The CRONE suspension

This paper deals with robust control and advanced suspension of vehicles, and more specifically, with a new system called the CRONE suspension, based on non-integer derivation. The CRONE suspension results from a traditional suspension model whose spring and damper are replaced by a mechanical and hydropneumatic system defined by a non-integer order force-displacement transmittance. This system is called the CRONE suspension because of the link with the second-generation CRONE control, i.e. the vertical template. That is why the principle of the second-generation CRONE control is used to synthesise the CRONE suspension's transmittance. The suspension parameters are determined from a constrained optimisation of a performance criterion. A two-degree-of-freedom quarter-car model is used to evaluate performance. The frequency and time responses, for various values of the vehicle load, reveal a great robustness of the degree of stability through the constancy of the resonance ratio in the frequency domain, and of the damping ratio in the time domain.