The paper presents the practical implementation of active seat suspension used in vehicles and machinery. The test object is a passive suspension system, in which the vibro-insulating properties have been improved by using an active system controlled by a pneumatic bellows cylinder. Bellows cylinders in pneumatic drives act as single-acting cylinders - push cylinders. The filled bellows cylinder under constant pressure acts as an air spring. The volume of the air cushion changes under the pressure inside. Proportional pressure valve was used to control the bellows cylinder and non-contact relative displacement laser triangulation sensor was used to measure displacement of the seat. A PD-fuzzy controller was used for the control. The use of Fuzzy Logic Controller FLC enables the transition from a quantitative description to a qualitative process. The system structure with a designated output control function has been presented. Test results on the seat suspension vibro-insulating properties of a working machine are presented.