Multi-robot and task-space force control with quadratic programming

We extend the task-space multi-objective controllers that write as quadratic programs (QP) to handle multi-robot systems as a single centralized control. The idea is to assemble all the ‘robots’ models and their interaction task constraints into a single QP formulation. By multi-robot we mean that whatever entities a given robot will interact with (solid or articulated systems, actuated or not or partially, fixed-base or floatingbase), we model them as robots and the controller computes the state of the overall system and their interaction forces in a physically consistent way. By doing so, the tasks specification simplifies substantially. At the heart of the interactions between the systems is the contact forces: we provide methodologies to achieve reliable force tracking with our multi-robot QP controller. The approach is assessed with a large panel of experiments on real complex robotic platforms (full-size humanoid, dexterous robotic hand, fixed-base anthropomorphic arm), performing whole-body manipulation, dexterous manipulation and robotrobot co-manipulation of rigid floating objects and articulated mechanisms such as doors, drawers, boxes, or even smaller mechanisms such as a spring-loaded click pen. The implementation code of the controller is made available in open source.