JP2014054692A - State discrimination method, robot, control device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily discriminate the state of a force sensor while preventing application of an excess force to the force sensor and other components.SOLUTION: An target object for state discrimination including an elastic body is deformed by an arm of a robot. A magnitude of deformation of the deformed target object for state discrimination is detected. A value representing a force or moment applied to a force sensor of the robot is determined from the detected magnitude of deformation. The state of the force sensor is discriminated based on the determined value representing the force or moment.

Description

  The present invention relates to a state determination method, a robot, a control device, and a program.

  For example, a robot equipped with a force sensor is known in order to prevent damage to a workpiece or an end effector. In general, a force sensor needs to be calibrated because detection accuracy may be lowered due to an excessive load or aging.

  For example, in Patent Document 1, a pair of end effectors are brought into contact with each other at the time of measurement, and act on the other end effector to be calibrated based on the measured value of a calibrated force sensor corresponding to one end effector. A force sensor that calculates a value indicating the force being updated and updates the conversion data so that the measured value of the force sensor corresponding to the other end effector to be calibrated is the same as the value indicating the calculated force The calibration method is described.

JP 2012-13537 A

  However, the above Patent Document 1 is based on the premise that the force sensor of one end effector is already calibrated at the time of measurement, and it is not possible to determine whether or not the one force sensor is operating normally. Can not. Therefore, a user's work is required in advance so that the one force sensor operates normally, and a user's work load is generated. In the first place, when the calibration of one of the force sensors is not appropriate, it cannot be determined whether or not the force sensor of the other end effector is operating normally.

  Moreover, in said patent document 1, a pair of end effector is mutually contact | abutted at the time of a measurement. Therefore, an excessive force may be applied to the force sensor and the end effector. In some cases, the force sensor or the end effector may be damaged.

  Therefore, an object of the present invention is to prevent an excessive force from being applied to the force sensor or the like and to easily determine the state of the force sensor.

  The present application includes a plurality of means for solving the above-described problems, and examples thereof are as follows.

  A first aspect of the present invention that solves the above problem is a state determination method for determining a state of a robot having an arm and a force sensor, and uses a state determination target including an elastic body. An operation step of operating the robot to deform the state determination target object by the arm; a detection step of detecting a deformation amount of the state determination target object deformed in the operation step; Based on the calculation step for calculating a value indicating the force or moment applied to the force sensor from the deformation amount detected in the detection step, and based on the value indicating the force or moment calculated in the calculation step, And a discrimination step of discriminating the state of the sense sensor.

  According to said structure, in order to discriminate | determine the state of a force sensor by making a force sensor etc. contact the state discrimination target object containing an elastic member, it is made not to apply excessive force to a force sensor etc. At the same time, the state of the force sensor can be easily determined.

  Here, the object for state determination further includes a rigid body, and in the operation step, the arm is brought into contact with the rigid body of the object for state determination and the state determination is performed by the arm. The object may be deformed.

  According to said structure, it becomes easy to apply the external force by an arm with respect to the object for state determination with a rigid body.

  The state determining object is configured such that both end surfaces of the elastic body are sandwiched between the rigid bodies. In the operation step, the rigid body on one end surface of the state determining object is In a state where the position and orientation are fixed, the arm may be brought into contact with the rigid body on the other end surface of the state determining object, and the state determining object may be deformed by the arm. .

  According to the above configuration, the rigid body can fix or support the state determination target object in a stable state, and can easily apply an external force from the arm to the state determination target object.

  The robot has a plurality of the arms, and in the operation step, the position and orientation of the rigid body on the one end surface are fixed by a first arm among the plurality of arms, and the plurality of arms It is good also as making the said 2nd arm contact the said rigid body of said other end surface, and deform | transforming the said object for state determination with said 2nd arm.

  According to said structure, compared with the case where the state determination target object is set | placed on a floor etc., a state determination target object can be reliably fixed with a 1st arm, and state determination can be performed.

  In the calculation step, a value indicating a force or moment applied to the force sensor of the arm from the deformation amount detected in the detection step for at least one of the first arm and the second arm. In the determination step, for at least one of the first arm and the second arm, based on a value indicating the force or moment calculated in the calculation step, the state of the force sensor of the arm It is good also as a feature to discriminate | determine.

  According to the above configuration, the state determination can be performed in parallel for both the first arm and the second arm, so that the time required for the state determination can be reduced.

  Further, in the detection step, the deformation amount is detected by photographing the state determination object and identifying a change in a position of a feature point of the state determination object based on the captured image information. This may be a feature.

  According to said structure, the variation | change_quantity of the object for state determination can be detected more easily.

  The feature point may be set in at least a part of the rigid body.

  According to said structure, since the position and direction of a feature point change integrally with the position and direction of a rigid body, it becomes easy to specify the deformation amount.

  In the calculation step, information for specifying a relationship between the deformation amount of the state determination target object and a force or a moment corresponding to the deformation amount is acquired, and the detection step detects the information based on the acquired information. A force or moment applied to the force sensor may be calculated from the deformation amount.

  According to the above configuration, the force or moment applied to the force sensor can be easily obtained from the deformation amount.

  In the determination step, a sensor value output from the force sensor in a state in which the state determination target object is deformed in the operation step is acquired, and the acquired sensor value and the calculation step are calculated. It may be characterized by determining whether or not a difference from a value indicating a force or a moment is within a predetermined range.

  According to said structure, the state of a force sensor can be discriminate | determined based on the sensor value of an actual force sensor.

  The force sensor is any one of first to third axial forces orthogonal to each other, and moments about first to third axes that are about the first to third axial directions. The state determining object is configured such that the rigid body on the one end surface and the rigid body on the other end surface are formed in parallel to each other. In the operation step, With respect to one axial direction, the arm is operated so that the rigid body on the other end surface approaches the rigid body on the one end surface in parallel, and the other end surface with respect to the second axial direction. The arm is operated so that the rigid body of the first end surface moves in the second axial direction while being parallel to the rigid body of the one end surface, and the third end of the other end surface is moved in the third axial direction. A rigid body is connected to the rigid body on the one end surface. The arm is operated so as to move in the third axial direction in a row, and the rigid body on the other end surface is parallel to the rigid body on the one end surface about the first axis. The arm is operated so as to rotate with reference to the first axial direction, and the rigid body on the other end surface rotates with respect to the second axial direction around the second axis. The arm is operated, and the arm is operated so that the rigid body on the other end surface rotates around the third axis with reference to the third axial direction. It is good.

  According to said structure, according to the force or moment of the state determination object of a force sensor, the state determination target object can be deformed.

  A second aspect of the present invention that solves the above-described problem is a robot for state determination, in which an arm, a force sensor, and the arm are operated, and the arm includes an elastic body. A control unit that deforms the object, a detection unit that detects a deformation amount of the state determination object deformed by the arm, and the deformation amount detected by the detection unit are added to the force sensor. A calculation unit that calculates a value indicating a force or a moment; and a determination unit that determines a state of the force sensor based on the value indicating the force or the moment calculated by the calculation unit. To do.

  According to the above configuration, in the robot, an excessive force is not applied to the force sensor or the like, and the state of the force sensor can be easily determined.

  A third aspect of the present invention that solves the above problem is a robot control device having an arm and a force sensor, wherein the arm is operated and the arm includes an elastic body. A control unit that deforms the object for determination, a detection unit that detects the deformation amount of the object for state determination deformed by the arm, and the deformation sensor detected by the detection unit are added to the force sensor. A calculation unit that calculates a value indicating the force or moment that is present, and a determination unit that determines the state of the force sensor based on the value indicating the force or moment calculated by the calculation unit. Features.

  According to the above configuration, in the control device, it is possible to prevent an excessive force from being applied to the force sensor or the like and to easily determine the state of the force sensor.

  A fourth aspect of the present invention that solves the above-described problem is a program for a robot control device having an arm and a force sensor, wherein the arm includes a state determination target including an elastic body. An operation step for deforming, a detection step for detecting a deformation amount of the object for state determination deformed in the operation step, and a force applied to the force sensor from the deformation amount detected in the detection step, or Causing the control device to execute a calculation step for calculating a value indicating a moment, and a determination step for determining a state of the force sensor based on the value indicating the force or the moment calculated in the calculation step. It is characterized by.

  According to the above configuration, it is possible to realize a control device that prevents excessive force from being applied to the force sensor or the like and can easily determine the state of the force sensor.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a schematic diagram illustrating an example of a robot system 1 according to a first embodiment of the present invention. It is a figure explaining the force and moment which force sensor 25 detects. It is a figure which shows an example of the state determination target object. 2 is a block diagram illustrating an example of a functional configuration of a robot system 1. FIG. 6 is a diagram illustrating an example of a conversion table 1100. FIG. 2 is a block diagram illustrating an example of a hardware configuration of a computer 50. FIG. It is a flowchart which shows an example of a state discrimination | determination process. It is a figure explaining the deformation | transformation of the operation | movement of the arm 21 of Fz, and the object 40 for state determination. It is a figure explaining the operation | movement of the arm 21 of Fx (or Fy), and the deformation | transformation of the object 40 for state determination. It is a figure explaining the deformation | transformation of the operation | movement of the arm 21 of Mz, and the object 40 for state determination. It is a figure explaining the deformation | transformation of the operation | movement of the arm 21 of Mx (or My), and the object 40 for state determination. It is a flowchart which shows an example of the state discrimination | determination process which concerns on 2nd embodiment of this invention. It is a figure explaining the deformation | transformation of the operation | movement of the arm 21, and the state determination target object. It is a figure which shows an example of the conversion table 1100A which concerns on 3rd embodiment of this invention. It is a figure explaining the deformation | transformation of the operation | movement of the arm 21, and the state determination target object. It is a figure explaining operation | movement of the arm 21 which concerns on 4th embodiment of this invention, and the deformation | transformation of the object 40 for state determination.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating an example of a robot system 1 according to an embodiment of the present invention. As shown in the figure, the robot system 1 includes a control device 10, a robot 20, and a photographing device 30. In addition, the robot system 1 uses a state determination object 40 to determine the state (for example, normal or abnormal) of the force sensor 25 of the robot 20.

  The control device 10 controls the operation of the robot 20. The control device 10 is communicably connected to the robot 20 and the imaging device 30 by wire or wireless.

  For example, the control device 10 acquires image information from the imaging device 30 and recognizes a work object (hereinafter, also referred to as “work”. The work also includes “state determination object”) by image recognition. To do. Further, for example, a series of operations of the robot 20 with respect to the recognized workpiece is determined. Further, for example, based on the output signals of the force sensor 25 of the robot 20, other sensors (not shown), and an encoder (not shown), the arm 21 (21a, 21b), the end effector 26, etc. of the robot 20 are the target. The robot 20 is controlled so as to be in the position and orientation.

  In the present embodiment, the control device 10 determines the state of the force sensor 25 of the robot 20 by using the state determination object 40 at a predetermined timing such as before starting work. That is, it is checked whether the force sensor 25 is normal.

  The robot 20 has two arms 21 (21a, 21b) attached to the robot body. A force sensor 25 is attached to the tip of the arm 21, and the end effector 26 can be attached and detached via the force sensor 25. The end effector 26 is, for example, a hand, and works by directly holding the work or working on the work with a tool such as an electric screwdriver.

  In the present embodiment, the end effector 26 is detached from the arm 21 when determining the state of the force sensor 25.

  The arm 21 has a plurality of joints 22 and a plurality of links 23. Each joint 22 connects the robot body and the link 23, the links 23, and the link 23 and the end effector 26 so as to be rotatable (but rotatable within a predetermined movable range). Each joint 22 is, for example, a rotary joint, and is provided so that the angle between the links can be changed and the link can be rotated about the axis.

  The robot 20 drives the joints 22 in conjunction with each other so that the tip of the arm 21 can be freely moved (within a predetermined movable range) and can be directed in any direction. . The arm 21 can be, for example, a seven-axis arm having seven joints.

  Note that actuators and sensors (not shown) are provided on the movable part of the robot 20. The actuator includes, for example, a motor, a drive circuit for the motor, an encoder, and the like. The encoder value output by the encoder and the sensor value output by the sensor are output to the control device 10 in order to control the operation of the movable part.

  The force sensor 25 is, for example, a six-axis force sensor as shown in FIG. 2 (a diagram illustrating the force and moment detected by the force sensor 25). That is, the force sensor 25 detects three force components Fx, Fy, and Fz that are orthogonal to each other and three force moment components Mx, My, and Mz around those axes. If the axes orthogonal to each other are the first to third axes, the force component Fz is the force in the direction of the first axis, the force component Fx is the force in the direction of the second axis, and the force component Fy is the first component. The force in the direction of the three axes. The force moment component Mz is a moment around the first axis, the force moment component Mx is a moment around the second axis, and the force moment component My is a moment around the third axis. .

  In the present embodiment, the force sensor 25 positioned at the tip of the arm 21 in a state where the end effector 26 is not attached is brought into contact with a predetermined position of the state determination target 40 to apply a force or a moment. Then, the object 40 for state determination is deformed. Therefore, the end surface of the force sensor 25 that is brought into contact with the state determination target object 40 is formed in a flat shape.

  In the present embodiment, when the force sensor 25 is brought into contact with the state determination object 40, a point (working point) WP at a predetermined position on the end surface of the force sensor 25 is set to the end surface of the state determination object 40. A point (target point) CP at a predetermined position is adjusted.

  The configuration of the robot 20 described above is not limited to the configuration described above because the main configuration has been described in describing the features of the present embodiment. In addition, the configuration of a general gripping robot is not excluded. For example, the number of axes (number of joints) and the number of links may be increased or decreased. In addition, the shape, size, arrangement, structure, and the like of various members such as an arm, an end effector, a link, a joint, and a force sensor may be appropriately changed.

  Returning to FIG. 1, the imaging device 30 captures the work space and generates image data. The imaging device 30 includes, for example, a camera. The imaging device 30 shoots a work space including a work, for example, under the control of the control device 10, generates image data, and outputs it to the control device 10. The installation location is not particularly limited, and can be, for example, on the floor, on the work table, the ceiling, or the wall. Of course, a plurality of imaging devices 30 may be provided according to the imaging range and the imaging direction.

  The state discriminating object 40 is a tool (also referred to as “tool” or “jig”) used to discriminate the state of the force sensor 25. The state determination target object 40 is shown in FIG. 3 (a diagram illustrating an example of the state determination target object 40), for example. FIG. 3 is a perspective view of the appearance of the state determination object 40.

  The object 40 for state determination is a cube shape as a whole, and is composed of a cubic elastic member 41 and flat rigid members 42 (42a, 42b) provided on both end faces of the elastic member 41 in parallel. Is done. Note that “parallel” in this application includes a parallel state and a substantially parallel state.

  In the present embodiment, the elastic member 41 is deformed by the tip portion of the arm 21 contacting the rigid member 42 and applying a force or moment. Then, based on the positional relationship between the feature points set in the rigid member 42a and the rigid member 42b, the deformation amount of the state determination object 40 is calculated.

  Therefore, the state determination object 40 is constituted by an elastic member 41 and a rigid member 42. For the elastic member 41, for example, rubber or resin having reversible deformability can be used so that the deformation amount can be accurately calculated and used repeatedly. For the rigid member 42, for example, rubber, metal, resin, or the like harder than the elastic member 41 can be used so as not to be deformed as much as possible by force or moment.

  The rigid member 42 can fix or support the object 40 for state determination in a stable state, and can easily apply force or moment. Also, by setting feature points in the rigid member 42, the position and orientation of the feature points change integrally with the position and orientation of the rigid member 42, so that it becomes easy to specify the amount of deformation described later.

  3 is an example, and the configuration, material, shape, and the like are not limited as long as the state determination of the force sensor 25 described later can be realized. For example, the whole may be configured by an elastic member, or an elastic member harder than the elastic member 41 may be used instead of the rigid member 42. In this case, the feature point may be set to the hard elastic member. For example, the shape may be a rectangular parallelepiped shape, a cylindrical shape, or the like.

  The configuration of the robot system 1 in FIG. 1 described above is the main configuration in describing the features of the present embodiment, and does not exclude the configuration of a general robot system. For example, the control device 10 may be included in the robot 20. For example, the imaging device 30 may be included in the control device 10 or the robot 20.

  FIG. 4 is a block diagram illustrating an example of a functional configuration of the robot system 1.

  The robot 20 includes a movable unit 200 and an operation control unit 210.

  The movable unit 200 is a part that can be changed in position and orientation (also referred to as “posture”). The movable unit 200 includes, for example, an arm 21, a joint 22, a link 23, and an end effector 26. Further, a unit related to the movable unit 200, for example, an actuator (motor, encoder, etc.) and various sensors (force sensor 25, etc.) are also included.

  The operation control unit 210 changes the position and orientation of the movable unit 200 in accordance with a control command from the control device 10. The operation control unit 210 directly rotates the joint 22 by directly controlling the rotation of the motor and the like, and changes the position and orientation of the movable unit 200. Further, the operation control unit 210 acquires the sensor value from the force sensor 25 and other sensors and outputs the sensor value to the control device 10. Further, the operation control unit 210 acquires the encoder value from the encoder and outputs it to the control device 10.

  The control device 10 includes a control unit 100 and a storage unit 110.

  The storage unit 110 stores the deformation amount of the state determination target 40 caused by an external force (including force and moment) applied from the force sensor 25, and the stress (force and moment) of the state determination target 40 with respect to the force sensor 25. The conversion information used for conversion to (including) is stored.

  The conversion information can be configured as a table as shown in FIG. 5 (a diagram showing an example of the conversion table 1100), for example. The conversion table 1100 includes conversion information for each of the six-axis components (Fx, Fy, Fz, Mx, My, Mz) 1101. The conversion information of each component 1101 includes a record in which a value (deformation amount) 1102 indicating a deformation amount corresponding to the component and a value (stress) 1103 indicating a stress corresponding to the value indicating each deformation amount are associated. It is.

  The component 1101 corresponds to each component of the force sensor 25. The deformation amount 1102 is obtained by quantifying the amount (size) of deformation generated in the state determination target object 40 by applying a specific amount (size) of force or moment to the state determination target object 40. It is. The stress 1103 is a numerical value of the amount (magnitude) of the stress generated with respect to the external force that causes the deformation. In the present embodiment, the external force and the stress are assumed to be equal.

  The conversion information can be created in advance, for example, by causing deformation of each component by experiment and measuring the deformation amount and the corresponding stress. Hereinafter, an example of a method for creating the conversion information will be specifically described with reference to FIGS.

  8 to 11 show a state viewed from the side surface in a state where the end surface of the rigid member 42b of the state determining object 40 is in contact with a flat surface such as a floor. The feature points are set at both ends (P1, P3) and the center (P2) of the side surface of the rigid member 42a, and both ends (P4, P6) and the center (P5) of the side surface of the rigid member 42b.

  Further, for example, the working point WP (see FIG. 2) set at the center of gravity of the end surface of the force sensor 25 and the end surface of the rigid member 42a are applied so as to apply a uniform force as much as possible to the entire state determination target 40. The force sensor 25 and the rigid member 42a are brought into contact so that the target point CP (see FIG. 3) set at the center of gravity is matched. (A) of each figure shows the state before deformation | transformation of the object 40 for state determination, (B) of each figure has shown the state after the deformation | transformation of the object 40 for state determination.

  In addition, when producing said conversion information, the state of the force sensor 25 shall be normal, and shall be calibrated appropriately. The measurement is performed so that the position and orientation of the rigid member 42b on the floor do not change (so that the position and orientation of the rigid member 42b can be handled as fixed).

<Fz component>
As shown in FIG. 8 (a diagram illustrating the operation of the Fz arm 21 and the deformation of the state determination target 40), the Fz direction between the feature points P2 and P5 before and after the deformation of the state determination target 40 is obtained. The difference between the linear distances D1 and D2 is defined as the deformation amount of the Fz component. By bringing the force sensor 25 into contact with the rigid member 42a and applying a force in the Fz direction, the deformation amount of the Fz component and the corresponding stress are measured. Then, Fz component conversion information is created based on the measurement result.

<Fx (or Fy) component>
Since Fx and Fy are orthogonal directions, they are the same except that different side surfaces forming the corners of the state determination target 40 are used. As shown in FIG. 9 (a diagram illustrating the operation of the arm 21 and the deformation of the state determination target 40 in FIG. 9), Fx of the feature points P2 and P5 before and after the deformation of the state determination target 40 is obtained. The difference between the linear distances D3 and D4 in the (or Fy) direction is defined as the deformation amount of the Fx (or Fy) component. By bringing the force sensor 25 into contact with the rigid member 42a and applying a force in the Fx (or Fy) direction, the deformation amount of the Fx (or Fy) component and the corresponding stress are measured. Then, conversion information of the Fx (or Fy) component is created based on the measurement result. When deforming, the contact surface of the force sensor 25 and the rigid member 42a and the contact surface of the rigid member 42b and the floor are pressed in the Fz direction so that they do not slip and shift, while in the Fx (or Fy) direction. Apply the power of.

<Mz component>
As shown in FIG. 10 (a diagram illustrating the operation of the Mz arm 21 and the deformation of the state determination target 40), Fx or Fy between the feature points P2 and P5 before and after the deformation of the state determination target 40 is obtained. The difference between the linear distances D5 and D6 in the direction (or the difference converted into a rotation angle) is defined as the deformation amount of the Mz component. By bringing the force sensor 25 into contact with the rigid member 42a and applying a moment in the Mz rotation direction, the deformation amount of the Mz component and the corresponding stress are measured. Then, conversion information of the Mz component is created based on the measurement result. When deforming, the contact surface of the force sensor 25 and the rigid member 42a and the contact surface of the rigid member 42b and the floor are pressed in the Fz direction so that they do not slip and shift, and the moment in the Mz rotation direction is increased. Multiply.

<Mx (or My) component>
Since Fx, which is the axis of Mx, and Fy, which is the axis of My, are orthogonal to each other, they are the same except that different side surfaces forming the corners of the state determination object 40 are used. As illustrated in FIG. 11 (a diagram illustrating the operation of the arm 21 and the deformation of the state determination target 40 in FIG. 11), between the feature points P3 and P4 before and after the deformation of the state determination target 40. The difference between the linear distances D7 and D8 in the Fz direction (or the difference converted to a rotation angle) is defined as the deformation amount of the Mx (or My) component. By bringing the force sensor 25 into contact with the rigid member 42a and applying a moment in the Mx (or My) rotation direction with respect to the Fx axis (or Fy axis), the deformation amount of the Mx (or My) component and the corresponding stress are obtained. measure. Then, conversion information of the Mx (or My) component is created based on the measurement result.

  The configuration of the conversion information and the creation method of the conversion information are examples, and the configuration and the creation method are not limited as long as the stress corresponding to the deformation amount can be obtained. For example, the position of the feature point, the definition of the deformation amount, and the like are not limited to the illustrated example. Further, when creating the conversion information, it is not necessary to actually use a robot. For example, a tool or a sensor that replaces the robot may be used. Further, for example, a relational expression between the deformation amount and stress of each component is derived based on values such as the Young's modulus and rigidity of the state determination target 40, and conversion information is created based on this relational expression. May be.

  Returning to FIG. 4, the control unit 100 comprehensively controls the control device 10. The control unit 100 includes an image acquisition unit 101, a robot control unit 102, a deformation amount detection unit 103, a stress calculation unit 104, a state determination unit 105, and a notification unit 106.

  The image acquisition unit 101 controls the imaging device 30 to acquire image information of the work space including the state determination target object 40.

  The robot control unit 102 analyzes the image information acquired by the image acquisition unit 101 and detects the position, orientation, shape, and the like of the state determination target object 40. The detection method of the state discrimination target 40 is not particularly limited, and various existing image recognition techniques can be used. For example, a feature point of the state determination target 40 can be extracted, and the state determination target 40 can be recognized by matching processing.

  Further, the robot control unit 102 generates and outputs a control command for controlling the operation of the robot 20. For example, the robot controller 102 brings the force sensor 25 into contact with the rigid member 42 of the state determination target 40 and further applies an external force of each component (Fx, Fy, Fz, Mx, My, Mz). The operation of the movable part 200 is controlled. Further, the robot control unit 102 acquires the sensor value of the force sensor 25 and outputs it to the state determination unit 105.

  The deformation amount detection unit 103 analyzes the image information acquired by the image acquisition unit 101 and detects the position, orientation, shape, and the like of the state determination target object 40. Further, the deformation amount detection unit 103 identifies the component of the external force applied to the state determination target object 40 by the robot 20, and the deformation corresponding to the specified component from the shape before and after the deformation of the state determination target object 40. Find the amount.

  The stress calculation unit 104 refers to the conversion table 1100, and the deformation amount 1102 corresponding to the deformation amount detected by the deformation amount detection unit 103 from the conversion information of the component 1101 corresponding to the external force applied to the state determination object 40. And the stress 1103 associated with the deformation amount 1102 is acquired.

  The state determination unit 105 acquires the sensor value of the force sensor 25 when the state determination target 40 is deformed by the robot 20 via the robot control unit 102. The stress calculated by the stress calculation unit 104 is acquired.

  In addition, the state determination unit 105 obtains a difference between the acquired sensor value and the acquired stress, and determines whether the difference is equal to or less than a predetermined threshold value. The predetermined threshold is a value for determining whether or not the detection accuracy of the force sensor 25 is appropriate (whether or not it is operating normally). If the difference is equal to or less than a predetermined threshold, it is determined that the difference is normal. One predetermined threshold may be prepared in common for each component of the force sensor 25, or different values may be prepared for at least some of the components.

  Ideally, if the force sensor 25 is normal, the stress calculated from the deformation amount of the state determination target object 40 matches the force detected by the force sensor 25. Based on this premise, the determination using the predetermined threshold as described above is performed in consideration of the tolerance of the deformation amount detection error and the like.

  The notification unit 106 outputs information indicating the determination result of the state determination unit 105. The output destination is, for example, a display, a storage device, an external device, or the like.

  The control device 10 described above includes, for example, a CPU (Central Processing Unit) 501, a memory 502, an HDD (Hard Disk Drive), etc. as shown in FIG. 6 (a block diagram showing an example of the hardware configuration of the computer 50). External storage device 503, communication device 504 for connecting to a communication network or robot by wire or wireless, input device 505 such as a mouse, keyboard, touch sensor, touch panel, output device 506 such as a liquid crystal display, DVD This can be realized by a computer 50 including a read / write device 507 for reading / writing information on a portable storage medium such as (Digital Versatile Disk) and an interface device 508 such as a USB (Universal Serial Bus) connected to an external device.

  For example, the storage unit 110 can be realized by the CPU 501 using the memory 502 or the external storage device 503. The control unit 100 can be realized by loading a predetermined program stored in the external storage device 503 into the memory 502 and executing it by the CPU 501. Communication between the control unit 100 and the imaging device 30 can be realized by the CPU 501 using the communication device 504 or the interface device 508, for example. Communication between the control unit 100 and the robot 20 can be realized by the CPU 501 using the communication device 504 or the interface device 508, for example.

  The predetermined program may be downloaded from the network to the external storage device 503 via the communication device 504, and then loaded onto the memory 502 and executed by the CPU 501. Alternatively, it may be loaded directly from the network onto the memory 502 via the communication device 504 and executed by the CPU 501. Further, the computer 50 may load the predetermined program into the external storage device 503 or the memory 502 from a storage medium set in the read / write device 507 or a storage medium connected to the interface device 508. .

  The above functional configuration is classified according to the main processing contents in order to facilitate understanding of the configuration of the robot system 1. The present invention is not limited by the way of classification and names of the constituent elements. The configuration of the robot system 1 can be classified into more components depending on the processing content. Moreover, it can also classify | categorize so that one component may perform more processes. Further, the processing of each component may be executed by one hardware or may be executed by a plurality of hardware.

  For example, at least a part of the functions of the control device 10 may be included in the robot 20. In this case, the imaging device 30 may be connected to the robot 20 instead of the control device 10 or may be built in the robot 20. Further, for example, the storage unit 110 may be prepared as an external device of the control device 10 and the robot 20.

  Next, a method for determining the state of the force sensor 25 performed in the robot system 1 will be described.

  In the state determination method of this embodiment, the end effector 26 is removed from the arm 21 having the force sensor 25 that is a state determination target. The state determination object 40 is placed so that the end surface of one rigid member 42b is in contact with a flat surface such as a floor. Further, the state of the force sensor 25 is determined by bringing the force sensor 25 as a state determination target into contact with the end surface of the other rigid member 42a of the state determination target 40. In addition, when the force sensor 25 is brought into contact with the object 40 for state determination, the point (working point) WP on the end surface of the force sensor 25 is set to the point (work point) WP on the end surface of the state determination object 40 ( (Target point) Set to CP.

  FIG. 7 is a flowchart showing an example of the state determination process. This flow shows processing for each component that can be detected by the force sensor 25. It is assumed that the component for state determination is specified by the user, for example.

  The robot control unit 102 acquires image information from the image acquisition unit 101, analyzes the acquired image information, and detects the position, orientation, shape, and the like of the state determination target 40 (S10). Then, the robot control unit 102 works on the end portion of the arm 21 where the end surface of the force sensor 25 as the state determination target contacts the end surface of the rigid member 42a of the state determination target object 40 in parallel. The position and orientation of the WP are obtained (S20). Here, the position and orientation of the work point WP that matches the target point CP of the rigid member 42a are obtained.

  In addition, the robot control unit 102 generates a trajectory for moving the work point WP to the position and orientation obtained in step S20 (S30). Then, the robot control unit 102 generates a control command according to the trajectory obtained in step S30 and outputs it to the robot 20, moves the work point WP, and brings the end face of the force sensor 25 into contact with the end face of the rigid member 42a. (S40). In this state, it is assumed that the state discriminating object 40 is brought into contact so as not to be deformed.

  The above steps S10 to S40 are processes common to the respective components. Steps S50 to S110 will be described in common for each component, and then the case of each component will be described using a specific example.

  The robot control unit 102 generates a trajectory of the work point WP that deforms the state determination target 40 in accordance with the state determination target component of the force sensor 25 (S50). Then, the robot control unit 102 generates a control command according to the trajectory obtained in step S50 and outputs the control command to the robot 20, moves the work point WP, and deforms the state determination target 40 (S60).

  The deformation amount detection unit 103 acquires image information including the state determination target object 40 in the state deformed in step S60 from the image acquisition unit 101, and recognizes the shape of the state determination target object 40 recognized from the image information (after deformation). ) And the shape before deformation, and the deformation amount of the component corresponding to the component for which the force sensor 25 is subjected to state determination is obtained (S70).

  Then, the stress calculation unit 104 refers to the conversion table 1100, and corresponds to the deformation amount obtained by the deformation amount detection unit 103 in step S70 from the conversion information of the component 1101 corresponding to the state determination target component of the force sensor 25. The deformation amount 1102 to be specified is specified, and the stress 1103 associated with the deformation amount 1102 is acquired (S80).

  Then, the state determination unit 105 transmits the sensor value corresponding to the state determination target component of the force sensor 25 in the state where the state determination target object 40 is deformed in step S60 via the robot control unit 102. Obtain (S90).

  Then, the state determination unit 105 obtains a difference between the sensor value acquired in step S90 and the stress calculated in step S89, and determines whether the difference is equal to or less than a predetermined threshold corresponding to the state determination target component. Determine (S100).

  When the difference between the sensor value and the stress exceeds a predetermined threshold (S100: N), for example, the notification unit 106 outputs that the force sensor 25 is abnormal in a display device or another device. For example, information for identifying the force sensor 25 determined to be abnormal (for example, the position of the right arm, the left arm, etc.) may be output. Further, for example, components determined to be abnormal (for example, Fx, Fy, etc.) may be output.

  When the difference between the sensor value and the stress is equal to or smaller than the predetermined threshold (S100: Y), the control device 10 ends this flow. In this case, the notification unit 106 may output that the force sensor 25 is normal.

  An example of a method for determining the state of each component will be specifically described with reference to FIGS. Note that, in order to appropriately calculate the deformation amount, the image acquisition unit 101 acquires the image information by controlling the imaging device 30 so that the feature points necessary for calculating the deformation amount are included in the image information. . In addition, the arm 21 is operated so that the position and orientation of the rigid member 42b on the floor do not change (so that the position and orientation of the rigid member 42b can be handled as fixed).

<For Fz>
FIG. 8 is a diagram for explaining the operation of the Fz arm 21 and the deformation of the object 40 for state determination.

  The robot control unit 102 controls the operation of the arm 21 so that the rigid member 42a moves in the Fz direction (downward in the figure) while keeping parallel to the rigid member 42b. That is, the robot control unit 102 operates the arm 21 so that the work point WP of the force sensor 25 moves linearly by a predetermined distance in the Fz direction.

  The deformation amount detection unit 103 obtains the linear distance D1 in the Fz direction between the feature points P2 and P5 before the deformation from the image information, or acquires the value when determined in advance. In addition, the deformation amount detection unit 103 obtains a linear distance D2 in the Fz direction between the deformed feature points P2 and P5 from the image information. Then, the difference between D1 and D2 is obtained as the deformation amount in the Fz direction.

  The stress calculation unit 104 refers to the conversion table 1100, specifies the deformation amount 1102 corresponding to the obtained deformation amount in the Fz direction from the conversion information of the Fz component 1101, and stress associated with the deformation amount 1102 1103 is acquired.

  The state determination unit 105 obtains a difference between the sensor value of the Fz component of the force sensor 25 in the state (B) and the stress of the acquired Fz component, and determines whether the difference is equal to or less than a predetermined threshold. .

<Fx (or Fy)>
FIG. 9 is a diagram illustrating the operation of the Fx (or Fy) arm 21 and the deformation of the state determination target 40. Since Fx and Fy are orthogonal directions, the processing contents are the same except that image information on different side surfaces forming the corner of the state determination target object 40 is used. Therefore, Fx and Fy will be described in common. Further, the description will be focused on the points different from FIG.

  The robot control unit 102 controls the operation of the arm 21 so that the rigid member 42a moves in the Fx (or Fy) direction (right direction in the drawing) while keeping parallel to the rigid member 42b. That is, the robot control unit 102 operates the arm 21 so that the work point WP of the force sensor 25 moves linearly by a predetermined distance in the Fx (or Fy) direction. Note that the robot control unit 102 presses the work point WP in the Fz direction so that the contact surface of the force sensor 25 and the rigid member 42a and the contact surface of the rigid member 42b and the floor do not slide and move in the Fz direction. Move in the (or Fy) direction.

  The deformation amount detection unit 103 obtains a linear distance D4 in the Fx direction between the deformed feature points P2 and P5 from the image information. Then, the difference between the linear distance D3 (D3 = 0) in the Fx direction between the feature points P2 and P5 before deformation and D4 is obtained as the deformation amount in the Fx (or Fy) direction.

  Since the stress calculation unit 104 and the state determination unit 105 may perform processing for Fx (or Fy), description thereof is omitted.

<In the case of Mz>
FIG. 10 is a diagram for explaining the operation of the Mz arm 21 and the deformation of the object 40 for state determination. In addition, in (B), the figure which looked at the object 40 for state determination from the rigid member 42a side is also shown. The points different from FIG. 8 will be mainly described.

  The robot control unit 102 controls the operation of the arm 21 so that the rigid member 42a rotates in the Mz direction (clockwise in the drawing) with the Fz axis as a reference while maintaining the parallelism with the rigid member 42b. That is, the arm 21 is operated so that the force sensor 25 rotates by a predetermined angle in the Mz rotation direction with respect to the Fz axis. In addition, the robot control unit 102 presses the work point WP in the Fz direction so that the contact surface of the force sensor 25 and the rigid member 42a and the contact surface of the rigid member 42b and the floor do not slip each other. Rotate in the direction of rotation.

  The deformation amount detection unit 103 obtains the linear distance D6 in the Fx or Fy direction between the deformed feature points P2 and P5 from the image information. Then, the difference between the linear distance D5 (D5 = 0) in the Fx or Fy direction between the feature points P2 and P5 before deformation and D6 (or the difference converted into a rotation angle) is used as the deformation amount of Mz. Ask.

  Since the stress calculation unit 104 and the state determination unit 105 only need to perform processing for Mz, description thereof is omitted.

<Mx (or My)>
FIG. 11 is a diagram for explaining the operation of the Mx (or My) arm 21 and the deformation of the object 40 for state determination. Since Fx, which is the axis of Mx, and Fy, which is the axis of My, are orthogonal to each other, the processing content is the same except that image information on different sides forming the corner of the state determination target object 40 is used. Therefore, Mx and My will be described in common. Further, the description will be focused on the points different from FIG.

  The robot control unit 102 controls the arm 21 so that the rigid member 42a rotates in the Mx (or My) rotation direction with the Fx (or Fy) axis as a reference. That is, the arm 21 is operated so that the working point WP of the force sensor 25 rotates by a predetermined angle in the Mx (or My) direction with reference to the Fx (or Fy) axis. Note that the robot control unit 102 presses the work point WP in the Fz direction so that the contact surface of the force sensor 25 and the rigid member 42a, and the contact surface of the rigid member 42b and the floor do not slip each other. (Or My) You may rotate in the rotation direction.

  The deformation amount detection unit 103 obtains the linear distance D7 in the Fz direction between the feature points P3 and P4 before the deformation from the image information, or acquires the value when determined in advance. Further, the deformation amount detection unit 103 obtains a linear distance D8 in the Fz direction between the feature points P3 and P4 after deformation from the image information. Then, a difference between D7 and D8 (or a value obtained by converting the difference into a rotation angle) is obtained as a deformation amount of Mx (or My).

  Since the stress calculation unit 104 and the state determination unit 105 only need to perform processing for Mx (or My), description thereof is omitted.

  7 shows the state determination process for each component. For example, when there is a component whose state determination has not ended after the end of step S100 or S110 for a certain component, In order to perform the state determination process for the component, the position and direction of the force sensor 21 may be returned to the state immediately after the end of step S40, and the process may proceed to step S50. If the state determination for all components has been completed, this flow may be terminated.

  Each processing unit in the flow of FIG. 7 is divided according to main processing contents in order to facilitate understanding of the processing of the control device 10. The present invention is not limited by the way of dividing the processing unit or the name. The processing of the control device 10 can be divided into more processing units according to the processing content. Moreover, it can also divide | segment so that one process unit may contain many processes. Moreover, as long as the objective of this invention can be achieved, you may change the order of each processing unit suitably.

  Heretofore, an example of the first embodiment of the present invention has been described. According to this embodiment, since the state of the force sensor is determined by bringing the force sensor into contact with the state determination target including the elastic member, it is possible to prevent an excessive force from being applied to the force sensor or the like. it can. In addition, since the force sensor is in contact with the object for state determination, the state of the force sensor is determined, so there is no need to use two arms or to calibrate one of the force sensors. The state of the force sensor can be determined.

<< Second Embodiment >>
In the first embodiment, the state determination process is performed in such a manner that the position and orientation of the rigid member 42b on the floor are not changed in a state where the state determination target object 40 is placed on a flat surface such as a floor. . On the other hand, in the second embodiment, the position determination object 40 is changed by the end effector 26 of the other arm 21 which is not the arm 21 having the force sensor 25 as the state determination target, and the position and orientation of the rigid member 42b are changed. The object 40 for state determination is supported so that it may not exist. In this state, state determination processing is performed. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 12 is a flowchart showing an example of state determination processing according to the second embodiment of the present invention. Steps S10 to S110 are the same as in FIG. Steps S <b> 1 to S <b> 6 are processes related to the other arm 21 that is not the arm 21 having the force sensor 25 as a state determination target. An end effector 26 is attached to the other arm 21.

  The robot control unit 102 acquires image information from the image acquisition unit 101, analyzes the acquired image information, and detects the position, orientation, shape, and the like of the state determination target 40 (S1). Then, the robot control unit 102 obtains the position and orientation of the end effector 26 of the other arm 21 that holds the rigid member 42b of the state determination target 40 (S2).

  Further, the robot control unit 102 generates a trajectory for moving the end effector 26 to the position and orientation obtained in step S2 (S3). Then, the robot control unit 102 generates a control command according to the trajectory obtained in step S3 and outputs it to the robot 20, moves the end effector 26, and causes the end effector 26 to grip the rigid member 42b (S4). In order to prevent the state determination target object 40 from being deformed as much as possible, for example, it is assumed that it is gripped by the end effector 26 so as not to touch the elastic member 41.

  Further, the robot control unit 102 moves to a predetermined position and orientation for performing the determination process of the force sensor 25 as the state determination target while holding the state determination target object 40 by the end effector 26 of the other arm 21. Is generated (S5). Then, the robot control unit 102 generates a control command according to the trajectory obtained in step S5 and outputs it to the robot 20, moves the end effector 26, and fixes the position and orientation (S6).

  Steps S <b> 10 to S <b> 110 are processes related to the arm 21 having the force sensor 25 as a state determination target. Steps S <b> 10 to S <b> 110 are performed using the state determination target object 40 whose position and orientation are fixed in step S <b> 6.

  FIG. 13 is a diagram for explaining the operation of the arm 21 and the deformation of the object 40 for state determination. This figure typically shows the case of Fz. As illustrated, in the present embodiment, the end effector 26 of the other arm 21 holds the rigid member 42b and fixes the position and orientation. Then, in a fixed state, the state discriminating object 40 is deformed by the force sensor 25 that is the state discriminating target of one arm 21 to perform the state discrimination of each component.

  In the present embodiment, since the position and orientation of the state determination target object 40 are fixed by the end effector 26 of the other arm 21, the rigid member 42b and the floor contact surface slide as in the first embodiment. There is no fear of slipping. Further, the state determination can be performed even when there is no appropriate floor for performing the state determination.

  Heretofore, an example of the second embodiment of the present invention has been described. According to this embodiment, it is possible to prevent an excessive force from being applied to the force sensor or the like. Also, because the force sensor is in contact with the object for state determination, it is not necessary to calibrate one of the force sensors, making it easy to determine the state of the force sensor. can do.

  In addition, since the position and orientation of the state determination target are fixed, it is possible to prevent a situation such as the state determination target moving during the state determination process. The state determination can be performed even when there is no appropriate floor for performing the state determination.

<< Third embodiment >>
In said 1st embodiment, the end effector 26 is not attached to the arm 21 which has the force sensor 25 of a state discrimination | determination object. On the other hand, in the third embodiment, the state determination process is performed in a state where the end effector 26 is attached to the arm 21 having the force sensor 25 to be a state determination target. Hereinafter, a description will be given focusing on differences from the first embodiment.

  Specifically, the robot control unit 102 determines the position and orientation of the end effector 26 of the arm 21 having the force sensor 25 that is a state determination target that holds the rigid member 42a of the state determination target object 40 in the state determination process. Ask for. Then, the end effector 26 is moved to the position and orientation, and the rigid member 42 a is gripped by the end effector 26. In order to prevent the state determination target object 40 from being deformed as much as possible, for example, it is assumed that it is gripped by the end effector 26 so as not to touch the elastic member 41.

  Then, the robot control unit 102 moves the work point WP according to the state determination target component of the force sensor 25 while holding the rigid member 42a by the end effector 26, and deforms the state determination target 40. . The deformation amount detection unit 103, the stress calculation unit 104, the state determination unit 105, and the notification unit 106 are the same as those in the first embodiment.

  However, since the end effector 26 grips the rigid member 42a, the manner in which an external force is applied to the state determination target 40 is different from that of the first embodiment. Therefore, the conversion information may be created based on the measurement result by measuring the deformation amount and the stress in a state where the end effector 26 is used.

  Further, for example, as shown in FIG. 14 (a diagram showing an example of the conversion table 1100A according to the third embodiment of the present invention), a conversion table may be prepared for each end effector type 1104. Note that “None” of the type 1104 in the figure indicates a case where the end effector 26 is not attached, as in the first embodiment.

  When the conversion table 1100A of FIG. 14 is used, the stress calculation unit 104 specifies the type of the end effector 26 attached to the arm 21 having the force sensor 25 that is the state determination target, and the type 1104 corresponding to the type. Reference may be made to the conversion table. Note that the type of the end effector 26 is recognized by, for example, the motion control unit 210 of the robot 20, and the stress calculation unit 104 acquires the type from the motion control unit 21 via the robot control unit 102. Good.

  FIG. 15 is a diagram for explaining the operation of the arm 21 and the deformation of the object 40 for state determination. This figure typically shows the case of Fz. As shown in the drawing, in the present embodiment, the rigid member 42a is held by the end effector 26 in a state where the object 40 for state determination is placed on the floor. Then, in the gripped state, the state determination object 40 is deformed to determine the state of each component.

  The example of the third embodiment of the present invention has been described above. According to this embodiment, it is possible to prevent an excessive force from being applied to the force sensor or the like. In addition, it is necessary to use two arms or to calibrate one of the force sensors in order to determine the state of the force sensor by bringing the force sensor into contact with the object for state determination via an end effector. It is possible to easily determine the state of the force sensor.

  Further, since the state determination process can be performed with the end effector attached, productivity such as removal of the end effector can be saved and the productivity can be further improved.

<< Fourth Embodiment >>
In the third embodiment, the state determination process is performed in a state where the state determination target object 40 is placed on a flat surface such as a floor. On the other hand, in the fourth embodiment, the second embodiment is combined with the third embodiment, and the state discriminating object 40 is replaced by the arm 21 that is not the arm 21 having the force sensor 25 as the state discriminating target. The end effector 26 supports the state determination target 40 so that the position and orientation of the rigid member 42b do not change. In this state, state determination processing is performed. The following description will focus on differences from the second embodiment and the third embodiment.

  FIG. 16 is a diagram illustrating the operation of the arm 21 and the deformation of the state determination target object 40 according to the fourth embodiment of the present invention. This figure typically shows the case of Fz. As illustrated, in the present embodiment, the end effector 26 of the other arm 21 holds the rigid member 42b and fixes the position and orientation. Then, in a fixed state, the rigid member 42 a is gripped by the end effector 26 of one arm 21. Then, in the gripped state, the state determination object 40 is deformed to determine the state of each component.

  The example of the fourth embodiment of the present invention has been described above. According to this embodiment, the same effect as the second and third embodiments can be obtained.

<< Fifth Embodiment >>
In the fourth embodiment described above, the force sensor 25 of one arm 21 is a state determination target. On the other hand, in the fifth embodiment, state determination processing is performed in parallel for the force sensors 25 of both arms 21. Hereinafter, a description will be given focusing on differences from the fourth embodiment.

  Specifically, the robot control unit 102 holds the rigid member 42b with the end effector 26 of one arm 21, and fixes the position and orientation. Further, in a fixed state, the rigid member 42 a is gripped by the end effector 26 of the other arm 21. Then, the state determination object 40 is deformed by the end effector 26 of the other arm 21 to determine the state of each component of the force sensor 25 of the other arm 21.

  Here, when an external force of a certain component (for example, Fz) is applied to the state determination target object 40 by the other end effector 21, the one force sense is transmitted via the end effector 21 of the one arm 21. An external force of the same component is also applied to the sensor 25. That is, the stress detected by the other force sensor 25 and the stress detected by the one force sensor 25 ideally match.

  Therefore, the stress calculation unit 104 refers to the conversion table 1100, specifies the deformation amount 1102 corresponding to the deformation amount obtained by the deformation amount detection unit 103 from the conversion information of the component 1101 corresponding to the state determination target component, The stress 1103 associated with the deformation amount 1102 is acquired as the stress related to both force sensors 25.

  Further, the state determination unit 105 acquires, via the robot control unit 102, sensor values corresponding to the state determination target components of both force sensors 25 in a state where the state determination target object 40 is deformed. To do.

  Further, the state determination unit 105 obtains a difference between the acquired sensor values of both force sensors 25 and the stress calculated by the stress calculation unit 104. Then, it is determined whether each of the obtained differences is equal to or less than a predetermined threshold corresponding to the state determination target component.

  A conversion table used for the force sensor 25 of the other arm 21 to be operated and a conversion table used for the force sensor 25 of the one arm 21 not to be operated may be prepared. Then, the stress calculation unit 104 may acquire the stress corresponding to the deformation amount from each conversion table. In this way, even when the stress generated in the force sensor 25 of the other arm 21 to be operated differs from the stress generated in the force sensor 25 of the one arm 21 not to be operated for the same deformation amount. Thus, the state can be determined with higher accuracy.

  The example of the fifth embodiment of the present invention has been described above. According to the present embodiment, since the state determination process can be performed in parallel on the force sensors of both arms, the efficiency of the state determination process can be improved.

  In the second embodiment, the state determination process may be performed in parallel for the force sensors 25 of both arms 21.

  The above embodiments of the present invention are intended to illustrate the gist and scope of the present invention and are not intended to be limiting. Many alternatives, modifications, and variations will be apparent to those skilled in the art.

  For example, instead of the conversion information, a calculation formula for obtaining stress from the deformation amount is defined for each component, and the stress calculation unit 104 uses the calculation formula to determine the deformation amount detected by the deformation amount detection unit 103. The stress may be calculated from In this way, it is not necessary to prepare conversion information. In addition, the said calculation formula can be defined based on values, such as the Young's modulus of the object 40 for state determination, and a rigidity modulus.

  Further, if the deformation amount of the state determination target 40 can be specified, for example, the feature points may be set only on the elastic member 41 or on both the elastic member 41 and the rigid member 42. In addition, as long as the deformation amount of the state determination target 40 can be specified, the positions and the number of feature points used for specifying the deformation amount are not limited to the examples described in the above embodiments.

1: Robot system, 10: Control device, 20: Robot, 21 (21a, 21b): Arm, 22: Joint, 23: Link, 25: Force sensor, 26: End effector, 30: Imaging device, 40: State Discrimination target, 41: elastic member, 42 (42a, 42b): rigid member, 100: control unit, 101: image acquisition unit, 102: robot control unit, 103: deformation amount detection unit, 104: stress calculation unit, 105: state determination unit, 106: notification unit, 110: storage unit, 200: movable unit, 210: operation control unit, 1100: conversion table, 1101: component, 1102: deformation amount, 1103: stress, 1100A: conversion table, 1104: Type, 50: Computer, 501: CPU, 502: Memory, 503: External storage device, 504: Communication device, 505: On Device, 506: output unit, 507: reading and writing apparatus, 508: interface device

Claims (13)

A state determination method for determining a state of a robot having an arm and a force sensor,
Using an object for state determination comprising an elastic body,
An operation step of operating the robot and deforming the object for state determination by the arm;
A detection step of detecting a deformation amount of the object for state determination deformed in the operation step;
A calculation step for calculating a value indicating a force or a moment applied to the force sensor from the deformation amount detected in the detection step;
A determination step of determining a state of the force sensor based on a value indicating the force or moment calculated in the calculation step.
A state determination method characterized by the above. The state determination method according to claim 1,
The state determination object further includes a rigid body,
In the operation step, the arm is brought into contact with the rigid body of the object for state determination, and the object for state determination is deformed by the arm.
A state determination method characterized by the above. The state determination method according to claim 2,
The state determining object is configured such that both end faces of the elastic body are sandwiched between the rigid bodies,
In the operation step, the arm is brought into contact with the rigid body on the other end surface of the state determination object in a state where the position and orientation of the rigid body on one end surface of the state determination object are fixed. And deforming the object for state determination by the arm,
A state determination method characterized by the above. The state determination method according to claim 3,
The robot has a plurality of the arms,
In the operation step, the first arm of the plurality of arms fixes the position and orientation of the rigid body on the one end surface, and the second arm of the plurality of arms is fixed on the other end surface. Deforming the object for state determination with the second arm in contact with a rigid body;
A state determination method characterized by the above. The state determination method according to claim 4,
In the calculating step, for at least one of the first arm and the second arm, a value indicating a force or moment applied to the force sensor of the arm is calculated from the deformation amount detected in the detecting step. And
In the determination step, for at least one of the first arm and the second arm, the state of the force sensor of the arm is determined based on a value indicating the force or moment calculated in the calculation step.
A state determination method characterized by the above. A state determination method according to any one of claims 1 to 5,
In the detection step, the deformation amount is detected by photographing the state determination object and identifying a change in the position of the feature point of the state determination object based on the captured image information.
A state determination method characterized by the above. The state determination method according to claim 6,
The feature point is set to the rigid body.
A state determination method characterized by the above. A state determination method according to any one of claims 1 to 7,
In the calculation step, information for specifying a relationship between a deformation amount of the state determination target object and a force or a moment corresponding to the deformation amount is acquired, and the deformation detected in the detection step based on the acquired information. Calculating the force or moment applied to the force sensor from the quantity,
A state determination method characterized by the above. A state determination method according to any one of claims 1 to 8,
In the determination step, a sensor value output from the force sensor in a state in which the state determination object is deformed in the operation step is acquired, and the acquired sensor value and the force calculated in the calculation step or Determine whether the difference from the value indicating the moment is within a predetermined range,
A state determination method characterized by the above. The state determination method according to claim 3 or 4,
The force sensor is any one or more of first to third axial forces orthogonal to each other and first to third moments around the first to third axial directions. Is to detect
In the object for state determination, the rigid body of the one end surface and the rigid body of the other end surface are formed in parallel to each other,
In the operation step,
With respect to the first axial direction, the arm is operated so that the rigid body on the other end face approaches the rigid body on the one end face while being parallel to the one end face,
With respect to the second axial direction, the arm is operated so that the rigid body on the other end surface moves in the second axial direction while being parallel to the rigid body on the one end surface,
For the third axial direction, the arm is operated so that the rigid body on the other end surface moves in the third axial direction while being parallel to the rigid body on the one end surface,
About the first axis, the arm is operated so that the rigid body of the other end surface rotates with respect to the first axial direction while being parallel to the rigid body of the one end surface,
About the second axis, the arm is operated so that the rigid body on the other end surface rotates based on the second axial direction,
About the third axis, the arm is operated so that the rigid body on the other end surface rotates based on the third axial direction.
A state determination method characterized by the above. A robot,
Arm,
A force sensor,
A control unit that operates the arm and causes the arm to deform a state determination target including an elastic body;
A detection unit for detecting a deformation amount of the object for state determination deformed by the arm;
A calculation unit for calculating a value indicating a force or moment applied to the force sensor from the deformation amount detected by the detection unit;
A determination unit that determines a state of the force sensor based on a value indicating the force or moment calculated by the calculation unit;
A robot characterized by that. A control device for a robot having an arm and a force sensor,
A control unit that operates the arm and causes the arm to deform a state determination target including an elastic body;
A detection unit for detecting a deformation amount of the object for state determination deformed by the arm;
A calculation unit for calculating a value indicating a force or moment applied to the force sensor from the deformation amount detected by the detection unit;
A determination unit that determines a state of the force sensor based on a value indicating the force or moment calculated by the calculation unit;
A control device characterized by that. A program for a control device of a robot having an arm and a force sensor,
An operation step of deforming a state determination target including an elastic body by the arm; and
A detection step of detecting a deformation amount of the object for state determination deformed in the operation step;
A calculation step for calculating a value indicating a force or a moment applied to the force sensor from the deformation amount detected in the detection step;
A determination step of determining a state of the force sensor based on a value indicating the force or moment calculated in the calculation step;
A program characterized by that.

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