JPH0415807A - Controller for servo mechanism - Google Patents

Abstract

PURPOSE:To reduce the power consumption by inputting the actual extent of movement of a mobile part from a position detecting sensor at the time of the stop of power supply to a servo motor and outputting a position abnormality signal in the case of deviation of the actual extent of movement from a preliminarily set allowable range. CONSTITUTION:Power supply to the servo motor is stopped by a brake operation control means to operate a brake device. The mobile part is stopped in a prescribed position; and if the actual extent of movement of the mobile part detected by the position detecting sensor is deviated from the preliminarily set allowable range in this state, an abnormality signal output means outputs the position abnormality signal. Thus, power supply to the servo motor is stopped and the stop of the mobile part in the prescribed position is monitored when a position control object is stopped in a prescribed position, and unnecessary power supply is prevented at the time of stop.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a servo mechanism that controls a moving position using a servo motor.

Conventional technology 1 Conventionally, a control device for a servo mechanism is disclosed in Japanese Patent Application Laid-Open No. 1-12114.
As disclosed in Japanese Patent No. 5, a servo motor is driven by a servo amplifier to move a positionally controlled object to a predetermined position. The servo amplifier receives a position command signal of a positionally controlled object and constantly controls the position of the servo motor so that the positionally controlled object is at a position corresponding to the position command signal.

``Problem to be solved by the invention 1 However, in the conventional servo mechanism control device, the servo motor is constantly driven by the servo amplifier, regardless of whether the controlled object is held at a predetermined position or moved to the target position. As a result, the servo motor continued to supply power even when the motor was not actually rotating.As a result, power was consumed even though the controlled object was not moving, reducing power consumption. There was a problem that the power consumption increased unnecessarily and that it was necessary to take into account the heat dissipation of heat generated by this power consumption.However, if the power supply to the servo mechanism is stopped, it becomes impossible to respond to the asymmetric movement of the position controlled object. could not.

An object of the present invention is to provide a control device for a servo mechanism that can reduce power consumption of the device by solving the above problems.

[Means for Solving the Problems] As a means for achieving the above object, the servo mechanism control device of the present invention is capable of moving a controlled object to a predetermined position, as illustrated in FIG. In a control device for a servo mechanism comprising one or more movable parts, a position detection sensor for detecting the movable position of the movable part, and a servo motor provided in the movable part, each of the movable parts A brake device is provided for each axis, and a brake operation control means that stops power supply to the servo motor when the servo motor is stopped, operates a brake device of a movable part driven by the servo motor, and stops the movable part at a predetermined position. When the power supply to the servo motor is stopped, the actual amount of movement of the movable part is input from the position detection sensor, and if the actual amount of movement is outside a preset tolerance range, a position error is detected. The gist of the present invention is to include an abnormal signal output means for outputting a signal.

[Operation] In the servo mechanism control device of the present invention, the brake operation control means stops power supply to the servo motor and operates the brake device. In addition, in this state, when the movable part is stopped at a predetermined position and the actual movement amount of the movable part detected by the position detection sensor deviates from a preset tolerance range, the abnormality signal output means detects the position abnormality. Output a signal.

As a result, when the position-controlled object is stopped at a predetermined position, the power supply to the servo motor is stopped, and it is monitored that the movable part is stopped at the predetermined position. Therefore, unnecessary power supply is not performed when the system is stopped. Furthermore, since asymmetric movement can be detected, it is possible to cope with asymmetric movement.

[Embodiment] Next, an embodiment of the servo mechanism control device of the present invention will be described.

FIG. 2 shows a block diagram of the control device 1 of the numerically controlled processing equipment of this embodiment. The control device 1 includes an equipment controller 3, an NC controller 5, and X and Y.

Z-axis servo amplifier 11, 12, 13, and X, Y.

Z axis - small motors 21, 22, 23, and X, Y.

Z-axis brake devices 31, 32, and 33 are provided. The control device 1 operates a three-axis (X, Y, Z-axis) type NC processing device (not shown) based on a preset procedure.

The equipment controller 3 has a configuration whose main part is a program controller such as a sequencer.

The equipment controller 3 outputs command signals such as an emergency stop command and a program execution command to the NC controller 5.

The NC controller 5 stores programs as exemplified in Table 1 below, brake operation processing shown in FIG. 3 and programs for servo mechanism abnormality processing shown in FIG. 4, which will be described later. Based on this, control signals are output to the X, Y, and Z-axis servo amplifiers 11, 12, and 13 in accordance with a pre-stored program.

The program shown in Table 1 is NC sequentially from line number N100.
When processed by the controller 5, the target position Pi (+=1.2.3°4.5) of the X, Y, and Z axes is moved as shown in FIG. These target positions @Pi are X,
It is output as a control signal to the Y and Z axis servo amplifiers 11, 12, and 13.

The X, Y, and Z-axis servo amplifiers 11, 12.13 drive the X, Y, and Z-axis servo motors 21, 22.23 based on control signals from the NC controller 5. Also, X, Y
, the Z-axis servo amplifiers 11, 12.13 turn on or off the power supply to the X, Y, and Z-axis brake devices 31, 32, and 33 based on the control signal from the NC controller 5. A circuit is provided.

X, Y, Z axis servo motor 21.22.23
, a servo motor section (not shown) driven by a Z-axis servo amplifier 11.12.13, and X, Y, Z (not shown)
X to detect the moving position of the axis.

It has Y and Z axis position sensor sections. The moving position of the X, Y, and Z axes detected by the position sensor unit is X.

The signal is transmitted to the Y- and Z-axis servo amplifiers 11, 12.13 and the NC controller 5.

The X, Y, and Z axis brake devices 31, 32, and 33 prevent movement of the X, Y, and Z axes by the urging force of a spring. When this X, Y, Z axis brake device 31.32.33 is supplied with power from the X, Y, Z axis servo amplifier 11.12.13, it releases the brakes of the X, Y, and Z axes, while the power supply is X when stopped.

Prevent movement on the Y and Z axes. Note that the X, Y, and Z axis brake devices 31, 32, and 33 are well known in the art, and their explanation will be omitted here.

Next, the brake operation process shown in FIG. 3 will be explained.

The brake operation process is executed at predetermined time intervals by a microcomputer (not shown) in the NC controller 5. Note that the brake operation process shown in FIG. 3 is executed individually for each of the X, Y, and Z axes. Here, an example regarding the X axis will be described. In the brake activation process, it is first determined whether or not there is an emergency stop (step 100, hereinafter simply referred to as 5100).

The determination of emergency stop is made when the equipment controller 3 outputs an emergency stop signal to the NC controller 5. The emergency stop signal is output when an emergency stop pushbutton (not shown) is pressed.

If it is determined that it is an emergency stop, then the X-axis brake device 3
At the same time, the function of the X-axis servo motor 21 is stopped (S110). The operation of the X-axis brake device 31 is executed by outputting a signal from the NC controller 5 to the X-axis servo amplifier 11 to stop the power supply to the X-axis brake device 31. The function of the X-axis servo motor 21 is stopped by outputting a signal from the NC controller 5 to the X-axis servo amplifier 11 to stop supplying power to the X-axis servo motor 21.

On the other hand, if it is determined that it is not an emergency stop (S100)
, Next, it is determined whether or not the axis is moving (S120). Judgment during axis movement is made by an X-, Y-, and Z-axis servo amplifier control processing routine (not shown) stored in the NC controller 5.
This is done depending on whether a control signal for changing and controlling X is output. That is, when the X-axis servo amplifier 11 actually drives the X-axis servo motor 21 to change the position, it is determined that the axis is moving. If the axis is moving, then the brake is released and servo function operation processing is performed (S130). The brake release is executed by outputting an energization signal to the X-axis brake device 3 from the NC controller 5 to the X-axis servo amplifier 11. The servo function operates from the NC controller 5 to the X-axis servo amplifier 1.
1 by outputting a power supply signal to the X-axis servo amplifier 21.

If the emergency stop is not in progress and the axis is not moving (S1
00. Sl 20>, then the current position and the next target position P
It is determined whether or not ix is the same (S140). If the current position and the next target position Pix are the same, that is, the X-axis target position Pix of the currently executing line number (see Table 1)
If Pix is the same as the target position Pix of the line number to be executed next, the process moves to the brake activation process (S110) described above. On the other hand, if the current position PiX and the next target position PiX are different, the brake release process described above (S13
0). As shown above, for example, when the programs shown in Table 1 are sequentially processed and the brake operation process shown in FIG. 3 is executed, each brake device 31, 3
In case 2.33, the brake operates as shown in the column of brake operation in Table 1. Therefore, when the target position PiX does not change, power supply to the X-axis servo motor 2 and the X-axis brake device 31 is stopped, thereby preventing power consumption thereof.

Next, the servo mechanism abnormality processing shown in FIG. 4 will be explained.

The servomechanism abnormality processing is executed at predetermined time intervals by a microcomputer (not shown) in the NC controller 5. In addition, the servo mechanism abnormality processing in Fig. 4 is performed for X, Y,
This is performed individually on the Z-axis cylinders. Here, an example regarding the X axis will be described.

In the servo mechanism abnormality processing, first, the servo function is stopped in step 5110 and it is determined whether the brake operation processing is being executed by the brake operation processing shown in FIG.
200>. If the process of Sl 30 is executed and the process of 5110 is not executed, this routine is temporarily ended. On the other hand, if it is determined that the process of 5110 is being executed, it is determined whether the axis is outside the allowable range (3210>.Here, as shown in FIG. 6, for the current target position P+x, This is to judge whether the actual position of the X-axis has deviated beyond the tolerance parameter PX.The value of the tolerance parameter px is changed as appropriate based on the specifications of the equipment and the contents of the processing work. , the tolerance parameter Px is input as a predetermined value to the NC controller 5 via the equipment controller 3 or directly.

If the axis is not outside the allowable range, this routine is temporarily terminated. On the other hand, if the axis is outside the allowable range, then the axis movement is stopped (S220>).The axis movement is stopped for other than the X-axis.

That is, the brake operation and servo function stop processing are executed for the Y-axis and the Z-axis in the same manner as in step 5110 described above. Next, an NC abnormal signal is output (3230>.N
The C abnormality signal is outputted from the NC controller 5 to the equipment controller 3, and is used as NC abnormality display data and an interrotation signal such as operation interruption during operation.

When the above-described control device 1 of the numerically controlled machining equipment does not move the axis, it stops supplying power to the servo motor that moves the axis, and maintains the current position of the axis using the brake device. Therefore, while movement of the shaft is stopped, power supply to the servo motor and brake device is stopped.

This reduces power consumption by the servo motor and brake device. As a result, energy saving can be achieved. Furthermore, since the amount of heat generated by the servo motor and brake device is reduced, the thermal expansion of mechanical elements connected to them is reduced.

In other words, positioning accuracy is improved.

Moreover, while the power supply to these servo motors and brake devices is stopped, the power consumed by the servo amplifier is reduced. Moreover, the servo amplifier generates less heat due to reduced power consumption per unit time.

As a result, the influence of heat is reduced, so the degree of integration of the electronic elements of the servo amplifier can be increased and the servo amplifier can be made smaller. Furthermore, the heat dissipation area of the control panel that accommodates the servo amplifier can be reduced, and the control panel can be made smaller.

When the axis movement is stopped, the current position of the axis is held by the urging force of the brake device, and the result of holding by this brake device is monitored to prevent the axis from moving asymmetrically due to external forces of machining work such as cutting load. Determining whether it has been moved. Furthermore, based on the result of this determination, the movement of each axis is stopped to prevent continuation of machining work with the axes moving asymmetrically. Therefore, an excellent effect is achieved in that the precision of the machining work can be maintained. Moreover, since the asymmetric movement of the axes is displayed externally, the continuation of the machining operation is not left stopped for a long time.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented in various forms without changing the gist of the present invention. For example, the servo motor can be of a rotary type or a linear movement type. Also, instead of the electric type, a pneumatic or hydraulic type may be used. Alternatively, it can be used as a manipulator instead of an NC processing device.

[Effects of the Invention] The servo mechanism control device of the present invention stops power supply to the servo motor in order to stop the movable part at a predetermined position,
In addition, when the brake device is operated, if this movable part actually moves out of a preset allowable range, a position abnormality signal is output to notify this. Thereby, when the movable part is stopped at a predetermined position, it is possible to know that the movable part has moved asymmetrically and take appropriate action. The present invention has extremely excellent effects in that it is possible to provide a control device for a servo mechanism that saves energy, reduces heat generation, and has high positioning accuracy and position holding ability even against heat.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of a control device for a servo mechanism according to the present invention, FIG. 2 is a block diagram showing the configuration of a control device according to an embodiment, and FIG. FIG. 4 is a flowchart of servo mechanism abnormality processing, FIG. 5 is an explanatory diagram of axis movement, and FIG. 6 is an explanatory diagram of tolerance parameters. 1... Control device 3... Equipment controller 5.
...NG controller 11...X-axis servo amplifier 12...Y-axis servo amplifier 13...Z-axis servo amplifier 21...X-axis servo motor 22...Y-axis servo motor 23...Z-axis Servo motor 31...X-axis brake device 32...Y-axis brake device 33...Z-axis brake device

Claims (1)

[Claims] 1. One or more movable parts for making it possible to move a controlled object to a predetermined position, a position detection sensor for detecting the movable position of the movable parts, and a position detection sensor provided on the movable parts. A control device for a servo mechanism equipped with a servo motor, comprising: a brake device for each axis provided individually for each of the movable parts, and a brake for the movable parts driven by the servo motor, which stops power supply to the servo motor when the servo motor is stopped. a brake operation control means for activating the device and stopping the movable part at a predetermined position; when power supply to the servo motor is stopped, inputting the actual amount of movement of the movable part from the position detection sensor;
1. A control device for a servo mechanism, comprising: abnormality signal output means for outputting a position abnormality signal when the actual amount of movement deviates from a preset tolerance range.