Higher Order Sliding Mode Controller for a Soft Pneumatic Gripper

Soft robots have recently become more popular in the robotic field. They can perform unique actions such as grasping delicate objects, robotic surgeries, etc. The mathematical modeling technique of soft robots is still in the development stage. In this paper mathematical model of a soft pneumatic, gripper has been proposed with finite element method and system identification technique. A soft pneumatic gripper or an actuator works on the principle of applied pressure which have limbs used to grasp objects of different shapes and size. The bending of these limbs has to be controlled to obtain perfect grasping. Classical sliding mode controller (SMC) is one of the popular control techniques that has been used the control the bending deformation of soft pneumatic grippers, but it suffers from the chattering problem. The higher-order sliding mode controller (HOSMC) technique has not been yet applied to control the bending deformation of the gripper. In this paper, HOSMC has been proposed to control the bending angle of the soft gripper which eliminates the unwanted chattering. The simulation results prove the efficacy of the controller.