JP2001251878A - Motor control unit and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control unit and a control method where positioning accuracy of the stop position of an object to be driven of a motor is high. SOLUTION: This motor control unit is equipped with a stop position predicting control which commands current flow cutoff to a motor. When the object to be driven reaches a speed measurement position which is this side of an aimed stop position of the object by a prescribed distance, the command is outputted after a prescribed time, corresponding to the present speed of the motor starting from the time the object reaches the measurement position. This motor control method commands current flow cutoff to the motor, after a prescribed time when the object reaches the speed measurement position which prescribed time corresponds to the present speed of the motor, when the object reaches the speed measurement position which is this side of the aimed stop position of the object by the prescribed distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device and a control method, and more particularly to a motor control device and a control method for performing stop position prediction control at the end of a deceleration control section.

[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. 6 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. 7 is a perspective view showing the configuration around the carriage 3 of the ink jet printer.

[0007] As shown in FIG. 7, the carriage 3 is connected to the carriage motor 4 via a pulley 30 by a timing belt 31, and is driven by a guide member 32 to move in parallel with 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 openings of the recording head 9 during non-printing and a pump unit 36 having the pump motor 7 shown in FIG. 6 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. 8 is an explanatory diagram schematically showing the configuration of the linear encoder 11 mounted on the carriage 3. As shown in FIG.

The encoder 11 shown in FIG. 8 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. 9 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. 9 (a) and 9 (b), the pulse ENC is used in 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. 9B, 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 reverse, 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 rotary encoder 13 for the PF motor 1 is 1/180 inch. The paper is fed by 1440 inches.

FIG. 10 is a perspective view showing a portion related to sheet feeding and sheet detection. The position of the paper detection sensor 15 shown in FIG. 6 will be described with reference to FIG. In FIG. 10, the printing paper 50 inserted into the paper feeding slot 61 of the printer 60 is fed into the printer 60 by the paper feeding roller 64 driven by the paper feeding motor 63. The leading end of the printing paper 50 sent into the printer 60 is detected by, for example, an optical paper detection sensor 15. The paper 50 whose leading end is detected by the paper detection sensor 15 is the PF motor 1
Feed roller 65 and driven roller 66 driven by
Paper feed is performed.

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 rotary shaft of the paper feed roller 65 includes a rotary encoder 13.
Are connected.

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. 11 is a block diagram showing a configuration of a DC unit 6 which is a conventional DC motor control device. FIG. 12 is a block diagram showing a CR motor 4 controlled by the DC unit 6.
5 is a graph showing motor current and motor speed of FIG.

The DC unit 6 shown in FIG. 11 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. 12A and 12B, D
The operation of the C 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 start of the CR motor 4 (FIGS. 12A and 12B).
reference). 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. 1).
2 (b)). Therefore, the current value supplied to the CR motor 4 has a step shape as shown in FIG. still,
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
The motor 5 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. 12A).

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. 12)
(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. 12 (b)), the position deviation becomes smaller and the target speed also becomes smaller, so that the speed deviation, ie, the subtractor 6e Becomes negative, the DC motor 4 is decelerated, and stops at time t6.

[0040]

However, in the conventional motor control device and control method, the motor is energized until the object to be driven by the motor reaches the target stop position. This is reflected in the positioning accuracy of the stop position of the object, and when the variation in the motor speed is large, there is a problem that the positioning accuracy of the stop position of the driving object may be reduced.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a motor control device and a control method with high positioning accuracy of a stop position of an object to be driven by a motor.

[0042]

According to the motor control device of the present invention, a predetermined condition when the driving object reaches a predetermined position a predetermined distance before the target stop position of the driving object of the motor is satisfied. A stop position prediction control unit for instructing the motor to be de-energized after the drive target reaches the predetermined position for a predetermined period of time.

According to a more specific configuration of the motor control device according to the present invention, the motor when the driving object reaches a speed measurement position a predetermined distance before the target stop position of the driving object of the motor. For a predetermined time according to the current speed, after the drive target reaches the speed measurement position, a stop position prediction control unit that instructs the motor to cut off the current is provided, Accordingly, it is possible to eliminate the influence of the variation in the motor speed on the positioning accuracy of the stop position of the driven object, and to improve the positioning accuracy of the stopped position of the driven object.

The predetermined time is set to a value within a range in which a command to cut off the power supply to the motor is issued before the driven object reaches the target stop position.

According to a more specific configuration of the motor control device according to the present invention, the current position of the object to be driven by the motor is calculated based on the encoder pulse output from the encoder in response to the rotation of the motor. A position calculating section for outputting, a speed calculating section for calculating and outputting a current speed of the motor based on the encoder pulse, and a target stop of the driving object based on outputs of the position calculating section and the speed calculating section. A predetermined time corresponding to the current speed of the motor when the drive target reaches the speed measurement position a predetermined distance before the position, and after the drive target reaches the speed measurement position for a predetermined time corresponding to the current speed of the motor, the motor And a stop position prediction control unit that outputs an energization disconnection command signal for instructing energization disconnection to the motor.

The predetermined time is set to a value within a range in which the power-off command signal is output before the driven object reaches the target stop position.

It is preferable that the apparatus further comprises a data storage section for storing data on a relationship between the current speed of the motor and the predetermined time when the object reaches the speed measurement position.

It is preferable that the stop position prediction control section measures the predetermined time by counting the number of encoder pulses. Alternatively, the stop position prediction control unit may measure the predetermined time by counting the number of pulses of a predetermined clock.

It is preferable that the output destination of the energization disconnection command signal is a drive signal generation unit that generates a drive signal for driving the motor to rotate.

The value of the predetermined time is set so that the driven object stops at the target stop position.

The predetermined time changes in inverse proportion to the current speed of the motor when the object reaches the speed measurement position.

According to the motor control method of the present invention, the motor is driven for a predetermined time according to a predetermined condition when the driving object reaches a predetermined position a predetermined distance before the target stop position of the driving object of the motor. An instruction to cut off the power supply to the motor is issued after the drive target reaches the predetermined position.

According to a more specific configuration of the motor control method according to the present invention, the motor when the driving object reaches a speed measurement position a predetermined distance before the target stop position of the driving object of the motor. For a predetermined time according to the current speed of the drive object, after the drive object has reached the speed measurement position, a command to cut off the power supply to the motor is issued. With this configuration, the stop position of the drive object is The influence of the variation in the motor speed on the positioning accuracy can be eliminated, and the positioning accuracy of the stop position of the driven object can be improved.

According to a more specific configuration of the motor control method according to the present invention, the current position of the object to be driven by the motor is measured, and the current position of the object to be driven is set to a speed measurement position a predetermined distance before the target stop position of the object to be driven. A first step of monitoring whether the driving object has reached, a second step of measuring the current speed of the motor when the driving object reaches the speed measurement position, and the speed measurement position A third step of determining a predetermined time according to the current speed of the motor when the driving object has reached, and the predetermined time after the driving object has reached the speed measurement position, And a fourth step of instructing a disconnection of current to the motor.

In order to determine the predetermined time, data on the relationship between the current speed of the motor and the predetermined time when the driving object reaches the speed measurement position is collected and stored in advance. Good.

It is assumed that the predetermined time is determined so as to instruct the motor to cut off the power supply before the object to be driven reaches the target stop position.

The predetermined time is determined so that the object to be driven stops at the target stop position.

The predetermined time changes substantially in inverse proportion to the current speed of the motor when the object reaches the speed measurement position.

The predetermined time may be measured by counting the number of encoder pulses output from the encoder in accordance with the rotation of the motor. Alternatively, the predetermined time may be measured by counting the number of pulses of a predetermined clock.

In the motor control device and control method according to the present invention, the motor may be any one of a DC motor, a stepping motor and an AC motor.

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

[0062]

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

FIG. 1 is a block diagram showing a configuration of a motor control device according to the present invention, FIG. 2 is a flowchart showing a procedure of a motor control method according to the present invention, and FIG. 4 is a graph showing a relationship between a current speed and a time (number of pulses) from when the current speed of the motor is measured to when a command to cut off the current supply to the motor is issued.

According to the motor control device and the control method of the present invention, the speed measurement position is set in advance by a predetermined distance from the target stop position of the object to be driven by the motor, and the object to be driven by the motor reaches the speed measurement position. After that, the power supply to the motor is instructed after a time corresponding to the current speed of the motor measured. That is, when the energization of the motor is cut off before the object driven by the motor reaches the target stop position, the object driven by the motor measures the speed at which the object driven by the motor stops exactly at the target stop position. This is to accurately predict from the current speed of the motor when the position is reached, and to instruct the motor to cut off the current at the time determined by the prediction. The time from the measurement of the current speed of the motor to the command to cut off the current to the motor is measured by the number of encoder pulses or the number of clock pulses.

The configuration of the motor control device according to the present invention shown in FIG. 1 is a configuration in a case where the motor to be controlled is a DC motor. Specifically, the stop position prediction control unit 60 is added to the normal DC unit 6, and the stop position prediction control unit 60 includes the output of the position calculation unit 6a and the speed calculation unit 6d, the output of the encoder 11, or the clock. Is entered. FIG. 1 shows a state in which both the output of the encoder 11 and the clock are input to the stop position prediction control unit 60, but only one of the output and the clock of the encoder 11 is input as necessary. You may do so. The stop position prediction control unit 60 has a function as a counter, and measures time based on the number of encoder pulses or the number of clock pulses.

The operation of the motor control device according to the present invention, that is, the procedure of the motor control method according to the present invention will be described with reference to FIGS.

When the motor control device and the control method according to the present invention are implemented, the speed measurement position is set in advance by a predetermined distance from the target stop position of the object to be driven by the motor. In addition, according to the current speed of the motor measured when the object to be driven by the motor reaches the speed measurement position, how long after the current speed of the motor is measured, the power supply to the motor is cut off. Whether the driven object stops at the target stop position is accurately measured by experiments, simulations, and the like, and sufficient data is collected and stored in one of the following units. This data may be provided, for example, with a memory provided inside the stop position prediction control unit 60, or may be provided with a memory provided outside the stop position prediction control unit 60, and may be read out by the stop position prediction control unit 60. You may do so. Stop position prediction control unit 6
When a memory is provided externally to store data, a dedicated memory may be provided so that the data can be read out to the stop position prediction control unit 60, or the ASIC 20, the PROM 21, the RAM 22, the EEPRO in FIG.
M23 and may be read out to the stop position prediction control unit 60 via the CPU 16.

The graph of FIG. 3 shows the current speed of the motor at the speed measurement position and the time from when the current speed of the motor is measured until the command to cut off the current to the motor (hereinafter referred to as “power cut-off command time”). Is shown.) Note that the energization disconnection command time is measured by the number of encoder pulses or the number of clock pulses as described above.

Here, the speeds are set to V01, V02, V03, V0.
4, V05 (V01 <V02 <V03 <V04 <V05). Then, the energization cutoff command time (the number of pulses) is determined depending on which section includes the measured current speed of the motor. Specifically, the current speed of the motor at the speed measurement position is 5 pulses after V01 or less, 4 pulses after V01 and V02 or less, 3 pulses after V02 and V03 or less, and V03. It is set to instruct the motor to cut off the power supply to the motor two pulses after exceeding V04, one pulse after exceeding V04 and below V05, and immediately after exceeding V05. As described above, the energization disconnection command time changes substantially in inverse proportion to the current speed of the motor when the driving target reaches the speed measurement position. However, when the energization cutoff command time is measured by the number of encoder pulses or the number of clock pulses, the energization cutoff command time changes stepwise. Further, even when the energization cutoff command time takes the maximum value, it is necessary to set the energization cutoff command to the motor before the drive target reaches the target stop position.

When the energization disconnection command time is measured by the number of encoder pulses during an experiment or simulation for data collection, the actual control operation is also measured by the number of encoder pulses to perform the experiment or simulation for data collection. When the energization disconnection command time is measured by the number of clock pulses in the case of the above, the actual control operation is also measured by the number of clock pulses. This is because the interval between the clock pulses always has a fixed value according to the setting, but since the interval between the encoder pulses varies according to the current speed of the motor, it is necessary to match them.

Since the stop position prediction control unit 60 measures the energization cutoff command time by the number of encoder pulses or the number of clock pulses, it must have a function as a counter as described above.

As described above, the motor control device and the control method according to the present invention are implemented after setting the speed measurement position, collecting and storing the data of the power-off command time in advance.

After the start of the drive control of the motor, the stop position prediction control unit 60 monitors whether or not the object to be driven by the motor has reached the speed measurement position based on the output of the position calculation unit 6a (step S1). When the motor reaches the position, the current speed of the motor is measured by the output of the speed calculator 6d (step S2).

Then, the stop position prediction control unit 60 determines, based on the data on the relationship between the current speed of the motor at the speed measurement position and the energization cutoff command time, how many pulses after the current motor speed is measured. A command to turn off the power is issued, that is, a time for commanding to turn off the power is determined (step S3). The data on the relationship between the current speed of the motor and the energization disconnection command time is made available in advance to the stop position prediction control unit 60 at any time.

The stop position prediction control section 60 determines the energization cutoff command time and immediately starts measuring the time.
That is, the number of pulses of either the output of the encoder 11 or the clock selected in advance is counted. When the count value of the number of pulses reaches the number of pulses corresponding to the determined energization cutoff command time, the stop position prediction control unit 60
An energization disconnection command signal for instructing the / A converter 6j to energize the motor is output (step S4). As a result, the power supply to the motor is cut off, the motor decelerates, and the object driven by the motor stops at the target stop position. In order to more accurately position the object to be driven by the motor at the target stop position, braking control such as a short brake may be used in combination during stop control.

As described above, in the motor control device and the control method according to the present invention, when the driving object reaches the speed measurement position a predetermined distance before the target stop position of the driving object of the motor, the motor The motor and its drive are controlled by measuring the current speed of the motor and controlling the motor to be turned off at a position before the target stop position of the driven object after the power-off command time corresponding to the current speed. Since the object is stopped, the influence of variation in the motor speed on the positioning accuracy of the stop position of the driving object can be eliminated, and the positioning accuracy of the stop position of the driving object can be improved.

In the above description, the case where the motor control device according to the present invention is a DC motor control device, that is, the case where the motor to be controlled is a DC motor, has been described. The control method can be similarly applied when the control target motor is a stepping motor, an AC motor, or the like.

In these cases, the procedure of the motor control method according to the present invention is the same, and the basic configuration of the motor control device according to the present invention is the same. That is, based on an encoder pulse output from the encoder in response to the rotation of the motor, a position calculation unit that calculates and outputs the current position of the object to be driven by the motor, and calculates a current speed of the motor based on the encoder pulse. The current speed of the motor when the driving object reaches the speed measurement position a predetermined distance before the target stop position of the driving object based on the outputs of the speed calculation unit and the position calculation unit and the speed calculation unit. For a predetermined period of time, after the drive target reaches the speed measurement position,
And a stop position prediction control unit that outputs an energization disconnection command signal for instructing the energization disconnection to the motor. The output destination of the energization disconnection command signal differs depending on the type of motor, but is common in that it is a drive signal generation unit that generates a drive signal for driving the motor to rotate. The drive signal generation unit is a drive signal generator when the motor to be controlled is a DC motor.
/ A converter.

When the motor control device and the control method according to the present invention are applied to a printer, the motor to be controlled is mainly a paper feed motor, but may be a carriage motor.

When the motor control device and the control method according to the present invention are applied to a printer, the power supply disconnection command time is determined not only by the current speed of the motor when the drive target reaches the speed measurement position, but also by the remaining ink. The amount may be changed according to the amount, type of recording paper, printer use frequency, environmental temperature, environmental humidity, and other conditions.

For example, in the case where the motor to be controlled is a paper feed motor, a sensor for detecting a predetermined condition used for changing the energization disconnection command time, for example, the type of recording paper, the frequency of use of the printer, the environmental temperature, the environmental humidity, etc. It is attached to the carriage 3. Note that the type of recording paper is not detected by a sensor, but is set in advance according to the type of recording paper to be used as a part of a predetermined condition used for changing the power-off command time on the motor control device side. It may be performed. When the motor to be controlled is a carriage motor, the carriage 3 is provided with sensors for detecting predetermined conditions used for changing the power-off command time, for example, the remaining amount of ink, printer use frequency, environmental temperature, environmental humidity, and the like. deep.

Then, the predetermined condition detected by the sensor is sent to the stop position prediction control unit 60, and the stop position prediction control unit 60 responds to the current speed of the motor when the drive target reaches the speed measurement position. When determining the energization cutoff command time, the correction based on the received predetermined condition is performed, and then the energization cutoff command time is determined.

Alternatively, the predetermined condition detected by the sensor is sent to a memory storing data on the power-off command time, and the data on the power-off command time is changed by correction based on the predetermined condition. You may do so. Thereby, the stop position prediction control unit 60
Determines the energization disconnection command time based on the changed data according to the current speed of the motor when the drive target reaches the speed measurement position.

Therefore, the conditions for determining the energization disconnection command time by the motor control device and the control method according to the present invention are not limited to the current speed of the motor at the time when the drive target reaches the speed measurement position, but may be various. Conditions can be used.
The means for detecting the condition is, as in the above example,
It is provided in advance.

That is, when the configuration of the motor control device according to the present invention is generalized, the predetermined condition when the driving object reaches a predetermined position a predetermined distance before the target stop position of the driving object of the motor is satisfied. A stop position prediction control unit for instructing to cut off the power supply to the motor after the drive target reaches the predetermined position for a predetermined period of time. Similarly, when the configuration of the motor control method according to the present invention is generalized, the motor control method according to the predetermined condition when the drive target reaches a predetermined position a predetermined distance before the target stop position of the drive target of the motor. It is characterized in that a command to cut off the power supply to the motor is issued after the drive target has reached the predetermined position for a predetermined time.

FIG. 4 is an explanatory view showing a recording medium on which a computer program for executing the motor control method according to the present invention is recorded, and an external configuration of a computer system using the recording medium. FIG. 3 is a block diagram showing a configuration of the computer system shown in FIG. A computer system 70 shown in FIG. 4 includes a computer main body 71 housed in a mini-tower type or the like housing and a CRT (Cath
ode Ray Tube: a display device 72 such as a cathode ray tube, a plasma display, a liquid crystal display device, a printer 73 as a recording output device, a keyboard 74a and a mouse 74b as input devices, a flexible disk drive device 76, and a CD-ROM. And a ROM drive device 77. FIG. 5 is a block diagram showing the configuration of the computer system 70. A RAM (Random Acc.
An internal memory 75 such as an ess memory and an external memory such as a hard disk drive unit 78 are further provided. A recording medium on which a computer program for executing the motor control method according to the present invention is recorded is used in the computer system 70. As a recording medium, for example, a flexible disk 81, a CD-ROM (Read
Only Memory) 82 is used.
gneto Optical) Disc, DVD (Digital Versatile)
Disk), other optical recording disks, card memories, magnetic tapes, and the like.

[0087]

According to the motor control device of the present invention,
The driving object moves to the speed measurement position for a predetermined time corresponding to the current speed of the motor when the driving object reaches a speed measurement position a predetermined distance before the target stop position of the motor driving object. Since the stop position prediction control unit for instructing the power supply to the motor to be turned off after the time is reached, it is possible to eliminate the influence of the variation in the motor speed on the positioning accuracy of the stop position of the driving object, and The positioning accuracy of the stop position of the object can be improved.

According to the motor control method of the present invention, the motor control method is based on the current speed of the motor when the drive object reaches a speed measurement position a predetermined distance before the target stop position of the motor drive object. Since a command to cut off the power supply to the motor is issued only after the drive object reaches the speed measurement position for a predetermined time, the influence of the variation in the motor speed on the positioning accuracy of the stop position of the drive object is eliminated. The positioning accuracy of the stop position of the driven object can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a motor control device according to the present invention.

FIG. 2 is a flowchart showing a procedure of a motor control method according to the present invention.

FIG. 3 is a graph showing a relationship between a current speed of a motor and a power-off command time (number of pulses) at a speed measurement position.

FIG. 4 is an explanatory diagram showing a recording medium on which a computer program for executing a motor control method according to the present invention is recorded and an external configuration of a computer system using the recording medium.

FIG. 5 is an exemplary block diagram showing the configuration of the computer system shown in FIG. 4;

FIG. 6 is a block diagram illustrating a schematic configuration of an inkjet printer.

FIG. 7 is a perspective view showing a configuration around a carriage 3 of the inkjet printer.

FIG. 8 is an explanatory diagram schematically showing a configuration of a linear encoder 11 attached to a carriage 3.

FIG. 9 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. 10 is a perspective view showing a portion related to paper feeding and paper detection.

FIG. 11 is a block diagram showing a configuration of a DC unit 6 which is a conventional DC motor control device.

FIG. 12 is a graph showing the motor current and the motor speed of the CR motor 4 controlled by the DC unit 6.

[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 60 Stop position prediction control unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02P 5/00 H02P 5/00 X F term (Reference) 2C480 CA01 CA02 CA10 CA31 CA40 CA44 CA47 CB02 CB31 CB35 CB45 DA04 EA08 EA26 EA27 EB03 3F048 AA05 BA21 BB02 BC08 CC02 CC03 DC06 EB33 5H530 AA12 BB12 BB14 CC02 CD02 CD13 CD24 CD28 CD36 CF01 5H550 AA15 DD04 DD06 DD07 FF03 FF04 FF05 GG02 GG03 JJ03 JJ17 JJ14 JJ17 JJ16 JJ17 JJ14 JJ17

Claims (18)

[Claims] 1. The driving object moves to the predetermined position for a predetermined time according to a predetermined condition when the driving object reaches a predetermined position a predetermined distance before a target stop position of the driving object of the motor. A motor control device comprising: a stop position prediction control unit that instructs the motor to cut off the current after reaching the stop position. 2. A method according to claim 1, wherein the driving object reaches a speed measurement position a predetermined distance before the target stop position of the driving object of the motor.
A motor control device comprising: a stop position prediction control unit that instructs the motor to cut off the current after the drive target reaches the speed measurement position. 3. The system according to claim 1, wherein the predetermined time is set to a value within a range in which a command to cut off the power supply to the motor is issued before the driven object reaches a target stop position. 3. The motor control device according to 2. 4. A position calculating section for calculating and outputting a current position of an object to be driven by the motor based on an encoder pulse output from an encoder in accordance with a rotational drive of the motor; A speed calculating unit that calculates and outputs the current speed of the driving object; and Stop for outputting an energization disconnection command signal for instructing the energization disconnection to the motor after a predetermined time corresponding to the current speed of the motor when the motor reaches the speed measurement position after the drive target reaches the speed measurement position. A motor control device comprising: a position prediction control unit. 5. The system according to claim 4, wherein the predetermined time is set to a value within a range in which the energization disconnection command signal is output before the driven object reaches a target stop position. 3. The motor control device according to claim 1. 6. A data storage unit for storing data on a relationship between a current speed of the motor and the predetermined time when the drive target reaches the speed measurement position. Item 6. The motor control device according to item 4 or 5. 7. The apparatus according to claim 4, wherein the stop position prediction control section measures the predetermined time by counting the number of pulses of the encoder pulse. Motor control device. 8. The motor according to claim 4, wherein the stop position prediction control section measures the predetermined time by counting the number of pulses of a predetermined clock. Control device. 9. The motor control according to claim 4, wherein the output destination of the energization disconnection command signal is a drive signal generation unit that generates a drive signal for rotating the motor. apparatus. 10. The apparatus according to claim 2, wherein the predetermined time changes in inverse proportion to a current speed of the motor when the driving object reaches the speed measurement position. The motor control device according to any one of the above. 11. The motor control according to claim 1, wherein the predetermined time is set so that the driven object stops at a target stop position. apparatus. 12. The motor control device according to claim 1, wherein said motor is a paper feed motor of a printer. 13. The driving object moves to the predetermined position for a predetermined time according to a predetermined condition when the driving object reaches a predetermined position a predetermined distance before a target stop position of the motor driving object. A motor control method, comprising issuing a command to cut off the power supply to the motor after the time has been reached. 14. A method according to claim 1, wherein the driving object is driven for a predetermined time corresponding to a current speed of the motor when the driving object reaches a speed measurement position a predetermined distance before the target stop position of the driving object of the motor. A motor control method, wherein a command to cut off the power supply to the motor is issued after reaching the speed measurement position. 15. A first method for measuring a current position of an object to be driven by a motor and monitoring whether or not the object to be driven has reached a speed measurement position a predetermined distance before a target stop position of the object to be driven. A second step of measuring a current speed of the motor when the driving object reaches the speed measurement position; and a current speed of the motor when the driving object reaches the speed measurement position. A third step of determining a predetermined time according to the following step; and a fourth step of instructing the motor to cut off the current after the predetermined time from when the driven object reaches the speed measurement position. A motor control method, comprising: 16. In order to determine the predetermined time, data on a relationship between a current speed of the motor when the driving object reaches the speed measurement position and the predetermined time is collected and stored in advance. The motor control method according to claim 14 or 15, wherein: 17. The motor control method according to claim 13, wherein said motor is a paper feed motor of a printer. 18. A recording medium for a computer program, wherein a computer program for executing the motor control method according to claim 13 in a computer system is recorded.