A spring-damper assembly includes a damper and an adjustable gas spring system coupled to the damper. The spring-damper assembly can be coupled to a vehicle as part of a suspension thereof. The adjustable gas spring system maintains the ride height of the vehicle while absorbing forces from changes in the terrain. The dampers control unwanted movement of the coil spring and dissipate forces from the suspension.

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 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.

A load estimation device includes: an air spring having a diaphragm that expands and contracts due to supply and exhaust of air, and configured to support a support body in a liftable manner; an auxiliary support portion configured to support the support body separately from the air spring; a displacement sensor configured to measure a length of the air spring; a pressure sensor configured to measure an internal pressure of the air spring; a temperature sensor disposed together with the air spring, and configured to measure a temperature of the air spring; and a calculation unit configured to calculate a spring load supported by the air spring based on measured results of the displacement sensor, the pressure sensor and the temperature sensor.

A load estimation device includes: an air spring having a diaphragm that expands and contracts due to supply and exhaust of air, and configured to support a support body in a liftable manner; an auxiliary support portion configured to support the support body separately from the air spring; a displacement sensor configured to measure a length of the air spring; a pressure sensor configured to measure an internal pressure of the air spring; a temperature sensor disposed together with the air spring, and configured to measure a temperature of the air spring; and a calculation unit configured to calculate a spring load supported by the air spring based on measured results of the displacement sensor, the pressure sensor and the temperature sensor.

An end member assembly can include a first end member section and a second end member section that together form an end member volume. A partition section is provided separately and is disposed within the end member volume to separate the end member volume into at least two volume portions. At least one passage extends through the partition section and at least one control device is disposed in fluid communication along the passage. The control device substantially fluidically isolates the two volume portions under conditions of use below a predetermined differential pressure threshold. The control device permits fluid communication between the two volume portions under conditions of use in which the predetermined pressure threshold is exceeded. Gas spring assemblies including such an end member assembly as well as suspension systems and methods of manufacture are also included.

A pneumatic suspension system for a vehicle, in which the pneumatic suspension system includes a supply tank, a first set of air springs positioned on a first side of the vehicle; a second set of air springs positioned on a second side of the vehicle, and a dual-action dynamic valve positioned between the first set of air springs and the second set of air springs. The dual-action dynamic valve is connected to the supply tank, the first set of air springs, and the second set of air springs by a series of air hoses. The dual-action dynamic valve is adapted to supply air to either one of the first set of air springs or the second set of air springs while simultaneously exhausting air from the other one of the first set of air springs or the second set of air springs.

A pneumatic suspension system for a vehicle, in which the pneumatic suspension system includes a supply tank, a first set of air springs positioned on a first side of the vehicle; a second set of air springs positioned on a second side of the vehicle, and a dual-action dynamic valve positioned between the first set of air springs and the second set of air springs. The dual-action dynamic valve is connected to the supply tank, the first set of air springs, and the second set of air springs by a series of air hoses. The dual-action dynamic valve is adapted to supply air to either one of the first set of air springs or the second set of air springs while simultaneously exhausting air from the other one of the first set of air springs or the second set of air springs.