JP2914719B2 - Industrial robot - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teaching-reproduction-type industrial robot, and more particularly to an industrial robot that can easily teach the same work to the inner and outer surfaces of a work. .

[Prior art] In recent years, teaching / reproduction-type industrial robots that can flexibly cope with various workpieces by changing operation programs have been developed in various fields as automatic machines that perform work such as painting and welding on behalf of humans. Used in

In the case of this type of industrial robot, the work on the inner and outer surfaces of the work, in which the position and orientation of the working tool are opposed to each other on the inner surface and the outer surface with the work interposed therebetween, has conventionally been taught separately. Had gone.

For example, when performing painting work on both sides of a plate with a constant thickness, the painting guns, which are work tools, face each other across the work on the inner and outer surfaces, respectively. Teaching work.

"Problems to be Solved by the Invention" For this reason, the conventional industrial robot has the following problems when performing the above-described operation.

(1) It takes time to teach.

(2) Since the teaching qualities of the inner surface and the outer surface cannot be made the same, a difference occurs in the coating quality of the inner surface and the outer surface.

In the case of a conventionally known industrial robot having a mirror image conversion function, the work is a mirror only when the inner and outer surfaces of the work are parallel planes and the direction of the working tool is orthogonal to these surfaces. With this conversion function, it is possible to convert the teaching data of one surface to the other and omit the teaching of the other surface.

However, when teaching is performed using the mirror image conversion function when the inner and outer surfaces of the work are curved surfaces, the distance between the work surface and the work implement differs between the outer surface and the inner surface of the work. That is, for example, when working on the inner and outer surfaces of a work having a constant thickness and a convex outer surface or a concave inner surface, a mirror conversion is performed based on the teaching data for the outer surface of the work and the inner surface of the work is subjected to mirror conversion. When the teaching data is calculated, the distance between the inner surface of the work and the work tool becomes longer. Conversely, when the teaching data for the outer surface of the work is calculated by mirror conversion based on the teaching data for the inner surface of the work, the outer surface of the work and the work tool are calculated. And the distance between them becomes shorter.

In such a case, the mirror image conversion function is invalid, and the inside and outside surfaces of the work must be separately taught, thus causing the above problem.

The present invention has been made in view of the above-mentioned conventional problems, and is a work on the inner and outer surfaces of a work, in which the position and orientation of each work tool are opposed to each other with the work interposed therebetween. It is an object of the present invention to provide an industrial robot which can eliminate the teaching work of the above and make the teaching quality of the inner and outer surfaces the same.

[Means for Solving the Problems] An industrial robot according to the present invention performs an operation on a work by moving the work tool based on data for determining the position and orientation of a mounted work tool. Setting means for setting a distance between a position and orientation of the work implement determined by the data and another position and orientation of the work implement opposed to the position and orientation with the work interposed therebetween; and work determined by the data. And a control operation unit for calculating new data which becomes another position and orientation of the work implement which moves while maintaining the distance set by the setting means with respect to the position and orientation of the implement.

[Operation] With the above configuration, the teaching work is performed only on one surface of the work, and the distance between the opposing working tools in the work on each surface of the work is input as the set value of the setting unit. For example, it is possible to work on both sides of the work.

That is, if the distance data is set by the setting means, new data is obtained by the control calculation unit from the distance data and the data of the work on one surface. Since the new data is data on the work on the other surface, the teaching data on the other surface is not required to be performed based on the new data having the same teaching quality as the teaching quality on one surface without performing the teaching work on the other surface. Surface work can also be performed.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 are views showing a painting robot for carrying out the present invention. FIG. 1 is an overall configuration diagram, and FIG. 2 is a block diagram showing a configuration of a robot controller.

In FIG. 1, what is denoted by reference numeral 1 is a robot main body. The robot body 1 has three axes on the main axis and a wrist
A 6-degree-of-freedom articulated robot having three axes in 1a, controlled by the robot controller 2 and having a wrist 1a
The work implement 3 (in this case, the coating gun) attached to the tip of the can be directed in any direction and moved to any position within the operation range.

In FIG. 1, what is indicated by reference numeral 4 is a plate-shaped work having an outer surface 4a and an inner surface 4b. This work 4
If the distance between the painted outer surface 4a and the inner surface 4b is constant (that is, the thickness is constant), and the position and orientation of the work implement 3 are opposed to each other in the painting work on each surface. Good thing.

In FIG. 1, reference numeral 5 denotes an outer surface of the work 4.
The target position of the work implement 3 when painting 4a is shown.

And in this industrial robot, for example, PTP
The posture data of the robot body 1 that determines the position and posture of the work implement 3 with respect to each target position 5 is sequentially stored in the robot controller 2 by the remote teaching method according to the method, and an operation program is created (that is, teaching is performed). It has become).

Here, the attitude data is the values of the joint angles θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ , θ ₆ of the robot body 1. Since the robot body 1 is a six-axis articulated robot, the position and orientation of the work implement 3 mounted on the wrist 1a is determined by these six joint angles.

In the following, these joint angles for six axes are collectively represented by a vector as follows.

(G) = [θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ , θ ₆ ] As shown in FIG. 2, the robot controller 2 has a key switch 2a, a servo controller 7, a memory 8, and an operation control. It is provided with a control operation unit 2b including a controller 6 and a coordinate conversion controller 9.

The operation controller 6 controls the flow of signals in the robot controller 2. The distance L and the direction of inversion in the new data generation function described later are set in the operation controller 6 by a key switch 2a (setting means). It has become so.

The servo controller 7 controls the position of a servo system for six axes. The memory 8 stores the taught attitude data.

Then, coordinate conversion controller 9 from the joint angles of the robot (g), the coordinate transformation matrix to determine the robot base coordinate system _{(X R, Y R, Z} R) the position and orientation of the work tool 3 as viewed from the 10 Is performed, or the reverse operation is performed.

Here, according to FIG. 3, this coordinate transformation matrix Will be described.

The robot base coordinate system 10 is the base of the robot body 1.
This is a rectangular coordinate system fixed at 1c. Symbol in FIG.
A tool coordinate system indicated by 11 is a tool coordinate system in which the origin is located at the tip of the work implement 3 (nozzle port of the paint gun) and the direction of the X axis matches the direction of the work implement 3 (the direction of the paint gun nozzle). This is a moving coordinate system that moves in the robot base coordinate system 10 with the operation of the work implement 3.

Also, in FIG. Are the unit vectors provided for each axis of the tool coordinate system 11, Are coordinate vectors representing the origin of the tool coordinate system 11 as viewed from the robot base coordinate system 10.

Then, when the coordinate system or the unit vector is represented in this manner, the tool coordinate system 11 is moved from the robot base coordinate system 10
Coordinate transformation matrix to Is a matrix of 4 rows and 4 columns as shown in the following equation.

In this industrial robot, when the teaching operation is performed by the above-described teaching method, when the robot body 1 moves and the joint angle (g) changes due to the operation of the operator, the joint angle (g) is changed by the motor of the robot body 1. A position detector (angle detector) provided for position control is detected for each axis and input to the servo controller 7 as a position feedback signal ( _g ) _f .

At this time, the operation control controller 6 reads the position feedback signal ( _g ) _f and stores it in the memory 8 by numbering it, whereby an operation program consisting of the numbered attitude data is stored in the memory 8. It is configured within.

Hereinafter, the joint angle ( _g ) _f read into the motion control controller 6 at the j-th time after the teaching is started is expressed as ( _g ) (j) as the j-th posture data. In this way, in the teaching operation, a plurality of (g) and (j) are stored in the memory 8 as numbered posture data groups to constitute an operation program.

Further, in this industrial robot, a reproduction operation is performed based on the posture data (g) (j) taught as described above, and the work implement 3 moves along a trajectory corresponding to the posture data. Then, the robot body 1 operates.

That is, at the time of reproduction, the operation controller 6 sequentially reads out the data (g) and (j) from the memory 8 according to the point number j, and outputs the output signal (g) _r (position command) corresponding to (g) and (j). Output to the controller 7. Then, a current is supplied from the servo controller 7 to the motor of the robot body 1 so that the current joint angle (g) _r of the robot body 1 matches the position command (g) _r , and the robot body 1 performs servo control. It is supposed to be.

Then, the control operation unit 2b including the operation control controller 6 and the coordinate conversion controller 9 determines the position and orientation of the work implement 3 based on the data (g) (j) taught as described above. It has a new data generation function of generating new data for determining the position and orientation of the work tool that has been translated in the same direction as the tool 3 and further reversed.

That is, the distance L of the parallel movement and the direction of the inversion are set by the key switch 2a. For example, when a command to activate the new data generation function is input by the key switch 2a, as shown in FIG. Next, the operation controller 6 performs the following steps S1 to S13.

[Step S1] The distance L set by the key switch 2a and the direction of reversal (“horizontal reversal” or “vertical reversal”) are read, and the process proceeds to step S2.

[Step S2] The value of the inversion flag f, which is an internal binary variable indicating the same inversion, is set to “0”, and the process proceeds to step S3.

[Step S3] If the flip direction command read in step S1 is “vertical flip”, step S4 is executed; otherwise, the process proceeds to step S5.

[Step S4] The value of the inversion flag f is set to “1”, and the process proceeds to step S5.

[Step S5] The posture data number j is incremented by 1 from “1” to j _end , and steps 6 to 13 are repeatedly executed to terminate the processing. Here, j _end is the number of the last posture data taught.

[Step S6] j-th posture data stored in the memory 8 (g)
(J) Read and proceed to step S7.

[Step S7] The data read in step S6 is manually input to the coordinate conversion controller 9 as a joint angle (g), and a coordinate conversion matrix for the data is input. Is calculated, and the process proceeds to step S8. (Where the coordinate transformation matrix Is represented by the above formula. [Step S8] If the value of the inversion flag f is “0”, the process proceeds to Step S9,
If the value of f is "1", the process proceeds to step 10.

[Step S9] The coordinate transformation matrix calculated in step S7 by the following equation Ingredients From the unit vector And proceeds to step S11.

[Step S10] The coordinate transformation matrix calculated in step S7 by the following equation Ingredients From the unit vector And proceeds to step S11.

[Step S11] The coordinate transformation matrix calculated in step S7 by the following equation Ingredients Displacement vector from And proceeds to step S12.

[Step S12] Converted coordinate transformation matrix represented by the following equation Is input to the coordinate transformation controller 9 and the coordinate transformation matrix Is calculated for the posture data (g) ′ for step S13.
Proceed to.

[Step S13] The posture data (g) ′ obtained in step S12 is stored in the memory 8 as another program data (g) ′ (j).

The other posture data (g) ′ (j) obtained by the processing of steps S1 to S13 is, as shown in FIG. 3 or 4, tool coordinates based on the taught posture data (g) (j). With respect to the system 11, the origin corresponds to the tool coordinate system 12 in which the origin moves in the X-axis direction by the distance L and the direction of the X-axis is reversed. When the direction of the inversion is set to “horizontal direction”, the inversion is performed around the Z axis, and when the direction is set to “vertical direction”, the inversion is Y
It is done around the axis.

In other words, according to the new data generation function, the different posture data (g) ′ (j) for determining the position and orientation of the work implement facing the position and orientation of the work implement taught is replaced with the taught posture data (g). ) (J) to be generated by calculation.

For this reason, for example, only the operation with respect to the outer surface 4a of the work 4 is taught, and the distance between work tools opposed to the outer surface 4a and the inner surface 4b across the work 4 is input as the distance L and the new data generation function is operated. Then, the posture data for the operation on the inner surface 4b is generated.

Therefore, according to the industrial robot of this embodiment, both surfaces of the work 4 can be painted by the teaching data corresponding to one of the outer surface 4a and the inner surface 4b of the work 4, and the following effects are obtained.

(1) The time required for teaching can be reduced by half.

(2) The coating quality on the inner and outer surfaces can be made uniform.

(3) Since only the surface that is easy to teach among the inner and outer surfaces need only be instructed with high accuracy, the teaching quality, that is, the coating quality is improved as a whole.

In the above embodiment, the setting of the distance L or the direction of inversion is performed by the key switch 2a independent of the operation control controller 6. However, the present invention is not limited to this. It may be performed. Further, such information may be registered in advance in the operation control controller 6 as a constant.

In the above embodiment, the new data is stored in a new area in the memory 8 and the original attitude data is stored. However, the new attitude may be updated and registered in the same area as the original attitude data.

Further, when the other surface not taught is painted without registering the new data (g) ′ (j) in the memory 8, the new data generation function is activated in real time to obtain the new data (g) ′ ( j) may be sequentially obtained and output directly as the command value (g) _r to perform the operation on the other surface.
With this configuration, in addition to the above-described effects, the number of teaching data to be stored is reduced by half, so that the effect that the capacity of the memory 8 can be saved can be obtained.

[Effects of the Invention] According to the industrial robot of the present invention, it is possible to work on the inner and outer surfaces of a curved work having a constant thickness by teaching data for one of the outer surface and the inner surface of the work. Is played.

(1) The time required for teaching can be reduced by half.

(2) The coating quality on the inner and outer surfaces can be made uniform.

(3) Since only the surface that is easy to teach among the inner and outer surfaces need only be instructed with high accuracy, the teaching quality, that is, the coating quality is improved as a whole.

[Brief description of the drawings]

1 to 5 are views showing one embodiment of the present invention,
FIG. 1 is an overall configuration diagram of an industrial robot, FIG. 2 is a configuration diagram of a robot controller, FIG. 3 and FIG. 4 are conceptual diagrams showing an operation of the present invention and a relation of a coordinate system, respectively, and FIG. FIG. 4 is a PAD diagram showing the operation of the control calculation unit. 1. Robot body 2. Robot controller 2a
Setting means (key switch), 2b Control arithmetic unit 3 Work implement 4 Work.

Claims (1)

(57) [Claims] An industrial robot for performing a work on a workpiece by moving said work implement based on data for determining the position and orientation of a mounted work implement, wherein the work implement is determined by said data. Setting means for setting a distance between a position and orientation and another position and orientation of the work implement opposed to the position and orientation with the work interposed therebetween; and the setting means for the position and orientation of the work implement determined by the data An industrial robot comprising: a control operation unit that calculates new data that is another position and orientation of a work tool that moves while maintaining a distance set by the following.