JP2017164899A - Robot hand, robot device, and control method of the robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and light-weight structure which can stably grip a workpiece of a various shape by a robot hand.SOLUTION: A drive mechanism makes gripping finger main body parts (50a) come close to or separate from each other independently. A rotation mechanism rotates rotating fingers 40, 60. Thereby, the number of gripping fingers to be used is selected in accordance with a workpiece to be gripped, and the workpiece of a various shape can be gripped stably.SELECTED DRAWING: Figure 2

Description

  The present invention includes at least three gripping fingers, a robot hand that grips an object via the gripping surface of each gripping finger and operates the object, a robot apparatus using the robot hand, and the robot hand Relates to the control method.

  Various types of robot hands (hereinafter sometimes simply referred to as “hands”) are used as end effectors constituting the gripping means of industrial robots. This type of robot hand generally includes a multi-finger hand provided with a palm and a plurality of gripping fingers (hereinafter sometimes referred to as “finger”) provided on the palm. This type of multi-fingered hand has a drive unit that operates at least one displaceable gripping finger, and controls the drive unit by a control device to open and close the gripping finger to grip or release an object. It is.

  In some multi-fingered hands, one joint at the base of a movable gripping finger is moved linearly to open and close to grip and release an object. In such a single-joint hand, prepare and replace multiple types of fingers with different gripping surface shapes and materials according to the shape, characteristics, weight, etc. of the object (for example, industrial product workpiece). Some specifications are used. A multi-fingered multi-fingered hand having a plurality of movable (swinging) joints on one gripping finger is also known. In a multi-fingered multi-fingered hand, for example, as shown in Patent Document 1, a gripping means having a structure simulating a human hand can be configured.

  The above-mentioned multi-joint / multi-fingered hand, similar to the human hand, has a flat or smooth curved surface in contact with the fingertip object in order to hold a variety of objects with different sizes and shapes. The object is gripped by the frictional force acting on the object and the fingertip. In this type of multi-finger / multi-joint hand, the tilt angles of the fingertips and the root part can be controlled separately. For this reason, it is often possible to deal with workpieces of various shapes, materials, and weights without preparing a dedicated shape suitable for the specific shape of the object.

  However, when gripping a workpiece with a multi-fingered hand, the gripped workpiece may slide down during conveyance due to the shape or surface properties of the workpiece. In order to solve this problem, a plurality of slip detection sensors are provided in the finger portion of the multi-fingered hand, and slip between the finger portion and the workpiece is detected via the detection value, and the workpiece is detected according to the detection value. There has been proposed a robot hand that controls a driving unit of a finger unit so as to increase a gripping force.

  For example, in the configuration of Patent Document 1, when gripping of a gripping target is detected while gripping a workpiece, control is performed to increase the gripping force of each finger by a predetermined amount. By such control, it is possible to prevent the object to be gripped from sliding down even with a small gripping force.

JP-A-4-189484

  In the robot hand of Patent Document 1, when a workpiece slip is detected when the workpiece is assembled to another part, a large force is required also in the assembling direction in addition to a gripping force that prevents the workpiece from dropping and being displaced. . For example, assuming that a joint structure as shown in Patent Document 1 is used, in an assembly operation in which a workpiece is pushed out toward the fingertip direction, an assembly force necessary for the assembly direction is generated on the gripping surface of the fingertip of the hand. This is guaranteed by the frictional force between the workpiece and the fingertip. Therefore, in such a configuration and assembly operation, a value obtained by multiplying the gripping force by the friction coefficient when the workpiece and the fingertip gripping surface come into contact is the maximum assembling force that can be generated as the assembling force.

  Therefore, in order to increase the assembly force, it is necessary to increase the gripping force generated at the fingertip or increase the friction coefficient of the gripping surface of the gripping finger. However, in order to increase the gripping force, the output of the drive unit is increased, and thus the drive unit of the finger naturally has to be large and heavy. In addition, since the friction coefficient also depends on the surface properties of the workpiece, it may be expected that a variety of workpieces cannot be handled simply by selecting the gripping surface characteristics.

  In view of the above problems, an object of the present invention is to provide a small and lightweight structure that can stably hold workpieces of various shapes by a robot hand and can sufficiently and appropriately control assembly of an object.

  In order to solve the above problems, in the present invention, in a robot hand that includes at least three gripping fingers and grips an object, a driving mechanism that allows the three gripping fingers to approach or separate independently from each other, and the three gripping operations In order to change the approach or separation direction of the two gripping fingers among the fingers, a configuration including a turning means for turning the two gripping fingers is adopted.

  According to the above configuration, it is possible to realize a small and lightweight robot hand that can stably hold workpieces of various shapes and can appropriately control assembly.

(A), (b) is explanatory drawing which each showed the different state of the robot hand which concerns on Example 1 of this invention from the side surface direction. (A), (b), (c) is explanatory drawing which each showed the robot hand of FIG. 1 from the fingertip direction of a holding finger in a different holding finger turning posture. (A), (b) is explanatory drawing which each showed the structure of the principal part of the robot hand of FIG. 1 from the side surface direction in the inclination angle of a different holding part. (A), (b) is explanatory drawing which each showed the structure of the holding surface of the robot hand of FIG. 1 from the side surface direction in the inclination angle of a different holding part. FIG. 2 is a block diagram illustrating a configuration example of a control system of the robot hand of FIG. 1. It is the diagram which showed the time change of the assembly | attachment force of the robot hand of FIG. It is explanatory drawing which showed the structural example of the force sensor of the robot hand of FIG. (A), (b) is explanatory drawing which each showed the force sensor of FIG. 7 from the different side surface direction. It is the flowchart figure which showed an example of the assembly | attachment control of the robot hand of FIG. (A), (b), and (c) corresponding to the control of FIG. 9 are explanatory views respectively showing the state of the robot hand of FIG. 1 from the side surface direction. It is explanatory drawing which showed the structure of the principal part of the robot hand in Example 2 of this invention from the side surface direction. (A), (b), (c) is explanatory drawing which respectively showed the structure of the principal part of the robot hand in Example 2 of this invention from the side surface direction in the inclination angle of a different holding part. 1 shows a configuration of a robot apparatus having a robot hand adopting the present invention, (a) is a schematic perspective view of the robot apparatus, and (b) is a block diagram showing a configuration of a control system of the apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to embodiments shown in the accompanying drawings. The following embodiment is merely an example, and for example, a detailed configuration can be appropriately changed by those skilled in the art without departing from the gist of the present invention. Moreover, the numerical value taken up by this embodiment is a reference numerical value, Comprising: This invention is not limited.

<Example 1>
First, an example of a schematic configuration of a robot hand 100 employing the present invention will be described with reference to FIGS. FIGS. 1A and 1B show different states of the robot hand 100 according to the first embodiment to which the present invention is applied from the side surface direction. 2A to 2C show a state in which the turning fingers of the robot hand 100 of FIG. 1 are in different directions from the fingertip direction of the hand.

In the following drawings, X, Y, and Z coordinate axes are indicated by symbols such as arrows, arrowheads, and arrow feathers in the drawings as necessary. The forces acting in the direction of each coordinate axis are shown in a format such as Fx, Fy, and Fz. In general, in a robot apparatus, an XYZ three-dimensional coordinate system may appropriately use a local coordinate system for a robot hand, a finger, and the like depending on the convenience of control in addition to the global coordinate system of the entire installation environment.

  The X, Y, and Z coordinate axes illustrated in the present embodiment are mainly set for each of a plurality of fingers, and mean local coordinate systems used for controlling each finger. In this embodiment, the coordinate axis extending in the fingertip direction of each finger at right angles from the base portion of each finger to the palm portion 1 is defined as the Y axis (the fingertip side is in the Y + direction: see FIG. 3A and the like). The Z axis is taken in the direction in which the finger is driven to open and close (relative to the other fingers) (the direction approaching the other finger is the Z + direction: see FIG. 2 (a) and the like). Also, the X axis is taken at a right angle to the Z axis.

  As shown in FIGS. 1 and 2, the robot hand 100 according to the present embodiment includes a palm portion 1, a fixed finger 20, a first turning finger 40, and a second turning finger 60 closer to the hand than the palm portion 1. Is arranged.

  A robot arm attachment portion 2 is disposed below the palm portion 1, and the robot hand 100 is attached to a robot arm (not shown) via the attachment portion 2.

  The first turning finger 40 is driven to turn by the actuator 46 about the turning shaft 47. The actuator 46 for turning driving is constituted by, for example, a motor or a speed reducer that rotationally drives the turning shaft 47. Further, the second turning finger 60 is driven to turn by an actuator for the turning finger 60 that is configured in the same manner as the actuator 46 around the turning shaft 67. In FIGS. 1 (a) and 1 (b), the turning finger 60 is not shown because it is positioned behind the turning finger 40 and in the same phase on the paper (for example, the state shown in FIG. 2 (a)). It has become.

  The turning means (46, 47) is for changing the angle formed by the surface of at least two gripping fingers including the gripping surface of one gripping finger and the surface of the other gripping finger including the gripping surface. belongs to. This swiveling means swivels the whole above the base material portions (41, 42) around the swivel axis (47).

  The fixed finger 20 does not have a turning means like the above-described actuator of the turning fingers 40 and 60, and therefore is referred to as a “fixed finger” for convenience. However, this does not have a swing drive mechanism described later. It doesn't mean.

  Moreover, even if there are only two of the turning fingers 40 and 60, it is possible to obtain the effect of the present invention with only two of the fixed finger 20 and the turning finger 40.

  With the finger structure of the fixed finger 20 and the turning fingers 40 and 60 described above, the robot hand 100 according to the present embodiment allows the fingers (20, 40, 60) suitable for the target object to be relatively opened and closed (the fingers approach each other). Or the direction of separation) can be controlled to be changeable. For example, in FIG. 2A, the turning fingers 40 and 60 are parallel to the fixed finger 20 in the opening / closing direction, that is, the Z axis (direction of the gripping force Fz) of the three-dimensional coordinate system taken for each of these fingers. The turning posture is controlled so that they are all parallel. In other words, the angle formed between the surface including the gripping surface of the fixed finger and the surface including the gripping surface of the turning finger is 0 degrees. The relative postures of the fixed finger 20 and the turning fingers 40 and 60 as shown in FIG. 2A are suitable for holding a rectangular workpiece 3 as shown in the figure, for example.

  In FIG. 2B, the turning fingers 40 and 60 are controlled in a turning posture so that the opening and closing directions of the turning fingers and the fixed finger 20 form an angle of (almost) 120 degrees. In other words, the angle formed between the surface including the holding surface of the fixed finger and the surface including the holding surface of the turning finger is 120 degrees. The turning posture of the fixed finger 20 and the turning fingers 40, 60 is such that the positive direction of the Z-axis (the direction of the gripping force Fz) of the three-dimensional coordinate system taken for each finger is one point at the center of each finger. It is a turning posture that concentrates and intersects. The relative postures of the fixed finger 20 and the turning fingers 40 and 60 as shown in FIG. 2B are suitable for holding the workpiece 4 (spherical or cylindrical) having a circular cross section as shown, for example.

  In FIG. 2 (c), the turning postures of the turning fingers 40 and 60 are just perpendicular to the posture of FIG. 2 (a). In other words, the angle formed between the surface including the holding surface of the fixed finger and the surface including the holding surface of the turning finger is 90 degrees. Thereby, the Z-axis of the three-dimensional coordinate system of the turning fingers 40 and 60 is substantially in a straight line, and the positive directions of the Z-axis (the direction of the gripping force Fz) are opposite to each other. The relative postures of the fixed finger 20 and the turning fingers 40 and 60 as shown in FIG. 2C are suitable for holding, for example, a small thin object 5 as shown in the figure.

  In the above description, the entire finger-shaped part of the gripping part is called the fixed finger 20 and the turning fingers 40 and 60, and these fixed finger 20 and the turning fingers 40 and 60 respectively act on the gripping of the object. A narrowly defined gripping finger 50 is provided.

  In addition, the shape of the gripping surface has a structure in which the gripping surface facing the workpiece is substantially parallel to the opening / closing drive direction of the gripping finger in order to secure a contact area between various shapes of the workpiece and the fingertip. . Furthermore, it is possible to stably grip workpieces of various shapes by independently performing the opening / closing drive of the gripping fingers while maintaining the parallel state.

  The parts of the fixed fingers 20 and the gripping fingers 50 and 50 of the turning finger 40 are shown enlarged in FIGS. FIGS. 3A and 3B show different postures in which the gripping portions 50b of the gripping fingers 50 and 50 have different inclination angles with respect to the gripping finger main body 50a.

  That is, the gripping fingers 50 and 50 of the fixed finger 20 and the turning finger 40 include a gripping finger main body portion 50a and a gripping portion 50b, respectively. Each gripping part 50b is swingably supported by a swinging fulcrum 55 arranged on the fingertip side of the gripping finger main body part 50a. Each gripping part 50b has a gripping surface 56 on the surface facing each gripping finger.

  In FIGS. 3A and 3B, the gripping portion 50b is controlled to take different inclination angles with respect to the gripping finger main body portion 50a by a swing drive mechanism described later. In any case, each gripping portion 50b takes a different inclination angle with respect to the gripping finger main body portion 50a by the swing drive mechanism in a state where the gripping surface 56 is folded inward so that the gripping surface 56 is opposed to each gripping finger. Can be controlled.

  The state of FIG. 3A corresponds to the initial posture of each gripping finger 50, 50, for example, in drive control described later. At this time, the gripping surfaces 56 and 56 of each gripping finger take a posture of facing each gripping finger. The gripping finger 50 according to the present embodiment is characterized in that it can take this initial posture folded along the gripping finger main body portions 50a and 50a via the swing fulcrums 55 and 55.

  Then, the gripping fingers 50, 50 of the present embodiment, for example, from the initial posture of FIG. 3A, as shown in FIG. 3B, the tips of the gripping portions 50b, 50b of the gripping fingers 50, 50 (see FIG. It can be driven to swing so that the middle lower side and the side close to the palm part are inclined to approach each other. The robot hand 100 according to the present embodiment thus takes a posture in which the gripping portions 50b and 50b are folded inward from the swinging fulcrum (swinging joint) on the distal end side of the finger, and the gripping portions 50b and 50b from this initial posture. There is one feature in the configuration that can be driven to swing so that the tip of the two approaches.

  The swing drive mechanism for swinging and driving the gripping portions 50b and 50b as described above can be configured as follows, for example. As shown in FIGS. 3A and 3B, the swing drive mechanism includes a link action portion 53, a link fixing portion 51, and a link movable portion 54 having a substantially triangular shape as a whole.

  As shown in FIG. 3A, for example, the outer end portions of the link movable portions 54 and 54 having a triangular pantograph shape are fixed to the link fixing portions 51 and 51 by fixing members (such as screws) 54a and 54a, respectively. Has been. The inner ends of the link movable parts 54 and 54 are respectively coupled to the gripping parts 50b and 50b that are the objects of swing driving. As the link movable parts 54, 54, although not shown in detail, for example, it is possible to use a metal material link configured in a triangular pantograph shape as shown in the figure via a ball bearing (ball link) or the like. It is done. Or the link movable parts 54 and 54 may be comprised from the resin board (what is called an elastic hinge) etc. which comprised the movable (deformation) site | part in the shape of a thin plate.

  In the layer of the link fixing portions 51, 51, for example, actuators 52, 52 including solenoids for opening / closing fixed fingers can be arranged. The armatures of the actuators 52 and 52 can be driven and controlled to the posture shown in FIG. 3A or 3B by a fingertip angle control unit 37 (described later). By switching the driving state of the actuators 52, 52, the outer halves of the link movable parts 54, 54 operate so as to draw circular arc trajectories around the fixed positions by the fixing members 54a, 54a.

  For example, when the armatures of the actuators 52 and 52 are in the controlled state as shown in FIG. 3A and the link action portions 53 and 53 are projected from below in the figure, the link movable portions 54 and 54 are held by the gripping portions 50b and 50b. Pull both sides to the initial position as shown in the figure. On the other hand, when the armatures of the actuators 52 and 52 are brought into the controlled state as shown in FIG. 3B from this state and the link action portions 53 and 53 are pulled downward in the drawing, the link movable portions 54 and 54 are moved to the gripping portion. Poke 50b and 50b inward. As a result, as shown in FIG. 3B, the gripping portions 50b and 50b are controlled in a swinging posture such that the tip portions closer to the root (palm portion 1 side) are closer to each other than the fingertip side. This swinging posture is held when the link movable portion 54 held by the actuator 52 opposes the pushing back force of the gripping surfaces 56, 56.

  Further, force sensors 45, 45 are arranged below the link fixing portions 51, 51. The force sensors 45 and 45 have a structure as will be described later with reference to FIG. 7, for example, and can detect forces in three axial directions received by the fingertip gripping surface 36. In particular, in the control described later, it is assumed that the force sensors 45 and 45 can detect the gripping force Fz and the assembly force Fy.

  Further, the robot hand 100 of the present embodiment is provided with an opening / closing drive mechanism that changes the distance between the gripping finger main body portions 50a and 50a of the gripping finger 50 and opens and closes the gripping finger main body portions 50a and 50a.

  That is, as shown in FIGS. 1A and 1B, the lower surfaces of the force sensors 45 and 45 of the fixed finger 20 and the turning finger 40 (same for 60) are attached to the base portions 42 and 42, It is supported by the parts 42 and 42. These base material parts 42 and 42 function as a link movable part. On the other hand, base material portions 41 and 41 are arranged on the palm portion 1 side as link fixing portions.

  The base material portions 41 and 41 are connected to the base material portions 42 and 42 via at least two links 43 and 43 having a rectangular (parallelogram) pantograph configuration. And about each finger, it is comprised so that the one drive shaft 44 of the link 43 can be rotationally driven via drive systems, such as a motor not shown in detail and a reduction gear. Thereby, the inclination angle with respect to the base material part 41 of the links 43 and 43 can be selected. With such a structure, the parts on the fingertip side with respect to the base parts 42 and 42 including the parts of the gripping fingers 50 and 50 are connected to the base parts 41 and 41 (or the palm part 1) through the links 43 and 43 of the pantograph configuration. ) Can be opened and closed (approached / separated) linearly while maintaining a substantially parallel posture.

  That is, the opening / closing drive mechanism is divided into a first base material portion (41, 41) and a second base material portion (42, 42) in order to change the distance between the gripping surfaces. A part. The first base material portion (41, 41) and the second base material portion (42, 42) are connected by a plurality of links (43, 43), and open and close at least one gripping finger.

  The operation of the opening / closing drive mechanism by the links 43 and 43 and the swing drive mechanism by the link movable parts 54 and 54 can be controlled independently by a control system described later. For this reason, the relative distance and the relative inclination angle (inclination posture) of the holding surfaces 56 and 56 of the holding portions 50b and 50b can be controlled independently.

  In FIGS. 1A and 1B, the second turning finger 60 is hidden behind the first turning finger 40 and is not shown, but has the same structure as the first turning finger 40 described above. Have. The first and second swivel fingers 40 and 60 that can be swiveled are structured to be independently driven and controlled, for example. However, the drive system and a part of the actuator are made common through an appropriate interlocking mechanism to be the same. You may comprise so that it may drive synchronously with an actuator.

  Next, the form when the robot hand of the present embodiment grips workpieces of various shapes will be described with reference to FIGS. In the robot hand 100 according to the present embodiment, for example, as shown in FIG. 2A, the gripping surfaces 56 and 76 are perpendicular to the fingertip gripping surface 56 of the fixed finger 20 (see FIG. 2C). ) Can be swung continuously. Such turning control is possible by selecting the drive amount of the turning shafts 47 and 67 of the first and second turning fingers 40 and 60. Further, depending on the structure of the turning drive system, it is possible not only to continuously and variably control the turning angle, but also to take a control system in which the specific angle pitch is driven stepwise. In either continuous control or stepwise control, the turning fingers 40 and 60 can be controlled to turn angles according to the shapes of various workpieces (3, 4, 5).

  When gripping the workpiece (3, 4, 5), the fixed finger 20 and the turning finger 40 (and 60) are opened as shown in FIG. 1A, and then the fixed finger as shown in FIG. 20 and the turning fingers 40 (and 60) are changed to the closed state. For this purpose, an actuator (not shown) for opening and closing the fixed finger 20, the first and second turning fingers 40 and 60 is driven. As a result, the base material portions 41 and 41 that are the link fixing portions operate so as to draw an arc orbit while the base material portions 42 and 42 that are the link movable portions are maintained in a parallel state, and FIG. In this way, the relative distance between the gripping surfaces 56 (76) of the three fingers is controlled to be small. In this way, the workpiece can be gripped. At this time, by using the detected value of the gripping force Fz of the force sensor 45, the gripping force for gripping the workpiece can be controlled to a target magnitude. As a result, it is possible to grip a workpiece with low rigidity without deforming the workpiece, and with respect to a workpiece that is easily damaged, without being damaged.

  The fingertip angle changing mechanism of the robot hand 100 of the present embodiment can have a structure as shown in FIGS. 3A and 3B, for example. 3 (a) and 3 (b), the gripping surfaces 56 and 56 of the swingable gripping portions 50b and 50b of the fixed finger 20 and the turning finger 40 are shown on FIGS. Relatively fine step shapes 56a and 56a as shown in b) can be formed. A similar step shape 56a can also be provided on the gripping surface of the turning finger 60 (76: FIGS. 2A to 2C). The scale of these step shapes 56a depends on the size of the entire hand or the workpiece 3 that is the object of operation, but can be selected as appropriate within a range of, for example, 1/10 mm to several mm in both pitch and height.

  The tilted states of the gripping portions 50b and 50b that can swing the fixed finger 20 and the swivel finger 40 in FIGS. 4A and 4B correspond to the tilt angles in FIGS. 3A and 3B, respectively. . That is, in FIG. 4A, the gripping portions 50b and 50b are substantially parallel to each other in a state of being folded inward so as to be substantially along the gripping finger main body portions 50a and 50a.

  The step shapes 56a and 56a of the gripping surfaces 56 and 56 of the gripping portions 50b and 50b can be provided in the following shapes, for example. That is, as shown in FIG. 4B, when one part surface S (or S1, S2) forming the step shapes 56a, 56a is swung so that the gripping parts 50b, 50b are inclined from the initial posture. The shape is such that it is locked to the corner of the work 3.

  In such a structure, when the gripping surface 56 is swung as shown in FIG. 4B, the flat surfaces S <b> 1 and S <b> 2 of the step shapes 56 a and 56 a are locked to the corners of the workpiece 3. Here, it is assumed that an operation for pushing the workpiece 3 in the Y direction against an assembly target (not shown) is performed. In this case, in the state of FIG. 4A, when the workpiece 3 is locked to the planes S1 and S2 of the step shapes 56a and 56a, the direction of the force acting on the planes S1 and S2 is relative to the assembly force Fy. Inclined. On the other hand, when the tip portions of the gripping portions 50b and 50b are inclined as shown in FIG. 4B from FIG. 4A (initial posture), the plane S1 of the step shapes 56a and 56a and The force vector acting on S2 substantially coincides with the direction of the assembly force Fy. Thereby, the planes S1 and S2 of the step shapes 56a and 56a are securely locked to the workpiece 3. In this state, for example, by moving the entire hand in the Y + direction, an assembly force Fy sufficient for assembly can be generated without causing slipping, and the workpiece 3 can be pushed into the assembly target.

  FIG. 5 shows a configuration example of a control system of the robot hand 100 including the fingertip angle control unit 37 described above. The control unit 200 constitutes a robot hand control unit. The control unit 200 can be configured by, for example, a CPU 201, a ROM 202, a RAM 203, and an interface 204.

  In the ROM 202, a robot hand control procedure described later can be read by the CPU 201 and stored in the form of an executable robot hand control program (or further control data), for example. The RAM 203 can be used as a work area when executing the robot hand control program.

  When a control program (to be described later) is recorded (stored) in the ROM 202 (or an external storage device such as an unillustrated flash memory or HDD), these recording media are computers storing control procedures for carrying out the present invention. A readable recording medium is configured. A program for executing a control procedure described later is stored in a fixed recording medium such as a ROM or HDD, and is also stored in a removable computer-readable recording medium such as various flash memories or optical (magnetic) disks. It may be stored. Such a storage form can be used when a control program for executing the control procedure of the present invention is installed or updated. In addition, when installing or updating a program for executing the control procedure of the present invention, in addition to using the removable recording medium as described above, a method of downloading the program via a network (not shown) (such as an intranet) May be used.

  The interface 204 (IF) includes an input interface for the force sensor 45, a drive interface for driving a finger opening / closing drive mechanism (for example, the actuator of the drive shaft 44 in FIGS. 1A and 1B), and the like. . In addition, the interface 204 includes a network interface for communicating with a control unit of a robot arm (not shown) to which the robot hand 100 is attached.

  The fingertip angle adjustment mechanism 202 in FIG. 5 corresponds to the actuators 52 and 52 (for example, solenoids) that drive the link movable parts 54 and 54 in FIGS. The driving of the fingertip angle adjusting mechanism 202 is controlled by the fingertip angle control unit 37 based on the force detection information output from the force sensor 45 (for example, the detected value of the assembly force Fy). The fingertip angle control unit 37 can be configured by hardware or by software of the CPU 201.

  In the case of the present embodiment, since the force sensor 45 and the fingertip angle adjustment mechanism 202 are independent for each finger (20, 40, 60), the fingertip angle control unit 37 is based on the output of each force sensor 45, The fingertip angle adjusting mechanism 202 of each finger can be controlled. However, for example, a method may be employed in which the fingertip angle adjustment mechanism 202 of the three fingers is controlled under common control conditions based on the output of a force sensor 45 of a certain finger.

  Further, the CPU 201 obtains a representative value (for example, a statistic such as a sum or average value) of the output of the force sensor 45 of each finger (20, 40, 60), and based on this, a fingertip angle adjustment mechanism for three fingers. 202 can also be controlled under common control conditions. Also, for example, when using a statistic such as a total or average value as a representative value of the output of the force sensor 45 of each finger (20, 40, 60), which sensor output is used among the three sensors? Is optional. For example, among the three sensors, any one of the outputs, two, or all three outputs may be used to obtain a statistic such as a sum or an average value. Below, based on the representative value of the output of this force sensor 45, it demonstrates on the premise of the control system which controls the fingertip angle adjustment mechanism 202 of three fingers on common control conditions.

  For example, FIG. 6 shows a state in which the workpiece 3 is held by the holding fingers 50 and 50 of the fixed finger 20 and the turning finger 40 in the state shown in FIG. The state of the operation at the time of pushing (pressing) is shown. FIG. 6 shows the time change of the assembly force Fy detected by the force sensor 45 when performing such an assembly operation. The CPU 201 compares the assembly force Fy detected by the force sensor 45 with a threshold value Fth (broken line) set for some finger control switching, and, for example, the assembly force Fy is a threshold value according to the comparison result. When the value Fth is exceeded, the control switching can be executed. An example of such finger control will be described in more detail later.

  In the above description, the control unit 200 (robot hand control unit) in FIG. 5 has been described as being independent of the control unit (not shown) of the robot arm. For example, the control unit of the robot arm executes a robot control program for performing a workpiece operation, and transmits control information such as gripping, releasing, and gripping force to the control unit 200 via the interface 204 as necessary.

  However, a structure in which the robot arm control unit also serves as the control unit 200 (robot hand control unit) may be considered depending on the mounting specifications of the robot apparatus. The broken lines in FIG. 5 are for illustrating a structure in which the control device 300 on the robot arm side also serves as the control unit 200 (robot hand control unit).

  FIGS. 7, 8 </ b> A, and 8 </ b> B are force detection devices that detect a force acting on the gripping finger 50 when gripping and operating a workpiece as a target object via the gripping surface 56 of the gripping unit 50 b. The example of a structure of the force sensor 45 is shown. The illustrated plane in FIG. 7 corresponds to the YZ plane of the XYZ coordinate system of this finger portion. FIGS. 8A and 8B show the details of the force sensor 45 shown in FIG. 7, and the illustrated planes correspond to the XY and YZ planes, respectively. For this reason, FIG. 8A corresponds to a state in which the force sensor 45 is shown from the left side of FIG. The illustrated plane of FIG. 8B coincides with FIG.

  As shown in FIGS. 7, 8A, and 8B, the force sensor 45 includes an Fx detection elastic body 451 and an Fy detection elastic body assembled in a rectangular parallelepiped box shape between the movable portion 450 and the fixed portion 455. 452, Fz detection elastic body 453 is included. As the material of these elastic bodies, a material that causes predetermined elastic deformation within the range of the work operating force handled by the robot hand 100, such as resin, hard rubber, or metal, may be selected. A sensor device such as a strain gauge is affixed to each elastic body as a detection unit along the direction of the force for detection. Note that the force detection method using a strain gauge is merely an example, and it is possible to use a different force detection method in which a reflective optical sensor or the like is disposed between ends of the elastic body that are deformed mutually. Not too long.

  As shown in FIG. 7, the movable portion 450 of the force sensor 45 is coupled to the link fixing portion 51 below the gripping finger 50. On the other hand, the fixed portion 455 is coupled to the base portion 42 (FIGS. 1A and 1B) of the turning or fixed finger.

  As shown in FIGS. 8A and 8B, the fixing portion 455 is coupled to an Fx detection elastic body 451 that elastically deforms in the Fx direction, and the Fx detection elastic body 451 elastically deforms in the Fy direction. To join. The Fy detection elastic body 452 is coupled to the Fz detection elastic body 453 that is elastically deformed in the Fz direction, and the Fz detection elastic body is coupled to the force sensor movable unit 450. As described above, strain gauges are attached to the Fx detection elastic body 451, the Fy detection elastic body 452, and the Fz detection elastic body 453 as sensor devices.

  By configuring the force sensor 45 as described above, when a force is applied to the gripping finger 50 via the gripping surface 56, the elastic bodies 451 to 453 of Fx, Fy, and Fz are elastically deformed to cause distortion. Arise. At this time, the fingertip angle control unit 37 can detect the translational or rotational components of the three axes of the force acting on the gripping finger 50 by detecting the output of the strain gauge as the sensor device.

  FIG. 9 shows an example of a control example for performing fingertip angle control using the swing drive mechanism shown in FIGS. 3A and 3B based on the output of the force sensor 45. The illustrated procedure can be implemented as part of a robot hand control program executed by the CPU 201. The procedure shown in FIG. 9 can be suitably used to control the assembling work as shown in FIGS.

  10A to 10C, the work 3 is gripped by the fixed finger 20 and the turning fingers 40 (and 60) gripping fingers 50 and 50 (50) and mounted on the assembly target 301. It is an operation. The gripping finger 50 includes the gripping finger main body 50a and the gripping part 50b that can be driven to swing as described above. The workpiece 3 has, for example, a ring shape, and the assembly target 301 has a cylinder shape, and is assembled at a predetermined relative position by click stop locking. In order to perform a click stop, for example, a ring-shaped groove 302 is formed on the outer periphery of the assembly target 301, while a ring-shaped protrusion 303 is formed on the inner periphery of the work 3. Although not shown for the sake of space, the coordinate system assigned to each gripping finger 50, 50 is the same as in FIG. 3 (a), with the top of the figure in the Y + direction and each finger inward. It is assumed that the direction to go is the Z + direction. Accordingly, the force for pushing the workpiece 3 into the upper assembly target 301 in the drawing is the assembly force Fy.

  In this assembling operation, first, as shown in FIG. 10A, the ring-shaped workpiece 3 is held by the fixed finger 20 and the holding fingers 50, 50 (, 50) of the turning fingers 40 (and 60). At this time, the CPU 201 protrudes the armature of the actuator 52 of the swing drive mechanism, and the gripping portions 50b and 50b (50b) are in the initial posture folded along the gripping finger main body 50a.

  Subsequently, by the position and orientation control of the robot arm (not shown), the workpiece 3 is moved toward the upper assembly target 301 in the drawing, the assembly target 301 and the workpiece 3 are fitted, and further pushed.

  This process corresponds to steps S11 to S12 in FIG. During this pushing operation, the CPU 201 detects the assembling force Fy output from the force sensor 45 (45, 45) (S11) and compares it with the threshold value Fth (S12). This assembling force Fy is a translational force in the Y-axis direction detected by, for example, three force sensors 45 (45, 45). As described above, the assembling force Fy is acquired as a predetermined representative value obtained by the CPU 201 performing a statistical calculation or the like using any of the three force sensors 45 (45, 45). If the value of the assembling force Fy is equal to or less than the threshold value Fth in step S12, the monitoring in step S11 (the pushing of the workpiece 3) is continued.

  On the other hand, if the operation of pushing the workpiece 3 is continued, the protrusion 303 on the inner periphery of the workpiece 3 is locked to the lower corner of the assembly target 301. In S12, the value of the assembly force Fy exceeds the threshold value Fth. Thereby, the control of FIG. 9 shifts from step S12 to S21.

  In step S21 in FIG. 9, the CPU 201 retracts the armature of the actuator 52 of the swing drive mechanism, and swings the gripping portions 50b and 50b (and 50b) in the direction in which these fingertips are close to each other as shown in FIG. Move. By this fingertip angle change, the gripping portions 50b, 50b (, 50b) are tilted so that the tip end side of the gripping portion 50b on the palm side of the hand is narrow as shown in the figure from a parallel state in which the workpiece 3 is pushed by relying on frictional force. Respectively. In the inclined posture of the gripping portions 50b, 50b (, 50b), since the corner portion of the work 3 is locked to the gripping portions 50b, 50b (, 50b), a large assembling force Fy can be generated more reliably. . In particular, when the stepped shape 56a as shown in FIG. 4 is formed on the gripping surfaces 56, 56, a large assembling force Fy can be generated with almost no slippage.

  During this time, for example, the push-in operation by the robot arm can be continued. During this time, the CPU 201 detects the assembly force Fy by the force sensor 45 (45, 45) (S22) and compares it with the threshold value Fth ( S23) is performed.

  When the protrusion 303 of the workpiece 3 gets over the lower corner of the assembly target 301 by the pushing operation by the robot arm and the protrusion 303 reaches the position of the groove 302 of the assembly target 301, a click stop occurs. . Thereby, the assembling force Fy detected by the force sensor 45 (45, 45) decreases. As a result, the control in FIG. 9 shifts from step S23 to S24, and the CPU 201 causes the armature of the actuator 52 of the swing drive mechanism to protrude again, for example, as shown in FIG. 10C, the gripping portions 50b, 50b (, 50b). ) Return the fingertip angle to 0 °. Further, the fixed finger 20 and the turning fingers 40 and 60 are opened by the finger opening / closing drive mechanism (the actuator of the drive shaft 44 in FIGS. 1A and 1B) to release the workpiece 3. FIG. 10C corresponds to a state in which the robot hand (100) is slightly retracted from the workpiece 3 mounted at a fixed position with respect to the assembly target 301 after the workpiece 3 is released from gripping.

  In FIG. 9, for ease of explanation, the same character expression is used for the threshold value Fth used in steps S12 and S23. However, the threshold value used in these steps depends on the purpose. Thus, a predetermined value can be used.

  Further, FIG. 9 illustrates that the branch from step S23 to S21 is repeatedly performed while waiting for the click engagement to occur. In this case, in the structure in which the angle of the gripping portions 50b, 50b (, 50b) can only take two values of the initial position (FIGS. 10A and 10C) and the swinging state (FIG. 10B), The fingertip angle is controlled to maintain the same swinging state. However, as shown in Example 2 described later, in a hardware structure in which the fingertip angle of the gripping portions 50b and 50b (, 50b) can be continuously changed, the fingertip angle is gradually increased every time the process proceeds from step S23 to S21. Control may be performed so as to increase.

  As described above, in the gripping finger 50 of this embodiment, in addition to the opening / closing drive mechanism (such as the actuator of the drive shaft 44 in FIGS. 1A and 1B) that opens and closes the gripping finger main body 50a, A dynamic drive mechanism is provided. In this swing drive mechanism, the gripping portion 50b is inclined from the initial posture folded along the gripping finger main body 50a via the swing fulcrum 55 to a posture in which the tips of the gripping portions approach each other. Configured to rock. In addition, a force sensor 45 is provided as a force detection device that detects a force acting on each gripping finger 50 when the workpiece (3) as an object is gripped via the gripping surface 56 of each gripping portion 50b and operated. .

  As a result, when the CPU 201 grips and operates the object with each gripping finger 50, the CPU 201 determines the inclination angle of the grip portion 50b via the swing drive mechanism according to the assembly force Fy detected by the force sensor 45. The fingertip control to be controlled can be executed. For example, according to the assembling force Fy detected by the fingertip force sensor, the fingertips of at least two grip portions 50b and 50b are inclined with respect to each other. In particular, as in the control shown in FIGS. 9 and 10, the fingertip (swinging) control is activated at a timing at which a large assembling force Fy should be generated during the workpiece pushing-in period, and the large assembling force Fy is surely generated. Can do. Thereby, the workpiece | work which has a click stop mechanism can be reliably assembled | attached to an assembly | attachment object. In a mechanism such as a click stop, it is possible to detect the assembly state based on the detected decrease in the assembly force Fy, and to perform control to deactivate the fingertip (swinging) control of the grip portions 50b and 50b. .

  According to the present embodiment, the gripping portion 50b is inclined from the initial posture folded along the gripping finger main body portion 50a via the swing fulcrum 55 to a posture in which the tips of the gripping portions approach each other. A swing drive mechanism for swinging is provided. For this reason, for example, in the operation of pushing the object in the forward direction of the gripping finger as described above, a large assembling force can be generated at a necessary timing. Therefore, the output scale of the drive source and drive system can be made smaller than the conventional robot hand (finger) drive mechanism that uses only the frictional force. For this reason, the entire robot hand can be configured to be small and light or simple and inexpensive. Further, since the swing drive mechanism of the gripping part 50b can be controlled according to the output of the force sensor 45 that detects the force acting on each gripping finger 50, for example, the timing when a large assembling force is required is ensured. Therefore, swing control can be performed as necessary.

  Further, in the present embodiment, the finger portion provided with the gripping finger 50 is provided with a fixed finger (20) and turning fingers (40, 60) capable of turning the base portion. For this reason, in the robot hand of the present embodiment, the turning angle of the turning fingers (40, 60) can be selected as shown in FIGS. A gripping posture suitable for (work) can be taken.

<Example 2>
In the first embodiment, as shown in FIGS. 3 (a), 3 (b), and 10 (a) to 10 (c), the swing drive mechanism for swinging the gripping portion 50b is, for example, an elastic hinge or the like. The structure using the link movable part 54 and the actuator 52 including, for example, a solenoid is illustrated. Such a configuration is suitable for swinging the gripping part 50b in a relatively small swing angle range of about 0 to several degrees. However, for example, when a larger assembling force Fy is desired in the operation of pushing the workpiece as shown in FIGS. 10A to 10C, a larger swing angle of 10 to several tens of degrees can be realized. A swing drive mechanism may be required.

  11 and 12 (a) to 12 (c) show the fixed finger 20 and the gripping finger 50 of the turning finger 40 in a form corresponding to FIGS. 3 (a) and 10 (a) to 10 (c) of the first embodiment, respectively. The different structure of the rocking | fluctuation drive mechanism which rock | fluctuates the holding part 50b of this is shown. The parts not shown in FIG. 11 and FIG. 12, such as the configuration of the robot hand and its control system, can be configured in the same manner as in the first embodiment, and detailed description thereof will be omitted below.

  FIG. 11 is different from FIG. 3A in the structure of the swing drive mechanism formed in the upper portion of the force sensor 45 above the link fixing portion 51. In this embodiment, a motor 521 is used as a drive source (actuator) of the swing drive mechanism. A pinion gear 522 mounted on the drive shaft of the motor 521 is meshed with a fan-shaped gear 531 supported on the link fixing portion 51.

The fan-shaped gear 531 drives a link mechanism 541 having two joints 5414 and 5414. The detailed structure of the link mechanism 541 is shown in the portion of the right fixed finger 20 in FIG. 11 (the link mechanisms 541 of the other turning fingers 40 (60) are the same). That is, the fan-shaped gear 531 controls the swing angle of the link 5411 of the link mechanism 541. Links 5412 and 5413 are coupled to the tip of the link 5411 in series via joints 5414 and 5414.

  The link 5413 at the tip of the link mechanism 541 is movably supported through the base of the gripping finger main body 50a of the gripping finger 50, for example. Accordingly, the link 5413 is retracted as shown in FIG. 11 (the same applies to FIGS. 12A and 12C) by changing the swing angle of the link 5411 via the pinion gear 522 and the gear 531 by the motor 521. From the state, it can project as shown in FIG. 12B from the state in which the holding fingers 50b and 50b (and 50b) are folded along the holding finger body 50a of the holding finger 50, as shown in FIG. 12B. Can be swung. In this way, the operation of swinging the gripping portions 50b and 50b (50b) so that the root interval is narrower than the tip of the gripping finger 50 as a whole is not possible with a conventional articulated finger like Patent Document 1, for example. It is possible.

  By using the pinion gear 522, the gear 531 and the multi-link link mechanism 541 as described above, a larger swing angle range than that of the first embodiment can be realized.

  12 (a) to 12 (c) show the operation of assembling the workpiece 3 to the assembly target 301 in the same manner as FIGS. 10 (a) to 10 (c). The workpiece 3 and the assembly target 301 are assembled at a fixed position by a click stop caused by the engagement between the protrusions 303 and the grooves 302. The control procedure shown in FIG. 9 can be used for this assembly control.

  In this assembling operation, first, as shown in FIG. 12A, the ring-shaped workpiece 3 is held by the fixed finger 20 and the holding fingers 50, 50 (, 50) of the turning fingers 40 (and 60). At this time, the CPU 201 controls the rotation angle of the motor 521 to control the posture of the link mechanism 541 so that the links 5413 and 5413 are pulled in the outward direction of each finger as shown in FIG. Thus, the gripping portions 50b and 50b (50b) take an initial posture folded along the gripping finger main body 50a.

  Subsequently, by the position and orientation control of the robot arm (not shown), the workpiece 3 is moved toward the upper assembly target 301 in the drawing, the assembly target 301 and the workpiece 3 are fitted, and further pushed.

  This process corresponds to steps S11 to S12 in FIG. During this pushing operation, as described above, the CPU 201 detects the assembly force Fy output from the force sensor 45 (45, 45) (S11) and compares it with the threshold value Fth (S12). If the value of the assembling force Fy is equal to or less than the threshold value Fth in step S12, the monitoring in step S11 (the pushing of the workpiece 3) is continued.

  If the operation of pushing the workpiece 3 is continued, the protrusion 303 on the inner periphery of the workpiece 3 is locked to the corner portion or the like of the lower end of the assembly target 301. Therefore, if the operation of pushing the workpiece 3 with the robot arm is continued, in step S12 The value of the assembly force Fy exceeds the threshold value Fth. Thereby, the control of FIG. 9 shifts from step S12 to S21.

  In step S21 in FIG. 9, the CPU 201 controls the rotation angle of the motor 521 and controls the swing drive mechanism as shown in FIG. That is, the posture of the link mechanism 541 is controlled so that the links 5413 and 5413 protrude inward of each finger as shown in FIG. Thereby, as shown in FIG.12 (b), the holding parts 50b and 50b (50b) are rock | fluctuated in the direction in which these fingertips adjoin. As a result, the gripping portions 50b, 50b (, 50b) swing from the parallel state in which the workpiece 3 is pushed by relying on the frictional force to a narrow inclined posture, as shown in FIG. Moved. According to the swing drive mechanism of the present embodiment, since a large amount of displacement can be obtained by the link mechanism 541, the swing angles of the gripping portions 50b and 50b (50b) are set to be different from those of the first embodiment as shown in FIG. Can also take a large angle. As a result, in the inclined posture of the gripping portions 50b, 50b (, 50b), the corner portion of the work 3 is locked to the gripping portions 50b, 50b (, 50b), so that a large assembling force Fy is generated more reliably. Can do. Particularly, when the stepped shape 56a as shown in FIG. 4 is formed on the gripping surfaces 56, 56, an extremely large assembling force Fy can be generated without causing almost any slippage. .

  During this time, for example, the push-in operation by the robot arm can be continued. During this time, the CPU 201 detects the assembly force Fy by the force sensor 45 (45, 45) (S22) and compares it with the threshold value Fth ( S23) is performed.

  When the protrusion 303 of the workpiece 3 gets over the lower corner of the assembly target 301 by the pushing operation by the robot arm and the protrusion 303 reaches the position of the groove 302 of the assembly target 301, a click stop occurs. . Thereby, the assembling force Fy detected by the force sensor 45 (45, 45) decreases. As a result, the control in FIG. 9 shifts from step S23 to S24, and the CPU 201 causes the armature of the actuator 52 of the swing drive mechanism to protrude again, for example, as shown in FIG. 12C, the gripping portions 50b, 50b (, 50b). ) Return the fingertip angle to 0 °. Further, the fixed finger 20 and the turning fingers 40 and 60 are opened by the finger opening / closing drive mechanism (the actuator of the drive shaft 44 in FIGS. 1A and 1B) to release the workpiece 3. FIG. 10C corresponds to a state in which the robot hand (100) is slightly retracted from the workpiece 3 mounted at a fixed position with respect to the assembly target 301 after the workpiece 3 is released from gripping.

  In the swing drive mechanism of the present embodiment, the fingertip angles of the grip portions 50b and 50b (, 50b) can be continuously changed. Therefore, when the branch from step S23 to S21 in FIG. 9 is repeatedly performed, it is possible to perform control such that the fingertip angle is gradually increased every time the process proceeds to step S21.

  As described above, according to the present embodiment, a configuration in which a large amount of displacement can be obtained by using the pinion gear 522, the gear 531, the link mechanism 541, and the like for the swing drive mechanism of the gripping portions 50b, 50b (, 50b) is used. ing. For this reason, even if the other configurations are the same, the robot hand of the present embodiment can generate a larger assembling force Fy than that of the first embodiment, and can prevent the workpiece 3 from dropping off. it can. That is, according to the configuration of the present embodiment, it is possible to provide a robot hand suitable for work requiring a larger assembling force by a small, light and simple configuration.

  Note that the stepped shape 56a as shown in FIG. 4 can be formed on the gripping surfaces 56, 56 (, 56) of the gripping portions 50b, 50b (, 50b), as in the first embodiment. Thereby, there is a possibility that a larger assembling force Fy can be generated. The gripping surfaces 56, 56 (, 56) of the gripping portions 50b, 50b (, 50b) are made of various materials having not only a step shape but also an elastic deformation rate and hardness suitable for the characteristics of the object (workpiece). Can be configured. For example, it is conceivable to use a hard rubber material or the like corresponding to the characteristics of the object (work) for the gripping surfaces 56, 56 (, 56). In the case of a rubber material, by selecting an appropriate elastic deformation rate, the gripping surface 56 of the rubber surface can be elastically deformed so that the corners of the work 3 and the like are caught by the swing driving of the gripping portion 50b. There is a possibility that the same assembling force enhancement effect equivalent to the step shape can be expected. Of course, even when the step shape 56a as shown in FIG. 4 is formed, it is considered that material selection such as using this kind of rubber material for the gripping surface 56 is effective.

<Example 3>
Hereinafter, with reference to FIGS. 13A and 13B, an example of the entire configuration of a robot apparatus in which the robot hand 100 described above is mounted as an end effector will be described.

  A robot apparatus 1500 shown in FIG. 13A is, for example, an industrial robot. A robot apparatus 1500 in FIG. 13A includes a robot arm 1101 that performs operations such as assembly of a workpiece W, a robot hand 100, a control apparatus 300 that controls the entire robot apparatus 1500, and a teaching pendant 1300.

  The robot arm 1101 is configured as an articulated robot arm, and the robot hand 100 is connected to the tip of the robot arm 1101 as an end effector.

  The robot hand 100 configured as described above is controlled by the control unit 200 configured as shown in FIG. In the example of FIG. 13A, the control unit 200 is configured separately from the control device 300 of the robot 100. In this case, for example, the control device 300 communicates with the control unit 200 of the robot hand 100, and the posture control of the robot arm 1101 and the grip control of the robot hand 100 are synchronized via this communication.

  A robot arm 1101 in FIG. 13A is a vertical articulated robot arm, and includes a base portion (base end link) 1103 fixed to a work table, and a plurality of links 1121 to 1126 that transmit displacement and force. ,have. The base portion 1103 and the plurality of links 1121 to 1126 are connected to each other so as to be rotatable or rotatable at a plurality of joints J1 to J6. In each of the joints J1 to J6, an encoder that detects the rotation angle of the rotation shaft and a drive source or a reduction device that drives the joints J1 to J6 are provided.

  The teaching pendant 1300 is configured to be connectable to the control device 300, and configured to transmit a command to drive and control the robot arm 1101 and the robot hand 100 to the control device 300 when connected to the control device 300.

  As shown in FIG. 13B, the control device 300 is configured around a CPU 1601 formed of, for example, a general-purpose microprocessor. In FIG. 13B, the control device 300 includes, for example, a CPU 1601, a RAM 1603 that temporarily stores data, a ROM 1602 that stores a robot control program for controlling each unit, and interfaces 1604 and 1605.

  The ROM 1602 corresponds to a recording medium readable by a computer (CPU 1601) that stores a robot control program including torque control as described later. The CPU 1601 executes robot control including torque control as described later by executing a robot control program stored in the ROM 1602, for example. Note that a part of the ROM 1602 can be configured by a rewritable nonvolatile area such as E (E) PROM. In that case, a computer-readable recording medium such as a flash memory or an optical disk (not shown), or a robot control program acquired via a network or the like can be newly installed in the rewritable nonvolatile area. Further, the robot control program stored in the rewritable nonvolatile area can be updated by the computer-readable recording medium or data acquired via a network or the like.

  The control device 300 supplies the required power required for the operation of the drive units of the joints J1 to J6 to each drive unit, and executes robot control for controlling the posture of each unit of the robot device 1500, particularly the robot arm 1101. . In this case, an interface 1605 is used for inputting / outputting signals to / from J1 to J6 or its driving unit, but the illustration of J1 to J6 (or its driving unit) is omitted in FIG. 13B for simplification. ing.

  In the robot control described above, the CPU 1601 inputs a command from the teaching pendant 1300 via the interface 1604, and controls the operation of each unit according to the command. Alternatively, the operation of each unit can be controlled according to the contents of a robot control program supplied from another program terminal or the like and stored in the RAM 1603 or the like.

  In the above configuration, the control device 300 moves the robot hand 100 to an arbitrary position and posture by operating the joints J1 to J6 of the robot arm 1101 via the interface 1605 in accordance with the input settings and the like.

  The control device 300 communicates with the control unit 200 of the robot hand 100 via the interface 1605 and operates the robot hand 100 in synchronization with the operation of the robot arm 1101. In this way, for example, the robot hand 100 can grip the work W at an arbitrary position and posture, and work such as assembly of the work W can be performed.

  As described with reference to FIG. 5, the control device 300 of the robot arm 1101 may also serve as the control unit 200 of the robot hand 100. In that case, as indicated by a broken line in FIG. 13B, the control device 300 of the robot arm 1101 directly communicates with the robot hand 100 via the interface 1605 to control the operation of the robot hand 100. In this case, it is assumed that the control device 300 is implemented by hardware or software in a configuration substantially equivalent to the above-described control unit 200 shown in FIG. 5 and can execute the above-described robot hand control.

  The control program for the robot arm 1101 can be recorded (stored) in the ROM 1602 (or an external storage device such as various flash memories (not shown) or HDD). In the configuration in which the control device 300 of the robot arm 1101 also serves as the control unit 200 of the robot hand 100, the control program for the robot hand 100 can also be stored in the ROM 1602 (or the external storage device described above). In that case, a recording medium such as the above-mentioned ROM 1602 (or the above-mentioned external storage device) constitutes a computer-readable recording medium storing a control procedure for carrying out the present invention. A program for executing a control procedure described later is stored in a fixed recording medium such as a ROM or HDD, and is also stored in a removable computer-readable recording medium such as various flash memories or optical (magnetic) disks. It may be stored. Such a storage form can be used when a control program for executing the control procedure of the present invention is installed or updated. In addition, when installing or updating a program for executing the control procedure of the present invention, in addition to using the removable recording medium as described above, a method of downloading the program via a network (not shown) (such as an intranet) May be used. These circumstances are the same as those described with reference to FIG.

  As described above, the robot apparatus 1500 can be configured using the robot hand 100 having the configuration of the first and second embodiments. For example, by adopting the robot hand 100 having the configuration of the first and second embodiments, it is possible to provide an excellent robot apparatus that can stably hold a workpiece having various shapes and can sufficiently and appropriately control an assembly force of an object. Can do.

  The present invention supplies a program that realizes one or more functions of each embodiment to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program It can also be realized by processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 100 ... Robot hand, 1 ... Palm part, 2 ... Mounting part, 3, 4, 5 ... Work, 20 ... Fixed finger, 40, 60 ... Turning finger, 37 ... Finger tip angle control part, 45 ... Force sensor, 47 ... Turning Axis, 50 ... gripping finger, 50a ... gripping finger main body, 50b ... gripping part, 54 ... link movable part, 55 ... rocking fulcrum, 201 ... CPU, 202 ... ROM, 203 ... RAM, 204 ... interface, 521 ... motor 531: Gear, 541: Link mechanism.

Claims (12)

In a robot hand that has at least three gripping fingers and grips an object,
A driving mechanism for independently approaching or separating the three gripping fingers;
A robot hand comprising: a turning means for turning the two gripping fingers in order to change the approach or separation direction of the two gripping fingers among the three gripping fingers.   2. The robot hand according to claim 1, wherein the driving mechanism and the turning unit are configured to hold the three gripping fingers in accordance with the object, and the two holding fingers that can be turned by the turning unit. A robot hand characterized by being capable of selecting either a gripping form or a gripping form.   3. The robot hand according to claim 2, wherein a gripping surface of one gripping finger and a gripping surface of the other gripping finger are used in gripping an object in a form of gripping with the two gripping fingers that can be swung by the swiveling means. A robot hand characterized in that the two gripping fingers are swung by the swivel means so as to be in an opposite posture.   The robot hand according to any one of claims 1 to 3, wherein the turning means includes the same actuator for turning the two gripping fingers capable of turning by synchronous driving.   5. The robot hand according to claim 1, wherein when the two gripping fingers that can be swung by the swivel means are used to grip the object, the other gripping fingers hold the gripping object. Robot hand characterized by not being involved in The robot hand according to any one of claims 1 to 5, wherein the drive mechanism includes:
A base material portion on which one of the three gripping fingers is disposed;
In order to change the distance between the three gripping fingers, the base portion is divided into a first base portion and a second base portion, and the first base portion and the second base portion are divided. A robot hand characterized in that the robot hand is a plurality of links connecting the base parts.   The robot hand according to any one of claims 1 to 6, wherein a force sensor is provided on the three gripping fingers.   A robot apparatus comprising the robot arm according to any one of claims 1 to 7 in a robot arm. In a control method of a robot hand that includes at least three gripping fingers and grips an object,
A driving step of independently approaching or separating the three gripping fingers;
And a turning step of turning the two gripping fingers in order to change the approaching or separation direction of the two gripping fingers among the three gripping fingers. .   10. The method of controlling a robot hand according to claim 9, wherein in the driving step and the turning step, the step of holding with the three holding fingers according to the object, and the two holding fingers that can be turned by a turning means. A method of controlling a robot hand, characterized in that either one of a gripping process and a gripping process can be selected.   The robot hand control method according to claim 10, wherein in grasping an object in a form of grasping with the two grasping fingers that can be swiveled by the turning means, the grasping surface of one grasping finger and the other grasping finger A control method for a robot hand, wherein the two gripping fingers are swung by the swiveling means so as to be in a posture facing a gripping surface. 12. The method of controlling a robot hand according to claim 10, wherein the turning means includes the same actuator for turning the two gripping fingers capable of turning by synchronous driving.

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