Model-based inspection of the three-dimensional printer usingoptimization algorithms

Three-dimensional (3D) bio-printers are used extensively in regenerative medicine and tissue engineering, especially in bio-printing of ear, nose and face-chin prostheses. Printing errors that differ from model to model are frequently seen in the bio-printing of artificial tissue and organ. Errors occurring on the surface of the model prevent the efficient use of the organ to be printed. The controller performance of the 3D printer needs to be improved so that errors in the artificial organ and tissue bio-printing process can be minimized. In this thesis, a novel adaptive PID controller based on Whale Optimization Algorithm (WOA) has been developed for bio-printing of artificial tissues and organs. The WOA algorithm is preferred to avoid local minima and to improve the transient response of the controller. The convergence speed of the proposed algorithm allows the parameters of the PID controller to be tuned quickly and accurately. The performance of the developed WOA based adaptive PID controller has been measured with the help of Integral of Time multiplied Squared Error (ITSE), which is one of the performance metrics. The performance of the proposed controller for the 3D printer has been compared to the classical PID and Genetic Algorithm (GA) based PID controllers' performance. From the experimental obtained results, it can be seen that the proposed WOA based adaptive PID controller significantly improves the transient response of the 3D printer and minimizes surface defects in the printed organs such as the nose and ear. The proposed WOA-based adaptive controller algorithm has been embedded on the originally designed 3D printer, and prints of organs such as ears and nose have been taken. Printed organ prints have been compared with models printed with classical PID and GA based PID controller algorithms. It has been observed that the WOA-based adaptive PID controller is quite successful in both printing time and minimizing surface defects compared to other controller algorithms.