Three-degree-of-freedom parallel mechanism type dual head for five-axis machine tools and control method

• Main Authors: CUI XUELIANG, HAN XIANGUO, CHEN WUYI
• Format: Patent
• Language: Chinese; English
• Published: 23.06.2010
• Subjects: COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOTDIRECTED TO A PARTICULAR RESULT; DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g.ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OFPARTICULAR DETAILS OR COMPONENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; TRANSPORTING

The invention relates to a three-degree-of-freedom parallel mechanism type dual head for five-axis machine tools, which comprises a static platform, a movable platform and four branch chains connected with the two platforms. A control method includes seven steps: (1) a Jacobian matrix is solved according to the inverse solution formula of the symmetric structure, and a corresponding model is established; (2) a Jacobian matrix is solved according to the inverse solution formula of the asymmetric structure, and a corresponding model is established; (3) a corresponding variable-structure controller is designed; (4) the tracking locus and external load of the dual head are set, and the internal force threshold of each branch chain is set; (5) the force feedback value of a force sensor on each non-redundant branch chain is acquired and compared with a set threshold; (6) according to the Jacobian matrix in the first step, the driving force of each motor is calculated, force control is adopted on the non-redundant b