JP3772052B2 - Control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device that controls a servo motor as a drive source of a numerical control device, a robot control device, or the like.
[0002]
[Prior art]
In a control device that controls a machine driven by a servo motor such as a numerical control device or a robot control device, each part of the control device, electrical parts of the machine, electrical members, electrical elements, etc. during maintenance and adjustment of the control device and the machine In some cases, it is desirable to investigate and analyze temporal changes in analog signals such as current and voltage flowing through the current. In such a case, it is usually investigated and analyzed using an oscilloscope.
[0003]
[Problems to be solved by the invention]
As described above, if an oscilloscope is not prepared for examining and analyzing analog information of various electric members of the control device and the machine, it is impossible to observe a temporal change of an arbitrary analog signal. However, an oscilloscope is a relatively expensive device, and it has been difficult for service personnel to carry it around.
Therefore, an object of the present invention is to provide a control device that can obtain data for analyzing the state of a device or a machine without preparing an oscilloscope.
Furthermore, the present invention is to provide a control device capable of observing a temporal change of an arbitrary analog signal by using a display included in the control device.
[0004]
[Means for Solving the Problems]
A control unit and a servo amplifier unit for controlling the servo motor are connected, and the control unit and the servo amplifier unit are connected by communication means, and at least one information on the position, speed, or current of the servo motor is obtained. in the control apparatus having a servo control processor for processing the control section, the invention related to the claims 1, an external analog signal input port is provided in the unit leading to the communication unit, processing the position, velocity or current, The analog signal input is converted into digital data by an analog / digital conversion means in a short cycle equal to or shorter than the cycle, and can be sent to the servo control processor.
[0005]
According to a second aspect of the present invention, the unit is a servo amplifier unit, and analog / digital conversion means for converting a current flowing in a servo motor provided in the servo amplifier unit into a digital signal is input from an external analog signal input port. It is used as means for converting an analog signal into a digital signal.
[0006]
The invention according to claim 3 further provides maintenance information by combining data obtained by digitally converting the analog signal received by the servo control processor and various data handled by the servo control processor.
The invention according to claim 4 further displays the maintenance information in a graph on the display means of the control unit.
In the invention according to claim 5, a digital input signal and a digital output signal for the control unit to control the machine are combined as the maintenance information, and the information is also displayed.
In the invention according to claim 6, the trigger condition for displaying the maintenance information can be set, and the function of the oscilloscope is provided by the display means of the control device.
Furthermore, the invention according to claim 7 outputs the maintenance information to the Internet so that the information can be displayed in a graph on an Internet terminal installed at a remote location.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a principal block diagram of an embodiment of a control device of the present invention. In this embodiment, the unit of the control unit 10 and the unit of the servo amplifier unit 20 are connected by a communication line L. The control unit 10 is connected to a main processor 11, a servo control processor (digital signal processor) 12, a shared memory 13 that can be accessed by the main processor 11 and the servo control processor 12, a graphic control circuit 14, and the like via a bus 15. Yes. The graphic control circuit 14 is connected to a display device, and the servo control processor 12 is connected to the communication LSI of the servo amplifier section 20 via a communication line L constituted by a high-speed serial bus. A memory such as a ROM and a RAM, an input / output interface connected to various actuators and sensors of the machine are also connected to the bus 15, but are omitted in FIG. The configuration of this control unit is the same as that of a CNC or robot control device that controls a conventional motor.
[0008]
The servo amplifier unit 20 includes an amplifier such as an inverter (not shown) that supplies driving power to the servo motor 30, a communication LSI 21 connected to the communication line L, and an analog / digital converter (A / D converter) 22. The sample and hold circuits 25a and 25b that sample and hold the analog signals detected by the current detectors 32a and 32b that detect the drive current of the servo motor 30 and the sample hold circuits 25a and 25b and the A / D converter 22 are selectively used. The analog switches 24a and 24b connected to the analog switch 24, the sample and hold circuits 25a and 25b, and the timing generation circuit 23 that generates timing pulses for controlling the operation timing of the analog switches 24a and 24b. The communication LSI 21 is connected to a position / speed detector 31 for detecting the position / speed of the servo motor attached to the servo motor 30, and the output of the position / speed detector 31 is transmitted via the communication LSI 21 and the communication line L. And fed back to the servo control processor of the control unit 10.
[0009]
The configuration of the servo amplifier unit 20 described above is the same as the conventional one, but the present invention further includes a sample hold circuit 25c and an analog switch 24c as a general-purpose analog input interface circuit. The controller 34 is connected to a probe 34 for measuring an analog signal such as a current and a voltage of a circuit under measurement 33 such as various electric devices and electric members of the machine. In FIG. 1, only a single-axis servomotor is shown, but the number of servo amplifiers 20, servomotors 30, and the like increase according to the number of axes controlled by the control unit 10.
[0010]
In the configuration as described above, the main processor 11 of the control unit 10 outputs a movement command to each axis based on a program for controlling a machine stored in a memory such as a RAM (not shown), and the servo control processor 12. Is detected by the position and speed feedback signal of the servo motor 30 sent from the movement command and the position / speed detector 31 via the communication LSI 21 and the communication line L, and further detected by the current detectors 32a and 32b. Based on the current feedback signal sent via the hold circuits 25a and 25b, the analog switches 24a and 24b, the A / D converter 22, the communication LSI, and the communication line L (the current feedback signal is for two phases). However, the other phase is calculated by calculation), position, speed, torque (current) is low Both perform one feedback control, feed to the communication LSI21 of servoamplifier 20 through the communication line L the drive control signal, controls the driving of the servo motor 30 to drive the amplifier such as an inverter.
[0011]
The operation described above is the same as the conventional operation. In this conventional operation, current detection signals are detected by the current detectors 32a and 32b, and current feedback signals are sent to the sample and hold circuits 25a and 25b, the analog switches 24a and 24b, the A / D converter 22, the communication LSI 21, and the communication line L. The operation is executed in the first part of the cycle of current processing executed by the servo control processor 11. Other than this initial period, the A / D converter 22 is idle.
Therefore, the present invention uses this idle time so that a general-purpose analog signal measured from the circuit under test 33 is A / D converted and transmitted to the control unit 10 so that measurement data can be collected by the control unit. It is a thing. And this data can be displayed on the display 16 which the control part 10 has.
[0012]
FIG. 2 is an explanatory diagram of current feedback executed for each current control period and a general-purpose analog signal transmission / reception operation measured from the circuit under test 33 in the embodiment shown in FIG.
In synchronization with the current control period, the sample generation signal is output from the timing generation circuit 23 to the sample hold circuits 25a, 25b, and 25c, and the analog signals detected by the current detectors 35a and 35b and the probe 34 are sampled and held. In FIG. 2, thereafter, the timing generation circuit 23 sequentially turns on the analog switches 24 a, 24 b, 24 c, sequentially selects the sample hold circuits 25 a, 25 b, 25 c and connects them to the A / D converter 22. The A / D converter 22 sequentially converts the detected current value and the analog signal measured by the circuit under test 33 into a digital signal, and transmits the digital signal to the servo control processor 11 via the communication LSI 21 and the communication line L. . In this embodiment, the R-phase and S-phase current values of the servo motor 30 are detected and sent to the A / D converter 22 via the sample hold circuits 25a and 25b and the analog switches 24a and 24b. ing. The analog signal of the circuit under test 33 detected by the probe 34 is sent to the A / D converter 22 via the sample hold circuit 25c and the analog switch 24c.
[0013]
The servo control processor 11 performs current feedback control based on the received current data as in the conventional case. The received general-purpose analog signal data (digital data of the analog signal measured by the circuit under test detected by the probe) is temporarily stored in the internal RAM. Further, at this time, the servo control processor 11 stores the internal information of various data such as the position, speed, torque (current), etc. that are processed by the processor 11 in association with the general-purpose analog signal data. The data is stored in the shared memory 13 every data exchange cycle between the main processor 11 and the servo control processor 12 (this data exchange cycle is long, for example, 64 current processing cycles are one cycle). . The received general-purpose analog signal data and handling data such as position, speed, and torque may be directly stored in the shared memory 13 without being temporarily stored in the internal RAM.
[0014]
FIG. 5 is an explanatory diagram showing the storage principle of the data storage table T provided in the shared memory 13. General-purpose analog signal data and handling data of the servo control processor 12 such as position, speed, and torque when this data is received are stored in association with each other. Further, the main processor 11 also writes digital input and digital output information for controlling the machine obtained via an input / output circuit (not shown) into this table T, and this table T is used to indicate the state of the entire control device. To get data.
[0015]
When a display command for measurement data is input from an input means (not shown) of the control device, the main processor 11 receives data measured from the circuit under measurement 33 stored in the shared memory 13, that is, the circuit under measurement 33. The analog signal data measured by the probe 34, sampled at each current cycle and digitized is read, graphed, and passed to the graphic control circuit 14 as image information. Based on the received image information, the graphic control circuit 14 displays this graph on the display 16 constituted by an LCD or CRT.
[0016]
In the control device, the current control cycle is the shortest. Therefore, if the analog signal measured by the probe 34 from the circuit under test 33 is sampled and held into digital data for each current control period to obtain digital data, data measured at short time intervals can be obtained, and highly accurate measurement data can be obtained. It is done. Therefore, if this measurement analog signal data is graphed and displayed on the display 16, it is possible to observe a temporal change or the like of the measurement data with high accuracy, and the same effect as that observed with an oscilloscope can be obtained.
[0017]
Furthermore, as described above, the shared memory 13 stores various data such as position, speed, torque (current), etc. handled by the servo control processor 12 as internal information in addition to the measured analog signal data. In addition, digital input and digital output information that the main processor 11 controls the machine is also stored as internal information. Therefore, the stored analog signal data and various data such as the stored position, speed, torque (current), etc., and the internal information of the digital input and digital output are simultaneously graphed and passed to the graphic control circuit 14 for display 16. Are simultaneously displayed, the state of the control device and the machine can be observed on one screen. For this reason, when it is determined from measurement analog signal data that noise is occurring, the position and speed of the servo motor when the noise is occurring can be observed at the same time. The same effect as when observing or an effect more than that can be obtained. Further, only necessary data may be displayed by selecting and selecting the type of data to be displayed.
[0018]
In the above-described embodiment, the measurement analog signal data and the like are stored and stored constantly by cyclically storing them in the table T provided in the shared memory 13. However, a measurement command may be issued and measured only when measurement analog signal data is necessary, or the servo control processor 12 handles the measurement data when the measurement data value exceeds a preset value. Measurement analog signal data and internal information are set when various data such as position, speed, torque, etc. and specified data among digital information such as digital input and digital output exceed the set value or deviate from the setting area. These data may be acquired and stored when the condition is satisfied. That is, a trigger condition for data collection is set in the control device in advance, and the main processor 11 or the servo control processor 12 monitors whether or not the set trigger condition is satisfied, and the set trigger condition is satisfied. Then, the measurement data from the circuit under test 33 and the above-described internal information may be stored in the shared memory 13 in a predetermined amount (for one display) and displayed on the display 16 as a graph. Further, the measurement data is stored in the shared memory 13 and the internal information is always circulated, and when the set trigger condition is satisfied, the subsequent stored data or the previous and subsequent stored data (measurement analog signal) Data, internal information data) may be graphed and displayed on the display 16.
[0019]
In any case, the time change of the measurement analog signal data inputted with general-purpose analog can be confirmed on the display screen of the control device on the same graph as the oscilloscope without using the oscilloscope. Then, the causal relationship of the signal change can be easily verified by displaying the graph of the necessary internal information over time.
[0020]
Further, as described above, the shared memory 13 stores the time series data of the measurement analog signal data inputted to the general-purpose analog and the time series data of the internal information indicating the state of the machine. Alternatively, the state of the machine can be automatically analyzed based on the data by executing the servo control processor 11. By storing an analysis program in advance and giving an analysis command, or by inputting the timing to start the analysis, such as when the machine is in an emergency stop, or when the trigger condition described above is satisfied, or The machine state can be automatically analyzed based on the stored data and the analysis program under a predetermined condition.
[0021]
In the embodiment described above, the general-purpose analog input signal is A / D converted for each current control period by using the operation idle time of the A / D converter 22 that converts the analog signal of the detected current and voltage in the servo amplifier into a digital signal. Thus, measurement analog signal data was obtained. Therefore, the obtained data is discrete data separated in time by the current control period. Therefore, in order to obtain more accurate measurement analog signal data, FIGS. 3 and 4 show a second embodiment in which measurement analog signal data is obtained at a sampling period obtained by further dividing the current control period. In the second embodiment, an example in which a graph is displayed by outputting to a personal computer on another network connected via the Internet is shown.
[0022]
Elements equivalent to those of the first embodiment shown in FIG. The control unit 10 is different from the first embodiment shown in FIG. 1 in that a network interface 17 is connected to the bus 15 instead of the graphic control circuit 14. As in the first embodiment, the graphic control circuit 14 may be further connected to the bus 15 and the display 16 may be connected to the graphic control circuit 14 in the second embodiment. .
[0023]
The network interface 17 can be connected to a personal computer 51 on another network via the Internet 50 or the like, and the above-described graph can be displayed on the display device of the personal computer 51.
The servo amplifier unit 20 is the same as the conventional servo amplifier unit and there is no difference. That is, in the first embodiment, the sample-and-hold circuit 25c and the analog switch 24c are added to the conventional servo amplifier unit as a general-purpose analog input interface circuit. However, in the second embodiment, a conventional servo Instead of adding a general-purpose analog input interface circuit to the amplifier unit, a general-purpose analog input interface circuit unit 40 is provided and connected to the communication LSI 21 of the servo amplifier unit 20 via the communication line L of the high-speed serial bus. Is. That is, they are connected by a daisy chain method. The servo amplifiers are also connected by a daisy chain method.
[0024]
The difference between the servo amplifier unit 20 and the first embodiment is that there are only two circuits of sample and hold circuits 25a and 25b connected to the current detectors 32a and 32b. The only difference is that there are two analog switches 24a and 24b connecting the sample and hold circuits 25a and 25b to the A / D converter 22.
[0025]
The added general-purpose analog input interface circuit unit 40 includes a communication LSI 41, an A / D converter 42, a timing generation circuit 43, and a sample hold circuit 44, and the communication LSI 41 is a communication LSI 21 of the servo amplifier unit 21. Are connected by a communication line L. The sample hold circuit 44 is connected to a probe 34 for measuring an analog signal such as a current and a voltage flowing in the circuit under test 33.
[0026]
FIG. 4 is a diagram showing the timing of digitization and transmission / reception of the measurement analog signal in the second embodiment. In the second embodiment, the timing generation circuit 43 divides the current control period into four in synchronization with the current control period, and outputs four sample hold signals within the current control period as shown in FIG. The A / D converter 42 performs A / D conversion four times within the current control period, and servo-controls the measurement analog signal data via the communication LSI 41, the communication line L, the communication LSI 21 of the servo amplifier unit 20, and the communication line L. To the processor 12. The processing of the servo control processor 12 is the same as that of the first embodiment described above, and the internal information such as the position, speed, torque and the like handled by the servo control processor 12 together with the measurement analog signal data is stored in the table of the shared memory 13. Stored in T. Further, the digital input and digital output signal data are also stored in the table T of the shared memory 13 by the main processor 11 as described above, and a table T as shown in FIG. 5 is created. Since the timing for creating the table T, the trigger condition, and the like are the same as those in the first embodiment, the description thereof will be omitted.
[0027]
Thus, the data stored in the table T of the shared memory 13 can be called from the personal computer 51 on another network via the Internet 50 and displayed as a graph. For this reason, the measurement location of the machine or device is clearly indicated to a field operator from a remote location, the analog signal of the measurement location (circuit under test 33) can be measured by the probe 34, data is collected, and the remote location A graph showing temporal changes in measurement data and internal information can be displayed on the display of the personal computer 51 at the place.
[0028]
In the case of the second embodiment, since the current control period is further divided and the measurement data is collected at a sampling period shorter than the current control period, data with high temporal resolution can be obtained.
In the case of an oscilloscope, settings such as the time range, voltage range, and trigger conditions are required, and these settings could only be operated by trained technicians. It is possible to easily measure and display a time change of an analog signal such as current and voltage at a measurement point in a graph.
[0029]
In each of the above-described embodiments, an example in which a servo control processor is provided in the control unit 10 has been described. However, this servo control processor is provided on the servo amplifier unit 20 side, and the main processor 11 and the servo amplifier unit of the control unit 10 are provided. The servo control processor may be connected by a signal line of a high-speed serial bus.
In the above-described embodiment, the present invention is used to measure an electrical analog signal using an electrical member of a machine or device as a circuit to be measured, but various states of the machine other than the electrical signal are detected and detected. May be converted into an electrical signal and connected to the analog signal input port provided in the present invention so that signals other than the electrical signal can be measured.
[0030]
【The invention's effect】
Since the present invention can collect data at a short cycle equal to or shorter than the current control cycle, it is not necessary to always carry an oscilloscope when performing maintenance work, installation, adjustment, investigation, etc. of the control device or machine. Work can be performed easily. Furthermore, since it is possible to perform the above work remotely through a network, it is not necessary for a service person to travel for installation, adjustment, maintenance, etc., and the system can be used economically. In addition, measurement analog signal data and internal information such as position, speed, torque, etc. of servo motors (machine moving parts driven by the motors) are stored. Based on these data, machine and device operations are automatically performed. The state can be analyzed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a main part of a first embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining the timing of acquisition of measurement analog signal data in the first embodiment;
FIG. 3 is a principal block diagram of a second embodiment of the present invention.
FIG. 4 is an explanatory diagram for explaining the timing of acquisition of measurement analog signal data in the second embodiment.
FIG. 5 is an explanatory diagram of a table storing measurement analog signal data and internal information data.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Control part 20 Servo amplifier part 30 Servo motor 31 Position / speed detector 24 Analog switch 25 Sample hold circuit 33 Circuit to be measured 34 Probe 40 Interface circuit unit 51 for general-purpose analog input Personal computer

Claims (7)

A control unit and a servo amplifier unit for controlling the servo motor; the control unit and the servo amplifier unit are connected by a communication means; and at least one of the position, speed, or current of the servo motor in the control apparatus having a servo control processor to the control unit for processing One information,
An external analog signal input port is provided in a unit connected to the communication means , and the analog signal input is converted into digital data by an analog / digital conversion means in a short cycle equal to or shorter than the cycle for processing the position, speed, or current , A control device characterized by being capable of being sent to a servo control processor. The unit is a servo amplifier unit, and the analog / digital conversion unit uses an analog / digital conversion unit that converts a current flowing in a servo motor provided in the servo amplifier unit detected by a current detector into a digital signal. Item 2. The control device according to Item 1. 3. The control device according to claim 1, wherein the data obtained by digitally converting the analog signal received by the servo control processor and various data handled by the servo control processor can be combined and provided as maintenance information. The control apparatus according to claim 3, wherein the maintenance information can be displayed as a graph on a display unit of the control unit. 5. The control apparatus according to claim 4, wherein the control unit also displays a combination of a digital input and a digital output signal for controlling the machine as the maintenance information. The control device according to claim 4 or 5, wherein a trigger condition for displaying a graph on the control unit can be set, and a graph is displayed when the set trigger condition is satisfied. 6. The control device according to claim 3, wherein the maintenance information is displayed on an internet terminal installed at a remote location by outputting the maintenance information to the internet.

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