Prescribed Performance Control of Nonlinear Active Suspension System With Uncertain Dynamics Based on Bionic Reference Model

In this paper, a prescribed performance control (PPC) strategy of a half-car active suspension system based on a bionic reference model is designed to solve the problems of internal uncertain parameters, external unknown disturbance, and energy consumption. Firstly, a new ideal reference model is designed according to the biological principle that the cheetah can keep posture stable when running fast, which is different from the existing control methods that set the expected trajectory of the car body to the 0 position, and provides a new expected trajectory for the motion control of sprung mass. Then, a new prescribed performance controller is designed by introducing the prescribed performance function (PPF) and backstepping method, which can ensure the transient and steady-state performance of the vertical and pitching motions of the sprung mass, improve the vibration reduction performance of the active suspension, avoid using complex function approximators, and improve the calculation efficiency. It is worth noting that the proposed controller can prevent the shortcoming that the suspension travel cannot be restored to the initial position after the tire passes through the stepped road in the existing control methods, so it has better road applicability. Finally, the simulation results show that the designed controller has better vibration reduction performance and lower energy consumption.