JPH0962343A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller which can detect various types of abnormality such as the overrun, overshoot, over-velocity, actuator abnormality, etc., of a plant (actuator) to be controlled without using directly the sensor output corresponding to every abnormality. SOLUTION: Two types of information are acquired when the current (i) applied to a plant P6 to be controlled and the position (ps) of the plant P6 are directly measured. These information are inputted to a complete dimension observer 7 and turned into the estimated quantity of state including the information on an estimated position αps, an estimated velocity α v and the estimated acceleration α adis via a state space equation and an output equation. The estimated quantity of state is inputted to an abnormality detection means 8, and the value of a single piece of information on the estimated quantity of state or the value of combination of plural pieces of information is compared with the prescribed value that is previously set. Thus various abnormality signals w1, w2... are outputted to show the presence or absence of the overrun, overshoot, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a control device,
More specifically, the present invention relates to a control device that can be applied to positioning of a seek system of an optical disc drive using a linear motor.

[0002]

2. Description of the Related Art As an example of a conventional control device, there is a method of detecting an abnormality of an actuator by using an output of a disturbance torque observer (see Japanese Patent Laid-Open No. 6-284764). This suppresses the disturbance by inputting the motor current and the rotation speed to a disturbance torque observer to estimate the disturbance torque and feeding back the estimated disturbance torque. Further, when the estimated disturbance torque value exceeds the allowable disturbance torque value, an abnormality is detected, and a current command for generating a reverse torque is added to the motor to quickly perform an overload avoidance operation.

In the case of the above-mentioned conventional example, it is possible to avoid the overload operation due to the disturbance and to quickly detect the collision of the object moved by the actuator, but only the estimated disturbance torque is used as the criterion for the abnormality detection of the device. Since it does not exist, abnormalities in speed and position cannot be detected. In addition, it is most common to use the output of the speed sensor or position sensor as it is as the criterion for the abnormality detection of speed or position. In that case, the abnormality detection accuracy and type are the accuracy and sensitivity of the sensor, the output of the sensor Depends on the noise contained in and the number of attached sensors.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and detects various abnormalities of a control device and suppresses the operation of a plant by detecting output of the abnormalities. In the control device that switches the operation amount of the plant according to the detection output of the plant, various kinds of high accuracy such as overshoot, overrun, overspeed, actuator abnormality, actuator installation abnormality can be achieved without directly using the speed sensor or acceleration sensor output. It is an object of the present invention to provide a control device that detects an abnormality.

[0005]

According to the invention of claim 1, a plant to be controlled, a controller for inputting a target position and the like and outputting an operation amount for controlling the plant, the operation amount and the plant. The state quantity measured is input, and has a full-dimensional observer that estimates and outputs the estimated state quantity including the nominal model of the plant and disturbance, and inputs the state quantity measured the plant and the estimated state quantity to the controller. Then, in the control device for feedback control of the plant, the estimated state quantity by the output of the complete dimension observer is input, and one information or a combination of a plurality of information in the estimated state quantity is compared with a predetermined value, and Equipped with abnormality detection means for detecting various abnormalities in the plant, the accuracy of the sensor is low, or there is a state quantity that is not measured because there is no sensor. , In which the various abnormality detection with high accuracy.

According to a second aspect of the present invention, in the first aspect, there is provided braking means for suppressing the operation of the plant, and means for operating the braking means by the output of the abnormality detecting means is provided, and the plant is mechanically operated. It is intended to keep it safe and high performance.

According to a third aspect of the present invention, in the first aspect, there is provided means for switching the operation amount from the controller to a predetermined value according to the output of the abnormality detecting means, and highly accurate control is possible without providing a special mechanism. To do.

According to a fourth aspect of the present invention, in the first aspect, a linear motor is used as an actuator in the plant and the load weight fluctuation is small, and the state quantity measured in the plant is a current sensor and a position. The applied current of the linear motor and the position of the carriage of the linear motor measured by the sensor, the abnormality detection means sets the target position to a predetermined value, and the estimated position estimated by the full dimensional observer exceeds the predetermined value. When this occurs, it is detected as an overshoot and the positioning is performed with high accuracy.

According to a fifth aspect of the present invention, in the fourth aspect, there is provided a limit sensor which indicates a movement limit of the carriage of the linear motor, and the abnormality detecting means sets the position of the limit sensor to a predetermined value, and the complete sensor is provided. When the estimated position estimated by the dimensional observer exceeds the predetermined value, it is detected as an overrun and positioning is performed with high accuracy.

According to a sixth aspect of the present invention, in the fourth aspect, when the estimated speed estimated by the perfect dimension observer exceeds a preset predetermined value, it is detected as an excessive speed, and The positioning is performed with high accuracy.

According to a seventh aspect of the present invention, in the fourth aspect, the abnormality detection means detects an actuator abnormality when the estimated acceleration disturbance estimated by the full-dimensional observer exceeds a preset predetermined value, It positions with high precision.

According to an eighth aspect of the present invention, in the fourth aspect, the abnormality detecting means includes a deviation between the target position and an estimated position estimated by the full dimensional observer, and an estimated acceleration disturbance estimated by the full dimensional observer. However, when each exceeds a preset predetermined value, it is detected as an actuator installation abnormality and positioning is performed with high accuracy.

[0013]

FIG. 1 is a block diagram of a control device for explaining an embodiment of the present invention. Target value r
Is input to the controller K1. The controller K1 outputs the operation amount u, and the operation amount u is the plant P2 of the state amount x.
Is input to The plant P2 outputs the plant output y, and the output y is input to the controller K1 and is feedback-controlled. In addition, manipulated variable u and plant output y
Is input to the full-dimensional observer 3 that estimates the state quantity of the plant in which the disturbance d is also considered as the state quantity, and the full-dimensional observer 3 outputs the estimated state quantity αx. Estimated state quantity αx
Is input to the controller K1, is feedback-controlled, and is input to the abnormality detecting means 4 for detecting various abnormalities of the control device. In the abnormality detection means 4, the estimated state quantity αx
Alternatively, the controller abnormality signal W is output by comparing the combination of the estimated state amount αx with a predetermined value. Note that W is various abnormal signal vectors. When the state space equation and the output equation of the plant P in which the disturbance is also treated as the state quantity are established, the equations (1) and (2) are obtained.

[0014]

[Equation 1]

Next, when the state space equation and the output equation in the full dimensional observer are established, the equations (3) and (4) are obtained.

[0016]

[Equation 2]

FIG. 2 is a diagram showing a concrete example of a plant. A linear motor having a thrust constant Kf and a load weight M is used, and the sensors for measuring the state quantity of the plant are a current sensor 15, a linear position sensor 14, and a limit sensor 16. Is a positioning control device in which the load weight does not change. The carriage 11 of the linear motor is driven by the voice coil motor 12 to which current is supplied from the current drive amplifier 13. The position of the carriage 11 is detected by the linear position sensor 14, the motor drive current is detected by the current sensor 15, and the limit sensor 16 indicates the movement limit of the carriage 11.

FIG. 3 is a block diagram of the control device shown in FIG. When the target value psr is input to the controller K5, the controller K5 outputs the current i, and the current i is input to the plant P6 whose state quantity is the position ps and the speed v. Then, the position output ps of the plant P6 is detected by the linear position sensor 14 and input to the controller K5, and the device is feedback-controlled. Also, the current i
And the position output ps are input to the full-dimensional observer 7 that estimates the state quantity of the plant, which also considers the acceleration disturbance adis as the state quantity, and the estimated state quantity αps (estimated position), αv (estimated speed), αadis (estimated acceleration disturbance). ) Is output. The estimated state quantities αps, αv, and αadis are also input to the controller K5, and are fed to the abnormality detection means 8 which feedback-controls the device and detects various abnormalities of the control device.

As described above, the present invention uses the full-dimensional observer 7 for estimating the estimated state quantity including the state quantity of the plant and the disturbance. In this full-dimensional observer 7, speed, position, and acceleration disturbances that are state quantities are estimated inside the observer based on the values (for example, current and position) detected by the sensor. As a result, it is possible to detect (estimate) acceleration disturbance and velocity that are not measured by the sensor.
Further, even when the position sensor has low accuracy, a highly accurate position signal can be obtained because the position value is estimated without directly using the measured value. All of these state quantities are used for abnormality detection to detect various apparatus abnormalities.

That is, in the abnormality detecting means 8, the estimated position α
Abnormal signal w1 of overshoot when ps exceeds the target position psr, and abnormal signal w2 of overrun when estimated position αps exceeds the setting position of the limit sensor.
When the estimated speed αv exceeds the set speed, the abnormal signal w3 of excess speed is calculated. When the estimated acceleration disturbance | αadis | exceeds the set acceleration disturbance, the abnormal signal w4 of the actuator is calculated as the target position psr and the estimated position. When both the deviation of αps and the estimated acceleration disturbance | αadis | exceed the respective set values, the actuator installation abnormality signal w5 is output. W = {w1, w2, w3, w4, w5}

Considering that the acceleration disturbance is stationary, the state space equation and the output equation of the plant P6 including the acceleration disturbance adis are set up as shown in equations (5) and (6).

[0022]

(Equation 3)

Next, when the state space equation and the output equation of the full dimensional observer are established, the equations (7) and (8) are obtained.

[0024]

(Equation 4)

FIG. 4 is a block diagram for explaining another embodiment of the present invention. In the block diagram of FIG.
Brake operation means 9 for operating the brakes attached to the plant P6 by receiving the abnormality signals w1 to w5 of the abnormality detection means 8 is provided.

FIG. 5 is a flow chart for explaining the braking operation, and the flow chart of FIG. 5 will be described below. First, in step S1, the abnormal signals w1, w2, w3
w4, w5 are read, and then w2 in step S2
When there is an output in any of w3, w4, and w5, the process proceeds to step S4, and the brake is operated to prevent danger. When none of w2, w3, w4, and w5 is output in step S2, the process proceeds to step S3, w1 is output, and when αv ≠ 0, the process proceeds to step S4 to operate the brake to prevent overshoot.

FIG. 6 is a diagram showing a positional change of the plant (actuator) between the device having the configuration of FIG. 4 and the conventional device when a disturbance occurs (the device is tilted) at time t ₁ . In the case of the conventional control without the disturbance observer, the deviation between the target position and the current position seems to increase.
Further, even if a disturbance observer is added, when current is passed through the actuator to maintain the parallel state, there is a limit to the current that can be passed through the actuator, and if the limit is exceeded, the actuator will move. In the present invention, if the current limit is exceeded due to the estimated disturbance, the brake is operated to mechanically suppress the actuator operation. Therefore, as shown in FIG. 6, the actuator is stopped while maintaining a substantially constant position deviation. To do.

FIG. 7 is a block diagram for explaining still another embodiment of the present invention. In the block diagram of FIG. 3, the abnormality signals w1 to w5 of the abnormality detecting means 8 are inputted and the manipulated variables are inputted. The operation amount control means 10 for controlling the is provided. FIG. 8 is a flow chart for explaining the operation of the manipulated variable control means 10, which will be described below. First, in step S6, the abnormal signals w1, w2, w3, w4, and w5 are read, then in step S7, if there is an output in either w1 or w2, the process proceeds to step S8, in which a reverse current command is given to suppress overshoot and overrun. prevent. Further, if there is no output to either w1 or w2 in step S7, the process proceeds to step S9, and if there is an output to any of w3, w4, and w5, the current command value is set to 0 in order to prevent danger in step S10.

FIG. 9 is a diagram showing a positioning operation to the target position psr according to the embodiment shown in FIG. When the plant is positioned from the position 0 to the target position psr, in the conventional case, when the gain of the controller K5 is large, an overshoot occurs, but in the present invention, when this overshoot occurs, w1 is output and the reverse direction is output. Since the current is applied to the actuator, the overshoot is suppressed lower than before.

FIG. 10 shows the block diagram of FIG. 1 and the plant of FIG. 2, in which the actuator is a linear motor,
It is a flowchart figure explaining the operation | movement of the abnormality detection means 4 of the positioning control apparatus with which the sensor which measures the state quantity of a plant is a current sensor, a linear position sensor, and a limit sensor, and a load weight does not change. Hereinafter, FIG. 10 will be described. First, in step S11, estimated state quantities αps, αv, αadis
Read. Then, in step S12, the estimated position αps
Is above the target position psr, an overshoot abnormality signal w1 is output in step S13. Next, when the estimated position αps exceeds the set position in step S14, the abnormal signal w2 of overrun is output in step S15. Next, when the estimated speed αv exceeds the set speed in step S16, an overspeed abnormal signal w3 is output in step S17. Next, when the estimated acceleration | αadis | exceeds the set acceleration disturbance in step S18, the actuator abnormality signal w4 is output in step S19. Next, in step S20, when the deviation between the target position psr and the estimated position αps and the estimated acceleration | αadis | both exceed their respective set values, in step S21 the actuator installation error signal w
5 is output.

[0031]

【The invention's effect】

Effect corresponding to claim 1: In the control device of claim 1, the measured state quantity of the plant is used, and the state quantity and disturbance of the plant including those not measured are estimated by the full-dimensional observer and fed back. Various disturbances of the control device can be detected by suppressing the disturbance and using the estimated state quantity for detecting the abnormality of the device. Also,
Since the estimated state quantity is used, the accuracy of the sensor is low,
Even if there is no sensor and direct measurement is not possible, highly accurate abnormality detection can be performed.

Effect corresponding to claim 2: In addition to the effect of claim 1, the control device of claim 2 overloads the actuator by mechanically suppressing the operation of the plant by the output of the abnormality detecting means. It is possible to keep it safe and highly accurate without applying.

Effect corresponding to claim 3: In addition to the effect of claim 1, the control device of claim 3 switches the operation amount by the output of the abnormality detection means, thereby providing no special mechanism. Inexpensive, safe and highly accurate control is possible.

Effect corresponding to claim 4: In addition to the effect of claim 1, the control device of claim 4 can perform highly accurate overshoot detection by using the estimated position.

Effect corresponding to claim 5: In addition to the effect of claim 4, the control device of claim 5 can perform highly accurate overrun detection by using the estimated position.

Effect corresponding to claim 6: In addition to the effect of claim 4, the control device of claim 6 can use the estimated speed to perform highly accurate overspeed detection without a speed sensor.

Effect corresponding to claim 7: In addition to the effect of claim 4, the control device of claim 7 can detect the abnormality of the actuator by using the estimated acceleration disturbance.

Effect corresponding to claim 8: In addition to the effect of claim 4, the control device of claim 8 can detect the installation abnormality of the actuator by combining the estimated state quantity.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device for explaining an embodiment of the present invention.

FIG. 2 is a diagram showing a specific example of a plant to be controlled.

FIG. 3 is a block diagram of the control device of FIG.

FIG. 4 is a block diagram for explaining another embodiment of the present invention.

FIG. 5 is a flow chart diagram for explaining a brake operation in FIG.

6] Disturbance occurred at time t ₁ (device tilted)
FIG. 9 is a diagram showing a change in position of an actuator between the device having the configuration of FIG.

FIG. 7 is a block diagram for explaining still another embodiment of the present invention.

8 is a flow chart for explaining the operation of the manipulated variable control means 10 in FIG.

FIG. 9 is a diagram showing a positioning operation to a target position psr according to the embodiment in FIG.

10 is a flowchart illustrating the operation of the abnormality detecting means 4 of the positioning control device in which the load weight does not change, which is shown in the block diagram of FIG. 1 and the plant of FIG.

[Explanation of symbols]

1, 5 ... Controller K, 2, 6 ... Plant P, 3, 7
... perfect dimensional observer, 4, 8 ... abnormality detecting means, 9 ... brake operating means, 10 ... manipulated variable control means, 11 ... carriage, 12 ... voice coil motor, 13 ... drive amplifier,
14 ... Position sensor, 15 ... Current sensor, 16 ... Limit sensor.

Claims (8)

[Claims] 1. A plant to be controlled, a controller that inputs a target position and the like and outputs a manipulated variable for controlling the plant, a manipulated variable and a state quantity measured for the plant are input, and the plant In a controller that has a full-dimensional observer that estimates and outputs an estimated state quantity including a nominal model and disturbance, inputs the state quantity measured for the plant and the estimated state quantity to a controller, and feedback-controls the plant. An abnormality detection means for detecting various abnormalities of the plant by inputting an estimated state quantity by the output of the full-dimensional observer and comparing one information or a combination of a plurality of information in the estimated state quantity with a predetermined value. A control device characterized by being provided. 2. The control device according to claim 1, further comprising a braking unit that suppresses an operation of the plant, and a unit that operates the braking unit according to an output of the abnormality detecting unit. 3. The control device according to claim 1, further comprising means for switching the operation amount from the controller to a predetermined value according to the output of the abnormality detecting means. 4. A linear motor is used as an actuator in the plant, and the load weight fluctuation is small, and the state quantity measured in the plant is an applied current of the linear motor measured by a current sensor and a position sensor. The position of the carriage of the linear motor, the abnormality detection means, the target position is a predetermined value, when the estimated position estimated by the perfect dimension observer exceeds the predetermined value,
The control device according to claim 1, wherein the control device detects an overshoot. 5. A limit sensor for indicating the movement limit of the carriage of the linear motor is provided, and the abnormality detection means sets the position of the limit sensor to a predetermined value, and the estimated position estimated by the full dimensional observer is the predetermined position. 5. The control device according to claim 4, wherein when it exceeds the value of, the overrun is detected. 6. The control according to claim 4, wherein the abnormality detecting means detects an excess speed when the estimated speed estimated by the full-dimensional observer exceeds a preset predetermined value. apparatus. 7. The abnormality detecting means detects an actuator abnormality when an estimated acceleration disturbance estimated by the full dimension observer exceeds a preset predetermined value. Control device. 8. The anomaly detection means includes a deviation between the target position and an estimated position estimated by the full-dimensional observer,
The control device according to claim 4, wherein when the estimated acceleration disturbance estimated by the full-dimensional observer exceeds a preset predetermined value, it is detected as an actuator installation abnormality.