JP2022169256A - Robot control device, robot control method, and robot control program - Google Patents

Abstract

To provide a robot control device capable of effectively reducing an influence on natural vibration.SOLUTION: A robot control device 300 includes: an acceleration sensor 211 for acquiring accelerations of a driven part 220 and a laser beam irradiation part 230 provided on joints 11 to 16 of a robot arm; a corrected driving signal generation part 340 for subjecting acceleration measured by the acceleration sensor 211 to at least one integration processing, and generating a correction driving signal for driving the driven part 220 and the laser beam irradiation part 230 in a direction opposite to natural vibration of the robot arm; and low frequency filters 341 and 343 for reducing a signal of a frequency lower than natural frequency of the robot arm before at least the one integration processing in the corrected driving signal generation part 340.SELECTED DRAWING: Figure 4

Description

The present invention relates to robot control technology.

2. Description of the Related Art At industrial sites such as factories, distribution warehouses, construction sites, and hospitals, robots have been introduced to perform various tasks in place of humans. A working part called an end effector having a shape and function according to the purpose of work is provided at the tip of a movable part of a robot such as a robot arm.

JP 2010-149247 A

When the robot arm works with the end effector while changing its position, the natural vibration of the natural frequency based on the structure of the robot arm may remain immediately after the movement of the robot arm. Since the working accuracy of the end effector deteriorates when the natural vibration remains, it is necessary to stop the work until the natural vibration is sufficiently attenuated, resulting in a decrease in work efficiency.

In Patent Document 1, in order to reduce the influence of the natural vibration, the acceleration of the working part measured by the acceleration sensor is integrated twice and converted into a position, and the position error of the working part based on the natural vibration is detected. is disclosed. However, as a result of independent investigation of this technology, it was found that the acceleration sensor can be a source of low-frequency noise that is lower than the natural frequency of the robot arm. If the acceleration is integrated in the presence of low-frequency noise, the error in the position of the working unit cannot be properly detected due to the integrated low-frequency noise.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a robot controller capable of effectively reducing the influence of natural vibration.

In order to solve the above-described problems, a robot control device according to one aspect of the present invention includes an acceleration acquisition section that acquires the acceleration of a working section provided in a movable section of a robot, and performs integration processing on the acceleration at least once. a correction drive signal generating section for generating a correction drive signal for driving the working section in a direction opposite to the natural vibration of the movable section; and a low frequency filter that reduces signals with frequencies below a certain frequency. According to this aspect, the low-frequency filter reduces the low-frequency noise of the acceleration acquisition section, so that the influence of the natural vibration of the movable section of the robot can be effectively reduced.

Another aspect of the present invention is also a robot controller. This device has an acceleration acquisition unit that acquires the acceleration of the working part provided in the movable part of the robot, and based on the acceleration, generates a correction drive signal representing the driving force that drives the working part in the direction opposite to the natural vibration of the movable part. and a correction drive signal generation unit for generating the correction drive signal. According to this aspect, since the correction drive signal generation section does not integrate the acceleration and the low frequency noise of the acceleration acquisition section is not integrated, the influence of the natural vibration of the movable section of the robot can be effectively reduced.

Any combination of the above constituent elements, and any conversion of expressions of the present invention into methods, devices, systems, recording media, computer programs, etc. are also effective as embodiments of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the robot control apparatus which can reduce the influence of natural vibration effectively can be provided.

The appearance of the robot arm is shown. The configuration of a processing head provided at the tip of a robot arm is schematically shown. An example of natural vibration remaining immediately after movement of the robot arm is shown. 1 shows a first configuration example of a robot control device. A specific example of low-frequency noise of an acceleration sensor is shown. A specific example of low-frequency noise of an acceleration sensor is shown. Fig. 3 shows the effect of a low frequency filter; A second configuration example of the robot control device is shown.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience in order to facilitate explanation, and should not be construed as limiting unless otherwise specified. The embodiments are illustrative and do not limit the scope of the invention in any way. Not all features or combinations thereof described in the embodiments are essential to the invention.

FIG. 1 is a perspective view showing the appearance of a robot arm 100 as an example of an industrial robot. This robot arm 100 is a vertically articulated robot arm with a serial link mechanism. Robot arms to which the present invention can be applied are not limited to those shown in the drawings, and robots of any configuration having joints (corresponding to the joints of the human body) connecting a plurality of links (corresponding to the bones of the human body) so as to allow relative movement. An arm is fine. A parallel link mechanism may be used instead of the serial link mechanism, and a horizontal articulated type may be used instead of the vertical articulated type. It should be noted that the present invention can be applied to any robot other than the robot arm. For example, the present invention can also be applied to a table drive device (robot) having a slider (movable part) that moves a table (work part) on which a work (work object) is placed along one or more drive shafts. is.

The robot arm 100 has, as a movable part of the robot, six joints, namely, a first joint 11, a second joint 12, a third joint 13, a fourth joint 14, a fifth joint 15, and a sixth joint 16, in this order from the base 10. has one axis. Each joint corresponds to each joint of the human body, the first joint 11 is the waist, the second joint 12 is the shoulder, the third joint 13 is the elbow, the fourth joint 14 is the arm (twisting), the fifth joint 15 is the wrist, the third joint is 6 joints 16 correspond to fingertips (twisting). The direction of each axis can be appropriately designed according to the purpose and application of the robot arm 100, but in this embodiment, assuming that the pedestal 10 is placed on a horizontal plane, the first joint 11 is positioned vertically (with respect to the pedestal 10, which is a horizontal plane). vertical), the second joint 12 and the third joint 13 in the horizontal direction (parallel to the pedestal 10 which is a horizontal plane), the fourth joint 14 in the vertical direction to the third joint 13, the fifth joint 15 in the horizontal direction , the sixth joint 16 is oriented perpendicular to the fifth joint 15 .

A sixth joint 16 at the tip of the robot arm 100 is attached with an end effector or a robot hand having a shape and function according to the purpose of work. For example, a grapple shape for grabbing things, a shovel shape for scooping things up, a fork shape for supporting and transporting things from below, a hook shape for hooking and transporting things, and a shape for lifting and transporting things. A variety of end effectors are available, such as crane-like. In this embodiment, an example of using a processing head as a laser processing unit that processes a processing target with a laser beam as an end effector will be described.

FIG. 2 schematically shows the configuration of a processing head 200 provided at the tip of the robot arm 100. As shown in FIG. In the XYZ orthogonal coordinate system defined by the mutually orthogonal X, Y, and Z axes, FIG. 2A is a side view showing the vertical YZ plane, and FIG. 2B shows the horizontal XY plane. is a top view showing. The processing head 200 includes a base 210 whose proximal end (-Y side end in FIG. 2) is attached to the sixth joint 16 at the distal end of the robot arm 100, and a distal end side of the base 210 (+Y side in FIG. 2). ), a driven portion 220 that is driven in each of the X-axis, Y-axis, and Z-axis directions with respect to the base 210, and the driven portion 220 that is attached to the distal end side (+Y side in FIG. 2) and mounted downward (FIG. 2 (-Z direction)) is provided as a working unit for irradiating a laser beam L to the object to be processed.

An acceleration sensor 211 as an acceleration acquisition unit and an actuator 212 are mounted on the surface of the base 210 (the surface on the +Z side in FIG. 2). The acceleration sensor 211 is a three-axis acceleration sensor capable of measuring the acceleration of the machining head 200 in each of the X-axis, Y-axis, and Z-axis directions. The acceleration sensor 211 may be configured as a 6-axis inertial sensor capable of measuring angular velocity and angular acceleration around each axis in addition to the acceleration of each axis. As will be described later, the acceleration sensor 211 is provided to detect natural vibrations remaining immediately after the movement of the robot arm 100 and to reduce the effects of the vibrations on the processing operation of the laser beam irradiation unit 230 .

The acceleration sensor 211 can be installed at any place where the natural vibration of the robot arm 100 can be detected. It may be installed in the section 230 . However, in the illustrated example, the acceleration sensor 211 and the actuator 212 can be mounted using the empty space on the front surface of the base 210 where the driven part 220 is provided on the back surface (surface on the -Z side in FIG. 2). Therefore, there is an advantage that the machining head 200 can be formed compactly. In addition, since the natural vibration can be detected on the side of the base 210 closer to the laser beam irradiation unit 230 (-Y side in FIG. 2), the influence of the vibration on the processing operation of the laser beam irradiation unit 230 can be effectively reduced.

The method of the acceleration sensor 211 is not limited, and any method such as a piezoelectric method using a piezoelectric element (piezo element), a mechanical method, an optical method, or the like can be adopted. In order to effectively reduce the influence of , it is preferable to use a capacitance-type acceleration sensor.

The actuator 212 includes an X-axis actuator, a Y-axis actuator, and a Z-axis actuator that drive the driven portion 220 in the X-axis, Y-axis, and Z-axis directions with respect to the base 210 . The actuator for each axis may be a linear motor that generates linear power along the corresponding axis, or one that converts rotational power generated by a motor with a rotor into linear power along the corresponding axis by a power conversion mechanism. It's okay. Hereinafter, the linear power or force generated by the linear motor in the former case and the rotational power or torque generated by the motor in the latter case will be collectively referred to as driving force for driving the driven portion 220 and the laser beam irradiation portion 230 .

The laser beam irradiation unit 230 integrally driven with the driven unit 220 by the actuator 212 includes an optical fiber 231 for introducing the laser beam L and various optical components such as a lens housed therein to emit the laser beam from the optical fiber 231. An optical component housing 232 is provided for irradiating light L downward (-Z direction in FIG. 2) to the workpiece. Instead of introducing the laser light from the optical fiber 231 , the laser light L may be generated inside the optical component housing 232 by housing a light emitting element such as a laser diode in the optical component housing 232 .

In the above configuration, the first to sixth joints 11 to 16 of the robot arm 100 are mainly responsible for driving a wide range (for example, over 100 mm cubic) or a large amount of movement (for example, over 100 mm), and the actuator 212 of the processing head 200 is for a narrow range. (e.g. within 100 mm cube) or small movement (e.g. 100 mm or less). When processing an object to be processed by the processing head 200, typically, as a first step, the actuator 212 is stopped and the processing head 200 is moved to the vicinity of the object to be processed by driving the first to sixth joints 11 to 16, In the following second step, the actuator 212 is driven while the first to sixth joints 11 to 16 are stopped, and the laser beam irradiation unit 230 finely changes the irradiation position of the laser beam L to finely process the object to be processed (fine drilling, etc.). ).

As described above, the movement or movement of the robot arm 100 by the first to sixth joints 11 to 16 often accompanies the actual processing by the laser beam irradiation unit 230, and the natural vibration that remains immediately after that is a problem. Become. In addition, when the processing area is wide (for example, over 100 mm cubic) and the required processing accuracy is low, the laser beam irradiation unit 230 is turned on by driving the first to sixth joints 11 to 16 of the robot arm 100. The object to be processed may be processed while the irradiation position of the light L is changed. At this time, the actuator 212 may be in a stopped state, or may be driven in order to reduce the effects of natural vibration accompanying movement of the robot arm 100, as will be described later.

FIG. 3 shows an example of natural vibrations remaining immediately after the robot arm 100 moves. The natural vibrations remaining in the directions of the XYZ axes when the robot arm 100 stops moving at a constant speed in the directions of the respective axes are shown. Assuming that the XYZ coordinates (positions) of the laser beam irradiation unit 230 when the robot arm 100 stops are 0, FIG. B) represents the position of the laser beam irradiation unit 230 in the Y-axis direction, and FIG. 3C represents the position of the laser beam irradiation unit 230 in the Z-axis direction. As shown in each figure, each axis has a substantially constant natural frequency or natural vibration with a resonant frequency. The natural frequency of each axis is determined based on the structure along each axis of the robot arm 100, but is typically between 5 Hz and 20 Hz (results of tests using the actual robot arm 100, 7 Hz, 10 Hz, Natural frequencies were confirmed near 15Hz and 20Hz). Since the machining accuracy of the laser beam irradiation unit 230 is reduced in a state where such natural vibrations remain, processing is interrupted until the natural vibrations of each axis are sufficiently damped, or correction is performed to reduce the effects of the natural vibrations. It needs to be processed.

FIG. 4 shows a first configuration example of a robot control device 300 for reducing the effects of natural vibration of the robot arm 100. As shown in FIG. The robot control device 300 includes an overall control device 310 responsible for controlling the robot arm 100 and the processing head 200, a robot arm drive control device 320 responsible for driving control of the robot arm 100, and a processing head driving device responsible for driving control of the processing head 200. A control device 330 and a correction drive signal generator 340 that generates a correction drive signal for reducing the influence of the natural vibration of the robot arm 100 are provided.

The overall control device 310 controls the robot arm 100 and the machining head 200 according to operation signals input by an operator who operates the robot arm 100 and the machining head 200 and a series of instructions contained in a computer program stored in a memory (not shown). 200 to generate commands to drive each.

A robot arm control unit 321 of the robot arm drive control device 320 receives a drive command for the robot arm 100 from the overall control device 310 and generates commands for rotationally driving the joints 11 to 16 of the robot arm 100 . Specifically, the robot arm control unit 321 generates a position command that specifies the angles (positions) of the joints 11-16. In addition to or instead of the position command, the robot arm control unit 321 provides a speed command that specifies the angular velocity (velocity) of each joint 11-16, an acceleration command that specifies the angular acceleration (acceleration) of each joint 11-16. , a driving force command specifying the torque (driving force) generated by the actuator 323 that rotationally drives the joints 11 to 16 may be generated.

A driver 322 provided after the robot arm control unit 321 receives a rotation drive command for each joint 11 to 16 from the robot arm control unit 321, and sends a drive signal to an actuator 323 that rotates each joint 11 to 16. is applied. When the actuator 323 is composed of an AC motor, the driver 322 is composed of an inverter that generates AC as a drive signal.

The processing head control unit 331 of the processing head drive control device 330 receives a drive command for the processing head 200 from the overall control device 310, and drives the driven unit 220 (and the laser beam irradiation unit 230) of the processing head 200. to generate directives for Specifically, the processing head control unit 331 generates a position command that specifies each XYZ coordinate (position) of the driven unit 220 . In this way, the processing head control section 331 configures a position command acquisition section that acquires a position command for the laser beam irradiation section 230 as a working section that is driven integrally with the driven section 220 . In addition to or in place of the position command, the machining head control unit 331 provides a speed command specifying the speed of the driven part 220 in the directions of the XYZ axes, the acceleration of the driven part 220 in the directions of the XYZ axes. and a driving force command designating the driving force (force or torque) generated by the actuator 212 that drives the driven part 220 in the directions of the XYZ axes.

A driver 332 provided after the processing head control unit 331 receives a command to drive the driven unit 220 from the processing head control unit 331 and applies a drive signal to the actuator 212 that drives the driven unit 220 . If the actuator 212 is composed of an AC motor, the driver 332 is composed of an inverter that generates AC as a drive signal.

The correction drive signal generator 340 includes a first low frequency filter 341, a first integrator 342, a second low frequency filter 343, a second integrator 344, and a correction drive amount calculator 345. . Correction drive signal generator 340 is provided to generate a correction drive signal for reducing the influence of the natural vibration remaining immediately after movement of robot arm 100 (immediately after rotation of each joint 11 to 16). Triggered by input of an in-position signal from the robot arm control unit 321 indicating that the robot arm has reached a specified position and stopped.

The acceleration sensor 211 measures the natural vibration (FIG. 3) remaining in the directions of the XYZ axes immediately after the movement of the robot arm 100 as acceleration, and the first integrator 342 integrates the acceleration measured by the acceleration sensor 211. A second integrator 344 integrates the velocity obtained by the first integration process and performs a second integration process of converting it into a position. In this way, as a result of performing two integration processes on the acceleration measured by the acceleration sensor 211, the natural vibration remaining immediately after the movement of the robot arm 100 can be obtained as position information in the directions of the XYZ axes.

Based on the positional information of the natural vibration, the correction drive amount calculation section 345 generates a correction drive signal for driving the driven section 220 (and the laser beam irradiation section 230) in the direction opposite to the natural vibration. Specifically, the corrected drive amount calculation unit 345 calculates the amount of displacement (corrected drive amount) from the reference position (0) in the directions of the XYZ axes caused by the natural vibration shown in FIG. It is provided to the processing head control section 331 as a correction drive signal for correcting the position of the driven section 220 (and the laser beam irradiation section 230). The machining head control unit 331 performs a correction process of subtracting the correction drive signal from the correction drive signal generation unit 340 from the position command of the driven unit 220 generated by itself in response to the drive command from the overall control device 310 . As a result of this correction processing, the driven unit 220 is driven by the actuator 212 based on the position command generated by the processing head control unit 331 itself, and at the same time, based on the correction drive signal generated by the correction drive signal generation unit 340 . Driven by actuator 212 to cancel vibrations. Therefore, it is possible to reduce the influence of the natural vibration on the laser beam irradiation section 230 that is driven integrally with the driven section 220 .

In the correction drive signal generator 340, a first low frequency filter 341 that reduces signals of frequencies lower than the natural frequency of each axis of the robot arm 100 before the first integration processing in the first integrator 342; After the first integration process and before the second integration process in the second integrator 344, a second low-frequency filter 343 is provided to reduce signals of frequencies lower than the natural frequency of each axis of the robot arm 100. be done. 4 in which the natural vibration is measured by the acceleration sensor 211, it has been found that the acceleration sensor 211 can be a source of low-frequency noise having a frequency lower than the natural vibration frequency of the robot arm 100. FIG. If the acceleration is integrated in the presence of low-frequency noise, the integrated low-frequency noise cannot generate an appropriate correction drive signal. A respective low frequency filter 341, 343 is provided for. A low-frequency filter may be provided before either one of the integrators 342 and 344 or may be provided after the second integrator 344 .

FIG. 5 shows a specific example of low-frequency noise of the acceleration sensor 211. FIG. FIG. 5A shows the acceleration measured by the piezoelectric acceleration sensor 211 together with the natural vibration of the robot arm 100 (displacement of the driven part 220). FIG. 5B shows the acceleration measured by the capacitive acceleration sensor 211 together with the natural vibration of the robot arm 100 (displacement of the driven part 220).

In FIG. 5A regarding the piezoelectric acceleration sensor 211, before about 1.5 seconds when the amplitude of the natural vibration attenuates to about 0.1 mm, an overshoot in which the amplitude of the acceleration becomes larger than the amplitude of the natural vibration is observed. After approximately 1.5 seconds, when the velocity attenuates to about 0.1 mm, a undulation in which the acceleration gently oscillates with a low frequency of 2 Hz or less, that is, a long period of 0.5 seconds or longer, is observed. In the piezoelectric acceleration sensor 211 using a piezoelectric element, a phenomenon occurs in which the voltage generated by the piezoelectric element quickly drops due to the applied pressure, and this degrades the responsiveness of the robot arm 100 to low-frequency operations. It is considered that overshoot and swell as described above occur.

On the other hand, in FIG. 5B relating to the capacitance type acceleration sensor 211, no overshoot is observed before about 1.5 seconds, and the swell after about 1.5 seconds is also greatly reduced. Thus, in order to effectively reduce the influence of the natural vibration of the robot arm 100, the capacitance method is preferable to the piezoelectric method of FIG. 5A. However, as shown in the enlarged view of Fig. 6(A), the low-frequency undulation of the acceleration was not completely eliminated, and after about 1.5 seconds, the acceleration was at a low frequency of 2 Hz or less, that is, at a long period of 0.5 seconds or longer. A slight undulation that oscillates gently remains. As with the piezoelectric acceleration sensor 211 shown in FIG. 5A, even in the electrostatic capacitance acceleration sensor 211, it is considered that low-frequency operation below the resolution appears as undulations.

FIG. 6B shows that the acceleration in which the low-frequency swell remains in FIG. The results are shown. As a result of integrating low-frequency noise in two integration processes, the waveform of the signal after about 1.5 seconds is greatly distorted. Such a signal is not only useless as a correction drive signal for removing the natural vibration, but also greatly distorts the original position command generated by the processing head control unit 331. 230 is prevented from being driven correctly.

Each low-frequency filter 341, 343 is a high-pass filter that removes low-frequency swells such as those seen in FIGS. Specifically, each of the low-frequency filters 341 and 343 removes low-frequency noise by subtracting a moving average of the signal to be processed over a predetermined period of time from the signal to be processed. Each low-frequency filter 341, 343 is designed, for example, as follows.

First, each of the low-frequency filters 341 and 343 needs to have a cutoff frequency smaller than the natural frequency and larger than the low-frequency noise in order to pass the natural vibration to be corrected and block the low-frequency noise to be removed. There is Since the natural frequency of the robot arm 100 is typically 5 Hz or more and the frequency of low frequency noise is typically 2 Hz or less, the cutoff frequency of each low frequency filter 341, 343 is between 2 Hz and 5 Hz. and preferably between 3Hz and 4Hz.

In addition, when the in-position signal is input from the robot arm control unit 321 and the low-frequency filters 341 and 343 start to operate, the low-frequency filters 341 and 343 need to acquire the processing target signal over a predetermined time period and calculate the moving average. The longer the moving average is taken, the higher the low-frequency noise removal effect can be expected. As a result of tests using an actual robot arm 100, it has been found that the moving average time is preferably between 100ms and 200ms, more preferably between 155ms and 170ms.

FIG. 7 shows the effect of the low frequency filters 341,343. FIG. 7A shows the displacement of the driven part 220 in the X-axis direction before being corrected by the correction drive signal, and the correction drive signal generated by the correction drive signal generator 340 by applying the low frequency filters 341 and 343. (correction driving amount) and the displacement of the driven part 220 in the X-axis direction after being corrected by the correction driving signal. The reason why the corrected displacement does not appear in about 0.3 seconds from about 0.7 seconds to about 1.0 seconds when the natural vibration occurs is that the low frequency filters 341 and 343 wait for the moving average as described above. Of this waiting time of about 0.3 seconds, the first low frequency filter 341 calculates the moving average for about 0.15 seconds in the first half, and the first low frequency filter 341 calculates the moving average for about 0.15 seconds in the latter half. Using the result, the moving average calculation in the second low frequency filter 343 is performed. The corrected displacement, which appears from about 1.0 seconds after the end of the waiting time, is within ±0.1 mm from the beginning, indicating that the natural vibration is attenuating more quickly than before the correction. Since it takes about 1.4 seconds for the displacement before correction to fall within ±0.1 mm, the low-frequency filters 341 and 343 achieve an improvement of about 0.4 seconds in damping the natural vibration.

FIG. 7B shows the effect of removing the offset of the acceleration sensor 211 by the low frequency filters 341 and 343. FIG. A substantially constant offset may appear in the output of the acceleration sensor 211 depending on the ambient environment such as temperature. In addition, since the electrostatic capacitance type acceleration sensor 211 can also measure gravitational acceleration, an offset of a substantially constant value appears in the output depending on the inclination of the installation surface or the like. If the acceleration is subjected to integration processing in the presence of such an offset, an appropriate correction drive signal cannot be generated due to the integrated offset, but the low-frequency filters 341 and 343 can remove the offset. As shown in FIG. 7B, it can be seen that the offset originally included in the output (voltage) of the acceleration sensor 211 is removed by passing through the first low-frequency filter 341 .

FIG. 8 shows a second configuration example of the robot control device 300 for reducing the influence of the natural vibration of the robot arm 100. As shown in FIG. The main difference from the first configuration example is that the correction drive signal generation unit 340 does not include an integrator, and the acceleration measured by the acceleration sensor 211 is subjected to processing such as amplification and averaging as it is, and the robot arm 100 is to generate a correction driving signal representing the driving force for driving the driven part 220 and the laser beam irradiation part 230 in the direction opposite to the natural vibration of the 100 . Here, the correction driving signal representing the driving force may specify or correct the driving force (force or torque) generated by the actuator 212 that drives the driven portion 220 in the directions of the XYZ axes. It may specify or correct the current or voltage applied to 212 . According to this configuration example, since the correction drive signal generator 340 does not integrate the acceleration and the low-frequency noise of the acceleration sensor 211 is not integrated, the influence of the natural vibration of the robot arm 100 can be effectively reduced. .

The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that the embodiments are examples, and that various modifications are possible in the combination of each component and each treatment process, and such modifications are also within the scope of the present invention.

Note that the functional configuration of each device described in the embodiments can be realized by hardware resources, software resources, or cooperation between hardware resources and software resources. Processors, ROMs, RAMs, and other LSIs can be used as hardware resources. Programs such as operating systems and applications can be used as software resources.

Reference Signs List 100 robot arm, 200 processing head, 210 base, 211 acceleration sensor, 212 actuator, 220 driven part, 230 laser beam irradiation part, 300 robot control device, 310 overall control device, 320 robot arm drive control device, 321 robot arm control Section 330 Machining head drive controller 331 Machining head controller 340 Correction drive signal generator 341 First low frequency filter 342 First integrator 343 Second low frequency filter 344 Second integration device, 345 correction drive amount calculation unit;

Claims (9)

an acceleration acquisition unit that acquires the acceleration of the working unit provided in the movable part of the robot;
a correction drive signal generation unit that integrates the acceleration at least once to generate a correction drive signal that drives the working unit in a direction opposite to the natural vibration of the movable unit;
a low-frequency filter that reduces a signal of a frequency lower than the natural frequency of the movable part before at least one integration process in the correction drive signal generation part;
A robot controller comprising: The correction drive signal generation unit performs a first integration process of integrating the acceleration and converting it into a velocity, and a second integration process of integrating the velocity and converting it into a position, so that the working part generating the correction drive signal for correcting the position;
The low-frequency filter includes a first low-frequency filter for reducing a signal having a frequency lower than the natural frequency before the first integration process, and a second integration process after the first integration process. a second low frequency filter that reduces signals at frequencies below the natural frequency prior to
The robot controller according to claim 1. 3. The robot controller according to claim 1, wherein said low-frequency filter subtracts a moving average of said signal to be processed from said signal to be processed. an acceleration acquisition unit that acquires the acceleration of the working unit provided in the movable part of the robot;
a correction drive signal generation unit that generates a correction drive signal representing a driving force for driving the working unit in a direction opposite to the natural vibration of the movable unit based on the acceleration;
A robot controller comprising: 5. The robot control device according to claim 1, wherein said acceleration acquisition unit is configured by a capacitive acceleration sensor. a position command acquisition unit that acquires a position command of the working unit;
an actuator that drives the working unit according to the position command and the correction drive signal;
The robot control device according to any one of claims 1 to 5, further comprising: The robot control device according to any one of claims 1 to 6, wherein the working section is a laser processing section that processes a processing target with a laser beam. a step of obtaining an acceleration of a working part provided in a movable part of the robot;
performing at least one integration process on the acceleration to generate a correction drive signal for driving the working part in a direction opposite to the natural vibration of the movable part;
reducing signals of frequencies lower than the natural frequency of the moving part before the at least one integration process;
A robot control method comprising: a step of obtaining an acceleration of a working part provided in a movable part of the robot;
performing at least one integration process on the acceleration to generate a correction drive signal for driving the working part in a direction opposite to the natural vibration of the movable part;
reducing signals of frequencies lower than the natural frequency of the moving part before the at least one integration process;
A robot control program that causes a computer to execute

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