High-precision five-axis machine for high-speed material processing using linear motors and parallel-serial kinematics

The paper describes some details of the mechanical and kinematics design of a five-axis mechanism. The design has been utilized to physically realize an industrial-scale five-axis milling machine that can carry a three KW spindle. However, the mechanism could be utilized in other material processing and factory automation applications. The mechanism has five rectilinear joints/axes. Two of these axes are arranged traditionally, i.e. in series, and the other three axes utilize the concept of parallel kinematics. This combination results in a design that allows three translational and two rotational two-mode degrees of freedom (DOFs). The design provides speed, accuracy and cost advantages over traditional five-axis machines. All axes are actuated using linear motors. <br /

Uncoupled actuation of pan-tilt wrists

Using algebraic properties of displacement (or rigid-body motion) subsets, the paper introduces new two-degree-of-freedom (2-DOF) nonoverconstrained orientation mechanisms. The angles of pan and tilt are also referred to as the angles of precession psi and nutation theta, respectively, employing the standard terminology of Enter angles. A serial array of two revolute pairs provides the kinematic constraint of an end-effector. For instance, the first axis of rotation is fixed vertically, and the second axis rotates around the first axis, remaining parallel to the horizontal plane. Such a 2-DOF wrist is fit for orienting various devices like telescopes, cameras, antennas, etc. The first axis is fixed, and can be actuated by any powerful heavy servomotor. The paper discloses new mechanisms that allow the actuation of the second movable axis by a fixed servomotor. Moreover, the actuation of the movable axis is not a function of the pan psi. In other words, the pan and the tilt are controlled independently or in a fully uncoupled manner

Uncoupled actuation of pan-tilt wrists

Using algebraic properties of displacement (or rigid-body motion) subsets, the paper introduces new two-degree-of-freedom (2-DOF) nonoverconstrained orientation mechanisms. The angles of pan and tilt are also referred to as the angles of precession psi and nutation theta, respectively, employing the standard terminology of Enter angles. A serial array of two revolute pairs provides the kinematic constraint of an end-effector. For instance, the first axis of rotation is fixed vertically, and the second axis rotates around the first axis, remaining parallel to the horizontal plane. Such a 2-DOF wrist is fit for orienting various devices like telescopes, cameras, antennas, etc. The first axis is fixed, and can be actuated by any powerful heavy servomotor. The paper discloses new mechanisms that allow the actuation of the second movable axis by a fixed servomotor. Moreover, the actuation of the movable axis is not a function of the pan psi. In other words, the pan and the tilt are controlled independently or in a fully uncoupled manner