Structural design and experiment of robotic fingertip for contact sensing

In this paper, we proposed a sensor structure that can be used to measure the tactile force of robot fingertip. The structure of the sensor was composed of a cylinder-shaped finger and a circular base. First, we analyzed the relationship between the contact position and the stress with elastic mechanics theory. Then the corresponding spline curve algorithm was designed to calculate the contact position and magnitude of force, while the finite element simulation was used to verify our conclusion. Finally, the fingertip sensor was fabricated and the experiment was carried out. By the fitting curve of data, the result showed that the error of magnitude of force is about 0.32N and the error of angle is about 2.876 degrees. This structure with algorithm could be used in robot fingertip in the future because its low cost and flexibility.