Burr removal control device and burr removal system

Abstract

Provided is a burr removal control device capable of easily determining a cause of burr removal failure. A burr removal control device according to an embodiment of the present disclosure controls burr removal processing in which a burr of a work is removed by moving a burr removal tool along a ridge line of the work by a robot, the burr removal control device including: a deviation amount calculation section that calculates a deviation amount between an actual trajectory of the robot and a taught trajectory; a pressing force acquisition section that acquires a pressing force of the burr removal tool; a rotational speed acquisition section that acquires a rotational speed of the burr removal tool; a failure detection section that detects burr removal failure in which the burr removal processing is not properly performed, based on the deviation amount, the pressing force, and the rotational speed; and a recording section that records, when the burr removal failure is detected, a failure reason that is a reason for the burr removal failure judged by the failure detection section.

Description

TECHNICAL FIELD

[0001] The present application relates to a burr removal control device and a burr removal system. BACKGROUND

[0002] A system that performs burr removal processing of a work by moving a tool along an edge line of the work by a robot is known. In such a system, sometimes burr removal processing cannot be normally performed for some reason.

[0003] Therefore, a technique that detects overload of a burr removal tool by mounting a force sensor or the like to a robot, and stops movement of the burr removal tool is known. Also, a scheme that retreats the burr removal tool in a direction in which the overload is reduced after stopping the burr removal tool is proposed (for example, refer to Patent Literature 1).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 9-11079 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] Burr removal failure can occur in various conditions such as a case where a burr removal tool cannot accurately move along a work, a case where the burr removal tool generates a chatter vibration, and the like. Therefore, in a case where the system automatically stops burr removal processing and retreats the burr removal tool, it can become difficult to restart the burr removal processing without determining a cause of the overload. Therefore, it is desirable to be able to easily determine a cause of generation of burr removal failure.

[0009] SOLUTION TO THE PROBLEM

[0010] A burr removal control device according to one embodiment of the present disclosure controls burr removal processing in which a burr of a work is removed by moving a burr removal tool along an edge line of the work by a robot, and includes: a deviation amount calculation section that calculates a deviation amount between an actual trajectory of the robot and a taught trajectory; a pressing force acquisition section that acquires a pressing force of the burr removal tool; a rotation speed acquisition section that acquires a rotation speed of the burr removal tool; a failure detection section that detects burr removal failure in which the burr removal processing cannot be properly performed, on the basis of the deviation amount, the pressing force, and the rotation speed; and a recording section that records a failure reason in which the burr removal failure is judged by the failure detection section, when the burr removal failure is detected.

[0011] EFFECT OF THE INVENTION

[0012] The burr removal control device and the burr removal system according to one embodiment of the present disclosure can easily determine the cause of burr removal failure. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic view showing the structure of a burr removal system according to one embodiment of the present disclosure.

[0014] Figure 2 is a schematic view illustrating one mode of burr removal failure detection by a burr removal control device according to Figure 1

[0015] Figure 3 is a chart illustrating another mode of burr removal failure detection by a burr removal control device according to Figure 1

[0016] Figure 4 is a chart illustrating another other mode of burr removal failure detection by a burr removal control device according to Figure 1 DETAILED DESCRIPTION

[0017] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Figure 1 is a schematic view showing the structure of a burr removal system 1 according to one embodiment of the present disclosure. The burr removal system 1 is a system that performs burr removal processing of a workpiece W.

[0018] The burr removal system 1 of the present embodiment is provided with a robot 2, a burr removal tool 3 held at the front end portion of the robot 2, a force / torque sensor 4 provided between the robot 2 and the burr removal tool 3, a rotational speed detector 5 for detecting the rotational speed of the burr removal tool 3, and a burr removal control device 6 for controlling the robot 2.

[0019] As the robot 2, a vertical multi-joint robot is typically used, but is not particularly limited, and for example, a horizontal joint robot, a parallel link robot, a Cartesian robot, or the like can also be used.

[0020] As the burr removal tool 3, for example, a sander, a reamer, or the like can be used. In addition, the shape of the burr removal tool 3 can be appropriately selected, for example, a cylindrical shape, a conical shape, or the like.

[0021] The force / torque sensor 4 is a sensor that measures the force and torque of three axes. That is, the force / torque sensor 4 can detect the force acting on the burr removal tool 3 as a three-dimensional vector. By using such a force / torque sensor 4, the force acting on the burr removal tool 3 in various directions can be accurately confirmed.

[0022] ​​​As the rotation speed detector 5, for example, a rotary encoder or the like configured to a rotation shaft of the burr removing tool 3 or a rotation shaft of a driving system that drives the burr removing tool 3 can be used.

[0023] The burr removing control device 6 controls burr removing processing in which a burr of the workpiece W is removed by moving the burr removing tool 3 along an edge line of the workpiece W by the robot 2. The burr removing control device 6 according to the present embodiment is provided with a robot control section 11, a processing position acquisition section 12, a deviation amount calculation section 13, a pressing force acquisition section 14, a rotation speed acquisition section 15, a defect detection section 16, a defective position determination section 17, a recording section 18, an interruption control section 19, and a restart control section 20.

[0024] The burr removing control device 6 can be realized by introducing an appropriate control program to one or a plurality of computer devices having a CPU, a memory, and the like. The respective constituent elements of the burr removing control device 6 described above are obtained by classifying the functions of the burr removing control device 6, and can not be elements that can be clearly distinguished in physical configuration and program configuration. In addition, the burr removing control device 6 can have other constituent elements that realize other functions.

[0025] The robot control section 11 moves the burr removing tool 3 along an edge line of the workpiece W by causing the robot 2 to act in accordance with the teaching data.

[0026] The processing position acquisition section 12 acquires data of an actual position of the burr removing tool 3 at every certain time, that is, an actual trajectory of the burr removing tool 3. The position of the burr removing tool 3 can be calculated on the basis of feedback data indicating an actual position of a driving shaft of the robot 2.

[0027] The deviation amount calculation section 13 calculates a deviation amount between the actual trajectory of the burr removing tool 3 and the taught trajectory. As an example, the deviation amount calculation section 13 can be configured to calculate a separation distance between a position of the burr removing tool 3 in accordance with the teaching data of the robot 2 and the actual position acquired by the processing position acquisition section 12 at every certain time.

[0028] The pressing force acquisition section 14 acquires a pressing force of the burr removing tool 3 against the workpiece W. The pressing force acquired by the pressing force acquisition section 14 is preferably vector data including information of a direction. As an example, the pressing force acquisition section 14 can be configured to acquire the pressing force of the burr removing tool 3 from the force sensor 4 provided to the robot 2. In addition, the pressing force acquisition section 14 can be configured to acquire the pressing force of the burr removing tool 3 from other detection units such as a strain sensor, for example.

[0029] The rotation speed acquisition section 15 can be configured to acquire the rotation speed of the burr removing tool 3 from the rotation speed detector 5.

[0030] The defect detection section 16 detects burr removing defects that have not been able to properly perform burr removing processing, based on the deviation amount confirmed by the deviation amount calculation section 13, the pressing force acquired by the pressing force acquisition section 14, and the rotation speed acquired by the rotation speed acquisition section 15. The defect detection section 16 can be configured to monitor changes in the deviation amount, the pressing force, and the rotation speed, and determine that a burr removing defect has occurred in the case where any of the parameters deviates from a proper range set in advance. By adopting such a determination method, burr removing defects can be detected more accurately.

[0031] As a specific example, the defect detection section 16 can be configured to determine that a burr removing defect has occurred in the case where the deviation amount (D) is greater than a threshold value (Dmax) set in advance (D > Dmax). This is because the burr removing tool 3 cannot remove the burr when the burr removing tool 3 is separated from the workpiece W, and the burr removing tool 3 excessively cuts the workpiece W when the burr removing tool 3 is deeply inserted into the workpiece W.

[0032] Figure 2 The change in the pressing force F of the burr removing tool 3 is exemplified. The defect detection section 16 can be configured to determine that a burr removing defect has occurred in the case where the pressing force F is greater than an upper limit value Fmax set in advance (F > Fmax). This is because the burr removing tool 3 is excessively pressed against the workpiece W, which results in excessive cutting of the workpiece. In addition, the defect detection section 16 can be configured to determine that a burr removing defect has occurred in the case where the pressing force F is less than a lower limit value Fmin set in advance (F < Fmin). This is because the burr removing tool 3 cannot completely remove the burr if the burr removing tool 3 is not pressed against the workpiece W with sufficient force.

[0033] Figure 3 The change in the differential value dF (amount of change in the pressing force per unit time) of the pressing force F of the burr removing tool 3 is exemplified. The defect detection section 16 can be configured to determine that a burr removing defect has occurred in the case where the differential value dF of the pressing force F is greater than a positive maximum value dFmax set in advance (dF > dFmax), and in the case where the differential value dF of the pressing force F is less than a negative minimum value dFmin set in advance (dF < dFmin). This is because it can be considered that the burr removing tool 3 is abnormally vibrating in the case where the absolute value of the differential value dF of the pressing force F is excessively large. In order to simplify, the defect detection section 16 can be configured to determine that a burr removing defect has occurred in the case where the absolute value of the differential value dF of the pressing force F is greater than a maximum value dFmax set in advance (|dF| > dFmax) by setting the absolute values of the maximum value dFmax and the minimum value dFmin to be equal.

[0034] Figure 4The change in the rotation speed R of the burr removing tool 3 is exemplified. The defect detection section 16 can be configured to judge that the burr removal is defective in a case where the rotation speed R is larger than a maximum value Rmax set in advance (R > Rmax). This is because the workpiece W is excessively cut when the rotation speed R of the burr removing tool 3 is excessively large. In addition, the defect detection section 16 can be configured to judge that the burr removal is defective in a case where the rotation speed R is smaller than a minimum value Rmin set in advance (R < Rmin). This is because it can be considered that the rotation speed R of the burr removing tool 3 is decreased due to overload. The set value of the minimum value Rmin can also be 0.

[0035] The defect position determination section 17 is used to determine a position where the burr removal is defective, i.e., a defective position. As an example, the defect position determination section 17 can be configured to judge the position of the burr removing tool 3 at the time when the offset amount, the pressing force, and the rotation speed, for which the burr removal is judged to be defective by the defect detection section 16, are acquired from among the actual positions of the burr removing tool 3 acquired by the machining position acquisition section 12 as the defective position.

[0036] As an alternative, the defect position determination section 17 can also be configured to determine the defective position based on image information acquired from a vision sensor that captures an image of the workpiece W. That is, the burr removal system 1 can also be provided with a vision sensor, which is not illustrated. Specifically, the defect position determination section 17 can calculate the machining depth, i.e., the distance between the profile of the workpiece W before the burr removal machining and the profile of the workpiece W after the burr removal machining, and judge the position where the machining depth is smaller than a minimum value set in advance as "a defective position where the burr is not sufficiently removed" and the position where the machining depth is larger than a maximum value set in advance as "a defective position where the workpiece W is excessively cut".

[0037] When the burr removal defect is detected, the recording section 18 records the reason for which the burr removal is judged to be defective by the defect detection section 16, i.e., a defective reason. Thus, the recording section 18 can be configured to record information on how any of the parameters of the offset amount, the pressing force, and the rotation speed deviates from an appropriate range. As a specific example, the defective reason can be set to any of an excessively large offset amount, an excessively large pressing force, an excessively small pressing force, an excessively large differential value of the pressing force, an excessively small differential value of the pressing force, an excessively large rotation speed, and an excessively small rotation speed. The recording section 18 can record these defective reasons by codes or flags corresponding to these defective reasons one by one, or the like.

[0038] It can also be that, in a case where the burr removal defect is detected, the recording section 18 records the values of any of the parameters of the offset amount, the pressing force, and the rotation speed, for which the burr removal is judged to be defective by the defect detection section 16. The degree of the burr removal defect can be inferred based on the values of the offset amount, the pressing force, and the rotation speed, and thus it is easy to take measures against the burr removal defect.

[0039] In addition, the recording section 18 can record the defective position determined by the defective position determination section 17, and preferably records the defective position in association with the time series data of any of the parameters judged to be defective, the deviation amount, the pressing force, and the rotational speed, and the defective cause. Thereby, the cause of the burr removal defect can be more accurately judged.

[0040] Upon detecting the burr removal defect, the interruption control section 19 interrupts the burr removal processing and retreats the burr removal tool 3. The interruption control section 19 preferably linearly retreats the burr removal tool 3 in the direction in which the pressing force acts, to eliminate the condition in which the burr removal defect occurs as soon as possible. However, the interruption control section 19 can also retreat the burr removal tool 3 in a direction perpendicular to the machined surface or in the normal direction of the workpiece W. The retreat distance of the burr removal tool 3 can be set to a distance set in advance.

[0041] After interrupting the burr removal processing, the restart control section 20 restarts the burr removal processing from the defective position. That is, the restart control section 20 can be configured to acquire the defective position from the recording section 18 and restart the burr removal processing from the position on the taught trajectory that is closest to the defective position. Thereby, it is possible to prevent the situation in which excessive cutting occurs due to the burr removal processing being performed again on the portion of the workpiece W in which the burr removal processing was normally completed.

[0042] The burr removal system 1 having the above-described structure includes the defect detection section 16 and the recording section 18, and thus the cause of the burr removal defect can be easily determined. Therefore, the burr removal system 1 can appropriately remove the burrs of the workpiece W.

[0043] The burr removal system 1 includes the defective position determination section 17, and thus by the user confirming the defective position when the burr removal defect occurs, it is possible to easily confirm whether the defective reason recorded in the recording section 18 is correct. In addition, the burr removal system 1 can appropriately restart the burr removal processing after the burr removal defect occurs, by including the defective position determination section 17.

[0044] The burr removal system 1 includes the interruption control section 19, and thus it is possible to minimize the damage to the workpiece W and the burr removal tool 3 when the burr removal defect occurs.

[0045] The above describes one embodiment of the burr removal system according to the present disclosure, but the scope of the present disclosure is not limited to the above-described embodiment. In addition, the effects described in the above-described embodiment are merely examples of the most optimal effects generated from the burr removal system according to the present disclosure, and the effects of the burr removal system according to the present disclosure are not limited to the effects described in the above-described embodiment.

[0046] As an example, in the burr removing control device according to the present disclosure, the defective position determination section, the interruption control section, and the restart control section are not necessarily provided.

[0047] Explanation of Reference Numerals

[0048] 1: burr removing system; 2: robot; 3: burr removing tool; 4: force sensor; 5: rotational speed detector; 6: burr removing control device; 11: robot control section; 12: processing position acquisition section; 13: deviation amount calculation section; 14: pressing force acquisition section; 15: rotational speed acquisition section; 16: defect detection section; 17: defective position determination section; 18: recording section; 19: interruption control section; 20: restart control section; W: workpiece.

Claims

1. A burr removal control device for controlling a burr removal process, wherein burrs on a workpiece are removed by a robot moving a burr removal tool along the edge of the workpiece, the burr removal control device comprising: The deviation calculation unit calculates the deviation between the robot's actual trajectory and the taught track. The pressure acquisition unit acquires the pressure applied by the burr removal tool; The rotation speed acquisition unit acquires the rotation speed of the burr removal tool; The defect detection unit detects burr removal defects that have not been properly performed based on the deviation amount, the pressing force, and the rotation speed. When the burr removal is detected as poor, the recording unit records the reason why the defect detection unit judged the burr removal as poor, i.e., the reason for the defect. The defect location determination unit is used to determine the location where the burr removal defect occurred, i.e., the defect location; the interruption control unit, when the burr removal defect is detected, interrupts the burr removal process and causes the burr removal tool to retract. as well as The restart control unit, after interrupting the deburring process, restarts the deburring process from the defective location. The recording unit also records the location of the defect.

2. The burr removal control device according to claim 1, wherein, The reason for the defect is any one of the following: excessive deviation, excessive pressing force, insufficient pressing force, excessive differential value of pressing force, insufficient differential value of pressing force, excessive rotation speed, and insufficient rotation speed.

3. The burr removal control device according to claim 1 or 2, wherein, It also includes a processing position acquisition unit, which acquires the actual position of the burr removal tool. The defect location determination unit determines the defect location as the position of the burr removal tool at the moment when the deviation amount, the pressing force, and the rotation speed are determined by the defect detection unit to be the defective position of the burr removal tool obtained by the processing position acquisition unit.

4. The burr removal control device according to claim 1 or 2, wherein, The defect location determination unit determines the defect location based on image information obtained from a vision sensor that captures an image of the workpiece.

5. The burr removal control device according to claim 1 or 2, wherein, The pressure acquisition unit acquires the pressure from a force sensor installed on the robot.

6. The burr removal control device according to claim 3, wherein, The pressure acquisition unit acquires the pressure from a force sensor installed on the robot.

7. The burr removal control device according to claim 4, wherein, The pressure acquisition unit acquires the pressure from a force sensor installed on the robot.

8. A burr removal system, comprising: The burr removal control device according to any one of claims 1 to 7; and A robot, controlled by the deburring control device, is used to move the deburring tool along the edge of the workpiece.

Images