Indoor testing should reproduce the real-world environment in order to be effective. In this article, an efficient methodology to reproduce road profiles on a four-poster rig is presented: such a method includes a complex rig control strategy based on an iterative process. Road profiles come from a purposely designed set of sensors fitted on the car which remains the same regardless of the vehicle or surface type. Particular stresses such as speed humps, potholes and manholes can be reproduced as well. Since there are no previous similar studies, a validation is provided by comparing road and rig data streams and using the maximum absolute error and root mean square error as performance indexes. Results show that the rig is able to reproduce road profiles and the related inputs to the vehicle successfully; hence, the method is reliable and effective.

This work analyses the effect of friction in suspension components on a race car vertical dynamics. It is a matter of fact that race cars aim at maximising their performance, focusing the attention mostly on aerodynamics and suspension tuning: suspension vertical and rolling stiffness and damping are parameters to be taken into account for an optimal setup. Furthermore, friction in suspension components must not be ignored. After a test session carried out with a F4 on a Four Poster rig, friction was detected on the front suspension. The real data gathered allow the validation of an analytical model with friction, confirming that its influence is relevant for low frequency values closed to the car pitch natural frequency. Finally, some setup proposals are presented to describe what should be done on actual race cars in order to correct vehicle behaviour when friction occurs

Four-wheeled vehicles are often tested on indoor, four-poster road simulator rigs. Road loads are simulated with the use of servo-hydraulic systems for suspension set-up optimisation, NVH analysis, and fatigue life cycles. The use of a road simulator is not such a common practice for two-wheeled vehicles despite problems to be faced being extremely similar. The paper presents a device for testing motorcycles on a Servotest ® four-poster. A dedicated restraint system had to be devised in order to support the motorcycle without altering its inertial characteristics. Additional pneumatic actuators with a purposely developed instrumentation have been designed to reproduce braking and power thrusts.

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