JPH1083216A - Numerical control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable safe operation and a process for shortening a cycle time as to the numerical control unit which sequentially executes respective blocks of part programs consisting of successive blocks. SOLUTION: A target position deviation decision means 13 checks the difference between a target position and a machine position each time it performs interpolation, and outputs a signal to an interpolation continuing means 14 when the difference becomes less than, for example, a previously set value. This means 14 decides whether or not there is a next block when the signal is inputted, and continues the interpolation when not and outputs a next block read-in command to a next-block read-in means 1 when there is the next block. An initializing process selecting means 10 decides whether or not the interpolating process of a last block is completed and outputs current block data to an interpolation continuation initializing means 11 when not. The initializing means 11 performs initialization for replacing the start point of the current block with a last interpolation position and also replacing the speed at the start point of the current block with a last feed speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical controller which sequentially executes each block of a part program consisting of continuous blocks, and more particularly to a numerical controller which is improved so as to shorten a cycle time.

[0002]

2. Description of the Related Art When a numerical controller is operated, in a means for ending one block of a part program consisting of continuous blocks and starting the next block, for a block which does not require positioning accuracy, a machine after an interpolation process is completed. The cycle time can be reduced by starting the next block without determining whether the target position has reached the target position or by starting the next block before the deceleration speed becomes 0 after the interpolation processing is completed. Has been shortened. FIG. 2 is a block diagram showing the configuration of a conventional numerical control device. The conventional device will be described together with the flowchart of FIG. The next block reading means 1 determines whether there is a next block based on the next block reading command SC (step S1). Command SA with next block
When it is determined that there is a next block, the block is read, converted into NC internal variables, and output to the interpolation initializing means 2 as block data DA (step S2). The interpolation initializing means 2 converts the block data DA into interpolation initializing data DB in a format in which the interpolation means 3 can perform interpolation. This interpolation initialization data DB corresponds to, for example, a target position, a feed speed, an interpolation mode (rapid feed, cutting feed) and the like if the block is a block that performs axis movement.
When the interpolation initialization data DB is input, the interpolation means 3
The interpolation process is performed at a constant cycle (step S3), and the interpolation data DC is output to the driving unit 4. The driving unit 4 drives the driving unit according to the input interpolation data DC. When the calculated value reaches the target position (step S
4) Output interpolation completion command SB and target position data DE to next block reading command means 5. The next block reading command means 5 receives the interpolation end command SB,
The machine position / speed data DD including the current machine position and the deceleration speed input from the driving means 4 is monitored. For example, when the current machine position reaches the target position or the deceleration speed becomes zero, The block is terminated, and the next block reading command SC is output to the next block reading means 1 (step S5). Here, the next block read command means 5
Then, after the interpolation end command SB is input from the interpolation means 3, the block is considered to be finished before the current machine position reaches the target position or before the deceleration speed becomes 0, if necessary. The cycle time is shortened by outputting to the next block reading means 1 or the like.

FIGS. 5, 6 and 7 are views for explaining the operation of a conventional numerical controller. FIG. 5 shows the part program, and FIG. 6 shows the program of FIG. 5 expanded to XY coordinates. N000 is a positioning block for (X1, Y1), N001 is (X2, Y1), N002
Is a positioning block for (X2, Y2). FIG. 7 shows the relationship between speed and time when this program is operated. vx is the feed speed in the X-axis direction, vy is the feed speed in the Y-axis direction, t1 is the interpolation processing end time of the axis movement in the X-axis direction specified by the N001 block, and t2 is N001.
The time when the machine position reaches the target position in the X-axis direction movement specified by the block, t3 is the interpolation processing end time of the Y-axis direction movement specified by the N002 block, t
Reference numeral 4 denotes a time required for the machine position to reach the target position in the axis movement in the Y-axis direction specified by the block N002. In the example shown in this figure, for the purpose of shortening the cycle time, the start of the N002 block, which is the next block, is performed not at the time of reaching the target position of the N001 block, but at the time of ending the interpolation processing of the N001 block.

FIG. 10 shows movement to a spindle position.
The case where the interference area is avoided by passing through the waypoints P0, P1, and P2 is shown. Here, P1 is a transit point provided to avoid interference during movement. In this case, P1
Since the accuracy of the positioning to P1 is not required, after the interpolation processing of the positioning command block to P1, the positioning to the next P2 is started without determining whether the machine position has actually reached P1. To shorten the cycle time.

[0005]

However, in the conventional numerical control device, the axis is always moved until the interpolation processing is completed in any case, and therefore, as shown in FIG. In the case where the interference area is small or the interference area disappears, the time required for positioning to the via point P1 is wasted. In these cases, the program must be modified each time in accordance with the relationship between the jig and the work. Considering that the test of the program is performed sequentially, a great deal of labor is required. On the other hand, since the next block is started without confirming that the machine position has reached the program target position, the trajectory on which the axis actually moves cannot be specified before the operation, and the machine must be operated once. Therefore, it is necessary to check the trajectory of the shaft, which is dangerous and time-consuming. The present invention has been made in view of such a point, and an object of the present invention is to provide a numerical control device capable of safe operation and reducing cycle time.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a numerical control device for sequentially executing each block of a part program consisting of continuous blocks, and an object of the present invention is to execute a program command every time an interpolation process is performed. A target position difference determining means for calculating a difference between the position and the current machine position and outputting a command within a difference range when the value becomes equal to or less than a predetermined value; It is determined whether there is a block to be executed.If there is, a next block read command is output.If not, an interpolation continuation unit that outputs an interpolation continuation command, and a block to be executed next based on the next block read command are determined. Means for selecting whether or not the interpolation processing up to the previous block has been completed when reading the data; and executing the next processing when it is determined that the interpolation processing up to the previous block has not been completed. By setting the axis movement start point of the block to be executed as the current interpolation position, and using the feed speed at the start point of the next block to be executed as the current feed speed, and interpolation continuation initialization means for initializing the interpolation processing. Is done. The numerical controller according to the present invention can execute the interpolation processing of the next block from an arbitrary position while maintaining the feed speed of the axis currently being interpolated even during the interpolation processing of the axis movement command block. It is.

[0007]

FIG. 1 is a block diagram showing the configuration of a numerical control apparatus according to the present invention. The apparatus of the present invention will be described with reference to the flowchart of FIG. 2 and FIG. 4 which are the block diagram and the flow chart of the conventional apparatus are denoted by the same reference numerals, and description thereof will be omitted. When the interpolation initialization data DB is input, the interpolation processing selection means 12 determines whether or not the block for which the interpolation processing is to be performed is the currently designated block (step S11). The designation of this block is, for example, G
It may be based on a code or a parameter. Hereinafter, a case where the interpolation initialization data DB indicates the currently designated block will be described.

[0008] When the interpolation initialization data DB is input, the interpolation means 3 'outputs the target position data DE to the target position difference determination means 13 and performs the interpolation processing at a fixed period similarly to the conventional apparatus. DC is output to the driving means 4 (step S3 '). Target position difference determination means 13
Is the machine position / speed data D input from the driving means 4
D and a difference between the target position data DE and determine whether or not the difference is equal to or less than a preset parameter value.
Is output to the interpolation continuation means 14 (step S12). When the command SD within the difference range is input, the interpolation continuation means 14 performs one of the following two based on the command SA with the next block. If there is a next block, a next block read command SC is output to the next block reading means 1 (step S1 '). If the next block does not exist, it is determined whether the interpolation processing in the previous block has been completed. If the interpolation processing has not been completed, the interpolation continuation command S
E is output to the interpolation means 3 ', and if it has been completed, the process waits for the next block to be generated (step S21). When the interpolation continuation command SE is input, the interpolation means 3 ′ continuously performs the interpolation processing at a constant cycle and outputs the interpolation data DC to the driving means 4. The target position difference determining means 13 determines the difference between the mechanical position / speed data DD from the driving means 4 and the target position data DE. In this case, the difference is already equal to or less than a predetermined value. Outputting the in-range command SD to the interpolation continuation means 14 is repeated until the next block is generated or the interpolation processing ends.
On the other hand, when the interpolation continuation means 14 outputs the next block reading command SC to the next block reading means 1, the reading means 1 reads the next block, converts it into NC internal variables, and initializes it as block data DA. Output to 10 The initialization processing selecting means 10 determines whether or not the interpolation processing in the previous block has been completed. If the processing has been completed, the processing proceeds to the interpolation initializing means 2; The block data DA is output to each of the block 11 (step S31). Interpolation continuation initialization means 11
When the block data DA is input, the start point of the current block, which is usually the command position of the previous block, is set as the immediately preceding interpolation position, and the speed at the start point of the current block, which is normally 0, is set to the immediately preceding interpolation position. Performs initialization processing for the feed rate,
The interpolation initialization data DB is output to the interpolation selection means 12 (step S32). The operation after the interpolation processing selecting means 12 is as described above.

FIGS. 8 and 9 are diagrams for explaining the operation of the numerical controller according to the present invention. FIG. 8 shows a case where the difference range of the command position in the axis movement in the X-axis direction is set to L by a parameter, for example, and this is an example in which the present invention exerts its effect in the N001 block of the part program of FIG. FIG. 9 shows the relationship between speed and time when this program is operated in comparison with FIG. In FIG. 9, tL is a time when the machine position in the axial movement of the N001 block in the X-axis direction reaches a position obtained by subtracting the difference range L from the command position X2. At this point, the next block, N002 block, is started.
Since the axis movement in the axial direction is still in the middle of interpolation, the command position X2
The position obtained by subtracting the difference range L from the above becomes the N002 block start point, and the current speed vx becomes the speed at the N002 block start point. In the N002 block, the speed command for the axis movement in the X-axis direction is not changed, so that interpolation is continued at the same speed in the X-axis direction. On the other hand, since the movement in the Y-axis direction is stopped, the speed of the axis movement at the start point of the N002 block is 0, and the acceleration is performed toward the feed speed vy of the axis movement in the Y-axis direction. The time t1 in FIG. 9 is the interpolation processing end time of the axis movement in the X-axis direction designated by the block N002, which is the same time as the time t1 in FIG. 7 showing the program operation in the conventional apparatus. Further, t4 'is a time to be compared with t4 in FIG. 7, and is a time required for the machine position to reach the target position in the axis movement in the Y-axis direction specified in the block N002.

[0010]

According to the numerical controller according to the present invention, even during the interpolation processing of the axis movement command block, the next block is maintained while keeping the current speed from the position intended by the operator. , The safe operation is possible and the cycle time can be shortened.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a numerical control device according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a conventional numerical control device.

FIG. 3 is a flowchart showing an operation example of the numerical control device according to the present invention.

FIG. 4 is a flowchart showing an operation example of a conventional numerical control device.

FIG. 5 is a program example for explaining the operation.

FIG. 6 is a diagram illustrating the operation of a conventional numerical control device.

FIG. 7 is a diagram illustrating the operation of a conventional numerical controller.

FIG. 8 is an explanatory diagram of an operation of the numerical control device according to the present invention.

FIG. 9 is an explanatory diagram of the operation of the numerical control device according to the present invention.

FIG. 10 is an operation explanatory diagram of a conventional numerical control device.

FIG. 11 is an operation explanatory diagram of a conventional numerical control device.

[Explanation of symbols]

 Primary block reading means 2 Interpolation initialization means 3, 3 'interpolation means 4 Driving means 5 Secondary block reading instruction means 10 Initialization processing selection means 11 Interpolation continuation initialization means 12 Interpolation processing selection means 13 Target position difference determination means 14 Interpolation Continuation means DA block data DB interpolation initialization data DC interpolation data DD machine position / speed data DE target position data SA next block presence command SB interpolation end command SC next block read command SD difference range command SE interpolation continuation command

Claims (3)

[Claims] 1. A numerical controller for sequentially executing each block of a part program consisting of continuous blocks,
Target position difference determining means for calculating a difference between the program command position and the current machine position each time the interpolation process is performed and outputting a difference within range command when the value falls below a predetermined value; Interpolation continuation means for judging whether there is a next block to be executed when a command is input, outputting a next block read command if there is one, and outputting an interpolation continuation command when there is no block, and reading the next block. Initialization processing selecting means for determining whether the interpolation processing up to the previous block has been completed when reading the next block to be executed based on the command,
If the initialization processing selecting means determines that the interpolation processing up to the previous block has not been completed, the axis movement start point of the next block to be executed is set as the current interpolation position, and the start point of the next block to be executed And an interpolation continuation initializing means for initializing the interpolation processing by using the feed speed at step (1) as a current feed speed. 2. The numerical controller according to claim 1, wherein a predetermined value in said target position difference determining means is set by a command of a program. 3. The numerical control device according to claim 1, wherein a predetermined value in said target position difference determination means is set by a parameter.