Method to control, through direct teaching, a closed robotised system and relative processing plant

A method to control a closed robotised system;

• the method comprising:
• a learning step, during which an operator moves an end effector of a robot manipulator of the robotised system by means of a driving assembly comprising a force/torque sensor and the movements made by the end effector are stored in a storage unit of the robotised system;
• a reproduction step, which takes place after the learning step and during which a control system operates the robot manipulator so that the end effector substantially repeats the movements stored in the storage unit;
• wherein, during the learning step, the operator exerts a force and/or a torque (Fc) upon the driving assembly, wherein the sensor detects an applied force and/or torque (Fext);
• and wherein a processing system carries out an admittance control obtaining, depending on the data detected by the sensor, indications (Xref, X*ref) of movement for the robot manipulator in the Cartesian space;
• the processing system, following the admittance control, delivers the indications (Xref, X*ref) of movement in the Cartesian space to a trajectory interpolation unit of the robotised system so as to generate a desired trajectory of the end effector through interpolation;
• the method comprising the further steps of:
• defining a dynamic target reference system (DTRF) for the robot manipulator, i.e. a time-varying reference system at least at a degree of freedom that the end effector must follow in Cartesian coordinates;
• setting the position of the end effector as the initial reference position of the dynamic target reference system (DTRF);
• synchronizing the position of the end effector with that of the dynamic target reference system (DTRF);
• changing the position of the dynamic target reference system (DTRF) abased on the indications (Xref, X*ref) of movement processed during the admittance control.