A method is provided for determining whether or not ground contact loss is imminent for a wheel of a vehicle, the vehicle including a vehicle body having a vertical extension in a vertical direction, the wheel being allowed to be subjected to a relative vertical displacement, in the vertical direction, in relation to the vehicle body, the vehicle further being such that a maximum value of a vertical displacement of the wheel relative to the vehicle body is limited to a relative vertical displacement limit, the method including determining an actual relative vertical displacement of the wheel relative to the vehicle body, determining a limit margin as the difference between the actual relative vertical displacement and the relative vertical position limit, and determining that ground contact loss is imminent for a wheel if the limit margin is within a predetermined vertical threshold range.

A semi-trailer for transporting a load to be moved has a wheeled front module having a right-hand front row and a left-hand front row of front bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a wheeled rear module comprising a right-hand rear row and a left-hand rear row of rear bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a coupling unit of the wheeled front module for the coupling to a tractor and comprising a pair of hydraulic jacks for transferring a part of the load to be moved to the tractor; a first hydraulic unit interposed between the hydraulic cylinders of the front and rear rows of bogies and configured in such a way that the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of the right front row and of the cylinders of the left-hand rear row is equal to the sum of the instantaneous pressures controlling the cylinders of the left-hand front row and of the cylinders of the right rear row; and a second hydraulic unit configured to control the hydraulic jacks based on the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of said right front row and of said left-hand front row.

A semi-trailer for transporting a load to be moved has a wheeled front module having a right-hand front row and a left-hand front row of front bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a wheeled rear module comprising a right-hand rear row and a left-hand rear row of rear bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a coupling unit of the wheeled front module for the coupling to a tractor and comprising a pair of hydraulic jacks for transferring a part of the load to be moved to the tractor; a first hydraulic unit interposed between the hydraulic cylinders of the front and rear rows of bogies and configured in such a way that the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of the right front row and of the cylinders of the left-hand rear row is equal to the sum of the instantaneous pressures controlling the cylinders of the left-hand front row and of the cylinders of the right rear row; and a second hydraulic unit configured to control the hydraulic jacks based on the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of said right front row and of said left-hand front row.

An air management system for a vehicle having a supply tank, a system controller integrated with the supply tank, a first pneumatic circuit pneumatically connected to the system controller, and a second pneumatic circuit pneumatically connected to the system controller. The system controller adjusts independently air pressure of the first pneumatic circuit and the second pneumatic circuit without establishing pneumatic communication between the first and second pneumatic circuits. The system controller establishes pneumatic communication between the first and second pneumatic circuits when the system controller is not adjusting independently the air pressure of the first pneumatic circuit and the second pneumatic circuit.

An air management system for a vehicle having a supply tank, a system controller integrated with the supply tank, a first pneumatic circuit pneumatically connected to the system controller, and a second pneumatic circuit pneumatically connected to the system controller. The system controller adjusts independently air pressure of the first pneumatic circuit and the second pneumatic circuit without establishing pneumatic communication between the first and second pneumatic circuits. The system controller establishes pneumatic communication between the first and second pneumatic circuits when the system controller is not adjusting independently the air pressure of the first pneumatic circuit and the second pneumatic circuit.

An air management system for a vehicle having a supply tank, a system controller integrated with the supply tank, a first pneumatic circuit pneumatically connected to the system controller, and a second pneumatic circuit pneumatically connected to the system controller. The system controller adjusts independently air pressure of the first pneumatic circuit and the second pneumatic circuit without establishing pneumatic communication between the first and second pneumatic circuits. The system controller establishes pneumatic communication between the first and second pneumatic circuits when the system controller is not adjusting independently the air pressure of the first pneumatic circuit and the second pneumatic circuit.

An air management system for a vehicle having a supply tank, a system controller integrated with the supply tank, a first pneumatic circuit pneumatically connected to the system controller, and a second pneumatic circuit pneumatically connected to the system controller. The system controller adjusts independently air pressure of the first pneumatic circuit and the second pneumatic circuit without establishing pneumatic communication between the first and second pneumatic circuits. The system controller establishes pneumatic communication between the first and second pneumatic circuits when the system controller is not adjusting independently the air pressure of the first pneumatic circuit and the second pneumatic circuit.

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.

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.

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.