Investigation of a Limited-State Active Suspension for Articulated Heavy Vehicles

An articulated vehicle suspension comprising a parallel combination of passive energy restoring and dissipative elements and a feedback controlled force generator is analyzed using H₂ control synthesis. The active suspension schemes based on limited-state measurements are formulated to minimize a performance measure comprising ride quality, cargo safety, suspension and tire dynamic deflections, and power requirements. The ride quality and the dynamic wheel load performance characteristics of these suspension schemes are compared to those of a vehicle with an ideal active suspension and an “optimum” passive suspension to demonstrate the performance potentials of the proposed limited-measurement-based suspension schemes. The results of the study reveal that the fail-safe limited state active suspensions, which utilize only readily available measurements, can yield significant performance benefits associated with the ride quality and the tire dynamic forces similar to those achieved using an ideal full-state feedback active suspension.