JP2017046427A - Motor control device, motor drive device, conveyance device and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict error change in position control or speed control.SOLUTION: A motor control device for driving a motor having a coil of a plurality of phases, comprises a limiting part that outputs a second output command value limiting a first output command value so that output indicated by the first output command value, which includes a plurality of values indicating the lengths of vectors of different phases and used for driving the motor, does not exceed the power source voltage of the motor control device. A second output command vector composed of the second output command values is the same as a first output command vector composed of the first output command values, or vectors of the same phase and different lengths.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor control device, a motor drive device, a transport device, and a motor control method.

  Conventionally, a non-commutator motor is rotationally driven by converting a direct current voltage into an alternating current voltage using an inverter device and applying it to a coil terminal.

  The AC voltage is subjected to PWM (Pulse Width Modulation) conversion in accordance with command values indicating amplitude and phase, and is applied to each phase coil. For example, in the case of a three-phase motor driven by a voltage obtained by PWM conversion of a sine wave, the modulated voltage is obtained by modulating a sine wave having a phase difference of 120 degrees with a carrier wave having an amplitude corresponding to the power supply voltage. Is applied to each phase coil.

  Here, as a countermeasure when a command value exceeding the power supply voltage is input, there is a method of increasing the degree of modulation (power supply voltage utilization rate) by switching between sine wave PWM drive, overmodulation PWM drive, and rectangular wave PWM drive. Are known.

  However, as a countermeasure when a command value exceeding the power supply voltage is input, when overmodulation PWM driving or rectangular wave PWM driving is used, the angle stable point of the instantaneous applied voltage takes a discrete value, and each phase A periodic phase error occurs in the applied voltage.

  The periodic phase error of the applied voltage may cause error fluctuations in position control and speed control, especially during low-speed rotation.

  The disclosed technology aims to suppress error fluctuations in position control and speed control.

  The disclosed technology is a motor control device for driving a motor including a plurality of phase coils, and is a first output command value including a plurality of values indicating the lengths of vectors having different phases, and drives the motor A limit unit that outputs a second output command value that limits the first output command value so that an output indicated by the first output command value does not exceed a power supply voltage of the motor control device; The second output command vector obtained by synthesizing the second output command value is the same as the first output command vector obtained by synthesizing the first output command value, or a vector having the same phase and a different length.

  According to the disclosed technology, error fluctuations in position control and speed control can be suppressed.

It is a figure which shows an example of a motor drive device. It is a figure which shows the definition of a dq axis coordinate system. It is a figure explaining a drive part. It is a figure explaining the upper arm of an inverter. It is a figure explaining operation | movement of a PWM part and a gate drive part. It is a figure explaining a current control part. It is a figure explaining a limit part. It is a figure which shows the change of the output vector by the process of a limit part. The example of the waveform of the terminal voltage command value when not having a limit part is shown. It is a figure which shows the example of the waveform of the terminal voltage by overmodulation PWM. It is a figure which shows an example of the waveform of the terminal voltage command value of this embodiment. It is the figure which compared the time of overmodulation and this embodiment about the phase of an applied voltage. 1 is a diagram illustrating an image forming apparatus equipped with a motor drive device according to an embodiment. FIG. 2 is a schematic configuration diagram of a transport device connected to the image forming apparatus.

  Embodiments will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a motor driving device.

  The motor drive device 100 according to the present embodiment includes a motor control device 200, a permanent magnet type motor 10, an encoder 20, a current detection unit 30, and a drive unit 40.

  A permanent magnet type motor (hereinafter referred to as a brushless motor) 10 according to the present embodiment includes a rotor 11, a coil 12, and a coil terminal 13.

  In the brushless motor 10 of this embodiment, the coil 12 has a phase difference of 120 degrees from each other, and is configured by three phases of a U phase, a V phase, and a W phase that are Y-connected. The rotor 11 is disposed at a position facing the coil 12. The rotor 11 is a permanent magnet in which S poles and N poles are alternately arranged.

  The brushless motor 10 rotates from the coil terminal 13 to the coil 12 by receiving a current that is commutated according to the angle of the rotor 11. Assuming that the coil current of each phase is Iu, Iv, Iw, it is a Y-shaped connection. Therefore, the relationship between the coil currents Iu, Iv, Iw of each phase is expressed by the following equation (1). In this embodiment, the permanent magnet of the rotor 11 has 2 × p poles (the number of pole pairs is p).

エンコーダ２０は、ブラシレスモータ１０の回転軸に接続され、回転子１１の回転に応じて、所定位相差をもつ２相のパルス信号と、回転子１１が所定の角度のときに出力される基準パルスとを出力する。尚、エンコーダ２０と回転子１１は、予め位置合わせされており、基準パルスが出力される回転子１１の角度は既知とする。

The encoder 20 is connected to the rotating shaft of the brushless motor 10, and according to the rotation of the rotor 11, a two-phase pulse signal having a predetermined phase difference and a reference pulse output when the rotor 11 has a predetermined angle. Is output. Note that the encoder 20 and the rotor 11 are aligned in advance, and the angle of the rotor 11 from which the reference pulse is output is known.

  The current detection unit 30 of the present embodiment detects U-phase and V-phase coil currents Iu and Iv. The current detection unit 30 includes a shunt resistor, a differential amplifier, and an AD conversion unit for each phase.

  In the current detection unit 30 of the present embodiment, the shunt resistor is inserted in series with the coil 12. The differential amplifier amplifies and outputs the voltage difference across the shunt resistor. The AD conversion unit samples the differential amplifier output, converts the sampled values into digital values, and outputs them as U-phase and V-phase detection current data d_Iu and d_Iv, respectively. The digital value is a value obtained by using a sampled value with a predetermined quantization resolution as a minimum unit.

  The drive unit 40 of the present embodiment applies a pulse-width modulated (PWM) voltage in accordance with terminal voltage command values Vu, Vv, and Vw indicating voltage values to be applied to the respective UVW phase coil terminals 13, thereby generating a brushless motor. 10 is supplied with coil currents Iu, Iv, and Iw. Details of the drive unit 40 of this embodiment will be described later.

  The motor control device 200 of the present embodiment outputs terminal voltage command values Vu, Vv, and Vw indicating voltage values to be applied to the respective UVW phase coil terminals 13 to the drive unit 40.

  The motor control apparatus 200 according to the present embodiment includes an angle detection unit 210, a coordinate conversion unit 220, a speed control unit 230, a current control unit 240, a limit unit 250, and a coordinate reverse conversion unit 260.

  The angle detection unit 210 counts up and down the edges of the two-phase pulse signal using the arrival of the reference pulse output from the encoder 20 as a reference for counting, and outputs this count value as the detection angle The. Further, the angle detection unit 210 measures the edge interval of the pulse signal, and outputs the reciprocal thereof as the detection speed wm. For convenience of explanation, the unit of the subsequent detection angle The is assumed to be rad.

  The coordinate conversion unit 220 converts the detected current data d_Iu and d_Iv from the UVW axis coordinate system to the dq axis coordinate system rotated by the detection angle The by the conversion equation shown in the following equation (2), and detects the dq axis. Output as current data d_Id, d_Iq.

ＵＶＷ軸座標系は、互いに１２０度の位相差をもつ座標系であり、ｄｑ軸座標系は、回転直交座標系である。座標変換部２２０による座標変換は、後述する図２に示す。

The UVW axis coordinate system is a coordinate system having a phase difference of 120 degrees, and the dq axis coordinate system is a rotational orthogonal coordinate system. The coordinate transformation by the coordinate transformation unit 220 is shown in FIG.

  The speed control unit 230 outputs a torque command value Te, which is a target value of torque to be generated, based on a target speed value wtgt input from the outside or a preset target speed value wtgt and a detected speed wm.

  The current control unit 240 outputs d-axis and q-axis output command values Vd and Vq indicating the voltage to be applied to the brushless motor 10 based on the torque command value Te. The output command values Vd and Vq of the present embodiment indicate the lengths of vectors having different phases, and are values corresponding to coil currents supplied to the brushless motor 10 in order to drive the brushless motor 10. Details of the current control unit 240 of this embodiment will be described later.

  Limit unit 250 limits output command values Vd and Vq according to the conditions, and outputs them as limit output command values Vld and Vlq. Details of the limit unit 250 will be described later.

  The coordinate inverse conversion unit 260 converts the limit output command values Vld and Vlq from the dq axis coordinate system to the UVW axis coordinate system according to the conversion formula shown in the following formula (3) (see FIG. 2), and the terminal voltage Output as command values Vu, Vv, Vw. FIG. 2 is a diagram showing the definition of the dq axis coordinate system.

次に、図３を参照し、本実施形態の駆動部４０について説明する。図３は、駆動部を説明する図である。

Next, the drive part 40 of this embodiment is demonstrated with reference to FIG. FIG. 3 is a diagram illustrating the driving unit.

  The drive unit 40 of this embodiment includes an output shaping unit 41, a PWM unit 42, a gate drive unit 43, and an inverter 50.

  The output shaping unit 41 according to the present embodiment shapes the signal with the three-phase terminal voltage command values Vu, Vv, and Vw while maintaining the difference between the values of the phases, and forms the shaped terminal voltage specified values Vmu, Vmv, and Vmw. Output.

  The process of the output shaping part 41 in this embodiment implements the process shown to the following formula | equation (4) with respect to the terminal voltage command value Vu, Vv, Vw of 3 phases.

出力整形部４１は、この処理により、３相の正弦波形である端子電圧指令値Ｖｕ、Ｖｖ、Ｖｗから、後述する図１１に示す波形の整形端子電圧指定値Ｖｍｕ、Ｖｍｖ、Ｖｍｗを得る。

Through this process, the output shaping unit 41 obtains waveform shaping terminal voltage designation values Vmu, Vmv, and Vmw having waveforms shown in FIG. 11 described later from the terminal voltage command values Vu, Vv, and Vw that are three-phase sine waveforms.

  According to the output shaping unit 41 of the present embodiment, by obtaining the shaping terminal voltage designation values Vmu, Vmv, Vmw, a predetermined power source is maintained while maintaining the voltage difference between the phases of the applied voltages to the coil terminals 13 of each phase. The voltage difference between the phases of the applied voltage can be shaped up to the maximum (= Vcc) under the voltage Vcc. Therefore, according to the present embodiment, it is possible to improve the utilization efficiency of the power supply voltage while maintaining the voltage difference between the phases of the voltages applied to the coil terminals 13 of the respective phases.

  In addition, the process of the output shaping part 41 of this embodiment is not restricted to this system, For example, a 2nd phase modulation has the same effect.

  The PWM unit 42 performs pulse width modulation on the shaped terminal voltage command values Vmu, Vmv, and Vmw, and outputs pulse width modulated (PWM) PWM signals Uon, Von, and Won.

  The gate drive unit 43 outputs gate signals (UH, VH, WH, UL, VL, WL) for driving the switching elements ON / OFF based on the PWM signals Uon, Von, Won. Details of operations of the PWM unit 42 and the gate drive unit 43 will be described later.

  The inverter 50 is configured in the same manner as the upper arm 51 connected to the power supply voltage Vcc side, and is configured by three-phase connection of the lower arm 52 connected to the ground GND side. Each switching element is driven ON / OFF by gate signals (UH, VH, WH, UL, VL, WL). The inverter 50 drives each switching element, applies a pulse width modulated voltage to the coil terminal 13 of the brushless motor 10, supplies coil currents Iu, Iv, Iw to the coil 12, and rotates the rotor 11. To drive.

  FIG. 4 is a diagram illustrating the upper arm of the inverter. In the upper arm 51 of this embodiment, a switching element 55 and a diode 56 are connected in parallel, and the switching element 55 is connected to a power supply voltage Vcc. The lower arm 52 has the same configuration and is connected to the GND side.

  Next, operations of the PWM unit 42 and the gate driving unit 43 of the present embodiment will be described with reference to FIG. FIG. 5 is a diagram for explaining the operation of the PWM unit and the gate driving unit. In the present embodiment, the U phase, the V phase, and the W phase have the same configuration and operate in the same manner, and therefore, only the U phase is described in FIG.

  The carrier wave Vc shown in the first stage of FIG. 5 is a triangular wave having a predetermined PWM cycle tpwm and has an amplitude from the ground GND to the power supply voltage Vcc.

  The PWM unit 42 compares the shaping terminal voltage command value Vmu and the carrier wave Vc with the median value (Vcc / 2) of the power supply voltage Vcc and the ground GND as a virtual zero in the carrier wave Vc, and shows the second stage in FIG. A PWM signal Uon is generated. The shaping terminal voltage command value Vmu is updated at the beginning of the PWM cycle.

  Next, the operation of the gate driver 43 will be described. The gate drive unit 43 of the present embodiment generates the gate signal UH shown in the third and fourth stages of FIG. The gate signal UH is a signal delayed by td with respect to the PWM signal Uon, and is supplied to the switching element of the upper arm 51.

  Further, the gate driving unit 43 generates a gate signal UL. The gate signal UL is a signal obtained by inverting the PWM signal Uon and delaying the rising edge (falling portion in Uon) by twice td, and is supplied to the switching element of the lower arm 52. Note that td is a short-circuit prevention section (dead time) provided for the purpose of preventing a short circuit between the switching elements of the upper arm 51 and the lower arm 52.

  Next, the current control unit 240 of this embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating the current control unit.

  The current control unit 240 of the present embodiment includes a target current generation unit 241 and two current controllers 242d and 242q having the same configuration, and indicates a voltage to be applied to the brushless motor 10 based on the torque command value Te. d-axis and q-axis output command values Vd and Vq are output.

  The target current generation unit 241 generates and outputs current command values Id and Iq from the torque command value Te. In the present embodiment, the d-axis current command value Id is always 0, and the q-axis current command value Iq is calculated by multiplying the torque command value Te by a predetermined coefficient (d-axis current zero control).

  Since the current controllers 242d and 242q are configured similarly, only the d-axis current controller 242d will be described. The d-axis current controller 242d is a proportional-integral controller, and integrates the value obtained by multiplying the difference between the d-axis current command value Id and the d-axis current data d_Id by the proportional gain Kp, and further calculates the integral gain Kp. A value obtained by adding the multiplied values is output as a d-axis output command value Vd.

  Next, the limit part 250 of this embodiment is demonstrated with reference to FIG.7 and FIG.8. FIG. 7 is a diagram illustrating the limit unit. FIG. 8 is a diagram illustrating a change in the output vector due to the processing of the limit unit.

  In the processing of the limit unit 250 of the present embodiment, first, the output phase α, which is the phase of the output command vector Vdq obtained by combining the dq-axis output command values Vd and Vq on the dq-axis coordinates, according to the following equation (5). calculate. The output phase α is shown in FIG. FIG. 8A shows the output phase.

ただし、このときｄｑ軸出力指令値Ｖｄ、Ｖｑは、絶対値をとる。

However, at this time, the dq-axis output command values Vd and Vq take absolute values.

  Next, using the calculated output phase α and the predetermined output limit value LimV, the d-axis, q-axis limit values LimVd and LimVq are calculated by the processing of the following equation (6).

尚、出力リミット値ＬｉｍＶは、前述の整形端子電圧指令値Ｖｍｕ、Ｖｍｖ、Ｖｍｗが、電源電圧Ｖｃｃを超えないように定められた値とする。次に、リミット部２５０は、以下の式（７）に示す論理にて、ｄｑ軸出力指令値Ｖｄ、Ｖｑそれぞれに対して、ｄ軸、ｑ軸リミット値ＬｉｍＶｄ、ＬｉｍＶｑを用いて制限を施し、リミット出力指令値Ｖｌｄ、Ｖｌｑとして出力する。

The output limit value LimV is a value determined so that the above-described shaping terminal voltage command values Vmu, Vmv, and Vmw do not exceed the power supply voltage Vcc. Next, the limit unit 250 limits the dq-axis output command values Vd and Vq using the d-axis, q-axis limit values LimVd and LimVq with the logic shown in the following equation (7), Output as limit output command values Vld, Vlq.

以上の処理により、本実施形態のリミット部２５０は、図８（Ｂ）に示すような、リミット出力指令値Ｖｌｄ、Ｖｌｑを生成する。図８（Ｂ）は、リミット出力指令ベクトルＶｌｄｑを示す図である。

Through the above processing, the limit unit 250 of the present embodiment generates limit output command values Vld and Vlq as shown in FIG. FIG. 8B shows a limit output command vector Vldq.

  The limit output command values Vld and Vlq of the present embodiment are the limit output in which the length of the output vector Vdq obtained by combining the output command values Vd and Vq is limited to the maximum output limit value LimV without changing the output phase α. A command vector Vldq is constructed.

  Next, effects of the present embodiment will be described with reference to FIGS. 9 to 12.

  FIG. 9 shows an example of the waveform of the terminal voltage command value when no limit unit is provided. More specifically, FIG. 9 shows a waveform example of the shaping terminal voltage command values Vmu, Vmv, and Vmw when an output command value exceeding the power supply voltage is input in a motor drive device that does not have a limit unit. ing.

  Here, considering the case of overmodulation PWM conversion, when the terminal voltage command values Vmu, Vmv, Vmw shown in FIG. 9 are PWM-converted into terminal voltages Vu, Vv, Vw applied to the coil terminal 13, The waveforms of the terminal voltages Vu, Vv, and Vw are as shown in FIG. FIG. 10 is a diagram illustrating an example of a waveform of a terminal voltage by overmodulation PWM.

  On the other hand, in the motor drive device 100 of the present embodiment including the limit unit 250, the shaping terminal voltage command value Vmu is output with respect to the output command value similar to the output command value input to the motor drive device that does not have the limit unit. , Vmv, and Vmw are as shown in FIG. FIG. 11 is a diagram illustrating an example of a waveform of the terminal voltage command value according to the present embodiment.

  In this embodiment, as shown in FIG. 11, if the output limit value LimV is appropriately set, the shaped terminal voltage command values Vmu, Vmv, and Vmw do not exceed the power supply voltage Vcc. In this embodiment, the terminal voltages Vu, Vv, and Vw are also applied according to the waveforms shown in FIG.

  That is, in the motor drive device that does not have the limit unit 250 and the motor drive device 100 of the present embodiment that has the limit unit 250, the terminal that is applied to the coil terminal when the output command value exceeds the power supply voltage Vcc. As shown in FIG. 10 and FIG. 11, a difference occurs in the voltage.

  11 and FIG. 10, the horizontal axis represents the phase of the command vector obtained by synthesizing the terminal voltage command value input to the drive unit 40, and the vertical axis represents the waveforms of FIG. 11 and FIG. FIG. 12 is a graph showing the phase (angle stable point) of the terminal voltage vector. FIG. 12 is a diagram comparing the phase of the applied voltage during overmodulation with this embodiment.

  As shown in FIG. 12, in the present embodiment, the phase of the command vector and the phase of the terminal voltage vector match. On the other hand, when overmodulation PWM control is performed, an error occurs in the phase of the terminal voltage vector with respect to the command vector. In FIG. 12, the error is shown on the second axis on the right side of the graph.

  As can be seen from this error, when overmodulation PWM control is performed, the phase of the terminal voltage vector with respect to the phase of the command vector fluctuates periodically. This variation becomes a variation in torque generated when the motor is driven, and causes a deterioration in control performance.

  In contrast, in the present embodiment, in the motor drive device 100 that PWM drives the brushless motor 10, when an output command value exceeding the power supply voltage is input, only the length is changed without changing the phase of the output command vector. In order to limit, each signal constituting the output command vector is limited. Therefore, according to the present embodiment, when an output command value exceeding the power supply voltage is input, the instantaneous stable angle of the applied voltage is a discrete value or a periodic phase error in the applied voltage. Can be prevented, and fluctuations in error during position control and speed control, particularly during low-speed rotation, can be suppressed.

  In addition, although the motor drive device 100 of the present embodiment has the brushless motor 10 and the encoder 20, the motor drive device 100 may not have the brushless motor 10 and the encoder 20.

  Next, a device on which the motor drive device 100 of this embodiment is mounted will be described. FIG. 13 is a diagram illustrating an image forming apparatus on which the motor driving device of this embodiment is mounted.

  The image forming apparatus 1 of this embodiment includes an ADF (Auto Document Feeder) 101A and an apparatus main body 101B. The apparatus main body 101B includes a paper feeding unit 102, an image reading unit 103, and an image forming unit 104.

  The ADF 101 </ b> A includes a document tray 110, a document feed roller 111, a document transport belt 112, a document discharge roller 113, and a document discharge tray 114. The ADF 101A is attached to the image reading unit 103 so as to be freely opened and closed via an opening and closing mechanism such as a hinge.

  The document feed roller 111 separates the documents one by one from the bundle of documents placed on the document tray 110 and conveys them to the image reading unit 103. The document transport belt 112 transports the document separated by the document feed roller 111 to the image reading unit 103. The document discharge roller 113 discharges a document discharged from the image reading unit 103 by the document conveyance belt 112 to a document discharge tray 114 below the document tray 110.

  The image reading unit 103 includes a housing 120, a scanning optical unit 121, a contact glass 122, and a driving unit. The scanning optical unit 121 includes an LED unit and is provided inside the housing 120. The scanning optical unit 121 emits light in the main scanning direction from the LED unit, and is scanned in the sub-scanning direction within the entire irradiation region by the driving unit. As a result, the scanning optical unit 121 reads a two-dimensional color image of the document.

  The contact glass 122 is provided on the upper portion of the housing 120 of the image reading unit 103 and constitutes the upper surface portion of the housing 120. The drive means includes a wire fixed to the scanning optical unit 121, a plurality of driven pulleys and drive pulleys bridged by the wire, and a motor that rotates the drive pulley.

  The sheet feeding unit 102 includes a sheet feeding cassette 130 and a sheet feeding unit 131. The paper feed cassette 130 stores paper sheets as recording media having different paper sizes. The paper feed unit 131 transports the paper stored in the paper feed cassette 130 to the main transport path 140 of the image forming unit 104.

  In addition, a manual feed tray 132 is disposed on the side surface of the image forming unit 104 so as to be openable and closable with respect to the image forming unit 104. The The uppermost paper in the manually fed paper bundle is sent out toward the main transport path 140 by the feed roller of the manual feed tray 132.

  A registration roller pair 141 a is disposed in the main conveyance path 140. The registration roller pair 141a sandwiches the sheet conveyed in the main conveyance path 140 between the rollers, and then feeds the sheet toward the secondary transfer nip at a predetermined timing.

  The image forming unit 104 includes an exposure unit 151, a tandem image forming unit 150, an intermediate transfer belt 154, an intermediate transfer roller 155, a secondary transfer device 152, a fixing unit 153, and the like. The image forming unit 104 includes a main transport path 140, a reverse transport path 143, a paper discharge path 160, and the like.

  As shown in FIG. 1, the exposure unit 151 is disposed adjacent to the tandem image forming unit 150. The exposure unit 151 exposes a photosensitive drum 170 provided corresponding to each of yellow, cyan, magenta, and black.

  The tandem image forming unit 150 includes four image forming units 171 of yellow, cyan, magenta, and black arranged on the intermediate transfer belt 154 along the rotation direction of the intermediate transfer belt 154. Although not shown in detail, each image forming unit 171 includes a charging device, a developing device, a photoconductor cleaning device, a static eliminator, and the like around the photoconductor drum 170 provided corresponding to each color. . Each photosensitive drum 170 and the above-described devices provided around it are unitized to constitute one process cartridge.

  The tandem image forming unit 150 forms a visible image (toner image) formed by toner on each photoconductive drum 170 based on image information read by the image reading unit 103 and separated by color. It has become. The visible image formed on each photoconductive drum 170 is transferred to the intermediate transfer belt 154 between each photoconductive drum 170 and the intermediate transfer roller 155.

  On the other hand, a secondary transfer device 152 is provided on the opposite side of the tandem image forming unit 150 with the intermediate transfer belt 154 interposed therebetween. The secondary transfer device 152 has a secondary transfer roller 180 as a transfer member. The secondary transfer nip is formed by pressing the secondary transfer roller 180 against the intermediate transfer belt 154. In the secondary transfer nip, the toner image formed on the intermediate transfer belt 154 is configured to be transferred from the sheet feeding unit 102 to the sheet conveyed via the main conveyance path 140.

  The sheet on which the toner image is transferred at the secondary transfer nip is sent to the fixing unit 153 by the sheet conveying belt 156 stretched around the two support rollers 157.

  The fixing unit 153 is configured by pressing a pressure roller 159 against a fixing belt 158 that is an endless belt. The fixing unit 153 applies heat and pressure to the paper by the pressure roller 159 to melt the toner of the toner image transferred onto the paper and fix it on the paper as a color image.

  The sheet on which the color image is fixed in this manner is stacked on a sheet discharge tray 161 outside the apparatus via a sheet discharge path 160 as a sheet discharge conveyance path.

  Further, as shown in FIG. 1, the reverse conveyance path 143 is provided below the secondary transfer device 152 and the fixing unit 153. The reverse conveyance path 143 is used for reversing the front and back of the paper discharged from the fixing unit 153 and supplying it again to the secondary transfer device 152 via the main conveyance path 140 in order to form images on both sides of the paper. Is.

  In the image forming apparatus 1 configured as described above, the ADF 101A functions as the sheet conveying apparatus 101 that conveys a document that is an example of a sheet. In addition, the sheet feeding unit 131 of the sheet feeding unit 102, the main conveyance path 140, the reverse conveyance path 143, the paper discharge path 160, and the like of the image forming unit 104 in the apparatus main body 101B each convey a sheet that is an example of a sheet. Functions as a device. These sheet conveying apparatuses convey a sheet by rotating a roller member by the power of a motor. The image forming apparatus 1 of the present embodiment includes a motor driving device 100 of the present embodiment in order to control the motors of these sheet conveying apparatuses.

  FIG. 14 is a schematic configuration diagram of a transport device connected to the image forming apparatus. As illustrated in FIG. 14, the transport apparatus 300 includes a sheet feeding main body 310 and a relay unit 320, and is configured to be able to connect a plurality of sheet feeding main body units 310 in series via the relay unit 320. The paper feed main body 310 feeds paper that is selectively removed from the paper feed trays 311 and 312 or paper from the upstream paper feed main body 310 connected in series via the relay unit 320 to the transport path P. And supplied to the image forming apparatus 1 connected via the connection unit 313. The relay unit 320 is connected to the upstream sheet feeding body 310 via the connection unit 321, and conveys the sheet supplied from the upstream sheet feeding body 310 to the downstream sheet feeding body 310.

  The conveyance device 300 configured as described above conveys a sheet, which is an example of a sheet, by rotating a roller member provided along the conveyance path P with the power of a motor. The motor drive device of this embodiment may be mounted on the transfer device 300, for example.

  The motor driving apparatus 100 according to the present embodiment is not limited to the image forming apparatus 1 and the conveying apparatus 300, and is effective for various sheet conveying apparatuses configured to convey a sheet by rotating a roller member with the power of the motor. Applicable to.

  In the present embodiment, the limit unit 250 corresponds to the limit unit in the claims, and the output phase α corresponds to the phase difference between the first output command vector and the rotor angle in the claims. . In the present embodiment, the d-axis and q-axis limit values LimVd and LimVq correspond to threshold values in the claims.

  In this embodiment, the output command vector Vdq corresponds to the first output command vector in the claims, and the limit output command vector Vldq corresponds to the second output command vector in the claims. Further, the output command values Vd and Vq of the present embodiment correspond to the first output command value in the claims, and the limit output command values Vld and Vlq correspond to the second output command values in the claims. Equivalent to.

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the gist of the present invention can be changed without departing from the scope of the present invention, and can be appropriately determined according to the application form.

1 Image forming apparatus 10 Brushless motor 11 Rotor 12 Coil (U phase, V phase, W phase)
13 coil terminal 20 encoder 30 current detection unit 40 drive unit 41 output shaping unit 42 PWM unit 43 gate drive unit 50 inverter 100 motor drive unit 200 motor control unit 210 angle detection unit 220 coordinate conversion unit 230 speed control unit 240 current control unit 241 Target current generation unit 242q, 242d Current controller 250 Limit unit 260 Coordinate reverse conversion unit 300 Conveying device

Japanese Patent No. 4729526

Claims (7)

A motor control device for driving a motor including a plurality of phase coils,
A first output command value including a plurality of values indicating the lengths of vectors having different phases, and an output indicated by the first output command value for driving the motor exceeds a power supply voltage of the motor control device. A limit unit that outputs a second output command value obtained by limiting the first output command value,
The second output command vector obtained by synthesizing the second output command value is the same as the first output command vector obtained by synthesizing the first output command value, or is a vector having the same phase and different length. Motor control device. The plurality of values included in the first output command value indicate a length of a plurality of vectors having a predetermined phase difference and rotating according to a rotor angle of the motor,
The limit part is
2. The phase difference between the first output command vector and the rotor angle is obtained, and a threshold value for limiting the magnitude of each of the plurality of values is changed based on the phase difference and a predetermined function. Motor control device.   The motor control device according to claim 2, wherein the predetermined phase difference between the plurality of vectors is an electrical angle of 90 degrees. A motor drive device for driving a motor including a plurality of phase coils,
A first output command value including a plurality of values indicating the lengths of vectors having different phases, and an output indicated by the first output command value for driving the motor exceeds a power supply voltage of the motor driving device. A limit unit for outputting a second output command value obtained by limiting the first output command value,
A commutation drive that is connected to each coil terminal of the motor and applies, to the coil terminal, a pulse-width-modulated voltage in which a voltage difference between the phases becomes a sine wave shape to each coil terminal according to the second output command value And comprising
The second output command vector obtained by synthesizing the second output command value is the same as the first output command vector obtained by synthesizing the first output command value, or is a vector having the same phase and different length. Motor drive device. The commutation drive unit is
5. The motor drive device according to claim 4, further comprising: an output forming unit configured to shape the voltage to be equal to or lower than the power supply voltage while maintaining a voltage difference between phases at each coil terminal. A conveying device having a motor including a plurality of phase coils and a motor driving device for driving the motor,
The motor driving device is
A first output command value including a plurality of values indicating the lengths of vectors having different phases, and an output indicated by the first output command value for driving the motor exceeds a power supply voltage of the motor driving device. A limit unit for outputting a second output command value obtained by limiting the first output command value,
A commutation drive that is connected to each coil terminal of the motor and applies, to the coil terminal, a pulse-width-modulated voltage in which a voltage difference between the phases becomes a sine wave shape to each coil terminal according to the second output command value And comprising
The second output command vector obtained by synthesizing the second output command value is the same as the first output command vector obtained by synthesizing the first output command value, or is a vector having the same phase and different length. Conveying device. A motor control method by a motor including a plurality of phase coils and a motor control device for driving the motor,
A first output command value including a plurality of values indicating the lengths of vectors having different phases, and an output indicated by the first output command value for driving the motor exceeds a power supply voltage of the motor control device. So as to output a second output command value in which the first output command value is limited,
The second output command vector obtained by synthesizing the second output command value is the same as the first output command vector obtained by synthesizing the first output command value, or the vector has the same phase and a different length. Motor control method.

Images