Vurpo

Vurpo: an interactive simulator of an octopus tentacle-like soft manipulator

Vurpo is the result of a research on the mathematical modeling and control of bio-inspired soft manipulators, using the tools of optimal control theory of PDEs and numerical techniques for constrained optimization. The simulator is based on the numerical solution of optimal control problems for a PDE related to the nonlinear Euler-Bernoulli beam model, namely a system of controlled, fourth order, partial differential algebraic equations. The model accounts for inextensibility and curvature constraints on the manipulator, plus the actuators, represented by distributed controls on the local curvature of the device symmetry axis. Several optimal control problems have been addressed in a stationary setting, including low energy consumption, reachability and grasping, also in presence of obstacles and in case of mechanical breakdowns. Discretization is performed by finite-differences in space combined with a velocity Verlet time integrator, while the numerical optimization employs augmented-Lagrangian methods.

For further details refer to the papers:

Cacace, S., Lai, A.C., Loreti, P., Modeling and optimal control of an octopus tentacle, (2020) SIAM Journal on Control and Optimization, 58 (1), pp. 59-84.

Cacace, S., Lai, A.C., Loreti, P., Multi-target optimal control problems for a tentacle-like soft manipulator, (2021) Proceedings of the 18th International Conference on Informatics in Control, Automation and Robotics, ICINCO 2021, pp. 39-48.

Cacace, S., Lai, A.C., Loreti, P., Optimal Reachability and Grasping for a Soft Manipulator, (2021) Lecture Notes in Electrical Engineering, 720, pp. 16-34.

Cacace, S., Lai, A.C., Loreti, P., Optimal reachability with obstacle avoidance for hyper-redundant and soft manipulators, (2020) ICINCO 2020 - Proceedings of the 17th International Conference on Informatics in Control, Automation and Robotics, pp. 134-141.

Cacace, S., Lai, A.C., Loreti, P., Control strategies for an octopus-like soft manipulator, (2019) ICINCO 2019 - Proceedings of the 16th International Conference on Informatics in Control, Automation and Robotics, 1, pp. 82-90.

A sample video of Vurpo in action for optimal reachability tasks
(in red the curvature controls and the target point)