Design of an interval type-2 fractional order fuzzy controller for a tractor active suspension system

•This study proposes a new optimal Interval type-2 fractional order fuzzy PID controller based on BBO algorithm.•The suggested controller is designed for a tractor active suspension system.•The performance values are reduced in the IT2FOFPID controller in comparison with conventional controllers.•The results are compared with other controllers in the presence of various field disturbances. Suspension systems are considered as critical parts of modern vehicles and are required in various types of tractors. To enhance drive comfort in case of road irregularities and isolate tractor user cabin from vibration performance, active suspension (AS) systems are utilized to handle its hydraulic actuator. In the present study, an interval type-2 fractional order fuzzy PID (IT2FOFPID) strategy was designed in tractor AS system to minimize the transmitted uneven surface fluctuations to the driver’s cabin. Therefore, biogeography-based optimization (BBO) algorithm was employed to regulate the parameters of controllers. To demonstrate the advantages of the IT2FOFPID controller, three different controllers involving type-1 fuzzy PID (T1FPID), fractional order fuzzy PID (FOFPID), and interval type-2 fuzzy PID (IT2FPID) control methods were considered. The validity of the proposed IT2FOFPID controller is demonstrated in comparative simulation results in the presence of various field disturbances. The findings revealed that the proposed controller makes outstanding yield in comparison to other controllers in the presence of road disturbances.