Mechanical Design of a Novel 4DOF Serial Manipulator

In this paper, a strategy to accomplish small stone carving operations using a four-degree-of-freedom (DOF) robotic arm is presented. This research work tries to design a novel robotic arm that is small enough that can be mounted on the table and create artwork by carving and shaping stones. In the past two decades, there were many different designs for the robotic arm from simple 3DoF serial manipulator to advanced hybrid one, but the main thing in those designs was that they have been designed in order to use on an industrial scale. In this design what we have considered as a priority is to create a manipulator that can be mounted on a small table and also could be used by nonprofessionals. The designed robot, CarveARM, has a unique End Effector (EE) which is rotating around itself so fast to carve a stone precisely. At first, by gathering the link transformation matrices between each joint and also using the Denavit-Hartenberg (DH) notations the CarveARM manipulator coordinate transformation is completely described. We have also used some robotics methods to achieve some particular tasks such as solving the forward kinematics description, inverse kinematics problem, workspace evaluation, and dexterity analysis. Besides the position control of EE, we also control the final angle of EE to handle the stone carving procedure more accurately.