Title: Case study of constructive commissioning

Author of the experiment: Luigi Ferrara, Francesco Basile

Description: The virtual process in the video is made of three conveyors, each equipped with three retroflective sensors, transporting boxes from the left to the right. The process must be controlled to fulfil two specifications: (1) At most two robots can simultaneously work; (2) A robot can not grasp more than two boxes consecutively if one of the other robots has not grasped a box At this aim, a supervisor control architecture is adopted. First, the supervisor is designed either as an automaton (using Supremica) or a Petri net (using PetriBaR). Then, the toolbox SUP2PLC (available at the software section) is used to automatically generate the PLC code, starting from a supervisor model. Finally, the closed-loop system is simulated: a virtual PLC is instantiated with PLC-SIM (Step 7), and the code is run. I/O signals are exchanged with Factory I/O through TCP/IP. More details in the paper F. Basile, L. Ferrara (2020), From supervisory control to PLC code: a way to speed-up Constructive/Virtual Commissioning of Manufacturing Systems, 15th IFAC Workshop on Discrete Event Systems (WODES 2020)

Title: Execution of time-optimal trajectories with the Franka Emika's Panda robot

Author of the experiment: Enrico Ferrentino, Heitor Judiss Savino

Description: Time-optimal trajectories are planned with a dynamic programming algorithm that exploits kinematic redundancy to minimize trajectory tracking time. The trajectories are planned for Franka Emika's Panda robot by considering a dynamic model with friction together with joint velocity, acceleration, jerk, torque and torque rate bounds. The planned trajectories are executed on the real robot to assess feasibility and tracking accuracy. Feasibility is obtained through interpolation and smoothing of the planned joint position references, while the tracking error in the joint space is lower than 0.8 degrees. Two trajectories are planned corresponding to a straight line of 0.50 m and an ellipse-shaped line of 1.45 m. Execution times are 0.62 s and 1.70 s respectively.

Title: Decentralized multi-arm planning

Author of the experiment: Alessandro Marino & Jolanda Coppola

Description: A two-layer decentralized framework for kinematic control of cooperative and collaborative multi-robot systems is developed and tested. The motion of the system is specified at the workpiece level, by adopting a task-oriented formulation for cooperative tasks. The first layer computes the motion of the single arms in the system. In detail, the control unit of each robot computes the end-effector motion references in a decentralized fashion on the basis of the knowledge of the assigned cooperative task and the motion references computed by its neighbors. Then, in the second layer, each control unit computes the reference joint motion of the corresponding manipulator from the end-effector reference motion.

Setup: 2 Comau SmartSix robots installed at the Automatica Laboratory of University of Salerno.

Title: Cooperative drilling of aeronautic hybrid stacks

Author of the experiment: Alessandro Marino

Description: The proposed technology consists in a general robot architecture and a cooperative drilling process using only standard low-cost robots and off-the-shelf components. A first robot is in charge of drilling the hybrid stack, while a second manipulator ensures the right clamping force between the parts of the stack. Both robots are equipped with force control capabilities to control the generalized forces raising during the interaction with the stack. Thanks to the adoption of a fuzzy inference system, the tuning of the force controllers might be carried out by operators that have knowledge of the drilling process but not of control system technology.

Setup: 2 Comau SmartSix robots equipped with force/torque sensors installed at the Automatica Laboratory of University of Salerno.