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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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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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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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A novel preview control for MLD models and its neural network approximation for real-time implementation: Application to semi-active vibration control of a vehicle suspension

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IET CONTROL THEORY AND APPLICATIONS 2023年第4期17卷 433-445页

作者： Sato, Kaoru Hiramoto, Kazuhiko Niigata Univ Grad Sch Sci & Technol Dept Adv Mat Sci & Technol Niigata Japan Niigata Univ Fac Engn Mech Engn Program Niigata Japan

Advances in image processing technology have made it possible to measure the surface shape of the road ahead while driving. A new semi-active suspension control method considering the forward road surface shape is proposed. A vehicle model equipped with a semi-active suspension can be expressed as an mixed logical dynamical model. When the shape of the road ahead can be measured, the information on future disturbances is available before the vehicle undergoes. In this paper, the finite time optimization problem for the mixed logical dynamical model is formulated to consider the future disturbances as a mixed integer quadratic programming problem in the same way as the conventional control problem without future disturbance. However, the mixed integer quadratic programming problem is hard to obtain the control action within the control cycle period required in the real-time vibration control with general computers for vehicles. In this paper, the reduction of the computational load is achieved by constructing an approximation function of the designed controller. A neural network is adopted for the approximation. The performance evaluation of the proposed method is evaluated by simulations. In the simulation study, the proposed method achieves better ride comfort with the equivalent suspension stroke compared to the traditional methods.

关键词： MLD models Optimisation techniques finite time optimization problem forward road surface shape semiactive suspension control method novel preview control future disturbance vehicle model equivalent suspension stroke image processing technology approximation function Control technology and theory (production) semiactive vibration control quadratic programming Mechanical components Optimal control Vibrations and shock waves (mechanical engineering) control system synthesis vehicle dynamics real-time implementation mixed integer quadratic programming problem control cycle period real-time vibration control Road-traffic system control integer programming control action optimal control mixed logical dynamical model vibration control vehicle suspension conventional control problem Control system analysis and synthesis methods predictive control Mechanical variables control neural network approximation Vehicle mechanics road vehicles suspensions (mechanical components)

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Practical vignetting correction method for digital camera with measurement of surface luminance distribution

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SIGNAL IMAGE AND VIDEO PROCESSING 2016年第8期10卷 1417-1424页

作者： Kordecki, Andrzej Palus, Henryk Bal, Artur Silesian Tech Univ Inst Automat Control Akad 16 PL-44100 Gliwice Poland

Vignetting refers to the fall-off pixel intensity from the centre towards the edges of the image. This effect is undesirable in image processing and analysis. In the literature, the most commonly used methods of vignetting correction assume radial characteristic of vignetting. In the case of camera lens systems with non-radial vignetting, such approach leads to insufficient correction. Additionally, the majority of vignetting correction methods need a reference image acquired from a uniformly illuminated scene, what can be difficult to achieve. In this paper, we propose a new method of vignetting correction based on the local parabolic model of non-radial vignetting and compensation of non-uniformity of scene luminance. The new method was tested on camera lens system with non-radial vignetting and non-uniformly illuminated scene. In these conditions, the proposed method gave the best correction results among the tested methods.

关键词： Vignetting correction Lens distortion Luminance non-uniformity approximation function

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On a novel method for approximation of FN diagram and setting ALARP borders

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JOURNAL OF MARINE SCIENCE AND TECHNOLOGY 2015年第1期20卷 14-36页

作者： Kaneko, Fujio Arima, Toshiro Yoshida, Koichi Yuzui, Tomohiro Natl Maritime Res Inst Mitaka Tokyo Japan Yokohama Natl Univ Ctr Ocean Studies & Integrated Educ Yokohama Kanagawa 240 Japan

This article thoroughly reviews the state-of-the-art methods for setting ALARP upper border as a straight line in logarithmic graph, which is the common practice in the risk assessments of nuclear, chemical plants and maritime facilities. It also reviews methods for setting ALARP upper border based on economic importance of a considered ship type. As a result, inconsistency related to ALARP upper border has been identified and new methods to resolve such inconsistency are developed. Here, firstly a method for approximating FN diagrams of existing major ship types is proposed and it is applied to ship types which consist of ships above 100 gross tonnage. After that the approximated FN diagrams were checked by goodness-of-fit test by 5 % significance level, and it was validated that those approximated FN diagrams well express corresponding FN diagrams made from IHSF casualty and ship databases. This method can extrapolate FN diagrams made from those databases to the area of severer accidents with more fatalities, which have not been occurred yet, rationally. Secondly, problems that accompany with an existing method for setting ALARP upper border are discussed and methods for resolving the problems using the approximated FN diagrams are proposed. The methods can set ALARP upper border keeping consistency of ALARP upper border between individual risk and FN diagram. Lastly, the new method for safety analysis of ships using approximated FN diagrams of major ship types is introduced. The method is used in order to find ships' groups which should be considered preferentially. The method for approximating FN diagrams and the method for setting ALARP upper border proposed here is so general that they can be applied to risk analysis of the fields which have a lot of accident records like maritime field, such as aviation or automotive fields.

关键词： FN diagram Power law with maximum value approximation function ALARP border

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