Methods and systems are provided for a vehicle suspension system. In some example methods, a height change request is received for a vehicle suspension having a displacement control for implementing height change requests. A displacement of at least one spring of the vehicle suspension may be determined, as well as whether the displacement satisfies a displacement control criteria. The height of the vehicle suspension may be changed using an air mass control in response to determining the displacement control criteria is not satisfied.

A vehicle includes a suspension system having a first damper, a second damper, and a controller. The dampers include housings and pistons sealingly interfaced with an inner diameter of the housing, dividing the damper into a first and second chamber. The suspension system includes proportional variable relief valves which control pressure of fluid entering or exiting one of the first and second chamber of one of the first and second damper. The controller controls the valves to control extension or compression of the first damper and extension or compression of the second damper based on a degree of roll of the vehicle during a turn of the vehicle or a degree of pitch of the vehicle during acceleration or deceleration of the vehicle. The first and second damper control a roll and pitch of the vehicle. The valves control a damping rate of one of the first and second damper.

An electric vehicle comprises: a main battery which is disposed under the floor of a vehicle interior; a front seat which is provided for a front part of the vehicle interior; a front housing chamber which is formed under a seating surface of the front seat; and an air-suspension device including an air spring which is made to expand and contract by air pressure, an air compressor which compresses air, and one or more first surge tanks which store high-pressure air or low-pressure air, in which the first surge tanks and the air compressor are disposed in a front housing chamber.

A vehicle includes a suspension system having a first damper, a second damper, valves and a controller. Each of the first damper and the second damper include a housing and a piston sealingly interfaced with an inner diameter of the housing, dividing the damper into a first and second chamber. Each valve controls flow rate of fluid entering or exiting at least one of the first and second chamber of at least one of the first damper and the second damper. The controller controls the valves to control extension or compression of at least one of the first damper and the second damper based on at least one of a degree of roll of the vehicle during a turn of the vehicle and a degree of pitch of the vehicle during acceleration of the vehicle or a degree of pitch of the vehicle during deceleration of the vehicle.

A work vehicle including: a first link having one end portion supported by a vehicle body so as to be pivotable; a second link having one end portion pivotally coupled to the other end portion of the first link so as to be pivotable, and another end portion that supports a travel wheel; a first hydraulic cylinder capable of changing a swing posture of the first link; and a second hydraulic cylinder capable of changing a swing posture of the second link relative to the first link. The action of the first hydraulic cylinder is controlled such that a swing position of the first link is located at a target position, based on the result of detection performed by a position detection sensor, and the action of the second hydraulic cylinder is controlled such that thrust has a target value, based on the results of detection performed by pressure sensors.

An control device for an oscillating axle suspension, in particular a front axle suspension, consisting at least of one hydraulic accumulator device (10), a suspension device (12) and a proportional valve (14) having a valve piston (26), wherein to said proportional valve (14) the two devices (10, 12) are connected via fluid ports (16, 18, 20, 22), is characterized in that the valve piston (26), actuatable by an electric motor (28), is longitudinally guided in a valve housing (24) of the proportional valve (14) and controls the fluid ports (16, 18, 20, 22) such that, in at least one functional position (1) of the valve piston (26), the axle oscillation is provided while the suspension is blocked and, in at least one further second functional position (2) of the valve piston (26), the suspension is provided while the axle oscillation is blocked.

A control system includes: a target volume module configured to determine a target volume of hydraulic fluid within a suspension system of a vehicle based on a target pressure of the hydraulic fluid within the suspension system; a volume command module configured to generate a volume command based on the target volume and a present volume of the hydraulic fluid within first and second circuits; a command module configured to, based on the volume command, generate: a pump command for an electric hydraulic fluid pump; and first and second valve commands for first and second seat valves that regulate hydraulic fluid flow to and from the first and second circuits, respectively; a valve control module that actuates the first and second seat valves based on the first and second valve commands, respectively; and a pump control module that controls operation of the pump based on the pump command.

A system includes: a state module configured to selectively set a present state to a first state; a valve control module configured to determine first target open and closed states for valves of a suspension system based on the present state and to open and close the valves according to the first target open and closed states, respectively; a pump control module configured to, when the valves are in the first target open and closed states, respectively, selectively operate an electric pump in a first direction to increase hydraulic fluid pressure in a first portion of the suspension system; and a leak module configured to selectively diagnose a leak in a first one of the valves associated with the first state based on a first pressure in the first portion of the suspension system while the valves are open and closed according to the first target open and closed states.

A suspension system and associated control methods that reduce temperature related fluctuations in the internal pressures and stiffness of the suspension system. A manifold assembly is connected in fluid communication with a plurality of dampers via hydraulic circuits and a pump assembly via a pump hydraulic line. Onboard sensors generate real-time data regarding the vehicle. A suspension control unit, arranged in electronic communication with the aforementioned components, monitors the real-time data, sets a target stiffness and a target pressure, calculates an effective stiffness based on the real-time data, determines if the effective stiffness is above or below the target stiffness and sets a new target pressure accordingly by making stepwise decreases or increases until the new target pressure is reached.

A state module selectively sets a present state to a first state in a predetermined order of states; a valve control module determines first target open and closed states for valves of a suspension system based on the present state and opens and closes the valves according to the first target open and closed states, respectively; a pump control module configured to, when the valves are in the first target open and closed states, respectively, selectively operate an electric pump of the suspension system in a first direction and pump hydraulic fluid toward the suspension system; and a diagnosis module configured to: record first and second values of pressures within the suspension system measured using pressure sensors, respectively, before and after the operation of the electric pump in the first direction, respectively; and selectively diagnose faults in a first subset of the valves based on whether pressure increases occurred.