Modeling of Shape Memory Alloy Artificial Wrist Joint via Modified Prandtl-Ishlinskii Hysteresis Model

Shape Memory Alloy (SMA) is a new type of innovative material that will restore to its original state at a specific temperature. It has been widely used in making flexible actuators. One of the main obstacles is that SMA actuators have certain nonlinear hysteresis behaviors associated with the input-output, which severely limits output accuracy. A shape memory alloy artificial wrist joint platform using SMA actuators is designed and verified using open-loop experimental data under input currents to understand these tasks better. The present article proposes a modified Generalized Prandtl-Ishlinskii (MGPI) model for characterizing the hysteresis behavior of an actuated system by combining the artificial wrist dynamic model. After that, contrast the output displacement of the experimental and the obtained model. Finally, the comparison verification will indicate the validity of the complete artificial wrist model.