JP2800669B2 - Industrial robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting an assembly error of an industrial robot.

[0002]

2. Description of the Related Art FIG. 6 is an explanatory view of a conventional detecting device for detecting an assembly error of an industrial robot disclosed in Japanese Patent Application Laid-Open No. 4-315587. In the figure, reference numeral 1 denotes an industrial robot main body. Reference numeral 3 denotes a traveling base on which the industrial robot main body 1 is mounted and moves along the linear guide 2. Reference numeral 4 denotes a linear guide 2.
Is a control device for controlling the driving of the industrial robot main body 1 and the traveling base 3, and 6 is a display unit for displaying the control status and information of the control device 5. Reference numeral 7 denotes a tow rope attached to the industrial robot main body 1, 8 denotes a spring scale connected to the tow rope 7, and 9 denotes an inspector operating the spring scale 8.

[0003] The inspection apparatus constructed as described above uses a rope 7 attached to the industrial robot body 1 as shown in FIG.
The inspector 9 moves the industrial robot body 1 through the spring balance 8
In the direction of travel. Then, the running resistance of the running base 3 is read from a change in the value of the spring balance 8. By such an inspection, the smoothness of the traveling operation of the industrial robot body 1 is checked, and the installation abnormality of the traveling robot is confirmed.
I am making adjustments.

[0004] By the above-mentioned inspection, the contents of the assembly abnormality can be specifically known as follows. (1) If the arrangement of the linear guide 2 is not horizontal and is downhill along the traction direction, the running resistance is reduced and the traction force of the spring scale is also reduced. (2) If there is a step at which the traveling vehicle rides along the traveling direction at the joint of the linear guide 2, the traveling resistance increases instantaneously, and the traction force of the spring scale instantaneously increases. (3) If the arrangement of the two linear guides 2 is not parallel and becomes narrower in the traveling direction, the running resistance gradually increases, and the traction force of the spring balance also gradually increases. Thus, if there is any abnormality in the assembly of the industrial robot, the running resistance to the running operation of the industrial robot main body 1 fluctuates. By detecting a state in which the movement of the traveling vehicle lacks smoothness due to the fluctuation of the traveling resistance, the presence or absence of an assembly abnormality of the traveling robot has been confirmed.

[0005]

However, such a conventional inspection apparatus for assembling abnormalities of an industrial robot has the following problems. (1) Preparation work such as preparing the tow rope 7 and the spring scale 8 each time and attaching the rope to the industrial robot main body 1 or the traveling base 3 and connecting the spring scale 8 is required, and much time is required. (2) The operation of pulling the robot main body 1 through the spring balance 8 and the operation of reading the scale of the spring balance 8 during the pulling need to be performed simultaneously. (3) A variable value of the spring balance 8 must be read, and in order to reduce a reading error, a sophisticated reading technique by a skilled inspector is required. (4) Since the inspector 9 is towing, the towing speed is not constant, and individual differences between the inspectors are large, making it difficult to absolutely evaluate the inspection result. (5) The towing work by the inspector 9 is performed on the pillow base 4 having a poor scaffold. Moreover, since the eyes of the inspector 9 are concentrated on the scale of the spring scale 8, it is dangerous work.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the detection preparation is simple, the absolute evaluation is continuously performed by automatic measurement, and the assembly abnormality is checked by a safe and reliable inspection work. An object of the present invention is to provide an assembly error detecting device for an industrial robot that can be easily detected.

[0007]

SUMMARY OF THE INVENTION The present invention provides a traveling base on which a main body is mounted, a linear guide for guiding traveling of the traveling base, an output command by comparing the speed of the traveling base with a traveling speed command. An industrial robot comprising: speed control means for outputting a value; driving means for driving the traveling base based on the output command value; and speed detecting means for detecting the traveling speed of the traveling base. A constant output command means for outputting a command value is provided, and when the assembly abnormality is detected, the driving means causes the traveling base to travel based on the constant output command value.

A traveling base on which the main body is mounted; a linear guide for guiding traveling of the traveling base; a position control means for comparing a position command with a position of the traveling base to output a speed command value; In an industrial robot including a driving unit that drives the traveling base based on a speed command value and a current detection unit that detects a driving current of the driving unit, a speed constant command unit that outputs a constant speed command value. The driving means is configured to cause the traveling base to travel on the basis of the constant speed command value when an assembly abnormality is detected.

In addition, the rotary arm includes a rotating arm that rotates around a joint of the main body, and rotation detecting means for detecting a rotation angle of the rotating arm.

[0010] Further, there is provided warning display means for displaying a detection signal of the detection means.

[0011]

According to the present invention, the traveling base is caused to travel at a constant output (torque) value, and the speed of the traveling base varies.
The change of the running resistance of the running base is estimated, and the assembly abnormality is detected. Further, according to the present invention, a change in the running resistance of the running base is measured based on a change in the driving current of the running base driven at a constant speed, and the assembly abnormality is detected. In addition, the present invention releases the brake of the rotating arm during traveling of the traveling base,
The tilt and vibration of the running base are measured by the swing of the rotating arm in the non-drive state, and the assembly abnormality is detected.

[0012]

[Embodiment 1] FIG. 1 is an explanatory diagram showing a configuration of an industrial robot according to one embodiment of the present invention. Parts similar to those in the related art shown in FIG. 6 are denoted by the same reference numerals and description thereof is omitted.
In the figure, reference numeral 10 denotes a motor as a driving means of the traveling base 3. 11 is an encoder connected to the motor 10,
Reference numeral 12 denotes a pinion gear connected to the motor 10. 1
3 is a rack gear meshed with the pinion gear 12,
It is fixed to the bed 4. 5a is the industrial robot body 1
And a control device that controls driving of the traveling base 3 and performs detection control of the assembly abnormality detection device of the present invention.

Reference numeral 14 denotes a current detector attached to the control device 5a, and detects a drive current of the motor 10. 6a
Displays the control status and information of the control device 5a,
It is a display unit for displaying a detection result of the assembly abnormality detection device. Reference numeral 15 denotes a rotating arm having one end attached to a support portion of the industrial robot main body 1. A rotary arm 16 is rotatably attached to the other end of the rotary arm 15 via a motor 18 with a brake, and an encoder 19 as a rotation detector is mounted on the motor 18. Reference numeral 17 denotes a jig attached to the tip of the rotating arm 16.

FIG. 2 is an explanatory diagram of the industrial robot and the assembly abnormality detecting means configured as described above. 21 in the figure
Is a position commander that indicates a predetermined position when the traveling base 3 is operated. The position signal output from the position command device 21 is input to the position controller 22. The position controller 22 controls the position signal and the encoder 1 of the traveling base 3.
1 and outputs a moving speed command to the speed controller 23.
Output to The speed controller 23 calculates the travel base 3 calculated by the speed signal converter 25 based on the output of the encoder 11.
Is compared with the moving speed command to output an output (torque) command value. The output (torque) command value of the speed controller 23 is input to the current controller 24 via the changeover switch 27. This changeover switch 27
Is configured to select either the output (torque) command value of the speed controller 23 or the command value of the constant output (torque) command device 26 and output the same to the current control 24.

One of the output (torque) command values switched by the changeover switch 27 is supplied to the current controller 24.
, The current controller 24 calculates and outputs a drive current for rotating the drive motor 10. When the drive motor 10 is driven to cause the travel base 3 to travel along the linear guide 2, travel resistance 28 is generated, which affects the travel of the travel base 3, and the amount of travel is detected by the encoder 11. Output of encoder 11 and speed signal converter 2
The speed signal of the traveling base 3 which is the output of 5 is input to the assembly abnormality calculator 29. The calculation result of the assembly abnormality calculator 29 is displayed on the display unit 6a shown in FIG.

FIG. 3 shows an example of a display screen 6a1 of the display unit 6a. The vertical axis indicates the traveling speed of the traveling base 3, and the horizontal axis indicates the position of the traveling base 3. In the figure 41
Represents the output of the speed signal converter 25 when the traveling base 3 travels at a constant output (torque), that is, a change in the speed of the traveling base 3. Reference numeral 42 denotes a display line indicating a value at which a warning is issued when the fluctuating speed value 41 of the traveling base 3 exceeds a predetermined value. Reference numeral 43 denotes a display line that issues an alarm when the fluctuating speed value 41 falls below this value. Reference numeral 44 indicates a section in which an alarm is issued in accordance with the position of the traveling base 3.

The industrial robot assembly abnormality detecting device having the above-mentioned structure operates as follows. In the explanatory diagram of the control means and the detection means of the assembly abnormality detecting device of FIG. 2, when the changeover switch 27 is connected to the speed controller side A during normal use as an industrial robot, the output of the position commander 21 is reduced. The output of the encoder 11 is compared and calculated by the position controller 22 to perform position feedback. Then, based on the output of the encoder 11, the speed controller 23 compares and calculates the speed conversion value of the traveling base 3 which is the output of the speed signal converter 25 and the moving speed command which is the output of the position controller 22, by the speed controller 23. Is performed. Also, the output of the current detector 14 and the output command value which is the output of the speed controller 23 are
The current feedback for the comparison operation is performed. In this way,
So-called feedback control is performed.

When inspecting an assembling abnormality of the industrial robot, by connecting the changeover switch 27 to the current controller 24 side B, a constant output (torque) based on the command value from the commander 26 is output. To drive the motor 10. At this time, the position feedback and the speed feedback are switched, are cut off by the switch 27 and become invalid, and only the current feedback becomes valid.

If the running resistance 28 fluctuates due to some abnormality, the disturbance will occur to the drive motor 10 and the rotation speed of the motor fluctuates. As a result, the output of the encoder 11 fluctuates. The fluctuation is directly input to the assembly abnormality calculator 29. Then, the variable speed signal input to the speed signal converter 25 is input to the assembly abnormality calculator 29. The assembling abnormality calculator 29 displays the speed variation corresponding to the position of the traveling unit on the display unit 6a in the form of a graph as shown by 41 in FIG. 3, and displays the upper limit value 42 or the lower limit value at which this speed does not generate an alarm. It is determined whether or not the position exceeds 43, and as a result, the position where the position has exceeded is displayed as a warning section 44 on the display unit 6a. The assembly resistance of the industrial robot can be recognized from the running resistance of the running base 3.

Embodiment 2 FIG. FIG. 4 is an explanatory diagram showing control means and assembly abnormality detection means of an industrial robot according to another embodiment of the present invention. 3 in the figure
1 is a constant speed commander for generating a constant speed command value, 3
Reference numeral 2 denotes a switch for switching between the output of the constant speed command device 31 and the output of the position controller 22. 3a2 in FIG. 3 is an example of a display screen of the display unit 6a, in which the output of the current detector 14 is shown on the vertical axis, and the position of the traveling base 3 is shown on the horizontal axis. In the drawing, reference numeral 45 denotes a value detected by the current detector 14 for the drive current of the motor 10 that drives the traveling base 3 at a constant speed, that is, a change in the motor drive current. Reference numeral 46 denotes a display line indicating a value when the fluctuating current value 45 exceeds this value and issues an alarm. 47 is the fluctuating current value 4
Reference numeral 5 is a display line indicating a value when an alarm is issued below this value. Reference numeral 48 denotes a section in which an alarm is issued in accordance with the position of the traveling base 3.

The industrial robot assembly abnormality detecting device thus configured operates as follows. As shown in FIG. 4, during normal use as an industrial robot, the changeover switch 32 is connected to the position controller side A in the figure, and has the same configuration as in the first embodiment, and performs feedback control.

When inspecting an assembly error as an industrial robot, first, the changeover switch 32 is set to the speed controller side B.
, The position feedback control is invalidated, and the motor 10 is driven at a constant speed while utilizing the speed feedback control and the current feedback control based on the command value from the constant speed command device 31.

Therefore, when the assembly abnormality is detected, the output of the encoder 11 decreases when the speed of the traveling base 3 decreases due to, for example, an increase in the traveling resistance 28 of the traveling base 3, but the output which is the output of the speed controller 23 due to the speed feedback. The (torque) command value is increased, the drive current of the drive motor 10 is increased by the current controller 24, and the output of the drive motor 10 is increased to maintain a constant speed. When the running resistance of the running base 3 is reduced and the speed is increased, the above devices operate in the opposite manner, reduce the drive current of the drive motor 10, lower the motor output, and maintain a constant speed. At this time, since the speed feedback control is effective, the change following the change is fast, and the change in the drive current is steep.

Here, with respect to the assembly abnormality detector 29, the fluctuation of the current value detected by the current
1 as well as displaying on the display unit 6a the change in the drive current corresponding to the position of the traveling unit as a change 45 in the motor drive current in FIG. 3, and this drive current does not give an alarm. It is determined whether the upper limit 46 or the lower limit 47 is not exceeded. As a result, if it exceeds, the position is displayed on the display unit 6a as an alarm section 48. In this manner, the state of the traveling resistance of the traveling base 3, that is, the assembly abnormality of the industrial robot and the position information can be recognized.

Embodiment 3 FIG. FIG. 5 is an explanatory view showing another embodiment of the control means and the assembly abnormality detecting means of the industrial robot. In the figure, reference numeral 33 denotes a rotary arm drive controller for controlling the drive of the rotary arm 16; 34, a switch for releasing a circuit for driving the rotary motor 18; 35, a rotary arm brake release commander;
A brake 37 connected to the brake arm 8 and released by the rotary arm brake release commander 35 indicates a state of a swing generated on the rotary arm as the traveling base 3 travels.

The industrial robot thus configured is
It works as follows. As shown in FIG. 5, during normal use as an industrial robot, by turning on a changeover switch 34, a rotating arm drive controller 33 operates according to a rotating arm rotation command (not shown), and a rotating arm brake release command. Only after the brake 36 is released by the command of the device 35, the rotary motor starts rotating. And encoder 1
In step 9, the rotation angle is fed back to the rotation arm drive controller 33 to rotate the rotation arm to a predetermined rotation position.

When inspecting an assembly error as an industrial robot, first, the switch 34 is opened, the rotary arm driving rotary motor 18 is turned off, and then the rotary arm brake 36 of the rotary arm is turned on by the rotary arm brake release commander 35. Is released so that the rotating arm 16 can rotate. The traveling base is normally installed together with the linear guide 2 so as to be horizontal. However, if the traveling base is inclined due to an abnormality in assembly or the like, the industrial robot main body 1 is inclined. Therefore, the weight of the jig 7 attached to the tip of the rotating arm 16 causes the rotating arm to rotate such that the tip of the rotating arm is at the lowest point.

The state in which the rotating arm rotates due to the weight of the rotating arm itself or the weight of the jig at the tip due to the inclination of the robot body,
The change is considered as a change in the output of the encoder 19 of the rotating arm.
The amount of change in the output and the output of the encoder 11 of the traveling base 3 are input to the assembly abnormality detector 29.
The amount of change in rotation of the rotating arm corresponding to the position of the traveling unit is displayed in a graph. As a result, it is possible to recognize the tilt state of the robot main body, that is, the assembly abnormality of the industrial robot and its positional information, as in the above embodiment.

When the traveling unit is driven at a constant output in the same manner as in the first embodiment, the speed of the traveling unit changes when the assembly is abnormal, and this acts on the rotating arm or the jig at the tip as acceleration to rotate the rotating arm. When this change is detected by the encoder and displayed on the display unit, it is possible to recognize the assembly error of the industrial robot and the position information as in the above embodiment.

Embodiment 4 FIG. FIG. 3 is an example of a display screen of the display unit 6a. As shown in the first and second embodiments, the measured values are aligned vertically with the position of the horizontal axis of the screen as the position of the traveling unit 3 as shown in FIG. This is a plurality of images displayed in two rows. Reference numeral 49 denotes a cursor for reading a measured value, which corresponds to the position of the traveling base 3. 51 is a numerical value indicating the position of the traveling base 3;
2 indicates the speed 41 at the cursor position, and 53 indicates the current at the cursor position. Incidentally, regarding the function of the cursor 49,
It is generally the same as that used in an oscilloscope or the like. Further, the display of arrows from a to c in the figure indicates a specific position of the traveling base.

The display unit of the industrial robot assembly abnormality detecting device having the above-described structure has the following effects. As shown in FIG. 3, for the positions A, B, and C of the traveling base 3, a speed decrease exceeding the lower limit value 43 or a sudden increase in the current value exceeding the upper limit value 46 is observed, and a warning display 44 is provided. 48 are displayed. Therefore, in these places, there is an abnormality in which the traveling resistance of the traveling base 3 increases for some reason, which indicates that the industrial robot needs to be adjusted for some assembly abnormality.

Further, in the figure, at the position of the traveling base 3 corresponding to d, the speed gradually increases, and the driving current has a substantially constant low value. In such a case, as an example, it can be seen that the linear guide 2 has a downward slope in the traveling direction in the changing section. That is, it is presumed that, because of the downhill slope having a constant slope, the speed increased at a constant acceleration at a speed, and the drive current became a substantially constant small value.

In this case, the warning display 44 is not displayed for the speed fluctuation, but the warning display 48 is displayed for the drive current. By juxtaposing a plurality of data in this way, the situation and degree of the abnormality can be easily determined. It can be judged by evaluation. In addition, when the position of the cursor and the displayed measured value are displayed as 51, 52, and 53 on the display screen, specific numerical values can be known.

As the industrial robot, not only the robot body and the traveling base separated from each other as described above, but also various shapes and configurations can be used. Needless to say, the assembly abnormality detecting device of the present invention can be applied to an industrial robot having a detector and a driving means.

[0035]

According to the industrial robot according to the present invention, the control device used for normal operation of the industrial robot incorporates the equipment used for detecting the assembly abnormality, so that the preparation for detection is simple. It has a remarkable effect such that the absolute evaluation is continuously performed by the automatic measurement and the assembly abnormality can be easily detected by the safe and reliable inspection work.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an industrial robot according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing control means and assembly abnormality detection means of the industrial robot of the embodiment of FIG.

FIG. 3 is an explanatory diagram of a display screen according to the first embodiment.

FIG. 4 is an explanatory diagram illustrating a control unit and an assembly abnormality detection unit of the industrial robot according to the second embodiment.

FIG. 5 is an explanatory diagram illustrating a control unit and an assembly abnormality detection unit of an industrial robot according to a third embodiment.

FIG. 6 is an explanatory diagram of a conventional detection device for detecting an assembly error of an industrial robot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Industrial robot main body 3 Travel base 5 Industrial robot control device 6 Display unit 11 Encoder 14 Current detector 26 Output constant commander 27/32/34 Changeover switch 29 Assembly abnormality calculator 31 Constant speed commander 41/45 Graph 44 ・ 48 Warning display

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B25J 5/02 B25J 19/06 B25J 13/00

Claims (4)

(57) [Claims] 1. A traveling base on which a main body is mounted, a linear guide for guiding traveling of the traveling base, and speed control means for comparing a speed of the traveling base with a traveling speed command to output an output command value. In an industrial robot including a driving unit that drives the traveling base based on the output command value and a speed detection unit that detects a traveling speed of the traveling base, an output constant command that outputs a constant output command value Means for driving the traveling base on the basis of the constant output command value when the assembly abnormality is detected. 2. A travel base on which a main body is mounted, a linear guide for guiding travel of the travel base, position control means for comparing a position command with a position of the travel base and outputting a speed command value; In an industrial robot including a driving unit that drives the traveling base based on a speed command value and a current detection unit that detects a driving current of the driving unit, a speed constant command unit that outputs a constant speed command value. The industrial robot according to claim 1, wherein the drive unit causes the traveling base to travel based on the constant speed command value when an assembly abnormality is detected. 3. The industrial device according to claim 1, further comprising a rotating arm that rotates around a joint of the main body and a rotation detecting unit that detects a rotation angle of the rotating arm. For robots. 4. The industrial robot according to claim 1, further comprising warning display means for displaying a detection signal of the detection means.