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The SAVGS (Series Active Variable Geometry Suspension) is a new type of electro-mechanical active suspension that is applicable to a wide range of road vehicles. It keeps all the elements of a standard passive suspension, and merely adds a mechanism between the shock absorber unit and the vehicle’s chassis. Through the action of an electro-mechanical actuator, the motion of this mechanism is controlled and the behaviour of the suspension is continuously adapted in order to improve ride comfort, reduce chassis attitude motions, and improve handling. A key advantage of the proposed system in comparison with other existing solutions is that the AVGS benefits from low power and energy consumption, low weight, and fail-safe operation.

Starting from the bare concept, this project aims to investigate the potential benefits of the SAVGS as well as to produce the required physical and virtual tools needed to study and develop it. A proof-of-concept experimental test rig has been built in the Mechanical Engineering Department, and high-fidelity nonlinear multi-domain models have been produced in order to simulate a full vehicle equipped with the SAVGS. Significant progress has also been made on the SAVGS control and on the design and component selection.

The control is performed in two stages: 1) an outer loop determines the desirable single-link position in each corner of the vehicle; and 2) several inner loops track this position reference whilst ensuring that none of the actuator constraints (voltage, current, power, torque and speed) are violated.

Current work focuses on:

  1. The optimal dimensioning of the SAVGS given certain requirements in terms of chassis attitude control compensation during steady-state forward and/or lateral acceleration.
  2. Design of Hinf robust control to improve passenger comfort and road holding whilst minimising suspension deflections.
  3. Effective blending of attitude and comfort control strategies.
  4. Refinement and expansion of the test rig facility.

CAP People

  • Simos A Evangelou,
  • Carlos Arana Remirez,
  • Cheng Cheng,
  • Yu Min,


  • Daniele Dini, ME Department, IC,