scholarly journals Backstepping Based Automatically Controlled Angiogenic Inhibition Therapy

2020 ◽  
Author(s):  
R. Ozgur Doruk
Keyword(s):  
Tumor Volume ◽  
Tracking Error ◽  
Setup Time ◽  
Injection Rate ◽  
Control Law ◽  
Order Model ◽  
Initial Value ◽  
Control Laws ◽  
Random Deviation ◽  
Control Methodology

AbstractIn this work, we present an automatically controlled angiogenic inhibition therapy where the variation profile of the inhibitory agent is generated by a control law that is derived using a back-stepping based control methodology. The angiogenic inhibition is described by a second order model representing the dynamics of tumor and supporting vasculature volumes. Backstepping control recursively stabilizes that dynamics and generates automatic control laws that allows the tumor volume to stay at a desired value. The desired value will be kept at one thousandth of its initial value. This will lead to a very small injection at the steady state. This is important as zero injection may lead to regrow of the tumor. The results will be presented in tabular and graphical forms. Tabular results present the variation of maximum injection rate and setup time. Graphical results present the variation of tumor and supporting vasculature volumes, injection rate and the tracking error between the reference and actual tumor volumes. In addition, we will also perform a simulation to test the capability of the closed loop to accomodate the parametric uncertainties in the rate constants. The uncertainties are represented by a random deviation in the range ±10% times the nominal value of the effected parameter. The control laws will be kept the same and the simulations will be repeated by 1000 times and each result will be superimposed on the graph. The area occupied by the curves will show the relative capability of the designs.

scholarly journals A Robust Observer—Based Adaptive Control of Second—Order Systems with Input Saturation via Dead-Zone Lyapunov Functions

Computation ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 82
Author(s):  
Alejandro Rincón ◽  
Gloria M. Restrepo ◽  
Fredy E. Hoyos
Keyword(s):  
Lyapunov Functions ◽  
Dead Zone ◽  
Tracking Error ◽  
Input Saturation ◽  
Chemical Reactor ◽  
Second Order ◽  
Control Law ◽  
Compact Set ◽  
State Variables ◽  
Robust Observer

In this study, a novel robust observer-based adaptive controller was formulated for systems represented by second-order input–output dynamics with unknown second state, and it was applied to concentration tracking in a chemical reactor. By using dead-zone Lyapunov functions and adaptive backstepping method, an improved control law was derived, exhibiting faster response to changes in the output tracking error while avoiding input chattering and providing robustness to uncertain model terms. Moreover, a state observer was formulated for estimating the unknown state. The main contributions with respect to closely related designs are (i) the control law, the update law and the observer equations involve no discontinuous signals; (ii) it is guaranteed that the developed controller leads to the convergence of the tracking error to a compact set whose width is user-defined, and it does not depend on upper bounds of model terms, state variables or disturbances; and (iii) the control law exhibits a fast response to changes in the tracking error, whereas the control effort can be reduced through the controller parameters. Finally, the effectiveness of the developed controller is illustrated by the simulation of concentration tracking in a stirred chemical reactor.

Industrial compliant robot bases in interaction tasks: a force tracking algorithm with coupled dynamics compensation

Robotica ◽  
2016 ◽  
Vol 35 (8) ◽  
pp. 1732-1746 ◽  
Author(s):  
Loris Roveda ◽  
Nicola Pedrocchi ◽  
Federico Vicentini ◽  
Lorenzo Molinari Tosatti
Keyword(s):  
Closed Loop ◽  
Control Law ◽  
Light Weight ◽  
Mobile Platforms ◽  
Control Laws ◽  
Assembly Task ◽  
Base Position ◽  
Force Tracking ◽  
Compliant Robot ◽  
Target Force

SUMMARYLight-weight manipulators are used in industrial tasks mounted on mobile platforms to improve flexibility. However, such mountings introduce compliance affecting the tasks. This work deals with such scenarios by designing a controller that also takes into account compliant environments. The controller allows the tracking of a target force using the estimation of the environment stiffness (EKF) and the estimation of the base position (KF), compensating the robot base deformation. The closed-loop stability has been analyzed. Observers and the control law have been validated in experiments. An assembly task is considered with a standard industrial non-actuated mobile platform. Control laws with and without base compensation are compared.

Active control of flexible one-link manipulators using wavelet networks

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1275-1283 ◽  
Author(s):  
V. I. Gervini ◽  
E. M. Hemerly ◽  
S. C. P. Gomes
Keyword(s):  
Dead Zone ◽  
Flexible Manipulator ◽  
Friction Compensation ◽  
Control Law ◽  
Wavelet Network ◽  
Stick Slip ◽  
Control Laws ◽  
Operational Conditions ◽  
Structure Control ◽  
Wavelet Networks

SUMMARYThe design of control laws for flexible manipulators is known to be a challenging problem, when using a conventional actuator, i.e., a motor with gear. This is due to the friction of the nonlinear actuator, which causes torque dead zone and stick-slip behavior, thereby hampering the good performance of the control system. The torque needed to attenuate the vibrations, although calculated by the control law, is consumed by the friction inside the actuator, rendering it ineffective to the flexible structure control. Nonlinear friction varies with different operational conditions of the actuator and a friction compensation mechanism based on these models cannot always keep a good performance. This study proposes a new control strategy using wavelet network to friction compensation. Experimental results obtained with a flexible manipulator attest to the good performance of the proposed control law.

scholarly journals Finite-Time Switching Control of Nonholonomic Mobile Robots for Moving Target Tracking Based on Polar Coordinates

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Hua Chen ◽  
Shen Xu ◽  
Lulu Chu ◽  
Fei Tong ◽  
Lei Chen
Keyword(s):  
Mobile Robots ◽  
Finite Time ◽  
Control Method ◽  
Tracking Error ◽  
Switching Control ◽  
Polar Coordinates ◽  
Control Law ◽  
Moving Target ◽  
Nonholonomic Mobile Robots ◽  
Time Switching

In this paper, finite-time tracking problem of nonholonomic mobile robots for a moving target is considered. First of all, polar coordinates are used to characterize the distance and azimuth between the moving target and the robot. Then, based on the distance and azimuth transported from the sensor installed on the robot, a finite-time tracking control law is designed for the nonholonomic mobile robot by the switching control method. Rigorous proof shows that the tracking error converges to zero in a finite time. Numerical simulation demonstrates the effectiveness of the proposed control method.

Scheduling Strategy of Multiple Semi-Active Controllers With Information on the Disturbance and the Structural Response

2016 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Active Control ◽  
Structural Response ◽  
Design Parameters ◽  
Control Law ◽  
Control Performance ◽  
Multiple Control ◽  
Control Laws ◽  
Scheduling Strategy

A scheduling strategy of multiple semi-active control laws for various earthquake disturbances is proposed to maximize the control performance. Generally, the semi-active controller for a given structural system is designed as a single control law and the single control law is used for all the forthcoming earthquake disturbances. It means that the general semi-active control should be designed to achieve a certain degree of the control performance for all the assumed disturbances with various time and/or frequency characteristics. Such requirement on the performance robustness becomes a constraint to obtain the optimal control performance. We propose a scheduling strategy of multiple semi-active control laws. Each semi-active control law is designed to achieve the optimal performance for a single earthquake disturbance. Such optimal control laws are scheduled with the available data in the control system. As the scheduling mechanism of the multiple control laws, a command signal generator (CSG) is defined in the control system. An artificial neural network (ANN) is adopted as the CSG. The ANN-based CSG works as an interpolator of the multiple control laws. Design parameters in the CSG are optimized with the genetic algorithm (GA). Simulation study shows the effectiveness of the approach.

scholarly journals Feedback Linearization Control of the Inertia Wheel Pendulum

2014 ◽  
Vol 14 (3) ◽  
pp. 96-109 ◽  
Author(s):  
Faculty of Automatics, Technical Un Enev
Keyword(s):  
Feedback Linearization ◽  
Wheel Speed ◽  
Control Law ◽  
Test Bed ◽  
Control Laws ◽  
Full State ◽  
Feedback Linearization Control ◽  
System Output ◽  
Inertia Wheel Pendulum ◽  
Definition Of

Abstract In this paper, two feedback linearizing control laws for the stabilization of the Inertia Wheel Pendulum are derived: a full-state linearizing controller, generalizing the existing results in literature, with friction ignored in the description and an inputoutput linearizing control law, based on a physically motivated definition of the system output. Experiments are carried out on a laboratory test bed with significant friction in order to test and verify the suggested performance and the results are presented and discussed. The main point to be made as a consequence of the experimental evaluation is the fact that actually the asymptotic stabilization was not achieved, but rather a limit cycling behavior was observed for the full-state linearizing controller. The input-output linearizing controller was able to drive the pendulum to the origin, with the wheel speed settling at a finite value

Decentralized Exergy/Entropy Thermodynamic Control for Collective Robotic Systems

2007 ◽  
Author(s):  
Rush D. Robinett ◽  
David G. Wilson
Keyword(s):  
Decentralized Control ◽  
Direct Method ◽  
Robotic Systems ◽  
Control Law ◽  
Thermodynamic Control ◽  
Order Accuracy ◽  
Control Laws ◽  
Vector Lyapunov Function ◽  
Collective Control ◽  
Plume Tracing

This paper develops a distributed decentralized control law for collective robotic systems. The control laws are developed based on exergy/entropy thermodynamic concepts and information theory. The source field is characterized through second-order accuracy. The proposed feedback control law stability for both the collective and individual robots are demonstrated by selecting a general Hamiltonian based solution developed as Fisher Information Equivalency as the vector Lyapunov function. Stability boundaries and system performance are then determined with Lyapunov’s direct method. A robot collective plume tracing numerical simulation example demonstrates this decentralized exergy/entropy collective control architecture.

scholarly journals State Transfer via On-Line State Estimation and Lyapunov-Based Feedback Control for a N-Qubit System

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 751 ◽  
Author(s):  
Sajede Harraz ◽  
Shuang Cong
Keyword(s):  
Feedback Control ◽  
State Estimation ◽  
Open Quantum Systems ◽  
State Feedback Control ◽  
Quantum Master Equation ◽  
Control Law ◽  
Control Laws ◽  
Quantum State Estimation ◽  
State Transfer ◽  
On Line

In this paper, we propose a Lyapunov-based state feedback control for state transfer based on the on-line quantum state estimation (OQSE). The OQSE is designed based on continuous weak measurements and compressed sensing. The controlled system is described by quantum master equation for open quantum systems, and the continuous measurement operators are derived according to the dynamic equation of system. The feedback control law is designed based on the Lyapunov stability theorem, and a strict proof of proposed control laws are given. At each sampling time, the state is estimated on-line, which is used to design the control law. The simulation experimental results show the effectiveness of the proposed feedback control strategy.

scholarly journals Accurate Motion Control of a Pneumatic Linear Peristaltic Actuator

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 63 ◽  
Author(s):  
João Falcão Carneiro ◽  
João Bravo Pinto ◽  
Fernando Gomes de Almeida
Keyword(s):  
Closed Loop ◽  
Low Cost ◽  
Dynamic Performance ◽  
Control Law ◽  
Control Loop ◽  
Control Laws ◽  
Loop Control ◽  
Error Band ◽  
Short Service Life ◽  
High Mechanical Stress

Pneumatic linear peristaltic actuators can offer some potential advantages when compared with conventional ones. The low cost, virtually unlimited stroke and easy implementation of curved motion profiles are among those benefits. On the downside, these actuators suffer high mechanical stress that can lead to short service life and increased leakage among chambers during the actuator lifetime. One way to cope with this problem is to impose the force—instead of the displacement—between rollers, as this has been shown to improve the endurance of the hose while reducing leakage during the actuator lifetime. This paper presents closed control loop results using such a setup. Previous studies with linear peristaltic actuators have revealed that, although it is possible to reach zero steady state error to constant references with closed loop control, the dynamic response obtained is very slow. This paper is mainly focused on this topic, namely on the development of several control laws to improve the dynamic performance of the system while avoiding limit cycles. The new developed control law leads to an average time of 1.67 s to reach a 0.1 mm error band in an experiment consisting of a series of 16 steps ranging from 0.02 to 0.32 m in amplitude.

scholarly journals Adaptive output regulation for a class of nonlinear systems with guaranteed transient performance

2019 ◽  
Vol 42 (6) ◽  
pp. 1180-1190
Author(s):  
Weijie Sun ◽  
Zhenhua Zhu ◽  
Jianglin Lan ◽  
Yunjian Peng
Keyword(s):  
Nonlinear Systems ◽  
Tracking Error ◽  
High Gain ◽  
Output Regulation ◽  
Control Law ◽  
Stabilization Problem ◽  
Transient Performance ◽  
Adaptive Stabilization ◽  
Output Tracking ◽  
Output Constraints

This paper is dedicated to adaptive output regulation for a class of nonlinear systems with asymptotic output tracking and guarantee of prescribed transient performance. With the employment of internal model principle, we first transform this problem into a specific adaptive stabilization problem with output constraints. Then, by integrating the time-varying Barrier Lyapunov Function (BLF) technique together with the high gain feedback method, we develop an output-based control law to solve the constrained stabilization problem and consequently confine the output tracking error to a predefined arbitrary region. The output-based control law enables adaptive output regulation in the sense that, under unknown exosystem dynamics, all the closed-loop system signals are bounded whilst the controlled output constraints are not violated. Finally, efficacy of the proposed design is illustrated through a simulation example.

Sign in / Sign up

Export Citation Format

Share Document