pHRI-CHAR-TACT: Character Dataset from Intrinsic Robot Tactile Sensing

The pHRI-CHAR-TACT dataset provides time-series data captured from an uninstrumented, 3D-printed touchpad interface mounted on the end-effector of a collaborative robot while users slide their finger to draw 36 characters ((26 letters and 10 digits)). This dataset facilitates research in intuitive robot control, physical human-robot collaboration, tactile sensing, and machine learning for touch recognition. It contains data collected using the intrinsic tactile sensing capabilities of a KUKA LBR iiwa 14 R820 robot, leveraging its joint torque sensors to interpret touch events on the touchpad. The dataset is presented in two versions: pHRI-CHAR-TACT_SingleUser: this dataset includes 4500 time series, with 150 samples corresponding to each character. All data was recorded from a single user interacting with the robot. pHRI-CHAR-TACT_MultipleUsers: this dataset also contains 4500 time series (150 per character), but the data was collected from three different users (2 female, 1 male; 2 right-handed, 1 left-handed). This version allows for the analysis of inter-user variability in touch patterns. Data format: Both datasets are provided as a single .mat file. Each .mat file contains a 5400x2 cell array. Column 1: time-series data for each touch event (i.e., drawing of a character). Each time series is represented as a 100x4 cell array. This represents the 100 temporal samples, each containing different information described below. Column 2: string label indicating the character (A,B,C, etc.). The time series data has been randomized for each dataset. Each time series represents approximately 3 seconds of data and is composed of 100 samples containing the following 4 cells: (1x7 cell) Robot joint torques (Nm). (1x7 cell) Robot joint positions (rad). (1x3 cell) Cartesian position of the end-effector (mm). (1x6 cell) Forces and moments the center of the touchpad (N for forces, Nm for moments). Hardware: Collaborative robot: KUKA LBR iiwa 14 R820. Touchpad: plexiglass, uninstrumented.