The present invention provides a motor comprising: a rotating shaft; a rotor including a hole through which the rotating shaft is inserted; and a stator disposed outside the rotor, wherein the rotor comprises a rotor core surrounding the rotating shaft, and a plurality of magnets coupled to the rotor core, the magnets are disposed such that each two magnets, adjacent to each other in the axial direction of the rotating shaft, have a predetermined spacing therebetween, and the sum of the spacings is 0.04 to 0.07 times the axial length of the stator.

A motor control system shorts motor windings of a motor by using enhancement metal-oxide-semiconductor field-effect transistors (MOSFETs) so that the motor generates braking torque when all or some electric control units of the motor are disabled or failed. The motor control system comprises: a motor comprising a plurality of motor phase terminals; a plurality of electric control units electrically connected to the motor and configured to control the motor, wherein the electric control units configured to output control signals, respectively; a plurality of power sources, each of the power sources electrically connected to a respective one of the electric control units; and a shorting circuit connected between the power sources and the motor, the shorting circuit configured to selectively short the motor phase terminals in response to one or more of the control signals of the electric control units.

A rotation detection apparatus, a rotation angle detection apparatus are provided which allow appropriate detection of an abnormality in a portion that detects rotation of a rotating shaft. A first arithmetic circuit calculates a rotating direction and a number of rotations of the rotating shaft based on a change in a combination of positivity and negativity of a first electric signal (first sine signal) and a third electric signal (first cosine signal). A second arithmetic circuit calculates a rotating direction and a number of rotations of the rotating shaft based on a change in a combination of positivity and negativity of a second electric signal (second sine signal) and a fourth electric signal (second cosine signal). An abnormality determination circuit determines whether each of the first and second arithmetic circuits and is abnormal based on the two rotating directions and calculated by the first and second arithmetic circuits respectively.

An apparatus for controlling an MDPS system including: an autonomous driving cancellation determination unit configured to determine whether to cancel autonomous driving, using column torque passed through a band stop filter, under an autonomous driving condition; and a signal processing unit configured to calculate command steering angle acceleration information using command steering angle information outputted from an autonomous driving system. When the steering angle acceleration information is equal to or greater than a predetermined reference value, the autonomous driving cancellation determination unit may determine that urgent steering is performed by the autonomous driving system, and forbid cancellation of the autonomous driving.

An electric power steering device includes a composite metal member. The composite metal member is formed by laminating a plurality of metal plates that have different thermal expansion coefficients. The composite metal member is capable of causing a worm shaft to oscillate and be displaced away from a worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become higher than a reference temperature. The composite metal member is also capable of causing the worm shaft to oscillate and be displaced towards the worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become lower than the reference temperature.

An electric power steering device includes a composite metal member. The composite metal member is formed by laminating a plurality of metal plates that have different thermal expansion coefficients. The composite metal member is capable of causing a worm shaft to oscillate and be displaced away from a worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become higher than a reference temperature. The composite metal member is also capable of causing the worm shaft to oscillate and be displaced towards the worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become lower than the reference temperature.

An electric power steering apparatus that calculates a first current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the first current command value, including: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end, wherein an offset is given to input or output of the viscoelastic model for preventing an overheat, resulting in suppressing a rack end hitting.

[Problem]

An object of the present invention is to provide a high-performance electric power steering apparatus that constitutes a control system based on a physical model, constitutes a model following control that an output (a distance to a rack end) of a controlled object follows-up to a reference model, eliminates or reduces the occurrences of a noisy sound and a shock force at an end hitting without giving any uncomfortable steering feeling to a driver, and reduces the end hitting.

[Means for solving the problem]

The present invention is the electric power steering apparatus that calculates a current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the current command value, comprising: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end so as to suppress a rack end hitting.

When relative positions of cages are changed from first positions to second positions, rollers are moved toward each other against an elastic biasing force of an elastic member such that an off state is achieved in which the rollers are disengaged from a cam surface or an inner peripheral surface portion to have a clearance therefrom. When the relative positions of the cages are changed from the second positions to the first positions, the rollers are moved away from each other by the elastic biasing force such that an on state is achieved in which one of the rollers on a downstream side engages with the cam surface or the inner peripheral surface portion without any clearance while the other of the rollers on an upstream side has a clearance from the cam surface or the inner peripheral surface portion.

Provided are a driving assistance apparatus and a steering control method thereof, which are capable of reducing impact on a steering wheel. The driving assistance apparatus includes a steering sensor that measures a steering manipulation signal based on a driver's manipulation of a steering wheel during control of a parking assistance device; and a control unit that, when the steering manipulation signal measured by the steering sensor is received, stops the control of the parking assistance device, changes a control torque value, which corresponds to a required steering angle when the control of the parking assistance device is stopped, to a target torque value based on the driver's manipulation of the steering wheel, wherein a torque variation is changed at a preset slope or for a preset time.