An optimal estimation of feet contact distributed normal reaction forces of walking bipeds

The motion of a walking biped has rich information about the contacts with the environment. This paper presents an optimal estimation method of the distributed normal reaction forces at the contact points on the feet soles of walking bipeds. The motion is acquired by employing the inertial measurement unit (IMU) and the joint-encoder readings into Newton-Euler dynamic equations without using any force sensor model. The quadratic programming optimization method is used. The validity of the proposed estimation method was confirmed by simulations on 3D dynamics model of the humanoid robot SURALP while walking.