Xudong Hu

Research on the generation of trajectory for shoe upper spraying based on structured light

The key problem in automatic shoe upper spraying system is how to get a reliable trajectory for spraying. To extract information of shoe upper and generate the trajectory for shoe upper spraying quickly, a method based on computer vision with structured light is described. After scanning a shoe lasted upper with the sensor of structured light and CCD camera, basic information of shoe upper rendered by three-dimensional point-cloud, which are located on the underside of shoe upper, can be extracted. To render the underside of shoe upper more obviously, 3D scan curves and a closed contour line are interpolated as B-spline curves. After approximately calculating the offset curve of contour line on the underside of shoe upper, the trajectory for shoe upper spraying could be generated. According to the above mentioned method, an experimental facility system is constructed and corresponding software is developed. Results show that the trajectory can be generated quickly and steadily. Moreover, the trajectory is successfully applied in a shoe upper spraying system with Staubli industrial robot. Thus, this method is validated effectively and feasibly.

Two Novel Spherical 3-DOF Parallel Manipulators With Circular Prismatic Pairs

Two novel spherical 3-DOF (degrees of freedom) parallel manipulators with circular prismatic pairs are proposed. One is 3-PC (RR)N parallel mechanism, where PC denotes a circular prismatic pair, (RR)N denotes two revolute pairs whose axes intersect at a common point N. The other is 3-PC RN S parallel mechanism. All the revolute axes in three limbs intersect at a common point N. The three circular prismatic pairs can be actuated. Mobility and singularity of this mechanism is analyzed via screw theory. Due to the circular prismatic pair, the rotational DOF of the moving platform about the z axis is decoupled from the other two rotational DOFs.Copyright

Jacobian Derivation of 5-DOF 3R2T Parallel Mechanisms

This paper presents a method for the Jacobian derivation of 5-DOF 3R2T PMs (parallel mechanisms), where 3R denotes three rotational DOFs (degrees of freedom) and 2T denotes two translational DOFs. First the mobility analysis of such kind of parallel mechanisms is reviewed briefly. The Jacobian matrix of the single limb kinematic chain is obtained via screw theory, which is a 6 × 5 matrix. Then it is shown that the mobility analysis of such kind of PM is important when simplifying the 6 × 5 matrix into a 5 × 5 Jacobian matrix. After obtaining the 5 × 5 Jacobian matrix for each limb, a 5 × 5 Jacobian matrix for the whole mechanism can be established.Copyright