Fractional Calculus Control of Road Vehicle Lateral Stability after a Tire Blowout

The lateral stability control of the vehicle can avoid serious traffic accidents when it had a tire blowout during the operation. This article proposes a robust nonlinear control method for controlling vehicle lateral stability after a tire blowout. To be exact, a seven degree of freedom dynamic model of vehicle with modified Dugoff tire model is established. The yaw moment of vehicle is performed by differential braking once the tire blowout occurring. As for control strategy, taking the linear two degree of freedom vehicle model as the reference, using the deviation of yaw rate and the vehicle side angle between the actual value and the reference value as the controller input parameters, the fractional calculus theory is utilized for yaw moment controller which was investigated by regulating the brake moment of blowout vehicle for improving its stability. The results of computer simulation show that the design controller of fractional PID can more effectively enhance the blowout vehicle performance stability compared with the vehicle with the non control, PID control, no matter in straight road or curve road.

Antidisturbance Control for Helicopter Stochastic Systems

In this paper, an antidisturbance controller is presented for helicopter stochastic systems under disturbances. To enhance the antidisturbance abilities, the nonlinear disturbance observer method is applied to reject the time-varying disturbances. Then, the antidisturbance nonlinear controller is designed by combining the backstepping control scheme. And the stochastic theory is used to guarantee that the closed-loop system is asymptotically bounded in mean square while the proposed control method is shown via some traditional nonlinear control techniques, which still show some common issues such as “dimension explosion” or others. The result of this paper can be regarded as a typical case of the nonlinear control method to help and promote the generation of advanced methods.

Synchronization of Liu-Su-Liu and Liu-Chen-Liu Chaotic Systems by Nonlinear Feedback Control

This paper investigates the global chaos synchronization of identical Liu-Su-Liu chaotic systems (2006) and non-identical Liu-Su-Liu chaotic system (2006) and Liu-Chen-Liu chaotic system (2007). In this paper, active nonlinear control method has been successfully applied to synchronize two identical Liu-Su-Liu chaotic systems and then to synchronize two different chaotic systems, viz. Liu-Su-Liu and Liu-Chen-Liu chaotic systems. Since the Lyapunov exponents are not required for these calculations, the active nonlinear control method is effective and convenient to synchronize Liu-Su-Liu and Liu-Chen-Liu chaotic systems. Numerical simulations are also given to illustrate the proposed synchronization approach.

Chaos-based Controlled System using Discrete Map

In this paper, the design of controller is done by synchronizing two-dimensional chaotic Henon map through nonlinear control method. One map is taken as a driver system and its initial value is considered as the set value of a specific process of a given system. Another map is taken as the driven system and its initial value is the primary process value of the given specified system. Both the systems become synchronized via nonlinear control law. The accumulation of error until synchronization is achieved has been converted into a suitable signal to operate the final control element to enhance or decrease the process value towards the set value. This self-repetitive process will achieved the control of the process parameter. The entire process has been implemented in hardware environment by using microcontroller ATMEGA 16 and also in the Proteus simulation software.