A system and method for interrupting a Global Navigation Satellite System (GNSS)-based automatic steering mode of a hydraulic steering system on a vehicle. When a steering wheel is manually turned by an operator, pressurized hydraulic fluid from a steering directional control valve activates an interrupter having an interrupter valve. The interrupter valve blocks pressurized fluid flow to the automatic steering system, thus overriding automatic steering and giving the operator full manual steering control via the steering wheel. The hydraulic interrupt system is mechanical with no electronic elements.

A hydraulic steering system (1) is described comprising a steering unit (3) and a pressure source (4), said steering unit (3) comprising a working port arrangement (L, R) having two working ports, a supply port arrangement having a high pressure port (P) and a low pressure port (5), a main flow path (7) having a main bleed (A1) and a metering device (8) and being arranged between said high pressure port (P) and said working port arrangement (L, R), an amplification flow path (9) having an amplification bleed (Au) and being arranged between said high pressure port (P) and said working port arrangement (L, R), said main bleed (A1) and said amplification bleed (Au) being controlled together by means of a steering handle (6) and being closed in neutral position of said steering handle, and said pressure source (4) having a variable displacement.

The invention relates to a steering system for at least one trailing or leading axle of a vehicle, comprising: a steering angle sensor for measuring a steering angle of wheels of a leading axle of the vehicle; a driving speed sensor for measuring a driving speed of the vehicle; an electric motor (1.2) that drives a hydraulic pump (2); a working cylinder (11) for steering the wheels of the trailing axle, which is joined to the hydraulic pump (2); a control device (1.1) which determines a trailing angle of wheels on the trailing axle of the vehicle, using the data of the steering angle sensor and the driving speed sensor, and which controls the electric motor in a corresponding manner, wherein the working cylinder (11) has a centre position borehole (1.3) via which hydraulic fluid can be emitted from the working cylinder (11), and a piston seals the centre position borehole (11.3) in the straight position of the wheels of the trailing axle, wherein the working cylinder (11) is connected to return valves (10 and 10.1), via which hydraulic fluid can flow back into a tank (6), wherein the centre position borehole (11.3) of the working cylinder (11) is connected to a centre position valve (12), via which hydraulic fluid can flow back into a tank (6), and wherein the return valves (10 and 10.1) and the centre position valve (12) are in the form of a poppet valve.

A machine includes a frame, a first steering arm, a second steering arm, a first hydraulic actuator coupled to the frame and the first steering arm, and a second hydraulic actuator coupled to the frame and the second steering arm. A first angle sensor measures a rotational displacement of the first hydraulic actuator relative to the first steering arm. A first link couples the first hydraulic actuator and the first sensor, and isolates movements other than the first rotational displacement. A second angle sensor measures a second rotational displacement of the second hydraulic actuator relative to the second steering arm. A second link couples the second hydraulic actuator and the second sensor, and isolates movements other than the second rotational displacement.

A control device for an unmanned vehicle includes a temperature data acquisition unit acquiring temperature data of hydraulic oil supplied to a first hydraulic actuator actuating a steering device of the unmanned vehicle, and a command output unit outputting a change command for changing a travel parameter of the unmanned vehicle based on the temperature data.

A control device for an unmanned vehicle includes a temperature data acquisition unit acquiring temperature data of hydraulic oil supplied to a first hydraulic actuator actuating a steering device of the unmanned vehicle, and a command output unit outputting a change command for changing a travel parameter of the unmanned vehicle based on the temperature data.

An electrohydraulic steer-by-wire steering system has an operator interface for specifying a turning angle, which is associated with a sensor for the acquisition of a position or movement of the operator interface. An electronic control device is connected to a first electrohydraulic circuit and to a second electrohydraulic circuit and set up in order to actuate the two electrohydraulic circuits as a function of a signal from the sensor. The system further includes a steering actuator for adjusting the turning angle of a steerable wheel. The steering actuator has two chambers each of which is connected simultaneously to the two electrohydraulic circuits.

A hydraulic system for controlling at least one steerable caster wheel of an agricultural machine includes a first actuator having a piston and including an inboard fluid port for supplying fluid to a first side of the piston to move the piston in a first direction, and an outboard fluid port for supplying fluid to a second side of the piston to move the piston in a second direction. A first fluid pressure equalizer is fluidically coupled to the first side actuator and operable to equalize fluid pressure over a period of time between the first side and the second side of the piston of the first side actuator.

A steering system for a work vehicle having a steerable wheel. The steering system includes a steering input device configured to provide a first steering input and a second steering input to move the steerable wheel. A pilot system is operatively connected to the steering input device and includes a first pilot line operatively connected to the first steering input and a second pilot line operatively connected to the second steering input. A piloted system is operatively connected to the pilot system and includes a direction control valve operatively connected to each of the first and second pilot lines and to a steering cylinder. The steering cylinder is coupled to the steerable wheel. The direction control valve responds to each of the pressure signals of the first and second pilot lines to adjust the position of the steering cylinder which in turn moves the steerable wheel.

A control apparatus controls the hydraulic connection between self steering wheels on a trailing vehicle, for example a grain cart, and the hydraulic system of a utility vehicle, for example a tractor, towing the trailing vehicle. An auxiliary circuit on the trailing vehicle forms a continuous loop receiving in series one or more wheel actuators associated with the self steering wheels. A valve arrangement is operable in a locked state or unlocked state in which the continuous loop is isolated from the tractor to prevent or allow a flow of fluid in the continuous loop regardless of the state of the tractor hydraulics. In a manual state, the flow in the loop is dependent upon the tractor hydraulics. In an automatic mode, a controller automatically operates the valve arrangement between the locked and unlocked states dependent upon one or more sensed operating conditions of the trailing vehicle.