Abstract: A rotor includes an inner wall and an outer wall, where the inner wall forms a space and is radially centered along a central longitudinal axis of the rotor. The rotor further includes a first magnetic pair of legs corresponding to a first pole. The first leg and a second leg of the first magnetic pair of legs are disposed within the rotor, and a first angular distance between the first leg and the second leg decreases from the outer wall to the inner wall. A second magnetic pair of legs corresponding to a second pole that differs from the first pole, a third leg and a fourth leg of the second magnetic pair of legs being disposed within the rotor to extend radially inward from the outer wall toward the inner wall, a second angular distance between the third leg and the fourth leg decreases from the outer wall to the inner wall.

Abstract: A rotor includes an inner wall and an outer wall, where the inner wall forms a space and is radially centered along a central longitudinal axis of the rotor. The rotor further includes a first magnetic pair of legs corresponding to a first pole. The first leg and a second leg of the first magnetic pair of legs are disposed within the rotor, and a first angular distance between the first leg and the second leg decreases from the outer wall to the inner wall. A second magnetic pair of legs corresponding to a second pole that differs from the first pole, a third leg and a fourth leg of the second magnetic pair of legs being disposed within the rotor to extend radially inward from the outer wall toward the inner wall, a second angular distance between the third leg and the fourth leg decreases from the outer wall to the inner wall.

Abstract: A rotor comprises a first rotor lamination and a second rotor lamination. The first rotor lamination and the second rotor lamination are configured for defining, when joined into rotor assembly, a central axis of rotation and a plurality of interior magnet pockets disposed symmetrically about the central axis of rotation, each pocket of the plurality of interior magnet pockets is configured for housing and retaining a permanent magnet. A method of forming a rotor comprises forming a first rotor lamination and a second rotor lamination, rotating the second rotor lamination about an axis of symmetry of the second rotor lamination; and mating the first rotor lamination to the second rotor lamination such that a first notch of the first rotor lamination is disposed adjacent to the first notch of the second rotor lamination.

Abstract: A motor control system is provided. The motor control system includes a motor, a position sensor, a current sensor, and a control module. The motor has a rotor and a stator. The motor generates an output torque based on a phase current applied to the motor. The output torque generated by the motor creates a torque ripple that is within a predefined range. The position sensor monitors the motor to determine a rotor position. The current sensor monitors the motor to determine the phase current. The control module is in communication with the motor, the position sensor, and the current sensor. The control module includes a lookup table that stores values of phase current commands. The control module determines a phase current command from the lookup table based on the rotor position and the phase current.

Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.

Abstract: A diagnostic system and method for an electric power steering system are provided. The diagnostic system includes a first microprocessor that determines a first relative position value indicating the relative rotational position of the rotatable shaft at the first time based on the signals from first and second position sensors. A second microprocessor determines a second relative position value indicating the relative rotational position of the rotatable shaft at the first time based on the signals from third and fourth position sensors. The first microprocessor determines whether the first relative position value is an acceptable value based on a difference between the first relative position value and the second relative position value.

Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.

Abstract: A rotor includes an inner wall and an outer wall, where the inner wall forms a space and is radially centered along a central longitudinal axis of the rotor. The rotor further includes a first magnetic pair of legs corresponding to a first pole. The first leg and a second leg of the first magnetic pair of legs are disposed within the rotor, and a first angular distance between the first leg and the second leg decreases from the outer wall to the inner wall. A second magnetic pair of legs corresponding to a second pole that differs from the first pole, a third leg and a fourth leg of the second magnetic pair of legs being disposed within the rotor to extend radially inward from the outer wall toward the inner wall, a second angular distance between the third leg and the fourth leg decreases from the outer wall to the inner wall.

Abstract: A non-contacting torque sensor comprises a magnetic flux generating rotor and a magnetic flux detecting probe. The magnetic flux generating rotor is disposed axially between a first stator and a second stator and has a radially outboard surface and plurality of N pole magnets and S pole magnets alternatingly disposed proximate the radially outboard surface. Each stator has a plurality of stator teeth, with each one of said plurality of stator teeth corresponding to a unique one of said plurality of N pole magnets and S pole magnets. The magnetic flux detecting probe is disposed at a distance from the radially outboard surface and configured for detecting variations in magnetic flux produced by the magnetic flux generating rotor to detect a change of a relative twist between the magnetic flux generating rotor and the first stator and second stator. The N pole magnets and S pole magnets are injection molded.

Abstract: An interior permanent magnet motor comprises a rotor assembly disposed within a stator assembly. The rotor assembly is configured for rotating about a central axis relatively to the stator assembly. The rotor assembly defines a plurality of magnet pockets within the rotor assembly along a radially outboard surface of the rotor assembly. Each magnet pocket is substantially rectangular in cross-sectional shape, and each magnet pocket is configured to facilitate insertion of a plurality of permanent magnets into and retention of the plurality of permanent magnets within, the magnet pocket. The rotor assembly further comprises a plurality of permanent magnet segments disposed in each magnet pocket.

Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.

Abstract: A rotor comprises a first rotor lamination and a second rotor lamination. The first rotor lamination and the second rotor lamination are configured for defining, when joined into rotor assembly, a central axis of rotation and a plurality of interior magnet pockets disposed symmetrically about the central axis of rotation, each pocket of the plurality of interior magnet pockets is configured for housing and retaining a permanent magnet. A method of forming a rotor comprises forming a first rotor lamination and a second rotor lamination, rotating the second rotor lamination about an axis of symmetry of the second rotor lamination; and mating the first rotor lamination to the second rotor lamination such that a first notch of the first rotor lamination is disposed adjacent to the first notch of the second rotor lamination.

Abstract: A non-contacting torque sensor comprises a magnetic flux generating rotor and a magnetic flux detecting probe. The magnetic flux generating rotor is disposed axially between a first stator and a second stator and has a radially outboard surface and plurality of N pole magnets and S pole magnets alternatingly disposed proximate the radially outboard surface. Each stator has a plurality of stator teeth, with each one of said plurality of stator teeth corresponding to a unique one of said plurality of N pole magnets and S pole magnets. The magnetic flux detecting probe is disposed at a distance from the radially outboard surface and configured for detecting variations in magnetic flux produced by the magnetic flux generating rotor to detect a change of a relative twist between the magnetic flux generating rotor and the first stator and second stator. The N pole magnets and S pole magnets are injection molded.

Abstract: A motor control system is provided. The motor control system includes a motor, a position sensor, a current sensor, and a control module. The motor has a rotor and a stator. The motor generates an output torque based on a phase current applied to the motor. The output torque generated by the motor creates a torque ripple that is within a predefined range. The position sensor monitors the motor to determine a rotor position. The current sensor monitors the motor to determine the phase current. The control module is in communication with the motor, the position sensor, and the current sensor. The control module includes a lookup table that stores values of phase current commands. The control module determines a phase current command from the lookup table based on the rotor position and the phase current.

Abstract: A torque sensing system having a torque sensor, and a steering system, are provided. The torque sensor includes a first rotor having apertures extending therethrough and bar magnets disposed in the apertures. The torque sensor further includes a second rotor defining an interior region with the first rotor being disposed in the interior region. The second rotor has tooth members extending toward the first rotor. The torque sensor further includes first and second Hall effect sensors disposed in an open region of the second rotor proximate to the first rotor. The first and second Hall effect sensors generate first and second signals, respectively, indicative of an amount of torque applied between the first rotor and the second rotor.

Abstract: An interior permanent magnet motor comprises a rotor assembly disposed within a stator assembly. The rotor assembly is configured for rotating about a central axis relatively to the stator assembly. The rotor assembly defines a plurality of magnet pockets within the rotor assembly along a radially outboard surface of the rotor assembly. Each magnet pocket is substantially rectangular in cross-sectional shape and is configured to facilitate insertion of a permanent magnet into, and retention of the permanent magnet within, the magnet pocket. The rotor assembly further defines at least one rotor notch disposed between each magnet pocket and the radially outboard surface.

Abstract: An actuator assembly including, a polar assembly including an inner tooth and an outer tooth, and a magnet disposed between the inner tooth and the outer tooth, the magnet operative to interact with the polar assembly to induce an electromagnetic torsion bar operative to impart a torque on a first shaft connected to the ring magnet.

Abstract: A method for designing a pole piece for a power assist steering system, includes: selecting a number of teeth, k, for the pole piece where k=n/2 and n represents an even number of poles; and selecting a ratio between an angle made by an inner tooth tip and an outer tooth tip, ?tp, and an angle made by a magnet pole width, ?mp, to provide a desired torque function for the steering system.

Abstract: A diagnostic system and method for an electric power steering system are provided. The diagnostic system includes a first microprocessor that determines a first relative position value indicating the relative rotational position of the rotatable shaft at the first time based on the signals from first and second position sensors. A second microprocessor determines a second relative position value indicating the relative rotational position of the rotatable shaft at the first time based on the signals from third and fourth position sensors. The first microprocessor determines whether the first relative position value is an acceptable value based on a difference between the first relative position value and the second relative position value.

Abstract: A torque sensing system having a torque sensor, and a steering system, are provided. The torque sensor includes a first rotor having apertures extending therethrough and bar magnets disposed in the apertures. The torque sensor further includes a second rotor defining an interior region with the first rotor being disposed in the interior region. The second rotor has tooth members extending toward the first rotor. The torque sensor further includes first and second Hall effect sensors disposed in an open region of the second rotor proximate to the first rotor. The first and second Hall effect sensors generate first and second signals, respectively, indicative of an amount of torque applied between the first rotor and the second rotor.