scholarly journals Centroidal Voronoi Partitioning using Virtual Nodes for MultiRobot Coverage

2018 ◽  
Vol 7 (2.21) ◽  
pp. 135 ◽  
Author(s):  
Vishnu G Nair ◽  
Guruprasad K R
Keyword(s):  
Load Distribution ◽  
Control Law ◽  
Uniform Load ◽  
Voronoi Cells ◽  
Voronoi Partition ◽  
Gradient Based ◽  
Simulation Results

This paper addresses the problem of Voronoi partitioning using Centroidal Voronoi configuration for a multi-robotic coverage strategy known as Voronoi Partition based Coverage (VPC) algorithm. In VPC, the area to be covered is divided into Voronoi cells and each robot covers the corresponding cell. We use the concept of Centroidal Voronoi Configuration (CVC) to achieve a more uniform load distribution among the robots in terms of the area covered. Instead of the robots moving physically into the CVC, we introduce a concept of virtual nodes, which are deployed into CVC. Once the Voronoi partition is created based on the virtual nods, the robots cover the corresponding Voronoi cells. A gradient based control law has been used for deployment of the virtual nodes. Simulation results are provided to demonstrate the proposed deployment and partitioning scheme. 

scholarly journals Robustness of Cyber-Physical Supply Networks in Cascading Failures

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 769
Author(s):  
Dong Mu ◽  
Xiongping Yue ◽  
Huanyu Ren
Keyword(s):  
Load Distribution ◽  
Cascading Failure ◽  
Cascading Failures ◽  
Supply Network ◽  
Supply Networks ◽  
Defense Strategies ◽  
Critical Thresholds ◽  
Network Load ◽  
Physical Node ◽  
Simulation Results

A cyber-physical supply network is composed of an undirected cyber supply network and a directed physical supply network. Such interdependence among firms increases efficiency but creates more vulnerabilities. The adverse effects of any failure can be amplified and propagated throughout the network. This paper aimed at investigating the robustness of the cyber-physical supply network against cascading failures. Considering that the cascading failure is triggered by overloading in the cyber supply network and is provoked by underload in the physical supply network, a realistic cascading model for cyber-physical supply networks is proposed. We conducted a numerical simulation under cyber node and physical node failure with varying parameters. The simulation results demonstrated that there are critical thresholds for both firm’s capacities, which can determine whether capacity expansion is helpful; there is also a cascade window for network load distribution, which can determine the cascading failures occurrence and scale. Our work may be beneficial for developing cascade control and defense strategies in cyber-physical supply networks.

A Design Method of LS-SVM Based Stable Adaptive Controller for a Class of Nonlinear Systems

2011 ◽  
Vol 48-49 ◽  
pp. 17-20
Author(s):  
Chun Li Xie ◽  
Tao Zhang ◽  
Dan Dan Zhao ◽  
Cheng Shao
Keyword(s):  
Nonlinear Systems ◽  
Design Method ◽  
Nonlinear Function ◽  
Lyapunov Stability Theory ◽  
Adaptive Controller ◽  
Control Law ◽  
Continuous Systems ◽  
Control Schemes ◽  
Closed Systems ◽  
Simulation Results

A design method of LS-SVM based stable adaptive controller is proposed for a class of nonlinear continuous systems with unknown nonlinear function in this paper. Due to the fact that the control law is derived based on the Lyapunov stability theory, the scheme can not only solve the tracking problem of this class of nonlinear systems, but also it can guarantee the asymptotic stability of the closed systems, which is superior to many LS-SVM based control schemes. The effectiveness of the proposed scheme is demonstrated by simulation results.

FEMLIB: An Object-Oriented Framework for Optimization and Simulation

1995 ◽  
Author(s):  
Michael M. Tiller ◽  
Jonathan A. Dantzig
Keyword(s):  
Material Properties ◽  
Object Oriented ◽  
The Finite Element Method ◽  
Simulation And Optimization ◽  
Gradient Based ◽  
Level Problem ◽  
Simulation Results ◽  
Optimization And Simulation ◽  
High Level ◽  
Simulation Parameters

Abstract In this paper we discuss the design of an object-oriented framework for simulation and optimization. Although oriented around high-level problem solving, the framework defines several classes of problems and includes concrete implementations of common algorithms for solving these problems. Simulations are run by combining these algorithms, as needed, for a particular problem. Included in this framework is the capability to compute the sensitivity of simulation results to the different simulation parameters (e.g. material properties, boundary conditions, etc). This sensitivity information is valuable in performing optimization because it allows the use of gradient-based optimization algorithms. Also included in the system are many useful abstractions and implementations related to the finite element method.

Autonomous Control and Transportation of Underslung Load with Single and Dual Lift Helicopter Systems

2021 ◽  
Author(s):  
Kuldeep K Dhiman ◽  
Mangal Kothari ◽  
Dr. Abhishek
Keyword(s):  
Load Distribution ◽  
Compressive Load ◽  
Force Sensor ◽  
Outdoor Environment ◽  
Measurement Unit ◽  
Control Law ◽  
Autonomous Flight ◽  
Practical Applications ◽  
Load Swing ◽  
Load Transportation

Abstract This paper discusses the development of a single lift and dual-lift helicopter underslung load transportation system for practical applications. A control law is developed to damp the load swing and stabilize the oscillation while performing the transportation task. For the dual-lift system, the load transportation is achieved by using a load distribution controller, developed for this purpose, to maintain equal load distribution among the vehicles. The load damping and load distribution controllers require accurate measurement of load states, which is achieved through the design and development of innovative, simple, and lightweight sensors units namely, Load Tension Measurement Unit (LTMU) and Load Swing Measurement Unit (LSMU). LTMU sensor consists of a unique design that utilizes a flexi-force sensor, capable of measuring compressive load, for measurement of cable tension. The cable inclination in the longitudinal and lateral directions is measured by the LSMU sensor. These units are integrated with the helicopter autopilot for autonomous flight. The performance of the developed system is experimentally validated in the outdoor environment with single and dual-lift systems.

Surface Profile Analysis for Conformable Interfaces

2003 ◽  
Vol 125 (3) ◽  
pp. 624-627 ◽  
Author(s):  
Mark C. Malburg
Keyword(s):  
Contact Area ◽  
Load Distribution ◽  
Profile Analysis ◽  
Surface Profile ◽  
Solid Surfaces ◽  
Analysis Method ◽  
Uniform Load ◽  
Morphological Filtering ◽  
Novel Method

This paper presents a novel method for the analysis of solid surfaces in contact with a conformable component. These applications are common in many engine and hydraulic applications, wherein conformable seals, gaskets, bushings, etc. are employed to prevent unwanted flow across an interface or provide a uniform load distribution. The proposed analysis method employs a combination of meanline (m-system) filtering and envelope (e-system) or morphological filtering. Through this analysis, a simulation of contact area and the associated voids or gaps can be assessed.

Integrated Aircraft Modeling Research for Accurate Flight Control System Design

2013 ◽  
Vol 791-793 ◽  
pp. 658-662
Author(s):  
Chao Zhang ◽  
Yi Nan Liu ◽  
Jian Hui Xu
Keyword(s):  
Control System ◽  
System Design ◽  
Flight Control ◽  
Time Delays ◽  
Flight Dynamics ◽  
Control System Design ◽  
Control Law ◽  
Flight Control System ◽  
Aircraft Model ◽  
Simulation Results

In order to realize accurate flight control system design and simulation, an integrated scheme of aircraft model which consists of flight dynamics, fly-by-wire (FBW) platform and flight environment is proposed. Flight environment includes gravity, wind, and atmosphere. And the actuator and sensors such as gyroscope and accelerometer models are considered in the FBW platform. All parts of the integrated model are closely connected and interacted with each other. Simulation results confirm the effectiveness of the integrated aircraft model and also indicate that the (Flight Control Law) FCL must be designed with robustness to sensor noise and time delays with the FBW platform in addition to the required robustness to model uncertainty in flight dynamics.

scholarly journals Multiattribute Utility Copulas for Multi-objective Coverage Control

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Christopher G. Valicka ◽  
Richard A. Rekoske ◽  
Dušan M. Stipanovic ◽  
Ali E. Abbas
Keyword(s):  
Multirobot Systems ◽  
Control Law ◽  
Objective Functions ◽  
Multiattribute Utility ◽  
Maximum Function ◽  
Differential Drive ◽  
Coverage Control ◽  
Gradient Based ◽  
Global Coverage ◽  
Nonnegative Definite

AbstractThis paper presents theoretical and experimental results related to the control and coordination of multirobot systems interested in dynamically covering a compact domain while remaining proximal, so as to promote robust inter-robot communications, and while remaining collision free with respect to each other and static obstacles. A design for a novel, gradient-based controller using nonnegative definite objective functions and an overapproximation to the maximum function is presented. By using a multiattribute utility copula to scalarize the multiobjective control problem, a control law is presented that allows for flexible tuning of the tradeofs between objectives. This procedure mitigates the controller’s dependence on objective function parameters and allows for the straightforward integration of a novel global coverage objective. Simulation and experiments demonstrate the controller’s efectiveness in promoting scenarios with collision free trajectories, robust communications, and satisfactory coverage of the entire coverage domain concurrently for a group of differential drive robots.

Iterative Learning Impedance Control in Gait Rehabilitation Robot

2014 ◽  
Vol 494-495 ◽  
pp. 1084-1087
Author(s):  
Fu Cheng Cao ◽  
Hai Xin Sun ◽  
Li Rong Wang
Keyword(s):  
Iterative Learning Control ◽  
Control Algorithm ◽  
Closed Loop ◽  
Impedance Control ◽  
Iterative Learning ◽  
Gait Rehabilitation ◽  
Control Law ◽  
Rehabilitation Robot ◽  
Simulation Results ◽  
Impedance Parameters

An iterative learning impedance control algorithm is presented to control a gait rehabilitation robot. According to the circumstances of the patient, the appropriate rehabilitation target impedance parameters are set. With the adoption of iterative learning control law, the impedance error in the closed loop is guaranteed to converge to zero and the iterative trajectories follow the desired trajectories over the entire operation interval. The effectiveness of the proposed method is shown through numerical simulation results.

A Mathematical Programming Technique for the Evaluation of Load Distribution and Optimal Modifications for Gear Systems

1973 ◽  
Vol 95 (4) ◽  
pp. 1115-1122 ◽  
Author(s):  
T. F. Conry ◽  
A. Seireg
Keyword(s):  
Mathematical Programming ◽  
Load Distribution ◽  
Effective Means ◽  
Uniform Load ◽  
Programming Technique ◽  
Type Algorithm ◽  
Gear Systems ◽  
Selection Of ◽  
Mathematical Programming Technique

A generalized technique is presented in this paper for evaluation of load distribution in gear systems and automated selection of optimal modification for the best possible distribution based on any prespecified type of modification. The procedure which utilizes a simplex-type algorithm provides an efficient and effective means for the design of gears with uniform load distribution.

OUTPUT FEEDBACK CONTROL OF UNIFIED CHAOTIC SYSTEMS BASED ON FEEDBACK PASSIVITY

2010 ◽  
Vol 20 (05) ◽  
pp. 1519-1525 ◽  
Author(s):  
TEERAWAT SANGPET ◽  
SUWAT KUNTANAPREEDA
Keyword(s):  
Chaos Control ◽  
Chaotic Systems ◽  
Output Feedback Control ◽  
Control Law ◽  
Control Laws ◽  
Unified Chaotic Systems ◽  
System Output ◽  
Simulation Results ◽  
Passivity Based Control ◽  
System States

Recently, the concept of feedback passivity-based control has drawn attention to chaos control. In all existing papers, the implementations of passivity-based control laws require the system states for feedback. In this paper, a passivity-based control law which only requires the knowledge of the system output is proposed. Simulation results are provided to show the effectiveness of the proposed solution.

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