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Prescribed Performance Control for Teleoperation System of Nonholonomic Constrained Mobile Manipulator Without Any approximation function

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IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 2024年第3期21卷 2900-2911页

作者： Yang, Yana Yan, Yuwei Hua, Changchun Li, Junpeng Pang, Keli Yanshan Univ Inst Elect Engn Qinhuangdao 066004 Peoples R China

The teleoperation system of mobile manipulator has been widely applied for space exploration, medical assistance, and other fields. To improve operational efficiency, this paper presents a novel prescribed performance synchronization control scheme without applying any approximation functions for a class of teleoperation system of the mobile manipulator with time-varying delays and nonholonomic constraints. Compared with the general manipulator system, the mobile manipulator has a larger workspace and stronger operability. Yet, the heterogeneity of master-slave robots and the nonholonomic constraint of slave robot bring many difficulties to the control of the system. Firstly, a prescribed performance function (PPF) is designed to guarantee that the position synchronization errors are remained within the predetermined boundary and converge to a small preset area within a preset time. Then, the direct force feedback information is introduced into the controller to improve the transparency of the teleoperation. In addition, there are no approximation functions applied in the proposed controller, which can significantly reduce the complexity and computation of the system. Finally, simulation and experimental results are made to illustrate the availability of this method for practical *** to Practitioners-The motivation of this paper is to develop an algorithm to improve the steady-state and transient-state performance of mobile manipulator teleoperation system without increasing the complexity of the controller. Compared with the existing works, in this paper, the control algorithm without any approximators is proposed and a time-varying prescribed performance function is introduced, which promotes the steady-state and transient-state performance of the system essentially. At the same time, the introduction of force feedback information improves the transparency of the teleoperation system. The feasibility and effectiveness of the algorithm are verified on

关键词： Prescribed performance control (PPC) teleoperation system mobile manipulator nonholonomic constraint approximation function

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LOWER BOUND FOR A DIOPHANTINE approximation function

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MONATSHEFTE FUR MATHEMATIK 1971年第5期75卷 398-&页

作者： CUSICK, TW Department of Mathematics State University of New York at Buffalo Buffalo USA

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What Number of Features is Optimal? A New Method Based on approximation function for Stance Detection Task 2019

What Number of Features is Optimal? A New Method Based on Ap...

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9th International Conference on Information Communication and Management (ICICM)

作者： Vychegzhanin, S. V. Razova, E. V. Kotelnikov, E. V. Vyatka State Univ Kirov Russia

ISBN: (纸本)9781450371889

Selecting a text representation model faces a crucial problem of choosing an optimal number of features. The optimality criterion is the minimum number of features, which allows to achieve (or preserve) the maximum performance. The article suggests a new method of determining the optimal number of features, in which both components of the optimality criterion are taken into consideration. Using the proposed method, we first construct the dependence of task performance on the number of features, then the obtained dependence is approximated on the basis of Weibull distribution function, and the optimal number of features is determined by analyzing the growth rate of this function. We called this method DOFNAF (Determining the Optimal Feature Number by the Approximating function). The proposed method is tested on stance detection task, consisting in identifying the position ("for" or "against"), which the author of the text supports towards the object (or objects) under discussion. The comparison involves constant methods, a method based on the function of the total number of features, a method of performance maximum, as well as Recursive Feature Elimination with Cross-Validation (RFECV) and Correlation-based Feature Selection (CFS) methods. The DOFNAF method allows to determine the minimum number of features compared with the existing methods and at the same time to maintain the classification performance.

关键词： Feature selection stance detection approximation function Weibull function Gini Index RFECV CFS

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Design Of The approximation function of a Pedometer based on Artificial Neural Network for the Healthy Life Style Promotion in Diabetic Patients

Design Of The Approximation Function of a Pedometer based on...

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7th Mexican International Conference on Artificial Intelligence (MICAI 2008)

作者： Vega-Corona, A. Zarate-Banda, M. Barron-Adame, J. M. Martinez-Celorio, R. A. Andina, D. Univ Guanajuato Lascurain Retana 5 Ctr Guanajuato Gto Mexico Univ Politecn Madrid Madrid Spain Ciudad Univ Mexico City DF Mexico

ISBN: (纸本)9780769534411

The present study describes the design of an Artificial Neural Network to synthesize the approximation function of a Pedometer for the Healthy Life Style Promotion. Experimentally, the approximation function is synthesized using three basic digital pedometers of low cost, these pedometers were calibrated with an advanced pedometer that calculates calories consumed and computes distance travelled with personal stride input. The synthesized approximation function by means of the designed neural network will allow to reply the calibration experiment for multiple patients with Diabetes Mellitus in Healthy Life Style promotion programs. Artificial Neural Networks have been developed for a wide variety of computational problems in cognition, pattern recognition, and decision making. The Healthy Life Style refer to adequate nutrient ingest, physical activity, time to rest, stress control, and a high self-esteem. The pedometer is a technological device that helps to control the physical activity in the diabetic patient. A brief description of the Artificial Neural Network designed to synthesize the approximation function, the obtained Artificial Neural Network structure and results in the, approximation function synthesis for three patients are presented. The advantages and disadvantages of the method are discussed and our conclusions are presented.

关键词： Artificial Neural Networks Pedometer approximation function Diabetes Mellitus Healthy Life Style

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A New approximation of the Matrix Rank function and Its Application to Matrix Rank Minimization

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JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS 2014年第2期163卷 569-594页

作者： Li, Chengjin Fujian Normal Univ Sch Math & Comp Sci Fuzhou 350007 Peoples R China

The matrix rank minimization problem is widely applied in many fields such as control, signal processing and system identification. However, the problem is NP-hard in general and is computationally hard to directly solve in practice. In this paper, we provide a new approximation function of the matrix rank function, and the corresponding approximation problems can be used to approximate the matrix rank minimization problem within any level of accuracy. Furthermore, the successive projected gradient method, which is designed based on the monotonicity and the Frechet derivative of these new approximation function, can be used to solve the matrix rank minimization this problem by using the projected gradient method to find the stationary points of a series of approximation problems. Finally, the convergence analysis and the preliminary numerical results are given.

关键词： Matrix rank minimization approximation function Projected gradient method Successive projected gradient method

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156 dB low-voltage low-power CMOS exponential function generator circuit

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INTEGRATION-THE VLSI JOURNAL 2025年 102卷

作者： Popa, Cosmin Radu Univ Politehn Bucuresti Fac Elect Telecommun & Informat Technol Bucharest Romania

An original exponential function generator is presented, the original approach allowing to extremely accurate approximate the exponential function. The circuit output dynamic range is approximately 156 dB, for a maximal approximation error equal with 1 dB. The new proposed method uses a very precise superior-order approximation function, which is developed for requiring a very ressonable hardware resources for its implementation in CMOS technology. For further improving the accuracy of the proposed function generator circuit, an additional new method using a convenient variable changing is used. The proposed computational structure is designed for low-voltage low-power operation. The circuit is supplied at 1.1 V and its maximal power consumption is approximately 5 mu W. The computational structure is developed for implementing in 0.18 mu TSMC CMOS process, the approximately area being 1600 mu m2. The SPICE simulations of the exponential function generator operation confirm the theoretical estimated results.

关键词： Exponential function generator approximation function CMOS current mode Translinear loop Output dynamic range

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Exponential function Generator with Fourth-Order approximation 6

Exponential Function Generator with Fourth-Order Approximati...

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6th European Conference on Electrical Engineering and Computer Science (ELECS)

作者： Popa, Cosmin Radu Fac Elect Telecommun & Informat Technol Bucharest Romania

ISBN: (纸本)9781665497794

The paper presents an original CMOS exponential function generator with improved accuracy. The area of application for CMOS exponential circuits is extremely large, including telecommunication field, medical structures and many analog signal processing blocks. The proposed design is based on a new approximation method for implementing the exponential function that allows a very important increasing of the circuit accuracy. Using a new forth-order approximation function, the original pseudo- exponential structure dynamic range will be more than 33dB, for an error less than 1dB. The circuit has a low-voltage operation and simulations match theoretical results. The circuit is designed for implementing in 0.35 m CMOS technology, being supplied at 3V. The architecture of the proposed exponential function generator allows implementing any continuous mathematical function, the resulted function synthesizer circuit being designed for a low-voltage operation.

关键词： exponential function analog signal processing approximation function Taylor series expansion

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approximation functionS TO EMDEN AND ASSOCIATED EMDEN functionS NEAR 1ST ZERO .2.

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ASTROPHYSICS AND SPACE SCIENCE 1975年第2期37卷 401-426页

作者： LINNELL, AP UNIV CAMBRIDGE INST ASTRONCAMBRIDGEENGLAND

Improved analytic expressions are presented to approximate the Emden function, θ, and the associated Emden functionsθ and the associated Emden functions ψ0 and ψ2 near the first zero of θ at ξ1. The error in θ ... 详细信息

关键词： approximation function Emden function

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Determination of the enantiomerization barrier of thalidomide by dynamic capillary electrokinetic chromatography

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ELECTROPHORESIS 2001年第15期22卷 3185-3190页

作者： Schoetz, G Trapp, O Schurig, V Univ Tubingen Inst Organ Chem D-72076 Tubingen Germany

Enantioselective chromatographic methods, representing the most commonly used techniques for the determination of enantiomeric ratios, can also be used for the evaluation of stereochemical integrity. In the present study, dynamic capillary electrokinetic chromatography (DEKC) was employed to determine the enantiomerization barrier of thalidomide. In the presence of the chiral mobile phase additive carboxymethyl-beta -cyclodextrin, the interconverting enantiomers of thalidomide produced characteristic elution profiles exhibiting plateaus and/or peak broadening between 25 and 55 degreesC at pH 8. To obtain the enantiomerization barrier of thalidomide from experimental data, the fast and efficient simulation program ChromWin was used to simulate the experimental interconversion profiles and to obtain the apparent rate constants k(1)(app)(T). Additionally, these values were compared with the novel approximation function for the direct calculation of enantiomerization barriers from chromatographic parameters of elution profiles. From the rate constants k(1)(app)(T) of temperature-dependent measurements the kinetic activation parameters DeltaG(T)(#),DeltaH(#), and DeltaS(#) of the enantiomerization of thalidomide were obtained. At 25 degreesC, the enantiomerization barrier DeltaG(#) was determined to be 102 +/- 1 kJ/mol at pH 8 in the dynamic electrokinetic chromatographic experiment.

关键词： approximation function ChromWin computer simulation dynamic electrokinetic chromatography enantiomerization thalidomide

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Optimal control approach for nonlinear chemical processes with uncertainty and application to a continuous stirred-tank reactor problem

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ARABIAN JOURNAL OF CHEMISTRY 2022年第11期15卷

作者： Wu, Xiang Hou, Yuzhou Zhang, Kanjian Guizhou Normal Univ Sch Math Sci Guiyang 550001 Peoples R China Guizhou Normal Univ Sch Life Sci Guiyang 550001 Peoples R China Southeast Univ Sch Elect Engn Nanjing 210096 Peoples R China Southeast Univ Sch Automat Nanjing 210096 Peoples R China Southeast Univ Key Lab Measurement & Control CSE Minist Educ Nanjing 210096 Peoples R China

Practical chemical process is usually a dynamic process including uncertainty. Stochastic constraints can be used to chemical process modeling, where constraints cannot be strictly satisfied or need not be fully satisfied. Thus, optimal control of nonlinear systems with stochastic constraints can be available to address practical nonlinear chemical process problems. This problem is hard to cope with due to the stochastic constraints. By introducing a novel smooth and differentiable approximation function, an approximation-based approach is proposed to address this issue, where the stochastic constraints are replaced by some deterministic ones. Following that, the stochastic constrained optimal control problem is converted into a deterministic parametric optimization problem. Convergence results show that the approximation function and the corresponding feasible set converge uniformly to that of the original problem. Then, the optimal solution of the determin-istic parametric optimization problem is guaranteed to converge uniformly to the optimal solution of the original problem. Following that, a computation approach is proposed for solving the orig-inal problem. Numerical results, obtained from a nonlinear continuous stirred-tank reactor prob-lem including stochastic constraints, show that the proposed approach is less conservative compared with the existing typical methods and can obtain a stable and robust performance when considering the small perturbations in initial system state.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Optimal control Nonlinear chemical processes Stochastic constraints approximation function Convergence analysis Stirred-tank reactor

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