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Open access

Joanna Ratajczak and Krzysztof Tchoń

Abstract

This paper presents the dynamically consistent Jacobian inverse for non-holonomic robotic system, and its application to solving the motion planning problem. The system’s kinematics are represented by a driftless control system, and defined in terms of its input-output map in accordance with the endogenous configuration space approach. The dynamically consistent Jacobian inverse (DCJI) has been introduced by means of a Riemannian metric in the endogenous configuration space, exploiting the reduced inertia matrix of the system’s dynamics. The consistency condition is formulated as the commutativity property of a diagram of maps. Singular configurations of DCJI are studied, and shown to coincide with the kinematic singularities. A parametric form of DCJI is derived, and used for solving example motion planning problems for the trident snake mobile robot. Some advantages in performance of DCJI in comparison to the Jacobian pseudoinverse are discovered.

Open access

Piotr Tatjewski

Abstract

Offset-free model predictive control (MPC) algorithms for nonlinear state-space process models, with modeling errors and under asymptotically constant external disturbances, is the subject of the paper. The main result of the paper is the presentation of a novel technique based on constant state disturbance prediction. It was introduced originally by the author for linear state-space models and is generalized to the nonlinear case in the paper. First the case with measured state is considered, in this case the technique allows to avoid disturbance estimation at all. For the cases with process outputs measured only and thus the necessity of state estimation, the technique allows the process state estimation only - as opposed to conventional approach of extended process-and-disturbance state estimation. This leads to simpler design with state observer/filter of lower order and, moreover, without the need of a decision of disturbance placement in the model (under certain restrictions), as in the conventional approach. A theoretical analysis of the proposed algorithm is provided, under applicability conditions which are weaker than in the conventional approach. The presented theory is illustrated by simulation results of nonlinear processes, showing competitiveness of the proposed algorithms.

Open access

Sundarapandian Vaidyanathan, Aceng Sambas, Mustafa Mamat and WS Mada Sanjaya

Abstract

This research work proposes a new three-dimensional chaotic system with a hidden attractor. The proposed chaotic system consists of only two quadratic nonlinearities and the system possesses no critical points. The phase portraits and basic qualitative properties of the new chaotic system such as Lyapunov exponents and Lyapunov dimension have been described in detail. Finally, we give some engineering applications of the new chaotic system like circuit simulation and control of wireless mobile robot.

Open access

Jozef Duda

Abstract

In the paper construction of a Lyapunov functional for time delay system with both lumped and distributed delay is presented. The Lyapunov functional is determined by means of the Lyapunov matrix. The method of determination of the Lyapunov matrix for time delay system with both lumped and distributed delay is presented. It is given the example illustrating the method.

Open access

Zhong Cao, Xiaorong Hou and Wenjing Zhao

Abstract

This paper investigates the problem of adaptive robust simultaneous stabilization (ARSS) of two dissipative Hamiltonian systems (DHSs), and proposes a number of results on the controller parameterization design. Firstly, an adaptive H control design approach is presented by using the dissipative Hamiltonian structural for the case that there are both external disturbances and parametric uncertainties in two DHSs. Secondly, an algorithm for solving tuning parameters of the controller is proposed using symbolic computation. The proposed controller parameterization method avoids solving Hamilton-Jacobi-Issacs (HJI) equations and the obtained controller is easier as compared to some existing ones. Finally, an illustrative example is presented to show that the ARSS controller obtained in this paper works very well.

Open access

Tamas Lukovich

Abstract

In the absence of any legal, political and institutional legitimacy, what can urban design do and how should future urban designers be educated? There appear to be as many questions in the subject as possible answers. However, in the last couple of decades a rather robust theoretical direction has been emerging, upon which a more responsive design practice and professional education can be placed. There is also an increasing international interest for urban design education.in the developed and rapidly developing world. The aims of the paper are to inform, to illuminate and to provoke, including the interrogation of our own values, practices and preferences.

Open access

Laszló Toth, Balint Horvath, Zsolt Fulop and Csaba Fogarassy

Abstract

The most notable role in the energy usage of rearing-related buildings belongs to barn climate. For animals, one of the most important climate parameter is the temperature of the barn atmosphere. This can be kept in the proper interval by either heating or cooling. Apart from the operation of technological solutions, the need for airing barns must be taken into consideration. This means there are special technical requirements for airing. Also, they can cause significant energy losses. The temperature limit of heating is mainly influenced by the technological temperature related to keeping the animal in question, its acceptable differences, the heat loss of the barn, and the airing requirement. Energy sources applicable to heating can be traditional sources (coal, oil, gas), renewable sources (solar, biomass, wind, water, or geothermal energy), or transformed energy (electricity). As these have specific operation systems, they also mean further challenges in implementing efficient energy usage. The usage of heating energy can either be optimised by the rational usage of the heating system, or machinery explicitly made for reserving energy. Sparing heating energy via recuperative heating exchange may cut costs significantly, which we also proved in this research with actual calculations. However, we have to state that the efficient usage of heat exchangers requires that the internal and external temperatures differ greatly, which has a huge impact on heat recovery performance.

Open access

József Domokos and Zsolt Attila Szakács

Abstract

This paper presents a Romanian language phonetic transcription web service and application built using Java technologies, on the top of the Phonetisaurus G2P, a Word Finite State Transducer (WFST)-driven Grapheme-to-Phoneme Conversion toolkit.

We used NaviRO Romanian language pronunciation dictionary for WFST model training, and MIT Language Modeling (MITLM) toolkit to estimate the needed joint sequence n-gram language model.

Dictionary evaluation tests are also included in the paper.

The service can be accessed for educational, research and other non-commercial usage at http://users.utcluj.ro/~jdomokos/naviro/.

Open access

Hongli Li, Xiaohuai Chen, Yinbao Cheng, Houde Liu, Hanbin Wang, Zhenying Cheng and Hongtao Wang

Abstract

Due to the variety of measurement tasks and the complexity of the errors of coordinate measuring machine (CMM), it is very difficult to reasonably evaluate the uncertainty of the measurement results of CMM. It has limited the application of CMM. Task oriented uncertainty evaluation has become a difficult problem to be solved. Taking dimension measurement as an example, this paper puts forward a practical method of uncertainty modeling and evaluation of CMM task oriented measurement (called SVCMM method). This method makes full use of the CMM acceptance or reinspection report and the Monte Carlo computer simulation method (MCM). The evaluation example is presented, and the results are evaluated by the traditional method given in GUM and the proposed method, respectively. The SVCMM method is verified to be feasible and practical. It can help CMM users to conveniently complete the measurement uncertainty evaluation through a single measurement cycle.

Open access

Katalin György

Abstract

In this brief, I study the finite and infinite nonlinear discrete time optimal control. The quadratic control problem for nonlinear case can be solved with different methods such as: linearization of the system model around each operation point or some different methods, where should be used an on-line parameter identification algorithm. In this paper, I study some properties of these algorithms in order to improve the control efficiency of the nonlinear process control. In this paper, I supposed the all states are accessible, so there is not necessary any state estimation algorithm for the implementation of the proposed optimal control (LQR - Linear Quadratic Regulators) methods.