JPH03215195A - Recording device - Google Patents

Abstract

PURPOSE:To suppress oscillation, and enable operation to be performed up to the range of high speed rotation, and improve a drawing quality by controlling a speed so that the acceleration of a stepping motor at the time of the acceleration or a deceleration may be changed continuously with a gentle curve. CONSTITUTION:A record controlling circuit 15 for controlling a stepping motor to be used for an X-axis motor 1 and a Y-axis motor 2 is composed of a processing circuit 16, a storage circuit 18 and a mechanical section controlling circuit 19. Then, a speed pattern is composed so that an acceleration at the time of controlling the acceleration or deceleration on the speed control of the stepping motor may be regulated with a continuous curve, and the speed control is contrived to be performed based on the speed pattern. In this case, as the time characteristic of the acceleration at the time of the acceleration or deceleration, a sine function is used, and this is integrated one time, and the speed pattern is contrived to be obtained and is controlled. As a result, oscillation is suppressed, and smooth rotational driving is realized, and a locus can be controlled in good order.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention uses a stepping motor as a driving source, the first axis and the second axis are configured to be substantially perpendicular to each other, and the recording means is scanned on this plane. This paper relates to improvements in recording devices that form visual images (so-called XY plotters). [Prior Art] In general, the general structure of a blocker is as shown in Fig. 5, in which a first axis (referred to as the X-axis) and a second axis (referred to as the Y-axis) are substantially perpendicular to each other, and an X-axis driving source is used as a drive source. Each motor, motor 1 and Y-axis drive motor 2, is installed to drive a recording device such as a plotter. 3a and 3b are X-axis drive pulleys, 3
c and 3d are idler pulleys, 4a and 4b are X-axis drive belts, and 5 is a Y-axis drive pulley. 6 is the Y-axis bar,
7 is the Y-axis drive belt. 8 is a pen carriage, 9 is a pen.
11 is the platen. 12 is recording paper. In addition, in this type of recording device. In many cases, a stepping motor is used as the drive motor. The drive pulse frequency response characteristics of the stepping motor used in this drive source are characteristic curves as shown in the starting torque curve (a) and escape torque curve (mouth) in Figure 8, and the stepping motor has a self-startable range. When operating at high speed beyond the through range (c) shown by the hatch in the same figure, the stepping motor is accelerated and decelerated according to an appropriate speed pattern while avoiding step-out of the stepping motor.

At this time, 1. In the conventional acceleration/deceleration control method. As shown in FIG. 6, the stepping motor is operated so that the speed increases or decreases linearly, that is, during acceleration/deceleration control, the stepping motor moves at a constant acceleration.

Here, the equation of motion of a stepping motor is generally expressed by the following equation. J-dω(t)/d t 1D・ω(t) 1Tf=T
...(1) Here. J is the rotor inertia of the motor. D is the viscosity coefficient, ω(1) is the angular velocity of the rotor, Tf is the static friction torque, and T is the torque generated by the motor. [Problems to be Solved by the Invention] In the case of the conventional linear acceleration/deceleration control method using constant acceleration, as is clear from Fig. 6, when the stepping motor is started and when transitioning from acceleration to constant speed. When transitioning from constant speed to deceleration or from deceleration to stop, the first term on the left side of equation (1) above, J・dω(t)/
This means that dt changes. Large vibrations occur as energy is consumed until the balance state immediately before this change settles into the next balance state. This vibration phenomenon is. This is a very inconvenient phenomenon in plotters and other recording devices that use stepping motors to control the trajectory, causing disturbances in the plot lines, and as a result, the performance of these recording devices has been degraded. As a prior art (second conventional example) that improves this drawback, a drive system using trapezoidal acceleration control as shown in Japanese Patent Publication No. 61-35799 has been proposed. This method uses a trapezoidal acceleration as shown in Figure 7 to ensure that the motor drive speed command is accurate at startup. Provides gentle curves when transitioning from acceleration to constant speed, from constant speed to deceleration, and from deceleration to stop. One of the purposes is to suppress vibrations that occur at each speed inflection point.

but. Even with this method, sufficient measures are not taken against sudden changes in acceleration, so although it has a vibration suppressing effect compared to linear acceleration/deceleration, as mentioned above, changes in acceleration affect the balance of the equation of motion. Collapse. The problem of vibration was not resolved. An object of the present invention is to provide a recording device equipped with a stepping motor speed control method that solves the above-mentioned problems of the conventional method. [Means for solving the problem] In order to solve this problem, the recording device of the present invention focuses on the equation of motion when the stepping motor is driven, and smoothly increases and decreases the acceleration during acceleration/deceleration control. A recording control circuit is provided that gently changes the left side of the equation of motion (1) by , and drives the stepping motor in accordance with the speed pattern calculated from this nonlinear acceleration.

To be more specific, the present invention includes stepping motors as drive sources for the first and second axes. In the recording device 1, an X-Y plane is configured such that the first axis and the second axis are substantially perpendicular to each other, and a recording means is scanned by one or both stepping motors on this plane to record and form a visual image. The present invention relates to a recording apparatus in which the speed pattern of the stepping motor is configured such that the acceleration during acceleration/deceleration control increases or decreases in a continuous curve, and the speed control is performed based on this speed pattern.

In this case, the recording device can be provided with a stepping motor that is controlled by using a sine function as the time characteristic of acceleration during deceleration and integrating it once to obtain a speed pattern. Also, when starting the stepping motor. When transitioning from acceleration to constant speed. When transitioning from constant speed to deceleration. Preferably, the speed pattern is configured so that the acceleration during transition from deceleration to stop increases or decreases in a continuous curve, and the recording apparatus is provided with a stepping motor that is controlled based on this speed pattern.

In this case, the time characteristic of acceleration during acceleration/deceleration is s
The speed pattern is obtained by integrating once the waveform of the in function with gentle curves at startup, transition from acceleration to constant speed, transition from constant speed to deceleration, and transition from deceleration to stop. The recording device may also be equipped with a stepping motor.

[Function] By being equipped with such a recording control circuit, the recording device of the present invention controls the speed of the stepping motor so that the acceleration during acceleration and deceleration changes continuously in a gentle curve, thereby suppressing vibration. However, it is possible to operate up to a high-speed rotation range, making it possible to realize a recording device with improved plotting quality. [Examples] The present invention will be specifically explained below using first and second examples shown in FIGS. 1 to 3. a. First Embodiment FIG. 1 shows a control pattern for acceleration and speed during acceleration and deceleration of a stepping motor provided in a recording apparatus according to a first embodiment of the present invention. In the first embodiment, the time change in acceleration during acceleration and deceleration is a pattern expressed by a sine function. In this case, the acceleration during acceleration/deceleration gradually increases or decreases according to a continuous curve of a sine function from the time when the stepping motor starts to move to a constant speed, and from the time when it moves to deceleration until it stops. Since there is no linear bending change during acceleration or deceleration, the first term on the left side of the equation of motion in equation (1) changes gradually. As a result, since the imbalance in equation (1) that occurs is gentle, the vibration of the stepping motor is not excited, and rotation during acceleration and deceleration is performed smoothly. Therefore, as shown in Figure 7. It is also possible to suppress vibrations that occur in the middle of acceleration and deceleration, which occurs in the conventional trapezoidal acceleration/deceleration control method.

Figure 3 shows a block diagram of the recording device A that performs the above-mentioned acceleration/deceleration control from an electrical circuit perspective. In the same figure,
Parts equivalent to those in FIG. 5 are shown with the same reference numerals 6. It consists of 18 circuits and one machine control circuit. In the storage circuit 18, as drive control data for the stepping motor, acceleration expressed by a sine function is integrated once, and the calculated results are stored as a speed data table.

When a plotting command that involves movement of the recording pen 9 is input from the host computer 13 through the interface circuit 17, the arithmetic processing circuit 16 sequentially reads data from the speed data table stored in the recording circuit 18 and reads the data programmed in advance. Processed by an arithmetic routine, I! A drive pulse is sent to the stepping motor at a predetermined timing via the structure control circuit 19.

As a result, the X-axis motor 1 and the Y-axis motor 2 are driven according to the speed control pattern shown in FIG.
Plotting is done by moving the recording means represented by . In addition, in the above explanation, we have explained the case where the increase/decrease in acceleration is made into a sine function, but instead of relying on the sine function, it is possible to use other appropriate curves to suit the conditions of the stepping motor drive system. A similar effect can be obtained by smoothly increasing and decreasing the acceleration. As described above, when the stepping motor is driven by the method of the first embodiment of the present invention, the seventh embodiment improves the vibration suppression effect.
It can exhibit a much greater vibration suppression effect than the conventional example shown in the figure. b. Second Embodiment In the second embodiment, the vibration suppression effect is applied when starting the stepping motor, when transitioning from acceleration to constant speed, and when transitioning from constant speed to deceleration. In order to make the deceleration affect the transition to a stop, increase or decrease the acceleration when the stepping motor is started, as shown in Figure 2. The transition from acceleration to constant speed, from constant speed to deceleration, and from deceleration to stop are all performed using gentle curves. Here is an example of how to actually drive a stepping motor. As shown in Fig. 2, the time characteristics of acceleration during acceleration/deceleration are as follows for the waveform of a sine function: at startup, when transitioning from acceleration to constant speed, and when transitioning from constant speed to deceleration. The recording device obtains a speed pattern by integrating once a gradual curve at the time of transition from deceleration to stop, and controls the speed of the stepping motor based on this speed pattern. Just do it.

As a result, vibrations are significantly suppressed from the time the stepping motor starts until it stops. It becomes possible to perform smooth rotational drive.

Note that the control circuit in this case can also be realized with the same configuration as the recording control circuit 15 shown in FIG. As mentioned above, the vibration suppression effect of the method shown in Figure 2 is compared to the conventional method shown in Figure 7, in which the speed of the stepping motor is controlled based on speed data obtained by once integrating smooth acceleration versus time displacement. For comparison, a tachometer generator was attached to the rotating shaft of the stepping motor installed in the recording device, and the speed change of the motor rotating shaft during actual drawing is shown in Figure 4. The solid line in the middle shows the speed change of the stepping motor driven by the acceleration/deceleration control method of the second embodiment of the present invention. (mouth) The solid line in the middle is the second
The speed changes of the same stepping motor driven by the acceleration/deceleration control method of the conventional example (Figure 7) are shown.
In addition, the dashed lines in Figures 4 (a) and 4 (portion) indicate the target speed one-time characteristic patterns, respectively. Same figure《
By comparing A) and (A), it can be seen that the stepping motor drive system of the recording device 1 of the present invention is superior in terms of vibration suppression effect. The embodiment of the present invention described above is the fifth embodiment of the present invention.
It is effective in suppressing vibration not only in the flatbed type plotter cited in the figure, but also in paper-moving type plotters that move the recording paper to form a single axis. [Effects of the Invention] As described above, the recording device of the present invention has
According to the bink motor drive method, when performing acceleration/deceleration control of a stepper sig motor for the purpose of high-speed operation, it suppresses vibrations that occur due to sudden changes in acceleration as in the past.
It becomes possible to realize smooth rotational drive and perform good trajectory control, thereby providing a recording device with improved plotting quality.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are a one-time acceleration characteristic diagram and a one-time velocity characteristic diagram in the first and second embodiments of the present invention, respectively. FIG. 3 is a block diagram showing an example of a speed control circuit to which the method of the present invention is applied. Moreover, FIG. 4 is a velocity one-hour characteristic diagram showing a comparison between the present invention and a conventional example. FIG. 5 is a perspective view showing a schematic configuration of a recording device 1 to which the method of the present invention is applied. FIG. 6 and FIG. 7 are a one-hour acceleration characteristic diagram and a one-hour velocity characteristic diagram, respectively, of the conventional example. FIG. 8 is a drive pulse frequency response characteristic diagram of a stepping motor used in a recording apparatus. 1 2 9 13 1 4 15 1 6 1 7 1 8 l 9: X-axis drive motor: Y-axis drive motor: Recording pen: Host computer: Recording device: Recording control circuit: Arithmetic processing circuit: Interface circuit: Recording circuit 2 Mechanism control circuit

Claims (1)

[Claims] 1. Stepping motors are provided as drive sources for the first and second axes, and an X-Y plane is configured so that the first and second axes are substantially perpendicular to each other, and this plane In the above recording device that records and forms a visual image by scanning the recording means with both or one of the stepping motors, the speed of the stepping motor is controlled such that the acceleration during acceleration/deceleration control is increased or decreased in a continuous curve. A recording device characterized in that a speed pattern is configured and recording is performed based on this speed pattern. 2. Configure the speed pattern so that the acceleration increases or decreases in a continuous curve when the stepping motor starts up, transitions from acceleration to constant speed, transitions from constant speed to deceleration, and transitions from deceleration to stop; 2. The recording apparatus according to claim 1, wherein the speed of the stepping motor is controlled based on the speed of the stepping motor. 3. Claim 1, further comprising a stepping motor whose speed is controlled by using a sine function as the time characteristic of acceleration during deceleration, and integrating this once to obtain a speed pattern.
Recording device as described. 4. As a time characteristic of acceleration during acceleration/deceleration, one time for the waveform of the sine function, with gentle curves at startup, transition from acceleration to constant speed, transition from constant speed to deceleration, and transition from deceleration to stop. 3. The recording apparatus according to claim 2, further comprising a stepping motor 2 whose speed is controlled by integrating to obtain a speed pattern.