Folding Assembly by Means of Dual-Arm Robotic Manipulation

In this paper, we consider folding assembly as an assembly primitive suitable for dual-arm robotic assembly, that can be integrated in a higher level assembly strategy. The system composed by two pieces in contact is modelled as an articulated object, connected by a prismatic-revolute joint. Different grasping scenarios were considered in order to model the system, and a simple controller based on feedback linearisation is proposed, using force torque measurements to compute the contact point kinematics. The folding assembly controller has been experimentally tested with two sample parts, in order to showcase folding assembly as a viable assembly primitive.Comment: 7 pages, accepted for ICRA 201

Asymmetric Dual-Arm Task Execution using an Extended Relative Jacobian

Coordinated dual-arm manipulation tasks can be broadly characterized as possessing absolute and relative motion components. Relative motion tasks, in particular, are inherently redundant in the way they can be distributed between end-effectors. In this work, we analyse cooperative manipulation in terms of the asymmetric resolution of relative motion tasks. We discuss how existing approaches enable the asymmetric execution of a relative motion task, and show how an asymmetric relative motion space can be defined. We leverage this result to propose an extended relative Jacobian to model the cooperative system, which allows a user to set a concrete degree of asymmetry in the task execution. This is achieved without the need for prescribing an absolute motion target. Instead, the absolute motion remains available as a functional redundancy to the system. We illustrate the properties of our proposed Jacobian through numerical simulations of a novel differential Inverse Kinematics algorithm.Comment: Accepted for presentation at ISRR19. 16 Page

Obstacle Avoidance in Dynamic Environments via Tunnel-following MPC with Adaptive Guiding Vector Fields

This paper proposes a motion control scheme for robots operating in a dynamic environment with concave obstacles. A Model Predictive Controller (MPC) is constructed to drive the robot towards a goal position while ensuring collision avoidance without direct use of obstacle information in the optimization problem. This is achieved by guaranteeing tracking performance of an appropriately designed receding horizon path. The path is computed using a guiding vector field defined in a subspace of the free workspace where each point in the subspace satisfies a criteria for minimum distance to all obstacles. The effectiveness of the control scheme is illustrated by means of simulation

Asymmetric Dual-Arm Task Execution Using an\ua0Extended Relative Jacobian

Coordinated dual-arm manipulation tasks can be broadly characterized as possessing absolute and relative motion components. Relative motion tasks, in particular, are inherently redundant in the way they can be distributed between end-effectors. In this work, we analyse cooperative manipulation in terms of the asymmetric resolution of relative motion tasks. We discuss how existing approaches enable the asymmetric execution of a relative motion task, and show how an asymmetric relative motion space can be defined. We leverage this result to propose an extended relative Jacobian to model the cooperative system, which allows a user to set a concrete degree of asymmetry in the task execution. This is achieved without the need for prescribing an absolute motion target. Instead, the absolute motion remains available as a functional redundancy to the system. We illustrate the properties of our proposed Jacobian through numerical simulations of a novel differential Inverse\ua0Kinematics algorithm

Planar Friction Modelling with LuGre Dynamics and Limit Surfaces

Contact surfaces in planar motion exhibit a coupling between tangential and rotational friction forces. This paper proposes planar friction models grounded in the LuGre model and limit surface theory. First, distributed planar extended state models are proposed and the Elasto-Plastic model is extended for multi-dimensional friction. Subsequently, we derive a reduced planar friction model, coupled with a pre-calculated limit surface, that offers reduced computational cost. The limit surface approximation through an ellipsoid is discussed. The properties of the planar friction models are assessed in various simulations, demonstrating that the reduced planar friction model achieves comparable performance to the distributed model while exhibiting ~80 times lower computational cost

Learning Shape Control of Elastoplastic Deformable Linear Objects

Deformable object manipulation tasks have long been regarded as challenging robotic problems. However, until recently very little work has been done on the subject, with most robotic manipulation methods being developed for rigid objects. Deformable objects are more difficult to model and simulate, which has limited the use of model-free Reinforcement Learning (RL) strategies, due to their need for large amounts of data that can only be satisfied in simulation. This paper proposes a new shape control task for Deformable Linear Objects (DLOs). More notably, we present the first study on the effects of elastoplastic properties on this type of problem. Objects with elastoplasticity such as metal wires, are found in various applications and are challenging to manipulate due to their nonlinear behavior. We first highlight the challenges of solving such a manipulation task from an RL perspective, particularly in defining the reward. Then, based on concepts from differential geometry, we propose an intrinsic shape representation using discrete curvature and torsion. Finally, we show through an empirical study that in order to successfully solve the proposed task using Deep Deterministic Policy Gradient (DDPG), the reward needs to include intrinsic information about the shape of the DLO

A survey of robot manipulation in contact

In this survey, we present the current status on robots performing manipulation tasks that require varying contact with the environment, such that the robot must either implicitly or explicitly control the contact force with the environment to complete the task. Robots can perform more and more manipulation tasks that are still done by humans, and there is a growing number of publications on the topics of (1) performing tasks that always require contact and (2) mitigating uncertainty by leveraging the environment in tasks that, under perfect information, could be performed without contact. The recent trends have seen robots perform tasks earlier left for humans, such as massage, and in the classical tasks, such as peg-in-hole, there is a more efficient generalization to other similar tasks, better error tolerance, and faster planning or learning of the tasks. Thus, in this survey we cover the current stage of robots performing such tasks, starting from surveying all the different in-contact tasks robots can perform, observing how these tasks are controlled and represented, and finally presenting the learning and planning of the skills required to complete these tasks

Новые подходы к синтезу гетероциклических производных пиридинкарбоновых кислот, акридина и пиразолона

ХИМИЯ ФАРМАЦЕВТИЧЕСКАЯГЕТЕРОЦИКЛИЧЕСКИЕ СОЕДИНЕНИЯ /ХИМ СИНТПИРИДИНКАРБОНОВЫЕ КИСЛОТЫНИАЦИН /ХИМНИКОТИНОВАЯ КИСЛОТА /ХИМИЗОНИКОТИНОВЫЕ КИСЛОТЫ /ХИМХЛОРАНГИДРИДЫЭФИРЫ СЛОЖНЫЕ /ХИМАЗОМЕТИНЫАКРИДИНЫ /ХИМХИНОЛИНЫ /ХИМПИРАЗОЛОНЫ /ХИМБИОЛОГИЧЕСКАЯ АКТИВНОСТЬОБЗОР ЛИТЕРАТУРЫАктуальной задачей современной фармацевтической химии является разработка новых методов синтеза, изучение химических свойств, а также поиск биологически активных соединений среди производных никотиновой и изоникотиновой кислот. В обзоре рассмотрены синтетические подходы к получению сложных эфиров карбоновых кислот, в том числе никотиновой и изоникотиновой кислот, приведены примеры биологической активности никотиновой и изоникотиновой кислот и их производных. Обсуждены методы синтеза азометинов, замещенных акридинов и пиразолонов, приведены примеры их биологической активности. Представлена перспективная концепция синтеза новых потенциальных лекарственных средств на основе гетероциклических производных никотиновой и изоникотиновой кислот. Рассмотренные в данном обзоре методы функционализации органических соединений применительно к синтезу гетероциклических производных никотиновой и изоникотиновой кислот позволяют получать новые перспективные соединения, потенциально обладающие антибактериальной, противовирусной, фунгицидной и противоопухолевой активностью.The urgent task of modern pharmaceutical chemistry is the development of new methods of synthesis, the study of chemical properties, as well as the search for biologically active compounds among derivatives of nicotinic and isonicotinic acids. The review examines synthetic approaches to the production of carboxylic acid esters including nicotinic and isonicotinic acids, gives examples of the biological activity of nicotinic and isonicotinic acids and their derivatives. The methods for the synthesis of azomethines, substituted acridines and pyrazolones are discussed, examples of their biological activity are given. A promising concept for the synthesis of new potential drugs based on heterocyclic derivatives of nicotinic and isonicotinic acids is presented. The methods of functionalization of organic compounds considered in this review with regard to the synthesis of heterocyclic derivatives of nicotinic and isonicotinic acids make it possible to obtain new promising compounds potentially having antibacterial, antiviral, fungicidal and antitumor activity

Разработка проекта электрической сети н.п. Глинище Хойникского района

In this paper, we present a technique for online generation of dual arm trajectories using constraint based programming based on bound margins. Using this formulation, we take both equality and inequality constraints into account, in a way that incorporates both feedback and feedforward terms, enabling e.g. tracking of timed trajectories in a new way. The technique is applied to a dual arm manipulator performing a bi-manual task. We present experimental validation of the approach, including comparisons between simulations and real experiments of a complex bimanual tracking task. We also show how to add force feedback to the framework, to account for modeling errors in the systems. We compare the results with and without feedback, and show how the resulting trajectory is modified to achieve the prescribed interaction forces.QC 20150630. QC 20200713European Union FP7 project RoboHow.Co