Linear motion analysis for a novel 4-DOF parallel kinematic machine

Abstract

Motion accuracy is significantly influenced by nonlinear behavior of parallel mechanisms. In this paper, an interpolation algorithm suitable for linear motions of a novel 4-DOF parallel kinematic machine is developed. In this interpolation scheme, velocity and orientation deviations are realized along with path nonlinearity of mechanism. Simulations showed that this algorithm has the capability of sustaining the kinematical constraints and maintaining the nonlinear error below the specified tolerances. Furthermore, to evaluate the linear motion capability of presented 4-DOF parallel mechanism, two digital data loggers recorded the nonlinear error during motion of end effector with pre-defined paths having various lengths and locations in workspace. Results indicated that the developed algorithm based on reducing the kinematic nonlinearity produces more accurate motions.