A control unit for a vehicle having an active steering system capable of changing a steering gear ratio between a steering angle of a steering wheel and a tire steering angle includes a steering turning assist controller and a left-right driving force controller. The steering turning assist controller controls the steering gear ratio so that a yaw rate generated by the vehicle becomes a target yaw rate to assist a turning of the vehicle. The left-right driving force controller controls, in the left and right electric drive wheels which each add a yaw moment to a vehicle body independently of a steering system and are able to be independently driven, driving forces of the electric drive wheels so that the yaw rate generated by the vehicle becomes the target yaw rate based on a roll of the vehicle.

A control apparatus calculates an axial force deviation, which is a difference between an estimated axial force and an ideal axial force based on a target pinion angle of a pinion shaft in association with a turning operation of steered wheels. The estimated axial force is based on a state variable that reflects vehicle behavior or a road condition. The control apparatus includes a steering angle ratio change control circuit configured to calculate a target pinion angle serving as a basis for calculation of the command value. The steering angle ratio change control circuit calculates a speed increasing ratio from a steering angle ratio set based on a vehicle speed and a base gear ratio of a steering mechanism, and calculates a correction angle for a target steering angle by multiplying the speed increasing ratio and the target steering angle together.

A clamping apparatus may include a stroke-generating disk that is rotatable about a clamping axis and is connected via a first stroke-generating gearing and a second stroke-generating gearing to a pressure disk, which is stationary relative to the rotation of the stroke-generating disk. The first stroke-generating gearing converts a relative rotation of the stroke-generating disk in a first actuating angle range in the clamping direction into a first axial stroke relative to the pressure disk. The second stroke-generating gearing converts a further rotation of the stroke-generating disk following the first actuating angle range in a second actuating angle range into a second axial stroke between the stroke-generating disk and the pressure disk. At least one of the stroke-generating gearings is a tilting pin gearing, with at least one tilting pin supported in the direction of its pin axis between corresponding bearing points on the stroke-generating disk and the pressure disk.

In a ball screw device, an inner peripheral rolling groove of a nut includes, between openings of mounting holes, a constant pitch circle diameter region where a pitch circle diameter is constant and gradually-changing pitch circle diameter regions where the pitch circle diameter gradually increases, in the ranges from opposite ends of the constant pitch circle diameter region to the respective openings. At least the constant pitch circle diameter region has a surface hardness greater than or equal to a predetermined value, among the constant pitch circle diameter region and the gradually-changing pitch circle diameter regions excluding edges at the boundaries between the respective openings and the inner peripheral rolling groove, and the edges at the boundaries between the respective openings and the inner peripheral rolling groove have a surface hardness less than the predetermined value.

A multifunctional steering column for a transportation vehicle having a steering bracket for connection of the steering column to a transportation vehicle body of the transportation vehicle; a steering tube held on the steering bracket and which has a steering tube axis; a steering wheel connection for mechanical coupling of the steering column to a steering wheel; and a steering gear end at which a steering gear coupling with a steering gear connection for mechanical coupling to a steering gear of the transportation vehicle is arranged. Also disclosed is a transportation vehicle and a method for operating a transportation vehicle.

A ratio of the distance by which a rack shaft moves in a first direction relative to the angle by which a pinion shaft rotates in a circumferential direction is defined as a stroke ratio. The stroke ratio is larger when the pinion meshes with one of a third rack and a fifth rack than when the pinion meshes with a first rack. The stroke ratio changes while the pinion moves on one of a second rack and a fourth rack. A clearance defined between a rack guide and a guide plug is smaller when the pinion meshes with one of the third rack and the fifth rack than when the pinion meshes with the first rack. The clearance defined between the rack guide and the guide plug changes while the pinion moves on one of the second rack and the fourth rack.

A high-performance electric power steering apparatus that includes a control system based on a physical model, includes 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. The electric power steering apparatus 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, 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 so as to suppress a rack end hitting.

An operation mode of a first actuator engaged with a steering rack is determined. An operation mode of a second actuator engaged with a steering column is determined. The operation mode of one of the first and second actuators is adjusted upon detecting a failure in the other of the first and second actuators. At least one of the steering rack and the steering column is actuated based on the operation mode. In an angle control mode, a predetermined steering angle is provided to the first and second actuators to adjust the steering rack according to the steering angle. In a torque control mode, a steering column torque from a torsion sensor disposed on the steering column is provided to the first and second actuators to adjust the steering rack according to the steering column torque.

A control unit for a vehicle having an active steering system capable of changing a steering gear ratio between a steering angle of a steering wheel and a tire steering angle includes a steering turning assist controller and a left-right driving force controller. The steering turning assist controller controls the steering gear ratio so that a yaw rate generated by the vehicle becomes a target yaw rate to assist a turning of the vehicle. The left-right driving force controller controls, in the left and right electric drive wheels which each add a yaw moment to a vehicle body independently of a steering system and are able to be independently driven, driving forces of the electric drive wheels so that the yaw rate generated by the vehicle becomes the target yaw rate based on a roll of the vehicle.

A ratio of the distance by which a rack shaft moves in a first direction relative to the angle by which a pinion shaft rotates in a circumferential direction is defined as a stroke ratio. The stroke ratio is larger when the pinion meshes with one of a third rack and a fifth rack than when the pinion meshes with a first rack. The stroke ratio changes while the pinion moves on one of a second rack and a fourth rack. A clearance defined between a rack guide and a guide plug is smaller when the pinion meshes with one of the third rack and the fifth rack than when the pinion meshes with the first rack. The clearance defined between the rack guide and the guide plug changes while the pinion moves on one of the second rack and the fourth rack.