Abstract: Disclosed is a level control system in which the operational readiness of the compressor (2) is tested by connecting the pressure sensor (10) to the output (6) of the compressor (2) via a compressed-air sensor line (8). All other compressed-air lines that are connected to the output (6) of the compressor (2) are locked by shutting directional control valves (201 to 20d and 30). The compressor (2) is then switched on and it is tested how rapidly the pressure increases on the pressure sensor (10). If the increase per interval exceeds a defined threshold value, the compressor is operationally ready.

Abstract: Disclosed is a level control system in which the operational readiness of the compressor (2) is tested by connecting the pressure sensor (10) to the output (6) of the compressor (2) via a compressed-air sensor line (8). All other compressed-air lines that are connected to the output (6) of the compressor (2) are locked by shutting directional control valves (201 to 20d and 30). The compressor (2) is then switched on and it is tested how rapidly the pressure increases on the pressure sensor (10). If the increase per interval exceeds a defined threshold value, the compressor is operationally ready.

Abstract: Disclosed is a pneumatic shock absorbing system (1) for a motor vehicle, comprising at least one pneumatic spring (18a, 18b, 18c, 18d) per motor vehicle wheel on at least one vehicle axle, at least one control device (36), at least one compressor (2), at least one pressure sensor (10), at least one on-off valve (20a, 20b, 20c, 20d), and at least one connecting pipe (8, 16a, 16b, 16c, 16d, 62, 64) which is connected to an external source (76) of compressed air. The control device (36) of the pneumatic shock absorbing system (1) receives a start signal for basic filling while at least one valve (20a, 20b, 20c, 20d) is triggered by the control device (36) in such a way that at least one component (8, 16a, 16b, 16c, 16d, 18a, 18b, 18c, 18d, 62, 64) of the pneumatic shock absorbing system (1) is basically filled.

Abstract: An air spring and shock absorber assembly (22) includes an air spring (4) and a shock absorber (24). The assembly further includes a level control unit (18) in addition to an elevation sensor (20) for determining and adjusting the spring elevation (hx) between the two end positions (h1, h2) and also includes a damper control (34) for adjusting the damping hardness given by the friction coefficient (&rgr;x) In order to avoid impacts against the end-position buffers (38) also in the deflected or extended state, the friction coefficient (&rgr;x) of the damper (24) is a function of the particular measured spring height (hx). The damper characteristic line &rgr;x=f(hx) is characterized by an increase of the friction coefficient (&rgr;x) in the direction toward at least one of the end positions (h1, h2) of the spring (4). The damper hardening can be realized with the aid of a pressure increase in the damper (24) in the case of an air damper.