JP2004130444A - Synchronous control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synchronous control device facilitating the creation of work instruction data and enabling work in synchronization with a master shaft independently driven. <P>SOLUTION: A work shape (X=8, Y=12, Z=4) for the work is input as instruction data for a work start position, a work end position and a slave shaft. With respect to an X-axis of the slave shaft moving in parallel with the master shaft, a synchronism magnification Sx (=3) is obtained by adding 1 to the value derived by dividing an X component of the work shape by a moving quantity of the master shaft required for the work. With respect to a Y-axis, a Z-axis of the other slave shafts, the values obtained by dividing the components by the moving quantity of the mater shaft required for the work are regarded as the synchronism magnifications Sy (=3), Sz (=1). Each shaft speed is derived by multiplying the synchronism magnifications Sx, Sy, Sz of each slave shaft by the speed Vm of the master shaft, and interpolation is performed. Even when a master speed changes or varies, the speed of the slave shaft correspondingly varies, and the slave shaft works moving the prescribed quantity while the master shaft moves within the prescribed moving quantity. The master shaft may be an independent shaft. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a synchronization control device for performing a certain operation on a workpiece that is a moving object.
[0002]
[Prior art]
2. Description of the Related Art As an apparatus for performing a predetermined operation on a workpiece conveyed by a conveying unit, an apparatus for performing an operation in synchronization with an electronic cam is known. In the synchronization method using the electronic cam, the drive control is performed on a master axis for driving the transport means in synchronization with the master axis and using another movable axis as a slave axis. The displacement data of the slave axis is registered in correspondence with the phase of the master axis from the master axis phase starting at 0 degree to one rotation, and based on the displacement data corresponding to the master axis phase that changes every moment. This controls the slave axis. (For example, see Patent Document 1)
[0003]
Also, the trajectory data (speed data) of the master axis and the trajectory data (speed data) of the slave axis are controlled in the same controller, and these trajectory data are synthesized for each servo cycle, and the position is determined based on the synthesized trajectory data. There is also known a technique in which a slave axis is operated while following a master axis by controlling (for example, see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-7-302103 [Patent Document 2]
JP-A-11-237919
[Problems to be solved by the invention]
In a device controlled by an electronic cam, the position of the slave axis with respect to the master axis is registered in advance as cam curve data, and the position of the slave axis is determined with respect to the position (phase) of the master axis to operate the axis. Since the cam data is not a simple curve, it takes a lot of man-hours to create, and there is a problem that it cannot be easily created for each object.
[0006]
Further, in patent documents 2 and the like, the master axis and the slave axis are controlled by the same controller, and it is not possible to cope with the one in which the master axis and the slave axis are controlled by different controllers. There's a problem.
Therefore, an object of the present invention is to provide a synchronous control device that can easily create work command data and can perform work in synchronization with an independently driven master axis.
[0007]
[Means for Solving the Problems]
The present invention relates to a synchronous control device for controlling a machine in which one or more slave axes follow a master axis and performs a work on a work conveyed by the master axis, wherein the position of the master axis and command data to the slave axis are controlled. And a synchronization speed calculation unit that calculates a synchronization speed of each slave axis based on the synchronization ratio calculated by the synchronization ratio calculation unit and the speed of the master axis. The drive speed of each slave axis is controlled at the synchronous speed calculated by the synchronous speed calculating means. The synchronous magnification calculating means computes the synchronous magnification by a function comprising a synchronous follow-up portion for the master axis and a relative movement part for the master axis. One or more functions are provided corresponding to the position of the master axis according to the work operation.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic diagram of one embodiment of the present invention. In this embodiment, an example is shown in which various operations are performed on a work 2 as a work object placed and conveyed on a belt conveyor 1 of a conveying means. In this example, an example is shown in which the work 2 is performed by the cutter 4 of the work machine 3.
[0009]
The belt conveyor 1 is defined as a master axis, and the direction in which the work 2 is conveyed by the belt conveyor 1 is defined as an X-axis direction. Further, the working machine 3 has an X-axis in the same direction as the conveying direction of the belt conveyor, a Y-axis orthogonal to the X-axis (in FIG. 1, a direction perpendicular to the paper surface), and a Z-axis orthogonal to the X, Y-axes. Each axis control means for driving and controlling the cutter 4 is provided, and these X, Y, and Z axes are used as slave axes.
[0010]
Reference numeral 5 denotes a sensor for detecting the work 2 conveyed by the belt conveyor 1. Further, the belt conveyor 1 is provided with an encoder 6 as a position detector for detecting the rotational position of the belt conveyor 1.
[0011]
FIG. 2 is a functional block diagram of the synchronization control device of this embodiment. The synchronous control device 10 is constituted by a numerical control device for controlling the work machine 3, and its numerical control processing unit 10a counts feedback pulses from the encoder 6 for detecting the position of the belt conveyor 1 as a master shaft, and The position of the shaft (the position of the belt conveyor) is obtained (10c), and the speed of the master shaft is obtained from the difference between the positions (10d). Further, based on the obtained master axis position and the command data 7, a synchronous magnification for each direction (X, Y, Z axes) of the slave axis is calculated (10e). Further, the speed of each slave axis is obtained based on the obtained synchronization magnification and the master speed (10f), and each slave axis control means 10g of the servo control processing unit 10b drives and controls each slave axis, thereby obtaining the master axis. The work is performed on the work by synchronizing the slave axis with the work. If a position / speed detector for detecting the position and speed is used instead of the encoder 6 for detecting the position, the speed of the master axis can be obtained without calculating the speed of the master axis from the position of the master axis. Can be.
[0012]
The synchronous magnification is divided into a synchronous follow-up portion that follows the master axis and a relative movement portion of the cutter 4 with respect to the workpiece. The synchronous tracking portion has only the X axis of the slave axis moving in a direction parallel to the master axis, and the Y and Z axes of the other slave axes are only the relative motion portions. As a result, when the cutter 4 linearly moves with respect to the work 2, if the synchronous magnification corresponding to the relative movement part of the X, Y, Z axes of the slave axis is Kx, Ky, Kz, each of X, Y, Z The synchronous magnifications Sx, Sy, Sz of the slave axis are as follows. Note that the synchronous magnifications Kx, Ky, Kz corresponding to the relative motion portions are constant regardless of the position Pm of the master axis.
[0013]
Sx = 1 + Kx (1)
Sy = Ky (2)
Sz = Kz (3)
When the cutter 4 performs an arc movement on the XY plane of the workpiece 2, the radius of the arc is normalized to R, and the position Pm of the master axis is normalized to an angle θ of 0 ° to 360 ° (θ = K · Pm (K: master Conversion constant from the position of the axis to the angle)), the master movement angle is determined at predetermined intervals, and assuming that the master angle in the cycle is θ, the synchronous magnifications Sx, Sy, Sx, Sy, Sz is as follows.
[0014]
Sx = 1 + Rcos θ (4)
Sy = Rsin θ (5)
Sz = 0 (6)
In the X axis synchronous magnification Sx in the arc motion, “Rcos θ” is a relative motion portion with respect to the work, and “1” corresponds to a synchronous follow-up portion that follows the master axis.
[0015]
The X-axis, Y-axis, and Z-axis velocities Vx, Vy, and Vz of the slave axis are obtained by multiplying the slave axis synchronization magnifications Sx, Sy, and Sz thus obtained by the master axis velocity Vm.
[0016]
Vx = Sx · Vm
Vy = Sy · Vm
Vz = Sz · Vm
By interpolating and driving each slave axis at this speed at predetermined intervals, even if the moving speed Vm of the belt conveyor 1 of the master axis changes or fluctuates, work can be performed as instructed.
[0017]
FIG. 3 is an explanatory diagram for explaining the relationship between the command data and the speeds of the master axis and the slave axes. In this embodiment, the command data for the synchronous control device that controls the work machine 3 including the slave axis includes a movement section of the master axis (work start position Ps, work completion position Pe) and trajectory data (movement) of the slave axis therebetween. It specifies the quantity and shape (straight or circular). In the example of the command data shown in FIG. 3A, while the master axis moves from the work start position Ps = 4 to the work completion position Pe = 8, 8 units in the X-axis direction, 12 units in the Y-axis direction, and Z unit. An example of a command for performing four-unit linear movement in the axial direction is shown. Thus, the format of the command data can be given in a format such as the EIA format. In this case, the synchronization magnifications Sx, Sy, Sz of each slave axis are obtained as follows, and are as shown in FIG.
[0018]
Sx = 1 + Kx = 1 + X component of work shape / movement amount of master axis required for work (= Pe−Ps) = 1 + 8/4 = 3
Sy = Ky = Y component of work shape / movement amount of master axis required for work (= Pe−Ps) = 12/4 = 3
Sz = Kz = Z component of work shape / movement amount of master axis required for work (= Pe−Ps) = 4/4 = 1
FIG. 3C shows the relationship between the position of the master axis and the speed of the slave axis corresponding to the speed. In FIG. 3 (c), the hatched portion is the moving distance of each axis. That is, while the master axis moves at a constant speed from the work start position 4 to the work completion position 8, the X axis of the slave axis is 12 units at a speed of 3 units (Vx = SxVm = 3.1 = 3). However, since the master axis moves by 4 units, the relative movement amount of the blade 4 with respect to the workpiece in the X-axis direction is 8 units.
[0019]
On the other hand, the Y axis of the slave axis is 12 units at a speed of 3 units (Vy = SyVm = 3.1 = 1 = 3) while the master axis moves from the work start position 4 to the work completion position 8 at a constant speed. Make a move. The Z axis of the slave axis moves by 4 units at a speed of 1 unit (Vz = Sz · Vm = 1 · 1 = 1) while moving at a constant speed from the work start position 4 to the work completion position 8.
[0020]
As a result, the linear movement of the X-axis component 8, the Y-axis component 12, and the Z-axis component 4 is performed while moving the work 2 from the work start position 4 to the work completion position 8 at a constant speed.
As described above, in the present invention, since the speed of the slave axis follows the speed of the master axis, work can be performed reliably even if the speed of the master axis fluctuates.
[0021]
In the case where the speed of the master axis and the speed of the slave axis are not linked but independent, if the speed of the master axis increases, the work may not be completed. That is, since the workable section distance is limited, the work must be completed while the master axis moves through the workable section distance, but if the speed of the slave axis is not linked to the speed of the master axis. This is because, when the speed of the master axis increases, the time required for the workable section distance decreases, and the slave axis may not be able to move to the target position within the shortened time.
However, in the present invention, since the speed of the slave axis is linked to the speed of the master axis, the above-described problem does not occur.
[0022]
In this regard, the Y-axis will be described. The movement amount of the master axis required for the work is L, and the movement command of the Y-axis is linearly moved by y while the master axis moves by L from the work start position to the work completion position. Suppose you have been instructed to do so. The Y axis synchronization magnification Sy is
Sy = y / L
The speed Vy is
Vy = Sy · Vm = y · Vm / L
It is. Since the Y axis moves the distance y at the speed Vy, the moving time t required to move the distance y is:
t = y / Vy = y / (y · Vm / L) = L / Vm
This is equal to the time T required for the master axis to move by the moving amount L at the speed Vm.
For example, in the above example, if y = 12 and the movement amount L of the master axis required for the work is L = 4,
Synchronization magnification Sy = y / L = 12/4 = 3.
Assuming that the speed Vm of the master axis is 1,
Vy = Sy.Vm = 3.1 = 3,
Time t = 12 / Vy = 12/3 = 4 for working the command movement amount y = 12,
During this time, the time required for the master axis to move by the moving amount 4 is T = L / Vm = 4/1 = 4.
[0023]
If the speed Vm of the master axis is 2,
Vy = SyVm = 3.2 = 6,
Time t = 12 / Vy = 12/6 = 2 for working the command movement amount y = 12,
During this time, the time required for the master axis to move by the movement amount 4 T = L / Vm = 4/2 = 2
[0024]
As described above, even when the master speed changes (Vm = 1 or 2), the time for the slave axis to work in the command work shape and the time for the master axis to move in the commanded section are constant. Conversely, even if the master speed changes, the slave axis can work on the commanded work shape while the master axis moves by a predetermined amount. This means that if the movement amount required for the work of the master axis and the movement amount of each slave axis in that section are specified, the work must be performed within the workable section even if the master speed fluctuates from the reference speed. Means to end.
[0025]
In this embodiment, it is assumed that a synchronous control device is constituted by a control device such as a numerical control device for controlling the work machine 3, and FIG. 4 is a block diagram of a main part of a control device of the work machine 3 constituting the synchronous control device. It is.
[0026]
The control device 10 includes a processor 11, a memory 12 such as a ROM and a RAM, a display device 13, a manual input means 14 such as a keyboard, an axis control means 15, a spindle control means, which are connected to the processor 11 via a bus 18. 16, an input / output circuit 17 and the like.
[0027]
The axis control means 15 controls the motors 22x, 22y, 22z of the respective slave axes for driving a blade (tool) attached to the tip of the main spindle in the X, Y, Z-axis directions. , A current feedback control means and the like. The axis control means 15 is connected to servo motors 22x, 22y, 22z of the respective slave axes via servo amplifiers 21x, 21y, 21z of the respective slave axes. A position / speed detector is attached to each of the servomotors 22x, 22y, 22z, and is configured to feed back the position and speed to the respective axis control means 15, but they are omitted in FIG. .
[0028]
The spindle control means 16 is connected to a spindle motor 24 via a spindle amplifier 23. The spindle control means 16 is a spindle speed command issued from the processor 11 and a speed detector (not shown) for detecting a spindle speed. And controls the drive of the spindle motor 24 so that the spindle becomes the commanded speed.
[0029]
The input / output circuit 17 is connected with a sensor 5 for detecting a work and an encoder 6 as a position detector for detecting the position of the belt conveyor 1 as a master shaft.
The above-described synchronous control device is the same as a numerical control device which is a control device for controlling a conventional machine tool.
[0030]
Next, the operation of the synchronous control device will be described. It is assumed that work command data for the work 2 is stored in the memory 12 of the synchronization control device 10. FIG. 5A shows an example of the command data. The command data shown in FIG. 5A is an example in which a command is made to move a straight line in section 1, a circular arc in section 2 following section 1, and a straight line in section 3, and in section 1, the master axis moves to the work start position. 4 to the work completion position 8, the X axis of the slave axis moves by 8 and the Y axis moves by 4 linearly. In the section 2, the work completion position 368 starts from the moment when the master axis reaches the work start position 8. During the movement to the point (Xs, Ys) = (8, 4) and the end point to (Xe, Ye) = (8, 4), in the section 3, the master axis is moved to the work start position. While moving from 368 to the work completion position 372, the X axis is moved by -8 and the Y axis is moved by -4 linearly. The synchronization magnifications Sx, Sy, and Sz in each section are as shown in FIG. FIG. 6 shows the relationship between the position of the master axis and the relative position of the slave axis based on the operation command data. The horizontal axis indicates the master axis position Pm, and the vertical axis indicates the relative position Px of the slave axis with respect to the master axis of the X axis and the relative position Py of the Y axis of the slave axis with respect to the master axis.
[0031]
FIG. 7 is a flowchart of the synchronization control process executed by the processor 11 of the synchronization control device 10. It is assumed that instruction data as shown in FIG. 5A is stored in the memory 12 of the synchronous control device 10, for example. When the power is turned on, the processor 11 monitors whether a detection signal of the work 2 has been input from the sensor 5 via the input / output circuit 17 (step A1). When a detection signal is output from the sensor 5 and is detected in step A1, the rotation of the belt conveyor 1, which is the master shaft, is detected and the number of pulses input via the input / output circuit 17 from the encoder 6 that generates pulses is counted. The register is cleared (step A2). As a result, this register indicates the amount of movement of the master axis after the sensor 5 has detected the work, that is, the (work 2) master axis position (the detected position of the work 2) Pm.
[0032]
Next, the data of the first section is read from the command data (step A3). If there is no command data, the process proceeds to step A20. If there is command data (step A4), the position Pm of the master axis, that is, the value of a register for counting feedback pulses from the encoder 6 is read (step A5). The position Pm is compared with the work start completion position Ps of the read command data, and waits until the position Pm matches (Step A6).
[0033]
When the position Pm of the master axis 1 matches the operation start position Ps of the command data, it is determined whether the command of the command data is a straight line command or an arc command (step A7), and as shown in FIG. If there is, the master axis position Pm is read (step A8), and the synchronization magnification of each slave axis is obtained (step A9). The X axis of the slave axis in a direction parallel to the master axis 1 is obtained by dividing the amount of movement of the X axis during the movement of the master axis from the work start position to the work completion position by the amount of movement of the master axis during this time. The synchronization magnification Sx is determined by adding the master axis follow-up component “1” to this part. Further, since only the relative motion components are provided for the Y axis and the Z axis of the slave axes, the movement amount of the master axis of each axis during the movement from the work start position to the work completion position is divided by the movement amount in each direction. Then, the synchronization magnifications Sy and Sz are obtained (step A9).
[0034]
In the example of section 1 in FIG. 5, the following is performed.
Sx = 1 + X component of machined shape / movement amount of master axis required for work = 1 + 8/4 = 3
Sy = Y component of machined shape / movement amount of master axis required for work = 4/4 = 1
Sz = Z component of machined shape / movement amount of master axis required for work = 0/4 = 0
Next, based on the master axis position detected in the previous cycle and the master axis position Pm detected in the current cycle (step A8), a master axis speed Vm is obtained (step A10), and synchronization of each slave axis with the master axis speed Vm is performed. The speeds Vx, Vy, Vz of the slave axis are obtained by multiplying the magnifications Sx, Sy, Sz (step A11). Then, at predetermined intervals, the movement command of each slave axis is interpolated based on the obtained axis speeds Vx, Vy, Vz and output to the axis control means 15 (step A12). Thereafter, at predetermined intervals, the movement command of the section read in step A3 is distributed and output, and the processing of step A8 and step A13 is repeatedly executed until the work of section 1 is completed (step A13). As means for determining the speed of the master axis, a tachometer or the like may be used to directly detect the speed in addition to the above.
[0035]
When the movement command for the section is output and the operation is completed (step A13), the process returns to step A3, and the next section of the command data is read. If the next section is an arc command as shown in FIG. 5, the process proceeds from step A7 to step A14, where the position Pm of the master axis is read, and the work start point position Ps of the arc is subtracted from the position Pm of the master axis. The rotation angle θ (= K · (Pm−Ps)) is obtained by multiplying the value by a variable constant K for normalization (step A15).
[0036]
Based on the rotation angle θ and the command radius R, the equations (4) and (5) are performed to determine the synchronous magnifications Sx and Sy of the X and Y axes of the slave axes. For the Z axis, the movement command is normally “0” and the synchronization magnification Sz is “0”. However, when there is a movement command, the movement amount of the master The movement command is divided to determine the Z axis synchronization magnification Sz (step A16).
[0037]
The speed Vm of the master axis is obtained (step A17), and the speeds Vx, Vy, Vz of each slave axis are obtained by multiplying the speed Vm of the master axis by the respective synchronous magnifications Sx, Sy, Sz of each slave axis (step A18). At every predetermined period, interpolation is performed on the basis of the axis speeds Vx, Vy, Vz for which the movement commands of the slave axes have been obtained, and output to the axis control means 15 (step A19). If the movement (work) of the section instructed is not completed (step A20), the process returns to step A14, and the processing of step A14 and subsequent steps is repeatedly executed at predetermined intervals.
[0038]
Thus, when the movement instructed in the section is completed and the work is completed, the process returns from step A20 to step A3 to read the next section, and if there is a command, the work in that section is performed. If there is no command, the process proceeds from step A4 to step A21, where each axis of the slave is returned to the home position, and the signal from the sensor 5 is monitored (step A1).
[0039]
Hereinafter, every time the work 2 is detected by the sensor 5, the above-described processing is repeated, and the work based on the command data is performed on the work 2.
[0040]
【The invention's effect】
The invention can be synchronized with a master axis that is driven independently of the slave axis. Also, even if the speed of the master axis is changed or fluctuated, the slave axis can be made to follow, and a command can be issued in an easy format such as the EIA format.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an embodiment of the present invention.
FIG. 2 is a functional block diagram of a synchronization control device according to the embodiment.
FIG. 3 is an explanatory diagram illustrating the relationship between command data and the speed of each axis of a master axis slave.
FIG. 4 is a block diagram of a main part of the embodiment.
FIG. 5 is a diagram showing an example of command data.
6 is a diagram showing a relative positional relationship between a master axis position and a slave axis according to the command data shown in FIG. 5;
FIG. 7 is a flowchart of a synchronization control process in the embodiment.
[Explanation of symbols]
1 Master axis (belt conveyor)
2 Work 3 Work implement 4 Blade 5 Sensor 6 Encoder 10 Control device 22x to 22z Servo motor 24 Spindle motor

Claims (5)

In a synchronous control device that controls a machine that operates on a work conveyed by the master axis in synchronization with the slave axis following the master axis,
Master axis position detecting means for detecting the position of the master axis,
Master axis speed calculation means for determining the speed of the master axis based on the position of the master axis detected at regular intervals by the master axis position detection means,
Information for specifying a work start position and a work completion position of the given master axis, a work path of the slave axis with respect to the object in the section between the work start position and the work completion position of the master axis, and the master axis position detection means. Synchronization magnification calculating means for calculating a synchronization magnification which is a speed ratio of each slave axis to the master axis based on the obtained master axis position;
Synchronous speed calculating means for calculating the synchronous speed of each slave axis based on the synchronous magnification calculated by the synchronous magnification calculating means and the master axis speed obtained by the master axis speed calculating means;
A synchronous control device for controlling the driving of each slave axis at the synchronous speed calculated by the synchronous speed calculating means. In a synchronous control device that controls a machine that operates on a work conveyed by the master axis in synchronization with the slave axis following the master axis,
Master axis position detecting means for detecting the position of the master axis,
Master axis speed detection means for detecting the speed of the master axis,
Information for specifying a work start position and a work completion position of the given master axis, a work path of the slave axis with respect to the object in the section between the work start position and the work completion position of the master axis, and the master axis position detection means. Synchronization magnification calculating means for calculating a synchronization magnification which is a speed ratio of each slave axis to the master axis based on the obtained master axis position;
Synchronization speed calculation means for calculating a synchronization speed of each slave axis based on the synchronization magnification calculated by the synchronization magnification calculation means and the master axis speed obtained by the master axis speed detection means;
A synchronous control device for controlling the driving of each slave axis at the synchronous speed calculated by the synchronous speed calculating means. 3. The synchronization control device according to claim 1, wherein the synchronization magnification calculating means calculates the synchronization magnification by using a function including a synchronization tracking corresponding portion with respect to the master axis and a relative movement portion with respect to the master axis. The synchronous control device according to claim 3, wherein one or more functions are provided corresponding to a position of a master axis according to the work operation. The synchronous control device according to claim 1, wherein the number of the slave axes is one or more.

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