CoG and MoI test equipment

Precise and efficient measurement of Centre of Gravity (CoG) and Moments of Inertia (MoI) for both full vehicles and vehicle components.

Why is accurate CoG and MoI testing important to vehicle development?

The CoG represents the point where the entire weight of a vehicle is concentrated and MoI describes how mass is distributed around different axes of rotation. When developing vehicles understanding and optimising the CoG and MoI are fundamental for creating vehicles that are stable, agile, and safe to handle during real-world driving. The MoI and CoG of a vehicle can be measured using several methods, depending on the level of accuracy and complexity required.

At AB Dynamics, our approach to CoG and MoI testing is via an optional add-on to our Kinematics and Compliance (K&C) test machine, the SPMM Plus. The option permits the measurement of the full mass inertia properties of vehicles and objects, in addition to a detailed analysis of a vehicle’s suspension characteristics under various loading conditions.

How the MIMS upgrade works

The moving body design of the SPMM Plus allows roll, pitch, bounce, and yaw motions to be applied to the vehicle body. This generates forces that are accurately measured using load cells located in the sill clamps. The simplicity of the moving body design also means the SPMM can be changed from K&C to MIMS measurement mode in less than 30 minutes, without the need to unload the vehicle. The MIMS option is available as an upgrade for both two and four-wheel station arrangements.

Key features and specifications

The SPMM Plus MIMS option provides accurate CoG and MoI data and is fundamental for understanding the ride and handling characteristics of the test vehicle.

  • A unique moving body, fixed ground plane design
  • Rotations are applied about measured CoG reducing parallel axis errors
  • Vertical, roll and tilt tests provide two or more independent measurements of CG X,Y,Z for increased accuracy
  • All cross products of inertia can be accurately determined
  • Changeover from K&C to MIMS measurement mode takes less than 30 minutes
  • Piezoelectric load cell sensitivities specially selected for the MIMS application
  • Measurement of standalone objects possible with Object add-on

Get the MIMs upgrade

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