Self-propelled vehicles that adjust the pitch of the vehicle during use are disclosed. The vehicle may include a suspension system position sensor and a control unit that adjusts a suspension element based at least in part on a signal from the suspension system position sensor. In some embodiments, the self-propelled vehicle may include an inclinometer for measuring the pitch of the terrain.

A device implementing a system for estimating device location includes at least one processor configured to receive a first and second set of signals, each set corresponding to location data and being received based on a sampling interval. The at least one processor is configured to, for each sampling period defined by the sampling interval, obtain sensor data corresponding to device motion during the sampling period, determine an orientation of the device relative to that of the vehicle based on the sensor data, calculate a non-holonomic constraint based on the orientation of the device relative to that of the vehicle such that the non-holonomic constraint is iteratively updated, and estimate a device state based on the non-holonomic constraint.

A suspension control system dynamically adjusts pistons located proximal to wheels of an agricultural machine to substantially equalize distribution of weight of the machine at each wheel and/or provide a substantially constant desired orientation of the machine above a ground surface thereby protecting laterally extending sprayer booms from contacting the ground. Articulation, pitch, roll and/or machine height can be determined from piston measurements on the machine to apply such height corrections. For sprayers, this allows controlling clearance and suspension height to maintain the boom parallel to the ground to prevent damage.

An air management system and method are provided. The system includes a pressurized air source. A manifold block is coupled to the pressurized air source and includes a plurality of suspension valves in fluid communication with the pressurized air source for controlling air flow to and from a plurality of air springs. An accumulator is coupled to the manifold block for storing air. An accumulator valve is in fluid communication with the plurality of suspension valves and the accumulator to allow exhausted air from the plurality of air springs into the accumulator. An electronic control unit is electrically coupled to the plurality of suspension valves and the accumulator valve for controlling a sequence of operating the accumulator valve and the plurality of suspension valves to provide enhanced exhaust flow from the plurality of air springs to maintain the vehicle in a level orientation while lowering the vehicle.

A control system for a variable damping force damper, includes: motion state quantity sensors configured to detect motion state quantities of a vehicle; a roll damping force base value setting unit configured to set a roll damping force base value based on the motion state quantities, the roll damping force base value being used to compute a target damping force of the variable damping force damper; a roll rate computation unit configured to compute a sprung mass roll rate and an unsprung mass roll rate of the vehicle based on the motion state quantities; and a roll damping force correction unit configured to correct the roll damping force base value based on a roll rate difference that is a difference between the sprung mass roll rate and the unsprung mass roll rate and to output the corrected roll damping force base value as the target damping force.

An auto-leveling drive axle device for a wheel tractor, and leveling method. The device comprises a transmission device and a leveling device. The device of the present invention changes only a vertical position of a drive axle with respect to a wheel, and a wheel shaft distance and wheel center spacing are not changed, thus improving traveling stability of a vehicle.

A vehicle of the present disclosure may include at least one pair of opposing wheels coupled to a tiltable central chassis by a four-bar linkage or the like, such that the wheels are configured to tilt in unison with the central chassis. A steering actuator and/or a tilting actuator may be discretely controllable by an electronic controller of the vehicle. The controller may include processing logic configured to maintain alignment between a median plane of the chassis and a net force vector caused by gravity and any induced centrifugal forces. Various control algorithms may be utilized to steer the vehicle along a desired path, either autonomously or semi-autonomously.

A suspension system may include a pneumatic spring at each wheel of a vehicle. The suspension system may be configured to determine and achieve a pressure set point in each of the pneumatic springs and a target ride height at each wheel of the vehicle. The pressure set point may be determined based on a load at each of the wheels and the center of gravity of the vehicle, such that upon reaching the pressure set point at each in each of the pneumatic springs, a target load and target ride height may be achieved at each of the wheels of the vehicle. The system may also be used to level the ride height of the vehicle and/or achieve a desired orientation.

A suspension apparatus includes: a damping device which damps a force generated between a vehicle body and a wheel; and a control section which controls a damping force of the damping device. The control section includes a multiplication section which multiplies a longitudinal acceleration of the vehicle body detected by a longitudinal acceleration sensor and a differential value of the longitudinal acceleration to thereby obtain a multiplication value.

An active roll control apparatus is provided. The apparatus includes a first actuator that is disposed adjacent to front wheels or rear wheels and is configured to adjust roll stiffness. A controller operates the first actuator in a reverse phase control manner in a roll angle increasing direction when a vehicle is in a low-friction turning driving state.