JP2521338B2 - Palletizing / depalletizing control method - Google Patents

Description

The present invention relates to a palletizing / depalletizing control method, and more particularly to a control method capable of palletizing and depalletizing according to an arbitrary operation pattern.

<Prior Art> There is a palletizing / depalletizing function as a function of defining the operation of a robot. This function is to stack the works in order from the lower stage to the upper part (palletizing) or to stack the works from the upper stage in order (depalletizing) by teaching a few points.

FIG. 8 (a) is an explanatory view of depalletizing for loading and unloading works from each row in one row, and FIG. 8 (b) is an illustration of palletizing for loading work on each point in one row.
FIG. 7C is an operation pattern explanatory diagram.

In the one-row palletizing / depalletizing shown in FIG. 8, the bottom point, which is the work position of the first stage of each stage
The number of Q _i1 (i = 1,2, ...) n (the number of columns), the number of steps s, the coordinate value of each bottom point Q _i1 , the operation start point P1 and the operation end on the first bottom point Q ₁₁ the coordinate point of the point R1, designates a work operation point of the uppermost on the first bottom point Q ₁₁ (the s stages).

In actual palletizing / depalletizing, the number of workpieces currently handled by the robot among the total number s × n is monitored, and the number of workpieces (current workpiece number) and the designated data are used to determine the number of workpieces to be handled. Lattice points Qij that are points (see FIG. 8 (c))
The coordinate values of, and then the operation starting point Pi on the grid point,
Calculate the coordinate value of the operation end point Ri.

When each coordinate value is obtained, the robot hand is moved from the robot side to position at the grid point Qij via the operation start point Pi, and then the work is gripped (depalletizing) at the grid point or the work is released. (Palletizing),
Thereafter, the hand is moved to the robot side via the operation end point Ri, and thereafter, the same operation is performed on all the works until the above operation is completed, and palletizing / depalletizing is performed.

The above is a description of palletizing / depalletizing in one line (not necessarily straight line), but FIG. 9 (a)
As shown in, it is possible to perform palletizing / depalletizing on n columns × m rows. In such a case, the number of columns n, the number of rows m, the number of stages s, the bottom point which is the work position of the first stage at the four corners.
_{Q 111, Q n11, Q nm1} , Q 1m1 ( Figure 9 (b) refer) and the coordinate values of the operation start point P1 and the operation end point on first bottom point Q ₁₁₁
Specify the coordinate value of R1 and the coordinate value of the grid point _Q11s , which is the work position of the uppermost stage (sth stage) of the first bottom point.

<Problems to be Solved by the Invention> By the way, conventionally, a motion pattern (passage,
(Including posture and auxiliary movement) is fixed to one. That is, in the example of FIG. 8, the hand is positioned at the lattice point Qij in a predetermined posture from the robot side via the operation start point Pi, and the auxiliary operation of gripping or releasing the work is performed here, and then the operation end point Ri is set. It is a pattern of returning to the robot side through, and the operation pattern cannot be changed for each bottom point or grid point.

Therefore, (i) the work is pressed against the inner side surface of the pallet for palletizing (the pressing direction differs depending on the work position), (ii) the operation pattern (passage, posture) is changed so as not to interfere with other works, (Iii) When the inclination of the work is changed step by step, the wrist posture cannot be changed sequentially.

From the above, the object of the present invention is to make it possible to associate an arbitrary motion pattern with each bottom point, change the motion pattern for each bottom point or for each grid point, and to achieve more flexible palletizing / depalletizing. It is to provide a control method that can be performed.

<Means for Solving the Problem> In the present invention, the above-mentioned problem is to create a position data file including data (operation pattern file number) designating an operation pattern for each bottom point, and associate the position data file with the number. Creating a motion pattern file for specifying a motion pattern, specifying a position data file with a palletizing / depalletizing command in the robot motion program, and bottom point data included in the specified position data file. A step of calculating a grid point which is a point of the work handled by the robot from the work height at the top stage and the current number of works, and an operation pattern defined at a bottom point just below the grid point passes through the grid point. The process of shifting and the robot hand based on the shifted operation pattern And the step of operating.

<Operation> A position data file including each bottom point, the work height of the uppermost stage, and data designating an operation pattern for each bottom point (operation pattern file number) is created, and
Create and register an operation pattern file for specifying an operation pattern corresponding to the operation pattern number.

Then, in the robot operation program, the position data file is specified along with the palletizing / depalletizing command, and the robot handles the work based on the bottom point data included in the specified position data file, the work height of the uppermost stage, and the current number of works. The grid point which is the point of is calculated and shifted so that the operation pattern defined at the bottom point immediately below the grid point passes through the grid point,
The path and posture of the robot hand are controlled based on the shifted motion pattern.

<Embodiment> FIG. 1 is a block diagram of a robot controller for realizing the present invention.

In the figure, 11 is a processor, 12 is a ROM in which a robot control program is stored, 13 is a storage area 13a for storing a robot operation program RBP, a storage area 13b for storing a position data file PFL, and an operation pattern file AFL. A storage area 13c, a RAM having a work area, and a data input / output device 14 for inputting / outputting various files and programs to / from an external storage medium (for example, floppy, paper tape, etc.) 15
Is an operation panel with a display, 17 is an axis control unit including a pulse distributor, an acceleration / deceleration circuit, a servo circuit, etc. for each axis, 18 is an interface circuit for controlling data exchange with the outside, and 21 is a robot.

Robot motion program RB that regulates robot motion
In the appropriate place of P (stored in the storage area 13a of RAM2), the second
As shown in the figure, a G code (G77) for instructing palletizing / depalletizing and an operand are inserted. Operands are from 1 to 6, (i) operand 1 indicates palletizing operation or depalletizing operation, (ii) operand 2 indicates position data file number (contents of position data file will be described later) , (Iii) Operand 3 indicates the number of the register that stores the numerical value that identifies the workpiece that is currently handled, (iv) Operand 4 indicates the presence or absence of automatic subtraction of the register (in the register Is set to the total number of palletizing / depalletizing works, and is usually stacked /
1 is subtracted for each loading / unloading), (v) Operand 5 indicates the posture of the hand at the lattice point (described later), and (vi) Operand 6 indicates the position of the escape point (described later). is there.

A position data file PFL is created corresponding to the position data file number (eg, PF □□□) that is operand 2 and is registered in advance in the memory area 13b of the RAM. Similarly, an operation pattern file designated by the position data file PFL An operation pattern file AFL corresponding to a number (for example, AF □□□) is created and registered in the storage area 13c of the RAM2.

The position data file PFL corresponds to the position data file number PF □□□□ as shown in FIG. 3, and (i) coordinate values of the bottom point, which is the work position of the first step of each step (position data, posture) Data) PD1 to PDn, and (ii) the number of columns n, the number of rows m, the uppermost stage of the first bottom point (s-th)
It has the coordinate values (position data, posture data) PDs of the work in (step), and (iii) the operation pattern file number AF □□□ for specifying the operation pattern of the robot hand for each bottom point.

The coordinate values include (i) position data (coordinate values of axes excluding the wrist rotation axis that is the posture axis) and (ii) posture data (rotational coordinate values of the wrist rotation axis).

The motion pattern file AFL is prepared in correspondence with the motion pattern file number AF □□□, and (i) position data (excluding the wrist rotation axis) that defines the motion path and posture data (wrist) at that point. Motion data PAT including rotation axis data), (ii) motion speed data FDD for instructing motion speed, (iii) movement method data MMD for instructing another motion such as linear movement and circular movement, (iv) hand (finger) ) Has auxiliary code data AXD for instructing auxiliary work such as opening and closing.

As shown in FIG. 4 (a), the movement data PAT should be in a path such that the hand reaches the lattice point Q from the robot side via the movement start point P and then returns to the robot side via the movement end point R. For example, the position data and attitude data at these points P, Q, R are specified in the order of movement, and
As shown in FIG. 4 (b), the hand reaches the lattice point Q from the robot side via the operation starting point P, and then the point S
If the path is such that it reaches a point and then returns to the robot side via the operation end point R, the position and orientation data at points P, Q, S, and R are specified in the order of movement.

FIG. 5 is a flow chart of the robot operation control processing in the present invention, and FIGS. 6 to 7 are operation explanatory views of the present invention. The process of the present invention will be described below with reference to the flowchart of FIG.
The robot operation program RBP and position data file P
It is assumed that the FL and the operation pattern file AFL are already created and stored in the predetermined storage area of the RAM 2.

First, the robot operation data of the i-th block (the initial value of i is 1) is read (step 101), it is judged whether it is the program end (step 102), and if it is the program end, the robot control is ended, and if it is not the program end. It is checked whether or not the palletizing / depalletizing instruction "G77" according to the present invention is included (step 103), and if not included, a normal robot control process is performed (step 103).
104) and increments i thereafter, and repeats the processing from step 101 onward.

On the other hand, if "G77" is included, (i) the bottom point coordinate value and (ii) the uppermost work position coordinate value at the first bottom point specified by the position data file specified by operand 2 ( iii) The coordinate value of the position (referred to as a lattice point) of the work to be handled by the robot is calculated from the number of works N and (iv) the arrangement specified separately (step 106). That is, the matrix of the work to be handled and the number of stages are calculated, the vector from the first bottom point designated by the operand 2 to the point of the top stage is divided, and the vector is added to the bottom point (bottom point) of the obtained matrix. To determine the grid points.

Then, if the grid point is calculated, the operation pattern file defined at the bottom point immediately below the grid point is read, and the path specified by the operation pattern file is shifted so as to pass through the grid point (step 107). .

FIG. 6 is an explanatory view of the passage shift, in which the passage specified by the motion pattern file is shown in FIG. 6 (a), the bottom corresponding point is Q, and the lattice points are shown in FIG. 6 (b). to if Q _ij, the passage is the passage pattern shifted to the bottom corresponding point Q path pattern matches the grid point Q _ij is as shown by a chain line. Actually, the operation start point P
And all other points (Q, R) except the operation end point R are shifted as described above, but the positions of the points P, R are operand 6
The position depends on one of the following instructions depending on the value of. That is, if the operand 6 is (i) "1", it becomes the positions P ', Q'shifted in the same manner as the other points as described with reference to FIG. 6, and (ii) if "2", the grid Bottom point Q _i1 just below point Q _ij
(See FIG. 6) When the bottom corresponding point Q is shifted so as to match (see dotted line), the operation start point and end point positions P ″, Q ″ are obtained (thus, the passage is as shown by the solid line in FIG. 5 (b)). (Iii) If (3) is “3”, it is the operation start point and the operation end point at the first bottom point.

The reason for controlling the operation start point and the operation end point in this way is to avoid excessive escape operation to shorten the cycle time, or to fully use the stroke to perform palletizing or depalletizing. ..Passage determination process When the passage determination process is completed, posture determination control is performed next.
In this attitude control, the attitude at the lattice point Q _ij is first determined by referring to the operand 5 indicating the hand attitude.
That is, if the value of the operand 5 is (i) “1”, the posture is the same as the posture of the first bottom point, and (ii) if it is “2”, the bottom point Q _{i1 immediately} below the grid point Q _ij
(Iii) If it is “3”, the change in the posture at the first bottom point and the change in the posture of the grid point at the uppermost stage of the bottom point are divided and the grid point Q _ij of interest is divided. The posture change up to the number of stages (jth stage) is obtained, and the posture change is calculated as the bottom point Q _immediately below the grid point Q _ij.
The posture is the one added to the posture in _i1 . By the posture determining method (iii), even when the inclination of the work WK sequentially changes step by step as shown in FIG. 7, the wrist posture can be changed accordingly.

Then, the posture at the bottom corresponding point Q is obtained from the motion pattern file defined for the bottom point Q _i1 immediately below the lattice point Q _ij , and the posture at the bottom corresponding point and the lattice point Q _{ij are obtained.}
The relative relationship of the postures (difference of each axis posture data) is obtained, and the postures at points P and S before and after the bottom corresponding point Q (FIG. 6) are changed by the difference to determine the postures before and after the grid point Q _ij. decide. The postures of the other points (R) are specified by the motion pattern (step 108). ... Attitude Determination Processing When the attitude determination processing is completed, the robot hand is operated using the determined path data and attitude data to execute the palletizing or depalletizing designated by operand 1 (step 109).

When the palletizing or the depalletizing is completed, it is checked whether or not the automatic subtraction is performed by referring to the operand 4 (step 110), and if "YES", the number of works set in the register is subtracted by V-1 → V ( Step 11
1) If "NO", the process returns to step 101 without subtracting, and the subsequent processing is repeated.

<Effects of the Invention> As described above, according to the present invention, since an arbitrary operation pattern is made to correspond to each bottom point, the operation pattern can be changed for each bottom point or for each grid point, and more flexible palletizing / deleting can be performed. Palletizing is possible, and even if the inclination of the work changes step by step, the wrist posture can be changed accordingly, and by changing the wrist posture, an array pattern in which the placement direction is different for each step is realized. You can also do it.

[Brief description of drawings]

FIG. 1 is a block diagram of a robot controller for implementing the present invention, FIG. 2 is an explanatory diagram of a robot operation program, FIG. 3 is an explanatory view of a position data file and an operation pattern file, and FIG. 4 is an explanation of an operation pattern. FIG. 5, FIG. 5 is a flow chart of processing of the present invention, FIG. 6 is an explanatory view of passage shift, FIG. 7 is an explanatory view of effects of wrist posture control, and FIGS. 8 and 9 are explanatory diagrams of palletizing / depalletizing operation. Is. RBP: Robot motion program, PFL: Position data file, AFL: Motion pattern file

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-169279 (JP, A) JP-A-61-26109 (JP, A) JP-A-62-46816 (JP, A) Actual development Sho-59- 91229 (JP, U)

Claims (4)

(57) [Claims] 1. A palletizing robot for arranging workpieces by stacking or unloading the workpieces on the bottom point by designating the coordinate value of the bottom point, which is the position of each workpiece on the first stage, and the height of the workpiece on the uppermost stage. In the depalletizing control method, a position data file including each bottom point, the work height of the uppermost stage, and an operation pattern file number for designating an operation pattern of the robot hand for each bottom point is created in advance, and the operation is performed. Create and register a motion pattern file to specify the motion pattern corresponding to the pattern file number, specify the position data file with the palletizing / depalletizing command in the robot motion program, and specify the specified position data. Bottom point data included in the file and the topmost work A grid point, which is an operation point of a work handled by the robot, is calculated from the height and the current number of works, and the operation pattern defined at the bottom point corresponding to the grid point is shifted so as to pass through the grid point. A palletizing / depalletizing control method characterized in that the robot hand is operated based on the generated operation pattern. 2. A point corresponding to a bottom point is specified in the operation pattern, and the operation pattern is shifted so that the bottom corresponding point coincides with a grid point. The palletizing / depalletizing control method according to the item. 3. The palletizing / depalletizing command includes data for specifying a hand posture, and the hand posture at a lattice point is controlled based on the posture data. Palletizing / depalletizing control method. 4. The relative relationship between the posture at the bottom corresponding point and the posture at the lattice point of the motion pattern is obtained, and the postures at points before and after the bottom corresponding point are changed based on the relative relation to determine the posture before and after the lattice point. The palletizing / depalletizing control method according to claim 3, wherein the posture is determined.