In this paper, perfect trajectory tracking control of a non-holonomic Wheeled Mobile Robot (WMR) is tackled. First, a Sliding Mode Controller (SMC) is proposed to convergence of WMR on desired position, velocity and orientation trajectories. Due to the weak performance of the SMC against exogenous inputs, a Mamdani-type fuzzy system is designed to improve the tracking p erformance of the controller. However, the Fuzzy SMC (FSMC) cannot remove the chattering phenomena completely. Therefore, a supervisory Adaptive FSMC (AFSMC) is proposed to suppress the chattering effects. The superiority of the adaptive approach to the non-adaptive methods has been revealed through simulations.

Polyethylene (PE) pipelines with electrofusion (EF) joining is an essential method of transportation of gas energy. EF joints are weak points for leakage and therefore, Nondestructive testing (NDT) methods including ultrasonic array technology are necessary. This paper presents a practical NDT method of fusion joints of polyethylene piping using intelligent ultrasonic image processing techniques. In the proposed method, to detect the defects of electrofusion joints, the NDT is applied based on an ANN-Wavelet method as a digital image processing technique. The proposed approach includes four steps. First an ultrasonic-phased array technique is used to provide real time images of high resolution. In the second step, the images are preprocessed by digital image processing techniques for noise reduction and detection of ROI (Region of Interest). Furthermore, to make more improvement on the images, mathematical morphology techniques such as dilation and erosion are applied. In the 3rd step, a wavelet transform is used to develop a feature vector containing 3-dimensional information on various types of defects. In the final step, all the feature vectors are classified through a backpropagation-based ANN algorithm. The obtained results show that the proposed algorithms are highly reliable and also precise for NDT monitoring.