Co-design of Control and Planning for Multi-rotor UAVs with Signal Temporal Logic Specifications

Urban Air Mobility (UAM), or the scenario where multiple manned and Unmanned\nAerial Vehicles (UAVs) carry out various tasks over urban airspaces, is a\ntransportation concept of the future that is gaining prominence. UAM missions\nwith complex spatial, temporal and reactive requirements can be succinctly\nrepresented using Signal Temporal Logic (STL), a behavioral specification\nlanguage. However, planning and control of systems with STL specifications is\ncomputationally intensive, usually resulting in planning approaches that do not\nguarantee dynamical feasibility, or control approaches that cannot handle\ncomplex STL specifications. Here, we present an approach to co-design the\nplanner and control such that a given STL specification (possibly over multiple\nUAVs) is satisfied with trajectories that are dynamically feasible and our\ncontroller can track them with a bounded tracking-error that the planner\naccounts for. The tracking controller is formulated for the non-linear dynamics\nof the individual UAVs, and the tracking error bound is computed for this\ncontroller when the trajectories satisfy some kinematic constraints. We also\naugment an existing multi-UAV STL-based trajectory generator in order to\ngenerate trajectories that satisfy such constraints. We show that this\nco-design allows for trajectories that satisfy a given STL specification, and\nare also dynamically feasible in the sense that they can be tracked with\nbounded error. The applicability of this approach is demonstrated through\nsimulations of multi-UAV missions.\n