JPH04116704A - Reproduction control method for position of robot and the like - Google Patents

Abstract

PURPOSE:To improve the load of arithmetic operation by reproducing and a actuating a moving axis of a robot machine and the like along a specified path point interpolation point. CONSTITUTION:In the reproduction of a path point near PJ between PJ-1, PJ and PJ+1, a teaching path is regularly reproduced to the path point between PJ-1 and PJ and an i-numbered path point interpolation point P1 calculated by an expression I is reproduced as a target. Thus, a robot axis moves through a path point moving path. In the expression I, it is set to be i=0 to N=1. Thus, the load of the actuation can considerably be reduced because the calculation of a target point in the middle of the execution of the path point interpolation requires only the simple operation.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a position regeneration control method applied to robots, manipulators, machine tools, transportation machines, etc.

<Conventional technology> An example of a conventional robot position regeneration mechanism is shown in FIG.

In the memory 2 shown in the figure, a plurality of points located on the path on which the robot should move are stored in advance as teaching point information.
Further, the CPU I is configured to receive information on teaching points stored in the memory 2 and position information from the robot axis 4 that drives the robot axis 4. Therefore, the CPU
I controls the robot axis 4 using the actuator 3 based on this information.

Conventionally, when reproducing a robot, CPU 1
The system continuously reproduces the information of teaching points that have already been taught from the memory 2, and sets a plurality of points as interpolation points on a teaching path that linearly connects the reproduced adjacent teaching points.

The result is output to the actuator 3, and the actuator 3 controls the robot axis 4 based on the set interpolation point. As a result, the robot axis 4 was moving along the taught path calculated by the CPUI.

<Problem to be solved by the invention> In the above-mentioned conventional technology, in the reproduction operation of the robot,
As a measure to improve cycle time, a bus point route correction function has been selectively added.

Here, the bus point route correction function refers to a curved route that is a shorter cut if you detour around the taught point, as shown in Figure 6, rather than a taught route that connects adjacent taught points with a straight line. The detoured taught point is called a bus point, and the detoured curved path is called a bus point movement route. The teaching point that is the pass point is
In most cases, straight lines connecting adjacent teaching points are orthogonal to each other.

However, in conventional bus point route correction methods, the route interpolation calculation methods include circular interpolation, quadratic curve approximation,
Complex curve interpolation such as spline interpolation was used.

For example, in the method shown in FIG. 6, the route is interpolated by circular interpolation.

That is, as shown in FIG. 6, adjacent teaching points Pj-1+P
Of I+PI, it is a shortcut to bypass the intermediate teaching point PIi, so the intermediate teaching point P.

is a pass point.

Therefore, the vicinity of the teaching point PIi, which is a pass point, for example, a range within a fixed distance is defined as a bus point area. Then, within that bus point area, the teaching point P I-1+
An arcuate path with a radius of curvature R that connects to the straight taught path between P j + P Il+ is set as a path point movement path. Furthermore, a plurality of interpolation points are set at regular intervals on this bus point movement route.

Here, adjacent teaching points PIi, PIi, PIi.

Assuming that the angle formed by the taught path connecting the points is 90°, the distance of the taught path within the pass point area is 2R, while the distance of the path point movement path is short, πR/2, allowing for quick movement. It turns out.

However, calculating a curved path such as a circular arc path as a path point movement path and setting a large number of interpolation points on the curved path requires a complex and large amount of calculation, and for this reason, the CPU This increases the load and becomes an obstacle to improving other functions, such as speed and route accuracy.

The present invention has been made in view of the above-mentioned prior art,
It is an object of the present invention to provide a robot position regeneration control method that can significantly improve the calculation load.

Means and operation for solving the problem> (1) Bus point interpolation point Pj is not approximated by a curve, but proportionally on a straight line connecting virtual interpolation point PIi on the approach side and virtual interpolation point Po+ on the exit side within the pass point area. I tried to find it only by calculation.

(2) Since only proportional calculation is performed in this way, the calculation is greatly simplified and an effect close to curve approximation can be obtained.

(3) Furthermore, since an effect similar to curve approximation can be obtained, functional improvements such as a significant increase in the degree of freedom in setting the speed within the pass point area can be obtained.

<Examples> The present invention will be described in detail below with reference to examples shown in the drawings.

1 to 3 show a position regeneration control method for a robot, etc., according to an embodiment of the present invention. The apparatus to which this method is applied includes a CPU 1, a memory 2, an actuator 3, and a robot axis 4, as shown in FIG.

In this embodiment, according to the flowchart shown in FIG.
The robot axis 4 is braked. .

That is, after reaching the teaching point PI-1, the CPU reproduces the coordinate position of the next teaching point PIi from the memory 2, and reads whether or not this teaching point PIi is to be used as a bus point.

If the next teaching point PIi is a pass-bond as shown in FIG. 2, the CPUI displays Nonosu point area entry point PIO+bus point area exit point P. Set N. Pass point area entry point P IO+ Bus point area exit point P. N is the boundary between the entrance and exit sides of the pass point area, and is the teaching point P I-1+
P4. This is a point on a teaching path that linearly connects successive teaching points PIi+1. The bus point area is within a certain distance L (bus point effective distance) from the teaching point PIi, which is a bus point.

Subsequently, the number of interpolation points n14 between the bus point area entry point PI0 and the teaching point P4. Bus point area escape point P
. The number of interpolation points no+ between N and teaching point 21 is calculated as shown in the formula below.

However, Vl is the teaching speed from p +-1 to PIi, V
.

+1 is the teaching speed from PIi to PIi+, t is C
This is the interpolation point calculation cycle of PU1.

Here, if the time taken to pass through the bus point area is the same as when there is no bus point, the number N of virtual interpolation points is expressed by the following equation.

N ”” (nz + nat) / 2 −
(3) Also, if speeding up is desired, it is better to use the following formula.

N<(nli+noI)/2-(4) The number N of virtual interpolation points is determined based on equation (3) or equation (4).

Furthermore, the pass point area entry point PIi. From teaching point P
Virtual interpolation point P between 4 and 11, bus point area escape point P. A virtual interpolation point P 01 between N and the teaching point 23 is calculated according to the following formula.

P Il= P l, + q< P I−P I. )
−151P at”P r+ −#−(PIiON
-P+)''(6) Pi=0 to N-1.

Next, pass point area entry point PIi.

From bus point area escape point P. The i-th bus point interpolation point Pj up to N is calculated according to the following formula.

Pl-Kojo Yunu "Giant" 2'... (7) N+1 Pi=o to N-1.

As described above, in the bus point regeneration near PIi between PIi-1→PIi→Pj+1, Pl-1→
After normally reproducing the taught route up to the pass point area between P3, by reproducing the i-th bus point interpolation point PIi calculated by the above equation (7) as the target,
As shown in FIG. 4, the robot axis 4 moves along the bus point movement path.

In the present invention, the bus point interpolation points are obtained by proportional calculation using the above (n formula), but the bus point movement route connecting the interpolation points is close to a curve approximation (
, has the same effect as curve approximation.

Furthermore, if the teaching point Pj is not a bus point as shown in Fig. 3, an interpolation point is set as usual on the teaching path of the teaching point Ps-1+PI+PIi+1, and the robot axis 4 is regenerated with the interpolation point as the target. let

<Effects of the Invention> As explained above in detail based on the embodiments, in the present invention, the target point calculation during execution of bus point interpolation requires only the simple calculation of the above equation (7). The load is significantly reduced. Further, since the speed during bus point interpolation is determined only by the number N of interpolations within the bus point area, the degree of freedom in speed setting is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a flow chart showing a position regeneration control method for a robot, etc. according to an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing the principle of the present invention, and FIG. FIG. 5 is an explanatory diagram showing the determined bus point route, FIG. 5 is a configuration diagram of a conventional robot position reproduction mechanism, and FIG. 6 is an explanatory diagram of a conventional bus point interpolation route. In the drawing, l stands for CPU. 2 is a memory, 3 is an actuator, and 4 is a robot axis.

Claims (1)

[Scope of Claims] In a position regeneration control method in which a moving axis of a robot machine or the like is regenerated along a teaching point P_j, within a pass point area in the vicinity of a teaching point P_j which is a pass point, adjacent teaching points P_j_- _i, P_j, P_j
A plurality of virtual interpolation points P_I_i and P_O_i are installed on the teaching path that linearly connects _+_i, and the teaching point P_j_-
Virtual interpolation point P_I_i and teaching point P_j between _i and P_j
, P_j_+__i, and the path point interpolation point P_i is proportionally calculated on the straight line connecting the virtual interpolation point P_O_i between P_j_+__i as shown in the formula below, and the movement axis of the robot machine, etc. is regenerated along this path point interpolation point P_i. A method for controlling position reproduction of a robot, etc., characterized by: P_i=(N+1-i)P_I_i+i・P_O_i/
N+1 However, i=0 to N-1, and N is the number of interpolation points.