Vehicle dynamics engineering consultancy, Team Rosberg Engineering (TRE), has boosted its testing and validation capabilities with the acquisition of a highly accurate Kinematics and Compliance (K&C) test machine. The rig is a SPMM Plus (Suspension Parameter Measurement Machine) from AB Dynamics, which is being installed at TRE’s headquarters in Germany and is due to become operational in early 2024.
The SPMM Plus enables OEMs and suppliers to accelerate the design and testing of a vehicle’s suspension system by accurately measuring and analysing suspension movement whilst subjecting it to a faithful replication of on-road vehicle behaviour.
As a quick explanation, kinematics refers to the motion of the suspension, which is determined by how the lengths of linkages and number of pivots govern the way the suspension will move through an arc, impacting aspects such as camber and toe, all in the absence of force. Compliance is the assessment of how the suspension system moves with the addition of load inputs, which helps to account for movement in rubber bushes and isolation components as well as the bending of linkages.
The machine utilises a novel moving centre table design that manipulates a vehicle’s body to generate the necessary movement and forces into the vehicle’s suspension. This design means the ground plane (the road) remains fixed when simulating vehicle cornering and braking. This architecture ensures the measurement equipment connected to the vehicle’s wheels remains relatively static, reducing the travel being measured, which improves test accuracy.
The table is controlled in six degrees of freedom by precision electromechanical actuators, which enable a combination of roll, pitch, bounce and yaw motion to be applied to the vehicle body. As a closed-loop system, it requires no iteration to reach the desired drive commands, which reduces testing time.
TRE opted for the optional Moment of Inertia Measurement System (MIMS) package for SPMM Plus, which adds the capability to measure a vehicle’s Centre of Gravity (CoG) and Moment of Inertia (MoI). The moving body fixed-ground design of the machine means the test vehicle can be subjected to the full axis rotation required to generate the CoG and MoI faster and more accurately than with traditional machines.
TRE will use the SPMM Plus machine to conduct K&C tests on various vehicle suspension systems. This will enable the consultancy to rapidly benchmark vehicles, monitor early series production vehicles and accelerate vehicle development. The machine will also be used to generate all the necessary chassis-based data required to create and correlate virtual vehicle models.
