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 height control system and method of increasing a vehicle height of a vehicle having a vehicle body and at least one axle assembly. The vehicle height control system includes a pressurized fluid supply system configured to supply a pressurized fluid, and a plurality of air springs provided to elastically support at least one section of the vehicle body of the vehicle above at least one axle assembly of the vehicle and configured to adjust the vehicle height of such sections of the vehicle body relative to a ground surface in response to the supply and discharge of the pressurized fluid. A control assembly of the vehicle height control system has a piston unit fluidically interconnected with the pressurized fluid supply system via a first control valve and is operable to adjust the vehicle height by adjusting a second control valve interposed between the pressurized fluid supply system and the air springs. A controller is configured to receive user input indicative of a Vehicle height adjustment operation desired by a user and to adjust the vehicle height by controlling the control assembly based on the user input.

An air suspension system includes an air supply system block including one or more air spring valves, where the one or more air spring valves are disposed within the air supply system block, the air supply system block having a valve block housing. The system further includes the air supply system block pneumatically coupled with one or more air springs, and at least one reservoir coupled with the air supply system block, at least one motor and pump disposed within the air supply system block. The air suspension further includes fast down leveling valves disposed within the air supply system block.

A primary air suspension system with the reliability of a secondary air suspension system by guaranteeing a minimum pressure in the air spring through a simple mechanical residual pressure valve. The residual pressure valve is set to the air spring pressure required to hold the rear of the unloaded pickup truck at the designed ride height if any of the components (compressor, tank, valves, air lines, Schrader valve, or electronic controller) failure.

A towable vehicle including a chassis, at least two wheels and a suspension assembly supporting each wheel. The suspension assembly includes a swing arm pivotally mounted to the chassis, an axle mounted proximate an end of the swing arm, the wheel being mounted on the axle, at least one shock absorber extending from the chassis to the swing arm, an airbag swing arm mounting pivotally coupled to the swing arm, an airbag chassis mounting coupled to the chassis, an airbag coupled to the airbag swing arm and airbag chassis mountings so that inflation of the airbag allows a suspension height to be adjusted over an operating range and a pivot arm pivotally mounted to the chassis and the airbag swing arm mounting to maintain an orientation of the airbag swing arm mounting over the operating range.

An air management system for a vehicle having a first pneumatic circuit and a second pneumatic circuit, in which the first and second pneumatic circuits are pneumatically connected in a neutral position via a cross-flow mechanism. The first pneumatic circuit includes a first leveling valve configured to adjust independently the height of a first side of the vehicle. The second pneumatic circuit includes a second leveling valve configured to adjust independently the height of a second side of the vehicle. The first and second leveling valves are configured to establish pneumatic communication between the first and second pneumatic circuits when the first leveling valve is not independently adjusting the height of the first side of the vehicle and the second leveling valve is not independently adjusting the height of the second side of the vehicle.

Systems and methods for load monitoring and/or braking control. The load monitoring may include calculating a weight on one or more axles of a vehicle or a trailer using cross-flow pressure information indicative of an air pressure within a cross-flow passage between first and second leveling valves of first and second pneumatic circuits configured to adjust independently heights on first and second sides, respectively, of the vehicle or the trailer. The braking control may include (i) using the cross-flow pressure and speed and/or acceleration information indicative of a speed and/or acceleration of the vehicle and/or the trailer to calculate first and second brake application levels and (ii) applying the calculated first and second brake application levels to first and second brakes on the first and second sides, respectively, of the vehicle or the trailer.

A method for controlling an air suspension system of a vehicle includes: a) determining a bellows pressure-time characteristic curve for air admission to and release from the bellows of one air spring or the bellows of a plurality of air springs, the characteristic curve being normalized with the value of a supply pressure in a reservoir for compressed air, b) sensor measurement of a current pressure in the spring bellows of the air springs as well as the current supply pressure immediately before air admission thereto or air release therefrom, c) determining, from the normalized characteristic curve, the opening duration for the associated shutoff valve using the ratio of the measured bellows pressure to the measured supply pressure and the ratio of the provided target pressure to the measured supply pressure, d) opening the associated shutoff valve for the determined opening duration in order to set the provided target pressure.

A dynamic weight shift suspension system for shifting the tandem axle loads on a vehicle. The system includes a first airbag connected between the drive axle of a tandem and the vehicle frame, and a second airbag connected between a tag axle of a tandem and the vehicle frame. The system also has a mechatronic control unit comprising at least one port and at least one solenoid. The mechatronic control unit is in direct fluid communication with the airbags and an air supply via fluid communication lines.

An air management system for a vehicle having a first pneumatic circuit and a second pneumatic circuit, in which the first and second pneumatic circuits are pneumatically connected in a neutral position via a cross-flow mechanism. The first pneumatic circuit is configured to independently adjust air pressure of a first side of the vehicle. The second pneumatic circuit is configured to independently adjust air pressure of a second side of the vehicle. The system is configured to establish pneumatic communication between the first and second pneumatic circuits when the air management system is not independently adjusting the adjust air pressure of the first side of the vehicle and the air pressure of the second side of the vehicle in the cross-flow mode.