JP7159945B2 - processing equipment - Google Patents

Description

The present invention relates to a technique for displaying time transition of predetermined information related to servo control operation of a target device.

Conventionally, in the field of FA (Factory Automation), robots, etc., there has been known a servo control system that automatically controls the position, orientation, attitude, etc. of a controlled object to follow a target value by controlling a motor. . In a servo control system, various parameters (servo parameters) for servo-controlling a motor are adjusted via a servo motor adjustment device according to the type of controlled object, the type of control method, the characteristics of the motor, and the like. When adjusting various parameters, the speed data, position data, etc. of each motor being driven under the servo control are measured at predetermined sampling intervals in order to appropriately perform the adjustment. For example, the measurement data is acquired, and the measurement data is displayed on a display device such as an LCD (Liquid Crystal Display) as a graph showing changes in velocity, position, etc. on the time axis.

For example, the technique disclosed in Patent Document 1 provides an environment in which a user can evaluate response characteristics during servo control operation of a motor from time-series changes in each measurement data displayed as a graph on a screen. In the adjustment work of servo control, adjustment of setting conditions of various parameters based on the evaluation result of response characteristics and evaluation of measurement data based on the adjusted setting conditions are repeated. Through such adjustment work, the setting conditions of the servo parameters for driving the motor are optimized.

Japanese Patent Application Laid-Open No. 2006-4195

Adjustment of servo parameters related to a target device (such as a motor) to be servo-controlled is work necessary to operate the target device as expected. In order to properly perform the work, it is necessary to confirm the actual operation of the target device for which the servo parameters have been set. When the transition of the motion is displayed to the user in order to confirm the motion of the target device, information about the motion transition must be acquired from the target device in operation and stored for display. must.

However, since the storage capacity allocated for storing the information is generally limited, when the target device is caused to perform the confirmation operation for adjusting the servo parameters, the transition information of the confirmation operation is sufficiently stored. may not be remembered. In general, when servo control is performed, the time required for the target device to reach a predetermined state (for example, reaching a predetermined position) can be an important factor in judging the suitability of servo parameters. cannot be sufficiently stored, the opportunity to confirm the operation of the target device near the end of the operation, which is particularly important, will be lost, and suitable servo parameter adjustment may be hindered.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and it is an object of the present invention to provide a technique capable of suitably confirming the operation of a target device when a user adjusts servo parameters or the like.

In order to solve the above problems, the present invention adopts a configuration in which the sampling period for acquiring predetermined information related to the servo control operation of the target device is changed based on the time required for the servo control operation. By adopting this configuration, it is possible to acquire the predetermined information related to the operation so as to fit within the storage capacity, and thus it is possible to suitably confirm the operation of the target device.

Specifically, the present invention is a processing device for displaying, on a display device, a time transition of predetermined information related to a servo control operation of a target device, wherein the servo control operation given to the target device is performed. a calculation unit that acquires information and calculates a measurement time for measuring a time transition of the predetermined information based on the operation information; a determining unit for determining a sampling period for obtaining the predetermined information; and an output unit for storing the predetermined information obtained according to the sampling period and outputting the stored predetermined information to the display device. And prepare.

The above processing device is a device for displaying the time transition of the predetermined information related to the operation, which is related to the target device that performs the servo control operation. A drive command to the target device for the servo control operation may be given to the target device by the processing device itself, or alternatively, may be given to the target device from a control device separate from the processing device. Also, the processing device may be formed integrally with the display device, in which case the information output by the output unit is displayed on the display device incorporated in the processing device. Alternatively, a display device formed separately from the processing device may receive the information output by the output unit and perform display processing thereon.

Here, the calculation unit acquires operation information of the servo control operation performed by the target device. The motion information is information that allows the user to understand the details of the motion of the target device under servo control. As an example, the operation information includes command information given to the target device for executing the servo control operation, and state-related information related to the state of the target device for determining the end of the servo control operation. and may include Regarding the command information, it may include command information relating to the entire servo control operation, or alternatively may include command information relating to a portion of the servo control operation. By including the command information, it is possible to grasp the time required for the command of the servo control operation by the target device.

Also, in general, the required time on the command can be the minimum required time, and due to the delay time in the servo control, it takes a certain amount of time to reach the state that can be regarded as the end of the operation after the required time on the command has passed. It takes time. Therefore, state-related information is used to grasp such delay times. An example of the state-related information is information related to a settling state that can be considered to have reached the target position when the target device reaches within a certain range from the target position. The range for the settling state can be appropriately set according to the details of the servo control operation required for the target device. The settling state may be applied not only to the position information of the target device, but also to velocity information and other physical parameters as well. Also, the state-related information may be information about a state other than the settling state of the target device, such as a vibration state of the target device. If the user wants to confirm that the vibration of the target device is kept below a predetermined level in order to determine the end of the servo control operation, it is useful to include information related to the vibration in the state-related information. Also, the operation information may include information other than the command information and state-related information described above.

Then, the calculation unit calculates the measurement time based on the motion information. The measured time means the execution time of the servo control of the target device, for which confirmation by the user is required via display on the display device. As an example, the measured time can be calculated as the sum of the commanded required time based on the command information and the required time until the end of the servo control operation based on the state-related information. The calculation unit may add other required times.

Then, the determination unit determines the sampling period so that the servo control operation of the target device during the calculated measurement time can be displayed on the display device. The sampling period is a time interval for acquiring predetermined information related to servo control operation. The shorter the sampling period, the more precisely the predetermined information can be acquired, but the amount of data of the predetermined information increases accordingly, and the required storage capacity increases, which may make it difficult to display on a display device. Therefore, the determination unit determines the sampling period in consideration of the measurement time of the servo control operation that is required to be displayed.

Then, the output unit acquires the predetermined information acquired according to the determined sampling period, stores it in the storage area, and outputs it to the display device. The display device that receives the predetermined information may display the predetermined information as it is, or may further process and display the predetermined information. With the processing device configured in this way, the sampling period is determined so that the transition of the predetermined information over time can be displayed on the display device. Operation confirmation can be suitably realized.

In the above processing device, the command information and the state-related information are the same operation as the servo control operation to be displayed, and a drive command has already been issued to the target device from a predetermined control device. It may also be information related to past actions. It may be the case that the processor cannot directly obtain command information for servo control operations. In such a case, as described above, command information related to the same motion that was performed in the past can be treated as command information that can be included in the motion information.

Further, the processing apparatus described above may further include an adjustment unit that adjusts acquisition start timing of the predetermined information according to the sampling period. If the sampling period is excessively lengthened to enable display on the display device, it becomes difficult to accurately display the transition of the predetermined information. Therefore, for example, when the upper limit of the sampling period is set, when the sampling period exceeding the upper limit is required for display, the adjustment unit adjusts the acquisition start timing while setting the sampling period to the upper limit. may be performed. In this case, preferably, the acquisition start timing may be determined so as to include the latter half of the servo control operation including the end timing of the servo control operation. Further, the acquisition start timing may be adjusted by the adjustment unit from a viewpoint other than the length of the sampling period.

It is possible to suitably confirm the operation of the target device.

It is a figure which shows the schematic structure of the control system containing a standard PLC and a servo driver, and the schematic structure of the computer connected to this control system. 3 is a diagram showing one form of a display screen of the processing device shown in FIG. 1; FIG. FIG. 10 is a diagram for explaining the state of a display screen of a computer when conventional trace processing is executed; It is a figure which shows the control structure of a servo driver. 4 is a flowchart of trace processing executed by a servo driver; 5 is a diagram for explaining the state of the display screen of the computer when the trace processing shown in FIG. 4 is executed; FIG.

<Application example>
An application example of the processing apparatus according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic configuration diagram of a control system to which the processing apparatus is applied. The control system includes a network 1, a servo driver 4, and a standard PLC (Programmable Logic Controller) 5
and The servo driver 4 is a servo control device for servo-controlling a device 6 having, for example, two motors 2a and 2b corresponding to two control axes, and corresponds to the processing device of this embodiment. An example of the device 6 is a carrier table for carrying a workpiece, where the carrier table is driven on a plane by motors 2a and 2b. The control system shown in FIG. 1 is configured such that one servo driver 4 can drive two control axes (motors). A configuration in which a plurality of servo drivers 4 are arranged and each servo driver 4 is connected by the network 1 can also be adopted. Commands for driving and controlling the device 6 are supplied from the standard PLC 5 to such a servo driver 4 .

In the above control system, motors 2a and 2b are servo-controlled in device 6 using commands sent from standard PLC 5. FIG. The servo control is control for positioning by each motor. In addition, the servo driver 4 to which the command is supplied from the standard PLC 5 receives the feedback signal output from each encoder connected to the motors 2a and 2b, so that the output of each motor follows the command. A drive current is supplied to 2a and 2b. AC power sent from an AC power supply to the servo driver 4 is used as the supplied current. In this embodiment, the servo driver 4 is of the type that receives three-phase alternating current, but it may be of the type that receives single-phase alternating current. In addition, in this application, the form of feedback control by the servo driver 4 is not limited to a specific one. Further, since the configuration of the servo driver 4 is not the core of the present invention, its detailed disclosure is omitted.

A computer 10 is electrically connected to the servo driver 4 . The electrical connection may be wired connection or wireless connection. The computer 10 is a device for setting and adjusting control parameters for the servo control of the motors 2a and 2b by the servo driver 4, and includes programs for adjustment. Specifically, the computer 10 has an arithmetic unit, a memory, a display (display device), etc., and has an adjustment program executable there. This adjustment program calculates, adjusts, and determines necessary control parameters according to the purpose of servo control performed by the servo driver 4 . For example, the adjustment program performs standard calculation processing for calculating, adjusting, and determining control parameters suitable for the mechanical characteristics, physical characteristics, etc. of the controlled object for each controlled object. In the standard calculation process, the control parameters may be calculated, adjusted, and determined while actually moving the device 6, or the physical model or the like corresponding to the device 6 may be used to calculate the operation without actually moving the device 6. You may calculate, adjust, and determine a control parameter by simulating.

In this embodiment, the servo control executed by the servo driver 4 is not limited to a specific form. For example, the servo driver 4 has a feedback system including a known position controller, speed controller, and current controller, and is configured to perform servo control. In general, the position controller performs proportional control (P control), for example. Specifically, the speed command vcmd is calculated by multiplying the position deviation, which is the deviation between the position command from the standard PLC 5 and the position detected by the motor, by a predetermined position proportional gain. Also, the speed controller performs, for example, proportional integral control (PI control). Specifically, the integral amount of the speed deviation, which is the difference between the speed command vcmd calculated by the position controller and the speed detected in the motor, is multiplied by a predetermined speed integral gain, and the sum of the calculation result and the speed deviation is summed to a predetermined value. is multiplied by the speed proportional gain to calculate the torque command τcmd. Also, the speed controller may perform P control instead of PI control. The current controller outputs a current command Ccmd based on the torque command τcmd calculated by the speed controller, thereby driving and controlling the motor. The current controller includes a filter (first-order low-pass filter) and one or a plurality of notch filters related to the torque command, and may have cutoff frequencies related to the performance of these filters as control parameters.

In order to adjust the servo parameters (position proportional gain, velocity integral gain, velocity proportional gain, cutoff frequency, etc.) for servo control by the servo driver 4, the computer 10 executes an adjustment program. However, it is required to confirm whether the servo parameters adjusted and set there are suitable for driving each motor constituting the device 6 . Therefore, each motor is driven by the servo driver 4 in which the adjusted servo parameters are set, and trace processing is performed to display the operation of each motor at that time. Specifically, motor driving for trace processing and acquisition of information related to the operation of each motor are performed by the servo driver 4 and displayed on the display of the computer 10 .

Here, FIG. 2 shows an example of a screen displayed on the display of the computer 10 when the trace processing is performed. In trace processing, set servo parameters are displayed in the upper part of the display so that the user can easily grasp them. In this embodiment, the position proportional gain, speed proportional gain, and speed integral gain are displayed. Further, as motor movement conditions executed in the trace processing, the movement distance, the (maximum) speed, and the time constant for reaching the speed are displayed below the servo parameters in the display. In addition, the transition of the speed of the motor when the movement under the movement conditions is performed with the servo parameters set is displayed. The information about the "speed" corresponds to one of the predetermined information related to the servo control operation of the motor.

In FIG. 2, the transition represented by the solid line L1 is the transition of the actual speed of the motor, and the transition represented by the dashed line L2 is the drive command given to the motor (command based on the above movement conditions). ). The actual speed of the motor is calculated from the detection signal of the encoder of each motor. Further, the driving command is based on a command given by a trace driving section 15, which will be described later. In the embodiment shown in FIG. 2, the speed transition related to one motor is displayed. good. Information such as "position" and "acceleration" can be used as the predetermined information in addition to "velocity".

Here, in order to perform the above-described trace processing, the servo driver 4 drives the motor to be processed by servo control, and at the same time, information (hereinafter simply referred to simply as "Speed information") must be obtained, temporarily stored, and output to cause the computer 10 to execute the display as shown in FIG. However, in the servo driver 4, since the storage capacity allocated for the trace processing is limited to a predetermined amount, there is an upper limit to the amount of speed information that can be displayed as a result of the trace processing.

For example, as shown in FIG. 3, the drive command related to the speed for tracing processing has a trapezoidal shape represented by a dashed line L2, and the time required for the drive command (the time from the rise of the drive command to the end of the drive command). , hereinafter simply referred to as "driving command time") is Δt1, the actual motor speed deviates from the driving command as indicated by the solid line L1 due to the delay time in the servo control. do. Therefore, the time Δt3 required for moving the target moving distance after the motor is driven is longer than the drive command time Δt1. When the arrival position of the motor falls within a predetermined range from the target position and reaches a stable state, it is determined that the movement of the motor for the target distance has been completed. Therefore, in the present application, the time from the elapse of the drive command time until the motor completes movement of the target movement distance is represented by Δt2 (Δt2=Δt3−Δt1). Note that the predetermined range defining the settling state is the device 6
may be appropriately set according to the configuration and use of the device.

When the motor takes such a speed transition, it may be difficult to obtain all information about the speed transition at time Δt3 shown in FIG. be. The information on the speed transition is acquired at each predetermined sampling period ΔT and stored in the assigned storage area each time. Therefore, if there is a limit to the capacity of the storage area, there is also an upper limit to the number of speed information that can be acquired, and as a result, the range of speed transitions that can be acquired and stored for display is also limited. In FIG. 3, Td indicates the range of storable velocity transition calculated from the predetermined sampling period ΔT and the capacity of the storage area. A range Td is a time range that starts simultaneously with the drive command indicated by the dashed line L2. The range Td is longer than the drive command time Δt1 but shorter than the time Δt3. Therefore, even if trace processing is performed, the servo driver 4 cannot acquire the entire velocity transition, and the display of the computer 10 cannot display the transition completely. In FIG. 3, Tng represents the time during which information on speed transition cannot be obtained. Since the time Tng includes the timing at which the motor reaches a settling state, it becomes impossible to display the speed transition at the end of the servo control operation, which is greatly related to the operation characteristics of the device 6 . As a result, it is difficult for the user to judge whether the set servo parameters are appropriate or not, and it becomes difficult to smoothly adjust the servo parameters.

Therefore, the servo driver 4 of the present embodiment includes a functional unit shown in FIG. 4 in order to appropriately display the predetermined information (speed information in the above example) that is to be displayed when performing trace processing. . FIG. 4 shows an image of functions possessed by the servo driver 4 , and processing of each functional unit is realized by a control program or the like executed by the servo driver 4 . Specifically, the servo driver 4 includes a calculation unit 11, a determination unit 12, an output unit 13, an adjustment unit 14, and a trace driving unit 15, but may have other functional units. Each functional unit will be described below.

First, the trace drive unit 15 is a functional unit that gives a drive command to a target motor in order to perform trace processing. In this embodiment, the computer 10 generates a driving command for the trace driving unit 15 based on the moving conditions (moving distance, speed, time constant) shown in FIG. , the trace drive unit 15 gives the drive command to the motor as a drive command for servo control. Instead of such a form, the standard PLC 5 may generate a drive command for trace processing and send it to the trace drive section 15 .

Next, the calculation unit 11 acquires the motion information given to the motor for the trace processing, and calculates the time (measurement time) for measuring the speed information in the trace processing based on the acquired motion information. It is a functional part. For example, as the operation information, information (command information) related to the drive command sent to the trace drive unit 15 and servo control information related to the motor stabilization state Servo parameter information (state-related information) such as position proportional gain that is exerted can be exemplified. Also, the measurement time is the time corresponding to Δt3 shown in FIG. For example, the delay time (substantially equivalent to Δt2) expected in servo control, which can be grasped from servo parameters such as the position proportional gain included in the state-related information, is added to the drive command time Δt1 that can be grasped from the command information. can be taken as the measurement time. For example, the expected delay time can be a predetermined number of times the time constant calculated from the position proportional gain. Alternatively, a preset expected delay time (fixed value) may be employed.

The determination unit 12 is a functional unit that determines a sampling period ΔT for acquiring speed information based on the measurement time calculated by the calculation unit 11 . The data volume of speed information in the measurement time is proportional to the number of speed information. The number of pieces of speed information increases as the sampling period .DELTA.T becomes smaller, so that the storage capacity required for storing them increases. Considering that the storage capacity has an upper limit, the sampling period ΔT is calculated by the following formula, where Dmax is the maximum number of data that can be stored, which is set based on the storage capacity.
Sampling period ΔT = measurement time/Dmax
As another method, the sampling period ΔT may be determined so that the sampling period ΔT increases stepwise as the measurement time increases, within a range in which the number of speed information acquisitions during the measurement time does not exceed Dmax.

The output unit 13 is a functional unit that stores the speed information acquired according to the sampling period ΔT determined by the determination unit 12, outputs the stored information to the computer 10, and displays it on its display. As a result of the output from the output unit 13, an output result of trace processing as shown in FIG. 2 is obtained. Further, the adjustment unit 14 is a functional unit that adjusts the start timing of obtaining the speed information according to the sampling period ΔT.

<Trace processing>
In the servo driver 4, the trace processing of this embodiment shown in FIG. 5 is executed by the cooperation of the functional units described above. FIG. 5 is a flow chart showing the flow of trace processing. Trace processing is repeatedly executed at predetermined intervals. First, in S101, it is determined whether or not there is a request for trace processing. In this embodiment, it is assumed that a request for trace processing is issued to the servo driver 4 from the computer 10 executing an adjustment program for adjusting servo parameters. That is, the computer 10 outputs a trace processing request to the servo driver 4 for the purpose of judging whether the adjusted servo parameters are appropriate or not, according to a request from the user. If an affirmative determination is made in S101, the process proceeds to S102, and if a negative determination is made, the trace process ends.

In S102, information (operation information) of servo control operation for trace processing is first acquired by the calculation unit 11 . As described above, the drive command for trace processing may be given from the computer 10 to the trace driver 15 or from the standard PLC 5 to the trace driver 15 . In the former case, the calculator 11 can acquire motion information from the computer 10 . Moreover, in the latter case, the calculation unit 11 can acquire the operation information from the standard PLC 5 . However, even in these cases, the servo driver 4 may not be able to directly obtain the drive command during trace processing. In such a case, for example, it is possible to use the drive command information issued to the motor when the servo parameters were adjusted in the past as the drive command information during the trace processing. However, for that purpose, the operation contents of the former drive command and the latter drive command must match. Subsequently, in S103, the calculation unit 11 calculates the measurement time for the trace processing.

Next, in S104, the sampling period ΔT is determined by the determination unit 12 based on the measurement time calculated in S103. As described above, this sampling period ΔT reflects the capacity of the storage area allocated for trace processing in the servo driver 4 . Then, in S105, it is determined whether or not the sampling period ΔT determined in S104 exceeds the preset upper limit. If the sampling period ΔT becomes excessively long, the speed information is obtained less frequently, and speed information that does not accurately reflect the transition of the actual speed information may be obtained, making it difficult to display the speed information appropriately. Therefore, an upper limit value of the sampling period .DELTA.T is set in order to avoid such deterioration in accuracy of the speed information. If an affirmative determination is made in S105, the process proceeds to S106, and if a negative determination is made, the process proceeds to S108.

Then, in S106, the adjustment unit 14 adjusts the speed information acquisition start timing ts (sampling start timing). Specifically, the maximum time Tdmax for which speed information can be obtained when the sampling period ΔT is set to the upper limit (this maximum time is calculated as the time obtained by multiplying the upper limit of the sampling period ΔT by the maximum number of data Dmax). possible) is set to the second half of the measurement time, the start timing of the maximum time is the speed information acquisition start timing ts, which is calculated by the following equation.
Acquisition start timing ts=measurement time−maximum time Tdmax
In addition, in S107, the sampling period ΔT is determined again to the above upper limit value.

In S108 after the processing of S107 is completed, or in S108 after a negative determination is made in S105, the trace driving section 15 gives a driving command for tracing processing to the motor. Along with this, in S109, acquisition of speed information is started according to the sampling period ΔT determined in the above-described processing, and the acquired speed information is stored in the allocated storage area by the output unit 13. After that, At S110, it is output to the computer 10 and displayed on its display.

When such trace processing is performed, if a negative determination is made in S105, as shown in the upper part (a) of FIG. is displayed. Therefore, the user can easily judge the appropriateness of the servo parameters being adjusted through the display. If the determination in S105 is affirmative, the sampling period ΔT is set to the upper limit as shown in the lower part (b) of FIG. The display range Tdmax is set so as to include the relatively important timing of reaching the settling state (immediately before the end of the measurement time Δt3). Therefore, in this case as well, the user can easily judge through the display whether or not the servo parameters being adjusted are appropriate.

<Appendix 1>
A processing device (4) for causing a display device to display a time transition of predetermined information related to servo control operations of target devices (2a, 2b),
A calculation unit (a calculation unit ( 11) and
a determination unit (12) for determining a sampling period for acquiring the predetermined information when the target devices (2a, 2b) perform the servo control operation based on the measured time;
an output unit (13) that stores the predetermined information acquired according to the sampling period and outputs the stored predetermined information to the display device;
A processor (4) comprising:

1: Network 2a, 2b: Motor 5: Standard PLC
10: Computer 11: Calculation Unit 12: Determination Unit 13: Output Unit 14: Adjustment Unit

Claims (4)

A processing device for causing a display device to display a time transition of predetermined information related to a servo control operation of a target device,
a calculation unit that acquires operation information of the servo control operation given to the target device and calculates a measurement time for measuring a time transition of the predetermined information based on the operation information;
a determination unit that determines a sampling period for acquiring the predetermined information when the target device performs the servo control operation based on the measured time and the capacity of a storage area that stores the predetermined information;
an output unit that stores the predetermined information acquired according to the sampling period in the storage area and outputs the stored predetermined information to the display device;
with
The operation information includes command information given to the target device for execution of the servo control operation, and state-related information related to the state of the target device for determining termination of the servo control operation. ,
The command information and the state-related information are related to a past operation that is the same as the displayed servo control operation and that a drive command has already been issued from a predetermined control device to the target device. is information to
processing equipment. A processing device for causing a display device to display a time transition of predetermined information related to a servo control operation of a target device,
a calculation unit that acquires operation information of the servo control operation given to the target device and calculates a measurement time for measuring a time transition of the predetermined information based on the operation information;
a determination unit that determines a sampling period for acquiring the predetermined information when the target device performs the servo control operation based on the measured time and the capacity of a storage area that stores the predetermined information;
an output unit that stores the predetermined information acquired according to the sampling period in the storage area and outputs the stored predetermined information to the display device;
an adjustment unit that adjusts acquisition start timing of the predetermined information according to the sampling period;
,
A processing device comprising: The operation information includes command information given to the target device for execution of the servo control operation, and state-related information related to the state of the target device for determining termination of the servo control operation. ,
3. A processing apparatus according to claim 2 . The command information and the state-related information are related to a past operation that is the same as the displayed servo control operation and that a drive command has already been issued from a predetermined control device to the target device. is information to
4. A processing apparatus according to claim 3 .

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