Adaptive gain first-order sliding mode control for a millimetric electrospinning device with output constraints

This work deals with the design of a millimetric electrospinning device (MED) controlled with the implemen-tation of a sliding mode controller taking into account states constraints or constraint sliding mode controller (CSM C). The proposed MED is integrated by two cartesian robots with two (injector system) and three (collector system) degrees of freedom, respectively. These two cartesian robots work in a coordinated manner to regulate the deposition processes for the generation of polymeric micro and nanofibers. This strategy addresses one of the most common problems of classic MEDs, guaranteeing that the fibers are deposited in a specific zone (aiming to create 3D polymeric structures). The suggested CSM C successfully restricts the motions of the MED to a predefined working space that led to the production of aligned polymer fibers, ensuring the convergence of the tracking error to the sliding surface in finite-time, while the state constraints are satisfied. Experimental results validate the effectiveness of the proposed CSMC by using the least mean square evaluation of the tracking error and the integral of the control signal. The evaluation is also done following a comparative analysis concerning the performance forced with respect to a state feedback form. The evaluation confirmed the effectiveness of the CDMC strategy compared to the state feedback form.