A head mechanism includes a base connectable to a body of a robot, a mounting member arranged above the base, a connecting member rotatably connected to the base and the mounting member. The connecting member, together with the mounting member, is rotatable relative to the base about a first axis, and the mounting member is rotatable relative to the connecting member about a second axis. The first axis and the second axis extend in different directions. The head mechanism further includes two first actuating mechanisms fixed to the base, and the two first actuating mechanisms are configured to drive the mounting member to rotate with respect to the base.

A parallel link apparatus includes: a base section; three or more deployment sections that extend radially from the base section and that are pivotable with end parts coupled to the base section being pivot axes; arm sections that are coupled to end parts, of the respective deployment sections, that are on opposite sides of the end parts coupled to the base section, and are pivotable with respect to the deployment sections and expandable and contractible in one direction independently of each other; and a movable section coupled to each of second ends, of the arm sections, that are on opposite sides of first ends, of the arm sections, coupled to the deployment sections.

A link actuation apparatus that actuates a parallel link mechanism where a spherical drive mechanism is constructed includes a controller configured to calculate, based on spherical trigonometry, an attitude of a second link hub from angles β.sub.A1 and β.sub.A2 that represent the attitude of a first end link member with respect to a first link hub in two of at least three link mechanisms. The link actuation apparatus capable of performing forward transformation in real time is thus provided.

A link actuation apparatus that actuates a parallel link mechanism where a spherical drive mechanism is constructed includes a controller configured to calculate, based on spherical trigonometry, an attitude of a second link hub from angles β.sub.A1 and β.sub.A2 that represent the attitude of a first end link member with respect to a first link hub in two of at least three link mechanisms. The link actuation apparatus capable of performing forward transformation in real time is thus provided.

The present invention relates to a class of over-constrained two-rotation parallel mechanism with same kinematics, which comprises a base, a moving platform and four branches connecting the base and the moving platform, wherein the base and the moving platform are equilateral triangles, both ends of each of the first branch, the second branch and the third branch are respectively connected to end points of the base and the moving platform, both ends of the fourth branch are respectively connected to center points of the base and the moving platform, the first branch and the third branch both consist of a first rotating pair. The parallel mechanism of the present invention has a large rotation space and high rigidity, and can be used for positioning equipment such as missile launchers.

The present invention relates to a class of over-constrained two-rotation parallel mechanism with same kinematics, which comprises a base, a moving platform and four branches connecting the base and the moving platform, wherein the base and the moving platform are equilateral triangles, both ends of each of the first branch, the second branch and the third branch are respectively connected to end points of the base and the moving platform, both ends of the fourth branch are respectively connected to center points of the base and the moving platform, the first branch and the third branch both consist of a first rotating pair. The parallel mechanism of the present invention has a large rotation space and high rigidity, and can be used for positioning equipment such as missile launchers.

A three-rotational-degree-of-freedom connection mechanism required for a robot that can make motion similar to a human has a simple structure, and there is no restriction on motion within a movable range. The three-rotational-degree-of-freedom connection mechanism includes a joint connecting a second member rotatably to a first member with three rotational degrees of freedom including rotation around a torsion axis, three actuators each including variable length links having a variable length, and power sources for generating force changing the lengths of variable length links and three first-member-side link attaching units provided in first member and the second-member-side link attaching units provided on the second member such that variable length links having a twisted relationship with respect to a torsion axis exist in each state within a movable range of joint.

A three-rotational-degree-of-freedom connection mechanism required for a robot that can make motion similar to a human has a simple structure, and there is no restriction on motion within a movable range. The three-rotational-degree-of-freedom connection mechanism includes a joint connecting a second member rotatably to a first member with three rotational degrees of freedom including rotation around a torsion axis, three actuators each including variable length links having a variable length, and power sources for generating force changing the lengths of variable length links and three first-member-side link attaching units provided in first member and the second-member-side link attaching units provided on the second member such that variable length links having a twisted relationship with respect to a torsion axis exist in each state within a movable range of joint.

A robot includes elbows connecting forearms rotatably to upper arms with two rotational degrees of freedom. The elbow includes: an elbow joint connecting the forearm and the upper arm with two rotational degrees of freedom; an elbow drive main link; an elbow drive auxiliary link; a forearm-side main link attaching unit attached with one end of the elbow drive main link with two rotational degrees of freedom, and provided in the forearm; an elbow-drive-main-link-side auxiliary link attaching unit attached with one end of the elbow drive auxiliary link with two rotational degrees of freedom, and provided on the elbow drive main link; and two linear actuators for moving two upper-arm-side link attaching units each attached with the other end of either the elbow drive main link or the elbow drive auxiliary link with two rotational degrees of freedom, and provided so as to be movable along the upper arm.

A robot includes elbows connecting forearms rotatably to upper arms with two rotational degrees of freedom. The elbow includes: an elbow joint connecting the forearm and the upper arm with two rotational degrees of freedom; an elbow drive main link; an elbow drive auxiliary link; a forearm-side main link attaching unit attached with one end of the elbow drive main link with two rotational degrees of freedom, and provided in the forearm; an elbow-drive-main-link-side auxiliary link attaching unit attached with one end of the elbow drive auxiliary link with two rotational degrees of freedom, and provided on the elbow drive main link; and two linear actuators for moving two upper-arm-side link attaching units each attached with the other end of either the elbow drive main link or the elbow drive auxiliary link with two rotational degrees of freedom, and provided so as to be movable along the upper arm.