Dynamic model of an online programmable textile soft actuator

Abstract

Soft actuators exhibiting versatile behaviors have potential applications in robotics. This paper proposes kinematics, kinetics, and dynamic models of an online-programmable soft actuator. The actuator is composed of four strings and an inflatable textile tube folded inside a housing structure. Each string is controlled by a single DC motor which has an optical encoder. Pulling a string produces bending in one direction, while pulling the four strings in a coordinated manner produces additional motions. With the proposed forward and inverse kinematic model, the actuator was able to follow a desired end-effector trajectory in the Cartesian space. Furthermore, due to the dynamic model, our simulation study shows that the soft actuator can handle external force changes at the end-effector, such as mass changes and friction forces.