JP5041912B2 - Motor control method, motor control device, motor control program, recording medium on which motor control program is recorded, and image forming apparatus - Google Patents

Description

  The present invention relates to a motor control method, a motor control device, a motor control program, a recording medium on which the motor control program is recorded, and an image forming apparatus.

  In the motor control method and the motor control device for driving the motor until the control target reaches the target position, the motor control device has a means for acquiring the position information of the control target, and drives the motor by setting the target position and stop accuracy. Conventionally known is a technique for determining the end of driving if stopped within “target position ± stop accuracy”. With such technology, setting the target to “target position ± stop accuracy” may cause problems such as excessive settling time for alignment when the target is only “target position”, and oscillation may occur. It prevents the occurrence of problems such as

  Such a motor control method and a motor control apparatus are used for an image forming apparatus that drives a motor, moves a carriage in the main scanning direction, and performs printing while conveying a sheet in the sub-scanning direction by a conveying unit. Can do. In such an image forming apparatus, the carriage stop position accuracy and drive time in the main scanning direction and the transport unit stop position accuracy and drive time in the sub-scanning direction are extremely important factors for maintaining a constant image quality. It is.

  However, in the conventional motor control method and motor control device, the tendency of the mode value and average value of the stopped position within the stop accuracy depends on the characteristics of each device, so the actual stop position is the target position. In some cases, for example, the positions of both ends of “target position ± stop accuracy” (the position of “target position-stop accuracy” or the position of “target position + stop accuracy”) are not distributed in the center. . In addition, the driving time may vary. Thus, the conventional motor control method cannot be said to be a sufficient method from the viewpoint of stopping accuracy and the variation of driving time. This will be described in more detail below.

  FIG. 5 is a flowchart showing an example of a conventional motor servo control method. In the conventional servo control method shown in FIG. 5, the target position and the stop accuracy range are set in advance, and the control object is driven by the motor, and the control object is stopped within “target position ± stop accuracy”. If it is determined that the servo control is completed. Hereinafter, a conventional servo control method will be described with reference to the flowchart of FIG.

  In step 100, servo control of the controlled object is started (S100).

  In step 101, for example, control parameters that need to be set for each operation, such as a target speed and a target position, and device information parameters that are parameters unique to the device, such as proportional gain and integral gain of the control parameters, are set (step 101). S101).

  In step 102, motor driving is started (S102).

  In step 103, in order to perform feedback control, it is determined whether or not there is an interrupt that occurs at regular intervals (S103). If it is determined in step 103 that “interrupt is present”, the process in step 104 is executed. If it is not determined that “interrupt is present”, the process in step 103 is repeated.

  In step 104, for example, the current position of the control object is acquired from the count amount of an encoder provided to detect the position and speed of the control object, and the relative position during movement is calculated (S104).

  In step 105, for example, the current speed of the control object is calculated from the count amount of an encoder provided for detecting the position and speed of the control object (S105).

  In step 106, it is determined whether or not the deviation amount between the preset target position and the current position calculated in step 104 is within a preset stop accuracy range (S106). If it is determined in step 106 that “it is within the stop accuracy range”, the process of step 108 is executed. If it is not determined that “is within the stop accuracy range”, the process of step 107 is executed. Is done.

  In step 107, a motor output value calculation necessary for stopping the control target within the stop accuracy range is performed from the control parameter, the current position and the current speed, and the motor output value is determined (S107). Processing is executed.

  In step 108, it is determined whether or not a predetermined stop condition is satisfied (S108). As the predetermined stop condition, for example, the controlled object is stopped for a certain time within a certain range. If it is determined in step 108 that “the stop condition is satisfied”, the process of step 109 is executed. If it is not determined that “the stop condition is satisfied”, the process of step 103 is performed. Executed.

  In step 109, the drive of the motor is stopped (S109), and the servo control ends (S110).

  FIG. 6 is a diagram showing an example of the tendency of the error amount between the target position and the actual stop position by the conventional servo control method of FIG. In FIG. 6, the horizontal axis represents the error amount between the target position and the actual stop position, and the vertical axis represents the number of samples. That is, the variation in the error amount is shown when the servo control is executed a plurality of times (number of samples). In FIG. 6, “0” is the target position, and the range within the dotted line is the stop accuracy range.

  In the servo control, it is desirable that the error amount between the stop position and the target position is zero. However, in the servo control method of FIG. 5, as shown in FIG. 6, the error amount (A) between the target position and the actual stop position is There is a case where the tendency tends to be biased (in the example of FIG. 6, the frequency with which the control object stops on the negative side of the stop accuracy range is high). Since this tendency varies depending on the characteristics of each machine, for example, in an image forming apparatus that requires high stop accuracy, it becomes a cause of deteriorating image quality.

  FIG. 7 is a diagram showing an example of a driving time tendency according to the conventional servo control method of FIG. In FIG. 7, the horizontal axis represents the time from the start of driving to the stop (driving time), and the vertical axis represents the number of samples. That is, it shows the variation in the drive time of the controlled object when the servo control is executed a plurality of times (number of samples). In the servo control method of FIG. 5, even when the target movement amount is the same, the time from the start of driving to the stop (hereinafter referred to as driving time) varies, and the variation of each machine tends to increase as shown in FIG. (Machines 1-3). For example, when a machine with a large mechanical resistance is compared with a machine with a small mechanical resistance, the machine drive with a large mechanical resistance slows down the motor drive, and as a result, it takes time to reach the target position (machine 2). In a small machine, the motor drive rises faster, and as a result, the target position is reached faster (machine 3). Due to such variation in driving time, for example, in an image forming apparatus or the like, variation in printing speed occurs for each machine, which hinders high-speed printing.

  In order to improve such problems, for the purpose of improving stopping accuracy and shortening the drive time (speeding up positioning), an item of travel time is provided in the condition for calculating the speed curve, and the natural frequency of the mechanical mechanism is set. In order to avoid this, a technique has been proposed in which a command speed that suppresses residual vibration at the time of stopping is output (see, for example, Patent Document 1).

However, in this technique, residual vibration due to the natural frequency of the mechanical mechanism can be suppressed, but deterioration in stop accuracy and variation in driving time due to variations in mechanical resistance cannot be sufficiently suppressed.
JP 2000-298521 A

  However, conventionally, a motor control method and a motor control device that take into account the stopping accuracy and driving time of the controlled object have been proposed, but it is possible to sufficiently suppress deterioration of the stopping accuracy of the controlled object and variations in driving time. There was a problem that I could not.

  The present invention has been made in view of the above, and has recorded a motor control method, a motor control device, a motor control program, and a motor control program that can simultaneously realize improvement in stopping accuracy of a controlled object and suppression of variation in driving time. It is an object to provide a recording medium and an image forming apparatus.

In one embodiment of the present invention, the control object is driven by a motor, the position of the control object is detected by a position detection unit, and the control object is set in advance based on the detection result of the position detection unit. A motor control method for controlling the motor so as to stop within a stop accuracy range, wherein the driving time for driving the motor is the estimated movement time of the controlled object driven by the motor. On the basis of this , the control of the motor is continued when the time preset for each control object has not elapsed.

  According to the present invention, there is provided a motor control method, a motor control device, a motor control program, a recording medium on which a motor control program is recorded, and an image forming apparatus capable of simultaneously realizing improvement in stopping accuracy of a controlled object and suppression of variation in driving time. Can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<Example 1>
FIG. 1 is a top view of an apparatus illustrating a schematic configuration of an inkjet image forming apparatus according to the present invention. FIG. 2 is a front view of the apparatus illustrating the schematic configuration of the inkjet image forming apparatus according to the present invention. In the ink jet image forming apparatus shown in FIGS. 1 and 2, the carriage 100 is held by a guide lot 104 horizontally mounted on left and right side plates (not shown), and is driven between a driving pulley 106 and a driven pulley 107 by a main scanning motor 105. The moving scanning is performed in the main scanning direction via the timing belt 102 passed to.

  The carriage 100 includes, for example, a recording head including four liquid discharge heads that discharge ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). The nozzle rows on the nozzle surface on which the (nozzles) are formed are arranged in a direction (sub-scanning direction) perpendicular to the main scanning direction, and are mounted with the ink discharge port direction facing downward. Although an independent droplet discharge head is used here, a configuration in which one or a plurality of heads having a plurality of nozzle rows that discharge droplets of recording liquid of each color can be used. Further, the number of colors and the arrangement order are not limited to this.

  As an inkjet head constituting a recording head, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change are used. A shape memory alloy actuator, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet can be used.

  The carriage 100 is provided with an encoder scale 103 formed with slits along the main scanning direction. Together with an encoder sensor that detects the slits of the encoder scale 103 provided on the carriage 100, the carriage 100 is moved in the main scanning direction. A linear encoder for detecting the position is configured.

  On the other hand, in order to convey the recording paper 108 as a medium, a conveyance belt 101 is provided as a conveying means for electrostatically attracting the recording paper 108 and conveying it at a position facing the recording head. The conveying belt 101 is an endless belt, is configured to wrap around the conveying roller 109 and the tension roller 110 and circulate in the belt conveying direction (sub-scanning direction). It is charged (charged) by 113.

  FIG. 3 is a diagram illustrating a schematic configuration of the control unit 200 of the inkjet image forming apparatus according to the present invention. In the figure, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted. The control unit 200 of the inkjet image forming apparatus shown in FIG. The sub-scanning motor driving unit 211 is configured.

  3 includes a printer driver 300, an operation panel 400, a recording device 500, a carriage 100 (recording head 115), a conveyance belt 101, a main scanning motor 105, a charging roller 113, and a head. The driver 116, the linear encoder 117, the sub-scanning motor 118, the wheel encoder 119, and other peripheral parts are connected.

  Here, the control unit 200, carriage 100 (recording head 115), conveyance belt 101, main scanning motor 105, linear encoder 117, sub-scanning motor 118, and wheel encoder 119 of the inkjet image forming apparatus shown in FIG. It can be said that it constitutes.

  The CPU 201 controls the entire inkjet image forming apparatus, drives the sub-scanning motor 118, drives the paper as a medium by the transport belt 101, and drives the main scanning motor 105, and moves the carriage 100 on which the recording head 115 is mounted. The control means for controlling the moving operation and the function as time elapse judgment means for judging whether or not the driving time for driving the main scanning motor 105 and the sub scanning motor 118 has passed a preset time. Have both.

  A ROM 202 is a read-only memory that stores programs including a motor control program executed by the CPU 201 and other fixed data. The RAM 203 is a rewritable memory that temporarily stores image data and the like, and the NVRAM 204 is a rewritable nonvolatile memory that can hold data even when the power of the inkjet image forming apparatus is shut off.

  The motor control program executed by the inkjet image forming apparatus according to the present invention is pre-installed in a memory such as the ROM 202, but is an installable or executable file, and the inkjet image forming apparatus according to the present invention. It may be configured to be recorded and provided on a recording medium that can be read by the recording device 500 such as a CD-ROM, FD, or DVD that is built in or externally attached.

  The ASIC 205 is an IC that processes various signal processing on image data, image processing that performs rearrangement, and other input / output signals for controlling the entire inkjet image forming apparatus. The host I / F 206 is an interface for transmitting and receiving data and signals to and from the host side. The print control unit 208 generates a drive waveform for driving the recording head 115 in the carriage 100, and outputs to the head driver 116 image data for selectively driving the pressure generating unit of the recording head 115 and various data associated therewith. Part.

  A main scanning motor driving unit 209 is a driving unit for driving the main scanning motor 105. The AC bias supply unit 210 is a supply unit that supplies an AC bias to the charging roller 113. The sub-scanning motor driving unit 211 is a driving unit for driving the sub-scanning motor 118 that transports the transport belt 101. An I / O 207 is a linear encoder 117 that is a position detecting unit that detects the position of the carriage 100, a detection pulse from a wheel encoder 119 that is a position detecting unit that detects the position of the conveying belt 101 that is a conveying unit, and various other sensors. An input / output unit capable of inputting a detection signal from (not shown). Each component of the control unit 200 is connected so that data and the like can be communicated with each other.

  The operation panel 400 is a panel for inputting and displaying information necessary for the inkjet image forming apparatus output from the control unit 200.

  The control unit 200 receives print data generated by a host printer driver 300 such as an information processing device such as a personal computer, an image reading device such as an image scanner, and an imaging device such as a digital camera via a cable or a network. Received at F206. The CPU 201 in the control unit 200 reads and analyzes the print data in the reception buffer of the host I / F 206, performs necessary image processing, data rearrangement processing, and the like in the ASIC 205, and sends the print data to the print control unit 208. The image data and the drive waveform are output from the print control unit 208 to the head driver 116 at a predetermined timing.

  The dot pattern data for image output may be generated by storing font data in the ROM 202, for example, or the image data is developed into bitmap data by the host-side printer driver 300, and the inkjet image forming apparatus You may make it forward to. Here, the printer driver 300 is used.

  The drive waveform generation unit of the print control unit 208 includes a D / A converter and an amplifier that perform D / A conversion on the drive pulse pattern data stored in the ROM 202 and read out by the CPU 201. A drive waveform composed of the drive pulses is output to the head driver 116.

  The head driver 116 generates drive pulses constituting a drive waveform provided from the drive waveform generation unit of the print control unit 208 based on image data (dot pattern data) corresponding to one line of the recording head 115 input serially. The recording head 115 is driven by selectively applying to the pressure generating means of the recording head 115. The head driver 116 is, for example, a shift register for inputting a clock signal and serial data as image data, a latch circuit for latching a register value of the shift register with a latch signal, and an output value of the latch circuit for changing the level. A level conversion circuit (level shifter) and an analog switch array (switch means) whose on / off is controlled by this level shifter, etc., and a predetermined drive pulse included in the drive waveform by controlling the on / off of the analog switch array Is selectively applied to the pressure generating means of the recording head 115.

  FIG. 4 is a diagram illustrating an outline of the main / sub-scanning operation sequence. In FIG. 4, the horizontal axis represents time, and the vertical axis represents speed. The outline of the main / sub-scanning operation sequence will be described with reference to FIGS. First, the carriage 100 operates in the forward direction (or the backward direction) in the main scanning direction with the conveyance belt 101 stopped, and printing is performed in the printing section (the first printing section in the main scanning a in FIG. 4). When the printing section is completed, the carriage 100 starts decelerating, and the conveyance belt 101 conveys the recording paper 108 (sub-scanning b in FIG. 4). When the conveyance is completed, the carriage 100 operates in the backward direction (or forward direction) of the main scanning direction, and printing is performed in the printing section (second printing section of the main scanning a in FIG. 4). By repeating these, image formation is performed.

  FIG. 8 is a flowchart showing an example of a servo control method of the motor in the inkjet image forming apparatus according to the present invention shown in FIGS. In the servo control method according to the present invention shown in FIG. 8, the target position and the stop accuracy range are set in advance, but the target time is set in advance and the drive time is set in advance. Until the time elapses, even if the deviation amount between the preset target position and the current position of the controlled object is within the stop accuracy range, the servo control of the motor is continued. The motor control method shown in FIG. 8 is incorporated in advance in a memory such as the ROM 202 as a motor control program executed by the CPU 201 in the inkjet image forming apparatus according to the present invention. Hereinafter, the servo control method according to the present invention will be described with reference to the flowchart of FIG.

  In step 200, servo control of the carriage 100 that is controlled in the main scanning direction or the conveyance belt 101 that is controlled in the sub-scanning direction is started (S200). The motor control method shown in the flowchart of FIG. 8 may be applied only to the carriage 100 or only to the transport belt 101. Further, the present invention may be applied to both the carriage 100 and the conveyance belt 101. At this time, parameters related to control such as target time are set independently for each control object, and each control object is independent. Controlled.

  In step 201, parameters related to control are set (S201). Here, the parameters relating to the control are, for example, control parameters that need to be set for each operation such as a target speed, a target position, and a stop accuracy range, and are specific to a device such as a proportional gain and an integral gain of the control parameter. A device information parameter that is a parameter.

  In step 202, driving of the main scanning motor 105 or the sub scanning motor 118 is started (S202).

  In step 203, in order to perform feedback control, it is determined whether or not there is an interrupt that occurs at regular intervals (S203). If it is determined in step 203 that “interrupt is present”, the process of step 204 is executed. If it is not determined that “interrupt is present”, the process of step 203 is repeated.

  In step 204, the count value of the linear encoder 117 or the wheel encoder 119 is acquired by referring to the register value of the ASIC 205, and the carriage 100 controlled in the main scanning direction, which is the control target, or the conveyance controlled in the sub scanning direction. The relative position during the movement of the belt 101 is calculated (S204).

  In step 205, the count values of the linear encoder 117 and the wheel encoder 119 are acquired by referring to the register values of the ASIC 205, and the carriage 100 controlled in the main scanning direction, which is the control target, or the conveyance controlled in the sub scanning direction. The current speed of the belt 101 is calculated (S205).

  In step 206, it is determined whether or not the deviation amount between the preset target position and the current position calculated in step 204 is within a preset stop accuracy range (S206). If it is determined in step 206 that “it is within the stop accuracy range”, the process of step 211 is executed. If it is not determined that “is within the stop accuracy range”, the process of step 207 is executed. Is done.

  In step 207, it is necessary to stop the carriage 100 controlled in the main scanning direction or the conveyance belt 101 controlled in the sub-scanning direction, which is the control target, from the control parameter, the current position, and the current speed within the stop accuracy range. The motor output value of the main scanning motor 105 or the sub-scanning motor 118 is calculated to determine the motor output value (S207), and the process of step 203 is executed.

  In step 211, whether or not the deviation between the preset target position and the current position calculated in step 204 is zero, or whether or not the drive time has passed the preset target time Is determined (S211). If it is determined in step 211 that “the deviation amount is zero or the target time has elapsed”, the processing of step 208 is executed, and “the deviation amount is zero or the target time is If it is not determined that “elapsed”, the process of step 207 is executed, and the control is continued.

  In step 208, it is determined whether or not a predetermined stop condition is satisfied (S208). Examples of the predetermined stop condition include stopping for a certain time within a certain range. If it is determined in step 208 that “the stop condition is satisfied”, the process of step 209 is executed. If it is not determined that “the stop condition is satisfied”, the process of step 203 is performed. Executed and control continues.

  In step 209, the drive of the motor is stopped (S209), and the servo control ends (S210).

<Example 2>
FIG. 9 is a flowchart showing an example different from FIG. 8 of the motor servo control method in the inkjet image forming apparatus according to the present invention shown in FIGS. In the figure, the same steps as those in FIG. 8 are denoted by the same reference numerals, and the description thereof is omitted. The difference from FIG. 8 is that a plurality of stop position accuracy, target time, and motor output calculations are set, and the stop position accuracy, which is a parameter related to control, is changed before and after the target time elapses. The motor control method shown in FIG. 9 is incorporated in advance in a memory such as the ROM 202 as a motor control program executed by the CPU 201 in the inkjet image forming apparatus according to the present invention. Hereinafter, the servo control method according to the present invention will be described with reference to the flowchart of FIG. 9 (only different parts from FIG. 8 will be described).

  In step 306, it is determined whether or not the deviation amount between the preset target position and the current position calculated in step 204 is within a preset stop accuracy range (deviation amount is less than ΔX0) ( S306). If it is determined in step 306 that “it is within the stop accuracy range (deviation amount is less than ΔX0)”, the processing of step 311-1 is executed, and “it is within the stop accuracy range (deviation amount is less than ΔX0). If it is not determined, the process of step 307-1 is executed.

  In step 307-1, from the control parameter, the current position, and the current speed, the carriage 100 controlled in the main scanning direction or the conveyance belt 101 controlled in the sub-scanning direction, which is the control target, is within the stop accuracy range (with a deviation amount). The motor output value calculation 1 of the main scanning motor 105 or the sub-scanning motor 118 necessary for stopping at (less than ΔX0) is performed, the output value of the motor is determined (S307-1), and the process of step 203 is executed and control is performed. Will continue.

  In Step 311-1, whether or not the deviation amount between the preset target position and the current position calculated in Step 204 is less than ΔX1, or the preset target time T1 has passed. It is determined whether or not (S311-1). If it is determined in step 311-1 that “the deviation amount is less than ΔX1 or the target time T1 has elapsed”, the processing of step 311-2 is executed, and “the deviation amount is less than ΔX1. If it is not determined that “there is a target time T1 or has passed,” the process of step 307-2 is executed.

  In step 307-2, the carriage 100 controlled in the main scanning direction or the conveyance belt 101 controlled in the sub-scanning direction, which is a control target, is calculated in step 204 from the control parameter, the current position, and the current speed. The motor output value calculation 2 of the main scanning motor 105 or the sub-scanning motor 118 necessary for stopping within the range where the deviation from the current position is less than ΔX1 is performed to determine the motor output value (S307-2). ), The process of step 203 is executed, and the control is continued.

  In step 311-2, whether or not the deviation amount between the preset target position and the current position calculated in step 204 is less than ΔX2, or the preset target time T2 has elapsed. It is determined whether or not (S311-2). In Step 311-2, when it is determined that “the deviation amount is less than ΔX2 or the target time T2 has elapsed”, the process of Step 208 is executed, and “the deviation amount is less than ΔX2. Alternatively, if it is not determined that the target time T2 has elapsed, the process of step 307-3 is executed.

  In step 307-3, the carriage 100 controlled in the main scanning direction or the conveyance belt 101 controlled in the sub-scanning direction, which is the control target, is calculated in step 204 from the control parameter, the current position, and the current speed. The motor output value calculation 3 of the main scanning motor 105 or the sub-scanning motor 118 necessary for stopping within the range where the deviation from the current position is less than ΔX2 is performed to determine the motor output value (S307-3). ), The process of step 203 is executed, and the control is continued.

  Here, “deviation amount ΔX0> deviation amount ΔX1> deviation amount ΔX2”, “target time T2> target time T1”.

  Furthermore, by setting the magnitude relationship of the control gain, which is one of the parameters related to the control, to “motor output value calculation 1> motor output value calculation 2> motor output value calculation 3”, the target position and the current position are As the deviation amount becomes smaller or as the drive time approaches the target time, the motor output can be gradually reduced, and more stable control can be performed.

  FIG. 10 is a diagram showing an example of a motor driving speed profile in the motor control method according to the present invention. In FIG. 10, the horizontal axis represents time, and the vertical axis represents speed. The target time shown in FIGS. 8 and 9 can be set as follows based on FIG. 10, for example. When motor driving is performed according to a speed profile such as A-B-C-D-E in FIG. 10, the AB section is an acceleration area, the B-C section is a constant speed area, the C-D section is a deceleration area, D -Section E corresponds to the alignment area. Since the total movement amount at this time corresponds to the area surrounded by A-B-C-D, if the speed Vt at the constant speed, the acceleration in the AB section, and the deceleration in the CD section are known Can estimate the movement time, and this movement estimation time can be set as the target time Tt1.

  Further, the target time Tt2 may be obtained by adding the alignment time of the DE section to Tt1. The image forming apparatus or the like has a standard value such as PPM (Pages Per Minute). The driving time required to achieve this standard value may be set as the target time Tt3. Here, PPM is one of performance indexes of an image forming apparatus or the like, and indicates the number of sheets that can be printed in one minute. For example, the printing speed of an image forming apparatus capable of printing 10 sheets per minute is 10 PPM. Further, the target time Tt4 may be a value arbitrarily set by an operator who requires a higher speed operation than the high stop accuracy or an operator who desires a higher stop accuracy than the high speed operation.

  FIG. 11 is a diagram showing an example of the tendency of the error amount between the target position and the actual stop position by the servo control method according to the present invention for setting the target time. In FIG. 11, the horizontal axis represents the error amount between the target position and the actual stop position, and the vertical axis represents the number of samples. That is, the variation in the error amount is shown when the servo control is executed a plurality of times (number of samples). In FIG. 11, “0” is the target position, and the range within the dotted line is the stop accuracy range. The error amount (A) is the same as the variation in the error amount by the conventional servo control method of FIG. 5 shown in FIG.

  In the servo control, it is desirable that the error between the stop position and the target position is zero. However, in the servo control method according to the present invention shown in FIGS. 8, 9, and 10, a predetermined target time is set and a predetermined target time is set. Even if the position of the control object is within the stop accuracy range within the target time, the control is continued to bring the position of the control object closer to the target position (the position of “0” in FIG. 11). As shown in the error amount (B) of FIG. 11, the mode value of the error amount between the stop position and the target position can be made close to zero.

  FIG. 12 is a diagram showing an example of the driving time tendency by the servo control method according to the present invention for setting the target time. In FIG. 12, the horizontal axis represents the time from the start of driving to the stop (driving time), and the vertical axis represents the number of samples. That is, it shows the variation in the drive time of the control target when the servo control is executed a plurality of times (number of samples). The drive time (A) is the same as the drive time variation according to the conventional servo control method of FIG. 5 shown in FIG. 7, and the drive time variation tends to increase. On the other hand, in the servo control method according to the present invention shown in FIGS. 8, 9 and 10, since the predetermined target time is set, the conventional servo control method as in the drive time (B) of FIG. Accordingly, it is possible to suppress the variation in the driving time rather than the driving time (A), and it is also possible to suppress the variation in the printing speed due to the characteristics of each machine.

  As described above, according to the present invention, when a predetermined target time is set in advance with respect to the motor driving time and the predetermined driving time of the motor has not passed, Regardless of whether the position of the object is within the stopping accuracy range, the motor control is continued to bring the position of the controlled object closer to the target position. Suppression can be realized simultaneously.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the embodiment of the present invention, the example in which the motor control method and the motor control device according to the present invention are used as the constituent elements of the inkjet image forming apparatus is shown, but the motor control method and the motor control device according to the present invention are Since the present invention is generally applicable to motor control, the present invention is not limited to an inkjet image forming apparatus, and can be applied to, for example, an image forming apparatus using laser light, and other various apparatuses that perform motor control.

  The motor control program that can be executed by the inkjet image forming apparatus according to the present invention may be configured to be obtained via a network such as the Internet.

  The processing performed in the motor control method and motor control device according to the present invention may be performed by digital signal processing calculation.

  In the embodiment of the present invention, one or two target times are set. However, three or more target times may be set.

  In the embodiment of the present invention, as an example of setting the target time set in advance, an example of setting based on the movement estimation time has been shown, but it may be set based on others. The target time may be set to a different value for each medium conveyed by the conveying unit, for each medium size, for each medium print mode, for each motor drive amount, for each motor drive speed, and for each stop accuracy. Absent.

1 is a device top view illustrating a schematic configuration of an inkjet image forming apparatus according to the present invention. 1 is a front view of an apparatus illustrating a schematic configuration of an inkjet image forming apparatus according to the present invention. It is a figure which illustrates the schematic structure of the control part 200 of the inkjet image forming apparatus which concerns on this invention. It is a figure which illustrates the outline of a main / sub-scanning operation sequence. It is a flowchart which shows an example of the servo control method of the conventional motor. It is a figure which shows an example of the tendency of the error amount of the target position and the actual stop position by the conventional servo control method of FIG. It is a figure which shows an example of the tendency of the drive time by the conventional servo control method of FIG. 4 is a flowchart showing an example of a motor servo control method in the inkjet image forming apparatus according to the present invention shown in FIGS. 1 to 3; 9 is a flowchart showing an example different from FIG. 8 of the motor servo control method in the inkjet image forming apparatus according to the present invention shown in FIGS. 1 to 3; It is a figure which shows the example of the speed profile of the motor drive in the motor control method which concerns on this invention. It is a figure which shows an example of the tendency of the error amount of the target position by the servo control method which concerns on this invention which sets target time, and an actual stop position. It is a figure which shows an example of the tendency of the drive time by the servo control method which sets a target time based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Carriage 101 Conveyance belt 102 Timing belt 103 Encoder scale 104 Guide lot 105 Main scanning motor 106 Drive pulley 107 Driven pulley 108 Recording paper 109 Conveyance roller 110 Tension roller 113 Charging roller 115 Recording head 116 Head driver 117 Linear encoder 118 Sub scanning motor 119 Wheel encoder 200 Control unit 201 CPU
202 ROM
203 RAM
204 NVRAM
205 ASIC
206 Host I / F
207 I / O
208 Print Control Unit 209 Main Scanning Motor Drive Unit 210 AC Bias Supply Unit 211 Main Scanning Motor Drive Unit 300 Printer Driver 400 Operation Panel 500 Recording Device a Main Scan b Sub Scan

Claims (21)

The control object is driven by a motor, the position of the control object is detected by a position detection means, and the control object is stopped within a preset stop accuracy range based on the detection result of the position detection means. A motor control method for controlling the motor,
When the driving time for driving the motor has not passed a preset time for each control object based on the estimated movement time of the control object driven by the motor, the motor The motor control method characterized by continuing control of this. The control object is driven by a motor, the position of the control object is detected by a position detection means, and the control object is stopped within a preset stop accuracy range based on the detection result of the position detection means. A motor control method for controlling the motor,
When the driving time for driving the motor has not passed the time preset for each control object based on the time required by a predetermined standard , the control of the motor is continued. A motor control method. The preset time is set to one or more,
Before and after the preset time elapses , as the deviation amount between the target position of the control object and the current position decreases, or as the drive time of the control object approaches the target time, the 3. The motor control method according to claim 1, wherein a parameter related to the control is changed so as to weaken the output of the motor. The motor control method according to claim 3 , wherein the parameter related to the control is a control gain that determines the strength of the force by which the motor drives the object to be controlled. If the drive time for driving the motor has not passed the preset time and the deviation amount between the target position and the current position is not zero, the control of the motor is continued. The motor control method according to any one of claims 1 to 4 , wherein the motor control method is characterized in that: When the driving time for driving the motor has passed the preset time, or when the deviation amount between the target position and the current position is zero, the control object has a predetermined stop condition. If meet, the motor control method according to any one of claims 1 to 5, characterized in that stops controlling the motor. A motor control program for causing a computer to execute the motor control method according to any one of claims 1 to 6 . A computer-readable recording medium on which the motor control program according to claim 7 is recorded. A motor for driving the control object;
Position detecting means for detecting the position of the control object;
A motor control device having control means for controlling the motor so that the control object stops within a preset stop accuracy range based on a detection result of the position detection means,
Time lapse for determining whether the drive time for driving the motor has passed a preset time for each control object based on the estimated movement time of the control object driven by the motor Having a judging means,
The said control means continues control of the said motor based on the determination result of the said time passage determination means, The motor control apparatus characterized by the above-mentioned. A motor for driving the control object;
Position detecting means for detecting the position of the control object;
A motor control device having control means for controlling the motor so that the control object stops within a preset stop accuracy range based on a detection result of the position detection means,
A time elapse determining means for determining whether or not a drive time for driving the motor has passed a preset time for each control object based on a time required by a predetermined standard ;
The said control means continues control of the said motor based on the determination result of the said time passage determination means, The motor control apparatus characterized by the above-mentioned. The preset time is set to one or more,
Before and after the time the preset has elapsed, further have a parameter changing means for changing the parameters relating to the control,
The parameter changing means gradually reduces the output of the motor as the deviation amount between the target position of the control object and the current position decreases or as the drive time of the control object approaches the target time. 11. The motor control device according to claim 9 , wherein a parameter related to the control is changed . 12. The motor control device according to claim 11 , wherein the parameter related to the control is a control gain that determines the strength of the force by which the motor drives the object to be controlled. The control means controls the motor when the driving time for driving the motor does not pass the preset time and the deviation amount between the target position and the current position is not zero. The motor control device according to any one of claims 9 to 12 , wherein the motor control device is continued. When the driving time for driving the motor has passed the preset time, or when the deviation amount between the target position and the current position is zero, the control object is The motor control device according to any one of claims 9 to 13 , wherein control of the motor is stopped when a predetermined stop condition is satisfied. A carriage equipped with a recording head for discharging droplets onto a medium;
Conveying means for conveying the medium;
A first motor for driving the carriage;
A second motor for driving the conveying means;
First position detecting means for detecting the position of the carriage;
Second position detecting means for detecting the position of the conveying means;
Based on the detection result of the first position detecting means, the first motor is controlled so that the carriage stops within a preset first stop accuracy range, and the second position detecting means An image forming apparatus including: a control unit configured to control the second motor so that the conveying unit stops within a preset second stop accuracy range based on a detection result;
A first determination is made as to whether or not a first driving time of the first motor has passed a preset first time based on an estimated movement time of the carriage driven by the first motor . The second driving time of the second motor has passed a second time set in advance based on the estimated movement time of the conveying means driven by the second motor. A second time lapse determining means for determining whether or not
The control means continues to control the first motor and / or the second motor based on a determination result of the first time passage determination means and / or the second time passage determination means. An image forming apparatus. A carriage equipped with a recording head for discharging droplets onto a medium;
Conveying means for conveying the medium;
A first motor for driving the carriage;
A second motor for driving the conveying means;
First position detecting means for detecting the position of the carriage;
Second position detecting means for detecting the position of the conveying means;
Based on the detection result of the first position detecting means, the first motor is controlled so that the carriage stops within a preset first stop accuracy range, and the second position detecting means An image forming apparatus including: a control unit configured to control the second motor so that the conveying unit stops within a preset second stop accuracy range based on a detection result;
First time elapse determining means for determining whether or not the first driving time of the first motor has passed a preset first time based on a time required by a predetermined standard; Alternatively, a second time elapse determining means for determining whether or not the second driving time of the second motor has passed a preset second time based on a time required by a predetermined standard. Have
The control means continues to control the first motor and / or the second motor based on a determination result of the first time passage determination means and / or the second time passage determination means. An image forming apparatus. A carriage equipped with a recording head for discharging droplets onto a medium;
Conveying means for conveying the medium;
A first motor for driving the carriage;
A second motor for driving the conveying means;
First position detecting means for detecting the position of the carriage;
Second position detecting means for detecting the position of the conveying means;
Based on the detection result of the first position detecting means, the first motor is controlled so that the carriage stops within a preset first stop accuracy range, and the second position detecting means An image forming apparatus including: a control unit configured to control the second motor so that the conveying unit stops within a preset second stop accuracy range based on a detection result;
First time elapse determining means for determining whether or not the first driving time of the first motor has arbitrarily passed a first time arbitrarily set by an operator, and / or the second motor. A second time elapse determination means for determining whether or not the second drive time has passed a second time arbitrarily preset by an operator ;
The control means continues to control the first motor and / or the second motor based on a determination result of the first time passage determination means and / or the second time passage determination means. An image forming apparatus. One or a plurality of the first time and / or the second time are set,
Before and after the first time and / or the second time elapses, further have a parameter changing means for changing the parameters relating to the control,
The parameter changing means gradually increases the first as the deviation amount between the target position of the carriage or the transport means and the current position becomes smaller, or as the drive time of the carriage or the transport means approaches the target time. The image forming apparatus according to claim 15 , wherein a parameter related to the control is changed so as to weaken an output of the second motor . 19. The image forming apparatus according to claim 18 , wherein the parameter related to the control is a control gain that determines the strength of the force by which the first or second motor drives the carriage or the transport unit . The control means is configured such that the driving time for driving the first or second motor does not pass the preset first or second time, and the deviation between the target position and the current position is If the amount is not zero, the image forming apparatus of any one of claims 15 to 19, characterized in that the continued control of the first or second motor. The control means is configured such that the drive time for driving the first or second motor has passed the preset first or second time, or a deviation amount between the target position and the current position. If There is zero, the carriage or the when the transport means is a predetermined stop condition is satisfied, any one of claims 15 to 20, characterized in that stops controlling of said first or second motor The image forming apparatus according to one item.

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