The present embodiments relate to a steering assist device and method, and a steering system. The steering assist device comprises: first and second input-side steering control modules for controlling an input-side steering motor so that an input-side instrument connected to a steering wheel is assisted; and first and second output-side steering control modules for controlling an output-side steering motor so that an output-side instrument mechanically separated from the input-side instrument and connected to a wheel is assisted, wherein the first and second input-side steering control modules and the first and second output-side steering control modules arbitrate a role assignment and can control a corresponding steering motor from among the input-side steering motor and the output-side steering motor according to the role assignment arbitration result.

A number of illustrative variations may include a system and method of using vehicle brakes to steer a vehicle where steer-by-wire steering systems have failed. The system may include supplying varying brake pressure, as needed, to different vehicle wheels to steer the vehicle. The system may include supplying engine system commands to maintain vehicle speed or acceleration such that in the event of steering system failure, a vehicle may continue to operate safely without effecting driver input.

A control device of a steering device, for a vehicle, which includes left and right steering mechanisms not mechanically coupled to each other, and which steers left and right steered wheels individually by driving force of steering actuators, includes: a steered angle determining unit that determines a target steered angle for each of the left and right steering mechanisms; and a steering command unit that generates drive signals corresponding to the target steered angles, and outputs the drive signals to each of the actuators. When an anomaly occurs in one of the left and right steering mechanisms, the steered angle determining unit sets the target steered angle for the steering mechanisms that is normal to be different from the target steered angle when both the left and right steering mechanisms are normal.

A control device for an on-board device including an actuator is configured to: supply power to a first microprocessor and a first driver circuit from a first power source through a first power supply path; supply power to a second microprocessor and a second driver circuit from a second power source through a second power supply path; and use the first and second driver circuits to drive the actuator. In this control device, the negative electrodes of the first and second power sources are electrically connected to a common ground portion. Furthermore, the control device includes a first and second sensor for measuring current or voltage between the vehicle body ground and the negative electrodes of the first and second power source, respectively. When detecting an abnormal current or voltage, the first and second microprocessors control the first and second driver circuits so as to place a limit on power supply to the actuator.

An electric multi-mode steer-by-wire system and a mode switching method thereof. The electric multi-mode steer-by-wire system includes a steering hand wheel unit including a steering hand wheel, a road-feeling motor, a reducer and an electromagnetic clutch, a steering execution unit including two steering electric motor mechanisms, a steering gear and two steering road wheels, an electronic control unit configured to control the steering hand wheel unit and the steering execution unit to achieve switching among two-side steering-road-wheel independent steer-by-wire mode, steering-trapezoidal steer-by-wire mode and electric power steering mode, and a mode selection and display unit. The electromagnetic clutch connected to the steering execution unit. The steering electric motor mechanisms drive the steering road wheels to steer independently through lead screw-nut pairs; or respectively form a hydraulic cylinder with the steering gear to jointly or independently drive the steering road wheels to steer with steering-trapezoidal manner.

A steering system of a vehicle, including an operation member to be operated by a driver, a steering device configured to steer a wheel, and a controller configured to control the steering system, wherein the controller is configured to parallelly execute a main process including a process in which the controller controls the steering device to perform steering of the wheel in accordance with an operation of the operation member and an auxiliary process relating to an operation of the steering system and configured to decrease an execution ratio of the main process and increase an execution ratio of the auxiliary process when a condition that a running speed of the vehicle is not lower than a threshold speed is satisfied.

An actuator that applies force to a member associated with steering, and a control device that controls the actuator, have duplex configuration. First and second control devices compute the same controlled variable as first and second controlled variables, respectively. In a normal mode, the control device controls the actuator according to the first controlled variable. The first and second control devices send and receive respectively computed controlled variables to and from each other via communications. When a discrepancy arises between the first and second controlled variables, or an abnormality occurs in communications between the first and second control devices, the operating mode is switched from the normal mode to an independent mode. In the independent mode, the first and second control devices control the first and second actuators, according to the first and second controlled variables, respectively.

Disclosed are a multifunctional electric recirculating ball steering system for commercial vehicles and a control method thereof, including: an electric power module, a mechanical transmission module and a control module; the electric power module includes: a dual-rotor motor module (14) and a power motor (22); the mechanical transmission module includes: a steering wheel (1), a steering shaft (4), couplings (5), a recirculating ball steering gear (16), a gear sector (19), a gear sector shaft (6), a steering drag link (7), a steering tie rod (12), a steering knuckle arm (8), a left tie rod arm (11), a right tie rod arm (26), a left steering knuckle (10), a right steering knuckle (25), a left wheel (9) and a right wheel (24); and the control module includes: an electronic control unit (21), torque sensors (3), a vehicle speed sensor (20), a steering angle sensor (2) and current sensors (23). The system ensures system reliability.

The present embodiments relates to a steering control device and method of a vehicle and may provide a steering control device and method for a vehicle, which may secure stably steered driving by controlling the output of the steering motor by changing the average steering ratio when the driver causes urgent steering in a failure situation and adjusting the rack stroke and rack speed.

An apparatus for use in turning at least one steerable vehicle wheel includes a steering member rotatably supported in a housing. The steering member rotates relative to the housing about a first axis to effect turning movement of the at least one steerable vehicle wheel. A ball nut is connected with an externally threaded portion of the steering member. The steering member is rotatable relative to the ball nut assembly to axially move the ball nut assembly relative to the housing. An electric motor is operable to apply a rotational force to the steering member to urge the steering member to rotate relative to the housing. The electric motor has an output shaft extending along a second axis extending generally parallel to the first axis. A first gear is rotatable about the second axis with the output shaft of the motor. A second gear in meshing engagement with the first gear is rotatable about a third axis extending transverse to the second axis. A third gear is rotatable with the second gear about the third axis. A fourth gear in meshing engagement with the third gear is rotatable with the steering member relative to the housing.