Structural Design and Performance Analysis of a Novel Deployable Robotic Gripper with Arc-Shaped Scissor Mechanism

This paper presents a novel deployable robotic gripper with arc-shaped scissor mechanism, which is made up of four fingers and a base mechanism, and each finger consists of several arc-shaped scissor units. Firstly, by studying the outer envelope conditions of large-scale unknown objects, the arc-shaped scissor mechanism unit is well designed by dividing the sphere equally, which offers not only a good deploy/fold performance but also a well single-mobility characteristics. Then multiple arc-shaped scissor mechanism units are effectively connected in series to form the finger of the robotic gripper. To achieve lightweight and form a multi-fingered robotic gripper, a base mechanism coupled with multiple fingers is developed, which effectively integrated the degrees of freedom of multiple fingers and made the entire robotic gripper contain only one degree of freedom, so only one actuator is needed to drive the robotic gripper in grasping operation. In addition, the performance analysis such as deploy/fold ratio analysis, kinematic analysis, and grasping analysis is also performed to know the basic performance of the robotic gripper. Finally, a group of grasping simulation is conducted, which shows that the robotic gripper has good grasping performances and can be used to grasp large-scale unknown objects.