JP3695361B2 - Control of carriage motor in printing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for controlling the operation of a carriage motor of a printing apparatus.
[0002]
[Prior art]
The ink jet printer includes a carriage on which a print head is mounted, a carriage motor for moving the carriage, and a drive control device for controlling the carriage motor. FIG. 9 is a block diagram showing a configuration of a conventional drive control device. This drive control device has a control circuit 300, a drive circuit 320, and a carriage motor 330. The carriage motor 330 is provided with an encoder 332 for detecting the current speed Vc of the carriage. The control circuit 300 includes a subtractor 302 for obtaining a deviation ΔV between the target speed Vt and the current speed Vc, a proportional element 304, an integral element 306, a differential element 308, and an adder 310. The three calculation elements 304, 306, and 308 output calculation results corresponding to the speed deviation ΔV, and these calculation results are added by the adder 310. This addition result ΣQ is supplied to the drive circuit 320 as a control signal. The drive circuit 320 supplies a drive signal Sdr corresponding to the control signal ΣQ to the carriage motor 330 to drive it.
[0003]
FIG. 10 is an explanatory diagram showing the relationship between the motor drive signal Sdr and the characteristics of the carriage motor 330. FIG. 10A shows a signal change of the motor drive signal Sdr. The duty Dt of the motor drive signal Sdr is a value obtained by dividing the period Ton at the on level by one cycle Tp of the drive signal. In this specification, the duty Dt of the motor drive signal Sdr is also referred to as “duty of the carriage motor”.
[0004]
When a brushed DC motor is used as the carriage motor 330, its torque / rotational speed characteristics are proportional to the duty Dt as shown in FIG. The drive circuit 320 generates the drive signal Sdr so that the duty Dt of the drive signal Sdr is proportional to the control signal ΣQ. As a result, the carriage motor 330 generates a driving force according to the control signal ΣQ given from the control circuit 300 to drive the carriage.
[0005]
[Problems to be solved by the invention]
A control circuit that performs normal PID control, such as the control circuit 300 described above, can control the speed and position of the carriage motor 330 with high accuracy. However, if the load on the carriage motor 330 becomes excessive for some reason, the control accuracy may decrease. For example, if the frictional force of the guide rail of the carriage increases or an excessive weight is mounted on the carriage, an excessive load is applied to the carriage motor 330.
[0006]
FIG. 11 is a graph illustrating a control state when an excessive load is applied to the carriage motor 330. In FIG. 11A, the horizontal axis is position (or time), and the vertical axis is speed. The target speed Vt is set in advance according to the deviation between the target position Pt of the carriage j and the current position. If an excessive load is applied to the carriage motor 330, as shown in FIG. 11B, even if the level of the control signal ΣQ reaches a value corresponding to the 100% duty of the carriage motor, the current speed Vc becomes the target speed Vt. May not reach. At this time, the level of the control signal ΣQ continues to increase further. This is because the speed deviation ΔV is kept positive, and the integration results in the integration element 306 are gradually accumulated.
[0007]
In this state, when the current position approaches the target position Pt, the target speed Vt decreases and becomes lower than the current speed Vc. As a result, the speed deviation ΔV becomes negative and the value of the control signal ΣQ starts to decrease. However, in the case of FIG. 11B, since the level of the control signal ΣQ can be said to be far beyond the value corresponding to 100% duty, the duty of the carriage motor is maintained at 100% for a while. Thereafter, the carriage starts to decelerate for the first time after the target speed Vt is significantly lowered and the control signal ΣQ falls below a value corresponding to 100% duty. As a result, even if the carriage reaches the target position Pt, the carriage motor 330 continues to operate, and stops only when the target position Pt is exceeded, as indicated by an arrow.
[0008]
As described above, conventionally, there has been a problem that appropriate control may not be performed when an excessive load is applied to the carriage motor.
[0009]
The present invention has been made to solve the above-described conventional problems, and provides a technique capable of performing appropriate control even when an excessive load is applied to the carriage motor of the printing apparatus. Objective.
[0010]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, a first printing apparatus of the present invention is a printing apparatus having a print head, the carriage having the print head mounted thereon, a carriage motor for moving the carriage, and the carriage motor. And a drive control device for controlling the operation. The drive control device includes a drive circuit that drives the carriage motor, a detection unit that detects a current speed of the carriage, a target speed generation unit that generates a target speed of the carriage, and a target speed and a current speed of the carriage. And a control unit that generates a control signal to be supplied to the drive circuit in accordance with the deviation. In addition, the control unit includes a proportional element and an integral element, a plurality of calculation elements each for obtaining a calculation result according to the speed deviation, an adder for adding the calculation results of the plurality of calculation elements, and the addition And an adjustment unit that adjusts the signal level of the control signal according to the addition result of the detector. The adjustment unit prevents the addition result from continuing to exceed the effective limit value by adjusting the integration result in the integration element when the addition result exceeds a predetermined effective limit value.
[0011]
In the first printing apparatus, when the addition result exceeds a predetermined effective limit value, the addition result in the integration element is adjusted to prevent the addition result from continuing to increase beyond the effective limit value. Even when an excessive load is applied to the carriage motor of the printing apparatus, if the speed deviation decreases, appropriate drive control can be immediately performed accordingly.
[0012]
The integration element updates the integration result by adding the previous integration result to the product ΔV · Ki of the speed deviation ΔV and the integration gain Ki, and the adjustment unit determines that the addition result is a predetermined effective value. When the limit value is exceeded, the value of the product ΔV · Ki may be set to 0 to adjust the integration result.
[0013]
Alternatively, when the addition result exceeds a predetermined effective limit value, the adjustment unit subtracts a difference between the addition result and the effective limit value from the integration result in the integration element, and the addition result is the effective value. The integration result may be adjusted by setting the value equal to the limit value.
[0014]
According to these configurations, it is possible to easily prevent the addition result from continuing to increase beyond the effective limit value.
[0015]
The effective limit value is preferably a value corresponding to the maximum output of the carriage motor.
[0016]
According to this configuration, it is possible to perform appropriate control while making full use of the capability of the carriage motor.
[0017]
In the second printing apparatus according to the present invention, the adjustment unit adjusts a target speed in the target speed generation unit when the addition result exceeds a predetermined effective limit value a predetermined number of times, thereby adjusting the target speed. The addition result is prevented from continuing to increase beyond the effective limit value.
[0018]
In the second printing apparatus, by adjusting the target speed in the target speed generation unit, the addition result is prevented from continuing to increase beyond the effective limit value, so that an excessive load is applied to the carriage motor of the printing apparatus. Also, when the speed deviation decreases, appropriate drive control can be immediately performed accordingly.
[0019]
The adjustment unit may set the target speed in the target speed generation unit to a value equal to the current speed when the addition result exceeds a predetermined effective limit value continuously a predetermined number of times. .
[0020]
According to this configuration, it is possible to easily prevent the addition result from continuing to increase beyond the effective limit value.
[0021]
The present invention can be realized in various forms. For example, a motor drive control method and apparatus, a print control method and a print control apparatus, a printing method and a printing apparatus, and functions of those methods or apparatuses. The present invention can be realized in the form of a computer program for realizing, a recording medium recording the computer program, a data signal including the computer program and embodied in a carrier wave, and the like.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in the following order based on examples.
A. Overall configuration of the device:
B. First embodiment:
C. Second embodiment:
D. Third embodiment:
E. Variation:
[0023]
A. Overall configuration of the device:
FIG. 1 is a schematic perspective view showing a main configuration of an ink jet printer 20 as an embodiment of the present invention. The printer 20 includes a paper feed motor 30 that sends the printing paper P in the sub-scanning direction SS, a platen 40, a carriage 50 that mounts the print head 52, a carriage motor 60 that moves the carriage 50 in the main scanning direction MS, It has.
[0024]
The carriage 50 is pulled by a pulling belt 62 driven by a carriage motor 60 and moves along a guide rail 64. In addition to the print head 52, a black cartridge 54 and a color ink cartridge 56 are mounted on the carriage 50.
[0025]
A capping device 80 for sealing the nozzle surface of the print head 52 when stopped is provided at the home position of the carriage 50 (the position on the right side in FIG. 1). When the print job ends and the carriage 50 reaches above the capping device 80, the capping device 80 is automatically raised by a mechanism (not shown) to seal the nozzle surface of the print head 52. This capping prevents the ink in the nozzles from drying out. The positioning control of the carriage 50 is performed to accurately position the carriage 50 at the position of the capping device 80, for example.
[0026]
FIG. 2 is a block diagram showing an electrical configuration of the printer 20. The printer 20 includes a main control circuit 102, a CPU 104, and various memories (ROM 110, RAM 112, EEPROM 114) connected to the main control circuit 102 and the CPU 104 via a bus. Connected to the main control circuit 102 are an interface circuit 120 that transmits and receives signals to and from an external device such as a personal computer, a paper feed motor drive circuit 130, a head drive circuit 140, and a CR motor drive circuit 150. ing.
[0027]
The paper feed motor 30 is driven by the paper feed motor drive circuit 130 to rotate the paper feed roller 34, thereby moving the printing paper P in the sub-scanning direction. The paper feed motor 30 is provided with a rotary encoder 32, and an output signal of the rotary encoder 32 is input to the main control circuit 102.
[0028]
A print head 52 having a plurality of nozzles (not shown) is provided on the bottom surface of the carriage 50. Each nozzle is driven by a head drive circuit 140 to eject ink droplets.
[0029]
The carriage motor 60 is driven by a CR motor driving circuit 150. The printer 20 includes a linear encoder 70 for detecting the position and speed of the carriage 50 along the main scanning direction. The linear encoder 70 includes a linear code plate 72 provided parallel to the main scanning direction and a photo sensor 74 provided on the carriage 50. The output signal of the linear encoder 70 is input to the main control circuit 102.
[0030]
The main control circuit 102 has a function of supplying control signals to the three drive circuits 130, 140, and 150, respectively, decodes various print commands received by the interface circuit 120, and print data It also has a function of executing control related to adjustment and monitoring of various sensors. On the other hand, the CPU 104 has various functions for assisting the main control circuit 102, and executes control of various memories, for example.
[0031]
FIG. 3 is a block diagram showing the configuration of the drive control device for the carriage motor 60. This drive control device includes a CR motor control circuit 200 and a CR motor drive circuit 150. The CR motor control circuit 200 is a part of the main control circuit 102 shown in FIG.
[0032]
The output signal Sen of the linear encoder 70 is input to the position calculation circuit 230 and the speed calculation circuit 232 in the CR motor control circuit 200. These circuits 230 and 232 obtain the current position Pc and the current speed Vc of the carriage using the A phase signal and the B phase signal (not shown) of the output signal Sen of the encoder 70, respectively. The first subtracter 202 calculates a deviation ΔP between the given target position Pt and the current position Pc and inputs it to the target speed generation circuit 204. The target speed generation circuit 204 generates a target speed Vt corresponding to the position deviation ΔP. The change pattern of the target speed Vt is, for example, the same as that indicated by the solid line in FIG.
[0033]
The second subtracter 206 obtains a deviation ΔV between the target speed Vt and the current speed Vc, and inputs this speed deviation ΔV to the proportional element 210, the integral element 212, and the differential element 214. The calculation results QP, QI, and QD of these three calculation elements 210, 212, and 214 are added by an adder 216 to calculate an addition result ΣQ.
[0034]
The outputs QP, QI, QD of the respective arithmetic elements 210, 212, 214 and their addition result ΣQ are given by, for example, the following equations (1) to (4).
QP (j) = ΔV (j) × Kp (1)
QI (j) = QI (j−1) + ΔV (j) × Ki (2)
QD (j) = {ΔV (j) −ΔV (j−1)} × Kd (3)
ΣQ (j) = QP (j) + QI (j) + QD (j) (4)
Here, j is time, Kp is a proportional gain, Ki is an integral gain, and Kd is a differential gain.
[0035]
The duty adjustment circuit 220 adjusts the level of the deedy signal Dt supplied to the drive circuit 150 by adjusting the integration element 212 or the target speed generation circuit 204 according to the addition result ΣQ (also referred to as “PID output”). To do. The duty signal Dt is a signal proportional to the addition result ΣQ and is a signal indicating the duty of the carriage motor 60. The processing contents of the duty adjustment circuit 220 will be described later.
[0036]
The CR motor drive circuit 150 includes a DC-DC converter 154 configured with a transistor bridge and a base drive circuit 152. The base drive circuit 152 generates a base signal to be applied to the base of the transistor of the DC-DC converter 154 in accordance with the duty signal Dt supplied from the CR motor control circuit 200. The DC-DC converter 154 generates a motor drive signal Sdr according to this base signal and supplies it to the carriage motor 60. The relationship between the motor drive signal Sdr and the characteristics of the carriage motor is the same as that shown in FIG.
[0037]
B. First embodiment:
FIG. 4 shows the operation of the CR motor control circuit in the comparative example. In this comparative example, a circuit in which the duty adjustment circuit 220 is omitted from the CR motor control circuit 200 shown in FIG. 3 is used. In other words, in the comparative example, it is assumed that normal PID control is performed without using the duty adjustment circuit 220.
[0038]
In the table of FIG. 4, time j, target speed Vt, current speed Vc, speed deviation ΔV, proportional output (P output) QP, integral output (I output) QI, and PI output ΣQ (= QP + QI) are shown in order from the top. )It is shown. As indicated in the remarks, the proportional gain Kp is assumed to be 1.5 and the integral gain Ki is assumed to be unity. The differential output is omitted (that is, the differential gain is set to 0). Note that these gain setting values are merely values for convenience of explanation.
[0039]
At time j = 0, it is assumed that the I output QI is 700. From time j = 1 to time j = 6, the target speed Vt is constant at 200 cps (character / second), and the current speed Vc gradually increases from 80 cps to 180 cps. During this time, since the speed deviation ΔV is positive, the I output QI also gradually increases.
[0040]
As shown in the lower part of FIG. 4, PI output ΣQ = 1000 corresponds to 100% duty, and when PI output ΣQ is 1000 or more, the duty of carriage motor 50 is set to 100%. Therefore, hereinafter, this value 1000 is referred to as “effective limit value ΣQmax of PI output ΣQ”.
[0041]
The PI output ΣQ exceeds this effective limit value ΣQmax after time j = 2, but since the speed deviation ΔV is kept positive, both the integrated output QI and the PI output ΣQ continue to increase. In the period from time j = 6 to time j = 9, the current speed Vc and the target speed Vt are kept constant, but the current speed Vc has not reached the target speed Vt. This is because the carriage motor 60 operates at the maximum output (that is, duty 100%) during this period, but the load is larger than the maximum output, so that the current speed Vc does not increase and is kept substantially constant. Because it ends up. As a result, the speed deviation ΔV is kept positive, so that both the integral output QI and the PI output ΣQ continue to increase.
[0042]
At time j = 11, the current position approaches the target position Pt (FIG. 11), so the target speed Vt starts to decrease. However, since the PI output ΣQ greatly exceeds the effective limit value ΣQmax in the period up to that time, it takes time for the PI output ΣQ to become equal to or less than the effective limit value ΣQmax even if the target speed Vt decreases. Actually, the duty of the drive signal of the carriage motor 60 becomes 100% or less only after the PI output ΣQ becomes equal to or less than the effective limit value ΣQmax, and then the motor starts decelerating.
[0043]
As described above, in simple PI control (or PID control), if the addition result ΣQ of the output of the computation element continues to increase beyond the effective limit value ΣQmax corresponding to the maximum output of the motor, the target speed Vt decreases. Even if it starts, it will take a considerable time for the current speed Vc to decrease. As a result, as described above with reference to FIG. 11, it is difficult for the carriage to stop at the target position Pt.
[0044]
FIG. 5 shows the operation of the CR motor control circuit 200 in the first embodiment of the present invention. In the first embodiment, the duty adjustment circuit 220 forcibly sets the product ΔV · Ki in the integration element 212 to zero when the PI output ΣQ exceeds the effective limit value ΣQmax = 1000. For example, at time j = 2, ΣQ = 1070, which exceeds the effective limit value ΣQmax. Therefore, the product ΔV · Ki is set to 0, the I output QI is reset to 820, and the PI output ΣQ is recalculated to 970. In FIG. 5, the arrow from the top to the bottom indicates that the adjustment by the duty adjustment circuit 220 is performed. The arrow to the upper right indicates that the adjusted integration result QI is used for the next integration calculation.
[0045]
At time j = 3, the I output QI is updated based on the I output QI = 820 at the previous time j = 2, but the PI output ΣQ is 1020, which exceeds the effective limit value ΣQmax = 1000. Therefore, the product ΔV · Ki is also set to 0 at time j = 3, the I output QI is reset to 820 accordingly, and the PI output ΣQ is recalculated to 940.
[0046]
Since the PI output ΣQ does not exceed the effective limit value ΣQmax from time j = 4 to time j = 7 thereafter, adjustment by the duty adjustment circuit 220 is not performed. Since the PI output ΣQ again exceeds the effective limit value ΣQmax from time j = 8 to time j = 10, the product ΔV · Ki is adjusted by the duty adjustment circuit 220, and the I output QI and the PI output ΣQ are also restored. Is set.
[0047]
When the target speed Vt starts to decrease from time j = 11 and the speed deviation ΔV becomes negative, the PI output ΣQ also decreases rapidly accordingly. Therefore, in the first embodiment, the current speed Vc starts to decrease from an earlier time compared to the comparative example shown in FIG. Specifically, in the comparative example of FIG. 4, since the PI output ΣQ exceeds the effective limit value ΣQmax even at time j = 11, 12, the duty of the drive signal of the carriage motor 60 is kept at 100%. As a result, the current speed Vc is kept the same. On the other hand, in the first embodiment of FIG. 5, the PI output ΣQ is less than or equal to the effective limit value ΣQmax at time j = 11, 12, so the duty of the drive signal of the carriage motor 60 is also less than 100%. As a result, the current speed Vc starts to decrease from time j = 12.
[0048]
FIG. 6 shows a comparison between the operations of the comparative example and the first embodiment. However, the graph of FIG. 6 does not completely correspond to the changes in the tables of FIG. 4 and FIG. 5, but only shows the tendency of those changes.
[0049]
As shown in FIG. 6A, during the period in which the target speed Vt is maintained constant, the change in the current speed Vc is not significantly different between the comparative example and the first example. The reason for this is that, as shown in FIG. 6B, in this period, in the comparative example, the PI output ΣQ is equal to or greater than the effective limit value ΣQmax, so the duty of the carriage motor 60 is 100%. This is because the duty of the carriage motor 60 is almost 100% because the PI output ΣQ is almost close to the effective limit value ΣQmax in the example as well.
[0050]
When the target speed Vt starts to decrease, the PI output ΣQ rapidly decreases in the first embodiment, so the current speed Vc also decreases immediately, and the carriage 50 stops substantially at the target position Pt. On the other hand, in the comparative example, even if the target speed Vt is decreased, the PI output ΣQ is equal to or greater than the effective limit value ΣQmax for a while, so that the speed decrease is delayed. As a result, the carriage 50 stops at a position beyond the target position Pt as indicated by an arrow.
[0051]
As described above, in the first embodiment, when the PI output ΣQ exceeds the predetermined effective limit value ΣQmax, the product ΔV · Ki in the integrating element 212 is forcibly set to zero. It can be set below the effective limit value ΣQmax. As a result, even if the state where the speed deviation ΔV is positive continues, the deviation ΔV is prevented from being excessively accumulated in the I output QI. Accordingly, when the target speed Vt starts to decrease, the operation of the carriage motor 60 can be controlled so that the current speed Vc decreases accordingly. Further, the carriage 50 can be stopped substantially at the target position Pt.
[0052]
C. Second embodiment:
FIG. 7 shows the operation of the CR motor control circuit 200 in the second embodiment of the present invention. In the second embodiment, when the PI output ΣQ exceeds the effective limit value ΣQmax, the duty adjustment circuit 220 subtracts the difference (ΣQ−ΣQmax) between the PI output ΣQ and the effective limit value ΣQmax from the I output QI. The output ΣQ is set equal to the effective limit value ΣQmax. For example, at time j = 2, the PI output ΣQ before adjustment is 1070, which exceeds the effective limit value ΣQmax, so the difference (ΣQ−ΣQmax) = 70 is subtracted from the I output QI. As a result, the PI output ΣQ is forcibly set to a value equal to ΣQmax = 1000.
[0053]
At time j = 3, the I output QI is updated based on the I output QI = 850 at the previous time j = 2, but the PI output ΣQ is 1050, which exceeds the effective limit value ΣQmax = 1000. Therefore, even at time j = 3, the difference (ΣQ−ΣQmax) = 50 is subtracted from the I output QI, and the PI output ΣQ is forcibly set to a value equal to ΣQmax = 1000. Since the processing after time j = 4 is the same, the description thereof is omitted.
[0054]
As described above, in the second embodiment, when the PI output ΣQ exceeds the predetermined effective limit value ΣQmax, the difference (ΣQ−ΣQmax) is subtracted from the I output QI, so that the PI output ΣQ becomes the effective limit value ΣQmax. Since the equal values are set, the PI output ΣQ can be kept below the effective limit value ΣQmax. As a result, even if the state where the speed deviation ΔV is positive continues, the deviation ΔV can be prevented from being excessively accumulated in the I output QI. Therefore, as in the first embodiment described above, when the target speed Vt starts to decrease, the operation of the carriage motor 60 can be controlled so that the current speed Vc immediately decreases accordingly. Further, the carriage 50 can be stopped substantially at the target position Pt.
[0055]
In the first and second embodiments, the duty adjustment circuit 220 adjusts the integration result (that is, the I output QI) in the integration element 212 when the PI output ΣQ exceeds the effective limit value ΣQmax, so that the PI output This is common in that ΣQ is prevented from continuing to increase beyond the effective limit value ΣQmax.
[0056]
D. Third embodiment:
FIG. 8 shows the operation of the CR motor control circuit 200 in the third embodiment of the present invention. In the third embodiment, when the PI output ΣQ exceeds the effective limit value ΣQmax N times, the duty adjustment circuit 220 resets the target speed Vt in the target speed generation circuit 204 to the current speed Vc at that time. Set. Here, the number of times N can be set to an arbitrary value of 1 or more, but N = 4 in the example of FIG.
[0057]
In the example of FIG. 8, since the PI output ΣQ exceeds the effective limit value ΣQmax at four times from time j = 2 to time j = 5, the target speed Vt from time j = 6 thereafter is The current speed Vc is reset to 180 cps. The value of the target speed Vt is then maintained until the time when the value of the target speed Vt before change changes (time j = 11).
[0058]
The PI output ΣQ exceeds the effective limit value ΣQmax = 1000 in the third embodiment, but since the speed deviation ΔV becomes 0, the speed deviation ΔV is not accumulated in the I output QI. Accordingly, since the I output QI and the PI output ΣQ can be suppressed to be smaller than those in the comparative example, the operation of the carriage motor 60 is performed so that when the target speed Vt starts to decrease, the current speed Vc immediately decreases accordingly. Can be controlled. Further, the carriage 50 can be stopped substantially at the target position Pt.
[0059]
E. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
[0060]
E1. Modification 1:
As the carriage motor 60, it is also possible to use a DC motor or an AC motor other than the brushed DC motor. The present invention can also be applied to control of a motor other than the carriage motor of the printer.
[0061]
E2. Modification 2:
In the above embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware. For example, part or all of the functions of the control circuit 200 (FIG. 3) can be realized by a computer program.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a main configuration of an inkjet printer 20 as an embodiment of the present invention.
FIG. 2 is a block diagram showing an electrical configuration of the printer 20;
FIG. 3 is a block diagram showing a configuration of a drive control device for a carriage motor 60;
FIG. 4 is an explanatory diagram showing the operation of a CR motor control circuit in a comparative example.
FIG. 5 is an explanatory diagram showing the operation of the CR motor control circuit 200 in the first embodiment.
FIG. 6 is a graph showing a comparison between the operation of the comparative example and the first embodiment.
FIG. 7 is an explanatory diagram showing an operation of a CR motor control circuit 200 in the second embodiment.
FIG. 8 is an explanatory diagram showing the operation of a CR motor control circuit 200 in the third embodiment.
FIG. 9 is a block diagram showing a configuration of a conventional drive control device.
10 is an explanatory diagram showing a relationship between a motor drive signal Sdr and the characteristics of the carriage motor 330. FIG.
FIG. 11 is a graph showing a state of control when an excessive load is applied to the carriage motor.
[Explanation of symbols]
20 ... Inkjet printer
30 ... paper feed motor
32 ... Rotary encoder
34 ... Paper feed roller
40 ... Platen
50 ... carriage
52. Print head
54 ... Black cartridge
56 ... Color ink cartridge
60 ... Carriage motor
62 ... Traction belt
64 ... Guide rail
70 ... Linear encoder
72. Code plate
74 ... Photo sensor
80 ... Capping device
102 ... Main control circuit
104 ... CPU
110 ... ROM
112 ... RAM
114… EEPROM
120 ... interface circuit
130: Paper feed motor drive circuit
140... Head drive circuit
150 ... CR motor drive circuit
152 ... Base drive circuit
154 ... DC-DC converter
200 ... CR motor control circuit
202 ... First subtractor
204 ... Target speed generation circuit
206 ... second subtractor
210 ... Proportional element
212 ... Integral element
214 ... Differential element
216 ... Adder
220 ... Duty adjustment circuit
230: Position calculation circuit
232 ... Speed calculation circuit
300 ... Control circuit
302 ... Subtractor
304 ... Proportional element
306 ... Integral element
308 ... Differential element
310 ... Adder
320 ... Drive circuit
330 ... Carriage motor
332: Encoder

Claims (10)

A printing apparatus having a print head,
A carriage carrying the print head;
A carriage motor for moving the carriage;
A drive control device for controlling the operation of the carriage motor;
With
The drive control device includes:
A drive circuit for driving the carriage motor;
A detection unit for detecting the current speed of the carriage;
A target speed generator for generating a target speed of the carriage;
A control unit that generates a control signal to be supplied to the drive circuit according to a deviation between the target speed of the carriage and the current speed;
Have
The controller is
A plurality of calculation elements each including a proportional element and an integral element, each for obtaining a calculation result according to the speed deviation;
An adder for adding calculation results of the plurality of calculation elements;
An adjustment unit that adjusts the signal level of the control signal according to the addition result of the adder;
Including
The adjustment unit prevents the addition result from continuing to exceed the effective limit value by adjusting the integration result in the integration element when the addition result exceeds a predetermined effective limit value. A printing apparatus characterized by the above. The printing apparatus according to claim 1,
The integration element updates the integration result by adding the previous integration result to the product ΔV · Ki of the speed deviation ΔV and the integration gain Ki,
The adjustment unit adjusts the integration result by setting a value of the product ΔV · Ki to 0 when the addition result exceeds a predetermined effective limit value. The printing apparatus according to claim 1,
The adjustment unit subtracts a difference between the addition result and the effective limit value from an integration result in the integration element when the addition result exceeds a predetermined effective limit value, and also adds the addition result to the effective limit value. A printing device that adjusts the integration result by setting to a value equal to. The printing apparatus according to any one of claims 1 to 3,
The printing apparatus, wherein the effective limit value is a value corresponding to a maximum output of the carriage motor. A printing apparatus having a print head,
A carriage carrying the print head;
A carriage motor for moving the carriage;
A drive control device for controlling the operation of the carriage motor;
With
The drive control device includes:
A drive circuit for driving the carriage motor;
A detection unit for detecting the current speed of the carriage;
A target speed generator for generating a target speed of the carriage;
A control unit that generates a control signal to be supplied to the drive circuit according to a deviation between the target speed of the carriage and the current speed;
Have
The controller is
A plurality of calculation elements each including a proportional element and an integral element, each for obtaining a calculation result according to the speed deviation;
An adder for adding calculation results of the plurality of calculation elements;
An adjustment unit that adjusts the signal level of the control signal according to the addition result of the adder;
Including
The adjustment unit adjusts a target speed in the target speed generation unit when the addition result exceeds a predetermined effective limit value continuously a predetermined number of times, so that the addition result exceeds the effective limit value. A printing apparatus characterized by preventing the increase. The printing apparatus according to claim 5, wherein
The adjusting unit sets a target speed in the target speed generating unit to a value equal to the current speed when the addition result exceeds a predetermined effective limit value continuously a predetermined number of times. A drive control device for controlling an operation of the carriage motor, used in a printing apparatus having a carriage having a print head mounted thereon and a carriage motor for moving the carriage.
A drive circuit for driving the carriage motor;
A detection unit for detecting the current speed of the carriage;
A target speed generator for generating a target speed of the carriage;
A control unit that generates a control signal to be supplied to the drive circuit according to a deviation between the target speed of the carriage and the current speed;
With
The controller is
A plurality of calculation elements each including a proportional element and an integral element, each for obtaining a calculation result according to the speed deviation;
An adder for adding calculation results of the plurality of calculation elements;
An adjustment unit that adjusts the signal level of the control signal according to the addition result of the adder;
Including
The adjustment unit prevents the addition result from continuing to exceed the effective limit value by adjusting the integration result in the integration element when the addition result exceeds a predetermined effective limit value. A drive control device characterized by the above. A drive control device for controlling an operation of the carriage motor, used in a printing apparatus having a carriage having a print head mounted thereon and a carriage motor for moving the carriage.
A drive circuit for driving the carriage motor;
A detection unit for detecting the current speed of the carriage;
A target speed generator for generating a target speed of the carriage;
A control unit that generates a control signal to be supplied to the drive circuit according to a deviation between the target speed of the carriage and the current speed;
With
The controller is
A plurality of calculation elements each including a proportional element and an integral element, each for obtaining a calculation result according to the speed deviation;
An adder for adding calculation results of the plurality of calculation elements;
An adjustment unit that adjusts the signal level of the control signal according to the addition result of the adder;
Including
The adjustment unit adjusts a target speed in the target speed generation unit when the addition result exceeds a predetermined effective limit value continuously a predetermined number of times, so that the addition result exceeds the effective limit value. A drive control device characterized by preventing the increase. A method of controlling the operation of a carriage motor that moves a carriage mounted with a print head,
(A) detecting the current speed of the carriage;
(B) generating a target speed of the carriage;
(C) generating a control signal to be supplied to the drive circuit of the carriage motor according to a deviation between the target speed of the carriage and the current speed;
With
The step (c)
(D) using a plurality of calculation elements including a proportional element and an integral element, and obtaining a plurality of calculation results according to the speed deviation;
(E) adding the plurality of calculation elements;
(F) adjusting the signal level of the control signal according to the addition result of the adder;
Including
The step (f) prevents the addition result from continuing to exceed the effective limit value by adjusting the integration result in the integration element when the addition result exceeds a predetermined effective limit value. A method for controlling a carriage motor. A method of controlling the operation of a carriage motor that moves a carriage mounted with a print head,
(A) detecting the current speed of the carriage;
(B) generating a target speed of the carriage;
(C) generating a control signal to be supplied to the drive circuit of the carriage motor according to a deviation between the target speed of the carriage and the current speed;
With
The step (c)
(D) using a plurality of calculation elements including a proportional element and an integral element, and obtaining a plurality of calculation results according to the speed deviation;
(E) adding the plurality of calculation elements;
(F) adjusting the signal level of the control signal according to the addition result of the adder;
Including
In the step (f), when the addition result exceeds a predetermined effective limit value continuously for a predetermined number of times, the addition result continues to increase beyond the effective limit value by adjusting the target speed. A control method for a carriage motor, characterized in that this is prevented.

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