JP2001224189A - Motor control method and control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control method and a control unit, which enable accurate control, while maintaining behavior stability of a motor in the case of reduction control. SOLUTION: In this motor control method, when the maximum, speed of the motor as the object of control is Vmax, reduction control section distance from a reduction control section starting position to an aimed stop position is N, and the distance from the starting position to a present position is x, a waveform pattern of a target speed Vc which is expressed by formula Vc= Vmax 1-(x/N)a}, where a is an arbitrary constant is formed in the reduction control section. Reduction in control of the motor is performed, on the basis of the waveform pattern of the aimed speed Vc. This motor control unit is provided with a speed commanding means, which forms the waveform pattern of the target velocity Vc and forms and outputs a speed command signal for commanding the aimed speed Vc, on the basis of the waveform pattern of the target speed Vc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control method and a control device, and more particularly, to a motor control method for stabilizing the behavior of a controlled object during deceleration control and enabling high-precision control. It relates to a control device.

[0002]

2. Description of the Related Art First, a schematic configuration and a control method of an ink jet printer using a DC motor control device will be described.

FIG. 3 is a block diagram showing a schematic configuration of an ink jet printer.

[0004] The ink jet printer shown in FIG.
A paper feed motor (hereinafter also referred to as a PF motor) 1 for feeding paper, a paper feed motor driver 2 for driving the paper feed motor 1, and a head 9 for discharging ink onto the printing paper 50 are fixed. And a carriage motor (hereinafter also referred to as a CR motor) 4 for driving the carriage 3 and a CR motor driver 5 for driving the carriage motor 4. A DC unit 6 for issuing a DC current command value to a CR motor driver 5, and a pump motor 7 for controlling ink suction for preventing clogging of a head 9.
And a pump motor driver 8 for driving the pump motor 7
A head driver 10 for driving and controlling the head 9, a linear encoder 11 fixed to the carriage 3, and a linear encoder 1 having slits formed at predetermined intervals.
1 code plate 12, a rotary encoder 13 for the PF motor 1, a paper detection sensor 15 for detecting the end position of the paper being printed, and a CP for controlling the entire printer.
U16, a timer IC 17 for periodically generating an interrupt signal to the CPU 16, and an interface unit (hereinafter, I / O) for transmitting and receiving data to and from the host computer 18.
Also called F. ) 19 and I from the host computer 18
An ASIC 20 that controls a printing resolution, a driving waveform of the head 9, and the like based on printing information transmitted via the F19.
A PROM 21 and a RAM 22 used as a work area and a program storage area of the ASIC 20 and the CPU 16.
And the EEPROM 23, the platen 25 supporting the printing paper 50, and the printing paper 50 driven by the PF motor 1.
, A pulley 30 attached to the rotation shaft of the CR motor 4, and a timing belt 31 driven by the pulley 30.

The DC unit 6 controls the driving of the paper feed motor driver 2 and the CR motor driver 5 based on the control commands sent from the CPU 16 and the outputs of the encoders 11 and 13. Also, the paper feed motor 1 and the CR motor 4
Are all composed of DC motors.

FIG. 4 is a perspective view showing the structure around the carriage 3 of the ink jet printer.

As shown in FIG. 4, the carriage 3 is connected to the carriage motor 4 via a pulley 30 by a timing belt 31 and is guided by a guide member 32 and driven to move parallel to the platen 25. On the surface of the carriage 3 facing the printing paper, a recording head 9 having a nozzle array for discharging black ink and a nozzle array for discharging color ink is provided. Each nozzle receives ink supplied from an ink cartridge 34 to perform printing. Prints characters and images by ejecting ink droplets on paper.

In the non-printing area of the carriage 3, a capping device 35 for sealing the nozzle opening of the recording head 9 during non-printing and a pump unit 36 having the pump motor 7 shown in FIG. 3 are provided. Have been. When the carriage 3 moves from the printing area to the non-printing area, the carriage 3 comes into contact with a lever (not shown), and the capping device 35 moves upward to seal the head 9.

When clogging occurs in the nozzle opening row of the head 9 or when the cartridge 34 is replaced,
When the ink is forcibly ejected from the pump unit, the pump unit is operated while the head 9 is sealed, and the ink is sucked out from the nozzle opening row by the negative pressure from the pump unit. As a result, dust and paper dust adhering in the vicinity of the nozzle opening row are washed, and the air bubbles in the head 9 are discharged to the cap 37 together with the ink.

FIG. 5 is an explanatory view schematically showing the configuration of the linear encoder 11 mounted on the carriage 3. As shown in FIG.

The encoder 11 shown in FIG. 5 includes a light emitting diode 11a, a collimator lens 11b, and a detection processing unit 11c. The detection processing unit 11c includes a plurality (four) of photodiodes 11d and the signal processing circuit 1
1e and two comparators 11fA and 11fB.

When a voltage VCC is applied to both ends of the light emitting diode 11a via a resistor, light is emitted from the light emitting diode 11a. This light is converged into parallel light by the collimator lens 11b and passes through the code plate 12. Code plate 1
2, slits are provided at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)).

The parallel light passing through the code plate 12 enters each photodiode 11d through a fixed slit (not shown) and is converted into an electric signal. The electric signals output from the four photodiodes 11d are subjected to signal processing in a signal processing circuit 11e, the signals output from the signal processing circuit 11e are compared in comparators 11fA and 11fB, and the comparison result is output as a pulse. Pulses ENC-A and E output from comparators 11fA and 11fB
NC-B is the output of the encoder 11.

FIG. 6 is a timing chart showing waveforms of two output signals of the encoder 11 at the time of forward rotation and reverse rotation of the CR motor.

As shown in FIGS. 6 (a) and 6 (b), the pulse ENC is applied to both the forward rotation and the reverse rotation of the CR motor.
-A and the pulse ENC-B differ in phase by 90 degrees. When the CR motor 4 is rotating forward, that is, when the carriage 3 is moving in the main scanning direction, FIG.
As shown in FIG. 6B, the phase of the pulse ENC-A is advanced by 90 degrees from the pulse ENC-B, and when the CR motor 4 is rotating in the reverse direction, as shown in FIG.
The encoder 4 is configured so that the phase is delayed by 90 degrees from the pulse ENC-B. One cycle T of the pulse is equal to the slit interval of the code plate 12 (for example, 1/1).
80 inches), which is equal to the time during which the carriage 3 moves through the slit interval.

On the other hand, the rotary encoder 13 for the PF motor 1 has the same configuration as the linear encoder 11 except that the code plate is a rotating disk that rotates in accordance with the rotation of the PF motor 1. Output pulses ENC-A,
Outputs ENC-B. In the ink jet printer, the slit interval of the plurality of slits provided on the code plate of the encoder 13 for the PF motor 1 is 1/180.
Inches, and the paper is fed by 1/1440 inch when the PF motor 1 rotates by one slit interval.

FIG. 7 is a perspective view showing a portion related to paper feeding and paper detection. The position of the paper detection sensor 15 shown in FIG. 3 will be described with reference to FIG. In FIG. 7, the printing paper 50 inserted into the paper feeding slot 61 of the printer 60 is fed by a paper feeding roller 6 driven by a paper feeding motor 63.
4 to the printer 60. Printer 6
The leading end of the printing paper 50 fed into the area 0 is detected by, for example, an optical paper detection sensor 15. Paper detection sensor 15
The paper 50 whose leading end is detected is fed by a paper feed roller 65 and a driven roller 66 driven by the PF motor 1.

Subsequently, printing is performed by dropping ink from a recording head (not shown) fixed to the carriage 3 moving along the carriage guide member 32. When the paper has been fed to a predetermined position, the end of the currently printed printing paper 50 is detected by the paper detection sensor 15. The printing paper 50 on which printing has been completed is transferred to the gear 6 via gears 67A and 67B driven by the PF motor 1.
7C driven by the paper discharge roller 68 and the driven roller 6
9, the paper is discharged from the paper discharge port 62 to the outside. The encoder 13 is connected to the rotation shaft of the paper feed roller 65.

Next, the configuration of a DC unit 6 which is a conventional DC motor control device for controlling the CR motor 4 of the above-described ink jet printer and a control method by the DC unit 6 will be described.

FIG. 8 is a block diagram showing the configuration of a DC unit 6 which is a conventional DC motor control device.
5 is a graph showing motor current and motor speed of the CR motor 4 controlled by the DC unit 6.

The DC unit 6 shown in FIG. 8 includes a position calculator 6a, a subtractor 6b, a target speed calculator 6c, a speed calculator 6d, a subtractor 6e, a proportional element 6f, and an integral element 6g. , A differential element 6h, an adder 6i, a D / A converter 6j, a timer 6k, and an acceleration control unit 6m.

The position calculator 6a detects the rising edge and the falling edge of each of the output pulses ENC-A and ENC-B of the encoder 11, counts the number of detected edges, and based on the count value. , The position of the carriage 3 is calculated. This count adds "+1" when one edge is detected when the CR motor 4 is rotating forward,
When the edge is reversed, if one edge is detected, “−”
1 "is added. Each period of the pulses ENC-A and ENC-B is equal to the slit interval of the code plate 12, and
Pulse ENC-A and pulse ENC-B differ in phase by 90 degrees. Therefore, the count value “1” of the above-mentioned count corresponds to １ ／ of the slit interval of the code plate 12. Thus, by multiplying the above-mentioned count value by １ ／ of the slit interval, the movement amount from the position of the carriage 3 corresponding to the count value of “0” can be obtained. At this time, the resolution of the encoder 11 is 1/1 of the interval between the slits of the code plate 12.
It becomes 4. If the interval between the slits is 1/180 inch, the resolution is 1/720 inch.

The subtractor 6b calculates a positional deviation between the target position sent from the CPU 16 and the actual position of the carriage 3 obtained by the position calculating section 6a.

The target speed calculator 6c calculates the target speed of the carriage 3 based on the position deviation output from the subtractor 6b. This calculation is performed by multiplying the position deviation by the gain KP. This gain KP is determined according to the position deviation. Incidentally, the value of the gain KP may be stored in a table (not shown).

The speed calculating section 6d determines the carriage 3 based on the output pulses ENC-A and ENC-B of the encoder 11.
Calculate the speed of This speed is determined as follows. First, output pulses ENC-A, E of encoder 11
Each rising edge and falling edge of NC-B is detected, and the time interval between edges corresponding to 1/4 of the slit interval of the code plate 12 is counted by a timer counter. If the count value is T and the slit interval of the code plate 12 is λ, the carriage speed is λ / (4T)
Is required. Here, the calculation of the speed is obtained by measuring one cycle of the output pulse ENC-A, for example, from the rising edge to the next rising edge using a timer counter.

The subtractor 6e has a target speed and a speed calculator 6
The speed deviation from the actual speed of the carriage 3 calculated by d is calculated.

The proportional element 6f is obtained by adding a constant Gp to the speed deviation.
And outputs the multiplication result. The integral element 6g integrates the value obtained by multiplying the speed deviation by a constant Gi. Differential element 6h
Multiplies the difference between the current speed deviation and the immediately preceding speed deviation by a constant Gd, and outputs the multiplication result. The calculation of the proportional element 6f, the integral element 6g, and the differential element 6h is performed by the encoder 11
, For example, in synchronization with the rising edge of the output pulse ENC-A for each cycle of the output pulse ENC-A.

The outputs of the proportional element 6f, the integral element 6g and the differential element 6h are added in an adder 6i. Then, the addition result, that is, the drive current of the CR motor 4 is sent to the D / A converter 6j and converted into an analog current. The CR motor 4 is driven by the driver 5 based on the analog voltage.

The timer 6k and the acceleration control unit 6m
PID control, which is used for acceleration control and uses the proportional element 6f, integral element 6g, and differential element 6h, is used for constant speed and deceleration control during acceleration.

The timer 6k generates a timer interrupt signal at predetermined time intervals based on a clock signal sent from the CPU 16.

The acceleration control unit 6m integrates a predetermined current value (for example, 20 mA) with the target current value every time the timer interrupt signal is received, and the integration result, that is, the target current value of the DC motor 4 during acceleration, is calculated. , D / A converter 6j. As in the case of the PID control, the target current value is D /
The current is converted into an analog current by the A converter 6j, and the CR motor 4 is driven by the driver 5 based on the analog current.

The driver 5 has, for example, four transistors, and turns on or off each of the above-mentioned transistors based on the output of the D / A converter 6j. (A) The operation of rotating the CR motor 4 forward or backward. Mode, (b) regenerative brake operation mode (short brake operation mode, that is, mode in which CR motor is stopped), (c) mode in which CR motor is to be stopped,
Is performed.

Next, referring to FIGS. 9A and 9B, the DC
The operation of the unit 6, that is, a conventional DC motor control method will be described.

When the CR motor 4 is stopped, CP
When a start command signal for starting the CR motor 4 is sent from the U16 to the DC unit 6, an initial start current value I0 is sent from the acceleration control unit 6m to the D / A converter 6j. The starting initial current value I0 is determined by the CPU together with the starting command signal.
16 to the acceleration control unit 6m. This current value I0 is converted into an analog voltage by the D / A converter 6j and sent to the driver 5, and the driver 5 starts the CR motor 4 (see FIGS. 9A and 9B). After receiving the start command signal, the timer 6k generates a timer interrupt signal at predetermined time intervals. Every time the acceleration control unit 6m receives the timer interrupt signal, the acceleration control unit 6m integrates a predetermined current value (for example, 20 mA) with the starting initial current value I0, and sends the integrated current value to the D / A converter 6j. Then, the integrated current value is converted into an analog current by the D / A converter 6j and sent to the driver 5. Then, the driver 5 controls the CR so that the value of the current supplied to the CR motor 4 becomes the integrated current value.
The motor is driven to increase the speed of the CR motor 4 (FIG. 9).
(B)). Therefore, the current value supplied to the CR motor 4 has a step shape as shown in FIG. At this time, the PID control system is also operating, but the D / A converter 6j selects and takes in the output of the acceleration control unit 6m.

The current value integration process of the acceleration control unit 6m is performed until the integrated current value becomes a constant current value IS.
When the current value integrated at time t1 reaches the predetermined value IS, the acceleration control unit 6m stops the integration process and supplies a constant current value IS to the D / A converter 6j. This gives C
It is driven by the driver 5 so that the value of the current supplied to the R motor 4 becomes the current value IS (see FIG. 9A).

Then, in order to prevent the speed of the CR motor 4 from overshooting, when the CR motor 4 reaches a predetermined speed V1 (see time t2), the current supplied to the CR motor 4 is reduced. Is controlled by the acceleration control unit 6m. At this time, the speed of the CR motor 4 further increases, but C
When the speed of the R motor 4 reaches a predetermined speed Vc (FIG. 9)
(See time t3 in (b)), the D / A converter 6j
The output of the ID control system, that is, the output of the adder 6i is selected.
ID control is performed.

That is, the target speed is calculated based on the positional deviation between the target position and the actual position obtained from the output of the encoder 11, and the speed between the target speed and the actual speed obtained from the output of the encoder 11 is calculated. The proportional element 6f, the integral element 6g, and the differential element 6h operate based on the deviation, and perform proportional, integral, and differential calculations, respectively, and control the CR motor 4 based on the sum of the calculation results. .
The above-described proportional, integral, and differential calculations are performed, for example, in synchronization with the rising edge of the output pulse ENC-A of the encoder 11. As a result, the speed of the DC motor 4 is controlled to a desired speed Ve. Note that a predetermined speed Vc
Is preferably 70 to 80% of the desired speed Ve.

From time t4, the DC motor 4 reaches the desired speed, so that the carriage 3 also reaches the desired constant speed Ve, and the printing process can be performed.

When the printing process is completed and the carriage 3 approaches the target position (see time t5 in FIG. 9 (b)), the position deviation decreases and the target speed also decreases, so that the speed deviation, ie, the subtractor 6e Output becomes negative and the DC motor 4
Is decelerated, and stops at time t6.

[0040]

Next, the conventional DC is used.
Problems in control by the motor control method and the control device will be described.

FIG. 10 is a graph showing the target speed near the target stop position and the current speed in the control by the conventional DC motor control method and control device.

As the target speed waveform near the target stop position in the control by the conventional DC motor control method and control device, the first target speed waveform pattern shown in FIG. 10A and the second target speed waveform shown in FIG. The target velocity waveform pattern was considered.

However, in the first target speed waveform pattern, constant speed control is not performed for the target speed VC1, and the control directly shifts from acceleration control to deceleration control. Therefore, since the change in the command speed at the time of shifting from the acceleration control to the deceleration control is very large, the behavior of the motor to be controlled becomes very unstable, and in some cases, the control may be disabled. Also, since there is a certain upper limit on the motor speed,
It is difficult to control the waveform of the target speed VC1 between the current position and the target stop position to always be a linear waveform having a constant slope. Therefore, it is impractical to control the target speed waveform to be the first target speed waveform pattern.

On the other hand, in the second target speed waveform pattern,
In consideration of the maximum value Vmax of the motor speed, the control of the target speed VC2 shifts to deceleration control after performing constant speed control at the maximum speed Vmax. However, even in this control pattern, the change in the command speed when shifting from the constant speed control to the deceleration control is large, and the current speed VP2 which is the actual motor speed is used.
As shown in the waveform, the behavior of the motor to be controlled becomes unstable, and it takes time for the behavior to stabilize again, and in some cases, the motor may stop with deviation from the target stop position . Therefore, it is difficult to perform high-precision control in the control in which the waveform of the target speed is used as the second target speed waveform pattern.

As described above, the speed control patterns near the target stop position in the conventional DC motor control method and control apparatus have problems, and high precision while maintaining stable behavior of the motor to be controlled. It was difficult to control.

The present invention has been made in view of the above-mentioned problems, and has as its object to provide a motor control method and a motor control capable of performing high-precision control while maintaining stable motor behavior during deceleration control. It is to provide a device.

[0047]

According to the motor control method of the present invention, the maximum speed of the motor to be controlled is set to Vma.
Assuming that x is the deceleration control section distance from the deceleration control section start position to the target stop position, and N is the distance from the deceleration control section start position to the current position, the following equation VC = Vmax ｛1- ( x / N) ^a ｝ (a is an arbitrary constant) to generate a waveform pattern of the target speed VC represented by:
The deceleration control of the motor is performed based on the waveform pattern of the target speed VC. With this configuration, the change in the waveform of the target speed VC becomes gentle, so that the behavior of the motor during the deceleration control is kept stable. Highly accurate control can be performed.

According to the motor control device of the present invention, the maximum speed of the motor to be controlled is Vmax, the deceleration control section distance from the deceleration control section start position to the target stop position is N, and the deceleration control section start position is X to distance to position
Then, in the deceleration control section, a waveform pattern of the target speed VC represented by the following equation VC = Vmax {1- (x / N) ^a } (a is an arbitrary constant) is generated,
A speed command means for generating and outputting a speed command signal for commanding the target speed VC based on the waveform pattern of the target speed VC is provided.
Since the change in the waveform of C becomes gentle, high-precision control can be performed while maintaining stable motor behavior during deceleration control.

The value of the arbitrary constant a may be set for each deceleration control section in accordance with the value of the maximum speed Vmax of the motor, the distance N of the deceleration control section, and the time of the deceleration control section. It may be set to a value.

The deceleration control can be applied to either one or both of the deceleration control for driving the motor in the normal direction and the deceleration control for driving in the reverse direction.

The motor may be any one of a DC motor, a stepping motor and an AC motor.

The motor may be a carriage motor of a printer or a paper feed motor.

[0053]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motor control method and a control device according to the present invention will be described below with reference to the drawings.

The motor control method and the control device according to the present invention are characterized in that the maximum speed of the motor to be controlled is Vmax, the deceleration control section distance from the deceleration control section start position to the target stop position is N, and the deceleration control section start position is Assuming that the distance to the current position is x, in the deceleration control section, the waveform pattern of the target speed VC expressed by the following equation: VC = Vmax ｛1− (x / N) ^a ｝ (a is an arbitrary constant) Generate
The motor deceleration control is performed based on the waveform pattern of the target speed VC. This is the greatest feature of the motor control method and control device according to the present invention.

FIG. 1 is a graph showing an example of a waveform pattern of the target speed VC generated by the motor control method and the control device according to the present invention.

In the example of the graph shown in FIG. 1, the deceleration control section distance N = 576 (the number of encoder pulses), the maximum motor speed Vmax = 6 (inch per second)
d)), and the target speed VC (a =
3) Waveform pattern and target speed VC with constant a = 10
(A = 10).

As can be seen from the graph of FIG. 1, when the value of the arbitrary constant a is small, the change in the waveform of the target speed VC becomes gentle, and therefore, it is easy to stabilize the behavior of the motor, and high accuracy is achieved. Control can be performed.

FIG. 2 is a graph showing an example of a waveform pattern of the target speed VC and the current speed VP of the motor generated by the motor control method and control device according to the present invention.

In the example of the graph shown in FIG. 2, the deceleration control section distance N = 576 (the number of encoder pulses), the maximum speed Vmax of the motor = 0.8 (inch per second).
cond)), and the target speed VC with the constant a = 5
(A = 5) and the waveform pattern of the current motor speed VP (a = 5), and the waveform pattern of the target speed VC (a = 15) and the current motor speed VP (a = 15) with the constant a = 15. It is shown.

From the graph of FIG. 2, when the value of the arbitrary constant a is small, the waveform of the target speed VC changes more slowly, the amplitude of the current speed VP of the motor with respect to the target speed VC is small, and the behavior of the motor is small. Is stable. Therefore, when the value of the constant a is small, it is easier to stabilize the behavior of the motor, and it is possible to perform highly accurate control.

However, the value of the arbitrary constant a can be set for each deceleration control section in accordance with the value of the maximum speed Vmax of the motor, the distance N of the deceleration control section, and the time of the deceleration control section. For example, when the time of the deceleration control section is to be shortened, the value of the constant a is increased within a range in which the behavior of the motor can be kept stable. It is better to make it smaller. Alternatively, when it is known from simulations or the like that the behavior of the motor can be kept stable, the value of the arbitrary constant a may be set to a constant value.

Referring to FIG. 2 and FIG. 10, the motor control method and control apparatus according to the present invention are compared with the prior art with respect to the amplitude of the current speed VP of the motor with respect to the target speed VC. The amplitude is small. Therefore, with the motor control method and the control device according to the present invention, high-precision control can be performed while maintaining stable motor behavior.

The motor control device according to the present invention generates a waveform pattern of the target speed VC as described above, and generates and outputs a speed command signal for commanding the target speed VC based on the waveform pattern of the target speed VC. The apparatus is provided with speed command means, and is configured to perform deceleration control of the motor. Or ASIC, PRO
A waveform pattern table of the target speed VC is set in advance in M, RAM, EEPROM or other storage means, and one or a plurality of waveform patterns are stored, and the target speed VC is commanded by referring to the waveform pattern table. Speed command means for generating and outputting a speed command signal to be output.

The motor control method and control device according to the present invention can be applied to any control method and control device for a DC motor, a stepping motor and an AC motor.

When the motor to be controlled is a DC motor, the hardware configuration of the motor control device according to the present invention is substantially the same as the configuration of the DC unit 6 which is a conventional motor control device. , In that the above-mentioned deceleration control is possible. In this case, the motor control device according to the present invention generates the above-described waveform pattern of the target speed VC in the acceleration control unit 6m shown in FIG. Is configured to generate and output a speed command signal for commanding supply of a current corresponding to the waveform pattern to the motor. Alternatively, the ASIC 20, the PROM 21, the RAM 22, the EEPR in FIG.
A waveform pattern table of the target speed VC is set in advance in the OM 23 or other storage means, and one or a plurality of waveform patterns are stored, and the acceleration control unit 6m shown in FIG.
However, referring to the waveform pattern table, the target speed VC
May be generated and output. In this case, the acceleration control unit 6m controls the ASIC 20, the PROM 21, the RAM 22, or the EE via the CPU 16.
By accessing any of the PROMs 23, the waveform pattern table is referred to. When the waveform pattern table is set in another storage unit, the acceleration control unit 6m may directly access the storage unit to refer to the waveform pattern table.

When the motor control method and control device according to the present invention are applied to a printer, the motor to be controlled is:
It may be a paper feed motor or a carriage motor. In this case, for example, the setting can be made such that the constant a is changed according to the ink weight, the medium, and the frequency of use of the printer.

Further, the deceleration control by the motor control method and the control device according to the present invention can be applied to both deceleration in forward rotation of the motor and deceleration in reverse rotation. Assuming that the maximum speed Vmax of the motor in Expression (1) representing the target speed VC is a value including a sign corresponding to the driving direction, Expression (1) is directly applied to the deceleration control in the reverse rotation direction driving. Can be.

[0068]

According to the motor control method of the present invention,
The maximum speed of the motor to be controlled is Vmax, the deceleration control section distance from the deceleration control section start position to the target stop position is N, and the distance from the deceleration control section start position to the current position is x.
Then, in the deceleration control section, a waveform pattern of the target speed VC represented by the following equation VC = Vmax {1- (x / N) ^a } (a is an arbitrary constant) is generated,
Since the deceleration control of the motor is performed based on the waveform pattern of the target speed VC, the waveform of the target speed VC changes gradually, and high-precision control is performed while maintaining stable motor behavior during the deceleration control. It can be carried out.

According to the motor control device of the present invention, the maximum speed of the motor to be controlled is Vmax, the deceleration control section distance from the deceleration control section start position to the target stop position is N, and the deceleration control section start position is X to distance to position
Then, in the deceleration control section, a waveform pattern of the target speed VC represented by the following equation VC = Vmax {1- (x / N) ^a } (a is an arbitrary constant) is generated,
Since the speed command means for generating and outputting a speed command signal for commanding the target speed VC based on the waveform pattern of the target speed VC is provided, the change in the waveform of the target speed VC becomes gradual, and the motor during the deceleration control is controlled. High-precision control can be performed while maintaining the stable behavior of.

[Brief description of the drawings]

FIG. 1 is a graph showing an example of a waveform pattern of a target speed VC generated by a motor control method and a control device according to the present invention.

FIG. 2 is a graph showing an example of waveform patterns of a target speed VC and a current motor speed VP generated by the motor control method and the control device according to the present invention.

FIG. 3 is a block diagram illustrating a schematic configuration of the inkjet printer.

FIG. 4 is a perspective view showing a configuration around a carriage 3 of the inkjet printer.

FIG. 5 is an explanatory view schematically showing a configuration of a linear encoder 11 attached to a carriage 3.

FIG. 6 is a timing chart showing waveforms of two output signals of the encoder 11 during forward rotation and reverse rotation of the CR motor.

FIG. 7 is a perspective view showing a portion related to paper feeding and paper detection.

FIG. 8 is a block diagram showing a configuration of a DC unit 6 which is a conventional DC motor control device.

FIG. 9 shows a CR motor 4 controlled by a DC unit 6.
4 is a graph showing motor current and motor speed of FIG.

FIG. 10 is a graph showing a target speed near a target stop position and a current speed in control by a conventional DC motor control method and control device.

[Explanation of symbols]

 1 Paper feed motor (PF motor) 2 Paper feed driver 3 Carriage 4 Carriage motor (CR motor) 5 Carriage motor driver (CR motor driver) 6 DC unit 6a Position calculator 6b Subtractor 6c Target speed calculator 6d Speed calculator 6e Subtractor 6f Proportional element 6g Integral element 6h Differential element 6j D / A converter 7 Pump motor 8 Pump motor driver 9 Recording head 10 Head driver 11 Linear encoder 12 Code plate 13 Encoder (rotary encoder) 15 Paper detection sensor 16 CPU 17 Timer IC 18 Host computer 19 Interface unit 20 ASIC 21 PROM 22 RAM 23 EEPROM 25 Platen 30 Pulley 31 Timing belt 32 Carriage motor guide member 34 Ink cartridge 35 Capping device 36 Pump unit 37 Cap 50 Recording paper

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) FB03 FD12 GG04 HH02

Claims (20)

[Claims] 1. The maximum speed of a motor to be controlled is Vma
Assuming that x is the deceleration control section distance from the deceleration control section start position to the target stop position, and N is the distance from the deceleration control section start position to the current position, the following equation VC = Vmax ｛1- ( x / N) ^a ｝ (a is an arbitrary constant) to generate a waveform pattern of the target speed VC represented by:
A motor control method, wherein deceleration control of the motor is performed based on the waveform pattern of the target speed VC. 2. The method according to claim 1, wherein the value of the arbitrary constant a is set for each deceleration control section in accordance with the maximum speed Vmax of the motor, the deceleration control section distance N, and the time of the deceleration control section. The motor control method according to claim 1, wherein: 3. The motor control method according to claim 1, wherein the value of the arbitrary constant a is set to a constant value. 4. The motor control method according to claim 1, wherein the deceleration control is deceleration control for driving the motor in a normal rotation direction. 5. The motor control method according to claim 1, wherein the deceleration control is a deceleration control for driving the motor in a reverse rotation direction. 6. The motor control method according to claim 1, wherein said motor is a DC motor. 7. The motor control method according to claim 1, wherein the motor is a stepping motor. 8. The motor control method according to claim 1, wherein said motor is an AC motor. 9. The motor control method according to claim 1, wherein said motor is a carriage motor of a printer. 10. A motor control method according to claim 1, wherein said motor is a paper feed motor of a printer. 11. The maximum speed of a motor to be controlled is Vma
Assuming that x is the deceleration control section distance from the deceleration control section start position to the target stop position, and N is the distance from the deceleration control section start position to the current position, the following equation VC = Vmax ｛1- ( x / N) ^a ｝ (a is an arbitrary constant) to generate a waveform pattern of the target speed VC represented by:
A motor control device comprising: speed command means for generating and outputting a speed command signal for commanding the target speed VC based on the waveform pattern of the target speed VC. 12. The method according to claim 1, wherein the value of the arbitrary constant a is set for each deceleration control section in accordance with the value of the maximum speed Vmax of the motor, the distance N of the deceleration control section, and the time of the deceleration control section. The motor control device according to claim 11, wherein: 13. The motor control device according to claim 11, wherein the value of the arbitrary constant a is set to a constant value. 14. The motor control device according to claim 11, wherein the deceleration control is a deceleration control for driving the motor in a normal rotation direction. 15. The motor control device according to claim 11, wherein the deceleration control is a deceleration control for driving the motor in a reverse rotation direction. 16. The motor control device according to claim 11, wherein said motor is a DC motor. 17. The motor control device according to claim 11, wherein said motor is a stepping motor. 18. The motor control device according to claim 11, wherein said motor is an AC motor. 19. The motor control device according to claim 11, wherein said motor is a carriage motor of a printer. 20. The motor control device according to claim 11, wherein said motor is a paper feed motor of a printer.