Mobile machines in the construction (e.g. excavators, wheel loader), agricultural (e.g. harvesters, beet diggers) and forestry (e.g. harvesters, forwarders) sector are usually used under harsh conditions such as dust, dirt, mud, wetness, cold or heat as well as in rough environments. They are also often very large, so that it must be ensured that operators can climb up and down safely and are provided with a sufficient field of view.