JP3353607B2 - Numerical control unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical controller for sequentially executing each part in accordance with a part program and realizing smooth axis driving at a joint between the parts.

[0002]

2. Description of the Related Art Conventionally, a numerical control device is configured as shown in FIGS. 6 and 7, and a part program is converted by a program analyzer 1 into position command data such as a shape, a movement amount of each axis, and a feed speed for each part. The position command data is analyzed and stored in the buffer memory 2 for each part. In FIG. 6, reference numeral 4 denotes a feed speed and a shape designation from the buffer memory 2;
Interpolation controllers that take out the movement amount for each axis and generate a servo command value for each axis per interpolation cycle, and 31 and 32 are acceleration / deceleration devices, respectively. The servo commands for each axis output from the interpolation controller 4 are Acceleration / deceleration processing is performed by filtering processing. 5
The drive motors M1 and 52 receive servo command values for each axis subjected to the acceleration / deceleration processing by the acceleration / deceleration units 31 and 32, respectively.
This is a servo unit that operates M2. FIG. 7 shows a numerical controller constituted by a difference in the arrangement of the acceleration / decelerator and the interpolation controller in the circuit configuration. Numeral 3 denotes an acceleration / deceleration device which extracts feed speed data from the buffer memory 2 and performs acceleration / deceleration processing. Reference numeral 4 denotes an interpolation controller for extracting the feed speed and acceleration / deceleration processed by the acceleration / deceleration unit 3, the shape designation, and the movement amount for each axis from the buffer memory 2, and generating a servo command value for each axis per interpolation cycle. , 52 are servo units that operate the drive motors M1 and M2 upon receiving the servo command values for each axis generated by the interpolation controller 4.

[0003] Next, a description will be given of the speed difference of each axis at the joint between the parts of the part program. For example, when laser processing is performed in two axes of X and Y, assuming that the preceding and following parts are composed of two linear trajectories that form an acute angle, the command feed speed of each part is allocated to the command feed speed of each axis. Is as shown in FIG. In FIG. 8, when attention is paid to the joint between the parts, speed differences occur in both the X-axis command feed and the Y-axis command feed speed, and these speed differences generate vibrations in the driven machine.

Therefore, in the conventional numerical controller, the smooth operation of the shaft is realized at the joint between the parts by the functions of the accelerators, decelerators 31, 32 and 3 arranged as shown in FIGS. I have. In the method shown in FIG. 6, since the acceleration / deceleration is performed by filtering, the speed difference is automatically changed to a smooth speed by filtering without paying particular attention to the joint between the parts. Further, in the circuit system shown in FIG. 7, the speed is smoothly changed by always performing the acceleration / deceleration processing at the joint between the parts.

However, in each case, the acceleration / deceleration processing is always performed for each part joint, so that the machining time becomes longer. Therefore, the speed difference of each axis at the joint of each part falls within the range of the allowable acceleration. The device was devised so that it could only decelerate to speed.

[0006]

However, when the interpolation controller 4 performs acceleration / deceleration by filtering after allocating the servo command to each axis as in the circuit system shown in FIG. 6, the time constants of the filters are set to one. This time constant must be a value within the range where the speed change at the joint between parts does not exceed the allowable acceleration for each axis, and this value is set assuming the worst case where the axis is reversed. This is a large value. The large time constant of the filter means that in the case of a circular arc shape, the degree of radius reduction becomes large, and the accuracy of the command locus deteriorates. On the other hand, when the feed rate is first accelerated / decelerated as in the circuit system of FIG. 7 and then the interpolation is performed by the interpolation controller 4, the degree of radius reduction is increased by a circular arc as in the case of the system of FIG. Although there is no problem that the trajectory accuracy is deteriorated, the machining time becomes longer because acceleration and deceleration must be performed at the joint between the parts. Therefore, in order to shorten this processing time, even if the speed difference of each axis at the joint between the parts is decelerated only to a speed within the range of the allowable acceleration, for example, if the joint has an obtuse angle, The machining speed does not need to be reduced as much as the machining shape is small. However, in the case of the machining shape in which the joint is an acute angle, the feed speed must be reduced to near zero.

The present invention is to solve such a conventional problem.

[0008]

According to a first aspect of the present invention, there is provided a numerical controller according to the first aspect of the present invention, in which a part program is analyzed, and a position such as a shape, a feed speed, and a movement amount for each axis is analyzed for each part. A program analyzer for converting the command data into command data; a buffer memory for storing a plurality of parts of the position command data output from the program analyzer; and an acceleration / deceleration for taking out the feed speed for each part from the buffer memory and performing acceleration / deceleration processing. Interpolation control for receiving the shape, the movement amount of each axis, and the feed speed subjected to acceleration / deceleration processing from the acceleration / deceleration device for each part from the buffer memory, and performing interpolation processing to output servo command values for each axis. A numerical controller including a servo unit and a plurality of servo units that respectively operate the drive motors of each axis in response to the servo command value. The interpolation path to the interpolator controller arranged in plural sets parallel, an adder for each axis servo command value from the interpolation control unit adds each collectively for each axis, the buffer
Speed vector of each part from position command data in memory
And its composite velocity vector, and add
The speed change due to the calculated servo command value for each axis.
To prevent the velocity vector from exceeding the allowable acceleration
Is calculated in advance,
A buffer added to the position command data in the buffer memory
Before and after the overlay data creator stored in memory
Start acceleration of subsequent part while executing previous part between parts
In order to make adjustments in different interpolation paths provided in parallel,
The superposition opening stored in the buffer memory
Start timing data and remaining movement amount data from the interpolation controller.
Command to start the overlay at the right time
The interpolation in the interpolation path with the acceleration / decelerator that gave the command
Start outputting the servo command value from the controller, and
Of the servo command value from the interpolation controller
A superposition start detector that starts superposition with force
And the servo command value output by multiple interpolation paths
The addition is performed to control each axis .

According to a second aspect of the present invention, in accordance with the first aspect of the present invention , the deceleration start timing data is generated by the superimposition data generator in accordance with the acceleration / deceleration method of the acceleration / decelerator.
Adjust the parameters used during said overlay data
It is provided with a parameter adjuster for outputting to the creator .

[0010] Further, the invention according to claim 3 is based on claim 1.
In the described invention , input a stop command such as a feed stop command or a single block stop command for temporarily stopping each part ,
A signal for stopping the operation of the overlay start detector
A switching device for outputting to the overlay start detector is provided.

According to a fourth aspect of the present invention, in accordance with the first aspect of the present invention , the deceleration of the superimposition data creator is started in response to a speed override command for changing a feed rate to a specified rate. Used when creating timing data
Adjust that parameter, the overlay into the data generator
An override meter adjuster for outputting is provided.

[0012]

According to the above construction, the invention according to the first aspect is characterized in that the deceleration of the preceding part and the acceleration of the subsequent part are superimposed on each axis at the joint between the parts and are viewed for each axis. The speed change is smoothly performed, and the timing of the deceleration start is adjusted so that the speed change of the overlapped portion does not exceed the allowable acceleration.

According to the second aspect of the present invention, the acceleration / deceleration-related data affecting the timing data generation of the superposition data generator changes in accordance with the change of the acceleration / deceleration system of the acceleration / deceleration device. It acts to adjust the parameters for creating timing data.

According to a third aspect of the present invention, when a stop command such as a feed stop command or a single block stop command is issued, it is necessary to stop within one part, so that a switching start detector for a superposition start detector is used. Acts to stop the operation.

According to a fourth aspect of the present invention, when the speed override is changed before or during execution of the part program, the timing data generated from the feed speed commanded by the part program and the actual feed speed are compared. Since the relationship becomes inconsistent, it acts to adjust the timing data generation parameters of the superimposition data generator in accordance with the speed override command.

An embodiment of a numerical controller according to the present invention will be described below with reference to FIGS.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG. That is, the part program is the program analyzer 1
Is analyzed into position command data such as a shape, a movement amount of each axis, and a feed speed for each part, and the position command data is stored in the buffer memory 2 for each part. Numerals 3a and 3b denote feed speed data from the buffer memory 2 for acceleration / deceleration processing. 4a and 4b are the acceleration / deceleration gears 3
Interpolation controllers 51 and 52, which take out the feed speed subjected to acceleration / deceleration processing by a and 3b, the shape designation, and the movement amount for each axis from the buffer memory 2 and generate servo command values for each axis per interpolation cycle, Drive motors M1, M2 receiving servo command values for each axis generated by interpolation controllers 4a, 4b
, And two sets of acceleration / decelerators 3a and 3b and interpolation controllers 4a and 4b exist in parallel. Reference numeral 6 denotes an overlay data generator which calculates overlay start timing data from the context of each part stored in the buffer memory 2, adds the calculated timing data to the position command data, and resets the data in the buffer memory 2. An example of this superimposition data creation will be described with reference to FIG. FIG. 5 shows, as a speed difference vector, the difference between the speed vector of the back part and the speed vector of the front part after the machining shape having a substantially right angle. When the shape having a substantially right angle as shown in FIG. 5 is inclined by 45 °, the speed difference between the axes becomes maximum at the joint, and this speed difference corresponds to the size of the speed difference vector in FIG. Therefore, a speed difference vector as shown in FIG.
The time required to change to 0 within the range is calculated and used as the timing data of the start of superposition. The overlay start detector 8 measures the overlay start timing based on the overlay start timing data in the buffer memory 2 and the remaining movement amount data from the interpolation controller 4a, and gives a start instruction to the accelerator 3b. . And the acceleration / deceleration device 3b
Receives the start command, retrieves the position command data of the subsequent part from the buffer memory 2, and starts the acceleration process. Upon receiving the speed data from the acceleration / deceleration unit 3b, the interpolation controller 4b generates a servo command value for the subsequent part. Thus, the servo command values output from the interpolation controllers 4a and 4b are added by the adders 71 and 72 for each axis, and
And 52.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to FIG. Figure 2 is intended to parameter adjuster 9 is added to the configuration of the first embodiment (FIG. 1), the acceleration and deceleration of the deceleration device type
The deceleration start time of the overlay data creator
Adjust the parameters used when creating the
It is to be output to overlay data generator. The parameter adjuster 9 determines whether the acceleration / deceleration method of the acceleration / deceleration units 3a and 3b is linear (when the acceleration is constant, and the timing is the required speed), or S-shaped or the like. Is used to adjust parameters for creating data at the timing of starting the superposition.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a feed stop in the configuration of the first embodiment (FIG. 1).
Single block stop that stops once for each command or each part
A stop command such as a command is input, and the superposition start detection is performed.
A signal for stopping the operation of the detector
, And a switch 10 for outputting the same . The switching device 10 stops the operation of the overlay start detector 6 when a stop command such as a feed stop command or a single block stop command for temporarily stopping each part is received.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 shows the feed rate in the configuration of the first embodiment (FIG. 1).
Override to change the speed to the specified percentage
Deceleration of the overlay data generator in response to the
Adjust parameters used when creating start timing data
An overlaid parameter adjuster 11 for outputting to the superimposition data generator is added. The override parameter adjuster 11 adjusts parameters when the overlay data generator 6 creates timing data for starting overlay in accordance with a speed override command for changing the feed rate to a specified rate.

The configuration common to the first to fourth embodiments is a program analyzer 1 that analyzes a part program and converts the part program into position command data such as a shape, a feed rate, and a movement amount for each axis for each part. Program analyzer 1
Memory 2 for storing a plurality of parts of the position command data output from the controller, and an acceleration / decelerator 3 for taking out the feed speed for each part from the buffer memory 2 and performing acceleration / deceleration processing
a, and receives the shape and the movement amount of each axis for each part from the buffer memory 2 and the feed speed subjected to the acceleration / deceleration processing from the acceleration / deceleration units 3a and 3b, performs interpolation processing, and outputs a servo command value for each axis. A numerical control device comprising interpolation controllers 4a and 4b for performing operations and servo units 51 and 52 for operating the drive motors M1 and M2 for the respective axes in response to the servo command values, wherein the acceleration / deceleration units 3a and 3b And interpolation controller 4
a, 4b are provided in parallel, and each interpolation controller 4a,
Adders 71 and 72 which collectively add the servo command value from each of the axes 4b for each axis, and between the parts before and after each part stored in the buffer memory 2 when the deceleration of the previous part already being executed is started. The superposition start detector 8 for starting the acceleration of the later part by using the acceleration / decelerators 3a, 3b and the interpolation controllers 4a, 4b provided in parallel, and the respective additions by the adders 71, 72 of each axis. Superimposition data for previously calculating deceleration start timing data from the position command data in the buffer memory 2 and adding to the position command data in the buffer memory 2 so that the speed change due to the servo command value for each axis does not exceed the allowable acceleration. A creator 6 is provided. With this common configuration, the arc shape does not deteriorate the command trajectory accuracy due to the reduced radius, does not increase the machining time, and smoothly drives the axis at the joint between the parts within the range of the allowable acceleration. be able to. In addition, the trajectory near the joint is inwardly deviated from the command due to the superimposition. However, since the timing data of the superposition start in the superimposition data generator 6 is calculated from the combined speed vector at the joint, the obtuse angle becomes smaller. And the degree of inward rotation increases as the speed change increases as in the case of an acute angle, but the degree of inward rotation can be reduced by increasing the allowable acceleration. Further, since the acceleration / deceleration units 3a and 3b are in front of the interpolation controllers 4a and 4b, even if the acceleration / deceleration system of the acceleration / deceleration unit changes to a linear type or an S-shape, the acceleration does not exceed the allowable acceleration. It can control and can respond to changes in speed override and stop commands.

[0022]

As described above, according to the first aspect of the present invention,
A numerical control device that performs interpolation control after accelerating and decelerating a feed speed, wherein a plurality of sets of interpolation paths from an acceleration / decelerator to an interpolation controller are arranged in parallel without causing a decrease in a command trajectory accuracy due to a decrease in a radius of a circular arc shape. The timing data of the start which does not exceed the allowable acceleration when the parts are superimposed before and after each part from the position command data in the buffer memory is created, added to the position command data in the buffer memory and reset. An overlay start detector that measures the overlay start timing from the overlay data creator, the overlay start timing data in the buffer memory, and the remaining movement amount of the interpolation controller, and commands the start of deceleration and the start of acceleration of the subsequent part. And an adder that collectively adds, for each axis, a servo command from an interpolation path from an acceleration / deceleration unit to an interpolation controller, which is installed in parallel with a plurality of sets. By the formation, in which an excellent effect that can smoothly control the speed changes at the joint without exceeding the allowable acceleration without prolonging the machining time.

Further, according to the invention of claim 2, according to claim 1
In addition to the effects of the invention, there is an excellent effect that the parameter of the timing data generation of the overlay data generator can be adjusted even if the method of acceleration / deceleration of the accelerator / decelerator changes.

Further, according to the third aspect of the invention, in addition to the effect of the first aspect, the switching device is provided when a stop command such as a feed stop command or a single block stop command for temporarily stopping each part is made. Thus, the operation of the overlay start detector can be stopped, and an excellent effect can be obtained in that it can be stopped within one part.

Further, the invention of claim 4 has an excellent effect that the control can be changed in accordance with the speed override command in addition to the effect of the invention of claim 1.

[Brief description of the drawings]

FIG. 1 is a block diagram of a numerical control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a numerical control device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a numerical control device according to a third embodiment of the present invention.

FIG. 4 is a block diagram of a numerical control device according to a fourth embodiment of the present invention.

FIG. 5 is a vector diagram showing a speed vector difference between front and rear parts;

FIG. 6 is a block diagram of a conventional numerical controller.

FIG. 7 is a block diagram of a conventional numerical controller.

FIG. 8 is a timing characteristic diagram showing a command feed speed in each axis at a joint between front and rear parts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Program analyzer 2 Buffer memory 3a, 3b Accelerator / decelerator 4a, 4b Interpolation controller 51, 52 Servo unit 6 Overlay data generator 7 Adder 8 Overlay start detector 9 Parameter adjuster 10 Switcher 11 Override parameter adjustment vessel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-36811 (JP, A) JP-A-6-187028 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05B 19/4103

Claims (4)

(57) [Claims] 1. A program analyzer for analyzing a part program and converting it into position command data such as a shape, a feed rate, and a movement amount for each axis for each part, and a plurality of parts of position command data output from the program analyzer. A buffer memory for storing the same, an acceleration / decelerator for taking out the feed speed for each part from the buffer memory and performing acceleration / deceleration processing,
An interpolation controller that receives the shape and the movement amount of each axis and the feed speed subjected to acceleration / deceleration processing from the acceleration / deceleration unit for each part from the buffer memory and performs interpolation processing to output a servo command value of each axis; A numerical control device comprising: a plurality of servo units that respectively operate the drive motors of the respective axes upon receiving the servo command values, wherein a plurality of sets of interpolation paths from the acceleration / decelerator to an interpolation controller are provided in parallel, From the adder for each axis, which collectively adds the servo command values from each interpolation controller for each axis, and the speed vector of each part and its combined speed vector from the position command data in the buffer memory,
Superimposition start timing data is calculated in advance so that the combined speed vector representing the speed change due to the servo command value for each axis added by the adder for each axis does not exceed the allowable acceleration, and A superposition data creator that adds to the position command data and stores it in the buffer memory, and another interpolation set provided in parallel to start and accelerate the next part during execution of the previous part between the preceding and following parts A command to start the overlay is given to the accelerator / decelerator in the path based on the overlay start timing data stored in the buffer memory and the remaining movement amount data from the interpolation controller. Start the output of the servo command value from the interpolation controller in the interpolation path with the speed reducer, and the servo command value from the interpolation controller that is outputting the servo command value Numerical controller that performs superposition and the superposition to start initiation detector provided, control of each by adding the servo command value output by the plurality of interpolation paths axis of the output. 2. The numerical control device according to claim 1, wherein
Create the overlay data according to the acceleration / deceleration method of the container
Used when creating deceleration start timing data
Data to be output to the overlay data generator.
Numerical control device with parameter adjuster. 3. The numerical control device according to claim 1, wherein
Stop command or single block stop that stops once for each part
Input a stop command such as a stop command,
The signal for stopping the operation of the output unit is detected as the start of the superposition.
Numerical control device equipped with a changeover device that outputs to the vessel. 4. The numerical control device according to claim 1, wherein
Speed overlay that changes the speed to a specified rate
Deceleration of the overlay data creator according to the command of
Adjust parameters used when creating start timing data
And output to the overlay data generator.
Numerical control device with dometer adjuster.