Mechanism and kinematical analysis of a 6-PSS parallel manipulator

Based on the screw theory, this paper calculates 6-PSS degrees of freedom for mechanism, establishes the local coordinate system, and analyzes the kinematic characteristics of mechanism. According to the input and output characteristics of parallel mechanism and the kinematic exponential product theoretic formula of serial manipulator, this paper constructs the branch chain inverse solution equation, works out the complete kinematical inverse solution for parallel mechanism, and then obtains the angles of the spherical hinge's change from the reverse data. Jacobian matrix of the mechanism can be achieved by using first order influence coefficient method. This paper solves the kinematic positive solution with numerical method, then works out the constraint equation of positive solution, and finally gets the mechanism positive solution by iterative procedure. The mechanism is simulated kinematically by ADAMS simulation software, and the kinematic inverse curve is acquired. According to the case analysis, and by comparing MATLAB inverse data, this paper verifies that the kinematic inverse solution is correct. These analytical results can provide important theoretical basis for such parallel mechanism's optimal design and control strategy.