Ahmed Chaibet

Design of Power Converters by Optimization Under Multiphysic Constraints: Application to a Two-Time-Scale AC/DC–DC Converter

The aim of this paper is to present an optimization-under-constraints approach to design power converters. In fact, the time-domain simulation is very useful to evaluate the performances of power converters when the design solution area of the studied converter is much reduced due to the designers experience and when only few design aspects are considered. However, the design of todays power converters is more and more complicated because it needs to consider multiphysic and multidomain constraints. In this context, a design approach using optimization under constraints allows exploring a large solution area by considering the multiphysic aspect and a high number of optimization parameters. In this way, this paper proposes the use of analytical models to carry out a compromise between the model accuracy and the computing time when optimizing power converters under volume, electromagnetic compatibility, efficiency, thermal, and control constraints. This approach is applied to optimize a two-time-scale flyback converter. The optimized converter is implemented, and the proposed approach is validated by measurements.

H-infinity robust control of 3-DOF helicopter

This paper proposes a robust control technique for a 3-DOF helicopter. The control algorithm uses a robust controllers synthesized by the H infinity loop shaping approach. The simulation results show that the robust controllers stabilize the system and reject the disturbances. The evaluate and the comparative studies between the classical controllers (PI, PD, PID) and the robust H infinity loop shaping controller are given with simulations results in presence of the noise disturbance in the closed loop control of the elevation, pitch and rotation.

Controller design for trajectory tracking of autonomous passenger vehicles

This paper presents controllers design procedure for dynamic trajectory tracking of a highly automated vehicle. The main objective is to follow the planned trajectories generated by a co-pilot module in the safe way despite the presence of vehicle model uncertainties and also to guarantee a passenger comfort by generating soft actions on the steering wheel and accelerations. A decoupled design approach of longitudinal and lateral controller is adopted. For the longitudinal controller, a proportional including a feedforward terms is adopted. On the other hand, an adaptive backstepping approach is used in lateral case to deal with model nonlinearities and parameter uncertainties. The developed controller is integrated and tested in simulation environment. Performance of this controller are presented to demonstrate the effectiveness of the proposed controllers.

Robust controller designs of switched reluctance motor for electrical vehicle

The strong nonlinear and uncertain parameters of the switched reluctance motor make the traditional controllers difficult to ensure its performance and stable operation under diverse operating conditions. In this paper, we present two designs of H∞, robust controller for switched reluctance motor drives for electrical vehicle to aim at attenuating the effect of disturbances and parameters uncertainties. For the application of the H∞ theory, we have adopted the cascade control architecture (velocity - torque). The first controller of velocity in the outer control loop products the total torque of SRM. Hence, a linear equivalent mechanical dynamic is obtained. In the inner control loop, the phase reference current is determined using the torque-angle-current (T-θ-i) characteristics stored in a tabular form, the torque is regulated indirectly through the second controller of current. The design of both speed and current robust controllers using modern H∞ control theory is then summarized. For each control loop, two H∞ synthesis approaches are used and compared by μ-analysis. The simulation results demonstrate the effectiveness of the designed robust controllers and confirm the ability of the proposed designs.

Experimental H-infinity robust control of aerial vehicle flight

This paper proposes and evaluates the comparative studies between the classical controllers (PI, PD and PID) with H∞ robust control technique for an 3-DOF helicopter. The control algorithm uses a robust controllers synthesized by the H∞ loop shaping approach. The experimental results show that the robust controllers stabilize the system and reject the disturbances when the system is subjected to uncertainties of a norm lower than the maximum stability margin.

Design of a Tele-Control Electrical Vehicle System using a Fuzzy Logic Control

This paper presents a fuzzy logic design of a tele-control electrical vehicle system. We showed that the application of fuzzy logic control allows the stability of tele-vehicle system in spite of communication delays between the operator and the vehicle. A robust bilateral controller design using fuzzy logic frameworks was proposed. This approach allows a convenient means to trade off robustness and stability for a pre-specified time-delay margin. Both the performance and robustness of the proposed method were demonstrated by simulation results for a constant time delay between the operator and the electrical vehicle system.

Experimental robust H ∞ controller design of switched reluctance motor for electrical vehicle application

To ensure high perfermance and robustness against external disturbances and modeling uncertainties under hard operating conditions for Switched Reluctance Motor in EV application, a reliable robust control must be designed. In this paper we present a robust control design based on fixed order H∞ loop shaping approach. Standard H∞ control is a powerful robust control technique for systems with uncertainties and disturbances. However, the designed controllers by this technique are complex, with a high order and, thus, not suitable for implementation in EV. The purpose of this paper is to overcome this drawback by applying the fixed structure H∞ loop shaping control for SRM drive. To show the performance of this control approach, a robustness analysis is performed by comparing fixed structure and conventional H∞ loop shaping controllers using the concept of the Singular Structured Value, i.e. the μ-analysis. The effectiveness of the proposed approach is highlighted by simulation and experimental results.

Fuzzy logic design for tele-control electrical vehicle

In this paper, a design of tele-control electrical vehicle system is presented using fuzzy logic control. We showed that the application fuzzy logic control allows the system in spite of the communication delays between the operator and the vehicle. This paper presents a robust bilateral controller design using the fuzzy logic frameworks. This approach allows a convenient means to tradeoff the robustness stability for a pre-specified time-delay margin. The validity of the proposed method is demonstrated by simulations results for constant time delay between the operator and the electrical vehicle system.

Fault tolerant control of piezoelectric traveling wave ultrasonic motor

Ultrasonic piezoelectric motor technology is an important system component in integrated mechatronics devices working on extreme operating conditions. Due to these constraints, robustness and performance of the control interfaces should be taken into account in the motor design. In this paper, we propose an architecture for a fault tolerant control using Youla parameterization for an ultrasonic piezoelectric motor. The distinguished feature of our controller architecture is that it shows structurally how the controller design for performance and robustness may be done separately which has the potential to overcome the conflict between performance and robustness in the traditional feedback framework. A fault tolerant control architecture includes two parts: one part for performance and the other part for robustness. The controller design works in such a way that the feedback control system will be solely controlled by PII performance controller for a nominal model without disturbances and H∞ robustification controller will only be activated in the presence of the uncertainties or an external disturbances. The simulation results demonstrate the effectiveness of the proposed fault tolerant control architecture.

An electric simulator of a vehicle transmission chain coupled to a vehicle dynamic model

The aim of this paper is to present a method to carry out a vehicle transmission simulator coupled to a vehicle dynamic model. The transmission simulator uses electric actuators with dedicated control laws to reproduce the mechanical characteristics of the real vehicle transmission chain. The vehicle dynamic model, takes into account the longitudinal, the vertical and the pitch motions. The coupled electric simulator allows to validate theoretical studies (control of automatic or robotized gearboxes, test of heat engine, dynamic behavior, passenger comfort, automated driving...) by measurements without need to the real transmission system and the real environment of the vehicle. Such a method allows to reduce significantly the cost and the time of the development phases of vehicles. The proposed method is validated by numerical simulation and measures.