Dexterity Analysis of a 4-UPS-RPS Parallel Mechanism

Abstract

A novel 4‐UPS‐RPS spatial 5 degrees of freedom parallel mechanism is introduced and its dexterity measures are analysed. The stationary platform of the parallel mechanism is connected with the moving platform by the same four UPS (universal joints‐prismatic pairs‐spherical joints) driving links and a RPS (revolute joints‐prismatic pairs‐spherical joints) link. The velocity Jacobian matrix and the force Jacobian matrix of the parallel mechanism are derived, and the dimensionless velocity Jacobian matrix is established. On this basis, the three dexterity measures, including average conditional number, the smallest singular value and operation, are obtained. According to these, the square mean dexterity coefficient, which is used to comprehensively evaluate the dexterity of various configurations, is proposed. In addition, the distribution of different dexterity measures above in the workspace is analysed respectively. This research can provide an important theoretical base for the dimensional synthesis and trajectory planning for a parallel mechanism

Reliability Optimization Design of Constrained Metamorphic Mechanism Based on the Augmented Assur Groups

“…PAN [27,28] used self-adaptive genetic algorithm and fuzzy genetic algorithm to optimize the cost-tolerance model of a 6-DOF parallel robot. CHEN et al [29,30] analyzed the kinematics performance of 4-UPS-RPU parallel mechanism, and optimized its structure parameters based on the global dexterity coefficient. NI et al [31] transformed the design of tolerances into a nonlinear optimization design with constraints based on sensitivity analysis, and applied genetic algorithm to distribute the manufacturing tolerances of a parallel machine tool finally.…”

Kinetoelastodynamics Modeling and Analysis of Spatial Parallel Mechanism

“…The spatial parallel mechanism has a series of advantages, such as high speed, high acceleration, stronger bearing capacity, and higher ratio of stiffness and weight [1,2]. At present, the main development trend of spatial parallel mechanism is constantly pursuing high speed, light weight, high precision, and high stability.…”

Rigid Dynamic Model and Analysis of 5-DOF Parallel Mechanism

“…The spatial parallel mechanism, as a new-structure mechanism, has been applied in many fields, such as machine building, aerospace, and industrial robotics [1][2][3]. The rigid dynamic model and the analysis of the parallel mechanism, which form the theoretical basis of design, motor control, simulation and performance optimization [4][5][6][7][8], must be investigated.…”