JPH10166671A - Method and device for controlling driving of motor in image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance position accuracy by a method wherein each of conveying rollers on sides for driving and following are driven by a servomotor and both of the servomotors are driven by biaxial synchronized controlling. SOLUTION: There is disclosed a motor driving controlling method for an image forming apparatus that performs recording by conveying a material to be conveyed by means of an endless belt 9 by using a servomotor as a driving source. The image forming apparatus comprises first and second servomotors 6a, 6b for driving first and second conveying rollers 7, 8 that convey the endless belt 9. Each of position control and speed control for the first and second servomotors is executed by respective feedback systems and a command torque for the second servomotor 6b corresponding to a following side is obtained by the synthetic torque of driving controlling systems of the servomotors 6a, 6b. As a result, biaxial synchronized controlling wherein movement of the second servomotor is matched with movement of the driving controlling system of the first servomotor 6a corresponding to a driving side is executed so that it is possible to eliminate influence due to slippage or expansion of the endless belt 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor drive control method for an image forming apparatus and a motor drive control apparatus using the method, and more particularly to a motor drive control method for an image forming apparatus which can be suitably applied to a coating apparatus used in a textile printing machine. The present invention relates to a control method and a motor drive control device using the method.

[0002]

2. Description of the Related Art Conventionally, an applicator for applying a predetermined coating material with a predetermined width to a cloth continuously conveyed by a belt conveyor has been used, and an apparatus for applying a predetermined width in a direction perpendicular to the conveying direction has been used. ing. Such an apparatus will be briefly described with reference to the drawings. FIG. 4 is an external perspective view showing the entire mechanical structure. FIG. 5 is a control block diagram connected to FIG.

First, in FIG. 4, a roller 101 is rotatably supported at a base (not shown), and a servo motor 1 is connected to one end of a rotating shaft via a coupling 100.
02 is fixed to the output shaft 105a of the speed reducer 105 attached to the motor. The first output shaft of the servomotor 102
Encoder 103 is directly connected. Roller 1
An endless belt 106, the other end of which is supported by rollers (not shown), is stretched over 01. A cloth 107 is adhered to the endless belt 106 as shown in the figure. It is configured to apply a predetermined width W on the sheet 107 in a direction orthogonal to the feeding direction of the endless belt 106.

On the other hand, in FIG. 5, feedback control of a speed control loop and a position control loop is performed based on a signal output from the first encoder 103, and a servo motor 102 is driven by a constant amount. By rotating the roller 101 in the direction of the arrow at the rotation speed reduced by the speed reducer 105, the cloth 107 is applied with the application width W while being transported.

However, according to the above-described conventional drive control method, an angle transmission error occurs due to accumulation of backlash generated between a large number of transmission gears constituting the speed reducer 105 and the like. As a result, the rotation amount of the servo motor 102 cannot be finally transmitted to the roller 101, and an error occurs in the rotation angle of the roller 101, so that the cloth 107 stuck on the endless belt 106 in an immovable state can be highly accurate. And there is a problem that an overlap portion Wa occurs in a coating width W to be coated by a coating device and a hollow portion Wb occurs.

To solve this problem, the applicant has previously disclosed in Japanese Patent Application No. 8-12290 a motor drive control method and apparatus for an image forming apparatus in which a cloth is conveyed by an endless belt using a servomotor as a drive source and recording is performed. Suggested.

In the proposed prior application, a driving roller for applying a driving force to an endless belt for transporting a cloth and a driven roller for following the driving of the endless belt are provided, and a servomotor for driving the driving roller is provided. A first encoder for directly detecting a rotational speed of the motor and a second encoder for detecting a rotational operation position of the drive roller; a rotational operation position of the drive roller based on an output signal of the second encoder; The feedback position control for the control is performed, and the feedback speed control of the servo motor based on the output signal of the first encoder is performed by taking in the output signal of the second encoder at a constant rate. It is.

Therefore, by rotating the servo motor by a fixed amount, the cloth stuck to the endless belt via the drive roller moves by a fixed amount, and the cloth is applied to the cloth by the coating device in a direction perpendicular to the conveying direction of the endless belt. It can be applied in a constant width.

[0009]

However, even in this prior application, the driven roller is free, so that even if high-precision positioning control is performed on the driving roller, the driven roller adheres to the endless belt due to the influence of the driven roller. There was a risk that the attached cloth could not be sent with high precision. This is because if the driven roller is free, the endless belt may slip or elongate due to the inertia of the roller or load fluctuation.

[0010] An object of the present invention is to solve the above-mentioned problems, and not only the conveying roller corresponding to the driving side but also the conveying roller corresponding to the driven side are driven by servo motors, and these two servo motors are biaxially driven. It is intended to improve position accuracy by performing synchronous control.

[0011]

According to the present invention, there is provided a motor driving control method for an image forming apparatus which conveys and records a member to be conveyed by using a servomotor as a drive source to achieve the above object. The first and second transport rollers transport the endless belt to be transported, and the first and second encoders detect the rotational speeds of the first and second servo motors that drive the first and second transport rollers. And the first and second
The second and fourth encoders detect the rotational operation position of the transport roller, and perform feedback speed control of the speeds of the first and second servomotors based on the output signals of the first and third encoders. And performing feedback position control of the rotational positions of the first and second transport rollers based on the output signal of the fourth encoder. The feedback speed control of the first and second servomotors is controlled by the first and third servomotors. Both the output signal of the encoder and the output signals of the second and fourth encoders are taken in at a fixed rate, and a first signal is provided on the upstream side in the transport direction of the transported member by the endless belt.
The second servomotor is driven and controlled by taking in the result of feedback speed control of the second servomotor provided on the downstream side.

According to the present invention, there is provided a motor drive control device for an image forming apparatus which conveys and conveys a member to be conveyed by using a servomotor as a driving source. A second transport roller, and first and second drive rollers for driving the first and second transport rollers.
Servo motors, first and third encoders for detecting rotation speeds of the first and second servo motors, and second and third encoders for detecting rotation operation positions of the first and second transport rollers. A fourth encoder performs feedback speed control for speed control based on output signals of the first and third encoders, and performs the first and second transports based on output signals of the second and fourth encoders. A feedback position control for controlling a rotational operation position of the roller is performed, and a first servo motor provided on an upstream side in a conveying direction of the conveyed member by the endless belt is provided with a second servo motor provided on a downstream side. The drive control is performed by taking in the result of the feedback speed control.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a motor drive control method for an image forming apparatus according to an embodiment of the present invention and a motor drive control device using the method will be described with reference to the drawings.

FIG. 1 shows the overall configuration of an image forming apparatus according to the present invention. In FIG. 1, the image forming apparatus conveys a long-sized cloth 1 as a conveyed member and performs recording thereon. The unrolled cloth 1 rotates the unrolled roller 2 to rotate the intermediate roller 3a. , 3b, and sequentially fed to the transport device A, transported by the transport device A, and coated by the coating device 4, and the coated fabric 1 is wound around the winding roller 5 via the intermediate rollers 3c and 3d. It is configured to take.

The transfer device A includes servo motors 6a, 6
b and the first transport roller 7 and the second transport roller 7 that can be driven and rotated.
The endless belt 9 is wound between the transfer rollers 8 and the first and second transfer rollers 7 and 8 are driven and rotated to rotate the endless belt 9 counterclockwise in FIG. To be transported. The endless belt 9 is made of a reinforced non-metallic member such as rubber, and has an adhesive layer formed on its surface. The cloth 1 unwound from the unwinding roller 2 is pressed and adhered to the adhesive layer of the endless belt 9 by the attaching roller 14, and is conveyed without floating from the belt 9.

Note that the endless belt 9 is
Is guided by platen rollers 10a and 10b in a predetermined range facing the recording head 4b, and the belt 9 at the portion is appropriately tensioned so that the cloth 1 is
Are transported.

The recording means as a means for applying in the applying apparatus 4 uses an ink jet recording method in which ink is ejected from a recording head 4b for recording. That is, the recording head has a fine liquid discharge port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and an energy generation section for generating droplet forming energy to act on the liquid in the action section. Means.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or the like, an electromagnetic wave such as a laser is irradiated to generate heat, and droplets are discharged by the action of the generated heat. There are a recording method using an energy generating means, and a recording method using an energy generating means for discharging a liquid by heating a liquid by an electrothermal converter such as a heating element having a heating resistor.

Among them, a recording head used in an ink jet recording method for discharging a liquid by thermal energy has a high density of liquid discharge ports (orifices) for discharging a recording liquid droplet to form a discharge liquid droplet. Since they can be arranged, high-resolution recording can be performed. Among them, a recording head using an electrothermal transducer as an energy generating means is advantageous because it can be easily made compact, easily mounted at a high density, and inexpensively manufactured.

In the present embodiment, the ink is ejected by energizing the electrothermal transducer in accordance with a recording signal and utilizing the film boiling caused by the heat energy to grow and shrink bubbles generated in the ink. The recording is performed by discharging the ink from the discharge port.

Then, two recording heads 4b are mounted on a carriage 4a movable in a direction perpendicular to the paper surface of FIG. 1, and the carriage 4a is moved with respect to the fabric 1 conveyed by the endless belt 9, and the recording heads 4b are moved. , A predetermined image is formed by ejecting ink from the printer. The coating device 4 is shown in FIG.
The endless belt 9 can also be easily replaced. Further, an HS station 11 for correcting unevenness in density of the recording head 4b is provided in the moving range of the coating apparatus 4.

The cloth 1 on which the predetermined image has been applied by the application device 4
Is guided from the adhesive layer of the endless belt 9 by being guided by the intermediate roller 3 c at the position of the first transport roller 7, and is wound up by the winding roller 5. At this time, a heater 12 is provided between the intermediate rollers 3c and 3d, and the fabric 1 from which the ink has been ejected by the recording unit 4 is blown with warm air to dry the ink, and then wound around the winding roller 5. Like that. The heater 12 may be one that irradiates infrared rays in addition to blowing hot air.

FIG. 2 shows a drive control device for the servo motor of the transfer device shown in FIG. 1. In FIG.
6a and 6b are servo motors fixed to the apparatus, 7 and 8 are first and second transport rollers rotatably supported by the apparatus, 1 is a cloth, 9 is an endless belt for transporting the cloth 1 It is.

A reduction gear 21 attached to the servo motor 6a is directly connected to one end of the first transport roller 7,
The first encoder 2 is connected to the output shaft of the servo motor 6a.
2 are directly connected. A second encoder 23 is directly connected to the other end of the first transport roller 7. Similarly, a speed reducer 24 attached to a servomotor 6b is directly connected to one end of the second transport roller 8 and a third shaft is connected to an output shaft of the servomotor 6b.
Encoder 25 is directly connected. A fourth encoder 26 is directly connected to the other end of the second transport roller 8.
An endless belt 9 is stretched over these two first and second transport rollers 7 and 8, and the fabric 1 is adhered thereon, and a direction perpendicular to the transport direction of the endless belt 9 with respect to the fabric 1. Is applied at a constant width W.

Next, FIG. 3 shows a drive control circuit for the servo motor shown in FIG. 2. The same command is given to both the first and second servo motors 6a and 6b at the command position. Of the servo motor 6a performs feedback position control of a position control loop by a second encoder 23 directly connected to the other end of the first transport roller 7, and performs feedback speed control of a speed control loop by the first encoder 22. . The second servo motor 6 b performs feedback position control of a position control loop by a fourth encoder 26 directly connected to the other end of the second transport roller 8, and performs feedback control of a speed control loop by a third encoder 25. Speed control is performed.

An incremental encoder is used as the first encoder 22. An encoder value generated by rotation is added to the first encoder 22 and, at a matching point 31, subtracted from the previous encoder value and then input to an operational amplifier 36. In the operational amplifier 36, a constant k ₁ after reading signals of the first encoder 22, the resolution of k ₁ = second encoder of the formula / (reduction ratio of resolution × reduction gear of the first encoder) Is multiplied by the coefficient k ₁ obtained from the above, the current speed of the servo motor 6 a is obtained, and then sent to the addition point 32. On the other hand, an incremental encoder is also used as the second encoder 23 for detecting the position of the first transport roller 7, and an encoder value generated with the rotation of the roller 7 is added. After the subtraction from the value, at the addition point 34, the current position is added to the previous current position, and the current position is added to the addition point 35.

In the above feedback system,
When the command position for the predetermined drive rotation of the first transport roller 7 is sent, at the addition point 35, the value indicating the current position is subtracted from the absolute position based on the command signal to obtain a position deviation. Send to the operational amplifier 38. In the operational amplifier 38, a target gain is obtained by multiplying by a position gain.
This target speed is subtracted from the current speed value at the addition point 32 to obtain a speed deviation. This deviation is sent to the operational amplifier 37 and multiplied by the speed gain to obtain the target torque. The drive current value of the motor driver connected to the servo motor 6a is set based on the target torque, and the servo motor 6a is driven.

The third encoder 25 is also of an incremental type, and an encoder value generated by rotation is added to the third encoder 25. At an addition point 41, the value is reduced from the previous encoder value.
Enter 6 In the operational amplifier 46, after reading the signal of the third encoder 25, the constant is k ₂ , and the following expression is k ₂ = resolution of the fourth encoder / (resolution of the third encoder × reduction ratio of the speed reducer). Coefficient k ₂ obtained from
, The current speed of the servo motor 6 b is obtained, and then sent to the addition point 42. On the other hand, the fourth encoder 26 for detecting the position of the second transport roller 8 is also of the incremental type, and an encoder value generated with the rotation of the second transport roller 8 is added to the fourth encoder 26 at the matching point 43. At the addition point 44 after the subtraction from the previous encoder value, the previous current position is added, and the current position is added and sent to the addition point 45.

In the above feedback system,
When the command position for the predetermined drive rotation of the second conveying roller 8 is sent, at the addition point 45, the value indicating the current position is subtracted from the absolute position based on the command signal to obtain a position deviation. Send to operational amplifier 48. In the operational amplifier 48, the target speed is obtained by multiplying by the position gain.
This target speed is subtracted from the current speed value at the addition point 42 to obtain a speed deviation.

The output of the operational amplifier 37 of the speed gain of the first servomotor 6a is output from an operational amplifier 50 to a variable C (C = C).
0-1) is multiplied and sent to the matching point 51, where the second servo motor 6b uses it as a torque command. The speed deviation obtained at the addition point 42 is sent to an operational amplifier 47, where it is multiplied by a speed gain, and further multiplied by (1-C) by an operational amplifier 49, sent to an addition point 51, and output from the operational amplifier 50. Is added to obtain the target torque. From this target torque, the second servo motor 6
The drive current value of the motor driver connected to the motor driver b is set to drive the second servo motor 6b.

Each of the target torques of the drive control systems of the first and second servomotors 6a and 6b is added to a matching point 52,5.
3, so that an offset torque is sent to the first and second servo motors 6a and 6b so as to perform control by providing a torque difference.

The constants K1 and K2 of the speed control loop are designed to unify the weight of the resolution per pulse in the position control loop and the resolution per pulse in the speed control loop.

In the above control system, when a command position for predetermined drive rotation is sent, the same command is sent to the drive control systems of the first and second servomotors 6a and 6b corresponding to the drive side and the driven side. Is given, and in each feedback system,
The position control and the speed control are performed, and the second
Of the first servo motor 6b corresponding to the drive side by making the command torque of the servo motor 6b of the first servo motor 6b the combined torque of the drive control systems of the first and second servo motors 6a and 6b. And two-axis synchronous control.
Further, in order to eliminate the influence of the slip and elongation of the endless belt, the offset torque is added to the target torque of the first and second servomotors 6a and 6b corresponding to the drive side and the driven side, and the first and second servomotors are driven. Control is performed by providing a torque difference between the servo motors 6a and 6b.

As described above, the first and second servo motors 6a and 6b corresponding to the driving side and the driven side are controlled by the two-axis synchronous control according to the command torque of the first servo motor 6a corresponding to the driving side. By rotating, the endless belt 9 did not slip or stretch via the first and second transport rollers 7 and 8 while being decelerated by the speed reducers 21 and 24, and was adhered to the endless belt 9. The cloth 1 is moved by a constant amount, and the coating apparatus can apply the cloth 1 to the cloth 1 in a direction perpendicular to the conveying direction of the endless belt 9 with a constant width. As well as the device.

In the above description, a case has been described in which the cloth 1 is fed with high precision to prevent the paint from overlapping and dropping out, but the member to be conveyed is not limited to the cloth.

[0036]

As described above, according to the present invention, the same command is given to the drive control systems of the first and second servomotors corresponding to the drive side and the driven side, and the position of each of the feedback systems is controlled. Control and speed control, and perform two-axis synchronous control in accordance with the movement of the drive control system of the first servomotor corresponding to the drive side by controlling the command torque of the second servomotor corresponding to the driven side. This eliminates the effects of belt slippage and elongation, and improves position accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a drive control device for a servo motor shown in FIG. 1;

FIG. 3 is a drive control block diagram of the servo motor shown in FIG. 2;

FIG. 4 is a configuration diagram of a conventional servo motor drive control device.

5 is a drive control block diagram of the servo motor shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cloth 4 Coating device 4b Recording head 6a 1st servo motor 6b 2nd servo motor 7 1st conveyance roller 8 2nd conveyance roller 9 Endless belt 21 Reduction gear 22 First encoder 23 Second encoder 24 Deceleration Machine 25 third encoder 26 fourth encoder

Claims (11)

[Claims] 1. A motor drive control method for an image forming apparatus for conveying and recording a member to be conveyed by using a servomotor as a driving source, wherein an endless belt for conveying the member to be conveyed is conveyed by first and second conveying rollers. The first and second encoders detect the rotational speeds of first and second servo motors that drive and drive the first and second transport rollers, and detect the rotational operating positions of the first and second transport rollers. Are detected by the second and fourth encoders, and the feedback speed control of the speeds of the first and second servomotors is performed based on the output signals of the first and third encoders. The feedback position control of the rotation positions of the first and second transport rollers is performed based on the signal, and the feedback speed control of the first and second servo motors is performed by using the output signals of the first and third encoders and the output signals of the first and third encoders. (2) Both of the output signals of the fourth encoder are taken in at a fixed rate, and the first servomotor provided on the upstream side in the conveying direction of the conveyed member by the endless belt is the second servomotor provided on the downstream side. A motor drive control method for an image forming apparatus, wherein the drive control is performed by taking in the result of feedback speed control of a servo motor. 2. The method according to claim 1, wherein the member to be conveyed is a cloth stuck on the endless belt, and the member is applied to the cloth by a coating device in a direction having a predetermined width and substantially perpendicular to a moving direction. The method for controlling the drive of a motor of an image forming apparatus according to claim 1. 3. The method according to claim 2, wherein the coating device has an ink jet recording head. 4. A motor drive control device for an image forming apparatus which conveys and conveys a member to be conveyed by using a servomotor as a drive source, wherein first and second conveyances for conveying and driving an endless belt for conveying the member to be conveyed. A roller and the first,
First and second servomotors for driving a second transport roller, first and third encoders for detecting rotation speeds of the first and second servomotors, and the first and second servomotors. And second and fourth encoders for detecting the rotational operation position of the transport rollers, and feedback speed control for speed control based on output signals of the first and third encoders, and second and fourth encoders. A feedback position control for controlling a rotational operation position of the first and second transport rollers based on the output signal of the first servomotor, and a first servomotor provided on the upstream side in the transport direction of the transported member by the endless belt. A motor drive control device for the image forming apparatus, wherein the drive control is performed by taking in the result of feedback speed control of the second servomotor provided on the downstream side. . 5. The feedback speed control according to claim 1, wherein both the output signals of the first and third encoders and the output signals of the second and fourth encoders are taken in at a fixed rate. Of the image forming apparatus. 6. A command torque to said first and second servomotors is obtained by calculating a result of feedback speed control, and a command torque to said first servomotor is supplied to a second servomotor. 2. The motor drive control device for an image forming apparatus according to claim 1, wherein the command drive torque is obtained. 7. The apparatus according to claim 7, wherein the member to be conveyed is a cloth stuck on the endless belt, and an application device for applying the cloth with a predetermined width in a direction substantially perpendicular to a moving direction is provided. The motor drive control device for an image forming apparatus according to claim 1, wherein: 8. The motor drive control device for an image forming apparatus according to claim 1, wherein said coating device is used in a textile printing machine and has an ink jet recording head. 9. The apparatus according to claim 1, wherein the endless belt is made of a non-metallic member. 10. A motor drive control device for an image forming apparatus which conveys and conveys a conveyed member by using a servo motor as a driving source, wherein a driving force is applied to an endless belt for conveying the conveyed member, A first drive roller provided on the upstream side in the transport direction of the first member, and a second drive roller provided on the downstream side in the transport direction of the member to be transported by applying a driving force to the endless belt for transporting the member to be transported. And first and second servomotors for driving the first and second drive rollers, and first and second servomotors directly connected to the first and second servomotors for detecting rotation speeds of the motors. A third encoder, second and fourth encoders for detecting rotational operation positions of the first and second drive rollers, and feedback for speed control based on output signals of the first and third encoders. While controlling the speed, the second,
Based on the output signal of the fourth encoder, feedback position control for controlling the rotational operation position of the first and second drive rollers is performed, the control result is taken in, drive control is performed, and two-axis synchronous control is performed. A motor drive control device for an image forming apparatus. 11. The feedback speed control according to claim 1, wherein both the output signals of the first and third encoders and the output signals of the second and fourth encoders are taken in at a fixed rate. Of the image forming apparatus.