• haptics
• prosthetics
• robotics
• tele-robotics

The aim of the thesis was to design, implement and test a wearable digital device that is able to render high frequency forces obtained during tele-robotics or during the use of a prosthetic device on the operator/subject’s skin. This device must be able to make the operator/subject feel the real roughness of the various surfaces the robotic hand is touching, and other events related to accelerations, such as contact information.
Firstly, I made an acquisition, analysis and elaboration of the acceleration signals acquired from accelerometers placed on a robotic hand fingernails. The goal was to obtain a filter able to insulate only the frequencies which could mean something in terms of tactile perception. The acquisition was made thanks to a special C++ code and modifications on the firmware of the control board which gets acceleration signals.
Once chosen the filter that satisfied my requirements, for the prosthetic application, I modified the firmware of the control board that controls the actuators (linear voice coil actuators controlled by PWM) in order to appropriately control actuators. Particularly, I modified the code in order to add the filtering function and many elaborations command and I controlled the output tension in order to not overcome the maximum power for the actuators. For the tele-robotics application, I wrote a ROS code able to acquire data from the accelerometers control board, to filter and elaborate them, and to send them, via modem, to the actuators control board. I also modified the firmware control boards.
For the testing part, I first designed 3D special cases for the actuators which allow them to be placed on the subjects’ skin for the prosthetic application. For the tele-robotic application, the actuators with their cases were stitched on a glove the users can wear during the tele-robotic experiments. The prosthetics experiments were conducted both on amputees and able-bodied using the SoftHand Pro robotic hand designed at the “Centro di ricerca E. Piaggio”, while the tele-robotics experiments were conducted using a humanoid robot present in the laboratory.