KR101133456B1 - Device and method for machine control - Google Patents

Abstract

A database (D) is provided for the machine control of the grinding machine to determine a time-efficient and collision-free transfer path, which database is at each individual coordinate point X, Y, Z, and A and for individual tool types. Has a collision variable of "0", "1" for each combination of (WZI) and workpiece types (WSJ). The collision variable is defined by the relative constellations assigned to the corresponding coordinate points X, Y, Z, and A, which represent the relative positions of the workpiece 11 and the tool 3, to a collision or spatial overlap of the tool and the workpiece. overlapping). The database D forms a lookup table that can be used to identify given paths or expansions or layout of the paths. Since time-consuming and computationally expensive collision operations are omitted, computation of efficient paths in time can be performed in seconds, even with limited computational performance. Reference is made to the pre-computed reference table for this.

Control, grinding machine, feed path, workpiece, collision

Description

Device and method for machine control

1 is a very schematic view of a grinding machine and its control device.

2 is a schematic representation of a two-dimensional individual working area, shown with individual workpiece types and individual tool types overlapping one another.

3 is a schematic representation of individual tool types.

4 is a schematic representation of other individual tool types.

5 shows a formula of a structure of a database for determining collision variables.

6 is a schematic illustration of a non-collision path determination around obstacles spaced apart in the work area of the two-dimensional example.

[Description of Reference Numerals]

1: grinding machine 2: grinding spindle carrier

3: tool 4, 5, 6: drive unit

7: control unit 8: memory unit

9: workpiece carrier 11: workpiece

12: drive unit 14: internal area

The present invention relates to a machine control device for a grinding machine or similar machine, and to a method for determining the conveying path of a tool, in particular a grinding tool and / or a corresponding workpiece.

In grinding machines or similar devices such as, for example, erosion devices, it is necessary to frequently adjust the workpieces and / or tools with respect to each other so that collisions do not occur. This is the case, for example, when the machining process performed with the grinding tool is completed and the other grinding tool comes into contact with the workpiece. The positioning of the workpiece and the grinding tool and the control of the paths to be transported are the purpose of the machine control program, which must be made by a machine control expert or machine operator with the aid of some intelligent programming. In general, a machine coordinator cannot provide position paths optimized over time. This is particularly true where these paths cannot be straight to bypass obstacles and avoid collisions. Once the machine control program is created, the grinding tools or workpieces must then be carefully tested for a long time to be free from the collision in order to avoid colliding with each other or with other parts. Obviously safer paths are taken to avoid collisions so that after the end of the work each tool is moved to a so-called safely stopped position, for example the starting position of a subsequent working step is approached or otherwise stopped Is approached from the first stop position, the transport paths are long and the positioning time is lengthened. The sum of the positioning times is a significant time loss, which must be avoided during grinding operations, especially for complex workpieces, for example drills, cutters and the like.

It is therefore an object of the present invention to provide a positioning method and a corresponding machine control apparatus in which the feed paths of tools and / or workpieces can be determined in a short time in a simple manner requiring a short positioning time.

This object is achieved by a machine control device according to claim 1 and a method according to claim 12.

The machine control device according to the invention assists the programmer in the determination or input of feed paths requiring short positioning times. The machine control device may be provided to automatically define these transport paths. The characteristics of the machine control device and the control method associated therewith are based on the fact that a pre-computed database is provided, which applies to the individual working areas and which each tool and each tool position and each workpiece and workpiece position and machining area It includes a collision variable for each separation element of. For example, this variable is "0" when there is no collision, when each workpiece position and tool position collide (the tool position is determined by a position in the machine coordinate area), which is the It means the overlapping path of the workpiece. Given the special path of the workpiece over the work area and / or the tool over the work area, it is determined via simple data retrieval whether the proposed path contains a collision. This can be done by searching for predetermined routes and can be a supporting measure to confirm during the determination of the transfer routes.

Searching the database is a very time consuming process, but it must be done only once. For example, if there is a work area that is divided into 100 individual steps in all three spatial directions, there are already 10,000 separate elements. For example, the first and individual tools may take 10,000 different positions in the predetermined direction of the workpiece. If the workpiece can take 100 individual directions, the individual working areas have 1,000,000 points. Collision variables of "0" or "1" are assigned to each separate element (cell) of the entire work area for each point, which means that each individual work-tool coordinate relationship (workpiece position and tool in the work area) Position). If the workpiece and the tool are in contact with each other or do not overlap each other, all the cells are "0". If contact or overlap occurs, only certain cells are "1", where contact or overlap occurs, for example.

The determination of the collision parameters in the manner described above is now preferably made for each individual type of tool in combination with each individual type of workpiece, and preferably the geometry of the raw member is selected as the workpiece. Then all coordinate relationships are entered into the database. Computing these databases can take a day or more, even on high-performance computers. The database forms a reference table through which the proposed path of the grinding tool and / or workpiece can be checked for collisions within a few seconds in the corresponding data batch.

The method and machine control device of the present invention achieves on a sole basis that can be checked for collisions during the programming of the transfer paths or during the automatic generation of the transfer paths. In particular, time efficient transfer paths can be determined very quickly through an iterative return to the database.

The database must be installed at one time by the machine manufacturer. This database can then be copied to all existing machines or grinding machines, and then to determine the desired transport path as much as possible. For example, a collision path is additionally selected among all possible paths between the starting and ending points of the path to be determined, which is as close as possible to the optimal path. Known standardization methods can additionally be used.

In individual cases, it may be sufficient for the database to include only the separate elements of the work area and its conflicting variables, which must be checked during positioning. Separation elements associated with marginal regions of the work area may be omitted. However, it is contemplated that all the separate elements of the work area be included so that each conflictable case is included in the database.

In addition, taking into account all the tools used in each machine, it is preferred that the tools are depicted by tool separating elements forming each type of tool. The workpieces are also separated and the unfinished parts to be machined in each grinding machine are individually used according to the design of the workpieces and the workpieces have a simple geometry such as cylinders, cones, stepped cylinders and the like.

The method of the present invention is particularly suitable for use in grinding machines where only a small amount of material is cut so that the workpiece changes very little in shape during machining. The workpiece design of the raw part remains generally the same during the machining of the workpiece.

The database consists of an indexed listing, which means a set of zeros that appear regularly. Data compression can be performed and limited to each of the paired tool types and workpieces so that only a partial database must be uncompressed (compressed) to ensure that there is no collision between the particular workpiece and the path of the particular tool. .

Other details of advantageous embodiments of the invention are shown in the drawings, the description, or the claims.

The grinding machine 1 is illustrated very briefly in FIG. 1. The grinding machine 1 comprises a tool 3, in particular a grinding spindle carrier 2 with a grinding tool. 1 shows a grinding wheel as an example of a tool 3. The grinding spindle carrier 2 can be adjusted linearly in several directions, for example in three directions X, Y, Z. Corresponding drive devices 4, 5, 6 are used for the adjustment, which are connected to the control unit 7 via control lines. The control unit is, for example, a machine control computer connected to the memory unit 8. The grinding machine 1 additionally includes a workpiece carrier 9, in which a rod-shaped workpiece 11 is mounted to the carrier as illustrated in FIG. 1. As such, the geometrical shape of the unworked part is selected as the work piece 11. For example, the workpiece carrier 9 can be rotatably mounted about axis A. The corresponding drive device 12 is connected to the control unit 7. If the grinding spindle carrier 2 can only move in the Y and Z directions, the workpiece carrier 9 can additionally move in the X direction. Then, the drive device 4 is connected to the tool carrier 9.

The coordinates X, Y, Z, and A form a four dimensional working area for the movement of the tool 3 and the workpiece 11. The control unit 7 controls the movement of the tool 3 and the workpiece 11 to achieve the desired grinding result. This additionally controls the movement of the tool 3 and / or the workpiece 11, for example, so that different tools may come in contact with the workpiece 11 in turn. The tool 3 and the work piece 11 should move in the shortest possible time, which means that efficient transport paths are pursued which are optimized for time or nearly optimized for time or at least for time. First of all, no collision should occur between the tool 3 and the workpiece 11 or any other member. Therefore, the control unit 7 serves to check the collision for the proposed path in the four-dimensional work area. It uses a database provided in the memory unit 8 which contains the collision parameters for all positions of the tool 3 and the workpiece 11 which are possible in separate four-dimensional working areas. This means that for every individual X, Y, Z position of the tool 3 in combination with every individual rotational position A of the workpiece 11, there is an overlap (collision) about the volume of the tool 3 and the workpiece 11. It is determined whether it happens. A two-dimensional example is shown in FIG. 2 for the work area R to illustrate this case. Individual coordinates extend from X ₀ to X _n and Y ₀ to Y _m . The individual working area R includes all possible individual relative positions of the tool 3 and the workpiece 11 only when there are adjustments in the two axes (adjustments in X and Y). The tool 3, recognized by the coordinates (X _k , Y _l ), is now experimentally moved at each point in the individual working area and the coordinates (X _k , Y _l ) are at the collision variable "1" when there is overlap. Is assigned, otherwise "0". A grid square "0" is shown empty in FIG.

Collision variables "0" and "1" are correspondingly determined for a three or four dimensional working area, which means that each collision variable is determined for each possible position of the tool or for each possible position of the workpiece 11. it means. Collision variables are stored as a database D in the memory unit 8. Expressed schematically, the database D comprises an overlap of the workpiece 11 and the tool 3 over the entire working area R. FIG. The overlap, shown here schematically with the operator "overl", includes a test of intersection for each relative position of the tool 3 and the workpiece 11 in a separate working area.

The control unit 7 now determines the path P as follows with the help of another two-dimensional example of FIG. 6.

The path without collision is retrieved from A to B in separate working areas (here two-dimensional X, Y). The route should be fairly short. Areas at risk of collision are indicated by diagonal lines and these are each recognized as "1" in the database D. FIG. The method of the present invention now searches for paths in the grid by separation leaving the area at risk of collision. This path is an optimal path that extends directly along the interior area 14 and is defined by a curve and the area 14 is recognized as a collision area. However, the path P is much more desirable than the traditional through-going path P ₀ , which travels through the parked positions, schematically input in FIG. 6.

Since the two-dimensional grating is not sufficient for the actual grinding machine 1, the work must be performed corresponding to the four-dimensional working area. This means that the collision variables "0" and "1" must all be defined and stored for four coordinates X, Y, Z and A, which means the possible relative positions of the tool and the workpiece, respectively. This database can then be used in a search for a path to determine whether the operator entered a partial path, or a recently determined partial path, or a selected path is a path without collisions, which is effortless to compute. This is done by checking the stored values.

Collision variables are preferably determined not only for a particular workpiece and for a particular tool and for the entire multidimensional working area, but also for all individual tools and for every individual workpiece at the same time. This is illustrated in FIGS. 3 and 4. 3 shows tools WZ1, WZ2, WZ3, which may include, for example, grinding wheels of all existing sizes and shapes in a set of gratings. In principle, the number of tool types is not limited. There are three types of current examples. Several types of workpieces are also shown, in particular these are three types of workpieces for cylindrically shaped parts of different sizes. The different types or workpieces WS1, WS2, WS3 are preferably each different by one separation step within a given separation. An approximately stepped arrangement may be selected as shown in FIG. 4. Now, overlaps of all types of workpieces and all types of tools are set up for the entire individual working area R to make a database as illustrated in FIG. 5. Such a database is available for each point in the individual work area R for possible relative positioning and for each possible pair (WZI, WSJ), where I and J represent the number of the tool type and the workpiece type, respectively. Contains conflicting variables that are assigned. Each collision variable requires only one bit, but the database contains several gigabytes for a four-dimensional working area, the coordinates of which are each divided into 100 separate steps. This applies for example when only a relatively small amount of three types of tools and three types of workpieces are used. Computing this amount of data can take days, even on very high-end computers, under certain circumstances. However, the database produced is widely applied to the grinding machine of the proposed type, which means that the database can be copied without difficulty to any grinding machine manufactured. After that, no new operations are needed.

As described above, the database may be stored in a compressed form. The database is preferably divided into partial databases and each partial database represents a tool-workpiece pair (DT = WZI overl WSJ / R). Then only a partial database is decompressed to determine if there is a collision of the positioning path applied to the particular tool or workpiece of interest. The decompressed database can be used to determine or check the path and the results can be used immediately in practice.

The database D can be used for machine control of the grinding machine to determine a time-efficient collision free path, the database for each individual coordinate point X, Y, Z, A and with a separate tool type (WZI) For each combination of workpiece type WSJ there is a collision variable of "0", "1". The collision variable shows whether a collision or spatial overlap of the tool and the workpiece occurs with respect to the coordinate relationship assigned to the corresponding coordinate points X, Y, Z, A, where the coordinate relationship of the workpiece 11 and the tool 3 It means relative position. This database D forms a reference table that can be used for stepwise placement of paths or for expansion or to check a given path. Since time-consuming and computationally-intensive collision operations are eliminated, computation of paths that are efficient in time can be performed within seconds, even with limited computational capacity. A pre-computed reference table is referenced for this.

Claims (12)

A grinding spindle carrier 2 and a workpiece carrier 9 which are movable relative to each other in the various directions X, Y, Z, A in the working region R by means of drive devices 4, 5, 6, 12; And a control unit (7) connected to the drive devices (4, 5, 6, 12) and having a memory unit (8). The memory unit 8 has a database D usable for the working area R, which is divided into separate elements, The database D is pre-computed such that collision variables 0 or 1 are pre-assigned to the separating elements for the predetermined tools 3 and the predetermined workpieces 11 at the predetermined positions, respectively. , By determining the existing collision variables (0 or 1) contained in the database (D), the collision of the feed path (P) is avoided. The machine control apparatus according to claim 1, wherein the database (D) comprises all the separating elements of the working area (R). The machine control device according to claim 1, wherein the tools (3) are represented by individual tool types (WZ1, WZ2, WZ3). 2. The machine control device according to claim 1, wherein the workpieces are represented as individual workpiece types (WS1, WS2, WS3). 2. The machine control apparatus according to claim 1, wherein the workpieces (11) have the geometric shapes of the raw parts. 2. The database (D) according to claim 1, wherein the database (D) identifies at least one workpiece type (WS1) and at least one tool type (WZ1) for the entire working area and for all positions in which the workpiece can be placed. Machine control device for a grinding machine comprising collision variables (0 or 1) pre-assigned to said separating elements for control. 2. The database (D) according to claim 1, wherein the database (D) identifies at least one workpiece type (WS1) and at least one tool type (WZ1) for the entire working area and for all positions in which the tool can be placed. Machine control device for a grinding machine comprising collision variables (0 or 1) pre-assigned to said separating elements for control. 2. The workpiece (D) according to claim 1, wherein the database (D) includes all workpiece types (WS1, WS2, WS3, ...) and all tools, for the entire working area and for all positions in which the workpiece can be placed. Machine control device for a grinding machine comprising collision variables (0 or 1) pre-assigned to the separating elements for types (WZ1, WZ2, WZ3, ...). The machine control apparatus according to claim 1, wherein the database (D) can be stored in a compressed form. 2. The method of claim 1, wherein the database (D) is divided into partial databases, wherein the partial databases comprise a workpiece-tool combination (WZ1-WS1) for all positions in which the workpiece and the tool can be placed; Machine control apparatus for a grinding machine comprising collision variables (0 or 1) pre-assigned to the separating elements for WZ1-WS2; WZ1-WS3; WZ2-WS1; WZ2-WS2. 11. The machine control apparatus according to claim 10, wherein the partial databases can be stored separately in respective compressed forms. A grinding spindle carrier 2 and a workpiece carrier 9 which are movable relative to each other in the various directions X, Y, Z, A in the working region R by means of drive devices 4, 5, 6, 12; And a control unit 7 connected to the drive devices 4, 5, 6, 12, and having a memory unit 8; a tool 3, a workpiece 11, or a tool on the grinding machine 1. (3) and the method for determining the conveyance path of the workpiece 11, The memory unit 8 has a database D usable for the working area R, which is divided into separate elements, The database D is pre-computed such that collision variables 0 or 1 are pre-assigned to the separating elements for the predetermined tools 3 and the predetermined workpieces 11 at the predetermined positions, respectively. , A method of determining a conveying path in which collision of a conveying path (P) is avoided by determining the existing collision variables (0 or 1) which are pre-computed and unchanged included in the database (D).

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