TAPNAV: a Unitree G1 humanoid navigates by touch, without any vision

Rather than being subject to odometry drift, the robot plans deliberate contacts with walls and obstacles in order to re-localise itself, and reaches its destination more often than the benchmark methods.

In a blind environment, a humanoid robot quickly loses track: its odometry drifts and uncertainty about its position accumulates. TAPNAV tackles the problem through active tactile perception: the robot will deliberately touch the structures around it to readjust its position estimation.

Plan where to touch

The system follows a probabilistic estimation of the pose from odometry, inertial measurement unit and tactile contacts. A global planner chooses routes that keep uncertainty within acceptable limits by providing opportunities for correction by touch. A local planner then selects the palpation gestures that provide the most information. A whole-body controller coordinates walking and hand contact.

Tested in simulation and on a Unitree G1, with various floor plans and obstacle shapes, TAPNAV achieves a lower estimation error and a better success rate than reference methods. For the authors, physically interacting with the environment may be enough to provide reliable landmarks where vision is lacking.