JPS6224306A - Self-diagnosis device for industrial robot - Google Patents

Abstract

PURPOSE:To detect the overrun direction with a simple constitution by fetching the output of a direction discriminator with the double phase signal given from a rotary encoder for detection of arm position and then fetching the output of the direction discriminator to a storage device with the signal given from a single overrun sensor. CONSTITUTION:The output of a rotary encoder 2 changes as shown in the diagrams into the right or left rotations by the double phase signals (A and B phases). These double phase signals are supplied to a direction discriminator 11. Then a direction signal 12 of one or zero showing the right or left rotation of the A-phase signal is delivered to a D type FF 13 with the rise timing of the B-phase signal. Under such conditions, an overrun signal 16 is supplied to a clock input terminal CK of the FF 13 serving as a storage device from an overrun sensor 6. While a direction signal 14 showing the rotating direction is delivered onto a data bus from an output terminal Q. Thus it is possible to know simply the overrun direction with reference to the information on the FF 13 even after the drive of a motor 1 is stopped with an emergency stop applied by an overrun phenomenon.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a self-diagnosis device for an industrial robot, and more specifically, a device for detecting in which direction the arm of the robot overruns. The present invention relates to a self-diagnosis device for industrial robots.

<Prior Art> Fig. 6.7 shows a conventional self-diagnosis device for an industrial robot, in which a reducer 3, a motor l, and a rotary encoder 2 are connected to a column or arm 4. An arm 5 is connected to the power transmission shaft 21, and the motor 1
By driving the arm 5, the arm 5 is driven via the speed reducer 3. The amount of movement at that time is detected and controlled by the rotary encoder 2. A right overrun sensor 6 for detecting that the arm 5 has moved out of the operating range on the right side in FIG. A left overrun sensor 8 that detects movement outside the operating range and its detection object 9 are provided on the arm 4 side and the arm 5 side, respectively, and the overrun sensor 6.8 and the detection object 7.9 are connected to each other. The positions of each are detected by facing each other.

And when overrun sensor 6.8 turns on,
Stop motor l to protect other machines from destruction.

However, since the conventional self-diagnosis device described above uses two overrun sensors 6.8, there is a problem that the reliability of the overrun sensor 6.8 as a whole deteriorates.
A problem arises in that the number of signal lines increases, and furthermore, there are two locations for installing the overrun sensors 6 and 8.

Therefore, as shown in FIGS. 8 and 9, a self-diagnosis device for industrial robots using only one overrun sensor has been proposed. The self-diagnosis device shown in FIG.
overrun sensors 6 and a semicircular detection object 10, the overrun sensor 6 has a detection object 10.
Left and right overruns are detected when the ends A and B of the two sides are opposed to each other. The self-diagnosis device shown in FIG. 9 includes one overrun sensor 6 and two detection objects 7.
9 is provided, and the overrun sensor 6 and the detection object 7.9 are provided.
By facing each other, left and right overruns are detected.

However, as shown in FIGS. 8 and 9 above, when one overrun sensor 6 is used to detect left and right overruns, it is difficult to identify which side the arm 5 has overrun, left or right. The problem is that it can't be done. Therefore, when there is an emergency stop due to overrun, it is impossible to determine in which direction the arm 5 should be turned to return, and there is a problem that automatic return cannot be performed.

<Object of the Invention> Therefore, an object of the present invention is to provide a self-diagnosis device for an industrial robot that can detect in which direction an overrun occurs using a single overrun sensor.

<Configuration of the Invention> In order to achieve the above object, the self-diagnosis device for an industrial robot of the present invention includes a motor that drives an arm, a rotary encoder that outputs a two-phase signal for detecting the position of the arm, and a rotary encoder that outputs a two-phase signal for detecting the position of the arm. one overrun sensor that detects when the motor has moved out of the operating range, a direction discriminator that determines the rotational direction of the motor based on the two-phase signal from the rotary encoder, and the output of the direction discriminator from the overrun sensor. and a storage device that captures data based on the signal of
The present invention is characterized in that the direction in which the arm overruns is detected is detected based on the output of the direction discriminator stored in the storage device.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a plan view of the above embodiment, where 2 is a phase 2 consisting of A phase and B phase for detecting the relative rotational position of the arm 5. A rotary encoder that outputs a phase signal, 6 is an overrun sensor that detects end A or B of the detection object 10 and turns on even when the arm overruns to the left or right, summer 1 is the rotary encoder a direction discriminator 13 that discriminates the rotational direction of the arm 5 based on the two-phase signal from the encoder 2;
is the direction discriminator l! A storage device that captures the direction signal I2 representing the rotational direction output from the overrun sensor 6 as the signal 16 from the overrun sensor 6. 5 is a storage device 13 and a data bus 14
This is an arithmetic unit that is connected to the arm 5 by a microcomputer 15 for controlling the motor l that rotates the arm 5 and for self-diagnosis.

The rotary encoder 2, as shown in FIG.
Detects whether the arm 5 is rotating clockwise or counterclockwise by outputting two-phase signals of A phase and B phase and checking whether the A phase is "L" or "0" at the rising timing of the B phase signal. As shown in FIG. B to terminal CK
The A-phase signal is input to the data input terminal, and therefore, the value at the output terminal Q of the D-type Furinobufu [1 tube 17] is a direction signal representing instantaneous left or right rotation. This direction signal is given a certain time constant by a resistor R and a capacitor C, and an amplifier 18 having a high input impedance is interposed to remove noise components and the like.

The storage device I3 is composed of a D type flip-flop as shown in FIG. 4, and has a clock input terminal C.
Input signal 16 from overrun sensor ~6 to K,
Direction signal 12 from direction discriminator II to data input terminal
is being entered.

In the above configuration, the output of rotary encoder 2 is A
When the arm 5 is rotated to the left or right using two-phase signals of phase and B phase, it becomes as shown in FIG. 3. This two-phase signal is input to the direction discriminator 11, and the direction discriminator 11 determines whether the A-phase signal is "bi" or "0" at the rising timing of the B-phase signal, that is, clockwise rotation or counterclockwise rotation. A direction signal 12 of "bi" or "0" representing the direction is output to the D type flip-flop 13. This direction signal 12 represents the rotational direction of the arm 5 at that time, and changes from moment to moment. In this state, the overrun signal 16 is input from the overrun sensor 6 to the clock input terminal CK of the D-type flip-flop 13, which is the storage device.
As shown in the time chart of FIG. 5, a direction signal I4 indicating the rotation direction when the overrun signal 16 is input is outputted from the output terminal Q onto the data bus.

In this way, even after the motor 1 is stopped due to an emergency stop due to an overrun, the direction of the overrun can be easily known by referring to the information in the D type flip-flop 13.

In this embodiment, the direction discriminator 11 and the storage device I3 have D.
Although a type flip-flop was used, similar results can be obtained using other types of flip-flops. Furthermore, although the storage device 13 is configured with hardware, if the microcomputer 15 has sufficient space,
It can also be processed using software. Further, the number of detection objects 7 detected by the overrun sensor 6 may be two per Ig.

<Effects of the Invention> As is clear from the above, according to the present invention, the output of the direction discriminator that discriminates the rotational direction of the motor based on the two-phase signal from the rotary encoder for detecting the position of the arm is
Since the signal from one overrun sensor is imported into the storage device, by referring to the information in the storage device, the reliability can be increased using the t@ overrun sensor, and with a simple configuration, Overrun direction can be detected.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a plan view of the overrun detection section of the above embodiment, Fig. 3 is a waveform diagram of a two-phase signal of the rotary encoder, and Fig. 4 is a direction determination diagram. FIG.
Figure 6 is a front view showing the overrun detection section of the arm of a conventional robot; Figure 7 is a view of Figure 6 seen from above; Figures 8 and 9 are overrun detection parts. FIG. 4 is a plan view of each detection unit. l...Motor, 2...Rotary encoder,
4.5...Arm, e, tail:-Overrun sensor, 11...Direction discriminator, 13...Storage device.

Claims (1)

[Claims] (1) In an industrial robot equipped with an arm, a motor that drives the arm, and a rotary encoder that outputs a two-phase signal for detecting the position of the arm, detecting that the arm has moved out of the operating range. comprising one overrun sensor, a direction discriminator that determines the rotational direction of the motor based on the two-phase signal of the rotary encoder, and a storage device that captures the output of the direction discriminator based on the signal from the overrun sensor, A self-diagnosis device for an industrial robot, characterized in that the direction in which the arm overruns is detected is detected based on the output of the direction discriminator stored in the storage device.