JP3060473U - Motor control device - Google Patents

Abstract

(57) [Summary] (With correction) [Problem] A system RO for storing a Ramp table
The area of M is reduced. A CPU calculates a rotation speed as a function of a step and stores the rotation speed in a RAM. For example, when a power-on reset signal or a reset signal is received, a coefficient is set to a constant corresponding to the 9-ips Ramp table of the carrier motor, and the calculation is performed by the calculating means 1a to obtain a 9-ips Ramp table. Store to 2a.
Subsequently, a constant corresponding to the 15-ips Ramp table of the carrier motor is set as a coefficient, and the calculation is performed by the calculating means 1a, and the obtained 15-ips Ramp table is stored in the Ramp table storage area 2a. The same applies to the carrier motor Ra for 23ips.
The mp table, the Samp ramp table for the feed motor, the Ramp table for the middle of the feed motor, and the Ramp table for the high of the feed motor were sequentially obtained.
The Ramp table is stored in the Ramp table storage area 2a.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention is characterized in that a motor control device for driving and controlling a pulse motor, in particular, a drive speed is set based on a table in which a rotation speed corresponding to a speed pattern of a pulse motor is stored for each drive control step and drive control is performed. Motor control device.

[0002]

[Prior art]

 A pulse motor is an electric motor used for converting the number of pulses into displacement, and has a configuration in which a rotor rotates by a predetermined angle in response to an elementary pulse of a given pulse signal. This angle is called a basic step angle. Specifically, when an elementary pulse is given, a predetermined amount of current is supplied to the stator, ie, the electromagnet, corresponding to the rotor stop position at that time and a target stop position determined from a preset rotation direction. The rotor is excited and the magnetic poles of the rotor are attracted and stopped. When distinguishing such a current supply state to the electromagnet by its target stop position, each state is called a phase. Further, by switching the phases in accordance with a predetermined sequence in accordance with the continuously supplied pulse signals, the rotor can be rotatably controlled.

The above-described pulse motor is easily used in a carriage drive mechanism (carrier motor) and a paper feed mechanism (feed motor) in a printing apparatus such as a thermal transfer printer or a serial printer because of its easy digital control. Have been.

FIG. 4 is a velocity diagram for explaining the concept of the drive control of the pulse motor, in which the horizontal axis corresponds to time, and the vertical axis corresponds to the rotation speed of the pulse motor. Of the rotational speed set as a target with the lapse of time.

[0005] In the figure, acceleration driving is performed during a period from time T0 to time T1 at which the speed line shows an upward gradient. The rotation speed of the pulse motor is proportional to the number of elementary pulses per unit time of the pulse signal. In other words, the rotation speed is inversely proportional to the interval between adjacent pulses of the pulse signal. Therefore, control is performed such that the period of the pulse signal is gradually shortened during this period. During the period from time T1 to time T2 when the speed line is level, constant speed driving for driving while keeping the rotation speed constant is performed. That is, during this period, the period of the pulse signal is kept constant.

[0006] During the period from time T2 to time T3 at which the speed line shows a downward slope, deceleration driving is performed. That is, control is performed so that the period of the pulse signal gradually increases during this period. For example, if the period of the pulse signal is 1 when the drive of the pulse motor is controlled at a rotation speed of 1600 pps, the rotation speed is reduced to 1200 pps by setting the period of the pulse signal to 4/3. By setting the cycle of the pulse signal to 2, the rotation speed is reduced to 800 pps. Further, by setting the period of the pulse signal to 4, the speed is reduced to 400 pps.

The cycle of the pulse signal is set based on a ramp table stored in a system ROM. The Ramp table stores the Ramp data representing the rotation speed corresponding to the speed pattern for each drive control step. When the drive control is performed in a plurality of speed patterns, the Ramp table corresponding to each of the Ramp tables is stored. Have prepared. Each Ramp table is read at the time of initialization, and is written to the RAM, which has a higher read operation speed than the ROM. Each time one step of drive control is performed, new ramp data is read from the RAM and used for setting the cycle of the pulse signal in the next step. That is, the area of the system ROM in which the Ramp table is stored is not read out at the time of drive control and is in an idle state.

A facsimile apparatus proposed in Japanese Patent Application Laid-Open No. 5-122470 is an invention characterized by a storage form of a plurality of tables related to drive control, wherein a slave CPU controlled by a host CPU controls a motor. In a facsimile apparatus that performs drive control, a plurality of acceleration information tables corresponding to speed patterns are stored in the host CPU side, and a required acceleration information table is selected and transferred prior to reading of a transmission original, thereby enabling It is an object of the present invention to reduce a burden on a slave CPU having a limited memory capacity.

[0009] By the way, reduction of the number of parts contributes to reduction of the manufacturing cost, and is recognized as an important issue by manufacturers. As a specific example, it is possible to reduce the memory capacity of an area in an idle state during drive control as described above.

A control device for a stepping motor proposed in Japanese Patent Application Laid-Open No. 3-139198 is an invention relating to a reduction in a memory capacity for speed control of a stepping motor (pulse motor). From one timing table (Ramp table) that indicates the switching cycle of the excitation signal corresponding to the pattern, a timing table corresponding to a plurality of speed patterns is created based on predetermined parameters and a calculation method. The purpose of this is to save the memory capacity for storing the timing table.

[0011]

[Problems to be solved by the invention]

 The effect of saving memory capacity by the above-described stepping motor control device does not extend to the memory capacity for storing one timing table that is the basis of a plurality of created timing tables. Therefore, as described above, in a situation where the Ramp table is read from the system ROM, temporarily written to the RAM, and then the Ramp table is read from the RAM again, the area of the system ROM where the Ramp table is idle during drive control is stored. There was room for reduction. In addition, since rewriting is impossible if the Ramp table is stored in the system ROM, it is difficult to perform the change because it is necessary to replace the system ROM before the change with a new system ROM.

The present invention has been made in view of such circumstances, and it is possible to reduce the capacity of a system ROM for storing a ramp table, and to easily cope with a change in the ramp table. It is an object of the present invention to provide a motor control device as described above.

[0013]

[Means for Solving the Problems]

 The motor control device according to the first invention has storage means for storing each step of drive control and the rotation speed of the motor in association with each other, and obtains the rotation speed by referring to the storage means according to the step. In the motor control device that generates a pulse signal corresponding to the rotation speed and supplies the pulse signal to the motor to perform drive control, prior to the start of the drive control, the rotation of the motor given in advance as a function of the step of the drive control is performed. There is provided a means for calculating a rotational speed of the motor associated with each step using a speed calculation formula, and storing the obtained rotational speed in the storage means.

Hereinafter, a method of designing a calculation formula will be described. First, for a driving mechanism of an actual machine, for example, a carrier motor of a carriage driving mechanism, the cycle of a pulse signal is variously changed, and a corresponding rotation speed is measured. The speed diagram of the actually measured values is approximated using a polynomial to obtain a correlation function between each step of the drive control and the rotation speed of the motor. Further, the correlation function is simplified in order to reduce the processing load of the operation. The following is an example of a simplified correlation function.

Equation 1 shows the drive control steps s derived based on the actual measured value when accelerating the carrier motor at a target speed of 3450 pps when converted to a transport speed of 23 ips (inch per second), that is, a rotational speed. This is a correlation function with the rotation speed of the motor. Speed ^{= {10 4 / (s +} 1)} + 210 ... ( Equation 1)

A ramp table is obtained using the rotational speed calculation formula thus obtained, and the motor is driven and controlled in accordance with the table. Also, by replacing the constant part of the correlation function similarly obtained for other measurement conditions with a coefficient, and substituting the constant selected according to the target rotation speed into the coefficient, one correlation function can be obtained. Multiple Ramp tables can be determined.

In this invention, the rotational speed of the motor associated with each step of the drive control is obtained using a given calculation formula, stored in the storage means, and obtained by referring to the storage means according to the step. Since the drive of the motor is controlled at the adjusted rotation speed, the area for storing the Ramp table in the system ROM can be reduced.

A motor control device according to the second invention generates a pulse signal corresponding to a predetermined rotation speed of a motor, and supplies the pulse signal to the motor to perform drive control. Accordingly, the apparatus includes means for determining the motor rotation speed using a motor rotation speed calculation formula given in advance as a function of the drive control step, and means for generating a pulse signal corresponding to the determined rotation speed. It is characterized.

In the present invention, the rotational speed of the motor associated with each step of the drive control is determined using a given formula, and the drive of the motor is controlled at the determined rotational speed. The area for storing the table can be reduced, and the area for storing the rotation speed of the motor associated with the drive control step can be reduced.

[0020]

[Embodiment of the invention]

 FIG. 1 is a block diagram showing the configuration of the motor control device according to the present invention. In the figure, a CPU 1 is provided with a program unit as a calculation unit 1a for obtaining a rotational speed of a motor associated with each step of drive control using a given calculation formula. The calculation result by the calculation means 1a, that is, Ramp data, is given to the RAM 2 and stored in the Ramp table storage area 2a. The Ramp data stored in the Ramp table storage area 2a can be read by the pulse generation circuit 3. The pulse generation circuit 3 is connected to a phase register 4 for storing phase information of the motor.

The pulse generation circuit 3 is supposed to accept the setting of the high-frequency clock and the driving direction. When a predetermined trigger signal is received, the pulse generation circuit 3 reads out the Ramp data read from the Ramp table storage area 2a of the RAM 2 and the phase register. A pulse signal is generated on the basis of the phase information read out from the drive signal 4 and the received driving direction, and the pulse signal is supplied to the motor driver 5. When receiving the pulse signal, the motor driver 5 supplies a predetermined current to the motor 6 according to the target stop position. Furthermore, each time the pulse generation circuit 3 outputs a pulse signal, it supplies a trigger signal to the phase identification circuit 7. The phase identification circuit 7 must accept the setting of the driving direction. When the trigger signal is accepted, the phase identifying circuit 7 identifies the phase transition based on the set driving direction and stores it in the phase register 4.

FIG. 2 is a flowchart showing a procedure for setting a Ramp table of the motor control device according to the present invention. When the CPU 1 receives the power-on reset signal or the reset signal, the coefficient is set to a constant corresponding to the 9-ips Ramp table of the carrier motor, the calculation is performed by the calculating means 1a, the 9-ips Ramp table is obtained, and the Ramp table storage area of the RAM 2 is obtained. It is stored in the area 2a (S1). Subsequently, a constant corresponding to the 15-ips Ramp table of the carrier motor is set as the coefficient, and the coefficient is calculated by the calculating means 1a, and the obtained 15-ips Ramp table is stored in the Ramp table storage area 2a (S2). In the same manner, the Ramp table for 23 ips of the carrier motor, the Ramp table for Slow of the feed motor, the Ramp table for Middle of the feed motor, and the Ramp table for High of the feed motor are sequentially obtained in the same manner, and each time the obtained Ramp table is obtained. It is stored in the Ramp table storage area 2a (S3) (S4) (S5) (S6).

The setting of a constant according to a required ramp table is received in advance by a device driver or the like, and the device driver gives the constant to the CPU 1 as necessary, and uses a calculation formula based on the constant. By using a configuration that generates a Ramp table, it is possible to respond to changes in the Ramp table by changing the constants set in the device driver, thereby eliminating the need to replace the system ROM with a new one. become.

FIG. 3 is a block diagram showing another configuration of the motor control device according to the present invention. In the figure, the pulse generation circuit 8 is provided with a program unit as a calculation unit 8a for obtaining a rotation speed of a motor associated with each step of drive control using a given calculation formula. The pulse generation circuit 8 is connected to the phase register 4 for storing phase information of the motor.

The pulse generation circuit 3 is supposed to accept the setting of the high-frequency clock and the driving direction. When a predetermined trigger signal is received, the pulse generation circuit 3 computes the Ramp data by the computing means 8a. A pulse signal is generated based on the phase information read from the phase register 4 and the received driving direction, and the pulse signal is supplied to the motor driver 5. Upon receiving the pulse signal, the motor driver 5 supplies a predetermined current to the motor 6 according to the target stop position. The same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

The setting of a constant according to a required Ramp table is received by a device driver or the like, and the constant received by the device driver is given to the pulse generation circuit 8. By using a configuration that generates a table, it is possible to respond to changes in the Ramp table by changing the constants set in the device driver, eliminating the need to replace the system ROM with a new one. become.

The setting of a constant corresponding to a required Ramp table is received in advance by a device driver or the like, and the device driver supplies the constant to the pulse generation circuit 8 as needed, and calculates based on the constant. By using a formula to determine the rotational speed of the motor that is associated with each step of the drive control, it is possible to change the ramp table by changing the constants set in the device driver. Therefore, it is possible to save the trouble of replacing the system ROM with a new one.

[0028]

[Effect of the invention]

 According to the motor control devices of the first invention and the second invention as described above, the rotational speed of the motor associated with each step of the drive control is obtained by using a given calculation formula, stored in the storage means, and according to the step. Thus, since the motor is driven and controlled at the rotation speed obtained by referring to the storage means, an excellent effect can be obtained in reducing the area of the system ROM storing the idle Ramp table during the drive control. In addition, a constant of a calculation formula corresponding to a required speed pattern is given from the device driver, and the rotation speed of the motor associated with each step of the drive control is obtained using the calculation formula based on the constant given by the device driver. The configuration has an excellent effect in facilitating the response when the ramp table is changed.

Further, according to the motor control device of the second invention, the rotation speed of the motor associated with each step of the drive control is obtained using a given calculation formula, and the motor is driven and controlled at the obtained rotation speed. Therefore, an excellent effect is obtained in reducing the area for storing the obtained motor rotation speed.

[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 illustrating a Ramp table setting procedure of the motor control device according to the present invention.

FIG. 3 is a block diagram showing another configuration of the motor control device according to the present invention.

FIG. 4 is a velocity diagram illustrating the concept of drive control of a pulse motor.

[Explanation of symbols]

 1 CPU 1a, 8a arithmetic means 2 RAM 2a Ramp table storage area 3, 8 pulse generation circuit

Claims (2)

[Utility model registration claims] 1. A storage unit for storing each step of drive control and a rotation speed of a motor in association with each other, and obtaining a rotation speed by referring to the storage unit in accordance with the step.
In a motor control device for generating a pulse signal corresponding to the rotation speed and supplying the pulse signal to the motor to perform drive control, a calculation of a motor rotation speed given in advance as a function of a drive control step prior to the start of drive control A motor control device comprising: means for calculating a rotation speed of a motor associated with each step using an equation, and storing the rotation speed in the storage means. 2. A motor control device for generating a pulse signal corresponding to a predetermined rotation speed of a motor and applying the pulse signal to the motor to control the drive, wherein a step of the drive control step is performed in accordance with a transition of the drive control step. What is claimed is: 1. A motor control device comprising: means for obtaining a motor rotation speed using a motor rotation speed calculation formula given in advance as a function; and means for generating a pulse signal corresponding to the obtained rotation speed.