The disclosure relates to a steering control system useful for providing stable control during high-speed operation of harvesters, such as self-propelled windrowers. The steering control system utilizes a sensor for detecting and regulating a position of a single steering cylinder associated with a first caster, a damper being free of sensing and providing passive damping to the second caster.

A vehicle includes a rear steering system and a front differential hydraulic drive system. A first front drive control valve is operable to output a defined fluid flow in response to a steering command input. A second front drive control valve is operable to selectively divert a portion of the defined fluid flow output from the first front drive control valve. When the vehicle is operating in a pre-defined condition, a steering controller may control the second front drive control valve to divert a portion of the defined fluid flow from the first front drive control valve to define a reduced fluid flow, which is communicated to the front differential hydraulic drive system, to reduce a steering ratio of the front differential hydraulic drive system relative to the rear steering system, to desensitize steering provided by the front differential hydraulic drive system.

A transport vehicle includes two non-steered drive wheels, two non-driven steered load wheels, drive motors for driving the drive wheels, a steering target value encoder, a device for detecting the steering angle of one of the load wheels, and an electric control unit. An actuation of the steering target value encoder displaces a steering pole along a steering pole axis. The steering target value encoder steers each of the load wheels from a first position in which the load wheels' axes run parallel to the drive wheels' axes into a second position in which the load wheels' axes are oriented to the steering pole which lies between the drive wheels. The electronic control unit influences a rotational speed of the drive motors as a function of the steering angle and reverses a direction of rotation of at least one of the drive motors as a function of the steering angle.

Self-propelled vehicles that include swiveling caster wheels and independent drive wheels are disclosed. The self-propelled vehicles are selectively steered in a caster wheel steering mode or a drive wheel steering mode. The vehicle includes a differential system that may include a differential valve that allows hydraulic fluid to be transferred between the left and right drive systems. The differential system may be operable during the caster wheel steering mode such as when the vehicle is driven for transport between sites.

Self-propelled vehicles that include swiveling caster wheels and independent drive wheels are disclosed. The self-propelled vehicles are selectively steered in a caster wheel steering mode or a drive wheel steering mode. The vehicle includes a differential system that may include a differential valve that allows hydraulic fluid to be transferred between the left and right drive systems. The differential system may be operable during the caster wheel steering mode such as when the vehicle is driven for transport between sites.

An identical steer control mechanism of a radial bar-link trapezoidal swing arm, a method and a multi-wheel vehicle thereof are disclosed. The radial bar-link trapezoidal swing arm is in a right triangle shape, and in combination with a two-dimensional composite control transmission arm of a cross-shaped groove formed by a transverse groove and a vertical groove, an elliptical gauge is shaped; the longitudinal cosine displacement is controlled by the sliders in the transverse groove, and the transverse sine displacement can be controlled by connecting the sliders in the vertical groove after the right-angle end bearing is hinged to connecting rods, the end bearing on the two-dimensional composite control transmission arm, namely the key control point bearing, draws a deflection elliptical trajectory, and the hinged slider to the key control point bearing is connected with a vector control swing arm sliding slot to generate a steering angle i.

A drive and control system is provided for use on a zero turn vehicle, and includes first and second hydraulic ground drives independently driving a set of driven wheels. Each ground drive has an electric actuator to control the output thereof. An operator mechanism generates a drive signal corresponding to a neutral drive position or to one of a plurality of non-neutral drive positions of the operator mechanism, and a steering signal corresponding to a neutral steering position or to one of a plurality of non-neutral steering positions of the operator mechanism. Sensors generate signals corresponding to sensed roll, pitch and yaw parameters. A stability control module includes a processor for receiving the drive and steering signals and for providing output signals to the electric actuators.

An oscillation limited driven steering track assembly includes a track mechanism coupled to and driven by a hydraulic motor. The motor is pivotally secured about a steering axis to a stub axle which partially supports a land vehicle. A longitudinally extensible and retractable apparatus extends between the track mechanism and the stub axle. One end of the apparatus is pivotally secured to a post secured to and extending from the track mechanism parallel with the motor shaft axis of rotation. A yoke is provided between the apparatus other end and pivotally secures the apparatus to the stub axle about the steering axis and, also, about a pivot axis perpendicular to the steering axis. Oscillation of the track mechanism about the motor shaft is limited by the apparatus. Simultaneously, the apparatus does not interfere with the track mechanism while the mechanism is rotated about the steering axis for steering the vehicle.

Systems for controlling the speed and direction of vehicles such as tractors, including vehicles that have low to zero turning radius capability. Systems include steering and speed coordination systems that control the direction and speed of rotation of vehicle drive units.

Systems for controlling the speed and direction of vehicles such as tractors, including vehicles that have low to zero turning radius capability. Systems include steering and speed coordination systems that control the direction and speed of rotation of vehicle drive units.