] In addition, in the robot system, the shielding member has a bottom and a wall portion that rises circumferentially from the bottom, and the circuit board is provided in a space formed by the bottom of the shielding member, the wall portion of the shielding member, and the detection electrode.

[0010] In addition, in the robot system, the shielding member is provided with a hole, and wiring electrically connected to the circuit board is arranged from the circuit board through the hole into the interior of the housing.

[0011] In the robot system, the detection electrodes have connection portions that protrude toward the circuit board, and the circuit board is electrically connected to the detection electrodes via the connection portions. [Effects of the Invention]

[0012] According to the robot system of the present invention, it is possible to suppress deterioration of the detection accuracy of the capacitance sensor. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a robot system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an example of a specific configuration of the sensor in FIG. [Figure 3] FIG. 2 is a diagram showing an example of a specific configuration of a fourth arm in FIG. 1; [Figure 4] FIG. 4 is a diagram showing an example of the internal configuration of the fourth arm of FIG. 3. [Figure 5] 5 is a diagram showing an example of the configuration around the circuit board in FIG. 4. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted where appropriate.

[0015] === Implementation form === <Overall structure> FIG. 1 is a diagram schematically illustrating an example of the overall configuration of a robot system 2 according to an embodiment of the present invention.

[0016] The robot system 2 is an industrial robot that performs processes such as machining and transporting a workpiece, and is also a collaborative robot that works in the same space as a person, for example.

[0017] As shown in FIG. 1, the robot system 2 mainly includes a robot 4, a control device 5, and a sensor 6.

[0018] The robot 4 is an articulated robot and has multiple arms and multiple joints. Specifically, the robot 4 includes a base 7, a first arm A1, a second arm A2, a third arm A3, and a fourth arm A4. The number of arms provided is not limited. The base 7 is the foundation of the robot 4. The base 7 is fixed to the floor or a wall and supports the entire robot 4. The first arm A1 is connected to the base 7 via a rotation shaft. The first arm A1 is rotated around the rotation shaft relative to the base 7 by a motor (not shown). The second arm A2, the third arm A3, and the fourth arm A4 are rotated around their respective rotation shafts by their respective motors (not shown), similar to the first arm A1. A tool 9 is provided at the tip of the fourth arm A4. The robot 4 performs a predetermined operation by moving each joint, and performs a predetermined process on a workpiece using the tool 9.

[0019] The control device 5 is an information processing device that controls the operation of the robot 4. The control device 5 controls the operation of each arm of the robot 4 and the tool 9, causing the robot 4 to perform a predetermined operation. For example, the control device 5 causes the robot 4 to perform a predetermined operation of gripping a workpiece with the tool 9 and transporting the workpiece from one position to another.

[0020] Furthermore, the control device 5 uses the output of the sensor 6 to stop the movement of the robot 4. Specifically, the control device 5 compares the output of the sensor 6 with a threshold value to determine whether or not an object such as a person is approaching the robot 4. If the control device 5 determines that an object such as a person is approaching the robot 4, it stops the movement of the robot 4. For example, if the output of the sensor 6 increases in response to the approach of an object, the control device 5 determines that an object is approaching when the output of the sensor 6 is equal to or greater than the threshold value. For example, the control device 5 stops the movement of the robot 4 even if the robot 4 is in the middle of a predetermined movement. Note that the control device 5 is not limited to stopping the movement of the robot 4, and may also slow down the movement of the robot 4.

[0021] The sensor 6 is a capacitance sensor that detects an object such as a person. In this way, the robot system 2 is equipped with a capacitance sensor. Note that the term "object" is a broad concept that includes a person and also includes objects such as workpieces. Specifically, the sensor 6 detects the proximity and displacement of an object.

[0022] The sensor 6 is provided on the robot 4. Specifically, the sensor 6 is provided on an arm of the robot 4. In this embodiment, a case where the sensor 6 is provided on the fourth arm A4 will be described as an example. However, the sensor 6 may also be provided on another part of the robot 4.

[0023] 2 is a diagram showing an example of a specific configuration of the sensor 6. The sensor 6 includes a detection electrode 11 and a circuit board 12.

[0024] The detection electrode 11 is an electrode that constitutes the sensor 6. The detection electrode 11 generates an electric field and detects an object that enters the area of ​​the generated electric field. Specifically, the detection electrode 11 forms a capacitance with the object. The example in FIG. 2 shows a person H as an example of an object. The detection electrode 11 faces the person H and forms a capacitance with the person H.

[0025] The circuit board 12 is connected to the detection electrode 11 and constitutes the sensor 6. Specifically, the circuit board 12 has a circuit for outputting a sensor value corresponding to the capacitance formed between the detection electrode 11 and an object. Specifically, the circuit board 12 is equipped with an arbitrary waveform generator 21, a resistor 22, a capacitor 23, a resistor 24, an instrumentation amplifier 26, a lock-in amplifier 27, and an A / D converter 28. The arbitrary waveform generator 21 inputs a sinusoidal voltage of a predetermined frequency to an RC bridge circuit 29. The RC bridge circuit 29 is configured by connecting the resistor 22, the capacitor 23, the resistor 24, and the detection electrode 11 in a bridge configuration. The voltage generated by the detection electrode 11 is input to the instrumentation amplifier 26, and the output of the instrumentation amplifier 26 is output to the lock-in amplifier 27 and the A / D converter 28. The output of the A / D converter 28 is output to the control device 5 as a sensor value.

[0026] For example, with a circuit configuration such as that shown in FIG. 2, a sensor value indicating a value corresponding to the capacitance generated depending on the state (distance) between the detection electrode 11 and the object is output.

[0027] In the above example, the circuit board 12 is described as being equipped with an arbitrary waveform generator 21, a resistor 22, a capacitor 23, a resistor 24, an instrumentation amplifier 26, a lock-in amplifier 27, and an A / D converter 28, but it may be equipped with only some of the components.

[0028] Note that the specific circuit configuration of the sensor 6 is not limited to that shown in Fig. 2, as long as a sensor value corresponding to the capacitance formed in the detection electrode 11 is output. That is, the circuit configuration mounted on the circuit board 12 is not limited to all or part of the circuit configuration shown in Fig. 2. Furthermore, in the above example, the control device 5 compares the output of the sensor 6 with a threshold value in order to stop (or slow down) the movement of the robot 4, but the threshold value determination process may be performed on the circuit board 12.

[0029] <Configuration example of sensor 6 mounted on the arm> Next, an example of a specific configuration in which the sensor 6 is mounted on an arm will be described. Note that the fourth arm A4 will be used as an example of the arm of the robot 4.

[0030] Fig. 3 is a diagram showing an example of a specific configuration of the fourth arm A4, and Fig. 4 is an exploded view showing an example of the internal configuration of the fourth arm A4 of Fig. 3.

[0031] As shown in FIG. 3, the exterior of the fourth arm A4 is made up of a housing 31 and an outer cover 32 that constitute the fourth arm A4.

[0032] The housing 31 has components such as a motor 30 for operation and wiring provided therein. Other components may be provided inside the fourth arm A4. The housing 31 is made of a metal material and is connected to earth (reference potential). The housing 31 has an opening 33 as shown in FIG. 4. The opening 33 is provided, for example, on the side surface of the fourth arm A4.

[0033] The external cover 32 covers the opening 33 of the housing 31 and is connected to the housing 31. The external cover 32 is made of a resin material. By making the external cover 32 from a resin material, the external cover 32 does not interfere with the electric field generated by the detection electrode 11, allowing the sensor 6 to normally detect an object. In this way, the exterior of the fourth arm A4 is formed by the housing 31 and the external cover 32.

[0034] As shown in FIG. 4, the detection electrode 11, the circuit board 12, and the shield member 35 are provided inside the fourth arm A4.

[0035] The detection electrode 11 is provided on the fourth arm A4 closer to the housing 31 than the external cover 32. Specifically, the detection electrode 11 is provided between the external cover 32 and the shield member 35. The detection electrode 11 is not exposed to the outside by the external cover 32 and is protected from the external environment. For example, the external cover 32 prevents the detection electrode 11 from becoming dirty.

[0036] The circuit board 12 is provided on the fourth arm A4 closer to the housing 31 than the detection electrode 11. Specifically, the circuit board 12 is provided between the detection electrode 11 and the shield member .

[0037] The shielding member 35 is provided on the fourth arm A4 closer to the housing 31 than the circuit board 12. The shielding member 35 is made of a metal material. The shielding member 35 is preferably made of the same material as the housing 31, for example. The shielding member 35 is electrically connected to the housing 31 and has the same potential as the housing 31. In other words, the shielding member 35 is grounded in the same way as the housing 31. This allows the shielding member 35 to function as an electromagnetic shield.

[0038] The shielding member 35 includes a bottom 37 and wall portions 38. The wall portions 38 are circumferentially raised relative to the bottom 37 in a direction perpendicular to the surface of the bottom 37. The bottom 37 and wall portions 38 form a recess in the shielding member 35, and the circuit board 12 is disposed in this recess. The circuit board 12 is disposed in a space defined by the bottom 37, the wall portions 38, and the detection electrode 11. The shielding member 35 electrically isolates the circuit board 12 from the interior of the housing 31, where the motor 30 and other components are disposed. That is, the shielding member 35 shields the circuit board 12 from the housing 31 (the interior of the housing 31). Specifically, the shielding member 35 prevents electromagnetic waves, such as noise, generated inside the housing 31 from reaching the circuit board 12 through the shielding member 35. For example, the shielding member 35 shields the circuit board 12 from noise generated by the motor 30. Furthermore, since the circuit board 12 is placed in a recess formed by the bottom 37 and wall 38 of the shielding member 35, it is effectively shielded by the shielding member 35.

[0039] The shielding member 35 also has an extending portion 39. The extending portion 39 extends outward beyond the bottom portion 37 and wall portions 38 on which the circuit board 12 is provided. For example, the extending portion 39 extends parallel to the surface of the bottom portion 37. As a result, the shielding member 35 electrically isolates the detection electrode 11 from the interior side of the housing 31 where the motor 30 and the like are provided. That is, the shielding member 35 shields the detection electrode 11 from the housing 31 (the interior side of the housing 31). Specifically, the shielding member 35 prevents electromagnetic waves such as noise generated inside the housing 31 from reaching the detection electrode 11 beyond the shielding member 35. For example, the shielding member 35 shields the detection electrode 11 from noise generated by the motor 30.

[0040] In this way, the shielding member 35 not only shields the circuit board 12 but also shields the detection electrodes 11 .

[0041] Fig. 5 is a diagram showing the area between the shield member 35 and the external cover 32. As shown in Fig. 5, the shield member 35, the circuit board 12, the detection electrode 11, and the external cover 32 are connected in this order. An active shield electrode 40 may be provided on the surface of the detection electrode 11 opposite to the external cover 32.

[0042] 5, the shielding member 35 has a hole 44. The hole 44 is provided in, for example, the bottom 37. Wiring 41 is electrically connected to the circuit board 12. The wiring 41 includes, for example, a power supply line and a signal line. The wiring 41 connected to the circuit board 12 is arranged from the circuit board 12 to the inside of the housing 31 through the hole 44 of the shielding member 35. In other words, the wiring 41 is not exposed to the outside of the housing 31 or the outer cover 32, but is arranged from the circuit board 12 to the inside of the housing 31.

[0043] 5, the detection electrode 11 has a connection portion 43 that protrudes toward the circuit board 12. For example, the connection portion 43 is formed by bending a part of the detection electrode 11 toward the circuit board 12. The wiring 42 is electrically connected to the connection portion 43, and the wiring 42 is electrically connected to the circuit board 12. As a result, the detection electrode 11 is electrically connected to the circuit board 12 in a state where the wiring 42 is not disposed outside the detection electrode 11.

[0044] <Action and effect> As described above, in this embodiment, the circuit board 12 and the detection electrode 11 are provided on the arm of the robot 4, and the shielding member 35 shields the circuit board 12 and the detection electrode 11 from noise generated inside the housing 31. Therefore, even when the robot 4 is equipped with a capacitance-type sensor 6, it is possible to suppress the effects of noise on the circuit board 12 and the detection electrode 11. This makes it possible to suppress deterioration in the detection accuracy of the sensor 6. The shielding member 35 can also protect the detection electrode 11 and the circuit board 12 from dirt such as oil inside the housing 31.

[0045] Furthermore, since the detection electrode 11 and the circuit board 12 are covered by the external cover 32, it is possible to protect the detection electrode 11 and the circuit board 12 from the external environment.

[0046] With the above configuration, the sensor 6, which is a capacitance sensor, can be practically mounted on the robot 4.

[0047] Furthermore, in the robot system 2, when the motor 30 is provided inside the housing 31, the shielding member 35 shields the circuit board 12 and the detection electrode 11 from noise generated by the motor 30. Therefore, even if a large amount of noise is generated by the motor 30, the shielding member 35 suppresses the influence of the noise on the circuit board 12 and the detection electrode 11.

[0048] Furthermore, in the robot system 2, the circuit board 12 is provided in a space defined by the bottom 37 of the shielding member 35, the wall 38, and the detection electrode 11. This effectively reduces the influence of noise on the circuit board 12.

[0049] Furthermore, in the robot system 2, the wiring 41 connected to the circuit board 12 is arranged inside the housing 31 through the hole 44 in the shielding member 35. Since the wiring 41 connected to the circuit board 12 is arranged inside the arm without being exposed to the outside, the influence of the wiring 41 on the sensor 6 is suppressed. For example, the sensor 6 is prevented from erroneously detecting the wiring 41 as an object approaching the robot 4.

[0050] Furthermore, in the robot system 2, the connection portion 43 of the detection electrode 11 that protrudes toward the circuit board 12 is electrically connected to the circuit board 12 via the wiring 42. Therefore, the wiring 42 is not disposed outside the detection electrode 11, and the influence of the wiring 42 on the sensor 6 is suppressed.

[0051] === Variations === The present invention is not limited to the above-described embodiments. In other words, designs that are produced by those skilled in the art with appropriate design modifications to the above-described specific examples are also included within the scope of the present invention as long as they include the features of the present invention. Furthermore, the elements of the above-described embodiments and the following modifications can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

[0052] For example, in the above embodiment, the exterior cover is made of a resin material, but the exterior cover may be made of a metal material. In this case, it is preferable that the exterior cover is not connected to earth and is in an open state so that the sensor 6 can detect an object through the exterior cover.

[0053] In the above embodiment, the shielding member 35 is made of the same material as the housing 31, but this is not limited to the above. For example, the shielding member 35 may be a resin member having a metal coating (or metal tape) on its surface. In other words, the specific configuration of the shielding member 35 is not limited as long as it has a shielding function.

[0054] Furthermore, in the above embodiment, the case where the sensor 6 is provided on the fourth arm A4 of the robot 4 has been described as an example, but the number of sensors to be provided is not limited. For example, a sensor 6 may be provided on each of the first arm A1, the second arm A2, the third arm A3, and the fourth arm A4. Also, multiple sensors 6 may be provided on one arm. It is particularly preferable to provide the sensor 6 on the arm on the tool 9 side, which moves significantly as part of the operation of the robot 4. [Explanation of symbols]

[0055] 2: Robot system 4: Robot 6: Sensor (capacitive sensor) 11: Detection electrode 12: Circuit board 30: Motor 31: Housing 32: External cover 33: Opening 35: Shielding material 37: Bottom 38: Wall part 41: Wiring 43: Connection part 44: Hole A1: First arm (arm) A2: Second arm (arm) A3: Third arm (arm) A4: 4th arm (arm)

Claims

1. A robot system equipped with a capacitance sensor, a housing that configures the arm of the robot and has an opening; an outer cover that covers the opening of the housing; a detection electrode that is provided closer to the housing than the external cover and that constitutes the capacitance-type sensor; a circuit board that is provided closer to the housing than the detection electrodes and is connected to the detection electrodes to form the capacitance-type sensor; a shielding member that is provided closer to the housing than the circuit board, has the same potential as the housing, and shields the circuit board from the housing and shields the detection electrode from the housing; A robot system comprising:

2. A motor is provided inside the housing, 2. The robot system according to claim 1, wherein the shielding member shields the circuit board and the detection electrode from noise generated by the motor.

3. The shield member has a bottom portion and a wall portion that stands upright in a circumferential direction from the bottom portion, 3. The robot system according to claim 1, wherein the circuit board is provided in a space defined by the bottom of the shielding member, the wall of the shielding member, and the detection electrode.

4. The shield member is provided with a hole, 3. The robot system according to claim 1, wherein wiring electrically connected to the circuit board is arranged from the circuit board to the inside of the housing through the hole.

5. the detection electrode has a connection portion that protrudes toward the circuit board, 3. The robot system according to claim 1, wherein the circuit board is electrically connected to the detection electrodes via the connection portions.

Images