No abstract

Abstract:In this paper we present classical PID controller approach in designing longitudinal Stability Augmentation System and pitch attitude control (SCAS) at nonlinear flight region for a high fidelity F-16 model including aerodynamic uncertainty. In high angle of attack, nonlinear effects of aerodynamic coefficients and atmospheric turbulence are the main challenge in designing and robustness of flight control system. A design scenario that combines deadbeat response and robust control (aerodynamic uncertainties and atmospheric turbulence) is presented. Simulation results show that the designed PI controller exhibits robustness property to system uncertainties.

Progress in aircraft designs heavily depend on automatic flight control system. Modern aircraft have a wide flight envelope (linear and nonlinear) region. This study considers the design of stability and control augmentation system (SCAS) in high angle of attack region for a modern type aircraft via back stepping method. Because of highly nonlinear phenomena in aerodynamic parameters, a locally valid linear in the parameters nonlinear aircraft model is defined, of which the unknown parameters are approximated by Lyapunov base update laws. The numerical simulations show that the controller is capable of control aircraft based on conventional handling qualities and has a better time response than the classical PI.

In this paper, a linear two degrees of freedom linear bicycle model is proposed to investigate the vehicle handling criterion. The study is based on simulation developed using MATLAB / Simulink to predict the vehicle dynamic stability. Steering angle is given as an input to the mathematical model for various vehicular manoeuvres. This model is validated using a step input which is adjusted to give 0.3g lateral acceleration. The system model is simulated under a typical front wheel steering to examine the highway vehicle prediction output within its manoeuvre. This input is also adjusted to keep lateral acceleration value in steady state region. It is found that changing the vehicle center of gravity (CG) position, vehicle mass, tire cornering stiffness and vehicle speed all have a significant influence on the vehicle dynamic stability.

A considerable amount of vibration energy in automotive is worth of being harvested through power dissipation using regenerative suspension systems. In this study, the vehicle dynamics and energy dissipated from a Multi-State Switchable Damper (MSSD) based suspension for various vibration dynamic modes are assessed. Quantification of the energy dissipated in a MSSD is achieved through an experimental test at laboratory environment. The test results showed a linear relationship between the dissipated power and the damping modes.