Dynamic update of a virtual cell for programming and safe monitoring of an industrial robot

A hardware/software architecture for robot motion planning and on-line safe monitoring has been developed with the objective to assure high flexibility in production control, safety for workers and machinery, with user-friendly interface. The architecture, developed using Microsoft Robotics Developers Studio and implemented for a six-dof COMAU NS 12 robot, established a bidirectional communication between the robot controller and a virtual replica of the real robotic cell. The working space of the real robot can then be easily limited for safety reasons by inserting virtual objects (or sensors) in such a virtual environment. This paper investigates the possibility to achieve an automatic, dynamic update of the virtual cell by using a low cost depth sensor (i.e., a commercial Microsoft Kinect) to detect the presence of completely unknown objects, moving inside the real cell. The experimental tests show that the developed architecture is able to recognize variously shaped mobile objects inside the monitored area and let the robot stop before colliding with them, if the objects are not too small

A new HW/SW architecture to move from AGVs towards Autonomous Mobile Robots

This paper proposes the basic concepts of a brand new HW/SW architecture, whose development is in progress through an academic/industrial collaboration, aimed at obtaining a mobile agent capable to merge in itself the standard characteristics of the Automated Guided Vehicles and some potentialities of the Autonomous Mobile Robots, with a particular care for safety issues. Its HW/SW features, together with its mechanical characteristics, make it potentially applicable both in industrial and research contexts

Development of a Virtual Collision Sensor for Industrial Robots

Collision detection is a fundamental issue for the safety of a robotic cell. While several common methods require specific sensors or the knowledge of the robot dynamic model, the proposed solution is constituted by a virtual collision sensor for industrial manipulators, which requires as inputs only the motor currents measured by the standard sensors that equip a manipulator and the estimated currents provided by an internal dynamic model of the robot (i.e., the one used inside its controller), whose structure, parameters and accuracy are not known. The collision detection is achieved by comparing the absolute value of the current residue with a time-varying, positive-valued threshold function, including an estimate of the model error and a bias term, corresponding to the minimum collision torque to be detected. The value of such a term, defining the sensor sensitivity, can be simply imposed as constant, or automatically customized for a specific robotic application through a learning phase and a subsequent adaptation process, to achieve a more robust and faster collision detection, as well as the avoidance of any false collision warnings, even in case of slow variations of the robot behavior. Experimental results are provided to confirm the validity of the proposed solution, which is already adopted in some industrial scenarios

The RoboLAB experience: aims, challenges and results of a joint academia-industry lab of industrial robotics

The paper illustrates the research activity of a joint research laboratory, established by COMAU and Politecnico di Torino, named "RoboLAB", and devoted to industrial robotics issues. The lab facilitates a stable cooperation between the academic and industrial partners, leading to satisfying results both from the scientific and the technological point of view. The paper illustrates in particular the most relevant results of the research activity carried out to make the industrial robots safe machines for themselves and for people working with them, dealing with collision detection and avoidance, and with solutions allowing robots to safely share spaces with humans

Robotics education: proposals for laboratory practices about manipulators

Robotics education at M. Sc. courses is quite challenging, especially in the organization of intriguing laboratory activities about industrial manipulators, to accompany and complete traditional material and lessons on kinematics, dynamics, motion planning and control issues. Time and space constraints, the number of students attending the labs, and the available software and equipments (and their cost) can seriously limit the lab practices that can be actually offered in a Robotics course. On the basis of the experience matured at Politecnico di Torino, this paper describes how lab practices about manipulators can be organized by using low-cost structures, built up from the standard LEGO Mindstorms Kit, so to let the students become familiar with manipulators in different ways. Such practices are then well completed by activities with an industrial robot, available at Politecnico

Development of a general friction identification framework for industrial manipulators

The paper proposes a general friction identification framework for industrial manipulators, including the automatic handling of all the required phases, from data acquisition and processing up to parameters identification. A complete static friction model is used, with the insertion of a rough approximation of the hysteretic behavior of friction; switching to a possible simpler model is also automatically executed when possible. The proposed solution has been implemented in a software module, which has been integrated into the control architecture of an industrial robot, and experimentally tested. The results have shown that a very accurate reconstruction of the actual motor currents is provided, when the friction estimated using the proposed framework is inserted in the robot dynamic model

A general procedure for collision detection between an industrial robot and the environment

A general procedure for collision detection between an industrial robot and the environment is proposed in this paper. The procedure does not use any external sensor, and does not rely on any particular information about the specific robot on which it is applied, so that it can be easily implemented in the software architecture of different manipulators without any customization. Experimental results on both lightweight and heavyweight industrial manipulators confirm its validity and the absence of false collision detections during standard work-cycle

Robotics education: proposals for laboratory practices about manipulators

Robotics education at M. Sc. courses is quite challenging, especially in the organization of intriguing laboratory activities about industrial manipulators, to accompany and complete traditional material and lessons on kinematics, dynamics, motion planning and control issues. Time and space constraints, the number of students attending the labs, and the available software and equipments (and their cost) can seriously limit the lab practices that can be actually offered in a Robotics course. On the basis of the experience matured at Politecnico di Torino, this paper describes how lab practices about manipulators can be organized by using low-cost structures, built up from the standard LEGO Mindstorms Kit, so to let the students become familiar with manipulators in different ways. Such practices are then well completed by activities with an industrial robot, available at Politecnico

Efficient implementation of iterative inverse kinematics in real time control architecture

The paper proposes a procedure for the iterative computation of a robot inverse kinematics that uses different algorithms in synergy, so to obtain a singularity-robust and rapidly convergent technique. The application of such a procedure allows the creation of a unified version of the executable code for large classes of industrial robots, with the possibility to introduce new kinematic chains or more complex structures without the need to entirely rewrite the code. The paper offers also some guidelines about the software implementation and optimization in the industrial environment, and it is completed by experimental results where the procedure is applied to real industrial robot

Friction modeling and identification for industrial manipulators

The paper is focused on the development of an adequate model of the friction acting on the joints of an industrial manipulator, suitable to be used for simulation and control purposes. The experimental tests required for the identification are executable via the standard interface for the robot programming, without any change in the path planning procedure or in the robot control. The proposed friction model is developed and validated for the six-dof Comau SMART NS12 manipulator