Realization and control of a 3D-printed gripper for robotic applications

In this thesis work, a prototype of a 2-finger grip hand was developed and manufactured. It was decided to design and to develop the CAD of this gripper and later to print the different parts using a 3D printer. Moreover, a computer control hardware and software were also developed for computer control of the prototype. A MATLAB code was developed for the motion control and force control of the fingers. The gripper was made in order to work in places that are not easily accessible. One possible application is to connect it to a robotic arm and taking advantage of telepresence technology. Therefore, one design specification was to obtain a prototype as small as possible in overall dimensions capable of grasping objects with about 10 cm in width. Moreover, the gripper should be easy to assemble and disassemble once printed. The gripper was also made with the aim of being very light, cheap and exerting a very good grip in terms of force due to the servomotor and transmission system. In order to drive the gripper, the Dynamixel MX 28 servomotor was used, which represents in the trade a good compromise between size and reliability, as well as having a built-in encoder useful as feedback for the measurements taken. Regarding the control of the robotic gripper, a USB to Dynamixel converter was used in combination with a Power Hub to enable communication between the servomotor and the PC. After developing the code for the control, several simulations were carried out to test the opening-closing movements and to test whether the gripper perceives the moment when it grasps the object. In addition, a load cell was used to measure the actual gripping force of the prototype's two fingers.