Control of an articulated spine is important for humanoids' dynamic and balanced motion. Although there have been many spinal structures for humanoids, their actuation is still limited due to the usage of geared motors for joints. This paper introduces position control of a distributed electrome-chanical spine in a vertical plane. The spine dynamics model is approximated as an open chain. Gravitational and spring torques are compensated for the control. Moreover, torque-to-current conversion for the actuator is developed. Experimental results show the implemented control of the electromechanical spine for undulatory motions.

This paper presents a distributed six-link two-dimensional electromechanical actuator that emulates a biological spine. The gearless actuator is made by stacking modules of E-shaped cores along with integrated springs. A coil excitation induces magnetic flux in the core, which produces electromechanical force in the air gap between two adjacent cores. The proposed actuator is driven by dc-dc converters with current control. Electromechanical force analysis for the proposed spine architecture with different air-gap distances and spring analysis that improve the actuator's performance are discussed. Experimental results show different biological motions with a prototype design. The prototype can produce a maximum torque of 1.4 N-m.

Electric propulsion of ships has experienced steady expansion for several decades. Since the early 20th century, icebreakers have employed the flexibility and easy control of direct current (dc) motors to provide for ship operations that split ice with back and forth motion of the ship. More recently, cruise ships have employed diesel-electric propulsion systems to take advantage of the flexibility of diesel, as opposed to steam engines, and because the electric plant can also be used for hotel loads. Research vessels, ferries, tankers, and special purpose vessels have also taken advantage of increased flexibility and fuel efficiency with electric propulsion. Today, the U.S. Navy is building an “all electric” destroyer to be named “Zumwalt,” which employs two induction motors for propulsion. There are several different classes of motors that might be considered for use in ship propulsion, ranging from dc (commutator) motors through conventional induction and synchronous motors to permanent magnet synchronous machines, doubly fed machines and superconducting alternating current (ac) and acyclic homopolar machines. This review paper describes features of some of the major classes of motor that might be used in ship propulsion.

We present simulations and demonstrate experimentally a new concept in winding a planar induction heater. The winding results in minimal ac magnetic field below the plane of the heater, while concentrating the flux above. Ferrites and other types of magnetic shielding are typically not required. The concept of a one-sided ac field can generalized to other geometries as well.