@article {3002, title = {On the Minimum-Time Control Problem for Differential Drive Robots with Bearing Constraints}, journal = {Journal of Optimization Theory and Applications}, year = {2017}, month = {04/2017}, pages = {1-27}, abstract = {

This paper presents a study of analysis of minimum-time trajectories for a differential drive robot equipped with a fixed and limited field-of-view camera, which must keep a given landmark in view during maneuvers. Previous works have considered the same physical problem and provided a complete analysis/synthesis for the problem of determining the shortest paths. The main difference in the two cost functions (length vs. time) lays on the rotation on the spot. Indeed, this maneuver has zero cost in terms of length and hence leads to a 2D shortest path synthesis. On the other hand, in case of minimum time, the synthesis depends also on the orientations of the vehicle. In other words, the not zero cost of the rotation on the spot maneuvers leads to a 3D minimum-time synthesis. Moreover, the shortest paths have been obtained by exploiting the geometric properties of the extremal arcs, i.e.,\ straight lines, rotations on the spot, logarithmic spirals and involute of circles. Conversely, in terms of time, even if the extremal arcs of the minimum-time control problem are exactly the same, the geometric properties of these arcs change, leading to a completely different analysis and characterization of optimal paths. In this paper, after proving the existence of optimal trajectories and showing the extremal arcs of the problem at hand, we provide the control laws that steer the vehicle along these arcs and the time-cost along each of them. Moreover, this being a crucial step toward numerical implementation, optimal trajectories are proved to be characterized by a finite number of switching points between different extremal arcs, i.e.,\ the concatenations of extremal arcs with infinitely many junction times are shown to violate the optimality conditions.

}, keywords = {Robotics}, doi = { 10.1007/s10957-017-1110-7}, url = {http://download.springer.com/static/pdf/641/art\%253A10.1007\%252Fs10957-017-1110-7.pdf?originUrl=http\%3A\%2F\%2Flink.springer.com\%2Farticle\%2F10.1007\%2Fs10957-017-1110-7\&token2=exp=1492507070~acl=\%2Fstatic\%2Fpdf\%2F641\%2Fart\%25253A10.1007\%25252Fs10957-017-111}, author = {A. Cristofaro and Salaris, P. and L. Pallottino and Giannoni, F. and A. Bicchi} } @conference {2893, title = {Motion Primitive Based Random Planning for Loco{\textendash}Manipulation Tasks}, booktitle = {IEEE International Conference on Humanoid Robots (HUMANOIDS 2016)}, year = {2016}, note = {
This work is supported by the European commission project Walk-Man EU FP7-ICT no. 611832 and the ECs Horizon 2020 robotics program ICT-23-2014 under grant agreement 644727 (CogIMon)
}, publisher = {IEEE}, organization = {IEEE}, address = {Cancun, Mexico, 15-17 Nov. 2016 }, abstract = {

Several advanced control laws are available for
complex robotic systems such as humanoid robots and mobile
manipulators. Controls are usually developed for locomotion or
for manipulation purposes. Resulting motions are usually executed
sequentially and the potentiality of the robotic platform
is not fully exploited.
In this work we consider the problem of loco{\textendash}manipulation
planning for a robot with given parametrized control laws
known as primitives. Such primitives, may have not been
designed to be executed simultaneously and by composing
them instability may easily arise. With the proposed approach,
primitives combination that guarantee stability of the system
are obtained resulting in complex whole{\textendash}body behavior.
A formal definition of motion primitives is provided and a
random sampling approach on a manifold with limited dimension
is investigated. Probabilistic completeness and asymptotic
optimality are also proved. The proposed approach is tested
both on a mobile manipulator and on the humanoid robot
Walk-Man, performing loco{\textendash}manipulation tasks.

}, keywords = {Robotics}, isbn = {978-1-5090-4718-5 }, doi = {10.1109/HUMANOIDS.2016.7803402}, url = {http://ieeexplore.ieee.org/document/7803402/}, author = {A Settimi and D. Caporale and P. Kryczka and M. Ferrati and L. Pallottino} } @conference {2810, title = {Multi{\textendash}object handling for robotic manufacturing}, booktitle = {IECON 2016: 42nd Annual Conference of the IEEE Industrial Electronics Society}, year = {2016}, month = {12/2016}, pages = {6887 - 6893}, publisher = {IEEE}, organization = {IEEE}, address = {Florence, Italy, October 24-27}, abstract = {

The purpose of this work is to move a step toward the automation of industrial plants through full exploitation of autonomous robots. A planning algorithm is proposed to move different objects in desired configurations with heterogeneous robots such as manipulators, mobile robots and conveyor belts.
The proposed approach allows different objects to be handled by different robots simultaneously in an efficient way and avoiding collisions with the environment and self{\textendash}collisions between robots. In particular, the integrated system will be capable of planning paths for a set of objects from various starting points in the environment (e.g. shelves) to their respective final destinations. The proposed approach unifies the active (e.g., grasping by a hand) and passive (e.g., holding by a table) steps involved in moving the objects in the environment by treating them as end{\textendash}effectors with constraints and capabilities.
Time varying graphs will be introduced to model the problem for simultaneous handling of objects by different end{\textendash}effectors.
Optimal exploration of such graphs will be used to determine paths for each object with time constraints. Results will be validated through simulations.

}, keywords = {Robotics}, doi = {http://ieeexplore.ieee.org/document/7793936/?reload=true}, url = {http://ieeexplore.ieee.org/document/7793936/?reload=true}, author = {M. Ferrati and H. Marino and A Settimi and S. Nardi and L. Pallottino} } @conference {1244, title = {Motion Planning for Two 3D-Dubins Vehicles with Distance Contraint}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012}, year = {2012}, month = {October 7 - 12}, pages = {4702 - 4707 }, address = {Vilamoura, Algarve, Portugal}, keywords = {Robotics}, author = {H. Marino and M. Bonizzato and R. Bartalucci and P Salaris and L. Pallottino} } @conference {WPb_cdc10_2, title = {Motion planning for Formations of Dubins Vehicles}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, pages = {2263 - 2269}, keywords = {Embedded Control, Robotics}, author = {H. Wang and L. Pallottino and A. Bicchi} } @conference {PPSB04, title = {Motion Planning through Symbols and Lattices}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2004}, pages = {3914-3919}, abstract = {

In this paper we propose a new approach to motion planning, based on the introduction of a lattice structure in the workspace of the robot, leading to efficient computations of plans for rather complex vehicles, and allowing for the implementation of optimization procedures in a rather straightforward way. The basic idea is the purposeful restriction of the set of possible inputfunctions to the vehicle to a finite set of symbols, or {\em control quanta},which, under suitable conditions, generate a regular lattice of reachable points. Once the lattice is generated and a convenient description computed, standard techniques in integer linear programming can be used to find a plan very efficiently. We also provide a correct and complete algorithm to the problem of finding an optimized plan (with respect e.g. to length minimization) consisting in a sequence of graph searches.

}, keywords = {Embedded Control, Robotics}, author = {S. Pancanti and L. Pallottino and D. Salvadorini and A. Bicchi} } @conference {PFB01-AIAA, title = {Mixed Integer Programming for Aircraft Conflict Resolution}, booktitle = {AIAA Guidance, Navigation and Control Conference and Exhibit}, year = {2001}, abstract = {

This paper considers the problem of solving conflicts between several aircraft. Considering the case when only aircraft heading changes are allowed, we propose a formulation of the multi-aircraft conflict avoidance problem as a mixed-integer linear program, whose solution may be obtained within seconds with standard optimization software. While such a problem formulation and solution is still unsuitable for operational implementation, it may be used as part of a real or fast-time simulation.

}, keywords = {Air Traffic Management Systems, Autonomous Vehicles, Navigation and Planning}, author = {L. Pallottino and E. Feron and A. Bicchi} }