Abstract: A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

Abstract: A first elastic body actuator and a second elastic body actuator are used for driving a first configuration member and a second configuration member to swing them with respect to each other. One end portion of the first elastic body actuator is secured to the first configuration member and the other end portion of the first elastic body actuator is secured to the second configuration member, and one end portion of the second elastic body actuator is secured to the first configuration member and the other end portion of the second elastic body actuator is secured to the second configuration member, such that the position at which the other end portion of the second elastic body actuator is secured to the second configuration member and the position at which the one end portion of the first elastic body actuator is secured to the second configuration member are substantially symmetric about a rotational joint.

Abstract: A first elastic body actuator and a second elastic body actuator are used for driving a first configuration member and a second configuration member to swing them with respect to each other. One end portion of the first elastic body actuator is secured to the first configuration member and the other end portion of the first elastic body actuator is secured to the second configuration member, and one end portion of the second elastic body actuator is secured to the first configuration member and the other end portion of the second elastic body actuator is secured to the second configuration member, such that the position at which the other end portion of the second elastic body actuator is secured to the second configuration member and the position at which the one end portion of the first elastic body actuator is secured to the second configuration member are substantially symmetric about a rotational joint.

Abstract: The invention relates to a parallel kinematic device with a fixed platform and with a moving platform based on rods (1, 11, 21, 41) and on actuators, at least one actuator (A, A1, A2) is provided in the form of a rod of a constant length with a foot (6, 16, 26, 46) that can move relative to the fixed platform and, with a rod of a constant length and fixed foot (1, 11, 21, 41) on the fixed platform, comprises a common head (2, 12, 22, 42) on the moving platform, and the retaining force remains largely independent of the angular position of the kinematic. The displaceable foot (6, 16, 26, 46) is guided along an arc of a circle by a steering rod (7, 17, 27, 49) with a fixed foot on the first platform, with which is connected in an articulated manner and it acts upon a point of application (10, 40) connected in a fixed manner thereto via a force introduction element (9, 49).

Abstract: The present invention relates to a link assembly for a robot arm which comprises first and second link members each adapted for limited movement one with respect to the other and resilient elastomeric material disposed between said first and second members and bonded or keyed thereto whereby movement between the first and second member results in shear movement within the elastomeric material disposed there between.

Abstract: A robotic surgical device for using in laparoscopic surgery, including two robotic arms, each having at least six joints providing a total of fourteen degrees of movement that accurately reproduce the movements of a human torso complete with arms.

Abstract: An articulated arm having a first arm member and a second arm member flexibly coupled mutually by a ball joint. From a plurality of through-holes provided in the first arm member 2 to a plurality of holding holes provided in the second arm member, compression coil springs 8 are inserted. Support shafts are inserted, movably back and forth freely, in the through-holes behind the rear end portion of the compression coil springs. A certain support shaft is moved forward by actuator or the like to push the compression coil spring while other support shaft are moved backward. As a result, the second arm member can be moved to a specified position by the ball joint. Stopping state of the second arm member at the specified position is maintained by the balance of position of support shaft and repulsive force of compression coil spring.

Abstract: This invention provides a manipulator that can facilitate a teaching method, improve the operation speed of an arm, and mount a heavy load in a narrow space. The manipulator includes a plurality of arm bodies provided in series, joint parts rotatably connecting two adjacent arm bodies, and the joint parts in which slope of rotation axes of the adjacent joints are 90 degrees, at least one linear body disposed in the joint parts coaxially with the rotation axes. The joint parts are composed of a servo motor, and a speed-reduction mechanism. The rotation axes of the servo motor, the speed-reduction mechanism and the joint parts become the same axis.

Abstract: An arm part of a manipulator of an industrial robot has at each end thereof a connector for connecting the arm part to a gear and a stiffener for stiffening the end region of the arm part. At least one aperture is arranged in a hollow structure of the stiffener for providing access to connecting members.

Abstract: In a “tip following” robotic arm, the apertures through which control cables pass are arranged to ensure that the cables are maintained in contact with at least a part of the aperture, leading to a more stable and controllable arrangement.

Abstract: A compliant joint capable of achieving passive compliance for a robot in order to prevent an injury to a human by collision with the robot. The compliant joint includes a housing, a cam member rotatably mounted in the housing, a roller spring device mounted to the cam member to be compressed and extended, a guiding member formed in the housing to guide compression and extension of the roller spring device in accordance with rotation of the cam member, and a receiving recess formed at the guiding member to engage the housing and the cam member with each other by receiving the roller spring device and release the engagement by separating from the roller spring device. Accordingly, robustness of the robot can be maintained when an impact less than a predetermined magnitude is applied, while being suddenly decreased when an impact greater than the magnitude is applied.

Abstract: A robot arm assembly a base unit with a shoulder assembly rotatably disposed on the base unit. A lower robot arm is pivotably attached to the shoulder assembly. An upper robot arm is pivotably attached to the lower robot arm. The base unit includes a first motor which rotates a main shaft fixed to the shoulder assembly to rotate the shoulder. A second motor in the base unit rotates a second shaft in the shoulder assembly extending through the main shaft to pivot the lower robot arm with respect to the shoulder.

Abstract: A joint structure of a robot performs a longitudinal swing motion and a lateral swing motion of a hand (8) coupled to an arm link (2). The joint structure includes: a base link (21) as a main body of the arm link (2) having a pair of facing portions (21a); a gimbal link (4) having a longitudinal shaft and (4a) a lateral shaft (4b) not parallel to each other for providing the longitudinal swing motion and lateral swing motion of the coupled body, the longitudinal shaft being supported between the pair of facing portions (21a); a main link (5) with one end thereof coupled to the lateral shaft (4b) of the gimbal link (4) and with the other end thereof coupled to the hand (8); and a sub link (6) with one end thereof coupled to the gimbal link (4) and with the other end thereof coupled to the hand (8), the sub link (6) being provided crosswise with the main link (5) to form a four link mechanism (1) therewith. This ensures a wide movable angle of the joint.

Abstract: A robot apparatus having a multi-link structure including a plurality of links and joints serving as link movable sections, and in which at least some of the links are driven by combination of position control and force control is disclosed. The apparatus includes: position control means for performing the position control on the links, which are driven by position control and force control; position control means with force constraint for placing the force control before the position control so as not to cause the magnitude of an external force to exceed a set value; force control means for performing the force control on the links; and integrated force/position control means for controlling driving of the joints by switching the position control means, the position control means with force constraint, and the force control means, and unifies the position control and the force control.

Abstract: A robot quick-release assembly has a first joint member and a robot component mounted thereon, the first joint member has a first coupler and a second joint member, a robot arm mounted thereon, has a second coupler, a clamp, and a locking collar. The first coupler can be coaxially aligned with the second coupler and pressed into the second joint member, and detachably connected to the second joint member. The first mechanical coupler is detachably connected to the second mechanical coupler for transferring power across the quick-release assembly. The robot component can receive an additional electrical connector, the additional electrical connector supplying power to the robot component. The quick-release assembly coupling assembly further exerts large forces with the application of a relatively small torque to the locking collar by applying a two stage wedge engagement and can further include a sequencing system.

Abstract: A controller is provided to control operations of a robot provided with a robot body having operation axes to be controlled and an additional mechanism having an additional operation axis. The controller comprises a manual operation device, determination means and control means. The manual operation device enables a user to manually operate the operations of the robot body and the additional mechanism in parallel to each other. The determination means determines whether or not the additional mechanism is a linked state in operations with the robot body.

Abstract: A controlled relative motion system comprising a base support, a pivot holder and a plurality of pivoting links with the pivoting links rotatably coupled to both the base support and to members of the pivot holder to rotate about axes which extend in different directions for each of these rotatable couplings in a link, typically in accord with specific geometrical arrangements, and in different directions from similar axes in another of such links. The foregoing various rotatable couplings are provided by insertable bearings or bushings in the supports and links. The pivoting links have larger portions thereof outside of the interior of the manipulator parts of which can extend outside in different directions. Such systems can incorporate a variety of force imparting members to control movements of various ones of the pivoting links or pivot holder members.

Abstract: A robotic arm comprising a plurality of segments, each comprising articulated links, and means for causing each segment to bend so the arm can follow a serpentine path. A helical spring is provided coaxially with the arm to urge the links to an initial datum position, and to distribute the bending over the links of each segment.

Abstract: A horizontal multijoint type robot is so constructed that it comprises a first arm connected through a first joint shaft to a base, a second arm connected through a second joint shaft to the first arm, and a working shaft provided rotatably and movably up and down on the distal end of the second arm, and that the arm length L1 of the first arm and the arm length L2 of the second arm are equal to each other so that the second arm is able to overlap the first arm.

Abstract: A linkage system which offers high rigidity and good assemblability and producibility, and enables parts such as rotary transmission components and actuators to be readily installed. A linkage system includes an input member disposed on an input side, an output member disposed on an output side, and three or more link mechanisms, each link mechanism consisting of end links rotatably coupled to the input member and the output member, respectively, a center link rotatably coupled to the end links on the input side and the output side, and four revolute joints by which the end links are rotatably coupled to the input and output members, and to the center link. The link mechanism being geometrically identical with respect to a center cross-sectional plane relative on the input and output sides. Each of the revolute joints of the link mechanism includes bearings that support at both ends of the revolute joint.

Abstract: A robot provided with a robot mechanism including a first member and a second member, the first member and the second member being movable relative to each other; and a laying structure for laying an umbilical member in the robot mechanism. The robot includes the umbilical member laid to extend between the first member and the second member; a movable clamp member movably provided in the first member to clamp the umbilical member; and a connecting member for connecting the movable clamp member to the second member in a correlatively movable manner. The connecting member transmits a force generating due to a movement of the second member relative to the first member to the movable clamp member, so as to move the clamp member in the first member.

Abstract: A joint driving apparatus for a robot comprises an oscillating internally meshing reduction mechanism, a center shaft member, a ring portion, and an oil seal disposed between the ring portion and the center shaft member. The oscillating internally meshing reduction mechanism is fixed to a first member and rotates the second member relatively with respect to the first member. An output member is arranged at the side of an external gear in an axial direction so as to output a relative rotation of an internal gear with the external gear. The center shaft member is fixed to the output member, and has a shaft portion extending up to the side opposite to the external gear in the axial direction of the output member. The ring portion is integrally formed with the first member and faces to the shaft portion of the center shaft member. The oil seal is disposed between the ring portion and the shaft portion.

Abstract: Methods and apparatus are provided for the use of a dual Selective Compliant Assembly Robot Arm (SCARA) robot. In some embodiments two SCARAs are provided, each including an elbow joint, wherein the two SCARAs are vertically stacked such that one SCARA is a first arm and the other SCARA is a second arm, and wherein the second arm is adapted to support a first substrate, and the first arm is adapted to extend to a full length when the second arm supports the first substrate, and wherein the first substrate supported by the second arm is coplanar with the elbow joint of the first arm, and the second arm is further adapted to move concurrently in parallel (and/or in a coordinated fashion) with the first arm a sufficient amount to avoid interference between the first substrate and the elbow joint of the first arm. Numerous other embodiments are provided.

Abstract: A joint of an industrial robot that includes attaching part (23) having positioning member (22) embedded in one or both of two relatively rotating members, and guide (24) through which positioning member (22) projectably slides. Meanwhile, the side of the positioning member is provided thereon with a reservoir groove for a lubricant and a projection position marker for indicating a given projection length. This makeup provides an inexpensive, highly accurate, and extremely trouble-saving origin adjusting device.

Abstract: A joint mechanism that can be used in an articulated finger unit of a robot hand has first and second actuators that are disposed facing each other from the front and back on either side of a perpendicular joint axle, and first and second drive bevel gears that are coaxially connected and fixed to distal ends of output axles thereof. A driven bevel gear fixedly mounted in coaxial manner on the perpendicular joint axle meshes with the first and second drive bevel gears. The perpendicular joint axle is rotatably driven by the two actuators, and a revolving bracket connected thereto revolves to the left and right. The drive torque of the joint axle can be increased without increasing the outside diameter dimensions of the mechanism.

Abstract: A manipulator comprises an operation command unit provided with an attitude adjusting unit and an end effector control unit, a connecting unit having one end connected to the operation command unit, a working unit connected to the other end of the connecting unit and provided with an end effector and a support unit supporting the end effector for motions, and a control unit that transmits an operation command provided by the attitude adjusting unit to the support unit to adjust the attitude of the end effector and transmits an operation command provided by the end effector control unit to the end effector to operate the end effector. The support unit includes a first joint capable of turning about a first axis perpendicular to the center axis of the connecting unit, and a second joint capable of turning about a second axis perpendicular to the first axis. The end effector can be turned for rolling about an axis substantially parallel to the second axis of the second joint.

Abstract: A surgical robotic system comprising a robotic arm, an end effector movably connected thereto and provided with a movable end effector element driven by an actuator, and a force sensor arranged between the robotic arm and the end effector. The actuator is formed by a hydraulic cylinder. The robotic arm is provided with a hydraulic line connected to said hydraulic cylinder of the end effector.

Abstract: A wrist assembly is provided for securing an end effector to a robotic arm. The wrist assembly comprises a first portion (205, 207) containing a slot for releasably engaging an end effector (231), and a second portion (203) which is attached to the first portion. The orientation of the first portion with respect to the second portion is adjustable to impart a leveling effect to the end effector.

Abstract: A sealing device provided to a joint section of a robot. The sealing device includes overlapped seal portions having a multi-stage configuration, provided for a driving mechanism incorporated into the joint section. The overlapped seal portions include a first seal portion including a first contact seal element sealing a first inter-member gap defined adjacent to a lubricant retaining section provided in the driving mechanism; and a second seal portion arranged outside the first seal portion and including a second contact seal element sealing a second inter-member gap defined in a circumferential wall of the joint section, the circumferential wall defining an accommodation space for accommodating the driving mechanism.

Abstract: An assembly of a milking robot with a milking robot feeding place, such as a milking robot feed trough, and a device for gripping and displacing material, such as for example roughage and/or concentrate for animals. The device is provided with a gripper (2) for gripping, then displacing and subsequently supplying the material. The device comprises control means for displacing the gripper (2) to the milking robot and for controlling the gripper for supplying the material to the milking robot feeding place of the milking robot.

Abstract: A robot arm is provided at a forward end thereof with a rotation shaft member rotatable about a rotation axis thereof, in which a hollow portion is formed along the rotation axis. A laying device for laying a line element includes a relaying means for relaying an arm side section of the line element, extending through the hollow portion out of a lead-out opening formed on a side of the rotation shaft member, to a tool side section of the line element extending from the tool. A direction in which the relaying means connects the line element is substantially parallel to a tool mount surface and forms an angle other than 0° with regard to a radial direction perpendicular to the rotation axis.

Abstract: An automatic lens blocking apparatus having a tracer and a lensmeter therein, for adhering a block to a lens by using a robot arm, is disclosed. The automatic lens blocking apparatus comprises: a tracer for obtaining data on a shape of a glass frame and data on a center of the glass frame; a lensmeter for obtaining data on an optical center of a blank lens by measuring physical property of the blank lens; an image camera part for obtaining an image of a shape and a position of the blank lens; and a blocker (a) for determining a blocking position to which a block is adhered on the basis of (i) the data on the shape of the glass frame and the data on the center of the glass frame obtained from the tracer, (ii) the data on the optical center of the blank lens and physical property of the blank lens obtained from the lensmeter and (iii) the image of the shape and the position of the blank lens obtained from the image camera part, (b) for moving the block and (c) for adhering the block to the blank lens.

Abstract: An autonomous mobile milking implement having a frame with, a sub-frame which is adjustable in height and which has at least one teat cup holder and a teat cup movable relative thereto. The teat cup holder is tiltable, via a tilting mechanism coupled to the teat cup holder and the frame between a substantially vertical position and a second partially inverted position. The milking implement protects the teat cups against contamination and is capable of storing them in a compact manner.

Abstract: A robotic surgical device for using in laparoscopic surgery, including two robotic arms, each having at least six joints providing a total of fourteen degrees of movement that accurately reproduce the movements of a human torso complete with arms.

Abstract: A joint structure includes a rotating guide pulley, a fixed guide, and a rotating guide pulley. The rotating guide pulley is coaxial with a rotating shaft of a revolute joint, and is arranged so as to be rotatable about the rotating shaft. The fixed guide is arranged in a first structure, and has an arc portion. The arc portion has the same radius as the rotating guide pulley and is coaxial with the rotating guide pulley. The rotating guide pulley is arranged in a second structure so as to be relatively movable. A wire is put round the rotating guide pulley, the movable rotating guide pulley, and the fixed guide in the order of them.

Abstract: A computer in a transport system includes: a shooting part for shooting a first calibration tray by controlling a camera; a tray position computing part for computing a tray position of the first calibration tray within a captured image which the shooting part shot; a hand position acquisition part for acquiring a hand position indicative of a position of the hand robot of when the hand robot installs onto the first calibration tray a first transported article used for calibration; a calibration part for computing a calibration data based on the tray position and the hand position; and a transported article installing part which, when the mobile robot reached a predetermined arrival area, controls, based on the calibration data, the hand robot so as to install a second transported article onto a second tray, the second tray which the mobile robot being provided with.

Abstract: A parallel kinematics mechanism is provided for uses such as robotics or machining. The mechanism has various limbs designed as elbow-linkages, at least some of which are actuatable, for moving an end component with multiple degrees of freedom. The mechanism advantageously facilitates an improved workspace-to-footprint ratio and a closed-form solution for the forward kinematics. The mechanism comprises a joint assembly having a plurality of revolute joints for connecting to at least three limbs. In various embodiments of the invention, the end component has three, four, five and six degrees of freedom.

Abstract: There is provided an industrial robot having no interference of a cable for an end effector or the like with a peripheral apparatus. An end effector 5 is fixed to a wrist flange 4 through an intermediate member 6. The intermediate member 6 takes the shape of a crankshaft in which a first flange 6a attached directly to the wrist flange 4, a second flange 6b provided at a predetermined interval in parallel with the first flange 6a and attached directly to the end effector 5, and two members 6c and 6d for coupling the first and second flanges 6a and 6b are arranged symmetrically.

Abstract: A robotic arm (10) for use with a pharmaceutical unit of use transport and storage system (200) comprises a base plate (14) with a first cam track segment (16) and a second cam track segment (18). A first arm segment (20) is rotatably attached to the base plate (14) and a second arm segment (26) is rotatably attached to the first arm segment (20) and includes a cam track follower (110) that engages with the first and second cam track segments (16, 18) to guide the movement of the second arm segment (26). A platform (36) is secured to an end of the second arm segment (26) and is adapted to engage a product (214). A series of orientation sprockets (102, 124, 126, 142) and drive chains (148, 150) cooperate to maintain the platform (36) rearwardly oriented as the arm (10) extends from a retracted position to an extended position.

Abstract: A robotic arm assembly (101) is provided which comprises a hub (103), a first arm segment (105) which is attached to the hub, and a second arm segment (107) which is attached to the first arm segment such that said second arm segment can rotate at least partially about its longitudinal axis.

Abstract: A hemispherical goniophotometer is disclosed, in which two pivoting arms are articulated on a revolving rotating arm and are each fitted with a measurement head. The geometry of the arrangement is chosen such that the measurement heads can move along the envelope surface of a hemisphere during rotating of the rotating arm through 360° and pivoting of the pivoting arms through 180°.

Abstract: Herein disclosed is a robot arm mechanism comprising a first arm link mechanism and a second arm link mechanism, a robot arm driving mechanism for driving the first arm link mechanism and the second arm link mechanism, and a link retaining mechanism for pivotably retaining the first arm link mechanism and the second arm link mechanism, in which a third arm link and a fourth arm link of the first arm link mechanism are kept forward in a first rotation direction, in which the first arm link mechanism and the second arm link mechanism are extended, thereby enabling to prevent the quadric crank chain constituting the robot arm mechanism from being flattened out while the first arm link mechanism and the second arm link mechanism are extended, and improving resistance to deformation, in comparison with the conventional robot arm mechanism.

Abstract: An industrial delta robot with an arm system rotatable in space and including a base section, a moveable plate, several multi-jointed pull rods and a telescopic axle arranged between the base section and the moveable plate, opposite ends of the pull rods and of the telescopic axle being connected with the base section and the moveable plate respectively, and the telescopic axle comprising an inner axle and an outer tube arranged on the inner axle and displaceable in a longitudinal direction where a pair of end-to-end torsional rigid bushings are arranged in a stationary manner on the outer tube in which the inner axle is mounted to be displaceable, the bushings being spaced apart at confronting inner ends to form a transversely extending lubrication pocket for continuous lubrication of the inner axle during movement relative to the bushings.

Abstract: A dual spherical ball clamp is employed to allow for pivotal adjustment of a robotic arm to support an object in a desired position. The clamp is formed by a pair of clamp halves bolted together to form a pair of sockets. Each socket receives a spherical ball of an arm. The faces of the dual spherical ball clamp are slightly inclined outwardly with respect to the lower surface of the dual spherical ball clamp to provide for additional range of motion of the arms.

Abstract: A robotic arm (10) for use with a pharmaceutical unit of use transport and storage system (200) comprises a base plate (14) with a first cam track segment (16) and a second cam track segment (18). A first arm segment (20) is rotatably attached to the base plate (14) and a second arm segment (26) is rotatably attached to the first arm segment (20) and includes a cam track follower (110) that engages with the first and second cam track segments (16, 18) to guide the movement of the second arm segment (26). A platform (36) is secured to an end of the second arm segment (26) and is adapted to engage a product (214). A series of orientation sprockets (102, 124, 126, 142) and drive chains (148, 150) cooperate to maintain the platform (36) rearwardly oriented as the arm (10) extends from a retracted position to an extended position.

Abstract: A hex-axis horizontal movement dynamic simulator is aimed at Modular Design without hydraulic or pneumatic system but which were conventionally used in the so called Stewart Platform; this dynamic simulator comprises three sets of movement control unit with symmetrical structure located at the positions relative to each other forming three sides of an equilateral triangle, and a load-carrying platform which connected to the three movement control by means of three sets of universal-joint yoke mechanism each relative position located on the load-carrying platform are each other arranged to form as three sides of an equilateral triangle too; with this type of arrangement, this dynamic simulator have a 6-degree of freedom motion when a sets of movement control unit makes different rectilinear motion, the load-carrying platform will generate a combination of spatial translation motion and angular motion.

Abstract: The screen-printing machine (10) comprises: a print station (12); at least one support surface (40A, 40B) for supporting the objects away from the print station (12); and at least one transfer device (18, 20) for transferring an object, which transfer device comprises a manipulator arm (54) equipped with an end clamp (56), the arm (54) being hinged relative to the support surface (40A, 40B) about a pivot axis (Z1-Z1) and the clamp (56) being hinged relative to the arm (54) about a tilt axis. The pivot axis (Z1-Z1) of the arm (54) defines with the normal to the support surface (40A, 40B) a non-zero angle of inclination that is less than 45°. Application to printing flasks.

Abstract: A linkage mechanism for a pick and place robot includes two rotatable drive members mounted on a base and connected to a platform by a respective two element linkage. The mid point of the two element linkage has a bell crank, the arms of which are connected to first and second location links anchored respectively at the base and platform. The platform may be configured to carry various implements, and the mechanism permits movement thereof in two dimensions by selective motion of the drive members.

Abstract: A two-arm transfer robot includes a swivel base arranged to swivel about a vertical swivel axis, and a pair of link arm mechanisms attached to the swivel base. These two link arm mechanisms are symmetrical in structure and function with respect to the swivel axis. A first hand member is supported by one of the link arm mechanisms for carrying a work, while a second hand member is supported by the other link arm mechanism for carrying a work. The first hand member and the second hand member are horizontally movable at the same height without interfering with each other.

Abstract: A manipulator comprises an operation command unit provided with an attitude adjusting unit and an end effector control unit, a connecting unit having one end connected to the operation command unit, a working unit connected to the other end of the connecting unit and provided with an end effector and a support unit supporting the end effector for motions, and a control unit that transmits an operation command provided by the attitude adjusting unit to the support unit to adjust the attitude of the end effector and transmits an operation command provided by the end effector control unit to the end effector to operate the end effector. The support unit includes a first joint capable of turning about a first axis perpendicular to the center axis of the connecting unit, and a second joint capable of turning about a second axis perpendicular to the first axis. The end effector can be turned for rolling about an axis substantially parallel to the second axis of the second joint.