JP2001202134A - Control device, its method and alarm output method for the control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for quickly and accurately detecting an abnormal state of an industrial robot control device or the like and technology for reflecting the detected result to the operation of the control device and previously preventing the occurrence of an accident. SOLUTION: An abnormal state is previously predicted by an abnormality deciding device 18 having a position command change rate operation part 181 for calculating a calculation error by dividing a speed command based on a position command to be continuously changed by the gain of a control loop, a decision value operation part 182 for calculating a decision value by correcting the calculated calculation error by a factor reflecting the state of the control device, a comparing/deciding part 183 for deciding whether the error of a practical position signal to be controlled corresponding to the position command exceeds the decision value or not, and an alarm output part 184 for outputting an alarm when the error exceeds the decision value. The alarm signal outputted from the device 18 is reflected to the operation of the control device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device such as a servo control device in an industrial robot control device, and more particularly to a control device capable of quickly detecting an abnormal state even at a low speed command.

[0002]

2. Description of the Related Art Various safety measures have been taken in various control driving devices, for example, industrial robot control devices, to prevent abnormal movement of robot arms and the like and unscheduled operation.

Japanese Patent Application Laid-Open No. 8-315553 discloses a technique for urgently stopping when an abnormal load such as a collision is applied to a movable unit in a transfer device of a machine tool. The emergency stop method disclosed in Japanese Patent Application Laid-Open No. 8-315553 has two types of overload detection levels, high and low.
The overload detection level is switched according to a movement command issued from the device, and appropriate overload detection is performed according to the state at the time of overload. However, the technique disclosed in Japanese Patent Laid-Open No. 8-315553 merely shows a post-action measure after a collision, and is not a technique for preventing an abnormal situation such as a collision beforehand.

Japanese Patent Application Laid-Open No. Hei 5-216147 discloses that in order to prevent an excessive drive current from being applied to a servomotor, it is detected that a command speed has exceeded a predetermined alarm value. Discloses a technique for stopping the occurrence of phenomena. However, the technique disclosed in Japanese Patent Application Laid-Open No. 5-216147 is a countermeasure after the command speed reaches a predetermined alarm value, and in such a case, an abnormal situation may already occur, After all, it is a technology that is close to post-measures such as some malfunction.

Japanese Patent Application Laid-Open No. Hei 6-33026 discloses a technique for monitoring an abnormality of a robot using predicted values of force sensor information that dynamically changes during operation of the robot and data in an allowable range. . That is, the method disclosed in Japanese Patent Application Laid-Open No. 6-33026 has a sensor data inspection table for storing a predicted value and an allowable range of each sensor data to be monitored, and a plurality of sensor data generated by the trajectory generation unit. Is input to the sensor data inspection table, and when the sensor data deviates from the allowable range of the predicted value, an alarm is notified to the trajectory generation unit. The technique disclosed in Japanese Patent Application Laid-Open No. 6-33026 has an advantage that, in principle, an abnormal movement of each part of the robot can be predicted in advance.

[0006]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 8-315553 cannot predict an abnormal state of the movement of each part of the robot deviating from the routine work. In such a case, it is necessary to rewrite the contents of the sensor data inspection table, and the operation becomes very complicated.

The technique disclosed in Japanese Patent Laid-Open No. Hei 6-33026 predicts that a controlled object such as an arm operates in accordance with the generation of a trajectory signal, and as a result, the position of one or a plurality of arms changes sequentially. For example, when one arm of the five-axis arm is moved,
It is virtually impossible to accurately predict all the continuous movements of the shaft arm, and it is usually meaningless for a robot or the like that assumes continuous movement from the start point to the end point. However, abnormal situations are such,
Originally, it can also occur in the process of continuous smooth movement, so if such a movement process is accurately predicted and a sensor data inspection table is created, the data amount of the table will be very enormous, It is impossible to create it and it is difficult to store it in the memory of the industrial robot controller.

In the technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-33026,
In particular, it is virtually impossible to rewrite the contents of such a sensor data inspection table every time the work content is changed. In particular, Japanese Patent Application Laid-Open No. Hei 6-330 describes a multi-purpose robot that performs various miscellaneous operations and whose contents are frequently changed.
It becomes difficult to apply the technology of Japanese Patent Publication No. 26-26.

Recently, in an industrial robot controller or the like, if such a state continues or if such a state continues, it is warned in advance that an abnormal situation will occur, and prompt measures are taken. It is desired to take. The predicted value disclosed in Japanese Patent Laying-Open No. 6-33026 is a predicted value (scheduled value) obtained by calculating in advance what kind of movement will occur when a certain operation is performed. Is not a value that predicts that if the movement continues, an abnormality of the robot will occur in the near future. Therefore, the technique disclosed in JP-A-6-33026 cannot predict the occurrence of such an abnormal situation that actually occurs.

It is important to predict abnormal situations as quickly as possible so that they do not become important. for that purpose,
For example, if the robot keeps moving even when the arm of the robot is moving at a low speed, it is desirable to detect an abnormal state or an abnormal state in advance if there is a possibility of causing an accident. On the other hand, if an abnormality is detected too early, it may be too sensitive to detect an abnormality, which may reduce the operation rate of the industrial robot and render it unusable. Therefore, it is desired to detect an abnormal situation appropriately and promptly.

Although the industrial robot controller has been exemplified above, appropriate and quick detection of the above-described abnormal situation is not limited to the industrial robot controller, but is demanded in controlling various machines.

An object of the present invention is to provide a method and apparatus capable of appropriately and promptly detecting an abnormal state, an alarm state, or a fault state of a control target. Another object of the present invention is to provide a method and apparatus capable of appropriately and promptly detecting an abnormal situation, an alarm state, or a malfunction state of a control target.

[0013]

According to a first aspect of the present invention, a step of calculating a calculation error by dividing a speed command based on a continuously changing position command by a gain of a control loop; Correcting the calculation error by a factor reflecting the situation of the control device to calculate a determination value, and outputting an alarm when an error of the actual position signal of the control target with respect to the position command exceeds the determination value. Is provided.

According to a second aspect of the present invention, a control method to which the alarm output method of the control device is applied, that is, an error between a position command that changes stepwise and an actual position detection signal of a control target is calculated. And calculating the calculation error by dividing the continuously changing speed command by the gain of the control loop, and correcting the calculation error by a factor reflecting the state of the control device to obtain a determination value. Calculating and outputting a warning when the error of the actual position signal of the control target with respect to the position command exceeds the determination value, and performing the control operation according to the calculated error when there is no alarm output. Is provided.

According to a second aspect of the present invention, an apparatus to which the above-described alarm output method of the control apparatus is applied, that is, a speed command based on a continuously changing position command is divided by a gain of a control loop to calculate Calculation error calculating means for calculating the error of
A judgment value calculating means for correcting the calculated error by a factor reflecting the state of the control device to calculate a judgment value, and an error of an actual position signal of the control target with respect to the position command exceeding the judgment value. An alarm output device of a control device, comprising: a determination / alarm output means for outputting an alarm when an alarm occurs.

According to a third aspect of the present invention, there is provided a control apparatus to which the above control method is applied, that is, a position error calculation for calculating an error between a continuously changing position command and an actual position detection signal of a control target. Means, calculate the calculation error by dividing the continuously changing speed command by the gain of the control loop,
An alarm judgment which corrects the calculation error by a factor reflecting the state of the control device to calculate a judgment value, and outputs an alarm when an error of the actual position signal of the control target with respect to the position command exceeds the judgment value. A control device is provided, comprising: control means for performing control calculation in accordance with the calculated error when there is no alarm output.

According to the fourth aspect of the present invention, the reference command changing stepwise is divided by the gain of the control loop to calculate the reference command change rate, and the time to reach the updated new reference command is calculated. Estimating, setting an allowable range up and down with respect to the calculated change rate, detecting an actual operation result of the control target, and calculating the change rate, and actual operation of the control target. There is provided an alarm output method for a control device, comprising: an abnormal state determination step of determining whether a result falls within the allowable range; and a step of outputting an alarm when an abnormal state is detected.

According to a fifth aspect of the present invention, the reference command changing stepwise is divided by the gain of the control loop to calculate the reference command change rate, and the time to reach the updated new reference command is calculated. Means for estimating, means for setting an allowable range up and down with respect to the calculated change rate, means for detecting the actual operation result of the controlled object and calculating the change rate, and actual operation of the controlled object There is provided an alarm output device of a control device having an abnormal condition judging unit for judging whether or not a result falls within the allowable range, and a unit for outputting an alarm when an abnormal state is detected.

According to the sixth aspect of the present invention, the reference command changing stepwise is divided by the gain of the control loop to calculate the reference command change rate, and the time to reach the updated new reference command is calculated. Estimate, set an upper and lower allowable range for the calculated change rate, calculate the change rate of the actual operation result of the control target, and calculate the actual operation result of the control target until the estimated time is reached. Determining whether the value falls within the allowable range, and outputting an alarm when the value deviates from the allowable range; and calculating an error between the reference command changing stepwise and an actual detection signal of the control target. And performing a control operation according to the calculated error when there is no alarm output.

According to a seventh aspect of the present invention, there is provided an error calculating means for calculating an error between the stepwise changing reference command and an actual detection signal of a control object, and a control operation corresponding to the calculated error. Control operation means to drive the actuator and calculate the reference command change rate by dividing the stepwise changing reference command by the gain of the control loop, and estimate the time to reach the updated new reference command, An allowable range is set up and down with respect to the calculated change rate, a change rate of the actual operation result of the control object is calculated, and the actual operation result of the control object is set to the allowable value until the estimated time is reached. Abnormality determination means for determining whether or not the actuator falls within the allowable range, and outputting an alarm when the value deviates from the allowable range, wherein the control operation means drives the actuator when an alarm is output from the abnormality determination means. Stop That the control device is provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An industrial robot controller as a first embodiment of the controller of the present invention will be described with reference to FIGS. FIG. 1 shows an industrial robot controller,
FIG. 2 is an industrial servo control block diagram showing a numerical control (NC) device and the like. The servo control block diagram of the industrial robot illustrated in FIG. 1 illustrates that the industrial robot control device 10 includes an interpolator 11, a subtraction unit 12, a control operation processing unit 14, and a speed controller 16. are doing. The industrial robot control device 10 further includes an abnormality determination device 18. The control target of the industrial robot controller is
For example, it is an arm of an industrial robot or a drive unit of a numerical controller, and is driven by a servomotor 21. The position of the arm or the like is detected by a rotary encoder 22 connected to the axis of the servomotor 21.

The interpolator 11 continuously outputs a position command of a driving unit such as an arm. The subtraction means 12 calculates a position error by subtracting the detection value of the rotary encoder 22 from the position command. The abnormality determination device 18 determines whether or not the change in the position error leads to an abnormal state. Details of the abnormality determination device 18 will be described later with reference to FIG. The control operation processing unit 14
Control calculation is performed based on the position error calculated by the subtraction means 12. The speed controller 16 controls the speed of the servomotor 21 based on the control calculation result of the control calculation processing unit 14. The servo motor 21 drives the arm. The rotation position of the servo motor 21 corresponding to the movement of the arm is detected by the rotary encoder 22 and is negatively fed back to the subtraction means 12.

The negative feedback loop illustrated in FIG. 1 constitutes a control system of a minor loop by the speed controller 15 and the servo motor 21, and further includes a minor loop by the speed controller 15 and the servo motor 21. , Subtraction means 1
2. A main control system including the control arithmetic processing unit 14 and the rotary encoder 22 is configured.

FIG. 2 is a block diagram of one embodiment of the abnormality judging device 18. The abnormality determination device 18 includes a position command change rate calculation unit 181, a determination value calculation unit 182, a comparison determination unit 18
3 and an alarm output unit 184.

The operation of the abnormality determination device 18 will be described with reference to the graph illustrated in FIG. FIG. 3 is a graph illustrating the operation of the abnormality determination device 18. The horizontal axis indicates a change in the position command, that is, a speed command, and the vertical axis indicates a position error.

The position command change rate calculating section 181 is provided with the interpolator 1
The position command output from 1 is input, and the rate of change F is calculated. The change rate F of the position command is shown by a curve C1 in FIG.

The judgment value calculation unit 182 calculates the judgment value f by multiplying the position change rate F by the coefficient a and further adding a constant b based on the following equation (1). The determination value f is indicated by a curve CV2 in FIG.

F = a × F + b (1)

The reason for multiplying the change rate F by the coefficient a and adding the constant b in the judgment value calculation unit 182 is that the displacement of the position error during acceleration and deceleration is considered. That is,
As a function of the speed that changes in accordance with the position command, a determination value f that is in accordance with the operation state of the industrial robot controller 10 is determined. The coefficient a and the constant b are determined according to the actual situation of the industrial robot controller 10.

The comparison / judgment unit 183 includes a judgment value calculation unit 182
Is compared with the position error ΔP calculated by the subtraction means 12 to determine whether the position error ΔP does not exceed the determination value f. When the position error ΔP exceeds the determination value f, the comparison determination unit 183 determines that an alarm state (or an abnormal state) has occurred and activates the alarm output unit 184.

The alarm output section 184 outputs an alarm. The alarm output from the alarm output unit 184 is output in the form of a message to a display device and a printing device provided in the industrial robot controller, and outputs an alarm signal for stopping the industrial robot controller.

The alarm signal from the alarm output section 184 is applied to the speed controller 16. The speed controller 16 includes an alarm output unit 18
When an alarm is input from step 4, the drive signal to the servo motor 21 is stopped to stop any further operation. The alarm signal of the alarm output unit 184 can be applied to the emergency stop means of the industrial robot control device to stop the industrial robot urgently.

A specific example of the operation of the above-described abnormality determination device 18 will be described with reference to the graph illustrated in FIG. As a result of the calculation by the position command change rate calculating unit 181, it is assumed that the gain of the control loop is 20 when the position command changes, that is, when the speed command is operating at a constant speed of 100 mm / sec. The calculated position error at this time is a change rate F = 10
0/20 = 5 mm. This calculated position error indicates the slope of the curve CV1. For example, the determination value calculation unit 182 sets the determination value f =
0.12 × 100 + 3 = 15 is obtained. Speed controller 16
If the servomotor 21 is stopped for some reason when a normal control signal is output from, the position command changes, but the detection value of the rotary encoder 22 does not change. The actual position error to be calculated increases. When the actual position error exceeds the calculated position error = 5 mm and becomes equal to or greater than the determination value f = 15, the comparison / determination unit 183 determines that there is an abnormality. then,
The alarm output unit 184 performs the above-described alarm processing.

In FIG. 3, when the position error abnormality determination value is set to 50 mm, in the conventional method, it takes time for abnormality detection until the 45 mm position command changes. When the position command is changing at 100 mm / sec, it takes 0.45 seconds in the abnormality detection time of the conventional method. When this embodiment is applied, the abnormality detection time is shortened until the position command changes by 10 mm. When the position command changes at 100 mm / sec, in this embodiment, the abnormality detection time is 0.1 second.

As described above, when the abnormality determination device 18 of the present embodiment is applied, the abnormality detection time can be reduced. As a result, the speed controller 16 that has received the alarm signal from the alarm output unit 184 stops the control command to the servomotor 21 promptly, or the emergency stop circuit operates to stop the operation of the industrial robot controller 10. It is possible to stop the operation and prevent a serious abnormal situation from occurring.

In the above-described conventional method, it takes time to detect an abnormality at a low speed. However, in the abnormal state detecting method of the present embodiment, particularly, the change in the position command is small, that is, as the command speed F becomes slower. This has the effect of shortening the abnormality detection time.

It should be noted that, in the above example, the servo motor 21
Has been described, but when the servo motor 21 operates excessively more than the position command from the interpolator 11, the above-described position error becomes excessive. Abnormality can be detected.

As described above, the calculation error based on the rate of change of the position command is calculated using the abnormality determination device 18 according to the first embodiment of the present invention, and the calculation error is added to the industrial robot control device. Calculating a judgment value that reflects the operation status, etc., and judging an abnormal state by comparing the judgment value with the actual position error, the abnormal state can be detected quickly. This has the effect of being able to detect. The configuration of the abnormality determination device 18 is simple, and its realization is easy. For example, each unit of the abnormality determination device 18, that is, the position command change rate calculation unit 181, the determination value calculation unit 182, the comparison determination unit 183, and the alarm output unit 184
Can be configured using a single microcomputer.

Second Embodiment A control device according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram of a control device according to a second embodiment of the present invention. The control device 50 illustrated in FIG. 4 includes a reference command generator 51, a subtraction unit 52, a control operation processing unit 54, and an abnormality determination device 58.

The reference command generator 51, unlike the interpolator 11 illustrated in FIG. 1, generates a reference command located in a preceding stage of the interpolator 11 in a stepwise manner as illustrated in FIG. Circuit. The interpolator 11 illustrated in FIG. 1 receives a reference position command from a circuit corresponding to the reference command generator 51,
The rate of change is calculated and sent to the subtraction means 12 as a position command that changes continuously and minutely. In the present embodiment, the reference command is sent directly to the subtraction means 52. The subtraction means 52 is equivalent to the subtraction means 12 illustrated in FIG.
The control operation processing unit 54 is a control operation processing unit 1 illustrated in FIG.
Equivalent to 4. Details of the abnormality determination device 58 will be described with reference to FIG.

The control arithmetic processing unit 54 controls an actuator 61 for driving a control target 63. The operation result of the control target 63 is detected by the sensor 62 and negatively fed back to the subtraction means 52 (feedback). The control target 63 in the present embodiment may be the arm of the industrial robot described above, or may be any object such as a normal position control target, an angle control target, or a temperature control target. Hereinafter, as an example, the control target 63 is a position control target. In that case, the sensor 62 is a position detection sensor, for example, an encoder, a position sensor, or the like.

The operation of the control loop by the reference command generator 51, the subtracting means 52, the control operation processing unit 54, the actuator 61, and the sensor 62 is a normal negative feedback control.

FIG. 5 shows a circuit configuration of the abnormality judging device 58. The abnormality determination device 58 includes a reference position command change rate calculation unit 5
81, a reference position command change rate allowable range setting unit 582,
An actual position change rate calculation unit 583, a comparison determination unit 584,
An alarm output unit 585.

The reference position command change rate calculation section 581 calculates the difference between the previous reference position command and the current reference position command when the reference position command REF in the reference command generator 51 changes. Is divided by the gain to calculate the rate of change of the reference position command. Further, the reference position command change rate calculation unit 581 estimates the time to reach the current reference position command changed from the change rate.

A specific example of the processing of the reference position command change rate calculating section 581 will be described. In this embodiment mode, FIG.
At time t1, the reference position command REF changes from 0 to REF1 at time t1.
2, the reference position command REF is changed from REF1 to REF2.
Shows the case where it has changed. Since the reference position command REF has changed from 0 to REF1 at time t1, the reference position command change rate calculator 581 calculates the position command change rate = (REF1-0) / gain at time t1. Furthermore, when the control proceeds at the change rate, the reference position command change rate calculation unit 581 calculates a time t11 to reach the reference position command REF1 in calculation. Even when the reference position command REF changes from REF1 to REF2 at time t2, the reference position command change rate calculation unit 581 calculates the position command change rate = (REF2−REF1) / gain at time t2. Further, the reference position command change rate calculation unit 581 calculates the reference position command R
The time t21 to reach EF2 is calculated. The change rate of the reference position command calculated in this manner is represented by a curve CV in FIG.
21.

Reference position command change rate allowable range setting section 582
Sets an allowable range above and below the reference position command change rate calculated by the reference position command change rate calculation unit 581. Various methods can be applied to the setting of the allowable range in the reference position command change rate allowable range setting unit 582.

As a method of setting the first allowable range, for example, as illustrated in FIG. 6B, a value obtained by adding and subtracting a predetermined value above and below the calculated position command change rate shown by the curve CV21 is an upper limit. The value is set as the value UL and the lower limit LL.
For example, when the calculated position command change rate is 50, the upper limit allowable value is set to 55 obtained by adding 5, and the lower limit allowable value is set to 45 obtained by subtracting 5. When the calculated position command change rate is 60, the upper limit allowable value is set to 65 and the lower limit allowable value is set to 55. When a certain allowable value is set as described above, there is a case where the control is monitored assuming that the value should be within the allowable range regardless of the value of the position command change rate.

The second allowable range is set by adding or subtracting a value obtained by multiplying the calculated position command change rate by a certain ratio above and below the calculated position command change rate shown by the curve CV21. For example, when the ratio is 10% and the calculated position command change rate is 50, the upper limit allowable value is 5
5. The lower limit is set to 45. When the calculated position command change rate is 60, the upper limit allowable value is set to 66 and the lower limit allowable value is set to 54. When the allowable value is set in consideration of the ratio as described above, the control is monitored while changing the allowable range according to the value of the position command change rate.

The actual position change rate calculator 583 is provided with the sensor 6
The actual position detection signal from the two encoders 22 is continuously input, and the change rate of the actual position detection signal from the past to the present for a certain period is calculated. In the calculation of the rate of change, the transition of the rate of change becomes slower when the certain period is made longer, and the rate of change rapidly changes when the certain period is made shorter. Therefore, as a period for calculating the change rate, an appropriate period, for example, the sensor 6 for 5 to 10 sampling periods is used.
Preferably, two detection signals are used.

The comparing and judging section 584 judges whether or not the position change data calculated by the actual position change rate calculating section 583 is within the allowable range set by the reference position command change rate allowable range setting section 582. When the position change data calculated by the actual position change rate calculation unit 583 is out of the allowable range, the comparison determination unit 584 activates the alarm output unit 585.

The alarm output section 585 outputs an alarm. The alarm output from the alarm output unit 585 is output in the form of a message to a display device and a printing device provided in the control device.
An alarm signal for stopping the control device can be output.

The alarm signal of the alarm output section 585 is applied to the control arithmetic processing section 54. When the alarm signal is input from the alarm output unit 585, the control arithmetic processing unit 54 stops outputting the drive signal to the actuator 61, and stops the further operation of the control target 63. Further, the alarm signal of the alarm output unit 585 is applied to the emergency stop means of the control device, so that the control device can be emergency stopped.

As described above, when the abnormality determination device 58 of the present embodiment is applied, since the determination is made based on the change rate, the abnormality detection time can be reduced as in the first embodiment. As a result, the control processing unit 54 that has received the alarm signal from the alarm output unit 585 stops the control command to the actuator 61 promptly, or the alarm output unit 585 operates the emergency stop circuit to operate the control device 50. Is stopped, and a serious abnormal situation can be avoided.

The method for detecting an abnormal state according to the present embodiment
As in the first embodiment, the smaller the change in the reference position command is, the shorter the abnormality detection time is.

As described above, the calculation error based on the change rate of the position command is calculated using the abnormality determination device 58 according to the second embodiment of the present invention, and the calculation error is added to the industrial robot control device. Calculating a judgment value that reflects the operation status, etc., and judging an abnormal state by comparing the judgment value with the actual position error, the abnormal state can be detected quickly. This has the effect of being able to detect. The configuration of the abnormality determination device 58 is simple, and its realization is easy. For example, each unit of the abnormality determination device 58, that is, the reference position command change rate calculation unit 581, the reference position command change rate allowable range setting unit 582, the actual position change rate calculation unit 583, the comparison determination unit 584, and the alarm output unit 585 It can be configured using a single microcomputer.

In implementing the second embodiment, various modifications can be made. For example, the control target 63 illustrated in FIG. 4 is not limited to a control target to be subjected to position control, and may be another control target such as a temperature control. When the control target 63 is a control target that performs temperature control, the sensor 62 is a temperature sensor, for example, a thermocouple.

[0057]

According to the alarm output method of the control device of the present invention, an abnormal state can be quickly detected.

According to the control method of the present invention, an abnormal state can be quickly detected.

According to the control device of the present invention, an abnormal state can be quickly detected.

[Brief description of the drawings]

FIG. 1 is a block diagram of an industrial robot control device as one embodiment of a control device of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the abnormality determination device illustrated in FIG. 1;

FIG. 3 is a graph illustrating an operation of the abnormality determination device illustrated in FIG. 2;

FIG. 4 is a block diagram of a control device as a control device according to a second embodiment of the present invention.

5 is a configuration diagram of an embodiment of the abnormality determination device illustrated in FIG. 4;

6A and 6B are graphs illustrating the operation of the abnormality determination device illustrated in FIG. 5;

[Explanation of symbols]

 10. Industrial robot control device 11. Interpolator 12. Subtraction means 14. Control operation processing unit 16. Speed controller 18. Abnormality judgment device 181 Position command change rate operation unit 182 Judgment Value calculation section 183 Comparison judgment section 184 Alarm output section 21 Servo motor 22 Rotary encoder 50 Industrial robot controller 51 Reference command generator 52 Subtraction means 54 Control calculation Processing unit 58 ··· Abnormality judgment device 581 ··· Position command change rate calculation unit 582 ··· Position command change rate allowable range setting unit 583 ··· Position change rate calculation unit 584 ··· Comparison / determination unit 585 ··· Warning output unit 61 ·・ Actuator 62 ・ ・ Sensor 63 ・ ・ Control object

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Claims (8)

[Claims] A step of calculating a calculation error by dividing a speed command based on a continuously changing position command by a gain of a control loop; and calculating the calculation error by a factor reflecting a state of a control device. Correcting the calculated judgment value, and outputting an alarm when an error of the actual position signal of the controlled object with respect to the position command exceeds the judgment value. Calculating an error between a continuously changing position command and an actual position detection signal of a control object; and calculating the error by dividing the continuously changing speed command by a gain of a control loop. Calculating an error, correcting the calculated error with a factor reflecting the state of the control device to calculate a determination value, and issuing an alarm when an error of the actual position signal of the control target with respect to the position command exceeds the determination value. And performing a control operation according to the calculated error when there is no alarm output. 3. A calculation error calculating means for calculating a calculation error by dividing a speed command based on a continuously changing position command by a gain of a control loop, and calculating the calculation error by calculating a condition of the control device. A judgment value calculating means for calculating a judgment value by correcting the factor by reflecting a factor, and a judgment / alarm output means for outputting an alarm when an error of the actual position signal of the control target with respect to the position command exceeds the judgment value. An alarm output device of a control device comprising: 4. A position error calculating means for calculating an error between a continuously changing position command and an actual position detection signal of a control object, and dividing the continuously changing speed command by a gain of a control loop. The calculation error is calculated, and the calculation error is corrected by a factor reflecting the state of the control device to calculate a judgment value. A control device comprising: an alarm determination unit that outputs an alarm when the alarm value is exceeded, and a control operation unit that performs a control operation according to the calculated error when there is no alarm output. 5. A step of calculating a reference command change rate by dividing a stepwise changing reference command by a gain of a control loop, and estimating a time to reach an updated new reference command. Setting the allowable range up and down with respect to the rate of change, detecting the actual operation result of the control target, and calculating the change rate; and determining whether the actual operation result of the control target falls within the allowable range. An alarm output method for a control device, comprising: an abnormal state determining step of determining whether an abnormal state is detected; and a step of outputting an alarm when an abnormal state is detected. 6. A means for calculating a reference command change rate by dividing a reference command changing stepwise by a gain of a control loop, and estimating a time to reach an updated new reference command. Means for setting an allowable range up and down with respect to the rate of change; means for detecting the actual operation result of the controlled object and calculating the rate of change; and the actual operation result of the controlled object falls within the allowable range. An alarm output device of a control device, comprising: an abnormal condition judging device for judging whether or not an abnormal condition is detected, and a device for outputting an alarm when an abnormal condition is detected. 7. A reference command changing rate is calculated by dividing a stepwise changing reference command by a gain of a control loop, and a time required to reach an updated new reference command is estimated. The upper and lower allowable ranges are set, and the rate of change of the actual operation result of the control target is calculated, and whether or not the actual operation result of the control target falls within the allowable range until the estimated time is reached. Determining, and outputting an alarm when deviating from the allowable range, and calculating an error between the stepwise changing reference command and the actual detection signal of the control target, and when there is no alarm output, Performing a control operation according to the calculated error. 8. An error calculating means for calculating an error between the stepwise changing reference command and an actual detection signal of a control object, and a control calculating means for performing a control calculation according to the calculated error and driving an actuator. And calculating the reference command change rate by dividing the stepwise changing reference command by the gain of the control loop, and estimating the time to reach the updated new reference command. Set the allowable range up and down, calculate the rate of change of the actual operation result of the control target, and determine whether the actual operation result of the control target falls within the allowable range until the estimated time is reached. A controller that outputs an alarm when the alarm value deviates from an allowable range, wherein the control operation unit stops driving the actuator when an alarm is output from the abnormality determination unit.