Vibration suppression in full car active suspension system using fractional order sliding mode controller

Abstract

Vehicle active suspension systems (VASS) are designed to improve ride comfort and road handling capacity in the automotive industry. This paper investigates the problem of vibration suppression in full car model (FCM) with active suspension system (ASS) whose aim is to reduce the effect of the vibrations generated by road irregularities on the human body. The mathematical model is developed for seven degrees of freedom (DOF) FCM. The main objective is to control vibration of FCM for various road disturbances such as bump and random road disturbance using a fractional order sliding mode controller (FOSMC) and sliding mode controller (SMC). The effectiveness of the controllers are validated using MATLAB/Simulink software in terms of root mean square (RMS) values of body acceleration (BA), pitch acceleration (PA) and roll acceleration (RA). Further the power spectrum density (PSD) of BA is considered to show the human sensitivity range. The simulation results are indicated that FOSMC shows superior performance at adapting bump and random road disturbances compared to SMC and passive suspension system (PSS).

Simulation study on ride comfort enhancement for a heavy duty vehicle with fractional order sliding mode controller

“…The Lyapunouv function used for SMC is V = ½ s 2 . A necessary condition for existence and reachability of a sliding surface is S(X, t) in the system state space is to choose the control variable u(t) such that the following condition is satisfied The suspension deflection (x 1 ) and car body velocity (x 2 ) is chosen as state variables for HDV to design SMC [24,25]. The vibration of the HDV is decreased by applying control force generated from actuator.…”

“…The various control strategies such as bat optimized proportional integral and derivative (PID) controller [11], fuzzy PID controller [12] and single neuron PID [13] are presented to reduce the effects of vibration in the HDV. The SMC [14], Fractional Order SMC (FOSMC) [15] and fractional order terminal SMC [16,17] are designed to arrest the vibration for quarter car and full car model which enhances the travel comfort of the passenger under irregular road profile. The speed control of HDV is foremost criteria to avoid the risk of accidents.…”

Suppression of chaotic vibrations in suspension system of vehicle dynamics using chattering-free optimal sliding mode control

“…In this control scheme, a performance index as follows is to be minimized. For the purpose of the design of the robust control system around the fixed point, an integral SMC can be applied in the system with uncertainties [12][13][14]. In order to obtain optimality as well as robustness in this control strategy, the switching function is defined as:…”

“…To ensure the existence and uniqueness of the optimal control problem, the c i 's must be chosen until L +f 2 ≻ 0 . In order to solve the optimal control problem for finding the optimal v, the control Lyapunov function approach is used [13][14][15][16][17][18][19].…”

“…However, due to the switching function in SMC structure, the chattering phenomenon is occurred in the control system. In order to best eliminate the chattering, the optimal strategy can be combined with the SMC structure [13][14][15][16].…”