A hydraulic system for controlling a pair of steerable caster wheels of an agricultural machine includes a fluidic tie rod fluid circuit interconnecting both a left side actuator and a right side actuator with a rear steering control valve in fluid communication, and forming a fluid tie rod between the left side actuator and the right side actuator. A tie rod control valve is disposed in the fluidic tie rod fluid circuit and is controllable between a first position allowing fluid communication through the fluidic tie rod fluid circuit to communicate fluid between the left side actuator, the right side actuator, and the rear steering control valve and a second position blocking fluid communication to the rear steering control valve while connecting the left side actuator and the right side actuator in fluid communication to increase stiffness of the fluid tie rod therebetween.

A vehicle control method for controlling a vehicle including executing a front wheel and a rear wheel including: front wheel-only steering operation control for turning the front wheel without turning the rear wheel in response to a steering instruction from a driving entity; executing rear wheel-only steering operation control for turning the rear wheel without turning the front wheel in response to the steering instruction from the driving entity; and executing a specified control execution process for executing one type of steering operation control specified by the driving entity among a plurality of types of steering operation control including at least the front wheel-only steering operation control and the rear wheel-only steering operation control.

A steer-by-wire system for a motor vehicle includes at least two wheels which are steerable independently of one another in a normal operating mode of the steer-by-wire system, at least two steering actuators, each one being assigned to one of the steerable wheels and being configured for adjusting a steering angle of the particular steerable wheel, and at least one steering electronics system which is signally connected to the steering actuators and which is configured for controlling the steering actuators individually on the basis of steering commands.

It is desired to reduce the manufacturing cost of a vehicle while ensuring stability of travel of the vehicle. The vehicle includes a steering force generating means, and a steering device (10, 20) for steering right and left wheels (w). The steering device (10, 20) includes tie rods (12 and 22) connected, respectively, to the right and left wheels (w), and configured to steer the respective right and left wheels, a pair of rack bars (53 and 54) connected to the respective tie rods (12 and 22), and a rack bar moving means (60) capable of moving, by a same distance, the pair of rack bars (53 and 54) in one of opposite directions or in one and the other of the opposite directions, respectively, whereby the pair of rack bars (53 and 54) are moved simultaneously with each other under the steering force generated by the steering force generating means.

A steering control system with which a steering angle accurately follows a steering angle command value is provided. An assist command value calculation circuit calculates a first assist component based on a value obtained by adding a basic assist controlled variable with a system stabilization controlled variable. The assist command value calculation circuit includes a pinion angle feedback control circuit that calculates a second assist component by executing angle feedback control based on a deviation between a pinion angle and a final pinion angle command value that is the sum of a pinion angle command value and an ADAS command angle. The assist command value calculation circuit outputs an assist command value based on the first assist component and the second assist component. The assist command value calculation circuit receives a steering torque obtained after the influence of viscosity and inertia is reduced by a steering torque compensation circuit.

A steering control system with which a steering angle accurately follows a steering angle command value is provided. An assist command value calculation circuit calculates a first assist component based on a value obtained by adding a basic assist controlled variable with a system stabilization controlled variable. The assist command value calculation circuit includes a pinion angle feedback control circuit that calculates a second assist component by executing angle feedback control based on a deviation between a pinion angle and a final pinion angle command value that is the sum of a pinion angle command value and an ADAS command angle. The assist command value calculation circuit outputs an assist command value based on the first assist component and the second assist component. The assist command value calculation circuit receives a steering torque obtained after the influence of viscosity and inertia is reduced by a steering torque compensation circuit.

A terminal tractor includes four independently steerable wheels, each with their own dedicated drive motor and each with their own dedicated steering device. The terminal tractor includes a controller operable to provide input commands to the drive motors and to the steering devices to operate the terminal tractor. The terminal tractor also includes a fifth wheel coupling which includes a lifting mechanism capable of raising and lowering the fifth wheel coupling a in single vertical direction.

A wheel steering device for a vehicle, including: a steering knuckle that constitutes a part of a suspension device and that is capable of moving relative to a body of the vehicle in an up-down direction, the steering knuckle holding a wheel such that the wheel is rotatable; and a steering actuator configured to cause the steering knuckle to be pivoted about a kingpin axis so steer the wheel, wherein a caster angle and a caster offset are both 0.

An automobile having sets of front and rear wheels, of which one or both sets are steerable wheels and one or both sets are driven wheels. Each steerable wheel is rotatably supported on a respective steering knuckle that is swivelable about an upright steering axis, and is coupled to the frame by a suspension system for relative movement upwardly and downwardly of the automobile's frame. The steering knuckle of each steerable wheel is movable through a ninety degree range between a straight-ahead position for longitudinally straight travel of the automobile in a normal road travel mode, and a ninety-degree position for lateral travel of the automobile in another mode.

A vehicle behavior stabilization system includes a yaw moment applying device configured to apply a yaw moment to the vehicle, a vehicle behavior stabilization control unit configured to selectively control the yaw moment applying device in such a way to stabilize a vehicle behavior according to a computed rear wheel slip angle in relation to a start threshold value and an end threshold value, and a threshold value correcting unit configured to correct the start threshold value and the end threshold value according to a change rate of the computed rear wheel slip angle and/or a change rate of a computed vehicle body slip angle.