JPS63253414A - Servo motor controller - Google Patents

Abstract

PURPOSE:To improve the degree of freedom for control to prevent the abnormality of the working state of a servo motor by providing a jump program into a loop for feedback control and performing the control based on the jump program when the jump conditions are satisfied. CONSTITUTION:The control data includes a working command program containing a set rotational speed, etc., a deciding command program like a jump condition program, a program obtained after jump, etc. Then the control data is supplied through a set input device 10 and stored in a control data memory 26. While a ROM 14 produces a control pattern based on said control data and stores the pattern into a control pattern memory 28. A program memory 24 of the ROM 14 stores a processing logic for execution of the control to the rotational speed, etc., based on a control pattern. A CPU 12 applies the driving control to a servo motor 18 according to the processing logic of the memory 24. If the rotational position of the motor 18, for example, exceeds the jump conditions during the drive control of the motor 18, the CPU 12 performs its control based on a jump program.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a control device for a servo motor, and in particular, it is possible to shift a servo motor that is currently operating according to an operation command program from mid-operation to another operation according to its operating state. The present invention relates to a control device.

BACKGROUND OF THE INVENTION Servo motors are widely used in various NC machine tools, robots, measuring devices, and the like. A control device that controls the operation of such a servo motor generally performs feedback control so that the servo motor operates according to a predetermined operation command program. That is, for example, when an operation command program that commands a target rotational position and a target rotational speed is set, the rotational speed of the servo motor is increased from 0 to the target rotational speed, and then the rotational speed is constant at that target rotational speed. The servo motor is feedback-controlled using the rotational position and rotational speed as control elements so that the rotational position and rotational speed are used as control elements so that the rotational position and rotational speed are used as control elements so that the target rotational position is reached when the rotational speed is reduced and the rotational speed becomes zero. Tokukai 1986
The device described in Japanese Patent No. 2084 is an example of a control device that performs feedback control of the rotational position and rotational speed of a servo motor as control elements.

Problems to be Solved by the Invention By the way, while such a conventional servo motor control device performs feedback control of the servo motor according to an operation command program, it usually performs other operations in the middle until the series of operations is completed. I couldn't get it to move. Therefore, for example, it is not possible to detect in advance that the operating state of the servo motor is abnormal and prevent accidents from occurring, or to change the operation of the servo motor midway depending on the work conditions, etc. The degree of freedom in controlling the operation of the servo motor was low, and it was difficult to say that it was necessarily meeting the needs of users.

Note that a torque sensor or the like is used to emergency stop the operation of the servo motor when the output torque of the servo motor becomes excessive, but this only acts as a safety device, and it allows the servo motor to This does not improve the degree of freedom in controlling the operation of the system.

Means for Solving the Problems The present invention has been made against the background of the above circumstances.
The purpose of this is to enable a servo motor that is currently in operation to move from mid-operation to another operation according to the operating state of the servo motor according to an operation command program.

In order to achieve this object, the present invention provides a device for feedback controlling a servo motor to operate according to a predetermined operation command program.
a) detection means for detecting the actual operating state of the servo motor; (C) determining whether or not a specified jump condition is satisfied, and operating the servo motor according to a predetermined jump program when it is determined that the jump condition is satisfied; It is characterized by comprising a setting means for setting the jump condition and the jump program.

Operation and Effects of the Invention In such a servo motor control device, the detection means detects the actual operating state of the servo motor, and the judgment processing means determines whether the actual operating state is determined by a jump predetermined by the setting means. It is determined whether the conditions are satisfied, and if the jump conditions are satisfied, the servo motor is operated according to a predetermined jump program.

Here, since the above-mentioned judgment processing means is provided in the control loop of feedback control, it is possible to judge in real time whether or not the actual operating state of the servo motor satisfies the jump condition, and it is also possible to Even if the operation of the servo motor is in the process of being controlled according to the jump program, it is possible to immediately operate the servo motor according to the skip program based on the judgment result.

Therefore, according to the servo motor control device of the present invention, by setting the jump condition and the jump program appropriately by the setting means, it is possible to detect in advance that the operating state of the servo motor is abnormal, for example. To prevent accidents from occurring, to change the operation of the servo motor midway depending on the work conditions, or when the operating condition reaches a certain condition in measuring equipment that uses a servo motor as a drive source. The degree of freedom in controlling the operation of the servo motor is greatly improved, such as by being able to automatically switch the operation of the servo motor.

The actual operating state of the servo motor to be detected by the detection means includes the operating time of the servo motor, one rotation position, three rotation speed, acceleration, output torque, etc., and the detection means detects at least one of these. Although it is sufficient to detect only one operating state, it is preferable to detect as many operating states as possible. Further, it is preferable that the servo motor is configured to be feedback-controlled based on the operating state such as the rotational position and rotational speed detected by the detection means, and the jump condition is determined by the number of operating conditions detected by the detection means. It is sufficient if it is set for at least one of the states.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, FIG. 1 is a block diagram showing the hardware configuration of the servo motor control device of this embodiment.
0. CPU12. It is equipped with ROM14 and RAM16. The setting input device 10 is for manually setting the control data of the AC servo motor 18, and inputs the control data to the CPU 12 using a key, tape, magnetic tape, etc.
Enter.

The control data consists of a plurality of series of process data, as shown in FIG. 2, for example, and the process data consists of a command program and command contents. The command programs include a position command program rPO3J, a judgment command program rTRAPJ, and an end command program rEND.
J, standby command program rTIMEj, data command program [JMPj, etc. Position command program rP
O3J constitutes an operation command program, and the command contents include the target rotational position X of the AC servo motor 18.

Target rotational speed F, target acceleration, and target rotational position X
It includes four setting elements for the target required time E to reach , and these are set to desired values based on the basic control pattern set in advance in the control device. This basic control pattern is, for example, as shown in FIG. -12 constant speed stage (■) and a deceleration stage (2) from time t2 to t3, the target rotational position The rotational speed V at stage (3) is determined, the acceleration at the acceleration stage (■) and the deceleration stage (2) is determined for the target acceleration, and the time t is determined for the target required time E, but any one of these four setting elements is determined. If these three are set, the remaining one is uniquely determined, so it is only necessary to arbitrarily select and set three of the four setting elements. Note that the target rotational position X, target rotational speed F, and target acceleration can also be set using the position, movement speed, and acceleration of the NC table 22 driven by the AC servo motor 18 via the feed screw 20.

In addition, the command contents of the judgment command program rTRAPJ are as follows:
It includes jump conditions and jump process data to be judged during execution of the next process data N1103, specifically, the actual rotational position PX of the AC servo motor 18 is 150.
The setting is such that when the value exceeds 000, process data control 10 is executed. In this example, this r P
150000J corresponds to the skipping condition and the process data shade 10 corresponds to the skipping program.

Further, the setting input device 1° for setting these data constitutes a setting means.

Furthermore, the termination command program rENDJ means the end of operation, the standby command program rTIMEJ is for stopping the operation for a certain period of time, and the data command program rJMPJ is for commanding process data to be executed next.

Returning to FIG. 1, the ROM 14 creates a control pattern based on the position command program rPO3J, and controls the rotational position 2 rotational speed and acceleration as control elements so that the AC servo motor 18 operates according to the control pattern. The RAM 16 includes a program memory 24 in which a series of processing logic for feedback control is stored, and the RAM 16 includes a control data memory 26 and a control pattern memory 28 in which the control data and control patterns are stored. And CPU12
performs signal processing according to the processing logic stored in the program memory 24 of the ROM 14, and outputs a drive signal SS for driving the AC servo motor 18 to the motor drive device 30.

In addition to the above control data, this CPU 12 is supplied with a current signal SA representing the actual motor current of the AC servo motor 18 from a motor current detector 32 via an A/D converter 34, and also supplied with an encoder 36 and a clock signal generator. A source 38 provides a position signal SX and a clock signal SC, each representative of the actual rotational position of the AC servo motor 18.

The servo motor control device configured in this manner has the functions shown in the block diagram of FIG. 4. This function is achieved by executing the processing logic stored in the program memory 24.
The control data manually entered from the setting input device 10 is first stored in the control data memory 26, and then a command program to perform feedback control in the control data;
In this embodiment, the position command program is read out for each process data and supplied to the control pattern creation block 40. The control pattern creation block 40 creates a control pattern for operating the AC servo motor 18 in accordance with the position command program, based on the read position command program and the basic control pattern. In this control pattern, as shown in FIG. 5, the theoretical rotational position at which the AC servo motor 18 should be located is determined at predetermined time intervals, for example, every 1 msec.

Here, the position command program usually includes arbitrary three values among the four setting elements, and the control pattern is created so as to satisfy the three values. However, if only two of the target rotational position X, target rotational speed F, target acceleration, and target required time E are set, the predetermined reference rotational speed and reference acceleration are set to A control pattern is created based on the target acceleration. That is, for example, if only the target rotational position X and target acceleration are set, or if only the target rotational position A pattern is created, and when only the target rotational position X and the target rotational speed F are set, the control pattern is created using the reference acceleration as the target acceleration.

Note that when only the target rotational position X and the target required time E are set, the control pattern may be created using the reference acceleration as the target acceleration.

In addition, if the target rotational position to convert the target rotational position Just do it.

The control pattern thus created for each process data in the control pattern creation block 40 is then stored in the control pattern memory 28. The control pattern is read out for each process data, and the theoretical rotational position is sequentially supplied to the position deviation calculation block 42 at the predetermined time intervals. The position deviation calculation block 42 is supplied with a position signal SX representing the actual rotational position of the AC servo motor 18 from the encoder 36, and the position deviation calculation block 42 is configured to calculate the actual rotational position and the theoretical rotation. The positional deviation from the position is calculated and the result is output to the first calculation block 44.

The first calculation block 44 calculates the theoretical rotational speed of the AC servo motor 18 at that time, that is, a value corresponding to one-time differentiation of the control pattern, by calculating the positional deviation according to a predetermined calculation formula. , and outputs it to the speed deviation calculation block 46. The speed deviation calculation block 46 is supplied with a signal representing the actual rotation speed of the AC servo motor 18 from a rotation speed calculation block 48 that calculates the actual rotation speed of the AC servo motor 18 based on the position signal SX. The speed deviation calculation block 46 calculates the speed deviation between the actual rotational speed and the theoretical rotational speed and outputs the result to the second calculation block 50.

The second calculation block 50 calculates the theoretical acceleration of the AC servo motor 18 at that time, that is, a value corresponding to the second differential of the control pattern, by calculating the speed deviation according to a predetermined calculation formula, It is output to the acceleration deviation calculation block 52. The acceleration deviation calculation block 52 is supplied with a signal representing the actual acceleration from an acceleration calculation block 54 that calculates the actual acceleration of the AC servo motor in one day based on the position signal SX. The deviation calculation block 52 calculates the acceleration deviation between the actual acceleration and the theoretical acceleration, and outputs the result to the third calculation block 56.

The third calculation block 56 outputs a final target current for operating the AC servo motor 18 to eliminate the acceleration deviation based on the acceleration deviation calculated by the acceleration deviation calculation block 52. This target current is determined to eliminate the position error and speed error. That is, the first calculation block 44
The second calculation block 50 performs calculation processing so that the target current output from the third calculation block 56 eliminates the position deviation and speed deviation.

The target current output from the third calculation block 56 is normally supplied directly to the phase synchronization block 60, but when the next process data level 3 of the judgment command program rTRAPJ is executed, the target current is supplied to the phase synchronization block 60. 60, decision processing block 58 is executed. The judgment processing block 58 includes the AC servo motor 18
As the actual operating state of the encoder 361 rotation speed calculation block 48. The acceleration calculation block 54 is supplied with signals representing the actual rotational position, rotational speed, and acceleration of the AC servo motor 18, and the output torque calculation block 62 is supplied with signals representing the actual rotational position, rotational speed, and acceleration of the AC servo motor 18. The operation time calculation block 64 supplies a signal representing the output torque of the process data, and a signal representing the operation time after starting the operation of one process data based on the clock signal SC. There is. In this embodiment, the actual rotational position is checked to see if the operating state satisfies the jump condition set in the judgment command program rTRAPJ.
It is determined whether or not oo has been exceeded, and if the target current has not been exceeded, the target current is supplied to the phase synchronization block 60, but if it has been exceeded, rTRAPJ is commanded without sending the target current to the phase synchronization block 60. Process data 1lhlO
The control pattern is read from the control pattern memory 28, and the position deviation calculation block 42 and subsequent steps are executed according to the theoretical rotational position of the process data l1hlO. This judgment processing block 58 constitutes judgment processing means, and encoder 361 rotational speed calculation block 48. Acceleration calculation block 54. The motor current detector 32° output torque calculation block 62 and the operating time calculation block 64 constitute a detection means for detecting the actual operating state of the AC servo motor 18.

On the other hand, the target current supplied to the phase synchronization block 60 is synchronized with the actual rotational phase of the AC servo motor 18, and then supplied to the current deviation calculation block 66, and the current difference between the motor current and the motor current represented by the current signal SA is The deviation is calculated. Then, the current deviation is converted into a voltage signal in the fourth calculation block 68, and the pulse width modulation block 70
After being pulse width modulated at , it is output to the motor drive device 30 as a drive signal SS.

As a result, the AC servo motor 18 is feedback-controlled using the rotational position 1 rotational speed and acceleration as control elements according to the control pattern created in the control pattern creation block 40, and the process data Nf1
During execution of 03, the rotational position of the AC servo motor 18 is 15.
If it exceeds 0000, the process data list 1 will be displayed from the middle of the operation.
0 is executed.

In this embodiment, a control pattern is read out for each process data from the control pattern memory 28 described above, the theoretical rotational position is supplied to the position deviation calculation processor 42, a series of signal processing is performed, and the drive signal SS is transmitted to the motor. A control loop for feedback controlling the ΔC servo motor 18 is configured by each block up to the supply to the drive device 30.

FIG. 6 is a time chart showing the rotational speed when the AC servo motor 18 is operated according to the control data shown in FIG.
A at time T2.
The rotational position of the C servo motor 18 is 0, which is set as the target rotational position X in the process data ko1. Further, during times T2 to T3, the AC servo motor 18 is operated according to the process data N1103, but at time T3, the rotational position of the AC servo motor 18 is 150000, which is set as the target rotational position X of the process data 11h03. Before reaching 200,000, the operation of the AC servo motor 18 is temporarily stopped and then activated according to the process data 10. Time T3~T is the state,
The rotational position of the AC servo motor 18 at time T4 is 300000, which is set as the target rotational position X in the process data NtlIO. Further, the time T4 to T is a state in which the operation of the AC servo motor 18 is stopped for one second by the process data 11, and the time T, to T6 is the state in which the operation of the AC servo motor 18 is stopped for 1 second by the process data 11h12, and the process data 1Vh01 commanded by the data command program of the process data 11h12. It is operated according to the following.

In this way, the servo motor control device of this embodiment includes the judgment processing block 58 in the control loop of feedback control.
is provided, and when the judgment command program is set, judgment processing is performed in real time to determine whether the actual operating state of the AC servo motor 18 satisfies the jump condition according to the contents of the command, and whether or not the jump condition is satisfied. Sometimes, the AC servo motor 18 is operated immediately according to another command program, so the AC servo motor 1
The degree of freedom in controlling the operation of 8 is improved. In particular, in this embodiment, since the actual operating state of the AC servo motor 18 is to detect the rotational position, rotational speed, acceleration, output torque, and operating time, the AC servo motor 18 can be adjusted by setting various jump conditions. The functions of the servo motor 18 can be greatly expanded.

For example, in the above example, a different command program is executed based on the rotational position, but by determining the jump conditions of the rotational position, acceleration, and output torque according to the machining conditions, etc., it is possible to reduce the wear and tear of the cutting tool. If the output torque exceeds the jump condition, the rotation speed is reduced and the NC table is It is also possible to adaptively control the AC servo motor 18 depending on the working conditions, such as by slowing down the moving speed of the motor 22. In addition, when the AC servo motor 18 is used to perform screw tightening work, etc., the output torque jump conditions are set and measurement control is performed so that the screw tightening work is completed when a certain tightening torque is reached, and the AC servo motor 18 In the case of a measuring device that uses the motor 18 instead of an engine to test transmissions, etc., the rotational speed can be changed in stages depending on the operating time. Other rotational positions.

Jump conditions are set for rotational speed, acceleration, output torque, and operation time, and when any one or all of them reach the jump condition, move to another operation. The operation can be controlled in various ways, such as by In the above example, the operation of the AC servo motor 18 is temporarily stopped, but depending on the jump conditions and the contents of the jump program, it is possible to continuously move to another operation.

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can also be implemented in other embodiments.

For example, in the above embodiment, the rotational position is 9 rotational speed.

Acceleration, output torque, and operation time are detected as the operating state of the AC servo motor 18, and by detecting one to four of these or other operating states, the detected operation can be determined. There is no problem even if judgment processing is performed regarding the state.

In addition, in the embodiment described above, a control pattern for commanding the theoretical rotational position is created, the positional deviation is determined, and then the speed deviation and the acceleration deviation are sequentially calculated and feedback control is performed. Create a control pattern that commands the rotation position, rotation speed, and acceleration as control elements to perform feedback control, or create control patterns that command the theoretical rotation position, theoretical rotation speed, and theoretical acceleration to perform feedback control. The mode of the feedback control control loop may be changed in various ways, such as by Note that it is not necessary to perform feedback control on all of the rotational position, rotational speed, and acceleration, and it is possible to perform feedback control on one or two of them. It is also possible to perform feedback control.

Further, in the above embodiment, the position command program is set based on the standard control pattern, but the standard control pattern can be changed as appropriate. etc. can also be set as an operation command program.

Although other examples are not given, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the configuration of a servo motor control device that is an embodiment of the present invention. FIG. 2 visually shows an example of control data that is manually set in the control device shown in FIG. FIG. 3 is a conceptual diagram of a basic control pattern preset in the apparatus of FIG. 1. FIG. 4 is a block diagram illustrating the functions of the device shown in FIG. 1. FIG. 5 is a conceptual diagram of a control pattern created in the control pattern creation block of FIG. 4. FIG. 6 is a time chart of the rotational speed when the servo motor shown in FIG. 1 is operated according to the control data shown in FIG. 10: Setting input device (setting means) 18: AC servo motor (servo motor) 32: Motor current detector 36: Encoder 38: Clock signal generation source 48: Rotation speed calculation block 54: Acceleration calculation block 58: Judgment processing block ( Judgment processing means) 62: Output torque calculation block 64: Operation time calculation block Process data 1lho1.03: Position command program (operation command program) Process data 02: Judgment command program (jump condition) Process data 10: Position command Program (skip program) Applicant Toyota Motor Corporation Figure 2 Figure 6 Figure 3 Figure 5 Moment

Claims (2)

[Claims] (1) A device that performs feedback control so that a servo motor operates according to a predetermined operation command program, comprising: a detection means for detecting the actual operating state of the servo motor; and a detection means provided in a control loop for the feedback control; It is determined whether the actual operating state of the servo motor detected by the detection means satisfies a predetermined jump condition, and when it is determined that the jump condition is satisfied, the predetermined jump is performed. A servo motor control device comprising: determination processing means for operating the servo motor according to a program; and setting means for setting the jump condition and the jump program. (2) The detection means detects the operating time, rotational position, rotational speed, acceleration, and output torque as the actual operating state of the servo motor, and the servo motor detects the actual operating state detected by the detection means. Feedback control is performed based on the operating state of the motor, and the jump condition is set for at least one of the operating time, rotational position, rotational speed, acceleration, and output torque. The servo motor control device according to scope 1.