JP2014006080A - Tool position detection device and tool position detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool position detection device capable of detecting a tool position with a simple structure.SOLUTION: A tool position detection device 100 for detecting the position of a fastening tool 40 suspended from a wire 30 includes a pulley 22 having the wire 30 set thereon, a support shaft 21 for vertically supporting the pulley 22 and rotated around an axis perpendicular to the rotary shaft of the pulley 22, a detection cover 23 disposed on a side where the wire 30 of the pulley 22 is delivered, rotated around the same axis as that of the pulley 22, and following in a direction where the wire 30 is delivered from the pulley 22, and a controller 50 for calculating the position of the fastening tool 40. The controller 50 converts the position of the fastening tool 40 from a spherical coordinate system into an orthogonal coordinate system to calculate it by using the rotational angle θ of the support shaft 21, the rotational angle ω of the pulley 22, and the rotational angle φ of the detection cover 23.

Description

  The present invention relates to a technique of a tool position detection device and a tool position detection method.

  In an automobile assembly process, there is a process of manually tightening a bolt or the like with a tightening tool, for example, assembling a part to a vehicle body. In such a manual tightening process, the number of tightening may be large and there may be a tightening order. In such a case, by monitoring (detecting) the tightening position by the operator, an error in the tightening position or an error in the tightening order by the operator is prevented.

  For example, Patent Literature 1 discloses a tightening position detection device that detects the tightening position of an operator by detecting the position of a tightening tool for fastening a component to a workpiece. However, in the tightening position detection device disclosed in Patent Document 1, a tightening tool and a moving carriage that moves in association with the workpiece conveyed in a certain direction are connected by a tape member, and the twist of the tape member Since the position of the tightening tool is calculated by detecting the bending and the bending with an optical fiber, the apparatus itself is expensive and complicated.

  As another means for detecting the tool position, a transmitter is attached to the tool, a plurality of receivers are installed at the work place, signals from the transmitters are received by the plurality of receivers, and the transmitter is determined from the time difference between transmission and reception. What calculates the position of (tool) is known. However, in such a detection means, the detection accuracy decreases due to the influence of factory noise and the like.

  Further, as a means for detecting the tool position, a tool that supports a tool with a multi-joint arm, measures a joint angle with an angle sensor attached to each joint of the arm, and calculates a tip position of the multi-joint arm is known. ing. However, in such a detection means, it is necessary to provide a large number of devices around the work to be performed, and workability is reduced in actual work. In addition, the device itself is expensive and complicated.

JP 2010-85390 A

  The problem to be solved by the present invention is to provide a tool position detecting device and a tool position detecting method capable of detecting a three-dimensional position of a tool with a simple configuration.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  In other words, according to a first aspect of the present invention, there is provided a tool position detecting device for detecting a position of a tool suspended on a wire, the pulley on which the wire is stretched, the pulley supported in a vertical direction, and the rotation of the pulley. A support shaft that rotates about an axis perpendicular to the moving shaft, and a detection shaft that is provided on a side where the wire of the pulley is sent out, rotates around the same axis as the pulley, and follows the direction in which the wire is sent out from the pulley. A cover, and a control unit that calculates the position of the tool, wherein the control unit includes a rotation angle of the support shaft, a rotation angle of the pulley, and a rotation angle of the detection cover. The tool position is calculated by converting the position of the tool from a spherical coordinate system to an orthogonal coordinate system.

  The tool position detection method according to claim 2, wherein the position of a tool suspended on a wire stretched on a rotatable pulley is detected, and the pulley is around an axis perpendicular to the rotation axis of the pulley. A detection cover that is supported in the vertical direction by a support shaft that rotates in the direction of the pulley and that rotates around the same axis as the pulley and that follows the direction in which the wire is fed out of the pulley is provided on the side where the wire of the pulley is fed out. And calculating the position of the tool from a spherical coordinate system to an orthogonal coordinate system using the rotation angle of the support shaft, the rotation angle of the pulley, and the rotation angle of the detection cover. is there.

  According to the tool position detection apparatus and the tool position detection method of the present invention, the three-dimensional position of a tool can be detected with a simple configuration.

The block diagram which showed the whole structure of the tool position detection apparatus. The side view and front view which similarly showed the structure of the pulley part. The flowchart which shows the flow of a tool position detection control.

The tool position detection apparatus 100 is demonstrated using FIG.1 and FIG.2.
In FIG. 1, the overall configuration of the tool position detection device 100 is shown. Moreover, the broken line of FIG. 1 represents the electric signal line. Further, FIG. 2A represents the side surface of the pulley unit 20, and FIG. 2B represents the front surface of the pulley unit 20. In the following, description will be given according to the XYZ axes described in FIGS. 1 and 2.

  The tool position detection device 100 is a device that detects the tightening position by detecting the position of the tightening tool 40 when the worker P performs the tightening operation. The operator P is assumed to tighten the bolt B to a plurality of determined positions of the workpiece W and in a determined order by the tightening tool 40.

The configuration of the tool position detection device 100 will be described.
The tool position detection device 100 mainly includes a spring balancer 10, a pulley unit 20, a wire 30, a tightening tool 40, and a controller 50 as a control unit.

  In the spring balancer 10, the wire 30 is pulled out freely, or the wire 30 is wound up freely. The spring balancer 10 is provided on the gantry 11. The gantry 11 is installed above the work space.

  The pulley unit 20 includes a support shaft 21, a pulley 22, and a detection cover 23.

  The support shaft 21 is provided on the gantry 11 and supports the pulley 22. The support shaft 21 is configured to rotate around the Z axis. An angle sensor 51 is provided on the support shaft 21. The angle sensor 51 is connected to the controller 50 and detects the rotation angle θ around the Z axis of the support shaft 21.

  Here, the rotation angle θ represents the angle of the fastening tool 40 with respect to the X axis when the support shaft 21 is the origin.

  The pulley 22 stretches the wire 30 and sends out the wire 30 drawn out from the spring balancer 10 or feeds the wire 30 wound up around the spring balancer 10. The pulley 22 is supported by the support shaft 21 and is configured to be rotatable around the Y axis.

  The pulley 22 is provided with an angle sensor 52. The angle sensor 52 is connected to the controller 50 and detects the rotation angle ω around the Y axis of the pulley 22.

  Here, the rotation angle ω represents the length of the drawn wire 30, that is, the position to the tightening tool 40 when the support shaft 21 is the origin.

  The detection cover 23 is configured to rotate around the same axis (Y axis) as the pulley 22, and follows the wire 30 delivered from the pulley 22. The detection cover 23 is provided on the delivery side of the wire 30 of the pulley 22.

  The detection cover 23 is provided with an angle sensor 53 (see FIG. 2B). The angle sensor 53 is connected to the controller 50 and detects the rotation angle φ around the Y axis of the detection cover 23.

  That is, the rotation angle φ represents the angle of the fastening tool 40 with respect to the Z axis when the support shaft 21 is the origin.

  The wire 30 is stretched around the pulley 22, suspends the fastening tool 40, and is pulled out or wound up by the spring balancer 10.

  The tightening tool 40 is suspended by the wire 30 in the work space. The tightening tool 40 is connected to the controller 50.

  The controller 50 is connected to the angle sensor 51, the angle sensor 52, the angle sensor 53, and the tightening tool 40. The controller 50 has a function of detecting the position of the tightening tool 40 by a tool position detection control S100 described later and transmitting an NG signal to the tightening tool 40 when the tightening position (the position of the tightening tool 40) is incorrect. doing.

The tool position detection control S100 will be described with reference to FIG.
In addition, in FIG. 3, the flow of tool position detection control S100 is represented by the flowchart.

  The tool position detection control S100 is a control for detecting the tightening position by detecting the position of the tightening tool 40 by the tool position detecting device 100 when the worker P performs the tightening operation.

  In step S <b> 110, the controller 50 detects the rotation angle θ around the Z axis of the support shaft 21 with the angle sensor 51, detects the rotation angle ω around the Y axis of the pulley 22 with the angle sensor 52, and the angle sensor 53. Thus, the rotation angle φ around the Y axis of the detection cover 23 is detected.

  In step S <b> 120, the controller 50 calculates the feed amount r of the wire 30 based on the rotation angle ω around the Y axis of the pulley 22 and the diameter R of the pulley 22. The diameter R of the pulley 22 is set in the controller 50 in advance.

Based on the rotation angle θ around the Z axis of the support shaft 21, the rotation angle φ around the Y axis of the detection cover 23, and the feed amount r of the wire 30, the controller 50 has orthogonal coordinates of the tightening tool 40. A tool position (x, y, z) as a position in the system is calculated. Specifically, as shown in Equation 1, the spherical coordinate system represented by the rotation angle θ, the rotation angle φ, and the feed amount r is converted into an orthogonal coordinate system.

  In step S120, the controller 50 determines whether the calculated tool position (x, y, z) is a correct tool position and a tool position in a correct tightening order. If it is the correct tool position and the tool position is in the correct tightening order, the process proceeds to step S140. If it is not the correct tool position or the tool position is not in the correct tightening order, the process proceeds to step S150.

  It is assumed that the correct tool position and the correct tightening order are stored in the controller 50 in advance. That is, the tool position (x, y, z) corresponding to each position of the workpiece W to which each bolt B is tightened is stored in the controller 50 in the tightening order of each bolt B.

  When the controller 50 determines that the position of the tightening tool 40 is the correct tool position and the tool position in the correct tightening order, the controller 50 transmits an OK signal to the tightening tool 40 in step S140. . The tightening tool 40 that has received the OK signal informs the operator P that it is the correct tightening position by voice or lighting of the lamp. In addition, when it is a correct fastening position, there is no need for voice or lighting of the lamp.

  When the controller 50 determines that the position of the tightening tool 40 is not the correct tool position or is not the tool position in the correct tightening sequence, the controller 50 transmits an NG signal to the tightening tool 40 in step S150. To do. The tightening tool 40 that has received the NG signal informs the operator P that the tightening position is wrong by voice or lighting of the lamp.

The effects of the tool position detection device 100 and the tool position detection control S100 will be described.
According to the tool position detection device 100 and the tool position detection control S100, the tool positions (x, x, x) can be obtained with a simple configuration by attaching the angle sensors 51 to 53 to members such as the spring balancer 10 and the pulley 22 that have been conventionally used. y, z) can be detected.

DESCRIPTION OF SYMBOLS 10 Spring balancer 20 Pulley part 21 Support shaft 22 Pulley 23 Detection cover 30 Wire 40 Tightening tool 50 Controller 100 Tool position detection apparatus

Claims (2)

A tool position detecting device for detecting the position of a tool suspended on a wire,
A pulley on which the wire is stretched;
A support shaft that supports the pulley in a vertical direction and rotates around an axis perpendicular to the rotation axis of the pulley;
A detection cover that is provided on a side where the wire of the pulley is fed out, rotates around the same axis as the pulley, and follows a direction in which the wire is fed out of the pulley;
A control unit for calculating the position of the tool;
Comprising
The control unit calculates the position of the tool from a spherical coordinate system to an orthogonal coordinate system using the rotation angle of the support shaft, the rotation angle of the pulley, and the rotation angle of the detection cover. To
Tool position detection device. A tool position detection method for detecting the position of a tool suspended on a wire stretched on a rotatable pulley,
The pulley is supported in a vertical direction on a support shaft that rotates about an axis perpendicular to the rotation axis of the pulley,
On the side where the wire of the pulley is fed out, a detection cover that rotates around the same axis as the pulley and follows the direction in which the wire is fed out of the pulley is provided,
Using the rotation angle of the support shaft, the rotation angle of the pulley, and the rotation angle of the detection cover to calculate the position of the tool from a spherical coordinate system to an orthogonal coordinate system;
Tool position detection method.

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