Development of a Novel Hybrid Soft Cable-Driven Parallel Robot

Abstract

Abstract This paper reports on the development of novel hybrid soft cable-driven parallel robots (HSCP). As the growth and refinement of the soft robotic field progresses, new methods of soft robotic actuation and control will continue to be developed. While most of the existing soft robotic systems have a serial structure, soft parallel robots have received a lot of attention recently. This is due to the wide range of applications of these systems in different industries such as the medical and the food industry. To the best of our knowledge, most of the existing soft parallel robots have active flexible legs. However, in this work for the first time, we have proposed a novel soft parallel robot with only passive flexible legs. In our hybrid design the stiffness of the robot is maintained through the passive soft legs and the actuation is based on a cable-driven mechanism. This will simplify the design and modeling of the robot. As an example of our design approach, a 6 degrees of freedom (DOF) hybrid soft parallel robot is designed which resembles the rigid Stewart mechanism. The mechanics of the robot are unique, being controlled only through cable actuation through six servo motors positioned around the base of the robot. The supports which were 3D printed with deformable Ninja Flex filament supply a nonlinear force to the robot, combined with the cable control enabling the robot to be able to execute basic movement within the workspace as well as being safer for human-machine interaction due to the soft support system. This paper also compares the kinematics and controls of this new robotic system to a typical rigid steward robot.