Electro-mechanical or electromechanical systems involve both electrical and mechanical functions, and typically operate by using an electrical signal to facilitate mechanical motion or vice versa. They are used for a number of applications in UAVs (unmanned aerial vehicles), robotics and unmanned systems.
Motors & Actuators
One of the most common examples of an electro-mechanical system is the electric motor. Motors typically use the attraction or repulsion of two magnetic fields to provide rotary or linear motion. Motors are used to rotate the propellers of drones to enable them to fly, as well as for UGV (unmanned ground vehicle) wheels and a number of other unmanned vehicle subsystems. Types of motor include brushed and brushless DC motors, permanent magnet motors, and servo motors.
Motors are part of the wider group of systems known as actuators. Electromechanical actuators output linear or rotary motion, and are used to move a variety of different parts within UAV platforms. These include flight and attitude control surfaces such elevators, ailerons, flaps and fins, as well as engine throttle and fuel valves, and doors for compartments housing weapons, sensors and other payloads.
Relays are another commonly-used electro-mechanical device within drones and robotics. Electromechanical relays typically use an electromagnet to open or close a set of switches that are isolated from the magnet, thus permitting the use of a small control signal to affect the flow of much higher currents.