1,721,006 research outputs found
An incremental model repair approach to timed discrete event systems
No full textNew results on the model repair for timed discrete systems, modeled as Time Petri net systems, are presented in this paper. Unexpected and missed behavior in the nominal model, leading to observed but unexpected events and missed event observations, are formulated as logical conditions that can be directly transformed into linear mixed-integer inequalities. The repair model algorithm is incremental, also when multiple deviations from the nominal behavior are observed at a time. A set of logical conditions is preliminarily built from the observed behavior, then a mixed-integer linear programming problem is solved to repair the model
Robot-Agnostic Interaction Controllers Based on ROS
No full textIn robotized industrial scenarios, the need for efficiency and flexibility is increasing, especially when tasks must be executed in dangerous environments and/or require the simultaneous manipulation of dangerous/fragile objects by multiple heterogeneous robots. However, the underlying hardware and software architecture is typically characterized by constraints imposed by the robots’ manufacturers, which complicates their integration and deployment. This work aims to demonstrate that widely used algorithms for robotics, such as interaction control, can be made independent of the hardware architecture, abstraction level, and functionality provided by the low-level proprietary controllers. As a consequence, a robot-independent control framework can be devised, which reduces the time and effort needed to configure the robotic system and adapt it to changing requirements. Robot-agnostic interaction controllers are implemented on top of the Robot Operating System (ROS) and made freely available to the robotic community. Experiments were performed on the Universal Robots UR10 research robot, the Comau Smart-Six industrial robot, and their digital twins, so as to demonstrate that the proposed control algorithms can be easily deployed on different hardware and simulators without reprogramming
Discrete fully probabilistic design: towards a control pipeline for the synthesis of policies from examples
No full textWe present the principled design of a control pipeline for the synthesis of policies from examples data. The pipeline, based on a discretized design, expounds the algorithm introduced in [1] to synthesize policies from examples for constrained, stochastic and nonlinear systems. The pipeline: (i) does not need the constraints to be fulfilled in the possibly noisy example data; (ii) enables control synthesis even when the data are collected from an example system that is different from the one under control. The design is benchmarked on an example that involves controlling an inverted pendulum with actuation constraints. The data that are used to synthesize the policy are collected from a pendulum that: (i) is different from the one under control; (ii) does not satisfy the actuation constraints
Planning of efficient trajectories in robotized assembly of aerostructures exploiting kinematic redundancy
No full textAerospace production volumes have increased over time and robotic solutions have been progressively introduced in the aeronautic assembly lines to achieve high-quality standards, high production rates, flexibility and cost reduction. Robotic workcells are sometimes characterized by robots mounted on slides to increase the robot workspace. The slide introduces an additional degree of freedom, making the system kinematically redundant, but this feature is rarely used to enhance performances. The paper proposes a new concept in trajectory planning, that exploits the redundancy to satisfy additional requirements. A dynamic programming technique is adopted, which computes optimized trajectories, minimizing or maximizing the performance indices of interest. The use case is defined on the LABOR (Lean robotized AssemBly and cOntrol of composite aeRostructures) project which adopts two cooperating six-axis robots mounted on linear axes to perform assembly operations on fuselage panels. Considering the needs of this workcell, unnecessary robot movements are minimized to increase safety, the mechanical stiffness is maximized to increase stability during the drilling operations, collisions are avoided, while joint limits and the available planning time are respected. Experiments are performed in a simulation environment, where the optimal trajectories are executed, highlighting the resulting performances and improvements with respect to non-optimized solutions
An auction-based approach to control automated warehouses using smart vehicles
No full textIn modern automated warehouses smart vehicles are becoming popular, allowing flexible
adaptation to changing requirements. Thus, encouraged by their considerable abilities, this paper proposes an auction-based approach for the control of automated warehouse systems with smart vehicles to provide modularity, near- realtime capabilities, scalability, robustness and services orientation to the whole system. In particular, the approach focuses on the mission assignment problem.
Moreover, to overcome the difficulties in design and development of the employed approach and to size and configure the system to be controlled, a hybrid model with an automatic model synthesis procedure to dynamically add/remove resources is presented
Globally optimal redundancy resolution with dynamic programming for robot planning: A ros implementation
No full textDynamic programming techniques have proven much more flexible than calculus of variations and other techniques in performing redundancy resolution through global optimization of performance indices. When the state and input spaces are discrete, and the time horizon is finite, they can easily accommodate generic constraints and objective functions and find Pareto-optimal sets. Several implementations have been proposed in previous works, but either they do not ensure the achievement of the globally optimal solution, or they have not been demonstrated on robots of practical relevance. In this communication, recent advances in dynamic programming redundancy resolution, so far only demonstrated on simple planar robots, are extended to be used with generic kinematic structures. This is done by expanding the Robot Operating System (ROS) and proposing a novel architecture meeting the requirements of maintainability, re-usability, modularity and flexibility that are usually required to robotic software libraries. The proposed ROS extension integrates seamlessly with the other software components of the ROS ecosystem, so as to encourage the reuse of the available visualization and analysis tools. The new architecture is demonstrated on a 7-DOF robot with a six-dimensional task, and topological analyses are carried out on both its state space and resulting joint-space solution
The Dynamic Model of the UR10 Robot and Its ROS2 Integration
No full textThis article presents the full dynamic model of the UR10 industrial robot. A triple-stage identification approach is adopted to estimate the manipulator's dynamic coefficients. First, linear parameters are computed using a standard linear regression algorithm. Subsequently, nonlinear friction parameters are estimated according to a sigmoidal model. Lastly, motor drive gains are devised to map estimated joint currents to torques. The overall identified model can be used for both control and planning purposes, as the accompanied ROS2 software can be easily reconfigured to account for a generic payload. The estimated robot model is experimentally validated against a set of exciting trajectories and compared to the state-of-the-art model for the same manipulator, achieving higher current prediction accuracy (up to a factor of 4.43) and more precise motor gains. The related software is available at https://codeocean.com/capsule/8515919/tree/v2
Corrections: The Dynamic Model of the UR10 Robot and its ROS2 Integration (IEEE Trans. Ind. Informat. (2025) 21:5 (3828–3838) DOI: 10.1109/TII.2025.3534415)
No full textThis addresses errors in [1]. Compared to the original article, we applied minor grammatical corrections and symbol refinements to clarify the adoption of the chosen notation and nomenclature
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