Abstract: Apparatus for testing a wheel suspension of a vehicle, comprising at least one measuring plate adapted to be moved by an excitation mechanism, a first measuring device for each measuring plate for measuring vertical forces exerted by an air tire of the vehicle on the measuring plate, a processing unit for processing measured values provided by the first measuring device and a display unit for displaying a measuring result. Further, a second measuring device is provided for measuring a selected one of a position, velocity and acceleration of the measuring plate. The processing unit being adapted to determine a transfer function of the wheel suspension from the measuring values of the first measured device and measured values of the second measuring device, the wheel suspension comprising a plurality of system elements, each of the system elements carrying a system value.

Abstract: An apparatus for testing the wheel suspension of a vehicle in the frequency domain, in particular the shock absorbing element of said suspension, comprises a measuring plate, a mechanism for oscillating the measuring plate with a frequency varying in a predetermined range, for example from 0-25 Hz, a measuring device for measuring the vertical forces exerted by a tire of the vehicle on the measuring plate, a memory for storing the measured force values and a logic circuit for processing the measured force values. The apparatus stores both the frequency values corresponding to the measured force values and a mathematical model of a linear second order mass spring system formed by the unsprung mass, the tire and the shock absorbing element, and determines the minimum force value and corresponding frequency value from the stored measured force values and corresponding frequency values.