Patent Description:
The present disclosure relates to a robot system and a control method.

For example, <CIT> (Patent Literature <NUM>) discloses a robot system including an articulated robot and a controller that controls the articulated robot. An end effector that grips a connector attached to one end portion of a cable is attached to the articulated robot disclosed in Patent Literature <NUM>. When the end effector grips the connector, the robot system disclosed in Patent Literature <NUM> captures an image of the connector with an imaging section in advance and moves the end effector based on a result of the capturing of the image to grip the connector.

Generally, document <NPL> describes a robotized assembly of a wire harness in car production line. The protype robot described in this document uses three robot arms. The general approach according to the document relies on the provision of specifically designed clamp covers with attached markers for recognition. Such markers serve for recognition of the wire harness by utilization of a vision based approach, e.g. applying an open source software package. Patent Document <CIT> describes a robot apparatus that performs the work of attaching a cable. Patent Document <CIT> describes a connector gripping device, connector inspection system comprising the device, and connector connection system.

However, in the related art, it is likely that the following deficiencies occur when it is attempted to adjust a posture while gripping the connector. For example, when the end portion of the cable, which is opposite to the one end portion, that is, the end portion to which the connector is fixed, is fixed to a substrate or the like, since a movable range of the connector is limited, when a hand moves in order to adjust the direction and the posture of the connector, excessive tension is applied to the cable depending on a position where the connector is gripped. Therefore, when the one end portion of the cable is fixed, it is difficult to adjust the posture of the connector.

The present disclosure can be implemented as the following application examples.

A robot system according to an application example includes the features of claim <NUM>.

A control method according to an application example is a control method for a robot system including the features of claim <NUM>.

A robot system and a control method according to the present disclosure are explained in detail below based on preferred embodiments shown in the accompanying drawings.

In <FIG>, three axes (an X axis, a Y axis, and a Z axis) orthogonal to one another are shown. In the following explanation, a direction parallel to the X axis is referred to as "X-axis direction" as well, a direction parallel to the Y axis is referred to as "Y-axis direction" as well, and a direction parallel to the Z axis is referred to as "Z-axis direction" as well. In the following explanation, a distal end side of arrows shown in the figures is referred to as "+ (plus)" and a proximal end side of the arrows is referred to as "- (minus)". The Z-axis direction coincides with the "vertical direction" and a direction parallel to an X-Y plane coincides with the "horizontal direction". A + (plus) side of the Z axis is represented as "upper" and a - (minus) side of the Z axis is represented as "lower". In <FIG>, illustration of a force detecting section <NUM> is omitted.

A robot system <NUM> shown in <FIG> and <FIG> is used to, for example, perform work for inserting a connector <NUM> into an insertion hole <NUM> formed in a substrate <NUM>. The robot system <NUM> includes a robot 1A, which is a first robot, a robot 1B, which is a second robot, and a control device <NUM> that controls driving of the robot 1A and the robot 1B.

In the robot system <NUM>, besides, as shown in <FIG>, a display device <NUM> including a monitor and an input device <NUM> functioning as an operation device configured by a mouse, a keyboard, and the like are respectively communicably coupled.

As shown in <FIG>, the substrate <NUM> is formed in a rectangular shape and is placed on a not-shown workbench. A cable <NUM> having flexibility is provided on the upper surface, that is, a surface on a +Z-axis side of the substrate <NUM>. The connector <NUM> is attached to one end portion of the cable <NUM>. The other end portion of the cable <NUM> is a fixed end fixed to the substrate <NUM>. This fixed portion deviates to a corner side on a -X-axis side and a -Y-axis side. On the other hand, the one end portion, that is the end portion on the connector <NUM> side of the cable <NUM> is a free end. The cable <NUM> is, for example, a long FPC (Flexible Printed Circuit) or FFC (Flexible Flat Cable) having flexibility.

The connector <NUM> is a polyhedron. As an example, in <FIG>, the connector <NUM> is a hexahedron. The connector <NUM> is inserted into, by the robot 1A, the insertion hole <NUM> provided on the side surface on a +Y-axis side of the substrate <NUM>. In that inserted state, the cable <NUM> and a not-shown circuit of the substrate <NUM> are electrically coupled via a not-shown terminal in the insertion hole <NUM>. A position where the insertion hole <NUM> is formed is not limited to the above and may be, for example, the side surface of the +Z-axis side of the substrate <NUM>.

First, the robot 1A and the robot 1B are explained. The robot 1A and the robot 1B have substantially the same configuration except that setting positions and the configurations of distal end portions are different. Therefore, in the following explanation, common features of the robot 1A and the robot 1B are representatively explained using the robot 1A. Thereafter, differences between the robot 1A and the robot 1B are explained.

As shown in <FIG> and <FIG>, the robot 1A and the robot 1B are so-called six-axis vertical articulated robots and include bases <NUM> and robot arms <NUM> coupled to the bases <NUM>. The robot 1A and the robot 1B are respectively single-arm type articulated robots. However, the robot 1A and the robot 1B are not limited to this. For example, one or both of the robot 1A and the robot 1B may be a SCARA robot. The robot 1A and the robot 1B may be a so-called double-arm type articulated robot obtained by integrating the robot 1A and the robot 1B.

The base <NUM> is a portion for attaching the robot 1A to any setting place. In this embodiment, the base <NUM> is set on, for example, a floor. The setting place of the base <NUM> is not limited to the floor or the like and may be, for example, a wall, a ceiling, or a movable truck.

As shown in <FIG> and <FIG>, the robot arm <NUM> includes an arm <NUM>, an arm <NUM>, an arm <NUM>, an arm <NUM>, an arm <NUM>, and an arm <NUM>. The arms <NUM> to <NUM> are coupled in this order from the proximal end side toward the distal end side. The arms <NUM> to <NUM> are turnable with respect to arms adjacent thereto or the base <NUM>. As shown in <FIG>, the arm <NUM> is formed in a disk shape and is turnable around an axis O6 with respect to the arm <NUM>.

The robot arm <NUM> of the robot 1A configures a first arm and the robot arm <NUM> of the robot 1B configures a second arm.

As shown in <FIG>, a hand <NUM>, which is a gripping section or a first gripping section that grips the cable <NUM> or the connector <NUM>, can be attached to the robot arm <NUM>. For example, the robot arm <NUM> includes a component having a female screw or a male screw used to attach the hand <NUM> by screwing, bolting, or the like or a not-shown attaching section including an engaging section such as a hook or an L-shaped groove. Consequently, it is possible to easily attach the hand <NUM> to an appropriate position. The configuration of the hand <NUM> is explained in detail below.

As shown in <FIG>, the force detecting section <NUM> is provided between the arm <NUM> and the hand <NUM> to be attachable to and detachable from the arm <NUM> and the hand <NUM>. The force detecting section <NUM> detects a force applied to the hand <NUM>. The force includes a moment. The force detecting section <NUM> is configured by, for example, a six-axis force sensor or a three-axis force sensor. The force detecting section <NUM> outputs detection information of a detected force to the control device <NUM>. As explained below, the force detecting section <NUM> functions as a detecting section that detects contact of the hand <NUM> and the connector <NUM>. Since the force detecting section <NUM> functioning as the detecting section is the force sensor, as explained, it is possible to quickly and accurately detect that the hand <NUM> performs second gripping. Accordingly, it is possible to prevent or suppress excessive tension from being applied to the cable <NUM>. The detecting section is not limited to the force detecting section <NUM> and may be, for example, a component that detects contact of the connector <NUM> and the hand <NUM> using a pressure sensor or a proximity sensor.

As shown in <FIG>, the robot 1A includes a driving section <NUM> including a motor, which turns one arm with respect to the other arm or the base <NUM>, and a speed reducer. As the motor, a servomotor such as an AC servomotor or a DC servomotor can be used. As the speed reducer, for example, a speed reducer of a planetary gear type or a wave motion gear device can be used. The robot 1A includes a position sensor <NUM>, which is an angle sensor that detects a rotation angle of a rotating shaft of the motor or the speed reducer. As the position sensor <NUM>, for example, a rotary encoder can be used. The driving section <NUM> and the position sensor <NUM> are provided in, for example, each of the arms <NUM> to <NUM>. In this embodiment, the robot 1A includes six driving sections <NUM> and six position sensors <NUM>. The driving sections <NUM> are electrically coupled to the control device <NUM> via, for example, a not-shown motor driver incorporated in the robot 1A. The position sensors <NUM> are also electrically coupled to the control device <NUM>.

As shown in <FIG>, the hand <NUM> functioning as the first gripping section is attached to the distal end portion of the robot arm <NUM> of the robot 1A. The hand <NUM> has a function of gripping the cable <NUM>, at one end of which the connector <NUM> is provided. The hand <NUM> can rotate around the axis O6 according to rotation of the arm <NUM>.

As shown in <FIG>, the hand <NUM> includes a pair of clamping pieces <NUM> configured to come into contact with and separate from each other and posture adjusting sections <NUM> that adjust the posture of the connector <NUM>. The clamping pieces <NUM> are coupled to a not-shown driving section. The driving section is electrically coupled to the control device <NUM>. The operation of the driving section is controlled by the control device <NUM>.

The clamping pieces <NUM> are claw sections. Cutouts <NUM> are respectively formed in opposed portions of the clamping pieces <NUM>. As shown in <FIG>, in a state in which the clamping pieces <NUM> are in contact, the cutouts <NUM> combine to form a defined space <NUM> defined by the clamping pieces <NUM>. On the other hand, as shown in <FIG>, in a state in which the clamping pieces <NUM> are separated, the defined space <NUM> shown in <FIG> opens. In this opened state, that is, the state in which the clamping pieces <NUM> are separated, the cable <NUM> can relatively move between the clamping pieces <NUM> along the longitudinal direction of the clamping pieces <NUM>.

When the cable <NUM> comes to the position of the cutouts <NUM>, as shown in <FIG>, the clamping pieces <NUM> are brought close to and into contact with each other, whereby the cable <NUM> is housed in the defined space <NUM>. In this state, the cable <NUM> is in a state in which the cable <NUM> is inserted through the defined space <NUM> and restricted from moving to the outer side of the defined space <NUM>, that is, a state in which the cable <NUM> is restricted from moving in the radial direction of the cable <NUM>.

The cable <NUM> can move in the radial direction in the defined space <NUM>. However, since the movement to the outer side of the defined space <NUM> is restricted, in this specification, the cable <NUM> being located in the defined space <NUM> is referred to as a state in which the movement in the radial direction of the cable <NUM> is restricted. That is, this state can be considered to be a state in which the cable <NUM> is gripped by the clamping pieces <NUM>. This gripping is hereinafter referred to as "first gripping". In other words, the state shown in <FIG> and <FIG> is a state in which the hand <NUM> is performing the first gripping on the cable <NUM>. In the state in which the first gripping is performed, the cable <NUM> is movable in the longitudinal direction of the cable <NUM> with respect to the hand <NUM>.

As explained above, the hand <NUM>, which is the gripping section, includes the two clamping pieces <NUM>, which are a first claw section and a second claw section that come into contact with and separate from each other. In the state in which the clamping pieces <NUM> are in contact, the clamping pieces <NUM> form the defined space <NUM>, which is a hole section through which the cable <NUM> is inserted. Consequently, it is possible to perform the first gripping. It is possible to perform operation for moving the hand <NUM> along the cable <NUM> as explained below. In the state in which the first gripping is performed, a clamping force is prevented or suppressed from being applied to the cable <NUM> more than necessary. It is possible to prevent or suppress damage to the cable <NUM>.

As shown in <FIG>, the cross-sectional area of the defined space <NUM>, which is the hole section, is larger than the cross-sectional area of the cable <NUM> and is smaller than the cross-sectional area of the connector <NUM> or the area of the end face on the cable <NUM> side of the connector <NUM>. That is, when viewed from the circumferential direction of the cable <NUM>, that is, a direction orthogonal to the thickness direction of the cable <NUM>, at least one of the two clamping pieces <NUM>, which are the first claw section and the second claw section, and the connector <NUM> overlap. Consequently, even if the operation for moving the hand <NUM> along the cable <NUM> while performing the first gripping is quickly performed as explained below, it is possible to more effectively prevent or suppress damage to the cable <NUM>.

As shown in <FIG>, the posture adjusting sections <NUM> are formed in block shapes respectively formed to project from one sides of the clamping pieces <NUM>. The posture adjusting sections <NUM> are located above the defined space <NUM>, that is, on the robot arm <NUM> side. As shown in <FIG>, in the state in which the clamping pieces <NUM> are in contact, the block bodies are also in contact to form one block shape. In this state, end faces on the lower sides in <FIG> of the posture adjusting sections <NUM>, that is, end faces on the opposite side of the robot arm <NUM> form one plane. As shown in <FIG>, this plane functions as a restricting surface <NUM> that comes into contact with the connector <NUM> to thereby restrict movement or rotation of the connector <NUM>.

The clamping pieces <NUM> and the posture adjusting sections <NUM> may be integrally formed or may be separately formed. When the clamping pieces <NUM> and the posture adjusting sections <NUM> are separately formed, the posture adjusting sections <NUM> can be configured by one block body or plate material.

The hand <NUM> moves to the connector <NUM> side along the longitudinal direction of the cable <NUM> in the state in which the first gripping is performed as shown in <FIG>, whereby, as shown in <FIG>, the connector <NUM> comes in to contact with the clamping pieces <NUM> and the posture adjusting sections <NUM>. In this contact state, the connector <NUM> is restricted from moving in a direction along the longitudinal direction of the cable <NUM> and rotating around an axis along the longitudinal direction of the cable <NUM> or around the center axis of the defined space <NUM> by the surfaces on the posture adjusting section <NUM> side of the clamping pieces <NUM> and the restricting surface <NUM> of the posture adjusting sections <NUM>. Consequently, in this state, the connector <NUM> is gripped by the hand <NUM>. This gripping is hereinafter referred to as "second gripping". In other words, the state shown in <FIG> is a state in which the hand <NUM> is performing the second gripping on the connector <NUM>.

A tool point is set at the tip of the hand <NUM>, that is, the tips of the clamping pieces <NUM>. A tip coordinate system having the tool point as an origin is set in the robot 1A.

As shown in <FIG>, a hand <NUM> functioning as a second gripping section is attached to the distal end portion of the robot arm <NUM> of the robot 1B. The hand <NUM> can rotate around the axis O6 according to rotation of the arm <NUM>. The hand <NUM> is the second gripping section having a function of gripping the connector <NUM>, on which the second gripping is performed by the hand <NUM>, and rotating the connector <NUM> to adjust the posture of the connector <NUM>. In this embodiment, as shown in <FIG>, the hand <NUM> includes a pair of clamping pieces <NUM> configured to come into contact with and separate from each other.

The clamping pieces <NUM> are coupled to a not-shown driving section. The driving section is electrically coupled to the control device <NUM>. The operation of the driving section is controlled by the control device <NUM>. The clamping pieces <NUM> move in a direction in which the clamping pieces <NUM> come into contact with each other, whereby the connector <NUM> can be gripped between the clamping pieces <NUM>. The clamping pieces <NUM> separate from each other, whereby the gripping of the connector <NUM> can be released.

In the configuration shown in <FIG>, the hand <NUM> is configured to grip the connector <NUM> with the pair of clamping pieces <NUM>. However, the hand <NUM> is not limited to this and may be configured to grip the connector <NUM> with three or more clamping pieces or may be configured to grip the connector <NUM> with attraction.

A tool point PB is set at the tip of the hand <NUM>, that is, the tips of the clamping pieces <NUM>. A tip coordinate system having the tool point PB as an origin is set in the robot 1B.

As shown in <FIG>, <FIG>, an imaging section <NUM> is provided at the distal end portion of the robot arm <NUM> of the robot 1B. As the imaging section <NUM>, for example, a CCD (Charge Coupled Device) camera can be used. The imaging section <NUM> is retracted further than the clamping pieces <NUM> of the hand <NUM>, that is, located on the robot arm <NUM> side. Consequently, when the clamping pieces <NUM> grip the connector <NUM>, it is easy to prevent the imaging section <NUM> from interfering with the connector <NUM>.

The imaging section <NUM> includes a light source <NUM> at the distal end portion thereof, that is, in the outer circumferential portion of a lens. Consequently, even if a space where the robot 1A and the robot 1B perform work is relatively dark or the connector <NUM> is shaded by the robot 1A depending on the position of illumination set in the space, it is possible to satisfactorily and clearly perform imaging of the connector <NUM>.

The imaging section <NUM> is electrically coupled to the control device <NUM>. An imaging result of the imaging section <NUM>, that is, an image is transmitted to the control device <NUM>. The image includes a still image and a moving image. The imaging section <NUM> is not limited to the CCD camera and may be a spectroscopic camera. In this case, spectral data, that is, spectral spectrum is transmitted to the control device <NUM>.

An image coordinate system is set in the image output by the imaging section <NUM>. The tip coordinate system of the hand <NUM>, the tip coordinate system of the hand <NUM>, described above, and the image coordinate system are associated with one another, that is, calibration of the tip coordinate system of the hand <NUM>, the tip coordinate system of the hand <NUM>, and the image coordinate system is finished.

As shown in <FIG>, the control device <NUM> has a function of controlling driving of the robot 1A, the robot 1B, and the like. The control device <NUM> is communicably coupled to the robot 1A and the robot 1B. These may be coupled to one another by wire or by radio. In the configuration shown in <FIG>, the control device <NUM> is disposed in a position different from the robot 1A and the robot 1B. However, the control device <NUM> may be incorporated in one of the robot 1A and the robot 1B or may be incorporated in both of the robot 1A and the robot 1B.

The display device <NUM> including a not-shown monitor and the input device <NUM> including, for example, a keyboard, a mouse, and a teaching pendant are coupled to the control device <NUM>.

As shown in <FIG>, the control device <NUM> includes a control section <NUM> including a processor, a storing section <NUM> including a memory, and an external input and output section <NUM> including an external interface (I/F). The components of the control device <NUM> are communicably coupled to one another via various buses.

The control section <NUM> includes a processor such as a CPU (Central Processing Unit) and executes various programs and the like stored in the storing section <NUM>. Consequently, it is possible to realize processing such as control of driving of the robot 1A and the robot 1B, various arithmetic operations, and determination.

Various programs executable by the control section <NUM>, for example, a program for executing a control method explained below and reference data, a threshold, a calibration curve, and the like used during a control operation are stored in the storing section <NUM>. Various data received by the external input and output section <NUM> can be stored in the storing section <NUM>. The storing section <NUM> includes, for example, a volatile memory such as a RAM (Random Access Memory) and a nonvolatile memory such as a ROM (Read Only Memory). The storing section <NUM> is not limited to a non-detachable type and may include a detachable external storage device (not shown in <FIG>). The storing section <NUM> may be set in another place via a network such as a LAN (Local Area Network).

The external input and output section <NUM> includes an external interface (I/F) and is used for coupling of the robot 1A, the robot 1B, the display device <NUM>, the input device <NUM>, and the like. The external input and output section <NUM> functions as a receiving section that receives information concerning an image output from the imaging section <NUM>.

Other components may be further added to the control device <NUM> in addition to the components explained above. The various programs, the data, and the like stored in the storing section <NUM> may be stored in the storing section <NUM> in advance, may be stored in a recording medium such as a CD-ROM and provided from the recording medium, or may be provided via a network or the like.

The control device <NUM> can perform position control and force control as a control operation for driving the robot arm <NUM>.

The position control means, for example, control for driving the robot 1A or the robot 1B such that the tool point is located in a predetermined coordinate. That is, the position control means control for driving the robot 1A or the robot 1B based on position information of a target and position information of the tool point. Such position control is control performed on the premise that an obstacle is absent in a route to a target position. The position control can move the robot arm <NUM> at speed higher than speed of the force control and contributes to quick work. Speed of the robot 1A or the robot 1B in the position control may be constant or may not be constant.

The force control means control for driving the robot 1A or the robot 1B based on a detection result of the force detecting section <NUM>. The force control includes, for example, impedance control and force trigger control.

In the force trigger control, force detection is performed by the force detecting section <NUM>. The robot 1A or the robot 1B is caused to perform operations such as movement and a change of a posture until the force detecting section <NUM> detects a predetermined force.

The impedance control includes following control. First, explaining briefly, in the impedance control, the operation of the robot 1A or the robot 1B is controlled to maintain a force applied to the distal end portion of the robot arm <NUM> and the hand <NUM> or the hand <NUM> at a predetermined force as much as possible, that is, maintain a force in a predetermined direction detected by the force detecting section <NUM> at a target value as much as possible.

A control operation performed by the control device <NUM> is explained mainly with reference to <FIG>, <FIG> and <FIG> to <NUM>.

In the following explanation, moving the tool point of the hand <NUM> to a predetermined position is referred to as "move the hand <NUM> to a predetermined position" or "move the robot 1A to a predetermined position".

The control method is a control method performed using the robot 1A and the robot 1B. The control method includes [<NUM>] a preparing step, [<NUM>] a first gripping step, [<NUM>] a moving step, [<NUM>] a second gripping step, [<NUM>] an imaging step, [<NUM>] a posture adjusting step, [<NUM>] an inserting step, and [<NUM>] a fixing step.

The preparing step is a step of preparing the robot 1A attached with the hand <NUM> and the robot 1B attached with the hand <NUM> and the imaging section <NUM>. "Preparing" means a step, such as the coordinate system calibration and the like explained above, performed until the robot system <NUM> is started up to an operable state when the robot system <NUM> performs coupling work.

In the preparing step, as shown in <FIG>, it is desirable to drive the robot 1B to move the hand <NUM> and the imaging section <NUM> to the +X-axis side and the +Z-axis side of the substrate <NUM> and direct the hand <NUM> and the imaging section <NUM> to the -X-axis side. Consequently, it is possible to smoothly perform [<NUM>] the imaging step and [<NUM>] the posture adjusting step. This movement may be performed simultaneously with any one of [<NUM>] the preparing step to [<NUM>] the second gripping step.

The first gripping step shown in <FIG> is a step of causing the hand <NUM> to perform the first gripping for gripping the cable <NUM> to restrict the cable <NUM> from moving in the radial direction of the cable <NUM>. Specifically, as shown in <FIG>, the hand <NUM> is moved to a position P1 and lowered toward the cable <NUM>, that is, a position P2 in the state in which the clamping pieces <NUM> are separated. Thereafter, the clamping pieces <NUM> are brought close to and into contact with each other, whereby the cable <NUM> is housed in the defined space <NUM> and the hand <NUM> performs the first gripping.

The position P1 and the position P2 are coordinates stored in the storing section <NUM> in advance. The coordinates may be input by an operator or may be coordinates specified based on an image captured by the imaging section <NUM> in advance. In this embodiment, the position P1 is any coordinate in the vicinity of the fixed end of the cable <NUM> and the position P2 is a coordinate on the -Z-axis side of the position P1.

In other words, a portion where the hand <NUM>, which is the gripping section, performs the first gripping is a portion deviating to the fixed end side in the cable <NUM>. The position of the fixed end is determined in advance. The vicinity of the fixed end in the cable <NUM> is located in a position generally decided irrespective of a position of the connector <NUM> on the substrate <NUM>. Therefore, the movement of the hand <NUM> until performing the first gripping can be controlled using the position control. Accordingly, it is possible to quickly perform the first gripping and perform the first gripping at high accuracy.

As shown in <FIG>, in the moving step, the hand <NUM> is moved toward the connector <NUM> side along the cable <NUM> in the state in which the first gripping is performed. In this step, in order to quickly perform the imaging step after this step, the hand <NUM> is moved toward a position P3 in the vicinity on the -X-axis side of the imaging section <NUM>. A route of this movement may be a straight line or may be an arcuate shape.

In this embodiment, when the hand <NUM> is moved from the position P2 to the position P3, the hand <NUM> is moved by the position control up to a position P4 immediately before the position P3 and is moved by the force control from the position P4 to the position P3. That is, when moving the hand <NUM>, which is the gripping section, toward the connector <NUM> along the cable <NUM> in the state in which the first gripping is performed, the control device <NUM> moves the hand <NUM> using the position control and the force control in this order. Consequently, quick movement can be performed by the position control. Further, as explained below, it is possible to accurately detect contact of the connector <NUM> and the hand <NUM>.

The position P4 is set on a moving route between the position P2 and the position P3. The position P3 and the position P4 are coordinates stored in the storing section <NUM> in advance. The position P4 desirably deviates to the position P3 side in the moving route between the position P2 and the position P3. Consequently, it is possible to more quickly move the hand <NUM> to the position P3. In the moving route of the hand <NUM>, the distance from the position P4 to the position P3 is desirably smaller than <NUM>% of the distance from the position P2 to the position P4. Consequently, it is possible to more markedly exert the effects explained above.

The position, that is, a bending state of the cable <NUM> changes according to the position on the substrate of the connector <NUM>. However, as explained above, in the state in which the first gripping is performed, the cable <NUM> is restricted from moving to the outer side of the defined space <NUM>. Consequently, in a portion of the cable <NUM> where the hand <NUM> has passed, the cable <NUM> extends generally along the moving route of the hand <NUM>. When the hand <NUM> is moved from the position P2 to the position P4 by the position control, since the area of the defined space <NUM> is larger than the cross-sectional area of the cable <NUM> as shown in <FIG>, it is possible to sufficiently reduce a contact opportunity of the cable <NUM> and the clamping pieces <NUM>. It is possible to prevent or suppress damage to the cable <NUM>.

When the hand <NUM> is moved to the position P4, the position control is switched to the force control. The force control is a mode for performing force detection by the force detecting section <NUM> while moving the hand <NUM> at moving speed lower than moving speed of the hand <NUM> in the position control. Therefore, when the hand <NUM> is moving to the position P3 and it is determined that the hand <NUM> and the connector <NUM> come into contact and the hand <NUM> grips the connector <NUM>, the movement of the hand <NUM> can be immediately stopped. It is possible to prevent or suppress tension from being excessively applied to the cable <NUM>.

In this embodiment, the moving step is performed immediately before the hand <NUM> and the connector <NUM> come into contact with each other.

The second gripping step is a step of stopping the movement of the hand <NUM> based on a detection result of the force detecting section <NUM> and performing the second gripping for causing the hand <NUM> to grip the connector <NUM> as shown in <FIG>, <FIG>. When the hand <NUM>, which is performing the first gripping, is moved toward the position P3 by the force control, the hand <NUM> and the connector <NUM> come into contact with each other. When a force received by the hand <NUM> when the hand <NUM> comes into contact with the connector <NUM>, that is, a force detected by the force detecting section <NUM> reaches a predetermined value, the movement of the hand <NUM> is stopped.

At this time, as shown in <FIG>, the connector <NUM> is restricted from moving in the direction along the longitudinal direction of the cable <NUM> and restricted from rotating around the axis along the longitudinal direction of the cable <NUM> or the center axis of the defined space <NUM> by the surfaces on the posture adjusting section <NUM> side of the clamping pieces <NUM> and the restricting surface <NUM> of the posture adjusting sections <NUM>. Consequently, it is possible to perform the second gripping.

In this way, the control section <NUM> causes the hand <NUM>, which is the first gripping section, to perform the first gripping for gripping the cable <NUM> to restrict the movement of the cable <NUM> in the thickness direction of the cable <NUM>, moves the hand <NUM> toward the connector <NUM> in a state in which the first gripping is performed, stops the movement of the hand <NUM> based on a detection result of the force detecting section <NUM>, and causes the hand <NUM> to perform the second gripping for gripping the connector <NUM>. That is, since the hand <NUM> sequentially performs the first gripping and the second gripping in this way, the connector <NUM> can be stably gripped by a simple method. In the past, for example, the entire substrate is imaged by the imaging section, a position of the substrate where the connector is disposed is specified, the hand is moved to the position, and the connector is gripped by the hand. In such a method in the past, a satisfactory image cannot be captured depending on imaging conditions such as brightness of a room and an imaging direction. It is difficult to specify the position of the connector. Further, in the method in the past, it is necessary to perform processing for specifying the connector in an image. Therefore, the processing is complicated. That is, in the method in the past, it is difficult to easily and accurately grip the connector. On the other hand, in the present disclosure, it is possible to accurately grip the connector without the necessity of performing the complicated processing in the past with a simple method in which the hand <NUM> sequentially performs the first gripping and the second gripping. Consequently, according to the present disclosure, it is possible to easily and accurately grip the connector.

In a state in which the second gripping is performed, a surface of the connector <NUM> in contact with the posture adjusting sections <NUM> is random every time. That is, in the state in which the hand <NUM> is performing the second gripping, it is unknown whether a posture of the connector <NUM> in the circumferential direction of the cable <NUM> is proper.

The imaging step is a step of imaging, with the imaging section <NUM>, the connector <NUM> on which the hand <NUM> is performing the second gripping, as shown in <FIG>. In the position P3, the connector <NUM> gripped by the hand <NUM> is located at the same height as the height of the imaging section <NUM>, that is, the position in the Z-axis direction of the connector <NUM> is located in substantially the same position as the position of the imaging section <NUM>. Consequently, when the connector <NUM> is imaged, the connector <NUM> is located in the center of an image. As explained above, when the imaging step is performed, since the hand <NUM> is located in advance in the position shown in <FIG>, the second gripping step can be quickly shifted to this step when the second gripping step is completed.

The image captured in this step is transmitted to the control device <NUM>.

The posture adjusting step is a step of, when the posture of the connector <NUM>, on which the second gripping is performed, is not a desired posture, causing the hand <NUM> to grip the connector <NUM> in the desired posture using the hand <NUM>. The posture adjusting step includes the following steps [6A] to [6E] as shown in <FIG>.

The step [6A] is a step of causing the hand <NUM> to grip the connector <NUM>, on which the second gripping is performed, as shown in <FIG>. That is, in this step, the connector <NUM> is gripped by the hand <NUM> and the hand <NUM>. Consequently, when the connector <NUM> is passed between the hand <NUM> and the hand <NUM>, it is possible to prevent the connector <NUM> from unintentionally dropping.

In the step [6B], as shown in <FIG>, the hand <NUM> is moved in a direction in which the hand <NUM> separates from the hand <NUM> and the second gripping performed by the hand <NUM> is released while the state in which the hand <NUM> grips the connector <NUM> is maintained. Consequently, only the hand <NUM> grips the connector <NUM> through this step.

The step [6C] is a step of rotating the hand <NUM> around the axis O6 to adjust the direction of the connector <NUM> to the desired posture as shown in <FIG>. In this step, a rotation amount of the hand <NUM> is determined based on the imaging result that is, the image obtained in [<NUM>] the imaging step.

Specifically, for example, it is possible to use a method of extracting a plurality of feature points in a captured image, comparing arrangement of the feature points with arrangement of feature points in an image of the connector <NUM> in the desired posture stored in the storing section <NUM> in advance, and calculating a rotation amount. It is also possible to use other methods such as a method of comparing the center line of an end face of the connector <NUM> with a center line in the image stored in the storing section <NUM> in advance and calculating a rotation amount from a deviation amount.

The connector <NUM> can be set to the desired posture through such a step [6C]. The desired posture means a posture in which the connector <NUM> can be inserted into the insertion hole <NUM> in a desired direction when the hand <NUM> thereafter traces a preset route in a state in which the hand <NUM> grips the connector <NUM>.

The step [6D] is a step of causing the hand <NUM> to grip the connector <NUM> in the desired posture gripped by the hand <NUM> as shown in <FIG>. That is, in this step, the connector <NUM> in the desired posture is gripped by the hand <NUM> and the hand <NUM>. Consequently, when the connector <NUM> is passed between the hand <NUM> and the hand <NUM>, it is possible to prevent the connector <NUM> from unintentionally dropping.

In the step [6E], as shown in <FIG>, the hand <NUM> is moved in a direction in which the hand <NUM> separates from the hand <NUM> and the gripping performed by the hand <NUM> is released while the state in which the hand <NUM> grips the connector <NUM> is maintained. Consequently, only the hand <NUM> grips the connector <NUM>, that is, only the hand <NUM> is performing the second gripping through this step.

By performing the steps [6A] to [6E] explained above, it is possible to adjust the posture of the connector <NUM> to the desired posture from the state in which the hand <NUM> is performing the second gripping and bring the hand <NUM> again into the state in which the hand <NUM> is performing the second gripping. Accordingly, in the following inserting step, it is possible to insert the connector <NUM> into the insertion hole <NUM> with simple control. It is possible to perform adjustment of a posture without excessively applying tension to the cable <NUM> with a simple method of changing the hold of and rotating the connector <NUM>.

When the connector <NUM> is in the desired posture in the captured image, it is possible to omit the steps [6A] to [6E] and shift to the inserting step.

After the step [6E] is completed, as shown in <FIG>, the hand <NUM> is rotated around the axis O6 and returned to the posture shown in <FIG> and moved to the initial position. Consequently, it is possible to smoothly perform the next imaging step.

The inserting step is a step of inserting the connector <NUM> into the insertion hole <NUM> of the substrate <NUM> as shown in <FIG>. Specifically, first, the tip of the hand <NUM>, which is performing the second gripping on the connector <NUM> in the desired posture, is moved to a preset position P5 in an arrow direction in <FIG>.

The position P5 is a coordinate on the +Y-axis side of the substrate <NUM> and in the same position in the X-axis direction as the center of the insertion hole <NUM>. The hand <NUM> is rotated around the axis O6 such that the end face of the connector <NUM> on the opposite side of the cable <NUM> faces the insertion hole <NUM>. Such movement and rotation may be simultaneously performed or may be sequentially performed. When the movement and the rotation are sequentially performed, the order of the movement and the rotation is not limited.

As shown in <FIG> and <FIG>, the hand <NUM> is moved to a position P6 set between the position P5 and the insertion hole <NUM>. The movement of the hand <NUM> to the position P5 and the position P6 is performed by the position control. However, after moving to the position P6, the hand <NUM> is moved to the insertion hole <NUM> side by the force control. When a force applied to the hand <NUM> when the insertion of the connector <NUM> into the insertion hole <NUM> is completed, that is, a force detected by the force detecting section <NUM> reaches a predetermined value, the movement of the hand <NUM> is stopped.

The predetermined value used in this step is a value stored in the storing section <NUM> in advance. The predetermined value is a value different from the value used to detect the contact of the hand <NUM> and the connector <NUM> when the second gripping is performed as explained above.

As shown in <FIG>, the insertion of the connector <NUM> into the insertion hole <NUM> is completed through the steps explained above.

The fixing step is a step of fixing a halfway part in the longitudinal direction of the cable <NUM> to the substrate <NUM> as shown in <FIG>. In this embodiment, two parts in the longitudinal direction of the cable <NUM> are fixed to the substrate <NUM>. A fixing section <NUM> and a fixing section <NUM> are provided in the substrate <NUM>. The fixing section <NUM> and the fixing section <NUM> are, for example, grooves or a pair of protrusions.

A position P7 is set in the fixing section <NUM>. A position P8 is set in the fixing section <NUM>. The position P7 and the position P8 are coordinates stored in the storing section <NUM> in advance. The coordinates may be input by the operator or may be coordinates specified based on an image captured by the imaging section <NUM> in advance.

As shown in <FIG>, the hand <NUM> is moved to the position P7, whereby the tip of the hand <NUM> can press the cable <NUM> against the fixing section <NUM> and fix the cable <NUM>. Thereafter, the hand <NUM> is moved to the position P8, whereby the tip of the hand <NUM> can press the cable <NUM> against the fixing section <NUM> and fix the cable <NUM>.

As shown in <FIG>, the connector <NUM> is inserted into the insertion hole <NUM> through the steps explained above. The halfway part in the longitudinal direction of the cable <NUM> can be fixed to the substrate <NUM>. The work of the robot system <NUM> is completed.

As explained above, the robot system <NUM> includes the robot 1A functioning as the first robot including the robot arm <NUM>, which is the first arm, the hand <NUM>, which is the first gripping section, coupled to the robot arm <NUM> of the robot 1A, the robot 1B functioning as the second robot including the robot arm <NUM>, which is the second arm, the hand <NUM>, which is the second gripping section, coupled to the robot arm <NUM> of the robot 1B, the imaging section <NUM> set in the robot arm <NUM> of the robot 1B, and the control section <NUM> that controls the operations of the robot arm <NUM> of the robot 1A, the robot arm <NUM> of the robot 1B, the hand <NUM>, the hand <NUM>, and the imaging section <NUM>. The control section <NUM> causes the hand <NUM> to grip the connector <NUM> of the cable <NUM>, at one end of which the connector <NUM> is provided and the other end of which is fixed, causes the imaging section <NUM> to image the connector <NUM>, causes the hand <NUM> to grip the connector <NUM> based on a result of the imaging by the imaging section <NUM> in a state in which the position of the hand <NUM> is maintained, causes the hand <NUM> to release the gripping of the connector <NUM>, causes the hand <NUM> to adjust the posture of the connector <NUM> based on the imaging result, and causes the hand <NUM> to grip the connector <NUM>, the posture of which is adjusted.

The control method for the robot system <NUM> is the control method for the robot system <NUM> including the robot 1A functioning as the first robot including the robot arm <NUM>, which is the first arm, the hand <NUM>, which is the first gripping section, coupled to the robot arm <NUM> of the robot 1A, the robot 1B functioning as the second robot including the robot arm <NUM>, which is the second arm, the hand <NUM>, which is the second gripping section, coupled to the robot arm <NUM> of the robot 1B, and the imaging section <NUM> set in the robot arm <NUM> of the robot 1B. The control method includes the step of gripping, with the hand <NUM>, the connector <NUM> of the cable <NUM>, at one end of which the connector <NUM> is provided and the other end of which is fixed, the step of imaging the connector <NUM> with the imaging section <NUM>, the step of gripping the connector <NUM> with the hand <NUM> based on a result of the imaging by the imaging section <NUM> in a state in which the position of the hand <NUM> is maintained, the step of releasing the gripping of the connector <NUM> with the hand <NUM>, the step of adjusting the posture of the connector <NUM> with the hand <NUM> based on the imaging result, and the step of gripping the connector <NUM>, the posture of which is adjusted, with the hand <NUM>.

According to the present disclosure explained above, it is possible to adjust the posture of the connector <NUM> to the desired posture in the state in which the hand <NUM> is gripping the connector <NUM>, that is, the hand <NUM> is performing the second gripping and cause the hand <NUM> to grip the connector <NUM> again. Accordingly, in the following inserting step, it is possible to insert the connector <NUM> into the insertion hole <NUM> with simple control. It is possible to perform adjustment of a posture without excessively applying tension to the cable <NUM> with a simple method of changing the hold of and rotating the connector <NUM>. Further, since the other end of the cable <NUM> is fixed to the substrate <NUM>, a movable range of the connector <NUM> is relatively narrow and limited. However, according to the present disclosure, it is possible to rotate the connector <NUM> and adjust the posture of the connector <NUM> without substantially moving the connector <NUM> on the spot. Therefore, it is possible to prevent or suppress excessive tension from being applied to the cable <NUM>.

In the step of causing the hand <NUM>, which is the first gripping section, to grip the connector <NUM>, the control section <NUM> causes the hand <NUM> to perform the first gripping for gripping the cable <NUM> to restrict the cable <NUM> from moving in the circumferential direction of the cable <NUM>, moves the hand <NUM> toward the connector <NUM> along the cable <NUM> in a state in which the first gripping is performed, stops the movement of the hand <NUM> when the hand <NUM> comes into contact with the connector <NUM>, and causes the hand <NUM> to perform the second gripping for gripping the connector <NUM>. Consequently, as explained above, it is possible to accurately grip the connector <NUM> without the necessity of performing the complicated processing in the past with a simple method in which the hand <NUM> sequentially performs the first gripping and the second gripping.

A robot system according to a second embodiment of the present disclosure is explained with reference to <FIG>. Differences from the first embodiment are mainly explained. Explanation of similarities is omitted.

As shown in <FIG>, in this embodiment, the hand <NUM> includes plate-like or block-like guide pieces <NUM> provided on the opposite side of the posture adjusting sections <NUM> of the clamping pieces <NUM>. The guide pieces <NUM> have a function of guiding the cable <NUM> to between the clamping pieces <NUM> while coming into contact with the cable <NUM> and adjusting the posture of the cable <NUM> when the hand <NUM> performs the first gripping.

According to this embodiment, the same effects as the effects in the first embodiment are obtained. Further, it is possible to more stably perform the first gripping.

<FIG> is a block diagram for explaining a robot system centering on hardware.

<FIG> shows the overall configuration of a robot system 100A in which the robot 1A and the robot 1B, a controller <NUM>, and a computer <NUM> are coupled. Control of the robot 1A and the robot 1B may be executed by reading out a command present in a memory with a processor present in the controller <NUM> or may be executed via the controller <NUM> by reading out the command present in the memory with a processor present in the computer <NUM>.

Therefore, one or both of the controller <NUM> and the computer <NUM> can be grasped as a "control device".

<FIG> is a block diagram showing a modification <NUM> centering on hardware of a robot system.

<FIG> shows the overall configuration of a robot system 100B in which a computer <NUM> is directly coupled to the robot 1A and the robot 1B. Control of the robot 1A and the robot 1B is directly executed by reading out a command present in a memory with a processor present in the computer <NUM>.

Therefore, the computer <NUM> can be grasped as a "control device".

<FIG> shows the overall configuration of a robot system 100C in which the robot 1A and the robot 1B incorporating controllers <NUM> and a computer <NUM> are coupled and the computer <NUM> is connected to cloud <NUM> via a network <NUM> such as a LAN. Control of the robot 1A and the robot 1B may be executed by reading out a command present in a memory with a processor present in the computer <NUM> or may be executed by reading out the command present in the memory with a processor prevent on the cloud <NUM> via the computer <NUM>.

Therefore, any one, any two, or three of the controller <NUM>, the computer <NUM>, and the cloud <NUM> can be grasped as a "control device".

The robot system and the control method according to the present disclosure are explained above based on the embodiments shown in the figures. However, the present disclosure is not limited to this. The components of the sections can be replaced with any components having the same functions. Any other components may be added to the present disclosure. The embodiments may be combined as appropriate.

Claim 1:
A robot system comprising:
a first robot (1A) including a first arm (<NUM>),
a first gripping section (<NUM>) coupled to the first arm (<NUM>),
a second robot (1B) including a second arm (<NUM>),
a second gripping section (<NUM>) coupled to the second arm (<NUM>),
an imaging section (<NUM>) set in the second arm (<NUM>), and
a control section (<NUM>) configured to control operations of the first robot (1A), the first gripping section (<NUM>), the second robot (1B), the second gripping section (<NUM>), and the imaging section (<NUM>), wherein
the control section is configured to cause the first gripping section (<NUM>) to perform a first gripping for gripping a cable (<NUM>), wherein a connector (<NUM>) is attached to one end portion of the cable (<NUM>) and the other end portion of the cable (<NUM>) is fixed, wherein the first gripping section (<NUM>) includes posture adjusting sections (<NUM>) configured to adjust the posture of the connector (<NUM>) and a plurality of clamping pieces (<NUM>) which are adapted to come into contact and to separate from each other, wherein, in a state in which the clamping pieces (<NUM>) are in contact,
the plurality of clamping pieces (<NUM>) is configured to form a space (<NUM>) through which the cable (<NUM>) is insertable to restrict movement of the cable (<NUM>) in a thickness direction of the cable (<NUM>), wherein the control section is further configured to move the first gripping section (<NUM>) toward the connector (<NUM>) in a state in which the first gripping is performed, to stop the movement of the first gripping section (<NUM>) when the
the connector (<NUM>) comes into contact with the plurality of clamping pieces (<NUM>) and the posture adjusting sections (<NUM>), to cause the first gripping section (<NUM>) to perform a second gripping for gripping the connector (<NUM>), to cause the imaging section (<NUM>) to image the connector (<NUM>), to cause, based on a result of the imaging by the imaging section (<NUM>), the second gripping section (<NUM>) to grip the connector (<NUM>) in a state in which a position of the first gripping section (<NUM>) is maintained, to cause the first gripping section (<NUM>) to release the gripping of the connector (<NUM>), to cause, based on the imaging result, the second gripping section (<NUM>) to adjust a posture of the connector (<NUM>), and to cause the first gripping section (<NUM>) to grip the connector (<NUM>), the posture of which being adjusted.