Design of 25kW Redundant Linear Electro-Mechanical Actuator for Thrust Vector Control Applications

Linear electro-mechanical actuators are finding increased use in the field of thrust vectoring of launch vehicles. Earlier, linear electro-hydraulic actuators were used especially in the lower stages of the launch vehicles where there is a requirement for large actuation forces. However, electro-mechanical actuators are being scrutinized for this purpose in an effort to provide lighter, cleaner and more reliant control actuators. The design philosophy, actuator configuration and selection of motor to meet the load dynamics, bearings, roller screw & sensor are discussed. Design verification of critical components like roller screw and rod end bearing assembly for their structural aspects is explained. Details of redundancy management scheme for the individual functional elements and the actuator qualification program are also covered. Keywords—high power electromechanical actuator, redundancy management