Control System

Abstract

Aim to supply power to both the detector and the motor. [Solution] A control system includes a driver and a motor to which power is supplied from the driver via a power line. The motor has an input unit that inputs power from the driver via the power line to a winding unit inside the motor, an extractor that extracts a portion of the power from the power line or the winding unit, a supply unit that supplies the power extracted by the extractor to a detector that detects movement of the motor's drive shaft, and a processing unit that sends a signal related to the power consumption required for operation of the detector to the driver. The driver has a receiving unit that receives the signal related to the power consumption applied by the processing unit, and an adjusting unit that adjusts the power supplied to the motor via the power line based on the signal related to the power consumption.

Description

[Technical Field]

[0001] The present invention relates to a motor control system. [Background technology]

[0002] For motors used to drive loads for various purposes, it is necessary to grasp the motor's state in order to accurately control it, and detectors such as encoders are generally used to do this. Power must be supplied to drive an encoder, and generally, a control system (e.g., a servo driver) and the encoder are connected by a cable, and power is supplied via the cable. As an alternative, Patent Document 1 discloses a configuration in which power is supplied to the encoder from a power supply configured differently from the control system. Specifically, Patent Document 1 discloses an auxiliary power supply for the encoder that operates when the power supplied to the encoder from the system drops for some reason.

[0003] Furthermore, as another form of power supply to an encoder, Patent Document 2 discloses a configuration in which power is supplied wirelessly from an external source to an encoder that communicates wirelessly with a servo system. Patent Document 3 also discloses a technology in which a portion of the power supplied from a driver to a motor for driving the motor is extracted and the extracted power is supplied to an encoder or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-251817 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-297389 [Patent Document 3] International Publication No. 2022 / 186199 Summary of the Invention [Problem to be solved by the invention]

[0005] To achieve precise control, such as servo control of a motor, an encoder is required to detect motor movement, and a detection signal related to the detected motor movement must be provided to a driver that performs servo control. In addition to encoders, a detector may detect the movement of the motor's drive shaft for motor drive control, and the detection results may be provided to the drive control. To operate such a detector, power must be supplied to the detector. This requires the installation of a cable to supply power to the detector, which can increase the wiring workload and the costs associated with the cable. While technologies for wirelessly supplying power to encoders have been proposed, it is not easy to implement them in practical situations.

[0006] On the other hand, while extracting a portion of the power supplied to the motor and supplying it to a detector such as an encoder, as in the prior art, may enable stable power supply to the detector, etc., there is a risk that the power supply to the motor may become unstable as a result of power extraction. In other words, if the power required to drive the motor as desired is supplied from the driver, there is a risk that the power extraction may result in a power shortage, which may hinder optimal motor control.

[0007] The present invention has been made in view of the above problems, and has an object to provide a technique for achieving both power supply to the detector and power supply to the motor. [Means for solving the problem]

[0008] A control system according to one aspect of the present invention includes a driver and a motor to which power is supplied from the driver via a power line. The motor has an input unit that inputs power from the driver via the power line to a winding unit inside the motor, an extractor that extracts a portion of the power from the power line or the winding unit, a supply unit that supplies the power extracted by the extractor to a detector that detects movement of a drive shaft of the motor, and a processing unit that transmits a signal related to power consumption required for operation of the detector to the driver. The driver has a receiving unit that receives the signal related to power consumption applied by the processing unit, and an adjusting unit that adjusts the power supplied to the motor via the power line based on the signal related to power consumption.

[0009] The motor may be a single-phase AC motor or a three-phase AC motor. The coils in the motor's winding section may be connected in a delta or star (or Y) configuration. The coils of the winding section may be wound around the motor's stator in a distributed or concentrated configuration. In other words, the motor of the present invention is not intended to impose any particular limitations on the specific configuration of the winding section. The detector may be, for example, an encoder, but is not limited to this. Other sensors capable of detecting the movement of the motor's drive shaft (such as a vibration sensor) may also be used.

[0010] The extractor may have any configuration as long as it has the function of extracting a portion of the power from the power line or the winding. As an example of the extractor, the extractor may be arranged so that a transformer structure is formed relative to the winding so that a portion of the power from the winding is input to its primary coil, and the extractor is configured to extract the portion of the power via the transformer structure. In this case, in the motor, the extractor extracts a portion of the driving power supplied to the motor via the power line as power for the detector, using the transformer structure arranged relative to the motor's winding. Here, the transformer structure is formed within the motor so that a portion of the AC current flowing through the winding is input to its primary coil. The transformer structure may be either an auto-winding transformer or a compound-winding transformer. In the case of an auto-winding transformer, the secondary coil refers to a portion of the primary coil that is shared by both the primary and secondary coils. An AC current is extracted from the secondary coil of the transformer structure according to the AC current flowing through the primary coil and the turns ratio (the ratio of the number of turns of the secondary coil to the number of turns of the primary coil) of the transformer structure. The supply unit may then rectify the extracted AC current and supply it to the detector. The supply unit may also transform the rectified voltage into a voltage suitable for driving the detector, as necessary. The supply unit may store the rectified power in a secondary battery, thereby enabling a more stable power supply to the detector.

[0011] In this way, by adopting a configuration in which a portion of the power in the power line or winding section is extracted as detector power and supplied to the detector, it is possible to supply power to the detector stably regardless of the position or posture of the motor, and since there is no need to run cables to supply power to the detector, the workload can be significantly reduced.

[0012] Here, the processing unit of the motor is configured to transmit to the driver a signal relating to the power consumption required for the operation of the detector, i.e., the power extracted by the extraction unit for power supply (hereinafter referred to as the "power consumption signal"). Any form can be adopted for the form of transmission of the power consumption signal by the processing unit. For example, the processing unit can apply a signal relating to the power consumption (power consumption signal) to the power line or the winding unit as a signal in a predetermined format so that the signal can be extracted on the driver side, thereby transmitting the signal relating to the power consumption to the driver. By adopting such a configuration, the power consumption signal is applied to the drive current flowing through the power line or the winding unit inside the motor, and is transmitted to the driver side via the winding unit and the power line connected thereto. Furthermore, the application of the power consumption signal can be in a predetermined format so that the power consumption signal can be extracted on the driver side. For example, the power consumption signal may be a signal having electrical characteristics (such as frequency or amplitude) that are physically distinguishable from the drive current flowing through the power line or windings to which the power consumption signal is applied.

[0013] As an alternative to the transmission of the power consumption signal by the processing unit, the processing unit may transmit the signal regarding the power consumption to the driver wirelessly. In this case, the driver may receive the power consumption signal directly from the processing unit, or may receive the signal via one or more repeaters arranged between the processing unit and the driver.

[0014] In the control system, the power consumption signal transmitted from the processing unit is received by a receiving unit on the driver side and is further used by an adjusting unit to adjust the power supply to the motor. That is, the adjusting unit on the driver side uses the power consumption signal transmitted from the motor side to adjust the power supply from the driver via the power line so that the power required to drive the motor as desired is appropriately supplied to the motor, even if power extraction for operating the detector is performed as described above.

[0015] As a result, in the above control system, it is possible to preferably supply power to the detector while reducing the wiring load on the detector, and it is also possible to ensure a suitable power supply to the motor, thereby achieving both power supply to the detector and power supply to the motor.

[0016] In the control system described above, the power adjustment by the adjustment unit may be performed by compensating the motor drive power required to drive the motor for the power consumption of the detector calculated based on the signal in the predetermined format. With this configuration, the power required to drive the motor as desired can be suitably supplied to the motor.

[0017] In the control system described above, the processing unit may be configured to transmit the detection signal of the detector to the driver together with the signal related to the power consumption. In particular, when the detection signal of the detector is transmitted to the driver by applying the power consumption signal together with the detection signal of the detector to the power line or the winding unit as described above, no communication cable is required for transmitting the detection signal, thereby reducing the work and costs required for wiring.

[0018] In the control system described above, the processing unit may be disposed on the power line, and the signal related to the power consumption may be transmitted wirelessly from the detector to the processing unit. Note that the arrangement of the processing unit and the transmission method from the detector to the processing unit are not limited to this, and any method may be adopted as long as no technical discrepancy occurs.

[0019] In the control system described above, the processing unit may be configured to apply the signal related to power consumption as a signal of the predetermined format having a fundamental frequency that does not overlap with a predetermined frequency related to the drive of the motor by the driver, and in this case, the processing unit may vary the fundamental frequency in accordance with fluctuations in the predetermined frequency. Note that if the predetermined frequency does not fluctuate or if the fluctuation is extremely small, it is not necessary to vary the fundamental frequency. In this way, for the signal of the predetermined format related to the application of the detection signal by the processing unit, by focusing on the predetermined frequency related to the drive of the motor and setting the fundamental frequency to a frequency that does not overlap with the predetermined frequency, it is possible to achieve reception of the detection signal on the driver side in a state that is less affected by the drive of the motor.

[0020] An example of the predetermined frequency may be the PWM frequency of the driver corresponding to the rotational speed of the motor, or a higher order frequency of the PWM frequency. Alternatively, the predetermined frequency may be a resonant frequency associated with a load driven by the motor. Alternatively, a frequency related to the driving of the motor in a manner other than those described above may be adopted as the predetermined frequency.

[0021] In the control system described above, the processing unit compares the signal relating to the power consumption with the amplitude of the drive current corresponding to a higher order frequency of the PWM frequency of the driver, and The predetermined format signal may be applied with an amplitude greater than or equal to a predetermined multiple. The predetermined multiple is a parameter that defines the scale of the signal to such an extent that, when extracting the signal related to power consumption in the driver, the signal related to power consumption can be stably distinguished when comparing the amplitude of the motor drive current and the amplitude of the signal related to power consumption. Therefore, the value of the predetermined multiple can be determined taking into consideration the accuracy of extraction of the signal related to power consumption in the driver.

[0022] In the control system described above, the extractor may be configured as a transformer having a primary coil and a secondary coil, and a portion of the power in the winding may be supplied from the primary coil to the supply unit via the secondary coil, and the processor may be configured to apply a signal related to the power consumption to the drive current of the motor flowing through the primary coil when the signal is input to the secondary coil. Note that the extractor and processor may have configurations other than those described above. That is, a transformer configuration corresponding to each of the extractor and processor may be installed in the motor. [Effects of the Invention]

[0023] It is possible to provide a technology that enables power supply to both the detector and the motor. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a control system that controls the drive of a motor. [Figure 2] FIG. 2 is a diagram illustrating a schematic configuration of a motor. [Figure 3] FIG. 1 is a first diagram schematically illustrating the arrangement of a winding section of a motor and a transformer structure provided for the winding section. [Figure 4] 10A and 10B are diagrams illustrating the fundamental frequency of a detection signal applied via a transformer structure provided in a winding portion. [Figure 5] 2 is a flowchart showing the flow of control regarding power supply executed between a motor and a driver in the control system shown in FIG. 1. [Figure 6] FIG. 10 is a diagram showing a schematic configuration of a motor according to a modified example. [Figure 7] FIG. 2 is a second diagram schematically illustrating the arrangement of the windings of the motor and the transformer structure provided for the windings. [Figure 8] FIG. 3 is a third diagram schematically illustrating the arrangement of the windings of the motor and the transformer structure provided for the windings. [Figure 9]FIG. 4 is a fourth diagram schematically illustrating the arrangement of the windings of the motor and the transformer structure provided for the windings. DETAILED DESCRIPTION OF THE INVENTION

[0025] Example 1 FIG. 1 is a diagram showing the schematic configuration of a control system that controls the drive of a motor. First, the control system will be described. The control system is a PLC (Programmable Logic Controller) 5 is connected to the network 1 as a host controller. A plurality of servo drivers 4 are connected to the network 1, and are configured to be able to send and receive signals to and from the PLC 5. Note that in FIG. 1, the functional configuration of one servo driver 4 is shown in detail as a representative example, but the other servo drivers 4a and 4b also have functional configurations equivalent to that of the servo driver 4. Also, the motor 2 is The motors 2a and 2b are connected to the servo drivers 4 via power lines 11 and receive a supply of driving power. Similarly, the motors 2a and 2b receive a supply of driving power from the servo drivers 4a and 4b via power lines 11a and 11b, respectively. Hereinafter, the structures of the motors and servo drivers will be described based on the motor 2 and servo driver 4 as representative examples.

[0026] Here, the motor 2 is driven and controlled according to commands from the PLC 5 to drive a predetermined load device. As an example, the load device may be various mechanical devices (e.g., an arm of an industrial robot or a conveying device), and the motor 2 is incorporated into the device as an actuator for driving the load device. The motor 2 is an AC servo motor. Alternatively, the motor 2 may be an induction motor or a DC motor. The motor 2 includes a motor body 21 having a stator including a winding formed by a coil wound around a stator core and a rotor incorporating a permanent magnet, and an encoder 22 having a detection disk that rotates in conjunction with the rotation of the rotor and can detect the rotation state of the rotor. The rotation detection by the encoder 22 may be an incremental method or an absolute method.

[0027] The detection signal from the encoder 22 is transmitted to the servo driver 4 via the power line 11 to a communication unit 42 of the servo driver 4, which will be described later. The transmitted detection signal is used for servo control in a control unit 41 of the servo driver 4, which will also be described later. The detection signal from the encoder 22 includes, for example, position information about the rotational position (angle) of the rotating shaft of the motor 2, information about the rotational speed of the rotating shaft, etc.

[0028] Here, the servo driver 4 has a control unit 41, a communication unit 42, and an adjustment unit 43. The control unit 41 is a functional unit that manages servo control of the motor 2 based on commands from the PLC 5. The control unit 41 receives an operation command signal related to the operation (motion) of the motor 2 from the PLC 5 via the network 1 and a detection signal transmitted from the encoder 22, and performs servo control related to the drive of the motor 2, i.e., calculates a command value related to the operation of the motor 2. The control unit 41 executes feedback control using a position controller, a speed controller, and a current controller. The control unit 41 is also configured to manage controls other than the servo control of the motor 2 that are performed by the servo driver 4.

[0029] The communication unit 42 is a functional unit that controls communication between the encoder 22 and the servo driver 4, such as receiving external signals, such as the detection signal from the encoder 22 and a power consumption signal (described later). In this embodiment, the detection signal from the encoder 22 is transmitted to the communication unit 42 via the power line 11, as will be described in detail later. The adjustment unit 43 is a functional unit that basically supplies drive power to the motor 2 via the power line 11 based on a command value related to the operation of the motor 2 calculated by the control unit 41, and further adjusts the power supplied to the motor 2 based on the power consumption signal received by the communication unit 42. Details of the adjustment unit 43 will be described later. The AC power sent from the AC power source 7 to the servo driver 4 is used to generate this supply power. In this embodiment, the servo driver 4 is a type that receives three-phase AC, but it may also be a type that receives single-phase AC. Alternatively, the servo driver 4 may be a type that receives DC.

[0030] Next, the schematic configuration of the motor 2 will be described with reference to FIG. 2. The motor 2 is a three-phase (U-phase, V-phase, W-phase) AC motor, and has a motor body 21 and an encoder 22. The motor body 21 includes a rotor 212 and a stator 213. A permanent magnet is incorporated in the rotor 212 and is rotatably supported. The stator 213 has a coil wound around a stator core formed from electromagnetic steel sheet, forming a winding section 25. In this embodiment, the connection mode of each phase in the winding section 25 is Y-connection, but it may alternatively be delta-connection. Furthermore, in this embodiment, the coil may be wound around the stator core in either distributed winding or concentrated winding. The configuration shown in FIG. 2 is merely schematic, and the details of the present invention will be described in detail below. The technical concept of the present invention can be applied regardless of the specific configuration of the motor.

[0031] The power line 11 for supplying drive power from the servo driver 4 is connected to a connector 211. The connector 211 corresponds to an input unit of the present invention. The connector 211 is connected to each phase of the winding unit 25. In the motor 2, a transformer structure (see 53, 63, 73, and 80 shown in FIG. 3 and the like; details will be described later) is arranged for the winding unit 25, and a processing unit 214 is provided that uses the transformer structure to perform predetermined electrical processing on the drive current of the motor 2 flowing through the winding unit 25. The transformer structure of the processing unit 214 allows electrical signals to be exchanged between the primary coil side and the secondary coil side while maintaining insulation between the winding unit 25 side and the encoder 22 side. Specifically, the processing unit 214 performs a first process of extracting a portion of the power generated by the motor drive current flowing through the winding unit 25 to be used as drive power for the encoder 22, and a second process of applying a signal related to the power consumption required for the operation of the encoder 22 (hereinafter referred to as the "power consumption signal") and a detection signal from the encoder 22 to the drive current of the motor 2 flowing through the winding unit 25 in order to transmit the signal to the servo driver 4. That is, the processing unit 214 functions as the extraction unit and the processing unit disclosed in the present application. The transformer structures 53, 63, and 73 shown in FIG. 3 and other figures are transformer structures for performing the first process for power extraction, and the transformer structure 80 is a transformer structure for performing the second process of applying the detection signal and the power consumption signal to the drive current to transmit the signal. Note that although the transformer structure for the second process shown in FIG. 3 and other figures is for one phase, two or three phases of transformer structures for the second process having the same function may be installed.

[0032] Alternatively, a common transformer structure may be used for both the first process and the second process. Specifically, in the embodiment shown in FIG. 3, transformer structures 53, 63, and 73 are used for extracting power in the first process and applying a power consumption signal in the second process. In this case, transformer structure 80 may be omitted. By sharing a transformer structure between the first process and the second process in this way, the size of processing unit 214 can be reduced.

[0033] 3, 7, and 8, transformer structures 53, 63, 73, and 80 are formed on winding portion 25 at the coil end of stator 213. In addition, in the embodiment shown in Fig. 9, the transformer structures are formed by winding the primary coils of transformer structures 53, 63, and 73 around the stator core together with the coil of winding portion 25 wound around the stator core, and transformer structure 80 is formed on winding portion 25 at the coil end of stator 213 in the same manner as in Fig. 3, etc. For the transformer structure, a configuration other than these may be adopted.

[0034] Here, a first process using the transformer structures 53, 63, and 73 will be described. In the first process, the processing unit 214 extracts power from the AC current output from the secondary coils of the transformer structures 53, 63, and 73 as power for the encoder 22. The power is then rectified by the supply unit 215, and, as necessary, is boosted or lowered to a DC voltage suitable for driving the encoder 22 by a DC-DC converter included in the supply unit 215. The supply unit 215 is electrically connected to the encoder 22 so that it can supply DC power to the encoder 22 when the encoder 22 is attached to the motor main body 21. The supply unit 215 may also have a secondary battery that can store the rectified DC power. In this case, power can be supplied to the encoder 22 even during periods when no drive current flows through the winding unit 25 or when the drive current is extremely low.

[0035] Next, the second process using the transformer structure 80 will be described. The encoder 22 has a detector 221 that detects the rotation state of the motor, and the signal detected thereby is called a detection signal. Specific detection signals include signals related to the position and speed of the motor, as well as the signal The power consumption signal may also include signals relating to acceleration and vibration obtained by processing the signal. The power consumption signal is a signal representing the power consumption required to operate the encoder 22 and cause the detection unit 221 to generate (detect) the detection signal. In other words, the power consumption signal is a signal representing the power extracted from the winding unit 25 by the first processing of the processing unit 214. The power consumption signal may be generated by the supply unit 215 that controls the power supply, and then passed to the detection unit 221, and subjected to the second processing together with the detection signal. The power consumption signal and the detection signal are transmitted to the processing unit 214 via a predetermined communication path (wired) formed within the motor 2.

[0036] In the second process, the detection signal and the power consumption signal are applied to the drive current flowing from the detector 221 of the encoder 22 through the winding 25, and the detection signal and the power consumption signal are transmitted to the servo driver 4 via the power line 11. The detection signal and the power consumption signal are then transmitted to the secondary coil of the transformer structure 80 of the processor 214 as a current containing a signal in a predetermined format. This allows the processor 214 to generate a current corresponding to the detection signal and the power consumption signal in the primary coil of each transformer structure, and transmit the current to the coil of the winding 25. In this case, the processor 214 may perform a predetermined amplification process on the detection signal and the power consumption signal. The amplification process can improve the noise resistance of the detection signal and the power consumption signal. The coil of the winding 25 is electrically connected to the servo driver 4 via the power line 11, allowing the encoder 22 to transmit the detection signal to the servo driver 4.

[0037] Here, the above-mentioned predetermined format for application of the detection signal will be explained. The predetermined format is a format related to the characteristics of the electrical signal, which is set so that the detection signal and power consumption signal applied via each transformer structure can be extracted and separated from the drive current on the servo driver 4 side. Specifically, the predetermined format is a format that determines the frequency, amplitude, etc. of the electrical signal. Details of the predetermined format will be explained later with reference to Figures 4 and 5.

[0038] Furthermore, in this embodiment, the second process may include a process of transmitting a predetermined signal from the servo driver 4 to the encoder 22 via the power line 11 and the winding unit 25. In this case, a current with a predetermined signal superimposed on the coil of the winding unit 25 is caused to flow from the servo driver 4 side, and the current flows through the primary coil side of the transformer structure, so that the processing unit 214 can generate a current corresponding to the predetermined signal on the secondary coil side of the transformer structure. Then, the generated signal is passed to the encoder 22.

[0039] (First form) Next, a first embodiment of the winding section 25 of the motor body 21 and the arrangement of the transformer structure provided for the winding section 25 are shown in FIG. 3. The winding section 25 includes winding sections L5, L6, and L7 for three phases: U, V, and W. The winding sections for each phase are connected in a Y-connection, with the junction of each winding section serving as a neutral point. For the U-phase winding section L5, in FIG. 3, its inductance component is indicated by 51 and its resistance component is indicated by 52. ​​Similarly, for the V-phase winding section L6, its inductance component is indicated by 61 and its resistance component is indicated by 62. Furthermore, for the W-phase winding section L7, its inductance component is indicated by 71 and its resistance component is indicated by 72.

[0040] A transformer structure forming processing section 214 is provided for each phase. Specifically, transformer structures 53, 63, and 73 are provided as transformer structures for the first processing. In the U phase, primary coil 531 of U-phase transformer structure 53 is connected in series to winding section L5. In the V phase, primary coil 631 of V-phase transformer structure 63 is connected in series to winding section L6. In the W phase, primary coil 731 of W-phase transformer structure 73 is connected in series to winding section L7. Secondary coil 532 of U-phase transformer structure 53, secondary coil 632 of V-phase transformer structure 63, and secondary coil 732 of W-phase transformer structure 73 are connected to supply section 215.

[0041] Furthermore, the processing unit 214 is provided with a transformer structure 80 as a transformer structure for the second processing. The transformer structure 80 is connected only to the U phase. Specifically, A primary coil 801 of the transformer structure 80 is connected in series to a primary coil 531 of the transformer structure 53. A secondary coil 802 of the transformer structure 80 is connected to the detection unit 221 of the encoder 22.

[0042] In this way, by arranging the transformer structure for the first processing in each of the U, V, and W phases, the encoder The driving power of the encoder 22 is supplied via the winding portion 25 of the motor 2. Therefore, the encoder 22 does not require a cable for supplying driving power, thereby significantly reducing the cable wiring work and reducing costs when installing the motor 2 in a system. Furthermore, since the transformer structure 80 for the second processing is also provided, the servo driver 4 (communication unit 42), which is the destination of the detection signal and power consumption signal, can receive the detection signal of the encoder 22 without using a transmission cable, thereby further reducing the cable wiring work and reducing costs.

[0043] The winding ratio (the ratio of the number of windings of the secondary coil to the number of windings of the primary coil) of the transformer structure of each phase is basically the same, but may be different. In the embodiment shown in FIG. 3, a transformer structure for the first treatment is provided for all three phases, but a transformer structure for the first treatment may be provided for at least one of the three phases. In addition, a transformer structure for the second treatment is provided for only one phase, but a transformer structure for the second treatment may be provided for all three phases.

[0044] Here, the point of applying the power consumption signal and the detection signal as signals in a predetermined format to the secondary coil side of the transformer structure 80 of the processing unit 214 will be described in detail with reference to Figs. 4 and 5. Fig. 4 shows the amplitude spectrum of the frequency components contained in the drive current flowing through the winding unit 25 of the motor 2. The horizontal axis of the graph shown in Fig. 4 represents frequency, and the vertical axis represents normalized amplitude. Here, the frequency f0 in Fig. 4 is the PWM frequency of the servo driver 4, and The amplitude of wave number f0 is the largest. In Figure 4, the frequency f0 is used as the reference frequency and the higher frequency components can be recognized.

[0045] Furthermore, the frequency components contained in the drive current flowing through winding portion 25 include a frequency related to the rotational speed (electrical angular frequency) of motor 2. This frequency changes depending on the rotational speed of motor 2. Furthermore, when a predetermined load (such as a robot arm) is driven by motor 2, if the resonant frequency of that load exists within the driving range of motor 2, the effect of that resonant frequency may appear as a frequency component contained in the drive current.

[0046] Considering that the drive current flowing through the winding portion 25 contains multiple frequency components related to the drive of the motor 2, a predetermined format for the power consumption signal and the detection signal is determined. Here, if the multiple frequency components contained in the drive current are defined as the predetermined frequencies, the PWM frequency of the servo driver 4 corresponding to the rotational speed of the motor 2 and higher-order frequencies of the PWM frequency are defined as the predetermined frequencies. The predetermined format employs a fundamental frequency that does not overlap with the predetermined frequencies (see frequencies f10 to f12 in FIG. 4). That is, the power consumption signal and the detection signal are applied to the secondary coil of the transformer structure 80 so that these signals are signals of the fundamental frequencies. Furthermore, by setting the fundamental frequency for the power consumption signal and the fundamental frequency for the detection signal to different frequencies (e.g., f10 and f11), the servo driver 4 can effectively distinguish between the power consumption signal and the detection signal. The detection signal applied as a signal of the predetermined format is delivered to the servo driver 4 via the power line 11. Since the frequencies of the power consumption signal and the detection signal do not overlap with the predetermined frequency, the servo driver 4 can suitably extract the power consumption signal and the detection signal.

[0047] Secondly, the predetermined format may be such that the resonant frequency of the load driven by the motor 2 is set as the predetermined frequency, and a fundamental frequency that does not overlap with the predetermined frequency is used as the predetermined format. In such a case, even if the load significantly resonates, the fundamental frequency for application does not overlap with the predetermined frequency (resonant frequency), so the servo driver 4 can suitably extract and separate the power consumption signal and the detection signal. In this case, too, it is preferable to set the fundamental frequency related to the power consumption signal and the fundamental frequency related to the detection signal to different frequencies.

[0048] Thirdly, as a predetermined format, the PWM frequency of the servo driver 4 is set to a high order frequency. As shown in FIG. 4, the amplitude of the driving current is generally larger than the amplitude of the driving current corresponding to the PWM frequency. Therefore, even if the fundamental frequency is a frequency that overlaps with the predetermined frequency, if the power consumption signal and the detection signal are applied as signals with amplitudes that are sufficiently large relative to the amplitude corresponding to the predetermined frequency, there will be no substantial hindrance to the extraction of the detection signal on the servo driver 4 side, and the detection signal can be suitably extracted. Even in this case, it is preferable to set the fundamental frequency of the power consumption signal and the fundamental frequency of the detection signal to different frequencies. For example, if the fundamental frequency of the applied power consumption signal is a high-order frequency f2 of the PWM frequency as shown in FIG. 4, 0, and the fundamental frequency of the detection signal is another higher frequency f2 of the PWM frequency. Even if they overlap with 1, if the amplitude of the applied signal is sufficiently large, the power consumption signal and the detection signal can be extracted by the servo driver 4 without any substantial problems.

[0049] <Power supply adjustment control> Here, control of power supply to motor 2 when driving motor 2 having the above-described transformer structure will be described with reference to FIG. 5. The power supply adjustment control shown in FIG. 5 is repeatedly executed between motor 2 and servo driver 4 in the control system shown in FIG. 1. As described above, by the first process via transformer structures 53, 63, and 73, which are processing unit 214, a portion of the power supplied from servo driver 4 is extracted for operation of encoder 22, which means that the power supplied to motor 2 is reduced. As a result, there is a risk that motor 2 will not be driven as desired in accordance with instructions from PLC 5. Therefore, to optimally drive motor 2, the power supply adjustment control shown in FIG. 5 is executed.

[0050] First, in S101, power extraction is performed by the first process of the processing unit 214. The received power is supplied to the encoder 22 by the supply unit 215, and at this time, the supplied power is measured by the supply unit 215, thereby generating a power consumption signal (processing of S102).The generated power consumption signal is then passed to the detection unit 221 of the encoder 22.

[0051] Next, in S103, the speed of the motor 2 is detected. The speed of the motor 2 is calculated based on the position signal of the motor 2 detected by the detection unit 221. Next, in S104, 2 is acquired. Specifically, before the drive of the motor 2 is started, data on the resonance frequency input by the user to the PLC 5 may be provided to the encoder 22 via the servo driver 4. Alternatively, if the detector 221 of the encoder 22 is configured to be able to detect the resonance of the load based on the detection signal, it is preferable to exclude the band of the resonance frequency related to that resonance when determining the fundamental frequency. Therefore, in S104, if the encoder 22 is able to detect the resonance of the load, In this case, data on the resonant frequency can also be obtained.

[0052] Then, the motor speed detected in S103 and the resonance frequency of the load acquired in S104 are used. Based on this, in S105, a fundamental frequency for transmitting the power consumption signal and the detection signal is determined by the second processing of the processing unit 214. In this determination, the fundamental frequency may be determined according to the first or second predetermined format described above. Alternatively, the fundamental frequency and amplitude for transmission may be determined according to the third predetermined format described above. Then, in S106, the power consumption signal and the detection signal are transmitted by the second processing of the processing unit 214 according to the fundamental frequency determined in S105.

[0053] Next, the processing on the servo driver 4 side will be described. In S201, the communication unit 42 receives the power consumption signal and detection signal transmitted from the motor 2 in S106. Then, in S202, the adjustment unit 43 adjusts the power supply to the motor 2. Specifically, the motor drive power required to drive the motor 2 based on the position command delivered from the PLC 5 is compensated for by the power required for the operation of the encoder 22 calculated based on the power consumption signal, i.e., the power extracted by the first processing of the processing unit 214, thereby adjusting the power supply to the motor 2. Then, in S203, power is supplied to the motor 2 in accordance with the adjusted supply power. Because the power required for the operation of the encoder 22 is not always constant, adjusting the power supply to the motor 2 based on the power consumption signal allows the motor 2 equipped with the processing unit 214 to be driven appropriately at all times.

[0054] 5 is constantly and repeatedly executed while the motor 2 is running, the fundamental frequency for applying the power consumption signal and the detection signal is adjusted in real time according to the speed of the motor 2 and transmitted to the servo driver 4. Furthermore, the servo driver 4 receives the power consumption signal and adjusts the power supply to the motor 2 in real time. As a result, power supply to the encoder 22 and power supply to the motor 2 are optimally matched.

[0055] <Variation 1> A modified example of the transmission of the power consumption signal and the detection signal to the servo driver 4 will now be described with reference to FIG. 6. FIG. 6 is a diagram showing a schematic configuration of the motor 2 according to this modified example. The motor 2 according to this modified example is provided with a processing unit 214 having a transformer structure for the winding unit 25, as in the embodiment shown in FIG. 2. However, the processing unit 214 only has the first processing function of extracting power and does not have the second processing function of transmitting the power consumption signal and the detection signal. Similarly to the above, the supply unit 215 generates a power consumption signal indicating the power consumption of the encoder 22 by supplying the extracted power to the encoder 22 and passes the signal to the detection unit 221. Furthermore, this modified example is provided with a processing unit 214b that can perform the first processing of power extraction and the second processing of transmitting the power consumption signal and the detection signal for the power line 11 connected to the connector 211. The first and second processing by the processing unit 214b are also achieved by providing a transformer structure electrically identical to the transformer structure shown in FIG. 3 for the power line 11.

[0056] The power extracted by the processing unit 214b is subjected to predetermined rectification processing and the like, and can be supplied as power to devices such as a temperature sensor and a vibration sensor arranged outside the motor 2. In addition, the extracted power can be stored in a secondary battery, thereby enabling stable power supply to the temperature sensor, etc. In the motor 2 shown in FIG. 6, the power extracted by the processing unit 214 is supplied to the encoder 22, but instead, the power extracted by the processing unit 214b may be supplied to the encoder 22, or the power extracted by both the processing units 214 and 214b may be supplied to the encoder 22.

[0057] In this modification, the processing unit 214b is configured to be able to wirelessly communicate with the detection unit 221 of the encoder 22. Note that, as power for wireless communication between the processing unit 214b and the detection unit 221, the processing unit 214b extracts power from the power line 11. The power extracted by the processing unit 214 is used in the detection unit 221 .

[0058] Here, the details of the processing unit 214b will be described. The processing unit 214b has a first communication unit 2141 and a second communication unit 2142. The first communication unit 2141 is capable of wireless communication with the detection unit 221, and receives a power consumption signal and a detection signal from the encoder 22 via wireless communication. The first communication unit 2141 can also transmit a signal to the encoder 22. The wireless communication method used by the first communication unit 2141 is not limited to a specific one. As described above, the processing unit 214b has a transformer structure for extracting power, and the second communication unit 2142 also functions as an interface for communicating with the servo driver 4 using this transformer structure. For example, the second communication unit 2142 can apply the power consumption signal and the detection signal received from the encoder 22 via the first communication unit 2141 to the current flowing through the power line 11. That is, when the second communication unit 2142 applies a signal to the power line 11, the second communication unit 2142 sends the signal to the secondary coil side of the transformer structure, thereby superimposing the output on the primary coil side on the current flowing through the power line 11. In this way, the second communication unit 2142 is configured to enable transmission and reception of signals between the power line 11 and the detection unit 221 of the encoder 22, and sends the signal to the communication unit 42 of the servo driver 4 via the power line 11.

[0059] Furthermore, the second communication unit 2142 can receive some signal from the servo driver 4 via the transformer structure, pass it to the first communication unit 2141, and the first communication unit 2141 can transmit it to the detection unit 221 of the encoder 22 via wireless communication. In other words, the processing unit 214b and the detection unit 221 can communicate with each other.

[0060] Even with such a configuration, there is no need to perform wiring work for supplying power to the encoder 22 and transmitting signals, which significantly reduces the workload required for configuring the servo system and enables optimal power supply to both the encoder 22 and the motor 2. As a further modified example, the processing unit 214b may be configured to wirelessly receive detection signals from a temperature sensor, vibration sensor, or the like at the power supply destination using the first communication unit 2141, and to superimpose the signals on the power line 11 using the second communication unit 2142 and transmit the superimposed signals to the servo driver 4.

[0061] <Variation 2> In the above-described embodiments, the processing units 214, 214b transmit the power consumption signal and the detection signal to the servo driver 4 by applying them to the driving current flowing through the winding unit 25 or the power line 11. However, instead of this configuration, the processing units 214, 214b may transmit the power consumption signal and the detection signal wirelessly to the communication unit 42 of the servo driver 4 directly or via one or more repeaters.

[0062] <Variation 3> In the above-described configuration, the processing units 214 and 214b transmit the power consumption signal and the detection signal to the servo driver 4 by applying them to the drive current flowing through the winding unit 25 or the power line 11. Alternatively, the processing units 214 and 214b may transmit the power consumption signal to the drive current flowing through the winding unit 25 or the power line 11, and may transmit the detection signal to the servo driver 4 via a wired transmission cable.

[0063] (Second form) Next, a second embodiment of the arrangement of the transformer structure in the winding section 25 of the motor 2 will be described with reference to FIG. 7. The configuration of the winding section 25 of the motor body 21 is the same as that of the first embodiment, so a detailed description thereof will be omitted. In the second embodiment, each transformer structure is arranged in a manner similar to that of the winding section 25. 25. Specifically, in the second embodiment, for the transformer structures 53, 63, and 73 related to the first process, a primary coil 531 of the transformer structure 53 is connected between the U and V phases so as to be parallel to the U and V phase winding portions L5 and L6, a primary coil 631 of the transformer structure 63 is connected between the V and W phases so as to be parallel to the V and W phase winding portions L6 and L7, and a primary coil 731 of the transformer structure 73 is connected between the W and U phases so as to be parallel to the W and U phase winding portions L7 and L5. The secondary coils 532 of the transformer structure 53, the secondary coil 632 of the transformer structure 63, and the secondary coil 732 of the transformer structure 73 are connected to the supply unit 215. For the transformer structure 80 related to the second process, a primary coil 801 of the transformer structure 80 is connected between the U and V phases, similar to the transformer structure 53, and a secondary coil 802 of the transformer structure 80 is connected to the encoder 22.

[0064] In the second embodiment, the winding ratio of the transformer structure for each phase is basically the same, but may be different. In the embodiment shown in Fig. 7, the transformer structure for the first treatment is disposed for all three interphases in winding section 25, but the transformer structure for the first treatment may be disposed for any of the three interphases. The transformer structure for the second treatment may be disposed for multiple interphases, not just one interphase.

[0065] By employing the winding section 25 and transformer structures 53, 63, 73, 80 configured in this manner, it is possible to achieve a favorable balance between transmitting a power consumption signal and a detection signal via the power line 11 and the winding section 25 and supplying power to the motor 2 and the encoder 22. With this configuration, no communication cable or power supply cable is required for the encoder 22, which significantly reduces the cabling work and reduces the cost.

[0066] (Third Form) Next, a third embodiment of the arrangement of the transformer structure in the winding section 25 of the motor 2 will be described with reference to FIG. 8. The configuration of the winding section 25 of the motor body 21 is the same as that of the first embodiment, and therefore a detailed description thereof will be omitted. In the third embodiment, the transformer structures are arranged relative to the phases of the winding section 25. Specifically, in the third embodiment, for the transformer structures 53, 63, and 73 related to the first treatment, the primary coil 531 of the transformer structure 53 corresponding to the U phase is connected in parallel to the winding portions L5, L6, and L7 of the three phases, and the primary coil 631 of the transformer structure 63 corresponding to the V phase is connected in parallel, and the primary coil 731 of the transformer structure 73 corresponding to the W phase is connected in parallel. Specifically, line L50 including primary coil 531, line L60 including primary coil 631, and line L70 including primary coil 731 are Y-connected, and the other ends are connected to U-phase winding portion L5, V-phase winding portion L6, and W-phase winding portion L7, respectively. Secondary coil 532 of transformer structure 53, secondary coil 632 of V-phase transformer structure 63, and secondary coil 732 of W-phase transformer structure 73 are connected to supply unit 215. Regarding transformer structure 80 related to the second process, primary coil 801 of transformer structure 80 is connected in series to primary coil 531 of transformer structure 53, and secondary coil 802 of transformer structure 80 is connected to encoder 22.

[0067] In the third embodiment, the winding ratio of the transformer structure for each phase is basically the same, but may be different. In the embodiment shown in Fig. 8, the transformer structure for the first treatment is arranged so as to correspond to all three interphases in the winding section 25, but the transformer structure for the first treatment may be arranged so as to correspond to any one of the three interphases. The transformer structure for the second treatment may be arranged so as to correspond to multiple interphases, not just one interphase.

[0068] By employing the winding section 25 and transformer structures 53, 63, 73, 80 configured in this manner, it is possible to achieve a favorable balance between transmitting a power consumption signal and a detection signal via the power line 11 and the winding section 25 and supplying power to the motor 2 and the encoder 22. With this configuration, no communication cable or power supply cable is required for the encoder 22, which significantly reduces the cabling work and reduces the cost.

[0069] (Fourth Form) Next, a fourth embodiment of the arrangement of the transformer structure in the winding section 25 of the motor 2 will be described with reference to FIG. 9. The configuration of the winding section 25 of the motor body 21 is the same as that of the first embodiment, and therefore a detailed description thereof will be omitted. In the fourth embodiment, the coil components 51, 61, and 71 of the winding portions L5, L6, and L7 of the respective phases are used as primary coils 531, 631, and 731 of the transformer structures 53, 63, and 73 related to the first process, corresponding to the respective phases. Specifically, in the U phase, the coil component 51 is used as the primary coil 531 to form the transformer structure 53; in the V phase, the coil component 61 is used as the primary coil 631 to form the transformer structure 63; and in the W phase, the coil component 71 is used as the primary coil 731 to form the transformer structure 73. Therefore, in the fourth embodiment, the secondary coils 532, 632, 732 of the transformer structures 53, 63, 73 of each phase are wound around the stator core together with the main coil of the winding portion, which is also the primary coil, to form the transformer structures 53, 63, 73 of each phase. The secondary coil 532 of the transformer structure 53, the secondary coil 632 of the V-phase transformer structure 63, and the secondary coil 732 of the W-phase transformer structure 73 are connected to the supply unit 215. In addition, with respect to the transformer structure 80 related to the second process, the primary coil 801 of the transformer structure 80 is connected in series to the primary coil 531 of the transformer structure 53, and the secondary coil 802 is connected to the encoder 22.

[0070] In the fourth embodiment, the winding ratio of the transformer structure for each phase is basically the same, but may be different. In the embodiment shown in Fig. 9, the transformer structure for the first treatment is disposed for all three interphases in winding section 25, but the transformer structure for the first treatment may be disposed for any of the three interphases. The transformer structure for the second treatment may be disposed for multiple interphases, not just one interphase.

[0071] By employing the winding section 25 and transformer structures 53, 63, 73, 80 configured in this manner, it is possible to achieve a favorable balance between transmitting a power consumption signal and a detection signal via the power line 11 and the winding section 25 and supplying power to the motor 2 and the encoder 22. With this configuration, no communication cable or power supply cable is required for the encoder 22, which significantly reduces the cabling work and reduces the cost.

[0072] (Variation) Transformer structures 53, 63, and 73 shown in Figure 9 and elsewhere are compound-winding transformer structures, but as a modification, single-winding transformer structures can also be employed. For example, when a single-winding transformer structure is employed in the configuration shown in Figure 9, the winding section 25 of motor 2 is used as a primary coil and a portion of winding section 25 is used as a secondary coil, thereby forming transformer structures 53, 63, and 73. In other words, the secondary coil portion of winding section 25 is shared between the primary side and the secondary side.

[0073] <Appendix 1> Driver (4) and a motor (2) to which power is supplied from the driver (4) via a power line (11); A control system comprising: The motor (2) an input section (211) through which power is input from the driver (4) to a winding section (25) inside the motor (2) via the power line (11); an extracting unit (214) that extracts a portion of the power in the power line (11) or the winding unit (25); a supply unit (215) that supplies the power extracted by the extraction unit (214) to a detector (22) that detects the movement of the drive shaft of the motor (2); a processing unit (214) for transmitting a signal relating to the power consumption required for the operation of the detector (22) to the driver (4); and The driver (4) a receiving unit (42) that receives a signal related to the power consumption applied by the processing unit (214); an adjusting unit (43) that adjusts the power supplied to the motor (2) through the power line (11) based on the signal related to the power consumption; A control system having: <Appendix 2> The processing unit (214) applies a signal in a predetermined format to the power line (11) or the winding unit (25) so that the signal related to the power consumption can be extracted on the driver (4) side, thereby transmitting the signal related to the power consumption to the driver (4). 10. The control system of claim 1. <Appendix 3> The processing unit (214) wirelessly transmits a signal related to the power consumption to the driver (4). 10. The control system of claim 1. <Appendix 4> The power adjustment by the adjustment unit (43) is performed by compensating the motor driving power required to drive the motor (2) for the power consumption of the detector (22) calculated based on the signal of the predetermined format. 10. The control system according to claim 1, wherein the control system is a control system for controlling a power supply. <Appendix 5> The processing unit (214) transmits a detection signal of the detector (22) together with a signal related to the power consumption to the driver (4). 5. The control system according to any one of claims 1 to 4. <Appendix 6> The processing section (214) is disposed on the power line (11), The signal relating to the power consumption is wirelessly transmitted from the detector (22) to the processing unit (214). 6. A control system according to any one of claims 1 to 5. <Appendix 7> the processing unit (214) is configured to apply the signal related to the power consumption as a signal of the predetermined format having a fundamental frequency that does not overlap with a predetermined frequency related to the driving of the motor (2) by the driver (4); The processing unit (214) varies the fundamental frequency in accordance with the variation of the predetermined frequency. 7. The control system according to any one of claims 1 to 6. <Appendix 8> The predetermined frequency is a PWM signal of the driver (4) corresponding to the rotation speed of the motor (2). frequency, and a higher order frequency of the PWM frequency, 8. The control system of claim 7. <Appendix 9> the predetermined frequency is a resonant frequency associated with a load driven by the motor (2); 8. The control system of claim 7. <Appendix 10> The processing unit (214) converts the signal relating to the power consumption into a PWM frequency of the driver (4). The drive current is configured to be applied as a signal of the predetermined format having an amplitude greater than or equal to a predetermined time as compared with the amplitude of the drive current corresponding to a higher-order frequency of wave numbers. 7. The control system according to any one of claims 1 to 6. <Appendix 11> the extractor (214) is formed as a transformer structure (53, 63, 73) having a primary coil and a secondary coil, and configured such that a portion of the power in the winding is supplied from the primary coil through the secondary coil to the supply; the processing unit (214) is configured to apply a signal related to the power consumption to a drive current of the motor flowing through the primary coil when the signal related to the power consumption is input to the secondary coil. 11. The control system of any one of claims 1 to 10. [Explanation of symbols]

[0074] 2 motors 4 Servo drivers 22 Encoder 41 Control Unit 42 Communications Department 43 Adjustment part 25 Winding section 53, 63, 73 Transformer structure 211 Connector (input part) 214 Processing section 214b Processing section 215 Supply section 221 Detector

Claims

1. Driver and a motor to which power is supplied from the driver via a power line; A control system comprising: The motor an input unit to which power is input from the driver to a winding unit inside the motor via the power line; an extractor that extracts a portion of the power in the power line or the winding; a supply unit that supplies the power extracted by the extraction unit to a detector that detects movement of a drive shaft of the motor; a processing unit that transmits a signal related to the power consumption required for the operation of the detector to the driver; and The driver a receiving unit that receives a signal related to the power consumption applied by the processing unit; an adjusting unit that adjusts the power supplied to the motor through the power line based on the signal related to the power consumption; A control system having:

2. the processing unit applies a signal in a predetermined format to the power line or the winding unit so that the signal related to the power consumption can be extracted on the driver side, thereby transmitting the signal related to the power consumption to the driver. The control system of claim 1 .

3. the processing unit wirelessly transmits a signal related to the power consumption to the driver; The control system of claim 1 .

4. the power adjustment by the adjustment unit is performed by compensating the motor drive power required to drive the motor for the power consumption of the detector calculated based on the signal in the predetermined format. A control system according to any one of claims 1 to 3.

5. the processing unit transmits the detection signal of the detector together with the signal related to the power consumption to the driver; A control system according to any one of claims 1 to 3.

6. the processing unit is disposed on the power line, the signal relating to the power consumption is wirelessly transmitted from the detector to the processing unit. A control system according to any one of claims 1 to 3.

7. the processing unit is configured to apply the signal related to the power consumption as a signal of the predetermined format having a fundamental frequency that does not overlap with a predetermined frequency related to driving of the motor by the driver; the processing unit varies the fundamental frequency in response to a variation in the predetermined frequency; The control system of claim 2 .

8. The predetermined frequency is a PWM frequency of the driver corresponding to the rotation speed of the motor, and A higher order frequency of the PWM frequency, The control system of claim 7.

9. the predetermined frequency is a resonant frequency associated with a load driven by the motor; The control system of claim 7.

10. The processing unit converts the signal relating to the power consumption into a signal having a higher order frequency than the PWM frequency of the driver. The predetermined format signal has an amplitude greater than or equal to a predetermined number of times the amplitude of the driving current corresponding to the predetermined number of times. The control system of claim 2 .

11. the extractor is formed as a transformer structure having a primary coil and a secondary coil, and is configured such that a portion of the power in the winding section is supplied from the primary coil through the secondary coil to the supply section; the processing unit is configured to apply a signal related to the power consumption to a drive current of the motor flowing through the primary coil when the signal related to the power consumption is input to the secondary coil, A control system according to any one of claims 1 to 3.

Images