JPH1029179A - Controlling device for industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain the facilitation of maintenance, and reduce a space for installing a cable. SOLUTION: A control device for controlling a robot is divided into a servo amplifier, a heavy current part 3 such as a power source for supplying electric power to the servo amplifier, and the control part of an information processing system other than the strong-electric part. The part 3 is adjoined or incorporated into a robot mechanism part 2. The control part 1 and the part 3 are connected by an optical fiber cable 5, and the control part 1 is installed in outside a safety fence 4. The existence of the control part in outside the safety fence 4 facilitates the operation and maintenance of the robot, and the high-speed serial communication by the optical fiber cable 5 can reduce the number of the cables only one, thereby reducing the space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a control device for controlling an industrial robot.

[0002]

2. Description of the Related Art In an industrial robot, since an arm of a robot mechanism moves, a safety fence is provided to surround a rotation range of the robot arm so as not to harm a person by the movement of the robot arm. The robot is operated so that no one enters the safety fence.

[0003] Usually, a control device for controlling the robot is arranged outside the safety fence, and the control device and the robot mechanism,
That is, an actuator such as a servomotor that drives each joint axis of the robot is connected by a cable. Recently, there has been proposed a structure in which the control device is adjacent to or incorporated in the robot mechanism. However, due to maintenance problems such as low maintenance cost, the control device is disposed outside the safety fence. Is more desirable.

[0004]

When the control device of the industrial robot is arranged adjacent to the robot mechanism, it is necessary to enter the safety fence at the time of maintenance and enter the operating range of the robot mechanism, that is, the moving range of the robot arm. There is. In this case, it is inconvenient for maintenance work because of the danger. In addition, when installing a control device outside the safety fence, a connecting cable must be installed between the control device and each axis servomotor of the robot mechanism, which requires space for installing the cable and requires a robot. Installation environment is restricted.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control device for an industrial robot which maintains easy maintenance and does not require a space for installing cables.

[0006]

According to the present invention, a control device for controlling a robot is divided into a high-power section and another control section, and the high-power section is disposed adjacent to or incorporated in the robot mechanism section. The servo amplifier installed in the section is connected by a single optical fiber cable, and the control section can be arranged outside the safety fence, making maintenance and operation easy and reducing the space occupied by the cable. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 is a block diagram showing the outline of the present embodiment. A control device 1 having a built-in control circuit board and the like other than a high-voltage section is provided outside a safety fence 4 surrounding a robot mechanism 2, and a servo amplifier and a power transformer are provided. And the like are arranged adjacent to the robot mechanism 2 or built in the robot mechanism 2. The controller 2 and the servo amplifier 15 are connected by an optical fiber cable 5.

FIG. 2 is a block diagram of the control device 1 and the high-voltage section 3 and a diagram showing the connections thereof. The control device 1 does not include a high-power section such as a servo amplifier and a power supply circuit such as a power transformer for supplying power to the servo amplifier, and includes an interface circuit (LSI) for communication with the high-power section as described later. It has the same configuration as the conventional robot control device except that it is provided. That is, it is composed of a processor for controlling the robot, a memory connected to the processor via a bus, a teaching operation panel, an axis control circuit (digital servo circuit) for feedback-controlling the position and speed of the servomotor of each joint axis, and the like. FIG. 2 shows only this axis control circuit 10. In the conventional control device, a servo amplifier is connected to the axis control circuit 10 and each servo amplifier is driven via a cable connected to the servo amplifier. An interface circuit 11 for communication is connected to 10.

The axis control circuit 10 performs position and speed feedback control based on a movement command distributed from the processor to each axis and a position and speed feedback signal, and outputs a command to the servomotor of each axis. The interface circuit 11 for communication receives this command data,
A parallel / serial converter for converting each command data from a parallel signal to a serial signal; an electric / optical converter for converting an electric signal converted to a serial signal into light and sending it to the optical fiber cable 5;
Optical / electrical converter for converting the position and speed feedback signals fed back through the optical to electrical converter, and converting the serial data to parallel data to convert the axis control circuit 10
And a serial / parallel converter for outputting the data.

The high-power section 3 includes a servo amplifier 15 and a power circuit 14 such as a power transformer for supplying power to the servo amplifier. The servo amplifier 15 includes interface circuits (LSIs) 13a to 13c for communication and motor control circuits 12a to 12c. In the present embodiment, each motor control circuit 12a to 12c of the servo amplifier
Drive control two servo motors respectively. The motor control circuits 12a to 12c include an interface circuit (L
SI) 13a to 13c are respectively connected, the interface circuit 13a is connected to the optical fiber cable 5, and the interface circuits 13a to 13c are electrically connected in a daisy chain system. The motor control circuit 12a in the servo amplifier 15 is connected to the first
Axis, the second axis servo motors M1 and M2, the motor control circuit 12b in the servo amplifier, the third axis and the fourth axis servo motors M3 and M4, and the motor control circuit 1 in the servo amplifier 15
2c controls the driving of the servomotors M5 and M6 for the fifth and sixth axes.

An interface circuit 13a to 13c for communication of the high-power section 3 includes an optical / electrical converter for converting an optical signal of command data transmitted from the control device 1 via the optical fiber cable 5 into an electrical signal. A serial / parallel converter that converts serial data into parallel data, a D / A converter that converts digital signals into analog signals, and signals from position detectors (not shown) attached to the servomotors M1 to M6. , A parallel / serial converter for converting parallel data to serial data for transmitting the data to the axis control circuit 10 of the control device 1 via the optical fiber cable 5, an electric / optical converter for converting an electric signal to an optical signal, and the like. ing.

The axis control circuit 10 of the control device 1 performs feedback based on the amount of movement distributed to each axis and the position and speed feedback signals fed back from the high-power section 3 via the optical fiber cable 5 and the interface circuit 11. Controlled, a command for each axis is generated and passed to the interface circuit 11. The interface circuit 11 converts the command data to each axis from parallel data to serial data, converts the command data into an optical signal, and outputs the optical signal to the optical fiber cable 5.

The interface circuits 13a-1 in the servo amplifier 15 of the high-power section connected in a daisy chain system
3c fetches its own command from the commands sent via the optical fiber cable 5, converts the serial data into parallel data, and further converts the parallel data into analog signals to convert each of the motor control circuits 12a to 12a. 12c, and the motor control circuits 12a to 12c receive the signal and drive the servo motors M1 to M6 of the respective axes.

A feedback signal from a position detector or the like attached to each of the servomotors M1 to M6 is converted into a serial signal in each of the interface circuits 13a to 13c. The converted serial data is sent to the interface circuit 13a by daisy chain connection, converted into an optical signal, sent to the optical fiber cable 5, and sent to the control device 1
The interface circuit 11 converts this signal into an electric signal and a parallel signal, and passes the signal to the axis control circuit 10. The axis control circuit 10 receives the signal and performs the above-described feedback control.

As described above, according to the present invention, the control device 1 and the servo amplifier 15 installed in the high-power section 3 are serially connected at high speed by one optical fiber cable, and the servo motors M1 to M1 are connected.
Since the drive of the M6 is controlled, the number of cables conventionally required to be provided for each axis servomotor can be reduced to one, so that the cable installation space can be reduced.

In the example shown in FIG. 2, an example is shown in which a six-axis robot is controlled. However, if there is an additional axis, another interface circuit is connected to the interface circuit 13c in a daisy chain system. The servo amplifier of the additional axis may be connected to the interface circuit so that the servo motor of the additional axis is driven and controlled by the servo amplifier, and the system can be easily expanded.

When two 6-axis robots are controlled by a controller capable of controlling 12 axes, as shown in FIG.
The control device 1 and the high-power sections 3 and 3 'of each robot may be connected by optical fiber cables 5 and 5', respectively, and the space occupied by the cables may be very small, and the positions of the robot and its peripheral devices may be arranged. Restrictions are reduced.

[0018]

According to the present invention, since the high-power section and the other control sections are separated and high-speed serially connected by an optical fiber cable therebetween, the control section is safe even if the high-power section is adjacent to or built in the robot mechanism. It can be installed outside the solution, and the space occupied by the cable can be reduced. Since the control unit can be arranged outside the safety fence, operation and maintenance of the robot are easy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of an embodiment of the present invention.

FIG. 2 is a block diagram of a control device (control unit) and a high-power unit according to the embodiment, and a diagram showing connections thereof.

FIG. 3 shows a control device capable of controlling 12 axes, which controls two 6-axis robots.
It is a figure showing other embodiments of the present invention which control a stand.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Control apparatus (control part) 2 Robot mechanism part 3 High voltage part 4 Safety fence 5 Optical fiber cable 11, 13a, 13b, 13c Interface circuit for communication 15 Servo amplifier

Claims (2)

[Claims] A control device for controlling a robot is divided into a high-power section and another control section, and the high-power section is disposed adjacent to or built in the robot mechanism section, and a servo amplifier installed in the control section and the high-power section is provided. A control device for an industrial robot, wherein the control device is connected by an optical fiber cable. 2. The industrial amplifier according to claim 2, wherein the servo amplifiers of the high-power section are connected in a daisy-chain system, and the servo amplifier installed in the high-power section and the control section are connected by one optical fiber cable. Robot control device.