JPS6258304A - Planar copying controller - Google Patents

Abstract

PURPOSE:To attain the planar copying control by calculating the interpolating points on a plane of the area enclosed by several teaching points on the plane and tracing basically those interpolation points. CONSTITUTION:A controller 5 first supplies at least four corner points T1-T4 on a working plane and calculates the dividing points P1-P3 on a line connecting two points T1 and T2 and then the dividing points Q1-Q3 on a line connecting both points T3 and T4 respectively. Furthermore a line interpolating means applies the linear interpolation between dividing points Pi and Qi. Then the controller 5 moves a working tool 3 via an orthogonal coordinate type working robot 2 so that the points T1-T4, Pi, Qi and the interpolating points obtained by the interpolation are traced. At the same time, the controller 5 gives the feedback control at least to the final shaft of the robot 2 based on the output signal delivered from a detecting means for working state of the robot.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention is capable of detecting points on the surface (area interpolation points) in an area surrounded by lines connecting the input points when predetermined points on the surface are input.
The present invention relates to a surface tracing control device that calculates and moves a work tool by basically tracing those points and also using feedback control.

"Prior art and its problems" Conventionally, when two points on a line are input, the points on the line between those two points (linear interpolation points) are calculated, and those points are traced to the basic point. Linear tracing control devices that also use feedback control to move a work tool are known.

Such a linear tracing control device is used, for example, when a welding robot performs fg welding work.

In other words, when the operator teaches several points on the welding line, the linear tracing control device finds interpolation points between the taught points, basically traces those points, and performs detailed tracing using arc sensor control, etc. The welding torch is moved by performing feedback correction.

By the way, for example, in polishing robots, painting robots, etc., surface movement is more problematic than linear movement. This is because the object of such work is a surface.

Therefore, it would be convenient to have a surface tracing control device that corresponds to the linear tracing control device described above.

However, conventionally, there is no such surface tracing control device, and there is a problem in that the burden of teaching surfaces such as polished surfaces and painted surfaces is extremely heavy.

``Object of the Invention'' The object of the present invention is that, if several points on a surface are taught, interpolation points on the surface in the area surrounded by the taught points are calculated, and those interpolation points are calculated. An object of the present invention is to provide a surface tracing control device that moves a work tool by basically tracing a point and making corrections using feedback control.

"Structure of the Invention" The surface tracing control device of the present invention provides at least four surfaces on a work surface.
corner points T+, T2. Input means for manually inputting T3 and T4, dividing points P2 and P on the line connecting corner points T2 and T2
2. ...+PTl-1 is calculated and the corner points T2, T
The dividing point Q1 on the line connecting 4. Division point calculation means for calculating Q2, ..., Qn-1, between corner points T1 and T3, between division points PL and QL (i=1 to n-1), and corner point T2,
a linear interpolation means for linearly interpolating between T, a detection means for detecting the working state, and a work robot moves the work tool so as to trace the nine corner dividing points and the interpolation point obtained by interpolation. The present invention is characterized in that it further comprises a working robot control means for performing feedback control of at least the final axis of the working robot based on the output signal from the detection means.

"Example" The present invention will be described in more detail below based on the example shown in the drawings. Here, Fig. 2 is a front view of a polishing robot system including the surface scanning control device of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a flowchart of in-plane interpolation processing, and Fig. 4 is a @polishing robot system. Flowchart of reproduction processing for work, Fig. 5 is a spatial conceptual diagram of corner points, etc., Fig. 6 is a flowchart of area processing, Fig. 7 is a spatial conceptual diagram of corner points, etc. is a flowchart of intra-plane interpolation processing, and FIGS. 9 to 11 are spatial conceptual diagrams of corner points, etc. Note that the present invention is not limited to these first embodiments.

Polishing robot system 1 shown in Figures 1 and 2
consists of a Cartesian coordinate robot 2 having three basic movement axes: The reaction force detector 4 and the control device that controls them! It basically consists of i5.

The orthogonal coordinate robot 2 has the same configuration as conventionally known, and as mentioned above, the arm part has the basic degrees of freedom in the three axes of X, Y, and Z, and in addition, the wrist part 21 has the basic degrees of freedom in the three axes, α, β, γ
It has three degrees of freedom of rotation.

The grinder 3 has the same structure as the conventionally known structure, and the grinding wheel 3
1 is rotated to perform polishing work.

The reaction force detector 4 has a conventionally known configuration, and specifically includes, for example, a load cell or a load current detector for a grinder.

The control device 5 has a convenience store as its center,
It has the same functions as a conventional control device, and also has the function of a surface tracing control device consisting of the following means.

That is, the control device 5 (1) (1) instructs the selection of planar interpolation, cylindrical interpolation, and spherical interpolation, and (2) instructs the four corner points of the polished surface, that is, the corner points T2, T,.

T2, "r, and ■ corner point T between corner points T2 and 73, and corner point T between corner points T2 and T1, and ■ corner point T7 and corner point T between corner points T1 and T2], Corner point T8 between T and corner points Ty, Ts (or T5, TG
) corner point T between ), ■ pitch p of the polishing line, ■ instruction to select sequential one-time polishing and skipped two-time polishing, ■ target reaction force R01 reaction force allowable width r0 and reaction force control direction ( (For example, front or rear); ■Grinder movement speed■; Input means for inputting (2) ■Calculation of division numbers n and n' based on @ grinding line pitch p; ■Corner point TI and corner point Dividing points PI+P2 by dividing the line segment connecting point T2 into n equal parts. ..., calculation of Pn-1, and (2) division points Q2, Q2, by dividing the line segment connecting corner point T3 and corner point T4 into n equal parts. ...Calculation of Qo-, ■Calculation of dividing points R1, R1, ...-Rn-1 by dividing the line segment connecting corner point T and corner point TG into n equal parts, ■Corner point' Calculation of dividing points p2, p2,...l Pfl-1 by dividing the space between corner point T1 and corner point T7 in n equal parts in the arc connecting r1, point T and corner point T2, and ■Corner Dividing points P ′ I + P ′2 + ”′, P ′ n− by dividing the space between corner point T7 and corner point T1 in the circular arc connecting point T1, corner point T7, and corner point T2 into n equal parts.
Calculation of 1, and dividing points Q2, Q2,... Calculation of Q, -, and ■ Division point Q'2 by dividing the space between corner point T8 and corner point T into n' equal parts in the arc connecting corner point T3 and corner point T, and corner point T. ,Q″2....,Q',-.

Calculation of , and ③ dividing point R+ + R2-..., Rn by equally dividing the space between corner point T5 and corner point T in the arc connecting corner point T8, corner point T, and corner point T6. -1, and dividing points R'2, R' by dividing the space between corner point T9 and corner point T6 into n equal parts in the arc connecting the point T5 between the [phase], the corner point T9, and the corner point T6. (3) Between corner points T1 and T3, between dividing points P' and Q, and between corner points T2 and T4. , plane interpolation calculation means for performing linear interpolation between a corner point and an adjacent dividing point, between dividing points P, and between dividing points Q; (4) corner point T1, corner point T, and corner point T;
3, dividing point P.

Circular interpolation is performed between , dividing point R, and dividing point Q, and between corner point T2, corner point TG, and corner point T, and between a corner point and an adjacent dividing point, and between dividing points P, (5) Curved surface interpolation calculation means for performing linear interpolation between the dividing points Q, and (5) each axis X, Y, Z, α, β, T of the robot 2 so as to trace the point between the two corner points and the interpolation point. The robot 2 has a configuration of a surface scanning control device that is equipped with a movement control means that moves the grindstone 33 by determining the rotational speed and performs feedback control of the T-axis of the robot 2 by controlling the reaction force.

Next, the operation of this polishing/robot system 1 is controlled by the third
This will be explained with reference to FIGS.

First, the surface to be polished is a flat surface, and the opening T shown in Fig. 5 is
, T2T,T, and from corner point T+1'1 to corner point T
, side, the operator selects plane interpolation since the polishing surface is a plane, and sends the selection instruction to the teaching box 5. of the control device 5.
Enter from. This is due to the function (2) of the input means in (1) above.

When planar interpolation is selected, the input method in (1) above allows ■
Only ■ to ■ are selected. Further, in the division point calculation means (2) above, only ■ to ■ are selected. Furthermore, the above +3
1 (Of the 41 interpolation calculation means, only (3) is selected.

Therefore, the four corner points Tl, T2, T3, and T+ are input. Here, the corner point T is the starting point of the polishing operation, the corner point T3 is the corner point that the grinder 3 reaches first after moving, the corner point T4 is the diagonal point of the corner point T, and the corner point T2 is a diagonal point of the corner point T].

Furthermore, the pitch p of the polishing line is input. Here, the pitch p of the polishing lines is the interval between scanning lines when polishing the polishing surface in a scanning manner.

Further, since polishing is performed once in one direction, an instruction to select polishing once in sequence is input.

Further, input the target reaction force 801, the allowable width of the reaction force, and the reaction force control direction.

Also, the grinder moving speed V is input.

When the above input processing, that is, step S1 in FIG. 3 is completed, the computer calculates the corner points T2, the interval between T2, the corner point T3.
Compare the T4 intervals and divide the larger interval by the pitch p. Then, divide the even value closest to the quotient into the division number n
(S2).

Next, the computer calculates a division point P that divides the line segment connecting the corner point T and T2 into n equal parts. Similarly, the corner point T
A dividing point Q, which divides the line segment connecting 3 and T1 into n equal parts, is calculated (S3).

Next, in step S4, based on the previously taught speed V, the dividing point P is set between the corner points T1 and T3.

and Q, between corner points T2 and T, between corner point T and dividing point Q
, between the dividing points p, 1-1 and R2, (where j =
1 to n/2-1), dividing point Q2+ and Q,
During Ill, linear interpolation is performed between the division point Pn-1 and the corner point T2 to obtain interpolation points Ul, U2 + u, .

Once P□, Q2, and U are determined as intra-plane interpolation points in this way, polishing work is performed based on these intra-plane interpolation points.

First, the computer determines the starting point T of the polishing work, the point X,
Output Y, Z, α, β, and T to robot 2.

As a result, grinding wheel 3. When reaches the initial position, T is advanced at a constant speed in the reaction force control direction while sensing the reaction force R.

When the reaction force R reaches a predetermined value R9 that is smaller than the target reaction force R0, X, Y, Z, α, β for the first interpolation point U1
is output to the robot 2, and the grinder starts moving.

At this time, regarding γ, if the reaction force R is smaller than R, -ro, γ is advanced in the reaction force control direction, and if the reaction force R is larger than R0+r0, γ is pulled in the opposite direction to the reaction force control direction, and the reaction force R is Ro-r
If it is between o and R110ro, the current position of T is maintained. That is, reaction force control is performed.

In this way, the regeneration process is performed as shown in FIG.
-T, -"Q, -...-4P2 j-1-op,
I→Q2゜-"Q2.+, →...-P n-1-7
Each degree of freedom X of the robot 2 is such that the grindstone 31 moves in the order of 2-74.

The y, z, α, and β are driven to basically trace the in-plane interpolation points, and reaction force control is performed on the T axis.

Here, "." may be 0, but in order to make the surface cut by the grinder uniform, it should be set to an appropriate small value (for example, 1 k
It is preferable to set g f ).

Such reaction force control can also be performed by mechanical control such as expansion and contraction of a spring.

FIG. 5 shows an example of an outline of a trace when the number of divisions is n-4.

Note that instead of finding all the interpolation points Ub at once by linear interpolation calculation, first find the interpolation point only between the corner points T1 and T3, and proceed with polishing between the corner points T and T. Then, find the interpolation point between the corner point T and the division point Q, and in this way find the interpolation point for only one section, proceed with polishing for that section, and during that polishing, calculate the interpolation point between the corner point T and the dividing point Q. Alternatively, interpolation points may be found for .

In addition, instead of reaction force control, or in addition to reaction force control,
Grinding wheel 3 uses a distance sensor to keep the distance within a certain range.
Distance control may be performed to control the feed amount of 1.

Now, in the above explanation, the forward polishing is selected and the number of times of VR polishing plate is set to one time, but it is more preferable to set the number of times of polishing to two times, and as shown in FIG. and 2
It is preferable to follow a different path for the second polishing, that is, it is better to select interlaced two-time polishing as the polishing mode.The case where two-interlaced polishing is selected will now be described.

In this case, the difference is that skip polishing is selected twice in step Sl, and a value twice n obtained in step S2 is used as the division number n, but other than that, the basic processing procedure is the same as in the step It is the same as 81 to S4.

The reason why the division number n is set to twice the value of n is that the path of the first polishing and the path of the second polishing are different.

As shown in Figure 6, the regeneration process when performing polishing work is such that for the first polishing, the path between even-numbered division points is passed through, and the path between odd-numbered division points is skipped. . Then, for the second polishing, the mirror moves in the opposite direction, passing along the path between the odd-numbered dividing points and skipping over the path between the even-numbered dividing points.

Incidentally, FIG. 7 shows the case of two-time interlaced polishing, where the number of divisions is n=8.

Next, a case where the surface to be polished is a curved surface will be described.

If the surface to be polished is a substantially cylindrical surface as shown in FIG. 9, the operator selects cylindrical surface interpolation.

Then, the input means in (11) above selects ■■■～■, the division point calculation means in (2) above selects ■～■, and the interpolation calculation means in (31 (4) above) selects only (4). is selected.

That is, the corner point T1. which is the starting point of the polishing operation. Its corner point T
A corner point T3 that is adjacent to 1 in the curved surface direction; a corner point T1 that is diagonal to the corner point T; and a corner point T that is diagonal to the corner point T3.
Enter 2. Also corner point T.

and T3, that is, corner point T5, and corner point T2
Input a corner point TG between and T.

Further, the pitch of the polishing line, etc. is input (S11).

The computer of the controller @5 divides the largest distance among the distance M between the corner point T and T2, the distance between T3 and T, and the distance between T and T6 by the pitch p, and calculates the distance by the pitch p. The even value closest to the quotient is set as the division number n (312).

Next, the straight line connecting corner points T1 and T2, the straight line connecting corner points T and TG, and the straight line connecting corner points T5 and TG are divided into equal parts according to the division number n, and dividing points P2 and Q are obtained.

and RL (+=1 to n-th are calculated (313).

Next, between corner point T, corner point T5 and corner point T, dividing point PI
Circular interpolation is performed between and R1 and Q, and between corner point T2, corner point T6, and corner point T4, and interpolation points IJ 1 and U2 are calculated.
1 U3 , . . . are calculated (S14).

Next, between corner point T3 and division point Q1, division point P2 +-+
and R21, dividing point Q9. A linear interpolation calculation is performed between and Q2+++ and between the division point Pn-1 and the corner point T2 to find an interpolation point (S15).

In this way, corner points Tl + T2 + T3, interpolation points within the curved surface surrounded by TG, are obtained.

When regenerating for polishing, step S5 described with reference to FIG. 4 and step S56 described with reference to FIG. 6 are performed. This is the same as S7.

FIG. 9 shows a schematic diagram of a case of 11 m 4 in which polishing is performed once in sequence, and FIG. 10 shows a case of n-8 in which polishing is performed two times in an intermittent manner.

If the surface to be polished is approximately spherical, the operator selects spherical interpolation.6 Then, in the input means (11) above, ■ to ■ are selected,
The division point calculation means (2) above selects ■■ to [phase], and the interpolation calculation means (41) selects only the surface interpolation calculation means (4).

The individual processing is the same as for the cylindrical surface described above.

FIG. 11 schematically shows the case of sequential polishing once with nwn'=4.

Note that the distances between corner points T3 and division point Q1, between division points p2+-1 and P2j, between division points Q21 and Q21+1, and between division point Pn-1 and corner point T2 are short, so Although linear interpolation is used as in the case of the cylindrical surface, it goes without saying that interpolation may be performed using circular arcs obtained by the first circular interpolation.

As another example, since reaction force control cannot be performed in the case of a painting robot, a distance detector such as an eddy current sensor is used to ensure that the distance between the painting gun and the painting surface is always the target capacity MD, and the allowable width d0. One example is one that performs feedback control of the position of the final axis of the robot so that it falls within the range of .

"Effects of the Invention" According to the present invention, at least four corner points Tl on the work surface
, T2, Tx, input means for inputting TG, corner point T2, dividing point p on the line connecting "R2.

, R7, . . . , Pn-+ are calculated, and dividing points Q2, Q2 . −． Division point calculation means for calculating Qn-i, between corner points T2 and T3, between division points PL and QB (i-1 to n 1), and corner point T
2. an intra-line interpolation means for performing intra-line interpolation between T, a detection means for detecting the working state, and a working robot moves the working tool so as to trace the nine corner dividing points and the interpolation points obtained by interpolation. There is provided an in-plane scanning control device characterized by comprising a work robot control means for performing feedback control on at least the final axis of the work robot based on the output signal from the detection means. 4 points or 6 points on the surface
When you input a point or 9 points, the interpolation points on the surface in the area surrounded by the line connecting those input points are obtained by calculation, and by basically tracing those points, it works to cover the entire area. The tool is moved.

Therefore, the burden of teaching work surfaces such as polished surfaces and painted surfaces is significantly reduced, and the teaching time is also significantly shortened.

At this time, the work tool is finely feedback-controlled according to the work situation, so there is no misalignment of the workpiece.

Work can be performed with high precision even if there are variations.

Therefore, the burden of teaching work can be reduced in that the accuracy of teaching can be made relatively rough.

[Brief explanation of the drawing]

Fig. 1 is a front view of a polishing robot system including the in-plane tracing control device of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a flowchart of in-plane interpolation processing, and Fig. 4 is for polishing work. Figure 5 is a spatial conceptual diagram of corner points, etc. Figure 6 is a flowchart of area interpolation processing, Figure 7 is a flowchart of the reproduction process.
The figure is a spatial conceptual diagram of corner points, etc., FIG. 8 is a flowchart of intra-plane interpolation processing, and FIGS. 9 to 11 are spatial conceptual diagrams of corner points, etc. (Explanation of symbols) 1... Polishing robot system 2... Orthogonal coordinate robot 28... Wrist part 3... Grinder 3,...
- Grindstone 4... Reaction force detector 5... Control device T2, T2. T3. "r,...corner points T2, T6
．． "r2,"r2, T, ... point P2, P2, ...
・,Q2,Q2,...,R,. R2...Dividing point.

Claims (1)

[Claims] 1. (a) At least four corner points T_1, T on the work surface
Input means for inputting _2, T_3, and T_4; (b) dividing point P_1 on the line connecting corner points T_1 and T_2;
P_2, ..., P_n_-_1 are calculated, and dividing points Q_1, Q_2, on the line connecting corner points T_3 and T_4 are calculated.
..., division point calculation means for calculating Q_n_-_1, (c) Between corner points T_1 and T_3, division points P_i, Q_i
linear interpolation means for linearly interpolating between (i=1 to n-1) and between corner points T_2 and T_4, (d) detection means for detecting the working state, and (e) the corner points and divisions. Work robot control means for causing the work robot to move the work tool so as to trace the point and the interpolation point obtained by interpolation, and for performing feedback control of at least the final axis of the work robot based on the output signal from the detection means. A surface tracing control device comprising: 2. The dividing point calculating means divides the line segment connecting the corner points T_1 and T_2 into n equal parts and calculates dividing points P_1, P_2, ..., P_n_
−_1, and also divides the line segment connecting corner points T_3 and T_4 into n equal parts, dividing points Q_1, Q_2, ..., Q_n_
-_1 is calculated. 3. The area scanning control device according to claim 1 or 2, wherein the linear interpolation means performs a linear interpolation calculation. 4. The input means is located between the corner points T_1 and T_3.
It is also possible to input the intermediate point T_6 between _5 and the corner points T_2 and T_4, and the dividing point calculation means divides the line segment connecting the intermediate points T_5 and T_6 into n equal parts and calculates dividing points R_1, R_2, ..., R_n_-_1
The linear interpolation means calculates the intermediate points T_5, T_6 and the dividing point R_j.
The area scanning control device according to claim 1, which performs circular interpolation calculation using. 5. The input means is located between the corner points T_1 and T_3.
An intermediate point T_6 between _5 and corner points T_2 and T_4 and an intermediate point T_7 between corner points T_1 and T_2 and corner points T_3 and T
It is also possible to input the intermediate point T_8 between _4 and the intermediate point T_9 between intermediate points T_5 and T_6, and the dividing point calculation means can input the intermediate point T_1, the intermediate point T_7, and the corner point T_2.
Dividing points P_1, P_2, ..., P_n on the arc connecting
_-_1 is calculated, corner point T_3, intermediate point T_8, corner point T_
Decomposition points Q_1, Q_2, ..., Q_ on the arc connecting 4
Calculate n_-_1 and divide the points R_1, R_2, ..., R_n_- on the arc connecting the intermediate points T_5, T_9, T_6.
_1, and the linear interpolation means calculates the intermediate points T_5, T_6, T_7, T_8,
2. The area scanning control device according to claim 1, wherein the circular interpolation calculation is also performed using T_9 and the dividing point R_j. 6. The surface scanning control device according to any one of claims 1 to 5, wherein the detection means is a reaction force detector, the working tool is a grinder, and the feedback control is reaction force control. . 7. The area scanning control device according to any one of claims 1 to 5, wherein the detection means is a distance detector, the working tool is a paint gun, and the feedback control is distance control. .