A Hyper-redundant Elephant’s Trunk Robot with an Open Structure: Design, Kinematics, Control and Prototype

Abstract

As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles, the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands. The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles. Compared with traditional robots, the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure. A hyper-redundant elephant’s trunk robot (HRETR) with an open structure is developed in this paper. The content includes mechanical structure design, kinematic analysis, virtual prototype simulation, control system design, and prototype building. This design is inspired by the flexible motion of an elephant’s trunk, which is expansible and is composed of six unit modules, namely, 3UPS-PS parallel in series. First, the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design. After that, the backbone mode method is used to establish the kinematic model of the robot. The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned. With the help of ANSYS, the static stiffness of each component and the whole robot is analyzed. On this basis, the materials of the weak parts of the mechanical structure and the hardware are selected reasonably. Next, the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria. Finally, the prototype is built and its performance is tested. The proposed research provides a method for the design and development for the hyper-redundant bionic robot.

Synchronized Motion Profiles for Inverse-Dynamics-Based Online Control of Three Inextensible Segments of Trunk-Type Robot Actuators

“…However, there are more trunk-type robot control approaches with inverse kinematics solutions. One proposal is to analyze the trunk-type robot kinematic characteristics with a computer program when the robot's trajectory end-moving platform is assigned [29]. Then, from model parameters using the spatial backbone modal method, the robot's kinematic model is established.…”

Design and kinematics of a lightweight cruciform continuum robot

“…Different sorts of soft manipulators have been developed to deal with diverse operational tasks and work environments (Rus and Tolley, 2015;Krovi and Nie, 2008;Zhao et al, 2020;Dong et al, 2016;Yarbasi and Samur, 2018;Yu et al, 2018). Continuum robots are known for their flexibility and dexterity, which have significant performance advantages in dealing with unstructured environments and non-cooperative target operations, making them always active at the forefront of robotics research.…”

A Survey on Design, Actuation, Modeling, and Control of Continuum Robot

“…Inspired by the tentacles of elephant trunks, snakes, and octopuses, continuum robots use a series of continuous arcs structurally rather than skeletal structures to generate bending motion [1], with flexibility, lightweight, inherent safety, scalability, and potential for low-cost parts. This design approach was initially applied primarily in industrial scenarios such as large-scale grasping, movement, and positioning [2] and even urban search and rescue operations in confined environments [3].…”