JP7607480B2 - Motor control device and image forming apparatus - Google Patents

Description

The present invention relates to motor control technology.

Motors are used as drive sources for various components of image forming devices. Motor characteristics may differ depending on the type of motor, so image forming devices need to change control parameters depending on the type of motor they are driving. Therefore, image forming devices need to determine the type of motor they are driving. Patent Document 1 discloses a method of measuring the time required to accelerate and decelerate a motor and determining the motor type from the measured time.

JP 2020-44741 A

The method of Patent Document 1 makes it impossible to determine the motor type before starting the motor, which can lead to unstable motor startup.

The present invention provides a technology for determining the motor type before startup and setting appropriate control parameters.

According to one aspect of the present invention, a motor control device includes a voltage application means for applying a voltage to a plurality of coils of a motor having a plurality of coils to pass a coil current through the plurality of coils; a measurement means for measuring a current value of the coil current; a control means for controlling the voltage application means to pass a coil current in each of a plurality of patterns through the plurality of coils and have the measurement means measure the current value of the coil current of each pattern, thereby acquiring measurement information including a plurality of measurement values; and a storage means for storing a plurality of reference information corresponding to a plurality of motor types, the reference information corresponding to the motor types indicating a plurality of reference values. The control means determines a corresponding reference value for each of the plurality of measurement values in the measurement information from the plurality of reference values in the reference information, calculates a difference between each of the plurality of measurement values in the measurement information and the corresponding reference value in the reference information, and calculates an error between the measurement information and the reference information based on the difference calculated for each of the plurality of measurement values in the measurement information, thereby calculating an error between the measurement information and each of the plurality of reference information, and determines the motor type of the motor to be the motor type corresponding to the reference information having the smallest error from the measurement information .

According to the present invention, the motor type can be determined before start-up and appropriate control parameters can be set.

FIG. 1 is a diagram illustrating the configuration of an image forming apparatus according to an embodiment. FIG. 2 is a control configuration diagram of an image forming apparatus according to an embodiment. FIG. 2 is a configuration diagram of a motor control unit according to one embodiment. FIG. 1 is a configuration diagram of a motor according to an embodiment. 6 is a diagram showing a voltage applied to a coil and a change in coil current over time in a rotor stop position detection process according to an embodiment. FIG. 5 is a diagram showing maximum values of coil current for each pattern of coil current at different rotor stop positions; FIG. 5 is a diagram showing maximum values of coil current for each pattern of coil current at different rotor stop positions; FIG. FIG. 1 illustrates a template according to one embodiment. FIG. 4 is a diagram illustrating a method for calculating an error for one template according to an embodiment. 11 is a flowchart of a coil type determination process according to an embodiment. 11 is a flowchart of a coil type determination process according to an embodiment.

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe multiple features, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicate explanations are omitted.

First Embodiment
FIG. 1 is a configuration diagram of an image forming apparatus 10 according to the present embodiment. The image forming apparatus 10 is, for example, a printer, a copier, a multifunction machine, a facsimile, or the like. A sheet stored in a cassette 25 is fed to a sheet conveying path by a feed roller 26. A conveying roller 27 conveys the fed sheet downstream. The image forming unit 1 forms a toner image on an internal image carrier based on image data, and transfers the formed toner image to a sheet. The sheet to which the toner image has been transferred is conveyed to a fixing unit 24. The fixing unit 24 heats and presses the sheet to fix the toner image to the sheet. After the toner image is fixed, the sheet is discharged to the outside of the image forming apparatus 10. A motor 15F is a driving source that drives the roller of the fixing unit 24. The image forming apparatus 10 may also have a motor other than the motor 15F that drives other members.

Figure 2 shows the control configuration of the image forming device 10. The printer control unit 11 controls the entire image forming device 10, including the image forming unit 1 and the fixing unit 24 described above. The printer control unit 11 has a processor (not shown) and a memory for storing programs and various control data. The processor of the printer control unit 11 executes programs stored in the memory of the printer control unit 11 to perform various processes for controlling the image forming device 10. Note that, at that time, the printer control unit 11 uses the control data stored in the memory. The communication controller 21 communicates with the host computer 22 and receives image data of the image formed by the image forming device 10 from the host computer 22. The motor control unit 14 controls the motor 15F under the control of the printer control unit 11.

Figure 3 shows the details of the control configuration of the motor 15F. The motor control unit 14 has a microcomputer (hereinafter referred to as MCU) 51. The MCU 51 communicates with the printer control unit 11 via a communication port 52. The reference clock generating unit 56 of the MCU 51 is connected to the crystal oscillator 50 and generates a reference clock based on the output of the crystal oscillator 50. The counter 54 counts based on the reference clock. The MCU 51 outputs a pulse width modulation signal (PWM signal) from the PWM port 58. In this embodiment, the MCU 51 outputs a total of six PWM signals, including high-side PWM signals (U-H, V-H, W-H) and low-side PWM signals (U-L, V-L, W-L), for each of the three phases (U, V, W) of the motor 15F. For this reason, the PWM port 58 has six terminals: U-H, V-H, W-H, U-L, V-L, and W-L.

Each terminal of the PWM port 58 is connected to a gate driver 61, which controls the ON/OFF of each switching element of the three-phase inverter 60 based on the PWM signal. The inverter 60 has a total of six switching elements, three on the high side and three on the low side for each phase, and the gate driver 61 controls each switching element based on the corresponding PWM signal. For example, a transistor or an FET can be used as the switching element. In this embodiment, when the PWM signal is high, the corresponding switching element is turned ON, and when the PWM signal is low, the corresponding switching device is turned OFF. The output 62 of the inverter 60 is connected to coils 73 (U phase), 74 (V phase), and 75 (W phase) of the motor 15F. By controlling the ON/OFF of each switching element of the inverter 60, the motor current (excitation current) of each coil 73, 74, and 75 can be controlled. In this way, the gate driver 61 and the inverter 60 function as a voltage application unit that applies a voltage to the coils 73, 74, and 75 to pass coil current through the coils 73, 74, and 75. The motor current flowing through each coil 73, 74, and 75 is converted by the resistor 63 into a voltage having a voltage value corresponding to the current value. The voltage value of the resistor 63 is input to the AD converter 53 of the microcomputer 51. The AD converter 53 converts the voltage value (analog value) of the resistor 63 into a digital value. The microcomputer 51 detects the current value of the coil current based on the digital value output by the AD converter 53. In this way, the resistor 63 and the AD converter 53 constitute a measurement unit that measures the current value of the coil current. The microcomputer 51 also has a non-volatile memory 55 and a memory 57 that hold and store various data used to control the motor 15F.

Figure 4 is a diagram of the motor 15F. The motor 15F has a six-slot stator 71 and a four-pole rotor 72. The stator 71 has coils 73, 74, and 75 for each phase. The rotor 72 is made of a permanent magnet and has two sets of north and south poles.

Generally, coils are constructed by winding copper wire around a core made of laminated electromagnetic steel sheets. The magnetic permeability of the electromagnetic steel sheets decreases in the presence of an external magnetic field. Since the inductance of a coil is proportional to the magnetic permeability of the core, as the magnetic permeability of the core decreases, the inductance of the coil also decreases. For example, the U-phase coil 73 in Figure 4 faces only the S pole of the rotor 72, so the rate of decrease in inductance is greater than that of the W-phase coil 75, which faces both the S pole and N pole of the rotor 72.

The amount of change in inductance also differs depending on whether the direction of the magnetic field generated by the coil current is the same as or opposite to the direction of the magnetic field generated by the magnetic poles of the rotor 72. Specifically, in the state shown in FIG. 4, if a coil current is passed through the U-phase coil 73 in the same direction as the magnetic field generated by the opposing S pole of the rotor 72, in other words, so that the U-phase becomes the N pole, the amount of decrease in inductance will be greater than if a coil current is passed through the U-phase to become the S pole. Also, as the inductance changes, the iron loss of the coil changes, and so does the resistance component of the coil.

As described above, the inductance and resistance of the coil, i.e., impedance, change depending on the stop position of the rotor 72 (rotation phase when stopped) and the coil current pattern. In this embodiment, the coil current pattern refers to a pattern specified by two phases (hereinafter, excitation phases) through which coil current flows to excite the motor, and the direction in which the coil current flows. Specifically, in this embodiment, since the motor 15F is three-phase, there are six patterns: "U-V", "U-W", "V-W", "V-U", "W-U", and "W-V". Here, "X-Y" means that the X-phase and Y-phase are excitation phases, and current flows from the X-phase coil to the Y-phase coil. In this embodiment, when the coil current pattern is "X-Y", the X-phase becomes the north pole and the Y-phase becomes the south pole.

Before starting the motor 15F, that is, when the motor 15F starts rotating, the motor control unit 14 needs to detect the stop position (rotation phase) of the rotor. In this embodiment, the motor control unit 14 detects the stop position of the rotor by passing the coil current of the above six patterns in sequence and comparing the maximum value of the coil current in each pattern. First, the PWM signal for passing the coil current of each pattern will be described.

Figure 5 shows the time change in the duty ratio of the PWM signal applied to the U-H terminal and the V-H terminal when the coil current of pattern "U-V" of the six patterns flows, and the time change in the coil current. In section A of Figure 5, the duty ratio of the PWM signal applied to the U-H terminal is changed to a sine wave. Section A corresponds to a half-wave period of a sine wave, and the duty ratio of the PWM signal applied to the U-H terminal is set to 0% at the start and end of section A. Although not shown, in section A, the duty ratio of the PWM signal applied to the V-L terminal is always 100%, that is, high level. Furthermore, in section A, the duty ratio of the PWM signal applied to the other terminals is always 0%, that is, low level. As a result, a current flows from the U-phase coil 73 to the V-phase coil 74. In the following section B, the duty ratio of the PWM signal applied to the V-H terminal is changed to a sine wave shape, similar to the PWM signal applied to the U-H terminal in section A. Although not shown, in section B, the duty ratio of the PWM signal applied to the U-L terminal is always high. Furthermore, in section B, the duty ratio of the PWM signal applied to the other terminals is always low. This allows the current from the U-phase coil 73 to the V-phase coil 74 to attenuate so that it approaches 0 at the end of section B. By applying the PWM signal as shown in FIG. 5, the coil current becomes sine wave. By making the coil current sine wave, it is possible to suppress noise generated by coil vibration. The same applies to the PWM signals applied to each terminal to pass other patterns of coil current.

6 and 7 show the maximum coil current when the coil currents of the six patterns are passed. The stopping position of the rotor 72 is different in each of Figs. 6(A) to 6(C) and Figs. 7(A) to 7(C). Specifically, the rotor 72 in Fig. 6(A) is stopped with its S pole facing the U-phase coil 73 and its N pole facing the V-phase coil 74, as shown in Fig. 4. The rotor 72 in Fig. 6(B) is stopped with its S pole facing the U-phase coil 73 and its N pole facing the W-phase coil 75. The rotor 72 in Fig. 6(C) is stopped with its S pole facing the V-phase coil 74 and its N pole facing the W-phase coil 75. The rotor 72 in FIG. 7(A) is stopped with its S pole facing the V-phase coil 74 and its N pole facing the U-phase coil 73. The rotor 72 in FIG. 7(B) is stopped with its S pole facing the W-phase coil 75 and its N pole facing the U-phase coil 73. The rotor 72 in FIG. 7(C) is stopped with its S pole facing the W-phase coil 75 and its N pole facing the V-phase coil 74.

For example, in FIG. 6(A), the maximum value of the coil current of pattern "U-V" is greater than the maximum value of the coil current of the other patterns. This is because, in the state of FIG. 4, when the coil current of pattern "U-V" is passed, the combined impedance of U-phase coil 73 and V-phase coil 74 becomes the smallest. Therefore, when the result of FIG. 6(A) is obtained, the motor control unit 14 can determine that the rotor 72 is stopped in the state of FIG. 4, that is, with its S pole facing the U-phase coil 73 and its N pole facing the V-phase coil 74. Then, the motor control unit 14 controls the coil current according to the determined stopping position of the rotor 72 to start the motor 15F.

Next, the reason why the motor control unit 14 determines the motor type will be explained. The motor control unit 14 generally controls the rotation speed and coil current of the motor 15F by PI control. When performing PI control, the motor control unit 14 sets the characteristics of the motor 15F, i.e., the optimal gain for the motor type, as the control parameter. If the set control parameter is not appropriate, unevenness may occur in the rotation speed of the motor 15F. If unevenness occurs in the rotation speed of the motor 15F, it will cause image defects in the image formed by the image forming device 10. For this reason, the motor control unit 14 needs to determine the motor type and set control parameters appropriate for the determined motor type.

Below, a method for determining the motor type will be described using an example in which two motors, type A and type B, may be used as the motor 15F of the image forming device 10. Type A and type B have different motor characteristic values such as inductance and resistance. Note that the present invention is also applicable to cases in which three or more types of motors may be used.

First, as shown in FIG. 6 and FIG. 7, the maximum value of each pattern of the coil current differs depending on the stop position of the rotor 72. However, the result of rearranging the maximum values of the coil current of the six patterns obtained at a certain stop position of the rotor 72 in descending or ascending order is approximately the same regardless of the stop position of the rotor 72. Therefore, in this embodiment, the maximum values of the coil current of the six patterns for each type of motor that can be used in the image forming device 10 are arranged in descending order to form a template for each type. FIG. 8 shows examples of templates for type A and type B. The template for type A is reference information for determining whether or not the motor is type A. Similarly, the template for type B is reference information for determining whether or not the motor is type B. The template for each type has six reference values arranged in descending order.

A type A template can be generated, for example, as follows. First, the rotor 72 of the type A motor is stopped at one of the six stop positions, and the coil current of each pattern is passed to measure the maximum value. The maximum values of each pattern are then sorted in descending order. The above process is performed for multiple type A motors at each of the six stop positions. A type A template can then be generated by finding the average value of the measured values with the same ranking. A type A template can also be generated by calculation based on the characteristics of the type A motor. The same applies to type B.

As described above, before starting the motor 15F, the motor control unit 14 passes six patterns of coil current and measures the maximum value as the measurement value in order to determine the stopping position of the rotor 72. That is, the motor control unit 14 measures six measurement values. The motor control unit 14 rearranges the six measurement values in the same descending order as the template to obtain measurement information. The motor control unit 14 obtains the error between the measurement information and the template. In this embodiment, the error between the measurement information and the template is defined as the integrated value of the square of the difference between the reference value of the template and the measurement value of the same rank as the reference value among the six measurement values of the measurement information. Figure 9 is an explanatory diagram of a method of calculating the error of the measurement information for the type A template shown in Figure 8.

As shown in FIG. 9, the motor control unit 14 obtains the difference between the kth (k is an integer from 1 to 6) reference value of the template and the kth measured value of the measurement information as ΔE _k . The motor control unit 14 then obtains the error ΔE of the measurement information for the template of type A as ΔE=Σ(E _k ² ). Here, Σ indicates the accumulation from k=1 to 6. The motor control unit 14 obtains the error ΔE with each template, and determines that the motor 15F is the type corresponding to the template with the smallest error ΔE. As described above, by setting the error ΔE as the square error, the error is calculated to be large, and it becomes easy to compare the error ΔE of each template. However, the error ΔE can also be the accumulated value of the absolute value of the difference between the measured value of the measurement information and the reference value of the corresponding rank of the template. In other words, the error ΔE can also be defined as ΔE=Σ|E _k |. Here, other values that can evaluate the degree of deviation between the measurement information and the reference information can also be set as the error.

Figure 10 is a flowchart of the motor type determination process according to this embodiment. The motor control unit 14 executes the process of Figure 10 before starting the motor 15F. In S10, the motor control unit 14 passes coil currents of each pattern to determine the stop position of the rotor 72, measures the maximum value as a measurement value, and thereby acquires measurement information. The motor control unit 14 determines the stop position of the rotor 72 based on the measurement value of each pattern. In S11, the motor control unit 14 rearranges the multiple measurement values of the measurement information in descending order. In S12, the motor control unit 14 obtains the error ΔE for each of the various templates as described above. In S13, the motor control unit 14 determines the type of the motor 15F by comparing the error ΔE for each of the various templates. More specifically, the motor control unit 14 determines that the type of the motor 15F is the type of the template with the smallest error ΔE. In S14, the motor control unit 14 sets control parameters suitable for the determined type. The relationship between the type and the control parameters is stored in advance in the non-volatile memory 55. After that, the motor control unit 14 starts controlling the rotation of the motor 15F.

As described above, in this embodiment, the motor type can be determined before starting the motor 15F. The motor type is determined by using the measured values measured by the motor control unit 14 to determine the stop position of the rotor 72. In this way, since no additional measurements are required to determine the motor type, the time until the motor is started is not extended. Furthermore, the information that is set in advance in the non-volatile memory 55 for one motor type is only one template, and the amount of data required to determine the motor type is small. Furthermore, since the motor type can be determined by simply comparing the template with the measurement information, the scale of the program executed by the microcomputer 51 is kept small, and the execution time is also short. Therefore, the time until the motor is started is prevented from being extended.

Second Embodiment
Next, the second embodiment will be described, focusing on the differences from the first embodiment. Fig. 11 is a flowchart of the motor type determination process according to this embodiment. Note that the same step numbers are given to the same process steps as those in the flowchart of the first embodiment shown in Fig. 10, and the description thereof will be omitted.

In this embodiment, the non-volatile memory 55 stores a threshold value for determining coil current abnormalities in advance. For example, when external noise is superimposed on the coil of the motor 15F, a current that exceeds the expected value may flow. Also, an excessive coil current may flow due to a circuit failure. The threshold value is determined so as to detect such coil current abnormalities.

In S12, the motor control unit 14 calculates the error ΔE for each type of template, and in S20, it determines whether the minimum value of the error ΔE is greater than a threshold value. If the minimum value of the error ΔE is not greater than the threshold value, the motor control unit 14 determines the motor type in S13, as in the first embodiment.

On the other hand, if the minimum value of the error ΔE is greater than the threshold value, the motor control unit 14 determines that the coil current is abnormal. If the coil current is abnormal, the motor control unit 14 cannot correctly determine the coil type, so repeats the process from S10 to reacquire the measurement information. Note that if the minimum value of the error ΔE is greater than the threshold value in S20 even after a predetermined number of repetitions, it is determined that a steady abnormality has occurred, not a transient abnormality, and the motor control unit 14 ends the process in FIG. 11. In this case, the motor control unit 14 displays that an abnormality has occurred. Note that if S20 is Yes, the process in FIG. 11 may be immediately ended and a display displayed that an abnormality has occurred.

In this embodiment, the reliability of motor type determination can be improved by determining abnormalities in the coil current. This can prevent inappropriate control parameters from being set.

In the above embodiments, the maximum value when a coil current that increases and decreases sinusoidally over a predetermined period of time is passed is taken as the measured value, and the stop position of the rotor 72 and the motor type are determined based on this. This is because the maximum value of the coil current differs depending on the impedance of the coil. However, the present invention is not limited to measuring the maximum value of the coil current, and can be configured to measure any other physical quantity that can determine the inductance or impedance of the motor. For example, the speed at which the coil current rises changes depending on the impedance. Therefore, the value of the coil current a predetermined period after the coil current begins to flow can be taken as the measured value. Also, the integral value of the coil current over the predetermined period during which the coil current is flowing can be taken as the measured value.

In the above embodiments, the motor type is determined, but what the motor control unit 14 does is to set control parameters suitable for the motor to be controlled. In other words, the motor control unit 14 may be configured to set control parameters corresponding to a template with the least error without recognizing the motor type. In this case, the "type template" in the above embodiments becomes a "control parameter template." Also, although the reference values of the template are arranged in descending order, and therefore the multiple measured values of the measurement information are also arranged in descending order, they may be arranged in ascending order.

In addition, in each of the above embodiments, the motor control unit 14 is described as a component of the image forming apparatus 10, but the motor control unit 14 can also be a single device and be considered as a motor control device. Also, a device including the printer control unit 11 and the motor control unit 14 can be considered as a motor control device. Also, in the above embodiments, the motor 15F was a motor for driving the fixing unit 24. However, the present invention can be applied to any motor for driving a rotating member of the image forming apparatus 10, such as a motor for driving a roller that transports a sheet, or a motor for driving a member of the image forming unit 1. Also, the configuration of the motor 15F is not limited to the configuration shown in FIG. 4, and it may be a motor with a different number of poles or phases.

[Other embodiments]
The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

The invention is not limited to the above-described embodiment, and various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to disclose the scope of the invention.

51: Microcontroller, 61: Gate driver, 60: Inverter, 63: Resistor, 53: AD converter, 55: Non-volatile memory

Claims (12)

a voltage application means for applying a voltage to a plurality of coils of a motor having a plurality of coils to pass a coil current through the plurality of coils;
A measuring means for measuring a current value of the coil current;
a control means for controlling the voltage application means to pass coil currents through the coils in a respective one of a plurality of patterns, and for causing the measurement means to measure the current values of the coil currents in each pattern, thereby acquiring measurement information including a plurality of measurement values;
a storage means for storing a plurality of pieces of reference information corresponding to a plurality of motor types, the plurality of pieces of reference information indicating a plurality of reference values corresponding to the respective motor types;
Equipped with
a motor control device characterized in that the control means determines a corresponding reference value from the multiple reference values in the reference information for each of the multiple measurement values of the measurement information, calculates a difference between the corresponding reference value of the reference information for each of the multiple measurement values of the measurement information, and calculates an error between the measurement information and each of the multiple reference information based on the difference calculated for each of the multiple measurement values of the measurement information, thereby calculating an error between the measurement information and each of the multiple reference information, and determines the motor type of the motor to be the motor type corresponding to the reference information having the smallest error from the measurement information . a voltage application means for applying a voltage to a plurality of coils of a motor having a plurality of coils to pass a coil current through the plurality of coils;
A measuring means for measuring a current value of the coil current;
a control means for controlling the voltage application means to pass coil currents through the coils in a respective one of a plurality of patterns, and for causing the measurement means to measure the current values of the coil currents in each pattern, thereby acquiring measurement information including a plurality of measurement values;
a storage means for storing a plurality of pieces of reference information corresponding to a plurality of control parameters, the reference information corresponding to the control parameters indicating a plurality of reference values of the coil currents of the plurality of patterns;
Equipped with
the control means determines a corresponding reference value from the multiple reference values in the reference information for each of the multiple measurement values of the measurement information, calculates a difference between the corresponding reference value in the reference information for each of the multiple measurement values of the measurement information, and calculates an error between the measurement information and each of the multiple reference information based on the difference calculated for each of the multiple measurement values of the measurement information, thereby calculating an error between the measurement information and each of the multiple reference information, and determines that the control parameters to be set when driving the motor are the control parameters corresponding to the reference information having the smallest error from the measurement information . The motor control device according to claim 1 or 2, characterized in that the control means determines a ranking of magnitude among the multiple measurement values for each of the multiple measurement values of the measurement information, determines a ranking of magnitude among the multiple reference values for each of the multiple reference values of the reference information, and determines that the reference value with the same ranking as the ranking of the measurement value is the reference value corresponding to the measurement value. 4. The motor control device according to claim 1 , wherein the control means determines an integrated value of the squares of the differences calculated for each of the plurality of measurement values of the measurement information as an error between the measurement information and the reference information. 4. The motor control device according to claim 1 , wherein the control means determines an integrated value of the absolute values of the differences calculated for each of the plurality of measurement values of the measurement information as an error between the measurement information and the reference information. 6. The motor control device according to claim 1 , wherein the control means reacquires the measurement information when a minimum value of an error between the measurement information and each of the plurality of reference information is greater than a threshold value. 7. The motor control device according to claim 1, wherein the plurality of patterns are identified by two coils among the plurality of coils through which a coil current flows and the direction of the coil current flowing through the two coils. The motor control device according to any one of claims 1 to 7, characterized in that the control means sets the maximum value or integral value of the coil current when the coil current is caused to flow for a predetermined period of time in each of the multiple patterns as the multiple measurement values. 8. The motor control device according to claim 1, wherein the control means sets the multiple measurement values to a rate of change of the coil current when the coil current is caused to flow in each of the multiple patterns. 10. The motor control device according to claim 1, wherein the control means further determines a stop position of the rotor of the motor based on the plurality of measured values. a rotating member for transporting the sheet along a transport path;
an image forming unit for forming an image on the sheet conveyed along the conveying path;
a motor for driving the rotating member or the image forming means;
A motor control means for controlling the motor;
An image forming apparatus comprising:
The motor control means
a voltage application means for applying a voltage to a plurality of coils of the motor to cause a coil current to flow through the plurality of coils;
A measuring means for measuring a current value of the coil current;
a control means for controlling the voltage application means to pass coil currents through the coils in a respective one of a plurality of patterns, and for causing the measurement means to measure the current values of the coil currents in each pattern, thereby acquiring measurement information including a plurality of measurement values;
a storage means for storing a plurality of pieces of reference information corresponding to a plurality of motor types, the plurality of pieces of reference information indicating a plurality of reference values corresponding to the respective motor types;
Equipped with
an error between the measurement information and each of the plurality of standard information by determining a corresponding standard value from the plurality of standard values in the standard information for each of the plurality of measurement values in the measurement information, calculating a difference between the corresponding standard value in the standard information for each of the plurality of measurement values in the measurement information, and calculating an error between the measurement information and each of the plurality of standard information based on the difference calculated for each of the plurality of measurement values in the measurement information, and determining a motor type of the motor to be the motor type corresponding to the standard information having the smallest error from the measurement information . a rotating member for transporting the sheet along a transport path;
an image forming unit for forming an image on the sheet conveyed along the conveying path;
a motor for driving the rotating member or the image forming means;
A motor control means for controlling the motor;
An image forming apparatus comprising:
The motor control means
a voltage application means for applying a voltage to a plurality of coils of the motor to cause a coil current to flow through the plurality of coils;
A measuring means for measuring a current value of the coil current;
a control means for controlling the voltage application means to pass coil currents through the coils in a respective one of a plurality of patterns, and for causing the measurement means to measure the current values of the coil currents in each pattern, thereby acquiring measurement information including a plurality of measurement values;
a storage means for storing a plurality of pieces of reference information corresponding to a plurality of control parameters, the reference information corresponding to the control parameters indicating a plurality of reference values of the coil currents of the plurality of patterns;
Equipped with
The image forming apparatus is characterized in that the control means determines a corresponding reference value from the multiple reference values of the standard information for each of the multiple measurement values of the measurement information, calculates a difference between the corresponding reference value of the standard information for each of the multiple measurement values of the measurement information, and calculates an error between the measurement information and each of the multiple reference information based on the difference calculated for each of the multiple measurement values of the measurement information, thereby calculating an error between the measurement information and each of the multiple reference information, and determines that the control parameters to be set when driving the motor are the control parameters corresponding to the standard information having the smallest error from the measurement information .

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