Abstract: A steering apparatus is provided which can suppress unintended movement of a steering wheel when a clutch is engaged. When a power switch is turned off and a steering wheel is steered, a reaction force control circuit makes a reaction force motor to generate a steering reaction force stronger than a normal steering reaction force to give a driver an appropriate feeling of response according to a steering torque. The strong steering reaction force is applied to a steering shaft to suppress steering of the steering wheel. A steering operation control circuit executes steering operation control, that is, control that makes an actual steered angle equal to a target steered angle based on a steering angle, and then a clutch is engaged. The clutch is engaged after confirmation of an immovable state of steered wheels, and thus rotation of the steering wheel unintended by the driver is suppressed.

Abstract: A steering system includes: a steering shaft to which a steering member is coupled; a worm wheel attached to the steering shaft so as to be rotatable integrally with the steering shaft; a housing that houses the worm wheel; an output shaft that is coaxial with the steering shaft and rotatable relative to the steering shaft and coupled to a steering operation mechanism; and a clutch mechanism that enables and disables transmission of power between the steering shaft and the output shaft. The clutch mechanism is housed and disposed in an internal space in the housing.

Abstract: A steering control apparatus is provided which allows mitigation of an adverse effect of a technique for fixing a regulation member to a vehicle body on a phenomenon resulting from execution of steering operation control on steered wheels. An axial-force acquisition processing circuit calculates a rack axial force based on currents iu, iv, and iw flowing through a steering operation motor. A correction processing circuit corrects a target steered angle based on the rack axial force to obtain a target steered angle. A steered angle control processing circuit calculates a torque command value as the amount of operation for adjusting a steered angle to the target steered angle through feedback control. An operation signal generation processing circuit controllably adjusts a torque of a steering operation motor to the torque command value.

Abstract: A steering system is provided in which a bearing of a tension pulley has a reduced load-carrying capacity. A belt tension adjusting mechanism has a seat provided on an inner surface of a reduction gear housing so as to be able to swing, a rod that is in abutting contact with the seat (bent portion), a feed nut that is screw-threaded over the rod, and a spring member (helical torsion spring) that is fixed to the feed nut at its one end and to the reduction gear housing at the other end. When the belt is loosened, the feed nut is rotated by an elastic force of the spring member, and in conjunction with the rotation, the rod moves away from the feed nut to push the seat (bent portion).

Abstract: A steer-by-wire assembly for a steering system in a vehicle is described. The system includes a shaft rotatable in response to a steering input, a clutch that includes a brake member rotatable with the shaft and a reaction member, and an electromagnetic actuator that is selectively actuated to selectively provide a force to selectively engage the brake and reaction members. When the actuator is not actuated, the force between the brake and reaction members limits or prevents rotation of the brake member relative to the reaction member. And when the actuator is actuated, the force between the brake and reaction members is reduced or removed to permit rotation of the brake member relative to the reaction member.

Abstract: A steering control apparatus controls includes a steering quantity generation unit generating a steering quantity indicative of an operation performed on the steering member, an adjustment torque generation unit generating an adjustment torque and adjusting a mechanical impedance corresponding to the adjustment torque, and a command value generation unit generating a command value and controlling the motor according to the command value using the adjustment torque generated by the adjustment torque generation unit. The steering quantity is a physical quantity that has different values at least in a state of rotating the steering member, a state of returning the steering member, or a state of retaining the steering member, and the steering quantity indicates an operation amount of rotating the steering member or an operation amount of returning the steering member.

Abstract: A steering system includes a steering unit including a first actuator; a turning unit including a second actuator; and a backup mechanism configured to mechanically couple the steering unit and the turning unit, wherein a maximum torque that the first actuator is able to transmit to the second actuator via the backup mechanism is larger than or equal to a maximum torque that the second actuator is able to transmit to the first actuator via the backup mechanism.

Abstract: A method is provided for assisting a driver of a vehicle during operation by providing the driver with a desired steering feel. The method includes determining a desired steering device guiding force including a part representing a desired friction in a steering arrangement, and providing the driver with the desired steering feel based on the determined steering device guiding force.

Abstract: The following description relates to a fault tolerant apparatus for an independent controlled steering in a four wheel system, particularly a fault tolerant apparatus for an independent controlled steering in a four wheel system which can stabilizes a vehicle body through actively adjusting a steering angle of a vehicle and a velocity of a vehicle according to a breakdown environment and a vehicle driving road environment. Further, a fault tolerant apparatus for an independent controlled steering in a four wheel system that may assist a safe driving environment by adjusting a turning function adoptively to a surrounding road environment.

Abstract: A reaction force actuator to be used in a steer-by-wire steering device includes an operating-side shaft, a motor, and a friction drive transmission. The operating-side shaft rotates integrally with an operating member that a driver operates. The motor includes a cylindrical motor output shaft disposed coaxially on an outer circumference of the operating-side shaft. The friction drive transmission changes a speed of a rotary motion of the motor output shaft and transmits the rotary motion to the operating-side shaft.

Abstract: A vehicle stop control device is provided which prevents, when a traveling mode is switched, unintended movement of a vehicle in which all wheels are capable of being independently turned, and which can travel in a non-normal mode. Provided is: traveling mode switching section which can switch among a lateral movement mode, a pinwheeling mode, a normal traveling mode, and a parking mode, as a control mode for selecting operation combined by turning devices and traveling drive mechanisms; and turning timing shift part configured to shift the timing for turning at least one of all the wheels relative to the timing for turning the other ones of the wheels at the time of mode switching by the traveling mode switching section.

Abstract: An ECU acquires a steering torque detected by a torque sensor (step S1). The ECU drives an electromagnet of a solenoid actuator (step S2). The ECU drives a steering operation motor in accordance with the direction of the detected steering torque acquired in step S1 to apply, to an output shaft of a clutch, a torque acting in such a direction that a torque being exerted on a clutch mechanism is reduced (step S3). When a predetermined time has elapsed since driving of the steering operation motor in step S3 (step S4: YES), the ECU 40 reverses a driving direction of the steering operation motor to apply, to the output shaft of the clutch, a torque acting in a direction opposite to the direction of the last torque applied (step S5).

Abstract: An in-lane drive assist device controls a turning amount of a turning unit that is mechanically detached from a steering unit-based on a steering amount of a steering unit when a lane deviation is determined to be absent. The in-lane drive assist device controls the turning amount based on a drive assist turning amount for generating a yaw moment to return a vehicle into a lane while the steering reaction force applied to the steering unit is controlled based on a target steering reaction force corresponding to a steering reaction force characteristic that is set so that a self-aligning torque increases as the steering reaction force increases when a lane deviation is determined to be present, and the steering reaction force characteristic is offset in a direction in which an absolute value of the steering reaction force increases as a lateral position of the vehicle approaches a white line.

Abstract: Aircraft, control-by-wire systems, and controllers are provided. The aircraft includes a flight control surface and a control-by-wire system. The control-by-wire system includes an input device and a controller. The input device is configured to control the flight control surface. The controller is communicatively coupled with the input device and configured to automatically offset a neutral force position of the input device based on a deviation of the aircraft from a reference condition while the aircraft is operated in a manual flight mode.

Abstract: A vehicle steering system that hardly gives a driver a feeling of strangeness even in mode switching is provided. Even if condition such as a defect of a system, which caused switching from SBW mode to EPS mode, has been resolved, a mode switching section waits for a timing of switching from EPS mode to SBW mode until a second condition is satisfied. The second condition is that the vehicle is in a certain state in which the driver hardly notices mode switching. The mode switching section waits for and judges a timing when the vehicle becomes into a certain state in which the driver hardly notices mode switching, and then performs switching from EPS mode to SBW mode.

Abstract: A steering system (10) includes a steering wheel (310), a steering column (30), provided with a first portion (31) associated to the steering wheel (310) and on which a first angular position sensor (316) is positioned, and a second portion (32), on which a second electric motor (325) and a second angular position sensor (326) are positioned, and a clutch (33) interposed between the first portion (31) and the second portion (32). The second portion (32) is associated to a hydrostatic steering unit (40) able to command a steering of a vehicle following a rotation imparted on the steering wheel (310) selectively by means of activating the second electric motor (325) when the clutch (33) is open or directly by means of the clutch (33) when the clutch is closed.

Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that does not give uncomfortable feeling to a driver by detecting that the driver steers a steering wheel in an automatic steering mode by means of a steering torque from a torque sensor and switching to a manual steering mode by a capacity (an integrated value) corresponding to the occurring torque magnitude.

Abstract: A vehicle steering control device and a vehicle steering control method achieve an ideal steering feeling. A turning controller is configured to set as a target turning angle of a turning wheel an addition value obtained by adding a steady steer control amount that is a control amount depending on a steering angle and a differential steer control amount that is a control amount depending on a steering angular velocity. In this situation, when a driver is increasingly turning a steering wheel, the differential steer control amount is computed to be smaller than the differential steer control amount when the driver is not increasingly turning the steering wheel. Accordingly, the phase of the turning angle with respect to the steering angle in the steering returning operation can be delayed as compared to the phase in the steering increasing operation.

Abstract: A clutch apparatus is configured such that a first mode, a second mode and a third can be switched among these three modes. In the first mode, the rotating force is not transmitted between the steering-wheel-side housing and the tire-side housing. In the second mode, the steering-wheel-side housing and the tire-side housing are being mutually locked in place and, in this locked state, the rotating force can be transmitted to for the rotation in the both directions. In the third mode, the transmission of the rotating force can be canceled such that while the rotating force can be transmitted, between the steering-wheel-side housing and the tire-side housing, relative to the rotation in one direction, the rotation of either the steering-wheel-side housing or the tire-side housing in the other direction is allowed.

Abstract: A vehicle steering system transmission comprising a driver connected to a driver shaft, the driver shaft connected to an output shaft by a flexible link, a first sensor sensing the driver shaft, a control unit receiving a signal from the first sensor, and the control unit transmitting a signal to the driver to control an output shaft movement.

Abstract: In an electric power steering system, a vehicle reactive force model computes a correction spring reactive torque in such a manner that an elasticity component included in a steering reactive force is increased with an increase in a lateral acceleration. As the lateral acceleration increases, an increase in a basic drive torque is suppressed by a larger amount. By an amount by which the magnitude of the basic drive torque is suppressed, a target pinion angle computed by a target pinion angle computing unit decreases and a correction component for a basic assist component is decreased. A steering assist force is decreased, and a steering reactive force is increased with a decrease in the steering assist force. Thus, it is possible to obtain an appropriate steering reactive force based on the magnitude of the lateral acceleration.

Abstract: A system for correcting steering wheel angle errors of a motor vehicle of the present disclosure may include a steering wheel angle sensor, an actuator angle sensor, and at least one of a wheel speed sensor and a lateral acceleration sensor. The system may further include a controller configured to receive signals from the steering wheel angle sensor, actuator angle sensor, and at least one of the wheel speed sensor and lateral acceleration sensor. The controller may be configured to calculate a correction angle based on the signals, and adjust a steering wheel angle of a steering wheel, as observed by a driver of the motor vehicle, based on the correction angle.

Abstract: A ball screw device has a plurality of spiral raceways. One end and the other end of each raceway is connected via a bridge. An annular flange of a ball nut has a plurality of mounting portions at equal intervals in a circumferential direction. A fixing screw is fitted to each mounting portion. The bridges arranged so as to overlap with the annular flange in position in an axial direction are arranged at positions different in the circumferential direction from positions at which the mounting portions are arranged, and are arranged at unequal intervals in the circumferential direction.

Abstract: A wheeled vehicle is steered by a yoke or other operator control the movement of which is limited so that the operator's hands need not change position on the control. The steering is under the control of a microprocessor responsive to an input from the control, the vehicle's speedometer, and to accelerometers responsive to forces acting on the vehicle laterally and perpendicular to the roadway. The relationship between the position of the steerable wheels and the displacement of, or force applied to, the operator control is a function that depends on the magnitude of the displacement or force, speed, and one or more time derivatives of the displacement of, or force on, the operator control. The relationship between the position of the steerable wheels and the displacement of, or force on, the control is overridden when the lateral force is such that the vehicle is in danger of rolling over.

Abstract: A steering method for an industrial truck includes manually steering at least one steerable wheel with a steering transducer. The at least one steerable wheel is hydraulically connected or mechanically connected with the steering transducer. An angular position of the at least one steerable wheel is detected. At least one additional steerable wheel is motor-steered as a function of the detected angular position.

Abstract: A system for powering a steering angle sensor coupled to a steering wheel and a controller comprising a switch, coupled to the sensor and the controller. The switch is activated upon motion of the steering wheel or steering shaft. The switch, when activated, connects a power supply, such as a vehicle battery, to the sensor and the controller so that a new steering angle may be sensed and stored. After a predetermined period of time, the controller sends a signal to deactivate the switch and disconnect the power supply.

Abstract: Embodiments of the invention provide methods and apparatus for reducing steering effort in a vehicle. In one embodiment, a method for installing a steering-assist system onto a vehicle having an electrically powered steering system is provided. The method includes placing a controller between a torque sensor and an electronic control unit (ECU) disposed on the vehicle, coupling a primary signal line from the torque sensor to be in electrical communication with the controller, and coupling a secondary signal line to the controller to be in electrical communication with the ECU, wherein, when movement is detected by the torque sensor, the torque sensor provides a primary signal to the controller and the controller provides a secondary signal to the ECU, the secondary signal being different than the primary signal.

Abstract: A steering system for an autonomously driven vehicle and methods of steering the vehicle are disclosed. A main controller signals a secondary steering assembly to operate in a first phase when a power steering controller is in a first mode and a second phase to steer the vehicle when the power steering controller is in a second mode. The main controller signals a friction device to actuate to a disengaged position when the power steering controller is in the first mode and the secondary steering assembly is in the first phase, and to signal the friction device to actuate to an engaged position to secure a steering wheel in an initial position when the power steering controller is in the second mode and the secondary steering assembly is in the second phase to allow the secondary steering assembly to steer the vehicle.

Abstract: A vehicle steering system includes a steering angle detecting unit; a reaction force actuator; and a reaction force actuator control unit. The reaction force actuator control unit determines whether the steering angle detected by the steering angle detecting unit is within a first steering angle range where the steering angle is smaller than or equal to a first change angle or a second steering angle range where the steering angle is larger than the first change angle, and controls the reaction force actuator such that the steering reaction force is increased to a maximum value with an increase in the steering angle when the steering angle is within the first steering angle range and the steering reaction force is monotonically decreased from the maximum value with an increase in the steering angle when the steering angle is within the second steering angle range.

Abstract: An electric power steering apparatus that is capable of obtaining a more safe and comfortable handling performance by signal processing of road information and disturbances is performed to realize easy tuning, and vibration absorption level for brake is improved by a filter and a gain unit considering a frequency characteristic and a decelerating acceleration.

Abstract: A vehicle steering system in which a steering member and a steered wheel are not mechanical coupled to each other includes a rotation angle restriction mechanism that restricts a rotation angle of the steering member within a restricted angular range. In a normal mode, drive control on a steered system actuator is executed on the basis of a steering angle detected by a steering angle sensor. In a failure mode for a situation in which there is a malfunction in the steering angle sensor, drive control on the steered system actuator is executed on the basis of a steering direction detected by a steering direction detection sensor. The steering direction detection sensors detect the steering direction on the basis of at which one of a pair of terminal ends of the restricted angular range, the rotation angle restriction mechanism is restricting the rotation angle of the steering member.

Abstract: A steering device for a motor vehicle has a steering wheel which is connected in a rotationally fixed fashion to a steering shaft which is continuously hollow and through which at least an electrical conductor is led in order to make electrical connection with steering-wheel-side equipment. The conductor, in particular flexible conductor tracks, highly flexible cables, and/or flat conductor ribbons, is guided in an axial direction through the entire steering shaft, and emerges therefrom at the two ends of the steering shaft, and is surrounded essentially by a protective device. The protective device has two protective tubes which can be changed in length in the axial direction, in particular by moving them in and out in a telescopic fashion.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. An engine driven pump connected with the power steering motor assembly is driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly. A controller increases engine speed when the vehicle is motionless and a steering wheel is rotated. A method for controlling the speed of an engine to provide a predetermined steering assist to a steering apparatus includes determining if the vehicle is motionless and determining if the steering wheel is being rotated. The speed of the engine is increased if the vehicle is motionless and the steering wheel is being rotated to provide the predetermined steering assist to the steering apparatus.

Abstract: A steering system for a vehicle includes a front wheel supported for rotation about a first axis and a pivot axis transverse to the first axis and spaced inboard of a centerline of the front wheel. The front wheel is movable about the pivot axis to change direction of the vehicle. A brake coupled to the front wheel provides braking rotation of the front wheel and a controller controls operation of the brake to generate a desired braking force in a direction determined to adjust a vehicle direction.

Abstract: This invention refers to an electrically assisted steering system that includes a torque sensor connected to a vehicle steering wheel. The system also includes a torque control ECU that is responsive to torque signals from the torque sensor to generate a motor assist requirement signal. The system further includes a motor control ECU responsive to the motor assist requirement signal to generate a motor control signal. The system additionally includes a steering assist motor responsive to the motor control signal to provide a steering assistance torque to the vehicle steering system. Finally, the system includes a safety domain ECU connected to at least one vehicle operational parameter sensor to generate a torque signal and send the same signal to the torque control ECU. The safety domain ECU is also being in communication with the torque control ECU and the Motor control ECU.

Abstract: A pulse active steering control system and method for use in a motor vehicle for improving vehicle stability by reducing a likelihood for rollover and/or skidding sends pulses to the steerable wheels whenever a rollover coefficient and/or the difference between the estimated and actual yaw rate is outside a predetermined range. The pulses are asymmetrical in the form of a smooth curve with a gradually increasing rapid rising edge and a slower falling edge and provide steering input that, along with the driver steering input, returns the rollover coefficient and/or yaw rate to the predetermined range to reduce the likelihood of rollover and/or skidding.

Abstract: The invention relates to a steering device for a road vehicle according to the steer-by-wire principle with a steering wheel that can be operated by a driver and with a steering gearbox that is not permanently mechanically coupled in a forcible manner, which is equipped with an electric motor drive for swivelling steered wheels, wherein the electric motor drive comprises an electric motor, a pinion (1), a belt (2) and a belt pulley (3), wherein the belt pulley (3) is coupled via the gearbox to a threaded spindle (4), and wherein an electromechanical blocking of the electric motor drive is provided on or in the steering gear.

Abstract: A vehicle steering apparatus in which a mechanical coupling between a steering member and steered wheels is uncoupled, includes a steering actuator for driving a steered mechanism and a control unit for drive-controlling the steering actuator. The control unit reduces steering-stiffness using a PID control portion for drive-controlling the steering actuator according to a deviation between a target steered angle and a steered-angle detected by the steered angle sensor. A gain setting portion sets gains of the PID control portion to be relatively low when a predetermined condition is satisfied.

Abstract: A method for determining the absolute angular position of a steering wheel of an electric power-assisted steering column of a motor vehicle, including a means for measuring a dynamic parameter while the vehicle is running and including among others, the steps of periodically determining a multi-turn relative angular position, determining at least one dynamic parameter relating to the running conditions of the vehicle using the means for measuring said parameter, determining an absolute steering-wheel angle calculated according to at least one dynamic parameter, and weighting the calculated value of the absolute steering-wheel angle according to a test of the validity of the calculated value of the absolute steering-wheel angle and the origin of said value, in other words, the measurement means used to determine said at least one dynamic parameter.

Abstract: A vehicle steering system includes a rotation restriction mechanism that restricts a rotation amount of a steering member within a predetermined angle. The rotation restriction mechanism includes at least one plate element that is interposed between a rotatable element, which is coaxially rotatable together with a rotary shaft of the steering member, and a non-rotatable element, and that is rotatable relative to the rotary shaft. Light projecting units are provided at one of the rotatable element and the non-rotatable element, and light receiving units are provided at the other one of the rotatable element and the non-rotatable element. The at least one plate element has light transmission portions that allows transmission of light that is emitted from the light projecting units and that enters the light receiving units when a rotation angle of the at least one plate element is a predetermined angle.

Abstract: A steering system includes: an operation mechanism that includes an operation member used to perform a steering operation; and a steered mechanism that is not mechanically coupled to the operation mechanism, and that steers a wheel based on the steering operation of the operation member. The operation mechanism includes a steering angle sensor that detects a steering angle of the operation member, and steering direction detection unit that detects only a steering direction of the operation member.

Abstract: A motor vehicle steering system steers vehicle wheels in response to the operation of an operation member for steering a vehicle. The system includes a rutted road judging unit which judges whether the vehicle is driving on a rutted road or not, and a steering enhancement control unit which enhances steering of vehicle wheels in response to operation of the operation member when the rutted road judging unit judges that the vehicle is driving on a rutted road than when the rutted road judging unit judges that the vehicle is not driving on a rutted road.

Abstract: A vehicular steering apparatus includes: a road-wheel turning mechanism mechanically separated from, but electrically connected to a steering wheel; a first rotation shaft connected to the steering wheel; a second rotation shaft connected to the road-wheel turning mechanism; and a connection mechanism for interconnecting the first and second rotation shafts in such a manner that the first and second rotation shafts can rotate idle relative to each other within a range of a predetermined relative rotational angle.

Abstract: Maneuverability and stability of a suspension unit for a vehicle are improved. A vehicle includes: a steer-by-wire system detecting a displacement of a steering wheel and displacing a steering rack steering steerable wheels on a basis of a detection result of the displacement and a suspension unit suspending the steerable wheels, the suspension unit including: wheel hub mechanisms, each wheel hub mechanism supporting a tire wheel on which a tire is attached, and a plurality of link members supporting the wheel hub mechanisms on the vehicle body; and a kingpin axis passing through an upper pivot point of the link members and lower pivot point of the link members being set to pass through a road surface contact area of the tire at a neutral position of the steering wheel.

Abstract: Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

Abstract: A steer-by-wire steering device includes a steering wheel connected with a steering shaft, a steering angle sensor, a steering reactive force motor, and a steering control unit for controlling a steering shaft drive motor and the steering reactive force motor. Provided is a power transmitting mechanism for transmitting the power from the steering shaft drive motor to the steering shaft. A changeover unit for selectively connecting and disconnecting the power is disposed on the way thereof. The changeover unit includes a clutch mechanism comprised of an input member and an output member juxtaposed in an axial direction for movement in the axial direction and, also, rotatable relative to each other, a clutch groove provided in one of those members, and a clutch rolling element provided in the other of those members and biased in a radial direction by the clutch groove so that it can be selectively engaged and disengaged.

Abstract: To prevent a generation of a large change of a steering reaction force at the time of starting and stopping steering so as to reduce a feeling of strangeness of a driver, while controlling driven wheels with high responsivity with respect to steering. A steering control unit 25 controls a steering motor 7 based on a final target turning angle ?t obtained by an addition of a first target turning angle ?1 and a second target turning angle ?2. A reaction force control unit 26 controls a reaction force motor 3 based on a final target steering reaction force Tt obtained by an addition of a first target steering reaction force T1 and a second target steering reaction force T2. In this case, a second target steering reaction force calculation unit 24 calculates the second target steering reaction force T2 based on a value obtained by a variation restriction of the second target turning angle ?2 based on a steering angular velocity ?t (second turning angle correction value ?2a).

Abstract: An apparatus (10) for turning steerable wheels (28, 124) of a vehicle (12) in response to input to a driver control interface (14) includes a sensor (18) for monitoring steering input to the driver control interface (14) and for providing a steering input signal indicative of the monitored steering input. Front and rear steering systems (24, 110 and 120, 126) are actuatable for turning front and rear sets of steerable wheels (28, 124), respectively. A controller (22), upon a malfunction of the front steering-system (24, 110), actuates only the rear steering system (120, 126) in response to the steering input signal.

Abstract: A vehicle steering system in which a steering member and a steered wheel are not mechanical coupled to each other includes a rotation angle restriction mechanism that restricts a rotation angle of the steering member within a restricted angular range. In a normal mode, drive control on a steered system actuator is executed on the basis of a steering angle detected by a steering angle sensor. In a failure mode for a situation in which there is a malfunction in the steering angle sensor, drive control on the steered system actuator is executed on the basis of a steering direction detected by a steering direction detection sensor. The steering direction detection sensors detect the steering direction on the basis of at which one of a pair of terminal ends of the restricted angular range, the rotation angle restriction mechanism is restricting the rotation angle of the steering member.

Abstract: A vehicle steering system includes a rotation restriction mechanism that restricts a rotation amount of a steering member within a predetermined angle. The rotation restriction mechanism includes at least one plate element that is interposed between a rotatable element, which is coaxially rotatable together with a rotary shaft of the steering member, and a non-rotatable element, and that is rotatable relative to the rotary shaft. Light projecting units are provided at one of the rotatable element and the non-rotatable element, and light receiving units are provided at the other one of the rotatable element and the non-rotatable element. The at least one plate element has light transmission portions that allows transmission of light that is emitted from the light projecting units and that enters the light receiving units when a rotation angle of the at least one plate element is a predetermined angle.