JPH05219799A - Recorder - Google Patents

Abstract

PURPOSE:To improve the throughput of positioning work in a low speed area by changing the length of a constant-speed division to a specified length according to the increase of arriving speed, when a motor is shifted to the constant-speed division at the intermediate section of an acceleration division for achieving a maximum speed. CONSTITUTION:A plotting data for input provided to an interface circuit 3 from a host computer 2, is housed in a RAM 6, and the inclination of a vector to be plotted by a CPU 5, long and short shafts, the length of the vector, an arriving speed, an acceleration division, a constant-speed division, and a deceleration division are specified. in this case, a time controlling data for generating a specified acceleration or deceleration pattern is previously housed in a ROM 7, and by processing linear interpolation, X-axis and Y-axis stepping motors 10, 12 are driven. At the same time, with a pen vertically-controlling circuit 15, the vertical movement of a recording pen is executed. The specified length of the the constant-speed division to be adopted for the ROM 7 when the accelerated division for achieving a maximum speed Vm is shifted to the constant-speed division at the intermediate section of the accelerated division, is set in relation to an equation along the increase curve C of the constant speed division according to the values of arriving speeds V1-V5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus using a step motor as a drive source for two axes which are orthogonal to each other, and particularly to a CA.
The present invention relates to improvement of an XY plotter used in the D field and the like.

[0002]

2. Description of the Related Art FIG. 5 schematically shows the internal structure of an XY plotter mechanism conventionally used in the CAD field and the like. In the figure, 10 is an X-axis step motor, 12 is a Y-axis step motor, 17 is an X-axis drive pulley, 18 is an X-axis drive belt, 1
9 is an X-axis idler pulley, 20 is an X-axis guide, 21 is an X
Axis slider, 22 Y-axis drive pulley, 23 Y-axis drive belt, 24 Y-axis idler pulley, 25 Y-axis guide,
26 is a carriage, 27 is a recording pen, 28 is a platen,
Reference numeral 29 indicates a recording medium. The operating principle of the XY plotter will be described below with reference to FIG. When a drive pulse is input to the X-axis step motor 10, the X-axis drive pulley 17 directly connected to the rotation shaft of the X-axis step motor 10 also rotates,
The X-axis drive belt 1 wound around the X-axis drive pulley 17
8 orbits around an X-axis idler pulley 19 that rotates freely and moves. On the other hand, a part of the X-axis drive belt 18 is fixed to the X-axis slider 21, and as a result, the rotation amount of the X-axis step motor 10 causes the Y-axis guide 25 fixed to the X-axis slider 21 to linearly move. Has been converted. The resolution of the linear movement amount at this time is controlled to be about 0.025 mm / step. Similarly to the X-axis, the Y-axis drive system is also fixed to the Y-axis drive belt 23 by linearly converting the rotation amount of the Y-axis step motor 12 with the Y-axis drive pulley 22, the Y-axis drive belt 23, and the Y-axis idler pulley 24. The carriage 26 is configured to be movable on the Y-axis guide 25 with a resolution of about 0.025 mm. The X-axis and Y-axis drive pulses are generated by a two-axis simultaneous control algorithm by an arithmetic processing circuit inside the plotter, and the recording pen 2 gripped by the carriage 26.
A desired trajectory is drawn on the recording medium 29 mounted on the platen 28 by combining with the intermittent vertical movement of 7.

In the XY plotter having such a structure, in order to reduce the price of the apparatus, an open loop control system is used for driving control of a step motor which is a driving source for the X axis and the Y axis. Due to the control method, there is no feedback of the current position, and a measure for completely preventing position deviation due to step-out caused by a vibration phenomenon of the step motor is taken in advance. As a measure for such measures, in order to operate the step motor as high as possible, the acceleration section from the start to the maximum drawing speed until the end of acceleration, the constant speed section from the end of acceleration to the start of deceleration, and the start to stop from deceleration. The driving pulse train is in accordance with a predetermined trapezoidal acceleration / deceleration pattern including deceleration sections up to. Usually, a visual image drawn by an XY plotter is often expressed by a set of short vectors, and therefore, it often shifts to a constant speed during the acceleration section, that is, before reaching the maximum drawing speed, and further decelerates and stops. To be done.

FIG. 6 shows an acceleration / deceleration pattern used for operating a step motor mounted on a conventional XY plotter. Acceleration / deceleration pattern when P3 'is the reaching speed V3, P
4'is the acceleration / deceleration pattern when the reaching speed V4, Pm is the acceleration / deceleration pattern when the maximum speed Vm, t4 is the acceleration end time of the acceleration / deceleration pattern P3 ', and t6 is the acceleration / deceleration pattern P.
4 ′ is the acceleration end time, t9 is the acceleration end time of the acceleration / deceleration pattern Pm, t13 is the constant speed end time of the acceleration / deceleration pattern P3 ′, t14 is the constant speed end time of the acceleration / deceleration pattern P4 ′, t
12 is the constant speed end time of the acceleration / deceleration pattern Pm, (t13-
t4) is a constant speed section of the acceleration / deceleration pattern P3 ′, (t14−
t6) shows the constant speed section of the acceleration / deceleration pattern P4 ′. In each pattern, the section from the constant speed end time to the stop indicates the deceleration section. In the conventional XY plotter, (t13-t4) =
(T14-t6) acceleration / deceleration patterns P3 ′ and P3
4 ′ is adopted, and in some cases (t13−t4) =
A triangular acceleration / deceleration pattern of (t14-t6) = 0 has been adopted.

[0005]

However, at the transition inflection point from the acceleration section to the constant speed section and from the constant speed section to the deceleration section, a rapid change in acceleration causes an unbalanced state in the equation of motion of the drive system. The unbalanced state is consumed as vibrational energy. In particular, the step motor of the drive source is sensitive to the influence of the unstable phenomenon excited by the vibration energy, and the magnitude of the generated vibration and the settling time vary depending on the operating speed, that is, the frequency of the drive pulse. Fig. 7 shows the drive pulse frequency and the generated vibration amplitude G.
Shows the relationship. In FIG. 7, f3 indicates a drive pulse frequency corresponding to the reaching speed V3, f4 indicates a driving pulse frequency corresponding to the reaching speed V4, and f4, that is, the reaching speed V4 is a region where large vibration is generated. Therefore, as described above, if the length of the constant speed section is fixed, the constant speed section is shifted to the deceleration section before the vibration is settled depending on the operating speed, and at the inflection point (for example, time t14). A large vibration is generated again, and in some cases, this vibration causes a step-out phenomenon of the step motor, which makes it impossible to control the current position.
There is a drawback that the reliability of the Y plotter is significantly impaired. On the other hand, although a constant speed section may be provided in advance with a constant length with a sufficient margin for the vibration settling, in this case, the extra constant speed section is a drawback that the throughput of the plotting operation is reduced. The above-mentioned drawbacks have been attributed to the fact that the optimization method of the acceleration / deceleration pattern has not been sufficiently studied in the operation method of the step motor used as the X-axis and Y-axis drive sources. Therefore, finally improve the acceleration / deceleration pattern of the step motor driving the recording pen,
In particular, we provided a recording device for high-speed plotting that improved the throughput of plotting operations by optimizing the length of the constant velocity segment after shifting from the acceleration segment to the constant velocity segment, and also prevented step-out and improved reliability. The purpose is to do.

[0006]

In order to solve the above problems, the acceleration / deceleration control of the step motor used as the XY axis drive source is achieved at a speed lower than the maximum drawing speed in the middle of the acceleration section reaching the maximum drawing speed. The object is achieved by operating in the acceleration / deceleration pattern in which the length of the constant speed section is changed to a predetermined length in accordance with the increase of the reaching speed when shifting to the constant speed section. Further, the object is achieved by operating in an acceleration / deceleration pattern in which the length of the constant speed section is extended from a predetermined length when shifting to the constant speed section of a specific speed.

[0007]

When such means is used, the constant speed section is shortened in the low speed region where the torque generated by the step motor has a margin to improve the throughput of the positioning operation, and further, the step motor is driven at a specific speed sensitive to vibration. Since the length of the constant speed section is changed by, it is possible to settle the vibration generated at the time of shifting from the acceleration section to the constant speed section to a predetermined amount and then shift to the deceleration section. By suppressing the vibration, step-out of the step motor can be prevented, the reliability of position management can be improved, and a series of these improvements can be realized while minimizing the decrease in the throughput of the drawing operation.

[0008]

FIG. 1 shows an acceleration / deceleration pattern used for operating the X-axis and Y-axis step motors in the recording apparatus of the present invention. Acceleration / deceleration pattern when P1 is the reaching speed V1, acceleration / deceleration pattern when P2 is the reaching speed V2, P3
Is an acceleration / deceleration pattern when the reaching speed V3, an acceleration / deceleration pattern when P4 is the reaching speed V4, an acceleration / deceleration pattern when P5 is the reaching speed V5, an acceleration / deceleration pattern when Pm is the maximum speed Vm of the drawing, t1 Is the acceleration end time of the acceleration / deceleration pattern P1, t3 is the acceleration end time of the acceleration / deceleration pattern P2,
t4 is the acceleration end time of the acceleration / deceleration pattern P3, t6 is the acceleration end time of the acceleration / deceleration pattern P4, t7 is the acceleration end time of the acceleration / deceleration pattern P5, t9 is the acceleration end time of the acceleration / deceleration pattern Pm, and t2 is the acceleration / deceleration pattern P1. Constant speed end time,
t5 is the constant speed end time of the acceleration / deceleration pattern P2, t8 is the constant speed end time of the acceleration / deceleration pattern P3, t10 ′ is the constant speed end time before the change of the acceleration / deceleration pattern P4, and t10 is the extension of the acceleration / deceleration pattern P4. Constant speed end time, t11 is the constant speed end time of the acceleration / deceleration pattern P5, and t12 is the acceleration / deceleration pattern P
Constant speed end time of m, (t2-t1) is acceleration / deceleration pattern P
1 is a constant speed section, (t5-t3) is a constant speed section of the acceleration / deceleration pattern P2, (t8-t4) is a constant speed section of the acceleration / deceleration pattern P3, and (t10'-t6) is before the change of the acceleration / deceleration pattern P4. Constant speed section, (t10-t6) is the acceleration / deceleration pattern P4.
Is a constant speed section after extension, (t11-t7) is a constant speed section of the acceleration / deceleration pattern P5, and (t12-t9) is a constant speed section of the acceleration / deceleration pattern Pm. In each of the acceleration / deceleration patterns, the section from the constant speed end time to the stop at the speed 0 indicates the deceleration section. C indicates an increase curve in the constant speed section.

Since the XY plotter draws a short vector, the predetermined length of the constant speed section adopted when shifting to the constant speed section in the middle of the acceleration section reaching the maximum drawing speed is the value of the reaching speeds V1 to V5. Along the increasing curve C in the constant speed section in accordance with (t2-t1) <(t5-t3) <(t8-t4) <
It is set in the relationship of (t10'-t6) <(t11-t7). Here, the relationship between the generated torque of the step motor operated at various speeds and the drive pulse frequency is as shown in FIG. 3, where PI is the pull-in torque curve of the step motor, PO is the exit torque curve, and L is as shown in FIG. Shows the torque required to drive the load when operating the step motor in a trapezoidal acceleration / deceleration pattern. Fm is the maximum speed V
The drive pulse frequency that achieves m is shown. Generally, when the step motor is accelerated / decelerated as shown in FIG. 1, the generated torque of the step motor is represented by an escape torque curve, and when the drive pulse frequency is low, there is a large margin in the generated torque with respect to the required torque L. Drive pulse frequency is fm
The torque margin decreases as it approaches. That is, there is sufficient torque margin in the low drive pulse frequency region, and in the low speed region, the step-out phenomenon of the step motor can be prevented even if the constant speed section is shortened. Further, shortening the constant speed section particularly in the low speed region is extremely effective for improving the throughput in the case where a fine positioning operation is frequently performed like a short vector.

Generally, when a step motor is connected to a predetermined load and is operated at various speeds, that is, drive pulse frequencies, the vibration characteristics at each speed can be grasped in advance as shown in FIG. In the case of FIG. 1, an oscillating operation locus larger than usual is shown in the vicinity of the arrival speed V4 of the acceleration / deceleration pattern P4, that is, the drive pulse frequency f4, and therefore the length of the constant velocity section is changed from (t10′−t6) to (t10). -T6) is changed to extend the length of the constant speed section for optimization. FIG. 2 shows an enlarged view of the acceleration / deceleration pattern P3 and the acceleration / deceleration pattern P4 in FIG.
The dotted chain line indicates the operation locus of the step motor operated in these acceleration / deceleration patterns. In the figure, a large vibration is generated by the step motor when shifting from the acceleration section to the constant speed section of the reaching speed V4. Therefore, the length of the constant speed section is extended until the vibration is settled to a predetermined amount. Deceleration pattern P4
Are formed. As a result, it becomes possible to shift from the constant speed section to the deceleration section at time t10 without being affected by the residual vibration of the vibration generated at time t6.
Further, in the normal short vector drawing, the constant speed section length along the increase curve C of the constant speed section is adopted, and the acceleration / deceleration pattern is formed so as to minimize the decrease in the throughput of the drawing operation due to the extension of the constant speed section. There is.

FIG. 4 shows the internal control circuit of the recording apparatus according to the present invention. In addition, the XY plotter mechanism used for explanation as one embodiment of the present invention is shown in FIG.
It is similar to the mechanism of. In FIG. 4, 1 is an XY plotter, 2 is a host computer, 3 is an interface circuit, 4 is a communication control circuit, 5 is a CPU (arithmetic processing unit), and 6 is a RAM.
(Readable / writable memory circuit), 7 ROM (read only memory circuit), 8 input / output control circuit (a), 9 X-axis motor control circuit, 10 X-axis step motor, 11 Y-axis motor control circuit, Reference numeral 12 is a Y-axis step motor, 13 is a pen up / down control circuit, 14 is a pen up / down drive solenoid, 15 is an input / output control circuit (b), and 16 is a manual operation means.

The internal control of the XY plotter 1 is sequentially executed by the CPU 5 in accordance with the control program stored in the ROM 7, and a series of processing operations are as follows. Interface circuit 3 of host computer 2 to XY plotter 1
The drawing data input via the is temporarily stored and stored in the RAM 6 via the communication control circuit 4, is sequentially read by the CPU 5 and is subjected to analysis processing. The arrival speed, acceleration section, constant speed section, and deceleration section are specified based on the length of.
When these processes are completed, linear interpolation is performed so as to generate a predetermined vector according to the designated acceleration / deceleration pattern. At this time, the time control data for generating a predetermined acceleration / deceleration pattern is stored in advance in the ROM 7, and the X-axis step motor 10 and the Y-axis step motor are executed by performing a linear interpolation process with reference to the time control data. A drive pulse train for driving 12 is generated. The generated drive pulse train is subjected to power amplification by the X-axis motor control circuit 9 and the Y-axis motor control circuit 11 via the input / output control circuit (a) 8, and then the X-axis step motor 10 and the Y-axis step motor. Twelve exciting energizations are performed. Each drawing vector includes information about the pen up / down movement, and the pen up / down control circuit 13 operates simultaneously with the operation of the X-axis and Y-axis step motors 10 and 12.
By driving the pen up-and-down drive solenoid by the power amplification, the up-and-down movement of the recording pen is performed, and a visual image is formed on the recording medium 29.

In the process of performing such a series of drawing processing,
It is possible to calculate the acceleration section, the constant speed section, the deceleration section, and the arrival speed at which the step motor is operated from the length of the vector to be plotted, and to calculate the constant speed section length along the increase curve C of the constant speed section in FIG. Settings are made. Further, when the calculated result of the arrival speed matches the arrival speed V4, the constant speed section is extended. This specified speed can be determined in advance in consideration of the vibration characteristics of the step motor as shown in FIG. 7, and the settling of vibration settles to a predetermined amount in the speed range where the vibration amplitude is large. The acceleration / deceleration pattern is determined so as to extend the constant speed section until. In order to improve the throughput of the plotting operation, the length of the constant velocity section used when shifting to the constant velocity section in the middle of the acceleration section that reaches the maximum plotting speed in order to plot a short vector Shorter is more effective, that is, when moving to a constant speed in the middle of the acceleration section reaching the maximum speed and further decelerating and stopping, the acceleration / deceleration pattern is changed by changing the length of the constant speed section according to the reached speed. The method of driving is taken. As a result, a normal short vector is provided with a constant speed section having a predetermined length according to the value of the reaching speed, and the acceleration / deceleration pattern is obtained by changing the length of the constant speed section only at a specific reaching speed. It becomes possible to operate the step motor for driving each axis.

[0014]

[Effect] As described above, in the operation of the step motor for driving the XY axes of the recording apparatus, the constant speed section is shortened in the low speed region where the torque generated by the step motor has a margin to improve the throughput of the plotting operation. Since the step motor changes the length of the constant speed section at a specific speed that is sensitive to vibration, it is possible to settle the vibration generated during the transition from the acceleration section to the constant speed section to a predetermined amount and then move to the deceleration section. By suppressing the vibration at the time of shifting to the deceleration section, stepping out of the step motor can be prevented, the reliability of position management can be improved, and the decrease in the throughput of drawing operation can be suppressed to the minimum. It is possible to provide a recording device that realizes the improvement. Further, the same effect can be obtained even when the present invention is applied to a paper moving type XY plotter in which the recording medium is moved to use either the X axis or the Y axis.

[0015]

[Brief description of drawings]

FIG. 1 shows an acceleration / deceleration pattern of a step motor mounted for driving an XY axis of a recording apparatus according to an embodiment of the present invention.

FIG. 2 shows a relationship between torque generated by a step motor and drive pulse frequency.

FIG. 3 is an enlarged view of an acceleration / deceleration pattern of a step motor mounted for driving the XY axes of the recording apparatus according to the embodiment of the present invention.

FIG. 4 shows an internal control circuit of a recording apparatus according to an embodiment of the present invention.

FIG. 5 shows a schematic structure of an XY plotter mechanism.

FIG. 6 shows an acceleration / deceleration pattern of a step motor according to a conventional example.

FIG. 7 shows the relationship between the drive pulse frequency of the step motor and the generated vibration amplitude G.

[Explanation of symbols]

 1: XY plotter 2: Host computer 5: CPU 6: RAM 7: ROM 8: Input / output control circuit (a) 9: X-axis motor control circuit 10: X-axis step motor 11: Y-axis motor control circuit 12: Y-axis Step motor 27: Recording pen 28: Platen 29: Recording medium P1 to P5: Acceleration / deceleration pattern of reaching speeds V1 to V5 Pm: Acceleration / deceleration pattern of maximum speed Vm

Claims (2)

[Claims] 1. A step in which a stepping motor is used as a drive source and is driven by a drive pulse train including an acceleration section from start to acceleration end, a constant speed section from acceleration end to deceleration start, and a deceleration section from deceleration start to stop. A carriage, which is interlocked with a motor and on which a recording pen can be mounted, can be moved on two logical axes that are substantially orthogonal to each other, and a visual image is formed by vertically moving the recording pen while scanning the carriage on a recording medium. In the recording device, in the middle of the acceleration section up to the maximum plotting speed, when shifting to the constant speed section of the reaching speed slower than the maximum plotting speed, the length of the constant speed section is set to a predetermined length according to the increase of the reaching speed. The recording device is characterized in that the stepping motor is operated with the acceleration / deceleration pattern changed to the above. 2. The step motor is operated in an acceleration / deceleration pattern in which the length of the constant speed section is extended from a predetermined length when the speed is changed to a constant speed section of a specific speed in the middle of the acceleration section reaching the maximum drawing speed. The recording apparatus according to claim 1, wherein: