JP3801264B2 - Industrial robot teaching method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a teaching method and apparatus for an industrial robot such as a painting robot.
[0002]
[Prior art]
In recent years, industrial robots have been introduced in various fields. Industrial robots perform various operations by attaching a tool such as a paint gun to the tip of an arm and moving the position of the tool by driving the arm. At this time, the work procedure of the robot needs to be taught in advance by the worker.
[0003]
Conventional teaching methods for industrial robots include a direct teaching method in which an operator moves the robot arm by hand and obtains the passing point of the arm as a teaching point, and the arm is operated and driven by an operation switch box or the like. There is known a remote teaching method for obtaining a passing point of an arm as a teaching point.
[0004]
The direct teaching method requires teaching at the work site, and high-precision positioning is difficult, but it can be used to visually understand the arm movement, so it does not require so high positioning accuracy. Suitable for robots.
[0005]
On the other hand, the remote teaching method requires that the operator always know the direction in which the arm is operated, that is, the coordinate system of the arm, and it is difficult to put the wrist and tool of the robot into an arbitrary posture, but on the other hand, it is highly accurate positioning. Therefore, it is used in robots that require relatively high precision positioning, for example, robots that operate in conjunction with machine tools.
[0006]
Several methods have been devised for facilitating teaching in the remote teaching method.
For example, the robot teaching method shown in FIG. 6 (Japanese Patent Laid-Open No. 2-279289) is based on the base 101, the swivel base 103, the first arm 104, the second arm 105, the work wrist 106, and the control device 113. When teaching a robot, the swivel base 103, the first arm 104, and the second arm are operated by operating an operation switch box 112 as shown in FIG. 7, for example, provided on the distal end side of the second arm 105. 105 and actuators 102, 107, 108, 109, 110, and 111 for driving the work wrist 106 are moved so that the operator can perform remote teaching in the sense of direct teaching.
[0007]
[Problems to be solved by the invention]
In the direct teaching method, in order for the operator to move the robot arm directly by hand, it is necessary to exert a constant force against the inertia weight of the arm and the frictional resistance of the drive system. In particular, parts having a large weight and a large inertia weight require a large mechanical torque in order to be moved manually. However, in general, a place where an industrial robot is used is often difficult to produce force because various devices are arranged on a scaffold, and it is difficult to provide accurate teaching. Moreover, in order to move the arm directly by hand, it is necessary to provide a mechanical clutch or the like in each drive system, and to balance the weight of the arm around the rotating shaft, resulting in a complicated configuration and high cost. There is a problem.
[0008]
On the other hand, in remote teaching, when changing the posture of a tool attached to a wrist, it is necessary to control a large number of arms in an unusual coordinate system such as an absolute coordinate system or a tool coordinate system. There is a problem that workability is lowered because multiple corrections are required. Further, as in the example shown in FIG. 6, when a special operation switch box is provided in order to facilitate teaching in the remote teaching method, there is a problem that the configuration becomes complicated and the cost is increased.
An object of the present invention is to provide a robot teaching method and apparatus capable of easily teaching with a simple configuration.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an industrial robot teaching method according to the present invention includes a base, a swivel provided on the base so as to be pivotable, and a base end side supported by the swivel so that the base end is swingable. 1 arm, a second arm whose base end side is swingably supported by the tip end side of the first arm, a wrist rotatably supported by the tip end side of the second arm, and the wrist , A plurality of actuators that respectively drive the swivel base, the first arm, the second arm, the wrist, and the tool, and a control device that stores the teaching contents and controls the plurality of actuators according to the teaching contents In the robot teaching method, the swivel base and the first and second arms are moved by remote operation to teach the position of the wrist, and the wrist is moved by direct operation to teach the posture of the tool.
[0010]
The teaching device for an industrial robot of the present invention includes a base, a swivel provided on the base so as to be turnable, a first arm whose base end side is swingably supported by the turntable, A second arm whose base end side is swingably supported on the distal end side of one arm, a wrist rotatably supported on the distal end side of the second arm, and a tool attached to the wrist; Industrial robot comprising a plurality of actuators for respectively driving a swivel base, a first arm, a second arm, a wrist, and a tool, and a controller for storing teaching contents and controlling the plurality of actuators according to the teaching contents In this teaching device, the control device teaches the remote teaching contents when the first and second arms are moved by remote operation to teach the position of the wrist and the posture of the tool by moving the wrist by direct operation. And a storage means for storing the direct teachings when.
[0011]
According to the present invention, since the heavy swivel base and the first and second arms are taught by remote operation, there is no need to provide a mechanical clutch in the drive system to move by direct teaching, thereby reducing the manufacturing cost. Can do. Moreover, remote teaching is performed only on the wrist position, and it is not necessary to consider an unusual coordinate system such as an absolute coordinate system or a tool coordinate system as in the prior art, so that workability can be improved.
[0012]
Since the wrist and the tool are taught by direct operation, the desired position can be easily taught. In addition, since these wrists and tools are relatively light in weight and do not require a large torque to move, it is only necessary to add inexpensive parts to move them by human power, and there is no problem in terms of cost. .
[0013]
Further, when the control device teaches the posture of the tool by direct operation, the control device controls the swivel base, the first arm, and the second arm so that the position of the tip of the tool does not move. Since the deviation of the tip position is always corrected, the time required for teaching can be shortened and the working efficiency can be further improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a configuration of a painting robot according to an embodiment of the present invention. The painting robot includes a base 1, a swivel 2, a first arm 3, a second arm 4, a wrist 5, a painting gun 6 as a tool, a control device 7, an operation switch box 8, a jig 9, and a motor. 11, 12, 13, 14, a paint supply pipe 15 and a compressed air pipe 16.
[0015]
A swivel base 2 is rotatably provided on the upper part of the base 1. The swivel base 2 is driven by a motor 11 provided inside the base 1. The first arm 3 is pivotally supported by a blanket having a base portion integrated with the swivel base 2 so as to be swingable, and is driven by a motor 12. The base of the second arm 4 is pivotally supported by the tip of the first arm 3 so as to be swingable, and is driven by a motor 13. Here, the swivel base 2, the first arm 3, and the second arm 4 are arbitrarily moved in the x, y, and z directions indicated by arrows by remote operation by the operation switch box 8, and the positions of the respective parts at that time are moved. It is configured to enable remote teaching as teaching contents. Each of the motors 11, 12, and 13 is provided with an encoder (not shown). Each encoder detects the rotation angle of each of the motors 11, 12, and 13 and outputs information indicating the rotation angle to the control device 7. .
[0016]
The wrist 5 is rotatably attached to the tip of the second arm 4 and is rotated by the motor 14 so as to swing up and down as indicated by an arrow indicated by a broken line. A paint gun 6 is rotatably attached to the wrist 5. Here, the wrist 5 and the painting gun 6 are configured so that direct teaching can be performed by a direct operation that the operator actually holds and moves with the hand.
[0017]
FIG. 2 is an enlarged view of the wrist 5 and the paint gun 6. A motor with an encoder (not shown) is provided inside the wrist 5, and the coating gun 6 is attached to the shaft of the motor so that the coating gun 6 is horizontal as indicated by an arrow shown by a solid line in FIG. 1. Swing to. At this time, the rotation angle from the reference position of the output shaft of the motor inside the wrist 5 is detected by the encoder, and information indicating the rotation angle is output to the control device 7. The paint gun 6 is connected with a paint supply pipe 15 and a compressed air pipe 16 for supplying paint and compressed air for jetting the paint, respectively.
[0018]
The jig 9 is attached to the tip of the painting gun 6, for example, a nozzle, when teaching the operation of the painting robot. The distance to the object to be coated is adjusted by the length of the jig 9, and the jig tip 10 determines the center of the painted surface.
[0019]
An operation switch box 8 for performing remote teaching is connected to the control device 7. The control device 8 includes a memory 17 for storing remote teaching contents and direct teaching contents to be described later.
[0020]
Hereinafter, the teaching operation of the painting robot will be described in detail. Here, as shown in FIG. 3, a teaching operation in the case of performing painting while moving the coating gun 6 from the point 30a to 30f of the workpiece 30 will be described.
[0021]
First, before teaching, the distance between the coating gun 6 and the workpiece 30 is kept constant, and the jig 9 having a preset length is attached to the coating gun 6 so that the coating is performed in the optimum coating range 31. Attach to the tip of.
[0022]
Thereafter, teaching is performed by actually operating the robot. Hereinafter, description will be made with reference to the change in the position of the robot according to the teaching shown in FIG. First, the swivel base 2 and the first and second arms 3 and 4 are remotely operated by the operation switch box 8, and the jig tip 10 is made to coincide with the point 30a that is a position to start painting (remote teaching). As a result, it is assumed that the first arm 3, the second arm 4, the wrist 5, the coating gun 6 and the jig 9 have moved to positions 3a, 4a, 5a, 6a and 9a indicated by solid lines, respectively.
[0023]
Here, although the jig tip 10 and the point 30 a coincide with each other, the jig 9 is located at the position 9 a, so that the nozzle of the coating gun 6 is not perpendicular to the surface of the workpiece 30. Therefore, if coating is performed in this state, the paint cannot be sprayed evenly onto the workpiece 30. Then, with the wrist 5 fixed at the position 5a, the paint gun 6 and the jig 9 are grasped by the hand and moved in the direction of the arrow S shown by the two-dot chain line, so that the jig 9 faces the surface of the workpiece 30 in a straight line. (Direct teaching) As a result, the coating gun 6, the jig 9, and the jig tip 10 move to positions 6b, 9b, and 10b indicated by the two-dot chain lines, respectively, and the jig tip 10 moves away from the point 30a. The posture of the painting gun 6 may be set at a certain angle with respect to the workpiece 30.
[0024]
Next, the remote operation by the operation switch box 8 is performed again while gazing at the jig 9, and the first and second arms 3 and 4 are moved in the direction of the arrow T indicated by the broken line, and the jig tip 10 is moved. Is returned to the point 10 a and the posture of the jig 9, that is, the posture of the coating gun 6 is corrected so as to be perpendicular to the workpiece 30. As a result, the first arm 3, the second arm 4, the wrist 5, the coating gun 6 and the jig 9 move to positions 3b, 4b, 5b, 6c and 9c indicated by broken lines, respectively. At this time, the rotation angle is detected in each of the encoder of the motor 14 for rotating the wrist 5 and the encoder of the motor for driving the painting gun, and the control is performed based on the value of the rotation angle and the preset length of the jig 9. If the apparatus 7 calculates the moving direction and moving distance of the jig tip 10 and automatically drives and controls the first and second arms 3 and 4 so that the jig tip 10 returns to the position 10a, There is no need to perform remote teaching again by the operation switch box 8.
[0025]
In this way, the rotation angles of the motors 11, 12, 13, 14 and the motor provided on the wrist 5 are detected with the position 6c of the jig 6 and the position 10a of the jig tip 10 determined respectively. Then, the information indicating the rotation angles of the motors 11, 12, and 13 is stored in the memory in the control device 7 as the remote teaching contents and the rotation angles of the motors provided on the motor 14 and the wrist 5 as the direct teaching contents. And it teaches similarly about the other points 30b-30f in the workpiece | work target 30. FIG.
[0026]
After teaching the robot in this way, the jig 9 is removed from the painting gun 6 and painting is started. As a result, the paint is supplied from the paint supply pipe 15, the compressed air is supplied from the compressed air pipe 16, the paint is ejected from the paint gun 6, and the remote teaching stored in the memory 17 in the control device 7. The swivel base 2, the first arm 3, the second arm 4, the wrist 5, and the painting gun 6 are operated based on the contents and the direct teaching contents, respectively, so that the workpiece 30 has a predetermined speed from the point 30a to the point 30f. The painting gun 9 moves and painting is performed.
[0027]
As described above, in the painting robot according to the present embodiment, the heavy turntable 2 and the first and second arms 3 and 4 are remotely taught, respectively. It is not necessary to provide a simple clutch, and the manufacturing cost can be reduced. Moreover, this remote teaching is for determining only the position of the wrist 5, and teaching to the motors 12, 13, and 14 is all performed in the x, y, and z coordinate systems. That is, since teaching can be performed by a method that matches the human senses of up and down, left and right, front and back, workability is not impaired unlike direct teaching of all robot drive systems as in the prior art.
[0028]
Further, since the posture of the paint gun 6 is set by directly teaching the wrist 5 and the paint gun 6, when remote teaching is performed on an unusual coordinate system such as an absolute coordinate system or a tool coordinate system as in the past, Unlikely, workability can be improved. In addition, since the parts such as the wrist 5 and the paint gun 6 are relatively light in weight and do not require a large torque to move, it is only necessary to add inexpensive parts in order to move them manually. There is no problem.
[0029]
【The invention's effect】
As described above, according to the present invention, the swivel base and the arm are remotely taught, and the wrist and the tool are directly taught, so that an unusual coordinate system such as an absolute coordinate system or a tool coordinate system can be considered in teaching. Therefore, it is possible to provide a teaching method and apparatus for an industrial robot that can be easily taught with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a painting robot according to an embodiment of the present invention. FIG. 2 is an enlarged view of a wrist and a jig in FIG. 1. FIG. FIG. 4 is a diagram showing the position of each part when teaching is performed in the present embodiment. FIG. 5 is a diagram showing a schematic configuration of a conventional industrial robot. FIG. 6 is an operation switch box in FIG. Diagram showing an example
DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Swivel 3 ... 1st arm 4 ... 2nd arm 5 ... Wrist 6 ... Paint gun 7 ... Control apparatus 8 ... Operation switch box 9 ... Jig 10 ... Jig tip 11, 12, 13 , 14 ... Motor 15 ... Paint supply pipe 16 ... Compressed air pipe 17 ... Memory 30 ... Work object 31 ... Painting range 101 ... Base 103 ... Swivel base 104 ... First arm 105 ... Second arm 106 ... Work wrist 112 ... Operation switch box 102, 107, 108, 109, 110, 111 ... Actuator

Claims (2)

A base, a swivel provided on the base so as to be capable of swiveling, a first arm supported on the swivel so that a base end side thereof is swingable, and a base end side on a distal end side of the first arm. A second arm supported so as to be able to swing, a wrist rotatably supported on a tip side of the second arm, a tool attached to the wrist, the swivel base, the first arm, In a robot teaching method comprising: a plurality of actuators that respectively drive the second arm, the wrist, and the tool; and a controller that stores teaching contents and controls the plurality of actuators according to the teaching contents.
Teach the swivel base, the first and second arms by remote operation to teach the position of the wrist to coincide with the position where the tip of the tool starts painting,
Teach the posture of the tool by moving the wrist by direct operation,
Detecting the rotation angle when driving the wrist by the direct operation,
When the posture of the tool is taught, the control device calculates a movement direction and a movement distance of the tool based on a rotation angle of the wrist and a preset length of the tool, and the tip of the tool is calculated. The swivel base, the first arm, and the second arm actuator are controlled so that the position returns to the coating start position shown when the wrist position is taught, thereby the wrist teaching position. An industrial robot teaching method characterized by determining A base, a swivel provided on the base so as to be capable of swiveling, a first arm supported on the swivel so that a base end side thereof is swingable, and a base end side on a distal end side of the first arm. A second arm supported so as to be able to swing, a wrist rotatably supported on a tip side of the second arm, a tool attached to the wrist, the swivel base, the first arm, An industrial robot teaching apparatus comprising: a plurality of actuators for driving the second arm, the wrist, and the tool; and a control device that stores teaching contents and controls the plurality of actuators according to the teaching contents. ,
The control device moves the first and second arms by remote operation to teach the position of the wrist so that the tip of the tool matches the position where the tip of the tool starts to paint, and the wrist directly Storage means for storing direct teaching contents representing a rotation angle of the wrist when the tool is moved by operation to teach the posture of the tool;
When the posture of the tool is taught, a movement direction and a movement distance of the tool are calculated based on a rotation angle of the wrist and a preset tool length, and the position of the tip of the tool is determined based on the wrist position. Means for controlling the actuator of the swivel base, the first arm and the second arm so as to return to the coating start position shown when the position of the position is taught, thereby determining the contents of the remote teaching. Industrial robot teaching apparatus characterized by the above.

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