JPH03149607A - Servo motor control device - Google Patents

Abstract

PURPOSE:To objectively and automatically judge the validity of responseness and stability by calculating a settling time, an undershooting value, or an overshooting value based upon feedback data obtained during the execution of positioning operation by a prescribed pattern and comparing each calculated value with a prescribed value. CONSTITUTION:The positioning operation is executed by the prescribed pattern, a deviation counter value or a speed feedback value is inputted at a prescribed time interval and the inputted data are stored in a memory 4 of a positioning device 1. The stored data are processed and then the settling time, undershooting value, or overshooting value is calculated by a CPU 2 to judge whether the gain of a feedback loop is proper or not by judging whether the gain is too small or too large. Consequently, the responsibility and stability of the device is proper or not can be automatically judged.

Description

[Detailed Description of the Invention] E Industrial Application Jfl This invention provides a servo motor that is capable of determining whether or not the responsiveness and stability of a servo motor control system controlled by a positioning device are appropriate. This relates to a control device.

[Conventional technology 1] Conventionally, a method for determining whether the responsiveness and stability of a servo motor control system controlled by a positioning device is appropriate is to directly observe the feedback waveform with the human eye using an oscilloscope. Vq is determined by observation.

[Problem to be solved by the invention 1 Conventionally, it was necessary to use an oscilloscope to judge the responsiveness and stability of the servo motor III system.
Special knowledge such as how to use Oscillus':I-'f, connection terminals, and criteria for judgment is also required, and there is a possibility that human error may occur in the judgment.

This invention was made in order to solve the above-mentioned problems, and the purpose is to obtain a servo motor control device that does not require devices such as an oscilloscope and automatically judges response and stability. shall be.

[Means for Solving the Problems 1] A servo motor control device according to the present invention has a data communication means between a positioning device and a servo control device, and causes the servo motor to perform a positioning operation according to a predetermined command pattern. means for capturing the deviation counter value or speed feedback value at predetermined time intervals during execution of the positioning operation and storing the data in the memory of the positioning device, and processing the data to determine the settling time and the amount of undershoot or overshoot. One product with a predetermined amount of means for calculating the amount, and the resulting settling time and amount of undershoot or overshoot! and a means for comparing it with a predetermined amount, and a position feedback loop or a speed feed bar based on the comparison result! This allows the user to judge whether or not the croup gain is appropriate.

[Sakugawa 1] The servo motor control device of the present invention executes a positioning operation in a predetermined pattern, captures a deviation counter value or a speed feedback value at a predetermined time interval during the execution of the positioning operation, and uses this data in the positioning device. Store in memory. The stored data is processed to calculate the settling time of 1 m and the amount of undershoot or overshoot. By comparing the settling time determined by rL with a predetermined time, it is determined whether the gain of the feedback loop is too small. Further, by comparing the calculated undershading amount or overshoot amount with a predetermined amount set in advance, it is determined whether the gain of the feedback loop 1 is too large. Through these two determinations, it is determined whether the gain of feedback loop 1 is appropriate. This automatically increases responsiveness,
It is determined whether the stability is adequate.

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In UA, 1 is a positioning device, 2 is a positioning device l
3 is a bus I/F for interfacing with the servo M control device 7; 4 is a memory for storing data read out from the 2-board memory 10 of the servo ailjll device 7; 5 is a setting display 6; interface section, 6
7 is a servo control device; 8 is a CPU of the servo control device 7; 9 is a bus I, /F, 10 for interfacing with the positioning device 1;
is the 2-board memory 11 that can be accessed by the CPU of the positioning device 1 and the servo TTSM device 7, and the servo motor 14
12 is a power amplifier, 13 is an A/D converter that converts the analog current value detected by the motor current detector 14 into a digital current value, and 14 is a power amplifier. A motor current detector 15 detects the motor current sent from the section 12, and a detector I/F 15 inputs the pulse signal from the detector 17, calculates a position feedback value and a speed feedback value, and sends the calculated values to the CPU 8.
is a servo motor, 17 is a detector that detects position information and speed information of the servo motor 16, and 18 is a positioning device Z1.
This is a bus cable that connects the servo control device 7 and the servo control device 7.

Next, the operation will be explained. First, the deviation counter value (
A method of capturing the difference between the command value and the position feedback value or the speed feedback value and transmitting it from the servo control device N7 to the positioning device Wl will be described. In FIG. 2, a clock signal 20 is a signal generated by a clock built in the positioning device 1fl, and this clock signal 20 is also sent to the servo control device 7 via the bus cable 18. One period of this clock signal 20 is 3 to 5t
ns, and data is transferred only once during that time.

Process A is a process performed by the servo control device 7, and execution begins when the CPU 8 of the servo Hi control device 7 detects the rising edge of the clock signal 20, and is always completed by the falling edge of the clock signal 20. It seems like there are. The part indicated by numeral 31 indicates that process A is being executed.

The contents of processing A are as shown in Fig. 3 or 9.
The method is to take in the deviation counter value or speed feedback value from the detector 1/F15 and write it in a defined area of the two-vote memory 10. As a result, one piece of feedback data is sampled into the two-vote memory 10 in one cycle of the clock signal 20.

Process B is a process performed by the positioning device 1, and is started when the CPU 2 of the positioning device 1 detects the fall of the clock signal 20, and is completed by the time the next clock signal 20 rises. It has become. In reality, it is sufficient that the process of accessing the 2-board memory IO is completed by the next rise of the clock signal 20, and the process of not accessing the 2-board memory IO is possible regardless of the clock signal 20.

The contents of process B are as shown in Figure 4 or Figure 10.
The method is to read a deviation counter value or a speed feedback value from a predetermined area of the boat memory 10 and write it into the memory 4 of the positioning device 1. The above is a procedure in which the positioning device 1 reads the data of the deviation counter value or the speed feedback value at the time interval determined by the clock signal 20, and stores it in the memory 4.

Next, processing using the deviation counter value will be explained with reference to FIG. First, 5th U! As shown in process C of 4, positioning operation according to a predetermined pattern is executed. As shown in FIG. 6, at the same time as the motor 16 starts rotating, it is determined whether or not positioning is being performed using the TRI (Sl). If positioning is being performed, the detector I, /
Get the deviation counter value from F15 and record 2 boats memory 1
0, read the deviation counter value from the 2-board memory 10 by process B, and write it to the memory 4 (S2).
.

Next, the address is updated to the address where the next deviation counter value will be written (S3). Next, it is determined whether the positioning is completed or not (S4) - If the positioning is not completed, the above procedure *S2. S3
．． By repeating S4, the deviation counter values are sequentially recorded in the memory 4. If positioning is completed in S4, the settling time T is determined using the deviation counter value stored in the memory 4 so far.
Calculate s and undershoot il◆S (S5),
The calculation method will be described later. The settling time Ts and undershoot amount φS obtained by rL are preset and input and compared with the predetermined time Tc and predetermined sum φC in S6. S7), Ts
<Tc and φS<φC, the setting display 6 displays that the responsiveness and stability are "good" (
S8), and when Ts<Tc, [gain small] is displayed.S9)+φS<φC, [gain large J
(SIO) to prompt gain adjustment.

Next, a method for calculating the settling time Ts and the undershoot amount φS will be explained with reference to FIG.

The settling time Ts is the time from the time point PO when the command value becomes zero to the time point Pe when the deviation counter value becomes almost zero, and is calculated by multiplying the number of data n during that time by the sampling interval 118, that is, one clock cycle t. It is calculated from the following formula.

Ts=nXt As shown in FIG. 8, the undershoot amount φS is a percentage of the deviation counter value PDR at the maximum overshoot point Pa, and is determined by the following equation.

KXPDRXPGN, /VFBmax,”,100%
Here, is a constant, PDR is the deviation counter value at point P, PGN is the position feedback loop 1 gain, and in the system shown in FIG. The data is stored in the positioning device M1 and transferred to the servo unit W7. VFBmax is the maximum velocity feedback value, and is a theoretical velocity feedback value when the velocity becomes V- in the command pattern of FIG.

Next, processing using the velocity feedback value will be explained with reference to FIG. First, as shown in FIG. 5, a positioning operation according to a predetermined pattern is executed in process C. In this positioning operation, as shown in FIG.
For example, a speed command (20 Orpm) as shown in FIG.
Outputs special type 1 of s. In the 12th TeA, at the same time as starting the positioning operation of this process C, it is determined whether or not positioning is being executed v11 Sl) - If positioning is being executed, process A is performed to detect the detector 1. /Fetch the speed feedback value from F15 and write it to 2-board memory 10,
Process B reads the speed feedback value from the 2-boat memory 10 and writes it to the memory 4 (S2), then updates the address to write the next speed feedback value (S3), and repeats the above process until positioning is completed. repeat.

When the positioning operation is completed (S4), the settling time Ts and overshoot iΦS are calculated from the velocity feedback values sampled so far and accumulated and stored in the memory 4 (Fig. 11) (S5). The calculation method will be described later. do.

The calculated settling time Ts and overshoot 14)s are compared with the predetermined time Tc and the predetermined overshoot ΦC (S6, S7), and it is determined that Ts<:I"c- and φS<φ
When C holds true, the setting display 6 shows the responsiveness of the control system.

A message indicating that the stability is "good" is displayed (S8).

Also, when I''s<Tc, "gain small" is displayed, and when S9)+φS<φC, "gain large" is displayed (SIO)--in both cases, adjustment of the gain of the speed feedback loop is prompted.

Next, a method of calculating the settling time Ts and the overshoot φS will be explained with reference to FIG.

The settling time is defined as the time when the speed feed bar I value is within 10% above or below the command value (for example, 20 rpm) from the command start point PO.
180 to 220 rpm), and the data I & n during that time is multiplied by the sampling time interval, that is, 11fil per crawl,
It is calculated using the following formula.

Ts=nXt Overshoot wrinkles are generated by command 20 in the example shown in FIG.
From the speed feedback value Va (rpm) at the high point of overshooting with respect to 0 rpm, [(Vugly - 200), 2
001y, calculated as 100%.

Generally, the stability and responsiveness of a control system are mainly controlled by the magnitude of the gain of the feed pump. If the gain is excessive, the response is good, but the amount of overshoot or undershoot increases, resulting in poor stability.

Furthermore, if the gain is too small, stability may be good, but settling time will be long and responsiveness will be poor. Therefore, a predetermined time Tc is determined as the settling time and amount of overshoot or undershoot that should be allowed in the control system.
By setting a predetermined value and a predetermined value φC and adjusting the gain so as not to deviate from these two limits, both responsiveness and stability can be improved. i
A control system is obtained.

[Effect of the Invention 1 As described above, according to the present invention, a positioning operation is executed in a predetermined pattern, and the settling time and the undershoot or overshoot amount are calculated from the feedback data during the execution, and the respective predetermined values are calculated. By comparing the gain to the feedback loop of a control system, it is determined whether the gain of the feedback loop of a control system is appropriate, eliminating the need for an oscilloscope or specialized knowledge, and automatically and objectively determining whether the response and stability are good or bad. There is an effect that can be done.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which 1 [J is a configuration diagram of a servo motor positioning control device, 2 is a timing diagram of data processing, 3 is a flowchart of processing A based on the deviation counter value, and 4 The figure is a flowchart of processing B based on the deviation counter value,
Figure 5 is a flowchart of the execution of the positioning operation, Figure 6 is a flowchart of processing using the deviation counter value, Figure 7 is a diagram of recording the deviation counter value in memory, and Figure 8 is the output of the command pattern and deviation counter value. Figure 9 is a flowchart of processing A based on the speed feedback value; Figure 10 is a flowchart of processing B based on the velocity feedback value; and Figure 11 is a diagram showing the speed feedback value recorded in memory. The figure is a flowchart of the processing using the speed feed value, Figure 13 is a diagram showing the command pattern and the output waveform of the speed feed value, and Figure 1
4U; 4 is a block diagram in the case of control based on a speed change command. In the figure, 1 is a positioning device, 4 is a memory 6 is a setting display, 7 is a servo a control device-10 is a 2-board memory, 16 is a servo motor, and 17 is a detector. In addition, in the figure, the symbol “T” indicates “T” or a corresponding part, −

Claims (2)

[Claims] (1) In a control device that has data communication means between a positioning device and a servo control device and causes a servo motor to execute a positioning operation according to a predetermined command pattern, a deviation counter is set at a predetermined time interval during the execution of the positioning operation. means for taking in the values and storing the data in the memory of the positioning device; means for processing the data to calculate the settling time and amount of undershoot; 1. A servo motor control device comprising means for comparing with a predetermined amount, and determining whether or not the gain of a position feedback loop is appropriate based on the comparison result. (2) In a control device that has a data communication means between the positioning device and the servo control device and causes the servo motor to execute a positioning operation according to a predetermined command pattern, speed feedback is provided at predetermined time intervals during the execution of the positioning operation. means for capturing the values and storing the data in the memory of the positioning device; means for processing the data to calculate the settling time and overshoot amount; 1. A servo motor control device comprising means for comparing with a predetermined amount, and determining whether or not the gain of a speed feedback loop is appropriate based on the comparison result.