CN111684711B - Servo system, sensor hub, and diagnostic method for industrial device - Google Patents

Abstract

The purpose of the present invention is to provide a servo system that can accommodate a wide variety of sensors of 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 controlling driving of the motor, and the sensor hub 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 signals to the servo amplifier.

Description

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

Technical Field

The present invention relates to a servo system, a sensor hub, and a diagnostic method for 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 FA (Factory Automation) field, it is required to construct an advanced communication system in which the detected signals are effectively used for controlling devices by detecting the operation states of industrial devices and the states of the surrounding environments by various sensors. 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 in order to control the rotation of the motor is mounted near the rotation axis of the motor. The servo amplifier controls the motor based on the drive instruction sent from the controller and the rotation information of the motor sent from the encoder.

In the servo system, a sensor for detecting the state of the motor or the periphery thereof is used. By using the sensor, the present invention can be effectively used for, for example, unsteady control of the driving sequence of the motor, improvement of control accuracy of the driven body of the motor, and change of the control mode of the motor. Further, the sensor is used to detect local abnormal noise, vibration, and the like around the motor or the motor, thereby being effective 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 detection signal is transmitted to an upper control device through the controller. On the other hand, in a servo system applied to an industrial apparatus, a servo amplifier and a controller are often provided at a position away 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 troublesome, and there is a possibility that the transmission characteristic of the detection signal is deteriorated.

In order to solve the above-described problems, patent document 1 discloses an encoder that detects an operation of a motor and generates a feedback signal indicating the detected operation, the encoder receives a detection signal from a sensor that detects a 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 complexity of wiring work.

Patent document 1: japanese patent application laid-open 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 by the sensor and a feedback signal detected by the encoder are output to a control device, an input unit corresponding to the specification of the sensor needs to be provided in advance to the encoder, and when a sensor having 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 of the present invention is to provide a servo system capable of coping with various sensors having different specifications. Further, the object is to provide a sensor hub to which a sensor can be connected. Further, it is an object to provide a diagnostic method for an industrial device using a sensor hub.

The servo system according to the present invention includes: a 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, the sensor hub including 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 a servo amplifier that performs drive control of the motor based on the encoder signal, the sensor signal, and a drive instruction transmitted from a controller, which are transmitted via the communication cable.

The sensor hub according to the present invention includes: a 1 st connection unit detachably connected to an encoder for detecting rotation of the motor; a 2 nd connection unit for connecting 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 the encoder signal outputted from the encoder via the 1 st connection unit and the sensor signal outputted from the sensor via the 2 nd connection unit to a servo amplifier that controls driving of the motor, and determining a connection state of the sensor connected to the 2 nd connection unit based on a voltage value of the sensor signal.

The present invention provides 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 current to the motor are detachably connected via a communication cable having a connector connectable to the encoder, the servo amplifier performing drive control by adjusting the current supplied to the motor based on a detection signal of the encoder transmitted via the communication cable, the diagnostic method comprising: a sensor hub having 1 st to 3 rd connection portions between the communication cable and the encoder, the sensor hub connecting the encoder to the 1 st connection portion, connecting a sensor detecting a state different from the rotation of the motor to the 2 nd connection portion, and connecting the connector of the communication cable to the 3 rd connection portion; transmitting the detection signal of the encoder from the encoder to the servo amplifier via the sensor hub and the communication cable; determining a connection condition of the sensor connected to the 2 nd connection unit based on a voltage value of a detection signal of the sensor, the sensor hub transmitting the determined connection condition to the servo amplifier; 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 connected to the encoder, the sensor, and the servo amplifier, and the sensor hub is detachably connected to the encoder, so that the sensor hub can be appropriately selected according to the specifications of the connected sensor, and can be used for various sensors. Further, according to the sensor hub of the present invention, the sensor hub is detachably connected to the encoder in accordance with 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 is added or replaced to the servo system, so that the sensor can be easily added or replaced to 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 a structure of a data frame generated by a 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 a 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. A servo system of a rotary servomotor having a 1-axis will be described below 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: an electric motor 10; a controller 11 that generates a drive instruction of the motor 10; a servo amplifier 12 for driving and controlling the motor 10; an encoder 13 that detects rotation of the motor 10; a sensor 14 that detects other states 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 state of the motor 10 or the periphery of the motor 10.

The motor 10 and the servo amplifier 12 are connected to each other via a power cable C3 in order to supply current to the armature of the motor 10. The servo amplifier 12 adjusts the current to be supplied based on the drive command from the controller 11 and the encoder signal S13 and the sensor signal S14 transmitted from the sensor hub 15, and performs drive control 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 connection portion 15a (hereinafter, referred to as an encoder connection portion) which connects the encoder 13; a 2 nd connection portion 15b (hereinafter, referred to as a sensor connection portion) to which a sensor cable C4 having one end connected to the sensor 14 is connected; and a 3 rd connection portion 15C (hereinafter, referred to as an amplifier connection portion) which connects one end to the communication cable C2 of the servo amplifier 12.

The encoder connection portion 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 a terminal hole corresponding to a connection pin of the encoder connection portion 15a of the sensor hub 15. The connection pins of the encoder connection portion 15a of the sensor hub 15 are fitted into the terminal holes of the connector 13a of the encoder 13, whereby the sensor hub 15 and the encoder 13 are detachably connected. 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. The encoder connection portion 15a of the sensor hub 15 and the connector 13a of the encoder 13 can also 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 the 3 sensor cables C4. The shape of the sensor connecting portion 15b and the number of connection pins are formed to correspond to the specifications of the connectors C4a, C4b, C4C of the sensor cable C4. Here, the number of the sensors 14 and the sensor cables C4 can be changed as appropriate. The connectors C4a, C4b, and C4C of the sensor cable C4 can 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 of the connector C2a of the communication cable C2 is fitted.

The shape, the number of connection pins, and the number of terminal holes of the encoder connection portion 15a, the sensor connection portion 15b, and the amplifier connection portion 15c included in the sensor hub 15 are not limited to the configuration shown in fig. 2, and can be appropriately changed in accordance with the application of the servo system 100. The encoder connection portion 15a, the sensor connection portion 15b, and the amplifier connection portion 15c may have a terminal hole and a terminal hole, respectively, corresponding to the corresponding connectors.

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

In response to a command from the servo amplifier 12, 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, and transmits the determination result to the servo amplifier 12. The connection status 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 during a predetermined period based on, for example, a change in the voltage value of the sensor signals S14.

The servo amplifier 12 receives the determination result, and the communication specification setting unit 122 sets the communication specification between the sensor hub 15 and the servo amplifier 12. 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 standard set by the communication standard 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 connection unit 15a detachably connected to the encoder 13; a sensor connection portion 15b connected to the sensor 14 via a sensor cable C4; and an amplifier connection unit 15C connected to the servo amplifier 12 via the 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, and transmits them 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 in accordance with the specification of the connected sensor 14, and the selected sensor hub 15 can be mounted on the encoder 13. Thus, even when a sensor 14 having a different specification is newly mounted, the encoder 13 does not need to be replaced, and thus a wide variety of sensors 14 can be immediately accommodated.

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 the periphery thereof to the sensor hub 15. With this configuration, 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 characteristic 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 unit 15b, and based on the determination result, the servo amplifier 12 sets the communication standard between the servo amplifier 12 and the sensor hub 15. With this configuration, when the servo system 100 replaces the sensor hub 15 or adds or alters the sensor 14 to the sensor hub 15, the servo amplifier 12 can immediately read the sensor signal S14.

The controller 11 generates a drive command for the position, speed pattern, and the like of the motor 10, and sends the drive command to the servo amplifier 12. The controller 11 is a control device having PLC (Programmable Logic Controller), CPU (Central Processing Unit) for driving a motor, 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. As the network cable C1, a general-purpose communication cable such as an ethernet (registered trademark) cable of twisted pair or an optical fiber cable can be used.

The servo amplifier 12 has: a transmitting/receiving unit 121 for transmitting/receiving signals to/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 status 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 transceiver 121, the communication specification setting 122, and the parallel conversion 123 of the servo amplifier 12 are realized by an electronic circuit including, for example, an industrial microcomputer (CPU), ASIC (application specific integrated circuit), FPGA (field-programmable gate array), CPLD (Complex Programmable Logic Device), or LSI (Large-Scale Integration). The data communication between the transmitting/receiving unit 121, the communication specification setting unit 122, and the parallel conversion unit 123 is performed by bus communication via a buffer, not shown, and a memory, which are 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 into 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 capable of bi-directional signal transmission and reception. The communication cable C2 is a cable including, for example, a signal line of a digital signal of at least 1 system, a signal line of an analog signal, and a power supply line for supplying a power supply voltage from the servo amplifier 12 to the sensor hub 15, and has a connector C2a connected to the amplifier connection portion 15C of the sensor hub 15. The signal line and the power line may be connected by cables different from each other.

The communication between the servo amplifier 12 and the sensor hub 15 applies serial communication. By applying serial communication, the number of signal lines of the communication cable C2 can be reduced. The communication system may be a half-duplex communication system, a full-duplex communication system, or a communication selection line for identifying the communication system 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 sends an encoder signal S13 indicating the detected rotation of the motor 10 to the sensor hub 15. The encoder 13 has a transceiver 131 for transmitting the encoder signal S13 to the sensor hub 15, and the transceiver 131 has a connector 13a for connecting with the encoder connection 15a of the sensor hub 15. The rotation of the motor 10 detected by the encoder 13 is, for example, the angle, angular velocity, or angular acceleration of the rotation shaft. The encoder 13 is mounted near the rotation axis 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 in order to output the state of a detection circuit of the encoder 13 and an alarm at the time of signal detection. The encoder 13 may have an acceleration sensor therein for detecting wear and deterioration of the bearing mechanism of the motor 10 and a driving reaction force during rotation of the motor. When the encoder 13 also detects a state different from the rotation of the motor 10, the detection result (detection result of a temperature sensor, an acceleration sensor, or 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 electrical signal transmitted from the transceiver 131 of the encoder 13 to the sensor hub 15, and is, 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, or 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 sends a sensor signal S14 indicating the detected state to the sensor hub 15. The sensor 14 detects, for example, the temperature, vibration, sound, or the like of the motor 10 or the periphery of the motor 10 as a state of a detection target different from the rotation of the motor 10. The periphery of the motor 10 is, for example, a driven body of the motor 10, a stage for fixing the motor 10, and an object to which the driven body acts. The object to 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 to this, 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 an object to which the driven body acts. In addition, a jig or a bracket may be used and provided around them. The sensor 14 may detect the absolute state of the object to be measured, or may detect the relative state.

The sensor signal S14 is an electrical signal transmitted from the sensor 14 to the sensor hub 15 via the sensor cable C4. Here, the sensor signal S14 transmitted and received 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 sensor 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. When the sensor 14 outputs a digital signal, the sensor hub 15 and the sensor 14 may be connected by parallel communication or by serial communication. By applying serial communication, the number of signal lines can be reduced.

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), I2S (Inter IC Sound), 1-Wire, ethernet (registered trademark)/IP, 10BaseT, and the like can be used for communication between the sensor 14 and the sensor hub 15. The transmission method of the serial communication may be synchronous or asynchronous.

The sensor cable C4 may have not only a signal line for transmitting the sensor signal S14 output from the sensor 14 to the sensor hub 15, but also a power 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 C may be covered with a bundle of vinyl resin, shield wires, or the like, and a part or the whole of the sensor cable C may be integrated as a composite communication cable. When a microphone and a camera are used as the sensor 14, an acoustic signal of the microphone and an image signal of the camera may be simultaneously transmitted by a transmission method such as TMDS (Transition Minimized Differential Signaling) via an HDMI (High-Definition Multimedia Interface) (registered trademark) cable.

In the case of using the sensor 14 capable of transmitting the sensor signal S14 by wireless, a wireless base station such as WSN (Wireless Sensor Networks) may be provided in the sensor hub 15 to receive the sensor signal S14 and transmit it to the transmitting/receiving unit 121 of the servo amplifier 12 via the communication cable C2. This shortens the distance traveled by radio, and improves 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 has: a transmitting/receiving 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 the transmitted and received signals; and a sensor determination unit 153 that determines the connection state of the sensor 14.

The signal processing unit 152 includes: an AD conversion unit 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 serial communication of the different 2 systems, for example.

Here, the serial conversion unit 152b may combine the encoder signal S13 and the sensor signal S14 into 1 serial signal, and transmit the 1 serial signal to the servo amplifier 12 through serial communication. When a plurality of sensors 14 are connected, the serial conversion unit 152b may combine the plurality of sensor signals S14 into 1 serial signal, and transmit the 1 serial signal to the servo amplifier 12 through serial communication. By providing serial communication of 1 system, the number of signal lines between the servo amplifier 12 and the sensor hub 15 can be reduced.

The serial conversion unit 152b may convert the interval of the sensor signal S14 into a signal having a period different from the sampling period of the sensor signal S14 by lengthening the interval, or may delete redundant data in order to reduce 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 an ambient temperature and an 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 sensors 14, the number of sensor signals S14, and the like as the connection status of the sensors 14 based on the voltage value of the sensor signals S14, for example, and outputs the determination result to the transceiver unit 151 of the sensor hub 15.

The signal processing unit 152 of the sensor hub 15 is implemented by an electronic circuit including an LSI such as an analog circuit, a package IC (Integrated Circuit), an industrial microcomputer (CPU), or ASIC, FPGA, CPLD. The signal processing unit 152 may include a filter processing unit and a buffer processing unit, not shown, in order to remove noise and improve communication accuracy. In the case where the types and the number of the analog sensor signals S14 subjected to the AD conversion are large, the signal processing unit 152 may include a multiplexer and a switching IC.

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

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

The data field is a region in which the framed encoder signal S13 or the sensor signal S14 is transmitted, and the signal is composed of 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 composed of 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, which are combined.

Next, the operation of the servo system 100 when the communication standard between the servo amplifier 12 and the sensor hub 15 is set will be described. Fig. 5 is a flowchart showing the operation of the servo system according to embodiment 1 of the present invention. Next, it is assumed that 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 analog sensor signal S14 into a digital signal by the AD converter 152a for a predetermined period of time (ST 103). The period for AD conversion is set to the shortest update period of serial communication that can be performed by the servo amplifier 12 or the sensor hub 15, for example.

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 based on the change in the voltage value of the sensor signals S14 by the sensor determination unit 153 (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, the number of sensor signals S14 is determined as if the sensor signal S14 is received.

The sensor hub 15 transmits the number of the sensor signals S14 determined by the sensor determination unit 153 to the servo amplifier 12 as the 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 number of data frames set by the communication specification setting unit 122 is determined in accordance with the number of sensor signals S14, the type of sensor signals S14, the data size of the sensor signals S14, the transmission order of the sensor signals S14, and the communication system between the sensor signals 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. Accordingly, the update cycle, communication speed, and communication data amount of the serial communication can be optimized in accordance with the sensor 14 connected to the sensor connection unit 15b of the sensor hub 15.

A part of ST101 to ST107 may be omitted, or a part of the order may be exchanged. 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, provided in the sensor hub 15. The operations of steps ST101 to ST107 can be omitted by calling the saved contents at the time of operation of the servo system 100.

Next, the operation of transmitting the signals detected by the encoder 13 and the sensor 14 to the servo amplifier 12 via the sensor hub 15 according to the communication standards 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. The encoder signal S13 detected by the encoder 13 is converted into a serial signal in 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 specifications set in ST101 to ST107 to the sensor hub 15 (ST 201). The 1 st communication request signal S01 specifies the communication specification such as the bit rate, the communication band, and the update period between the servo amplifier 12 and the sensor hub 15, and requests the response of the encoder signal S13 or the sensor signal S14.

The sensor hub 15 generates a 2 nd communication request signal S02 for requesting a response from the encoder 13 according to the set communication standard based on the 1 ST communication request signal S01, and transmits the generated 2 nd communication request signal to the encoder 13 (ST 202). The 2 nd communication request signal S02 specifies a communication specification such as a bit rate, a communication band, an update period, etc. between the encoder 13 and the sensor hub 15, and requests the response of the encoder signal S13 from the encoder 13. 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 the sensor signal S14 into a digital signal by the AD converter 152a (ST 204). The serial conversion unit 152b performs serial conversion of the sensor signal S14 in accordance with the communication standard specified by the 1 st communication request signal S01. The serial conversion unit 152b, for example, compounds the plurality of sensor signals S14 into a serial signal in response to the compound request signal S04 requesting the compound of the plurality of sensor signals S14 generated based on the 1 ST communication request signal S01 by the transmission/reception unit 151 of the sensor hub 15, and outputs the serial signal as the sensor compound 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 separates the sensor composite signal S15 as a parallel signal by the parallel conversion unit 123, and obtains the encoder signal S13 and the sensor signal S14 (ST 207). At this time, the sensor composite signal S15 includes the sensor discrimination signal S16, thereby enabling the separation of the sensor composite signal S15 by the parallel conversion section 123 of the servo amplifier 12.

The servo system 100 executes ST201 to ST207, and thereby can 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.

Some of ST201 to ST207 may be omitted or some may be exchanged in order. The communication method of the serial signal is not limited to the step synchronization method. The serial signal may be communicated in any of half duplex and full duplex manners. In addition, the various request signals may include clock signals for synchronous communication. The 2 nd communication request signal S02 is a signal indicating whether or not the content is to be changed according to the type of the motor 10 and the encoder 13, and the 2 nd communication request signal S02 may not be used according to 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 has the sensor hub 15 detachably connected to the encoder 13, and the encoder signal S13 and the sensor signal S14 are transmitted to the servo amplifier 12 via the sensor hub 15. With this configuration, the sensor hub 15 can be appropriately selected in accordance with the specification of the sensor 14, and can be connected to the encoder 13. Thus, the driving of the motor 10 can be controlled by using information from 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, when the sensor hub 15 is replaced or the sensor 14 is added to or changed from the sensor hub 15, the servo system 100 can immediately read the sensor signal S14 by the servo amplifier 12. In addition, the servo system 100 can optimize the update period, the communication speed, and the communication data amount of the serial communication between the sensor hub 15 and the servo amplifier 12.

The encoder connection portion 15a of the sensor hub 15 is preferably formed by the same pin assignment, in the same shape as the connector C2a of the communication cable C2. The amplifier connection portion 15c of the sensor hub 15 is preferably formed by the same pin assignment, with the same shape as the connector 13a of the encoder 13.

With the above configuration, the sensor hub 15 is used at the time of starting and maintenance of the servo system 100, and the sensor hub 15 used at the time of operation is detached, so that 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 is 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 line of the communication cable C2, and is supplied to the circuit board, not shown, of the encoder 13 and the sensor 14 via the sensor hub 15.

With the above configuration, the sensor hub 15 can be powered 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 step-up or step-down circuit to increase the types of power lines supplied to the sensors 14. This can increase the number of sensors 14 connected to the sensor hub 15. In order to prevent the influence of voltage fluctuations of the servo amplifier 12 and the device power supply, a battery may be mounted on the sensor hub 15. When the supply power of the servo amplifier 12 is short, or when the supply voltage varies greatly, power may be supplied from outside the sensor hub 15 to any 1 or more of the sensor hub 15, the encoder 13, and the sensor 14.

The sensor hubs 15 are preferably configured to be able to limit the specifications of the sensors 14 corresponding to 1 sensor hub 15, and the sensor hubs 15 are preferably replaced appropriately according to the specifications of the sensors 14. Thus, compared with the case where 1 sensor hub 15 corresponds to a wide variety of sensors 14, the substrate size and setting data of the sensor hubs 15 can be kept small without making hardware and software redundant.

In fig. 1, the sensor hub 15 is shown as being mounted on the motor 10 from the vertical side, but the sensor hub 15 may be disposed in a place where space is easily secured or a place where EMC (Electromagnetic Compatibity) is good around the encoder 13. The sensor hub 15 may divide the circuit board and the structure into 2 or more. For example, the encoder connection part 15a and the signal processing part 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 repeated with the servo system 100 according to embodiment 1 is appropriately simplified or omitted. In fig. 7, the same reference numerals as those in embodiment 1 denote the same or corresponding parts. The servo system 100 according to the present embodiment includes a sensor hub 15 to which a sensor 14b that outputs a digital signal in a serial form can be connected in addition to a 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 connection portion 15a, a sensor connection portion 15b, and an amplifier connection portion 15c, and the encoder connection portion 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 digital signals in a serial format via a sensor cable C4. The number of the sensors 14, 14b and the sensor cable C4 is not limited thereto, and can be changed as appropriate.

The sensor 14b is, for example, a microphone, and transmits a monaural acoustic signal as a sensor signal S14b in serial form to the sensor hub 15. The sensor 14b communicates with the sensor hub 15, for example, via the I2S format. At this time, the sensor cable C4 contains transmission lines of SCLK (Serial Clock) signal, WDCLK (Word Clock) signal and 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 the 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 the sensors 14, 14b, the number of sensor signals S14, S14b, and the like are determined as the connection status of the sensors 14, 14 b.

When setting the communication standard between the sensor 14b and the sensor hub 15, the servo amplifier 12 sequentially transmits the 3 rd communication request signal S05 of the various serial communication methods corresponding to the sensor hub 15 to the sensor 14b via the sensor hub 15.

The 3 rd communication request signal S05 specifies the communication specification such as the bit rate, the communication band, and the update period between the sensor 14b corresponding to the sensor hub 15 and the sensor hub 15, and requests the response of the sensor signal S14 b. For example, if it is confirmed whether or not the response to the sensor 14b by the I2S method is possible, the servo amplifier 12 transmits the WDCLK signal and the SCLK signal, and confirms whether or not the response specified by the communication standard of the I2S method is possible to be obtained at a predetermined timing. Thereby, the communication specification between the sensor hub 15 and the sensor 14b can be set.

In addition to I2S, the communication between the sensor hub 15 and the sensor 14b may be performed by using, for example, RS (TIA/EIA) 232/422/485, USB (Universal Serial Bus), I2C (Inter Integrated Circuit), SPI (Serial Peripheral Interface), 1-Wire, ethernet/IP (registered trademark), 10BaseT, or other serial communication standards, and the serial communication may be performed in a synchronous or asynchronous manner. The serial interface 152c may be implemented by 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 condition 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 via the encoder connection unit 15a and the sensor signals S14 and S14b transmitted via the sensor connection unit 15b to the servo amplifier 12 via the communication cable C2 connected to the amplifier connection unit 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 connection unit 15a detachably connected to the encoder 13; a sensor connection unit 15b that can connect the sensors 14b output in a serial form; and an amplifier connection unit 15C for connecting the communication cable C2 for transmitting the encoder signal S13 and the sensor signals S14 and S14b to the servo amplifier 12, and for appropriately selecting the sensor hub 15 in accordance with the specifications of the sensor 14 and attaching the sensor hub to the encoder 13, thereby enabling the sensor to be used for various sensors 14.

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

Further, the specification of the serial communication scheme between the sensor 14b and the sensor hub 15 may be defined. This can reduce the number of types of serial communication ports provided in the sensor connection unit 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 repeated with the servo system 100 according to embodiment 1 is appropriately simplified or omitted. In fig. 8 and 9, the same reference numerals as those in embodiment 1 denote the same or corresponding parts. 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 is configured to combine the encoder signal S13 and the sensor signal S14 and communicate in a serial format of 1 system, with respect 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 has: an encoder connection unit 15a detachably connected to the encoder 13; a sensor connection portion 15b having one end connected to a sensor cable C4 of the sensor 14; and an amplifier connection section 15C having one end connected to the communication cable C2 of the servo amplifier 12.

The signal processing unit 152 of the sensor hub 15 receives the encoder signal S13 on the basis of the sensor signal S14. The transceiver 151 of the sensor hub 15 generates a composite request signal S04 requesting to composite 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 conversion unit 152b combines the encoder signal S13 and the sensor signal S14 into a serial signal in response to the combination request signal S04, and outputs the serial signal as a combination 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 2-byte encoder signal S13 and the 5-byte total sensor signal S14 are combined and transmitted from the sensor hub 15 to the servo amplifier 12. The sensor 14 is here an acceleration sensor, a pressure sensor, and a microphone.

The sensor signals S14 are acceleration sensor signals S141a, S141b, S141c, a pressure sensor signal S142, and a 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, S143, the number of sensors 14, and the structure of the data frame of the 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 related to the structure of a data frame for simultaneously transmitting the 2-byte encoder signal S13 and the 5-byte sensor signal S14 by serial communication of 1 system.

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

In the case described above, the data transmitted for each update period is divided, the interval is increased, and compression is performed. For example, the serial conversion unit 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 either one or both of the encoder signal S13 and the sensor signal S14.

Fig. 9 is an example of a structure of a data frame of serial communication generated by the serial conversion section. 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, the instruction causing generation of a data frame of each of the sensor signals S141a to c, S142, S143 to be transmitted every 2 update cycles every time the encoder signal S13 necessary for rotation control of the motor 10 is transmitted. In response to this instruction, the serial conversion unit 152b generates a data frame shown in fig. 9, and transmits the data frame in addition to the data field of the serial communication.

Here, the example in which the sensor hub 15 divides data for each update period is illustrated, but signal processing to lengthen the interval of data may be performed for either or both of the encoder signal S13 and the sensor signal S14. The sensor hub 15 may perform signal processing for compressing data with respect to either or both of the encoder signal S13 and the sensor signal S14.

In addition, the data S200 that is defective when the interval of the data is lengthened or compressed may be superimposed as additional information. In fig. 9, in the update period of the even number, data S200 is appended to the communication capacity of 1 data frame (1 byte).

In order to reduce the data capacity transmitted from the sensor hub 15, the characteristic 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 converting data from a time zone into data in a frequency zone for either 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 detachable from the encoder 13, so that the sensor hub 15 can be appropriately selected in accordance with the specifications of the sensor 14 and connected to the encoder 13, and can be used for various sensors 14. The servo system 100 generates a composite signal S17, which is a composite of the encoder signal S13 and the sensor signal S14, from the sensor hub 15, and can transmit the composite signal to the servo amplifier 12 by serial communication of 1 system, thereby saving wiring of the signal line of the communication cable C2.

The sensor hub 15 performs signal processing such as dividing data, lengthening the interval between data, and compressing the data for each update cycle with respect to the encoder signal S13 and the sensor signal S14, and thus can transmit the encoder signal S13 and the sensor signal S14 even when the data capacity is large with respect 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 repeated with the servo system 100 according to embodiment 1 is appropriately simplified or omitted. In fig. 10, the same reference numerals as those in embodiment 1 denote the same or corresponding parts. The servo system 100 according to the present embodiment includes a higher-level processing device 101, and the higher-level processing device 101 specifies the drive timing of the servo system 100 based on the execution plan of the entire industrial device including the servo system 100.

The upper processing device 101 is a control device of an industrial device including, for example, a cloud, an edge computer, IPC (IndustrialPersonal Computer), MES (Manufacturing Execution System), and the like, for the purpose of centralized management of the entire system.

The higher-level processing device 101 is connected to the controller 11 via a network cable C0 capable of transmitting and receiving signals in both directions. The servo system 100 includes a higher-level 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 processing device 101 can diagnose the degradation of the industrial device with time and the like by analyzing the sensor signal S14 from the sensor 14, and perform preventive maintenance and planned maintenance of each device used in the servo system 100, the driven body 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 and operated, the conventional communication cable is used as the communication cable C2 shown in fig. 10, and the sensor hub 15 is connected between the conventional communication cable and the encoder 13, so that the industrial equipment can be diagnosed by the host processing device 101 based on the sensor signal S14 from the sensor 14 connected to the sensor hub 15.

The servo system 100 may be configured to replace the existing sensor hub 15 with a new sensor hub 15 that can connect or identify the sensor 14 when the sensor hub 15 is already connected and the new sensor 14 cannot be connected or identified by the existing sensor hub 15. If the diagnosis is temporary, the replaced sensor hub 15 may be restored to the original sensor hub 15 after the diagnosis, or the replaced sensor hub 15 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 encoder connection portion 15a may not be provided in the sensor hub 15, and 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 driving control of the motor 10, the sensor hub 15 is provided with a function of transmitting the encoder signal S13 from the encoder 13 to the servo amplifier 12.

Embodiment 5.

Next, an example of implementation of a method for diagnosing an industrial device by connecting the sensor hub 15 to the servo system 100 will be described. Fig. 11 is a flowchart showing a process of introducing a sensor hub into a servo system according to embodiment 5 of the present invention. Next, a description will be given of a case where the sensor hub 15 is added to the conventional 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 of 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 connection 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 connection portion 15 b. Here, the mounting operation may be exchanged in order.

The user of the servo system 100 confirms that there is no wiring error among the servo amplifier 12, the encoder 13, the sensor 14, and the sensor hub 15 by visual observation, a detector, or the like (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 that 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 easily confirm that the power is normally supplied, the sensor hub 15 may monitor the fluctuation of the power supply voltage by an arithmetic circuit such as an industrial microcomputer, and notify a power alarm by lighting or blinking a lamp or a beep of the sensor hub 15 or the servo amplifier 12. When the sensor hub 15 outputs a power alarm, an external power source may be used for the sensor 14 or the sensor hub 15 added to the servo system 100.

In the case where the power supply from the servo amplifier 12 to the sensor hub 15 or the sensor 14 is not normally performed, the sensor 14 or the sensor hub 15 having different specifications of operating voltage and current capacity 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 standard 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 upper processing device 101 according to the set communication standard (ST 307). The detailed operations of (ST 306) and (ST 307) are the same as those of (ST 101) to (ST 107) and (ST 201) to (ST 207) of embodiment 1, and thus omitted.

By performing ST301 to ST307, the encoder signal S13 and the sensor signal S14 are transmitted to the servo amplifier 12 and the upper processing device 101, and diagnosis for performing drive control and preventive maintenance of the industrial device including the servo system 100 can be performed. In the diagnostic method of the industrial device using the sensor hub 15 according to embodiment 5 of the present invention, the sensor hub 15 is added or replaced, so that the existing motor 10, communication cable C2, and encoder 13 can be used, and therefore, the sensor 14 can be easily added to the servo system 100.

(ST 301) to (ST 307) may be performed by omitting a part or by exchanging a part of the order. 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 assembled to the servo system 100 when the servo system 100 is newly installed.

In embodiments 1 to 5, the rotary motor having one axis is described as the motor 10, but the present invention is not limited to the rotary motor, and a linear motor that drives the movable element in the translational direction with respect to the fixed element may be used.

In addition, the present invention may appropriately combine a plurality of the constituent elements disclosed in embodiments 1 to 4 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 encoder, 14 sensor, 15 sensor hub, 15a encoder 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:

a 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, the sensor hub including 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

a servo amplifier for performing drive control of the motor based on the encoder signal, the sensor signal, and a drive command transmitted from a controller transmitted via the communication cable,

the connection status of the sensors includes the number of the sensors, the category of the sensors, or the number of the sensor signals.

2. A servo system as recited in claim 1, wherein,

the sensor hub transmits the connection status determined by the sensor determination unit to the servo amplifier via the communication cable.

3. A servo system as claimed in claim 1 or 2, characterized in that,

the communication cable has a connector connected to the 3 rd connection of the sensor hub,

the encoder has a connector detachably connected to the 1 st connection portion of the sensor hub,

the connector of the communication cable is connectable with the connector of the encoder.

4. A servo system as claimed in claim 1 or 2, characterized in that,

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

5. A servo system as claimed in claim 1 or 2, characterized in that,

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 status of the sensor connected to the 2 nd connection unit of the sensor hub.

6. A sensor hub, comprising:

a 1 st connection unit detachably connected to an encoder for detecting rotation of the motor;

A 2 nd connection unit for connecting a sensor for detecting a state different from the rotation; and

a 3 rd connection unit connected to a communication cable for transmitting at least any one of the encoder signal outputted from the encoder via the 1 st connection unit and the sensor signal outputted from the sensor via the 2 nd connection unit to a servo amplifier for controlling driving of the motor,

determining a connection condition of the sensor connected to the 2 nd connection portion based on a voltage value of the sensor signal,

the connection status of the sensors includes the number of the sensors, the category of the sensors, or the number of the sensor signals.

7. The sensor hub of claim 6, wherein the sensor hub is configured to,

the connection status of the sensor is sent to the servo amplifier via the communication cable.

8. The sensor hub of claim 6 or 7, wherein,

comprises a signal processing unit for converting the encoder signal and the sensor signal into serial signals,

and transmitting the sensor signal to the servo amplifier according to the set communication standard according to the connection status of the sensor connected to the 2 nd connection part.

9. A diagnostic method for an industrial device comprising a servo system in which an encoder for detecting rotation of a motor and a servo amplifier for supplying 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 diagnostic method of the industrial device is characterized by comprising the following steps:

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

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

Determining a connection condition of the sensor connected to the 2 nd connection unit based on a voltage value of a detection signal of the sensor, the sensor hub transmitting the determined connection condition to the servo amplifier;

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,

the connection status of the sensors includes the number of the sensors, the category of the sensors, or the number of the sensor signals.

10. The method for diagnosing an industrial apparatus according to claim 9, wherein,

and transmitting the determined connection information to the servo amplifier via the cable.

11. A diagnostic method for an industrial device according to claim 9 or 10, wherein,

the method includes the step of 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.