Transmission path used for robot

Abstract

To improve noise resistance of a transmission path used for a robot.SOLUTION: A transmission path (20) comprises: a signal line (21); an insulation layer (22) which is formed from a cylindrical insulation material, and is so provided as to cover an outer peripheral surface of the signal line; and a cylindrical power line (23) which is so provided as to cover an outer peripheral surface of the insulation layer and to be coaxially with the signal line and the insulation layer, and supplies electric power to a proximity sensor (10) mounted on a robot (1).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a transmission line used in a robot. [Background technology]

[0002] Conventionally, a transmission line configured with multiple signal lines has been known, and a capacitance-type proximity sensor that detects an object by detecting a change in capacitance that occurs between the object and the sensor has also been known.

[0003] In this regard, Patent Document 1 discloses a signal cable including a twisted wire formed by twisting a plurality of signal wires together, and a plurality of power line composite cables which are distributed on a circumference concentric with the twisted wire so as to surround the periphery of the twisted wire and are twisted around the twisted wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-85302 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, the change in voltage that occurs with the detection of an object in a capacitance-type proximity sensor is extremely small, and the sensor is easily affected by noise generated in power lines, etc. The technology described in Patent Document 1 has a problem in that when a signal cable is used with a capacitance-type proximity sensor, if a change in voltage occurs, it is difficult to determine whether the change is due to the detection of an object or noise generated in the power line.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a transmission line for use in a robot that can improve noise resistance. [Means for solving the problem]

[0007] In order to solve the above problem, a robot is provided with a signal line, an insulating layer formed of a cylindrical insulating material and arranged to cover the outer surface of the signal line, and a cylindrical power line that covers the outer surface of the insulating layer and is arranged coaxially with the signal line and the insulating layer, and supplies power to a proximity sensor mounted on the robot.

[0008] The proximity sensor is a capacitance sensor, and the signal line transmits a signal to and from the capacitance sensor.

[0009] The power lines are also provided inside the frame of the movable arm of the robot.

[0010] The insulating layer has an outer diameter that is larger than the outer diameter of the signal wire and is equal to or smaller than twice the outer diameter of the signal wire.

[0011] The power lines are also spacers for the circuit board. [Effects of the Invention]

[0012] According to the present invention, the noise resistance of the transmission line used in the robot can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the overall configuration of a robot equipped with a transmission line according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view taken along line ii-ii of the transmission line shown in FIG. 1. [Figure 3A] 1. FIG. 4 is a perspective view showing another example of the transmission line shown in FIG. 1 together with a capacitance sensor. [Figure 3B] FIG. 3B is a side view of the capacitance sensor shown in FIG. 3A. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components and steps in each drawing will be designated by the same reference numerals as much as possible, and redundant description will be omitted.

[0015] FIG. 1 is a diagram showing the overall configuration of a robot 1 equipped with a transmission line 20 according to this embodiment. The robot 1 is an industrial device having a movable part that can move within a space within a predetermined distance from the robot 1, such as a robot with an articulated arm, a machine tool, or a tester. In this embodiment, a case will be described in which the robot 1 is a robot with an articulated arm. As shown in FIG. 1, the robot 1 is mainly composed of a capacitance sensor 10, a transmission line 20, an arm unit 30, a wrist unit 40, a base unit 50, and a control device 60.

[0016] The capacitance sensor 10 is a proximity sensor that detects the presence or absence of an object in a space facing a detection surface. Specifically, the capacitance sensor 10 detects changes in capacitance in the space using detection electrodes arranged along the detection surface, and detects the presence or absence of an object in the space based on the detected changes in capacitance. The capacitance sensor 10 is communicatively connected to a control device 60 via a transmission path 20, receives power from a power line 23 of the transmission path 20 (described later), and transmits and receives signals to and from the control device 60 via a signal line 21 of the transmission path 20 (described later). The capacitance sensor 10 is provided on the surface of the arm near the tip of the arm 30 or on the tip of the arm 30.

[0017] The transmission path 20 is, for example, a signal cable such as a coaxial cable or a composite cable, and is provided inside the frame of the arm unit 30 of the robot 1, connecting the capacitance sensor 10 and the control device 60. The transmission path 20 transmits signals between the capacitance sensor 10 and the control device 60 via a signal line 21. The transmission path 20 also supplies power from the control device 60 to the capacitance sensor 10 via a power line 23. The structure of the transmission path 20 will be described in detail later, so its description will be omitted here.

[0018] The arm unit 30 is, for example, a multi-jointed movable arm, and its main part is made up of multiple arms and multiple drive units. One end of the arm unit 30 is connected to the base unit 50, and the other end is connected to the wrist unit 40. The arm unit 30 is also provided with a capacitance sensor 10 on the surface of the arm near the tip or on the tip. In this embodiment, the capacitance sensor 10 is provided on the surface of the arm near the tip of the arm unit 30 or on the tip, but this is not limited to this. The capacitance sensor 10 may be provided anywhere on the surface of the robot 1.

[0019] The wrist 40 is connected to the tip of the arm 30 and performs various operations on a workpiece (not shown). The various operations include, for example, irradiation with X-rays, gripping, transporting, rotating, attaching to another workpiece, injecting or applying a substance, polishing, screwing, heating, etc.

[0020] The base unit 50 is a base for supporting the arm unit 30, and is installed so as to be in contact with an installation surface (not shown) of the robot 1. The base unit 50 is connected to the arm unit 30. The base unit 50 is also connected to the control device 60 so as to be able to communicate with it.

[0021] The control device 60 is configured to be able to communicate with each component of the robot 1, and transmits control commands to each component to control its operation. The control device 60 also acquires various information from each component of the robot 1 and stores the acquired information. The control device 60 reflects the stored information in controlling the operation of the arm unit 30 and the wrist unit 40, and notifies the manager or user of the robot 1 by displaying on a screen or outputting audio. The control device 60 supplies power to the capacitance sensor 10, one of the components of the robot 1, via a transmission path 20, and transmits and receives signals via the transmission path 20.

[0022] The configuration of the robot 1 has been described above. Next, the transmission path 20 will be described with reference to FIG. 2. FIG. 2 is a cross-sectional view of the transmission path 20 taken along line ii-ii shown in FIG. 1. As shown in FIG. 2, the transmission path 20 is configured to include, for example, a signal line 21, an insulating layer 22, and a power line 23, in this order from the inside to the outside in the radial direction. In other words, the signal line 21, the insulating layer 22, and the power line 23 are arranged isotropically and concentrically.

[0023] The signal line 21 is a line for transmitting and receiving signals between the capacitance sensor 10 and the control device 60, and is made of a conductor such as copper or aluminum. The signal line 21 is provided at the center of the transmission path 20 along the axis A, and has an outer diameter of length D1.

[0024] The insulating layer 22 is a layer for providing electrical insulation between the signal line 21 and the power line 23, and is formed into a cylindrical shape from an insulating material. The insulating material is a synthetic resin such as foamed polyethylene or polytetrafluoroethylene. The insulating layer 22 is provided so as to cover the outer surface of the signal line 21, and has an outer diameter D2 that is larger than the outer diameter D1 of the signal line 21 (D2>D1).

[0025] The power line 23 is a line for supplying power to the capacitance sensor 10, and is formed into a cylindrical shape from a conductor such as copper or aluminum. The power line 23 is provided so as to cover the outer peripheral surface of the insulating layer 22 and to be coaxial with the signal line 21 and the insulating layer 22. The power line 23 has an outer diameter D3 that is larger than the outer diameter D2 of the insulating layer 22 (D3>D2). Note that, because the power line 23 is provided coaxially with the signal line 21, the shortest distance from the inner peripheral surface of the power line 23 to the outer peripheral surface of the signal line 21 is substantially the same at any point.

[0026] In this example, the transmission line 20 is formed to have flexibility to the extent that it can be bent, but this is not limiting and the transmission line 20 may have flexibility to the extent that it is difficult to bend by hand. Furthermore, the transmission line 20 may further be provided with an outer coating made of an insulating material such as polyethylene, polyvinyl chloride, or polytetrafluoroethylene, which covers the outer circumferential surface of the power line 23 and provides insulation between the transmission line 20 and the outside of the transmission line 20.

[0027] <Action and effect> As described above, in this embodiment, the transmission line 20 has the cylindrical power line 23 arranged coaxially with the signal line 21 and the insulating layer 22. As a result, in the transmission line 20, noise imparted to the signal line 21 by a predetermined position on the inner circumference of the power line 23 is subtracted and reduced by noise imparted to the signal line 21 by a position symmetrical to the predetermined position, with the signal line 21 as the base point. Specifically, as shown in FIG. 2 , the magnetic field B1 imparted to the signal line 21 by position P1 is equal in magnitude to but opposite in direction to the magnetic field B2 imparted to the signal line 21 by position P2, which is symmetrical to position P1, with the signal line 21 as the base point. Therefore, the noise imparted to the signal flowing through the signal line 21 by the current flowing through the power line 23 is reduced, thereby improving the noise resistance of the transmission line 20.

[0028] In this embodiment, the power line 23 supplies power to the capacitance sensor 10. The signal line 21 transmits signals to and from the capacitance sensor 10. Therefore, the transmission path 20 can improve noise resistance even when transmitting signals to the capacitance sensor 10, which is susceptible to noise caused by the power supplied by the power line.

[0029] In addition, in this embodiment, the power line 23 is provided inside the frame of the movable arm of the robot 1. Therefore, since the transmission path 20 is provided inside the robot 1, it is possible to save the space occupied by the transmission path 20 in the robot 1 and improve the noise resistance. Also, in the case of a conventional transmission path, when the transmission path is bent, the relative positional relationship between the signal line and the power line changes. In contrast, in the transmission path 20 of this embodiment, even when the transmission path 20 is bent due to the movement of the movable arm, the signal line 21 and the power line 23 are arranged isotropically and concentrically, so the relative positional relationship between the signal line 21 and the power line 23 is unlikely to change. Therefore, the transmission path 20 can maintain the effect of improving the noise resistance.

[0030] <Modification Example> Note that the present invention is not limited to the above embodiment. That is, modifications appropriately made by those skilled in the art to the above embodiment are also included in the scope of the present invention as long as they have the features of the present invention. Also, each element included in the above embodiment and the modification examples described later can be combined as far as technically possible, and combinations thereof are also included in the scope of the present invention as long as they include the features of the present invention.

[0031] For example, in this embodiment, as shown in FIG. 2, the transmission path 20 has an outer diameter D2 of the insulating layer 22 that is greater than twice the outer diameter D1 of the signal line 21, but it is not limited to this. The transmission path 20 may have an outer diameter D2 of the insulating layer 22 that is longer than the outer diameter D1 of the signal line 21 and not more than twice D1. (D1 < D2 ≤ 2 × D1) According to this configuration, since the outer diameter of the insulating layer 22 of the transmission path 20 is small, it is possible to suppress a decrease in noise resistance when the distance between the signal line 21 and the power line 23 changes due to deformation of the insulating layer 22 caused by an external force or the like.

[0032] Furthermore, in this embodiment, the power line 23 of the transmission line 20 is formed in a cylindrical shape, but this is not limited to this. The transmission line 20 may have any shape as long as the power line 23 is symmetrical with respect to the signal line 21 when viewed along line ii-ii. For example, the power line 23 may be formed so that its cross section is a regular even polygon such as a regular hexagon or a square when viewed along line ii-ii. With this configuration, the noise resistance of the transmission line 20 can be improved even when the power line 23 is formed in various shapes.

[0033] In this embodiment, the transmission path 20 is a signal cable such as a coaxial cable or a composite cable, but is not limited to this. The transmission path 20 may be configured to include, for example, a spacer for a circuit board and a signal line passing through the inner circumference of the spacer. Here, other examples of the transmission path 20 will be described with reference to FIGS. 3A and 3B. FIG. 3A is a diagram showing another example of the transmission path 20 shown in FIG. 1 together with the capacitance sensor 10. FIG. 3B is an enlarged view for explaining the structure of the transmission path 201 shown in FIG. 3A.

[0034] 3A, the capacitance sensor 10 includes, for example, a substrate 11, a signal wiring 12, a power wiring 13, a circuit 14, and a detection electrode 15. The capacitance sensor 10 is supplied with power from a transmission path 201 and operates in accordance with a signal transmitted from the transmission path 201.

[0035] The substrate 11 is, for example, a printed circuit board, and has signal wiring 12, power wiring 13, circuits 14, and detection electrodes 15 provided on its upper surface. Furthermore, substrate spacers 121 are connected to the four corners of the substrate 11 by screws 16.

[0036] The signal wiring 12 is a wiring provided on the substrate 11, and connects the signal line 120 of the transmission path 201 to the circuit 14 to transmit signals. The power wiring 13 is a wiring provided on the substrate 11, and connects the spacer 121 of the transmission path 201 to the circuit 14 to supply power supplied from the spacer 121 to the circuit 14.

[0037] The circuit 14 is an electric circuit for controlling the operation of the capacitance sensor 10. The circuit 14 is supplied with power from the power wiring 13, and transmits a signal for controlling the object detection operation by the detection electrode 15 in accordance with a signal transmitted from the signal wiring 12. The circuit 14 also receives a signal indicating whether or not an object has been detected from the detection electrode 15, performs electrical processing such as noise removal on the received signal, and then transmits the processed signal to the control device 60 via the signal wiring 12.

[0038] The detection electrode 15 is an electrode that detects the presence or absence of a conductor in space facing the detection surface. The detection electrode 15 performs detection operations in accordance with signals sent from the circuit 14, and transmits signals indicating the detection results to the circuit 14. The detection electrode 15 is formed on the substrate 11 in a linear or planar shape using a conductor.

[0039] The transmission path 201 includes, for example, a spacer 121, a signal line 120, and a screw 16. Specifically, as shown in FIG. 3B , the transmission path 201 includes the signal line 120 extending in the direction of axis B, a cylindrical spacer 121 provided coaxially with the signal line 120, and a screw 16 for connecting the spacer 121 to the substrate 11. In the transmission path 201, the space between the inner periphery of the spacer 121 and the outer periphery of the signal line 120 functions as an insulating layer, but this space may also be filled with an insulating material.

[0040] The spacer 121 is a member for providing a space between the substrate 11 and other components, and is provided on the substrate 11 so as to extend in a direction perpendicular to the surface of the substrate 11 and pass through a hole provided in the substrate 11. The spacer 121 is formed into a cylindrical shape from a conductor such as copper or aluminum, and functions as a power line. Power is supplied to the spacer 121 from the control device 60 via a power cable or the like. The spacer 121 also supplies power to the circuit 14 via the power wiring 13.

[0041] The signal line 120 is arranged to pass through the center of the interior of the spacer 121. The signal line 120 transmits signals between the control device 60 and the signal wiring 12. The outer periphery of the signal line 120 is covered with a coating made of an insulating material at a position where it passes through the hole in the substrate 11 for passing the spacer 121 through. Note that almost the entire outer periphery of the signal line 120 may be covered with a coating made of an insulating material.

[0042] According to this configuration, the transmission line 201 uses the spacer 121 for the substrate 11 as a power line. Therefore, the transmission line 201 can improve noise resistance while saving space compared to a case where a transmission line is provided separately from the spacer 121. [Explanation of symbols]

[0043] 1...robot, 10...capacitive sensor (proximity sensor), 11...substrate, 121...spacer (power line), 20...transmission path, 21...signal line, 22...insulating layer, 23...power line, 120...signal line, 201...transmission path

Claims

1. A signal line and an insulating layer formed of a cylindrical insulating material and covering an outer peripheral surface of the signal line; a cylindrical power line that covers an outer peripheral surface of the insulating layer, is arranged coaxially with the signal line and the insulating layer, and supplies power to a proximity sensor mounted on the robot; A transmission line for use in a robot, comprising:

2. the proximity sensor is a capacitance sensor, 2. The transmission path for use in a robot according to claim 1, wherein the signal line transmits signals to and from the capacitance sensor.

3. 3. The transmission line for use in a robot according to claim 1, wherein the power line is provided inside a frame of a movable arm of the robot.

4. 3. The transmission line for use in a robot according to claim 1, wherein the insulating layer has an outer diameter that is larger than the outer diameter of the signal line but not larger than twice the outer diameter of the signal line.

5. 3. The transmission line for use in a robot according to claim 1, wherein the power line is a spacer for a circuit board.

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