A vehicle suspension system for vehicle height adjustment comprises: a damper for adjusting a height of a vehicle with neutral pressure by driving a piston up and down in a space inside a damping cylinder in which fluid is accommodated to a pressurization region in a pressurization direction and a restoration region in a restoration direction; an actuator, connected to a flow path of the damper, for adjusting the neutral pressure of the damper; a two-way control valve that operates on and off to allow and block movement of the fluid in the damping cylinder and the fluid in the hydraulic cylinder in both directions; a reservoir for regulating gas pressure in the damping cylinder; and a control unit that controls a pressure of the motor pump of the actuator.

An agricultural machine includes a frame, a ground-engaging element, a suspension system that movably supports the frame relative to the ground-engaging element, wherein the suspension system is configured to apply, for a given displacement of the frame relative to the ground-engaging element, a force based on a force-to-displacement relationship. A control system is configured to receive an input indicative of an operational state of the agricultural machine during operation on a terrain, and automatically control the suspension system to adjust the force-to-displacement relationship of the suspension system based on the operational state.

Two or more sensors positioned at a wheel of a stopped vehicle may detect an unwanted substance, and transmit signals, based on which a height level of the substance is determined. The system may also determine a type of the substance, such as water, snow, sand or mud, based on electrical resistance of the substance detected by the sensors. Cameras or other imaging equipment, including LIDAR, may also be used to determine the substance height and/or composition. Accordingly, actions to protect the vehicle may be taken, such as raising or lowering the ride height of the vehicle body using an adjustable suspension of the vehicle. Other protective actions may include closing vents, seals, valves and battery isolation units, and transmitting messages to a vehicle driver and/or to emergency personnel.

A hydraulic suspension system for a motor vehicle having at least a pair of road engaging wheels. The suspension system includes, a hydraulic cylinder coupled with the each of the pair of road engaging wheels, the hydraulic cylinder defining a cap end volume and a rod end volume separated by a piston. A hydraulic supply circuit for the hydraulic cylinder includes, a high pressure hydraulic source, a low pressure hydraulic drain, a pair of hydraulic sub circuits each coupled to one of the hydraulic cylinder cap and rod end volumes. Each hydraulic sub circuit includes, a proportional supply flow valve coupled with the high pressure hydraulic source and one of the cylinder volumes, a return flow control proportional valve coupled with the low pressure hydraulic drain and the one cylinder volume, and an accumulator coupled to the associated hydraulic cylinder volume through an accumulator fill control proportional valve.

Two or more sensors positioned at a wheel of a stopped vehicle may detect an unwanted substance, and transmit signals, based on which a height level of the substance is determined. The system may also determine a type of the substance, such as water, snow, sand or mud, based on electrical resistance of the substance detected by the sensors. Cameras or other imaging equipment, including LIDAR, may also be used to determine the substance height and/or composition. Accordingly, actions to protect the vehicle may be taken, such as raising or lowering the ride height of the vehicle body using an adjustable suspension of the vehicle. Other protective actions may include closing vents, seals, valves and battery isolation units, and transmitting messages to a vehicle driver and/or to emergency personnel.