Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system and method for a vehicle having steerable front and rear wheels has rear hydraulic steering device that may be coupled to one or more of the rear wheels. A rear valve assembly may hydraulically control the rear hydraulic steering device to steer the rear wheels based upon a rear steering command from a controller. In a manual steering mode, the controller does not determine a rear steering command for the rear valve assembly such that the rear wheels are freely rotatable. In a rear steering assist mode, the controller determines the rear steering command based upon, at least in part, the manual steering input.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system and method for a vehicle having steerable front and rear wheels has rear hydraulic steering device that may be coupled to one or more of the rear wheels. A rear valve assembly may hydraulically control the rear hydraulic steering device to steer the rear wheels based upon a rear steering command from a controller. In a manual steering mode, the controller does not determine a rear steering command for the rear valve assembly such that the rear wheels are freely rotatable. In a rear steering assist mode, the controller determines the rear steering command based upon, at least in part, the manual steering input.

Abstract: A steering system and method are described for a vehicle having steerable wheels. A steering device may be coupled to one or more of the wheels. A parked state of the vehicle and a present orientation of the hydraulic steering device may be determined. The present orientation of the steering device may be compared with a neutral orientation of the steering device. Based upon a determined parked state of the vehicle and the comparing of the present and neutral orientations of the steering device, the steering device may be moved from the present orientation toward the neutral orientation.

Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system and method are described for a vehicle having steerable wheels. A steering device may be coupled to one or more of the wheels. A parked state of the vehicle and a present orientation of the hydraulic steering device may be determined. The present orientation of the steering device may be compared with a neutral orientation of the steering device. Based upon a determined parked state of the vehicle and the comparing of the present and neutral orientations of the steering device, the steering device may be moved from the present orientation toward the neutral orientation.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle, and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A steering system and method are described for a vehicle having steerable wheels. A steering device may be coupled to one or more of the wheels. A parked state of the vehicle and a present orientation of the hydraulic steering device may be determined. The present orientation of the steering device may be compared with a neutral orientation of the steering device. Based upon a determined parked state of the vehicle and the comparing of the present and neutral orientations of the steering device, the steering device may be moved from the present orientation toward the neutral orientation.

Abstract: A steering system and method are described for a vehicle having steerable front and rear wheels. A rear hydraulic steering device may be coupled to one or more of the rear wheels. A rear valve assembly may hydraulically control the rear hydraulic steering device to steer the rear wheels based upon a rear steering command. In a rear steering assist mode, the rear steering command may be determined based upon a manual steering input received at a steering input device. In an automated steering mode, the rear steering command may be determined based upon a target path of the agricultural vehicle that is determined independently of the manual steering input.

Abstract: A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle, and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A steering system and method are described for a vehicle having steerable front and rear wheels. A rear hydraulic steering device may be coupled to one or more of the rear wheels. A rear valve assembly may hydraulically control the rear hydraulic steering device to steer the rear wheels based upon a rear steering command. In a rear steering assist mode, the rear steering command may be determined based upon a manual steering input received at a steering input device. In an automated steering mode, the rear steering command may be determined based upon a target path of the agricultural vehicle that is determined independently of the manual steering input.

Abstract: A steering system and method are described for a vehicle having steerable wheels. A steering device may be coupled to one or more of the wheels. A parked state of the vehicle and a present orientation of the hydraulic steering device may be determined. The present orientation of the steering device may be compared with a neutral orientation of the steering device. Based upon a determined parked state of the vehicle and the comparing of the present and neutral orientations of the steering device, the steering device may be moved from the present orientation toward the neutral orientation.

Abstract: A steering system and method are described for a vehicle having steerable wheels, with steering of the wheels controlled, at least in part, by a valve assembly. A ground speed of the vehicle may be determined. Whether a steering command is being provided to a valve assembly may also be determined. An operational pressure at the valve assembly may be determined with a pressure sensor. A threshold pressure may be determined based upon the ground speed and/or whether a steering command is currently being provided. The operational pressure may then be compared with the operational pressure, and steering control with the valve assembly disabled based upon the comparison.

Abstract: A four-bar linkage is provided as a mechanical interface for transferring respective outputs from a speed/direction control device and a hydraulic steering cylinder to displacement control arms of a pair of pumps of a dual-path hydrostatic transmission including a pair of motors respectively coupled for driving a pair of front wheels of a vehicle. The hydraulic steering cylinder is fixed and has a piston rod slidably coupled to an input arm of the four-bar linkage in such a way that a rotation speed decrease occurs as the arm and a linked control plate are pivoted from a neutral position, the control plate transferring pivotal movement to effect differential movement of the displacement control arms. This results in the vehicle speed decreasing during a turn.