@conference {3390, title = {Parametric Trajectory Libraries for Online Motion Planning with Application to Soft Robots}, booktitle = {18th International Symposium on Robotics Research}, year = {2017}, abstract = {

In this paper we propose a method for online motion planning of constrained nonlinear systems. The method consists of three steps: the offline generation of a library of parametric trajectories via direct trajectory optimization, the online search in the library for the best candidate solution to the optimal control problem we aim to solve, and the online refinement of this trajectory. The last phase of this process takes advantage of a sensitivity-like analysis and guarantees to comply with the first-order approximation of the constraints even in case of active set changes. Efficiency of the trajectory generation process is discussed and a valid strategy to minimize online computations is proposed; together with this, an effective procedure for searching the candidate trajectory is also presented. As a case study, we examine optimal control of a planar soft manipulator performing a pick-and-place task: through simulations and experiments, we show how crucial online computation times are to achieve considerable energy savings in the presence of variability of the task to perform.

}, author = {T. Marcucci and M. Garabini and Gasparri, G. M. and Alessio Artoni and M Gabiccini and A. Bicchi} } @article {2724, title = {On the Problem of Moving Objects With Autonomous Robots: A Unifying High-Level Planning Approach}, journal = {IEEE ROBOTICS AND AUTOMATION LETTERS}, volume = {1}, year = {2016}, month = {01/2016}, pages = {469-476}, abstract = {

Moving objects with autonomous robots is a wide topic that includes single-arm pick-and-place tasks, object regrasping, object passing between two or more arms in the air or using support surfaces such as tables and similar. Each task has been extensively studied and many planning solutions are already present in the literature. In this letter, we present a planning scheme which, based on the use of pre-defined elementary manipulation skills, aims to unify solutions which are usually obtained by means of different planning strategies rooted on hardcoded behaviors. Both robotic manipulators and environment fixed support surfaces are treated as end-effectors of movable and non-movable types, respectively. The task of the robot can thus be broken down into elementary building blocks, which are endeffector manipulation skills, that are then planned at the kinematic level. Feasibility is ensured by propagating unforeseen low-level failures at the higher level and by synthesizing different behaviors. The validity of the proposed solution is shown via experiments on a bimanual robot setup and in simulations involving a more complex setup similar to an assembly line.

}, keywords = {Robotics}, doi = {10.1109/LRA.2016.2519149}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7384694}, author = {H. Marino and M. Ferrati and A Settimi and C. Rosales and M Gabiccini} } @conference {2120, title = {The Patched Intrinsic Tactile Object: a Tool to Investigate Human Grasps}, booktitle = {Proc. IEEE/RSJ Intl Conf. on Intelligent Robots and Systems (IROS 2014)}, year = {2014}, pages = {1261 - 1268}, address = {Chicago, USA}, abstract = {

In this paper we report on the development of a modular multi-DoF F/T sensor and its use in the implementation of a sensorized object capable of multi-touch detection. The sensor is composed of six 6-axis F/T sensors spatially organized on the faces of a cube. Different calibration methods are presented to directly tackle the coupling phenomena inherent to the spatial organization of the faces and the lightweight construction of the sensor which would have, otherwise, degraded its accuracy. To assess the performances of the calibration methods, a comparison is reported with respect to the measurements obtained with a commercial force/torque sensor considered as ground truth (ATI Delta). Thanks to the modular design and the possibility to cover the sensitive faces with surface patches of different geometry, a variety of sensorized objects with different shapes can be realized. The peculiar feature that all the components of the contact wrench can be measured on each face with high accuracy, renders it a unique tool in the study of grasp force distribution in humans, with envisioned use both in neuroscience investigations and robotic applications.

}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2014.6942719}, author = {A. Serio and E. Riccomini and V. Tartaglia and I. Sarakoglou and M Gabiccini and N G Tsagarakis and A. Bicchi} }