A steering control device, a steering control method, and a steering control system according to the present invention determines a rear wheel steering angle control command for returning a rear wheel steering angle to a predetermined steering angle earlier than a front wheel steering angle when steering wheel operation (that is, operation of a steering wheel) shifts from a state of additional turning to a state of cutback turning, in steering control that steers a rear wheel steering angle of a vehicle in opposite-phase with respect to a front wheel steering angle, and outputs the determined rear wheel steering angle control command to a rear wheel steering device, so that hysteresis of a yaw rate is reduced or eliminated, reducing or eliminating a sense of discomfort given to a driver.

A method is for operating a steering system, more particularly a steer-by-wire steering system. The steering system includes at least one wheel steering angle control element which is provided to influence and/or change a wheel steering angle of at least one vehicle wheel depending on a target specification signal correlated with a steering specification. The wheel steering angle control element has a limited maximum wheel steering angle control range for changing the wheel steering angle, and the target specification signal is limited by a saturation to the maximum wheel steering angle control range. The target specification signal is modified in such a manner that the, more particularly modified, target specification signal has a constant and differentiable curve at least in an edge range of the wheel steering angle control range.

A steer-by-wire steering system includes a controller configured to execute a steering control process and a determining process of determining a converted operation amount by converting an actual wheel steering amount to an operation amount of an operation member based on an inverse of a steering gear ratio. In the determining process, when the steering gear ratio abruptly changes, the controller converts a gap of the converted operation amount generated at a time point of occurrence of the abrupt change to a gap of the wheel steering amount to grasp a converted steering amount offset value. While gradually decreasing the converted steering amount offset value, the controller thereafter re-converts the converted steering amount offset value to the gap of the converted operation amount based on the inverse of the steering gear ratio to determine a converted operation amount correction value and corrects the converted operation amount based on the value.

The present invention provides a driving assist apparatus, a driving assist method, and a driving assist system capable of realizing driving assist in consideration of a delay in a driver's operation regardless of a configuration of a vehicle. A driving assist apparatus includes a standard running route acquisition portion configured to acquire a standard running route calculated based on curve information ahead of a vehicle that is acquired by an external world recognition portion, and an actuator control output portion configured to acquire a standard vehicle motion amount when the vehicle runs the standard running route, calculate an instruction that guides a motion amount of the vehicle toward the standard vehicle motion amount based on the standard vehicle motion amount and a current vehicle motion amount of the vehicle, and output the instruction to an actuator portion configured to provide at least one of a curving force and a braking force to the vehicle.

A differential cooperative active steering system for a front-axle independent-drive vehicle with electric wheels includes a steering rack which is arranged between a first steering wheel and a second steering wheel, and is able to generate lateral displacement and pull the first and second steering wheels to steer; a planetary gear mechanism, including a first input end, a second input end and an output end; a steering angle coupling motor, connected to the first input end; and an input shaft of the steering wheel, connected to the second input end. The planetary gear mechanism can realize the coupling between an input steering angle of an input shaft of the steering wheel and an input steering angle of the steering angle coupling motor. In addition, a method for controlling the differential cooperative active steering system is provided.

The disclosure relates to a method for operating a steer-by-wire steering system which includes at least one steering input element, at least one steering actuating element operatively connected to the steering input element, at least one first end stop for mechanically limiting a movement of the steering actuating element in a first direction of movement and at least one second end stop for mechanically limiting a movement of the steering actuating element in a second direction of movement, wherein a steering ratio between the steering input element and the steering actuating element is adapted such that a maximum deflection of the steering input element in a first steering direction, in which the steering actuating element reaches the first end stop, and a maximum deflection of the steering input element in a second steering direction, in which the steering actuating element reaches the second end stop, are at least substantially identical.

A steering system includes a controller configured to: execute a normal control to control a front-wheel steering device or a rear-wheel steering device based on a target steering angle when a steering-related frequency is determined to fall outside a resonance frequency band; and execute a limiting control when the steering-related frequency is determined to fall within the resonance frequency band. In the limiting control, the controller controls the front-wheel or rear-wheel steering device such that (i) an actual steering angle is constant at a predetermined value, (ii) an absolute value of the actual steering angle gradually decreases from a specific value, (iii) a frequency of the actual steering angle falls outside the resonance frequency band, or (iv) the absolute value of the actual steering angle is less than an absolute value of the latest value of a target extreme value that is an extreme value of the target steering angle.

A driving assistance control device outputs a driving assistance command value to a steering control device as information indicating a target course that is generated on the basis of the detection result of a vehicle-mounted sensor. The driving assistance command value is output as a torque component or an angle component depending on the design of the driving assistance control device. In response, processing in which a driving assistance command value input from the exterior of the steering control device is used as input for angle control processing or input for torque control processing within an assist command value calculation unit is performed by a microcomputer as assistance command value input processing by an assistance command value input processing unit.

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.

A steering device includes: an electric motor configured to apply a driving force to cause a wheel of a vehicle to roll; a transmission unit configured to transmit the driving force of the electric motor to the wheel; an input determination unit 221 configured to determine whether an excessive external force equal to or greater than a predetermined force is input, or likely to be input, to the transmission unit via the wheel while the electric motor is applying the driving force; and a final target current setting unit 23 configured to, in response to the input determination unit 221 determining that the excessive force is input, or likely to be input, to the transmission unit, reduce the driving force of the electric motor so that a load on the transmission unit does not exceed an upper limit that is preset according to strength of the transmission unit.