Abstract: An apparatus and method of controlling an electric motor (26) having a rotor (34) that is formed from a series of laminations (48) and has a plurality of rotor poles (36) and a stator (30) that encircles the rotor (34) and has a plurality of stator poles (32), each with a respective stator winding (38). A first sensor (46) senses actual inductance in the respective stator winding (38). A second sensor (46) senses a position of the rotor (34) relative to the stator (30). A controller (42) determines a reference inductance based on the rotor position signal, determines a difference between the actual inductance and the reference inductance, and prevents further energization of the stator windings (38) when the difference exceeds a predetermined amount.

Abstract: An electronic power assisted steering system and method wherein vehicle operating parameters, such as steering rack rate and position, are employed to predict future current requirements of the power assisted steering system, and adjust vehicle operating parameters, such as engine and alternator systems, to assure the appropriate power supply to the power assisted steering system without voltage peaks or sags.

Abstract: An electronic power assisted steering system and method wherein vehicle operating parameters, such as steering rack rate and position, are employed to predict future current requirements of the power assisted steering system, and adjust vehicle operating parameters, such as engine and alternator systems, to assure the appropriate power supply to the power assisted steering system without voltage peaks or sags.

Abstract: An improved vehicle steering apparatus (10) includes an electric motor (28) which is continuously energized during operation of the vehicle. A pair of clutch assemblies (42 and 44) are connected with a steering shaft (48) which extends from the vehicle steering wheel (12) to steering gear (14) connected with steerable vehicle wheels (16 and 18). A drive assembly (38) continuously transmits force from the motor (28) to the clutch assemblies (42 and 44) during operation of the vehicle. Upon turning of the steering wheel (12), a control unit (56) provides an output to an electromagnet (102) in one of the clutch assemblies (42 or 44) to energize the electromagnet. Energizing the electromagnet (102) increases the resistance of a rheological fluid (98) in the clutch assembly (42 and 44) to shear.

Abstract: A control arrangement for an electric assist steering system having a variable reluctance motor (26) includes sensing (54) motor position and sensing (110) applied steering torque. A controller determines a desired motor torque assist value in response to the applied steering torque. A plurality of look-up tables are provided having a plurality of motor current values versus motor position values stored therein. The stored motor current values are functionally related to motor position values. The controller selects a first (T1) and second (T2) torque look-up table from the plurality of look-up tables. The first look-up table corresponds to a torque value less than the desired motor torque assist value. The second look-up table corresponds to a torque value greater than the desired motor torque assist value. A first motor current value (I1) is determined by interpolating between two current values corresponding to two motor positions stored in the first look-up table closest to the sensed motor position.