This paper describes the development of a fuzzy control scheme for functional electrical stimulation, (FES)-assisted paraplegic walking with wheel walker. The simulation in this study starts with a model of humanoid w...
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ISBN:
(纸本)9781424466146;9780769540160
This paper describes the development of a fuzzy control scheme for functional electrical stimulation, (FES)-assisted paraplegic walking with wheel walker. The simulation in this study starts with a model of humanoid with wheel walker using the Visual Nastran (Vn4D) dynamic simulation software. The humanoid model is designed based on anthropometric data. Two stimulated muscle models, quadriceps and hamstrings, are developed for knee extension and flexion. A fuzzy logic controller is designed to control the walking gait. It is designed in Matlab/Simulink to regulate the muscle stimulation pulse width required to drive FES-assisted walking gait. The body weight transfer technique is introduced to improve the paraplegic walking performance. The results show that body weight transfer can reduce torque required for FES-assisted paraplegic walking with wheel walker.
Mathematical technicalities, which are involved in the modern theory of non-linear control systems, many times prevents a wider use of the impressive theoretical results in practice. Attempts to overlap this gap betwe...
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Mathematical technicalities, which are involved in the modern theory of non-linear control systems, many times prevents a wider use of the impressive theoretical results in practice. Attempts to overlap this gap between theory and practice are usually more than welcome and form the main scope of our interest in this work. An important control problem given by the disturbance decoupling is studied for a real laboratory model of coupled tanks. It is shown that the theoretical solution to the disturbance decoupling problem does not satisfy practical control requirememts. Accordingly, the solution is modified and yields a nonlinear controller with the distrubance decoupling. Experiments on the real plant, verifying and comparing the results with and without the disturbance decoupling, are included as well. It is shown that the disturbances practically do not affect the system output.
This work aims at the development of a versatile control strategy for operating unknown mechanically constrained devices such as drawers or doors. Few assumptions on the device's shape as well as the utilized hard...
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This work aims at the development of a versatile control strategy for operating unknown mechanically constrained devices such as drawers or doors. Few assumptions on the device's shape as well as the utilized hardware are required. Our approach is based on an on-line estimation of the constraint manifold which serves as a reference input for an admittance-type controller providing the compliance required. The direction estimation is obtained from the velocity signal in task space. An on-line adaptation of the admittance controller according to the estimated moving direction reduces contact forces. The functionality of the control strategy is demonstrated on a mobile manipulator in a kitchen environment.
作者：
Vörös, JozefSlovak University of Technology
Faculty of Electrical Engineering and Information Technology Institute of Control and Industrial Informatics Ilkovicova 3 Bratislava 812 19 Slovakia
One of the main difficulties in the automaticcontrol is caused by the fact that real systems are generally nonlinear. For better mathematical tractability of control system descriptions we are usually forced to make ...
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In recent years, especially in industrial processes, model predictive control has become a prominent advanced control technique. In this paper a nonlinear plant is considered to be controlled by linear model predictiv...
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In recent years, especially in industrial processes, model predictive control has become a prominent advanced control technique. In this paper a nonlinear plant is considered to be controlled by linear model predictive control. Particularly this study is carried out on the Four-Tank system to show the performance of linear model predictive control for nonlinear plant. Since linear model predictive control is used instead of nonlinear model predictive control the problems of complexity of the algorithm and non-convexity of the optimization are avoided.
This paper presents the development of paraplegic muscle model with Adaptive Neuro-Fuzzy Inference System (ANFIS). A series of experiments using Functional electrical Stimulation (FES) with different stimulation frequ...
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ISBN:
(纸本)9781424459827;9780769539744
This paper presents the development of paraplegic muscle model with Adaptive Neuro-Fuzzy Inference System (ANFIS). A series of experiments using Functional electrical Stimulation (FES) with different stimulation frequencies, pulse width and pulse duration to investigate the impact on muscle output torque are conducted. The data that is obtained is used to develop the paraplegic muscle model. 500 training data and 300 testing data set are used in the development of muscle model. The muscle model thus developed is validated with clinical data from one paraplegic subject and in comparison with two other muscle models from previous researchers. The ANFIS muscle model is found to be the most accurate muscle model representing paraplegic muscle model. The established model is then used to predict the behaviour of the underlying system and will be used in the future for the design and evaluation of various control strategies.
The paper deals with the frequency domain decentralized discrete-time controller design methodology to guarantee specified performance of the overall system. The underlying theory evolves from the stability conditions...
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The paper deals with the frequency domain decentralized discrete-time controller design methodology to guarantee specified performance of the overall system. The underlying theory evolves from the stability conditions developed in the “Equivalent Subsystems Method” approach and applies closed-loop performance specification based on the relationship between phase margins of equivalent subsystems and maximum overshoot of the full system. To design local PI controllers for specified phase margin, Bode plots of discrete equivalent subsystems are used. Designed local continuous controllers are then converted to their discrete versions and implemented for the controlled plant. The design procedure is illustrated on the case study.
Safety and reliability belong to the main quality attributes of a safety relevant control system. If a communication system is a component of a safety relevant control system then because of its properties it can also...
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ISBN:
(纸本)9788070438657
Safety and reliability belong to the main quality attributes of a safety relevant control system. If a communication system is a component of a safety relevant control system then because of its properties it can also significantly affect the safety and reliability of the entire safety relevant control system. Safety and reliability attributes of a communication system can be influenced by a proper application of a so-called ratio criterion. Although the ratio criterion is often being utilised in practical applications, the parameters of ratio criterion are usually set intuitively. The contribution is focused on the problem of ratio counter parameters choice, which in co-operation with the safety code decoder provides operational checking of a non-trusted transmission system.
An important issue in the analysis of two-dimensional electrophoresis images is the detection and quantification of protein spots. The main challenges in the segmentation of 2DGE images are to separate overlapping pro...
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An important issue in the analysis of two-dimensional electrophoresis images is the detection and quantification of protein spots. The main challenges in the segmentation of 2DGE images are to separate overlapping protein spots correctly and to find the abundance of weak protein spots. To enable comparison of protein patterns between different samples, it is necessary to match the patterns so that homologous spots are identified. In this paper we describe a new robust technique to segment and model the different spots present in the gels. The watershed segmentation algorithm is modified to handle the problem of over segmentation by initially partitioning the image to mosaic regions using the composition of fuzzy relations. The experimental results showed the effectiveness of the proposed algorithm to overcome the over segmentation problem associated with the available algorithms.
This work presents the co-simulation approach to the analysis of control systems containing detailed models of electromagnetic and electromechanical converters. In this method of analysis the attention is paid to the ...
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This work presents the co-simulation approach to the analysis of control systems containing detailed models of electromagnetic and electromechanical converters. In this method of analysis the attention is paid to the whole system and not only to its electromagnetic part. The latter is described by equations resulted from the two-dimensional finite element discretisation of the Maxwell equations, and is coupled weakly with the remaining part of the system. The simulation is carried out in Matlab/Simulink environment wherein the coupling is realised through the S-function. Example results regarding simulation of the operation of the control system of an electrical machine and the operation of a power electronic converter are presented and compared with available reference data.
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