Adaptive On-Line Estimation of Road Profile in Semi-active Suspension

An on-line algebraic estimator for parameter identification is integrated a recent road profile estimator. The classical version of a road profile estimator that is based transmission characteristics suffered from parametric variation. Sprung mass is variable by changing the weight of passengers and baggage’s. Furthermore, the damping of semi-active suspension does change rapidly during vehicle driving. The challenge is to identify all imperceptible modifications that can threaten the vehicle performances and to keep the credibility of road profile estimator online. A Differential algebra and operational calculus rules can be helpful to overcome the impact of variation in real time. The algebraic estimator has the fastest detection time and non-asymptotic behavior. In literature, the algebraic observers shown a good estimation of vehicle mass uncertainties. Additionally, this estimator requires a lower number of sensors and has a lower computational overhead. Measurements of vertical accelerations are only required to algebraically identify the sprung mass and damping coefficient of a quarter car model. Some numerical simulation results in time domain and frequency domain are provided. This new version of adaptive estimator can be integrated with the active controller in the future with easy implementation.