This paper deals with the global position control problem of robot manipulators in joint space, a new family of control schemes consisting of a suitable combination of hyperbolic functions is presented. The proposed control family includes a large class of bounded hyperbolic-type control schemes to drive both position error and derivative action terms plus gravity compensation. To ensure global asymptotic stability of closed-loop system equilibrium point, we propose an energy-shaping based strict Lyapunov function. To verify the efficiency of the proposed control algorithm, an experimental comparative analysis between the well known unbounded linear PD control and three hyperbolic-type control schemes of the proposed family on a three degrees of freedom direct-drive robot manipulator is analysed.
In this paper, a family of hybrid control algorithms is presented; where it is merged a free camera-calibration image-based control scheme and a direct force controller, both with the same priority level. The aim of this generalised hybrid controller is to regulate the robot-environment interaction into a two-dimensional task-space. The design of the proposed control structure takes into account most of the dynamic effects present in robot manipulators whose inputs are torque signals. As examples of this generalised structure of hybrid force/vision controllers, a linear proportional-derivative structure and a nonlinear proportional-derivative one (based on the hyperbolic tangent function) are presented. The corresponding stability analysis, using Lyapunov's direct method and invariance theory, is performed to proof the asymptotic stability of the equilibrium vector of the closed-loop system. Experimental tests of the control scheme are presented and a suitable performance is observed in all the cases. Unlike most of the previously presented hybrid schemes, the control structure proposed herein achieves soft contact forces without overshoots, fast convergence of force and position error signals, robustness of the controller in the face of some uncertainties (such as camera rotation), and safe operation of the robot actuators when saturating functions (non-linear case) are used in the mathematical structure. This is one of the first works to propose a generalized structure of hybrid force/vision control that includes a closed loop stability analysis for torque-driven robot manipulators.
Fundamentals of the theory of system alliances are briefly reviewed. An accent is put on interfaces (IFs). The model of IFs consisting of a pair of finite deterministic automata sharing a part of their internal state space is introduced. The presented model of alliance interface can be successfully implemented for the study of typical phenomena in complex heterogeneous objects with a significant degree of uncertainty.
A control system architecture design for an underwater ROV, primarily Class I - Pure Observation underwater ROV is presented in this paper. A non-linear plant model was designed using SolidWorks 3D modeling tool and is imported to MATLAB as a 3D model. The non-linear modeled plant is linearized using the MATLAB linear analysis toolbox to have a linear approximate model of the system. The authors designed controllers for the linear plant model of underwater ROV. PID controllers are utilized as a controller of the modeled plant. The PID tuning tools by MATLAB are utilized to tune the controller of the plant model of underwater ROV. The researchers test the control design of underwater ROV using MATLAB Simulink by analyzing the response of the system and troubleshoot the control design to achieve the objective parameters for the control design of underwater ROV.
This article deals with reconstructing chaotic arractor through Freescale digital signal processor 56800 family. The system is designed to be used in the mechatronics applications for simulating dynamic‘s states of prothetic‘s knuckle. This conception fully supplants chaotic analog circuits. and Obsahuje seznam literatury
Haar's Lemma (1918) deals with the algebraic characterization of the inclusion of polyhedral sets. This Lemma has been involved many times in automatic control of linear dynamical systems via positive invariance of polyhedrons. More recently, it has been used to characterize stochastic comparison w.r.t. linear/integral ordering of Markov (reward) chains. In this paper we develop a state space oriented approach to the control of Discrete Event Systems (DES) based on the remark that most of control constraints of practical interest are naturally expressed as the inclusion of two systems of linear (w.r.t. idempotent semiring or semifield operations) inequalities. Thus, we establish tropical version of Haar's Lemma to obtain the algebraic characterization of such inclusion. As in the linear case this Lemma exhibits the links between two apparently different problems: comparison of DES and control via positive invariance. Our approach to the control differs from the ones based on formal series and is a kind of dual approach of the geometric one recently developed. Control oriented applications of the main results of the paper are given. One of these applications concerns the study of transportation networks which evolve according to a time table. Although complexity of calculus is discussed the algorithmic implementation needs further work and is beyond the scope of this paper.
Jednou z ústredných etických obáv, ktoré vyvoláva vyhliadka na použitie vojenských autonómnych smrtiacich robotov, je otázka morálnej zodpovednosti za ich konanie. Robert Sparrow tvrdí, že vojenské roboty vybavené schopnosťou učiť sa by boli natoľko nezávislé a samostatné, že by umožnili ľudským aktérom odmietnuť zodpovednosť za ich konanie, čím by vznikla situácia, ktorú Andreas Matthias označil ako „medzeru v zodpovednosti“. Medzera v zodpovednosti je stav, keď nie je nikto zodpovedný za konanie učiacich sa autonómnych robotov. Tento stav je dôsledkom neschopnosti ľudí plne kontrolovať a predpovedať konanie takýchto technológií. V článku argumentujem, že uvedený záver je nesprávny, pretože autonómne technológie nezbavujú ľudí zodpovednosti za dôsledky ich použitia. Kontrola a predvídateľnosť nie sú nevyhnutnou podmienkou pripísania zodpovednosti. Vzhľadom na riziká, ktoré použitie takýchto zbraní predstavuje, sú tí, ktorí ich vytvárajú alebo používajú, morálne zodpovední za ich konanie. Hoci nasadenie autonómnych smrtiacich zbraní nemusí byť dobrý nápad, „medzera v zodpovednosti“ ich ešte nerobí nemorálnymi., One of the primary ethical concerns raised by the prospect of using military autonomous killer robots is the question of the moral responsibility for their use. Robert Sparrow argues that military robots fitted up with the ability to learn would be so independent and self-contained that they would allow human actors to deny responsibility for their use, creating a situation that Andreas Matthias called a “responsibility gap.” A responsibility gap occurs in situations where no one is responsible for the actions of autonomous learning robots. This situation results from the inability of people to fully control and predict the actions of these technologies. In the article, I argue that this conclusion is not a correct one because autonomous technologies do not mitigate people of responsibility for the consequences of using them. Control and predictability are not inevitable prerequisites for attributing responsibility. Given the risks that the use of such weapons presents, those who create or use these weapons are morally responsible for the weapons’ actions. Even though the deployment of autonomous lethal weapons might not be a good idea, the “responsibility gap” does not by itself make them immoral., and Eine der zentralen ethischen Befürchtungen, hervorgerufen durch die reale Aussicht auf die Anwendung tödlicher autonomer Waffensysteme, ist die Frage nach der moralischen Verantwortung für deren Wirken. Robert Sparrow behauptet, dass lernfähige Militärroboter in einem Maße unabhängig und selbstständig seien, dass sie es den beteiligten Human-Akteuren ermöglichten, die Verantwortung für das Tun dieser Roboter abzulehnen. Dadurch entstünde eine Situation, die Andreas Matthias als „Verantwortungslücke“ bezeichnet. Eine Verantwortungslücke ist ein Zustand, in dem niemand für das Wirken lernfähiger autonomer Roboter verantwortlich ist. Dieser Zustand ist die Folge der Unfähigkeit des Menschen, die Handlungen dieser Technologien vollständig zu kontrollieren und vorherzusehen. Die Argumentation im Artikel zielt auf eine Ablehnung dieser These, da autonome Technologien den Menschen nicht von der Verantwortung für die Folgen ihrer Anwendung entbinden. Kontrolle und Vorhersehbarkeit sind keine unabdingbaren Voraussetzungen für die Zuschreibung von Verantwortung. In Anbetracht der Risiken, die sich aus der Anwendung derartiger Waffensysteme ergeben, sind diejenigen, die diese Systeme entwickeln oder einsetzen, moralisch für das Wirken dieser Waffen verantwortlich. Obwohl der Einsatz tödlicher autonomer Waffensysteme nicht unbedingt eine gute Idee sein muss, macht die „Verantwortungslücke“ sie nicht unbedingt unmoralisch
Autor v úvode svojej state nastoľuje viacero vedeckých problémov zameraných najmä na štátoprávne otázky. Poukazuje na skutočnosť, že štát si na svoju kontrolu vytvára kontrolné mechanizmy (všeobecné ale aj špecifické), ktoré ak majú napĺňať svoj zmysel, musia byť oddelené od priamej mocenskej politiky štátu, a to nielen formálne (inštitucionálne). Potom rozvíja úvahy o „kontrolnej moci“ ako novej moci v hierarchii štátnej moci. Každý štát má v súčasnosti vybudovaný mechanizmus kontroly hospodárenia verejnej moci ako aj najvyššiu kontrolnú inštitúciu, ktorá má zabezpečenú nezávislosť zvyčajne ústavným spôsobom. Tento fakt ilustruje na variantnosti inštitucionálneho usporiadania kontroly a poukazuje na konkrétne modely v rôznych krajinách až sa pristavuje na osobitnej inštitúcii EÚ – Európskom dvore audítorov ako kolektívnom orgáne externej kontroly Európskej únie ako verejnej entity. Jeho právny status podrobne charakterizuje prostredníctvom takých hlavných právnych pilierov ako je napr. nezávislosť, subsidiarita a proporcionalita, kolegiálnosť – kolektívnosť, profesionalita – odborná spôsobilosť a ďalšie. Činnosť Dvora prezentuje aj prostredníctvom troch typov auditov, ktoré Dvor vykonáva a podrobne sa
venuje štruktúre Európskeho dvora audítorov a pravidlám jeho rokovania. Prináša zaujímavú kauzu riešenú Európskym súdnym dvorom o kontrolných právomociach Dvora audítorov.V závere state poukazuje autor na auditorskú prácu ako náročný a vysokoprofesijný proces. and The author in the introduction raises several scientific problems, primarily focused on state and law issues. It refers to the fact that the state creates control mechanism of its own (general as well as specific) which, if they are to fulfill its purpose, must be separated from direct state politics, and not
only formally (institutionally). Then it goes on to present consideration about a “supervisory power” as a new power in the hierarchy of state power.Every state now has control mechanism management of public authority and supreme audit institutions, whose independence is usually secured in a constitutional manner. This fact is illustrated on the institutional structure and points to specific models in different countries as well as the European Court of Auditors as a collective body of external control of the European Union. Its legal status is characterized in detail by major legislative pillars such as
sovereignty, subsidiarity and proportionality, collegiality – collectivity, professionalism – competence and others. The activity of the Court is presented through three types of audits conducted by the Court,
a detailed structure is given by the European Court of Auditors and the rules of its proceedings. The article presents an interesting case of the European Court of Justice regarding the Court’s supervisory powers. In conclusion, the author points out the challenging nature of state audit work.
Invasions by alien plant species significantly affect biodiversity and ecosystem functioning. Investigations of the soil seed banks of invasive plant species and changes in the composition and structure of resident seed banks following plant invasions can provide valuable insight into the long-term implications of plant invasions. Soil seed banks play a major role as reservoirs of species and genetic diversity and allow for the persistence of a species at a locality, buffering environmental changes that may occur over time. Despite the emerging body of literature on ecological impacts of invasive plants on the diversity of resident communities, the long-term implications of impoverished soil seed banks for vegetation dynamics and ecosystem functioning have only recently begun receiving attention. Evidence has so far indicated that there is a correlation between the invasiveness of a species and the characteristics of its seed bank, and that changes in the seed banks of resident communities associated with plant invasions affect their biotic resistance to primary and secondary invasions. To promote the study of soil seed banks in the context of invasive species, we (i) summarize the functional roles of soil seed banks; (ii) describe how the capacity to form a seed bank may contribute to a species’ invasiveness using data from the flora of the Czech Republic, showing an increasing representation of species capable of forming long-term persistent seed bank from casual to naturalized to invasion stage; (iii) assess the impact of invasive plants on seed banks of resident communities, including the potential creation of conditions that favour secondary invasions by other alien species or native weeds, and long-term implications of such impact; and (iv) describe the potential effects of climate change on the soil seed bank in the context of plant invasions. We conclude with highlighting promising avenues for future research on invaded soil seed banks, and emphasize the importance of this knowledge in the development of control programs and restoration strategies.
This study seeks to derive an original multicriterial decision making model for operative control of water quality in the water reservoir. The model design is based on the theory of dynamic systems control. It incorporates simulation modelling methods with the hydrodynamic reservoir and multicriterial optimization methods. The research aims to derive an algorithm for operating rules of the reservoir under any operating conditions and for the given criteria of control. The study presents the outcomes of the application of model quality control of water withdrawal from the Římov reservoir on the Malše River. and Studie odvozuje původní vícekriteriální rozhodovací model pro operativní řízení kvality odebírané vody z vodárenské nádrže. Model vychází z teorie řízení dynamických systémů a propojuje se v něm metodologie simulačního modelování s hydrodynamikou nádrží a metodami vícekriteriální optimalizace. Cílem řešení je odvodit algoritmus pro regulační zásahy (manipulace) na nádrži při libovolných provozních podmínkách a pro stanovená kritéria řízení. Studie uvádí výsledky aplikace modelového řízení kvality vody v nádrži Římov na Malši.