A feedback linearization controller combined with a data-driven subspace-based prediction method for vehicle handling stabilization

2018 ◽  
Vol 233 (4) ◽  
pp. 1156-1180
Author(s):  
Jianwu Zhang ◽  
Weimiao Yang ◽  
Pengpeng Feng
Keyword(s):  
Feedback Linearization ◽  
Prediction Method ◽  
Data Driven ◽  
Nonlinear Controller ◽  
Lateral Velocity ◽  
Vehicle Handling ◽  
Handling Performance ◽  
System A ◽  
The One ◽  
Prediction Approach

Obtaining precise yaw rate and lateral velocity as well as developing a nonlinear controller becomes more and more essential for improving the vehicle handling performance. Different from traditional methods, a data-driven subspace-based prediction approach is introduced by integrating propagator with predictor-based subspace identification method in this paper. Based on an identifiable vehicle model, the prediction process is validated by standard road tests data. To employ this data-driven prediction method in the vehicle handling stabilization and solve the controlling problem of nonlinear lateral dynamic system, a feedback linearization controller based on the new piecewise tire model is elaborately developed. On account of that the one-step prediction output reduces the time delay between actuator and lateral dynamic response, the subspace-based controller can theoretically improve the vehicle handling performance. By road simulation results, the proposed feedback linearization controller combined with a data-driven subspace-based prediction method greatly enhances the handling performance and provides a more effective technique for both vehicle parameter estimation and handling stabilization.

A comprehensive active-steering control method for improvement of vehicle handling performance

2017 ◽  
Vol 232 (3) ◽  
pp. 413-425 ◽  
Author(s):  
Weimiao Yang ◽  
Pengpeng Feng ◽  
Jianwu Zhang
Keyword(s):  
Linear System ◽  
Feedback Linearization ◽  
Control Method ◽  
System Control ◽  
Steering Control ◽  
Vehicle Handling ◽  
Handling Performance ◽  
Non Linear ◽  
Tyre Modelling ◽  
Non Linear System

Non-linear system control has always been a difficult point for vehicle stabilization. To improve the vehicle handling performance, a comprehensive active-steering control method is proposed and derived. Different from traditional strategy, this new controller is based on a piecewise tyre modelling ideology combined with feedback linearization controlling method. In the linear region of wheel–terrain contact, vehicle dynamic system turns to be a linear system, an optimal control is designed for the sake of rapid response in tracking desired values. In the non-linear region, where the controlling difficulty always lies in, the tyre lateral force is described by a new polynomial formula model, which is simpler than magic formula model and more accurate than linear model. This new tyre modelling ideology ensures the feasibility of feedback linearization method in non-linear system control. To verify the proposed controller, a numerical seven-degrees-of-freedom vehicle model is built and validated by standard input simulation. Then, simulation under limit conditions, including high friction case and low friction case, are conducted and results are presented and discussed. Compared with optimal controller and free-control method, comprehensive controller has a much more desirable applicability in both cases and greatly improves the vehicle handling performance.

A simplified dynamic model and control for a multiple launch rocket system

2021 ◽  
pp. 107754632110093
Author(s):  
Bo Li ◽  
Xiaoting Rui ◽  
Guoping Wang
Keyword(s):  
Dynamic Model ◽  
Feedback Linearization ◽  
Controller Design ◽  
Euler Method ◽  
Nonlinear Controller ◽  
Nonlinear Dynamic Model ◽  
Position Accuracy ◽  
System A ◽  
And Control ◽  
Rocket System

Multiple launch rocket system, a type of launching platform used to launch kinetic load to hit the target, is an extremely complicated mechanical system with strong vibration because of the jet force. In this study, a nonlinear dynamic model and vibration control of a multiple launch rocket system are presented to reduce vibration and improve position accuracy. A simplified dynamic model of the multiple launch rocket system is derived using the Newton–Euler method, which facilitates the controller design considering the strong complexity of the multiple launch rocket system. On this basis, the feedback linearization technique is introduced to design a nonlinear controller based on the deduced dynamic model. The simulated and experimental results show that the simplified dynamic model–based control effectively can reduce vibration level of the launching system and make the azimuth and elevation angles reach the desired values with smaller error despite of each rocket’s jet force.

scholarly journals Direct Data-Driven Control for Cascade Control System

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hong Jianwang ◽  
Ricardo A. Ramirez-Mendoza ◽  
Tang Xiaojun
Keyword(s):  
Control System ◽  
Optimization Problems ◽  
Flight Simulation ◽  
Cascade Control ◽  
Gradient Algorithm ◽  
Data Driven ◽  
Nonlinear Controller ◽  
System A ◽  
Direct Data ◽  
Cascade Control System

This paper combines system identification, direct data-driven control, and optimization algorithm to design two controllers for one cascade control system, that is, the inner controller and the outer controller. More specifically, when these two controllers in the cascade control system are parameterized by two unknown parameter vectors, respectively, the problem of controller design is changed to parameter identification. To avoid the modeling process for the unknown plants in the cascade control system, a direct data-driven control scheme is proposed to identify those two parameter vectors through minimizing two optimization problems, which do not need any knowledge of the unknown plants. Furthermore, the detailed first-order gradient algorithm is applied to solve our constructed optimization problems, and its convergence property is also analyzed. To extend the above idea to design a nonlinear controller in the cascade control system, a direct data-driven scheme is proposed to get one optimal nonlinear controller, by using some spectral knowledge. Finally, one simulation example of flight simulation is used to prove the efficiency of our proposed direct data-driven control for the cascade control system.

Purification of a Specific Placental Plasminogen Activator Inhibitor by Monoclonal Antibody and Its Complex Formation with Plasminogen Activator

1985 ◽  
Vol 53 (01) ◽  
pp. 122-125 ◽  
Author(s):  
B Åstedt ◽  
Ingegerd Lecander ◽  
T Brodin ◽  
A Lundblad ◽  
Karin Löw
Keyword(s):  
Monoclonal Antibody ◽  
Complex Formation ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
System A ◽  
The One ◽  
Fast Acting ◽  
Chain Form ◽  
Activator Inhibitor

SummaryA monoclonal antibody of IgG2a-type was obtained against a specific fast acting plasminogen activator inhibitor found in placenta. The placental inhibitor was purified by affinity chromatography using the monoclonal antibody and additionally in a FPLC-system. A strong complex formation was found between the inhibitor and urokinase and also with the two-chain form of plasminogen activator of the tissue-type. A weaker complex was found between the placental inhibitor and the one- chain form of the tissue-type activator.

scholarly journals IIMLP: integrated information-entropy-based method for LncRNA prediction

2021 ◽  
Vol 22 (S3) ◽  
Author(s):  
Junyi Li ◽  
Huinian Li ◽  
Xiao Ye ◽  
Li Zhang ◽  
Qingzhe Xu ◽  
...  
Keyword(s):  
Machine Learning ◽  
Dna Sequences ◽  
Information Entropy ◽  
Area Under The Curve ◽  
Prediction Method ◽  
Machine Learning Algorithms ◽  
Reading Frame ◽  
Non Coding Rna ◽  
The One ◽  
Long Non Coding Rna

Abstract Background The prediction of long non-coding RNA (lncRNA) has attracted great attention from researchers, as more and more evidence indicate that various complex human diseases are closely related to lncRNAs. In the era of bio-med big data, in addition to the prediction of lncRNAs by biological experimental methods, many computational methods based on machine learning have been proposed to make better use of the sequence resources of lncRNAs. Results We developed the lncRNA prediction method by integrating information-entropy-based features and machine learning algorithms. We calculate generalized topological entropy and generate 6 novel features for lncRNA sequences. By employing these 6 features and other features such as open reading frame, we apply supporting vector machine, XGBoost and random forest algorithms to distinguish human lncRNAs. We compare our method with the one which has more K-mer features and results show that our method has higher area under the curve up to 99.7905%. Conclusions We develop an accurate and efficient method which has novel information entropy features to analyze and classify lncRNAs. Our method is also extendable for research on the other functional elements in DNA sequences.

The Impact of Stationarity, Regularity, and Context on the Predictability of Individual Human Mobility

2021 ◽  
Vol 7 (4) ◽  
pp. 1-24
Author(s):  
Douglas Do Couto Teixeira ◽  
Aline Carneiro Viana ◽  
Jussara M. Almeida ◽  
Mrio S. Alvim
Keyword(s):  
State Of The Art ◽  
Human Mobility ◽  
Contextual Information ◽  
Prediction Method ◽  
Mobility Prediction ◽  
Mobility Patterns ◽  
Distinct Cell ◽  
Inherent Nature ◽  
The One ◽  
The Impact

Predicting mobility-related behavior is an important yet challenging task. On the one hand, factors such as one’s routine or preferences for a few favorite locations may help in predicting their mobility. On the other hand, several contextual factors, such as variations in individual preferences, weather, traffic, or even a person’s social contacts, can affect mobility patterns and make its modeling significantly more challenging. A fundamental approach to study mobility-related behavior is to assess how predictable such behavior is, deriving theoretical limits on the accuracy that a prediction model can achieve given a specific dataset. This approach focuses on the inherent nature and fundamental patterns of human behavior captured in that dataset, filtering out factors that depend on the specificities of the prediction method adopted. However, the current state-of-the-art method to estimate predictability in human mobility suffers from two major limitations: low interpretability and hardness to incorporate external factors that are known to help mobility prediction (i.e., contextual information). In this article, we revisit this state-of-the-art method, aiming at tackling these limitations. Specifically, we conduct a thorough analysis of how this widely used method works by looking into two different metrics that are easier to understand and, at the same time, capture reasonably well the effects of the original technique. We evaluate these metrics in the context of two different mobility prediction tasks, notably, next cell and next distinct cell prediction, which have different degrees of difficulty. Additionally, we propose alternative strategies to incorporate different types of contextual information into the existing technique. Our evaluation of these strategies offer quantitative measures of the impact of adding context to the predictability estimate, revealing the challenges associated with doing so in practical scenarios.

Data-driven prediction method for characteristics of voltage sag based on fuzzy time series

2022 ◽  
Vol 134 ◽  
pp. 107394
Author(s):  
Ying Wang ◽  
Min-hui Yang ◽  
Hua-ying Zhang ◽  
Xian Wu ◽  
Wen-xi Hu
Keyword(s):  
Time Series ◽  
Prediction Method ◽  
Fuzzy Time Series ◽  
Data Driven ◽  
Voltage Sag

DETERMINING ROBUST PARAMETERS IN STABILIZING SET OF BACKSTEPPING BASED NONLINEAR CONTROLLER FOR SHIP COURSE KEEPING

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
X K Zhang ◽  
G Q Zhang
Keyword(s):  
Closed Loop ◽  
Simulation Experiment ◽  
Empirical Knowledge ◽  
Backstepping Method ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Robust Performance ◽  
System A ◽  
Uniformly Asymptotic Stability ◽  
Novel Method

In order to solve the problem that backstepping method cannot effectively guarantee the robust performance of the closed-loop system, a novel method of determining parameter is developed in this note. Based on the ship manoeuvring empirical knowledge and the closed-loop shaping theory, the derived parameters belong to a reduced robust group in the original stabilizing set. The uniformly asymptotic stability is achieved theoretically. The training vessel “Yulong” and the tanker “Daqing232” are selected as the plants in the simulation experiment. And the simulation results are presented to demonstrate the effectiveness of the proposed algorithm.

Clinical Notes on Haemorrhages in General Paralysis

1886 ◽  
Vol 31 (136) ◽  
pp. 504-507
Author(s):  
Geo. H. Savage
Keyword(s):  
Nervous System ◽  
Nervous Disease ◽  
General Paralysis ◽  
Clinical Notes ◽  
System A ◽  
General Pathology ◽  
Mental Symptoms ◽  
The One ◽  
Nutritional Changes

In so-called nervous disorders it is common to find changes occur in other of the bodily systems than the nervous. The pathology of nervous disease should be looked upon as a general pathology, and it is certain that we cannot look to the one system alone for causes of all the nervous disorders without greatly misunderstanding the whole subject. The more exact we become in limiting the causes, the more liable are we to error. We are all prepared to consider general paralysis of the insane as essentially a disease of the nervous system, a disease in which nearly every part of the nervous system may suffer sooner or later. But beside the essentially nervous symptoms which occur in the disease, we are constantly struck by the regular series of nutritional changes which occur in general paralysis, and this is so much the case that we are quite prepared to recognise as general paralysis a disorder in which any mental symptoms have been present, but have after a brief period of acuteness been followed by a state of fatness and weak-mindedness which again has been followed by a period of wasting and further mental weakness. We have here nervous symptoms related very directly with nutritional changes.

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