A vehicle steering system includes a first sensor sensing a pinion angle of a handwheel and a second sensor sensing a torsion bar windup angle. An autonomous steering module generates a steering command having an input torque signal. A steering angle controller is configured to determine a filtered handwheel acceleration based on the pinion angle and the windup angle. The steering angle controller also determines an offset torque based on the filtered handwheel acceleration. Further, the steering angle controller applies the offset torque to the input torque signal to define a refined torque signal that compensates for inertia and off-center mass of the handwheel.

A steering control device capable of transmitting road surface state to a driver is provided. An ideal vehicle model computes first spring reaction force torque based on a target pinion angle and second spring reaction force torque based on at least lateral acceleration as components of a spring component of a steering assist force. The ideal vehicle model combines the first and second spring reaction force torques with specified proportions of use to compute the spring component. The ideal vehicle model decides the proportions of use of the first and second spring reaction force torques on the basis of a distribution gain set in accordance with the difference value between the first and second spring reaction force torques. The ideal vehicle model increases the proportion of use of the second spring reaction force torque as the difference value between the first and second spring reaction force torques is increased.

A steered-angle command value calculation circuit calculates a steered-angle command value by adding a steering torque to a first assist component that is a sum of a basic assist control amount, a hysteresis control amount and a damping control amount. A steered-angle feedback control circuit calculates a second assist component by angle feedback control based on the steered-angle command value. A compensation control circuit generates the hysteresis control amount and the damping control amount based on a determination flag generated by a hand release determination circuit and indicating whether or not the steering state corresponds to a hand release state. The hand release determination circuit determines whether or not the steering state corresponds to the hand release state based on signs of a steering angle calculated by a steering-angle calculation circuit, a steering angular velocity that is a differential value of the steering angle, and a steering angle acceleration.

The present invention relates to an electronic control unit and a method for compensating for a torque steer. The electronic control unit includes: a driving torque calculation unit that calculates a drive shaft driving torque value, which is a torque value transmitted from an engine to a drive shaft; a torque steer degree calculation unit that calculates the actual driving torque value of a vehicle based on the drive shaft driving torque value, and calculates a torque steer degree by using the actual driving torque value; a compensation current calculation unit that calculates a torque steer compensation current value that compensates for the torque steer using the torque steer degree; a direction compensation unit that calculates a direction compensation current value according to a travelling direction of the vehicle; and a motor driving control unit that calculates a basic control current value using a steering angle and a steering torque value, calculates the final control current value by adding the torque steer compensation current value and the direction compensation current value to the basic control current value, and generates a control current according to the final control current value in order to supply the control current value to an electric motor.

A lane departure avoidance system disables start of steering control or terminate running steering control upon determination that a value of a at least one selected variation, which is selected from a first variation, a second variation, a third variation, and a fourth variation, is equal to or more than a corresponding threshold. The first variation is a variation of a lateral position of an own vehicle relative to lane marking lines recognized by a recognition unit, and the second variation is a variation of a yaw angle of the own vehicle relative to the recognized lane marking lines. The third variation is a variation of a curvature of the recognized lane marking lines, and the fourth variation is a variation of a pitch angle of the own vehicle.

A synchronization signal generating portion of a transmitter microcomputer generates a synchronization signal that is synchronized with a drive timing of the own microcomputer and also causes to synchronize the drive timing of microcomputers, and transmits to a receiver microcomputer. A timing corrector of the receiver microcomputer is capable of correcting the drive timing of the own microcomputer so as to synchronize with the received synchronization signal, and includes a timing determiner which determines whether the received synchronization signal is normal or abnormal. The receiver microcomputer permits the timing correction if the synchronization signal is determined to be normal in the timing determination, and prohibits timing correction and drives the motor asynchronously with the transmitter microcomputer if the synchronization signal is determined to be abnormal.

A synchronization signal generating portion of a transmitter microcomputer generates a synchronization signal that is synchronized with a drive timing of the own microcomputer and also causes to synchronize the drive timing of microcomputers, and transmits to a receiver microcomputer. A timing corrector of the receiver microcomputer is capable of correcting the drive timing of the own microcomputer so as to synchronize with the received synchronization signal, and includes a timing determiner which determines whether the received synchronization signal is normal or abnormal. The receiver microcomputer permits the timing correction if the synchronization signal is determined to be normal in the timing determination, and prohibits timing correction and drives the motor asynchronously with the transmitter microcomputer if the synchronization signal is determined to be abnormal.

A vehicle steering device includes a turning shaft held in a housing so as to be movable in the axial direction, a ball screw transmitting drive force produced by an electric motor to the turning shaft, a bearing supporting a nut, which is a component of the ball screw, so as to be rotatable relative to the housing, and annular elastic members that support side faces of the bearing in the axial direction of the turning shaft across the entire circumference, and are formed of an elastic material. The elastic members include respective first elastic portions having a first load characteristic that gently increases the ratio of compression load per a unit compression amount deforming in the axial direction of the turning shaft, and respective second elastic portions having a second load characteristic that keenly increases the ratio in comparison with the first load characteristic.

A steering system includes a rotation angle sensor that detects a signal related to an absolute steering angle, and an assist circuit that acquires the signal related to the absolute steering angle while an ignition switch is off in order to reduce battery consumption. The assist circuit includes a counter that updates a count value based on a result of detection by a first rotating direction determining unit and a second rotating direction determining unit that determine a rotating direction of a motor, and an abnormality detecting unit that detects an abnormality in absolute steering angle based on a past value and a current value of the count value in the counter.

An electric power steering apparatus is configured to provide steering assistance as rotary torque of a driving toothed-pulley fixedly fitted to a rotary shaft of an electric motor is transmitted through a toothed belt to a driven toothed-pulley that rotates together with a ball screw nut in an integrated manner. The electric power steering apparatus is configured such that the amount of axial travel of a rack shaft is limited when a rack end and a housing come into contact with each other in the axial direction. The electric power steering apparatus includes a tilt allowing portion configured to cause the ball screw nut to tilt relative to a ball screw shaft such that the distance between the center of rotation of the driven toothed-pulley and that of the driving toothed-pulley increases when the rack end and the housing come into contact with each other in the axial direction.