About Rigs

Rig Types.

Two types of test rig are used to optimise the suspensions of road and competition vehicles:

"Four Post" Rigs comprise four road input electro-hydraulic actuators, one supporting each wheel. The position of each actuator is controlled independently to follow a prescribed displacement time history. Four post rigs are usually equipped with two or more passive devices to simulate non-varying aerodynamic forces acting on the vehicle sprung mass.

"Seven Post" (or even eight post) Rigs comprise four road input electro-hydraulic actuators, one supporting each wheel, and a further three (or four) actuators attached directly to the vehicle sprung mass. The forces applied by the additional actuators are controlled independently to allow pitching and rolling moments acting on the sprung mass to be simulated, as well as varying aerodynamic forces acting on the sprung mass.