System identification and robust tracking of a 3D printed soft actuator

Current three-dimensional (3D) printing allows for the fabrication of controllable 3D printed soft actuators with growing applications in soft robotics, like cell manipulation and drug delivery. Therefore, a precise and computationally efficient control algorithm for robust trajectory tracking of the 3D printed soft actuators has become important. The results of the primary model of the soft actuator deviated from experimental results due to uncertainties such as time-varying characteristics of the actuator. Hence, a second-order type nonsingular terminal sliding mode controller (NTSMC) for robust stabilization and trajectory tracking of the 3D printed actuator is proposed. It is shown via experiments that the system can track the predefined trajectory in the presence of modeling uncertainties using the proposed control scheme. The results are compared with the first order NTSMC and the conventional SMC via the experimental tests to verify tracking of the predefined trajectory and rejection of persistent disturbances of the designed controller.