Theory and experimentation with an 'Elephant's Trunk' robotic manipulator

Traditionally, robotic manipulators have been comprised of a small number of serially connected rigid links and actuated joints. Though these manipulators prove to be very effective for many tasks, they are not without their limitations. These limitations are due in the most part to their lack of maneuverability or total degrees of freedom. However, continuum style (i.e. continuous “backbone”) robots exhibit a wide range of maneuverability, and can have a large number of degrees of freedom. The motions exhibited by these continuum style robots are produced by bending the individual sections of the robot over their entire length; unlike traditional robots where the motions occur in discrete locations, i.e. joints. The motions displayed by continuum manipulators are often compared to those of biological manipulators such as trunks and tentacles. Continuum style robots can achieve postures that could only be obtainable by conventionally designed robots that contain many more degrees of freedom.; This doctoral dissertation describes underlying theory and experimental validation with one such continuum style robot named the Elephant's Trunk Robotic Manipulator. An in-depth review of continuum robots is presented. As well as the basic properties they exhibit and how they relate to the start of art. Next, the design considerations and the mechanical construction for the Elephant's Trunk robot are presented. A detailed formulation and explanation of a fundamentally new kinematic model is then introduced. The model not only applies to the Elephant's Trunk Robot, but also to a large number of other continuum style robots. Not only are the positional kinematics described, but also the velocity kinematics and how they can be used to plan the motions of the robot. Finally, several experiments are then provided that help to verify the legitimacy of our model as applied to the Elephant's Trunk Robot. Several different strategies that use the kinematics to accomplish various tasks are then presented. First the concept of using continuum robots for obstacle avoidance is explored. Next the idea of grasping with continuum style robots is investigated, and finally a strategy is devised that uses high speed image processing to help control the motions of the robot.