Four-wheel steering of a vehicle, e.g., in which leading wheels and trailing wheels are steered independently of each other, can provide improved maneuverability and stability. A first vehicle model may be used to determine trajectories for execution by a vehicle equipped with four-wheel steering. A second vehicle model may be used to control the vehicle relative to the determined trajectories. For instance, the second vehicle model can determine leading wheels steering angles for steering leading wheels of the vehicle and trailing wheels steering angles for steering trailing wheels of the vehicle, independently of the leading wheels.

A steer-by-wire steering system, including: a pair of wheel steering devices respectively provided for right and left wheels of a vehicle, each of the pair of wheel steering devices including an actuator and configured to steer a corresponding one of the right and left wheels independently of the other of the right and left wheels; and a controller configured to control the pair of wheel steering devices such that steering amounts of the respective right and left wheels are equal to respective amounts based on a steering request, wherein the controller executes a steering-amount stabilizing control to reduce a change in the steering amounts in an external-force-dependent steering situation in which the right and left wheels are steered or likely to be steered by an external force applied to the right and left wheels.

An assembly for plausibility checking and/or reinitializing a rear wheel steering system of a vehicle having a rear wheel steering unit, which includes at least one rear wheel actuator for adjusting a rear-wheel steering angle and a sensor for detecting the set position of the rear wheel actuator, with at least one reference sensor for detecting a reference signal and with an electronic control unit for carrying out the plausibility check and/or reinitialization of the sensor. The reference sensor is part of a vehicle unit different from the rear wheel steering unit and is designed to detect a vehicle-status-dependent reference signal. Furthermore, the control unit includes at least one mathematical model which, based on the vehicle-status-dependent reference signal, can determine a reference value and/or a reference vehicle status, with which the plausibility check and/or reinitialization can be carried out by the control unit.

The four-wheel steering system includes a front-wheel steering system that steers front wheels of a vehicle and a rear-wheel steering system that steers rear wheels of the vehicle in accordance with a steering angle that is a rotation angle of a steering wheel. The rear-wheel steering system includes a second ECU that, when the vehicle speed is equal to or lower than a vehicle speed threshold, performs antiphase control in which the rear wheels are steered in the opposite direction to that in which the front wheels are steered. When the vehicle speed is equal to or lower than the vehicle speed threshold, the second ECU performs in-phase control in which the rear wheels are steered in the same direction as that in which the front wheels are steered, in response to a specific trigger operation that is performed via the steering wheel.

A four-wheel steering control device for independently controlling steering of each of first to fourth wheels disposed in a vehicle. A commanded steering angle acquiring part acquires first to fourth commanded steering angles for first to fourth wheels of a vehicle. A four-wheel turning control rate calculating part determines first to fourth residual angles, by which the first to fourth wheels realize the first to fourth commanded steering angles, from current steering angles and calculate first to fourth turning control rates of the first to fourth wheels on basis of the first to fourth residual angles determined. A control part independently controls steering of each of the first to fourth wheels using the first to fourth turning control rates calculated.

A method to control a road vehicle with rear steering wheels and having, while driving along a curve, the steps of: determining a desired steering angle for the rear wheels; comparing the desired steering angle with a threshold value; applying, while driving along a curve and if the desired steering angle is greater than the threshold value, to both rear wheels a same actual steering angle that is equal to the desired steering angle; and applying, while driving along a curve and if the desired steering angle is smaller than the threshold value, to a rear wheel on the outside of the curve an actual steering angle greater than the desired steering angle and applying to a rear wheel on the inside of the curve a zero actual steering angle.

A mobility system includes a mobility module that measures and controls a mobility state of the mobility system and an operation module that receives a movement input of the mobility system. The operation module is configured to identify the mobility state through the mobility module, measure a force or torque depending on the movement input, calculate a restoring torque satisfying a critical velocity or a critical acceleration, based on the mobility state and the measured force or torque, and provide feedback on the movement input depending on the determined restoring torque.

A method is proposed for stabilizing a tractor-trailer combination comprising a tractor vehicle and a trailer. The tractor vehicle has front and rear axle steering. The distinguishing feature of the method is that while driving, and braking while rounding a curved trajectory, the steering angle of the wheels on the rear axle is set to be in the same direction as the steering angle of the wheels on the front axle in order to stabilize the tractor-trailer combination.

A system of an electric vehicle configured to compensate for spin of the electric vehicle that results from slipping of one or more wheels. A controller detects when one or more wheels are slipping and/or a spin (e.g., rotation) of the electric vehicle that results from a torsion force as a result of the slipping. The controller instructs the steering system to orient one or more of the wheels that are not slipping in a direction opposite the direction of rotation to attempt to reduce or eliminate rotation of the electric vehicle and/or to maintain the present direction of travel.

A steering controller includes processing circuitry configured to execute a first operation process that, when an angle command value is not input from outside of the processing circuitry, calculates a first torque command value corresponding to a steering-side operation amount and operating a drive circuit of an electric motor to adjust torque of the electric motor to the first torque command value. The processing circuitry is further configured to execute a second operation process that, when the angle command value is input from the outside of the processing circuitry, calculates a second torque command value corresponding to at least an angle-side operation amount of the steering-side operation amount and the angle-side operation amount and operating the drive circuit of the electric motor to adjust the torque of the electric motor to the second torque command value.