Dynamic Control of Mobile Multirobot Systems: The Cluster Space Formulation

The formation control technique called cluster space control promotes simplified specification and monitoring of the motion of mobile multirobot systems of limited size. Previous paper has established the conceptual foundation of this approach and has experimentally verified and validated its use for various systems implementing kinematic controllers. In this paper, we briefly review the definition of the cluster space framework and introduce a new cluster space dynamic model. This model represents the dynamics of the formation as a whole as a function of the dynamics of the member robots. Given this model, generalized cluster space forces can be applied to the formation, and a Jacobian transpose controller can be implemented to transform cluster space compensation forces into robot-level forces to be applied to the robots in the formation. Then, a nonlinear model-based partition controller is proposed. This controller cancels out the formation dynamics and effectively decouples the cluster space variables. Computer simulations and experimental results using three autonomous surface vessels and four land rovers show the effectiveness of the approach. Finally, sensitivity to errors in the estimation of cluster model parameters is analyzed.Fil: Mas, Ignacio Agustin. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kitts, Christopher. Santa Clara University; Estados Unido

Synchronized computational architecture for generalized bilateral control of robot arms

A master six degree of freedom Force Reflecting Hand Controller (FRHC) is available at a master site where a received image displays, in essentially real time, a remote robotic manipulator which is being controlled in the corresponding six degree freedom by command signals which are transmitted to the remote site in accordance with the movement of the FRHC at the master site. Software is user-initiated at the master site in order to establish the basic system conditions, and then a physical movement of the FRHC in Cartesean space is reflected at the master site by six absolute numbers that are sensed, translated and computed as a difference signal relative to the earlier position. The change in position is then transmitted in that differential signal form over a high speed synchronized bilateral communication channel which simultaneously returns robot-sensed response information to the master site as forces applied to the FRHC so that the FRHC reflects the feel of what is taking place at the remote site. A system wide clock rate is selected at a sufficiently high rate that the operator at the master site experiences the Force Reflecting operation in real time

Safe-guarded multi-agent control for mechatronic systems: implementation framework and design patterns

This thesis addresses two issues: (i) developing an implementation framework for Multi-Agent Control Systems (MACS); and (ii) developing a pattern-based safe-guarded MACS design method.\ud \ud The Multi-Agent Controller Implementation Framework (MACIF), developed by Van Breemen (2001), is selected as the starting point because of its capability to produce MACS for solving complex control problems with two useful features:\ud • MACS is hierarchically structured in terms of a coordinated group of elementary and/or composite controller-agents;\ud • MACS has an open architecture such that controller-agents can be added, modified or removed without redesigning and/or reprogramming the remaining part of the MACS

Manipulator control of the Robotized TMS System with Incurved TMS Coil Case

Objective: This study shows the force/torque control strategy for the robotized TMS system whose TMS coil's floor is incurved. The strategy considered the adhesion and friction between the coil and the subject's head. Methods: Hybrid position/force control and proportional torque were used for the strategy. The force magnitude applied for the force control was scheduled by the error between the coil's current position and the target point. Results: The larger desired force for the force controller makes the error quickly. By scheduling the force magnitude applied for the force control, the low error between the coil's current and target positions is maintained with the relatively small force after the larger force is applied for around 10 seconds. The proportional torque made the adhesion better by locating the contact area between the coil and the head close to the coil. I was shown by checking the ${\tau}_c/F_c$ value from the experimental results. While the head slowly moved away from the coil during the TMS treatment, the coil still interacted with the head. Using that characteristic, the coil could locate the new target point using the force/torque strategy without any trajectory planning. Conclusion: The proposed force/torque controller enhanced the adhesion between the incurved TMS coil and the subject's head. It also reduced the error quickly by scheduling the magnitude of the force applied. Significance: This study proposes the robotized TMS system's force/torque control strategy considering the physical characteristics from the contact between the incurved TMS coil case and the subject's head

Multi-robot cooperation

Abstract. This bachelor’s thesis familiarizes with multi-robot cooperation. The main interest is in two robot manipulators. This thesis is a literature review. The operation of the robot and the phenomena that act on them while in operation are investigated from kinematics and command architecture point of view. This thesis is based on manuals from two KUKA robots from University of Oulu, so in the future the use and understanding of their cooperation would be easier. The results gave good understanding of robot software calculations for trajectories and geometrics and what other has to consider when controlling a multi-robot system. This is a good base for deeper theoretical research for robot system software and practical testing.Usean robotin yhteiskäyttö. Tiivistelmä. Tässä opinnäytetyössä perehdytään usean robotin yhteiskäyttöön, jossa mielenkiinnon kohteena on kahden robottikäden yhteistoiminta. Työ on kirjallisuuskatsaus. Robottien toimintaa ja niihin vaikuttavia asioita tarkastellaan niin kinematiikan, kuin ohjelmisto- ja käskyarkkitehtuurin kautta. Työn pohjana käytettiin yliopistolla olevien KUKA robottikäsien oppaita, jotta jatkossa niiden yhteiskäyttö olisi helpommin ymmärrettävissä. Työn tulokset avasivat sitä, miten robottien ohjelmisto ohjaa ja laskee tarvittavat liikeradat ja geometriat ja mitä kaikkea usean robotin ohjauksessa pitää ottaa huomioon. Tämä on hyvä pohja syvemmälle teoreettiselle robottiohjelmistolle tai käytännön testaamiselle

Agent-based modeling and simulation of a small scale cyber-physical system using NetLogo

The Cyber-Physical System (CPS) paradigm promotes the decentralization and distribution of the logic control as well as the integration of cyber and physical counterparts. In parallel, self-organization allows the dynamic and automatic system re-configuration responding to condition and environment changes. Modeling and simulation assume a crucial importance in the design of such complex, distributed, and self-organized systems, in the way that the detected and debugged errors may be corrected before the deployment into the real system, as well different strategies can be tested and evaluated. Agent-based modeling tools are computational frameworks able to analyze, experiment and compare systems populated by cooperative agents, supporting the fast prototyping of agent-based solutions exhibiting self-* properties. In this paper, the NetLogo tool was used to model and simulate the agent-based control layer of a small scale CPS, which control uses self-organization principles.info:eu-repo/semantics/publishedVersio

A new lean change methodology for small & medium sized enterprises

SMEs find it difficult to implement productivity improvement tools, particularly those associated with Lean Manufacturing. Larger companies have more success due to greater access to resources. To provide the SMEs with a way to implement Lean sustainably, the European project ERIP develops a new lean change methodology for SMEs. In this paper the methodology is explained and three test cases show the strength of the methodology. The method is a sequence of achieving management and company support, starting with data analysis and identifying problems and consequently solving these problems. Within the workshops, training of employees is conducted. The three test cases show that even through limited efforts, a good productivity improvement can be achieved in a sustainable manner

Investigations in robotic-assisted design: Strategies for symbiotic agencies in material-directed generative design processes

The research described in this article utilises a phase-changing material, three-dimensional scanning technologies and a six-axis industrial robotic arms as vehicles to enable a novel framework where robotic technology is utilised as an ‘amplifier’ of the design process to realise geometries that derive from both constructive visions and architectural visions through iterative feedback loops between them. The robot in this scenario is not a fabrication tool but the enabler of an environment where the material, robotic and human agencies interact. This article describes the exploratory research for the development of a dialogic design process, sets the framework for its implementation, carries out an evaluation based on designer use and concludes with a set of observations. One of the main findings of this article is that a deeper collaboration that acknowledges the potential of these tools, in a learning-by-design method, can lead to new choreographies for architectural design and fabricatio