JP6858353B2 - Robot control device, abnormality diagnosis method, and abnormality diagnosis program - Google Patents

Description

The present invention relates to a robot control device, an abnormality diagnosis method, and an abnormality diagnosis program.

In a production line that manufactures industrial products, a plurality of robots operate in cooperation with each other, so if even one robot breaks down, the production line may stop. For example, in a robot body configured to amplify the output torque of a motor with a speed reducer and transmit it to the arm, if the inside of the speed reducer is damaged, unnecessary vibration is generated when driving the arm, and the arm Positioning accuracy may decrease. Since it may take a long time to repair or replace a robot part (for example, a speed reducer), if the production line is stopped for a long time due to a robot failure, serious damage may occur. In view of such circumstances, Patent Document 1 describes an operation in which the natural frequency of the arm is measured at the joint portion of the robot body, and the arm resonates most due to the vibration generated by the motor that drives the arm and its speed reducer. The torque fluctuation value calculated from the motor torque value that has been temperature-corrected using the temperature sensor installed in the motor or reducer, with constant speed operation at speed as the operating condition for detecting abnormalities in the robot body, sets a preset threshold value. We are proposing an abnormality detection method for robots that determines that an abnormality has occurred in the robot body when it exceeds the limit.

Japanese Unexamined Patent Publication No. 2006-281421

By the way, it is known that the frequency of the vibration component generated due to the damage of the parts of the robot (for example, the damage inside the speed reducer) is proportional to the rotation speed of the motor.

However, it does not mean that there is no problem in detecting vibration components caused by abnormalities at any rotation speed of the motor. For example, a frequency band higher than the response frequency determined by the performance of the vibration sensor that detects vibration components and the fixing method. In, it becomes difficult to detect the vibration component caused by the abnormality. Similarly, even when a torque sensor that detects a vibration component superimposed on the output torque of the motor is used, it becomes difficult to detect the vibration component caused by the abnormality in the frequency band higher than the response frequency. On the other hand, when the rotation speed of the motor is extremely low, the vibration component caused by the abnormality is less likely to appear, which makes detection difficult. As described above, the range of the rotation speed of the motor is unsuitable for detecting the vibration component caused by the abnormality.

On the other hand, each robot used in a production line is designed to repeatedly perform a predetermined specific operation (for example, transfer of parts, assembly, welding, etc.) according to its role. Such an operation of the robot is called teaching playback, and many robots used in the production line operate based on the teaching playback. For example, when operating the robot arm based on teaching playback, an operation command to move the arm from a certain coordinate to the target coordinate is input from the controller to the servo driver, and the arm operates according to the operation command. Current is supplied from the servo driver to the motor. In such a case, conventionally, the operation command input from the controller to the servo driver does not include the operation command for specifying the rotation speed of the motor, and the rotation speed of the motor is a vibration component caused by an abnormality. It was difficult to accurately diagnose the abnormality of the robot because it may fall within a range unsuitable for detection.

Further, if the arm is operated based on the teaching playback at the time of abnormality diagnosis, the operating range of the arm may be insufficient to detect the vibration component caused by the abnormality for one cycle or more. In such a case, there is a problem that sufficient information on the vibration component necessary for accurately diagnosing the abnormality cannot be obtained.

Therefore, it is an object of the present invention to propose a technique for solving such a problem and improving the accuracy of abnormality diagnosis of the robot body.

In order to solve the above-mentioned problems, the robot control device according to one aspect of the present invention sets a rotation axis for transmitting power to the arm so that the arm performs a predetermined motion from a starting angle position to a first target angle position. Performs anomaly diagnosis of the robot body equipped with a motor that rotates the robot. In this robot control device, among the vibration components generated by the rotation of the rotation axis, the vibration component caused by an abnormality can be detected. The rotation axis moves from the starting angle position to the second target angle position at a substantially constant rotation speed. A drive control unit that drives the motor to rotate to, a vibration detection unit that detects vibration components, a diagnosis unit that performs abnormality diagnosis based on the detected vibration components, and a second target angle position from the starting angle position. When the angle range up to is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis exceeds the operating range when the arm performs a predetermined operation. It is equipped with an output device that outputs warning information to warn. Here, the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by an abnormality. In the abnormality diagnosis, by rotating the rotation axis from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation axis, the vibration components of one cycle or more due to the abnormality are detected. be able to. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage. In addition, by maintaining the rotation speed of the rotating shaft at the time of abnormality diagnosis at a substantially constant value, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the amplitude fluctuation caused by the fluctuation of the frequency of the vibration component. Can be suppressed. Due to such a warning, for example, the user moves the robot body to be diagnosed abnormally or is the target of the abnormality diagnosis so that the robot body to be diagnosed abnormally does not interfere with other robots or devices. It is possible to take measures such as moving other robots or devices around the robot body. In addition, this warning can alert the user to avoid the danger of interference between the robot body and the operator, which is the target of the abnormality diagnosis.

The rotation speed profile of the rotation axis when the rotation axis rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis is that the rotation axis is the first from the departure angle position when the arm performs a predetermined operation. It may be different from the rotation speed profile of the rotation axis when rotating to the target angle position. As a result, the rotation shaft can be rotated with a rotation speed profile suitable for abnormality diagnosis.

The rotation speed profile of the rotation shaft when the rotation shaft rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis may be a substantially trapezoidal shape including a period during which the rotation speed of the rotation shaft becomes substantially constant. By maintaining the rotation speed of the rotating shaft at the time of abnormality diagnosis at a substantially constant value, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the fluctuation of the amplitude caused by the fluctuation of the frequency of the vibration component is suppressed. can do.

An abnormality diagnosing method relating to another aspect of the present invention is a robot including a motor that rotates a rotation axis that transmits power to the arm from a starting angle position to a first target angle position so that the arm performs a predetermined operation. This is an abnormality diagnosis method in which the robot control device diagnoses an abnormality in the main body, and the robot control device can detect a vibration component caused by the abnormality among the vibration components generated by the rotation of the rotating shaft. A step of driving the motor so that the rotation axis rotates from the starting angle position to the second target angle position at the rotation speed, a step of detecting a vibration component, and an abnormality diagnosis of the robot body based on the detected vibration component. When the step to be performed and the angle range from the starting angle position to the second target angle position are wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis is the arm. Performs a step of outputting warning information that warns that the operating range will be exceeded when performing a predetermined operation. Here, the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by an abnormality. In the abnormality diagnosis, by rotating the rotation axis from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation axis, the vibration components of one cycle or more due to the abnormality are detected. be able to. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage. In addition, by maintaining the rotation speed of the rotating shaft at the time of abnormality diagnosis at a substantially constant value, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the amplitude fluctuation caused by the fluctuation of the frequency of the vibration component. Can be suppressed.

An abnormality diagnosis program relating to another aspect of the present invention is a robot including a motor that rotates a rotation axis that transmits power to the arm from a starting angle position to a first target angle position so that the arm performs a predetermined operation. It is an abnormality diagnosis program for causing the robot control device to execute the abnormality diagnosis of the main body, and enables the robot control device to detect the vibration component caused by the abnormality among the vibration components generated by the rotation of the rotating shaft. A step of driving the motor so that the rotation axis rotates from the starting angle position to the second target angle position at a substantially constant rotation speed, a step of detecting a vibration component, and an abnormality diagnosis based on the detected vibration component. When the step to be performed and the angle range from the starting angle position to the second target angle position are wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis is the arm. A step of outputting warning information for warning that the operating range is exceeded when performing a predetermined operation is executed. Here, the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by an abnormality. In the abnormality diagnosis, by rotating the rotation axis from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation axis, the vibration components of one cycle or more due to the abnormality are detected. be able to. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage. In addition, by maintaining the rotation speed of the rotating shaft at the time of abnormality diagnosis at a substantially constant value, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the amplitude fluctuation caused by the fluctuation of the frequency of the vibration component. Can be suppressed.

According to the present invention, the accuracy of abnormality diagnosis of the robot body can be improved.

It is explanatory drawing which shows an example of the structure of the robot which concerns on this Embodiment. It is explanatory drawing which shows an example of the 1st hardware configuration of the robot which concerns on this Embodiment. It is explanatory drawing which shows an example of the rotation speed profile of the rotation axis at the time of a normal operation of an arm. It is explanatory drawing which shows an example of the rotation speed profile of the rotation axis in the abnormality diagnosis method which concerns on this Embodiment. It is a graph which shows an example of the vibration component detected when the arm operates normally. It is a graph which shows an example of the vibration component detected by the abnormality diagnosis method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the 1st angular position and the 2nd angular position. It is explanatory drawing which shows the relationship between the 1st angular position and the 2nd angular position. It is a flowchart which shows an example of the abnormality diagnosis method of the robot main body which concerns on this Embodiment. It is explanatory drawing which shows an example of the 2nd hardware composition of the robot which concerns on this Embodiment.

Hereinafter, embodiments relating to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to the drawings. The present embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. The present invention can be modified or improved without departing from the spirit thereof, and the present invention also includes an equivalent thereof. It should be noted that the same reference numerals indicate the same components, and duplicate description will be omitted.

[Application example]
First, an application example of the present invention will be described with reference to FIG. FIG. 1 shows an example of the configuration of the robot 100 according to the present embodiment. The robot 100 may include, for example, a robot body 200 and a robot control device 300. The robot control device 300 is a computer system that controls the operation of the robot body 200. Specific examples of the robot 100 include a vertical articulated robot, a horizontal articulated robot, a Cartesian robot, and a parallel link robot. The robot 100 operates as a manipulator that operates autonomously, and can be used for any purpose such as assembling, transporting, painting, inspecting, polishing, or cleaning parts.

The robot body 200 is increased by, for example, reducing the rotation speed of the arm 203 that operates as a manipulator, the motor 201 that rotates the rotating shaft 204 that transmits power to the arm 203, and the rotating shaft 204 to increase the torque. A speed reducer 202 that transmits torque-bearing power to the arm 203 through the output shaft 205 may be provided. The rotating shaft 204 may be, for example, the output shaft of the motor 201. In this case, the rotating speed of the motor 201 and the rotating speed of the rotating shaft 204 match. For convenience of explanation, FIG. 1 illustrates a case where the number of axes (number of joints) of the robot body 200 is 1, but the number of axes may be 2 or more (for example, 4 to 7 axes).

The robot control device 300 includes, for example, an operation command unit 302 that generates an operation command of the motor 201, a drive control unit 304 that controls the drive of the motor 201 in response to an operation command from the operation command unit 302, and the motor 201. A vibration detection unit 305 that detects the vibration component generated by the rotation of the rotating shaft 204 that rotates by the power from the vibration detection unit 305, and a diagnosis unit 303 that frequency-analyzes the vibration component detected by the vibration detection unit 305 and performs an abnormality diagnosis. May be provided. The vibration detection unit 305 may detect a vibration component superimposed on the output torque of the motor 201, or may detect a vibration component generated from a component of the robot body 200 (for example, the speed reducer 202). .. The robot control device 300 may include, for example, a control unit 301 having a microcomputer, and the functions of the operation command unit 302 and the diagnosis unit 303 may be realized by the information processing function of the control unit 301 by the microcomputer. The robot control device 300 may further include an output device 316 that outputs warning information described later.

The robot 100 may be designed so that the arm 203 performs a predetermined motion based on, for example, teaching playback. In the present specification, the operation predetermined by teaching is also referred to as a normal operation in order to distinguish it from the operation of the arm 203 at the time of abnormality diagnosis. The arm 203 performs the normal operation by rotating the rotation shaft 204 from the starting angle position for the normal operation to the target angle position for the normal operation by the motor 201. Here, the starting angle position for normal operation is the angular position of the rotation shaft 204 when the arm 203 starts normal operation. The target angular position for normal operation is the angular position of the rotation shaft 204 when the arm 203 ends the normal operation.

In the present specification, the abnormality of the robot means a state in which the normal operation of the robot is hindered or a state in which the occurrence of such a hindrance is expected in the future, for example, failure, damage, wear, and so on. Includes distortion, deformation, etc. Among the abnormalities, a state in which the operation of the robot is significantly hindered is called a failure. In the abnormality diagnosis, among the vibration components generated by the rotation of the rotation shaft 204, the target angle position for the abnormality diagnosis of the rotation shaft 204 that enables the detection of the vibration component of one cycle or more caused by the abnormality is determined. To. In the present specification, for convenience of explanation, the target angle position for normal operation of the rotation shaft 204 is referred to as a first target angle position, and the target angle position for abnormality diagnosis of the rotation shaft 204 is referred to as a second target angle position. , Distinguish between the two. Since the starting angle position for normal operation of the rotating shaft 204 is the same as the starting angle position for abnormality diagnosis of the rotating shaft 204, both are simply referred to as starting angle positions unless the two are particularly distinguished. .. The second target angle position may be determined by the user who maintains and manages the robot 100, or may be determined by the calculation function of the operation command unit 302 or the calculation function of the host controller 400 described later. Then, in response to the operation command from the operation command unit 302, the drive control unit 304 makes it possible to detect the vibration component caused by the abnormality. The motor 201 is driven so as to rotate to the target angle position. Here, the upper limit of the rotational speed of the rotating shaft 204 capable of detecting the vibration component caused by the abnormality is, for example, the performance of the vibration detecting unit 305 (for example, the response frequency) or the structure of the speed reducer 202 (for example, the bearing). It may be determined by the pitch circle, the diameter, the number of rolling elements, the contact angle, etc.) or the specifications (for example, the reduction ratio). The lower limit of the rotation speed of the rotating shaft 204, which enables detection of the vibration component caused by the abnormality, may be set to, for example, a rotation speed at which the vibration component is less likely to appear when the lower limit is exceeded. In the abnormality diagnosis, it is desirable to set the rotation speed of the rotation shaft 204 between the upper limit and the lower limit of the rotation speed of the rotation shaft 204 which enables the detection of the vibration component caused by the abnormality, and particularly due to the abnormality. It is desirable to set the rotation speed to a substantially constant speed so that the amplitude of an appropriately large vibration component can be stably detected. The rotation speed profile of the rotation shaft 204 at the time of abnormality diagnosis may be different from the rotation speed profile of the rotation shaft 204 at the time of normal operation. As used herein, the rotational speed profile means a characteristic of the rotational speed over time. The diagnosis unit 303 performs an abnormality diagnosis (for example, determination of the presence or absence of damage to a component linked to the rotation of the rotation shaft 204) based on the vibration component detected by the vibration detection unit 305.

The output device 316 may output warning information when the angle range from the departure angle position to the second target angle position is wider than the angle range from the departure angle position to the first target angle position. This warning information warns, for example, that the operating range of the arm 203 at the time of abnormality diagnosis exceeds the operating range of the arm 203 at the time of normal operation. The output device 316 may be, for example, a display device that displays visually recognizable warning information such as a text message, or an acoustic device that outputs audibly recognizable warning information such as a voice message. The output device 316 may be, for example, a vibration device that conveys a warning through vibration. The output device 316 may convey a warning by combining any two or more of visually recognizable warning information, audibly recognizable warning information, and vibration. The output device 316 may be, for example, a communication device that transmits warning information via a wired line or a wireless line. The destination of the warning information may be, for example, a user's communication terminal (for example, a mobile communication terminal called a smartphone, smart watch or tablet terminal, or a personal computer having a communication function), or an external device having a communication function. .. The communication terminal or the external device that has received the warning information may convey the warning by combining any two or more of the visually recognizable warning information, the audibly recognizable warning information, and the vibration.

In this way, in the abnormality diagnosis, by rotating the rotation shaft 204 from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation shaft 204, one cycle or more due to the abnormality Vibration component can be detected. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage. Further, by maintaining the rotation speed of the rotating shaft 204 at the time of abnormality diagnosis at a substantially constant value, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the amplitude caused by the fluctuation of the frequency of the vibration component is increased. Fluctuations can be suppressed. Further, when the angle range from the starting angle position to the second target angle position is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm 203 at the time of abnormality diagnosis is the normal operation. By warning that the operating range of the arm 203 is exceeded, the user can take measures such as moving the robot 100 so that the robot 100 does not interfere with other robots or devices.

[First hardware configuration]
Next, an example of the first hardware configuration of the robot 100 will be described with reference to FIG. 1 with reference to FIG. 2 as appropriate.
The robot body 200 includes a servomotor 206 with an encoder as an example of the motor 201 shown in FIG.
The robot control device 300 includes a controller 306 as an example of the control unit 301 shown in FIG.

The controller 306 may be a microcomputer including, for example, a processor 307, a storage resource 308, and an input / output interface 309 as hardware resources. The storage resource 308 may store the abnormality diagnosis program 310, and the abnormality diagnosis program 310 includes an operation command module 311 and a diagnosis module 312 which are a plurality of software modules called and executed in the main program thereof. You may. The storage resource 308 is a storage area provided by a computer-readable recording medium such as a semiconductor memory or a disk medium.

The operation command module 311 is interpreted and executed by the processor 307, and the hardware resources of the controller 306 and the operation command module 311 cooperate with each other to realize the function as the operation command unit 302 shown in FIG. Similarly, the diagnostic module 312 is interpreted and executed by the processor 307, and the hardware resources of the controller 306 and the diagnostic module 312 cooperate with each other to realize the function as the diagnostic unit 303 shown in FIG. As described above, the functions of the operation command unit 302 and the diagnosis unit 303 may be realized by the cooperation between the hardware resource of the controller 306 and the abnormality diagnosis program 310, or the dedicated hardware resource (for example, a specific application). It may be realized by using an integrated circuit (ASIC), a field programmable gate array (FPGA), etc.) or firmware.

The robot control device 300 includes a servo driver 313 as an example of the drive control unit 304 shown in FIG.
The robot control device 300 includes a torque sensor 314 for detecting a vibration component superimposed on the output torque of the motor 201 as an example of the vibration detection unit 305 shown in FIG. The torque sensor 314 is not indispensable as a means for detecting the output torque of the servomotor 206. For example, the output of the servomotor 206 is obtained from the command torque of the servo driver 313 or the torque obtained from the output current value of the servomotor 206. Torque may be detected.

The speed reducer 202 may include, for example, a bearing mechanism or a gear mechanism that rotates in conjunction with the rotation of the rotating shaft 204, and distortion due to damage to the bearing mechanism or the gear mechanism (for example, damage or deterioration over time). Etc.) may cause vibration components. It is known that the frequency of the vibration component generated due to such damage to the bearing mechanism or the gear mechanism is proportional to the rotation speed of the rotating shaft 204 ("Equipment Management Technical Dictionary", 2003, p. 574). ). The cause of the generation of the vibration component is not limited to the damage of the speed reducer 202, and may be, for example, the damage of the parts linked to the rotation of the rotating shaft 204. As the speed reducer 202, for example, a strain wave gearing device called a harmonic drive (registered trademark) may be used.

The output device 316 may be, for example, a display device (for example, a flat display such as a liquid crystal display, an electric field emitting display, or a plasma display) that displays visually recognizable warning information such as a text message, or a voice message or the like. An acoustic device (for example, a speaker device) that outputs audibly recognizable warning information may be used.

FIG. 3 shows an example of the rotation speed profile of the rotation shaft 204 when the rotation shaft 204 rotates from the starting angle position to the first target angle position when the arm 203 normally operates. The horizontal axis of FIG. 3 indicates time, and the vertical axis indicates rotation speed (the same applies to FIG. 4). Reference numeral RV1 indicates an upper limit of the rotation speed of the rotation shaft 204 that enables detection of the vibration component caused by the abnormality of the robot body 200, and the rotation speed profile shown in FIG. 3 shows the accuracy of the vibration component caused by the abnormality. Is difficult to detect. FIG. 4 shows an example of the rotation speed profile of the rotation shaft 204 when the rotation shaft 204 rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis. In the example shown in FIG. 4, the rotation speed of the rotation shaft 204 at the time of abnormality diagnosis is the rotation speed RV2 between the upper limit RV1 and the lower limit RV3 of the rotation speed of the rotation shaft 204 that enables detection of the vibration component caused by the abnormality. Is set to. It is desirable that the rotation speed RV2 is a rotation speed that can stably detect the amplitude of an appropriate magnitude of the vibration component caused by the abnormality. The rotation speed profile of the rotation shaft 204 at the time of abnormality diagnosis may be substantially trapezoidal so as to include the period T2 in which the rotation speed of the rotation shaft 204 is maintained at RV2.

Reference numeral T1 indicates a rise time from 0 to the rotation speed of the rotation shaft 204 reaching RV2. Reference numeral T3 indicates a fall time from RV2 until the rotation speed of the rotation shaft 204 reaches 0. The total time T of T1, T2, and T3 corresponds to the time required for the rotation shaft 204 to rotate from the starting angle position to the second target angle position. When T1 and T3 are sufficiently shorter than T2, the number of cycles of the vibration component caused by the abnormality among the vibration components detected by the torque sensor 314 is substantially different depending on the length of the period T2. It is decided. The number of cycles of the vibration component required for detection may be determined, for example, according to the specifications of the motor 201 or the speed reducer 202.

FIG. 5 shows a vibration component generated with the rotation of the rotation shaft 204 when the arm 203 normally operates, and reference numeral VC1 indicates a vibration component caused by an abnormality among these vibration components. .. As shown in FIG. 3, the rotation speed of the rotation shaft 204 when the arm 203 normally operates is continuously changed with the passage of time, so that the frequency of the vibration component VC1 due to the abnormality is not stable and the vibration component VC1 is not stable. The amplitude also fluctuates in conjunction with the fluctuation of the frequency of. FIG. 6 shows the vibration components generated with the rotation of the rotating shaft 204 at the time of abnormality diagnosis, and the reference numeral VC2 indicates the vibration components caused by the abnormality among these vibration components. As shown in FIG. 4, the rotation speed of the rotation shaft 204 at the time of abnormality diagnosis is maintained at the rotation speed RV2 that can stably detect the amplitude of the vibration component VC2 due to the abnormality with an appropriate magnitude. The frequency and amplitude of VC2 are stable. In the example shown in FIG. 6, the case where the length of the period T2 is necessary and sufficient to detect the vibration component VC2 for three cycles is illustrated.

7 and 8 are explanatory views showing the relationship between the first angular position and the second angular position. As shown in FIG. 7, when the angle range θ2 from the starting angle position to the second target angle position is narrower than the angle range θ1 from the starting angle position to the first target angle position, the arm 203 at the time of abnormality diagnosis Since the operating range does not exceed the operating range of the arm 203 during normal operation, the robot 100 does not interfere with other robots or devices even if an abnormality diagnosis is performed. On the other hand, as shown in FIG. 8, when the angle range θ2 from the starting angle position to the second target angle position is wider than the angle range θ1 from the starting angle position to the first target angle position, an abnormality is diagnosed. Since the operating range of the arm 203 in the above exceeds the operating range of the arm 203 during normal operation, the robot 100 may interfere with other robots or devices at the time of abnormality diagnosis. In such a case, it is desirable to warn the user that the operating range of the arm 203 at the time of abnormality diagnosis exceeds the operating range of the arm 203 at the time of normal operation.

FIG. 9 is a flowchart showing an example of an abnormality diagnosis method for the robot body 200.
In step 901, the inspector determines the rotation axis of the rotation axis 204 of the robot body 200 to be the target of the abnormality diagnosis. FIG. 2 illustrates a case where the number of rotating shafts 204 (number of joints) of the robot body 200 is one, but the number of rotating shafts 204 may be two or more, and the number of rotating shafts 204 may be two or more. The rotation axis to be the target of abnormality diagnosis is determined.

In step 902, the inspector, for example, the performance of the torque sensor 314 (eg, the response frequency), the structure of the speed reducer 202 (eg, the circular pitch of the bearings, the diameter, number, and contact angles of the rolling elements, etc.), the speed reducer. Taking into consideration the specifications of 202 (for example, reduction ratio), the characteristics of the servomotor 206 or the servo driver 313, and the like, the rotation speed RV2 of the rotation shaft 204 capable of detecting the vibration component caused by the abnormality is determined. The inspector determines the second target angle position in consideration of the number of cycles required for detecting the vibration component caused by the abnormality. For example, as shown in FIG. 6, when detecting the vibration component VC2 for three cycles, the angular position of the rotation shaft 204 capable of detecting the vibration component VC2 for three cycles is determined as the second target angle position. The inspector gives a command to the controller 306 through the host controller 400 to perform an abnormality diagnosis of the rotating shaft 204. This command includes information that specifies the rotational speed RV2 and the second target angular position.

The rotation speed RV2 does not necessarily have to be determined by the inspector, and may be, for example, the rotation speed recommended by the manufacturer of the robot 100 for abnormality diagnosis. The rotation speed RV2 may be determined by the calculation function of the operation command unit 302 or the calculation function of the host controller 400.

In step 903, the controller 306 takes into consideration the information (rotational speed RV2 and information for designating the second target angle position) included in the command given in step 902, and the rotation speed of the rotation shaft 204 at the time of abnormality diagnosis. Determine the profile.

In step 904, the controller 306 checks whether the operating range of the arm 203 at the time of abnormality diagnosis is narrower than the operating range of the arm 203 at the time of normal operation.

In step 905, the controller 306 gives the servo driver 313 a command to rotate the rotation shaft 204 with the rotation speed profile determined in step 903. The servo driver 313 includes a feedback signal from the servomotor 206 (for example, information such as an angle position and a rotation speed) and a command value from the controller 306 (for example, a command value such as a second target angle position and a rotation speed RV2). The supply of current to the servomotor 206 is feedback-controlled so that the deviation of is zero, and the rotation shaft 204 is rotated.

In step 906, the torque sensor 314 detects a vibration component superimposed on the output torque of the servomotor 206, and outputs information related to the detected vibration component to the controller 306.

In step 907, the diagnostic module 312 performs frequency analysis (for example, fast Fourier transform) of information related to the vibration component input to the controller 306 to perform an abnormality diagnosis. For example, when the amplitude of the vibration component of a specific frequency exceeds the amplitude of the vibration component of another frequency and is significantly larger than the amplitude, the diagnostic module 312 determines that the vibration component of the specific frequency is a vibration caused by an abnormality. It may be determined that it is an ingredient.

In step 908, the controller 306 instructs the output device 316 to output the warning information. In response to this instruction, the output device 316 outputs warning information warning that the operating range of the arm 203 at the time of abnormality diagnosis exceeds the operating range of the arm 203 at the time of normal operation.

In step 909, the inspector gives a command to the controller 306 through the host controller 400 to specify whether or not to allow the execution of the abnormality diagnosis operation.

In the abnormality diagnosis of the robot 10 in the first hardware configuration, the performance of the torque sensor 314 (for example, the response frequency), the structure of the speed reducer 202 (for example, the pitch circle of the bearing, the diameter, the number, and the contact angle of the rolling elements). , Etc.), the specifications of the speed reducer 202 (for example, reduction ratio), or the characteristics of the servo motor 206 or servo driver 313, etc., the rotation speed of the rotation shaft 204 that enables detection of vibration components caused by abnormalities. RV2 is determined. Then, by rotating the rotation shaft 204 from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation shaft 204, the vibration components of one cycle or more due to the abnormality are detected. be able to. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage.

Further, by maintaining the rotation speed of the rotating shaft 204 at RV2 at the time of abnormality diagnosis, the frequency of the vibration component caused by the abnormality is stabilized at a substantially constant frequency, and the fluctuation of the amplitude caused by the fluctuation of the frequency of the vibration component is prevented. It can be suppressed. The rotation speed of the rotation shaft 204 at the time of abnormality diagnosis does not necessarily have to exactly match RV2, and a slight error within a range that does not substantially affect the fluctuation of the frequency of the vibration component is practically allowed. Can be done.

Further, by warning when the operating range of the arm 203 at the time of abnormality diagnosis exceeds the operating range of the arm 203 at the time of normal operation, for example, the user can use the robot 100 to be diagnosed as another robot. Alternatively, measures can be taken such as moving the robot 100 that is the target of the abnormality diagnosis or moving other robots or devices around the robot 100 that is the target of the abnormality diagnosis so as not to interfere with the equipment. .. In addition, this warning can alert the user to avoid the danger of interference between the robot body 200, which is the target of the abnormality diagnosis, and the operator.

[Second hardware configuration]
Next, an example of the second hardware configuration of the robot 100 will be described with reference to FIG. 2 with reference to FIG. 10 as appropriate.
The robot 100 in the second hardware configuration detects a vibration component generated from a component (for example, a speed reducer 202) of the robot body 200 instead of the torque sensor 314 in the first hardware configuration shown in FIG. It is different from the robot 100 in the first hardware configuration in that it is provided with the vibration sensor 315 of the above, and is common in other points.

In the abnormality diagnosis of the robot 100 in the second hardware configuration, the performance of the vibration sensor 315 (for example, the response frequency), the structure of the speed reducer 202 (for example, the pitch circle of the bearing, the diameter, the number, and the contact angle of the rolling elements). , Etc.), the specifications of the speed reducer 202 (for example, reduction ratio), or the characteristics of the servo motor 206 or the servo driver 313, the rotation speed of the rotation shaft 204 that enables detection of vibration components caused by abnormalities. RV2 is determined. Then, by rotating the rotation shaft 204 from the starting angle position to the second target angle position, among the vibration components generated by the rotation of the rotation shaft 204, the vibration components of one cycle or more due to the abnormality are detected. be able to. As a result, it is possible to obtain information on vibration components necessary for accurate abnormality diagnosis without any shortage.

The other effects produced by the robot 100 in the second hardware configuration are the same as the effects produced by the robot 100 in the first hardware configuration.

The robot 100 according to the present embodiment is not limited to the industrial robot used for factory automation, and is, for example, a robot used in the service industry (for example, an operating robot, a medical robot, a cleaning robot, a rescue robot, etc.). It may be a security robot, etc.).

Some or all of the above embodiments may be described, but not limited to:
(Appendix 1)
Robot control that performs abnormality diagnosis of the robot body 200 including the motor 201 that rotates the rotating shaft 204 that transmits power to the arm 203 from the starting angle position to the first target angle position so that the arm 203 performs a predetermined operation. Device 300
Of the vibration components generated by the rotation of the rotation shaft 204, the vibration component caused by an abnormality can be detected. The rotation shaft 204 rotates from the starting angle position to the second target angle position at a substantially constant rotation speed. The drive control unit 304 that drives the motor 201, and the second target angle position is the angular position of the rotation shaft 204 that enables detection of vibration components for one cycle or more due to an abnormality. 304 and
Vibration detection unit 305 that detects vibration components, and
Diagnosis unit 303 that performs abnormality diagnosis based on the detected vibration component,
A robot control device 300 comprising.

(Appendix 2)
The robot control device 300 according to Appendix 1.
When the angle range from the starting angle position to the second target angle position is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm 203 at the time of abnormality diagnosis is predetermined by the arm 203. The robot control device 300 further includes an output device 316 that outputs warning information for warning that the operating range is exceeded when performing the specified operation.

(Appendix 3)
The robot control device 300 according to Appendix 1 or 2.
The rotational speed profile of the rotating shaft 204 when the rotating shaft 204 rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis is that the rotating shaft 204 is in the starting angle position when the arm 203 performs a predetermined operation. The robot control device 300 is different from the rotation speed profile of the rotation shaft 204 when rotating from the first to the first target angle position.

(Appendix 4)
The robot control device 300 according to any one of Supplementary note 1 to 3.
The rotation speed profile of the rotation shaft 204 when the rotation shaft 204 rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis is a substantially trapezoidal shape including a period during which the rotation speed of the rotation shaft 204 becomes substantially constant. , Robot control device 300.

(Appendix 5)
The robot control device 300 detects an abnormality in the robot body 300 including the motor 201 that rotates the rotating shaft 204 that transmits power to the arm 203 from the starting angle position to the first target angle position so that the arm 203 performs a predetermined operation. Is a method of diagnosing abnormalities
The robot control device 300
Of the vibration components generated by the rotation of the rotation shaft 204, the vibration component caused by an abnormality can be detected. The rotation shaft 204 rotates from the starting angle position to the second target angle position at a substantially constant rotation speed. In step 905, which drives the motor 201, the second target angular position is the angular position of the rotating shaft 204, which enables detection of a vibration component for one cycle or more due to an abnormality.
Step 906 to detect the vibration component and
Step 907, which makes an abnormality diagnosis based on the detected vibration component,
Abnormal diagnosis method to execute.

(Appendix 6)
A robot control device that diagnoses an abnormality in a robot body 200 including a motor 201 that rotates a rotating shaft 204 that transmits power to the arm 203 from a starting angle position to a first target angle position so that the arm 203 performs a predetermined operation. An abnormality diagnosis program 310 for causing 300 to execute.
To the robot control device 300,
Of the vibration components generated by the rotation of the rotation shaft 204, the vibration component caused by an abnormality can be detected. The rotation shaft 204 rotates from the starting angle position to the second target angle position at a substantially constant rotation speed. In step 905, which drives the motor 201, the second target angular position is the angular position of the rotating shaft 204, which enables detection of a vibration component for one cycle or more due to an abnormality.
Step 906 to detect the vibration component and
Step 907, which makes an abnormality diagnosis based on the detected vibration component,
Abnormality diagnosis program 310 to execute.

100 ... Robot 200 ... Robot body 201 ... Motor 202 ... Reducer 203 ... Arm 204 ... Rotating shaft 205 ... Output shaft 206 ... Servo motor 300 ... Robot control device 301 ... Control unit 302 ... Operation command unit 303 ... Diagnosis unit 304 ... Drive Control unit 305 ... Vibration detection unit 306 ... Controller 307 ... Processor 308 ... Storage resource 309 ... Input / output interface 310 ... Abnormality diagnosis program 311 ... Operation command module 312 ... Diagnostic module 313 ... Servo driver 314 ... Torque sensor 315 ... Vibration sensor 316 ... Output device 400 ... Upper controller

Claims (5)

A robot control device that diagnoses abnormalities in a robot body including a motor that rotates a rotation axis that transmits power to the arm from a starting angle position to a first target angle position so that the arm performs a predetermined operation. ,
Among the vibration components generated by the rotation of the rotation shaft, the rotation shaft rotates from the starting angle position to the second target angle position at a substantially constant rotation speed that enables detection of the vibration component caused by an abnormality. The drive control unit that drives the motor as described above, wherein the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by the abnormality. Control unit and
A vibration detection unit that detects the vibration component and
A diagnostic unit that performs the abnormality diagnosis based on the detected vibration component, and
When the angle range from the starting angle position to the second target angle position is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis is the said. An output device that outputs warning information that warns that the arm exceeds the operating range when performing the predetermined operation, and
A robot control device equipped with. The robot control device according to claim 1.
The rotational speed profile of the rotating shaft when the rotating shaft rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis is such that the rotating shaft moves when the arm performs the predetermined operation. A robot control device different from the rotation speed profile of the rotation axis when rotating from the starting angle position to the first target angle position. The robot control device according to claim 1 or 2.
The rotation speed profile of the rotation shaft when the rotation shaft rotates from the starting angle position to the second target angle position at the time of abnormality diagnosis has a substantially trapezoidal shape including a period during which the rotation speed of the rotation shaft becomes substantially constant. Is a robot control device. Abnormality diagnosis in which the robot control device diagnoses an abnormality in a robot body including a motor that rotates a rotation axis that transmits power to the arm from a starting angle position to a first target angle position so that the arm performs a predetermined operation. It ’s a method,
The robot control device
Among the vibration components generated by the rotation of the rotation shaft, the rotation shaft rotates from the starting angle position to the second target angle position at a substantially constant rotation speed that enables detection of the vibration component caused by an abnormality. In the step of driving the motor as described above, the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by the abnormality.
The step of detecting the vibration component and
A step of performing an abnormality diagnosis of the robot body based on the detected vibration component, and
When the angle range from the starting angle position to the second target angle position is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis is the said. A step of outputting warning information warning that the arm exceeds the operating range when performing the predetermined operation, and a step of outputting warning information .
Abnormal diagnosis method to execute. To cause the robot control device to perform abnormality diagnosis of a robot body including a motor that rotates a rotation axis that transmits power to the arm from a starting angle position to a first target angle position so that the arm performs a predetermined operation. Abnormality diagnosis program
To the robot control device
Among the vibration components generated by the rotation of the rotation shaft, the rotation shaft rotates from the starting angle position to the second target angle position at a substantially constant rotation speed that enables detection of the vibration component caused by an abnormality. In the step of driving the motor as described above, the second target angular position is an angular position of the rotation axis that enables detection of a vibration component for one cycle or more caused by the abnormality.
The step of detecting the vibration component and
The step of performing the abnormality diagnosis based on the detected vibration component, and
When the angle range from the starting angle position to the second target angle position is wider than the angle range from the starting angle position to the first target angle position, the operating range of the arm at the time of abnormality diagnosis is the said. A step of outputting warning information warning that the arm exceeds the operating range when performing the predetermined operation, and a step of outputting warning information .
Abnormal diagnosis program to execute.

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