JPH08223995A - Controller for motor - Google Patents

Abstract

PURPOSE: To obtain a controller for a motor in which troubles due to undue temperature rise of the motor can be eliminated. CONSTITUTION: A robot 1 employs a motor 2 provided with a sensor 20 for detecting the surface temperature thereof and outputting an analog temperature signal Vm. A signal is fed from a pendent 6 to the control section 5 in the controller 3 for the motor 2. The analog temperature signal Vm from the motor temperature sensor 20 is converted through an A/D converter into a temperature data Dm of digital signals and fed to a CPU 7. The keyboard 12 in the pendant 6 is provided with a temperature indication key for setting the display mode of the surface temperature of the motor 2, detected by the motor temperature sensor 20, at the display section 14 in the pendant. The surface temperature of the motor 2 is shown on the display section 14 by the operating the temperature display key.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device, and more particularly to a motor control device for controlling a driving state of a stepping motor used in an industrial robot (hereinafter referred to as a robot).

[0002]

2. Description of the Related Art Conventionally, as a drive source of an industrial robot (hereinafter, robot), for example, A phase, A bar phase, B phase
A stepping motor (hereinafter referred to as a motor) that uses four-phase and B-bar phase drive currents is used. Here, the A-bar phase and the B-bar phase are currents in which the phases of the drive currents of the A-phase and the B-phase are inverted by 180 °. Two of these motors are used to
A Cartesian coordinate robot that can move to any position on the XY plane formed by the axes is configured. The control of the rotation speed, rotation time, and rotation direction of the motor, which is the drive source of such a robot, is controlled by a control device using a microcomputer.

When actually using such a robot, it is necessary to consider the temperatures of the control device and the motor. In the control device, if the temperature of the circuit board on which the various integrated circuit elements are arranged rises excessively, the electrical characteristics of the integrated circuit elements change and the designed operation cannot be realized. Further, when the temperature of the motor rises excessively, the motor coil becomes overheated and the motor characteristics change. This also causes a problem that the designed operation cannot be realized.

[0004]

Conventionally, in order to prevent the occurrence of the above-mentioned problems, a temperature sensor is installed on the circuit board, and when the temperature of the circuit board exceeds a reference temperature and becomes an overheat state. The temperature sensor detects this, and the emergency processing such as rotation of the motor is stopped. On the other hand, with respect to the motor temperature, a configuration such as a temperature sensor for detecting the motor temperature is not used, and the margin of the motor temperature with respect to the limit temperature is not recognized when the temperature of the motor rises. Therefore,
However, there is a problem in that it is not possible to effectively prevent the occurrence of the above-mentioned problem due to the temperature rise of the motor.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to accurately recognize a temperature rise of a motor, thereby preventing a problem due to an excessive temperature rise of the motor. It is an object of the present invention to provide a motor control device capable of controlling the motor.

[0006]

According to a first aspect of the present invention, there is provided a motor control device, a motor temperature detecting member for detecting a surface temperature of a motor, and a display for displaying the surface temperature detected by the motor temperature detecting member. It is equipped with a container, by which the above-mentioned object can be achieved.

In the invention of claim 1, there may be a case where a board temperature detecting member for detecting the temperature of the circuit board on which a circuit element for supplying a driving current to the motor is mounted.

[0008]

According to the first aspect of the present invention, the surface temperature of the motor is detected by the motor temperature detecting member, and the detected surface temperature of the motor is displayed by the display. As a result, the surface temperature of the motor can be confirmed by the display as needed, and regarding the temperature rise of the motor,
The margin of the motor temperature with respect to the limit temperature can be recognized as necessary. Therefore, it is possible to prevent the temperature of the motor from excessively rising due to the operation of the motor, prevent the occurrence of an overheated state of the motor, and prevent the designed operation from being realized due to an undesired change in the motor characteristics due to heat. The occurrence can be effectively prevented.

Further, in the invention of claim 2, when a substrate temperature detecting member for detecting a temperature of a circuit board on which a circuit element for supplying a drive current to the motor is mounted, the circuit is detected by the substrate temperature detecting member. Since the board temperature of the board can be monitored, the temperature of the circuit board is prevented from rising excessively, and the electrical characteristics of the circuit elements mounted on the circuit board change undesirably due to heat, realizing the designed operation. It is possible to effectively prevent the occurrence of a failure that cannot be performed.

[0010]

1 is a block diagram for explaining the electrical configuration of an industrial robot (hereinafter referred to as a robot) 1 according to an embodiment of the present invention, and FIG. 2 is a teaching pendant which is a teaching device used in the robot 1. Hereafter, it is a front view of a pendant). The electrical configuration of the robot 1 of this embodiment will be described below with reference to FIGS. 1 and 2. A two-phase stepping motor (hereinafter referred to as a motor) 2 is used as an example of a drive source in the robot 1. The motor 2 is used to translate or rotate the actuator part of the industrial robot, for example, in the X-axis direction or the Y-axis direction. The motor 2 is provided with a motor temperature sensor 20 that detects the surface temperature of the motor 2 and outputs a temperature signal Vm of an analog amount. The control device 3 for the motor 2 includes a motor drive unit (hereinafter, drive unit) 4, a control unit 5, and the pendant 6. The pendant 6 is used to teach the control unit 5 the necessary rotation speed, rotation time, and rotation direction of the motor 2 in advance.

A CPU (central processing unit), which is realized by using a microcomputer or the like for inputting signals from the pendant 6 to the control unit 5 and performing various kinds of signal processing, etc.
7, an input / output unit 8 for communicating between the CPU 7 and the pendant 6, and a memory 9 for storing various data input from the pendant 6 and various data or signals necessary for driving the motor 2. A temperature sensor 10 for detecting the substrate temperature of a circuit substrate, which will be described later, is connected. An analog temperature signal Vm from the motor temperature sensor 20.
Is an analog / digital conversion circuit (hereinafter, conversion circuit) 2
When converted to digital signal temperature data Dm by 1, CP
Supplied to U7. The drive unit 3 includes a plurality of switching transistors for supplying a drive current to the motor 2 and outputs a drive current for rotating the motor 2 at a predetermined rotation speed and rotation direction based on a signal from the CPU 7. A circuit 11 is provided, and the temperature of the circuit board on which the drive circuit 11 is mounted is detected by the temperature sensor 10.

The pendant 6 is a remote control device which is connected to the control section 5 of the robot 1 and which starts / stops the motor 2 and teaches a moving path in the operation of the robot 1. Such a pendant 6 includes a keyboard 12, a teaching unit 13, and a display unit 14 including, for example, a plurality of digits of a letter segment. Keyboard 1
2 is a start switch 15, a stop switch 16, a numerical key group 17 for inputting various commands and numerical values, a teaching mode key 1
8, an enter key 19 for confirming input data and commands, and a temperature display key 22 for setting the display mode of the display unit 14 to the display mode of the surface temperature of the motor 2 detected by the motor temperature sensor 20. I have it. The instruction input from the keyboard 12 is, for example, a teaching unit 13 including a microcomputer or the like.
Is displayed on the display unit 14 or output to the control unit 5.

FIG. 3 is a graph of various temperatures associated with the motor 2. The operation of this embodiment will be described below with reference to FIGS. Before starting the motor 2 of the robot 1, first, the robot 1 is moved by the pendant 6.
Teach the movement route of. This is the rotation speed of the motor 2,
The rotation period and the rotation direction are set by operating the teaching mode key 18 of the pendant 6, inputting a predetermined numerical value using the numerical keypad group 17 or the like, and operating the enter key 19. As a result, the rotation state of the motor 2 over the entire operation period is stored in the memory 9.

After the motor 2 is started, the surface temperature Ts of the motor 2 changes as shown by the curve in FIG. 3 (1), for example.
tm is detected by the motor temperature sensor 20,
The analog-type temperature signal Vm that changes as shown in FIG. 3B is converted into digital-value temperature data Dm by the conversion circuit 21 and read by the CPU 7. Here, when the temperature display key 22 of the pendant 6 is operated, a monitor activation command Cs is output from the pendant 6 to the control unit 5, and the CPU 7 of the control unit 5 causes the temperature data Dθ to be output.
To the pendant 6. Teaching part 13 of pendant 6
Converts the transmitted temperature data Dθ into display data on the display unit 14, and displays on the display unit 14 the surface temperature T of the motor 2.
Display stm. The operator operates the displayed surface temperature T
After confirming stm, the temperature rise ΔT of the motor 2 with respect to the room temperature Ta measured separately is obtained by ΔT = Ta−Tstm (1).

With respect to the motor 2, the limit value ΔTth of the temperature rise with respect to the room temperature Ta, the limit value Tth of the temperature of the motor 2 and the like are specified as specifications. The operator compares the measured surface temperature Tstm or the calculated temperature rise ΔT with the respective limit values Tth and ΔTth, and compares the temperature Tst of the motor 2 with the current operation of the motor 2.
It is possible to easily determine how much margin m or the temperature increase ΔT has with respect to the respective limit values Tth and ΔTth. As a result, it is possible to reliably prevent the situation where the motor 2 overheats during operation. Therefore, it is possible to prevent the occurrence of an overheated state of the motor 2, and it is possible to effectively prevent the occurrence of the problem that the designed operation cannot be realized due to an undesired change in the motor characteristics due to heat.

Further, in the rotation pattern of the motor 2 for moving the robot 1 along the movement path of the robot 1 taught by the pendant 6, when the motor 2 causes overheating, the occurrence of this overheating is described above. By monitoring the surface temperature Tstm displayed on the display unit 14, it can be easily recognized in advance.
Accordingly, another operation pattern that does not cause overheating of the motor 2 can be set before the actual overheating of the motor 2. This also effectively prevents the occurrence of the problem that the designed operation cannot be realized due to an undesired change in the motor characteristics due to heat.

The board temperature of the circuit board on which the drive circuit 11 is mounted is detected by the temperature sensor 10. Therefore, when the board temperature of the circuit board rises excessively, the CPU 7 stops the motor 2 in an emergency. Let the pendant 6
It is possible to cause the display unit 14 to display that overheat has occurred in the circuit board. This allows the operator to easily recognize the occurrence of overheat in the drive circuit 11. Further, the surface temperature of the motor 2 and the substrate temperature of the circuit board may be alternately displayed by operating the temperature display key 22 of the pendant 6. By doing so, the temperature of the circuit board can be constantly monitored, the danger can be recognized before the circuit board becomes overheated, and the operation of the control device 3 can be performed without causing overheat. It is possible to stop and set other operation patterns. As a result, it is possible to effectively prevent the occurrence of the problem that the designed operation cannot be realized due to an undesired change in the characteristics of the circuit element mounted on the circuit board due to heat.

As another embodiment of the present invention, a CPU
7 predicts a change in temperature rise ΔT with respect to the surface temperature Tstm of the motor 2 or the room temperature Ta due to the set operation of the motor 2 based on the temperature data Dm from the motor temperature sensor 20, and the respective limit values Tth and ΔTth. When it is determined that the pendant 6 may rise above the
The display unit 14 may notify the operator to that effect. In this way, the operator does not need to constantly visually monitor the display unit 14 of the pendant 6, and the effects described above are achieved, and the usability of the robot 1 is further improved.

The above embodiments are examples of the present invention and do not limit the scope of the present invention. The present invention includes a wide range of modifications without departing from the spirit of the present invention.

[0020]

As described above, according to the present invention, the surface temperature of the motor is detected by the motor temperature detecting member, and the detected surface temperature of the motor is displayed on the display. Thereby, the surface temperature of the motor can be confirmed by the display device as necessary, and the margin of the motor temperature with respect to the limit temperature can be recognized as necessary with respect to the temperature rise of the motor. Therefore, it is possible to prevent the temperature of the motor from excessively rising due to the operation of the motor, prevent the occurrence of an overheated state of the motor, and prevent the designed operation from being realized due to an undesired change in the motor characteristics due to heat. The occurrence can be effectively prevented.

Further, in the invention of claim 2, when a board temperature detecting member for detecting the temperature of the circuit board on which a circuit element for supplying a driving current to the motor is mounted, the circuit is detected by the board temperature detecting member. Since the board temperature of the board can be monitored, the temperature of the circuit board is prevented from rising excessively, and the electrical characteristics of the circuit elements mounted on the circuit board change undesirably due to heat, realizing the designed operation. It is possible to effectively prevent the occurrence of a failure that cannot be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of an industrial robot 1 according to an embodiment of the present invention.

FIG. 2 is a front view of a pendant 6 of the robot 1 of this embodiment.

FIG. 3 is a graph of various temperatures associated with the motor 2.

[Explanation of symbols]

 1 Robot 2 Motor 3 Control Device 4 Motor Drive Section 5 Control Section 6 Pendant 7 CPU 10 Temperature Sensor 11 Drive Circuit 12 Keyboard 13 Teaching Section 14 Display Section 20 Motor Temperature Sensor 22 Temperature Display Key Dm Temperature Data Vm Analog Temperature Signal

Claims (2)

[Claims] 1. A motor control device comprising: a motor temperature detecting member for detecting a surface temperature of a motor; and an indicator for displaying the surface temperature detected by the motor temperature detecting member. 2. The motor controller according to claim 1, further comprising a board temperature detecting member for detecting a temperature of a circuit board on which a circuit element for supplying a drive current to the motor is mounted.