JP6280326B2 - Brushless DC motor control device, brushless DC motor control method, and motor system - Google Patents

Description

  The present invention relates to a control device that controls the operation of a brushless DC motor, a control method, and a motor system including the control device.

  A motor system using a brushless DC motor is used in, for example, the home appliance field, the electric vehicle field, or the industrial equipment field. When a plurality of brushless DC motors are used, for example, the plurality of brushless DC motors are usually controlled so that their rotational operations are synchronized with each other. In the case of the industrial equipment field, for example, in a transport device including a plurality of rollers arranged with their rotation axes parallel to each other, the plurality of rollers include so-called motor-incorporated rollers in which a brushless DC motor is incorporated every predetermined number. Including. And since the conveyed product conveyed by this conveying device may be conveyed by the plurality of motor built-in rollers, each brushless DC motor built in the plurality of motor built-in rollers rotates synchronously. There is a need to. A technique for synchronizing the rotational operations of such a plurality of brushless DC motors is disclosed in Patent Document 1, for example. The motor control system disclosed in Patent Document 1 is a motor control system that controls two or more motors, and the two or more motors are forcibly synchronously rotated by a mechanically connected rotating unit. Each of the two or more motors has a control device, and each of the control devices increases or decreases the current supplied to the motor so that the rotating portion of the motor has a predetermined number of rotations. All devices have a lower limit to the current supplied according to the rotational speed of the motor, and the current supplied to each motor does not fall below the lower limit according to the rotational speed.

JP 2013-27254 A

  In the prior art described in Patent Document 1, a control device is required for each of two or more motors. For this reason, a large installation space for the control device is required, and the cost reduction is hindered.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a brushless DC motor control device, a brushless DC motor control method, and a brushless DC motor control method capable of controlling the rotational operations of a plurality of brushless DC motors with a single control device. It is to provide a motor system.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below.

  That is, the brushless DC motor control device according to one aspect of the present invention detects a rotational position of the rotor relative to the stator, outputs a rotational position signal representing the rotational position, and outputs a plurality of rotational positions with a predetermined interval in the rotational direction. Superposition of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases of the phases are superimposed for each phase A specific brushless DC motor among the plurality of brushless DC motors based on a signal input unit for inputting a signal and a specific phase superimposed signal among the superimposed signals of each phase input to the signal input unit A detection unit for detecting a rotation position signal in the motor, and the specific position based on the rotation position signal in the specific brushless DC motor detected by the detection unit. A drive control unit that generates a drive signal for driving the laciless DC motor, and a signal output unit for outputting the drive signal generated by the drive control unit as a drive signal for each of the plurality of brushless DC motors. And

  In the above brushless DC motor control device, preferably, the detection unit is provided for each phase, a plurality of voltage change detection units for detecting a voltage change of the superimposed signal, and for each phase. A plurality of current change detection units for detecting a current change in the superimposed signal; the voltage change detected by a voltage change detection unit corresponding to the specific phase among the plurality of voltage change detection units; Of the plurality of brushless DC motors by alternately prioritizing the current change detected by the current change detection unit corresponding to the specific phase of the current change detection unit of the plurality of brushless DC motors. A rotational position detection unit that detects the rotational position signal of the motor.

  According to this configuration, in the brushless DC motor control device, the plurality of brushless DC control devices are based on the superposed signals of specific phases among the superposed signals of the phases input to the signal input unit by the detecting unit. A rotation position signal in a specific brushless DC motor among the DC motors is detected, and the specific brushless DC motor is detected based on the rotation position signal in the specific brushless DC motor detected by the detection unit by the drive control unit. A drive signal for driving is generated. For this reason, such a brushless DC motor control device outputs the drive signals from the signal output unit even when the superimposed signals from a plurality of brushless DC motors are input to the signal input unit. Brushless DC motor can be driven. Therefore, such a brushless DC motor control device can drive the plurality of brushless DC motors with a single device.

  In another aspect, in the brushless DC motor control device, the plurality of brushless DC motors are two first and second brushless DC motors, and the detection unit is configured to detect the first brushless DC motor. The rotational position signal of the specific phase and the rotational position signal of the specific phase of the second brushless DC motor are alternately detected, and a predetermined condition is satisfied among the detected rotational position signals It is preferable that the brushless DC motor corresponding to the rotational position signal is the specific brushless DC motor.

  According to this configuration, the brushless DC motor control device alternately detects the rotational position signal of the first brushless DC motor and the rotational position signal of the second brushless DC motor, and satisfies the predetermined condition. The brushless DC motor corresponding to the satisfied rotational position signal is defined as the specific brushless DC motor, and the first brushless DC motor includes the rotational position detection unit that detects the rotational position signal in the specific brushless DC motor. Regardless of the load applied to either the motor or the second brushless DC motor, the speed can be controlled to be constant.

  In another aspect, in the brushless DC motor control device, the plurality of brushless DC motors are N brushless DC motors (N is an integer of 3 or more), and the detection unit is provided for each phase. A plurality of current change detectors for detecting a current change of the superimposed signal, and an i th rise detected by a current change detector corresponding to the specific phase among the plurality of current change detectors. Rotational position for detecting the rotational position signal in the specific brushless DC motor among the N brushless DC motors by the current change at the fall and the current change at the i-th rise (i is a natural number equal to or less than N). And detecting the rotational position signals of the specific phases of the N brushless DC motors in order, and detecting the detected rotational position signals. Chi, it is preferable to the brushless DC motor corresponding to the rotational position signal satisfies a predetermined condition and the specific brushless DC motor.

  In these brushless DC motor control devices described above, the predetermined condition is that the length of one cycle of the rotational position signal is equal to or greater than a preset threshold value.

  According to this configuration, the brushless DC motor control device sequentially detects the rotational position signals of the three or more brushless DC motors, and the brushless DC signals corresponding to the rotational position signals satisfying the predetermined condition. Regardless of whether the load is applied to any of the three or more brushless DC motors, the DC motor is the specific brushless DC motor, and the rotational position detection unit detects the rotational position signal in the specific brushless DC motor. The speed can be controlled to be constant.

  In another aspect, in the brushless DC motor control device described above, the detection unit is provided for each of the phases, and a plurality of voltage change detection units for detecting a voltage change of the superimposed signal, and for each of the phases. A plurality of current change detectors for detecting a current change of the superimposed signal, and after detecting a current change of the superimposed signal of each phase by the plurality of current change detectors, first, the voltage of the superimposed signal is detected. It is preferable to include a detection target determination unit that sets the phase corresponding to the voltage change detection unit that has detected the change as the specific phase.

  According to this configuration, such a brushless DC motor control device includes the detection target determining unit, and thus can determine the specific phase from the superimposed signals of the respective phases.

  In another aspect, in the brushless DC motor control device described above, a forced commutation drive signal for driving the plurality of brushless DC motors by forced commutation is generated, and the generated forced commutation drive signal is output as the signal. It is preferable to further include a forced commutation drive control unit that outputs from the unit.

  According to this configuration, since the brushless DC motor control device further includes the forced commutation drive control unit, the plurality of stopped brushless DC motors can be started.

  In the brushless DC motor control method according to one aspect of the present invention, the rotational position of the rotor with respect to the stator is detected, a rotational position signal representing the rotational position is output, and a plurality of the rotational directions are provided at predetermined intervals. Superposition of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases of the phases are superimposed for each phase A specific brushless DC motor of the plurality of brushless DC motors based on a signal input process of receiving a signal at a signal input unit and a specific phase of the superimposed signal of each phase received by the signal input process A detection step of detecting a rotational position signal in the motor, and a rotational position signal in the specific brushless DC motor detected in the detection step A drive control step for generating a drive signal for driving the specific brushless DC motor based on the signal output unit for outputting the drive signal generated in the drive control step as a drive signal for each of the plurality of brushless DC motors from the signal output unit And a process.

  According to this configuration, in the brushless DC motor control method, the plurality of brushless DC motors are detected based on a superposed signal of a specific phase among superposed signals of each phase input to the signal input unit in the detection step. A drive signal for detecting a rotational position signal in a specific brushless DC motor of the motors and driving the specific brushless DC motor based on the detected rotational position signal in the specific brushless DC motor by a drive control step Is generated. For this reason, in such a brushless DC motor control method, even if the superimposed signals from a plurality of brushless DC motors are input to the signal input unit, the drive signal is output from the signal output unit, thereby Brushless DC motor can be driven. Therefore, such a brushless DC motor control method can drive the plurality of brushless DC motors with a single device.

  The motor system according to one aspect of the present invention detects a rotational position of the rotor with respect to the stator, outputs a rotational position signal indicating the rotational position, and outputs the rotational position signal in a plurality of phases at predetermined intervals in the rotational direction. A plurality of brushless DC motors provided with a plurality of position detection sensors arranged in correspondence with each other, and the brushless DC motor control device according to any of the above-described ones.

According to this configuration, such a motor system includes any one of the above-described brushless DC motor control devices, so that the plurality of brushless DC motors can be driven by one brushless DC motor control device.
The brassless DC motor control method according to the first aspect of the present invention detects a rotational position of a rotor with respect to a stator, outputs a rotational position signal representing the rotational position, and outputs a plurality of rotational signals at predetermined intervals in the rotational direction. A superimposed signal of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases are superimposed for each phase In a specific brushless DC motor among the plurality of brushless DC motors based on a signal input step of receiving the signal at the signal input unit and a specific phase of the superimposed signal of each phase received by the signal input step A detection step of detecting a rotational position signal, and a rotational position signal of the specific brushless DC motor detected in the detection step. A drive control step for generating a drive signal for driving the specific brushless DC motor, and a signal output step for outputting the drive signal generated in the drive control step as a drive signal for each of the plurality of brushless DC motors from a signal output unit The detection step is provided for each of the phases, and a plurality of voltage change detection steps for detecting a voltage change of the superimposed signal are provided for each of the phases, and the current change of the superimposed signal is detected. A plurality of current change detection steps to detect, a voltage change detected by a voltage change detection step corresponding to the specific phase of the plurality of voltage change detection steps, and a plurality of current change detection steps The plurality of brushless DC motors alternately prioritize the current change detected by the current change detection step corresponding to the specific phase. A rotational position detecting step of the detecting the rotational position signal at a specific brushless DC motor out, in that it comprises the features.
The brassless DC motor control method according to the second aspect of the present invention detects the rotational position of the rotor with respect to the stator, outputs a rotational position signal representing the rotational position, and outputs a plurality of signals at predetermined intervals in the rotational direction. A superimposed signal of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases are superimposed for each phase In a specific brushless DC motor among the plurality of brushless DC motors based on a signal input step of receiving the signal at the signal input unit and a specific phase of the superimposed signal of each phase received by the signal input step A detection step of detecting a rotational position signal, and a rotational position signal of the specific brushless DC motor detected in the detection step. A drive control step for generating a drive signal for driving the specific brushless DC motor, and a signal output step for outputting the drive signal generated in the drive control step as a drive signal for each of the plurality of brushless DC motors from a signal output unit The plurality of brushless DC motors are two first and second brushless DC motors, and the detecting step includes the rotational position signal of the specific phase of the first brushless DC motor and the The brushless DC motor that alternately detects the rotational position signal of the specific phase of the second brushless DC motor, and that corresponds to the rotational position signal that satisfies a predetermined condition among the detected rotational position signals. Is the specific brushless DC motor.
The brassless DC motor control method according to the third aspect of the present invention detects a rotational position of a rotor relative to a stator, outputs a rotational position signal indicating the rotational position, and outputs a plurality of rotational positions at predetermined intervals in the rotational direction. A superimposed signal of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases are superimposed for each phase In a specific brushless DC motor among the plurality of brushless DC motors based on a signal input step of receiving the signal at the signal input unit and a specific phase of the superimposed signal of each phase received by the signal input step A detection step of detecting a rotational position signal, and a rotational position signal of the specific brushless DC motor detected in the detection step. A drive control step for generating a drive signal for driving the specific brushless DC motor, and a signal output step for outputting the drive signal generated in the drive control step as a drive signal for each of the plurality of brushless DC motors from a signal output unit The plurality of brushless DC motors are N brushless DC motors (N is an integer of 3 or more), and the detection step is provided for each phase, and the current change of the superimposed signal is detected. A plurality of current change detection steps to be detected, and the current change at the i-th fall and the i-th rise detected by the current change detection step corresponding to the specific phase among the plurality of current change detection steps. Due to the current change (i is a natural number equal to or less than N), the specific brushless DC motor among the N brushless DC motors A rotational position detection step of detecting a rotational position signal, detecting the rotational position signals of the specific phase of the N brushless DC motors in order, and among the detected rotational position signals, The brushless DC motor corresponding to the rotational position signal that satisfies the above condition is the specific brushless DC motor.
A brassless DC motor control method according to a fourth aspect of the present invention detects a rotational position of a rotor relative to a stator, outputs a rotational position signal representing the rotational position, and outputs a plurality of rotational positions at predetermined intervals in the rotational direction. A superimposed signal of each phase in which a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors provided with a plurality of position detection sensors arranged corresponding to the phases are superimposed for each phase In a specific brushless DC motor among the plurality of brushless DC motors based on a signal input step of receiving the signal at the signal input unit and a specific phase of the superimposed signal of each phase received by the signal input step A detection step of detecting a rotational position signal, and a rotational position signal of the specific brushless DC motor detected in the detection step. A drive control step for generating a drive signal for driving the specific brushless DC motor, and a signal output step for outputting the drive signal generated in the drive control step as a drive signal for each of the plurality of brushless DC motors from a signal output unit The detection step is provided for each of the phases, and a plurality of voltage change detection steps for detecting a voltage change of the superimposed signal are provided for each of the phases, and the current change of the superimposed signal is detected. Corresponding to a plurality of current change detection steps to be detected and a voltage change detection step in which a voltage change of the superimposed signal is first detected after detecting a current change of the superimposed signal of each phase by the plurality of current change detection steps. And a detection target determining step in which the phase is the specific phase.

  The brushless DC motor control device, brushless DC motor control method, and motor system according to the present invention can control the rotational operations of a plurality of brushless DC motors with a single control device.

It is a block diagram which shows the structure of the motor system which concerns on this embodiment. It is a timing chart for demonstrating the change timing of the waveform of the rotation position signal which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the motor system which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the period control (S107) in operation | movement of the motor system shown in FIG. It is a timing chart for demonstrating the control which the control apparatus of a prior art performs. It is a figure which shows the structure of the roller with a built-in motor using the motor system which concerns on this embodiment. It is a figure which shows the structure of the conveying apparatus using the motor system which concerns on this embodiment. It is a figure which shows the structure of the other conveying apparatus using the motor system which concerns on this embodiment. It is a flowchart which shows another operation | movement of the period control (S107) in operation | movement of the motor system shown in FIG.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably unless there is description of special change etc.

  FIG. 1 is a block diagram showing a configuration of a motor system MS according to the present embodiment. In the present embodiment, for example, the motor system MS includes the control device 1 and a plurality of three-phase brushless DC motors (hereinafter also simply referred to as motors). The number of the plurality of motors may be an arbitrary number, but in the example shown in FIG. The control device 1 is connected to two motors, a motor 21 and a motor 22. Moreover, the control apparatus 1 is connected to the power supply Vdc.

  The power source Vdc is a DC voltage source that supplies power, for example, and is connected to a DC power source such as a battery (for example, a secondary battery), a solar cell, and a fuel cell, or an AC power source such as a commercial power source, and AC / DC converts the AC power. AC-DC (Alternating Current-Direct Current) converters that output DC power. Specifically, the power supply Vdc is connected to the drive control unit 12 via a positive electrode side terminal Pe1 and a negative electrode side terminal Pe2 described later included in the control device 1.

  One control device 1 controls the rotation operation of a plurality of motors. In the present embodiment, the control device 1 performs control to synchronize the rotation operations of a plurality of motors. Note that the synchronous control of the rotational operation is control in which the rotational speed of the rotor or the rotational speed of the rotor is substantially matched among a plurality of motors. In the present embodiment, the control device 1 performs control of the entire motor system MS including the motors 21 and 22, various calculations, and the like. The control device 1 includes, for example, a signal input unit 13, a signal output unit 14, a detection unit 17, and a drive control unit 12. The signal input unit 13 is connected to the detection unit 17 and is also connected to the drive control unit 12. The signal output unit 14 is connected to the drive control unit 12. The control device 1 is used to supply power to, for example, a pair of power supply terminals Pe (positive electrode side terminal Pe1 and negative electrode side terminal Pe2) for connection to the power supply Vdc and the Hall ICs 211 and 221 of the motors 21 and 22. It further has a power supply unit 15 and a GND terminal 16. The power supply terminal Pe is connected to the drive control unit 12. The power supply unit 15 is connected to a low-voltage DC power supply unit (not shown) that generates a voltage of 5 V, for example, and the drive control unit 12. The GND terminal 16 is grounded and is set to a reference potential, for example, 0V.

  The signal input unit 13 (13u, 13v, 13w) includes a plurality of terminals corresponding to each phase, and the rotation of the rotor relative to the stator output from each of the plurality of position detection sensors in the plurality of brushless DC motors. A superimposed signal (hereinafter also referred to as a superimposed rotational position signal) of each phase in which a plurality of rotational position signals representing positions (hereinafter also referred to as individual rotational position signals) are superimposed for each phase (for example, u phase, v phase, and w phase). ) Is entered. Each individual rotational position signal is output from each of the Hall ICs 211u, 211v, 211w of the motor 21 and the Hall ICs 221u, 221v, 221w of the motor 22, which are examples of a plurality of position detection sensors. The letters u, v, and w at the end of the code indicate that they correspond to the u-phase, v-phase, and w-phase, respectively, and are attached to the end of the code when distinguishing three phases, and so on. .

  The detection unit 17 outputs an individual rotational position signal in a specific motor among the plurality of motors based on the superimposed rotational position signal of a specific phase among the superimposed rotational position signals of each phase input to the signal input unit 13. To detect. The control apparatus 1 of this embodiment performs control which synchronizes rotation operation of a some motor, for example using the superimposition rotation position signal of any one phase in three phases. That is, the control device 1 of the present embodiment detects any individual rotational position signal in a specific motor based on the superimposed rotational position signal of the specific phase, with any one of the three phases as a specific phase. Control for synchronizing the rotational operations of the plurality of motors is performed. The specific motor will be described later.

  For example, the detection unit 17 is provided for each phase, and includes resistors Ru, Rv, and Rw that are examples of a plurality of current change detection units that detect a current change of the superimposed rotation position signal, and is provided for each phase. A detection circuit 11a including a plurality of voltage change detection units (a u-phase voltage change detection unit, a v-phase voltage change detection unit, and a w-phase voltage change detection unit) that detect a voltage change of the rotational position signal; and among the plurality of motors A rotation position detection unit 11b that detects an individual rotation position signal in the specific motor, and a detection target determination unit 11c that determines the specific phase. The current detection resistors Ru, Rv, and Rw have known resistance values in advance, and are connected between the signal input units 13u, 13v, and 13w and the GND, respectively. The detection circuit 11a detects the voltages across the resistors Ru, Rv, and Rw.

  When there are two motors connected to the control device 1, for example, the detection unit 17 has an individual rotational position signal of the specific phase out of two motors, for example, a first motor and a second motor. The motor that satisfies the condition is set as the specific motor. When the number of motors connected to the control device 1 is three or more, the detection unit 17 selects the motor of which the individual rotational position signal of the specific phase among the three or more motors satisfies a predetermined condition. The specific motor is used. As described above, when the detection unit 17 determines a specific motor, the drive control unit 12 according to the present embodiment can detect a specific motor among the plurality of motors based on, for example, a current change in the superimposed rotation position signal of the specific phase. An individual rotational position signal is detected for the motor, and control based on the individual rotational position signal is performed. Therefore, even if a load is applied to the specific motor, the drive control unit 12 can control the specific motor at, for example, a constant speed in consideration of the load. That is, when there are two motors, the detection unit 17 sets the motor satisfying the predetermined condition among the first motor and the second motor out of the two as the specific motor, so that the first motor Regardless of whether a load is applied to either the motor (for example, the motor 21) or the second motor (for example, the motor 22), the drive control unit 12 can control the speed to be constant. Further, when there are three or more motors, the detection unit 17 sets the motor satisfying the predetermined condition among the three or more motors as the specific motor, so that any of the three or more motors can be selected. Even if a load is applied, the drive control unit 12 can control the speed to be constant.

  The signal output unit 14 (14u, 14v, 14w) outputs a drive signal for driving the specific motor generated by the drive control unit 12 to each of the plurality of motors as a drive signal for each of the plurality of motors. In the present embodiment, the signal output unit 14 outputs the same three-phase drive signal (hereinafter also referred to as drive power) that causes the motors 21 and 22 to rotate.

  The drive control unit 12 generates a drive signal for driving the specific motor based on the individual rotational position signal in the specific motor detected by the detection unit 17. The drive control unit 12 includes, for example, a control calculation unit 11 and a plurality of switching elements Sw. The control calculation unit 11 is connected to the plurality of switching elements Sw, the power supply unit 15, and the signal input unit 13 (13u, 13v, 13w), and is further grounded to the GND. The plurality of switching elements Sw are connected to the power supply terminal Pe and the signal output unit 14, and are also connected to the control calculation unit 11.

  The plurality of switching elements Sw receive power supply from the power supply Vdc and generate a drive signal (drive power) for driving the specific motor in accordance with the control signal Sx output from the control calculation unit 11. The plurality of switching elements Sw include six switching elements a1, a2, b1, b2, c1, and c2 because the motors 21 and 22 are driven in three phases. Each of the switching elements a1 to c2 is, for example, a power transistor (including a power MOS-FET (Metal Oxide Semiconductor-Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like, and is a power MOS-FET in the present embodiment. is there. The switching elements a1, b1, and c1 are, for example, P-channel MOS-FETs, and the switching elements a2, b2, and c2 are, for example, N-channel MOS-FETs. The plurality of switching elements Sw constitute a so-called three-phase full bridge inverter.

  Switching element a1 and switching element a2 are connected in series, switching element b1 and switching element b2 are connected in series, and switching element c1 and switching element c2 are connected in series. In addition, each of the switching element a1, the switching element a2, the switching element b1, the switching element b2, the switching element c1, and the switching element c2 has a diode d1, a diode d2, a diode d3, a diode d4, and a diode d5 for flowing a reflux current, respectively. The diode d6 is connected in parallel. More specifically, the switching element a1, the switching element b1, the drain of the switching element c1, and the cathode terminals of the diode d1, the diode d3, and the diode d5 are connected to the positive terminal Pe1 of the power supply terminal Pe. The source of each switching element a2, the switching element b2, and the switching element c2, and the anode terminals of the diode d2, the diode d4, and the diode d6 are connected to the negative electrode side terminal Pe2. A capacitor Cpa is connected between the source and gate of the switching element a2, a capacitor Cpb is connected between the source and gate of the switching element b2, and a capacitor Cpc is connected between the source and gate of the switching element c2. It is connected.

  The anode of the diode d1 and the source of the switching element a1, and the cathode of the diode d2 and the drain of the switching element a2 are connected to the signal output unit 14u. The anode of the diode 3 and the source of the switching element b1, and the cathode of the diode 4 and the drain of the switching element b2 are connected to the signal output unit 14v. The anode of the diode d5 and the source of the switching element c1, and the cathode of the diode d6 and the drain of the switching element c2 are connected to the signal output unit 14w.

  Note that capacitors Cp1 and Cp2 for noise reduction are connected between the positive terminal Pe1 and the negative terminal Pe2 of the power supply terminal Pe. Capacitor Cp1 is connected to a series circuit including switching element a1 and switching element a2. Capacitor Cp2 is connected to a series circuit composed of switching element c1 and switching element c2. Further, a capacitor Cp3 for noise reduction is connected between the power supply unit 15 and the GND.

  Based on the individual rotational position signal in the specific motor detected by the detection unit 17, the control calculation unit 11 drives the specific motor with a plurality of switching elements Sw for the plurality of switching elements Sw. A control signal Sx for generating is output. For example, when the motor 21 is a specific motor, the control signal Sx is supplied from the signal output unit 14 to the three-phase brushless DC motor 21 by a three-phase drive current (drive signal) that is 120 degrees out of phase with each other. Thus, the signal is for controlling on / off of each of the switching elements a1 to c2. The control calculation unit 11 further performs, for example, overall control of the motor system MS and various calculations. The control arithmetic unit 11 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), and peripheral circuits thereof.

  In the present embodiment, the control calculation unit 11 internally detects, for example, a current change of the superimposed rotation position signal from the signal input units 13u, 13v, and 13w by current-voltage conversion by the resistors Ru, Rv, and Rw and detects the change in voltage. 11a. Furthermore, the detection circuit 11a also detects a voltage change of a high level (High Level) and a low level (Low Level) of the superimposed rotation position signal. The control device 1 generates a control signal Sx that generates a drive signal for driving the specific motor based on the current change and the voltage change of the superimposed rotation position signal, and the generated control signal Sx is switched to a plurality of switching signals. Output to each gate of the element Sw. In the present embodiment, the control calculation unit 11 includes, for example, among the plurality of voltage change detection units (u-phase voltage change detection unit, v-phase voltage change detection unit, w-phase voltage change detection unit) in the detection circuit 11a, for example. The voltage change of the superimposed rotation position signal detected by the voltage change detection unit corresponding to the specific phase and the current change detection unit corresponding to the specific phase of the plurality of current change detection units A rotation position detector 11b is further provided for detecting an individual rotation position signal in a specific motor among the plurality of motors based on a current change in the superimposed rotation position signal. That is, the rotational position detection unit 11b receives notification of each current change (voltage change) of the superimposed rotational position signal from the detection circuit 11a, for example, and receives the individual rotational position signal of each motor corresponding to each change timing of the superimposed rotational position signal. Each change timing is detected.

  The control calculation unit 11 internally detects, for example, a plurality of current change detection units (in this embodiment, resistors Ru, Rv, Rw) and detects a current change in the superimposed rotational position signal of each phase, and then first superimposes rotational position signal. The detection circuit 11a further includes a detection target determination unit 11c that sets the phase corresponding to the voltage change detection unit in the detection circuit 11a that has detected the voltage change to the specific phase. The detection circuit 11a, the rotational position detection unit 11b, and the detection target determination unit 11c are examples of the detection unit 17. The control calculation unit 11 further generates, for example, a forced commutation drive signal that drives the plurality of motors by forced commutation, and outputs the generated forced commutation drive signal from the signal output unit 14. A portion 11d is provided. In the control of forced commutation, the individual rotational position signal from each Hall IC is not used, and all the motors connected to the control device 1 are set in the control device 1 in order to similarly start the rotation operation. A predetermined frequency (rotational speed) obtained in advance through experiments or the like is used.

  The control calculation unit 11 is connected to each gate of the switching element a1, the switching element a2, the switching element b1, the switching element b2, the switching element c1, and the switching element c2. The switching signals Sa1, Sa2, Sb1, Sb2, Sc1, and Sc2 are output. The switching elements a1 to c2 and the switching signals Sa1 to Sc2 correspond in this order.

  In the present embodiment, the control calculation unit 11 determines, for example, the maximum value as the rated value from the maximum value of the current of the superimposed rotation position signal and the rated value of the output current from the Hall IC 211 (or Hall IC 221). By dividing, the number of connected motors is calculated. Note that the number of connected motors may be set from the outside by an operator input from an input unit (not shown) before the motors start rotating, for example.

  The detection circuit 11a has a function of detecting the voltage of the signal input to the detection circuit 11a. For example, the detection circuit 11a detects the voltages across the resistors Ru, Rv, and Rw, which are examples of a plurality of current change detection units. The change in the current of the superimposed rotational position signal of each phase is detected. Specifically, for example, the detection circuit 11a has a function of quantizing and detecting voltage values (Vu, Vv, Vw) of the respective superimposed rotation position signals with m values (m is a natural number of 3 or more). When the number of motors connected to the control device 1 is N, the voltage value of the superimposed rotation position signal is (N + 1), and the detected value is represented by (N + 1) value. In this embodiment, since there are two motors, the value is ternary. The voltage values Vu, Vv, Vw of the respective superimposed rotation position signals input to the detection circuit 11a are substantially equal to the voltages at both ends of the resistors Ru, Rv, Rw, which are current change detection units, and are superimposed rotation. Since the timing of the current change of the position signal coincides with the timing of the change of the voltage at both ends, the current change of the currents Iu, Iv, and Iw can be detected by the voltage change detected by the detection circuit 11a with the m value.

  In the present embodiment, the detection circuit 11a is provided for each of the phases, and includes a plurality of voltage change detection units (u-phase voltage change detection units, v, v) that detect high-level and low-level voltage changes of the superimposed rotation position signal. Phase voltage change detector, w-phase voltage change detector). Specifically, each voltage change detection unit is configured to use a predetermined threshold value for the voltage of the superimposed rotation position signal input from the signal input units 13u, 13v, and 13w to the control calculation unit 11, and a binary value at a high level and a low level. To detect (hereinafter also referred to as binary voltage). The detection circuit 11a measures the voltage of each phase signal input from the signal input units 13u, 13v, and 13w, and the binary voltage value (high level, low level) and the superimposed rotation of each phase. The m voltage value corresponding to the current value of the position signal is simultaneously detected.

  For example, when there are two motors, the rotational position detection unit 11b includes a voltage change of the superimposed rotational position signal detected by the voltage change detection unit corresponding to the specific phase among the plurality of voltage change detection units, and By alternately prioritizing the current change of the superimposed rotational position signal detected by the current change detection unit corresponding to the specific phase among the plurality of current change detection units, the identification of the plurality of motors The individual rotational position signal in the motor is detected. In addition, when there are three or more motors, for example, the rotational position detection unit 11b has two consecutive currents detected by the current change detection unit corresponding to the specific phase among the plurality of current change detection units. According to the change, an individual rotational position signal in the specific motor among the three or more motors is detected. In the present embodiment, the rotational position detection unit 11b is configured such that, for example, the rotor of each of a plurality of motors connected to the control device 1 based on the detection result of the voltage change and the current change of the superimposed rotational position signal by the detection circuit 11a. The change timing of the current change of the individual rotational position signal is detected. The control calculation unit 11 outputs the control signal Sx to the plurality of switching elements Sw using the detection result.

  For example, after the detection circuit 11a detects the current change of the superimposed rotational position signal by the detection circuit 11a detecting the voltage changes at the both ends of the resistors Ru, Rv, and Rw, the detection target determining unit 11c first detects the voltage change of the superimposed rotational position signal. The phase corresponding to the voltage change detection unit in the detection circuit 11a that detects the above is defined as the specific phase. In this embodiment, the forced commutation drive control unit 11d causes the motors 21 and 22 to start rotating operation by the forced commutation when the motors 21 and 22 are started.

  Next, the motors 21 and 22 will be described. The motors 21 and 22 are, for example, transport motors for transport equipment used in the production line. Since the configurations of the motor 21 and the motor 22 are the same, the configuration of the motor 21 will be mainly described below as a representative. The motor 21 is a Hall IC 211 (211u, 211v, 211w) which is an example of a plurality of position detection sensors, a position signal output unit 212 (212u, 212v, 212w), a motor main body 213 having a stator and a rotor, and power input. Section 214 (214u, 214v, 214w), a power supply section 215 for supplying power to the Hall IC 211, and a GND terminal 216. Each of the Hall ICs 211 (211u, 211v, 211w) is connected to a power supply unit 215 and a GND terminal 216, and each position signal output unit 212 (212u, 212v, 212w) is connected in phase. . The power input unit 214 (214u, 214v, 214w) is connected to the input of each phase of the motor main body 213 in accordance with the phases.

  The motor main body 213 has, for example, a so-called star-connected three-pole field coil (u phase, v phase, w phase) that generates a rotating magnetic field by a three-phase drive signal input from the power input unit 214. A three-phase driving power, comprising: a stator; and a rotor having a two-pole permanent magnet with N and S poles opposed to the field coil and rotating about a rotation axis with respect to the stator. , And a rotational force is output from the rotating shaft by the rotation of the rotor. The power input unit 214 (214u, 214v, 214W) is connected to the field coil of each phase, and the power input unit 214 receives the three-phase driving power for rotating the motor 21 (motor main body unit 213). Entered.

  The Hall IC 211 (211u, 211v, 211w) detects the rotational position of the rotor relative to the stator and outputs an individual rotational position signal indicating the rotational position, and corresponds to a plurality of phases at predetermined intervals in the rotational direction. It is an example of a plurality of position detection sensors arranged. Specifically, the Hall IC 211 (211u, 211v, 211w) is supplied with power by, for example, a power supply unit 215 and a GND terminal 216, and detects the contact / separation of the permanent magnets of the rotor, thereby rotating the rotor with respect to the stator. , And the individual rotational position signal H1 (H1u, H1v, H1w) is output to each position signal output unit 212. Specifically, each of the Hall ICs 211u, 211v, and 211w switches from a low level to a high level by detecting the approach of the N-pole permanent magnet in the rotor, for example, while the rotor makes one rotation (hereinafter, referred to as “the low IC”). Switching from the low level to the high level is referred to as an up edge). For example, the individual rotation position signals H1u and H1v that switch from the high level to the low level by detecting the separation of the N-pole permanent magnet in the rotor after half a rotation. , H1w are output (hereinafter, switching from a high level to a low level is referred to as a down edge). By detecting the timing at which the individual rotational position signals H1u, H1v, and H1w from each motor are switched, it is possible to detect the rotational position of the rotor with respect to the stator in each motor. Each of the Hall ICs 211u, 211v, 211w is disposed at a predetermined position of the stator with an interval of 120 degrees (mechanical angle), for example, in the rotation direction of the rotor. Therefore, the individual rotation position signals H1u, H1v, and H1w are out of phase with each other by 120 degrees.

  The correspondence relationship between the motor 21 and the motor 22 will be described. The Hall IC 221 (221u, 221v, 221w) of the motor 22, the position signal output unit 222 (222u, 222v, 222w), the motor main body unit 223, and the power input unit 224. (224u, 224v, 224w), the power supply unit 225, and the GND terminal 226 are the Hall IC 211 (211u, 211v, 211w), the position signal output unit 212 (212u, 212v, 212w) of the motor 21, and the motor body 213, respectively. , Power input unit 214 (214u, 214v, 214w), power supply unit 215, and GND terminal 216. From the motor 22, an individual rotational position signal H2 (H2u, H2v, H2w) corresponding to the individual rotational position signal H1 (H1u, H1v, H1w) is output.

  Next, the connection relationship between the motor 21 and the motor 22 and the control device 1 will be described.

  The power input units 214u, 214v, and 214w of the motor 21 are connected to the signal output units 14u, 14v, and 14w of the control device 1, respectively. The position signal output units 212u, 212v, and 212w of the motor 21 are connected to the signal input units 13u, 13v, and 13w of the control device 1, respectively. Further, the power supply unit 215 and the GND terminal 216 of the motor 21 are respectively connected to the power supply unit 15 and the GND terminal 16 of the control device 1. On the other hand, the power input units 224u, 224v, and 224w of the motor 22 are connected to the signal output units 14u, 14v, and 14w of the control device 1, respectively. The position signal output units 222u, 222v, and 222w of the motor 22 are connected to the signal input units 13u, 13v, and 13w of the control device 1, respectively. Further, the power supply unit 225 and the GND terminal 226 of the motor 21 are respectively connected to the power supply unit 15 and the GND terminal 16 of the control device 1. Note that each of the power input units 214u, 214v, and 214w of the motor 21 and each of the power input units 224u, 224v, and 224w of the motor 22 are connected to the signal output units 14u, 14v, and 14w, or outside the control device 1. Each phase is connected to each other. Therefore, the drive signal output from the signal output unit 14 is output to the motor 21 and the motor 22 in common. In addition, each of the position signal output units 212u, 212v, and 212w of the motor 21 and each of the position signal output units 222u, 222v, and 222w of the motor 22 is connected to the signal input units 13u, 13v, and 13w, or external to the control device 1. Are connected to each other. Therefore, the individual rotation position signal of the position signal output unit 212 and the individual rotation position signal of the position signal output unit 222 are superimposed for each phase. With the above configuration, the individual rotation position signal H1 (H1u, H1v, H1w) output from the position signal output unit 212 of each phase of the motor 21 and the individual rotation output from the position signal output unit 222 of each phase of the motor 22 The superimposed rotation position signal H (Hu, Hv, Hw) on which the position signal H2 (H2u, H2v, H2w) is superimposed for each phase is applied to the signal input unit 13 (13u, 13v, 13w) of the control device 1. Are input together. Further, the same drive power is input to each of the power input units 214u, 214v, 214w of the motor 21 and the power input units 224u, 224v, 224w of the motor 22 in phase.

  Next, the superimposed rotational position signal H on which the individual rotational position signal is superimposed will be described.

  FIG. 2 is a timing for explaining the waveform change timing of the superimposed rotation position signal H (Hu, Hv, Hw) that is superimposed and input to the signal input unit 13 (13u, 13v, 13w) of the control device 1. It is a chart. FIG. 2A shows binary voltage waveform diagrams of the superimposed rotational position signals Hu, Hv, and Hw in order from the top, and the horizontal axis represents the rotational position (mechanical angle) of the rotor. FIG. 2B shows, in order from the top, a binary voltage waveform diagram of the individual rotational position signal H1u of the motor 21, a binary voltage waveform diagram of the individual rotational position signal H2u of the motor 22, and a binary voltage waveform diagram of the superimposed rotational position signal Hu. , And a schematic diagram of a current waveform represented by the m value of the current Iu of the superimposed rotational position signal Hu, and the horizontal axis represents the rotational position (mechanical angle) of the rotor. In the present embodiment, since there are two motors, a schematic diagram of a current waveform quantized into three values (m = 3) is shown. In FIG. 2A, the waveforms of the superimposed rotational position signal Hu and the waveform of Hv, and the waveforms of the superimposed rotational position signal Hv and the waveform of Hw are only 120 degrees out of phase, and the three waveforms are the same. Change. As shown in FIG. 2A, the superimposed rotational position signal Hu is a low level signal between the mechanical angles θ2 to θ3, and a high signal between the mechanical angles 0 ° to θ2 and between the mechanical angles θ3 to 360 °. Level (0 degrees <θ1 <θ2 <θ3 <θ4 <360 degrees).

  As shown in FIG. 2B, the superimposed rotational position signal Hu includes the individual rotational position signal H1u of the motor 21 having the one-dot chain line waveform in FIG. 2B and the motor 22 having the two-dot chain line waveform in FIG. The individual rotation position signal H2u is superimposed on the signal. In the individual rotational position signal H1u, since the Hall IC 211u detects that the N pole of the permanent magnet is separated at the timing of the mechanical angle θ1, the signal between the mechanical angles θ1 to θ3 is at a low level, and the permanent magnet is detected at the timing of the mechanical angle θ3. Since the Hall IC 211u has detected that the N poles have approached, the signals between the mechanical angles θ3 to 360 ° and between the mechanical angles 0 ° to θ1 are at a high level. Here, the angle difference (mechanical angle) between the mechanical angles θ1 to θ3 is referred to as a reference value in the individual rotational position signal H1u of the motor 21. Normally, the mechanical angle between the mechanical angles θ1 to θ3 and the mechanical angle θ3 to (mechanical angle 0 degree) to θ1 are approximately 180 degrees in mechanical angle. In the individual rotational position signal H2u, since the Hall IC 221u detects that the N pole of the permanent magnet is separated at the timing of the mechanical angle θ2, the signal between the mechanical angles θ2 to θ4 is at a low level, and the permanent magnet is detected at the timing of the mechanical angle θ4. Since the Hall IC 221u has detected that the N poles have approached, the signals between the mechanical angles θ4 to 360 degrees and the mechanical angles 0 degrees to θ2 are at a high level. Here, the angle difference (mechanical angle) between the mechanical angles θ2 to θ4 is referred to as a reference value in the individual rotational position signal H2u of the motor 22. Usually, the mechanical angle between the mechanical angles θ2 to θ4 and the mechanical angle θ4 to (mechanical angle 0 degree) to θ2 are each about 180 degrees in mechanical angle. As described above, the superimposed rotational position signal Hu obtained by superimposing the individual rotational position signal H1u and the individual rotational position signal H2u has a low level signal between the mechanical angles θ2 to θ3, a mechanical angle between θ3 to 360 degrees, and a mechanical angle. The signal is at a high level between 0 degrees and θ2, but the mechanical angles between mechanical angles θ2 and θ3 and between mechanical angles θ3 and (mechanical angle 0 degrees) to θ2 are not substantially 180 degrees in mechanical angles. This is due to the following reason.

  The voltage of the individual rotational position signal H1u and the voltage of the individual rotational position signal H2u are both high level at mechanical angles 0 to θ1 and mechanical angles θ4 to 360 degrees, and the voltage of the individual rotational position signal H1u at mechanical angles θ1 to θ2. Is low level, the voltage of the individual rotational position signal H2u is high level, the mechanical rotational angle θ2 to θ3, the voltage of the individual rotational position signal H1u and the voltage of the individual rotational position signal H2u are both low level, and the individual rotational position is mechanical angle θ3 to θ4. The voltage of the signal H1u is high and the voltage of the individual rotational position signal H2u is low. When the voltage of the individual rotational position signal is at a high level, a current that maintains the voltage of the individual rotational position signal at a high level is output from the Hall IC. Therefore, the waveform of the current Iu of the superimposed rotation position signal Hu is changed to a mechanical angle of 0 degrees to θ1 and a mechanical angle of θ4 to 360 degrees in accordance with the change of the voltage of the individual rotation position signal H1u and the voltage waveform of the individual rotation position signal H2u. The current value is Ia, the mechanical angle θ1 to θ2 is the current value Ib, the mechanical angle θ2 to θ3 is the current value zero, and the mechanical angle θ3 to θ4 is the current value Ib. Here, current value Ia> current value Ib, and normal current value Ia is about twice the current value Ib. Thus, there is a phase difference between the individual rotational position signals (here, H1u and H2u) corresponding to the change timing of each individual rotational position signal that changes in response to the change in the rotational position of each rotor. Thus, a plurality of combinations of the up edge and the down edge in the change of the current waveform are caused by the phase difference.

  Since the voltage Vu is the product of the resistance value of the resistor Ru and the current Iu, the waveform represented by the m value of the voltage Vu of the superimposed rotation position signal Hu has the same tendency as the waveform of the current Iu. The change timing substantially coincides with the change timing of the current Iu. Therefore, when the high-level voltage value of the individual rotational position signal H1u and the individual rotational position signal H2u is Vb, the voltage Vu is zero at the mechanical angles θ2 to θ3, and the mechanical angles θ1 to θ2 and the mechanical angles θ3. The voltage value in the section of .about..theta.4 is Vb, and the voltage value in the section of the mechanical angle 0.degree. To .theta.1 and the mechanical angle .theta.4 to 360 degrees is a voltage value Va that is approximately twice the voltage value Vb. Since the voltage value Vb is set to a high level when binary quantization is performed, sections of the mechanical angles 0 to θ2 and the mechanical angles θ3 to 360 degrees that are equal to or greater than the voltage value Vb are 2 of the superimposed rotation position signal Hu. It becomes high level in the voltage waveform represented by the value. From the above, from the voltage value of each phase signal input from the signal input units 13u, 13v, 13w, the binary voltage value (high level, low level) and the superimposed rotational position signal of each phase The m-value voltage value corresponding to the current value can be detected simultaneously by the detection circuit 11a. Note that the one-dot chain line waveform portion between the mechanical angles θ1 to θ2 and the two-dot chain line waveform portion between the mechanical angles θ3 to θ4 shown in FIG. 2A are the individual rotational position signals as shown in FIG. One of H1u and the individual rotational position signal H2u is at a low level, and for the above reason, the voltage of the superimposed rotational position signal Hu is a high level.

  From the above description, from the current waveform of the superimposed rotational position signal Hu detected by the detection circuit 11a, the rotational position detector 11b indicates that both the individual rotational position signal H1u and the individual rotational position signal H2u are at a high level at a predetermined mechanical angle. It is possible to detect whether they are both low, or only one of them is high (or low). Therefore, changes in the current waveform of the superimposed rotation position signal Hu (for example, a down edge where the current value changes from Ia to Ib, a down edge where the current value changes from Ib to zero, and an up where the current value changes from zero to Ib) The rotational position detector 11b can detect the current change timing of the individual rotational position signal H1u and the individual rotational position signal H2u from the timing of the edge and the current value (up edge where the current value changes from Ib to Ia). The rotational position of the rotor in can be detected individually. The control device 1 uses the detection result to synchronously control the rotation operations of the two motors as described below. The detection circuit 11a detects a down edge where the binary voltage waveform of the superimposed rotation position signal Hu switches from a high level to a low level or an up edge where the binary voltage waveform switches from a low level to a high level. The control device 1 according to the present embodiment synchronously controls the rotation operations of the two motors using the binary voltage waveform change detected by the detection circuit 11a.

  In the above description, the rotation operation of the two motors has been described. However, the same applies to N motors (N is an integer of 3 or more), and a series of falling current changes are started from a mechanical angle of 0 degrees. The first falling current change is the first falling current change, and the last falling current change is the Nth falling current change. After this, a series of rising current changes are started, the first rising current change is the first rising current change, and the last rising current change is the Nth rising current change.

  Next, the operation of the motor system MS of this embodiment will be described. FIG. 3 is a flowchart showing an example of the operation of the motor system MS of the present embodiment. Hereinafter, an example will be described in which the motor system MS is used for, for example, a transport device and the transported object is transported by driving the motors 21 and 22.

  When the motor system MS is started, the forced commutation drive control unit 11d first starts rotating the motors 21 and 22 by a so-called forced commutation drive signal (step S101). That is, in the forced commutation control, the forced commutation drive control unit 11d drives the motors 21 and 22 at the predetermined frequency by forced commutation, so that each of the switching elements Sw is turned on and off by 120 degrees. A forced commutation drive signal of each phase shifted by a phase is generated, and the generated forced commutation drive signal is input from the signal output unit 14 to the input unit 214u and the input unit 224u, the input unit 214v and the input unit 224v, and the input unit. It outputs to each of 214w and input part 224w.

  After the forced commutation is started, in step S103, for example, the control calculation unit 11 calculates the number of motors connected to the control device 1 from the maximum current value and the rated value, and calculates the calculated motor. Are stored in an EEPROM (not shown). In step S103, for example, the detection circuit 11a detects a voltage change in any one phase of a signal (hereinafter also referred to as an input unit signal) H (Hu, Hv, Hw) input to the signal input unit 13. Then, it is detected whether or not the input unit signal is always at the high level. When a plurality of motors are connected to the control device 1, the voltage of the input signal (in this case, the superimposed rotation position signal) is always at a high level by superimposing the individual rotation position signals from the plurality of motors. Cases can occur. When the superimposed rotation position signal is always at a high level, voltage changes (up edge and down edge) of the superimposed rotation position signal cannot be detected, and the rotation operation of each motor (motors 21 and 22 in this embodiment) is stopped.

  Next, the control calculation unit 11 reads out the calculation result of the number of motors calculated in step S103 from the EEPROM (not shown), and determines whether there are a plurality of motors connected to the control device 1 (step S1). S105). When there are a plurality of motors connected to the control device 1 (YES in step S105), the control calculation unit 11 performs periodic control described later a predetermined number of times (step S107). When the number of motors connected to the control device 1 is one (NO in step S105), the control calculation unit 11 performs normal control (step S301).

  In step S301, since there is one motor, the control calculation unit 11 controls the motor using the input unit signal from the Hall IC (normal control). Since the number of motors connected to the control device 1 is one, the input unit signal is an individual rotational position signal, not a superimposed rotational position signal. In normal control, the control calculation unit 11 feeds back the rotational speed of the motor calculated from the cycle of the individual rotational position signal of the motor, for example, so as to keep the transport speed of the transported object constant, so-called PI (Proportional). (Integral) control or PID (Proportional Integral Derivative) control is performed. Next, the control calculation unit 11 determines whether or not a system stop signal is input to a stop processing unit (not shown) by the operator of the motor system MS (step S303). When the stop signal is input (YES in step S303), the control calculation unit 11 stops the operation of the motor system MS. When the stop signal is not input (NO in step S303), the control calculation unit 11 returns the process to step S301, and repeats the normal control and stop determination described above (steps S301 and S303).

  In step S107, the control calculation unit 11 determines whether or not a system stop signal is input to a stop processing unit (not shown) by the operator of the motor system MS after performing the cycle control a predetermined number of times (step S109). ). When the stop signal is input (YES in step S109), the control calculation unit 11 stops the operation of the motor system MS. When no stop signal is input (NO in step S109), whether or not there is a change in the magnitude of the load next is, for example, a drive current value output from the signal output unit 14 and a predetermined second threshold value The control calculation unit 11 determines by comparing (step S111). Since the drive current value increases as the load increases, for example, the drive current value being larger than the predetermined second threshold indicates that the load has changed. If there is a change in the magnitude of the load (YES in step S111), the control calculation unit 11 performs the cycle control again a predetermined number of times again (step S107). If there is no change in the magnitude of the load (NO in step S111), the control calculation unit 11 then performs control to rotate the motors 21 and 22 at a predetermined second frequency (step S113), and the above stop And the determination of load fluctuation are repeated (steps S109 and S111).

  In addition, when performing the periodic control, the control calculation unit 11 may determine whether each motor has caused so-called step-out. For example, when the drive voltage is within a predetermined range and the frequency (rotational speed) of the motor 21 or 22 is lower than a predetermined value, the control calculation unit 11 determines that the motor has stepped out. When the motor performs the step-out, the rotation operation of the motors 21 and 22 is stopped. The motors 21 and 22 may be restarted after the stop. The determination of the occurrence of step-out may be performed in the normal control.

  Next, the cycle control will be described. In the cyclic control, for example, the detection unit 17 detects individual rotation position signals of the specific phase of a plurality of motors connected to the control device 1, and the individual rotation position signal of one motor among the plurality of motors is a predetermined condition. Is satisfied, the detection unit 17 sets the one motor corresponding to the individual rotational position signal satisfying the predetermined condition as the specific motor, and the specific motor detected by the rotational position detection unit 11b. In this control, the control calculation unit 11 outputs a control signal Sx to each gate of the plurality of switching elements Sw based on the individual rotational position signal. The predetermined condition is, for example, that the cycle of the individual rotational position signal of any one of the plurality of motors (specific motor) is equal to or greater than a preset threshold value. That the cycle of the individual rotational position signal of the specific motor is equal to or greater than a preset threshold indicates that the rotational speed of the specific motor is lower than the allowable rotational speed for normal operation due to, for example, a load. In the present embodiment, a value twice the reference value in the individual rotational position signal H1u of the motor 21 or the individual rotational position signal H2u of the motor 22 is the cycle of the individual rotational position signal of each motor. The predetermined condition is that the multiplication is equal to or greater than a preset threshold value. The predetermined condition is determined by the detection unit 17. The specific motor is determined as follows. When there are two motors, the detection unit 17 alternately detects and detects the individual rotational position signal of the specific phase of the motor 21 and the individual rotational position signal of the specific phase of the motor 22. Among the individual rotational position signals, a motor corresponding to the individual rotational position signal that satisfies the predetermined condition is set as the specific motor. When there are three or more motors, the detecting unit 17 detects the individual rotational position signals of the specific phases of the three or more brushless DC motors in order, and detects the detected individual rotational position signals. Among these, the motor corresponding to the individual rotational position signal that satisfies the predetermined condition is set as the specific motor.

  In the present embodiment, the superimposed rotation position signal includes at least a first change mode in which a second change in which the voltage of the superimposed rotation position signal changes after a first change in which the current in the superimposed rotation position signal changes, and superimposed rotation. And a second change mode in which a fourth change in which the current of the superimposed rotation position signal changes after a third change in which the voltage of the position signal changes, and the second change mode occurs after the first change mode. The first change pattern is periodically repeated. Therefore, in this embodiment, the detection unit 17 detects each individual rotational position signal of the specific phase, and sets the motor corresponding to the individual rotational position signal that satisfies the predetermined condition as the specific motor. Then, the rotational position detection unit 11b corresponds to the specific phase among the plurality of voltage change detection units in the detection circuit 11a based on the first change pattern that is periodically repeated in the superimposed rotational position signal of the specific phase. The voltage change detected by the detected voltage change detection unit, and the current change detected by the current change detection unit corresponding to the specific phase among the resistors Ru, Rv, and Rw as the plurality of current change detection units. Are alternately prioritized to detect the current change timing of the rotational position signal in the specific motor among the plurality of motors. When the predetermined condition is satisfied, the control calculation unit 11 generates a control signal Sx for generating a drive signal for driving the specific motor based on the detected rotation position signal in the specific motor. Output to each gate of the plurality of switching elements Sw. In the cycle control, the control calculation unit 11 feeds back the rotation speed of a specific motor calculated from the cycle of the individual rotation position signal of the specific motor, for example, in order to keep the conveyance speed of the conveyed product constant. So-called PI control or PID control is performed.

  FIG. 4 is a flowchart showing an example of the cycle control operation in step S107. Step S107 is executed by the control calculation unit 11 after the step S105 or the step S111 as described above. In the cycle control, any one of superimposed rotation position signals Hu, Hv, and Hw is used. First, the detection circuit 11a detects the current change of the superimposed rotational position signal of each phase by detecting the voltage change of the voltage across the resistors Ru, Rv, and Rw as a plurality of current change detection units as described above. Then, the detection target determining unit 11c detects, for example, a current change such as a down edge of the superimposed rotational position signal of each phase by the resistors Ru, Rv, Rw, and then the voltages of the superimposed rotational position signals Hu, Hv, Hw. The phase change corresponding to the voltage change detecting unit detecting the down edge is used by the voltage change detecting unit of each phase in the detection circuit 11a detecting the signal in which the down edge is generated first in the waveform. The signal phase (specific phase) is set (step S1071). By using any one of the superimposed rotation position signals Hu, Hv, and Hw, a constant period is obtained compared to the case where a plurality of signals of the superimposed rotation position signals Hu, Hv, and Hw are used. Changes can be detected. In the following, the down edge of the superimposed rotation position signal Hu is detected first, and the detection target determining unit 11c uses the superimposed rotation position signal Hu as the u phase as the specific phase.

  Since the cycle control is performed a predetermined number of times, next, the control calculation unit 11 resets the variable T for counting the number of times (step S1072). Thereafter, the detection circuit 11a detects the first change in the current waveform of the superimposed rotation position signal Hu from the voltage change in the voltage across the resistor Ru as a plurality of current change detection units. Specifically, after the first down edge is detected in the voltage waveform of the superimposed rotation position signal Hu in step S1071, for example, the current waveform of the superimposed rotation position signal Hu includes a plurality of down edges. The first down edge is detected (step S1073). Subsequently, the detection circuit 11a detects a second change in the voltage waveform of the superimposed rotation position signal Hu. Specifically, the detection circuit 11a detects, for example, the first up edge of the voltage waveform of the superimposed rotation position signal Hu after all the down edges of the current waveform of the superimposed rotation position signal Hu (step S1074). The detection unit 17 detects the individual rotation position signal by giving priority to the current change and the voltage change thus detected in this order.

  Thereafter, the detection circuit 11a detects a third change in the voltage waveform of the superimposed rotation position signal Hu. Specifically, the detection circuit 11a detects the first down edge of the voltage waveform of the superimposed rotation position signal Hu after the up edge of the voltage waveform of the superimposed rotation position signal Hu, for example (step S1075). Subsequently, the detection circuit 11a detects the fourth change in the current waveform of the superimposed rotation position signal Hu from the voltage change in the voltage across the resistor Ru as a plurality of current change detection units. Specifically, the detection circuit 11a detects the up edge of the first current waveform after the detection of the down edge of the voltage waveform of the superimposed rotation position signal Hu in step S1075. For example, since a plurality of up edges are included in the current waveform of the superimposed rotation position signal Hu, the detection circuit 11a determines the last up edge from among the plurality of up edges following the up edge of the current waveform detected first. Detection is performed (step S1076). Since the rotational position detector 11b counts the number of up edges and the like of the current waveform at the last up edge of the current waveform, the up edge is the “total number of motors connected to the control device 1” in the current change. It turns out from that. The up edge of the superimposed rotation position signal is detected from the voltage waveform for the first one as described above. Therefore, in this embodiment, the last up edge of the current waveform detected by the rotation position detection unit 11b. Is “(total number of motors connected to the control device 1) −1”. The detection unit 17 detects the individual rotation position signal by giving priority to the voltage change and the current change thus detected in this order.

  In each step of Step S1073 to Step S1076, when the individual rotational position signal of the motor 21 or the motor 22 satisfies the predetermined condition, the detection unit 17 performs a motor corresponding to the individual rotational position signal that satisfies the predetermined condition. Let (the motor 21 or the motor 22) be the specific motor. Then, the rotational position detection unit 11b detects the rotational position signal in the specific motor (motor 21 or motor 22) of a plurality of motors by alternately giving priority to the voltage change and the current change. Based on the individual rotational position signal in this specific motor, the control calculation unit 11 outputs a control signal Sx to each gate of the plurality of switching elements Sw. For example, when the cycle of the individual rotational position signal of a specific motor is equal to or greater than a preset threshold value and the rotation speed of the specific motor is reduced, in order to recover the reduced rotation speed to the rotation speed of normal operation, The control calculation unit 11 outputs a control signal Sx for increasing the voltage of the drive signal to each gate of the plurality of switching elements Sw. When the individual rotational position signals of the motor 21 and the motor 22 do not satisfy the predetermined condition, the control calculation unit 11 outputs the control signal Sx so as to maintain the drive signal output so far. Keep it as it is.

  Next, whether or not the cycle control has been performed a predetermined number of times is determined by the control calculation unit 11 by comparing the variable T with the predetermined number of times (step S1077). When the variable T has not reached the predetermined number of times (NO in step S1077), the control calculation unit 11 increments the variable T (step S1078) and repeats the flow from step S1073 to step S1077. If the variable T is equal to the predetermined number of times (YES in step S1077), then the determination in step S109 of FIG.

  In step S1074 and step S1075, the detection circuit 11a detects the voltage change of the superimposed rotation position signal Hu, and detects the up edge in step S1074 and the down edge in step S1075. The current waveform change may be detected from the voltage change of the voltages across the resistors Ru, Rv, and Rw, which are a plurality of current change detection units, which have substantially the same change timing as the change, and the detection may be performed. In this case, the last up edge of the current waveform detected by the rotational position detector 11b is the “total number of motors connected to the control device 1”.

  In the cycle control flowchart, step A consisting of steps S1073 and S1074 for detecting the first change mode of the superimposed rotational position signal, and step S1075 and step S1076 for detecting the second change mode of the superimposed rotational position signal. B is repeated a predetermined number of times. For example, in FIG. 2B, since the individual rotational position signal H1u is an output from the motor 21 and the individual rotational position signal H2u is an output from the motor 22, the process A includes the individual rotational position signal of the motor 21. The process B is a process in which the individual rotational position signal of the motor 22 is detected. That is, the detection unit 17 alternately gives priority to the current change and the voltage change in this order by repeating Step A while the detection operation of Step A and the detection operation of Step B are alternately repeated. By detecting the rotational position signal of the specific phase of the motor 21 and repeating the step B to alternately prioritize the voltage change and the current change in this order, the specific phase of the motor 22 is detected. The rotational position signal is detected.

  In step S1073, in step S1073, the down edge waveform of the voltage waveform of the individual rotational position signal H1u is not detected from the down edge of the voltage waveform of the superimposed rotational position signal Hu, but as shown in FIG. The down edge waveform change timing of the voltage waveform of the individual rotation position signal H1u can be detected from the change timing of the current waveform of the individual rotation position signal H1u. Subsequently, in step S1074, the up-edge waveform of the voltage waveform of the individual rotational position signal H1u can be detected from the up-edge of the voltage waveform of the superimposed rotational position signal Hu. In step S1075, the down edge waveform of the voltage waveform of the individual rotation position signal H2u can be detected from the down edge of the voltage waveform of the superimposed rotation position signal Hu. Subsequently, in step S1076, the up edge waveform of the voltage waveform of the individual rotation position signal H2u is not detected from the up edge of the voltage waveform of the superimposed rotation position signal Hu, but as shown in FIG. The up edge waveform change timing of the voltage waveform of the signal H2u can be detected from the change timing of the current waveform of the individual rotational position signal H2u. According to this configuration, the control device 1 detects the individual rotational position signal of the motor 21 and the individual rotational position signal of the motor 22 alternately, and selects the motor corresponding to the rotational position signal that satisfies the predetermined condition. By providing the specific motor and the rotational position detector 11b that detects the individual rotational position signal in the specific motor, the speed can be controlled to be constant regardless of whether the motor 21 or the motor 22 is loaded.

  Contrary to the above example, when the individual rotational position signal H1u in FIG. 2B is an output from the motor 22 and the individual rotational position signal H2u is an output from the motor 21, the transport device transports. When the motors 21 and 22 can output a torque capable of conveying an object, it is possible to synchronously control the two rotational operations of the motor 21 and the motor 22 connected by the single control device 1 by the cycle control. is there. When the motors 21 and 22 cannot output the torque with which the transport device can transport the transported object, the motor 21 or the motor 22 steps out, so the motor 21 or the motor 22 is stopped.

  Next, the prior art in which one motor is connected to one control device will be described. Here, FIG. 1 is used, and an example in which only the motor 21 is connected to the control device 1 will be described. In this case, the rotational position signal H (Hu, Hv, Hw) is not superimposed and is an individual rotational position signal of the motor 21.

  FIG. 5 is a timing chart for explaining the control performed by the conventional control device. In FIG. 5, the waveform diagram of the rotational position signal, the waveform diagram of the output voltage of the signal output unit 14, and the switching element in which the ON signal is input to the gate are represented by the mechanical angle on the horizontal axis. In the waveform diagram of the rotational position signal, waveforms of the rotational position signals Hu, Hv, and Hw are shown in order from the top. In the output voltage waveform diagram, waveforms of output voltages of the signal output units 14u, 14v, and 14w are shown in order from the top. Regarding the switching elements in which the ON signal is input to the gate, the reference numerals of the two switching elements in which the ON signal is input to the gate are shown in a predetermined section of the mechanical angle.

  Since the motor 21 has three magnetic field coils on the stator side and two permanent magnets on the rotor, the rotational position signal Hu is switched from a low level to a high level at a mechanical angle of 60 degrees, for example. Switch from high level to low level at 240 degrees. The rotational position signal Hv switches from a low level to a high level at a mechanical angle of 180 degrees, for example, and switches from a high level to a low level at a mechanical angle of 360 degrees (0 degrees). The rotational position signal Hw switches from a low level to a high level at a mechanical angle of 300 degrees, for example, and switches from a high level to a low level at a mechanical angle of 120 degrees. In response to such a change in each rotation position signal, the control calculation unit 11 outputs a signal for turning on each switch with the following regularity, for example, to each gate of the plurality of switching elements Sw. That is, the control calculation unit 11 has a mechanical angle of 0 degrees to 60 degrees and a mechanical angle of 60 degrees to 120 degrees with respect to the switching elements c1 and b2, and a mechanical angle of 120 degrees to 180 degrees with respect to the switching elements a1 and b2. With respect to the switching elements a1 and c2, the mechanical angle is 180 degrees to 240 degrees, and with respect to the switching elements b1 and c2, the mechanical angle is 240 degrees to 300 degrees, and the mechanical angle is 300 degrees to 360 degrees with respect to the switching elements b1 and a2. A high level signal is output to the switching elements c1 and a2 at (0 degree).

  As a result, the output voltage of the signal output unit 14u is 0v at a mechanical angle of 0 to 60 degrees, positive voltage at a mechanical angle of 60 to 180 degrees, 0 v at a mechanical angle of 180 to 240 degrees, and negative at a mechanical angle of 240 to 360 degrees. It is a voltage. The output voltage of the signal output unit 14v is a negative voltage at a mechanical angle of 0 to 120 degrees, 0 v at a mechanical angle of 120 to 180 degrees, a positive voltage at a mechanical angle of 180 to 300 degrees, and 0 v at a mechanical angle of 300 to 360 degrees. It has become. The output voltage of the signal output unit 14w is a positive voltage when the mechanical angle is 0 to 60 degrees, 0 v when the mechanical angle is 60 to 120 degrees, a negative voltage when the mechanical angle is 120 to 240 degrees, and 0 v when the mechanical angle is 240 to 300 degrees. A positive voltage is obtained at an angle of 300 to 360 degrees.

  As described above, in the conventional technique in which only one motor is connected to one control device, the control calculation unit 11 switches each switching corresponding to each rotational position signal Hu, Hv, Hw shown in FIG. On / off control of the elements a1 to c2 is performed. However, when a plurality of motors are connected to one control device as in the present embodiment, the rotational position signals (individual rotational position signals) from each motor are superimposed and input to the control device. As described above, the high-level section and the low-level section of each (superimposed) rotational position signal Hu, Hv, and Hw do not have a mechanical angle of 180 degrees, and the prior art control device performs each rotation for each motor. The position signals Hu, Hv, Hw cannot be detected. Therefore, the conventional control device cannot synchronize the rotation operations of the plurality of motors.

  On the other hand, the brushless DC motor control device 1 and the motor system MS of the present embodiment have a superimposed rotational position signal that changes due to a phase difference between the individual rotational position signals generated according to the rotational position of each of the rotors. For example, the current change timing of the individual rotational position signal (individual rotational position signal H1u or the like) superimposed on the superimposed rotational position signal can be detected from the current change in the superimposed rotational position signal Hu or the like. Therefore, the brushless DC motor control device 1 and the motor system MS of the present embodiment rotate in a predetermined phase (for example, u phase) as shown in FIG. 5 based on the detected individual rotation position signal of the specific motor. Based on the change timing of the position signal, it is possible to control to output an ON signal at a predetermined mechanical angle to each switching element.

  As described above, the brushless DC motor control device 1 and the motor system MS according to the present embodiment have a specific phase (e.g., u phase) in the superimposed rotational position signal of each phase input to the signal input unit 13 by the detection unit 17. ) To detect the individual rotational position signal in a specific motor among the plurality of motors, and the drive control unit 12 detects the individual rotational position signal in the specific motor detected by the detection unit 17. Based on this, a drive signal for driving a specific motor is generated. That is, the brushless DC motor control device 1 and the motor system MS can output a plurality of drive signals by outputting a drive signal from the signal output unit 14 even if superimposed rotation position signals from a plurality of motors are input to the signal input unit 13. Can be driven. Therefore, the brushless DC motor control device 1 and the motor system MS can drive a plurality of motors with a single device.

  Next, an example in which the motor system MS of the present embodiment is applied to a transport device used in a production line will be described. FIG. 6 is a diagram showing a configuration of a motor built-in roller using the motor system MS of the present embodiment. FIG. 7 is a diagram illustrating a configuration of a transport device using the motor system MS of the present embodiment. FIG. 8 is a diagram illustrating a configuration of another transport device using the motor system MS of the present embodiment. FIG. 6 shows an example of a roller with a built-in motor used in a conveying device in which two motors 21 and 22 are built in both ends of one roller. FIG. 7 shows a conveying device L that uses six driven rollers that freely rotate without a built-in motor and one built-in motor roller that is disposed between the motors 21 and is built in the production line. And a built-in motor with six driven rollers and one motor 22 built in between, and spaced apart from the conveying device L so that the conveying directions are parallel and in the same direction. An example of a transport device R in which one roller is used is shown. FIG. 7 shows the transfer devices L and R in a part of the production line. 8 includes a plurality of driven rollers and a plurality of motor built-in rollers (two motors 21 and 22 in FIG. 8) disposed with a predetermined interval therebetween. An example of SI is shown. FIG. 8 shows the transfer device SI in a part of the production line.

  In FIG. 6, since one roller is rotated by two motors, the two motors need to rotate synchronously. In FIG. 7, the two production lines are used when, for example, a long and narrow conveyance object is conveyed, and the two production lines are perpendicular to the traveling direction of the two production lines and the longitudinal direction of the conveyance object. When the transported object is being transported, the two motors need to rotate synchronously. Moreover, in FIG. 8, when one conveyed product is simultaneously conveyed by two motor built-in rollers, the two motors need to rotate synchronously. Therefore, by using the motor system MS of the present embodiment, it becomes possible to synchronously control the rotation operations of the two motors with a single control device, and therefore it is suitably used for the devices shown in the drawings.

  In the above embodiment, the number of motors connected to one control device 1 is two. However, N (N is an integer of 3 or more) three-phase brushless DC motors are connected to one control device 1. May be. The rotational position detector 11b individually rotates specific motors for all the rotors of, for example, 1 to N three-phase brushless DC motors based on the detection result of the current change of the superimposed rotational position signal in the detection circuit 11a. When the change timing of the current of the position signal is detected, the control calculation unit 11 drives the specific motor using the detection result when the individual rotational position signal of one motor satisfies a predetermined condition. A control signal Sx for generating a driving signal is output to each gate of the plurality of switching elements Sw. In this case, the superimposed rotation position signal includes at least a first change mode and a third change in which a sixth change in which the current in the superimposed rotation position signal changes after the fifth change in which the current in the superimposed rotation position signal changes. And a second change pattern in which the third change mode occurs after the first change mode and the second change mode occurs after the third change mode. Repeat periodically. Therefore, the detection unit 17 detects each individual rotational position signal of the specific phase, and sets the motor corresponding to the individual rotational position signal that satisfies the predetermined condition as the specific motor. Then, the rotational position detector 11b is based on the second change pattern that is periodically repeated in the superimposed rotational position signal of a specific phase, and the specific one of the resistances Ru, Rv, and Rw as the plurality of current change detectors. The timing of the current change of the individual rotational position signal in the specific motor among the three or more brushless DC motors is detected by two continuous current changes detected by the current change detection unit corresponding to the phase. When the predetermined condition is satisfied, the control calculation unit 11 generates a control signal Sx for generating a drive signal for driving the specific motor based on the detected rotation position signal in the specific motor. Output to each gate of the plurality of switching elements Sw. In this case, the following periodic control is performed. FIG. 9 is a flowchart showing another operation in which there are three or more motors in the periodic control operation in step S107. With reference to FIG. 9, a description will be given below with an example of the superimposed rotation position signal Hu, centering on points different from FIG.

  For example, when the number of motors connected to the control device 1 is five (N = 5), first, for the first motor, the detection circuit 11a detects the voltage change of the voltage across the resistor Ru as a plurality of current change detection units. The first down edge of the current change in the superimposed rotation position signal Hu is detected (step S1073 ′, corresponding to step S1073), and then the up edge of the voltage waveform of the superimposed rotation position signal Hu is detected (step S1074 ′, step S1074). (Step A ′).

  Next, for the second motor, the detection circuit 11a detects the second (second) down edge next to the current change of the superimposed rotation position signal Hu from the voltage change of the voltage across the resistor Ru as a plurality of current change detection units. After that, the second up edge of the current change of the superimposed rotation position signal Hu is detected (step S1079) (step A (2)). Similarly, for each of the third and fourth motors, the detection circuit 11a sequentially detects the third down edge of the current change in the superimposed rotation position signal Hu and the third up edge that occurs after the down edge (step S1080). (Step A (3)), and the fourth down edge and the fourth up edge generated after the down edge are detected (Step S1081) (Step A (4)). In step A (2) to step A (4), the third change mode of the superimposed rotation position signal is detected. In addition, the rotational position detection part 11b is the resistance of Ru, Rv, Rw about the 2nd-4th motor among the said 5 motors like said process A (2) -A (4). A current change in two consecutive superimposed rotation position signals detected by the resistors Ru, Rv, Rw (in this embodiment, the resistance Ru) corresponding to the specific phase (the current change in the superimposed rotation position signal Hu). An individual rotational position signal in a specific motor among the three or more brushless DC motors is detected by a down edge and a subsequent up edge).

  Next, for the fifth motor, the detection circuit 11a detects the down edge of the voltage waveform of the superimposed rotation position signal Hu (step S1075 ′, which corresponds to step S1075), and then a plurality of resistors Ru serving as a plurality of current change detection units. The fifth up edge of the current change of the superimposed rotation position signal Hu is detected from the voltage change of the both-end voltage (step S1076 ′, corresponding to step S1076) (step B ′). Note that after step B ', the steps after step A' are repeated up to a predetermined number of times (NO in step S1077).

  In each of the steps A ′, A (2), A (3), A (4) and the step B ′, the detection unit 17 sequentially outputs the individual rotational position signals of the five motors. And when any of the five motors detects that the individual rotational position signal satisfies a predetermined condition, the motor corresponding to the individual rotational position signal that satisfies the predetermined condition is A specific motor is used. The rotational position detection unit 11b is configured to rotate the rotational position when two of the five motors (for example, the first motor and the fifth motor) are the specific motors. The detection unit 11b detects the voltage change detected by the voltage change detection unit corresponding to the specific phase among the plurality of voltage change detection units, and the specific phase among the plurality of current change detection units. The rotational position signal is detected by alternately giving priority to the current change detected by the corresponding current change detection unit. In addition, when a motor other than the predetermined two motors among the five motors (for example, the second motor to the fourth motor) is the specific motor, a rotational position detector 11b detects the rotational position signal based on two consecutive current changes detected by a current change detector corresponding to the specific phase among the plurality of current change detectors. The control calculation unit 11 outputs a control signal Sx to each gate of the plurality of switching elements Sw. When the individual rotational position signals of the motor 21 and the motor 22 do not satisfy the predetermined condition, the control calculation unit 11 performs a plurality of switching of the control signal Sx that maintains the output of the drive signal that has been output until then. Output to each gate of the element Sw.

  Although not illustrated in FIG. 2B, when there are three or more motors, the phase difference α between the individual rotational position signal H1u and the individual rotational position signal H2u in FIG. 2B is the largest. In this case, there are one or more individual rotational position signals whose phase difference from the individual rotational position signal H1u is smaller than the phase difference α. The individual rotational position signal (not shown) can be detected as follows. By observing the current signal of the superimposed rotational position signal Hu, the down edge of the individual rotational position signal H1u, which is the first down edge of the current signal, can be detected, and the timing of the down edge of the voltage waveform of the superimposed rotational position signal Hu. Substantially coincides with the timing of the down edge of the individual rotational position signal H2u, which is the last down edge of the current signal, so that the timing of the last down edge of the current signal can be detected. In addition, the rotational position detection unit 11b can detect each down edge between the first down edge and the last down edge of the current signal by counting the number of down edges of the current signal, and the plurality of the above-described inconveniences. Each down edge of the illustrated individual rotational position signal can be detected. On the other hand, the timing of the up edge of the voltage waveform of the superimposed rotation position signal Hu substantially coincides with the timing of the up edge of the individual rotation position signal H1u, which is the first up edge of the current signal. Is detectable. Further, the current signal of the superimposed rotational position signal Hu is observed, and the rotational position detector 11b detects the down edge of the individual rotational position signal H2u that is the last up edge of the current signal by counting the number of up edges. Is possible. Further, the rotational position detector 11b can detect each up edge between the first up edge and the last up edge of the current signal by counting the number of down edges, and a plurality of the individual rotations (not shown). Each up edge of the position signal is detectable. As described above, in the processes A ′, A (2), A (3), A (4), and B ′, the up edge and the down edge of the individual rotational position signal from each motor are It can be detected.

  According to this configuration, the control device 1 includes the three units by the periodic control including the step A ′, the step A (2), A (3), A (4), the step B ′, and the like. Rotation position detection for detecting the individual rotation position signals of the above motors in order, and detecting the individual rotation position signal in the specific motor using the motor corresponding to the individual rotation position signal satisfying the predetermined condition as the specific motor. By providing the unit 11b, the speed can be controlled to be constant regardless of the load applied to any of the three or more motors.

  The control for synchronizing the rotational operations of the N units (N is an integer of 3 or more) of the three-phase brushless DC motors is not limited to the above. For example, the steps A and B described with reference to FIG. The cycle control included may be included. This is due to the following reason. That is, in FIG. 2B, when the phase difference α between the individual rotational position signal H1u of the first motor and the individual rotational position signal H2u of the Nth motor is the largest, 2− (N−1 ) The phase difference between the individual rotational position signal of the first motor and the individual rotational position signal of the first motor is the level of the individual rotational position signal of the first motor and the individual rotational position signal of the Nth motor. It is smaller than the phase difference α. Therefore, if the first motor and the Nth motor are rotating synchronously, the remaining 2- (N-1) th motors can also rotate synchronously. is there. In this case, the specific motor is the first motor or the Nth motor. At this time, the detection unit 17 alternately detects the individual rotational position signals of the specific phase of the first motor and the individual rotational position signals of the specific phase of the Nth motor. The motor corresponding to the individual rotational position signal that satisfies the predetermined condition is set as the specific motor. Then, the rotational position detector 11b includes the first and N-th three-phase brushless direct currents based on the first change pattern that is periodically repeated including the first change mode and the second change mode. The current change timing of the individual rotational position signal is detected for the two rotors of the motor. The control calculation unit 11 performs cycle control for outputting a control signal Sx for generating a drive signal for driving the specific motor to each gate of the plurality of switching elements Sw using the detection result.

  When the load applied to each motor does not reach step-out, the process A ′ and the process A described using FIG. 9 by the periodic control including the process A and the process B (FIG. 4). (2), A (3)... A (N-1) and the control including the step B ′ are simpler than the periodic control, and one controller 1 can rotate a plurality of brushless DC motors. Synchronous control is possible.

  In order to express the present invention, the present invention has been described appropriately and fully through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

H, Hu, Hv, Hw Superposition rotation position signal (superposition signal)
H1, H1u, H1v, H1w, H2, H2u, H2v, H2w Individual rotation position signal (rotation position signal)
Iu, Iv, Iw Current value of superimposed rotation position signal Vu, Vv, Vw Voltage value of superimposed rotation position signal 1 Controller 11a Detection circuit (including voltage change detection unit)
11b Rotational position detection unit 11c Detection target determination unit 11d Forced commutation drive control unit 12 Drive control unit 13, 13u, 13v, 13w Signal input unit 14, 14u, 14v, 14w Signal output unit 17 Detection unit 21, 22 Brushless DC motor 211, 211u, 211v, 211w, 221, 221u, 221v, 221w Hall IC (position detection sensor)
Ru, Rv, Rw resistance (current change detector)

Claims (11)

A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input unit for inputting a superimposed signal of each phase obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detecting unit for detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superimposed signal of a specific phase among superimposed signals of each phase input to the signal input unit;
A drive control unit that generates a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected by the detection unit;
A signal output unit for outputting a drive signal generated by the drive control unit as a drive signal of each of the plurality of brushless DC motors;
The detector is
A plurality of voltage change detection units provided for each of the phases and detecting a voltage change of the superimposed signal;
A plurality of current change detection units that are provided for each phase and detect a current change of the superimposed signal;
The voltage change detected by the voltage change detection unit corresponding to the specific phase among the plurality of voltage change detection units, and the current change detection corresponding to the specific phase among the plurality of current change detection units. A rotation position detection unit that detects the rotation position signal in the specific brushless DC motor among the plurality of brushless DC motors by alternately giving priority to the current change detected by the unit. features and be Lube Rashiresu DC motor controller. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input unit for inputting a superimposed signal of each phase obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detecting unit for detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superimposed signal of a specific phase among superimposed signals of each phase input to the signal input unit;
A drive control unit that generates a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected by the detection unit;
A signal output unit for outputting a drive signal generated by the drive control unit as a drive signal of each of the plurality of brushless DC motors;
The plurality of brushless DC motors are two first and second brushless DC motors,
The detection unit alternately detects and detects the rotational position signal of the specific phase of the first brushless DC motor and the rotational position signal of the specific phase of the second brushless DC motor. of the rotating position signal, the rotation of said brushless DC motor corresponding to a position signal the specific brushless DC motor, wherein the to Lube Rashiresu DC motor controller to a predetermined condition is satisfied. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input unit for inputting a superimposed signal of each phase obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detecting unit for detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superimposed signal of a specific phase among superimposed signals of each phase input to the signal input unit;
A drive control unit that generates a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected by the detection unit;
A signal output unit for outputting a drive signal generated by the drive control unit as a drive signal of each of the plurality of brushless DC motors;
The plurality of brushless DC motors are N brushless DC motors (N is an integer of 3 or more),
The detector is
A plurality of current change detection units that are provided for each phase and detect a current change of the superimposed signal;
The i-th falling current change detected by the current change detecting unit corresponding to the specific phase among the plurality of current change detecting units and the i-th rising current change (i is N or less). A natural number), a rotational position detection unit for detecting the rotational position signal in the specific brushless DC motor among the N brushless DC motors,
The rotational position signals of the specific phase of the N brushless DC motors are sequentially detected, and the brushless corresponding to the rotational position signal satisfying a predetermined condition among the detected rotational position signals. features and be Lube Rashiresu DC motor controller to the DC motor and the specific brushless DC motor. The brushless DC motor control device according to claim 2 or 3 , wherein the predetermined condition is that a length of one cycle of the rotational position signal is equal to or greater than a preset threshold value. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input unit for inputting a superimposed signal of each phase obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detecting unit for detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superimposed signal of a specific phase among superimposed signals of each phase input to the signal input unit;
A drive control unit that generates a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected by the detection unit;
A signal output unit for outputting a drive signal generated by the drive control unit as a drive signal of each of the plurality of brushless DC motors;
The detector is
A plurality of voltage change detection units provided for each of the phases and detecting a voltage change of the superimposed signal;
A plurality of current change detection units that are provided for each phase and detect a current change of the superimposed signal;
After detecting the current change of the superimposed signal of each phase by the plurality of current change detection units, the detection target having the phase corresponding to the voltage change detection unit that first detected the voltage change of the superimposed signal as the specific phase features and be Lube Rashiresu DC motor controller further comprising a determination unit. A forced commutation drive control unit configured to generate a forced commutation drive signal for driving the plurality of brushless DC motors by forced commutation, and to output the generated forced commutation drive signal from the signal output unit. The brushless DC motor control device according to any one of claims 1 to 5 . A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A plurality of brushless DC motors,
A motor system comprising: the brushless DC motor control device according to any one of claims 1 to 6 . A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input step of receiving a superimposed signal of each phase, which is obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detection step of detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superposition signal of a specific phase among the superposition signals of each phase received in the signal input step;
A drive control step of generating a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected in the detection step;
A signal output step of outputting the drive signal generated in the drive control step as a drive signal of each of the plurality of brushless DC motors from a signal output unit,
The detection step includes
A plurality of voltage change detection steps provided for each of the phases and detecting a voltage change of the superimposed signal;
A plurality of current change detection steps provided for each of the phases and detecting a current change of the superimposed signal;
The voltage change detected by the voltage change detection step corresponding to the specific phase of the plurality of voltage change detection steps, and a current change detection corresponding to the specific phase of the plurality of current change detection steps. A rotation position detection step of detecting the rotation position signal in the specific brushless DC motor among the plurality of brushless DC motors by alternately giving priority to the current change detected in the step. A brushless DC motor control method characterized by the above. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input step of receiving a superimposed signal of each phase, which is obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detection step of detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superposition signal of a specific phase among the superposition signals of each phase received in the signal input step;
A drive control step of generating a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected in the detection step;
A signal output step of outputting the drive signal generated in the drive control step as a drive signal of each of the plurality of brushless DC motors from a signal output unit,
The plurality of brushless DC motors are two first and second brushless DC motors,
The detecting step alternately detects and detects the rotational position signal of the specific phase of the first brushless DC motor and the rotational position signal of the specific phase of the second brushless DC motor. A brushless DC motor control method, wherein the brushless DC motor corresponding to the rotation position signal satisfying a predetermined condition among the rotation position signals is set as the specific brushless DC motor. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input step of receiving a superimposed signal of each phase, which is obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detection step of detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superposition signal of a specific phase among the superposition signals of each phase received in the signal input step;
A drive control step of generating a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected in the detection step;
A signal output step of outputting the drive signal generated in the drive control step as a drive signal of each of the plurality of brushless DC motors from a signal output unit,
The plurality of brushless DC motors are N brushless DC motors (N is an integer of 3 or more),
The detection step includes
A plurality of current change detection steps provided for each of the phases and detecting a current change of the superimposed signal;
The i-th falling current change detected by the current change detecting step corresponding to the specific phase among the plurality of current change detecting steps and the i-th rising current change (i is N or less). A natural position), a rotational position detecting step for detecting the rotational position signal in the specific brushless DC motor among the N brushless DC motors,
The rotational position signals of the specific phase of the N brushless DC motors are sequentially detected, and the brushless corresponding to the rotational position signal satisfying a predetermined condition among the detected rotational position signals. A brushless DC motor control method, wherein the DC motor is the specific brushless DC motor. A plurality of position detection sensors arranged to correspond to a plurality of phases at predetermined intervals in the rotation direction, detecting a rotation position of the rotor with respect to the stator and outputting a rotation position signal representing the rotation position. A signal input step of receiving a superimposed signal of each phase, which is obtained by superimposing a plurality of rotational position signals output from each of the plurality of position detection sensors in each of the plurality of position detection sensors in a plurality of brushless DC motors, for each phase;
A detection step of detecting a rotational position signal in a specific brushless DC motor among the plurality of brushless DC motors based on a superposition signal of a specific phase among the superposition signals of each phase received in the signal input step;
A drive control step of generating a drive signal for driving the specific brushless DC motor based on a rotational position signal in the specific brushless DC motor detected in the detection step;
A signal output step of outputting the drive signal generated in the drive control step as a drive signal of each of the plurality of brushless DC motors from a signal output unit,
The detection step includes
A plurality of voltage change detection steps provided for each of the phases and detecting a voltage change of the superimposed signal;
A plurality of current change detection steps provided for each of the phases and detecting a current change of the superimposed signal;
After detecting the current change of the superimposed signal of each phase by the plurality of current change detection steps, the detection target having the phase corresponding to the voltage change detection step of first detecting the voltage change of the superimposed signal as the specific phase And a determining step. A brushless DC motor control method comprising:

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