Unknown System Dynamics Estimator for Active Vehicle Suspension Control Systems With Time-Varying Delay

Area of Science:

• Control Engineering
• Automotive Systems
• Nonlinear Dynamics

Background:

• Vehicle active suspension systems face challenges from unknown nonlinearities and time-varying input delays.
• Traditional methods often require complex function approximators or observers, increasing computational load.

Purpose of the Study:

• To propose a novel control method for vehicle active suspension systems.
• To address challenges posed by unknown nonlinearities and time-varying input delays.
• To improve vibration attenuation and maintain suspension performance.

Main Methods:

• Development of an Unknown System Dynamics Estimator (USDE) using first-order low-pass filters.
• Implementation of a predictor-based compensation strategy for time-varying input delay.
• Design of a feedback controller integrating the USDE and predictor.
• Stability analysis using Lyapunov-Krasovkii functional.

Main Results:

• The USDE effectively estimates unknown nonlinearities with reduced computational burden and simple tuning.
• The predictor-based strategy successfully compensates for time-varying input delays.
• The integrated controller demonstrates significant vibration attenuation for the vehicle body.
• Lyapunov-Krasovkii functional analysis confirms the closed-loop system's stability.
• Carsim simulations validate the proposed control scheme's efficiency.

Conclusions:

• The proposed control method offers an efficient and stable solution for vehicle active suspension systems.
• The novel USDE simplifies the handling of unknown nonlinearities without complex approximations.
• The integrated approach effectively manages input delays, enhancing overall suspension performance.