CN111684711A - Servo system, sensor hub, and method for diagnosing industrial device - Google Patents

Abstract

The invention aims to provide a servo system capable of corresponding to various sensors with different specifications. The sensor hub is connected to an encoder for detecting rotation of the motor, a sensor for detecting a state different from the rotation, and a servo amplifier for drive-controlling the motor, and is detachably connected to the encoder. The sensor hub performs signal processing on the encoder signal output from the encoder and the sensor signal output from the sensor, and transmits the processed signals to the servo amplifier.

Description

Servo system, sensor hub, and method for diagnosing industrial device

Technical Field

The present invention relates to a servo system, a sensor hub, and a method for diagnosing an industrial device, and more particularly, to a servo system having a sensor that is effectively used for control and maintenance of an industrial device.

Background

In the field of fa (factory automation), the operating state of an industrial device and the state of its surrounding environment are detected by various sensors, and it is required to construct a high-level communication system in which the detected signals are effectively used for controlling instruments. One of them is a servo system for controlling the driving of an industrial device. A typical servo system includes a motor, a servo amplifier for driving the motor, and a controller for sending a drive command to the servo amplifier. An encoder for detecting rotation information such as an angle and an angular velocity to control rotation of the motor is attached near a rotating shaft of the motor. The servo amplifier controls the motor based on the drive command transmitted from the controller and the rotation information of the motor transmitted from the encoder.

In the servo system, a sensor for detecting a state of the motor or its periphery is used. The use of the sensor is effective for, for example, unsteady control of the driving sequence of the motor, improvement of the control accuracy of the driven object of the motor, and change of the control mode of the motor. Further, by detecting local abnormal noise, vibration, and the like of the motor or its periphery using the sensor, the sensor can be effectively used for maintenance of the industrial device. As described above, in order to effectively use the detection signal of the sensor for drive control and maintenance, a servo amplifier or a controller is required, or the servo amplifier or the controller transmits the detection signal to a higher-level control device. On the other hand, in a servo system applied to an industrial device, a servo amplifier and a controller are often provided at a position remote from a motor. In the case described above, the signal line for transmitting the detection signal of the sensor provided in the motor or the periphery thereof to the servo amplifier and the controller becomes long, whereby the wiring work becomes complicated and the transmission characteristic of the detection signal may deteriorate.

In order to solve the above-described problems, patent document 1 discloses an encoder for detecting the operation of a motor and generating a feedback signal indicating the detected operation, wherein the encoder receives a detection signal from a sensor for detecting the state of a driven body of the motor via a sensor cable and outputs the feedback signal and the detection signal to a control device, thereby shortening the length of the sensor cable and improving the complexity of wiring work.

Patent document 1: japanese patent laid-open publication No. 2015-95221

Disclosure of Invention

However, in a configuration in which a sensor cable is connected to an encoder and a detection signal detected from the sensor and a feedback signal detected from the encoder are output to a control device, an input unit corresponding to the specification of the sensor needs to be provided in advance in the encoder, and when a sensor of a specification that does not correspond to the input unit of the encoder is used, there is a problem in that the encoder needs to be replaced every time.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a servo system capable of coping with various sensors having different specifications. In addition, the purpose is to provide a sensor hub to which sensors can be connected. Another object is to provide a diagnostic method for an industrial device using a sensor hub.

The servo system according to the present invention includes: an electric motor; an encoder that detects rotation of the motor; a sensor hub including a 1 st connection unit, a 2 nd connection unit, and a 3 rd connection unit, the 1 st connection unit being detachably connected to the encoder, the 2 nd connection unit being connected to a sensor that detects a state different from the rotation, the 3 rd connection unit being connected to a communication cable that transmits an encoder signal output from the encoder via the 1 st connection unit and a sensor signal output from the sensor via the 2 nd connection unit; and a servo amplifier that drive-controls the motor based on the encoder signal, the sensor signal, and the drive command transmitted from the controller.

The sensor hub according to the present invention includes: a 1 st connecting part which is detachably connected with an encoder for detecting the rotation of the motor; a 2 nd connecting part which is connected with a sensor for detecting a state different from the rotation; and a 3 rd connection unit to which a communication cable is connected, the communication cable transmitting at least one of an encoder signal output from the encoder via the 1 st connection unit and a sensor signal output from the sensor via the 2 nd connection unit to a servo amplifier that drives and controls the motor.

A diagnostic method for an industrial device according to the present invention is a diagnostic method for an industrial device including a servo system in which an encoder for detecting rotation of a motor and a servo amplifier for supplying a current to the motor are detachably connected to each other via a communication cable having a connector connectable to the encoder, the servo amplifier adjusting the current supplied to the motor based on a detection signal of the encoder transmitted via the communication cable and performing drive control, the diagnostic method comprising: connecting a sensor hub having 1 st to 3 rd connection parts between the communication cable and the encoder, wherein the encoder is connected to the 1 st connection part, a sensor for detecting a state different from the rotation of the motor is connected to the 2 nd connection part, and a connector of the communication cable is connected to the 3 rd connection part; transmitting a detection signal of the encoder from the encoder to the servo amplifier via the sensor hub and the communication cable; transmitting a detection signal of the sensor from the sensor to the servo amplifier via the sensor hub and the communication cable; and diagnosing the industrial device based on the detection signal of the encoder and the detection signal of the sensor.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the servo system of the present invention, the sensor hub is configured to be connected to the encoder, the sensor, and the servo amplifier, respectively, and the sensor hub is detachably connected to the encoder, so that the sensor hub can be appropriately selected according to the specification of the connected sensor, and can be adapted to various sensors. Further, according to the sensor hub of the present invention, the encoder is detachably connected according to the specification of the sensor, and thus signals output from the encoder and the sensor can be transmitted to the servo amplifier. In addition, according to the diagnostic method of the industrial device of the present invention, the sensor hub can be easily added to or replaced in the servo system by adding or replacing the sensor hub to or replacing the servo system.

Drawings

Fig. 1 is a schematic configuration diagram of a servo system according to embodiment 1 of the present invention.

Fig. 2 is a schematic configuration diagram of a sensor hub according to embodiment 1 of the present invention.

Fig. 3 is a schematic configuration diagram of a sensor hub according to embodiment 1 of the present invention.

Fig. 4 is a schematic diagram showing an example of the structure of a data frame generated by the sensor hub according to embodiment 1 of the present invention.

Fig. 5 is a flowchart showing the operation of the servo system according to embodiment 1 of the present invention.

Fig. 6 is a flowchart showing the operation of the servo system according to embodiment 1 of the present invention.

Fig. 7 is a schematic configuration diagram of a servo system according to embodiment 2 of the present invention.

Fig. 8 is a schematic configuration diagram of a sensor hub according to embodiment 3 of the present invention.

Fig. 9 is a schematic diagram showing an example of the structure of a data frame generated by the sensor hub according to embodiment 3 of the present invention.

Fig. 10 is a schematic configuration diagram of a servo system according to embodiment 4 of the present invention.

Fig. 11 is a flowchart showing a process of introducing a sensor hub into the servo system according to embodiment 5 of the present invention.

Detailed Description

A servo system according to an embodiment of the present invention will be described with reference to the drawings. Next, a servo system having a 1-axis rotary servomotor will be described as an example.

Embodiment 1.

Fig. 1 is a schematic configuration diagram of a servo system according to embodiment 1 of the present invention. As shown in fig. 1, the servo system 100 includes: a motor 10; a controller 11 that generates a drive command for the motor 10; a servo amplifier 12 that controls driving of the motor 10; an encoder 13 that detects rotation of the motor 10; a sensor 14 for detecting another state not detected by the encoder 13; and a sensor hub 15 that receives the encoder signal S13 output from the encoder 13 and the sensor signal S14 output from the sensor 14 and transmits the signals to the servo amplifier 12. Here, the sensor 14 detects the motor 10 or the state around the motor 10.

The motor 10 and the servo amplifier 12 are connected to each other via a power line cable C3 in order to supply current to an armature of the motor 10. The servo amplifier 12 adjusts the supplied current based on a drive command from the controller 11 and the encoder signal S13 and the sensor signal S14 transmitted from the sensor hub 15, and controls the drive of the motor 10.

Fig. 2 is a schematic configuration diagram of a sensor hub according to embodiment 1 of the present invention. As shown in fig. 2, the sensor hub 15 has: a 1 st link 15a (hereinafter, referred to as an encoder link) to which the encoder 13 is connected; a 2 nd connection part 15b (hereinafter, referred to as a sensor connection part) to which a sensor cable C4 having one end connected to the sensor 14 is connected; and a 3 rd connection unit 15C (hereinafter, referred to as an amplifier connection unit) to which a communication cable C2 having one end connected to the servo amplifier 12 is connected.

The encoder connector 15a of the sensor hub 15 is, for example, a connector having a plurality of connection pins for connecting the encoder 13. The encoder 13 has, for example, a connector 13a formed with terminal holes corresponding to the connection pins of the encoder connection portion 15a of the sensor hub 15. The sensor hub 15 and the encoder 13 are detachably connected by fitting a connecting pin of the encoder connecting portion 15a of the sensor hub 15 into a terminal hole of the connector 13a of the encoder 13. Here, the encoder connection portion 15a of the sensor hub 15 may be a wiring board printed with a conductive portion and may be connected by fitting with the connector 13a of the encoder 13. Further, the encoder connecting portion 15a of the sensor hub 15 and the connector 13a of the encoder 13 may be connected to each other via a cable.

The sensor connection portion 15b of the sensor hub 15 is, for example, a connector having a plurality of connection pins for connecting 3 sensor cables C4. The shape of the sensor connecting portion 15b and the number of connecting pins are formed to correspond to the specifications of the connectors C4a, C4b, and C4C of the sensor cable C4. Here, the number of the sensors 14 and the sensor cables C4 can be changed as appropriate. Further, the connectors C4a, C4b, and C4C of the sensor cable C4 may be integrated.

The amplifier connection portion 15C of the sensor hub 15 is, for example, a connector having a terminal hole into which a connection pin included in the connector C2a of the communication cable C2 is fitted.

Here, the shapes, the number of connection pins, and the number of terminal holes of the encoder connection unit 15a, the sensor connection unit 15b, and the amplifier connection unit 15c of the sensor hub 15 are not limited to those shown in fig. 2, and may be appropriately changed according to the application of the servo system 100. The encoder connecting unit 15a, the sensor connecting unit 15b, and the amplifier connecting unit 15c may have connecting pins as terminal holes and terminal holes as connecting pins, respectively, corresponding to the corresponding connectors.

The sensor hub 15 receives an encoder signal S13 output from the encoder 13 via the encoder connector 15a and a sensor signal S14 output from the sensor 14 via the sensor connector 15b, and transmits the signals to the servo amplifier 12 via a communication cable C2 connected to the amplifier connector 15C.

The sensor hub 15 determines the connection state of the sensor 14 connected to the sensor connection unit 15b by the sensor determination unit 153 in accordance with a command from the servo amplifier 12, and transmits the determination result to the servo amplifier 12. The connection state of the sensors 14 refers to, for example, the number of sensors 14 connected to the sensor connection portion 15b, the type of the sensors 14, the number of sensor signals S14, and the like. The connection state of the sensor 14 is determined by counting the number of sensor signals S14 detected in a predetermined period based on, for example, a change in the voltage value of the sensor signal S14.

The servo amplifier 12 receives the determination result and sets the communication specification between the sensor hub 15 and the servo amplifier 12 by the communication specification setting unit 122. The sensor hub 15 converts the encoder signal S13 and the sensor signal S14 into serial signals by the signal processing unit 152 in accordance with the set communication standard. The sensor hub 15 transmits the encoder signal S13 and the sensor signal S14 to the servo amplifier 12 via the communication cable C2 connected to the amplifier connection unit 15C in accordance with the communication specification set by the communication specification setting unit 122.

As described above, the servo system 100 according to embodiment 1 of the present invention includes the sensor hub 15, and the sensor hub 15 includes: an encoder connector 15a detachably connected to the encoder 13; a sensor connection unit 15b connected to the sensor 14 via a sensor cable C4; and an amplifier connection unit 15C connected to the servo amplifier 12 via a communication cable C2, wherein the sensor hub 15 receives the encoder signal S13 and the sensor signal S14 via the encoder connection unit 15a and the sensor connection unit 15b, respectively, and transmits the signals to the servo amplifier 12 via the amplifier connection unit 15C and the communication cable C2.

With the above configuration, the sensor hub 15 can be appropriately selected according to the specification of the connected sensor 14, and the selected sensor hub 15 can be attached to the encoder 13. Thus, even when a sensor 14 of a different specification is newly mounted, the encoder 13 does not need to be replaced, and thus the encoder can be immediately applied to a variety of sensors 14.

In addition, the servo system 100 connects the encoder 13 provided in the motor 10 and the sensor cable C4 connected to the sensor 14 provided in the motor 10 or its periphery to the sensor hub 15. With this configuration, as compared with the case where the sensor cable C4 is connected to the controller 11 or the servo amplifier 12 provided at a position distant from the motor 10, the complexity of the wiring work of the sensor cable C4 can be improved, and the transmission characteristics of the sensor signal S14 detected by the sensor 14 can be improved.

In the servo system 100, the sensor hub 15 determines the connection state of the sensor 14 connected to the sensor connection portion 15b, and based on the determination result, the servo amplifier 12 sets the communication specification between the servo amplifier 12 and the sensor hub 15. With this configuration, when the sensor hub 15 is replaced or the sensor 14 is added to or changed from the sensor hub 15, the servo amplifier 12 can immediately read the sensor signal S14.

The controller 11 generates a drive command such as a position and a velocity pattern of the motor 10 and transmits the drive command to the servo amplifier 12. The controller 11 is a control device including a plc (programmable Logic controller), a motor driving cpu (central processing unit), a dsp (digital Signal processor), a pulse generator, and the like.

The controller 11 and the servo amplifier 12 are connected via a network cable C1. A general-purpose communication cable such as a twisted pair ethernet (registered trademark) cable or an optical fiber cable can be used as the network cable C1.

The servo amplifier 12 includes: a transceiver unit 121 that transmits and receives signals to and from the sensor hub 15; a communication specification setting unit 122 that sets a communication specification between the servo amplifier 12 and the sensor hub 15 in accordance with the connection state of the sensor 14 determined by the sensor hub 15; and a parallel conversion unit 123 that converts the serial signal transmitted from the sensor hub 15 into a parallel signal.

The transmitting/receiving unit 121, the communication specification setting unit 122, and the parallel conversion unit 123 of the servo amplifier 12 are realized by an electronic circuit including an LSI (Large-Scale Integration) such as an industrial microcomputer (CPU), an asic (application specific integrated circuit), an FPGA (field-Programmable gate array), and a cpld (complex Programmable Logic device), for example. The data communication among the transmission/reception unit 121, the communication specification setting unit 122, and the parallel conversion unit 123 is performed by bus communication via a buffer and a memory, not shown, included in the servo amplifier 12. Either 1 or both of the communication specification setting unit 122 and the parallel conversion unit 123 may be incorporated in an external device of the servo amplifier 12.

The servo amplifier 12 and the sensor hub 15 are connected to each other via a communication cable C2 that enables bidirectional signal transmission and reception. The communication cable C2 includes a connector C2a connected to the amplifier connection unit 15C of the sensor hub 15, and includes, for example, signal lines of digital signals of at least 1 system, signal lines of analog signals, and a power supply line for supplying a power supply voltage from the servo amplifier 12 to the sensor hub 15. The signal line and the power line may be connected by different cables from each other.

The communication between the servo amplifier 12 and the sensor hub 15 applies serial communication. By applying the serial communication, the number of signal lines of the communication cable C2 can be reduced. The communication method may be a half-duplex communication method or a full-duplex communication method, and a communication selection line for identifying the communication method by the sensor hub 15 may be included in the communication cable C2. In order to transmit signals of a temperature sensor, an acceleration sensor, and the like, not shown, built in the encoder 13, a communication line transmitted from the motor 10 to the controller 11 may be included in the communication cable C2.

The encoder 13 detects the rotation of the motor 10, and transmits an encoder signal S13 indicating the detected rotation of the motor 10 to the sensor hub 15. The encoder 13 includes a transmission/reception unit 131 for transmitting the encoder signal S13 to the sensor hub 15, and the transmission/reception unit 131 includes a connector 13a for connecting to the encoder connecting unit 15a of the sensor hub 15. The rotation of the motor 10 detected by the encoder 13 is, for example, an angle, an angular velocity, and an angular acceleration of the rotation shaft. The encoder 13 is mounted near the rotation shaft of the motor 10, for example.

The detection method of the encoder 13 is an absolute value method, an incremental method, or the like. The encoder 13 may have a detector such as a temperature sensor therein for outputting a state of a detection circuit of the encoder 13 or an alarm at the time of signal detection. The encoder 13 may have an acceleration sensor therein, for example, to detect wear and deterioration of a bearing mechanism included in the motor 10 and a driving reaction force generated when the motor rotates. When the encoder 13 detects another state different from the rotation of the motor 10, the detection result (the detection result of the temperature sensor, the acceleration sensor, and the like provided in the encoder 13) is transmitted to the sensor hub 15 together with the rotation information of the motor 10.

The encoder signal S13 is an electric signal transmitted from the transmitter/receiver 131 of the encoder 13 to the sensor hub 15, and includes, for example, rotation information of the motor 10 detected by the encoder 13, internal information of the encoder 13 detected by a temperature sensor or the like included in a detection circuit of the encoder 13, and alarm information of the encoder 13.

The sensor 14 detects a state of a detection target different from the rotation of the motor 10 which is a detection target of the encoder 13, and transmits a sensor signal S14 indicating the detected state to the sensor hub 15. The sensor 14 detects a state of a detection target different from the rotation of the motor 10, for example, a temperature, vibration, sound, or the like of the motor 10 or the periphery of the motor 10. The periphery of the motor 10 is an object on which a driven object of the motor 10, a stand for fixing the motor 10, or a driven object acts, for example. The object on which the driven body acts is, for example, a member gripped by a robot driven by the motor 10, a workpiece processed by a processing machine driven by the motor 10, or the like. The sensor 14 is, for example, an acceleration sensor or a camera. In addition, a position sensor, a speed sensor, a pressure sensor, a microphone, a gyro sensor, a flow sensor, a temperature sensor, an illuminance sensor, a magnetic sensor, an infrared sensor, or the like may be used.

The sensor 14 is provided in at least any one of the motor 10, the encoder 13, a driven body of the motor 10, a stage for fixing the motor 10, and a subject acting on the driven body. Further, a jig or a bracket may be used and may be provided around the periphery thereof. The sensor 14 may detect an absolute state of the object to be measured, or may detect a relative state.

The sensor signal S14 is an electrical signal that the sensor 14 sends to the sensor hub 15 via the sensor cable C4. Here, the sensor signal S14 transceived between the sensor 14 and the sensor hub 15 may be compressed or modulated. The sensor signal S14 transmitted and received between the sensor 14 and the sensor hub 15 is, for example, a signal including an analog signal or a digital signal transmitted by a single-ended method or a differential method, and a ground signal indicating a reference of the signal.

The sensors 14 and the sensor hub 15 are connected to each other via a sensor cable C4. The sensor cable C4 is at least 1 communication cable that transmits the sensor signal S14 output by the sensor 14 to the sensor hub 15. In the case where the sensors 14 output digital signals, the sensor hub 15 and the sensors 14 may be connected by parallel communication or may be connected by serial communication. By applying serial communication, the number of signal lines can be reduced.

The communication between the sensor 14 and the sensor hub 15 can be, for example, RS (TIA/EIA)232/422/485, usb (universal Serial bus), I2C (Inter Integrated Circuit), spi (Serial peripheral interface), I2S (Inter IC Sound), 1-Wire, Ethernet (registered trademark)/IP, 10BaseT, or other Serial communication standards. The transmission method of the serial communication may be synchronous or asynchronous.

The sensor cable C4 may include not only a signal line for transmitting the sensor signal S14 output by the sensor 14 to the sensor hub 15, but also a power supply line for supplying power from the sensor hub 15 to the sensor 14. In the case where the sensor cable C4 has a plurality of signal lines and power lines, the sensor cable C4 may be wrapped with a bundle of vinyl resin, a shield wire, or the like, and may be partially or entirely integrated as a composite communication cable. When the microphone and the camera are used as the sensor 14, an acoustic signal of the microphone and a video signal of the camera may be simultaneously transmitted by a transmission method such as tmds (transition Minimized Differential signaling) via an HDMI (registered trademark) cable.

In the case of using the Sensor 14 capable of wirelessly transmitting the Sensor signal S14, the Sensor hub 15 may be provided with a wireless base station such as wsn (wireless Sensor networks) to receive the Sensor signal S14 and transmit the received signal to the transmitter/receiver unit 121 of the servo amplifier 12 via the communication cable C2. This can shorten the distance traveled by the radio, and improve the delay and reliability of communication, as compared with the case where a base station is provided in the controller 11 or the servo amplifier 12.

Fig. 3 is a schematic configuration diagram showing a sensor hub according to embodiment 1 of the present invention. The sensor hub 15 includes: a transmission/reception unit 151 that transmits/receives signals to/from the encoder 13, the sensor 14, and the servo amplifier 12; a signal processing unit 152 that processes a signal to be transmitted and received; and a sensor determination unit 153 for determining the connection state of the sensor 14.

The signal processing unit 152 includes: an AD converter 152a that converts an analog signal into a digital signal; and a serial conversion unit 152b that converts the parallel signal into a serial signal. The serial conversion unit 152b converts the sensor signal S14 into a serial signal based on the configuration of the data frame of the serial communication set by the communication specification setting unit 122 of the servo amplifier 12. The sensor hub 15 transmits the encoder signal S13 and the sensor signal S14 to the servo amplifier 12 by, for example, serial communication of 2 different systems.

Here, the serial converter 152b may combine the encoder signal S13 and the sensor signal S14 into 1 serial signal, and transmit the signal to the servo amplifier 12 by 1-system serial communication. When the plurality of sensors 14 are connected, the serial converter 152b may multiplex the plurality of sensor signals S14 into 1 serial signal and transmit the signal to the servo amplifier 12 by serial communication of 1 system. The number of signal lines between the servo amplifier 12 and the sensor hub 15 can be reduced by serial communication of 1 system.

The serial converter 152b may convert the intervals of the sensor signals S14 into signals having a period different from the sampling period of the sensor signals S14 by increasing the intervals, or may delete redundant data in order to suppress the data capacity. The sensor hub 15 may superimpose alarm information such as a communication alarm signal and a power alarm signal generated when a communication error or a power error is detected on the serial signal, or may superimpose diagnostic information such as the ambient temperature and the operation time of the sensor hub 15 on the serial signal.

The sensor determination unit 153 determines the number of sensors 14, the type of the sensors 14, the number of sensor signals S14, and the like as the connection state of the sensors 14 based on, for example, the voltage value of the sensor signal S14, and outputs the determination result to the transmission/reception unit 151 of the sensor hub 15.

The signal processing unit 152 of the sensor hub 15 is realized by an electronic circuit including an LSI such as an analog circuit, a package ic (integrated circuit), an industrial microcomputer (CPU), an ASIC, an FPGA, or a CPLD. The signal processing unit 152 may include a filter processing means and a buffer processing means, not shown, for removing noise and improving communication accuracy. The signal processing unit 152 may include a multiplexer and a switching IC when the number and the type of the analog sensor signals S14 subjected to AD conversion are large.

Fig. 4(a) and (b) are diagrams showing an example of the structure of a data frame for serial communication generated by the serial conversion unit of the sensor hub according to embodiment 1 of the present invention. Fig. 4(a) and (b) show data frames of the encoder signal S13 and the sensor signal S14, respectively. As shown in fig. 4(a), (b), the encoder signal S13 and the sensor signal S14 are transmitted by serial communication of, for example, different 2 systems.

A data frame of serial communication is composed of, for example, a header, a data field, and a trailer. The header is a region for transmitting communication specifications such as alarm information and a bit rate related to the operation state of the encoder 13 and the sensor 14. The tail is a region for transmitting the error detection code, and the servo amplifier 12 detects an error such as transmission path noise associated with data transfer based on the tail. As an error detection method, parity, checksum, cyclic redundancy check, and the like can be applied.

The data field is a region for transmitting the framed encoder signal S13 or sensor signal S14, and the signal includes a start bit, a data bit, a parity bit, a stop bit, and the like. As shown in fig. 4(b), in the case of an acceleration sensor and a pressure sensor, for example, the sensor 14 has a data field in which 3 acceleration sensor signals S141a, S141b, S141c in the X-axis, Y-axis, and Z-axis directions output from the acceleration sensor and a pressure sensor signal S142 output from the pressure sensor are combined.

Next, the operation of the servo system 100 when setting the communication specification between the servo amplifier 12 and the sensor hub 15 will be described. Fig. 5 is a flowchart showing the operation of the servo system according to embodiment 1 of the present invention. Next, the sensor signal S14 from the sensor 14 is output to the sensor hub 15 in an analog form.

The servo amplifier 12 transmits a discrimination request signal S03 requesting discrimination of the sensor 14 to the sensor hub 15(ST 101). The sensor hub 15 receives the sensor signal S14 from the sensor 14(ST 102). The sensor hub 15 converts the received sensor signal S14 in analog form into a digital signal by the AD converter 152a for a predetermined period of time (ST 103). The period for performing AD conversion is set to, for example, the shortest update cycle of the serial communication that can be performed by the servo amplifier 12 or the sensor hub 15.

The sensor hub 15 converts the sensor signal S14 into a serial signal by the serial conversion unit 152b (ST 104). The sensor hub 15 determines the number of sensor signals S14 by the sensor determination unit 153 based on the change in the voltage value of the sensor signal S14(ST 105). For example, when the voltage of the sensor signal S14 is greater than or less than the threshold value for a certain period of time, the number of sensor signals S14 is determined as if the sensor signal S14 is received.

The sensor hub 15 transmits the number of sensor signals S14 determined by the sensor determination unit 153 to the servo amplifier 12 as a sensor determination signal S16 (ST 106).

The communication specification setting unit 122 of the servo amplifier 12 sets the communication specification between the servo amplifier 12 and the sensor hub 15 based on the sensor determination signal S16 (ST 107). The communication specification setting unit 122 sets a data frame of serial communication between the servo amplifier 12 and the sensor hub 15. The data frame set by the communication specification setting unit 122 is determined in accordance with the number of the sensor signals S14, the type of the sensor signal S14, the data size of the sensor signal S14, the transmission order of the sensor signal S14, and the communication method between the sensor 14 and the sensor hub 15.

The servo system 100 can set the communication specification between the sensor hub 15 and the servo amplifier 12 in accordance with the sensor 14 connected to the sensor hub 15 by executing ST101 to ST 107. This makes it possible to optimize the update cycle, communication speed, and communication data amount of serial communication according to the sensor 14 connected to the sensor connection unit 15b of the sensor hub 15.

Some of ST101 to ST107 may be omitted, or some of them may be performed by reversing their order. For example, the parallel sensor signal S14 converted into a digital signal by the AD converter 152a may be transmitted to the sensor determination unit 153 without passing through the serial converter 152 b. The number of sensor signals S14 determined by the sensor determination unit 153 and the communication specification between the servo amplifier 12 and the sensor hub 15 may be stored in a recording circuit, not shown, included in the sensor hub 15. By calling the saved content at the time of operating the servo system 100, the operations of steps ST101 to ST107 can be omitted.

Next, an operation of transmitting the signals detected by the encoder 13 and the sensor 14 to the servo amplifier 12 via the sensor hub 15 in accordance with the communication specifications set in ST101 to ST107 will be described with reference to fig. 6. Fig. 6 is a flowchart showing the operation of the servo system according to embodiment 1 of the present invention. Next, the encoder signal S13 detected by the encoder 13 is converted into a serial signal inside the encoder 13, and serial communication is performed between the encoder 13 and the sensor hub 15.

The servo amplifier 12 transmits a 1 ST communication request signal S01 requesting a response under the communication specification set in ST101 to ST107 to the sensor hub 15(ST 201). The 1 st communication request signal S01 specifies communication specifications such as a bit rate, a communication band, and an update cycle between the servo amplifier 12 and the sensor hub 15, and requests a response of the encoder signal S13 or the sensor signal S14.

The sensor hub 15 generates a 2 nd communication request signal S02 requesting a response from the encoder 13 in accordance with the set communication standard based on the 1 ST communication request signal S01, and transmits the signal to the encoder 13(ST 202). The 2 nd communication request signal S02 specifies communication specifications such as a bit rate, a communication band, and an update cycle between the encoder 13 and the sensor hub 15, and requests the encoder 13 for a response of the encoder signal S13. The encoder 13 transmits the encoder signal S13 to the sensor hub 15 in accordance with the communication specification specified by the 2 nd communication request signal S02 (ST 203).

The sensor hub 15 receives the sensor signal S14 from the sensor 14, and converts it into a digital signal by the AD converter 152a (ST 204). The serial conversion unit 152b performs serial conversion on the sensor signal S14 in accordance with the communication specification specified by the 1 st communication request signal S01. The serial converter 152b, for example, in response to a composite request signal S04 requesting the composite of the plurality of sensor signals S14 generated by the transceiver 151 of the sensor hub 15 based on the 1 ST communication request signal S01, composites the plurality of sensor signals S14 into a serial signal and outputs the composite signal as a sensor composite signal S15 (ST 205).

The sensor hub 15 transmits the encoder signal S13 and the sensor composite signal S15 to the servo amplifier 12, respectively, for example, through serial communication of different 2 systems (ST 206).

The servo amplifier 12 divides the sensor composite signal S15 into parallel signals by the parallel converter 123, and acquires an encoder signal S13 and a sensor signal S14(ST 207). At this time, the sensor discrimination signal S16 is contained in the sensor composite signal S15, whereby the sensor composite signal S15 can be made separable by the parallel conversion section 123 of the servo amplifier 12.

The servo system 100 executes ST201 to ST207, thereby being able to acquire the encoder signal S13 and the sensor signal S14 based on the communication specification set by the communication specification setting unit 122 of the servo amplifier 12.

ST201 to ST207 may be partially omitted or partially reversed in order. The communication method of the serial signal is not limited to the cadence synchronization method. The serial signal may be communicated in any of half-duplex and full-duplex modes. In addition, the various request signals may include a clock signal for performing synchronous communications. The 2 nd communication request signal S02 is a signal that requires whether or not the contents of the motor 10 and the encoder 13 need to be changed, and the 2 nd communication request signal S02 may not be used depending on the type of the motor 10 and the encoder 13.

As described above, the servo system 100 according to embodiment 1 of the present invention includes the sensor hub 15 detachably connected to the encoder 13, and transmits the encoder signal S13 and the sensor signal S14 to the servo amplifier 12 via the sensor hub 15. With this configuration, the sensor hub 15 can be appropriately selected according to the specification of the sensor 14 and connected to the encoder 13. This allows the drive of the motor 10 to be controlled using information from the various sensors 14.

The servo system 100 determines the connection state of the sensor 14 by the sensor determination unit 153 of the sensor hub 15, and sets the communication specification between the servo amplifier 12 and the sensor hub 15 by the communication specification setting unit 122 of the servo amplifier 12 based on the determination result. With this configuration, the servo system 100 can immediately read the sensor signal S14 by the servo amplifier 12 when the sensor hub 15 is replaced or the sensor 14 is added to or changed from the sensor hub 15. In addition, the servo system 100 can optimize the update cycle, the communication speed, and the communication data amount of the serial communication between the sensor hub 15 and the servo amplifier 12.

The encoder connector 15a of the sensor hub 15 is preferably configured to have the same shape as the connector C2a of the communication cable C2, and to be configured by the same pin assignment. The amplifier connection portion 15c of the sensor hub 15 is preferably configured to have the same shape as the connector 13a of the encoder 13 and to have the same pin assignment.

With the above configuration, the sensor hub 15 is used at the time of startup and maintenance of the servo system 100, and the sensor hub 15 used at the time of operation is removed, whereby the connector C2a of the communication cable C2 can be connected to the encoder 13.

In the servo system 100, it is preferable that power be supplied from the servo amplifier 12 to the sensor hub 15, the encoder 13, and the sensor 14. The power supplied from the servo amplifier 12 is transmitted as a power signal to the sensor hub 15 via the power supply line of the communication cable C2, and is supplied to the not-shown circuit board of the encoder 13 and the sensor 14 via the sensor hub 15.

By configuring as described above, the sensor hub 15 can receive power from the servo amplifier 12, and the sensor hub 15 can be easily replaced.

Here, the power signal includes, for example, a positive or negative electric wire and a ground wire. The power transmitted by the power signal may be a direct current signal or an alternating current signal. The sensor hub 15 may include a voltage boosting or reducing circuit to increase the number of types of power lines to be supplied to the sensors 14. Thereby, the number of sensors 14 connected to the sensor hub 15 can be increased. In addition, a battery may be mounted on the sensor hub 15 so as to be not affected by the servo amplifier 12 and the voltage variation of the device power supply. When the supply power of the servo amplifier 12 is short or when the variation of the supply voltage is large, the power can be supplied from the outside of the sensor hub 15 to any one or more of the sensor hub 15, the encoder 13, and the sensor 14.

The sensor hub 15 is preferably configured to be able to limit the specifications of the sensors 14 corresponding to 1 sensor hub 15, and the sensor hub 15 is preferably replaced according to the specifications of the sensors 14. Thus, as compared with the case where 1 sensor hub 15 corresponds to a plurality of kinds of sensors 14, it is not necessary to make hardware and software redundant, and the substrate size and setting data of the sensor hub 15 can be suppressed to be small.

In fig. 1, an example is shown in which the sensor hub 15 is mounted on the motor 10 from the vertical direction, but the sensor hub 15 may be disposed at a position where space is easily secured and a position where emc (electromagnetic compatibility) is good around the encoder 13. In addition, the sensor hub 15 may divide the circuit substrate and the structure into 2 or more. For example, the encoder connecting portion 15a and the signal processing portion 152 may be connected via a cable.

Embodiment 2.

A servo system 100 according to embodiment 2 for implementing the present invention will be described with reference to fig. 7. Here, the description overlapping with the servo system 100 according to embodiment 1 is simplified or omitted as appropriate. In fig. 7, the same reference numerals as those in embodiment 1 denote the same or corresponding portions. The servo system 100 according to the present embodiment includes the sensor hub 15 to which the sensor 14b that outputs a digital signal in a serial format can be connected in addition to the sensor 14 that outputs an analog signal.

Fig. 7 is a schematic configuration diagram of a servo system according to embodiment 2 of the present invention. The sensor hub 15 includes an encoder connector 15a, a sensor connector 15b, and an amplifier connector 15c, and the encoder connector 15a is detachably connected to the encoder 13. The sensor connection unit 15b of the sensor hub 15 is connected to, for example, 3 sensors 14 that output analog signals and a sensor 14b that outputs a digital signal in serial form via a sensor cable C4. The number of the sensors 14 and 14b and the sensor cables C4 is not limited to this, and can be changed as appropriate.

The sensor 14b is, for example, a microphone, and transmits a mono acoustic signal to the sensor hub 15 in serial form as a sensor signal S14 b. The sensors 14b communicate with the sensor hub 15, for example, by way of I2S. At this time, the sensor cable C4 includes transmission lines of an sclk (serial clock) signal, a wdclk (word clock) signal, and an sd (serial data) signal.

The signal processing unit 152 of the sensor hub 15 has a serial interface (serial I/F)152c for converting the SD signal transmitted from the sensor 14b in the I2S format into a voltage value. The sensor signal S14b converted into a voltage value by the serial interface 152c is output to the sensor determination unit 153, and the number of sensors 14, 14b, the type of sensors 14, 14b, the number of sensor signals S14, S14b, and the like are determined as the connection state of the sensors 14, 14 b.

When the communication specification between the sensor 14b and the sensor hub 15 is set, the servo amplifier 12 sequentially transmits the 3 rd communication request signal S05 of each serial communication method corresponding to the sensor hub 15 to the sensor 14b via the sensor hub 15.

The 3 rd communication request signal S05 specifies communication specifications such as a bit rate, a communication band, and an update cycle between the sensor 14b corresponding to the sensor hub 15 and the sensor hub 15, and requests a response of the sensor signal S14 b. For example, if it is confirmed whether or not the sensor 14b can respond to the I2S system, the servo amplifier 12 transmits the WDCLK signal and the SCLK signal, and confirms whether or not a response specified by the communication specification of the I2S system can be acquired at a predetermined timing. This enables setting of the communication specification between the sensor hub 15 and the sensor 14 b.

The communication format between the sensor hub 15 and the sensor 14b may be, for example, Serial communication standards such as RS (TIA/EIA)232/422/485, usb (universal Serial bus), I2C (Inter Integrated Circuit), spi (Serial Peripheral interface), 1-Wire, Ethernet/IP (registered trademark), and 10BaseT, in addition to I2S, and the transmission method of the Serial communication may be synchronous or asynchronous. The serial interface 152c may be implemented by a URAT (Universal Asynchronous Receiver/Transmitter) transceiver IC of an industrial microcomputer.

The communication specification setting unit 122 of the servo amplifier 12 sets the communication specification between the sensor hub 15 and the servo amplifier 12 in accordance with the connection state of the sensors 14 and 14b determined by the sensor determination unit 153 of the sensor hub 15. The sensor hub 15 transmits the encoder signal S13 transmitted through the encoder connector 15a and the sensor signals S14 and S14b transmitted through the sensor connector 15b to the servo amplifier 12 through the communication cable C2 connected to the amplifier connector 15C in accordance with the set communication standard.

As described above, the servo system 100 according to embodiment 2 of the present invention includes the sensor hub 15, and the sensor hub 15 includes: an encoder connector 15a detachably connected to the encoder 13; a sensor connection unit 15b to which the sensor 14b that outputs in a serial form can be connected; and an amplifier connection unit 15C to which a communication cable C2 for transmitting the encoder signal S13 and the sensor signals S14 and S14b to the servo amplifier 12 is connected, and which is attached to the encoder 13 by appropriately selecting the sensor hub 15 according to the specifications of the sensor 14, thereby being capable of accommodating a wide variety of sensors 14.

Even when the sensor 14b and the sensor hub 15 transmit and receive data through serial communication, the sensor determination unit 153 can determine the connection state of the sensors 14 and 14b, and the communication specification of the serial communication between the servo amplifier 12 and the sensor hub 15 is set in accordance with the determination result, so that the update cycle, the communication speed, and the communication data amount of the serial communication can be optimized.

Further, the specification of the serial communication method between the sensor 14b and the sensor hub 15 may be limited. This can reduce the number of types of ports for serial communication provided in the sensor connection portion 15b, and can reduce the size and cost of the sensor hub 15.

Embodiment 3.

A servo system 100 according to embodiment 3 for implementing the present invention will be described with reference to fig. 8 and 9. Here, the description overlapping with the servo system 100 according to embodiment 1 is simplified or omitted as appropriate. In fig. 8 and 9, the same reference numerals as those in embodiment 1 denote the same or corresponding portions. The servo system 100 according to the present embodiment is configured to communicate the encoder signal S13 and the sensor signal S14 in a serial format of 2 different systems, and to communicate the encoder signal S13 and the sensor signal S14 in a serial format of 1 system, in contrast to the servo system 100 according to embodiment 1.

Fig. 8 is a schematic configuration diagram of a sensor hub according to embodiment 3 of the present invention. As shown in fig. 8, the sensor hub 15 includes: an encoder connector 15a detachably connected to the encoder 13; a sensor connector 15b to which a sensor cable C4 having one end connected to the sensor 14 is connected; and an amplifier connection unit 15C having one end connected to the communication cable C2 of the servo amplifier 12.

The signal processing section 152 of the sensor hub 15 receives the encoder signal S13 in addition to the sensor signal S14. The transceiver 151 of the sensor hub 15 generates a composite request signal S04 requesting the composition of the encoder signal S13 and the sensor signal S14 in accordance with the structure of the data frame of the serial signal specified by the 1 st communication request signal S01. The serial converter 152b combines the encoder signal S13 and the sensor signal S14 into a serial signal in response to the composite request signal S04, and outputs the serial signal as a composite signal S17. The sensor hub 15 transmits the composite signal S17 to the servo amplifier 12 through serial communication of 1 system.

As an example, a case will be described in which the encoder signal S13 of 2 bytes and the sensor signal S14 of 5 bytes in total are combined and transmitted from the sensor hub 15 to the servo amplifier 12. Here, the sensor 14 is an acceleration sensor, a pressure sensor, and a microphone.

The sensor signals S14 are acceleration sensor signals S141a, S141b, S141c, pressure sensor signal S142, and microphone signal S143 in the X-axis, Y-axis, and Z-axis directions, which are digital data of 1byte, respectively. Here, the data size of the encoder signal S13 and the sensor signals S141a, S141b, S141c, S142, and S143, the number of sensors 14, and the structure of the data frame for serial communication can be changed as appropriate.

The communication specification setting unit 122 of the servo amplifier 12 transmits the 1 st communication request signal S01 to the serial conversion unit 152b if it recognizes that the number of the sensor signals S14 received by the signal processing unit 152 is 5 based on the sensor determination signal S16. The 1 st communication request signal S01 contains information on the structure of a data frame for simultaneously transmitting the encoder signal S13 of 2 bytes and the sensor signal S14 of 5 bytes in total through serial communication of 1 system.

While the data capacity of serial communication that can be transmitted by one update is 5 bytes, the sum of the data capacities of the encoder signal S13 and the sensor signals S141a, S141b, S141c, S142, and S143 is 7 bytes.

In the case described above, the data transmitted for each update cycle is divided, the interval is made longer, compression is performed, and the like. For example, the serial converter 152b of the sensor hub 15 performs signal processing for dividing data for each update cycle of serial communication between the servo amplifier 12 and the sensor hub 15 for 1 or two of the encoder signal S13 and the sensor signal S14.

Fig. 9 shows an example of the structure of a serial communication data frame generated by the serial conversion unit. As shown in fig. 9, the communication specification setting unit 122 of the servo amplifier 12 transmits an instruction to the serial conversion unit 152b of the sensor hub 15 so as to generate a data frame of the sensor signals S141 a-c, S142, and S143, which are transmitted every time the encoder signal S13 necessary for controlling the rotation of the motor 10 is transmitted and every 2 update cycles. In accordance with this instruction, the serial conversion unit 152b generates the data frame shown in fig. 9, and adds the data frame to the data field of the serial communication and transmits the data frame.

Here, although the example in which the sensor hub 15 divides data for each update cycle is illustrated, signal processing for increasing the interval of data may be performed on 1 or both of the encoder signal S13 and the sensor signal S14. The sensor hub 15 may perform signal processing for compressing data on 1 or both of the encoder signal S13 and the sensor signal S14.

Further, the data S200 that is defective when the interval of the data is made longer or compressed may be superimposed as additional information. In fig. 9, in the update cycle of the even number, data S200 is added to the communication capacity of 1 data frame (1 byte).

In order to reduce the data capacity transmitted from the sensor hub 15, the feature amount of the encoder signal S13 or the sensor signal S14 may be extracted and transmitted to the servo amplifier 12. For example, the sensor hub 15 may perform signal processing of data transformation from the data of the time region to the data of the frequency region for either 1 or both of the encoder signal S13 and the sensor signal S14.

As described above, according to the servo system 100 according to embodiment 3 of the present invention, the sensor hub 15 is detachably attached to the encoder 13, so that the sensor hub 15 can be appropriately selected according to the specification of the sensor 14 and connected to the encoder 13, and thus the servo system can cope with various types of sensors 14. The servo system 100 generates the composite signal S17 obtained by combining the encoder signal S13 and the sensor signal S14 by the sensor hub 15, and can transmit the composite signal to the servo amplifier 12 by serial communication of 1 system, thereby realizing the power-saving wiring of the signal line of the communication cable C2.

Further, the sensor hub 15 performs signal processing such as data division, data interval lengthening, and data compression for each update cycle on the encoder signal S13 and the sensor signal S14, and thereby can transmit the encoder signal S13 and the sensor signal S14 even when the data capacity is large relative to the data capacity of serial communication that can be transmitted by one update.

Embodiment 4.

A servo system 100 according to embodiment 4 for implementing the present invention will be described with reference to fig. 10. Here, the description overlapping with the servo system 100 according to embodiment 1 is simplified or omitted as appropriate. In fig. 10, the same reference numerals as those in embodiment 1 denote the same or corresponding portions. The servo system 100 according to the present embodiment includes a host processing device 101, and the host processing device 101 specifies the drive timing of the servo system 100 based on an execution plan of the entire industrial device including the servo system 100.

The upper-level processing device 101 is a control device of an industrial device for the purpose of centralized management of the entire system, including, for example, a cloud, an edge computer, an ipc (industrial personal computer), an mes (manufacturing Execution system), and the like.

The host processing apparatus 101 is connected to the controller 11 via a network cable C0 that can transmit and receive signals in both directions. The servo system 100 includes a host processing device 101, and the controller 11 can control the rotation of the motor 10 based on the execution plan of the entire industrial device by specifying the driving timing of the motor 10.

Further, the upper-level processing device 101 can diagnose the deterioration over time of the industrial device by analyzing the sensor signal S14 from the sensor 14, and perform preventive maintenance or scheduled maintenance of the devices used in the servo system 100, the driven object of the motor 10, and the like.

For example, in the conventional servo system 100 in which the encoder 13 and the servo amplifier 12 are directly connected to each other via a predetermined communication cable to operate, the conventional communication cable is used as the communication cable C2 shown in fig. 10, the sensor hub 15 is connected between the conventional communication cable and the encoder 13, and the host processing device 101 can diagnose the industrial device based on the sensor signal S14 from the sensor 14 connected to the sensor hub 15.

When the sensor hub 15 is already connected and a new sensor 14 cannot be connected or identified by the existing sensor hub 15, the servo system 100 may be configured to replace the existing sensor hub 15 with a new sensor hub 15 to which the sensor 14 can be connected or identified. If the diagnosis is temporary, the sensor hub 15 after replacement may be restored to the original sensor hub 15 after the diagnosis, or the sensor hub 15 after replacement may be used for driving control of the motor 10. The sensor hub 15 for diagnosis may transmit the encoder signal S13 from the encoder 13 to the upper processing device 101 for diagnosis, or may not use the encoder signal S13 for diagnosis.

The sensor hub 15 may not be provided with the encoder connector 15a, and the diagnosis may be performed in a state where the encoder 13 is not connected to the sensor hub 15. When the replaced sensor hub 15 is also used for drive control of the motor 10, the sensor hub 15 is provided with a function of transmitting an encoder signal S13 from the encoder 13 to the servo amplifier 12.

Embodiment 5.

Next, an example of an implementation of a method for connecting the sensor hub 15 to the servo system 100 to diagnose the industrial device will be described. Fig. 11 is a flowchart showing a process of introducing a sensor hub into the servo system according to embodiment 5 of the present invention. Next, a case will be described in which the sensor hub 15 is added to the existing servo system 100 to which the servo amplifier 12 and the encoder 13 are connected.

The user of the servo system 100 disconnects the power supply to the servo amplifier 12 to attach the sensor hub 15, and removes the connector C2a of the communication cable C2 from the connector 13a of the encoder 13(ST 301).

The user of the servo system 100 connects the sensor hub 15 to the servo amplifier 12, the encoder 13, and the sensor 14, respectively (ST 302). The user of the servo system 100 connects the servo amplifier 12 and the sensor hub 15 by connecting the connector C2a of the communication cable C2 to the amplifier connection portion 15C of the sensor hub 15. Further, the user of the servo system 100 attaches the sensor hub 15 to the encoder 13 by connecting the encoder connecting portion 15a to the connector 13a of the encoder 13. The user of the servo system 100 connects the sensor 14 and the sensor hub 15 by connecting the connector C4a of the sensor cable C4 to the sensor connecting portion 15 b. Here, the order of the mounting work may be reversed.

The user of the servo system 100 confirms visually, by a detector, etc., that there is no wiring error between the servo amplifier 12, the encoder 13, the sensor 14, and the sensor hub 15(ST 303).

The user of the servo system 100 turns on the power supply of the servo amplifier 12 and supplies power from the servo amplifier 12 to the sensor hub 15, the encoder 13, and the sensor 14(ST 304). The user of the servo system 100 confirms whether the power supply to the sensor hub 15, the encoder 13, and the sensor 14 is normal by visual observation, a detector, or the like (ST 305).

In order to make it easy to confirm that the power is normally supplied, the sensor hub 15 may monitor a variation in the power supply voltage by an arithmetic circuit such as an industrial microcomputer, and notify a power alarm by lighting, blinking, or beeping a lamp provided in the sensor hub 15 or the servo amplifier 12. When the sensor hub 15 outputs a power alarm, an external power supply may be used for the sensor 14 or the sensor hub 15 added to the servo system 100.

In addition, when the power supply from the servo amplifier 12 to the sensor hub 15 or the sensor 14 cannot be performed normally, the sensor 14 or the sensor hub 15 of a specification having different operating voltages and current capacities may be replaced so that the power supply is possible. Returning to the case of replacing the sensor 14 or the sensor hub 15(ST 302).

When the power supply to the sensor hub 15 is normal, the sensor determination unit 153 of the sensor hub 15 determines the connection state of the sensor 14 connected to the sensor connection unit 15b, and the servo amplifier 12 sets the communication specification between the servo amplifier 12 and the sensor hub 15(ST 306). The sensor hub 15 transmits the encoder signal S13 and the sensor signal S14 to the servo amplifier 12 and the host processing device 101 in accordance with the set communication standard (ST 307). The detailed operations (ST306) and (ST307) are the same as those (ST101) to (ST107) and (ST201) to (ST207) of embodiment 1, and therefore are omitted.

By executing ST301 to ST307, the encoder signal S13 and the sensor signal S14 are transmitted to the servo amplifier 12 and the host processing device 101, whereby diagnosis for performing drive control and preventive maintenance of the industrial device including the servo system 100 can be performed. The diagnostic method for an industrial device using the sensor hub 15 according to embodiment 5 of the present invention can use the existing motor 10, communication cable C2, and encoder 13 by adding or replacing the sensor hub 15, and thus can easily add the sensor 14 to the servo system 100.

The steps (ST301) to (ST307) may be partially omitted or partially reversed. In addition, although the method of adding the sensor hub 15 to the existing servo system 100 is shown in this embodiment, the sensor hub 15 may be incorporated into the servo system 100 when the servo system 100 is newly installed.

In embodiments 1 to 5, the description has been given of the case where the motor 10 is a rotary motor having one shaft, but the motor is not limited to the rotary motor, and a linear motor that drives the movable element in the translational direction with respect to the stationary element may be used.

In the present invention, a plurality of components disclosed in embodiments 1 to 4 may be appropriately combined without departing from the scope of the present invention.

Description of the reference numerals

100 servo system, 10 motor, 11 controller, 12 servo amplifier, 13 coder, 14 sensor, 15 sensor hub, 15a coder connecting part, 15b sensor connecting part, 15c amplifier connecting part, 151 transceiver part, 152 signal processing part, 153 sensor discriminating part.

Claims (11)

1. A servo system, comprising:

an electric motor;

an encoder that detects rotation of the motor;

a sensor hub including a 1 st connection unit, a 2 nd connection unit, and a 3 rd connection unit, the 1 st connection unit being detachably connected to the encoder, the 2 nd connection unit being connected to a sensor that detects a state different from the rotation, the 3 rd connection unit being connected to a communication cable that transmits an encoder signal output from the encoder via the 1 st connection unit and a sensor signal output from the sensor via the 2 nd connection unit; and

and a servo amplifier that drive-controls the motor based on the encoder signal, the sensor signal, and a drive command transmitted from a controller, the encoder signal, the sensor signal, and the drive command being transmitted via the communication cable.

2. The servo system of claim 1,

the communication cable has a connector connected to the 3 rd connecting portion of the sensor hub, the encoder has a connector detachably connected to the 1 st connecting portion of the sensor hub, and the connector of the communication cable is connectable to the connector of the encoder.

3. Servo system according to claim 1 or 2,

the sensor hub includes a signal processing unit that converts at least one of the encoder signal and the sensor signal into a serial signal.

4. Servo system according to any of claims 1 to 3,

the sensor hub sends the encoder signal and the sensor signal to the servo amplifier through serial communication of different systems.

5. The servo system of claim 3,

the sensor hub combines the encoder signal and the sensor signal by the signal processing unit, and transmits the combined signal to the servo amplifier by serial communication of 1 system.

6. Servo system according to any of claims 1 to 5,

the sensor hub includes a sensor determination unit that determines a connection state of the sensor connected to the 2 nd connection unit based on a voltage value of the sensor signal, and transmits the determined connection state to the servo amplifier via the communication cable.

7. The servo system of claim 6,

the servo amplifier includes a communication specification setting unit that sets a communication specification between the servo amplifier and the sensor hub based on the connection state determined by the sensor determination unit of the sensor hub.

8. A sensor hub, comprising:

a 1 st connecting part which is detachably connected with an encoder for detecting the rotation of the motor;

a 2 nd connecting part which connects a sensor for detecting a state different from the rotation; and

and a 3 rd connection unit to which a communication cable is connected, the communication cable transmitting at least one of an encoder signal output from the encoder via the 1 st connection unit and a sensor signal output from the sensor via the 2 nd connection unit to a servo amplifier that drives and controls the motor.

9. The sensor hub according to claim 8,

comprising: a signal processing unit that converts the encoder signal and the sensor signal into a serial signal; and a sensor determination unit configured to determine a connection status of the sensor connected to the 2 nd connection unit based on a voltage value of the sensor signal, wherein the sensor hub transmits the connection status of the sensor to the servo amplifier via the 3 rd connection unit and the communication cable.

10. A method for diagnosing an industrial device including a servo system in which an encoder for detecting rotation of a motor and a servo amplifier for supplying a current to the motor are detachably connected via a communication cable having a connector connectable to the encoder, the servo amplifier adjusting the current supplied to the motor based on a detection signal of the encoder transmitted via the communication cable to perform drive control,

the method for diagnosing an industrial device is characterized by comprising the following steps:

connecting a sensor hub having 1 st to 3 rd connection parts between the communication cable and the encoder, the sensor hub connecting the encoder to the 1 st connection part, the sensor detecting a state different from the rotation of the motor to the 2 nd connection part, and the connector of the communication cable to the 3 rd connection part;

transmitting the detection signal of the encoder from the encoder to the servo amplifier via the sensor hub and the communication cable;

transmitting a detection signal of the sensor from the sensor to the servo amplifier via the sensor hub and the communication cable; and

diagnosing the industrial device based on the detection signal of the encoder and the detection signal of the sensor.

11. The method for diagnosing an industrial device according to claim 10,

the method includes converting the detection signal of the encoder and the detection signal of the sensor into serial signals, and transmitting the serial signals to the servo amplifier via the sensor hub and the communication cable.

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