Integrated Barometric Pressure Sensors on Legged Robots for Enhanced Tactile Exploration of Edges

This letter presents a new tactile sensor that utilizes an array of barometric pressure sensors encased in a deformable rubber sphere. Designed as an end effector foot of the legged quadruped robot Unitree Go1, the proposed sensor is able to withstand repeated impacts of at least 40 N at the feet. Tactile sensing in legged robotics extends their utility specifically in the context of edge detection and exploration. The presented tactile contact framework processes the pressure data to classify the type of contact (no contact, flat or edge) and the orientation of the edges relative to robot base. To assess the performance of the sensors and their ability for tactile edge exploration we extensively test with the legged robot in varied conditions including different terrains, changing payloads, exposure to dynamic disturbances, and sloped edges. The edge detection is compared against the original scalar force sensors. Experiments demonstrate a mean absolute error of 2
$^{\circ }$
for predicted edge orientation at a detection range of 14 mm and robust operation in realistic operating conditions for medium-sized quadruped robots. With this contribution, we aim to enhance the capabilities and safety of legged robots in various applications.