Abstract: A steering control system for an autonomous machine has a manual steering control valve for directing fluid from a pump to either a head end chamber or a rod end chamber of a hydraulic steering actuator. In one embodiment, an electrically actuated steering valve device is disposed in series flow relationship between the pump and the manual steering control valve and is operative to direct fluid from the pump to the head end and rod end chambers. In another embodiment, a electrically actuated device mechanically actuates the manual steering control valve for steering the machine.

Abstract: Regeneration valves are useful in directing fluid expelled from a contracting chamber of a hydraulic actuator to its expanding chamber to increase the actuation speed of the actuator. The present remotely controlled regeneration circuit improves the controllability of the regeneration valve by positioning the regeneration valve between the pump and the control valve so that the fluid expelled from the contracting chamber and combined with the pump flow to the expanding chamber passes through and is controlled by the control valve. The regeneration valve is moved to its regeneration position by pressurized fluid from a solenoid valve which can be selectively energized by the operator manually closing a switch mounted to a control lever.