Floor treatment system with self-propelled and self-steering floor treatment unit

Floor treatment system comprising:

• a self-propelled and self steering floor treatment unit having an electrically driven floor treatment assembly and a rechargeable power supply unit, and
• a central charging station for recharging the power supply unit, wherein:
• the floor treatment unit is adapted to be electrically connected to the charging station by means of respective electrical connecting elements disposed on the charging station and on the floor treatment unit;
• at least one of the respective connecting elements is spring-mounted;
• the floor treatment unit comprises a collision detection sensor with an associated spring-mounted sensing element, the movement of the sensing element in relation to a chassis of the floor treatment unit can be sensed to provide a collision detection signal;
• and
• the spring mounting of the at least one electrical connecting element has a lower spring constant than the spring mounting of the sensing element.