JP2937007B2 - Auto tuning controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tuning controller for automatically adjusting various controlled objects having different characteristics and controlled objects whose characteristics change.

[0002]

2. Description of the Related Art In a conventional auto-tuning controller, in an auto-tuning for determining a control parameter related to speed control, a servo motor is actually operated by a step command or the like in order to estimate a characteristic of a control target. The control parameter is determined by estimating the control target from (speed response) (Japanese Patent Laid-Open No. 3-2681).
No. 02).

[0003]

However, in the above-mentioned auto tuning, the operation pattern (constant speed time, acceleration / deceleration time, rotation direction, rotation amount, etc.) set to obtain the operation characteristic of the control target is limited. In some cases, since the operation pattern of the servo motor when it is actually used in an actual machine is different, auto tuning cannot be applied after the servo motor is actually attached to the actual machine.

The present invention has been made based on the above circumstances, and has as its object to control parameters for characterizing the operation characteristics of a control target without being limited to the operation pattern of an actual machine to which a servomotor is attached. It is an object of the present invention to provide an auto-tuning controller that can determine

[0005]

In order to achieve the above object, the present invention employs the following technical means for each claim. According to claim 1, a position detecting means for detecting a position of the controlled object, a speed command output unit for outputting a speed command for stopping the controlled object, and a speed control parameter characterizing a speed control characteristic of the controlled object are provided. By using the deviation between the actual speed of the controlled object obtained from the detected value of the position detecting means and the speed command output from the speed command output unit, a current command required to stop the controlled object is obtained. A speed control unit for performing, a current control unit for feedback-controlling a current for stopping the control target based on the current command, and a control unit that determines whether the control target is stationary or vibrates based on a detection value of the position detection unit. Determining means for determining whether the object is in a vibration state, and when the control means determines that the controlled object is in a vibration state, the vibration frequency is set to a preset frequency. Is optionally less than the fixed percentage of the speed control parameter is the larger, the case vibration frequency is equal to or greater than the rate constant for the set frequency,
A speed control parameter adjustment unit for reducing the speed control parameter.

According to a second aspect of the present invention, in the auto-tuning controller according to the first aspect, the speed control parameter adjusting unit obtains the speed control parameter when the determination unit determines that the control target is in a stationary state. The maximum value to be obtained.

According to a third aspect of the present invention, a position detecting means for detecting a position of the controlled object, a speed command output section for outputting a speed command for stopping the controlled object, and a speed characterizing a speed control characteristic of the controlled object Using a control parameter, a deviation between the actual speed of the controlled object obtained from the detected value of the position detecting means and the speed command output from the speed command output unit is necessary to stop the controlled object. A speed control unit for performing a current command, a current control unit for performing feedback control of a current for stopping the control target based on the current command, and a current detection unit for detecting a current flowing from the current control unit to the control target And a torque calculation for calculating a torque required to stop the control target based on a detection value of the position detection means and a detection value of the current detection means. And a determining means for determining whether the controlled object is stationary or vibrating based on the torque calculated by the torque calculating means, and determining that the controlled object is vibrating by the determining means. A speed control parameter adjustment unit that determines the speed control parameter such that the torque ripple calculated by the torque calculation means is minimized when the speed control is performed.

According to a fourth aspect of the present invention, in the auto-tuning controller according to the third aspect, the speed control parameter adjusting section obtains the speed control parameter when the determining means determines that the control target is in a stationary state. The maximum value to be obtained.

According to a fifth aspect of the present invention, in the auto-tuning controller according to the first or second aspect, a position command output section for outputting a position command for stopping the controlled object, and a position characterizing a position control characteristic of the controlled object. Using a control parameter, a speed command required to stop the control target is output to the speed control unit by a deviation between a detection value of the position detection unit and the position command output from the position command output unit. A position control unit to perform, when the control target is determined to be in a vibration state by the determination means, if the vibration frequency is smaller than a predetermined ratio to a preset frequency, the position control parameter When the vibration frequency is higher than a certain ratio with respect to the set frequency, the position control parameter for decreasing the position control parameter is increased. And a chromatography data adjustment unit. The above
The "position command for stopping the controlled object" in
When the position command is "0", that is, the finger for holding the current position
It is an order.

According to a sixth aspect of the present invention, in the auto-tuning controller according to the fifth aspect, the position control parameter adjusting section obtains the position control parameter when the determining means determines that the control target is in a stationary state. The maximum value to be obtained.

According to a seventh aspect of the present invention, in the auto-tuning controller according to the third or fourth aspect, a position command output section for outputting a position command for stopping the controlled object, and a position characterizing a position control characteristic of the controlled object. Using a control parameter, a speed command required to stop the control target is output to the speed control unit by a deviation between a detection value of the position detection unit and the position command output from the position command output unit. And a position control unit that determines the position control parameter such that a torque ripple calculated by the torque calculating unit is minimized when the control unit determines that the control target is in a vibration state. A parameter adjustment unit. Note that the “control pair
The position command to stop the elephant "means that the relative position command is
"0", that is, a command for holding the current position.

According to an eighth aspect of the present invention, in the auto tuning controller according to the seventh aspect, the position control parameter adjusting unit obtains the position control parameter when the determination means determines that the control target is in a stationary state. The maximum value to be obtained.

[0013]

According to the first aspect of the present invention, in the state where the speed command for stopping the controlled object is output, the determining means determines whether the controlled object is in the stationary state or the vibration state. Here, when it is determined that the control target is in the vibration state, the control target can be brought into the stationary state by adjusting the speed control parameter based on the vibration frequency. Specifically, when the vibration frequency is smaller than a predetermined ratio with respect to a preset frequency, the speed control parameter is increased by the speed control parameter adjustment unit, and the vibration frequency is equal to or higher than the predetermined ratio with respect to the set frequency. In the case of, the speed control parameter is reduced.

According to the third aspect of the present invention, a torque required for stopping the controlled object is calculated, and it is determined whether the controlled object is in the stationary state or the vibration state based on the torque. Here, when it is determined that the control target is in the vibration state, the speed control parameter is determined so that the torque ripple is minimized.

According to a fifth aspect of the present invention, after the speed control parameter is determined according to the first or second aspect, when the determining means determines that the controlled object is in a vibration state, the vibration frequency is set in advance. If the ratio is smaller than a certain ratio with respect to the set frequency, the position control parameter is increased by the position control parameter adjustment unit. Smaller.

According to a seventh aspect of the present invention, after the speed control parameter is determined according to the third or fourth aspect, when the determination means determines that the controlled object is in a vibration state, the torque ripple is minimized. The position control parameters are determined so that

[0017]

Next, an embodiment of the auto-tuning controller according to the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram showing a configuration of the auto tuning controller.

The auto-tuning controller 1 of the present embodiment includes a position sensor 3 attached to a control target 2 and a power-on sequence control unit 4, an operation pattern command unit 5, a position control unit 6, a speed control unit 7, A control unit 8, a stationary command unit 9, a vibration frequency estimating unit 10, a torque estimating unit 11, a vibration pulse judging unit 12, an auto tuning unit 13, and the like are built in. The control target 2 includes a servomotor (not shown) and a load attached to a motor shaft of the servomotor.

The position sensor 3 is a position detecting means for detecting the actual position of the control target 2, and more specifically, a rotary encoder attached to a servomotor can be used. The rotary encoder can determine the rotation direction by generating pulses having a phase difference of 90 °, and can determine the origin by obtaining an output of one pulse per rotation. .

When the power is turned on, the power-on sequence control unit 4 performs a self-diagnosis on the inside of the auto-tuning controller 1 for any abnormality. As described above, the switch 14 in the auto tuning controller 1 is switched to the stationary instruction section 9 side (position a in the figure) to bring the control target 2 into the stationary state. The switch 14 is selectively switched between the stationary command unit 9 side and the position control unit 6 side (position b in the drawing).

The operation pattern instructing section 5 is a language or signal capable of interpreting a user program (operation instruction program of the control target 2) in a high-level language or a specialized language created by a user on a personal computer, an operation panel, or the like. The command (position command) of the position to be moved in the unit of time is given to the position control unit 6 via the switch 15 at every certain sampling time.
The switch 15 is located on the side of the stationary command section 9 (position a in the figure).
And the operation pattern command unit 5 (position b in the figure).

The position control unit 6 calculates a deviation between a position command output from the stationary command unit 9 or the operation pattern command unit 5 at every certain sampling time and an actual position of the control target 2 fed back from the position sensor 3. Then, PI control is performed using the current position control parameters, and a speed command is given to the speed control unit 7.

The speed controller 7 outputs the actual speed obtained by differentiating the actual position of the control target 2 fed back from the position sensor 3 by the differential operator 16 and the stationary command 9 or the position controller 6. PID control is performed using a current speed control parameter (more precisely, a parameter called a speed proportional gain, a speed integral gain, or a speed differential gain) from a deviation from the current speed command, and a current command is given to the current control unit 8. .

The current control unit 8 is preset by the control object 2 based on a deviation between the actual current fed back from the current sensor 17 for detecting the current actually flowing to the servomotor and the current command from the speed control unit 7. PI control is performed using the current control parameters thus supplied, and a current is supplied to the servomotor.

The stationary command unit 9 supplies a speed command and a position command for stopping the controlled object 2 to the speed control unit 7 and the position control unit 6 during the self-diagnosis.

The vibration frequency estimating unit 10 receives the actual position of the control target 2 fed back from the position sensor 3, and estimates the actual speed and the vibration frequency and amplitude of the actual position.

The torque estimating unit 11 takes in the actual current fed back from the current sensor 17 and the actual position of the control target 2 fed back from the position sensor 3 and obtains the current electric current of the servo motor obtained from the actual position. Based on the angle and the actual current, a torque required to stop the control target 2 is estimated. Note that this torque can be calculated based on the following equation.

[0028]

TRQ = KT × ia / sin θ where TRQ = estimated torque, KT = torque constant, ia =
Actual current, θ = motor electrical angle.

The vibration pulse judging unit 12 (judging means of the present invention) takes in the vibration frequency estimated by the vibration frequency estimating unit 10 and the estimated torque estimated by the torque estimating unit 11, and determines the current state of the controlled object 2. It is determined whether it is in a completely stationary state or vibrating, and if it is vibrating, a vibration cycle is detected. However, when determining whether the control target 2 is stationary or vibrating, it is necessary to consider a quantum error of the position sensor 3 (rotary encoder). Therefore, when the actual speed or the vibration amplitude α of the estimated torque is smaller than a preset value, it is determined that there is no vibration.

The auto tuning unit 13 determines (adjusts) a speed control parameter and a position control parameter based on the determination result of the vibration pulse determination unit 12.

Next, the operation for determining the speed control parameter and the position control parameter will be described with reference to the flowchart shown in FIG. Power on (step S
After 1), the switch 14 is switched to the stationary command section 9 (step S2). Thereby, the auto tuning controller 1 stops the control target 2 based on the speed control parameter updated when the power was last turned on. When the control target 2 is to be statically controlled, the control target
Stop when the 2 moves (for example, move to the left if you move to the right
Move to the left, move to the right and stop
Is still stationary (slight vibration)
State). If the power is turned on for the first time this time, an initial value (default value) previously stored in the auto tuning controller 1 is used as a speed control parameter.

In this state, in the speed control unit 7, the actual speed obtained by differentiating the actual position of the controlled object 2 fed back from the position sensor 3 and the speed command from the stationary command unit 9 (0 in this case). ), PID control is performed using the current speed control parameters, and a current command necessary for stopping the controlled object 2 is given to the current control unit 8.

The current control unit 8 uses a current control parameter that is set in advance to calculate the P based on the deviation between the current command from the speed control unit 7 and the actual current detected by the current sensor 17.
I control is performed, and a current for stopping the control target 2 is given.

Subsequently, the actual current detected by the current sensor 17 and the actual position detected by the position sensor 3 are taken into the torque estimating unit 11, and the current electric angle and actual current of the servo motor obtained from the actual position are obtained. Thus, the torque required for stopping the control target 2 is estimated (step S3). Further, the actual position detected by the position sensor 3 is taken into the vibration frequency estimating unit 10, and the vibration amplitude α and the vibration frequency x of the actual speed are determined (step S3).

[0035] Subsequently, the oscillation pulse determination unit 12, the current state of the controlled object 2 is quiescent state (stationary appearance state)
Is determined (step S
4). In this determination, when the vibration amplitude α of the actual speed (or the torque) is smaller than a preset value, it is determined that there is no vibration, and when the vibration amplitude α is equal to or greater than the preset value, the vibration state is determined. It is determined that there is.

Subsequently, the decision result in the step S4 is YES.
In other words, when it is determined that the control target 2 is in the vibration state, it is determined whether or not the vibration frequency x is smaller than a certain ratio with respect to the sampling time frequency fs at which the speed control unit 7 performs control. (Step S5). here,
It is determined whether the speed control parameter is vibrating because it is too small or too large. That is, if the speed control parameter is too small, vibration occurs at a low frequency, and if the speed control parameter is too large, vibration occurs at a high frequency. Therefore, step S5
Is YES, that is, when the vibration frequency x is smaller than a certain ratio with respect to the frequency fs (x / fs <
A) is that the vibration amplitude α of the actual speed becomes equal to or less than the set value.
(Until it is determined in step S4 that the vehicle is in a stationary state,
), Speed control parameters in the auto tuning unit 13
Is gradually increased (step S6).

On the other hand, if the decision result in the step S5 is NO, that is, if the vibration frequency x is at least a fixed ratio to the frequency fs (x / fs ≧ A), the vibration amplitude at the actual speed
Until α becomes less than or equal to the set value (still at step S4
Auto-tuning section until it is determined that the
13 to gradually decrease the speed control parameter (s
Step S7).

[0038] whether When the determination result of step S4 is NO, that is, when the controlled object 2 is determined to be at rest is the maximum possible value in the quiescent state of the speed control parameter is the control object 2 Is determined (step S8). When the determination is NO, that is, when the speed control parameter is determined not to be the maximum value, speed system
Increase until the control parameter reaches the maximum possible value
(Step S9).

If the result of the determination in step S8 is YES,
That is, up to the maximum value that the speed control parameter can take.
When it becomes difficult, the maximum speed control parameter is updated as the speed control parameter used by the speed control unit 7 and used as the control parameter at the time of the command operation by the operation pattern command unit 5.

After updating the speed control parameters, the switch 14 is switched to the position control unit 6 and the switch 15 is switched to the stationary command unit 9 (step S1).
0), the control target 2 is stopped.

Subsequently, the actual current detected by the current sensor 17 and the actual position detected by the position sensor 3 are taken into the torque estimating unit 11, and the current electrical angle and actual current of the servo motor obtained from the actual position are obtained. Is used to estimate the torque required to stop the control target 2 (step S11). Further, the actual position detected by the position sensor 3 is taken into the vibration frequency estimating unit 10, and the vibration amplitude β and the vibration frequency y of the actual position are determined (step S11).

[0042] Subsequently, the oscillation pulse determination unit 12, the current state of the controlled object 2 is quiescent state (stationary appearance state)
Is determined (step S1).
2). If the result of this determination is YES, that is,
Is determined to be in the vibration state, it is determined whether or not the vibration frequency y is smaller than a certain ratio with respect to the frequency fp of the sampling time at which the position control unit 6 performs control (step S13).

If the result of this determination is YES, that is, if the vibration frequency y is smaller than a certain ratio with respect to the frequency fp (y / fp <B), the vibration amplitude β at the actual position is set.
Until it becomes equal to or less than the value (the stationary state in step S12).
Until it is determined that the
The control parameters are gradually increased (Step S1)
4).

If the result of the determination in step S13 is NO, that is, if the vibration frequency y is equal to or more than a fixed ratio with respect to the frequency fp (y / fp ≧ B), the vibration
Until the width β becomes equal to or less than the set value (in step S12,
Auto-tuning until it is determined to be stationary)
Gradually reduce the position control parameters in the
(Step S15).

[0045] whether When the determination result of step S12 is NO, that is, when the controlled object 2 is determined to be at rest is the maximum value position置制control parameter can take in a stationary state of the control object 2 Is determined (step S16). When the determination is NO, that is, when the position control parameter is determined not to be the maximum value, the position
Increase until the control parameter reaches the maximum possible value
(Step S17).

If the decision result in the above step S17 is YES
In other words, up to the maximum possible value of the position control parameter
When it becomes larger, the maximum position control parameter is updated as a position control parameter used by the position control unit 6 and used as a control parameter at the time of the command operation by the operation pattern command unit 5.

Thereafter, at the same time that the power-on sequence control section 4 determines that the auto tuning controller 1 is ready, the switch 15 is switched to the operation pattern command section 5 side (the switch 14 remains at the position control section 6 side). Step S18)), the operation is started by a command from the operation pattern command unit 5.

[Modification] In the present embodiment, the optimum values of the speed control parameter and the position control parameter are obtained from the actual speed and the vibration of the actual position, but based on the data obtained by the torque estimating unit 11 at each stage. It is also possible to obtain the torque ripple γ and determine the speed control parameter and the position control parameter so that the ripple γ is minimized.

[0049]

According to the auto tuning controller of the present invention, the speed control parameter and the position control parameter are adjusted in the stationary state of the servo motor (stationary command state), thereby limiting the operation pattern of the actual machine to which the servo motor is mounted. Without this, the optimum speed control parameter and position control parameter can be determined in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an auto tuning controller.

FIG. 2 is a flowchart illustrating the operation of the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Auto-tuning controller 2 Control object 3 Position sensor (position detection means) 6 Position control part 7 Speed control part 8 Current control part 9 Stationary command part (speed command output part, position command output part) 11 Torque estimation part (torque calculation means 12 Vibration pulse determination unit (determination means) 13 Auto tuning unit (speed control parameter adjustment unit, position control parameter adjustment unit) 17 Current sensor (current detection unit)

Claims (8)

(57) [Claims] A) a position detecting means for detecting a position of a control target; b) a speed command output unit for outputting a speed command for stopping the control target; c) a speed control characteristic of the control target. Using the characterizing speed control parameter, the control object is stopped by the deviation between the actual speed of the control object obtained from the detection value of the position detection means and the speed command output from the speed command output unit. A) a speed control unit for performing a current command necessary for the current control; d) a current control unit for performing feedback control of a current for stopping the control target based on the current command; and e) a current control unit based on a detection value of the position detection unit. Determining means for determining whether the controlled object is stationary or vibrating; f) when the determining means determines that the controlled object is vibrating, the vibration frequency is When the vibration frequency is higher than a certain ratio with respect to the set frequency, the speed control parameter is made smaller. An auto-tuning controller including a speed control parameter adjustment unit. 2. The auto-tuning controller according to claim 1, wherein the speed control parameter adjusting section is configured to determine a maximum value of the speed control parameter when the control means determines that the control target is in a stationary state. An auto-tuning controller characterized by the following. 3. a) position detecting means for detecting a position of a control target; b) a speed command output unit for outputting a speed command for stopping the control target; c) a speed control characteristic of the control target. Using the characterizing speed control parameter, the control object is stopped by the deviation between the actual speed of the control object obtained from the detection value of the position detection means and the speed command output from the speed command output unit. A) a speed control unit that issues a current command necessary for the current control; d) a current control unit that feedback-controls a current for stopping the control object based on the current command; and e) a current flowing from the current control unit to the control object. Current detection means for detecting a current; f) calculating a torque required to stop the control target based on a detection value of the position detection means and a detection value of the current detection means. G) determining means for determining whether the controlled object is stationary or vibrating based on the torque calculated by the torque calculating means; and h) determining the controlled object by the determining means. An auto-tuning controller comprising: a speed control parameter adjustment unit that determines the speed control parameter such that a torque ripple calculated by the torque calculation unit is minimized when it is determined that the vehicle is in a vibration state. 4. The auto-tuning controller according to claim 3, wherein the speed control parameter adjusting unit is configured to determine a maximum value of the speed control parameter when the determination unit determines that the control target is stationary. An auto-tuning controller characterized by the following. 5. The auto-tuning controller according to claim 1, wherein a position command output unit for outputting a position command for stopping the control target, and a position control parameter characterizing the position control characteristic of the control target. A position control that outputs a speed command necessary for stopping the control target to the speed control unit based on a deviation between a detection value of the position detection unit and the position command output from the position command output unit. And, when the control target is determined to be in a vibration state by the determination means, if the vibration frequency is smaller than a predetermined ratio to a preset frequency, the position control parameter is increased, When the vibration frequency is equal to or more than a fixed ratio with respect to the set frequency, a position control parameter adjustment unit that reduces the position control parameter. Auto-tuning controller, comprising the. 6. The auto-tuning controller according to claim 5, wherein the position control parameter adjusting unit is configured to obtain the maximum value of the position control parameter when the control unit determines that the control target is in a stationary state. An auto-tuning controller characterized by the following. 7. The auto-tuning controller according to claim 3, wherein a position command output unit for outputting a position command for stopping the control target, and a position control parameter characterizing the position control characteristic of the control target. A position control that outputs a speed command necessary for stopping the control target to the speed control unit based on a deviation between a detection value of the position detection unit and the position command output from the position command output unit. And a position control parameter adjustment unit that determines the position control parameter so that the torque ripple calculated by the torque calculation unit is minimized when the determination unit determines that the control target is in a vibration state. An auto-tuning controller comprising: 8. The auto-tuning controller according to claim 7, wherein the position control parameter adjusting unit is configured to determine a maximum value of the position control parameter when the control unit determines that the control target is stationary. An auto-tuning controller characterized by the following.