We propose a unified approach for automatically generating multiple robot-model descriptions for modular robot manipulators. Modular robots need models for kinematics and dynamics to deploy motion control schemes with high performance as it is possible for their fixed structure counterparts. Additionally, these models are also necessary for enabling the optimization of their assembly to optimally meet task and environmental constraints. Manual derivation of models for every different assembly is impractical as the number of possible arrangements can be large. We propose a systematic approach for characterizing single modules and for automatically generating the following widely adopted robot model descriptions for kinematics and dynamics: standard and modified Denavit-Hartenberg, product of exponentials formulation, and the unified robot description format. We numerically verify our approach also considering experimental data from a real modular robot manipulator.

We apply input allocation to a redundantly actuated platform driven by tilting aerodynamic propulsion units: the ROtor graSPing Omnidirectional (ROSPO). This platform represents a novel testbed for redundancy allocation designs in propeller driven platforms. The control solution is based on a hierarchical architecture, made of a high level controller for trajectory tracking, and a nonlinear input allocation algorithm. The algorithm exploits the input redundancy to take into account soft constraints associated to physical saturation limits of the actuators, and also induce reduced energy consumption. The actuator dynamics is fully taken into account in the framework and a rigorous proof of asymptotic tracking of time-varying references is guaranteed despite the impossibility of an instantaneous force execution. The experiments on the ROSPO platform clearly show the practicability and effectiveness of the proposed approach, as well as its scalability with different degrees of over-actuation levels.

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