Lin Shi

Bio: Lin Shi is an academic researcher from Dartmouth College. The author has contributed to research in topics: Adaptive control & Control theory. The author has an hindex of 4, co-authored 6 publications receiving 505 citations.

Decentralized adaptive controller design for large-scale systems with higher order interconnections

Abstract: Decentralized robust adaptive controller designs for large-scale interconnected systems are investigated. Motivated by real mechanical systems, the authors consider a general representation of interconnections when the strength of the interconnections is bounded by a pth-order polynomial in states. This is in contrast to other studies which have made simpler assumptions about the strength of the interconnections. The authors investigate several scenarios as the control computations become more distributed until the controllers are completely decentralized. The possible bound of the interconnections is assumed to be known for the decentralized semiadaptive controller. Without the knowledge of these bounds, two adaptive controllers are designed: a decentralized adaptive controller with partially centralized compensation and a fully adaptive decentralized controller. >

Decentralized Adaptive Controller Design For Large-Scale Systems With Higher-Order Interconnections

Abstract: We investigate robust decentralized adaptive controller design for interconnected systems. Motivated by real mechanical systems, we consider a general representation of interconnections when the strength of the interconnections is bounded by a pth-order polynomial in states. This is in contrast to other works which have made simpler assumptions about the strength of the interconnections. The possible bound of the interconnections is assumed to be known for the decentralized semi-adaptive controller. Without the knowledge of these bounds, two adaptive controllers are designed; a decentralized adaptive controller with partially centralized compensation and a fully-adaptive decentralized controller.

Decentralized control for interconnected uncertain systems: extensions to higher-order uncertainties

Abstract: Decentralized controller design for large-scale uncertain systems with higher-order uncertainties is investigated. The uncertainties are assumed to be bounded by a known or unknown pth-order polynomial in states. A non-adaptive controller is proposed to handle the case when the pth-order polynomial is known. An adaptive controller is proposed to deal with the unknown case. The effectiveness of the proposed decentralized control schemes is demonstrated by a numerical simulation of two inverted pendulums on carts.

Decentralized Control For Interconnected Uncertain Systems: Extensions To Higher-Order Uncertainties

Abstract: Dectralized controller design for large-scale uncertain systems with higher-order uncertainties is investigated. The uncertainties are assumed to be bounded by a knows or unknown pth-order polynomial in states. A non-adaptive controller is proposed to handle the case when the pth-order polynomial is known. An adaptive controller is proposed to deal with the unknown case. The effectiveness of the proposed decentralized control schemes is demonstrated by a numerical simulation of two inverted pendulums on carts.

Robust adaptive controllers for interconnected mechanical systems : influence of types of interconnections on time-invariant and time-varying systems

Abstract: We investigate robust adaptive controller designs for interconnected systems when no exact knowledge about the structure of the nonlinear interconnections between various subsystems is available. In this study, we concentrate on several different tupes of systems. We deal with both linear time-invariant (LTI) and linear time-varying (LTV) systems with nonlinear interconnections. For LTI systems, we examine the following types of interconnections: . interconnections that are bounded by first order polynomials in state space. . slowly time varying interconnections. . interconnections bounded by higher-order polynomials in state-space together with input channel interconnections. For LTV systems we deal with interconnections bounded by first-order polynomials in state space

Stable adaptive neural network controller

Abstract: An adaptive control system uses a neural network to provide adaptive control when the plant is operating within a normal operating range, but shifts to other types of control as the plant operating conditions move outside of the normal operating range. The controller uses a structure which allows the neural network parameters to be determined from minimal information about plant structure and the neural network is trained on-line during normal plant operation. The resulting system can be proven to be stable over all possible conditions. Further, with the inventive techniques, the tracking accuracy can be controlled by appropriate network design.

Robust Adaptive Tracking Control for Nonlinear Systems Based on Bounds of Fuzzy Approximation Parameters

Abstract: A robust adaptive fuzzy control approach is developed for a class of multi-input-multi-output (MIMO) nonlinear systems with modeling uncertainties and external disturbances by using both the approximation property of the fuzzy logic systems and the backstepping technique. The MIMO systems are composed of interconnected subsystems in the strict-feedback form. The main characteristics of the developed approach are that the online computation burden is alleviated and the robustness to dynamic uncertainties and external disturbances is improved. It is proven that all the signals of the resulting closed-loop system are uniformly bounded and that the tracking errors converge to a small neighborhood around zero. Two simulation experiments are presented to demonstrate the feasibility of the approach developed in this paper.

Decentralized adaptive controller design for large-scale systems with higher order interconnections

Abstract: Decentralized robust adaptive controller designs for large-scale interconnected systems are investigated. Motivated by real mechanical systems, the authors consider a general representation of interconnections when the strength of the interconnections is bounded by a pth-order polynomial in states. This is in contrast to other studies which have made simpler assumptions about the strength of the interconnections. The authors investigate several scenarios as the control computations become more distributed until the controllers are completely decentralized. The possible bound of the interconnections is assumed to be known for the decentralized semiadaptive controller. Without the knowledge of these bounds, two adaptive controllers are designed: a decentralized adaptive controller with partially centralized compensation and a fully adaptive decentralized controller. >