Balance of Humanoid robot in Multi-contact and Sliding Scenarios
This addresses balance control for humanoid robots in complex, real-world scenarios like cleaning or manipulation, but it is incremental as it builds on existing convex area methods.
The study tackled the problem of maintaining humanoid robot balance during multi-contact tasks with sliding motions by computing a center-of-mass support area and optimizing its position. They demonstrated the approach with experiments on the HRP-4 robot, achieving stable pushing and wiping tasks.
This study deals with the balance of humanoid or multi-legged robots in a multi-contact setting where a chosen subset of contacts is undergoing desired sliding-task motions. One method to keep balance is to hold the center-of-mass (CoM) within an admissible convex area. This area should be calculated based on the contact positions and forces. We introduce a methodology to compute this CoM support area (CSA) for multiple fixed and sliding contacts. To select the most appropriate CoM position inside CSA, we account for (i) constraints of multiple fixed and sliding contacts, (ii) desired wrench distribution for contacts, and (iii) desired position of CoM (eventually dictated by other tasks). These are formulated as a quadratic programming optimization problem. We illustrate our approach with pushing against a wall and wiping and conducted experiments using the HRP-4 humanoid robot.