JPH07121215A - Method for determining allowable robot hand area - Google Patents

Abstract

PURPOSE:To objectively and easily specify the hand area wherein no interference is caused in robot operation. CONSTITUTION:On an off-line programming device, the respective occupation areas F1-F4 of a robot main body, a fixed tool, a peripheral equipment, and a work storage part are set and on a wrist coordinate system SIGMA, a hand original shape area H0 is set as the initial state of a hand area H. Simulation based upon a robot operation program is performed to move the robot in the order of an initial position P0, P1...P5. At each interpolation point in the moving process, interference areas between the hand area H (initial state; H0) and the respective areas F1-F4 are removed. For the purpose, set arithmetic for finding differences between the area H0 and the respective areas F1-F4 at the point of time is repeated, or the area H0 is set as a gathering of fine areas and a process for removing fine areas interfering with the respective areas F1-F3 is repeatedly performed at each interpolation point. The hand area Hfin. left after those interfering areas are removed shows the permissible hand area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a space area allowed for a robot hand by using an off-line programming device, and more specifically, a robot motion simulation suitable for an application on the off-line programming device. The present invention relates to a method of automatically determining a space area allowed for a robot hand through a process of executing.

[0002]

2. Description of the Related Art When performing various tasks using a robot, a robot hand is attached to the face surface at the tip of a robot arm, and a tool or work (when a stationary tool is used) is attached through this robot hand. Often support. Originally speaking, when designing this robot hand, the environment assumed during actual robot operation, that is, other objects that may occur during the entire operation of the robot (such as workpieces, peripheral devices, stationary tools and the robot itself) The hand area (the space area occupied by the hand attached to the robot, hereinafter the same) should be determined in consideration of interference with the occupied space area).

For example, when the size and shape of a robot hand used for deburring with a stationary tool is not appropriate, different deburring parts and the type of stationary tool for the same work (large and small burrs are used properly). ) Etc., there is a risk of causing a situation in which another hand must be prepared according to the above.

However, so far, there is no known technique for objectively and simply specifying the area allowed for the hand area in consideration of the interference condition assumed during the operation of the robot. It was a major factor that made it difficult to design a simple robot hand.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for objectively and simply specifying a hand area which does not interfere with an object or the like existing in a work space during the operation of a robot. Is intended to effectively support the design work of the robot hand.

[0006]

The present invention has, as a basic configuration for solving the above-mentioned problems, "expresses an original shape of an occupation area of a hand attached to a robot on an off-line promming apparatus. Setting a hand prototype area, setting a hand non-permissible area where interference with the occupation area of the hand attached to the robot is not allowed, and preparing at least one robot operation program, Simulating a robot motion according to the motion program, and performing arithmetic processing for eliminating a region that interferes with the hand non-permissible region from the set hand prototype region through the robot motion simulation stage. A method for determining a permissible robot hand area which is a feature. " Configuration described in 1).

Further, in the above method, regarding the content of the calculation for excluding the interference area from the set hand original area, "the interference area exclusion arithmetic processing starts from the hand original area and is performed in the robot motion simulation. One of the allowable robot hand area determination methods is specified by imposing a requirement of "including a sequential set operation for sequentially excluding a spatial area that interferes with the hand non-allowable area corresponding to the operation step". There is (configuration according to claim 2).

Furthermore, regarding the method of setting the hand original area in the above method and the content of the hand non-permissible area exclusion calculation from the method, "The setting of the hand original area sets a set of a large number of minute space areas. Form, and the interference area exclusion calculation processing starts from a hand prototype area set as an aggregate of the large number of minute space areas, and corresponds to an operation step in the robot operation simulation with the hand non-allowable area. Another aspect of the allowable robot hand area determination method is specified by imposing a requirement "including a process of sequentially eliminating interfering minute areas" (configuration described in claim 3).

[0009]

According to the present invention, the allowable robot hand area is defined by executing a simulation imitating an actual work environment and robot operation on the offline programming device. Therefore, on the off-line promming device, a hand prototype area that represents the prototype of the occupation area of the hand attached to the robot is set. This original area is usually a spatial area (for example, a rectangular parallelepiped area, a cylindrical area, or a spherical area) on the tool coordinate system or wrist coordinate system (coordinate system set on the hand attachment surface) of the robot defined on the offline programming device. Etc.). Therefore, when the simulation of the robot operation is started on the offline programming device, the set original shape region is also referenced at the same time as the reference coordinate system defined on the offline programming device (coordinate system fixed in the work space, for example, the robot base coordinate system). ) Start exercising on.

Therefore, if an area expressing peripheral devices, workpieces, the robot itself, etc. is set in advance in a form imitating actual working conditions as a hand non-permissible area, interference that may actually occur is offline through the robot operation simulation. It becomes possible to check on the programming device.

Specifically, the robot operation is simulated by performing a reproduction operation of an operation program created imitating an actual work on an off-line programming device, and the robot operation is started from the hand prototype area. A method is adopted in which the allowable robot hand area is narrowed down by sequentially scraping away the area where interference with the hand non-allowable area occurs.

As a practical data processing method used for performing this narrowing down, a method by a sequential set operation and a method by a sequential interference elimination process for a minute area are considered. The former is a method of narrowing the allowable robot hand area by repeatedly executing a set operation with the hand non-allowable area at each step of the robot operation, and the latter is a method of narrowing the hand prototype area to a small area. The permissible robot is set as a body, and the presence or absence of interference with the hand non-permissible area is checked in units of minute areas at each step of robot operation, and the minute area in which interference occurs is removed each time. This is a method of narrowing down the hand area.

The above is an outline of the present invention, and a specific example of how to proceed with data preparation and processing for implementing the method according to the above principle on an offline proming apparatus will be described.
This will be described in the following example.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the outline of the construction of an off-line programming apparatus that can be used for carrying out the method of the present invention. In the figure, 1 is a microprocessor (hereinafter referred to as CPU), 7 is a ROM storing a control program of the automatic programming device, and 2 is a system program loaded from a floppy disk or a hard disk (hereinafter simply referred to as a disk) 11. RAM for storing data and various data, 3 is a keyboard,
Reference numeral 4 is a CRT display device (hereinafter referred to as CRT), 9 is a tablet device, 8 is a disk controller, 10 is an XY plotter for outputting a drawing, and 5 is a printer. Connected through.

The tablet device 9 has a screen corresponding area 9a and a menu table 9b, and the tablet cursor 9c is moved within the screen corresponding area 9a to move the graphic cursor on the CRT 4 to perform an instruction operation.
Various menu items can be selected from the system program prepared on the disk 11 by designating an arbitrary position on the screen of No. 4 or moving the tablet cursor 9c on the menu table 9b and performing an instruction operation. Has become. The procedure for carrying out the method of the present invention using the above-mentioned offline programming device will be described below. First, an application case assumed in this embodiment will be described with reference to FIG. FIG. 2 is a schematic diagram showing a robot path according to a work environment and an operation program set on an offline programming device for deburring work using a stationary tool. Each 3D area is drawn in a 2D area. It is shown. In the figure, F1 represents the occupation area of the robot main body portion set in the three-dimensional work space Γ. Similarly, F2 is the area occupied by the stationary tool, F3 is the area occupied by peripherals (eg, stationary visual sensors),
F4 represents an area occupied by the work accommodating portion.

As the robot path according to the robot operation program, starting from the initial position P0, each teaching point P
Consider what follows 1 → P2 → P3 → P4 → P5. P1
Is an approach point to the stationary tool F2, P2 to P3 are deburring machining execution sections, P4 is an escape point, and P5 is a placement point of a machining completed work.

Reference numeral H0 is an original hand region defined on the wrist coordinate system Σh, and one or a plurality of rectangular parallelepiped regions,
It is set as a cylindrical region or a spherical region. However, when the small area interference elimination process is applied, the original area is set as an aggregate of small cubes, for example. Σt is a tool coordinate system, which has a fixed position / orientation relationship with the wrist coordinate system Σh. Further, Σw represents a reference coordinate system on the work space Γ.

FIG. 3 is a flow chart showing an outline of a system program for "allowable hand area determination processing by robot motion simulation" stored in the disk 11. The processing operation of this embodiment will be described below with reference to this. Will be explained. When performing the simulation under the working environment shown in FIG. 2, the operator firstly, the operation program data including the data representing the areas F1 to F4 prepared on the disk 11 and the position data of the respective teaching points P1 to P5. , Data representing the original area H0, each coordinate system Σt, Σh
, Σw data and the like are once read into the RAM 2 and the data are used to set each coordinate system Σt, Σh, Σw, each region F0 to F4, and the original region H0. When applying the small area interference elimination processing,
A parameter for specifying the setting contents of the minute area (for example, a parameter δ that determines the size of the minute area unit or a division equal fraction along each axis of the wrist coordinate system) is also set.

Then, the setting contents are set in an appropriate format on the CRT 4
Display it above and confirm the settings. In order to visually confirm the set work environment, it is preferable that the CRT 4 can display a display screen (three-dimensional graphic display if possible) as shown in FIG.

If errors or insufficiencies in the data are confirmed, a shape element related to the figure displayed on the CRT 4 is designated by a shape element pointing operation using the tablet cursor 9c, and a data correction tool is used. Take actions such as correcting and replenishing the data using. When the above preparation is completed, the operator operates the tablet device 9,
One system program of "allowable hand area determination processing by robot motion simulation" is downloaded from the menu table 9b, the CPU 1 is activated, and the processing shown in the flowchart of FIG. 3 is started (at the start of processing, the robot is set to P0). Yes, the hand area H is set to the original area H0; H = H0).

First, the CPU 1 reads one block of the operation program (step S1), confirms that it is not a processing end command (step S2), and then starts interpolation calculation (step S3). Here, first, the position / orientation of the robot at the first interpolation point between P0 and P1 is determined. The determined robot position / orientation is displayed on the screen of the CRT 4 in an appropriately set cycle (for example, every 10 interpolation points or each time a predetermined time elapses) (step S
4, 5), exclusion processing of the non-permissible area H'based on the set operation or the minute area interference check processing is executed (step S6). That is, in the case of the set calculation method, the hand area H and the respective areas F1, F2, F3, F at that time are set.
Set operation (HF-F1-
F2-F3-F4 or H and F1 + F2 + F3 + F4
H ') is performed with the common part of H.sub.2 being H' (the H'in FIG. 2 exemplifies the state where the common part with F.sub.3 exists).

When the removal processing by interference check of a minute area is performed, the hand area H at that point
With respect to all the minute regions constituting the above, all the interference relations with the regions F1 to F4 are checked, and a process of removing the minute regions having the interference relations sequentially or collectively is executed.

When step S6 is completed by either method, the result is displayed on the CRT4 screen (step S7). For example, it is conceivable to display the hand area H remaining at that time in blue and the removed area in red, overlapping the display in step S5.

Next, the teaching point section (first P0 P1
(Interpolation point) remains (step S
8), if left, steps S3 to S
The process of 8 is repeated.

When the robot advances to the next teaching point P1 as the simulation progresses, the process returns from step S8 to step S1 to read the next one block of the robot operation program. Hereinafter, when the simulated robot reaches the final teaching point P5 by repeating the above-described steps S2 to S8, an end command is issued in step S2, and the CPU 1 ends all the processes. The hand area Hfin. That has survived without being removed at this point becomes the allowable hand area.

If another operation program or a plurality of operating programs or work environments are prepared and the above processing is repeatedly executed under the condition of H0 = Hfin., A more versatile permissible hand area can be determined. That is clear.

[0027]

According to the present invention, it is possible to objectively and easily specify a hand area that does not interfere with an object or the like existing in the work space during the operation of the robot.

As a result, the work of designing the robot hand adapted to the individual application is remarkably streamlined, and it becomes easy to prevent design errors from occurring.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of the configuration of an off-line programming device that can be used when performing the method of the present invention.

[Fig. 2] Regarding deburring work using a stationary tool,
It is a schematic diagram showing a robot environment according to a work environment and an operation program set on an offline programming device.

FIG. 3 is a flowchart showing an outline of a system program for an allowable hand area determination process in the embodiment.

[Explanation of symbols]

1 Microprocessor (CPU) 2 RAM 4 CRT display device 6 Bus 7 ROM 8 Disk controller 9 Tablet device 11 Disk (floppy disk or hard disk) F1 Robot (occupied area) F2 Stationary tool (occupied area) F3 Peripheral device (occupied area) F4 Work accommodating part (occupied area) H hand area H0 hand original area H'Hand non-permissible area P0 Robot initial position (simulation) P1 to P5 Teaching point (simulation) Γ working space Σh Wrist coordinate system Σt Tool coordinate system Σw Reference coordinate system

Claims (3)

[Claims] 1. On an offline promming device,
Setting a hand prototype area that represents the original shape of the occupation area of the hand attached to the robot, and setting a hand non-permissible area where interference with the occupation area of the hand attached to the robot is not allowed Stages,
The method includes the steps of preparing at least one robot motion program and simulating a robot motion in accordance with the motion program, wherein the set hand prototype region interferes with the hand non-permissible region through the robot motion simulation stage. A method for determining a permissible robot hand area, characterized in that arithmetic processing for excluding an area to be performed is executed. 2. The interference area excluding calculation process is started from the hand original area, and sequentially eliminates a spatial area that interferes with the hand non-allowable area corresponding to an operation step in the robot operation simulation. The allowable robot hand area determining method according to claim 1, further comprising a set operation. 3. The hand original area is set in the form of setting a large number of minute space areas, and the interference area exclusion calculation process is set as a large number of minute space areas. 2. The allowance according to claim 1, further comprising a process of starting from a hand original region and sequentially excluding a minute region that interferes with the hand non-allowable region corresponding to an operation step in the robot operation simulation. Robot hand area determination method.