An air suspension system of a commercial vehicle comprises an electronic control device with a level control valve device. A valve element is coupled to a drive element mechanically coupled to a vehicle wheel or axle. In a first relative position of the valve element and a counter valve element, a port for an air suspension bellow is blocked. In a second relative position, the port for the air suspension bellow is connected to a port for an aeration device. In a third relative position, the port for the air suspension bellow is connected to a port for a deaeration device. Control logic generates a control signal for an actuator which, when a level change is set by an operator, correspondingly changes the relative position of the valve element and the counter valve element or the relative position of the counter valve element and a valve housing.

A vehicle height control apparatus includes an information acquisition device that acquires pressure data on a pressure inside an air tank storing compressed air and obstacle data on an obstacle in front of a vehicle, and a controller that calculates a target vehicle height based on the obstacle data, calculates a required distance required to reach the target vehicle height based on the pressure of the compressed air inside the air tank, and determines a vehicle height control timing, resolving a problem that the vehicle height is unnecessarily quickly controlled compared to the position of the obstacle, or is controlled after the vehicle passes through the obstacle to reduce the ride comfort.

A method and device utilizing pressure and/or height measurements across an axle of a vehicle to detect when the vehicle turns and, when a turn is detected, a control action is taken to avoid pneumatic pressure loss by inhibiting active leveling via the height adjustable suspension.

This motor shaft state detection method has: a rotation determination step for determining, using a detected current waveform of a motor, whether or not to be a non-rotational state in which the rotational speed of the motor is smaller than a predetermined speed; a current determination step for determining whether or not to be a supply state in which the absolute value of current supplied to the motor is larger than a predetermined reference value; and a determination step for, when it is determined to be the non-rotational state in the rotation determination step and it is determined to be the supply state in the current determination step, determining that the motor is in a shaft locked state.

An air suspension system for a motor vehicle and a method of operating thereof includes an air suspension device for adjusting a ride-height position of the motor vehicle by the feeding and removal of compressed air into a plurality of air springs. The system also includes a dryer supplied via a compressed-air supply unit which has a compressor driven by an electric motor. A control unit for performing a ride-height control function has instruction for: raising the ride-height position to a first ride-height position; subsequently lowering the ride-height position to a second ride-height position; checking a first condition whether a determined air quantity ratio is less than a first predetermined air quantity limit value; checking a second condition whether a saturation level of the dryer is greater than a saturation limit value, and activating the ride-height control function when either the first or the second condition is satisfied.

A vehicle includes an outside sensor configured to acquire information on an outside circumstance of the vehicle, a vehicle height adjusting device configured to adjust a vehicle height, and a control device configured to control the vehicle. The control device is configured to control the vehicle height adjusting device such that the vehicle height becomes a vehicle height corresponding to a platform condition at a predetermined stop position when the vehicle stops at the predetermined stop position. The control device is configured to control the vehicle height adjusting device based on a height of an obstacle such that the obstacle does not interfere with the vehicle when the obstacle is detected at the predetermined stop position by the outside sensor.

A vehicle height adjustment system includes: a cylinder housing part having an inner space configured to receive working fluid; a piston part positioned in the cylinder housing part, the piston part configured to move linearly in response to the working fluid transferred to the cylinder housing; a damper rod part positioned in the piston part; a protrusion part protruding outward from the damper rod part; and a guide part formed in the piston part facing the protrusion part, wherein the protrusion part is inserted into the guide part.

An electromechanical vehicle height adjustment unit comprises a displaceable member having an abutment surface for abutment of an end of a vehicle spring or for abutment of a vehicle body and a displacement mechanism coupled to the displaceable member and operative to displace the displaceable member in a height direction. The electromechanical vehicle height adjustment unit comprises a rechargeable energy storage device coupled to the electric motor to store electric energy output by the displacement mechanism during a vehicle lowering operation.

A motor vehicle chassis is provided having a base structure that can be hydraulically adjusted in level between a raised and a lowered position. A hydraulic adjuster is assigned to one of the two foot points of the corresponding suspension spring in each of the four wheel suspensions. At least two of the adjusters can be pressurized in parallel by a common hydraulic aggregate comprising a tank and a motor-pump unit and activated by a control unit. The at least two hydraulic adjusters that can be pressurized by the common hydraulic aggregate communicate hydraulically with the accumulator chamber of a spring-piston accumulator, which has at least one piston-position transmitter linked by signal transmission to the control unit.

An air pressure adjusting device includes a compressor configured to compress air taken in from outside, a dryer connected to the compressor and filled with a reversible dehumidifying agent, a connection port through which air dehumidified by the dryer is supplied to another device, an exhaust valve provided between the compressor and the dryer and configured to discharge air in the dryer, and a switch valve provided between the dryer and the connection port and configured to switch between a first flow path having a large air flow rate and a second flow path having a small air flow rate.