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Sports Performance of the 3-TPT Parallel Mechanism

YANG Hui, ZHAO Heng-hua, FU Hong-shuan

Abstract （399）

PDF （556KB）（317）

The 3-TPT parallel mechanism was studied. Through the establishment of positive solutions and negative solutions of the kinematics equations, the Jacobian matrix and its inverse matrix of the mechanism will be calculated. And on this basis, the singularity of the machine, the dexterity and the stationarity were simulated and analyzed by using the MATLAB software and the LabVIEW software.The results show that the singularity of 3-TPT parallel mechanism doesnt exist and also have better dexterity and stationarity.These provide a theoretical basis for the optimal design and control system design of parallel mechanism, and offer a design basis to determining body size and shape and position of work.

2012, 25 (3): 74-78. DOI: 10.3969/j.issn.1006-396X.2012.03.017

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Research on the Singularity of Parallel Machine Tools

WANG Chuan-qiang, ZHAO Heng-hua

Abstract （661）

PDF （567KB）（405）

The singularity of parallel machine tools was researched, which was based on the research objects of the speed matrix determinant, Jacobian matrix determinant det([WTHX]J[WTBZ]) and operability W respectively. The researches provided a basis for the design of the structural parameters about parallel machine tools.The singularity of bodies about parallel machine tools can be divided into three categories when the speed matrix determinant was put as the research object. Parallel machine tools can be judged at the singularity when det([WTHX]J[WTBZ])=0 or the operability was zero.The singularity was researched for a new type of 3-legged 3-DOF parallel machine tool when det([WTHX]J[WTBZ]) and the operability W were [KG*4]put as the research objects. The mathematical model of the [KG*4]machine [KG*4]tool [KG*4]was [KG*4]established. The [KG*4]Jacobian [KG*4]matrix [KG*4]of [KG*4]the [KG*4]machine [KG*4]tool [KG*4]were [KG*4]derived. [KG*4]The [KG*4]expressions [KG*4]of [KG*4]|det([WTHX]J[WTBZ])| and the operability W about the machine tool by Matlab had been worked out. |det([WTHX]J[WTBZ])|=W>0 and |det([WTHX]J[WTBZ])|=W≠∞ were obtained by the analysis. That is, there is no singularity about the machine tool. Besides, the machine tool has good operability. The stationarity of the machine tool was researched in the environment of Matlab. The simulation results show that the machine tool has good stationarity.

2010, 23 (2): 84-88.

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Gear's Predictor-Corrector Algorithms on Molecular Dynamics Simulation of Nanometer Grinding

ZHAO Heng-hua，CAI Guang-qi

Abstract （228）

PDF （1736KB）（293）

Nanometer grinding is the important methods of achieving the super- precision machining.The extremely thin chips can be produced by nanometer grinding. The experimental showed that the very fine chips can be down to 1 nm. Therefore molecular dynamics computer simulation can be used to analyze the mechanism of nanometer grinding.The subject which deals with the interaction between the grinding grain particles and workpiece particles was studied by the method of Gear’s predictor-corrector algorithms. The equation of motion was built up, and solved by numerical method. Then the speed and displacement of these particles were obtained.

2007, 20 (2): 63-65.