A three-toe biped foot with Hall-effect sensing

This paper describes a novel foot for biped robots designed to provide a reliable and low-cost solution for sensing the Center of Pressure (CoP) on flat and uneven surfaces. The foot uses a new method for detecting contact forces based on measuring the deflection of three flexural toes using Hall-effect magnetic field sensors. We experimentally compare five mathematical models for calculating the CoP coordinates from the sensor data. Results confirm that with the proposed method it is possible to obtain the same level of accuracy and reliability as with standard force sensing resistors, but without some the drawbacks of that approach.