Abstract: An active suspension system for a suspended device. The system has an electromagnetic actuator that produces force on the suspended device and that is powered by a power source, and a control system that provides control signals that cause the electromagnetic actuator to exert force on the suspended device. The control system is adapted to receive a turn-off signal that results in disabling the electromagnetic actuator from producing force on the suspended device. When the control system receives a turn-off signal it provides actuator turn-off control signals that cause the force exerted by the electromagnetic actuator to progressively transition to zero over a transition time period.

Abstract: An architecture shape memory alloy (SMA) actuators is presented called Segmented Binary Control (SBC). Instead of controlling the phase transition of the entire SMA wire as a single plant, we divide the SMA wire into many segments, each of which is controlled separately as an ON-OFF finite-state process. SBC produces a displacement as the addition of small displacements generated by the individual segments. Furthermore, the segmented architecture of SMA wires is extended to a multi-axis actuator array by arranging them in a two-dimensional array, so that the multi-axis control may be streamlined and coordinated. Moreover, the 2-D segmentation can be so designed that coordinated gross motion as well as independent fine movements may be generated with minimum complexity and minimum control loops.