JP2020110907A - Robot system and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot system in which a first object and a second object are not easily scratched, and a method for controlling the robot system. A robot system is a robot system that performs work involving contact between a first object 50 and a second object 52, and has a first end effector 10 that grips the second object 52 and a first object. The first robot arm 12 to which the end effector 10 is mounted, the contact detection unit 40 that detects the contact between the first object 50 and the second object 52, and the second contraction based on the detection result of the contact detection unit 40. It has one piezo element 42, and the first piezo element 42 contracts, so that the first object 50 and the second object 52 are separated from each other. [Selection diagram] Fig. 2

Description

The present invention relates to a robot system and a robot system control method.

When the robot hand grips the second target object and contacts the first target object to be inserted, if the contact speed is too fast, the impact force at the time of contact is large and the first target object and the second target object are damaged. Give (scratch, destruction). In order to prevent the impact force from being generated, it is necessary to reduce the contact speed. Reducing the contact speed significantly reduces the work cycle time. In order to make the contact speed fast and suppress the impact force, it is necessary to control at a faster control cycle, but the movable part of the robot has a large mass of the movable housing part, and the position control delay due to the reducer is also delayed. Therefore, it was difficult to suppress and control the impact force.

On the other hand, there has been proposed a configuration in which a robot hand has a spring mechanism to absorb an impact (see, for example, Patent Document 1).

JP-A-6-226671

However, in Patent Document 1, since the spring is used, the hand or the object may be damaged depending on the weight and the speed.

A robot system of the present application is a robot system that performs a work involving contact between a first object and a second object, and a first end effector that grips the second object and the first end effector are attached to the robot system. A first robot arm, a contact detection unit that detects contact between the first object and the second object, and a first piezo element that contracts based on the detection result of the contact detection unit. The first piezo element contracts, and the first object and the second object are separated from each other by the contraction of the first piezo element.

In the robot system described above, it is preferable that the first piezo element contracts along a direction in which the first robot arm and the first end effector are arranged.

In the above robot system, the first piezo element is provided between the first robot arm and the first end effector, and the direction in which the first piezo element contracts is set such that the second object is The direction away from the first object is preferable.

In the above robot system, the first piezo element is provided between the first object and a mounting table on which the first object is mounted, or on a surface of the mounting table on which the first object is mounted. Is provided on the opposite surface side, and the direction in which the first piezo element contracts is preferably the direction in which the first object separates from the second object.

In the above robot system, it is preferable that the contact detection unit is provided between the first robot arm and the first end effector.

In the robot system described above, the contact detection unit is between the first object and a mounting table on which the first object is mounted, or a surface of the mounting table on which the first object is mounted. It is preferably provided on the opposite surface side.

In the robot system described above, the contact detection unit is preferably a force sensor.

In the robot system described above, it is preferable that the contact detection unit is a second piezo element.

In the above robot system, it is preferable that the contact detection unit is the first piezo element.

The robot system includes a drive control unit that controls driving of the first end effector and the first robot arm, and a piezo controller that controls contraction of the first piezo element based on the detection result of the contact detection unit. It is preferable that the piezo control unit includes a control unit, and the piezo control unit controls the contact detection unit and the first piezo element at a control cycle faster than that of the drive control unit.

The robot system preferably includes a second end effector that holds the first object or the second object, and a second robot arm to which the second end effector is attached.

A control method for a robot system according to the present application detects a contact between a first end effector that grips a work target object, a first robot arm on which the first end effector is mounted, and the work target object and a contact target object. A robot that has a contact detection unit, a first piezo element, and a piezo control unit that controls contraction of the first piezo element, and performs work involving contact between the work target and the contact target. A system control method, wherein the piezo control unit contracts the first piezo element in a direction in which the work target and the contact target are separated from each other based on the detection result of the contact detection unit. Is characterized by.

FIG. 3 is a perspective view showing the robot system according to the first embodiment. The block diagram which shows the robot system which concerns on 1st Embodiment. The block diagram of the robot system which concerns on 1st Embodiment. The figure explaining the control at the time of contact of the 1st target object and the 2nd target object concerning a 1st embodiment. The figure explaining the control at the time of the contact of the 1st target object and the 2nd target object which concern on 1st Embodiment. The flowchart explaining the control at the time of contact of the 1st target object and 2nd target object which concern on 1st Embodiment. The figure which shows the other example of the arrangement position of the contact detection part which concerns on 2nd Embodiment. The figure which shows the other example of the arrangement position of the contact detection part which concerns on 2nd Embodiment. The figure which shows the other example of the arrangement position of the piezo element which concerns on 3rd Embodiment. The figure which shows the other example of the arrangement position of the piezo element which concerns on 3rd Embodiment. The perspective view which shows the robot system which concerns on 4th Embodiment.

Hereinafter, embodiments that embody the present invention will be described with reference to the drawings. It should be noted that the drawings used are appropriately enlarged or reduced so that the portions to be described can be recognized.

(First embodiment)
FIG. 1 is a perspective view showing a robot system according to this embodiment. FIG. 2 is a configuration diagram showing the robot system according to the present embodiment. FIG. 3 is a block diagram of the robot system according to the present embodiment.
As shown in FIGS. 1 and 2, the robot system 100 according to the present embodiment includes a robot body 2, a drive control unit 8 that controls driving of the robot body 2, and a first piezo element provided in the robot body 2. And a piezo control section 36 for controlling the contraction of the piezo element 42.

The robot body 2 includes a hand 10 as a first end effector that holds a second target object 52 that is a work target, a robot arm 12 as a first robot arm on which the hand 10 is mounted, and a contact detection unit. A force sensor 40, a piezo element 42, and a base 14 to which the robot arm 12 is rotatably connected are provided. It can be said that the first target object 50 is a contact target object. The first object 50 is mounted on the mounting table 54. The mounting table 54 mounts the first target object 50.

The robot body 2 uses the robot arm 12 to which the hand 10 is attached, for example, to perform work such as material supply, material removal, conveyance, and assembly of precision equipment and components that constitute the precision equipment. The robot body 2 is a so-called 6-axis vertical articulated robot. That is, the robot system 100 can perform work involving contact between the first target object 50 and the second target object 52.

The base 14 is fixed to, for example, a floor, a wall, a ceiling, a movable carriage, or the like. Further, the robot arm 12 includes a first arm 16 rotatably connected to the base 14, a second arm 18 rotatably connected to the first arm 16, and a second arm 18. A third arm 20 rotatably connected to the arm 18, a fourth arm 22 rotatably connected to the third arm 20, and a fourth arm 22 rotatable. A fifth arm 24 connected to the fifth arm 24, a sixth arm 26 rotatably connected to the fifth arm 24, and a hand 10 detachably connected to the sixth arm 26. The portion that bends or rotates the two members, which are connected to each other, of the base 14 and the first arm 16 to the sixth arm 26 constitutes a "joint portion".

As shown in FIG. 3, the robot body 2 also includes a drive unit 28 that drives the joints of the robot arm 12, and an angle sensor 30 that detects the drive state of the joints of the robot arm 12. The drive unit 28 is configured to include, for example, a motor and a speed reducer. The angle sensor 30 includes, for example, a magnetic or optical rotary encoder.

The force sensor 40 detects contact between the first target object 50 and the second target object 52. The force sensor 40 detects contact between the first target object 50 placed on the mounting table 54 and the second target object 52 held by the hand 10.

The force sensor 40 is provided between the robot arm 12 and the hand 10. The force sensor 40 is provided between the fifth arm 24 and the hand 10. The force sensor 40 is provided between the sixth arm 26 and the hand 10. According to this, the contact between the first target object 50 and the second target object 52 can be easily detected.

The force sensor 40 is a contact detection unit. According to this, the force sensor 40 can easily configure the contact detection unit.

The force sensor 40 is a sensor that detects vibration of the robot arm 12 caused by an external force applied to the robot arm 12. By providing such a force sensor 40, when an external force is applied to the robot arm 12 or the hand 10, the external force is transmitted as a vibration to the force sensor 40 via the robot arm 12, and the force sensor 40 detects the external force. The magnitude of vibration can be detected. Therefore, the contact between the first target object 50 and the second target object 52 can be detected based on the vibration detected by the force sensor 40.

The force sensor 40 uses a 6-axis force sensor capable of detecting the 6-axis components of the external force applied to the force sensor 40. The 6-axis component is composed of translational force components in the respective directions of the α-axis, β-axis, and γ-axis, which are three axes orthogonal to each other, and rotational force components around these three axes.

The piezo element 42 contracts based on the detection result of the force sensor 40. The contraction of the piezo element 42 separates the first object 50 and the second object 52. The piezo element 42 contracts in the direction in which the first target object 50 and the second target object 52 separate based on the detection result of the force sensor 40. The piezo element 42 contracts in a direction in which the first target object 50 placed on the mounting table 54 and the second target object 52 held by the hand 10 are separated from each other.

The piezo element 42 contracts along the direction in which the robot arm 12 and the hand 10 are lined up. The piezo element 42 contracts along the direction in which the fifth arm 24 and the hand 10 are lined up. The piezo element 42 contracts along the direction in which the sixth arm 26 and the hand 10 are lined up. According to this, the first target object 50 and the second target object 52 can be efficiently separated by the contraction of the piezo element 42.

The piezo element 42 is provided between the robot arm 12 and the hand 10. The piezo element 42 is provided between the fifth arm 24 and the hand 10. The piezo element 42 is provided between the sixth arm 26 and the hand 10. The piezo element 42 is provided on the tip side of the force sensor 40. The direction in which the piezo element 42 contracts is the direction in which the second object 52 moves away from the first object 50. The piezo element 42 contracts the second object 52 in a direction away from the first object 50. According to this, the vibration of the contact between the first target object 50 and the second target object 52 can be efficiently suppressed.

The piezo element 42 suppresses contact high-frequency vibration indicating an impact force when the first object 50 and the second object 52 contact each other. When the force sensor 40 senses the contact, a voltage is applied to the piezo element 42 and the piezo element 42 contracts in the opposite direction in which the robot arm 12 extends. The contraction of the piezo element 42 also increases depending on the magnitude of the impact force. The displacement amount of the piezo element 42 is determined by the piezoelectric constant, the element shape, and the applied voltage. Although the displacement amount of the piezo element 42 is small, the displacement amount changes at high speed. Since the piezo element 42 uses the solid deformation by voltage driving, it has high precision, high speed response, high stop holding force, low power consumption, no electromagnetic noise, small size and high density arrangement, and simple structure.

The piezo controller 36 controls the contraction of the piezo element 42 based on the detection result of the force sensor 40. The piezo control unit 36 contracts the piezo element 42 when the high-speed force sense fluctuation component of the vibration detected by the force sensor 40 reaches or exceeds a certain value. The piezo controller 36 controls the piezo element 42 so as to extend it to the original state when the high-speed force sense fluctuation component is equal to or less than a certain value. The high-speed force sense fluctuation component is a force sense value output from the force sensor 40 when the second target object 52 contacts the first target object 50.

The piezo controller 36 controls the contraction of the piezo element 42 by changing the voltage applied to the piezo element 42 based on the rate of change of the vibration detected by the force sensor 40. The piezo controller 36 controls the magnitude of the voltage output from the piezo element driver 58 to the piezo element 42 according to the rate of change of contact.

The piezo controller 36 and the drive controller 8 are separate bodies. The piezo controller 36 controls the piezo element 42 at a control cycle faster than that of the drive controller 8. The piezo control unit 36 executes sampling at a control cycle faster than that of the drive control unit 8 and controls the piezo element 42 faster. For example, in the force detection of the robot body 2, when the drive control unit 8 is performing force sense sampling and control at a frequency of 500 Hz, the piezo control unit 36 performs force sense sampling of 12.5 kHz to 50 kHz and the piezo element 42. By executing the control of 1, it is possible to suppress the high-speed force sense fluctuation. At this time, it is desirable that the displacement speed of the piezo element 42 can be changed faster than the relative speed between the first object 50 and the second object 52. According to this, the piezo control unit 36 can control the impact force by controlling at a control cycle faster than the drive control unit 8.

Since the control system of the robot body 2 has the piezo control unit 36 having a control cycle faster than that of the drive control unit 8, even if the first target object 50 and the second target object 52 come into contact with each other at high speed during the haptic motion, Damage to the first object 50 and the second object 52 can be suppressed. The piezo element 42, which is installed on the second target object 52 or the first target object 50 and has a quicker response than that of the robot body 2, suppresses the impact force at a control cycle faster than the robot control cycle. A work with a faster cycle time is realized without damaging the second object 52.

As a specific example of control, when the force sense value at the time of contact becomes larger than a threshold value, the piezo element 42 is controlled to control the position in a direction in which the first object 50 and the second object 52 are separated from each other, When the haptic value becomes smaller than the threshold value, the impact force can be controlled within the threshold value by controlling the position of the first object 50 and the second object 52 in the approaching direction.

4A and 4B are diagrams illustrating control when the first target object 50 and the second target object 52 are in contact with each other according to the present embodiment.
The control system of the robot body 2 performs force control of the force sensor at 500 Hz or less. The momentum is M×v1, and the impact force F is F=M×v1/t. Note that M is the mass of the second target object 52, and v1 is the speed of the second target object 52 in contact with the first target object 50.

The control including the piezo element 42 performs force sense control at a speed higher than 500 Hz. Since the apparent momentum is M×(v1-v2), the momentum is controlled so as to change over time. Note that v2 is the speed of the first object 50 moving away from the second object 52.

Since the control system of the robot main body 2 is slow with respect to the force sense fluctuation of the impact force generated when the first target object 50 and the second target object 52 come into contact with each other, as shown in FIG. The haptic profile 60 changes its luck amount in a short time upon contact. A large force is generated in a short time, resulting in a large impact force.

In the control including the piezo element 42, the first target object 50 and the second target object 50 and the second target object are contacted at the moment when the contact occurs and the force sense fluctuates due to the measurement of the force sense value in a fast control cycle and the operation speed v2 of the piezo element 42 which changes rapidly. The relative speed with respect to the object 52 can be changed. As shown in FIG. 4B, by slowing the relative speed, the force sense profile 62 at the time of high speed control can change the momentum in a long time, and the peak of the generated force can be reduced.

It should be noted that in the above, only the vertical force sensation fluctuation is focused on in the figure, but similar control is possible in other directions. For example, the second object may contact the first object at an angle.
Further, the attention has been paid to the impact force when the first object 50 and the second object 52 come into contact with each other by the robot system 100, but the same applies to the suppression of other rapid force sense fluctuations including the high speed force sense change component. The effect of can be obtained.

The drive controller 8 controls driving of the hand 10 and the robot arm 12. The drive control unit 8 has a function of controlling the drive of the robot arm 12 based on the detection result of the force sensor 40.
As shown in FIG. 3, the drive control unit 8 includes a processor such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an I/F (interface circuit). , Is provided. Then, the drive control unit 8 realizes processing such as control of operations of the robot arm 12 and the hand 10, various calculations, and determinations by the processor appropriately reading and executing the program stored in the memory. Further, the I/F is configured to be able to communicate with each of the robot body 2, the hand 10, and the force sensor 40.

Although the drive control unit 8 is arranged in the base 14 of the robot body 2 in the configuration of FIG. 1, the drive control unit 8 is not limited to this and is arranged, for example, outside the base 14 or in the robot arm 12. May be. Further, the drive control unit 8 may be connected to a display device including a monitor such as a display, for example, an input device such as a mouse and a keyboard.

The configuration of the robot system 100 has been described above in detail.
Next, a control method of the robot system 100 will be described based on the flowchart shown in FIG.
FIG. 5 is a flowchart illustrating control when the first target object 50 and the second target object 52 are in contact with each other according to the present embodiment.

In the control method of the robot system 100 according to the present embodiment, the hand 10 that holds the second target object 52 as a work target object, the robot arm 12 to which the hand 10 is attached, the second target object 52 and the contact target object. A force sensor 40 for detecting contact with a first object 50 as an object, a piezo element 42, and a piezo controller 36 for controlling contraction of the piezo element 42, and a second object 52 and a second object 52. 1 is a control method of a robot system 100 that performs a work involving contact with a first target object 50, wherein a piezo control unit 36 sets a piezo element 42 to a second target object 52 based on a detection result of a force sensor 40. 1 The object 50 is contracted in a direction away from the object 50. In the control method of the robot system 100, the piezo element 42 contracts in the direction in which the first target object 50 and the second target object 52 are separated from each other. A control method when the first target object 50 and the second target object 52 contact each other will be described.

First, in step S10, the piezo controller 36 measures a force sense value via the force sense sensor 40. The robot body 2 brings the second object 52 closer to the first object 50 while constantly measuring the force value. For example, the hand 10 holding the second object 52 is lowered to bring the second object 52 closer to the first object 50. The piezo control unit 36 performs control faster than the normal control of the drive control unit 8 at a control cycle of 12.5 kHz to 50 kHz, for example.

Next, in step S20, the piezo control unit 36 acquires the force sense value measured from the force sense sensor 40 and determines whether or not there is a high-speed force sense variation component. When there is no high-speed force sense fluctuation component in the force sense value (none), the process proceeds to step S30. When the force sense value has a high-speed force sense fluctuation component (Yes), the process proceeds to step S50.

Next, in step S30, the drive control unit 8 performs normal control in response to the case where there is no high-speed force sense fluctuation component of the piezo control unit 36. The drive control unit 8 normally controls, for example, at a control cycle of 500 Hz. The robot control executes normal force sense control. For example, control is performed at 2 ms intervals. The robot system 100 performs normal control if the high-speed force sense fluctuation component is not detected when the second object 52 moves.

Next, in step S40, the drive control unit 8 determines whether the operation of attaching the second target object 52 to the first target object 50 is completed. If the operation is not completed (N), the process returns to step S10. When the operation is completed (Y), the operation process is ended.

Next, in step S50, the piezo control unit 36 compares the threshold value with the acquired force sense value. When the measured force value is larger than the threshold value (<), the process proceeds to step S60. When the threshold value and the measured force sense value are equal (=), the process proceeds to step S70. If the measured force value is smaller than the threshold value (>), the process proceeds to step S80. The robot system 100 implements a control cycle faster than the normal control cycle because the high-speed force sense fluctuation component is detected when the second object 52 contacts the first object 50.

Next, in step S60, the piezo controller 36 contracts the piezo element 42. The piezo control unit 36 contracts the piezo element 42 in a direction in which the first object 50 and the second object 52 are separated from each other, and reduces the force value measured by the force sensor 40. Then, the process returns to step S10.

Next, in step S70, the piezo control unit 36 stops the contraction of the piezo element 42. The piezo controller 36 stops the contraction of the piezo element 42 and maintains the force sense value measured by the force sensor 40. Then, the process returns to step S10.

Next, in step S80, the piezo control unit 36 releases the contraction of the piezo element 42. The piezo control unit 36 releases the contraction of the piezo element 42 in the direction in which the first object 50 and the second object 52 approach each other, and increases the force value measured by the force sensor 40. Then, the process returns to step S10.

According to the present embodiment, when the first target object 50 and the second target object 52 come into contact with each other, the piezo element 42 contracts in the direction in which the first target object 50 and the second target object 52 are separated from each other. It is possible to prevent the object 50 and the second object 52 from being easily scratched.

Further, the robot arm 12 of the robot body 2 has a large mass and needs a large force to give a sharp acceleration. In addition, an overshoot for the encoder value occurs due to the influence of the speed reducer at the joint of the robot body 2.
On the other hand, by installing a piezo element on the hand 10, the first object 50, or the mounting table 54, it becomes possible to apply a large acceleration with a smaller force. No overshoot. As a result, it is possible to shorten the time required to reach the contact operation, which is the basis of the force-sensing operation of the robot body 2, and speed up the operation of the robot body 2.

The contact detection unit may be a piezo element as a second piezo element different from the piezo element 42. According to this, the contact detection unit can be easily configured by the piezo element.

The piezo element 42 may also serve as the contact detection unit. The contact detection unit may be the piezo element 42. The piezo element 42 has both a contact detection function of detecting a contact between the first target object 50 and the second target object 52, and a function of contracting the first target object 50 and the second target object 52 in the direction of separating from each other. May be. In such a case, the contact between the first object 50 and the second object 52 may be detected from the current detected by the piezo element 42. According to this, the piezo element 42 has both the contact detection function and the function of contracting the first target object 50 and the second target object 52 in the direction in which the first target object 50 and the second target object 52 are separated from each other. Can be improved. At this time, both the force sensor 40 and the piezo element 42 may function as a contact detection unit, or only the piezo element 42 may function as a contact detection unit.

(Second embodiment)
FIG. 6A and FIG. 6B are diagrams showing another arrangement position example of the contact detection unit according to the present embodiment. Hereinafter, the structure of the robot system will be described with reference to FIGS. 6A and 6B.

The robot system of the present embodiment is different from that of the first embodiment in that a contact detection unit is provided on the mounting table 54 side. Hereinafter, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted or simplified.

As shown in FIG. 6A, the force sensor 44 as the contact detection unit according to the present embodiment is provided on the surface of the mounting table 54 opposite to the surface on which the first object 50 is mounted. Further, the force sensor 44 may be provided between the first object 50 and the mounting table 54, as shown in FIG. 6B.

According to this embodiment, it is possible to improve the degree of freedom in the arrangement position of the force sensor 44 with respect to the mounting table 54.

Both the force sensors 40 and 44 as the contact detection unit may be provided, or only the force sensor 44 may be provided.
Although the force sensor 44 is provided as the contact detection unit, it may be a piezo element as the second piezo element. The piezoelectric element may be deformed to output electric charges. According to this, the contact detection unit can be easily configured by the piezo element.

(Third Embodiment)
FIG. 7A and FIG. 7B are diagrams showing another example of the arrangement position of the piezo element according to the present embodiment. Hereinafter, the structure of the robot system will be described with reference to FIGS. 7A and 7B.

The robot system of this embodiment is different from that of the first embodiment in that a piezo element 56 is provided on the mounting table 54 side. Hereinafter, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted or simplified.

As shown in FIG. 7A, the piezo element 56 according to the present embodiment is provided on the surface of the mounting table 54 opposite to the surface on which the first object 50 is mounted. Further, the piezo element 56 may be provided between the first object 50 and the mounting table 54, as shown in FIG. 7B. The direction in which the piezo element 56 contracts is the direction in which the first object 50 separates from the second object 52. The piezo element 56 contracts the first object 50 in a direction away from the second object 52. The piezo element 56 changes the surface height of the first object 50.

The piezo element 56 is provided separately from the piezo element 42. The piezo element 42 suppresses the force sense variation due to overshoot. The piezo element 56 has a slower rate of change than the piezo element 42, but is given a large amount of displacement. The piezo control unit 36 is provided on the mounting table 54 when a vibration component due to overshoot, specifically, a vibration component having a cycle shorter than the contact high-frequency vibration but a cycle higher than the robot control frequency becomes a certain value or more. The piezo element 56 thus obtained is contracted. The piezo control unit 36 controls the piezo element 56 so as to extend it to the original state if the high-speed force sense fluctuation component is equal to or less than a certain value.

According to this embodiment, it is possible to improve the degree of freedom in the arrangement position of the piezo element 56 with respect to the mounting table 54.
Both the piezoelectric elements 42 and 56 may be provided, or only the piezoelectric element 56 may be provided.

(Fourth Embodiment)
FIG. 8 is a perspective view showing the robot system according to the present embodiment.
The robot system according to this embodiment includes a robot main body 300 and a drive control unit 8 connected to the robot main body 300. The robot body 300 is a dual-arm robot having two robot arms 310L as first robot arms and two robot arms 310R as second robot arms. Force sensors 330L and 330R, a hand 350L as a first end effector, and a hand 350R as a second end effector are attached to the robot arms 310L and 310R. Two cameras 370L and 370R are provided on the head of the robot body 300. The hands 350L and 350R are gripping mechanisms capable of gripping a work or a tool.

The hand 350L holds the second object 52. The hand 350R holds the first target object 50 or the second target object 52. For example, the hand 350R grips the first target object 50.

The drive controller 8 controls driving of the hand 350L and the robot arm 310L, the hand 350R and the robot arm 310R.

The piezo element 42 contracts along the direction in which the robot arm 310L and the hand 350L are arranged.

The piezo element 42 is provided between the robot arm 310L and the hand 350L. The piezo element 42 contracts the second object 52 in a direction away from the first object 50.

The force sensor 330L as a contact detection unit is provided between the robot arm 310L and the hand 350L.

According to the present embodiment, it is possible to prevent the first target object 50 and the second target object 52 from being easily scratched even in the dual-arm robot.

The piezo element 42 may be provided between the robot arm 310R and the hand 350R. The piezo element 42 contracts the first object in a direction away from the second object.

In addition, the contact detection unit may be provided between the robot arm 310R and the hand 350R.

Although the robot system and the method for controlling the robot system according to the present invention have been described above based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each unit is an arbitrary configuration having the same function. Can be replaced. Further, other arbitrary constituents may be added to the present invention.

Further, the robot body of the present invention is not limited to a 6-axis vertical multi-joint robot or a dual-arm robot, and may be another robot such as a SCARA robot. Further, the number of arms or the number of joints of the robot arm is not limited to the number in the above-described embodiment, and may be 1 or more and 5 or less or 7 or more.

The contents derived from the embodiment will be described below.

The robot system is a robot system that performs work involving contact between a first target object and a second target object, and is equipped with a first end effector that grips the second target object and the first end effector. A first robot arm, a contact detection unit that detects contact between the first object and the second object, and a first piezo element that contracts based on the detection result of the contact detection unit. The contraction of the first piezo element causes the first object and the second object to separate from each other.
According to this, when the first target object and the second target object come into contact with each other, the piezo element contracts in the direction in which the first target object and the second target object move away from each other, so that the first target object and the second target object are It is possible to prevent scratches.

In the robot system described above, it is preferable that the first piezo element contracts along a direction in which the first robot arm and the first end effector are arranged.
According to this, it is possible to efficiently separate the first object and the second object by contraction of the first piezo element.

In the above robot system, the first piezo element is provided between the first robot arm and the first end effector, and the direction in which the first piezo element contracts is set such that the second object is The direction away from the first object is preferable.
According to this, the vibration of the contact between the first object and the second object can be efficiently suppressed.

In the above robot system, the first piezo element is provided between the first object and a mounting table on which the first object is mounted, or on a surface of the mounting table on which the first object is mounted. Is provided on the opposite surface side, and the direction in which the first piezo element contracts is preferably the direction in which the first object separates from the second object.
According to this, the degree of freedom of the arrangement position of the first piezo element with respect to the mounting table can be improved.

In the above robot system, it is preferable that the contact detection unit is provided between the first robot arm and the first end effector.
According to this, it is possible to easily detect the contact between the first object and the second object.

In the robot system described above, the contact detection unit is between the first object and a mounting table on which the first object is mounted, or a surface of the mounting table on which the first object is mounted. It is preferably provided on the opposite surface side.
According to this, the degree of freedom of the arrangement position of the contact detection unit with respect to the mounting table can be improved.

In the robot system described above, the contact detection unit is preferably a force sensor.
According to this, the contact detection unit can be easily configured by the force sensor.

In the robot system described above, it is preferable that the contact detection unit is a second piezo element.
According to this, the contact detection unit can be easily configured with the second piezo element.

In the above robot system, it is preferable that the contact detection unit is the first piezo element.
According to this, the first piezo element has both the contact detection function and the function of contracting the first target object and the second target object in the direction in which the first target object and the second target object are separated from each other. Can be improved.

The robot system includes a drive control unit that controls driving of the first end effector and the first robot arm, and a piezo controller that controls contraction of the first piezo element based on the detection result of the contact detection unit. It is preferable that the piezo control unit includes a control unit, and the piezo control unit controls the contact detection unit and the first piezo element at a control cycle faster than that of the drive control unit.
According to this, it is possible to suppress the impact force by the piezo control unit controlling at a control cycle faster than that of the drive control unit.

The robot system preferably includes a second end effector that holds the first object or the second object, and a second robot arm to which the second end effector is attached.
According to this, even in the dual-arm robot, it is possible to prevent the first object and the second object from being easily scratched.

A control method of a robot system includes a first end effector that grips a work target object, a first robot arm to which the first end effector is attached, and a contact that detects contact between the work target object and the contact target object. A robot system that includes a detection unit, a first piezo element, and a piezo control unit that controls contraction of the first piezo element, and that performs work involving contact between the work target and the contact target. A control method, wherein the piezo control unit contracts the first piezo element in a direction in which the work target and the contact target are separated based on the detection result of the contact detection unit. And
According to this, when the first target object and the second target object come into contact with each other, the piezo element contracts in the direction in which the first target object and the second target object move away from each other, so that the first target object and the second target object are It is possible to prevent scratches.

2... Robot body 8... Drive control unit 10... Hand (first end effector) 12... Robot arm (first robot arm) 14... Base 16... First arm 18... Second arm 20... Third arm 22... Second 4 arm 24... 5th arm 26... 6th arm 28... Drive part 30... Angle sensor 36... Piezo control part 40... Force sensor (contact detection part) 42... Piezo element (1st piezo element) (contact detection part) 44... Force sensor (contact detection unit) 50... First target object (contact target object) 52... Second target object (work target object) 54... Mounting table 56... Piezo element (second piezo element) (contact detection) 58) Piezo element driver 60, 62... Force profile 100... Robot system 300... Robot body 310L... Robot arm (first robot arm) 310R... Robot arm (second robot arm) 330L, 330R... Force sensor ( Contact detection unit) 350L... Hand (first end effector) 350R... Hand (second end effector) 370L, 370R... Camera.

Claims (12)

A robot system for performing work involving contact between a first object and a second object,
A first end effector for gripping the second object,
A first robot arm equipped with the first end effector;
A contact detector that detects contact between the first object and the second object;
A first piezo element that contracts based on the detection result of the contact detection unit;
Have
A robot system, wherein the first object and the second object are separated by the contraction of the first piezo element. The robot system according to claim 1,
The robot system according to claim 1, wherein the first piezo element contracts along a direction in which the first robot arm and the first end effector are lined up. The robot system according to claim 1 or 2,
The first piezo element is provided between the first robot arm and the first end effector,
The robot system, wherein the direction in which the first piezo element contracts is the direction in which the second object separates from the first object. The robot system according to claim 1 or 2,
The first piezo element is provided between the first object and a mounting table on which the first object is mounted, or on a surface side of the mounting table opposite to a surface on which the first object is mounted. Is provided,
The robot system, wherein the direction in which the first piezo element contracts is a direction in which the first object separates from the second object. The robot system according to any one of claims 1 to 4,
The robot system, wherein the contact detection unit is provided between the first robot arm and the first end effector. The robot system according to any one of claims 1 to 4,
The contact detection unit is provided between the first object and a mounting table on which the first object is mounted, or on the surface side of the mounting table opposite to the surface on which the first object is mounted. A robot system characterized by being used. The robot system according to any one of claims 1 to 6,
The robot system, wherein the contact detector is a force sensor. The robot system according to any one of claims 1 to 6,
The robot system, wherein the contact detector is a second piezo element. The robot system according to any one of claims 1 to 5,
The robot system, wherein the contact detector is the first piezo element. The robot system according to any one of claims 1 to 9,
A drive controller that controls the drive of the first end effector and the first robot arm;
A piezo control unit that controls contraction of the first piezo element based on the detection result of the contact detection unit;
Have
The robot system, wherein the piezo controller controls the contact detector and the first piezo element at a control cycle faster than that of the drive controller. The robot system according to any one of claims 1 to 10,
A second end effector for gripping the first object or the second object;
A second robot arm equipped with the second end effector;
A robot system comprising: A first end effector for gripping a work target object, a first robot arm having the first end effector attached thereto, a contact detection unit for detecting contact between the work target object and a contact target object, and a first piezoelectric element. A method of controlling a robot system, comprising: an element; and a piezo control unit that controls contraction of the first piezo element, and performing a work involving contact between the work target and the contact target.
The control of the robot system, wherein the piezo control unit contracts the first piezo element in a direction in which the work target and the contact target are separated based on the detection result of the contact detection unit. Method.

Images