JP2013111665A - Horizontal articulated robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a horizontal articulated robot capable of effectively suppressing the vibration of an arm.SOLUTION: The horizontal articulated robot includes a first arm connected to a base, a second arm connected to the base via the first arm, a first driving source built in the base for turning the first arm in the horizontal direction, a second driving source built in the second arm for turning the second arm in the horizontal direction, and an angular velocity sensor installed in the second arm. An installation position B satisfies L2>0.5L1 and L3<0.2L1 where L1 is a length from a turn axis A of the second arm to be turned by the second driving source to the front end of the second arm, L2 is a distance from the turn axis A to the installation position B of the angular velocity sensor, and L3 is a distance from a gravity center J of the second arm to the installation position B of the angular velocity sensor. Based on an angular velocity obtained from the angular velocity sensor, the first driving source and/or the second driving source is driven to suppress the vibration of the second arm.

Description

  The present invention relates to a horizontal articulated robot.

  Conventionally, for example, as described in Patent Document 1, a horizontal articulated robot that suppresses vibration generated in an arm by detecting the angular velocity of the arm with an angular velocity sensor is known. In this horizontal articulated robot, when the first arm that can rotate with respect to the base is rotated by receiving the driving force of the first drive source, the angular velocity sensor mounted on the first arm causes the first arm to move. Angular velocity is detected. Based on the detected angular velocity, the drive amount of the first drive source is controlled so that the vibration generated in the first arm is suppressed.

JP 2005-242794 A

  However, in the horizontal articulated robot described in Patent Document 1, since the position and method of attaching the angular velocity sensor to the arm are not specified at all, in the horizontal articulated robot, the need for higher speed and higher accuracy is increasing. There was a problem that sufficient arm vibration could not be suppressed.

  The present invention has been made to solve the above-described problems, and can be implemented as the following application examples or forms.

  Application Example 1 A horizontal articulated robot according to this application example is built in a base, a first arm connected to the base, a second arm connected to the base via at least the first arm, and the base. A first drive source that rotates the first arm in the horizontal direction, a second drive source that is built in the second arm and rotates the second arm in the horizontal direction, and an angular velocity sensor installed in the second arm. The length from the rotation axis A where the second arm is rotated by the second drive source to the tip of the second arm is L1, and the distance from the rotation axis A to the installation position B of the angular velocity sensor is When L2 is set and the distance from the center of gravity J of the second arm to the installation position B is L3, the installation position B satisfies L2> 0.5L1 and L3 <0.2L1, and the angular velocity obtained from the angular velocity sensor is 1st drive source and / or 2nd drive source are driven based on , Characterized by damping the second arm.

According to this application example, by setting the installation position B of the angular velocity sensor attached to the second arm to L2> 0.5L1, it is possible to detect the horizontal vibration of the second arm with higher sensitivity. In addition, by setting the position B of the angular velocity sensor attached to the second arm to L3 <0.2L1, which is closer to the position of the center of gravity to be controlled, the vibration in the horizontal direction of the second arm can be detected and controlled more accurately. Is possible.
Accordingly, the first drive source and / or the second drive source is driven based on the angular velocity detected with higher sensitivity and more accurately, and the second arm is damped, thereby further increasing the speed and accuracy. In a horizontal articulated robot whose needs are increasing, it is possible to provide a horizontal articulated robot in which arm vibration is more effectively suppressed.

  Application Example 2 In the horizontal articulated robot according to the application example, the angular velocity sensor is installed on a surface opposite to the surface on which the second drive source of the bottom base member constituting the second arm is attached. It is characterized by.

  According to this application example, since the angular velocity sensor is installed on the surface of the bottom base material that constitutes the second arm on the surface opposite to the surface on which the second driving source is attached, the angular velocity sensor is separated from the second driving source. The influence of the dust received can be reduced.

  Application Example 3 In the horizontal articulated robot according to the application example, the angular velocity sensor is installed in a concave portion formed in a bottom base material constituting the second arm.

  According to this application example, since the angular velocity sensor is installed in the recess formed in the bottom base material that constitutes the second arm, the angular velocity sensor is installed without protruding from the bottom base material that constitutes the second arm. can do. As a result, the second arm can be turned more smoothly.

  Application Example 4 In the horizontal articulated robot according to the application example described above, the angular velocity sensor is installed in a through hole formed in a bottom base material constituting the second arm.

  According to this application example, since the angular velocity sensor is installed inside the through hole formed in the bottom base material constituting the second arm, the angular velocity sensor protrudes from the bottom base material constituting the second arm. It can be installed without As a result, the second arm can be turned more smoothly. Further, since the wiring to the angular velocity sensor can be laid through the through hole, the second arm can be configured more simply.

The perspective view which shows the example of the horizontal articulated robot which concerns on embodiment. (A) Side view of a 2nd arm, (b) Sectional drawing of the direction orthogonal to the extension direction of the 2nd arm of an angular velocity sensor installation position. (A), (b), (c) 2nd arm side sectional drawing which shows an angular velocity sensor installation position.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(Embodiment)
First, the horizontal articulated robot according to the embodiment will be described.
FIG. 1 is a perspective view illustrating an example of a horizontal articulated robot 100 according to the embodiment.
The horizontal articulated robot 100 includes a base 1, a first arm 10, a first motor unit 11, a second arm 20, a second motor unit 21, an end effector 30, an end effector drive unit 31, a gyro sensor module 50, and a controller 60. The electric wiring 61 is included.

The base 1 incorporates a first motor unit 11 as a first drive source for rotating the first arm 10 and is installed horizontally on a floor or the like. In addition, level means a level equivalent to a surface such as a floor in a normal living environment.
One end of the first arm 10 is connected at the upper end of the base 1 by the drive shaft of the first motor unit 11, and rotates in the horizontal direction around the axis along the vertical direction.

  The second arm 20 incorporates a second motor unit 21 and an end effector drive unit 31 as a second drive source. Also, one end of the second arm 20 is connected to the other end of the first arm 10 by a drive shaft 21j of the second motor unit 21, and rotates in the horizontal direction around the axis along the vertical direction. Move.

Each of the first motor unit 11 and the second motor unit 21 includes a rotary encoder that detects information on a rotation angle.
The 1st arm 10 and the 2nd arm 20 are formed with metal materials, such as cast iron, and have high rigidity in the length direction, the turning direction, etc.
In the present embodiment, the second arm 20 is directly connected to the first arm 10. However, the present invention is not limited to this, and a plurality of arms are provided between the second arm 20 and the first arm 10. It may be in the form of being connected via.

The end effector 30 includes a slide shaft 32 that moves up and down in the vertical direction via a belt (not shown) by an end effector drive unit 31, a tool (not shown) provided at the lower end, and the like. Installed at the end.
The second arm 20 has an arm cover 22 that covers the upper part of the second arm 20 including the second motor unit 21 and the end effector drive unit 31 from one end to the other end. The arm cover 22 is formed of, for example, a resin material, and protects the inside of the second arm 20 while suppressing dust generated from an inner belt and the like from being scattered around.

The gyro sensor module 50 includes an angular velocity sensor 51, an ADC (Analog to Digital Converter) circuit, and the like, and is installed in the second arm 20.
As the angular velocity sensor 51, a vibration type gyroscope using a crystal resonator is used as a preferred example.
The gyro sensor module 50 is attached so that the angular velocity sensor 51 can detect the angular velocity in the movement in the same direction as the rotation direction of the second arm 20. Information on the detected angular velocity is transmitted to the controller 60 via the electrical wiring 61.

  The controller 60 controls the entire horizontal articulated robot 100 according to a predetermined program. Further, the controller 60 controls the first motor unit 11 and / or the second motor unit 21 so that horizontal vibration due to the driving of the second arm 20 is suppressed based on a signal input from the gyro sensor module 50. Control the drive. Specifically, the controller 60 acquires the rotation angle of the first motor unit 11 and the rotation angle of the second motor unit 21 from the respective rotary encoders. Further, the angular velocity information of the second arm 20 is acquired from the gyro sensor module 50. The controller 60 estimates the angular velocity of the first arm 10 based on these pieces of information, and controls the driving of the first motor unit 11 and / or the second motor unit 21 so that the vibration of the second arm 20 is suppressed. .

  The electrical wiring 61 includes a signal line connected from the gyro sensor module 50 to the controller 60, a piping member that collects power lines for driving the second motor unit 21 and the end effector drive unit 31, and the like. Connected to stand 1.

Next, the position where the angular velocity sensor 51 (gyro sensor module 50) is attached will be described.
In order to more effectively suppress the vibration of the second arm 20 based on the angular velocity detected by the angular velocity sensor 51, the angular velocity sensor 51 needs to detect the vibration of the second arm 20 with high sensitivity and accuracy. . Moreover, it is desirable that the vibration to be detected is a vibration at a target position to be controlled. In general, the behavior of an object can be treated as the behavior of a mass point at the center of gravity. Therefore, a more effective damping parameter can be derived by detecting the vibration of the part closer to the center of gravity.

2A is a side view of the second arm 20, and FIG. 2B is a cross-sectional view in a direction orthogonal to the extending direction of the second arm 20 at the angular velocity sensor installation position.
The second arm 20 includes a bottom base material 20a, a side base material 20b, and the like, and has high rigidity in the length direction and the turning direction.
2A and 2B, J indicates the position of the center of gravity of the second arm 20 (hereinafter referred to as the center of gravity J). 2A and 2B, the length from the rotation axis A of the drive shaft 21j of the second motor unit 21 to the tip of the second arm 20 is L1, and the angular velocity sensor from the rotation axis A is shown. The distance from the center 51 of the second arm 20 to the installation position B of the angular velocity sensor 51 is L3.

In this case, the installation position B of the angular velocity sensor 51 mounted on the horizontal articulated robot 100 is a position that satisfies L2> 0.5L1 and L3 <0.2L1.
Specifically, the installation position of the gyro sensor module 50 on which the angular velocity sensor 51 is mounted is set to a position where the above relationship is satisfied, and the gyro sensor module 50 is firmly fixed to the bottom substrate 20a or the like.

As described above, according to the horizontal articulated robot 100 according to the present embodiment, the following effects can be obtained.
By setting the installation position B of the angular velocity sensor 51 attached to the second arm 20 to L2> 0.5L1, the installation position of the angular velocity sensor 51 is further away from the rotation axis A. Therefore, the second arm is more sensitive. 20 horizontal vibrations can be detected. Further, by setting the installation position B of the angular velocity sensor 51 attached to the second arm 20 to L3 <0.2L1, which is closer to the position of the center of gravity J to be controlled, the horizontal vibration of the second arm 20 can be detected more accurately. It is possible to control the vibration.
Accordingly, the first motor unit 11 and / or the second motor unit 21 is driven based on the angular velocity detected with higher sensitivity and more accurately, and the second arm 20 is damped, thereby increasing the speed and the speed. In a horizontal articulated robot whose needs for accuracy are increasing, it is possible to provide a horizontal articulated robot in which arm vibration is more effectively suppressed.

  As shown in FIG. 2B, the gyro sensor module 50 may be fixed to the bottom base member 20a or the like via a spacer 53 or the like, but it is fixed as shown in the following examples. Is preferred.

FIGS. 3A, 3 </ b> B, and 3 </ b> C are side cross-sectional views of the second arm showing an example of an installation position of the gyro sensor module 50 on which the angular velocity sensor 51 is mounted. 3A, 3B, and 3C, many of the built-in members are omitted.
Example 1
Example 1 is shown in FIG.
In the present embodiment, the gyro sensor module 50 is directly fixed to the back surface (lower surface) of the bottom base material 20a within a range that satisfies the positional relationship described above. In this embodiment, the gyro sensor module 50 is formed with a recess 20d in the bottom base 20a so that the gyro sensor module 50 does not protrude downward from the bottom base 20a and prevent the second arm 20 from rotating. 50 is embedded. In addition, it is necessary to consider suitably about electric wirings, such as a signal wire | line to the gyro sensor module 50, and electrical insulation with the bottom part base material 20a.

  According to the present embodiment, since the gyro sensor module 50 on which the angular velocity sensor 51 is mounted is installed on the back surface of the bottom base material 20a constituting the second arm 20, the angular velocity sensor 51 is built in the second arm 20. 2 The influence of dust received from the motor unit 21, the end effector drive unit 31, the belt, etc. can be reduced.

  Further, since the gyro sensor module 50 is installed in the recess 20d formed in the bottom base material 20a constituting the second arm 20, the gyro sensor module 50 projects from the bottom base material 20a constituting the second arm 20. It can be installed without doing. As a result, the second arm 20 can be turned more smoothly.

(Example 2)
Example 2 is shown in FIG.
In the present embodiment, the gyro sensor module 50 is directly installed in the through hole 20h formed in the bottom base material 20a within a range satisfying the positional relationship described above. In this embodiment, the gyro sensor module 50 is fixed to the bottom base material 20a via the frame 24 so as to be fixed inside the through hole 20h.

  According to the present embodiment, since the gyro sensor module 50 is installed inside the through hole 20h formed in the bottom base material 20a constituting the second arm 20, the gyro sensor module 50 has the second arm 20 mounted thereon. It can install, without protruding from the bottom base material 20a to comprise. As a result, the second arm 20 can be turned more smoothly. Further, since the wiring to the gyro sensor module 50 can be laid through the through hole 20h, the second arm 20 can be configured more simply.

(Example 3)
Example 3 is shown in FIG.
In this embodiment, the gyro sensor module 50 is directly fixed to the surface (upper surface) of the bottom base material 20a within a range that satisfies the positional relationship described above. In this embodiment, the gyro sensor module 50 does not hinder the rotation of the second arm 20 by projecting downward from the bottom base material 20a. Further, the wiring to the angular velocity sensor 51 can be laid more easily.

  DESCRIPTION OF SYMBOLS 1 ... Base, 10 ... 1st arm, 11 ... 1st motor unit, 20 ... 2nd arm, 20a ... Bottom base material, 20b ... Side part base material, 20d ... Recessed part, 20h ... Through-hole, 21 ... 2nd Motor unit, 21j ... drive shaft, 22 ... arm cover, 24 ... frame, 30 ... end effector, 31 ... end effector drive unit, 32 ... slide shaft, 50 ... gyro sensor module, 51 ... angular velocity sensor, 53 ... spacer, 60 ... Controller, 61 ... Electrical wiring, 100 ... Horizontal articulated robot.

Claims (4)

A first arm connected to the base;
A second arm coupled to the base via at least the first arm;
A first drive source built in the base and rotating the first arm in a horizontal direction;
A second drive source built in the second arm and rotating the second arm in a horizontal direction;
An angular velocity sensor installed on the second arm,
The length from the rotation axis A where the second arm is rotated by the second drive source to the tip of the second arm is L1, and the distance from the rotation axis A to the installation position B of the angular velocity sensor. Is L2, and when the distance from the center of gravity J of the second arm to the installation position B is L3,
The installation position B satisfies L2> 0.5L1 and L3 <0.2L1,
A horizontal articulated robot characterized in that the first drive source and / or the second drive source is driven based on an angular velocity obtained from the angular velocity sensor to control the vibration of the second arm.   2. The horizontal articulated joint according to claim 1, wherein the angular velocity sensor is installed on a surface opposite to a surface to which the second drive source is attached of a bottom base material constituting the second arm. robot.   The horizontal articulated robot according to claim 1, wherein the angular velocity sensor is installed in a recess formed in a bottom base material constituting the second arm.   2. The horizontal articulated robot according to claim 1, wherein the angular velocity sensor is installed in a through hole formed in a bottom base material constituting the second arm.

Images