Motor vehicle air spring system having an ultrasonic measurement arrangement

An air spring system for a motor vehicle, the air spring system comprising:

• a first connecting part defining a cover plate;
• a second connecting part defining a roll-off piston;
• said first and second connecting parts being disposed at a spacing from each other which rapidly changes with the movement of said motor vehicle over a road surface;
• a flexible member having a first end connected to said first connecting part and a second and connected to said second connecting part;
• an ultrasonic arrangement for making contactless measurements of the distance between said first and second connecting parts;
• said ultrasonic arrangement including an ultrasonic transmitter/receiver mounted on one of said connecting parts and a reflector mounted on the other one of said connecting parts;
• said reflector being configured as a two-step reflector having first and second steps;
• and,
• one of said steps being a target reflector and the other one of said steps being a reference reflector and both of said reflectors being at respective distances from said ultrasonic transmitter/receiver which likewise rapidly change as said spacing changes.