Thanh-Phong Pham

• Doctor of Engineering
• Lecturer at University of Technology and Education- The university of Da nang

This work presents an H∞ observer design for road profile estimation in the automotive semi-active suspension system. The dynamics of the quarter-car augmented with a nonlinear dynamic model of the semi-active damper are written into the descriptor system with road profile as the system states. Then an H∞ observer is developed to estimate the road...

This letter extends the unified observer design problem to the class of Nonlinear Parameter Varying (NLPV) systems with parameter dependence in both the dynamics and the control input matrices. First, parameterization of the observer matrices, herein generalized for the NLPV case, allows us to decouple the input disturbance from the estimation erro...

This paper proposes an H∞ Non Linear Parameter Varying (NLPV) observer for fault estimation in semi-active Electro-Rheological (ER) suspensions. The damper fault (a loss-of-efficiency factor) is modeled as a lost force of unknown/free dynamics to be estimated. Thanks to the parameter-dependent descriptor-form system modeling, there is no assumption...

In this paper, we present an LMI-based approach for comfort-oriented cruise control of an autonomous vehicle. First, vehicle longitudinal dynamics and a corresponding parameter-dependent state-space representation are explained and discussed. An LMI-based polytopic LQR controller is then designed for the vehicle speed to track the reference value i...

The real-time knowledge of the damper force is of paramount importance in controlling and diagnosing automotive suspension systems. This study presents a generalized H2/LPV observer for damper force estimation of a semi-active electro-rheological (ER) suspension system. First, an extended quarter-car model augmented with the nonlinear and dynamical...

Dampers in semi-active suspension systems may be subject to various types of damper faults, e.g., oil leakage and electrical issues, that need to be estimated for diagnosis and isolation purposes. A new method to design the so-called multi-objective grid-based Lipschitz Nonlinear Parameter Varying (NLPV) Proportional Integral (PI) observer is here...

Dampers in semi-active suspension systems may be subject to various types of damper faults, e.g., oil leakage and electrical issues, that need to be estimated for diagnosis and isolation purposes. A new method to design the so-called multi-objective grid-based Lipschitz Nonlinear Parameter Varying (NLPV) Proportional Integral (PI) observer is here...

This work presents an H∞ observer design for road profile estimation in the automotive semi-active suspension system. The dynamics of the quarter-car augmented with a nonlinear dynamic model of the semi-active damper are written into the descriptor system with road profile as the system states. Then an H∞ observer is developed to estimate the road...

This work concerns the design of a multi-objective unified qLPV observer for the state estimation problem in LPV systems with a parameter-dependent control input matrix. The standard forms of the system and the observer are first presented, where the observer matrices are functions of the estimated states (qLPV problem). The effects of bounded unkn...

This paper proposes a nonlinear parameter varying (NLPV) observer to estimate, in real‐time, the damper force of an electrorheological (ER) damper in a road vehicle suspension system. The objectives are to minimize the effects of bounded unknown road profile disturbances and measurement noises on the estimation errors in the framework. Furthermore,...

This paper presents an integrated linear parameter-varying (LPV) control approach of an autonomous vehicle with an objective to guarantee driving comfort, consisting of cruise and semi-active suspension control. First, the vehicle longitudinal and vertical dynamics (equipped with a semi-active suspension system) are presented and written into LPV s...

This work concerns the design of a multi-objective unified qLPV observer for the state estimation problem in LPV systems with a parameter-dependent control input matrix. The standard forms of the system and the observer are first presented, where the observer matrices are functions of the estimated states (qLPV problem). The effects of bounded unkn...

This paper presents a comparative study between different nonlinear damper models, developed for a semi-active Electro-Rheological damper. The first model is developed by extending the hysteresis model to obtain the dynamic characteristic of the damper. To improve the accuracy of capturing the damper’s behavior, a nonlinear Bouc-Wen model is develo...

The paper's objective is to evaluate passenger comfort in order to define a reference speed. In other words, we need to build conditions and criteria for defining the car's speed in a road profile. This paper shows how the criteria were established, how the tests worked, and the results obtained when applying them to the INOVE testbed.

This work presents a concise control-oriented model for electro-rheological (ER) dampers. This model can serve for fault-tolerant control purposes, considering automotive suspension performance enhancement. ER dampers present, basically, a resistance against shearing that varies according to a controlled electric field. The main purpose of this wor...

Nowadays, the semi-active suspensions have received a lot of consideration from industry and academia due to their advantages compared to active and passive suspensions in reducing the effects of the road disturbances on the on-board passengers (comfort) and in maintaining tire-road contact (safety). The research studies of this thesis focus on the...

This paper aims at comparing three robust observers used to estimate the damping force of electrorheological (ER) dampers in a vehicle suspension system. Firstly, a nonlinear quarter-car model, augmented with a first-order dynamical nonlinear damper model, is developed. The first two methods are designed considering the nonlinearity as an unknown i...

This letter presents an extension of the synthesis of a unified $\mathcal {H_{\infty }}$ observer for a specific class of nonlinear systems. The objectives are to decouple the effects of bounded unknown input disturbances and to minimize the effects of measurement noises on the estimation errors of the state variables by using $\mathcal {H_{\inf...

The real-time estimation of damper force is crucial for control and diagnosis of suspension systems in road vehicles. In this study, we consider a semi-active electrorheological (ER) suspension system. First, a nonlinear quarter-car model is proposed that takes the nonlinear and dynamical characteristics of the semi-active damper into account. The...

This paper presents an LPV damping force observer of Electro Rheological (ER) dampers for a real automotive suspension system, taking the dynamic characteristic of damper into account. First, an extended nonlinear quarter-car model is considered, where the time constant representing the damper dynamics is varying according to the control level. Thi...

This paper proposes a nonlinear parameter varying (NLPV) observer to estimate in real-time the damper force of an electrorheological (ER) damper in road vehicle suspension system. First, a nonlinear quarter-car model equipped with the dynamic nonlinear model of ER damper is presented, which captures the main behavior of the suspension system. The e...

Rollover accidents of heavy vehicles are especially dangerous and cause greater damage and injury than other accidents. The relatively low roll stability of heavy vehicles is the main cause of rollover and contributes to the total number of vehicle accidents. Most modern heavy vehicles are equipped with passive anti-roll bars, in order to enhance t...

Issues of differentiation-free multiswitching neuroadaptive tracking control of strict-feedback systems are presented. It mainly consists of a set of nominal adaptive neural network compensators plus an auxiliary switched linear controller that ensures the semiglobally/globally ultimately uniformly bounded stability when the unknown nonlinearities...

The paper presents a global tracking fuzzy control design for strict feedback systems with unknown control affine nonlinearities. In particular, the so-called explosion of complexity problem alleviated via using a modified dynamic surface control (DSC) technique. The modification mainly involves a firstorder filter with a space-modulated input, whi...