Design of a new (Lusaro) caravan chassis

A caravan is basically a central axle trailer, with part of the load carried by the towing car through the coupling point. A car-caravan combination thus becomes unstable beyond a certain speed, whereby the critical speed depends on the caravan's centre of gravity, mass, axle cornering stiffness and draw bar length. Most of these parameters are a result of the weight and weight distribution, applied by the user in stowing his luggage in the caravan, resulting in considerable risk of instabilities on a trip to the sunny beaches of Italy or Spain.  

Research with Lusaro

The Lusaro company has adopted the idea of adding an additional nose wheel to the front of a caravan, and at the same time shifting the rear axle rearward. The cornering and stability properties have been investigated by HAN Automotive Research and Lusaro by means of simulation studies and experimental research, using a first chassis prototype.  

Modified behaviour

It has been shown that by restricting the nose wheel using rotational springs and dampers, the behaviour of the car-caravan combination can be modified such that:

• cornering behaviour is improved with respect to a conventional caravan
• stability is improved, i.e. the critical speed at which the combination becomes unstable exceeds by far this speed for the corresponding conventional caravan
• shimmy behaviour is not apparent