A mover is configured to be electromagnetically propelled along a track in a linear motor track system with a force that is calculated to include compensation for gravity. A multi-axis accelerometer arranged in each segment of the track can detect an orientation or angle of the track segment for determining gravity with respect to the particular section. As a result, if the track is at an incline, such as a ramp, a desired force for moving a mover along the track can be compensated to include gravity due to the incline for achieving a desired motion result. In addition, the detected orientation of the track can be compared to an expected orientation stored by a control program to avoid a loss of performance due to physical changes in the track not matching an expected/programmed configuration of the track.

A multi degree-of-freedom electromagnetic machine includes an outer case, an inner case, a stator, stator windings, a voice coil winding, a tilt magnet, a rotor, and rotor magnets. The inner case is disposed within an inner cavity of the outer case and is mounted to rotate relative to the outer case about one or more rotational axes. The stator is fixedly mounted within the inner case, and the stator windings are wound thereon. The voice coil winding is fixedly coupled to either the inner surface of the outer case or the outer surface of the inner case. The tilt magnet is fixedly coupled to either the outer surface of the inner case or the inner surface of the outer case. The rotor is rotationally mounted within the inner case and is operable to rotate, relative to the stator, about a rotational axis.

A curvilinear track section of a linear motor system for use with a moving element including a machine readable medium, the track section including: a curvilinear track portion having a predetermined curved shape; a plurality of sensors provided to the track portion such that each of the plurality of sensors is oriented perpendicular to the direction of motion while the plurality of sensors are placed along the direction of motion and the plurality of sensors are configured such that the machine readable medium will overlap at least two of the plurality of sensors at the same time; and a processor configured to determine a position of the moving element on the curvilinear track section based on the readings from the sensors.

A curvilinear track section of a linear motor system for use with a moving element including a machine readable medium, the track section including: a curvilinear track portion having a predetermined curved shape; a plurality of sensors provided to the track portion such that each of the plurality of sensors is oriented perpendicular to the direction of motion while the plurality of sensors are placed along the direction of motion and the plurality of sensors are configured such that the machine readable medium will overlap at least two of the plurality of sensors at the same time; and a processor configured to determine a position of the moving element on the curvilinear track section based on the readings from the sensors.

A positioning system, including: a first plate; a second plate coupled to the first plate and pivotable about an axis; a pair of voice coil actuators configured to rotate the second plate about this axis; and a processor configured to drive currents to the pair of voice coil actuators; wherein the pair of voice coil actuators comprises a first and second magnet structures mounted on the first plate at equal and opposite distance from the axis, and a first and second coils mounted on the second plate and positioned such that the respective first and second magnet structures move in and out of the first and second coils when the second plate rotates about the axis; wherein each of the first and second magnet structures substantially conforms to an arc having a center at the axis and a radius equal to the distance of the magnet structure from the axis.

A method for manufacturing a curvilinear track section including: forming a curvilinear track portion; cutting out a first slot grouping from an exterior edge of the curvilinear track portion, wherein the first slot grouping is at a first predetermined angle; cutting out a second slot grouping from the exterior edge of the curvilinear track portion, wherein the second slot grouping is at a second predetermined angle; and inserting motor units into the first and second slot groupings. A curvilinear track section having: a curvilinear track portion; a first slot grouping formed in an exterior edge of the curvilinear track portion, wherein the first slot grouping is at a predetermined angle relative to the exterior edge; a second slot grouping formed in the exterior edge of the curvilinear track portion, wherein the second slot grouping is at a second predetermined angle; and motor units inserted into the first and second slot groupings.

An electromagnetic actuator is described the actuator comprising: a magnet assembly comprising: an array of permanent magnets arranged in a first direction and configured to generate, outside the magnet assembly, a spatially varying magnetic field distribution in the first direction; a ferromagnetic member onto which the array of permanent magnets is mounted; a coil assembly, at least partly arranged in the spatially varying magnetic field distribution, configured to co-operate with the magnet assembly to generate an electromagnetic force;
wherein a thickness of the array of permanent magnets in a second direction perpendicular to the first direction varies along the first direction and wherein a thickness of the ferromagnetic member in the second direction varies along the first direction such that a combined thickness of the array of permanent magnets and the ferromagnetic member in the second direction is substantially constant along the first direction.

Drive coils in sections of a linear motor track that are normally used to electromagnetically propel movers along the track when such movers are nearby can be used to generate a mid-bus voltage for the section when not being used to propel movers. Such drive coils not being used to propel movers are considered idle and available for mid-bus voltage generation. The mid-bus voltage, and a full-bus voltage from which the mid-bus voltage is derived, in turn, can be applied across other drive coils that are near movers with varying polarities and magnitudes to propel movers along the track. Track sensors can be positioned along the track to detect presences or absences of movers with respect to drive coils for determining propulsion of such movers or generation of the mid-bus voltage. Accordingly, power supplies can be used more efficiently by not requiring them to generate mid-bus voltages in addition to full-bus voltages and DC references.

According to one embodiment, a magnetic disk device includes a base that includes a bottom wall and side walls standing along a circumference of the bottom wall, a housing that includes a cover facing the bottom wall and closing the base, an actuator assembly that is housed inside the housing and is rotatable around a rotation axis, a head movably supported by the actuator assembly, a control circuit board provided outside of the housing, a first sensor disposed on the control circuit board, and a second sensor disposed inside the housing.

A moving magnet voice coil actuator includes a bobbin that defines a non-straight opening for receiving a magnetic piece. The bobbin may be additively manufactured to a desired shape. The moving magnetic piece may be a curved piece that has a shape that corresponds to the shape of the opening. The magnetic piece may include a stack of magnets, which may be tapered, to allow limited tilting movement of the magnetic piece within the opening. The actuator may be part of a pair of actuators for tilting an object, for example a mirror, about a pivot point. The pair of actuators may be part of a system that includes an additional pair of actuators configured to tilt the object in a second direction that is different from the first direction.