A New Multifunctional Three-Dimensional Tactile Sensor Using Three Coils

A new three-dimensional tactile sensor has been developed imitating the human finger based on multifunctional sensing technology. This sensor consists of three coils and two mediums. A step-by-step method is used to realize the multifunctional sensing and in each step, a different quantity is sensed. The processing method in spherical coordinates is introduced to resolve the force vector. On the basis of the unique structure of the sensor and ingenious measurement methods, the authors realized the aim of testing more than one quantity, that is, the magnitude and two direction angles of the force vector, with a single sensor. Here, we discuss the design guideline for and the structure of the sensor, with in-depth studies of the step-by-step measurement method and the experimental results.