JP5635900B2 - Control device - Google Patents

Description

  The present invention relates to an ink jet printer that records ink by discharging ink from a recording head onto a recording material, and more particularly to motor drive control.

  An ink jet printer is a so-called serial type image printer that performs recording on the surface of a recording medium by moving a carriage mounted with a recording head in a width direction orthogonal to the conveyance direction of the recording medium such as recording paper. In the serial type image printer, the recording of the recording medium and recording by carriage scanning are alternately repeated to record an image on the entire recording medium.

  As these driving means, a feedback control system using a DC motor and an encoder is mainly used in order to achieve both high accuracy and low noise. In the drive means for transporting the recording medium, it is important to ensure stop accuracy, and it is essential to reduce the speed before stopping and to remove the disturbance torque before stopping (stabilize the low-speed driving just before stopping). By turning off the motor power at a constant and sufficiently slow speed, the establishment time, which is the time from when the motor starts to rotate until it stops, and the stopping accuracy of the motor can be stabilized. In a driving unit that performs carriage scanning, in order to improve image quality by stabilizing the ink landing position, stabilization of speed fluctuation during scanning is emphasized.

  In such a driving means, disturbance torque is removed by feedback control represented by generally known PID control for torque fluctuation having a large period. However, since the frequency that can be solved by the above feedback control is exceeded, there is a problem that the torque fluctuation represented by the motor cogging cycle cannot be controlled.

  The following means are known as means for eliminating the influence of cogging torque ripple in the carriage drive system. That is, there are known means for correcting the voltage applied in the direction of canceling torque fluctuation, and means for driving the head by obtaining a correction value for timing of ink ejection from the resulting speed fluctuation amount (for example, Patent Document 1). A good image can be obtained by combining the correction with the voltage and the discharge correction.

JP 2006-256226 A

  Two carriage motors are provided as drive sources, and power is transmitted to the carriage via the belt. On the platen, the carriage repeats a reciprocating motion to form an image on a recording medium. The state of the carriage is detected by a linear scale, and a feedback control system for calculating command values to the two carriage motors is configured. In the case of such a configuration, since there are a plurality of motors serving as driving sources, it is conceivable that each cogging torque ripple is superimposed. That is, it is conceivable that torque fluctuation twice as large as that of a single motor occurs, and the influence on the printed matter at that time can be easily imagined.

  In the conventional example, since there are a plurality of motors, there are infinite combinations of cogging torque ripple occurrence positions, and it is difficult to correlate with a state that is not affected by the transport error.

  In the invention described in Patent Document 1, the operation with a single motor is considered, which is different from the conditions with a plurality of motors.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a printer control apparatus that suppresses the influence of cogging torque ripple and is less susceptible to speed fluctuations in a drive control system in which a plurality of motors are present as drive sources.

  The printer control device of the present invention includes a state detector that detects position and speed information of a control target, a controller that calculates an operation amount that is a difference value between a control command value and the position and speed information of the control target; A first drive source for inputting the manipulated variable, and a second drive source, and the generated torque generated by the first drive source and the generated torque generated by the second drive source are added together. A printer control device for driving the control object based on a combined torque, wherein a power breaker that cuts off the power of the second drive source and the power breaker cuts off the power of the second drive source In this state, the first correction value estimator for estimating the first correction estimated value for canceling the cogging torque ripple of the first driving source based on the position and speed information, and the state detector The detected motor angle information and the first correction value A first cogging torque correction that calculates a first correction amount that is a motor operation amount capable of canceling out the motor torque ripple of the first drive source based on the first correction estimated value estimated by the setter. And a cogging torque of the second drive source based on the position and speed information in a state in which the power breaker does not cut off the power of the second drive source. A second correction value estimator for estimating a second correction estimated value for canceling the ripple; the motor angle information detected by the state detector; and the second correction value estimated by the second correction value estimator. A second feedforward control including a second cogging torque corrector that calculates a second correction amount that is a motor operation amount capable of canceling out the motor torque ripple of the second drive source based on the estimated value. System and above A feedback control system for applying feedback based on position and velocity information, a combination of the feedback control system, the first feedforward control system, and the second feedforward control system; and the feedback control system And a combination of the first feedforward control system and a combination of the feedback control system and the second feedforward control system.

  According to the present invention, in a drive control system in which a plurality of motors are present as drive sources, the effect of cogging torque ripple is suppressed and the effect of being less susceptible to the effects of speed fluctuations and the like is achieved. Therefore, by combining a plurality of inexpensive motors, it is possible to realize a drive system that secures drive force, and to provide a product with high appeal to the user.

1 shows an inkjet printer PR1 that is an embodiment of the present invention. It is a figure explaining the control structure of inkjet printer PR1. 2 is a block diagram illustrating a detailed configuration of a printer controller 406. FIG. It is a figure which implement | achieves the drive system which suppressed the influence of cogging torque ripple. It is a figure which implement | achieves the drive system which suppressed the influence of cogging torque ripple. It is a figure which shows the concept regarding correction | amendment of a cogging torque ripple. It is a flowchart which calculates a cogging torque ripple correction value. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce. It is a figure which shows the relationship between a drive waveform and a correction object area | region. It is a figure which shows the relationship between a drive waveform and a correction object area | region. It is a block diagram which shows connection switching. It is a flowchart which calculates a cogging torque ripple correction value. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce. It is a figure which shows the torque which motor MT1 and motor MT2 generate | occur | produce.

  The mode for carrying out the invention is the following embodiment.

  FIG. 1 is a schematic perspective view of an ink jet printer PR1 according to an embodiment of the present invention.

  The ink jet printer PR1 is a serial ink jet printer equipped with an ink jet head to which an ink tank can be attached and detached. That is, the ink jet printer PR1 is an ink jet printer that forms an image by reciprocally scanning a carriage on which an ink jet head is mounted while intermittently transporting a recording medium. The embodiment can also be applied to a so-called line printer having a long recording head that does not scan in the row direction of the recording medium.

  A guide shaft 103 that guides the carriage 102 to be slidable in the main scanning direction is fixed to the printer chassis 114. A cartridge type recording head 101 to which an ink tank can be attached and detached is detachably mounted on the carriage 102. A belt 104 serving as a carriage drive transmission unit is engaged with a part of the carriage 102, and the belt 104 is wound around a rotation shaft and a pulley of a drive motor 105 serving as a carriage drive unit in an arrangement along the guide shaft 103. is there. Thus, by driving the drive motor 105, the carriage 102 on which the recording head 101 is mounted can move in the main scanning direction.

  The recording paper 115 is a sheet member (recording medium) supplied from the paper supply base 106, and conveys the recording paper 115 in a direction crossing the main scanning direction, and preferably in a direction orthogonal thereto. On the platen 112, a conveyance roller 110 that causes the recording paper 115 to face the recording head 101 is rotatably attached to the chassis 114. The pinch roller 111 is disposed in a state where the pinch roller 111 is driven to rotate with the transport roller 110 and is pressed against the transport roller 110 by a pinch roller spring (not shown). A conveyance roller gear 109 is attached to the shaft end of the conveyance roller 110. The conveyance roller gear 109 meshes with a motor gear 108 attached to the rotation shaft of a conveyance motor 107 that is a DC motor.

  In addition, a code wheel 116 is press-fitted and attached to the shaft portion of the transport roller 110, and an encoder sensor 117 is disposed on the periphery of the code wheel 116.

  As the recording head 101, in addition to a mode in which droplets are ejected from a nozzle by utilizing film boiling when heat energy is applied to a liquid, an electric signal is input to the thin film element, and the thin film element is made minute. A configuration in which liquid is displaced and liquid is ejected from the nozzle can be applied.

  During recording standby of such a printer, the recording paper 115 is stacked (stacked) on the paper supply base 106, and at the start of recording, a paper supply roller (not shown) feeds the recording paper 115 into the apparatus. .

  In order to transport the fed recording paper 115, the transport roller 110 is rotated by the driving force of the transport motor 107, which is a DC motor, via a gear train (motor gear 108, transport roller gear 109), which is a drive transmission means. Let Then, the recording paper 115 sandwiched between the transport roller 110 and the pinch roller 111 that is driven and rotated by the transport roller 110 is transported by an appropriate feed amount. Here, the encoder sensor 117 detects and counts a slit (not shown) on the code wheel (rotary encoder film) 116 at the shaft end of the conveyance roller 110, whereby the conveyance amount of the recording paper 115 is managed. Then, while the carriage 102 is scanned, ink droplets are ejected from the recording head 101 to the recording paper 115 pressed against the platen 112 based on the image information, thereby recording one line.

  A desired image is formed on the recording paper 115 by alternately repeating such carriage scanning and intermittent paper conveyance. After the image formation is completed, the paper discharge roller 113 discharges and the recording operation is completed. “Recording” means the formation of a simple diagram having no meaning in addition to characters and graphics.

  FIG. 2 is a block diagram illustrating a control configuration of the inkjet printer PR1 shown in FIG.

  A printer control CPU 401 of the ink jet printer PR1 controls a printing process by using a printer control program, printer emulation, and a recording font stored in the ROM 402. The RAM 403 stores decompressed data for recording and data received from the host. The motor driver 405 drives the motor, and the printer controller 406 performs access control of the RAM 403, exchange of data with the host device, and transmission of control signals to the motor driver. The temperature sensor 407 includes a thermistor and detects the temperature of the ink jet printer PR1.

  The CPU 401 performs mechanical / electrical control of the main body according to a control program in the ROM 402. Further, the CPU 401 reads information such as an emulation command transmitted from the host device to the ink jet printer PR 1 from the I / O data register in the printer controller 406. Then, control corresponding to the command is written to and read from an I / O register and an I / O port in the printer controller 406.

  FIG. 3 is a block diagram illustrating a detailed configuration of the printer controller 406 shown in FIG. The same components as those shown in FIG. 2 are denoted by the same reference numerals.

  The I / O data register 501 exchanges data at the command level with the host. The reception buffer controller 502 directly writes the reception data from the I / O data register 501 into the RAM 403. The print buffer controller 503 reads the recording data from the recording data buffer of the RAM 403 and sends the data to the recording head 101 during recording. The memory controller 504 controls memory access in three directions with respect to the RAM 403. The print sequence controller 505 controls the print sequence. The host interface 231 manages communication with the host.

  FIG. 4 is a diagram showing the drive system 100 of the ink jet printer PR1 in which the influence of the cogging torque ripple is suppressed.

  The drive system 100 of the inkjet printer PR1 includes a PID computing unit 16, a cogging torque ripple correction unit TA10, a control target 14, an encoder 15, an adder A3, a power breaker 31, and a first correction value estimator. ES1 and a second correction value estimator ES2. That is, the drive system 100 of the ink jet printer PR1 includes a first feedforward control system FFC1, a second feedforward control system FFC2, and a feedback control system FBC.

  When the control object 14 is a conveyance roller that nipping and conveying the sheet member, the motors MT1 and MT2 are motors that drive the conveyance roller. When the control target 14 is a carriage, the motors MT1 and MT2 are motors that drive the carriage. Drive transmission means for transmitting the driving force of the motor MT1 and the motor MT2 to the transport roller is provided. The encoder 15 is a state detector that detects the position and speed of the transport roller. The power breaker 31 cuts off the power of the motor MT2.

  The control target in the drive system 100 of the ink jet printer PR1 shown in FIG. 4 and the drive system 200 of the ink jet printer PR1 shown in FIG. 5 are both the carriage 102 and the transport roller 110 shown in FIG. Not. When the control target is a transport roller, the mechanical configuration has two transport motors 107 shown in FIG. 1, and when the control target is a carriage, there are two drive motors 105 shown in FIG. This is a mechanical configuration.

  The first correction value estimator ES1 is a first correction estimated value for canceling the cogging torque ripple of the motor MT1 based on the position / speed information 32 in a state where the power breaker 31 cuts off the power of the motor MT2. Is estimated. That is, the first correction value estimator ES1 executes a feedback control process for driving the controlled object at the first constant speed. In addition, the first correction value estimator ES1 analyzes the actual drive speed of the control target at each position of the encoder detected by the state detector including the encoder in the feedback control process in units of 360 degrees per cycle. Then, a process for making a correction value is executed. The first constant speed is an operation speed that is within a range in which the motor can operate alone.

  The second correction value estimator ES2 is a second correction estimated value for canceling the cogging torque ripple of the motor MT2 based on the position / speed information 32 in a state where the power breaker 31 does not cut off the power of the motor MT2. Is estimated. That is, the second correction value estimator ES2 realizes a feedback control process for driving the controlled object at the second constant speed. In addition, the second correction value estimator ES2 analyzes the actual drive speed of the control target for each encoder position detected by the state detector including the encoder in the feedback control process in units of 360 degrees per cycle. To realize the correction value processing. The second constant speed is the same speed as the first constant speed, which is the operating speed in which the motor can operate alone, or the third constant speed in which the two motors can operate. Constant speed.

  The first constant speed and the second constant speed are speeds corresponding to a very low speed region immediately before the sheet member conveying device and the carriage are stopped. Further, the distance to drive the control object corresponding to one cycle of 360 degrees is equal to the driving distance corresponding to one cycle of cogging torque fluctuation of the drive source or the driving distance of the control object corresponding to one cycle of 360 degrees. It is the distance which selected several places from the range. Alternatively, the distance for driving the control target corresponding to one cycle of 360 degrees is a distance that is a multiple of the driving distance of the control target corresponding to one cycle of 360 degrees and becomes the maximum region operable in the scanning range of the carriage and the conveyance roller. . The first constant speed is a low speed at which the carriage and the transport roller operate during the mechanical initialization operation. The second constant speed is a printing speed for printing on a recording medium and a conveyance speed for conveying the recording medium.

  The first feedforward control system FFC1 includes a first correction value estimator ES1 and a first cogging torque corrector TA1. The first cogging torque corrector TA1 calculates the first correction amount 28 based on the motor angle information 26 detected by the encoder 15 and the first correction estimated value estimated by the first correction value estimator ES1. calculate. The first correction amount 28 is a motor operation amount that can cancel the motor torque ripple of the motor MT1.

  The second feedforward control system FFC2 includes a second correction value estimator ES2 and a second cogging torque corrector TA2. The second cogging torque corrector TA2 calculates the second correction amount 30 based on the motor angle information 26 detected by the encoder 15 and the second correction estimated value estimated by the second correction value estimator ES2. To do. The second correction amount 30 is a motor operation amount that can cancel the motor torque ripple of the motor MT2.

  The feedback control system FBC applies feedback based on the position / speed information 32.

  The combination of the feedback control system FBC, the first feedforward control system FFC1, and the second feedforward control system FFC2 is the first combination. A combination of the feedback control system FBC and the first feedforward control system FFC1 is a second combination. A combination of the feedback control system FBC and the second feedforward control system FFC2 is a third combination. Then, the drive system 100 of the ink jet printer PR1 selects any one of the first combination, the second combination, and the third combination.

  Further, instead of the encoder 15, a state detector other than the encoder 15 may be provided. Instead of the PID calculator 16, another controller that calculates an operation amount 17 that is a difference value between the control command value and the position and speed information of the control target may be provided. Furthermore, instead of the motors MT1 and MT2, a drive source other than the motor may be provided. The motor angle information 26 is state information detected by the state detector.

  In addition, the driving distance of the control target 14 corresponding to one cycle of 360 degrees is the driving distance for one period of the cogging torque fluctuation of the motor, or the driving distance for one period of the cogging torque fluctuation of the motor and the driving for one rotation of the conveying roller. It is a distance consisting of the least common multiple of the distance.

  FIG. 6 is a diagram illustrating a concept related to correction of cogging torque ripple.

  FIG. 6A is a diagram illustrating torque generated by the motor. FIG. 6B is a diagram illustrating the operation amount input to the motor. Note that a PWM drive method is generally used as an operation amount input to the motor.

  The horizontal axis in FIG. 6 is angle information for one rotation of the motor, the vertical axis in FIG. 6 (1) is the generated torque value, and the vertical axis in FIG. 6 (2) is PWM Duty [%]. It is. A command PWM (thin solid line) in FIG. 6 is a state when a command is issued at a constant value, and in this case, a 50% duty command is sent to all angles of the motor. The torque characteristic that should be desired is the ideal torque (thick solid line) shown in FIG. 6 (1), but in reality, the torque characteristic becomes the actual torque (thin solid line) due to the influence of the cogging torque ripple.

  In the motor angle, the vicinity of 25 °, 150 °, and 275 ° is the place where the torque is generated most, and the vicinity of 90 °, 215 °, and 330 ° is the area where the torque is reduced most. The characteristic obtained by measuring the torque fluctuation amount of the actual torque (thin solid line) and correcting the operation amount so that the torque fluctuation depending on the motor angle is offset is the correction PWM (thin dotted line).

  By adjusting the motor angle so that the operation amount decreases near 25 °, 150 °, and 275 °, and the operation amount increases near 90 °, 215 °, and 330 °, the torque actually generated is This is the state of the correction torque (thin dotted line).

  The drive system 100 shown in FIG. 4 and the drive system 200 shown in FIG. 5 differ in the application method of cogging torque ripple correction. That is, the motor target for reflecting the correction value is different. That is, in the drive system 100 shown in FIG. 4, the torque ripple in the total torque transmitted to the controlled object is suppressed by reflecting the correction value in both of the two motors MT1 and MT2 arranged in the drive system. On the other hand, in the drive system 200 shown in FIG. 5, the torque ripple in the total torque transmitted to the controlled object is suppressed by reflecting the correction value only in the motor MT1.

  Next, the drive system 100 shown in FIG. 4 will be described.

  A control command value 13 is determined as the operation target value of the controlled object 14. The state of the control target is measured by the encoder 15, and the position / speed information 32 is input to the PID calculator 16. The PID calculator 16 performs a PID calculation based on the deviation amount between the control command value 13 and the position / speed information 32 and outputs an operation amount 17 as a next command. The operation amount 17 is input to each of the motor MT1 and the motor MT2 and outputs a generated torque 19 and a generated torque 21, respectively. The generated torque 19 and the generated torque 21 are connected to a mechanical mechanism, and this combined torque 22 is applied to the control target 14. The series of processes described above is the feedback control system FBC, and the control target 14 is controlled and driven according to the operation specifications by performing this feedback control as needed.

  The first cogging torque corrector TA1 cancels the motor torque ripple of the motor MT1 based on the motor angle information 26 detected by the encoder 15 and the first correction estimated value estimated by the first correction value estimator ES1. A first correction amount 28 that is a possible motor operation amount is calculated. That is, the first cogging torque corrector TA1 confirms the motor angle in the current state from the motor angle information 26 obtained from the encoder 15, and the first cogging torque corrector TA1 suppresses the cogging torque ripple according to the confirmed angle. A correction amount 28 is calculated. The adder A1 adds the first correction amount 28 to the operation amount 17, and this addition value is input to the motor MT1 via the motor driver 28d. The correction value uniquely determined by the motor angle is added instead of correcting the value as needed from the error state of the control object 14. This control loop is the first feedforward control system FFC1.

  The second cogging torque corrector TA2 cancels the motor torque ripple of the motor MT2 based on the motor angle information 26 detected by the encoder 15 and the second correction estimated value estimated by the second correction value estimator ES2. A second correction amount 30 that is a possible motor operation amount is calculated. That is, the second cogging torque corrector TA2 confirms the motor angle in the current state based on the motor angle information 26 obtained from the encoder 15, and the second cogging torque corrector TA2 suppresses cogging torque ripple according to the angle. The correction amount 30 is calculated. The adder A2 adds the second correction amount 30 to the operation amount 17, and this addition value is input to the motor MT2 via the motor driver 30d. This control loop is the second feedforward control system FFC2.

  FIG. 7 is a flowchart showing the operation for calculating the cogging torque ripple correction value.

  The power to the motor MT2 is interrupted by the power circuit breaker 31, and the correction value calculation flowchart described in FIG. 7 is executed.

  The cogging torque ripple correction unit TA10 is a part where a series of processing is executed by the first cogging torque corrector TA1 and the second cogging torque corrector TA2. The drive system 100 of the ink jet printer PR1 uses a feedback control system FBC, a first feedforward control system FFC1, and a second feedforward control system FFC2. Therefore, even in a drive control system in which two motors exist with respect to the controlled object 14, the cogging torque ripple is suppressed and stable driving is possible.

  In order to appropriately perform the cogging torque ripple correction according to the control block diagram shown in FIG. 4, the first first correction amount 28 and the first correction amount 28 in the first cogging torque corrector TA1 and the second cogging torque corrector TA2 are used. It is necessary to identify the parameter for calculating the correction amount 30 of 2.

  8, 9, and 10 are diagrams showing torques generated by the motor MT1 and the motor MT2 in the flowchart.

  FIGS. 8 (1), 9 (1), and 10 (1) are diagrams showing torque generated by the motor. FIGS. 8 (2), 9 (2), and 10 (2) are motors. It is a figure which shows the operation amount input into.

  The horizontal axis in FIGS. 8 to 10 is angle information for one rotation of the motor, and the vertical axes in FIGS. 8 (1), 9 (1), and 10 (1) are generated torque values. The vertical axis of 8 (2), FIG. 9 (2), and FIG. 10 (2) is the PWM duty [%]. Consider a case where 50% Duty is designated as the operation amount.

  The motors MT1 and MT2 shown in FIGS. 8, 9, and 10 correspond to the motor MT1 and the motor MT2 shown in FIG. 4, respectively.

  FIG. 8 is a diagram illustrating a state before the adjustment is started. A constant 50% duty is applied to both the PWM of the motor MT1 (solid line) and the PWM of the motor MT2 (dotted line). However, the actually generated torque varies due to the influence of cogging torque ripple. That is, in both cases, the motor angle is the region where the torque is most generated in the vicinity of 25 °, 150 °, and 275 °, and the region where the torque is the smallest is the region near 90 °, 215 °, and 330 °. Since the two motors have similar torque fluctuation characteristics, the combined torque (thick line) has doubled torque fluctuation characteristics compared to a single motor.

  In S <b> 1 shown in FIG. 7, the power to the motor MT <b> 2 is shut off using the power breaker 31. In S1, since the influence of the cogging torque ripple from the motor MT2 in the control system is deleted, a correction value only for the cogging torque ripple of the motor MT1 can be calculated. However, this is a drive system that is supposed to be driven by the combined torque of the two motors, and one of the outputs is lost, so that the operable range is limited. To this end, in S2, a target operating speed (low speed) V1 for detecting a correction value is determined in a low speed region within a range where the single motor can operate.

  In S3, the control system is driven at the target operating speed (low speed) V1, and the torque characteristics of the motor MT1 alone are confirmed. If it is determined in S4 that the motor MT1 is excellent in cogging torque ripple to the extent that correction is not required, the process proceeds to S9 described later. If correction is necessary, the process proceeds to S5, and a correction value calculation parameter ADUST1 is set in the first cogging torque corrector TA1 in order to perform torque correction at the motor angle.

  The correction value calculation calculation parameter ADUST1 is a correction value of the motor MT1 for canceling the cogging torque ripple of the motor MT1 in a state where the power breaker 31 cuts off the power of the motor MT2. When the correction value calculation calculation parameter ADUST1 is detected, a speed fluctuation component caused by cogging torque ripple is detected from the speed information, and a value that minimizes the speed fluctuation is detected while changing the PWMDUTY value to the motor MT1. . The value with the smallest speed fluctuation is the correction value calculation calculation parameter ADUST1.

  In S6, with the second feedforward control system FFC2 enabled, the motor MT1 is driven at the target operating speed (low speed) V1. In S7, the correction result is confirmed. If the correction is properly performed, the correction to the motor MT1 is started in S8, and the power cutoff to the motor MT2 is released in S9. This completes the correction for the motor MT1. If an adjustment error is determined in S7, the process returns to S5, the set value is changed, and the correction is confirmed again. This is the operation for calculating the correction value for the motor MT1.

  FIG. 9 is a diagram illustrating a state of generated torque when power to the motor MT2 is restored in S9.

  In the case shown in FIG. 8, the PWM of the motor MT1 is fixed to 50% Duty, but is corrected so as to be in the opposite phase of the cogging torque ripple. Compared to the case shown in FIG. 8, the torque of the motor MT1 changes to a state in which the torque fluctuation is suppressed, and the fluctuation amount of the combined torque is also suppressed to about half that in the case shown in FIG.

  In S10, a target speed for detecting a correction value in a state where there are two motors is determined. This speed depends on the speed region to be corrected. Specifically, with respect to the conveyance roller drive system, the speed fluctuation in the low speed region immediately before the stop is stabilized, and therefore the object is to improve the stop accuracy. For this reason, the correction speed is set in the low speed region. In this case, it is conceivable that the motor can operate at its own speed, and the target operation speed (low speed) V1 is set to the correction area speed and applied to the correction value detection speeds of both the motor MT1 and the motor MT2. Is desirable. This process is S12.

  FIG. 11 is a diagram illustrating the relationship between the drive waveform and the correction target region in S12 (when the detection speed is set to the target operation speed (low speed) V1).

  In FIG. 11, the horizontal axis indicates time, and the vertical axis indicates speed. The drive speed waveform reaches the target value through acceleration, constant speed, and deceleration. The correction target area is a movable area surrounded by a circle immediately before stopping. On the other hand, the left arrow in FIG. 11 indicates a movable area when there is one motor and a movable area when there are two motors. In either of the movable regions, the movable region surrounded by a circle in FIG. 11 can be moved, so that correction value detection is performed at the low speed of the movable region surrounded by a circle.

  The purpose of the carriage drive system is to stabilize speed fluctuations during printing. In this case, a speed that can be realized only when the two motors are added is often obtained, and a target operation speed (high speed) V2 corresponding to the printing speed is set. This process is S11.

  FIG. 12 is a diagram illustrating the relationship between the drive waveform and the correction target region.

  In FIG. 12, the horizontal axis indicates time, and the vertical axis indicates speed. The drive speed waveform reaches the target value through acceleration, constant speed, and deceleration. The correction target area is a constant speed area (a part surrounded by a circle) where ink is ejected.

  On the other hand, the left arrow in FIG. 12 indicates the movable area with one motor and the movable area with two motors. The correction target area is an area that can be operated by only two motors. For this reason, when the motor is driven alone, it operates at a low speed, and when two motors are driven, it is used properly so as to operate at a high speed in a circled region. However, also in the carriage drive system, a method of detecting the correction value in the manner shown in FIG. 11 and adding the conversion coefficient corresponding to the speed can be considered.

  The control system is driven in S13 according to the set speed determined in S11 or S12, and the torque characteristic in the motor MT2 is confirmed. Note that the cogging torque ripple in the motor MT1 is suppressed by the steps so far.

  If the motor MT2 is excellent in cogging torque ripple to the extent that correction is not necessary in S14, the process proceeds to the end of adjustment. If correction is necessary, the process proceeds to S15, and a correction value calculation calculation parameter ADUST2 is set in the second cogging torque corrector TA2 in order to perform torque correction at the motor angle.

  The correction value calculation calculation parameter ADUST2 cancels the power interruption of the power breaker 31, and corrects the motor MT2 to cancel the cogging torque ripple of the motor MT2 in a state where the total torque of the motors MT1 and MT2 is the total torque 22. This is a parameter for obtaining a value. In the combined torque 22 at this time, the influence of the cogging torque ripple of the motor MT1 can be ignored by the first cogging torque corrector TA1.

  In S16, the motors MT1 and MT2 are driven at a set speed (V1 or V2) while the second feedforward control system FFC2 is enabled. In S17, the correction result is confirmed. If the correction is properly performed, the adjustment is terminated. If it is determined that there is an adjustment error, the process returns to S15, the set value is changed, and the correction is confirmed again.

  FIG. 10 is a diagram illustrating a state of generated torque at the end of adjustment.

  The PWM of the motor MT1 is in the corrected state as in FIG. The PWM of the motor MT2 is fixed to 50% Duty in FIGS. 8 and 9, but is corrected so as to have an opposite phase to the cogging torque ripple. The torque of the motor MT2 also changes to a state where the torque fluctuation is suppressed as compared with the case shown in FIG. 8, and the torque fluctuation is substantially suppressed when viewed in terms of the combined torque.

  Moreover, several means can be considered about the power interruption to the motor MT2 in S1.

  FIG. 13 is a block diagram showing the cogging torque ripple correction unit TA30.

  A cogging torque ripple correction unit TA30 shown in FIG. 13 is a diagram showing a case where a power breaker (switcher 38) having different means is added to the cogging torque ripple correction unit TA10 shown in FIG.

  The power circuit breaker 31 employs a system that blocks the power transmission path from the motor MT2 to the controlled object 14 from the mechanical configuration. On the other hand, the switching unit 38 employs a system that cuts off the power just before the motor MT2 and cuts off the electrical connection to the motor MT2. The switch 38 is positioned on the operation amount 17 and employs a method of cutting off the power in software by setting the operation amount input to the motor MT2 to zero. From these methods, an appropriate one in terms of configuration is selected, and correction value calculation of the motor MT1 is executed. Of the configurations shown in FIG. 13, configurations corresponding to the same symbols as those shown in FIG. 4 are synonymous.

  In the above embodiment, the combination of the feedback control system FBC and the second feedforward control system FFC2 is a combination in which a correction value is input only to the motor MT2. This combination corresponds to an embodiment in which the control of the first feedforward control system FFC1 is not used in the embodiment shown in FIG. That is, when the torque ripple characteristic of the motor MT1 is excellent and correction of the first feedforward control system FFC1 is not required, the control of the first feedforward control system FFC1 is executed in the example shown in FIG. do not do.

  FIG. 5 is a block diagram showing a drive system 200 of the inkjet printer PR1 that performs correction on one of the two motors.

  Of the configurations shown in FIG. 5, configurations corresponding to the same reference numerals as those shown in FIG. 4 are synonymous. In the drive system 200 of the inkjet printer PR1, the first cogging torque corrector TA1 and the third cogging torque corrector TA3 apply cogging torque ripple correction to the motor MT1.

  The drive system 200 of the ink jet printer PR1 has a third feedforward control system FFC3. The third feedforward control system FFC3 includes a third cogging torque corrector TA3 and an adder A4.

  The first cogging torque corrector TA1 confirms the motor angle in the current state based on the motor angle information 26 from the encoder 15 while the power breaker 31 cuts off the power of the motor MT2. Then, the first correction amount 28 for suppressing the cogging torque ripple is calculated according to the confirmed angle. As a result, the torque fluctuation characteristic of the motor MT1 is suppressed.

  The third cogging torque corrector TA3 is the third correction estimated by the motor angle information 26 from the encoder 15 and the third correction value estimator ES3 in a state where the power breaker 31 does not cut off the power of the motor MT2. The motor angle in the current state is confirmed based on the estimated value. Then, the third correction amount 35 for suppressing the cogging torque ripple is calculated according to the confirmed angle. This suppresses the torque fluctuation characteristic of the motor MT2.

  That is, the third correction value estimator ES3 cancels the cogging torque ripple of the motor MT2 based on the position and speed information detected by the encoder 15 in a state where the power breaker 31 does not cut off the power of the motor MT2. A third correction estimated value is estimated. The third cogging torque corrector TA3 cancels the motor torque ripple of the motor MT2 based on the motor angle information detected by the encoder 15 and the third correction estimated value estimated by the third correction value estimator 3. A third correction amount 35 that is a motor operation amount to be obtained is calculated. The calculated correction amount 35 is given to the motor MT1.

  The feedback control system FBC applies feedback based on the position / speed information 32.

  Then, the drive system 200 of the ink jet printer PR1 selects one of the following first combination, second combination, and third combination. The first combination is a combination of a feedback control system FBC, a first feedforward control system FFC1, and a third feedforward control system FFC3. The second combination is a combination of the feedback control system FBC and the first feedforward control system FFC1. The third combination is a combination of a feedback control system FBC and a third feedforward control system FFC3.

  A value obtained by adding the first correction amount 28 and the third correction amount 35 to the operation amount 17 is input to the motor MT1. This series of control loops is the third feedforward control system FFC3. The cogging torque ripple correction unit TA20 executes a series of processes of the third cogging torque corrector TA3.

  By using the feedback control system FBC and the third feedforward control system FFC3 in combination, even in a drive control system in which two motors exist for the control target 14, the cogging torque ripple is suppressed and stabilized. It can be driven.

  In order to properly correct the cogging torque ripple according to the control block diagram shown in FIG. 5, the first correction amount 28 by the first cogging torque corrector TA1 and the third correction by the third cogging torque corrector TA3. It is necessary to identify the parameter of the calculation operation of the quantity 35.

  Several positions of the power breaker 31 shown in FIG. 4 can be considered. FIG. 13 is a diagram showing an example of the possibility of change based on FIG. Therefore, the example shown in FIG. 13 is a control system targeted for the first feedforward control system FFC1 and the second feedforward control system FFC2.

  FIG. 14 is a flowchart for calculating a cogging torque ripple correction value.

  FIGS. 15, 16, and 17 are diagrams showing torques generated by the motor MT1 and the motor MT2. FIG. 15 (1), FIG. 16 (1), and FIG. 17 (1) are diagrams showing torque generated by the motor. FIGS. 15 (2), 16 (2), and 17 (2) are diagrams illustrating the operation amount input to the motor. 15, 16, and 17 indicate angle information when the motor makes one revolution, and the vertical axes in FIGS. 15 (1), 16 (1), and 17 (1) indicate generated torque. 15 (2), FIG. 16 (2), and FIG. 17 (2), the vertical axis represents PWM Duty [%]. Consider a case where 50% Duty is designated as the operation amount. The motors MT1 and MT2 shown in FIGS. 15, 16, and 17 correspond to the motors MT1 and MT2 shown in FIG.

  FIG. 15 is a diagram showing a state before starting the adjustment, which is the same state as the state shown in FIG. The processes of S1 to S12 shown in FIG. 14 are the same as the processes shown in FIG.

  FIG. 16 is a diagram showing a state of generated torque at the end in S9. The state of this generated torque is also the same as in FIG.

  At S18, the control system is driven by the set speed determined at S11 or S12, and the torque characteristics at the motor MT2 are confirmed. Note that the cogging torque ripple in the motor MT1 is suppressed by the steps so far. If the motor MT2 is excellent in cogging torque ripple to the extent that the motor MT2 does not need to be corrected in S19, the process proceeds to the end of adjustment. If it is determined in S19 that correction is necessary, in S20, a correction value calculation calculation parameter ADUST3 is set in the third cogging torque corrector TA3 in order to perform torque correction at the motor angle.

  The correction value calculation calculation parameter ADUST3 is a motor correction value for canceling the cogging torque ripple of the motor MT2 in a state where the power breaker 31 does not cut off the power of the motor MT2. The generated torque 19 includes a torque fluctuation component corresponding to the torque ripple of the motor MT2. In the combined torque 22, the torque fluctuation component and the torque ripple of the motor MT2 cancel each other. The torque ripple of the motor MT1 is removed by the first cogging torque corrector TA1. Therefore, focusing on the torque component finally transmitted to the controlled object, the torque ripple components of the motor MT1 and the motor MT2 are removed.

  When detecting the correction value calculation calculation parameter ADUST3, the speed fluctuation component caused by the cogging torque ripple of the motor MT2 is detected from the speed information, and the speed fluctuation caused by the motor MT2 is minimized while changing the PWMDUTY value to the motor MT1. Is detected. The value with the smallest speed fluctuation is the correction value calculation calculation parameter ADUST3.

  When only the output of the motor MT1 is viewed, there is a torque ripple that is intentionally generated, but the torque ripple interferes with the torque ripple of the MT2 and can be canceled out. Therefore, in the combined torque 22, there is a torque ripple. Disappear.

  In S21, the motor MT1 and the motor MT2 are driven at the set speed (V1 or V2) while the third feedforward control system FFC3 is enabled. In S22, the correction result is confirmed, and if it is corrected appropriately, the adjustment is terminated. If it is determined that there is an adjustment error, the process returns to S20, the set value is changed, and the correction is confirmed again.

  FIG. 17 is a diagram illustrating a state of generated torque in the adjustment end stage.

  The PWM of the motor MT1 is subjected to a correction corresponding to the opposite phase of the motor MT2 in addition to the correction value for the motor MT1 shown in FIG. The PWM of the motor MT2 remains a fixed value. The torque of the motor MT1 changes from a state where the torque fluctuation shown in FIG. 16 is suppressed to a state in which the phase of the torque of the motor MT2 is reversed. In the total torque (thick line) obtained by adding the torque of the motor MT1 and the torque of the motor MT2, the torque fluctuation is canceled out, and the fluctuation with respect to the torque finally input to the controlled object 14 is substantially suppressed.

  Since the control system 14 selects and executes either the drive system 100 shown in FIG. 4 or the drive system 200 shown in FIG. 5 as correction means when there are two motors, the cogging torque ripple is reduced. In addition, good operating characteristics can be realized. Before the function is installed in the printer, it is determined whether the correction unit shown in FIG. 4 or the correction unit shown in FIG. 5 is selected.

  In the case of the above selection, an appropriate one is selected according to various conditions constituting the drive system. For example, in the case of the carriage drive system shown in FIG. 13, and considering the vibration transmission path, it is desirable to select the correction method shown in FIG. Further, if the frequency to be corrected is high, it is conceivable to obtain the reflection speed of the correction value according to the frequency. In this case, it is more appropriate to show in FIG. Seem. Further, the means for reflecting the correction value is not limited to designation on software, but means for executing correction by an electric hardware configuration using ASIC or the like is also conceivable. From these conditions and the like, a method appropriate for the drive system to be controlled 14 is selected to realize suppression of cogging torque ripple. In the above embodiment, a system having three or more drive sources can be dealt with by increasing the number of correction targets by the number of drive sources.

PR1 ... Inkjet printer,
100, 200: drive system of inkjet printer PR1,
MT1, MT2 ... motors
14: Control object,
31 ... Power circuit breaker.

Claims (15)

Position of the control object, and a state detector for detecting the speed information, a controller for calculating an operation amount which is a difference value between the control command value and the control position of the object, the speed information, the first to enter the operation amount of the drive source, and a second drive source, the controlled object based on the first summation torque the torque generated which drive source is generated the second drive source the sum of the torque generated A control device for driving,
A power circuit breaker for interrupting the power of the second drive source;
In a state in which the power circuit breaker has cut off the power of the second drive source, said position on the basis of the speed information, estimating a first correction estimates for canceling the cogging torque ripple of the first drive source the first correction value estimator, based on the first correction estimate the motor angle information first correction value estimator estimated that the state detector detects, the first drive source for A first feedforward control system including a first cogging torque corrector that calculates a first correction amount that is a motor operation amount that can cancel the motor torque ripple of the motor;
In a state in which the power circuit breaker does not cut off the power of the second drive source, said position on the basis of the speed information, estimate a second correction estimates for canceling the cogging torque ripple of the second drive source the second correction value estimator, on the basis of the second correction estimate motor angle information and the second correction value estimator estimated that the state detector detects, the second drive source for A second feedforward control system including a second cogging torque corrector that calculates a second correction amount that is a motor operation amount that can cancel the motor torque ripple of the motor;
A feedback control system for applying feedback based on the position and velocity information;
Has, the feedback control system and said first feed-forward control system and combined with the second feed-forward control system, and combination of the feedback control system and the first feed-forward control system, the feedback control device and selects one of the combinations of the control system and the second feed-forward control system. Position of the control object, and a state detector for detecting the speed information, a controller for calculating an operation amount which is a difference value between the control command value and the control position of the object, the speed information, the first to enter the operation amount of the drive source, and a second drive source, the controlled object based on the first summation torque the torque generated which drive source is generated the second drive source the sum of the torque generated A control device for driving,
A power circuit breaker for interrupting the power of the second drive source;
In a state in which the power circuit breaker has cut off the power of the second drive source, said position on the basis of the speed information, the first of the first drive source for canceling the cogging torque ripple of the first drive source based of the first correction value estimator for estimating a correction estimate, the said first correction estimate the motor angle information first correction value estimator estimated that the state detector detects, A first feedforward control system including a first cogging torque corrector that calculates a first correction amount that is a motor operation amount capable of canceling out the motor torque ripple of the first drive source;
In a state in which the power circuit breaker does not cut off the power of the second drive source, said position on the basis of the speed information, the third of the first drive source for canceling the cogging torque ripple of the second drive source based of the third correction value estimator for estimating a correction estimate, the said third correction estimate the motor angle information third correction value estimator estimated that the state detector detects, A third feedforward including a third cogging torque corrector that calculates a third correction amount, which is a motor operation amount capable of canceling out the motor torque ripple of the second drive source, and applies the third correction amount to the first drive source; Control system;
A feedback control system for applying feedback based on the position and velocity information;
Has, the feedback control system and said first feed-forward control system and combination of the third feed-forward control system, and combination of the feedback control system and the first feed-forward control system, the feedback control device and selects one of the combinations of the control system and the third feed-forward control system. The power breaker, a method for blocking software manner by the operation amount input the to the second drive source to 0, the method for blocking the electrical connection of the the second drive source, to claim 1 or claim 2, characterized in that by selecting one of the system and method of blocking the transmission path to the control target from the mechanical structure of the second drive source is a means for interrupting the power The control device described. Said first correction value estimator, a feedback control process for driving the controlled object at a first constant speed, in the feedback control process, the control target at each position of the encoder which is detected by the state detector comprising an encoder The control device according to claim 1, wherein the control device is configured to execute a process of analyzing the actual drive speed in units of 360 degrees per cycle to obtain a correction value. The control device according to claim 4, wherein the first constant speed is an operation speed in a range in which the drive source can operate alone. The second correction value estimator, a feedback control process for driving the controlled object at a second constant speed, in the feedback control process, the control target at each position of the encoder which is detected by the state detector comprising an encoder The control device according to claim 1 or 2, wherein the control device is configured to realize a process of analyzing the actual driving speed in units of 360 degrees per cycle to obtain a correction value. It said second constant speed, the drive source is first constant speed equivalent to the speed of the operation speed of the operable range even alone, or driving source a third of the operable range by two The control device according to claim 6, wherein the control device has a constant speed. The control target is a conveying roller for conveying by sandwiching the sheet member, the driving source is a motor,
Claim 1, characterized in that a drive transmission means for transmitting the driving force of the motor for driving the conveying roller to the conveyance roller, the position of the conveying roller, and a condition detector for detecting a speed provided Or the control apparatus of Claim 2. The driving distance of the control target corresponding to 360 degrees for one cycle is the driving distance for one cycle of cogging torque fluctuation of the driving source, or the driving distance for one period of cogging torque fluctuation of the driving source and the driving distance for one rotation of the conveying roller. The control device according to claim 8, wherein the distance is a least common multiple. 9. The control device according to claim 8, wherein the first constant speed and the second constant speed are speeds corresponding to a very low speed region immediately before the sheet member transport device stops. The control target includes a carriage carrying the recording head, said first drive source, according to claim 1 a driving force of the second driving source, characterized in that in a drive transmitting means for transmitting to said carriage or The control device according to claim 2. The distance to drive the control target corresponding to one cycle of 360 degrees in the control device is the driving distance corresponding to one cycle of cogging torque fluctuation of the driving source, and the driving distance of the control target corresponding to one cycle of 360 degrees from the scanning range of the carriage. 12. The distance according to claim 11, wherein the distance is selected at several locations, or a distance that is a multiple of the driving distance of the control target corresponding to 360 degrees per cycle and becomes a maximum area operable in the scanning range of the carriage. Control device . Said first constant speed in the control device, the control device according to claim 11, wherein the carriage to the mechanical initializing operation is a low speed operating. Second constant speed in the control device, the control device according to claim 11, characterized in that the printing speed for printing on the recording medium. 12. The control device according to claim 8, wherein the printer is a serial ink jet printer that forms an image by reciprocally scanning a carriage on which an ink jet head is mounted while intermittently conveying a recording medium.

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