Mixed Skyhook and Power Driven Damper: A New Low Jerk Semi Active Suspension Control Based on Power Flow Analysis

Abstract

In practice, semiactive suspensions provide better tradeoffs between performances and costs than passive or active damping. Many different semiactive control algorithms have been developed, including skyhook (SH), accelerationdrivendamper (ADD), powerdrivendamper (PDD), mixed SH and ADD (SHADD), and others. Among them, it has been shown that the SHADD is quasioptimal in reducing the sprung mass vibration. In this paper, we analyze the abilities of vehicular suspension components, the shock absorber and the spring, from the perspective of energy transfer between the sprung mass and the unsprung mass, and propose a new sprung mass control algorithm named mixed SH and PDD (SHPDD). The proposed algorithm defines a switching law that is capable of mixing SH and PDD, and simultaneously carries their advantages to achieve a better suspension performance. As a result, the proposed SHPDD is effective in reducing the sprung mass vibration across the whole frequency spectrum, similar to SHADD and much better than SH, PDD, and ADD, while eliminating the control chattering and highjerk behaviors as occurred in SHADD. The superior characteristics of the SHPDD are verified in numerical analysis as well as experiments. In addition, the proposed switching law is extended to mix other semiactive control algorithms such as the mixed hard damping and soft damping, and the mixed SH and clippedoptimal linear quadratic regulator (LQR).