JP2020169918A - Rotary encoder, robotic system, control method of robotic system, control program, recording medium, and manufacturing method article - Google Patents

Abstract

To provide a rotary encoder disposed to a joint of a robotic system capable of properly removing and collecting dust that interferes with position detection.SOLUTION: The rotary encoder has a scale 234 that includes an optical pattern, which is fixed to the axis of rotation to rotate together with the axis of rotation. A rotation detection sensor 254 detects the optical pattern of the scale 234. The scale 234 (rotating optical surface) and rotation detection sensor 254 are accommodated in a container having a sealed space 41. The container has an opening 44 capable of being opened/closed. In the opening 44, a dust collection means such as nozzle and duct for blowing, suction, etc may be arranged.SELECTED DRAWING: Figure 4

Description

The present invention relates to a rotary encoder, a robot device, a control method for the robot device, a control program, a recording medium, and a method for manufacturing an article.

It is known that the joint portion connecting the links of the robot arm is provided with a rotary encoder for detecting the rotation position on the output side with high accuracy. If dust adheres to the rotational optical surface of such a rotary encoder or an optical sensor as a rotational detection sensor, the accuracy of detecting the rotational position may decrease or the rotational position may not be detected.

In view of this point, a structure has been proposed in which the encoder mounting portion is used as a closed space to prevent dust from entering from the outside, and a configuration in which the attached dust is moved from the optical surface by a blowing means (for example, Patent Document 1 below). ). Further, a means for moving the dust by providing an air blowing means is also proposed assuming the adhesion of dust that hinders the detection of the rotation position of the encoder (for example, Patent Document 2 below). Further, in the handling of silicon wafers and the like, a configuration has been proposed in which, after the dust that becomes an obstacle is moved by blowing air, the dust is prevented from reattaching and becoming an obstacle again (for example, the following patent documents). 3).

Japanese Unexamined Patent Publication No. 2015-1505 JP-A-11-344361A Japanese Unexamined Patent Publication No. 2001-79505

However, even if the encoder is arranged inside a closed space as described in Patent Document 1, for example, dust unintentionally enters the closed space during assembly, or it is generated when parts are fitted together during assembly. Abrasion powder, etc. may be generated. In particular, dust that has entered during assembly may not be detected by a check or the like after assembly. When the robot arm is operated, dust existing in the enclosed space may move and adhere to the rotation optical surface of the encoder or the rotation detection sensor, which may interfere with the rotation position detection by the output shaft encoder.

In general, an optical encoder has a rotation axis, a holding member attached coaxially with the rotation axis, and a rotation optical surface attached to the holding member and provided with a rotation detection pattern, as opposed to an optical sensor as a rotation detection sensor. It has a structure that rotates relative to each other. Therefore, dust may be generated from sliding parts such as bearings for rotating the rotating shaft with respect to the fixed portion, seal parts arranged between the rotating member and the fixing member constituting the closed space, and the like. .. In this case as well, the attached dust affects the detection performance, and therefore needs to be removed.

Further, as described in Patent Document 2 and the like, a method of moving dust adhering to the inside of the encoder from the optical surface by a blowing means has been proposed. However, if the moved dust is not collected or discharged to the outside, when the robot arm is operated again, the moved dust reattaches to the rotary optical surface of the encoder or the rotation detection sensor, and the rotary position of the encoder is reattached. It can interfere with detection.

Further, in the configuration as shown in Patent Document 3, a filter for collecting dust after being blown by a fluid blowing nozzle to move obstructive dust and sucking by an intake nozzle is provided, and dust is reattached. Is designed to prevent. However, in such a configuration, the mechanism for collecting dust tends to be complicated, and there is a possibility that the dust cannot be sufficiently removed unless the relative positional relationship between the air blower or the intake part and the part where the dust is attached is adjusted. There is.

Further, in the methods described in Patent Documents 2 and 3, when moving or collecting dust, it is necessary to arrange a blowing means in the vicinity of the robot arm. However, there are devices necessary for production around the robot arm mounted on a production line or the like, and it may be difficult to arrange the blowing means in the vicinity. In order to arrange the ventilation means, it is necessary to remove the peripheral device once or move the robot arm from the production line to the maintenance space, and there is a problem that the production line for manufacturing the article must be stopped for a long time. ..

An object of the present invention is to make it possible to appropriately remove and collect dust that hinders position detection from a rotary encoder arranged at a joint of a robot device or the like.

In order to solve the above problems, in the present invention, a rotating optical surface having an optical pattern fixed to the rotating shaft and rotating together with the rotating shaft, an optical sensor for detecting the optical pattern, and the rotating optical surface. A configuration is adopted which includes a container for accommodating the optical sensor in a closed space, a closeable opening provided in the container, and a dust collecting member arranged facing the opening. ..

According to the above configuration, dust that hinders position detection can be appropriately removed and collected from a rotary encoder arranged at a joint of a robot device or the like.

It is a perspective view which showed the whole structure of the robot apparatus which concerns on embodiment of this invention. It is a perspective view of the main part of the rotary encoder which concerns on embodiment of this invention. The rotary encoder according to the embodiment of the present invention, particularly the scale thereof and the parts of the sensor substrate are shown, (a) is a perspective view of the rotary encoder, (b) is an exploded perspective view of the rotary encoder, and (c) is a rotary encoder. It is a side view of. It is sectional drawing which showed the whole structure of the rotary encoder. It is sectional drawing which showed the structure of the main part of the rotary encoder. It is sectional drawing which showed the structure of the main part of the rotary encoder. It is sectional drawing which showed the structure of the rotary encoder and the plug member which closes the opening. It is sectional drawing which showed the structure of the main part of the rotary encoder. It is sectional drawing which showed the structure of the main part of the rotary encoder. It is sectional drawing which showed the structure of the main part of the rotary encoder. (A) is a cross-sectional view showing the structure of the main part of the rotary encoder, and (b) is a cross-sectional view showing the structure of the main part of the rotary encoder. It is sectional drawing which showed the structure of the main part of the rotary encoder. (A), (b), and (c) are diagram showing a method of detecting a dust adhesion position in the rotary encoder. It is a flowchart which showed the control procedure of the dust removal which concerns on this invention. It is a perspective view which showed the structure of the robot apparatus equipped with the end effector driven by compressed air. It is a block diagram which showed the structure of the robot control apparatus of FIG. 1 as an example of the control system which executes the dust removal control which concerns on this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The configuration shown below is merely an example. For example, a person skilled in the art can appropriately change the detailed configuration without departing from the spirit of the present invention. Further, the numerical values taken up in the present embodiment are reference numerical values and do not limit the present invention.

(Outline configuration of robot device)
First, for example, a schematic configuration of a robot device to which the configurations of each embodiment described later can be applied, particularly a robot apparatus having an output shaft encoder at a joint portion will be described. The schematic configuration of the robot device in this embodiment will be described. FIG. 1 shows a schematic configuration of a robot device. In the figure, the robot device 100 includes a robot arm 200 configured as an articulated robot, a robot control device 300 for controlling the robot arm 200, and a teaching pendant 400. It has. The teaching pendant 400 is a teaching device that transmits posture data of a plurality of robot devices to the robot control device 300, and is mainly used by an operator to specify the operation of the robot arm 200 at the installation site of the robot device 100. .. A configuration example (FIG. 16) of the robot control device 300 will be described later.

The robot arm 200 is composed of 6-axis articulated joints. The robot arm 200 has a plurality of (six) rotation mechanisms 201 to 206 that rotationally drive the joints J1 to J6 around the joint axes A1 to A6, respectively. In the following, the notation "Jn axis" may be used to refer to the joint Jn. In the following, when the members of the reference code having the suffix of the alphabet in parentheses are collectively referred to, the reference code without the suffix may be used.

The rotation mechanisms 201 to 206 relatively rotate the first and second arm structure portions (so-called links) to which the joints J1 to J6 are connected. The rotation mechanisms 201-206 include drive sources 211-216 and rotary encoders 221-226 that detect the relative rotation position of the second structure with respect to the first arm structure. Although the present embodiment shows a configuration example in which the rotary encoders 221 to 226 are included in all the joint axes, the present invention can be implemented even in a configuration in which only a part of the axes are included. Further, in the configuration of FIG. 1, the drive system and the rotary encoder are arranged adjacent to each other in the drive system, but the positional relationship between the drive source and the rotary encoder in the drive system is arbitrary.

By controlling the rotation angles of the joints J1 to J6 by the robot control device 300, the robot arm 200 can be placed in any three-dimensional position within the movable range and in any three-direction posture (robot arm 200). The tip of the robot can be turned. In the following, if necessary, only the reference numerals of L1 to L6 may be used to refer to the second arm structure portions L1 to L6 of each joint. Hereinafter, some examples relating to various configurations of the robot device 100 will be described.

(Example 1)
In this embodiment, the robot device 100 and the configuration related to the rotation mechanism of each of the joints will be described with reference to FIGS. 1, 2, 3, and 4. Here, as an example, the schematic configuration of the rotary encoder 225 provided in the J5-axis rotation mechanism 205 of FIG. 1 will be described with reference to FIGS. 2 to 4. 2 to 4 show the configuration of the J5-axis rotary encoder 225 in this embodiment. Needless to say, the same configuration can be implemented in the rotation mechanisms 201 to 204 and 206 in the other J1 to J4 and J6 axes.

As shown in FIGS. 2 to 4, in the rotary encoder 225, an annular scale 234 provided with a rotation detection pattern (rotation optical surface 284) and rotation detection sensors 254 (a) and 254 (b) are L4 side frames. It is fixed to the 40 and the L5 side frame 50, respectively. In the case of an optical encoder, the rotation detection sensor 254 is composed of an optical sensor, and the rotation detection pattern of the rotation optical surface 284 is composed of an optical pattern that forms a pattern of transmitted light or reflected light that can be detected by the optical sensor. The rotation detection sensors 254 (a) and 254 (b) are mounted on two sensor substrates 244 (a) and 244 (b).

The scale 234 rotates relative to these sensor substrates 244, and the rotation detection sensor 254 reads a rotation detection pattern of the rotation optical surface 284 provided on the scale 234. As a result, the rotation angle of the scale 234 can be detected, and the rotation position of the joint can be detected. In this embodiment, an example in which two sensor boards 244 are arranged on the rotary encoder is shown, but the internal configuration of the rotary encoder is arbitrary, and the rotation detection sensor 254 is also limited to one with respect to the sensor board 244. It's not something.

As shown in FIGS. 2 to 4, the J5 axis is composed of an L4 side frame 40 and an L5 side frame 50 corresponding to the above-mentioned first arm structure and the second arm structure, respectively, and is relatively rotated by the rotation mechanism 205. .. The sensor substrates 244 (a) and (b) constituting the rotary encoder 225 are fixed to the substrate base 274, and are further held and fixed to the L4 side frame 40 constituting the L4 frame. The L4 side frame 40 constituting the L4 frame is fixed to the outer diameter side of the bearing 285, which is the rotation reference of the J5 axis, and the L5 side frame 50 is fixed to the inner diameter side of the bearing 285, respectively, and the L4 side frame 40 and the L5 side frame 50 are fixed. Relative rotation.

The scale 234 constituting the rotary encoder 225 is held by the hub 265 (FIG. 8), and the hub 265 is held and fixed to the L5 side frame 50. The sensor substrates 244 (a) and 244 (b) are fixed to the L4 side frame 40 via the substrate base 274, and the scale 235 is fixed to the L5 side frame 50 via the hub 265. Therefore, when the L4 side frame 40 and the L5 side frame 50 rotate relative to each other, the rotation angle thereof is measured by the rotary encoder 225.

In this embodiment, as shown in FIG. 5, a concave mounting portion 41 is provided on the L4 side frame 40, and the rotary encoder 225 is installed inside the mounting portion 41. The L4 side frame 40 is connected to the L5 side frame 50 via a bearing 285 (FIG. 4), and after the connection, the L4 side frame 40 has a substantially integral shape as shown in FIG. In this embodiment, for example, the configuration of a deep groove ball bearing is shown as the bearing 285, but the type of the bearing 285 is arbitrary, and other types may be used.

The L4 side frame 40 and the L5 side frame 50 rotate relative to each other by the bearing 285, but the passage of dust or the like in the rotating sliding portion is prevented by the bearing 285. To prevent the passage of dust and the like, it is preferable to use a shield type or a seal type for the bearing 285. Further, in order to improve the dustproof property, the dustproof property of the rotary encoder can be improved by using a sealing member such as an O-ring at the fitting portion between the bearing and the frame.

As shown in FIG. 7, after the L4 side frame 40 and the L5 side frame 50 shown in FIG. 6 are combined, the L4 side frame 40 is closed with the lid 42, the seal 43, and the opening 44 with the plug member 48. As a result, the mounting portion 41 inside the L4 side frame 40 becomes a container having a closed space in which the rotary encoder 225 can be stored. Therefore, in the following, the enclosed space defined by the mounting portion 41 is also referred to by the reference reference numeral “41”.

In the operation using the plug member 48, for example, in the normal process operation of manufacturing an article by the robot arm 200, the opening 44 can be closed by the plug member 48 and the closed space 41 can be defined. This makes it possible to prevent dust from entering the rotary encoder 225 from the outside, for example. Then, in the removal work when the presence or absence (or its position) of dust is detected as described later, the plug member 48 is removed as necessary, and a pressure pipe such as a nozzle for blowing or suction is provided in the opening 44. Can be installed. With this pressure pipe, the pressure inside the container that defines the closed space 41 can be controlled. As a configuration in which the opening 44 can be closed by the stopper member 48, a configuration in which the stopper member 48 is made of an elastic material such as silicon rubber or cork can be considered. Further, a male-female fitting groove or the like may be provided between the plug member 48 and the opening 44, or an O-ring or the like may be interposed between the two by screwing.

The mechanical configuration of the container defining the rotating optical surface of the rotary encoder 225 and the closed space 41 accommodating the optical sensor is arbitrary. For example, if a closed space can be formed like the L4 side frame 40 and the L5 side frame 50, any member may be used to form the container for accommodating the rotating optical surface and the optical sensor.

Further, in this embodiment, two openings 44 (a) and 44 (b) are provided on the side wall of the mounting portion 41, and the surface of the closed space 41 of the lid 42 constituting the container of the rotary encoder 225 and the L4 side frame. The adhesive collecting member 45 is mounted on the cylindrical surface of the 40. The collecting member 45 has a structure in which, for example, a sticky adhesive sheet material is attached or an adhesive is applied.

In such a structure, a pressure pipe such as a nozzle 101 for blowing (or taking in) air is connected to the opening 44 as shown in FIG. 8, or the nozzle 101 and the intake nozzle 102 are connected as shown in FIG. By connecting, an air flow w can be generated in the closed space 41.

If dust adheres to the rotation optical surface 284 of the scale 234 of the rotary encoder 225 or the rotation detection sensor 254, the accuracy of the rotary encoder may be lowered, the rotation position may not be detected, or the like. In such a case, the airflow nozzle 101 and the intake nozzle 102 generate an airflow w inside the closed space 41, and the airflow w can move the adhering dust. Further, since the dust collecting member 45 is arranged, the dust moved by the air flow w from the place where the dust is attached can be attached to the collecting member 45, and the rotation optical surface 284 of the scale 235 or the rotation detection sensor. It is possible to suppress reattachment to 254. Since the collecting member 45 is arranged in the closed space, the nozzle 101 and the intake nozzle 102 may have a simple structure that only blows air or takes in air.

If at least one opening is installed, a duct (nozzle) for ventilation (or intake or both) can be inserted. Further, as shown in FIGS. 8 and 9, a plurality of locations are provided. For example, as shown in FIG. 8, a blower nozzle is connected to the opening 44 (a) to communicate the opening 44 (b) with the atmosphere and keep it open. The configuration may be used. Since the airflow w generated in the closed space 41 is discharged to the outside from 44 (b), there is a high possibility that the moved dust does not adhere to the collecting member 45, and the dust can be discharged to the outside. The possibility of reattachment is low.

Further, as shown in FIG. 9, if the intake nozzle 102 is connected to the opening 44 (b), the effect of equalizing the air flow flowing in the closed space 41 as a whole is enhanced, and the possibility of reattachment of dust is further reduced. It is possible to make it.

Further, as shown in FIG. 10, by adding a collection member 45 (a to d) at a plurality of locations such as the side wall portion of the mounting portion 41 and the periphery of the hub 265 holding the scale, dust can be reattached. The possibility can be further reduced.

FIG. 10 shows a configuration in which the closed space 41 is a space having a substantially cylindrical shape or an annular shape along the outer diameter shape of the scale 234 constituting the rotary encoder 225. According to such a configuration, since the airflow generated by the blower nozzle or the like flows inside the closed space along the scale constituting the rotary encoder, the effect of removing dust adhering to the scale can be enhanced. The opening 44 can be sealed by a plug member 48 (FIG. 7: sealing member) if it is not necessary to connect a nozzle or the like, and dust or the like does not enter during normal use.

(Example 2)
Hereinafter, the J5-axis rotation mechanism 205 in the second embodiment will be described with reference to FIGS. 11A and 11B. In the following, the J5 axis will be described as an example, but the same configuration can be implemented in the rotation mechanisms 201 to 204 and 206 in the other joint axes.

In this embodiment, the configuration of the J5 axis and the rotation mechanism 205 is the same as the configuration described in the first embodiment. Further, in this embodiment, as shown in FIGS. 11A and 11B, an opening 44 installed in the closed space 41 is provided in the L4 side frame 40. The L4 side frame 40 is a member on the side that holds and fixes the sensor board 244 on which the rotation detection sensor 254 constituting the rotary encoder 225 is mounted. Further, as shown in FIG. 11B, the openings 44 (a) and (b) are counterclockwise with respect to the rotation detection sensors 254 (a) and (b) with respect to the rotation axis of the rotary encoder 225, respectively. Both clockwise and clockwise are provided at positions in substantially the same phase.

If dust adheres to the rotation detection sensor, the accuracy of the rotary encoder 225 may decrease and the rotary encoder 225 may become unreadable. However, according to this embodiment, the opening 44 is provided in the component on the side that holds and fixes the rotation detection sensor constituting the rotary encoder. Therefore, the distance from the opening 44 to the rotation detection sensor 254 is constant regardless of the relative angle between the input side and the output side of the joint portion of the robot arm 200. Further, since the opening 44 is provided at a position substantially in phase with the rotation detection sensor 254 with reference to the rotation axis, the rotation detection sensor 254 is always close to the opening 44. If the rotation detection sensor 254 and the opening 44 are arranged close to each other, the dust adhering to the rotation detection sensor 254 can be easily removed, and the air volume required for the movement of the dust can be reduced. Further, it is possible to reduce the possibility that the dust is crushed by the wind pressure of the air flow and sticks to the rotation detection sensor 254 due to the air flow and cannot move.

(Example 3)
Hereinafter, the rotation mechanism 205 of the J5 axis in the third embodiment will be described with reference to FIG. Hereinafter, the J5 axis will be described, but the same configuration can be provided for the rotation mechanisms 201 to 204 and 206 on the other axes as in the first and second embodiments.

In the third embodiment, as shown in FIG. 12, the opening 44, which communicates with the closed space 41 and is arranged on the side surface of the L4 side frame 40, constitutes a scale with respect to the rotation direction of the rotary encoder 225. And the rotation detection sensor 254 at a height position. According to such a configuration, in addition to the effect of the second embodiment, the airflow w generated for dust removal flows in the gap between the rotation optical surface 284 and the rotation detection sensor 254, and the rotation optical surface 284 or rotation detection. The movement of the dust adhering to the sensor 254 due to the air flow becomes easier. Therefore, according to this embodiment, the air volume required for the movement of dust can be reduced. Further, it is possible to reduce the possibility that the dust is crushed by the wind pressure of the air flow and adheres to the sensor or the rotating optical surface in a state where it cannot be moved by the air flow.

(Dust adhesion position detection method)
In particular, when the rotary encoder has an absolute encoder configuration, the position where dust is attached can be easily detected as shown in FIG. For example, a rotation detection sensor is separately set at a position that realizes a detection resolution (for example, 256 μm) different from the scale pitch detection (128, 512 μm) for acquiring absolute information provided on the scale 234, and the signal amplitude of the encoder is set at that resolution. To confirm. Here, FIG. 13A shows two-phase detection signals S1 (A) and S1 (B) having a 128 μm scale pitch, and FIG. 13 (c) shows two-phase detection signals S3 (A) and S3 (C) having a 512 μm scale pitch. B) is shown. Further, FIG. 13B shows two-phase detection signals S2 (A) and S2 (B) having a 256 μm scale pitch for dust detection.

When the joint is driven, the detection signals of the 128 μm and 512 μm scale pitches that acquire absolute information vibrate according to the driving amount as shown in FIGS. 13 (a) and 13 (c). On the other hand, the signal amplitude of the 256 μm scale pitch for dust detection, which is not used for rotation detection, remains zero (small amplitude) as shown on the left and right of FIG. 13 (b).

However, when dust adheres to the scale 234, the signal amplitude of the dust detection scale pitch (256 μm) not used for rotation detection becomes abnormally large as shown in the central portion of FIG. 13 (b) at the adhered position. .. This rotation position can be specified by performing rotation position detection using detection signals of 128 μm and 512 μm scale pitches. In this way, the position on the scale 234 to which dust has adhered can be detected.

(Example 4)
Hereinafter, an example of dust removal control of the rotary encoder 225 of the first embodiment mounted on the robot arm 200 of the robot device 100 will be described. FIG. 14 shows a control procedure configured so that the robot arm 200 mounted on the production line can remove dust during the process operation. First, with reference to FIG. 16, a configuration example of the robot control device 300 will be described as an example of a control system that executes this dust removal control.

FIG. 16 shows an example of a specific configuration of a control system for controlling the dust removal mode (FIG. 14) of the present invention, for example, the robot control device 300 of FIG. The control system of FIG. 16 can be configured by a CPU 1601 as a main control means, a ROM 1602 as a storage device, and PC hardware including a RAM 1603. The ROM 1602 can store a control program of the CPU 1601 and constant information for realizing the manufacturing procedure described later. Further, the RAM 1603 is used as a work area of the CPU 1601 when executing the control procedure. Further, an external storage device 1606 is connected to the control system of FIG. The external storage device 1606 is not necessarily necessary for the practice of the present invention, but can be configured from an HDD, an SSD, an external storage device of another network-mounted system, or the like.

The control program of the CPU 1601 for realizing the dust removal control (dust removal mode: FIG. 14) of the present embodiment is stored in a storage unit such as the external storage device 1606 or the ROM 1602 (for example, EEPROM area). Can be left. In that case, the control program of the CPU 1601 for realizing the control procedure of the present embodiment can be supplied to each of the above-mentioned storage units via the network interface 1607, and can be updated to a new (another) program. Alternatively, the control program of the CPU 1601 for realizing the control procedure described later is supplied to each of the above storage units via storage means such as various magnetic disks, optical disks, and flash memories, and a drive device for that purpose. The contents can also be updated. Various storage means, storage units, or storage devices in a state in which the control program of the CPU 1601 for realizing the control procedure of the present embodiment is stored constitutes a computer-readable recording medium in which the control procedure of the present invention is stored. It will be.

The network interface 1607 can be configured using, for example, a wired communication standard such as IEEE 802.3 or a wireless communication standard such as IEEE 802.11, 802.11. The CPU 1601 can exchange control signals and data with other devices 1104 via the network interface 1607. The device 1104 corresponds to, for example, a control control device such as a PLC related to the manufacture of articles, a management server, or the like, and controls or logs the robot device 100 or the production line in which the robot device 100 is arranged. Further, the control device of FIG. 16 is connected to the teaching pendant 400 described above, which is composed of a UI device (user interface device) operation unit, a display device, and the like.

A motor driver circuit for driving each joint of the robot arm 200 is connected to the interface 1605, and the detection circuits of the rotary encoders 221 to 226 are connected to the interface 1605. The CPU 1601 controls the robot arm 200 by controlling the rotation positions of the joints J1 to J6 of the robot arm 200 based on the rotation position detection signals of the rotary encoders 221 to 226 input via the interface 1605. When the robot arm 200 is arranged on a production line that manufactures articles such as industrial products and its parts, the CPU 1601 controls the robot arm 200 to a position and posture required for the manufacturing process through the above joint control. Can be done.

In the control procedure of FIG. 14, it is assumed that the robot arm 200 is arranged on a production line for manufacturing articles such as industrial products and parts thereof, and continues a certain process operation (step S10). At this time, the robot arm 200 is controlled so as not to interfere with peripheral devices arranged in the vicinity of the arm. During the process operation of the robot arm 200 (S10), the presence or absence of dust is determined by, for example, the method described with reference to FIG. 13 of the third embodiment (S11). That is, the presence or absence of dust is determined constantly or periodically (intermittently) from a detection signal having a detection resolution different from the scale pitch detection signal for acquiring absolute information. If the dust determination (S11) is OK (no dust), the process returns to step S10 and the process operation is continued. On the other hand, when dust adheres to the scale 234 in the rotary encoders 221 to 226 of the joints J1 to J6 of the robot arm 200, the dust determination (S11) becomes NG and the mode shifts to the dust removal mode (S11-> S21). The dust detected in this case includes dust that has unintentionally entered the rotary encoders 221 to 226 from the outside, and dust such as abrasion powder generated when the parts are fitted together during assembly.

In this dust removal mode, for example, the dust position is specified by the dust adhesion position detection method described with reference to FIG. 13 (step S21 of FIG. 14: dust position detection step or dust position detection means). After that, the process operation is performed again (S22), the dust position is moved to the vicinity of the opening 44 by driving the joint, and the process is stopped after the movement (S23: joint drive process). In this example, since the movement to the dust adhesion position (S23) can be performed during the process operation, there is no problem of causing an obstacle such as interfering with peripheral devices arranged in the vicinity of the robot arm 200, for example.

In this state, since the dust position has moved to the vicinity of the opening 44, the dust is removed, collected, and discharged by the method of the above-mentioned Examples 2 to 3 in the posture of the stopped robot arm 200 ( S24: Dust collection step). This dust removal work should be performed manually by the operator operating the suction or blow nozzle, or by remote or automatic control without manual work if the suction or blow nozzle is always attached. Can be done.

Subsequently, the subsequent process operation (S25) is performed, and the dust determination (S26) is performed in the process. If the dust determination is OK, the dust removal mode is terminated and the process returns to the normal process operation (for example, S10). On the other hand, when the dust determination is NG, the process returns to the dust adhesion position detection (S21), and the operation of the dust removal mode is repeated until the dust determination is OK in step S26.

As described above, the dust of the rotary encoder arranged on the joint of the robot arm 200 without moving the robot arm 200 from the production line or moving the peripheral devices in the vicinity of the robot arm 200. Can perform removal work. Further, according to the above control, the dust adhesion position is automatically moved to the vicinity of the opening of the rotary encoder for dust removal, so that the dust removal work is further simplified and the return time to the normal process operation is reduced. It can be significantly shortened.

(Example 5)
In the third embodiment, with reference to FIG. 15, a configuration in which a compressed gas (compressed air or other compressed gas) for driving an end effector is used for removing dust is shown. In the robot arm 200 shown in FIG. 15, an end effector 70 driven by compressed air is attached to the tip of the robot device. A pressure pipe 80 is connected to the end effector 70 as a driving pipe for supplying compressed air. In this example, the pressure pipe 80 is arranged so as to crawl on the outside of the arm, but it may be piped so as to pass through the inside of the arm.

If the pressure pipe 80 is branched and connected to the opening 44 provided in the closed space 41 of the rotary encoder described above, it can be used for blowing air into the closed space 51. The connection of the branch pipe (not shown in detail) of the pressure pipe 80 to the opening 44 can be always made by providing, for example, a valve that opens only when dust is removed. Further, the connection of the branch pipe (not shown in detail) of the pressure pipe 80 to the opening 44 may be manually performed by the operator during the work of removing dust.

According to this embodiment, it is not necessary to separately prepare and connect a blower nozzle, an intake nozzle, etc. to be connected to the opening for removing dust of the rotary encoder, and the dust removal work of the rotary encoder can be remarkably simplified. .. Further, when the connection of the branch pipe (details not shown) of the pressure pipe 80 to the opening 44 is always connected, the dust of the encoder can be removed by, for example, remote work or automatic control. In that case, the operator does not need to approach the robot arm 200 for branching or connection operation of the pressure pipe 80.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 ... Robot device, J1-J6 ... Joint (part), 221-226 ... Rotary encoder.

Claims (11)

A rotating optical surface with an optical pattern that is fixed to the rotating shaft and rotates with the rotating shaft.
An optical sensor that detects the optical pattern and
A container for accommodating the rotating optical surface and the optical sensor in a closed space,
With the closureable opening provided in the container,
A rotary encoder including a dust collecting member arranged facing the opening. The rotary encoder according to claim 1, wherein the closed space of the container has a cylindrical or annular shape along the outer diameter shape of the rotating optical surface. The rotary encoder according to claim 1 or 2, wherein the opening is provided at a rotation position having the same phase as that of the optical sensor and the rotation axis. The rotary encoder according to any one of claims 1 to 3, wherein the opening is provided on the side surface of the container between the rotational optical surface and the optical sensor. In a robot device in which the rotary encoder according to any one of claims 1 to 4 is provided in a joint portion connected to a link, and the rotary encoder detects the rotation position of the rotation axis of the joint portion.
A dust position detecting means for identifying the rotation position of dust adhering to the rotation optical surface through error detection of the rotation position of the joint detected based on the detection signal of the optical sensor.
A robot device including a control device for driving the joint portion so that the position of the dust faces the opening based on the rotation position of the dust adhering to the rotational optical surface specified by the dust position detecting means. In the robot device according to claim 5, a pressure pipe for controlling the pressure inside the container is connected to the opening of the rotary encoder, the pressure is controlled via the pressure pipe, and the pressure is controlled through the opening. A robot device that collects dust. The robot device according to claim 6, further comprising an end effector driven by a compressed gas, wherein the pressure pipe branches the end effector from a pipe for driving the end effector by the compressed gas. The method for controlling a robot device in which the rotary encoder according to any one of claims 1 to 4 is provided in a joint portion to be connected to a link, and the rotary encoder detects the rotation position of the rotation axis of the joint portion.
A dust position detection step of identifying the rotation position of dust adhering to the rotation optical surface through error detection of the rotation position of the joint detected by the control device based on the detection signal of the optical sensor.
A joint driving step in which the control device drives the joint portion so that the dust position faces the opening based on the rotation position of the dust adhering to the rotational optical surface specified in the dust position detecting step.
A method for controlling a robot device, which comprises a dust collecting step of collecting the dust through the opening. A control program for causing a computer to execute the dust position detection step and the joint driving step according to claim 8. A computer-readable recording medium containing the control program according to claim 9. A method for manufacturing an article by using the robot device according to any one of claims 5 to 7.

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