Optimal design of electromechanical actuators for active loads

The proliferation of electromechanical actuation promises reduced maintenance requirements and cost, improved efficiency and reliability, and more environmentally friendly operation. Within this paper, the issue of optimal component selection for actuator design is addressed. Optimality is defined as an engineering trade-off concerning power transfer to the load, efficiency, and torque demand. An equivalent circuit for the actuator/active load system is developed and represented in the phasor domain. Sinusoidal steady-state techniques are employed for system analysis and definition of the conditions for optimality in applications where load force and velocity profiles are known. The actuator application of thrust vector control on the Space Shuttle main engine is specifically addressed.