Patent Application
20250170723
The present technology relates to a robot apparatus including a hand portion and to a sensor apparatus.
In recent years, automation of work using a robot has been discussed in various scenes as working population is reduced. For example, when a holding target object (hereinafter, also referred to as a workpiece) placed on a working table is picked up by a robot hand in a factory, a shop, or the like, there is a need to highly accurately detect a force acting on a region being in contact with the workpiece. For example, Patent Literature 1 discloses a robot hand having a holding surface on which a pressure sensitive sensor is installed.
In order to perform the behavior control of a robot to a high degree, it is desirable that a direction in which a multiaxial force acts on a holding surface can be detected. However, if a plurality of elements each having a single detection axis is combined to detect a multiaxial force, the structure is enlarged. Further, if the elements are arranged so as to perform detection in a surface distribution, those elements occupy a large space.
Furthermore, since there are no nodes on a sensor end surface, a force acting on a fingertip of a robot hand cannot be detected. Therefore, there is a problem that a holding operation for a relatively thin lightweight workpiece such as a coin or a card is hard to perform. In addition, since a contact between the fingertip and the working table or workpiece cannot be detected, there is a possibility that the robot hand is damaged due to excessive stress applied to the fingertip.
In view of the circumstances as described above, it is an object of the present technology to provide a robot apparatus and a sensor apparatus that are capable of detecting stress applied to a fingertip.
A robot apparatus according to one embodiment of the present technology includes a hand portion, a sensor portion, and a holding member.
The hand portion includes a plurality of finger portions disposed to face each other in a direction of a first axis.
The sensor portion includes a first pressure sensor and a deformation layer. The first pressure sensor is disposed on at least one of the plurality of finger portions and is capable of detecting a pressure distribution. The deformation layer is disposed on the first pressure sensor and is made of a viscoelastic material.
The holding member is supported by the deformation layer and includes a claw portion that protrudes from a tip of the at least one of the finger portions in a direction of a second axis intersecting with the first axis and is capable of holding a workpiece.
The robot apparatus includes the holding member including the claw portion protruding from the tip of the finger portion, and detects a pressure acting on the claw portion by the first pressure sensor via the deformation layer. This makes it possible to detect stress applied to the tip of the finger portion without disposing a sensor on the tip of the hand.
The first pressure sensor may be configured to detect an in-plane pressure distribution perpendicular to the direction of the first axis.
The holding member may further include a base that is disposed to face the first pressure sensor in the direction of the first axis with the deformation layer being sandwiched therebetween.
This makes it possible to ensure rigidity of the claw portion and also to take a large detection range of the first pressure sensor.
The plurality of sensor portions may further include a second pressure sensor that is disposed on the holding member and is capable of detecting an in-plane pressure distribution perpendicular to the direction of the first axis.
This makes it possible to detect not only the pressure distribution but also shear stress applied to the deformation layer.
The claw portion may be a plate member having a holding surface perpendicular to the direction of the first axis.
Alternatively, the claw portion may be a single or a plurality of columnar bodies extending perpendicular to the direction of the first axis.
The finger portion may have a first main surface and a second main surface each perpendicular to the direction of the first axis. The first main surface may be an inner side surface on the side on which the workpiece is held, and the second main surface may be an outer side surface opposite to the first main surface.
The first pressure sensor may be disposed on the first main surface.
Alternatively, the first pressure sensor may be disposed on the second main surface.
The holding member may include a coupling portion that couples the claw portion and the base to each other, and a shaft portion that is supported by the hand portion and rotatably supports the coupling portion about a third axis orthogonal to the first axis and the second axis.
The claw portion may include a groove that extends along a direction of the third axis and is capable of housing the workpiece.
This makes it possible to stably hold a linear or bar-like workpiece.
The robot apparatus may further include a control unit that generates a control command for controlling the hand portion on the basis of an output of the sensor portion.
A sensor apparatus according to one embodiment of the present technology includes a pressure sensor, a deformation layer, and a holding member.
The pressure sensor is disposed on at least one of a plurality of finger portions capable of holding a workpiece in a direction of a first axis and is configured to be capable of detecting an in-plane pressure distribution perpendicular to the direction of the first axis.
The deformation layer is disposed on the pressure sensor and is made of a viscoelastic material.
The holding member is supported by the deformation layer and includes a claw portion that protrudes from a tip of the at least one of the finger portions in a direction of a second axis orthogonal to the first axis and holds the workpiece.
Hereinafter, embodiments according to the present technology will be described with reference to the drawings.
As shown in
The arm portion 1 includes a plurality of joint portions 1a, and the hand portion 3 can be moved to any position by the driving of the joint portions 1a. The wrist portion 2 is rotatably connected to the arm portion 1, and the hand portion 3 can be rotated by the rotation of the wrist portion 2.
The hand portion 3 includes a plurality of finger portions capable of holding a holding target object (workpiece). In this embodiment, the hand portion 3 includes two finger portions 3a and 3b that face each other, and a workpiece can be held between the two finger portions 3a and 3b by the two finger portions 3a and 3b being driven. Note that the number of finger portions can be changed appropriately to three, four or more, or the like.
Sensor apparatuses 20a and 20b are provided to the surfaces facing each other of the two finger portions 3a and 3b. The sensor apparatuses 20a and 20b each have a pressure detection surface and are each configured to be capable of detecting a pressure component that is applied to the pressure detection surface in a perpendicular direction and an in-plane distribution of the pressure component. Further, the sensor apparatuses 20a and 20b may also be a three-axis sensor capable of detecting not only a pressure distribution but also a shear force parallel to the pressure detection surface and an in-plane distribution thereof. Note that the configuration of the sensor apparatuses 20a and 20b will be described later with reference to
The robot apparatus 10 is driven by the control of a controller 11. The controller 11 includes a control section, a storage section, and the like. The control section is, for example, a central processing unit (CPU) and controls driving of each portion of the robot apparatus 10 on the basis of a program stored in the storage section. The controller 11 may be a dedicated device in the robot apparatus 10 or may be a general-purpose apparatus. The controller 11 may be, for example, a personal computer (PC) connected to the robot apparatus 10 through a wired or wireless connection, a server apparatus on a network, or the like. The controller 11 may be configured as a part of the robot apparatus 10.
Subsequently, details of the sensor apparatuses 20a and 20b will be described. The sensor apparatuses 20a and 20b each have the same configuration. The sensor apparatuses 20a and 20b are each formed of a sensor sheet capable of detecting a pressure distribution of the pressure detection surface as described above.
The sensor apparatuses 20a and 20b are respectively disposed on one side surface portions of the finger portions 3a and 3b. As shown in
The sensor apparatuses 20a and 20b each include a pressure sensor 21 (first pressure sensor), a deformation layer 22, and a holding member 40. The pressure sensor 21 and the deformation layer 22 correspond to a sensor portion 25 of the robot apparatus 10 (see
The pressure sensor 21 is a pressure distribution sensor that is capable of detecting an in-plane (XZ-plane) pressure distribution perpendicular to the Y-axis direction. The pressure sensor 21 is a sensor sheet parallel to the XZ-plane. The pressure sensor 21 has a shape of a rectangular flat plate as a whole in plan view. Note that the shape of the pressure sensor 20 in plan view is not particularly limited and only needs to be appropriately set in accordance with the shape of a location where each of the sensor apparatuses 20a and 20b is disposed. For example, the shape of the pressure sensor 21 in plan view may be a polygon other than a rectangle, a circle, or an ellipse.
As shown in
The sensor electrode layer 211 includes a flexible printed circuit board or the like. As shown in
The main body 51 of the sensor electrode layer 211 includes a base material 511 having flexibility, and a plurality of sensing portions 21s provided on a front surface of the base material 511 or provided inside the base material 511. For example, a polymer resin such as polyethylene terephthalate, polyimide, polycarbonate, or an acrylic resin is used as the material of the base material 511. The sensing portions 21s are regularly arranged in a matrix at predetermined intervals in directions of length and width (length: the y-axis direction, width: the x-axis direction). In the example shown in
The sensing portion 21s includes a capacitive element (detection element) capable of detecting a change in distance from the reference electrode layer 212 as a change in capacitance. For example, as shown in
Note that the structure of the sensing portion 21s is not limited to the example described above, and any structure may be used. For example, the sensor electrode layer 211 may be formed of a laminate of a first electrode sheet having a lattice-shaped first electrode pattern extending in the X-axis direction and a second electrode sheet having a lattice-shaped second electrode pattern extending in the Z-axis direction. In this case, the sensing portion 21s is formed at an intersection of the first electrode pattern and the second electrode pattern.
The extended portion 52 of the sensor electrode layer 211 is equipped with a control unit 70 that calculates a force in the in-plane direction on the basis of information of the pressure detected by the pressure sensor 21. The control unit 70 is typically a computer including a central processing unit (CPU) and includes an integrated circuit such as an IC chip. The control unit 70 is mounted on the sensor electrode layer 211 (extended portion 52) and is configured to drive the pressure sensor 21 and to input output signals from the pressure sensor 21. Note that the control unit 70 is not limited to the example in which the control unit 70 is mounted on the sensor electrode layer 211.
The reference electrode layer 212 is connected to a reference potential. In this embodiment, the reference electrode layer 212 is a so-called grounding electrode and is connected to a ground potential. The reference electrode layer 212 has flexibility and has a thickness of, for example, approximately 0.05 μm to 0.5 μm. For example, an inorganic conductive material, an organic conductive material, or a conductive material including both the inorganic conductive material and the organic conductive material is used as the material of the reference electrode layer 212.
Examples of the inorganic conductive material include metals such as aluminum, copper, and silver, alloys such as stainless steel, and metal oxides such as zinc oxide and indium oxide. Further, examples of the organic conductive material include carbon materials such as carbon black and carbon fibers, and conductive polymers such as substituted or unsubstituted polyaniline and polypyrrole. The reference electrode layer 212 may be formed of a thin metal plate made of stainless steel, aluminum, or the like, a conductive fiber, a conductive nonwoven fabric, or the like. The reference electrode layer 212 may be formed on a plastic film by, for example, a method such as vapor deposition, sputtering, bonding, or coating.
The elastic layer 213 is disposed between the sensor electrode layer 211 and the reference electrode layer 212. The elastic layer 213 has a thickness of, for example, approximately 100 μm to 1000 μm. The elastic layer 213 is formed of an elastic material that is elastically deformable in response to an external force. When an external force is applied to the pressure sensor 21 in the perpendicular direction (the Y-axis direction), the elastic layer 213 elastically deforms in response to the external force, and the reference electrode layer 212 approaches the sensor electrode layer 211. At that time, a capacitance between the pulse electrode 512 and the sense electrode 513 changes in the sensing portion 21s, and thus the sensing portion 21s is capable of detecting such a change in capacitance as a pressure value.
The thickness of the elastic layer 213 is set to be, for example, larger than 100 μm and equal to or less than 1000 μm, and the basis weight of the elastic layer 213 is set to be, for example, 50 mg/cm2 or less. Setting the thickness and the basis weight of the elastic layer 213 within the above ranges makes it possible to improve the detection sensitivity of the pressure sensor 21 in the perpendicular direction.
A lower limit of the thickness of the elastic layer 213 is not particularly limited as along as the lower limit is larger than 100 μm, and the lower limit may be, for example, 150 μm or more, 200 μm or more, 250 μm or more, or 300 μm or more. Further, an upper limit of the thickness of the elastic layer 213 is not particularly limited as long as the upper limit is 1000 μm or less, and the upper limit may be, for example, 950 μm or more, 900 μm or less, 850 μm or less, or 800 or less.
Examples of the elastic material that forms the elastic layer 213 include urethane foam. Other than the urethane foam, for example, a rubber material made of acrylic or silicon, and a viscoelastic material such as an adhesive are also applicable. The elastic layer 213 is not limited to the film structure and may have a patterning structure having a predetermined shape. For example, in order to facilitate the deformation in the Y-axis direction, the elastic layer 213 may have, for example, a patterning structure including a column structure. Various structures such as a matrix structure, a stripe structure, a mesh structure, a radial structure, a geometric structure, and a spiral structure may be adopted as the patterning structure.
The deformation layer 22 is disposed between the pressure sensor 21 and the holding member 40 via adhesive layers (not shown). The deformation layer 22 is made of a viscoelastic material that is deformed by a load applied to the pressure sensor 21 via the holding member 40.
Examples of the viscoelastic material that forms the deformation layer 22 include a silicon gel, a urethane gel, synthetic rubber, and foam. The deformation layer 22 is favorably made of a material harder than the elastic layer 213 of the pressure sensor 21. This makes it possible to properly input a holding force applied to the holding member 40 to the pressure sensor 21. A thickness of the deformation layer 22 is not particularly limited, and is, for example, 200 μm or more and 5000 μm or less. A planar shape of the deformation layer 22 is not particularly limited and is typically rectangular or circular.
(Holding Member) The holding member 40 is supported by the deformation layer 22 and includes a claw portion 41 protruding from each of tips 3a1 and 3b1 of the finger portions 3a and 3b in the Z-axis (second axis) direction. The surfaces facing each other of the claw portions 41 of the respective holding members 40 form holding surfaces 42 for holding a workpiece. The holding member 40 is made of, for example, a plastic material, a ceramics material, or a glass material such as reinforced glass, which has higher rigidity than that of the deformation layer 22, or a rubber material or a metal material, which has a relatively high hardness. For example, the holding member 40 is rectangular in plan view and is a plate member having the same width as a base 43 (see (A)
The holding member 40 is attached to the deformation layer 22 such that the claw portion 41 thereof protrudes from each of the tips 3a1 and 3b1 of the finger portions 3a and 3b in the Z-axis direction (downwardly in
The holding member 40 includes the base 43 that is disposed to face the pressure sensor 21 in the Y-axis direction with the deformation layer 22 interposed therebetween. The base 43 is formed to have such a size that the entire surface of the pressure sensor 21 is covered. Accordingly, causing the base 42 to function as a protective layer for protecting the pressure sensor 21 and the deformation layer 22 makes it possible to enhance the durability of the pressure sensor 21 and the deformation layer 22. Note that a protective layer for protecting the peripheral surfaces of the pressure sensor 21 and the deformation layer 22 may be separately provided as necessary.
The claw portion 41 of the holding member 40 is a region extending from the base 41 in the Z-axis direction. In other words, the region protruding from each of the tips 3a1 and 3b1 of the finger portions 3a and 3b as viewed from the Y-axis direction forms the claw portion 41 of the holding member 40.
The length of the claw portion 41 of the holding member 40 (that is, the amount of protrusion from the tips 3a1 and 3b1 of the finger portions 3a and 3b) is not particularly limited. For example, as the length of the claw portion 41 becomes larger, a reaction force (moment) applied from the holding member 40 to the pressure sensor 21 when the workpiece W is held becomes larger, so that the detection sensitivity of a holding force P1 by the pressure sensor 21 can be enhanced. On the other hand, there is a possibility that a stable handling operation for the workpiece W is impaired due to an increase in the amount of deformation of the claw portion 41 or the amount of compressive deformation of the deformation layer 21. Therefore, the amount of protrusion of the claw portion 41 is adjusted in accordance with the rigidity such as hardness of the holding member 40 or the deformation layer 21, the size or shape of the workpiece W, a weight, and the like.
As described above, the robot apparatus 10 of this embodiment includes the holding member 40 protruding from each of the tips 3a1 and 3b1 of the finger portions 3a and 3b and is configured to detect a pressure acting on the claw portion 41 of the holding member 40 by the pressure sensor 21 via the deformation layer 22. This makes it possible to detect a holding force to the workpiece W without disposing a sensor on the holding surface 42 at the tip of the hand.
For example, as in the case of a hand portion 4 shown in
Further, the hand portion 4 shown in
On the other hand, since the hand portion 3 in this embodiment includes the claw portions 41 of the holding members 40, the claw portions 41 protruding downwardly from the tips 3a1 and 3b1 of the finger portions 3a and 3b, the holding forces P1 applied to the holding surfaces 42 of those claw portions 41 act not only on the tip regions of the pressure sensors 21 but also over the regions adjacent to the tip regions. In other words, the claw portions 41 are inclined about the X-axis in
In addition, according to this embodiment, the stress acting on the claw portion 41 in the Z-axis direction can also be detected. For example, even when the claw portion 41 abuts on the workpiece W or the working table on which the workpiece W is placed, the movement of the claw portion 41 in the Z-axis direction or the inclination thereof about the X-axis can be detected by the pressure sensor 21. This makes it possible to, for example, suitably control the holding position (height) of the finger portions 3a and 3b relative to the workpiece W while monitoring the stress acting on the claw portion 41. As described above, according to the robot apparatus 10 of this embodiment, the stress applied to the fingertip can be detected without disposing a sensor on the fingertip.
The control unit 70 includes a control section, a storage section, and the like. The control section is, for example, a central processing unit (CPU), and executes a program stored in the storage section on the basis of a control command from the controller 11 to control the driving of each portion in the hand portion 3. Typically, the control unit 70 acquires information of the pressures detected by the sensor apparatuses 20a and 20b, and controls the driving of the hand portion 3 so as to stably hold a target object with a suitable holding force.
The storage section includes a nonvolatile memory in which various programs and data necessary for processing of the control section are stored, and a volatile memory used as a work area of the control section. Various programs may be read from a portable recording medium such as a semiconductor memory, or may be downloaded from a server apparatus on a network.
The control unit 70 is electrically connected to the sensor apparatuses 20a and 20b and is configured to calculate a pressure acting on the finger portions 3a and 3b on the basis of the outputs of the sensor apparatuses 20a and 20b. The control unit 70 is further electrically connected to the controller 11 and outputs, on the basis of a control command from the controller 11, a hold command to a drive unit 12a that drives the finger portions 3a and 3b of the hand portion 3.
The controller 11 and the control unit 70 are configured as a control apparatus that controls the operation of the hand portion 3. In this embodiment, a hold command supplied to the drive unit 12a that drives the finger portions 3a and 3b is generated in the control unit 70, but instead of this, a hold command may be generated by the controller 11 that controls the whole operation of the robot apparatus 10. In this case, the controller 11 is configured as the control apparatus.
As shown in
The acquisition section 71 receives a pressure detection position and a pressure value thereof that are output from each of the sensor apparatuses 20a and 20b, and a control command output from the controller 11. Pressure information including the pressure detection positions and the pressure values thereof that are output from the sensor apparatuses 20a and 20b is information regarding stress detected when the hand portion 3 (finger portions 3a and 3b) comes into contact with a workpiece or a placing surface on which the workpiece is placed, and regarding stress acting on the sensor apparatuses 20a and 20b when the hand portion 3 (finger portions 3a and 3b) is holding the workpiece.
The computing section 72 calculates the pressure detection positions in the in-plane direction and the pressure values thereof, which are detected by the sensor apparatuses 20a and 20b. The load perpendicular to the pressure detection surface is calculated from, for example, the sum of the perpendicular loads acquired by the respective sensing portions 28 of the sensor apparatuses 20a and 20b.
The signal generation section 73 generates a hold command for causing the hand portion 3 to hold a workpiece on the basis of the control command from the controller 11. The hold command includes information regarding the holding force of the hand portion 3 with respect to the workpiece. The signal generation section 73 outputs the generated hold command to the drive unit 12a of the hand portion 3.
The drive unit 12a is an actuator that causes the finger portions 3a and 3b to move between a holding position and a non-holding position. In this embodiment, the drive unit 12a is, for example, a pulse motor capable of fine feed control.
The storage section 74 is typically a semiconductor memory. The storage section 74 stores a program and various parameters for performing a processing procedure of calculating a pressure or an in-plane distribution thereof on the basis of the pressure detection position in the in-plane direction, which is detected by the pressure sensor 21.
The sensor apparatuses 20a and 20b constitute one of the various sensors described above. On the basis of a control command from the controller 11, the control unit 70 outputs a hold command for holding a workpiece to the drive unit 12a that drives the finger portions 3a and 3b of the hand portion 3. The sensor apparatuses 20a and 20b each detect the pressure acting on the claw portion 41, calculate a value of the above-mentioned pressure in the control unit 70, and input the calculated value to the controller 11. The controller 11 generates a drive signal for controlling the positions or postures of the arm portion 1 and the hand portion 3 (finger portions 3a and 3b), and outputs the drive signal to the drive section 12. The drive section 12 is typically an actuator such as an electric motor or a fluid pressure cylinder, and drives the arm portion 1, the hand portion 3, and the like on the basis of the drive signal from the controller 11.
As described above, in this embodiment, the hold control of the hand portion 3 is configured to be performed in the control unit 70. The present technology is not limited to the above, and the controller 11 may directly output a hold command to the drive unit 12a to perform the hold control of the hand portion 3. In this case, the control unit 70 performs only the functions of calculating a pressure acting on the sensor apparatuses 20a and 20b and of outputting the calculated pressure to the controller 11.
The hand portion 103 of this embodiment is different from that of the first embodiment in the configuration of a holding member 140. In other words, in this embodiment, the holding member 140 is disposed on an end surface of a deformation layer 22 to serve as a claw portion protruding in the Z-axis direction (downwardly in
In the hand portion 103 thus configured in this embodiment, a holding force P1 of the workpiece W that acts on the holding surface 142 of the holding member 140 is detected as a change in pressure distribution applied to a pressure sensor 21. In addition, also when an upward load acts on the holding member 140 in
The hand portion 203 of this embodiment includes, as in the first embodiment, a pressure sensor 21, a deformation layer 22, and a holding member 240. This embodiment is different from the first embodiment described above in that the pressure sensor 21 is disposed on a second main surface 32 that is an outer side surface of each of finger portions 3a and 3b. The deformation layer 22 and the holding member 240 are disposed on the pressure sensor 21 in the stated order.
Here, the finger portions 3a and 3b are movable in a direction approaching each other and a direction away from each other (arrow A1) in synchronization with a base 30 of the hand portion 203 in the Y-axis direction. In other words, the finger portions 3a and 3b move in the direction approaching each other when holding a workpiece, and moves in the direction away from each other when releasing the workpiece. Note that the present technology is not limited to the above, and only one of the finger portions 3a and 3b may be configured to be movable in the Y-axis direction.
The holding member 40 includes a claw portion 241 having a holding surface 242 for holding a workpiece, a base 243 supported by the deformation layer 22, a coupling portion 244 that couples the claw portion 241 and the base 243 to each other, and a shaft portion 245 that rotatably supports the coupling portion 244 about the X-axis.
The claw portion 241 extends along the Z-axis direction so as to protrude downwardly relative to tips 3a1 and 3b1 of the finger portions 3a and 3b. In this embodiment, a linear workpiece W1 is to be held. Thus, the claw portion 241 on the finger portion 3a side and the claw portion 241 on the finger portion 3b side are disposed to be offset from each other in the X-axis direction and are configured to partially overlap with each other in the X-axis direction in the closing state shown in the figure (when holding the workpiece W1) (see
A groove 242a capable of housing the workpiece W1 is formed in the holding surface 242 of the claw portion 241 so as to extend along the X-axis direction. The workpiece W1 is held by being sandwiched between the bottom portions of the grooves 242a of both the claw portions 241. The cross-sectional shape of the groove 242a is a substantially triangular shape, but it is not limited thereto and only needs to be a shape capable of stably holding the workpiece W1, such as an arc shape.
As in the first embodiment, the base 243 is disposed to face the pressure sensor 21 in the Y-axis direction with the deformation layer 22 interposed therebetween. The base 243 is formed in such a shape or size that substantially the whole region of the pressure sensor 21 is covered.
The coupling portion 244 is formed in a substantially L-shape and includes a first arm V1 extending from the base 243 in the longitudinal direction (the Z-axis direction) and a second arm V2 extending from the tip of the first arm V1 toward the claw portion 241 in the lateral direction (the Y-axis direction). Since each claw portion 241 is located immediately below each of the tips 3a1 and 3b1 of the finger portions 3a and 3b, the second arm V2 extends from the tip of the first arm V1 toward the inside (toward the center side of the hand portion 203).
The shaft portion 245 is supported by each of the finger portions 3a and 3b and penetrates the coupling portion 244 in the X-axis direction. The shaft portion 245 is supported by a support portion 33 provided to each of the finger portions 3a and 3b. The support portion 33 or the shaft portion 245 of the finger portion extends in the Y-axis direction from the vicinity of the tips 3a1 and 3b1 of the finger portions 3a and 3b toward the first arm V1 of the coupling portion 244, and supports the shaft portion 245 that pivotally supports the first arm V1. Note that the shaft portion 245 may be configured as a component separate from the holding member 240 or may be configured as a part of the holding member 240 (the coupling portion 244).
The hand portion 203 in the robot apparatus of this embodiment is used in, for example, a process of holding a predetermined part of the workpiece W1 retained at a predetermined posture (e.g., horizontal posture) in a space and conveying the workpiece W1 to a predetermined position. When the workpiece W1 is held, the finger portions 3a and 3b are moved to an open position, and a predetermined gap is formed between the claw portions 241 of the respective finger portions 3a and 3b. After the hand portion 203 is moved to a position where the workpiece W1 is to be located between both the claw portions 241, the finger portions 3a and 3b are moved to a holding position to sandwich the workpiece W1 by the two claw portions 241 (see
The holding force with respect to the workpiece W1 is converted into a rotational force of the holding member 240 centering on the shaft portion 245 as indicated by the arrow A2 in
If the workpiece W1 has flexibility, a certain level of tension can be given to the workpiece W1 by the movement of the hand portion 203 in a predetermined direction. For example, in a state in which the workpiece W1 with one end thereof fixed is held with a target holding force, when the hand portion 203 is moved in a direction in which the workpiece W1 is pulled in the extending direction of the workpiece W1, the tension can be detected by the pressure sensor 21 as a change in pressure distribution corresponding to that tension.
As described above, in the holding member 240 in this embodiment, the claw portion 241 and the base 243 are coupled to each other via the coupling portion 244, and thus adjusting the shape of the coupling portion 244 makes it possible to discretionally set the interval between the claw portions 241, which is different from the interval between the bases 243. This makes it possible to easily perform a holding operation of the workpiece W1 having a width or diameter smaller than the interval between the bases 243.
Further, according to this embodiment, the holding member 240 is configured to be rotatable about the shaft portion 245, which makes it possible to detect a holding force with respect to the workpiece W1 by the outer side surface (second main surface 32) of each of the finger portions 3a and 3b. Accordingly, the pressure sensor 21 and the deformation layer 22 can be disposed on the outer side surface of each of the finger portions 3a and 3b having a relatively high degree of freedom for installation, so that the degree of freedom in design of the hand portion 203 can be enhanced.
In addition, according to this embodiment, the holding member 240 is configured to be rotatable about the shaft portion 245, which makes it possible to amplify the holding force to be applied to the pressure sensor 21 at an amplification rate corresponding to the ratio of the distance between the base 243 and the shaft portion 245 to the distance between the shaft portion 245 and the claw portion 241 (holding surface 242). In this embodiment, as shown in
In addition, according to this embodiment, the two claw portions 241 are disposed at the positions offset from each other in the X-axis direction, which makes it possible to avoid a contact between the claw portions 241 in the holding operation of the workpiece W1 and to stably detect only the holding force accordingly. Further, each claw portion 241 can also hold the workpiece W1 in a positional relationship in which a shear force is applied to the workpiece W1 in the holding direction (the Y-axis direction). Such a configuration is particularly effective, for example, in a case where a card-shaped workpiece is held in its thickness direction, in addition to the case where a workpiece W1 having a relatively small (extra-fine) wire diameter is held as in this embodiment.
For example, in each embodiment described above, the robot apparatus in which the sensor apparatuses 20a and 20b are respectively provided to the finger portions 3a and 3b has been described as an example, but the present technology is not limited thereto. The sensor apparatus only needs to be provided to at least one of the finger portions.
Further, in the first embodiment described above, the case where the claw portion 41 of the holding member 40 has a plate shape has been described as an example as shown in (A) of
Further, in each embodiment described above, the base 43 of the holding member 40 is formed to have such a size that the whole surface region of the deformation layer 22 can be covered, but the present technology is not limited thereto. For example, as shown in (A) of
Further, as shown in (B) of
Further, as shown in (C) of
In addition, in the embodiments described above, the pressure sensor 21 is configured to be capable of detecting an in-plane pressure distribution perpendicular to the holding direction, but instead of this, for example, as shown in (D) of
In addition, in the embodiments described above, the case where the claw portion of the holding member protrudes downwardly relative to the fingertip portion has been described as an example, but the protruding direction of the claw portion is not limited thereto and may be a front direction (in
Note that the present technology can also take the following configurations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-034842 | Mar 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/000953 | 1/16/2023 | WO |
