JPS62107308A - Speed limiting device for robot - Google Patents

Abstract

PURPOSE:To prevent a runaway, etc., at the time of an abnormality by controlling a supply voltage to a driving system of a robot by switching a tap of a transformer, executing a speed limit, coping with the case when a work at a low speed is necessary, such as at the time of a teaching operation, etc., and also providing a voltage monitor device so that an interlock is applied at the time of an abnormality. CONSTITUTION:When an operation mode setting device 2 of a robot is in a low speed mode 3, a switch 12 is switched to a low voltage tap 11 by a speed selecting switch 1, a secondary side output of a transformer 9 is set to a low voltage and rectified by a rectifier 13, and thereafter, supplied to a driving system 15. At the same time, a switch 4 of the mode setting device 2 is closed. Also, an output voltage of the rectifier 13 is monitored by a voltage monitor device 14, and in case of the low speed mode 3, when a supply voltage to the driving system 15 corresponding to this mode has been detected, a switch 6 of the mode setting device 2 is also closed thereby. When an abnormality exists in a tap changeover switch 12 or the rectifier 13, etc., an abnormal voltage is detected by the voltage monitor device 14, a permitting device 7 is set to an inhibited state by opening a switch 6, a switch 16 is set to a cut-off state, and a runaway is prevented by applying an interlock.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a control device for an industrial robot, and in particular, when a worker works close to the robot, the operating speed is limited to a low speed so that the worker can control the robot. The present invention relates to a robot speed limiting device suitable for ensuring safety.

[Background of the invention]

Conventional speed limiting devices for manual operation of industrial robots include, for example, inserting a resistor to lower the motor's armature voltage to reduce the speed, and at high speeds, close the switch contacts to short-circuit the resistor. A method was adopted. However, such conventional devices have a problem in that sufficient consideration is not given to the safety of workers.

[Purpose of the invention]

The purpose of the present invention is to ensure safety for workers by slowing down the robot's operating speed by manual operation when the worker approaches the robot's operating area for purposes such as teaching a boat. Our goal is to provide you with the reliable robot speed limiting device you need.

[Summary of the invention]

The present invention provides a simple structure and operating method using parts that are as reliable as possible, since ensuring the safety of robot workers greatly depends on the reliability of the control device itself, the usage procedure, and the method of handling abnormalities. Focusing on the need to apply an interlock, we controlled the supply voltage to the robot's drive system by changing the taps of the transformer to limit the speed, and when low-speed work is required such as when teaching the robot. In addition to dealing with this, the supply voltage to the drive and system is
In order to deal with abnormalities in the transformer tap changeover switch and rectifier used to obtain the output from the rectified output on the next side, a voltage monitoring device is installed and a busy interlock is applied in the event of an abnormality to prevent runaway operation in the event of an abnormality. This is a speed limiter for robots that ensures safety for workers.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram showing an embodiment of a speed limiting device for a robot according to the present invention. In Fig. 1, 1 is a speed selection switch (speed changeover switch), 2 is a mode setting device (mode selector), 3 is a low speed mode, 4, 5.6
is a switch, 7 is a permission device, 8 is a drive command value generator, 9
is a transformer, 10 is a high voltage tap, 11 is a low voltage tap, 12 is a tap changeover switch, and 15 is a rectifier.

14 is a rectifier, 15 is a drive system, and 16 is a switch.

6 The device of FIG. 1 has a speed selection switch 1, by means of which a tap changeover switch 12 is switched. The robot operating mode setting device 2 has a low speed mode S, etc., and is composed of switches 4, 5.6 and a permission device 7 that operates when all of these are closed. A drive command value generator 8 provides a command value to a drive system 15 of the robot. The secondary side of the transformer 9 has a tap that can be switched from a high voltage tap 10 to a low voltage tap 11, and is configured to supply voltage to the drive system 15 via a rectifier 15 that rectifies the secondary side output of the transformer 9. It is. It also includes a voltage monitoring device 14 that detects the voltage supplied to the drive system 15, and further includes a switch 16 that cuts off the voltage supplied to the drive system 15.

With this configuration, if the robot operation mode setting device 2 is currently set to low speed mode 5 such as robot teaching,
Switch 5 closes. Next, in the case of such low speed mode 5, the speed is constant.

The selection switch 1 switches the switch 12 to the low voltage tap 11, and the secondary output of the transformer 90 is made into a low voltage, rectified by the rectifier 15, and then supplied to the drive system 15. At the same time, the switch 4 of the mode setter 2 is closed based on the low speed switching information from the speed selection switch 1. Further, the rectifier ISO output voltage is monitored by the voltage monitoring device 14,
In the case of low speed mode 5, when the corresponding supply voltage to the drive system 15 is detected, the trap closes the switch 6 of the mode setting device 2. When the switches A and 5.6 of the mode setting device 2 are closed as described above, the permission device 7
operates and enters the permission state, closes the switch 16 and supplies the output voltage of the rectifier 15 to the drive system 15. Here, the output of the drive system 15 is obtained by supplying the command value from the command value generator 8 to the drive system 15, and since it is currently the low speed mode 5, the output of the drive system 15 becomes the output of the low speed mode 5. A low speed movement of the robot is performed.

Here, even if the operation mode setting device 2 of the robot is in low speed mode 5 and the switching information of the speed selection switch 1 is low speed, if there is an abnormality in the tap changeover switch 12 or the rectifier 15, etc. Without the device 14, there is a risk that abnormal voltage will be supplied to the drive system 15 and the robot will continue to operate abnormally, resulting in a runaway operation.
By providing a voltage monitoring device 14, when an abnormal voltage is detected from K, the switch 6 is opened, the permission device 7 is inhibited, and the switch 16 is cut off, thereby applying a constant interlock to prevent runaway. can. Furthermore, when the mode setter 2 is in low speed mode 5, the supply voltage to the drive system 15 is controlled to a low voltage by changing the tap of the speed selection switch 1, and an abnormality occurs in the drive command value generator 80 command value. In some cases, the robot's movements can be slowed down.

FIG. 2 is a block diagram showing another embodiment of the speed limiting device for a robot according to the present invention.

In FIG. 2, the same symbols as in FIG. 1 indicate the same parts,
17 is a switch. The difference between the device shown in FIG. 2 and the device shown in FIG. 1 is that in FIG. In FIG. 2, the command value from the command value generator 8 is cut off by the switch 17, thereby preventing an abnormality in the supply voltage to the drive system 15.

In the embodiments shown in FIGS. 1 and 2, the transformer 9, rectifier 15, etc. are single-phase, but they can also be implemented in a multi-phase, such as five-phase, configuration.

As described above, according to this embodiment, firstly, the voltage supplied to the drive system is controlled by changing the taps of the transformer, so it is mechanical and highly reliable. Second, since power is directly supplied to the drive system from the power supply, there are very few defects due to component failure, and reliability is improved. Fifth, it has a means to detect the voltage supplied to the drive system by changing the tap of the transformer, which makes it possible to cut off the output from the drive system in the event of an abnormality, and functions as a protection system in the event of an abnormality. This has the effect of ensuring the reliability and safety of the control device.

〔Effect of the invention〕

As described above, according to the robot speed limiting device of the present invention, when an operator works close to the robot, the robot's operating speed is reliably limited to a low speed to prevent the robot from running out of control. This has the effect of ensuring safety for users and increasing reliability.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of the speed limiter for a robot according to the present invention, and Fig. 2 is a block diagram showing another embodiment of the robot speed limiter according to the present invention. switch) 2...Mode setting device, 5...
・Low speed mode, to 4 6... switch, 7... permission device, 8... command value generator, 9... transformer, 10 high voltage tap, 11... low voltage tap, 12... - Tap changeover switch, 15... Rectifier, 14... Voltage monitoring device, 15... Drive system, j6.17... Switch.

Claims (1)

[Claims] 1. A speed changeover switch is provided, and the speed changeover switch switches the tap of the power transformer to control the voltage supplied to the drive system of the robot, thereby controlling the drive system according to the drive command value output. A means for controlling the output and a voltage monitoring device for detecting the voltage supplied to the drive system are provided, and detection information of the voltage monitoring device, switching information of the speed changeover switch, and information on the robot's operation mode including a low speed mode are provided. A speed limiting device for a robot, comprising means for interlocking the operation of the drive system accordingly. 2. When the operation mode of the robot is in a low-speed mode such as teaching mode, the speed changeover switch switches the tap of the power transformer to forcibly limit the maximum output of the drive system, thereby reducing the drive command value output. 2. The speed limiting device for a robot according to claim 1, which limits the maximum speed to a low speed range when an abnormality occurs in the robot.