Singularities in Axisymmetric Vectoring Exhaust Nozzle and a Feasible Singularity-Free Approach

Abstract

The singularities are the inherent disadvantage of parallel manipulators, which negatively influence the static properties and motion concreteness of parallel manipulators. An axisymmetric vectoring exhaust nozzle (AVEN), which turn and/or vector the exhaust flow and thrust of the gas turbine engine powering the aircraft, is driven by a symmetrical parallel manipulator to vector the exhaust nozzle universally. The serious negative influences of the singularities existing in the AVEN on the safety and maneuverability of the aircrafts have not been paid enough attention or aware of by the experts in the field. In this paper, two kinds of singularities existing in the AVEN for the nozzle vectoring drive mechanism of the parallel manipulator and the suspending mechanism of the divergent flaps are analyzed at first. To solve these singularities problem and ensure the safety of the aircrafts equipped with the AVEN, a feasible singularity-free approach for parallel manipulators applied in aerospace engineering via adjusting the input kinematic parameters is proposed.