Pattern Generation for Walking on Slippery Terrains
This addresses the challenge of robotic stability on slippery surfaces, which is incremental as it builds on existing MPC methods.
The paper tackles the problem of generating safe bipedal walking on slippery terrains by extending Model Predictive Control (MPC) to balance walking velocity, Zero Moment Point modulation, and Required Coefficient of Friction regulation, showing in simulations that increasing velocity raises slippage risk while reducing slippage conflicts with tip-over prevention.
In this paper, we extend state of the art Model Predictive Control (MPC) approaches to generate safe bipedal walking on slippery surfaces. In this setting, we formulate walking as a trade off between realizing a desired walking velocity and preserving robust foot-ground contact. Exploiting this formulation inside MPC, we show that safe walking on various flat terrains can be achieved by compromising three main attributes, i. e. walking velocity tracking, the Zero Moment Point (ZMP) modulation, and the Required Coefficient of Friction (RCoF) regulation. Simulation results show that increasing the walking velocity increases the possibility of slippage, while reducing the slippage possibility conflicts with reducing the tip-over possibility of the contact and vice versa.