Abstract: The present invention introduces a new concept of applying a parallel mechanism in automated fiber placement for aerospace part manufacturing. The proposed system requirements are 4DOF parallel mechanism consisting of two RPS and two UPS limbs with two rotational and two translational motions. Both inverse and forward kinematics models are obtained and solved analytically. Based on the overall Jacobian matrix in screw theory, singularity loci are presented and the singularity-free workspace is correspondingly illustrated. To maximize the singularity-free workspace, locations of the two UPS limbs with the platform and base sizes are used in the optimization which gives a new design of a 4DOF parallel mechanism. A dimensionless Jacobian matrix is also defined and its condition number is used for optimizing the kinematics performance in the optimization process. A numerical example is presented with physical constraint considerations of a test bed design for automated fiber placement.

Abstract: The present invention introduces a new concept of applying a parallel mechanism in automated fiber placement for aerospace part manufacturing. The proposed system requirements are 4DOF parallel mechanism consisting of two RPS and two UPS limbs with two rotational and two translational motions. Both inverse and forward kinematics models are obtained and solved analytically. Based on the overall Jacobian matrix in screw theory, singularity loci are presented and the singularity-free workspace is correspondingly illustrated. To maximize the singularity-free workspace, locations of the two UPS limbs with the platform and base sizes are used in the optimization which gives a new design of a 4DOF parallel mechanism. A dimensionless Jacobian matrix is also defined and its condition number is used for optimizing the kinematics performance in the optimization process. A numerical example is presented with physical constraint considerations of a test bed design for automated fiber placement.

Abstract: An actuator (10) includes a body (12), an output member (14) slidably received in the body (12) along— a first axis (X1), an electric motor (18) arranged to set into rotation a motor shaft (20) about a, second axis (X2) and a motion conversion mechanism (22) for converting the rotary motion produced by the electric motor (18) about the second axis (X2) into a translational motion of the output member (14) along the first axis (X1). The motion conversion mechanism (22) includes a driving pulley (24) which is drivingly connected for rotation with the motor shaft (20) and an elongated mechanical transmission member which is wound onto the driving pulley (24) and is fastened at its two opposite ends to the output member (14) to draw this latter in either direction along the first axis (X1) as a result of the rotation of the driving pulley (24) in either direction. The output member (14) is shaped as a rod and is received in a cylindrical cavity (16) of the body (12) so as to project partially therefrom.

Abstract: An actuator (10) includes a body (12), an output member (14) slidably received in the body (12) along—a first axis (X1), an electric motor (18) arranged to set into rotation a motor shaft (20) about a, second axis (X2) and a motion conversion mechanism (22) for converting the rotary motion produced by the electric motor (18) about the second axis (X2) into a translational motion of the output member (14) along the first axis (X1). The motion conversion mechanism (22) includes a driving pulley (24) which is drivingly connected for rotation with the motor shaft (20) and an elongated mechanical transmission member which is wound onto the driving pulley (24) and is fastened at its two opposite ends to the output member (14) to draw this latter in either direction along the first axis (X1) as a result of the rotation of the driving pulley (24) in either direction. The output member (14) is shaped as a rod and is received in a cylindrical cavity (16) of the body (12) so as to project partially therefrom.