JPS62191903A - Work robot - Google Patents

Abstract

PURPOSE:To remarkably diversify the attitude actions of a tool, to enhance its control function, to eliminate the interruption and stop of work and to improve the work efficiency by incorporating a slope action axis between the slew action axis of a robot wrist part and a rotational action axis. CONSTITUTION:The slew action axis 14 to slew and operate a welding torch (a) is continuously installed on the end of a robot arm, that is, the end of a vertical action axis 13. The slope action axis 15 to incliningly operating the welding torch (a) is perpendicularly disposed on the end of the slew action shaft 14, and the rotational action axis 16 with a work tool holder 17 to rotate and operate said torch (a) is protrusively disposed perpendicular to both axis 14 and 15, thereby constituting the robot wrist part. A computer 23 sots out the actions of the axis 14 and 15 for positional direction due to the slew of the torch (a), proceeding and reteating angles due to inclination and an inclination angle due to rotation, and controls the axis 14 and 15 through numerical analysis using coordinate inversion. The computer calculates the angles of respective shafts, selects answers which can switch the shaft angle in an attitude at the leading edge to that in an attitude at the tailing edge, and issues an action command to a robot main body 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a working robot applied to various works such as arc welding.

(Prior art) To explain a conventional example of a robot for arc welding work, the posture of a welding torch (work tool) held and operated by the robot wrist provided at the end of the robot arm and the trajectory drawn by its tip are Continuously changing control is required for the welding line, but since the stroke of each axis of motion of the robot is finite in response to this requirement, the operator has to control the welding line (working position) of the workpiece. , the welding torch position at the end of the welding line and the position during the welding line are assumed, and the starting position is determined before teaching (teaching). As a result, there is a large difference in teaching time depending on the skill of the worker, which has an impact on the robot's operating rate.

In addition, with the advancement of software, control devices with coordinate conversion functions are being used, and robots that are controlled by detecting positional deviation when setting a workpiece and shifting teaching data to match the setting state of the workpiece have appeared. However, if the workpiece is moving in parallel, there will be no particular problem, but if the workpiece is rotationally misaligned, the posture of the welding torch at the start and end of the welding line will change from when it was taught, causing the robot to There are cases where the stroke range of the operating axis is exceeded, rendering work impossible, and the function cannot be used effectively.

On the other hand, in order to prevent the stroke from extending beyond the stroke range, it is possible to increase the stroke of the operating axis, but considering the tension of the welding wire conduit that connects to the welding torch, there is a limit due to the design and it is not economical. It cannot be said that it is an effective method.

A conventional example of an arc welding robot will be explained with reference to FIG. 6, which includes a horizontal operating shaft (1), a horizontal operating shaft (2) disposed in the orthogonal direction to the horizontal operating shaft (1), and In a robot arm (1, 2, 3) consisting of a vertical up-and-down operating shaft (3) disposed at the end of a box (2), a welding torch (for both work) (
A rotating shaft (4) for rotating the welding torch (α) is arranged in series, and a rotating shaft (6) for rotating and tilting the welding torch (α) projects at a right angle at the tip of the rotating shaft (4). The welding torch (α), which is held by the work tool holder (force) at the tip of the rotational movement axis (6), is moved forward and backward, horizontally and vertically by the robot arm, and rotates by the robot wrist ( 104), and by the rotational movement (106), it is directed to, for example, the welding line (C) of the workpiece (b) shown in FIG. 7, and the movement is controlled along it.

In addition, the welding torch (α) is moved from the solid line position to the chain line position by posture control as shown by the arrow according to the teaching data with respect to the set position of the workpiece (b) shown in FIG. 8(A), but in actual During work, the set may be rotated by α degrees as shown in the workpiece (7) shown in FIG. 8(B).

(Problems to be Solved by the Invention) In the above-mentioned conventional work robot, the range of motion for the robot changes due to workpiece shift, etc. during operation different from the time of teaching to the robot, and the movement axis that occurs due to this changes. There are problems such as the robot becoming trapped due to being out of the stroke range, causing the robot to stop and the work to be interrupted.

(Means for Solving Problems) The present invention is intended to solve the above-mentioned problems. a tilting operation shaft disposed perpendicularly to the end of the shaft for tilting the work implement; and a work implement holder protruding from the tilting operation shaft and disposed perpendicular to the axes for rotationally operating the work implement. By configuring the robot wrist with a rotary motion axis, the operating posture of the work tool can be diversified, and each axis can be used to change the position direction by turning the work tool, forward/backward angles and rotation by #l tilt. We have attached a work tool control device that uses MfP + angle according to the numerical analysis using coordinate transformation, and uses this control to determine the continuity of the work tool's motion with respect to the workpiece and selectively control it. This improves performance and solves the problems mentioned above.

(Function) By incorporating a tilting motion axis between the rotation motion axis and rotation motion axis of the robot wrist, the operating posture of the work tool is diversified, and the work tool can be moved forward and backward by the tilting motion axis. Corner control elements have been added, making it possible to control the operating posture of the work tool in response to workpiece misalignment, etc.

(Example) An example of the present invention is shown in FIGS. 1 to 5,
As shown in Figure 1, a welding torch (for both work) (α) is attached to the end of the robot arm, that is, the end of its vertical movement axis (13).
A pivoting shaft (14) for rotating the welding torch (α) is arranged in series, and a tilting shaft (15) for tilting the welding torch (α) is disposed at right angles to the end of the pivoting shaft (14). A rotary operation shaft (16) with a work tool holder (17) for rotating the welding torch (α) is attached to the shaft (15).
) (15), and is configured on the robot wrist portion so as to protrude at right angles to (15). In the figure (104) is the turning movement by the turning movement axis α, and (105) is the forward movement by the tilting movement axis (15).
The backward tilt movement (106) is a rotation movement by the rotation movement axis (16).

Furthermore, the welding torch (α), ie, the work tool control device,
As shown in Fig. 4, it consists of a sensor (21) (or position information input device) that detects the position of the workpiece (b), an interface (22), a computer (23), a memory (24), etc. c) The respective axes (14), (15), and (16) are defined by the position direction by turning the welding torch (α) (working tool), the forward/backward angle by tilting (tilting motion axis 15), and the rotation. The computer (23) of the present invention transmits teaching data of the workpiece position to the robot body (20), and in particular, the computer (23) of the present invention is controlled by mathematical analysis using coordinate conversion. 21) The displacement amount (including rotational displacement) of the workpiece (b) is calculated using the position data of the workpiece (b) inputted in step 21) and the previously taught data, and the welding data specified in the taught data is calculated using the tile analysis. Calculate the welding torch posture at the start end and end end by the amount of deviation, calculate the axis angle of each of the movement axes of the robot based on the calculation result, and convert the axis angle from the start end posture to the end posture, The function is to select an answer that allows continuous movement within the movement range (stroke) of each movement axis, and issue a movement command to the robot body (20).

The embodiment of the present invention has the above-mentioned structure, and its operation will be explained as follows.As shown in FIG. 16) The robot wrist portion of the present invention includes the second
As shown in Figures (B) and (C), each axis (14) and (1
By reversing the direction of 5λ (16) (iso0 rotation), the welding torch (work tool) (α) can take the same posture.

When the rotation angle of each axis shown in Fig. 2 (A) is set to 0°, the second
In the diagram), the rotation axis (14) is QO1, the tilt axis (15) is +900, and the rotation axis (16) is Oo
In addition, in Fig. 2 (C), the rotation axis (
14) has a 180°% tilting motion axis (15) at -900°, a rotating motion axis (16) at 180°, and a welding torch (α
) can have the same posture.

In the above two postures (B) and (C), when the turning motion axis αa is operated, if the motion range (stroke) of l1Ill (14) is ±180° (total 360°), the welding torch (α In the state shown in ) of Fig. 2, the operation of ) is 36, with the stroke end being marked E shown in Fig. 3 (A).
While the operating range is 0°, in the state shown in Fig. 2 (G), the stroke end is marked F shown in Fig. 3 (B).
The operating range becomes 60°, and the operating range is reversed by 180° in Fig. 2 (q). ),
By properly using the state (C), it is possible to perform continuous welding without going out of the operating range during welding.

The flow of the algorithm for the operation can be shown as shown in FIG. Control elements for forward and backward angles have been added to control the working implements as described above. tIIJ control is possible.

In the embodiments described above, welding work was mainly explained, but the present invention is applicable to various types of work.

(Effects of the Invention) The present invention has the above-mentioned configuration, and by incorporating a tilting movement axis between the rotation movement axis and the rotation movement axis of the robot wrist, the posture movement of the work tool is significantly diversified. What is the forward and backward angle of the work implement due to the tilting movement axis? With the addition of 1 control element, the control function of the work tool in response to workpiece misalignment has been significantly improved, work interruptions and stoppages have been eliminated, work efficiency has been improved, teaching time has been significantly shortened, and robot control has been improved. This has the effect of increasing the operating rate.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a perspective view of a robot wrist showing an embodiment of the present invention, FIGS. Figures (A) and (B) are explanatory diagrams showing the operating range of the work tool when Figure 2 (B) < Q, Figure 4 is a block diagram of the control device, and Figure 5 is a flow diagram of the operation algorithm of the present invention. , Fig. 6 is a perspective view of a conventional robot wrist, Fig. 7 is a perspective view showing a welding posture by a conventional robot, and Fig. 8 (A) and (B) show normal setting of workpieces and workpiece misalignment. FIG. α: Work tool (welding torch), 13: Robot arm (vertical operation axis), 14: Swivel operation axis, 15: '#l oblique operation axis, 16 2-rotation operation axis, 17: Work tool holder, 21: Sensor , 22: Interface, 23: Computer, 24: Memory Sub-Agent Patent Attorney Kaihon Important Literature 2 People Figure 1 Figure 2 (A) Child Figure 3 (A) (B) Rabbit Figure 5

Claims (1)

[Claims] a rotational movement axis that is connected to an end of the robot arm and rotates the work tool; a tilting movement axis that is disposed at right angles to the end of the rotational movement axis and tilts the workpiece; The robot wrist is provided with a rotary operation axis with a work tool holder that is protruded and arranged at right angles to the two axes and rotates the work tool, and the robot wrist part is provided with a rotary operation axis with a work tool holder that is protruded and arranged perpendicularly to the two axes, and that rotates the work tool. Equipped with a work tool control device that controls the direction, advance/retreat angle due to tilt, and tilt angle due to rotation through mathematical analysis using coordinate transformation, and determines and selectively controls the continuity of the work tool's motion with respect to the workpiece through this control. A working robot that is characterized by the following: