Described herein are steer-by-wire systems and methods of operating these systems in vehicles. A steer-by-wire system comprises a steering wheel assembly, comprising a steering wheel, sensors, and a torque generator. The system comprises a rack assembly, comprising a steering rack, sensors, and a rack actuator. The steering wheel assembly and the rack assembly are communicatively coupled by a steer-by-wire system controller, without having any direct mechanical links between the assemblies. In some examples, the controller instructs the rack assembly to control the steering rack position based on the steering input, such as changes in the steering wheel position. A steering map is used to determine the desired steering rack position based on the current steering wheel position. In some examples, a steering map is selected from a steering map set based on, e.g., the vehicle speed, vehicle direction, driver preference, and the like.

A fail safe apparatus for an MDPS system may include: a vehicle speed sensor configured to measure a vehicle speed; a gear stage input unit configured to receive a gear stage from a transmission of the vehicle; a GPS vehicle speed calculation unit configured to calculate a GPS vehicle speed based on location information of the vehicle; and a control unit configured to determine whether the vehicle speed is an error, based on one or more of the vehicle speed, the gear stage, and the GPS vehicle speed, and determine vehicle speed data of the MDPS system based on one or more of the gear stage and the GPS vehicle speed.

A variable mechanical advantage shaft coupling (1), typically used in an electric power assisted steering system, comprising: an input shaft (2); an output shaft (3); and at least one lever (9), each lever comprising: a lever body; a first connection (5) connecting the lever body to a first shaft (2) of the input shaft and the output shaft at a point offset from an axis of rotation of the first shaft so that the lever body can pivot relative to the first shaft; a second connection (11) connecting the lever body to a second (3), different, shaft of the input shaft and the output shaft at a point offset from its axis of rotation so that the lever body can pivot relative to the second shaft; and a fulcrum point about which the lever body can pivot; in which each first connection (5) is able to slide along an axis substantially parallel to the axes of rotation of the first and second shafts (2, 3) along the respective lever body, each lever connecting the input and output shafts (2, 3) with a mechanical advantage that varies dependent upon the position of each sliding connection along the first shaft.

A variable mechanical advantage shaft coupling (1), typically used in an electric power assisted steering system, comprising: an input shaft (2); an output shaft (3); and at least one lever (9), each lever comprising: a lever body; a first connection (5) connecting the lever body to a first shaft (2) of the input shaft and the output shaft at a point offset from an axis of rotation of the first shaft so that the lever body can pivot relative to the first shaft; a second connection (11) connecting the lever body to a second (3), different, shaft of the input shaft and the output shaft at a point offset from its axis of rotation so that the lever body can pivot relative to the second shaft; and a fulcrum point about which the lever body can pivot; in which each first connection (5) is able to slide along an axis substantially parallel to the axes of rotation of the first and second shafts (2, 3) along the respective lever body, each lever connecting the input and output shafts (2, 3) with a mechanical advantage that varies dependent upon the position of each sliding connection along the first shaft.

According to the present embodiments, it is possible to enhance the driver's steering feel with a simplified structure, reduce components, save manufacturing and processing costs, and prevent overshoot to secure the driver's safety.

A variable steering angle steering device rotationally drives a rotational element using a steering angle ratio adjustment motor so as to change the relationship between the amount of rotation of a first rotating shaft and the amount of rotation of a second rotating shaft, thereby changing the relationship between the amount of steering of the steering wheel and the amount of change in steering angle. The steering angle ratio adjustment motor is supported and fixed at a part of a steering column forward than a portion at which the steering column is supported with respect to a support frame. In the event of primary collision, the steering angle ratio adjustment motor collides with the support frame and is thereby prevented from being displaced rearward beyond the support frame.

An angle superimposition apparatus for a vehicle steering device with a planetary gear. The apparatus includes—a first shaft and a second shaft, which are arranged in a longitudinal direction so as to be rotatable relative to one another about the common longitudinal axis thereof. —A carrier arrangement is fixedly arranged to the body shell, on which carrier arrangement the first shaft and the second shaft and a rotor shaft are at least partially mounted and positioned so as to be rotatable. —An auxiliary drive with a stator is arranged on the carrier arrangement and with a rotor shaft, having a rotor, mounted rotatably and arranged coaxially with respect to the longitudinal axis and one of the shafts. —A planetary gear having a worm, which is arranged as a sun wheel so as to be rotatable about an axis of rotation and is arranged on the rotor shaft.

A steer-by-wire system includes a steering reaction torque generation device mechanically separated from a turning device for turning wheels and configured to apply a reaction torque to a steering wheel. The steering reaction torque generation device has a duplex configuration including a first system and a second system, each system including a reaction torque motor. When both systems are normal, a control device generates the reaction torque having a normal characteristic by controlling an operation of the reaction torque motor of at least one system. In a case of single failure where one of the systems fails, the control device generates the reaction torque having a first characteristic by controlling an operation of the reaction torque motor of another of the systems. The reaction torque having the first characteristic is different from the reaction torque having the normal characteristic with respect to a same steering angle.

A steer-by-wire system and method for a vehicle, including and utilizing: a steering wheel system including a steering wheel, an angle sensor or mechanism coupled or applied to the steering wheel and for determining an angular magnitude of the steering wheel and provide a corresponding control signal, and an angular rate sensor or mechanism coupled or applied to the steering wheel and for determining an angular rate of the steering wheel and provide a corresponding control signal offset; and a steering actuator system including a wheel angle actuator coupled to one or more wheels of the vehicle and for receiving the collective control signal and control signal offset and turning the wheels in response. The steering wheel system further includes an angular rate filter/tuner for receiving an angular rate input from the angular rate sensor or mechanism and deriving an angular offset output corresponding to the control signal offset.

A steer-by-wire steering apparatus comprises a plurality of locking projections that project radially outward of a upper shaft; a rotation range limiting projection that is fixed to the upper shaft and has an engaged portion located on the radially outer side of outer peripheral ends of the locking projections; a radially movable lock member that is located on the radially outer side than the locking projections when a drive source switch is ON, and has at least a part located at the same radial position as the locking projections when the switch is OFF; and a rotation range limiting member that has at least a part located at the same radial position as the engaged portion regardless of whether or not a steering actuator that changes steered angle of steered wheels is in an operable state when the switch is at least ON.