JPS6329811A - Control device for plural arms - Google Patents

Abstract

PURPOSE:To easily teach the positioning work of plural arms by selectively switching an arm on an operating position to be taught and properly switching the arm to be taught at the time of teaching. CONSTITUTION:A signal (a) indicating simultaneously operation is inputted to a simultaneous operation command means 1 and an identification number (b) of an arm to be a reference and objective position data (c) for operating the reference arm are simultaneously inputted to an objective position arm selecting and switching means 3 and a plural arm operating position determining means 5. A start position detecting means 2 and the means 3 are started by a simultaneous operation command means 1 and the means 2 detects the starting positions of respective arms and sends the detected results to a relative position determining means 4 and the means 5. The means 4 receives the arm ID number (b) sent from the means 3, calculates a relative position for the selected arm starting position out of respective arm starting positions and sends the calculated result to the means 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an industrial robot having multiple arms, and in particular to teaching and reproduction of simultaneous motion of multiple arms.

BACKGROUND OF THE INVENTION The following methods have been considered for teaching motions when a plurality of arms perform simultaneous motions.

In the first method, the movement position is taught separately for each arm, and the start and end of the movement are synchronized when reproducing the movement. In this method, the operating position is stored for each arm.

The second method is offline teaching, typically using CAD/CAM and simulators, in which arm movement procedures and position data are edited using an offline teaching system.
Information regarding the operating position is downloaded to each arm's controller. In this method, all operating positions of multiple arms in a work operation are determined at the time of teaching, and each arm performs a certain operation according to downloaded data.

The third method uses a master slap method, in which the slap arm has a mechanism that performs the same operation as the master arm. In this case, the movement of the slave arm is always determined by the movement of the master arm.

Problems to be Solved by the Invention In the first method, since the operation position is taught for each arm, it is difficult to teach the operation while maintaining the relative positions between the arms. In addition, in the case of simultaneous movement of two arms, it is necessary to teach the movement position of two arms for one movement, so that the simultaneous movement of multiple arms can be taught separately for each arm. However, there is a problem that teaching is time-consuming.

In the second method, the motion position data is edited by off-line teaching, so the relative positions between the arms can be taken into account. However, since the movement position or movement path of each arm is determined at the time of teaching, it is difficult to perform playback operations, for example, when carrying a workpiece with multiple arms, a sensor is used to change the relative position depending on variations in the size of the workpiece. If it is necessary to change the relative positions between the arms during execution, there is a problem that the already taught positions of the plurality of arms and the changing relative positions conflict with each other and cannot be handled.

In the third method, when the relative position between the arms is changed during execution of the playback operation, it is possible to handle the case by using the master-slave function.

However, since the reference for all positioning is the master arm, all operating positions are designated by the master arm, which imposes restrictions on teaching the motion. For example, as shown in Figure 3, when using the master-slave arm to rotate the workpiece half a turn on the spot,
The operating position of the master arm remains the same, and when the size of the workpiece changes and the relative position between the arms changes, the workpiece position changes. In this way, when all reference positions for work are not determined directly from the master arm, it is time-consuming to create a corresponding movement program.

Means for Solving the Problems In order to solve the above-mentioned problems, the multi-arm control device of the present invention provides that the movement target position data given when a plurality of arms move simultaneously is related to one arm. The first invention further comprises a target position arm selection switching means for selecting and switching which arm's operation target position is the target position, and a start position detecting means for determining the position of each arm at the time of starting the simultaneous operation. , a relative position determining means for determining the relative position of each arm at the time of starting the simultaneous motion, and determining the target motion position or path of each arm from the position and relative position of each arm at the time of starting the simultaneous motion and the given target motion position. In the second invention, the target displacement determination means determines the direction and distance in which each arm should move from the simultaneous movement start position of the selected arms and the given movement target position. and a plurality of arm operation position determining means for determining the target operation position or path of each arm from the simultaneous operation start position of each arm, the direction and distance in which each arm should operate.

Operation FIG. 1 is an explanatory diagram of the first invention. When a simultaneous relative position holding operation is performed at a certain step of the operation program in the control device, a signal a indicating simultaneous operation is input to the simultaneous operation specifying means, and at the same time, the identification number of the reference arm is inputted to the simultaneous operation specifying means. The target position data C at which the reference arm should operate is input to the target position arm selection switching means and the plural arm operation position determining means, respectively. The simultaneous operation designation means activates the start position detection means and the target position arm selection switching means, and the start position detection means detects the start position of each arm and sends it to the relative position determination means and the multiple arm operation determination means. The relative position determining means receives the arm identification number sent from the target position arm selection switching means, calculates the relative position of each arm starting position with respect to the selected arm starting position, and sends it to the multiple arm operation position determining means. The multiple arm operation position determination means determines the operation target position of each arm from the given target position data and the relative position of each arm, and sends a command position signal corresponding to each operation target position to the drive means of each arm.

FIG. 2 is an explanatory diagram of the second invention. This invention differs from the first invention in the following points. The given motion target position data C is input to the target displacement determining means, and the target displacement determining means calculates the motion target displacement of each arm from this and the starting position of the selected arm, and the multiple arm motion position determining means calculates the target motion displacement of each arm. The multiple arm operation position determining means determines the target operation position of each arm from the start position and target displacement of each arm.

FIG. 4 is an explanatory diagram showing the difference in point sequences taught by the conventional method and the method using the apparatus of the present invention. In this example, arm 1 and arm 2 operate simultaneously, and arm 1
, P2. Ps and P4 are operated, and arm 2 operates Ps and Pa.
, P7, and Ps are operated. In (a), the positions of all points are taught for two arms. In (b), arm 1 is the master arm and arm 2 is the slave arm, and only the operating point of arm 1 is taught, and the operating point of arm 2 is determined by the operation of arm 1.

(C) is the case using the present invention, where Pl, P2゜P
s, Ps, and Ps are taught. The operating position P6 of the arm 2 is determined from the relative position of Pl and Ps and the operating position P2 of the arm 1, and the operating position P4 of the arm 1 is determined from the relative position of Pl and Ps.
Relative position of s and P7 and arm 2 The arm is a vertical multi-joint arm that can move in 6 degrees of freedom, each joint is driven by a motor, and the position and posture of the hand are controlled within the operating range by commands from the control device. can be taken arbitrarily.

Here, the hand position refers to the movement position that is referenced by the work movement program as necessary to perform work at the tip of the arm, and in the case of an arm that can move with 6 degrees of freedom as shown in Figure 6. , signifies the position and posture of the hand, which is marked with 9 at the end of the arm. The position and posture of the hand can be determined, for example, using an orthogonal coordinate system (xn, Yn, Zn
) and Euler angles (θ, φ, ψ) and the corresponding 4×4 matrix. Diagram O is an explanatory diagram of the configuration of the control device. It is.

The functions of the operation position command means, the position data conversion means, each position detection means i, and each drive means i are realized by programmed microcomputers. The hand position of each arm is detected by the position detection means and sent to the operation position command means. The position detection means is
The rotation angle of each joint is detected by an encoder attached to the motor that drives the joint, and the hand position is calculated using data such as a preset arm length and the offset of the hand position from the arm tip. Each drive means receives a motion target position of the hand position from the motion position command means, converts this to calculate a joint angle of the motion target, and drives a motor to move the hand to the target position. When the driving means completes the movement of the hand, it returns an operation completion signal to the operation position command means, and the operation position command means commands the arm that has completed the movement to perform the next operation.

Each arm has an individually associated Cartesian coordinate system.
The position detection means and drive means convert the position data of this coordinate system and the joint angle of the arm, but the relative relationship of the position data between the coordinate systems of each arm is calculated by the position data conversion means, and the necessary According to the command from the operation position command means, conversion between the coordinate systems of each arm is performed.

The operation position command means uses a work program by the arm as position data for the arm to operate, and issues an operation command to each arm. In the example, there is a robot language program code such as the following◇ ■ArmI GOTOPa1nt1 ■Arm1.2 GOTOPa1nt20F Arm2
re1■' Arm1.2 GOTOPo1nt20
F Arm1 rel■Arm1.2 GOTOPo
1nt20F Arm2 par
1nt1 to move to the position specified. This type of code operates each arm independently, and the operation position command means can operate each arm asynchronously. Therefore, when performing simultaneous operations on a plurality of arms, a wait is made until confirmation of an operation completion signal in response to the immediately previous operation command from the driving means of the arms performing the simultaneous operations.

■ is to operate arm 1 and arm 2 at the same time. Arm 2 is moved to the position instructed by Po1nt2, and arm 1 maintains the relative position of the hand of arm 1 and the hand of arm 2. Operate in position.

■' is the same as ■, but the positions of arm 1 and arm 2 are reversed. In other words, arm 1 is moved to the position indicated by Pa1nt2, and arm 2 is moved so as to maintain its relative position with arm 1. 0.2 also moves arm 1 and arm 2 at the same time, but The difference is that arms 1 and 2 move in the same direction and the same distance, rather than maintaining relative positions in terms of direction.

The operation of ■ is realized by the first invention, and the operation of ■ is realized by the second invention.
Realized by invention. In both cases, arms 1 and 2 that perform simultaneous operations are specified, movement target position data is specified as hand position Pa1nt2 of one arm among the plurality of arms, and the specified position data is related to arm 2. The choices are the same.

To explain the case in which the operation (2) is executed, first, as a result of the interpretation of the program code, a signal instructing simultaneous movements and the numbers 1 and 2 of the arms to be operated simultaneously are input to the simultaneous movement specifying means, and the target movement position data Po1nt 2 and P
At o1nt2, the number 2 of the arm to be operated is input to the plural arm operation position determining means and the target position arm selection switching means, respectively.

The start position detection means is activated by the simultaneous operation specifying means, and detects the current position of arms 1 and 2 that perform simultaneous operations, or detects the planned position at the time of starting the simultaneous operation according to the previous operation command. The relative position determining means calculates the relative position of the hand position of arm 1 with respect to the selected hand position of arm 2 at the time of starting the simultaneous operation.

Then, the relative position "12" of the hand position of arm 1 with respect to the hand position of arm 2 is calculated as a transposed matrix of R2T:R2.

Furthermore, the multiple arm motion position determining means interpolates a position sequence T2(j) (j =o-n) However, T2(o)=T2. T2(n) = Create a T-work to create the movement path of arm 2, and set the relative position T12 to this.
From this, the sequence of positions representing the motion path of arm 1 is calculated by T1(j)=T2(j)TI2 (J=O-n), T10) is used as the drive means of arm 1, and T20
) is repeatedly and synchronously sent to the driving means of the arm 2 in j=1 to n), thereby the arms 1 and 2 operate while maintaining the relative positions of their hands.

To explain the case in which the operation (2) is executed, first, as a result of the interpretation of the program code, a signal instructing simultaneous movements and the numbers 1 and 2 of the arms to be operated simultaneously are input to the simultaneous movement specifying means, and the target movement position data Pa1nt2 and Po
1nt2iC The number 2 of the arm to be operated is input to the target displacement determining means and the target position arm selection switching means, respectively. The start position detecting means is activated by the simultaneous operation specifying means, and detects the position T1. T2 is calculated, and the target displacement determining means determines the position of each arm from the simultaneous operation start position T2 of arm 2 selected by the target position arm selection switching means and the position T specified by the given operation target position data Pa1nt2. A sequence D(j) (j=1 to n) of displacement amounts to be operated is calculated. However, D(j) is the position obtained by interpolating D(n) and D(n).

Further, the multiple arm operation position determining means determines the operation position of each arm from the position of each arm at the time of starting simultaneous operation and the amount of displacement to be performed, as follows: T, (j) = Ti - D (D (i = 1121 j
=1 to n), and by repeatedly sending signals to the driving means of each arm in synchronization with each other, arm 1 and arm 2 move in parallel by the same amount of motion.

Effects of the Invention As described above, according to the present invention, the number of teaching points for multi-arm work is reduced, and the effort required for teaching by manually moving the arm to the work position is reduced. Further, since the arm at the operating position to be taught can be selectively switched, teaching the positioning work of multiple arms can be facilitated by appropriately switching the arm to be taught at the time of teaching. Furthermore, since the relative positions of multiple arms that perform simultaneous operations are determined at the start of simultaneous operations during execution of a work operation, if the relative positions need to be changed during work based on sensor information, etc., there may be a conflict with the taught position. This also makes it easy to create an operating program.

[Brief explanation of drawings]

FIGS. 1 and 2 are detailed explanatory diagrams of the present invention, FIG. 3 is an explanatory diagram of an example of a multi-arm motion, FIG. 4 is an explanatory diagram of a multi-arm motion teaching point, and FIG. 5 is an explanatory diagram of an example of the present invention. An explanatory diagram of an arm and a control device according to an embodiment. FIG. 8 is an explanatory diagram regarding the configuration of a control device according to an embodiment of the present invention. 1...Simultaneous operation designation means, 2...Start position detection means, 3...Target position arm selection switching means, 4...Relative position determination means, 5...
...Multiple arm operation position determining means, 6...-Target displacement determining means, 7...Sleip arm, 8...
... Master arm, 9 ... Arm 1.1
0...Arm 2.11...Control device,
12...Arm, 13...Position detecting means, 14...Driving means, 15...Operation position commanding means, 16...Position Data conversion means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure (1,b c (1(i=frn) εj
(j=:1qn) Fig. 2 α bc 6 (i=fNn)
εl (Nniihe〇) Figure 3 M4 Figure 5 @ Figure 6

Claims (6)

[Claims] (1) A hand position detecting means for each arm that controls a plurality of arms capable of independently operating; and an operation position command means that generates a command position signal based on given operation target position data. , a control device comprising an arm driving means for moving a hand to a position according to the command position signal, and a means for mutually converting position data between coordinate systems of each arm, wherein the position command means simultaneously moves a plurality of arms. A simultaneous motion designating means for specifying that a relative position holding motion is to be performed, and motion target position data given when performing simultaneous motions are related to one hand position, and the motion target position data is related to which arm's hand. a target position arm selection switching means for selecting and switching between the two arms, a start position detection means for detecting or calculating the hand position of each arm at the time of starting the simultaneous motion, and a start position detection means for detecting or calculating the hand position of each arm at the time of starting the simultaneous motion; Relative position determination means for calculating the relative position of the hand with respect to the selected arm hand; 1. A control device for a plurality of arms, comprising: a plurality of arm movement target position determining means for determining a movement target position or a movement target path of the plurality of arms. (2) When the arm movement is completed, the drive means returns an arm movement completion signal to the movement position command means, and if simultaneous movement is performed, whether or not all arms performing simultaneous movement have completed the previous movement. 2. The control device for a plurality of arms according to claim 1, wherein said simultaneous operation designation means confirms the operation completion signal based on an operation completion signal, and waits for the completion of the previous operation. (3) When the number of arms is three or more, the simultaneous operation specifying means is capable of simultaneously operating any combination of arms by determining the combination of arms that perform simultaneous operations. A multi-arm control device according to scope 2. (4) A hand position detection means for each arm, which controls a plurality of arms capable of independently operating, and an operation position command means that generates a command position signal based on given operation target position data. , a control device comprising an arm driving means for moving a hand to a position according to the command position signal, and a means for mutually converting position data between coordinate systems of each arm, wherein the position command means simultaneously moves a plurality of arms. Simultaneous motion designation means for specifying that parallel motions are to be performed, and motion target position data given when performing simultaneous motions, which relate to one hand position, and which arm's hand the motion target position data relates to. target position arm selection switching means for selecting and switching the target position arm; starting position detecting means for detecting or calculating the hand position at the start of simultaneous motion of each arm that performs simultaneous motion; target displacement determining means for determining the direction and distance in which each arm should move based on the movement target position data; 1. A control device for a plurality of arms, comprising a plurality of arm movement target position determining means for determining a position or a movement target path. (5) When the arm movement is completed, the driving means returns an arm movement completion signal to the movement position command means, and when performing simultaneous movements, checks whether all arms performing simultaneous movements have completed their previous movements. 5. The control device for a plurality of arms according to claim 4, wherein said simultaneous operation designation means confirms the operation completion signal based on an operation completion signal, and waits for the completion of the previous operation. (6) When the number of arms is three or more, the simultaneous operation designating means is capable of simultaneously operating any combination of arms by determining the combination of arms that perform simultaneous operations. A multi-arm control device according to scope 5.