Abstract: In a system which includes a driven shaft that has limited angular rotation capabilities from a start position clockwise and counterclockwise through a common overlapping angular region, a device for enabling the determination of which desired direction the shaft should be rotated from the region in order to return to the start position including a first member connected for motion with the shaft rotation and a second member mounted for independent motion when moved by the first member in a first direction, the second member being held in the start position with motion of the first member in a second direction, and a sensor to sense the presence of the second member in the start position as an indication of the desired direction.

Abstract: A control moment gyroscope for providing directional control in a spacecraft. The control moment gyroscope has a rotor which is electrostatically or magnetically supported within a gimbal housing so as not to touch any of the interior surfaces of the housing. The housing is mounted on a gimbal support which in turn is mounted on the spacecraft. Connected to the gimbal housing is a torque motor which rotates the housing around a gimbal axis. In order to induce a direction changing torque on the spacecraft, the rotor is first spun about its rotor axis. A torque is then induced on the rotor about the output axis. This induced torque will cause the rotor to precess about the gimbal axis which the torque motor follow. The torque induced around the output axis is transferred directly to the spacecraft.

Abstract: A magnetic actuator for providing a single-axis, noncontacting force capability with unconstrained cross-axis mobility utilizes flux feedback force linearization. Electromagnets cooperating with an armature suspended therebetween are energized by a bias flux and a signal derived from flux densities sensed in the air gaps. The bias flux density may be optimized to minimize the peak power required by the actuator. The flux density signals are applied in a closed force loop to provide a net force directly proportional to the commanded flux.