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Tractor-trailer wheeled mobile robot (TTWMR) is a robotic system that consists of a tractor module towing a trailer. Trajectory tracking is one of the challenging problems which is focused in the context of wheeled mobile robots (WMRs) that has been discussed in this paper. First, kinematic equations of TTWMR are obtained. Then, reference trajectories for tracking problem are produced. Subsequently, an output feedback kinematic control law and a dynamic Fuzzy Sliding Mode Control (FSMC) are designed for the TTWMR. The proposed controller steer the TTWMR asymptotically follow reference trajectories. Finally, experimental results of the designed controller on an experimental setup and comparison results are presented. Obtained results show the effectiveness of the proposed controller.

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Shape memory alloys (SMAs) are suitable candidates in various fields of engineering. One advantage of these alloys is their capabilities in developing high strain and force. In addition to these great features, lightweight and super-elastic behavior are other traits of these materials. These specifications are of such an importance that make SMAs to be suitably used in further engineering applications. However, their intrinsic hysteresis non-linear behavior make their usage as position actuators difficult. Despite this challenge, there are various methods proposed in the literatures to model the hysteresis behavior of such materials. In this paper, a generalized Prandtl- Ishlinskii model, because of its simplicity, efficiency and inverse analytical capability, has been used for modeling the SMA behavior. In addition, the hysteresis modeling has been validated via experimental data of one of the articles. In the control section, however, two control systems consisting PID and fuzzy sliding mode controllers have been used. Fuzzy sliding mode control system is a method that can be used in systems without mathematical model and leads to increase in their robustness. It is shown in this paper that by using this method, it is possible to apply a suitable control input to the system in order to vanish the error signal. However, by using PID controllers, the error signal is not acceptable due to the constant controller coefficients. The results indicate the more efficient performance of fuzzy sliding mode controller with respect to the classical PID controller.